Genetic variation of rs3811463 is associated with gestational diabetes mellitus susceptibility

Growth-suppressor microRNAs mediate synaptic overgrowth and behavioral deficits in Fragile X mental retardation protein deficiency

Abnormal neuronal and synapse growth is a core pathology resulting from deficiency of the Fragile X mental retardation protein (FMRP), but molecular links underlying the excessive synthesis of key synaptic proteins remain incompletely defined. We find that basal brain levels of the growth suppressor let-7 microRNA (miRNA) family are selectively lowered in FMRP-deficient mice and activity-dependent let-7 downregulation is abrogated. Primary let-7 miRNA transcripts are not altered in FMRP-deficiency and posttranscriptional misregulation occurs downstream of MAPK pathway induction and elevation of Lin28a, a let-7 biogenesis inhibitor. Neonatal restoration of brain let-7 miRNAs corrects hallmarks of FMRP-deficiency, including dendritic spine overgrowth and social and cognitive behavioral deficits, in adult mice. Blockade of MAPK hyperactivation normalizes let-7 miRNA levels in both brain and peripheral blood plasma from Fmr1 KO mice. These results implicate dysregulated let-7 miRNA biogenesis in the pathogenesis of FMRP-deficiency, and highlight let-7 miRNA-based strategies for future biomarker and therapeutic development.

Interference of KLF9 relieved the development of gestational diabetes mellitus by upregulating DDAH2

Gestational diabetes mellitus (GDM) is a situation where glucose intolerance is found in pregnant women without a previous diagnosis of diabetes. The role of Kruppel-like factor 9 (KLF9) has not been investigated in GDM, which constituted the aim of our study. HTR8/SVneo cells were induced by high glucose (HG) and pregnant mice were treated with streptozocin (STZ) to establish GDM model in vitro and in vivo, respectively. The expression level of KLF9 was detected by real-time PCR, immunohistochemical staining, and Western blot. Cell viability, apoptosis, inflammation, and oxidative stress were investigated by cell counting kit-8 (CCK-8), TUNEL, enzyme-linked immunosorbent assay (ELISA) and oxidative stress detection kits, respectively. The interaction of KLF9 with dimethylarginine dimethylaminohydrolase 2 (DDAH2) was predicted by bioinformatic tools and confirmed by luciferase reporter assay and chromatin immunoprecipitation (ChIP). The expression of KLF9 was increased in the placental tissues of GDM patients and HG-induced HTR8/SVneo cells. Silencing of KLF9 increased cell viability, reduced cell apoptosis, and suppressed inflammation and oxidative stress in HG-induced HTR8/SVneo cells. KLF9 could bind to DDAH2 promoter and negatively regulate DDAH2 expression. Inhibition of DDAH2 partly weakened the effects of KLF9 silencing on cell apoptosis, inflammation, and oxidative stress. The suppressive effects of KLF9 silencing on blood glucose and insulin concentration in vivo were also abolished by DDAH2 knockdown. In conclusion, we provided evidence that interference of KLF9 could hinder the development of GDM by alleviating cell apoptosis, inflammation, and oxidative stress through upregulating DDAH2, which might instruct the targeting therapies against GDM.Abbreviations: KLF9: Kruppel-like factor 9; DDAH2: dimethylarginine dimethylaminohydrolase 2 ; GDM: gestational diabetes mellitus; ELISA: enzyme-linked immunosorbent assay; CCK-8: cell counting kit-8; ChIP: chromatin immunoprecipitation; sh: short hairpin; HG: high glucose; PBS: phosphate-buffered saline; DAPI: 4, 6-diamidino-2-phenylindole; IL-6: Interleukin-6; TNF-α: tumor necrosis factor-α; ROS: reactive oxygen species; MDA: malondialdehyde; SOD: superoxide dismutase; wt: wild-type; mut: mutant.

Polysaccharide IV from Lycium barbarum L. Improves Lipid Profiles of Gestational Diabetes Mellitus of Pregnancy by Upregulating ABCA1 and Downregulating Sterol Regulatory Element-Binding Transcription 1 via miR-33

Lycium barbarum L. (LBL) has beneficial effects on gestational diabetes mellitus (GDM) but the related mechanism remains unclear. Polysaccharides of LBL (LBLP) are the main bioactive components of LBL. miR-33, ATP-binding cassette transporter A1 (ABCA1) and sterol regulatory element-binding transcription 1 (SREBF1) affect lipid profiles, which are associated with GDM risk. LBLP may exert protective against GDM by affecting these molecules. Four LBLP fractions: LBLP-I, LBLP-II, LBLP-III, and LBLP-IV were isolated from LBL and further purified by using DEAE-Sephadex column. The effects of purified each fraction on pancreatic beta cells were comparatively evaluated. A total of 158 GDM patients were recruited and randomly divided into LBL group (LG) and placebo group (CG). miR-33 levels, lipid profiles, insulin resistance and secretory functions were measured. The association between serum miR-33 levels and lipid profiles were evaluated by using Spearman's rank-order correlation test. After 4-week therapy, LBL reduced miR-33 level, insulin resistance and increased insulin secretion of GDM patients. LBL increased the levels of ABCA1, high-density lipoprotein cholesterol (HDL-C) and reduced miR-33, SREBF1, low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG), and malondialdehyde. Homeostatic model assessment of β-cell function and insulin resistance was lower in LG than in CG, whereas homeostatic model assessment of β-cell function and insulin secretory function was higher in LG than in CG. There was a strong positive association between miR-33 level and TG, or TC and or LDL-C, and a strong negative association between miR-33 level and HDL-C. The levels of miR-33 had negative relation with ABCA1 and positive relation with SREBF1. ABCA1 has negative relation with TG, TC, and LDL-C and positive relation with HDL-C. Inversely, SREBF1 had positive relation with TG, TC, and LDL-C and negative relation with HDL-C. The main bioactive compound LBLP-IV of LBL increased insulin secretion of beta cells and the levels of ABCA1, and reduced miR-33 levels and SREBF1 in beta cells. However, LBLP-IV could not change the levels of these molecules anymore when miR-33 was overexpressed or silenced. LBLP-IV had the similar effects with LBL on beta cells while other components had no such effects. Thus, LBLP-IV from LBL improves lipid profiles by upregulating ABCA1 and downregulating SREBF1 via miR-33.