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Extracellular Ubiquitin: Role in Myocyte Apoptosis and Myocardial Remodeling

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ABSTRACT

Ubiquitin (UB) is a highly conserved low molecular weight (8.5 kDa) protein. It consists of 76 amino acid residues and is found in all eukaryotic cells. The covalent linkage of UB to a variety of cellular proteins (ubiquitination) is one of the most common posttranslational modifications in eukaryotic cells. This modification generally regulates protein turnover and protects the cells from damaged or misfolded proteins. The polyubiquitination of proteins serves as a signal for degradation via the 26S proteasome pathway. UB is present in trace amounts in body fluids. Elevated levels of UB are described in the serum or plasma of patients under a variety of conditions. Extracellular UB is proposed to have pleiotropic roles including regulation of immune response, anti‐inflammatory, and neuroprotective activities. CXCR4 is identified as receptor for extracellular UB in hematopoietic cells. Heart failure represents a major cause of morbidity and mortality in western society. Cardiac remodeling is a determinant of the clinical course of heart failure. The components involved in myocardial remodeling include—myocytes, fibroblasts, interstitium, and coronary vasculature. Increased sympathetic nerve activity in the form of norepinephrine is a common feature during heart failure. Acting via β‐adrenergic receptor (β‐AR), norepinephrine is shown to induce myocyte apoptosis and myocardial fibrosis. β‐AR stimulation increases extracellular levels of UB in myocytes, and UB inhibits β‐AR‐stimulated increases in myocyte apoptosis and myocardial fibrosis. This review summarizes intracellular and extracellular functions of UB with particular emphasis on the role of extracellular UB in cardiac myocyte apoptosis and myocardial remodeling. © 2016 American Physiological Society. Compr Physiol 6:527‐560, 2016.

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Figure 1. Figure 1. A ribbon diagram of UB. The dark orange segment (black arrow) of the orange β‐sheet indicates the N‐terminus of UB. The yellow, orange and purple planes indicate the mixed β‐sheet, lime green indicates the large α‐helix. The hydrophobic surface patch residues surrounding Ile‐44, common interaction residues are indicated by red sticks and labeled accordingly. Light blue Asp‐58 indicates a hydrophilic binding area, pink Phe‐4 indicates a hydrophobic interaction site and the forest green C‐terminus indicates the flexible di‐glycine residues. [Vijay‐Kumar et al., PDB File: 1UBQ, Ref. Accelrys Software Inc., Discovery Studio Visualizer, Release 4.0, San Diego: Accelrys Software Inc., 2013].
Figure 2. Figure 2. The complete amino acid sequence for human UB. Important hydrophobic residue is in pink, hydrophilic binding area is in light blue, amino acid residues of hydrophobic patch are in red and lysine residues available for polyubiquitination are shown in green.
Figure 3. Figure 3. Representative diagram of the UB‐proteasome pathway first proposed by Hershko et al. At the time (1980), UB had not yet been identified and was referred to as APF‐1 (green circles). The diagram demonstrates ATP‐dependent polyubiquitination in step 1. Step 2 incorporates what we now know to the proteasome but was initially referred to as “peptidases” which break the protein down into amino acids (blue circles). Step 3 shows the cleavage of polyUB from the protein into free ubiquitin, which then becomes available for binding to another protein, tagging it for degradation as well. [Adapted from Hershko et al. 1980 (88)].
Figure 4. Figure 4. Simplified schematic representation of UB‐proteasome pathway. UB (black circle) becomes activated (green circle) by E1 UB activating protein and ATP (step 1). Activated UB is then transferred to E2 UB carrier protein (step 2) where it is carried and transferred to E3 UB ligase (step 3). The E3 ligase covalently binds the UB to a lysine residue (step 4) on the target protein (pink). This process continues (steps 5‐8) until four or more UB molecules are bound to the protein of interest at which point the 26S proteasome recognizes the polyUB tagged protein (step 9) for degradation utilizing ATP.
Figure 5. Figure 5. A ribbon diagram of chemokine C‐X‐C motif receptor 4 (CXCR4) with seven differently colored transmembrane helices. The ECLs are at the top of the figure, the intracellular loops are at the bottom, and the helices reside within the lipid bilayer. The proposed UB‐CXCR4 interaction sites are displayed in blue, with labels. ECL2 and ECL3 denote ECLs of CXCR4 that are thought to be critical for UB binding. [Wu B et al., PDB File: 3ODU, Ref. Accelrys Software Inc., Discovery Studio Visualizer, Release 4.0, San Diego: Accelrys Software Inc., 2013.]
Figure 6. Figure 6. Ribbon diagram of UB interacting with CXCR4 with adjusted docking based on charge complementarity and mutational data. UB is blue and CXCR4 is pink. Sites believed to be critical binding components are labeled with their amino acid one letter code and location. “E” denotes ECLs and “I” denotes intracellular loops. [From Saini et al. 2011 (181) with permission.]
Figure 7. Figure 7. Flow diagram displaying three pathways of apoptosis. (A) Intrinsic pathway triggered by nutrient deprivation or cellular stress increases expression of BH3‐only proteins including BID, BAD and BIM which contribute to mitochondrial damage by means of BAK‐BAX oligomeric channels. Antiapoptotic Bcl‐2 proteins can interact with the BH3‐only proteins to inhibit mitochondrial channel formation. BAK‐BAX oligomeric channels cause cytochrome c (yellow circles) to leak from the mitochondria into the cytosol triggering formation of apoptotsomes and activation of caspase‐9. (B) Extrinsic or receptor‐mediated pathway involves death signal TNF‐α or FasL binding to the death receptor, leading to its interaction with FADD and activating caspase‐8 (represented by the scissor opening). Active caspase‐8 may cleave BID to tBid, which contributes to channel formation in the mitochondria, causing leakage of cytochrome c. Caspase‐8 can also directly activate caspase‐7 and caspase‐3. (C) Granzyme pathway initiates apoptosis via the activation of caspase‐3, which can then activate other caspases. The granzyme B pathway can also act via BID cleavage.
Figure 8. Figure 8. Proteome map depicting identification of UB in the conditioned media of ARVMs. ARVMs, plated for 24 h, were treated with ISO (10 μmol/L) for 3 h. Conditioned media were analyzed by two‐dimensional gel electrophoresis. The gels were stained with SYPRO Ruby fluorescent protein stain. The circled protein was analyzed by MALDI‐TOF MS/MS and identified as UB. [From Singh et al. (205). Extracellular UB inhibits β‐AR‐stimulated apoptosis in cardiac myocytes: role of GSK‐3β and mitochondrial pathways. Cardiovascular Research, 2010, 86(1): 20‐28, by permission of Oxford University Press.]
Figure 9. Figure 9. UB treatment inhibits β‐AR‐stimulated apoptosis in ARVMs. ARVMs, plated for 24 h, were pretreated with UB (10 μg/mL) for 30 min followed by treatment with ISO (10 μmol/L; UB+ISO) or pretreated with ISO (10 μmol/L) for 30 min followed by treatment with UB (10 μg/mL; ISO + UB). Measurement of apoptosis using TUNEL‐assay indicated that pretreatment with UB inhibits β‐AR‐stimulated apoptosis. The antiapoptotic effects of UB were preserved even when the cells were treated with UB 30 min after β‐AR stimulation. CTL, control; *P < 0.05 versus CTL; #P < 0.05 versus ISO. [From Singh et al., (205). Extracellular ubiquitin inhibits β‐AR‐stimulated apoptosis in cardiac myocytes: role of GSK‐3β and mitochondrial pathways. Cardiovascular Research, 2010, 86(1): 20‐28, by permission of Oxford University Press.]
Figure 10. Figure 10. Exogenous UB decreases β‐AR‐stimulated apoptosis in the heart. β‐AR agonist ISO (7 days) infusion increases the percentage of apoptotic myocyte. Exogenous UB in the presence of ISO (ISO + UB) significantly decreased the percentage of apoptotic myocytes. UB infusion alone had no effect on apoptosis. *P < 0.05 versus sham; #P < 0.05 versus ISO [From Daniels et al. 2012 (50) with permission.]
Figure 11. Figure 11. Summary diagram illustrating the potential pathway for UB in β‐AR‐stimulated myocardial remodeling. β1‐AR stimulated interaction with Gαs increases cAMP levels and activates PKA, leading to activation of JNKs, GSK‐3β, CAMKII, and mitochondrial death pathway of apoptosis. β‐AR stimulation also increases extracellular levels of UB. Extracellular UB can then stimulate intracellular signaling via its interaction with CXCR4 (a potential receptor in cardiac cells). UB‐mediated intracellular signaling may then play an antiapoptotic and antifibrotic roles via the activation of PI3‐kinase/Akt pathway. UB may also influence the remodeling process of the heart by acting as a proangiogenic factor.
Figure 12. Figure 12. Exogenous UB inhibits β‐AR‐stimulated myocardial fibrosis. Heart sections were stained with Masson's trichrome staining to distinguish muscle tissue (red) from fibrosis (blue). ISO infusion (7 days) increases myocardial fibrosis. Exogenous UB in the presence of ISO (ISO + UB) decreases myocardial fibrosis. UB infusion alone had no effect on myocardial fibrosis. [From Daniels et al. 2012 (50) with permission.]
Figure 13. Figure 13. Treatment with UB promotes angiogenesis in CMECs. Matrigel assay demonstrating angiogenic potential of UB (20 μg/mL), methylated UB (unable to form polyUB chains; 20 μg/mL), fetal bovine serum (FBS; 20%), and SDF‐1α (CXCL12; 1 nM). AMD3100 (CXCR4 antagonist; 100 μmol/L) pretreatment negated the proangiogenic effect of UB. Panel A depicts 10× magnification of tubular structures, whereas panel B depicts 20× magnification. Black arrows indicate tubule sprouting. Panel C depicts quantitation of the percent area occupied by the tubular structure. [From Steagall et al. (209). Microcirculation. Extracellular ubiquitin increases expression of angiogenic molecules and stimulates angiogenesis in CMECs, 21(4): 324‐332, doi: 10.1111/micc.12109, with permission.]


