Metallothionein alleviates glutathione depletion-induced oxidative cardiomyopathy in murine hearts.

Journal Article

OBJECTIVE: Antioxidant therapy has shown some promise in critical care medicine in which glutathione depletion and heart failure are often seen in critically ill patients. This study was designed to examine the impact of glutathione depletion and the free radical scavenger, metallothionein (MT), on cardiac function. DESIGN: Friend virus B and MT transgenic mice were given the glutathione synthase inhibitor buthionine sulfoximine (buthionine sulfoximine [BSO], 30 mmol/L) in drinking water for 2 wks. MEASUREMENTS: Echocardiographic and cardiomyocyte functions were evaluated, including myocardial geometry, fraction shortening, peak shortening, time-to-90% relengthening (TR90), maximal velocity of shortening/relengthening (+/-dL/dt), intracellular Ca2+ rise, sarcoplasmic reticulum Ca2+ release, and intracellular Ca2+ decay rate. Sacro (endo)plasmic reticulum Ca2+-ATPase function was evaluated by 45Ca uptake. Highly reactive oxygen species, caspase-3, and aconitase activity were detected by fluorescent probe and colorimetric assays. MAIN RESULT: BSO elicited lipid peroxidation, protein carbonyl formation, mitochondrial damage, and apoptosis. BSO also reduced wall thickness, enhanced end systolic diameter, depressed fraction shortening, peak shortening, +/-dL/dt, sarcoplasmic reticulum Ca2+ release, 45Ca uptake, and intracellular Ca2+ decay, leading to prolonged TR90. BSO-induced mitochondrial loss and myofilament aberration. MT transgene itself had little effect on myocardial mechanics and ultrastructure. However, it alleviated BSO-induced myocardial functional, morphologic, and carbonyl changes. Western blot analysis showed reduced expression of sacro (endo)plasmic reticulum Ca2+-ATPase2a, Bcl-2 and phosphorylated GSK-3beta, enhanced calreticulin, Bax, p53, myosin heavy chain-beta isozyme switch, and IkappaB phosphorylation in FVB-BSO mice, all of which with the exception of p53 were nullified by MT. CONCLUSION: Our findings suggest a pathologic role of glutathione depletion in cardiac dysfunction and the therapeutic potential of antioxidants.

Full Text

Duke Authors

Cited Authors

  • Ren, J; Privratsky, JR; Yang, X; Dong, F; Carlson, EC

Published Date

  • July 2008

Published In

Volume / Issue

  • 36 / 7

Start / End Page

  • 2106 - 2116

PubMed ID

  • 18552690

Electronic International Standard Serial Number (EISSN)

  • 1530-0293

International Standard Serial Number (ISSN)

  • 0090-3493

Digital Object Identifier (DOI)

  • 10.1097/ccm.0b013e31817bf925

Language

  • eng