Heat shock modulates adipokines expression in 3T3-L1 adipocytes

Abstract

Studies have demonstrated that heat shock is associated with alteration in energy metabolism. In this study, we investigated the effect of heat shock on gene expression and secretion of adiponectin and leptin, and gene expression of Hspa2 and Pparg in 3T3-L1 adipocytes. Compared with 37 8C, adiponectin mRNA was higher at 39 8C, and lower at 41 8C. Leptin mRNA was higher when adipocytes were exposed to 41 8C compared with 37 and 39 8C. Secretion of adiponectin increased at 39 8C, and when cells were exposed to 41 8C it was not detectable. Leptin secretion increased significantly at 41 8C, compared with 37 and 39 8C. Hspa2 mRNA was increased at 39 8C, and the highest level was reached at 41 8C. Pparg mRNA exhibited a substantial increase in a temperature-dependent manner. The study provides the first evidence of a possible direct effect of heat shock on adiponectin and leptin gene expression and secretion, and demonstrates that the expression of the two adipokines is differentially regulated at the temperatures tested.

Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows

“…In fact, results suggested that heat stress may not directly affect the expression Table 3 (P<0.05). The up-regulation of adiponectin observed in this study agrees with previous findings in mice and 3T3-L1 adipocytes (Bernabucci et al, 2009;Morera et al, 2012), confirming a role of heat stress in modulating adiponectin expression. Park et al (2005) pointed out that heat stress induced an increase in the fluidity of membrane lipids, may cause signal transduction that would induce the cellular heat shock response to increase the HSP expression, which could directly stimulate adiponectin expression.…”

“…Heat stress up-regulates leptin expression and secretion in mice and 3T3-L1 adipocytes (Bernabucci et al, 2009;Morera et al, 2012). Very little work has been done to evaluate changes and the biological role of leptin in heat-stressed dairy cows.…”

Chronic heat stress up-regulates leptin and adiponectin secretion and expression and improves leptin, adiponectin and insulin sensitivity in mice

“…with our previous in vitro findings (Bernabucci et al 2009), confirming a role of HS in modulating leptin and adiponectin gene and protein expression. In HS and FR mice, the circulating leptin and adiponectin levels paralleled the respective responses in WAT leptin and adiponectin gene expression.…”

“…To our knowledge, only such studies concern the effects of HS on leptin gene expression and secretion in birds (Al-Azraqi 2008, Dridi et al 2008 and in lactating pigs (Renaudeau et al 2003) and on leptin and adiponectin gene expression and secretion in mouse adipocytes (Bernabucci et al 2009). …”

“…On the basis of our previous results (Bernabucci et al 2009), we conducted a study to evaluate whether chronic HS rather than a reduction in voluntary food intake is associated with changes in the expression and secretion of leptin and adiponectin and in insulin sensitivity and glucose metabolism in peripheral tissues.…”