Figure 1. A ribbon diagram of UB. The dark orange segment (black arrow) of the orange β‐sheet indicates the N‐terminus of UB. The yellow, orange and purple planes indicate the mixed β‐sheet, lime green indicates the large α‐helix. The hydrophobic surface patch residues surrounding Ile‐44, common interaction residues are indicated by red sticks and labeled accordingly. Light blue Asp‐58 indicates a hydrophilic binding area, pink Phe‐4 indicates a hydrophobic interaction site and the forest green C‐terminus indicates the flexible di‐glycine residues. [Vijay‐Kumar et al., PDB File: 1UBQ, Ref. Accelrys Software Inc., Discovery Studio Visualizer, Release 4.0, San Diego: Accelrys Software Inc., 2013].


Figure 2. The complete amino acid sequence for human UB. Important hydrophobic residue is in pink, hydrophilic binding area is in light blue, amino acid residues of hydrophobic patch are in red and lysine residues available for polyubiquitination are shown in green.


Figure 3. Representative diagram of the UB‐proteasome pathway first proposed by Hershko et al. At the time (1980), UB had not yet been identified and was referred to as APF‐1 (green circles). The diagram demonstrates ATP‐dependent polyubiquitination in step 1. Step 2 incorporates what we now know to the proteasome but was initially referred to as “peptidases” which break the protein down into amino acids (blue circles). Step 3 shows the cleavage of polyUB from the protein into free ubiquitin, which then becomes available for binding to another protein, tagging it for degradation as well. [Adapted from Hershko et al. 1980 (88)].


Figure 4. Simplified schematic representation of UB‐proteasome pathway. UB (black circle) becomes activated (green circle) by E1 UB activating protein and ATP (step 1). Activated UB is then transferred to E2 UB carrier protein (step 2) where it is carried and transferred to E3 UB ligase (step 3). The E3 ligase covalently binds the UB to a lysine residue (step 4) on the target protein (pink). This process continues (steps 5‐8) until four or more UB molecules are bound to the protein of interest at which point the 26S proteasome recognizes the polyUB tagged protein (step 9) for degradation utilizing ATP.


Figure 5. A ribbon diagram of chemokine C‐X‐C motif receptor 4 (CXCR4) with seven differently colored transmembrane helices. The ECLs are at the top of the figure, the intracellular loops are at the bottom, and the helices reside within the lipid bilayer. The proposed UB‐CXCR4 interaction sites are displayed in blue, with labels. ECL2 and ECL3 denote ECLs of CXCR4 that are thought to be critical for UB binding. [Wu B et al., PDB File: 3ODU, Ref. Accelrys Software Inc., Discovery Studio Visualizer, Release 4.0, San Diego: Accelrys Software Inc., 2013.]


Figure 6. Ribbon diagram of UB interacting with CXCR4 with adjusted docking based on charge complementarity and mutational data. UB is blue and CXCR4 is pink. Sites believed to be critical binding components are labeled with their amino acid one letter code and location. “E” denotes ECLs and “I” denotes intracellular loops. [From Saini et al. 2011 (181) with permission.]


Figure 7. Flow diagram displaying three pathways of apoptosis. (A) Intrinsic pathway triggered by nutrient deprivation or cellular stress increases expression of BH3‐only proteins including BID, BAD and BIM which contribute to mitochondrial damage by means of BAK‐BAX oligomeric channels. Antiapoptotic Bcl‐2 proteins can interact with the BH3‐only proteins to inhibit mitochondrial channel formation. BAK‐BAX oligomeric channels cause cytochrome c (yellow circles) to leak from the mitochondria into the cytosol triggering formation of apoptotsomes and activation of caspase‐9. (B) Extrinsic or receptor‐mediated pathway involves death signal TNF‐α or FasL binding to the death receptor, leading to its interaction with FADD and activating caspase‐8 (represented by the scissor opening). Active caspase‐8 may cleave BID to tBid, which contributes to channel formation in the mitochondria, causing leakage of cytochrome c. Caspase‐8 can also directly activate caspase‐7 and caspase‐3. (C) Granzyme pathway initiates apoptosis via the activation of caspase‐3, which can then activate other caspases. The granzyme B pathway can also act via BID cleavage.


Figure 8. Proteome map depicting identification of UB in the conditioned media of ARVMs. ARVMs, plated for 24 h, were treated with ISO (10 μmol/L) for 3 h. Conditioned media were analyzed by two‐dimensional gel electrophoresis. The gels were stained with SYPRO Ruby fluorescent protein stain. The circled protein was analyzed by MALDI‐TOF MS/MS and identified as UB. [From Singh et al. (205). Extracellular UB inhibits β‐AR‐stimulated apoptosis in cardiac myocytes: role of GSK‐3β and mitochondrial pathways. Cardiovascular Research, 2010, 86(1): 20‐28, by permission of Oxford University Press.]


Figure 9. UB treatment inhibits β‐AR‐stimulated apoptosis in ARVMs. ARVMs, plated for 24 h, were pretreated with UB (10 μg/mL) for 30 min followed by treatment with ISO (10 μmol/L; UB+ISO) or pretreated with ISO (10 μmol/L) for 30 min followed by treatment with UB (10 μg/mL; ISO + UB). Measurement of apoptosis using TUNEL‐assay indicated that pretreatment with UB inhibits β‐AR‐stimulated apoptosis. The antiapoptotic effects of UB were preserved even when the cells were treated with UB 30 min after β‐AR stimulation. CTL, control; *P < 0.05 versus CTL; #P < 0.05 versus ISO. [From Singh et al., (205). Extracellular ubiquitin inhibits β‐AR‐stimulated apoptosis in cardiac myocytes: role of GSK‐3β and mitochondrial pathways. Cardiovascular Research, 2010, 86(1): 20‐28, by permission of Oxford University Press.]


Figure 10. Exogenous UB decreases β‐AR‐stimulated apoptosis in the heart. β‐AR agonist ISO (7 days) infusion increases the percentage of apoptotic myocyte. Exogenous UB in the presence of ISO (ISO + UB) significantly decreased the percentage of apoptotic myocytes. UB infusion alone had no effect on apoptosis. *P < 0.05 versus sham; #P < 0.05 versus ISO [From Daniels et al. 2012 (50) with permission.]


Figure 11. Summary diagram illustrating the potential pathway for UB in β‐AR‐stimulated myocardial remodeling. β1‐AR stimulated interaction with Gαs increases cAMP levels and activates PKA, leading to activation of JNKs, GSK‐3β, CAMKII, and mitochondrial death pathway of apoptosis. β‐AR stimulation also increases extracellular levels of UB. Extracellular UB can then stimulate intracellular signaling via its interaction with CXCR4 (a potential receptor in cardiac cells). UB‐mediated intracellular signaling may then play an antiapoptotic and antifibrotic roles via the activation of PI3‐kinase/Akt pathway. UB may also influence the remodeling process of the heart by acting as a proangiogenic factor.


Figure 12. Exogenous UB inhibits β‐AR‐stimulated myocardial fibrosis. Heart sections were stained with Masson's trichrome staining to distinguish muscle tissue (red) from fibrosis (blue). ISO infusion (7 days) increases myocardial fibrosis. Exogenous UB in the presence of ISO (ISO + UB) decreases myocardial fibrosis. UB infusion alone had no effect on myocardial fibrosis. [From Daniels et al. 2012 (50) with permission.]


