The protease inhibitor UCF-101 ameliorates streptozotocin-induced mouse cardiomyocyte contractile dysfunction in vitro: role of AMP-activated protein kinase.
5-[5-(2-Nitrophenyl) furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid (UCF-101) is a protease inhibitor which was reported to protect against ischaemic heart damage and apoptosis. This study evaluated the impact of UCF-101 on steptozotocin (STZ)-induced diabetic cardiomyocyte dysfunction. Adult FVB mice were made diabetic with a single injection of STZ (200 mg kg(1)). Two weeks after STZ injection, cardiomyocytes from control and STZ-treated mice were isolated and treated with UCF-101 (20 mum for 1 h). Cardiomyocyte contractile properties were analysed, including peak shortening (PS), maximal velocity of shortening/relengthening (+/-dL/dt), time to PS (TPS) and time to 90% relengthening (TR(90)). Steptozotocin-induced diabetes depressed PS and +/-dL/dt and prolonged TPS and TR(90) in cardiomyocytes, all of which were significantly alleviated by UCF-101. Immunoblotting analysis showed that UCF-101 significantly alleviated STZ-induced loss of phospholamban phosphorylation without affecting sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) and phospholamban. Steptozotocin reduced AMP-activated protein kinase (AMPK) phosphorylation at Thr172 of the catalytic subunit without affecting total AMPK expression, which was restored by UCF-101. Short-term exposure to UCF-101 did not change the expression of X-linked inhibitor of apoptosis protein (XIAP) and Omi stress-regulated endoprotease, high temperature requirement protein A2 (Omi/HtrA2), favouring an apoptosis-independent mechanism. Both the AMPK activator resveratrol and the antioxidant N-acetylcysteine mimicked the UCF-101-induced beneficial effect in STZ-induced diabetic cardiomyocytes. In addition, UCF-101 promoted the phosphorylation of p38 mitogen-activated protein kinases and c-Jun N-terminal kinase (JNK) after 15 min of incubation, while it failed to affect the phosphorylation of extracellular signal-regulated kinase (ERK) and glycogen synthase kinase-3beta (GSK-3beta) within 120 min in H9C2 myoblasts. Taken together, these results indicate that UCF-101 protects against STZ-induced cardiomyocyte contractile dysfunction, possibly via an AMPK-associated mechanism.
Li
Qun
Q
Division of Pharmaceutical Sciences, University of Wyoming, Laramie, WY 82071, USA.
Hueckstaedt
Lindsay K
LK
Ren
Jun
J
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000378:metabolism; D009202:Cardiomyopathies / Q000150:complications / Q000503:physiopathology / Q000517:prevention & control; D048909:Diabetes Complications / Q000503:physiopathology / Q000517:prevention & control; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000503:physiopathology; D000074923:High-Temperature Requirement A Serine Peptidase 2; D066298:In Vitro Techniques; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D051379:Mice; D024101:Mitochondrial Proteins / Q000378:metabolism; D009200:Myocardial Contraction / Q000187:drug effects* / Q000502:physiology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D011480:Protease Inhibitors / Q000494:pharmacology*; D011744:Pyrimidinones / Q000494:pharmacology*; D000077185:Resveratrol; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D013267:Stilbenes / Q000494:pharmacology; D013311:Streptozocin / Q000633:toxicity; D013871:Thiones / Q000494:pharmacology*; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism; D000099211:Phospholamban
D055372:AMP-Activated Protein Kinases; D000111:Acetylcysteine; D000975:Antioxidants; D002135:Calcium-Binding Proteins; D000074923:High-Temperature Requirement A Serine Peptidase 2; D024101:Mitochondrial Proteins; D011480:Protease Inhibitors; D011744:Pyrimidinones; D000077185:Resveratrol; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D012697:Serine Endopeptidases; D013267:Stilbenes; D013311:Streptozocin; D013871:Thiones; D051636:X-Linked Inhibitor of Apoptosis Protein; D000099211:Phospholamban; C501517:UCF 101; C000615915:Htra2 protein, mouse; C506947:Atp2a2 protein, mouse