Epidemiological studies have suggested a link between vitamin D deficiency and increased risk for nonalcoholic fatty liver disease (NAFLD); however, the underlying mechanisms have remained unclear. Here, using both clinical samples and experimental rodent models along with several biochemical approaches, we explored the specific effects and mechanisms of vitamin D deficiency in NAFLD pathology. Serum vitamin D levels were significantly lower in individuals with NAFLD and in high-fat diet (HFD)-fed mice than in healthy controls and chow-fed mice, respectively. Vitamin D supplementation ameliorated HFD-induced hepatic steatosis and insulin resistance in mice. Hepatic expression of vitamin D receptor (VDR) was up-regulated in three models of NAFLD, including HFD-fed mice, methionine/choline-deficient diet (MCD)-fed mice, and genetically obese (ob/ob) mice. Liver-specific VDR deletion significantly exacerbated HFD- or MCD-induced hepatic steatosis and insulin resistance and also diminished the protective effect of vitamin D supplementation on NAFLD. Mechanistic experiments revealed that VDR interacted with hepatocyte nuclear factor 4 α (HNF4α) and that overexpression of HNF4α improved HFD-induced NAFLD and metabolic abnormalities in liver-specific VDR-knockout mice. These results suggest that vitamin D ameliorates NAFLD and metabolic abnormalities by activating hepatic VDR, leading to its interaction with HNF4α. Our findings highlight a potential value of using vitamin D for preventing and managing NAFLD by targeting VDR.

Background The endometrial preparation during frozen embryo transfer (FET) can be performed by natural cycle (NC), hormone replacement therapy (HRT) cycle and cycle with ovulation induction (OI). Whether different FET preparation protocols can affect maternal and neonatal outcomes is still inconclusive. Methods This was a retrospective cohort study that included 6886 women who delivered singleton live birth babies after 28 weeks of pregnancy underwent FET from January, 2015 to July, 2018. Women were divided into three groups according to the protocols used for endometrial preparation during FET: NC group (N = 4727), HRT group (N = 1642) and OI group (N = 517). Results After adjusting for the effect of age, body mass index (BMI), irregular menstruation, antral follicle count (AFC), endometrial thickness, the levels of testosterone, anti-Müllerian hormone (AMH), preconceptional fasting glucose (PFG), systolic and diastolic pressure et al., the HRT group had higher risk of hypertensive disorders of pregnancy (HDP) compared with the NC group (adjusted odds ratio (aOR) 2.00, 95% confidence interval (CI) 1.54–2.60). Singletons born after HRT FET were at increased risk of low birth weight (LBW) compared to NC group (aOR 1.49, 95%CI 1.09–2.06). The risks of preterm birth (PTB) in the HRT and OI group were elevated compared with the NC group (aOR 1.78, 95%CI 1.39–2.28 and aOR 1.51, 95%CI 1.02–2.23, respectively). Conclusions The HRT protocol for endometrial preparation during frozen embryo transfer of blastocysts was associated with increased risk of maternal and neonatal complications, compared to the NC and OI protocol.

ObjectiveTo characterize the ovarian reserve indicators for premature ovarian insufficiency (POI) at different disease stages and with various etiologies.MethodsAccording to different FSH levels and menstrual conditions, patients with normal ovarian reserve (NOR with 5 IU/L<FSH<10 IU/L, n=987), precursor stage of POI (pre-POI with 10 IU/L<FSH ≤ 25 IU/L, n=410), early POI (25 IU/L<FSH ≤ 40 IU/L n=147), and premature ovarian failure (POF with FSH>40 IU/L, n=454) were retrospectively screened and their records were abstracted from Reproductive Hospital Affiliated to Shandong University between 2014 and 2019. Based on the known etiologies, POI patients were subdivided into genetic, iatrogenic, autoimmune and idiopathic subsets according to the known etiologies. The phenotypic features were compared within different subgroups, and the predictive value of ovarian reserve markers was analyzed.ResultsThe ovarian reserve indicators consecutively deteriorated with the progress of ovarian insufficiency, indicated as an increase of FSH and LH but decrease of AMH, inhibin B, AFC, E2 and T (P<0.01). Most of them changed significantly from NOR to pre-POI while remained relatively stable at a low level or even undetectable at early POI and POF stage. AMH showed the highest predictive value for pre-POI (AUC 0.932, 95% CI 0.918-0.945) and POI (AUC 0.944, 95% CI 0.933-0.954), and the combination of AMH and AFC was highly promising for early prediction. Additionally, significant differences existed in AMH, inhibin B and AFC among women with different etiologies of POI (P<0.05), and the genetic POI presented the worst hormone status.ConclusionsOur study indicated a high heterogeneity of POI in both endocrine hormones and etiological phenotypes. The quantitative changes and cutoff values of AMH and AFC could provide new insights in the prediction and early diagnosis of POI.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

BACKGROUNDIt is well known that nonalcoholic fatty liver disease (NAFLD) is associated with insulin resistance (IR). LB100, a serine/threonine protein phosphatase 2A (PP2A) inhibitor, is closely related to IR. However, there is little data regarding its direct influence on NAFLD.AIMTo elucidate the effect and underlying mechanism of LB100 in NAFLD.METHODSAfter 10 wk of high fat diet (HFD) feeding, male C57BL/6 mice were injected intraperitoneally with vehicle or LB100 for an additional 6 wk (three times a week). The L02 cell line was treated with LB100 and free fatty acids (FFAs) for 24 h. Hematoxylin and eosin and oil red O staining were performed for histological examination. Western blot analysis was used to detect the protein expression of Sirtuin 1 (Sirt1), total and phosphorylated AMP-activated protein kinase α (AMPKα), and the proteins involved in lipogenesis and fatty acid oxidation. The mRNA levels were determined by qPCR. Pharmacological inhibition of AMPK was performed to further examine the exact mechanism of LB100 in NAFLD.RESULTSLB100 significantly ameliorated HFD-induced obesity, hepatic lipid accumulation and hepatic injury in mice. In addition, LB100 significantly downregulated the protein levels of acetyl-CoA carboxylase, sterol regulatory element-binding protein 1 and its lipogenesis target genes, including stearoyl-CoA desaturase-1 and fatty acid synthase, and upregulated the levels of proteins involved in fatty acid β-oxidation, such as peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), carnitine palmitoyltransferase 1α, acyl-CoA oxidase 1 and uncoupling protein 2, as well as the upstream mediators Sirt1 and AMPKα in the livers of HFD-fed mice. In vitro, LB100 alleviated FFA-induced lipid accumulation in L02 cells through the AMPK/Sirt1 signaling pathway. Further studies showed that the curative effect of LB100 on lipid accumulation was abolished by inhibiting AMPKα in L02 cells.CONCLUSIONPP2A inhibition by LB100 significantly ameliorates hepatic steatosis by regulating hepatic lipogenesis and fatty acid oxidation via the AMPK/Sirt1 pathway. LB100 may be a potential therapeutic agent for NAFLD.