Figure 13. Treatment with UB promotes angiogenesis in CMECs. Matrigel assay demonstrating angiogenic potential of UB (20 μg/mL), methylated UB (unable to form polyUB chains; 20 μg/mL), fetal bovine serum (FBS; 20%), and SDF‐1α (CXCL12; 1 nM). AMD3100 (CXCR4 antagonist; 100 μmol/L) pretreatment negated the proangiogenic effect of UB. Panel A depicts 10× magnification of tubular structures, whereas panel B depicts 20× magnification. Black arrows indicate tubule sprouting. Panel C depicts quantitation of the percent area occupied by the tubular structure. [From Steagall et al. (209). Microcirculation. Extracellular ubiquitin increases expression of angiogenic molecules and stimulates angiogenesis in CMECs, 21(4): 324‐332, doi: 10.1111/micc.12109, with permission.]
References
 1.Murphy SL, Kochanek KD, Xu J, Heron M. Deaths: Final Data for 2012. National Vital Statistics Reports 63: 1‐117, 2015.
 2. Adameova A , Abdellatif Y , Dhalla NS . Role of the excessive amounts of circulating catecholamines and glucocorticoids in stress‐induced heart disease. Can J Physiol Pharmacol 87: 493‐514, 2009.
 3. Aebersold DM , Shaul YD , Yung Y , Yarom N , Yao Z , Hanoch T , Seger R . Extracellular signal‐regulated kinase 1c (ERK1c), a novel 42‐kilodalton ERK, demonstrates unique modes of regulation, localization, and function. Mol Cell Biol 24: 10000‐10015, 2004.
 4. Agarwal U , Ghalayini W , Dong F , Weber K , Zou YR , Rabbany SY , Rafii S , Penn MS . Role of cardiac myocyte CXCR4 expression in development and left ventricular remodeling after acute myocardial infarction. Circ Res 107: 667‐676, 2010.
 5. Ahmet I , Krawczyk M , Zhu W , Woo AY , Morrell C , Poosala S , Xiao RP , Lakatta EG , Talan MI . Cardioprotective and survival benefits of long‐term combined therapy with beta2 adrenoreceptor (AR) agonist and beta1 AR blocker in dilated cardiomyopathy postmyocardial infarction. J Pharmacol Exp Ther 325: 491‐499, 2008.
 6. Akarsu E , Pirim I , Capoğlu I , Deniz O , Akçay G , Unüvar N . Relationship between electroneurographic changes and serum ubiquitin levels in patients with type 2 diabetes. Diabetes Care 24: 100‐103, 2001.
 7. Amin P , Singh M , Singh K . β‐Adrenergic receptor‐stimulated cardiac myocyte apoptosis: Role of β1 integrins. J Signal Transduct 2011: 179057, 2011.
 8. An H , Krist DT , Statsyuk AV . Crosstalk between kinases and Nedd4 family ubiquitin ligases. Mol Biosyst 10: 1643‐1657, 2014.
 9. Andersson DC , Fauconnier J , Yamada T , Lacampagne A , Zhang SJ , Katz A , Westerblad H . Mitochondrial production of reactive oxygen species contributes to the β‐adrenergic stimulation of mouse cardiomycytes. J Physiol 589: 1791‐1801, 2011.
 10. Askari AT , Unzek S , Popovic ZB , Goldman CK , Forudi F , Kiedrowski M , Rovner A , Ellis SG , Thomas JD , DiCorleto PE , Topol EJ , Penn MS . Effect of stromal‐cell‐derived factor 1 on stem‐cell homing and tissue regeneration in ischaemic cardiomyopathy. Lancet 362: 697‐703, 2003.
 11. Asseman C , Pancre V , Delanoye A , Capron A , Auriault C . A radioimmunoassay for the quantification of human ubiquitin in biological fluids: application to parasitic and allergic diseases. Journal of Immunological Methods 173: 8, 1994.
 12. Bach HH , Wong YM , Tripathi A , Nevins AM , Gamelli RL , Volkman BF , Byron KL , Majetschak M . Chemokine (C‐X‐C motif) receptor 4 and atypical chemokine receptor 3 regulate vascular α1‐adrenergic receptor function. Mol Med 20: 435‐447, 2014.
 13. Badalzadeh R , Mokhtari B , Yavari R . Contribution of apoptosis in myocardial reperfusion injury and loss of cardioprotection in diabetes mellitus. J Physiol Sci, 2015.
 14. Bangalore S , Messerli FH , Kostis JB , Pepine CJ . Cardiovascular protection using beta‐blockers: A critical review of the evidence. J Am Coll Cardiol 50: 563‐572, 2007.
 15. Behonick GS , Novak MJ , Nealley EW , Baskin SI . Toxicology update: The cardiotoxicity of the oxidative stress metabolites of catecholamines (aminochromes). J Appl Toxicol 21(Suppl 1): S15‐22, 2001.
 16. Ben‐Neriah Y . Regulatory functions of ubiquitination in the immune system. Nat Immunol 3: 20‐26, 2002.
 17. Bergman MR , Teerlink JR , Mahimkar R , Li L , Zhu BQ , Nguyen A , Dahi S , Karliner JS , Lovett DH . Cardiac matrix metalloproteinase‐2 expression independently induces marked ventricular remodeling and systolic dysfunction. Am J Physiol Heart Circ Physiol 292: H1847‐H1860, 2007.
 18. Bisognano JD , Weinberger HD , Bohlmeyer TJ , Pende A , Raynolds MV , Sastravaha A , Roden R , Asano K , Blaxall BC , Wu SC , Communal C , Singh K , Colucci W , Bristow MR , Port DJ . Myocardial‐directed overexpression of the human beta(1)‐adrenergic receptor in transgenic mice. J Mol Cell Cardiol 32: 817‐830, 2000.
 19. Blommaart EF , Luiken JJ , Meijer AJ . Autophagic proteolysis: Control and specificity. Histochem J 29: 365‐385, 1997.
 20. Bos R , Mougenot N , Findji L , Médiani O , Vanhoutte PM , Lechat P . Inhibition of catecholamine‐induced cardiac fibrosis by an aldosterone antagonist. J Cardiovasc Pharmacol 45: 8‐13, 2005.
 21. Busillo JM , Benovic JL . Regulation of CXCR4 signaling. Biochim Biophys Acta 1768: 952‐963, 2007.
 22. Cai D , Lee KK , Li M , Tang MK , Chan KM . Ubiquitin expression is up‐regulated in human and rat skeletal muscles during aging. Arch Biochem Biophys 425: 42‐50, 2004.
 23. Cao Y , Li C , Zhang Q , Wang Y , Xia R . Extracellular ubiquitin enhances the suppressive effects of regulatory T cells on effector T cell responses. Clin Lab 60: 1983‐1991, 2014.
 24. Carlsson L , Abrahamsson T , Almgren O . Local release of myocardial norepinephrine during acute ischemia: An experimental study in the isolated perfused rat heart. J Cardiovasc Pharmacol 7: 791‐798, 1985.
 25. Carr AN , Howard BW , Yang HT , Eby‐Wilkens E , Loos P , Varbanov A , Qu A , DeMuth JP , Davis MG , Proia A , Terjung RL , Peters KG . Efficacy of systemic administration of SDF‐1 in a model of vascular insufficiency: Support for an endothelium‐dependent mechanism. Cardiovasc Res 69: 925‐935, 2006.
 26. Carter RS , Pennington KN , Ungurait BJ , Arrate P , Ballard DW . Signal‐induced ubiquitination of I kappaB Kinase‐beta. J Biol Chem 278: 48903‐48906, 2003.
 27. Chiong M , Wang ZV , Pedrozo Z , Cao DJ , Troncoso R , Ibacache M , Criollo A , Nemchenko A , Hill JA , Lavandero S . Cardiomyocyte death: Mechanisms and translational implications. Cell Death Dis 2: e244, 2011.
 28. Chu PY , Mariani J , Finch S , McMullen JR , Sadoshima J , Marshall T , Kaye DM . Bone marrow‐derived cells contribute to fibrosis in the chronically failing heart. Am J Pathol 176: 1735‐1742, 2010.
 29. Chung ES , Packer M , Lo KH , Fasanmade AA , Willerson JT , Investigators A‐TTACHF. Randomized, double‐blind, placebo‐controlled, pilot trial of infliximab, a chimeric monoclonal antibody to tumor necrosis factor‐alpha, in patients with moderate‐to‐severe heart failure: Results of the anti‐TNF Therapy Against Congestive Heart Failure (ATTACH) trial. Circulation 107: 3133‐3140, 2003.
 30. Ciechanover A , Heller H , Elias S , Haas AL , Hershko A . ATP‐dependent conjugation of reticulocyte proteins with the polypeptide required for protein degradation. Proc Natl Acad Sci U S A 77: 1365‐1368, 1980.
 31. Ciehanover A , Hod Y , Hershko A . A heat‐stable polypeptide component of an ATP‐dependent proteolytic system from reticulocytes. Biochem Biophys Res Commun 81: 1100‐1105, 1978.
 32. Cochain C , Channon KM , Silvestre JS . Angiogenesis in the infarcted myocardium. Antioxid Redox Signal 18: 1100‐1113, 2013.
 33. Coker ML , Doscher MA , Thomas CV , Galis ZS , Spinale FG . Matrix metalloproteinase synthesis and expression in isolated LV myocyte preparations. Am J Physiol 277: H777‐787, 1999.
 34. Coleman ML , Sahai EA , Yeo M , Bosch M , Dewar A , Olson MF . Membrane blebbing during apoptosis results from caspase‐mediated activation of ROCK I. Nat Cell Biol 3: 339‐345, 2001.
 35. Colucci WS . The effects of norepinephrine on myocardial biology: Implications for the therapy of heart failure. Clin Cardiol 21: I20‐24, 1998.
 36. Colucci WS , Sawyer DB , Singh K , Communal C . Adrenergic overload and apoptosis in heart failure: Implications for therapy. J Card Fail 6: 1‐7, 2000.
 37. Communal C , Colucci WS , Singh K . p38 mitogen‐activated protein kinase pathway protects adult rat ventricular myocytes against beta‐adrenergic receptor‐stimulated apoptosis. Evidence for Gi‐dependent activation. J Biol Chem 275: 19395‐19400, 2000.
