Effect of Acute Cold Exposure on the Expression of the Adiponectin, Resistin and Leptin Genes in Rat White and Brown Adipose Tissues

Abstract

Leptin, adiponectin, and resistin are key hormones produced by adipose tissue. In the present study, we have examined the effects of acute cold exposure (18 h at 6 degrees C) on the expression of the genes encoding these hormones in both brown and white fat of rats. Acute cold exposure resulted in a significant (p < 0.001) increase in the level of UCP1 and metallothionein-1 mRNAs in brown adipose tissue, indicative of an activation of thermogenesis. Leptin mRNA was decreased (p < 0.001) in brown fat in the cold, and there was also a small but statistically significant (p < 0.05) decrease in adiponectin mRNA; resistin mRNA did not change significantly (p > 0.05). In white fat, the level of leptin mRNA also fell in the cold (p < 0.05), but there was no significant change (p > 0.05) in either adiponectin or resistin mRNA. The serum concentration of adiponectin was unchanged following acute cold exposure. We conclude that while leptin gene expression is inhibited by exposure to cold, there is no major effect on the expression of either the adiponectin or resistin genes in white or brown fat despite the cold-induced stimulation of sympathetic activity and fatty acid flux. Thus, adiponectin and resistin are unlikely to play a key role in the extensive metabolic adaptations to cold.

Berardinelli-Seip congenital lipodystrophy 2 regulates adipocyte lipolysis, browning, and energy balance in adult animals

“…Global gene expression profi ling and biochemical data suggest that Bscl2 regulates cAMP/PKA signaling in WAT and BAT, and that its loss promotes lipolysis and TG breakdown in vivo. Notably, the changes in gene expression profi le in eWAT consequent to acquired Bscl2 deletion largely resemble those observed with ␤ 3-AR agonist stimulation and cold exposure, including lipolysis and browning (45)(46)(47)(48), acute repression of leptin (49)(50)(51)(52), increased Gyk expression, and cholesterol metabolism ( 53 ), infl ammation, and ER stress (54)(55)(56). Browning may result from the direct conversion of mature white adipocytes into beige cells, given that Bscl2 deletion is directed toward adiponectin-expressing cells in our model.…”

Cold exposure restores the decrease in leptin receptors (OB-Rb) caused by neonatal leptin treatment in 30-day-old rats

“…Cold exposure is associated with rapid activation of the hypothalamus-pituitary-thyroid axis (Hefco et al 1975, Joseph-Bravo et al 1998 and peripheral conversion of thyroxine (T 4 ) into tri-iodothyronine (T 3 ; Pazos- Moura et al 1991, Reed et al 1994, Lisboa et al 2003. In contrast, cold exposure reduces the circulating leptin levels (Hardie et al 1996, Bing et al 1998) and the expression of the ob gene in brown adipose tissue (BAT) and white adipose tissue (WAT) of rodents (Trayhurn et al 1995, Puerta et al 2002. These findings may be caused by the cold-induced increase in sympathetic activity in these tissues (Trayhurn et al 1995).…”

Resistin expression and plasma concentration peak at different times during pregnancy in rats

“…However, the contrasting observation of diminished resistin expression in the WAT of obese animals (Juan et al 2001, Le Lay et al 2001, Moore et al 2001, Way et al 2001, Fujita et al 2002, Milan et al 2002 together with the inhibition of expression by insulin in 3T3-L1 cells (Haugen et al 2001, Shojima et al 2002 has cast doubt on the role of resistin in the development of insulin resistance. Additionally, in some physiological states related with an altered insulin sensitivity, no changes in resistin expression have been found , Puerta et al 2002. Nonetheless, mice lacking resistin show reduced hepatic glucose production, suggesting a role for resistin in glucose metabolism (Banerjee et al 2004).…”