Adiposity dependent apelin gene expression: relationships with oxidative and inflammation markers

Abstract

It has been reported that apelin functions as an adipokine, which has been associated to obesity and insulin resistance. The objective of this study was to analyze the apelin mRNA expression in white adipose tissue (WAT) from high-fat (Cafeteria) fed rats, in order to examine potential relationships with obesity markers and other related risk factors. Animals fed on the high-fat diet during 56 days increased their body weight, total body fat and WAT depots weights when compared to controls. Apelin subcutaneous mRNA expression was higher in the Cafeteria than in the Control fed group and this increase was partially reversed by dietary vitamin C supplementation. Statistically significant associations between subcutaneous apelin gene expression and almost all the studied variables were identified, being of special interest the correlations found with serum leptin (r=0.517), liver malondialdehyde (MDA) levels (r=0.477), and leptin, IRS-3 and IL-1ra retroperitoneal mRNA expression (r=0.701; r=0.692 and r=0.561, respectively). These associations evidence a possible role for apelin in the excessive weight gain induced by high-fat feeding and increased adiposity, insulin-resistance, liver oxidative stress and inflammation.

Vitamin C inhibits leptin secretion and some glucose/lipid metabolic pathways in primary rat adipocytes

“…It has been described that rats fed with high-fat diet with VC supplementation presented a decreased isoproterenol-induced lipolysis compared with the rats fed with high-fat diet alone (Garcia-Diaz et al 2009). Regarding the secretion and expression of some adipokines, this study has demonstrated an important inhibitory effect of VC on leptin secretion, which is in agreement with the previously reported reducing effects on leptin circulatory levels of a diet with VC supplementation given to high-fat diet-fed rats for 56 days (Garcia-Diaz et al 2007). In that work, the observed reduction in leptin secretion was accompanied by a decrease in body weight and adiposity.…”

“…It has been observed that VC induced a slight decrease in Irs3 mRNA expression in subcutaneous and retroperitoneal fat pads of high-fat VC-supplemented diet-fed rats with respect to the high-fat diet-alone-fed obese rats (Garcia-Diaz et al 2007). This slight mRNA inhibition was also observed in the current study, especially in cells under insulin treatment, suggesting a direct relationship between VC and insulin resistance/sensitivity pathways.…”

“…Studies by our research group have found a high-fat diet-induced adiposity reduction by VC supplementation in rats , Garcia-Diaz et al 2007 and modifications in adipocyte catecholamine-induced lipolysis (Garcia-Diaz et al 2009). In vitro studies have reported controversial VC effects on adipocyte differentiation (Ono et al 1990, Krieger-Brauer & Kather 1995, Galinier et al 2006.…”

Serum apelin is associated with affective disorders in peritoneal dialysis patients

“…12 On the other hand, an increasing amount of evidence has suggested a close relation between apelin, oxidative stress and inflammation. [43][44][45] Therefore, considering that major depression is associated with inflammatory status, we speculate that apelinergic system may be involved in depressive disorders through inflammatory pathway.…”

The Effects of High Fat Diets With and Without N-Acetylcysteine Supplementation on the Lipin-1 Levels of Serum and Various Tissues in Rats

“…In addition, they did not find significant differences in HDL-C and LDL-C after low and high fat diets. Similarly, Garcia-Diaz et al [22] did not find any significant change in TG levels after feeding high fat cafeteria diet (59.2% of energy as lipids) for 65 days in male Wistar rats. In the present study a borderline significant positive correlation (r= 0.943; P= 0.05) between serum TC and HDL-C was found in the HFD group (data not shown).…”