 38. Communal C , Singh K , Pimentel DR , Colucci WS . Norepinephrine stimulates apoptosis in adult rat ventricular myocytes by activation of the beta‐adrenergic pathway. Circulation 98: 1329‐1334, 1998.
 39. Communal C , Singh K , Sawyer DB , Colucci WS . Opposing effects of beta(1)‐ and beta(2)‐adrenergic receptors on cardiac myocyte apoptosis: Role of a pertussis toxin‐sensitive G protein. Circulation 100: 2210‐2212, 1999.
 40. Communal C , Singh M , Menon B , Xie Z , Colucci WS , Singh K . beta1 integrins expression in adult rat ventricular myocytes and its role in the regulation of beta‐adrenergic receptor‐stimulated apoptosis. J Cell Biochem 89: 381‐388, 2003.
 41. Consortium TU . UniProt: A hub for protein information. Nucleic Acids Res 43: D204‐D212, 2015.
 42. Crafts TD , Jensen AR , Blocher‐Smith EC , Markel TA . Vascular endothelial growth factor: Therapeutic possibilities and challenges for the treatment of ischemia. Cytokine 71: 385‐393, 2015.
 43. Daaka Y , Luttrell LM , Lefkowitz RJ . Switching of the coupling of the beta2‐adrenergic receptor to different G proteins by protein kinase A. Nature 390: 88‐91, 1997.
 44. Dahi S , Karliner JS , Sarkar R , Lovett DH . Transgenic expression of matrix metalloproteinase‐2 induces coronary artery ectasia. Int J Exp Pathol 92: 50‐56, 2011.
 45. Dai S , Yuan F , Mu J , Li C , Chen N , Guo S , Kingery J , Prabhu SD , Bolli R , Rokosh G . Chronic AMD3100 antagonism of SDF‐1alpha‐CXCR4 exacerbates cardiac dysfunction and remodeling after myocardial infarction. J Mol Cell Cardiol 49: 587‐597, 2010.
 46. Daino H , Matsumura I , Takada K , Odajima J , Tanaka H , Ueda S , Shibayama H , Ikeda H , Hibi M , Machii T , Hirano T , Kanakura Y . Induction of apoptosis by extracellular ubiquitin in human hematopoietic cells: Possible involvement of STAT3 degradation by proteasome pathway in interleukin 6‐dependent hematopoietic cells. Blood 95: 2577‐2585, 2000.
 47. Daino H , Shibayama H , Machii T , Kitani T . Extracellular ubiquitin regulates the growth of human hematopoietic cells. Biochem Biophys Res Commun 223: 226‐228, 1996.
 48. Dammer EB , Na CH , Xu P , Seyfried NT , Duong DM , Cheng D , Gearing M , Rees H , Lah JJ , Levey AI , Rush J , Peng J . Polyubiquitin linkage profiles in three models of proteolytic stress suggest the etiology of Alzheimer disease. J Biol Chem 286: 10457‐10465, 2011.
 49. Daniel LL , Joyner WL , Singh M , Singh K . Integrins: Implications for aging in heart failure therapy. In: Jugdutt BI , editor. Aging and Heart Failure. New York: Springer, 2014, pp. 401‐410.
 50. Daniels CR , Foster CR , Yakoob S , Dalal S , Joyner WL , Singh M , Singh K . Exogenous ubiquitin modulates chronic β‐adrenergic receptor‐stimulated myocardial remodeling: role in Akt activity and matrix metalloproteinase expression. Am J Physiol Heart Circ Physiol 303: H1459‐H1468, 2012.
 51. Davis J , Molkentin JD . Myofibroblasts: Trust your heart and let fate decide. J Mol Cell Cardiol 70: 9‐18, 2014.
 52. de Lucia C , Femminella GD , Gambino G , Pagano G , Allocca E , Rengo C , Silvestri C , Leosco D , Ferrara N , Rengo G . Adrenal adrenoceptors in heart failure. Front Physiol 5: 246, 2014.
 53. DeGeorge BR , Gao E , Boucher M , Vinge LE , Martini JS , Raake PW , Chuprun JK , Harris DM , Kim GW , Soltys S , Eckhart AD , Koch WJ . Targeted inhibition of cardiomyocyte Gi signaling enhances susceptibility to apoptotic cell death in response to ischemic stress. Circulation 117: 1378‐1387, 2008.
 54. Deschamps AM , Spinale FG . Pathways of matrix metalloproteinase induction in heart failure: bioactive molecules and transcriptional regulation. Cardiovasc Res 69: 666‐676, 2006.
 55. Doherty FJ , Osborn NU , Wassell JA , Heggie PE , Laszlo L , Mayer RJ . Ubiquitin‐protein conjugates accumulate in the lysosomal system of fibroblasts treated with cysteine proteinase inhibitors. Biochem J 263: 47‐55, 1989.
 56. Dong RQ , Wang ZF , Zhao C , Gu HR , Hu ZW , Xie J , Wu YQ . Toll‐like receptor 4 knockout protects against isoproterenol‐induced cardiac fibrosis: The role of autophagy. J Cardiovasc Pharmacol Ther 20: 84‐92, 2015.
 57. Dorn GW , Brown JH . Gq signaling in cardiac adaptation and maladaptation. Trends Cardiovasc Med 9: 26‐34, 1999.
 58. Downing SE , Chen V . Myocardial injury following endogenous catecholamine release in rabbits. J Mol Cell Cardiol 17: 377‐387, 1985.
 59. Earle SA , El‐Haddad A , Patel MB , Ruiz P , Pham SM , Majetschak M . Prolongation of skin graft survival by exogenous ubiquitin. Transplantation 82: 1544‐1546, 2006.
 60. Earle SA , Proctor KG , Patel MB , Majetschak M . Ubiquitin reduces fluid shifts after traumatic brain injury. Surgery 138: 431‐438, 2005.
 61. Eghbali M . Cardiac fibroblasts: Function, regulation of gene expression, and phenotypic modulation. Basic Res Cardiol 87(Suppl 2): 183‐189, 1992.
 62. Esler M , Kaye D , Lambert G , Esler D , Jennings G . Adrenergic nervous system in heart failure. Am J Cardiol 80: 7L‐14L, 1997.
 63. Esposito G , Rapacciuolo A , Naga Prasad SV , Takaoka H , Thomas SA , Koch WJ , Rockman HA . Genetic alterations that inhibit in vivo pressure‐overload hypertrophy prevent cardiac dysfunction despite increased wall stress. Circulation 105: 85‐92, 2002.
 64. Etlinger JD , Goldberg AL . A soluble ATP‐dependent proteolytic system responsible for the degradation of abnormal proteins in reticulocytes. Proc Natl Acad Sci U S A 74: 54‐58, 1977.
 65. Fan D , Takawale A , Lee J , Kassiri Z . Cardiac fibroblasts, fibrosis and extracellular matrix remodeling in heart disease. Fibrogenesis Tissue Repair 5: 15, 2012.
 66. Finley D , Sadis S , Monia BP , Boucher P , Ecker DJ , Crooke ST , Chau V . Inhibition of proteolysis and cell cycle progression in a multiubiquitination‐deficient yeast mutant. Mol Cell Biol 14: 5501‐5509, 1994.
 67. Frangogiannis NG . The mechanistic basis of infarct healing. Antioxid Redox Signal 8: 1907‐1939, 2006.
 68. Frangogiannis NG . The stromal cell‐derived factor‐1/CXCR4 axis in cardiac injury and repair. J Am Coll Cardiol 58: 2424‐2426, 2011.
 69. Frangogiannis NG , Smith CW , Entman ML . The inflammatory response in myocardial infarction. Cardiovasc Res 53: 31‐47, 2002.
 70. Freitas C , Desnoyer A , Meuris F , Bachelerie F , Balabanian K , Machelon V . The relevance of the chemokine receptor ACKR3/CXCR7 on CXCL12‐mediated effects in cancers with a focus on virus‐related cancers. Cytokine Growth Factor Rev 25: 307‐316, 2014.
 71. Fu Y , Xiao H , Zhang Y . Beta‐adrenoceptor signaling pathways mediate cardiac pathological remodeling. Front Biosci (Elite Ed) 4: 1625‐1637, 2012.
 72. Fukazawa T , Fujiwara T , Uno F , Teraishi F , Kadowaki Y , Itoshima T , Takata Y , Kagawa S , Roth JA , Tschopp J , Tanaka N . Accelerated degradation of cellular FLIP protein through the ubiquitin‐proteasome pathway in p53‐mediated apoptosis of human cancer cells. Oncogene 20: 5225‐5231, 2001.
 73. Fulda S , Debatin KM . Extrinsic versus intrinsic apoptosis pathways in anticancer chemotherapy. Oncogene 25: 4798‐4811, 2006.
 74. Galluzzi L , Vitale I , Abrams JM , Alnemri ES , Baehrecke EH , Blagosklonny MV , Dawson TM , Dawson VL , El‐Deiry WS , Fulda S , Gottlieb E , Green DR , Hengartner MO , Kepp O , Knight RA , Kumar S , Lipton SA , Lu X , Madeo F , Malorni W , Mehlen P , Nuñez G , Peter ME , Piacentini M , Rubinsztein DC , Shi Y , Simon HU , Vandenabeele P , White E , Yuan J , Zhivotovsky B , Melino G , Kroemer G . Molecular definitions of cell death subroutines: Recommendations of the Nomenclature Committee on Cell Death 2012. Cell Death Differ 19: 107‐120, 2012.
 75. Garcia‐Covarrubias L , Manning EW , Sorell LT , Pham SM , Majetschak M . Ubiquitin enhances the Th2 cytokine response and attenuates ischemia‐reperfusion injury in the lung. Crit Care Med 36: 979‐982, 2008.
 76. Geng YJ , Ishikawa Y , Vatner DE , Wagner TE , Bishop SP , Vatner SF , Homcy CJ . Apoptosis of cardiac myocytes in Gsalpha transgenic mice. Circ Res 84: 34‐42, 1999.
 77. Gerdes AM . Cardiac myocyte remodeling in hypertrophy and progression to failure. J Card Fail 8: S264‐268, 2002.
 78. Goldberg AL . Protein degradation and protection against misfolded or damaged proteins. Nature 426: 895‐899, 2003.
 79. Goldstein G , Scheid M , Hammerling U , Schlesinger DH , Niall HD , Boyse EA . Isolation of a polypeptide that has lymphocyte‐differentiating properties and is probably represented universally in living cells. Proc Natl Acad Sci U S A 72: 11‐15, 1975.
 80. Griebenow M , Casalis P , Woiciechowsky C , Majetschak M , Thomale UW . Ubiquitin reduces contusion volume after controlled cortical impact injury in rats. J Neurotrauma 24: 1529‐1535, 2007.
