Role of Hsp70 and the Associated Signaling Molecules in Fish Adipocytes during Pollutants Induced Hypoxia

Abstract

Adipose tissue is highly specialized to store lipid and/or release energy from lipid stores in response to a variety of signals. Adipose remodeling is the critical physiological process which involves lipogenesis and lipolysis to exhibit energy homeostasis. Recently, interest in the study of fish adipocytes has burgeoned due to the rising incidence of polluted environment. Determination of changes in adipocyte during stress provides the underlying mechanism involved in the survival process and adipose remodeling. Hence the present study was undertaken to evaluate the stress markers such as LHP and PC along with FA in fish adipocytes. Redox status was assessed by GPX, GST, GR, GRR and Trx. Alterations in structural contour and functional groups were identified by SEM and FTIR respectively. Expression of apoptotic and antiapoptotic proteins were monitored by analyzing HIF1α, TNFα, HSP70 and ASK1. Significance of HSP70 was studied with the novel HSP70 inhibitor Pifithrin-µ. Result of current research work depicts increased oxidative damage as assessed by elevated LHP, PC, HIF1α, TNFα, ASK1 and FA along with the reduction in level of GPX, GST, GR, GRR. However increased Trx expression was noted in stressed fish adipocyte. SEM and FTIR spectroscopy results demonstrated variations in structural morphology and thiol status. However adipocytes are functional which may be due to increased HSP70 in stressed fish adipocyte which was substantiated by its inhibition and its mediated alteration of stress markers, along with induction of ASK1. Present results proclaim the importance of HSP70 in adipocytes survival and maturation during pollutants induced hypoxia. Keywords: Adipocytes, Antiapoptotic, Hypoxia, Heat shock protein 70, Lipogenesis