Objectives Metformin (MET) has protective effect on diabetic nephropathy (DN). This study aims to demystify the mechanism of MET function in DN. Methods Mouse glomerular membrane epithelial cell line SV40-MES-13 was treated with normal or high glucose combined with or without MET. The relationships among H19, miR-143-3p and TGF-β1 were evaluated by luciferase reporter assay. MTT assay was performed to detect cell proliferation. The levels of inflammatory factors were investigated by enzyme-linked immunosorbent assay. Quantitative real-time PCR and western blot were performed to examine gene and protein expression. Key Findings H19 was up-regulated in the SV40-MES-13 cells after treated with high glucose, which was effectively repressed by MET treatment. MET promoted extracellular matrix accumulation, inflammation and proliferation in the SV40-MES-13 cells after treated with high glucose. These influences conferred by MET were abolished by H19 overexpression. H19 regulated TGF-β1 expression by sponging miR-143-3p. Furthermore, MET inhibited extracellular matrix accumulation, inflammation and proliferation by regulating H19/miR-143-3p/TGF-β1 axis. Conclusions Our studies demonstrated that the protective effect of MET on DN was attributed to the inhibition of proliferation, inflammation and ECM accumulation in mesangial cells via H19/miR-143-3p/TGF-β1 axis, which suggested that the H19/miR-143-3p/TGF-β1 axis could be a valuable target for DN therapies.

Background: The available data on the significance of circulating apelin, chemerin and omentin in women with gestational diabetes mellitus (GDM) are inconsistent. This analysis includes a systematic review of the evidence associating the serum concentrations of these adipokines with GDM. Methods: Publications through December 2019 were retrieved from PubMed, Embase, the Cochrane Library, and Web of Science. Subgroup analysis and meta-regression were conducted to evaluate sources of heterogeneity. Results: Analysis of 20 studies, including 1493 GDM patients and 1488 normal pregnant women did not find significant differences in circulating apelin and chemerin levels (apelin standardized mean difference [SMD] = 0.43, 95% confidence interval (CI): − 0.40 to 1.26, P = 0.31; chemerin SMD = 0.77, 95% CI − 0.07 to 1.61, P = 0.07). Circulating omentin was significantly lower in women with GDM than in healthy controls (SMD = − 0.72, 95% CI − 1.26 to − 0.19, P = 0.007). Publication bias was not found; sensitivity analysis confirmed the robustness of the pooled results. Conclusions: Circulating omentin was decreased in GDM patients, but apelin and chemerin levels were not changed. The results suggest that omentin has potential as a novel biomarker for the prediction and early diagnosis of GDM.

Objective: Recent studies have investigated the circulating adipocyte fatty acid binding protein (FABP4), nesfatin-1, and osteocalcin (OC) concentrations in women diagnosed with gestational diabetes mellitus (GDM), but the findings prove to be conflicting. The objective of this research was to systematically assess the relationship of circulating levels of above adipokines with GDM. Methods: Pubmed, Embase, Web of Science, Cochrane library, OVID, and Scopus were performed to locate articles published up to January 31, 2020. Pooled standard mean differences (SMDs) with 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated by random-effects models to compare levels of adipokines between GDM cases and control groups. Cumulative and single-arm meta-analyses were also performed. Results: Thirty-one studies comprising 4590 participants were included. No significant differences were found between GDM women and healthy controls in circulating nesfatin-1 levels (4.56 vs. 5.02 ng/mL; SMD = − 0.11, 95% CI-0.61-0.38, 95% PI-1.63-1.41). Nevertheless, circulating FABP4 and OC levels observed in GDM women outnumbered normal controls (FABP4, 23.68 vs. 16.04 ng/mL; SMD = 2.99, 95% CI 2.28-3.69, 95% PI 0.28-5.71; OC, 52.34 vs. 51.04 ng/mL; SMD = 0.68, 95% CI 0.31-1.05, 95% PI-0.48-1.84). The cumulative meta-analysis showed that the SMDs of circulating FABP4 and OC levels had stabilized between the two groups. Conclusions: Elevated circulating FABP4 and OC levels were observed in GDM women, but nesfatin-1 levels did not change, the PI of OC crossed the no-effect threshold. The results suggested that FABP4 is more suitable as a biomarker of GDM compared to OC in a future study, which is useful in identifying pregnant women who are likely to develop GDM and providing prompt management strategies.