 81. Gropper R , Brandt RA , Elias S , Bearer CF , Mayer A , Schwartz AL , Ciechanover A . The ubiquitin‐activating enzyme, E1, is required for stress‐induced lysosomal degradation of cellular proteins. J Biol Chem 266: 3602‐3610, 1991.
 82. Haglund K , Dikic I . Ubiquitylation and cell signaling. EMBO J 24: 3353‐3359, 2005.
 83. Hasking GJ , Esler MD , Jennings GL , Burton D , Johns JA , Korner PI . Norepinephrine spillover to plasma in patients with congestive heart failure: Evidence of increased overall and cardiorenal sympathetic nervous activity. Circulation 73: 615‐621, 1986.
 84. Haunstetter A , Izumo S . Future perspectives and potential implications of cardiac myocyte apoptosis. Cardiovasc Res 45: 795‐801, 2000.
 85. Hausenloy DJ , Yellon DM . Myocardial ischemia‐reperfusion injury: A neglected therapeutic target. J Clin Invest 123: 92‐100, 2013.
 86. Hefti MA , Harder BA , Eppenberger HM , Schaub MC . Signaling pathways in cardiac myocyte hypertrophy. J Mol Cell Cardiol 29: 2873‐2892, 1997.
 87. Hershko A . Regulation of Gene Expression in Eukaryotic Cells. In: Harris M , Thompson B , editors. Regulation of Gene Expression in Eukaryotic Cells. Washington, D.C.: U.S. Printing Office, 1974, pp. 85‐96.
 88. Hershko A , Ciechanover A , Heller H , Haas AL , Rose IA . Proposed role of ATP in protein breakdown: Conjugation of protein with multiple chains of the polypeptide of ATP‐dependent proteolysis. Proc Natl Acad Sci U S A 77: 1783‐1786, 1980.
 89. Hicke L . Gettin' down with ubiquitin: Turning off cell‐surface receptors, transporters and channels. Trends Cell Biol 9: 107‐112, 1999.
 90. Hicke L . Protein regulation by monoubiquitin. Nat Rev Mol Cell Biol 2: 195‐201, 2001.
 91. Hicke L . Ubiquitin‐dependent internalization and down‐regulation of plasma membrane proteins. FASEB J 11: 1215‐1226, 1997.
 92. Hicke L , Riezman H . Ubiquitination of a yeast plasma membrane receptor signals its ligand‐stimulated endocytosis. Cell 84: 277‐287, 1996.
 93. Hitomi J , Christofferson DE , Ng A , Yao J , Degterev A , Xavier RJ , Yuan J . Identification of a molecular signaling network that regulates a cellular necrotic cell death pathway. Cell 135: 1311‐1323, 2008.
 94. Hori Y , Yoshioka K , Kanai K , Hoshi F , Itoh N , Higuchi S . Spironolactone decreases isoproterenol‐induced ventricular fibrosis and matrix metalloproteinase‐2 in rats. Biol Pharm Bull 34: 61‐65, 2011.
 95. Hu X , Dai S , Wu WJ , Tan W , Zhu X , Mu J , Guo Y , Bolli R , Rokosh G . Stromal cell derived factor‐1 alpha confers protection against myocardial ischemia/reperfusion injury: Role of the cardiac stromal cell derived factor‐1 alpha CXCR4 axis. Circulation 116: 654‐663, 2007.
 96. Huang DC , Strasser A . BH3‐Only proteins‐essential initiators of apoptotic cell death. Cell 103: 839‐842, 2000.
 97. Iwase M , Bishop SP , Uechi M , Vatner DE , Shannon RP , Kudej RK , Wight DC , Wagner TE , Ishikawa Y , Homcy CJ , Vatner SF . Adverse effects of chronic endogenous sympathetic drive induced by cardiac GS alpha overexpression. Circ Res 78: 517‐524, 1996.
 98. Jope RS , Johnson GV . The glamour and gloom of glycogen synthase kinase‐3. Trends Biochem Sci 29: 95‐102, 2004.
 99. Kajstura J , Bolli R , Sonnenblick EH , Anversa P , Leri A . Cause of death: Suicide. J Mol Cell Cardiol 40: 425‐437, 2006.
 100. Kajstura J , Cheng W , Reiss K , Clark WA , Sonnenblick EH , Krajewski S , Reed JC , Olivetti G , Anversa P . Apoptotic and necrotic myocyte cell deaths are independent contributing variables of infarct size in rats. Lab Invest 74: 86‐107, 1996.
 101. Kajstura J , Cigola E , Malhotra A , Li P , Cheng W , Meggs LG , Anversa P . Angiotensin II induces apoptosis of adult ventricular myocytes in vitro. J Mol Cell Cardiol 29: 859‐870, 1997.
 102. Kanki S , Segers VF , Wu W , Kakkar R , Gannon J , Sys SU , Sandrasagra A , Lee RT . Stromal cell‐derived factor‐1 retention and cardioprotection for ischemic myocardium. Circ Heart Fail 4: 509‐518, 2011.
 103. Karin N . The multiple faces of CXCL12 (SDF‐1alpha) in the regulation of immunity during health and disease. J Leukoc Biol 88: 463‐473, 2010.
 104. Katz AM . Evolving concepts of heart failure: cooling furnace, malfunctioning pump, enlarging muscle. Part II: Hypertrophy and dilatation of the failing heart. J Card Fail 4: 67‐81, 1998.
 105. Katz AM . Molecular and cellular basis of contraction. In: Colucci WS , Braunwald E , editors. Atlas of Heart Failure, Cardiac Function and Dysfunction. Philadelphia, PA, USA, 1999.
 106. Kawai K , Qin F , Shite J , Mao W , Fukuoka S , Liang CS . Importance of antioxidant and antiapoptotic effects of beta‐receptor blockers in heart failure therapy. Am J Physiol Heart Circ Physiol 287: H1003‐H1012, 2004.
 107. Kawauchi K , Ogasawara T , Yasuyama M , Otsuka K , Yamada O . The PI3K/Akt pathway as a target in the treatment of hematologic malignancies. Anticancer Agents Med Chem 9: 550‐559, 2009.
 108. Kerr JF , Wyllie AH , Currie AR . Apoptosis: A basic biological phenomenon with wide‐ranging implications in tissue kinetics. Br J Cancer 26: 239‐257, 1972.
 109. Kieffer AE , Goumon Y , Ruh O , Chasserot‐Golaz S , Nullans G , Gasnier C , Aunis D , Metz‐Boutigue MH . The N‐ and C‐terminal fragments of ubiquitin are important for the antimicrobial activities. FASEB J 17: 776‐778, 2003.
 110. Kobilka B . Adrenergic receptors as models for G protein‐coupled receptors. Annu Rev Neurosci 15: 87‐114, 1992.
 111. Koitabashi N , Danner T , Zaiman AL , Pinto YM , Rowell J , Mankowski J , Zhang D , Nakamura T , Takimoto E , Kass DA . Pivotal role of cardiomyocyte TGF‐β signaling in the murine pathological response to sustained pressure overload. J Clin Invest 121: 2301‐2312, 2011.
 112. Kong P , Christia P , Frangogiannis NG . The pathogenesis of cardiac fibrosis. Cell Mol Life Sci 71: 549‐574, 2014.
 113. Kostin S , Pool L , Elsässer A , Hein S , Drexler HC , Arnon E , Hayakawa Y , Zimmermann R , Bauer E , Klövekorn WP , Schaper J . Myocytes die by multiple mechanisms in failing human hearts. Circ Res 92: 715‐724, 2003.
 114. Krishnamurthy P , Subramanian V , Singh M , Singh K . Beta1 integrins modulate beta‐adrenergic receptor‐stimulated cardiac myocyte apoptosis and myocardial remodeling. Hypertension 49: 865‐872, 2007.
 115. Krishnamurthy P , Subramanian V , Singh M , Singh K . Deficiency of beta1 integrins results in increased myocardial dysfunction after myocardial infarction. Heart 92: 1309‐1315, 2006.
 116. Kroemer G , Galluzzi L , Brenner C . Mitochondrial membrane permeabilization in cell death. Physiol Rev 87: 99‐163, 2007.
 117. Kutty BC , Pasupathy K , Mishra KP . Effects of exogenous ubiquitin on cell division cycle mutants of Schizosaccharomyces pombe. FEMS Microbiol Lett 244: 187‐191, 2005.
 118. Laflamme MA , Murry CE . Heart regeneration. Nature 473: 326‐335, 2011.
 119. Lajiness JD , Conway SJ . Origin, development, and differentiation of cardiac fibroblasts. J Mol Cell Cardiol 70: 2‐8, 2014.
 120. Lalaoui N , Lindqvist LM , Sandow JJ , Ekert PG . The molecular relationships between apoptosis, autophagy and necroptosis. Semin Cell Dev Biol, 2015.
 121. Larocca TJ , Jeong D , Kohlbrenner E , Lee A , Chen J , Hajjar RJ , Tarzami ST . CXCR4 gene transfer prevents pressure overload induced heart failure. J Mol Cell Cardiol 53: 223‐232, 2012.
 122. LaRocca TJ , Schwarzkopf M , Altman P , Zhang S , Gupta A , Gomes I , Alvin Z , Champion HC , Haddad G , Hajjar RJ , Devi LA , Schecter AD , Tarzami ST . β2‐Adrenergic receptor signaling in the cardiac myocyte is modulated by interactions with CXCR4. J Cardiovasc Pharmacol 56: 548‐559, 2010.
 123. Laszlo L , Doherty FJ , Osborn NU , Mayer RJ . Ubiquitinated protein conjugates are specifically enriched in the lysosomal system of fibroblasts. FEBS Lett 261: 365‐368, 1990.
 124. Leask A . Getting to the heart of the matter: New insights into cardiac fibrosis. Circ Res 116: 1269‐1276, 2015.
 125. Lecker SH , Goldberg AL , Mitch WE . Protein degradation by the ubiquitin‐proteasome pathway in normal and disease states. J Am Soc Nephrol 17: 1807‐1819, 2006.
 126. Lefkowitz RJ , Rockman HA , Koch WJ . Catecholamines, cardiac beta‐adrenergic receptors, and heart failure. Circulation 101: 1634‐1637, 2000.
 127. Leineweber K , Heusch G , Schulz R . Regulation and role of the presynaptic and myocardial Na+/H +exchanger NHE1: effects on the sympathetic nervous system in heart failure. Cardiovasc Drug Rev 25: 123‐131, 2007.
 128. Li YY , McTiernan CF , Feldman AM . Interplay of matrix metalloproteinases, tissue inhibitors of metalloproteinases and their regulators in cardiac matrix remodeling. Cardiovasc Res 46: 214‐224, 2000.
