Treatment with the TGF-b superfamily cytokine MIC-1/GDF15 reduces the adiposity and corrects the metabolic dysfunction of mice with diet-induced obesity.

OBJECTIVES: To test the potential efficacy of recombinant macrophage inhibitory cytokine-1 (MIC-1/GDF15) as an obesity therapeutic. METHODS: Male C57BL/6 J mice, either fed on normal chow or high-fat diet for 16 weeks to induce diet-induced obesity, were infused with either recombinant MIC-1/GDF15 or vehicle for 34 days by osmotic minipump. During the experimental period metabolic parameters were measured. Blood and tissue were collected for analysis of inflammatory markers. RESULTS: MIC-1/GDF15 decreased food intake and body weight of high-fat-fed and chow-fed mice compared with their vehicle-treated control mice. MIC-1/GDF15 reduced body weight, accompanied by greater reduction in fat mass in high-fat-fed mice compared to its effect on chow-fed mice. Further, whilst MIC-1/GDF15-treated chow-fed mice lost lean as well as fat mass, MIC-1/GDF15-treated high-fat-fed mice lost fat mass alone. This reduction in body weight and adiposity was due largely to reduced food intake, but MIC-1/GDF15-treated high-fat-fed mice also displayed increased energy expenditure that may be due to increased thermogenesis. MIC-1/GDF15-treated high-fat-fed mice also had higher circulating level of adiponectin and lower tissue expression, and circulating levels of leptin and inflammatory mediators associated with insulin resistance. Peripheral insulin and glucose intolerance were improved in both MIC-1/GDF15-treated high-fat-fed and chow-fed mice compared to that of their vehicle-treated control mice. CONCLUSIONS: MIC-1/GDF15 is highly effective in reducing adiposity and correcting the metabolic dysfunction of mice with high-fat fed. These studies suggest that MIC-1/GDF15 may be a candidate anti-obesity therapeutic.

MIC-1/GDF15 in Barrett's oesophagus and oesophageal adenocarcinoma.

BACKGROUND: Biomarkers are needed to improve current diagnosis and surveillance strategies for patients with Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC). Macrophage inhibitory cytokine 1/growth differentiation factor 15 (MIC-1/GDF15) tissue and plasma levels have been shown to predict disease progression in other cancer types and was therefore evaluated in BO/OAC. METHODS: One hundred thirty-eight patients were studied: 45 normal oesophagus (NE), 37 BO, 16 BO with low-grade dysplasia (LGD) and 40 OAC. RESULTS: Median tissue expression of MIC-1/GDF15 mRNA was ⩾25-fold higher in BO and LGD compared to NE (P<0.001); two-fold higher in OAC vs BO (P=0.039); and 47-fold higher in OAC vs NE (P<0.001). Relative MIC-1/GDF15 tissue expression >720 discriminated between the presence of either OAC or LGD vs NE with 94% sensitivity and 71% specificity (ROC AUC 0.86, 95% CI 0.73-0.96; P<0.001). Macrophage inhibitory cytokine 1/growth differentiation factor 15 plasma values were also elevated in patients with OAC vs NE (P<0.001) or BO (P=0.015).High MIC-1/GDF15 plasma levels (⩾1140 pg ml(-1)) were an independent predictor of poor survival for patients with OAC (HR 3.87, 95% CI 1.01-14.75; P=0.047). CONCLUSIONS: Plasma and tissue levels of MIC-1/GDF15 are significantly elevated in patients with BO, LGD and OAC. Plasma MIC-1/GDF15 may have value in diagnosis and monitoring of Barrett's disease.