Heat-shock protein 90 alpha (HSP90α) modulates signaling pathways towards tolerance of oxidative stress and enhanced survival of hepatocytes of Mugil cephalus

Abstract

Oxidative stress causes damage at the cellular level and activates a number of signaling pathways. Earlier, we have demonstrated that pollutant-related oxidative stress upregulates heat-shock protein 90 alpha (HSP90α) against stress insult in hepatocytes of Mugil cephalus living in a polluted estuary. However, the impact of pollution-induced HSP90α upregulation on stress tolerance is not clear. Here we propose that the effect of stress resistance depends on the ability of HSP90α to modulate the signaling pathways involving proteins such as apoptosis signal-regulating kinase 1, c-Jun NH 2 -terminal protein kinase 1/2, signal transducers and activators of transcription, extracellular signal-regulated kinase 1/2, protein kinase B, nuclear factor-kappa binding, Ets-like protein 1, and B cell lymphoma-2. In order to investigate this, the activation of HSP90α-associated signaling molecules was examined by Western blotting and immunohistochemistry. The relationship between the protein expression patterns was identified by Spearman's rank correlation analysis. The signaling proteins exhibited differential modulation as revealed from their expression patterns in pollutant-exposed fish hepatocytes, in comparison with the control fish hepatocytes. The results suggested that in spite of the prevalence of oxidative stress in pollutantexposed fish hepatocytes, the stress-mediated induction of HSP90α enabled the hepatocytes to become stress tolerant and to survive by modulating the actions of key proteins and kinases in the signal transduction pathways.

The importance of propolis in alleviating the negative physiological effects of heat stress in quail chicks

“…The protective effect of Hsp70 does not correlate with the intestinal morphology under heat stress, but it may be strongly correlated with the increased activity of the digestive enzymes [ 49 ]. Moreover, many signaling pathways correlated with apoptosis and protein transcription are modulated by Hsp90 to improve the tolerance to stress [ 73 ]. The study of Xie et al [ 15 ] indicated that mRNA expression of Hsp90 in the liver of broiler breeder hens increased after a long-term heat treatment.…”

Complex responses to Si quantum dots accumulation in carp liver tissue: Beyond oxidative stress

“…Hsp90 mRNA and protein levels were significantly increased only in the first week of exposure. A recent study on fish hepatocytes primary cultures revealed that under pollutant stress, Hsp90 overexpression blocks apoptosis by inhibiting apoptosis signal-regulating kinase 1 (ASK1) activation induced by the oxidative stress [64]. Additionally, it has been shown that Hsp90 actively supports cytoskeleton components [65], an aspect that is of great importance considering that QDs accumulation in cells might cause strain and alteration in the cytoskeleton structure [66].…”

The Kinetic Response of the Proteome in A549 Cells Exposed to ZnSO4 Stress

“…These conservative changes just with different ratios coupled with the four expression patterns (especially patterns 1 and 4), could facilitate the prediction of the time-dependent differential expression of uncharacterized proteins that respond to Zn treatment. For example, proteins Hsp90α and hnRNPA1 involved in cell physiology including zinc homeostasis by previous reports were found to be significantly up- and down regulated after Zn-treatment for 24 h, respectively ( S1 File ) [ 35 , 43 – 46 ]. The changes in the expression of these two proteins after Zn 2+ treatment over time conformed to pattern 1 (up-regulated with rapid initial induction and subsequent repression) and pattern 4 (down-regulated with steady repression), respectively.…”