 129. Li YY , McTiernan CF , Feldman AM . Proinflammatory cytokines regulate tissue inhibitors of metalloproteinases and disintegrin metalloproteinase in cardiac cells. Cardiovasc Res 42: 162‐172, 1999.
 130. Liang Z , Brooks J , Willard M , Liang K , Yoon Y , Kang S , Shim H . CXCR4/CXCL12 axis promotes VEGF‐mediated tumor angiogenesis through Akt signaling pathway. Biochem Biophys Res Commun 359: 716‐722, 2007.
 131.Liehn EA, Tuchscheerer N, Kanzler I, Drechsler M, Fraemohs L, Schuh A, Koenen RR, Zander S, Soehnlein O, Hristov M, Grigorescu G, Urs AO, Leabu M, Bucur I, Merx MW, Zernecke A, Ehling J, Gremse F, Lammers T, Kiessling F, Bernhagen J, Schober A, Weber C. Double‐edged role of the CXCL12/CXCR4 axis in experimental myocardial infarction. J Am Coll Cardiol 58: 2415‐2423, 2011.
 132. Locksley RM , Killeen N , Lenardo MJ . The TNF and TNF receptor superfamilies: Integrating mammalian biology. Cell 104: 487‐501, 2001.
 133. Lu Z , Xu S , Joazeiro C , Cobb MH , Hunter T . The PHD domain of MEKK1 acts as an E3 ubiquitin ligase and mediates ubiquitination and degradation of ERK1/2. Mol Cell 9: 945‐956, 2002.
 134. Madamanchi A . Beta‐adrenergic receptor signaling in cardiac function and heart failure. Mcgill J Med 10: 99‐104, 2007.
 135. Majetschak M . Extracellular ubiquitin: immune modulator and endogenous opponent of damage‐associated molecular pattern molecules. J Leukoc Biol 89: 205‐219, 2011.
 136. Majetschak M , Cohn SM , Nelson JA , Burton EH , Obertacke U , Proctor KG . Effects of exogenous ubiquitin in lethal endotoxemia. Surgery 135: 536‐543, 2004.
 137. Majetschak M , Cohn SM , Obertacke U , Proctor KG . Therapeutic potential of exogenous ubiquitin during resuscitation from severe trauma. J Trauma 56: 991‐999; discussion 999‐1000, 2004.
 138. Majetschak M , King DR , Krehmeier U , Busby LT , Thome C , Vajkoczy S , Proctor KG . Ubiquitin immunoreactivity in cerebrospinal fluid after traumatic brain injury: Clinical and experimental findings. Crit Care Med 33: 1589‐1594, 2005.
 139. Majetschak M , Krehmeier U , Bardenheuer M , Denz C , Quintel M , Voggenreiter G , Obertacke U . Extracellular ubiquitin inhibits the TNF‐alpha response to endotoxin in peripheral blood mononuclear cells and regulates endotoxin hyporesponsiveness in critical illness. Blood 101: 1882‐1890, 2003.
 140. Majetschak M , Zedler S , Hostmann A , Sorell LT , Patel MB , Novar LT , Kraft R , Habib F , de Moya MA , Ertel W , Faist E , Schade U . Systemic ubiquitin release after blunt trauma and burns: association with injury severity, posttraumatic complications, and survival. J Trauma 64: 586‐596; discussion 596‐588, 2008.
 141. Mangmool S , Shukla AK , Rockman HA . beta‐Arrestin‐dependent activation of Ca(2+)/calmodulin kinase II after beta(1)‐adrenergic receptor stimulation. J Cell Biol 189: 573‐587, 2010.
 142. Mann DL , Kent RL , Parsons B , Cooper G . Adrenergic effects on the biology of the adult mammalian cardiocyte. Circulation 85: 790‐804, 1992.
 143. Marchese A , Benovic JL . Agonist‐promoted ubiquitination of the G protein‐coupled receptor CXCR4 mediates lysosomal sorting. J Biol Chem 276: 45509‐45512, 2001.
 144. Marchese A , Raiborg C , Santini F , Keen JH , Stenmark H , Benovic JL . The E3 ubiquitin ligase AIP4 mediates ubiquitination and sorting of the G protein‐coupled receptor CXCR4. Dev Cell 5: 709‐722, 2003.
 145. Martinvalet D , Zhu P , Lieberman J . Granzyme A induces caspase‐independent mitochondrial damage, a required first step for apoptosis. Immunity 22: 355‐370, 2005.
 146. Menon B , Johnson JN , Ross RS , Singh M , Singh K . Glycogen synthase kinase‐3beta plays a pro‐apoptotic role in beta‐adrenergic receptor‐stimulated apoptosis in adult rat ventricular myocytes: Role of beta1 integrins. J Mol Cell Cardiol 42: 653‐661, 2007.
 147. Menon B , Singh M , Ross RS , Johnson JN , Singh K . beta‐Adrenergic receptor‐stimulated apoptosis in adult cardiac myocytes involves MMP‐2‐mediated disruption of beta1 integrin signaling and mitochondrial pathway. Am J Physiol Cell Physiol 290: C254‐261, 2006.
 148. Menon B , Singh M , Singh K . Matrix metalloproteinases mediate beta‐adrenergic receptor‐stimulated apoptosis in adult rat ventricular myocytes. Am J Physiol Cell Physiol 289: C168‐176, 2005.
 149. Mewton N , Liu CY , Croisille P , Bluemke D , Lima JA . Assessment of myocardial fibrosis with cardiovascular magnetic resonance. J Am Coll Cardiol 57: 891‐903, 2011.
 150. Mikaelian I , Coluccio D , Morgan KT , Johnson T , Ryan AL , Rasmussen E , Nicklaus R , Kanwal C , Hilton H , Frank K , Fritzky L , Wheeldon EB . Temporal gene expression profiling indicates early up‐regulation of interleukin‐6 in isoproterenol‐induced myocardial necrosis in rat. Toxicol Pathol 36: 256‐264, 2008.
 151. Mohrman DE , Heller LJ . Cardiovascular Physiology. New York: McGraw‐Hill, 2006.
 152. Möllmann H , Nef HM , Kostin S , von Kalle C , Pilz I , Weber M , Schaper J , Hamm CW , Elsässer A . Bone marrow‐derived cells contribute to infarct remodelling. Cardiovasc Res 71: 661‐671, 2006.
 153. Mukhopadhyay D , Riezman H . Proteasome‐independent functions of ubiquitin in endocytosis and signaling. Science 315: 201‐205, 2007.
 154. Mustapha S , Kirshner A , De Moissac D , Kirshenbaum LA . A direct requirement of nuclear factor‐kappa B for suppression of apoptosis in ventricular myocytes. Am J Physiol Heart Circ Physiol 279: H939‐H945, 2000.
 155. Nabika T , Terashima M , Momose I , Hosokawa Y , Nagasue N , Tanigawa Y . Synergistic effect of ubiquitin on lipopolysaccharide‐induced TNF‐alpha production in murine macrophage cell line RAW 264.7 cells. Biochim Biophys Acta 1450: 25‐34, 1999.
 156. Nadal‐Ginard B , Kajstura J , Leri A , Anversa P . Myocyte death, growth, and regeneration in cardiac hypertrophy and failure. Circ Res 92: 139‐150, 2003.
 157. Nag AC . Study of non‐muscle cells of the adult mammalian heart: A fine structural analysis and distribution. Cytobios 28: 41‐61, 1980.
 158. O'Connell TD , Jensen BC , Baker AJ , Simpson PC . Cardiac alpha1‐adrenergic receptors: novel aspects of expression, signaling mechanisms, physiologic function, and clinical importance. Pharmacol Rev 66: 308‐333, 2014.
 159. Okada M , Miyazaki S , Hirasawa Y . Increase in plasma concentration of ubiquitin in dialysis patients: Possible involvement in beta 2‐microglobulin amyloidosis. Clin Chim Acta 220: 135‐144, 1993.
 160. Onizawa M , Oshima S , Schulze‐Topphoff U , Oses‐Prieto JA , Lu T , Tavares R , Prodhomme T , Duong B , Whang MI , Advincula R , Agelidis A , Barrera J , Wu H , Burlingame A , Malynn BA , Zamvil SS , Ma A . The ubiquitin‐modifying enzyme A20 restricts ubiquitination of the kinase RIPK3 and protects cells from necroptosis. Nat Immunol 16: 618‐627, 2015.
 161. Opie LH , Commerford PJ , Gersh BJ , Pfeffer MA . Controversies in ventricular remodelling. Lancet 367: 356‐367, 2006.
 162. Orogo AM , Gustafsson Å . Cell death in the myocardium: My heart won't go on. IUBMB Life 65: 651‐656, 2013.
 163. Pancré V , Pierce RJ , Fournier F , Mehtali M , Delanoye A , Capron A , Auriault C . Effect of ubiquitin on platelet functions: Possible identity with platelet activity suppressive lymphokine (PASL). Eur J Immunol 21: 2735‐2741, 1991.
 164. Parthasarathy A , Gopi V , Devi KMS , Balaji N , Vellaichamy E . Aminoguanidine inhibits ventricular fibrosis and remodeling process in isoproterenol‐induced hypertrophied rat hearts by suppressing ROS and MMPs. Life Sci 118: 15‐26, 2014.
 165. Patel MB , Proctor KG , Majetschak M . Extracellular ubiquitin increases in packed red blood cell units during storage. J Surg Res 135: 226‐232, 2006.
 166. Patnaik A , Chau V , Wills JW . Ubiquitin is part of the retrovirus budding machinery. Proc Natl Acad Sci U S A 97: 13069‐13074, 2000.
 167. Peters JH , de Groot BL . Ubiquitin dynamics in complexes reveal molecular recognition mechanisms beyond induced fit and conformational selection. PLoS Comput Biol 8: e1002704, 2012.
 168. Pfeffer MA . Cardiac Remodeling and Its Prevention. In: Colucci WS , editor. Atlas of Heart Failure (2 ed). Philadelphia: Blackwell Science, 1999, pp. 5.2‐5.9.
 169. Pham AD , Sauer F . Ubiquitin‐activating/conjugating activity of TAFII250, a mediator of activation of gene expression in Drosophila. Science 289: 2357‐2360, 2000.
 170. Powers SK , Murlasits Z , Wu M , Kavazis AN . Ischemia‐reperfusion‐induced cardiac injury: A brief review. Med Sci Sports Exerc 39: 1529‐1536, 2007.
