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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Activation of Both the Calpain and Ubiquitin-Proteasome Systems Contributes to Septic Cardiomyopathy through Dystrophin Loss/Disruption and mTOR Inhibition

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Silva Freitas, Ana Caroline ; Figueiredo, Maria Jose ; Campos, Erica Carolina ; Soave, Danilo Figueiredo ; Ramos, Simone Gusmao ; Tanowitz, Herbert B. ; Celes, Mara Rubia N.
Total Authors: 7
Document type: Journal article
Source: PLoS One; v. 11, n. 11 NOV 23 2016.
Web of Science Citations: 4

Cardiac dysfunction caused by the impairment of myocardial contractility has been recognized as an important factor contributing to the high mortality in sepsis. Calpain activation in the heart takes place in response to increased intracellular calcium influx resulting in proteolysis of structural and contractile proteins with subsequent myocardial dysfunction. The purpose of the present study was to test the hypothesis that increased levels of calpain in the septic heart leads to disruption of structural and contractile proteins and that administration of calpain inhibitor-1 (N-acetyl-leucinyl-leucinyl-norleucinal (ALLN)) after sepsis induced by cecal ligation and puncture prevents cardiac protein degradation. We also tested the hypothesis that calpain plays a role in the modulation of protein synthesis/degradation through the activation of proteasome-dependent proteolysis and inhibition of the mTOR pathway. Severe sepsis significantly increased heart calpain-1 levels and promoted ubiquitin and Pa28 beta over-expression with a reduction in the mTOR levels. In addition, sepsis reduced the expression of structural proteins dystrophin and beta-dystroglycan as well as the contractile proteins actin and myosin. ALLN administration prevented sepsis-induced increases in calpain and ubiquitin levels in the heart, which resulted in decreased of structural and contractile proteins degradation and basal mTOR expression levels were re-established. Our results support the concept that increased calpain concentrations may be part of an important mechanism of sepsis-induced cardiac muscle proteolysis. (AU)

FAPESP's process: 12/23649-0 - Septic cardiomyophaty as a component of multiple organ dysfunction syndrome in severe sepsis
Grantee:Simone Gusmão Ramos
Support Opportunities: Regular Research Grants
FAPESP's process: 12/17542-8 - Role of the phosphoinositide-3-kinase/serin-treonin kinase (PI3K/AKT) signaling pathway in the expression of dystrophin in the myocardium of animals submitted to cecal ligation and puncture (CLP)
Grantee:Simone Gusmão Ramos
Support Opportunities: Regular Research Grants