The cytoprotective effect of biglycan core protein involves Toll-like receptor 4 signaling in cardiomyocytes

Gáspár, Renáta and Pipicz, Márton and Hawchar, F. and Kovács, Dávid and Djirackor, Luna Kutiti and Görbe, Anikó and Varga, Zoltán and Csontné Kiricsi, Mónika and Petrovski, Goran and Gácser, Attila and Csonka, Csaba and Csont, Tamás Bálint (2016) The cytoprotective effect of biglycan core protein involves Toll-like receptor 4 signaling in cardiomyocytes. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY, 99. pp. 138-150. ISSN 0022-2828

Text Gaspar_JMCC_2016_1_s2.0_S0022282816302474_main_u.pdf Restricted to Repository staff only Download (2MB) | Request a copy

Abstract

Exogenously administered biglycan (core protein with high-molecular weight glycosaminoglycan chains) has been shown to protect neonatal cardiomyocytes against simulated ischemia/reperfusion injury (SI/R), however, the mechanism of action is not clear. In this study we aimed to investigate, which structural component of biglycan is responsible for its cardiocytoprotective effect and to further explore the molecular mechanisms involved in the cytoprotection. Methods and results A pilot study was conducted to demonstrate that both native (glycanated) and deglycanated biglycan can attenuate cell death induced by SI/R in a dose-dependent manner in primary neonatal cardiomyocytes isolated from Wistar rats. In separate experiments, we have shown that similarly to glycanated biglycan, recombinant human biglycan core protein (rhBGNc) protects cardiomyocytes against SI/R injury. In contrast, the glycosaminoglycan component dermatan sulfate had no significant effect on cell viability, while chondroitin sulfate further enhanced cell death induced by SI/R. Treatment of cardiomyocytes with rhBGNc reverses the effect of SI/R upon markers of necrosis, apoptosis, mitochondrial membrane potential, and autophagy. We have also shown that pharmacological blockade of Toll-like receptor 4 (TLR4) signaling or its downstream mediators (IRAK1/4, ERK, JNK and p38 MAP kinases) abolished the cytoprotective effect of rhBGNc against SI/R injury. Pretreatment of cardiomyocytes with rhBGNc for 20 h resulted in increased Akt phosphorylation and NO production without having significant effect on phosphorylation of ERK1/2, STAT3, and on the production of superoxide. Treatment over 10 min and 1 h with rhBGNc increased ERK1 phosphorylation, while the SI/R-induced increase in superoxide production was attenuated by rhBGNc. Blockade of NO synthesis also prevented the cardiocytoprotective effect of rhBGNc. Conclusions The core protein of exogenous biglycan protects myocardial cells from SI/R injury via TLR4-mediated mechanisms involving activation of ERK, JNK and p38 MAP kinases and increased NO production. The cytoprotective effect of rhBGNc is due to modulation of SI/R-induced changes in necrosis, apoptosis and autophagy. © 2016 Elsevier Ltd

Actions (login required)

Edit Item