 171. Punia N , Smith S , Thomson JV , Irshad A , Nair P , Sehmi R . Interleukin‐4 and interleukin‐13 prime migrational responses of haemopoietic progenitor cells to stromal cell‐derived factor‐1α. Clin Exp Allergy 42: 255‐264, 2012.
 172. Quijada P , Sussman MA . Circulating around the tissue: Hematopoietic cell‐based fusion versus transdifferentiation. Circ Res 116: 563‐565, 2015.
 173. Rao L , Perez D , White E . Lamin proteolysis facilitates nuclear events during apoptosis. J Cell Biol 135: 1441‐1455, 1996.
 174. Remondino A , Kwon SH , Communal C , Pimentel DR , Sawyer DB , Singh K , Colucci WS . Beta‐adrenergic receptor‐stimulated apoptosis in cardiac myocytes is mediated by reactive oxygen species/c‐Jun NH2‐terminal kinase‐dependent activation of the mitochondrial pathway. Circ Res 92: 136‐138, 2003.
 175. Reynaud E . Protein misfolding and degenerative diseases. Nature Education 3: 1, 2010.
 176. Ribatti D , Baiguera S . Phase II angiogenesis stimulators. Expert Opin Investig Drugs 22: 1157‐1166, 2013.
 177. Roest HP , van Klaveren J , de Wit J , van Gurp CG , Koken MH , Vermey M , van Roijen JH , Hoogerbrugge JW , Vreeburg JT , Baarends WM , Bootsma D , Grootegoed JA , Hoeijmakers JH . Inactivation of the HR6B ubiquitin‐conjugating DNA repair enzyme in mice causes male sterility associated with chromatin modification. Cell 86: 799‐810, 1996.
 178. Rona G . Catecholamine cardiotoxicity. J Mol Cell Cardiol 17: 291‐306, 1985.
 179. Rona G , Chappel CI , Balazs T , Gaudry R . An infarct‐like myocardial lesion and other toxic manifestations produced by isoproterenol in the rat. AMA Arch Pathol 67: 443‐455, 1959.
 180. Rouet‐Benzineb P , Buhler JM , Dreyfus P , Delcourt A , Dorent R , Perennec J , Crozatier B , Harf A , Lafuma C . Altered balance between matrix gelatinases (MMP‐2 and MMP‐9) and their tissue inhibitors in human dilated cardiomyopathy: Potential role of MMP‐9 in myosin‐heavy chain degradation. Eur J Heart Fail 1: 337‐352, 1999.
 181. Saini V , Marchese A , Majetschak M . CXC chemokine receptor 4 is a cell surface receptor for extracellular ubiquitin. J Biol Chem 285: 15566‐15576, 2010.
 182. Saini V , Marchese A , Tang WJ , Majetschak M . Structural determinants of ubiquitin‐CXC chemokine receptor 4 interaction. J Biol Chem 286: 44145‐44152, 2011.
 183. Saini V , Romero J , Marchese A , Majetschak M . Ubiquitin receptor binding and signaling in primary human leukocytes. Commun Integr Biol 3: 608‐610, 2010.
 184. Saini V , Staren DM , Ziarek JJ , Nashaat ZN , Campbell EM , Volkman BF , Marchese A , Majetschak M . The CXC chemokine receptor 4 ligands ubiquitin and stromal cell‐derived factor‐1α function through distinct receptor interactions. J Biol Chem 286: 33466‐33477, 2011.
 185. Santiago JJ , Dangerfield AL , Rattan SG , Bathe KL , Cunnington RH , Raizman JE , Bedosky KM , Freed DH , Kardami E , Dixon IM . Cardiac fibroblast to myofibroblast differentiation in vivo and in vitro: expression of focal adhesion components in neonatal and adult rat ventricular myofibroblasts. Dev Dyn 239: 1573‐1584, 2010.
 186. Savergnini SQ , Ianzer D , Carvalho MB , Ferreira AJ , Silva GA , Marques FD , Peluso AA , Beiman M , Cojocaru G , Cohen Y , Almeida AP , Rotman G , Santos RA . The novel Mas agonist, CGEN‐856S, attenuates isoproterenol‐induced cardiac remodeling and myocardial infarction injury in rats. PLoS One 8: e57757, 2013.
 187. Saxena A , Fish JE , White MD , Yu S , Smyth JW , Shaw RM , DiMaio JM , Srivastava D . Stromal cell‐derived factor‐1alpha is cardioprotective after myocardial infarction. Circulation 117: 2224‐2231, 2008.
 188. Schedi MP , Goldstein G , Boyce EA . Differentiation of T cells in nude mice. Science 190: 1211‐1213, 1975.
 189. Schlesinger DH , Goldstein G , Niall HD . The complete amino acid sequence of ubiquitin, an adenylate cyclase stimulating polypeptide probably universal in living cells. Biochemistry 14: 2214‐2218, 1975.
 190. Schömig A , Richardt G . Cardiac sympathetic activity in myocardial ischemia: Release and effects of noradrenaline. Basic Res Cardiol 85(Suppl 1): 9‐30, 1990.
 191. Schulz R . Intracellular targets of matrix metalloproteinase‐2 in cardiac disease: Rationale and therapeutic approaches. Annu Rev Pharmacol Toxicol 47: 211‐242, 2007.
 192. Sebbagh M , Renvoizé C , Hamelin J , Riché N , Bertoglio J , Bréard J . Caspase‐3‐mediated cleavage of ROCK I induces MLC phosphorylation and apoptotic membrane blebbing. Nat Cell Biol 3: 346‐352, 2001.
 193. Segers VF , Tokunou T , Higgins LJ , MacGillivray C , Gannon J , Lee RT . Local delivery of protease‐resistant stromal cell derived factor‐1 for stem cell recruitment after myocardial infarction. Circulation 116: 1683‐1692, 2007.
 194. Seifter J , Ratner A , Sloane D . Concepts in Medical Physiology. Philadelphia, PA, USA: Lippincott Williams & Wilkins, 2005.
 195. Serini G , Bochaton‐Piallat ML , Ropraz P , Geinoz A , Borsi L , Zardi L , Gabbiani G . The fibronectin domain ED‐A is crucial for myofibroblastic phenotype induction by transforming growth factor‐beta1. J Cell Biol 142: 873‐881, 1998.
 196. Shah AM , Mann DL . In search of new therapeutic targets and strategies for heart failure: Recent advances in basic science. Lancet 378: 704‐712, 2011.
 197. Sharp PM , Li WH . Ubiquitin genes as a paradigm of concerted evolution of tandem repeats. J Mol Evol 25: 58‐64, 1987.
 198. Shenoy SK , McDonald PH , Kohout TA , Lefkowitz RJ . Regulation of receptor fate by ubiquitination of activated beta 2‐adrenergic receptor and beta‐arrestin. Science 294: 1307‐1313, 2001.
 199. Shinde AV , Frangogiannis NG . Fibroblasts in myocardial infarction: A role in inflammation and repair. J Mol Cell Cardiol 70: 74‐82, 2014.
 200. Shiojima I , Sato K , Izumiya Y , Schiekofer S , Ito M , Liao R , Colucci WS , Walsh K . Disruption of coordinated cardiac hypertrophy and angiogenesis contributes to the transition to heart failure. J Clin Invest 115: 2108‐2118, 2005.
 201. Shizukuda Y , Buttrick PM , Geenen DL , Borczuk AC , Kitsis RN , Sonnenblick EH . beta‐adrenergic stimulation causes cardiocyte apoptosis: Influence of tachycardia and hypertrophy. Am J Physiol 275: H961‐H968, 1998.
 202. Siddiqi S , Sussman MA . The heart: Mostly postmitotic or mostly premitotic? Myocyte cell cycle, senescence, and quiescence. Can J Cardiol 30: 1270‐1278, 2014.
 203. Simko F , Bednarova KR , Krajcirovicova K , Hrenak J , Celec P , Kamodyova N , Gajdosechova L , Zorad S , Adamcova M . Melatonin reduces cardiac remodeling and improves survival in rats with isoproterenol‐induced heart failure. J Pineal Res 57: 177‐184, 2014.
 204. Singh K , Communal C , Sawyer DB , Colucci WS . Adrenergic regulation of myocardial apoptosis. Cardiovasc Res 45: 713‐719, 2000.
 205. Singh K , Xiao L , Remondino A , Sawyer DB , Colucci WS . Adrenergic regulation of cardiac myocyte apoptosis. J Cell Physiol 189: 257‐265, 2001.
 206. Singh M , Roginskaya M , Dalal S , Menon B , Kaverina E , Boluyt MO , Singh K . Extracellular ubiquitin inhibits beta‐AR‐stimulated apoptosis in cardiac myocytes: Role of GSK‐3beta and mitochondrial pathways. Cardiovasc Res 86: 20‐28, 2010.
 207. Souders CA , Bowers SL , Baudino TA . Cardiac fibroblast: The renaissance cell. Circ Res 105: 1164‐1176, 2009.
 208. Spinale FG . Myocardial matrix remodeling and the matrix metalloproteinases: Influence on cardiac form and function. Physiol Rev 87: 1285‐1342, 2007.
 209. Spinale FG , Janicki JS , Zile MR . Membrane‐associated matrix proteolysis and heart failure. Circ Res 112: 195‐208, 2013.
 210. Steagall RJ , Daniels CR , Dalal S , Joyner WL , Singh M , Singh K . Extracellular ubiquitin increases expression of angiogenic molecules and stimulates angiogenesis in cardiac microvascular endothelial cells. Microcirculation 21: 324‐332, 2014.
 211. Steffensen B , Wallon UM , Overall CM . Extracellular matrix binding properties of recombinant fibronectin type II‐like modules of human 72‐kDa gelatinase/type IV collagenase. High affinity binding to native type I collagen but not native type IV collagen. J Biol Chem 270: 11555‐11566, 1995.
 212. Swedberg K , Viquerat C , Rouleau JL , Roizen M , Atherton B , Parmley WW , Chatterjee K . Comparison of myocardial catecholamine balance in chronic congestive heart failure and in angina pectoris without failure. Am J Cardiol 54: 783‐786, 1984.
 213. Szardien S , Nef HM , Troidl C , Willmer M , Voss S , Liebetrau C , Hoffmann J , Rolf A , Rixe J , Elsässer A , Hamm CW , Möllmann H . Bone marrow‐derived cells contribute to cell turnover in aging murine hearts. Int J Mol Med 30: 283‐287, 2012.
