These data show that adiponectin may have a role in the pathogenesis of human NASH and should be investigated further.

Sex and sex hormones can affect responses of patients with nonalcoholic fatty liver disease (NAFLD) to metabolic stress and development of hepatocyte injury and inflammation. We collected data from 3 large US studies of patients with NAFLD (between October 2004 and June 2013) to assess the association between histologic severity and sex, menopause status, synthetic hormone use, and menstrual abnormalities in 1112 patients with a histologic diagnosis of NAFLD. We performed logistic or ordinal logistic regression models, adjusting for covariates relevant to an increase of hepatic metabolic stress. We found that pre-menopausal women were at an increased risk of lobular inflammation, hepatocyte ballooning, and Mallory-Denk bodies than men and also at an increased risk of lobular inflammation and Mallory-Denk bodies than post-menopausal women (P<.01). Use of oral contraceptives was associated with an increased risk of lobular inflammation and Mallory-Denk bodies in pre-menopausal women, whereas hormone replacement therapy was associated with an increased risk of lobular inflammation in post-menopausal women (P<.05). We conclude that being a pre-menopausal woman or a female user of synthetic hormones is associated with increased histologic severity of hepatocyte injury and inflammation among patients with NAFLD at given levels of hepatic metabolic stress.

Obesity is a growing epidemic with limited effective treatments. The neurotrophic factor glial cell line-derived neurotrophic factor (GDNF) was recently shown to enhance β-cell mass and improve glucose control in rodents. Its role in obesity is, however, not well characterized. In this study, we investigated the ability of GDNF to protect against high-fat diet (HFD)-induced obesity. GDNF transgenic (Tg) mice that overexpress GDNF under the control of the glial fibrillary acidic protein promoter and wild-type (WT) littermates were maintained on a HFD or regular rodent diet for 11 wk, and weight gain, energy expenditure, and insulin sensitivity were monitored. Differentiated mouse brown adipocytes and 3T3-L1 white adipocytes were used to study the effects of GDNF in vitro. Tg mice resisted the HFD-induced weight gain, insulin resistance, dyslipidemia, hyperleptinemia, and hepatic steatosis seen in WT mice despite similar food intake and activity levels. They exhibited significantly (P<0.001) higher energy expenditure than WT mice and increased expression in skeletal muscle and brown adipose tissue of peroxisome proliferator activated receptor-α and β1- and β3-adrenergic receptor genes, which are associated with increased lipolysis and enhanced lipid β-oxidation. In vitro, GDNF enhanced β-adrenergic-mediated cAMP release in brown adipocytes and suppressed lipid accumulation in differentiated 3T3L-1 cells through a p38MAPK signaling pathway. Our studies demonstrate a novel role for GDNF in the regulation of high-fat diet-induced obesity through increased energy expenditure. They show that GDNF and its receptor agonists may be potential targets for the treatment or prevention of obesity.

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