Adiponectin, a key adipokine in obesity related liver diseases

Inflammation and oxidative stress in obesity-related glomerulopathy

Obesity-related glomerulopathy is an increasing cause of end-stage renal disease. Obesity has been considered a state of chronic low-grade systemic inflammation and chronic oxidative stress. Augmented inflammation in adipose and kidney tissues promotes the progression of kidney damage in obesity. Adipose tissue, which is accumulated in obesity, is a key endocrine organ that produces multiple biologically active molecules, including leptin, adiponectin, resistin, that affect inflammation, and subsequent deregulation of cell function in renal glomeruli that leads to pathological changes. Oxidative stress is also associated with obesity-related renal diseases and may trigger the initiation or progression of renal damage in obesity. In this paper, we focus on inflammation and oxidative stress in the progression of obesity-related glomerulopathy and possible interventions to prevent kidney injury in obesity.

Nature of fatty acids in high fat diets differentially delineates obesity-linked metabolic syndrome components in male and female C57BL/6J mice

BACKGROUND

Adverse effects of high-fat diets (HFD) on metabolic homeostasis are linked to adipose tissue dysfunction. The goal of this study was to examine the effect of the HFD nature on adipose tissue activity, metabolic disturbances and glucose homeostasis alterations in male mice compared with female mice.

METHODS

C57BL/6J mice were fed either a chow diet or HFD including vegetal (VD) or animal (AD) fat. Body weight, plasmatic parameters and adipose tissue mRNA expression levels of key genes were evaluated after 20 weeks of HFD feeding.

RESULTS

HFD-fed mice were significantly heavier than control at the end of the protocol. Greater abdominal visceral fat accumulation was observed in mice fed with AD compared to those fed a chow diet or VD. Correlated with weight gain, leptin levels in systemic circulation were increased in HFD-fed mice in both sexes with a significant higher level in AD group compared to VD group. Circulating adiponectin levels as well as adipose tissue mRNA expression levels were significantly decreased in HFD-fed male mice. Although its plasma levels remained unchanged in females, adiponectin mRNA levels were significantly reduced in adipose tissue of both HFD-fed groups with a more marked decrease in AD group compared to VD group. Only HFD-fed male mice were diabetic with increased fasting glycaemia. On the other hand, insulin levels were only increased in AD-fed group in both sexes associated with increased resistin levels. VD did not induce any apparent metabolic alteration in females despite the increased weight gain. Peroxisome Proliferator-Activated Receptors gamma-2 (PPARγ2) and estrogen receptor alpha (ERα) mRNA expression levels in adipose tissue were decreased up to 70% in HFD-fed mice but were more markedly reduced in male mice as compared with female mice.

CONCLUSIONS

The nature of dietary fat determines the extent of metabolic alterations reflected in adipocytes through modifications in the pattern of adipokines secretion and modulation of key genes mRNA expression. Compared with males, female mice demonstrate higher capacity in controlling glucose homeostasis in response to 20 weeks HFD feeding. Our data suggest gender specific interactions between the diet's fatty acid source, the adipocyte-secreted proteins and metabolic disorders.