 214. Szewczuk Z , Stefanowicz P , Wilczyński A , Staszewska A , Siemion IZ , Zimecki M , Wieczorek Z . Immunosuppressory activity of ubiquitin fragments containing retro‐RGD sequence. Biopolymers 74: 352‐362, 2004.
 215. Szobi A , Rajtik T , Carnicka S , Ravingerova T , Adameova A . Mitigation of postischemic cardiac contractile dysfunction by CaMKII inhibition: Effects on programmed necrotic and apoptotic cell death. Mol Cell Biochem 388: 269‐276, 2014.
 216. Tachibana K , Hirota S , Iizasa H , Yoshida H , Kawabata K , Kataoka Y , Kitamura Y , Matsushima K , Yoshida N , Nishikawa S , Kishimoto T , Nagasawa T . The chemokine receptor CXCR4 is essential for vascularization of the gastrointestinal tract. Nature 393: 591‐594, 1998.
 217. Takagi M , Yamauchi M , Toda G , Takada K , Hirakawa T , Ohkawa K . Serum ubiquitin levels in patients with alcoholic liver disease. Alcohol Clin Exp Res 23: 76S‐80S, 1999.
 218. Takemura G , Kanoh M , Minatoguchi S , Fujiwara H . Cardiomyocyte apoptosis in the failing heart–a critical review from definition and classification of cell death. Int J Cardiol 167: 2373‐2386, 2013.
 219. Taylor RC , Cullen SP , Martin SJ . Apoptosis: Controlled demolition at the cellular level. Nat Rev Mol Cell Biol 9: 231‐241, 2008.
 220. Terrell J , Shih S , Dunn R , Hicke L . A function for monoubiquitination in the internalization of a G protein‐coupled receptor. Mol Cell 1: 193‐202, 1998.
 221. Thompson SJ , Loftus LT , Ashley MD , Meller R . Ubiquitin‐proteasome system as a modulator of cell fate. Curr Opin Pharmacol 8: 90‐95, 2008.
 222. Thrower JS , Hoffman L , Rechsteiner M , Pickart CM . Recognition of the polyubiquitin proteolytic signal. EMBO J 19: 94‐102, 2000.
 223. Tomasek JJ , Gabbiani G , Hinz B , Chaponnier C , Brown RA . Myofibroblasts and mechano‐regulation of connective tissue remodelling. Nat Rev Mol Cell Biol 3: 349‐363, 2002.
 224. Tower J . Programmed cell death in aging. Ageing Res Rev 23: 90‐100, 2015.
 225. Tripathi A , Davis JD , Staren DM , Volkman BF , Majetschak M . CXC chemokine receptor 4 signaling upon co‐activation with stromal cell‐derived factor‐1α and ubiquitin. Cytokine 65: 121‐125, 2014.
 226. Tripathi A , Saini V , Marchese A , Volkman BF , Tang WJ , Majetschak M . Modulation of the CXC chemokine receptor 4 agonist activity of ubiquitin through C‐terminal protein modification. Biochemistry 52: 4184‐4192, 2013.
 227. Tripathi A , Vana PG , Chavan TS , Brueggemann LI , Byron KL , Tarasova NI , Volkman BF , Gaponenko V , Majetschak M . Heteromerization of chemokine (C‐X‐C motif) receptor 4 with α1A/B‐adrenergic receptors controls α1‐adrenergic receptor function. Proc Natl Acad Sci U S A 112: E1659‐1668, 2015.
 228. van der Laan AM , Piek JJ , van Royen N . Targeting angiogenesis to restore the microcirculation after reperfused MI. Nat Rev Cardiol 6: 515‐523, 2009.
 229. van Leeuwen FW , de Kleijn DP , van den Hurk HH , Neubauer A , Sonnemans MA , Sluijs JA , Köycü S , Ramdjielal RD , Salehi A , Martens GJ , Grosveld FG , Peter J , Burbach H , Hol EM . Frameshift mutants of beta amyloid precursor protein and ubiquitin‐B in Alzheimer's and Down patients. Science 279: 242‐247, 1998.
 230. Vijay‐Kumar S , Bugg CE , Cook WJ . Structure of ubiquitin refined at 1.8 A resolution. J Mol Biol 194: 531‐544, 1987.
 231. Wang ER , Jarrah AA , Benard L , Chen J , Schwarzkopf M , Hadri L , Tarzami ST . Deletion of CXCR4 in cardiomyocytes exacerbates cardiac dysfunction following isoproterenol administration. Gene Ther 21: 496‐506, 2014.
 232. Wang W , Zhu W , Wang S , Yang D , Crow MT , Xiao RP , Cheng H . Sustained beta1‐adrenergic stimulation modulates cardiac contractility by Ca2+/calmodulin kinase signaling pathway. Circ Res 95: 798‐806, 2004.
 233. Wang Y , Dohlman HG . Regulation of G protein and mitogen‐activated protein kinase signaling by ubiquitination: insights from model organisms. Circ Res 99: 1305‐1314, 2006.
 234. Weekes J , Morrison K , Mullen A , Wait R , Barton P , Dunn MJ . Hyperubiquitination of proteins in dilated cardiomyopathy. Proteomics 3: 208‐216, 2003.
 235. Welchman RL , Gordon C , Mayer RJ . Ubiquitin and ubiquitin‐like proteins as multifunctional signals. Nat Rev Mol Cell Biol 6: 599‐609, 2005.
 236. Wexler BC , Greenberg BP . Protective effects of clofibrate on isoproterenol‐induced myocardial infarction in arteriosclerotic and non‐arteriosclerotic rats. Atherosclerosis 29: 373‐395, 1978.
 237. Whelan RS , Kaplinskiy V , Kitsis RN . Cell death in the pathogenesis of heart disease: Mechanisms and significance. Annu Rev Physiol 72: 19‐44, 2010.
 238. Wiborg O , Pedersen MS , Wind A , Berglund LE , Marcker KA , Vuust J . The human ubiquitin multigene family: Some genes contain multiple directly repeated ubiquitin coding sequences. EMBO J 4: 755‐759, 1985.
 239. Wilkinson KD , Cox MJ , O'Connor LB , Shapira R . Structure and activities of a variant ubiquitin sequence from bakers' yeast. Biochemistry 25: 4999‐5004, 1986.
 240. Wilkinson KD , Urban MK , Haas AL . Ubiquitin is the ATP‐dependent proteolysis factor I of rabbit reticulocytes. J Biol Chem 255: 7529‐7532, 1980.
 241. Witowsky JA , Johnson GL . Ubiquitylation of MEKK1 inhibits its phosphorylation of MKK1 and MKK4 and activation of the ERK1/2 and JNK pathways. J Biol Chem 278: 1403‐1406, 2003.
 242. Wu B , Chien EYT , Mol CD , Fenalti G , Liu W , Katritch V , Abagyan R , Brooun A , Wells P , Bi FC , Hamel DJ , Kuhn P , Handel TM , Cherezov V , Stevens RC . Structures of the CXCR4 chemokine receptor in complex with small molecule and cyclic peptide antagonists. Science 330: 5, 2010.
 243. Wu CF , Bishopric NH , Pratt RE . Atrial natriuretic peptide induces apoptosis in neonatal rat cardiac myocytes. J Biol Chem 272: 14860‐14866, 1997.
 244. Xin Y , Liu S , Xu XF , Li WB , Huang YM , Luo Y , Zhou YJ . Primary culture and biological characteristics of cardiac fibroblasts of adult mice. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 28: 1194‐1199, 2012.
 245. Xu P , Duong DM , Seyfried NT , Cheng D , Xie Y , Robert J , Rush J , Hochstrasser M , Finley D , Peng J . Quantitative proteomics reveals the function of unconventional ubiquitin chains in proteasomal degradation. Cell 137: 133‐145, 2009.
 246. Yang BC , Zander DS , Mehta JL . Hypoxia‐reoxygenation‐induced apoptosis in cultured adult rat myocytes and the protective effect of platelets and transforming growth factor‐beta(1). J Pharmacol Exp Ther 291: 733‐738, 1999.
 247. Yang Y , Jiang G , Zhang P , Fan J . Programmed cell death and its role in inflammation. Mil Med Res 2: 12, 2015.
 248. Yasmin , McEniery CM , Wallace S , Dakham Z , Pulsalkar P , Pusalkar P , Maki‐Petaja K , Ashby MJ , Cockcroft JR , Wilkinson IB . Matrix metalloproteinase‐9 (MMP‐9), MMP‐2, and serum elastase activity are associated with systolic hypertension and arterial stiffness. Arterioscler Thromb Vasc Biol 25: 372, 2005.
 249. Zak R . Development and proliferative capacity of cardiac muscle cells. Circ Res 35(suppl II): 17‐26, 1974.
 250. Zaruba MM , Franz WM . Role of the SDF‐1‐CXCR4 axis in stem cell‐based therapies for ischemic cardiomyopathy. Expert Opin Biol Ther 10: 321‐335, 2010.
 251. Zhang HG , Wang J , Yang X , Hsu HC , Mountz JD . Regulation of apoptosis proteins in cancer cells by ubiquitin. Oncogene 23: 2009‐2015, 2004.
 252. Zhang M , Mal N , Kiedrowski M , Chacko M , Askari AT , Popovic ZB , Koc ON , Penn MS . SDF‐1 expression by mesenchymal stem cells results in trophic support of cardiac myocytes after myocardial infarction. FASEB J 21: 3197‐3207, 2007.
 253. Zhou HZ , Ma X , Gray MO , Zhu BQ , Nguyen AP , Baker AJ , Simonis U , Cecchini G , Lovett DH , Karliner JS . Transgenic MMP‐2 expression induces latent cardiac mitochondrial dysfunction. Biochem Biophys Res Commun 358: 189‐195, 2007.
 254. Zhu W , Woo AY , Yang D , Cheng H , Crow MT , Xiao RP . Activation of CaMKIIdeltaC is a common intermediate of diverse death stimuli‐induced heart muscle cell apoptosis. J Biol Chem 282: 10833‐10839, 2007.
 255. Zhu WZ , Wang SQ , Chakir K , Yang D , Zhang T , Brown JH , Devic E , Kobilka BK , Cheng H , Xiao RP . Linkage of beta1‐adrenergic stimulation to apoptotic heart cell death through protein kinase A‐independent activation of Ca2+/calmodulin kinase II. J Clin Invest 111: 617‐625, 2003.

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Stephanie L.C. Scofield, Parthiv Amin, Mahipal Singh, Krishna Singh. Extracellular Ubiquitin: Role in Myocyte Apoptosis and Myocardial Remodeling. Compr Physiol 2015, 6: 527-560. doi: 10.1002/cphy.c150025