Ginger polysaccharide promotes myeloid-derived suppressor cell apoptosis by regulating lipid metabolism.

Recently, targeting myeloid-derived suppressor cells (MDSCs) which mainly play an immunosuppressive role in tumor microenvironment has become a hot spot in tumor immunotherapy. This study focuses on biological effect of ginger polysaccharide extracted from natural plants on promoting apoptosis of MDSCs by regulating lipid metabolism. An MTT assay was used to detect the inhibitory effect of ginger polysaccharide on the growth of an MDSC-like cell line (MSC-2). The apoptosis-promoting effect of ginger polysaccharide on MSC-2 cells was detected by flow cytometry. Expression levels of apoptosis proteins (caspase 9 and Bcl-2) and lipid metabolism enzymes (fatty acid synthase (FASN) and diacylglycerol acyltransferase 2) in MSC-2 cells treated with different concentrations of ginger polysaccharide were detected by western blot assay. Nile red staining was used to quantitatively detect the effect of ginger polysaccharide on lipid droplet synthesis. Ginger polysaccharide inhibited proliferation of MSC-2 cells and promoted their apoptosis by upregulating pro-apoptotic caspase 9 protein, downregulating anti-apoptotic Bcl-2 protein, inhibiting expression of FASN and diacylglycerol acyltransferase 2 (key enzymes in fatty acid synthesis and lipid droplet formation, respectively). Ginger polysaccharide promoted apoptosis of MDSCs by regulating key lipid metabolism enzymes, inhibiting fatty acid synthesis and lipid droplet accumulation, and reducing the energy supply of cells.

[Effect of Danlou Tablets on alleviating hepatic adipogenesis, inflammatory response, and insulin resistance in db/db mice].

This study explored the effect and potential mechanism of Danlou Tablets(DLT) on insulin resistance in db/db mice with type 2 diabetic mellitus(T2 DM). The db/db male mice were randomly assigned into model control(MC) group, metformin(MET, tablet, 100 mg·kg~(-1)) group, and DLT(1 g·kg~(-1)) group, and C57 BL/6 J mice were taken as normal control(NC) group. The mice in the MET group and DLT group were given corresponding drugs by gavage once a day for 16 weeks. The fasting blood glucose, glucose tolerance, and insulin tolerance were measured to evaluate the effect of DLT on blood glucose and insulin resistance in diabetic mice. The serum free fatty acid, triacylglycerol, and total cholesterol levels were determined to evaluate the effect of DLT on blood lipids in diabetic mice. The liver index and perirenal fat index were calculated to measure the effect of DLT on lipid accumulation in non-adipose tissue and adipose tissue. Western blot was performed to determine the protein levels of insulin receptor-ß(IRß), phospho-IRß(p-IRß), phosphatidylinositol 3-kinase(PI3 K), and insulin receptor substrate-1(IRS-1) involved in IRS-1/PI3 K/Akt signaling pathway in the livers of mice to reveal the mechanism of DLT in alleviating insulin resistance in diabetic mice. The protein levels of sterol regulatory element binding protein-1(SREBP-1) and the mRNA levels of sterol regulatory element binding protein-1 c(SREBP-1 c), fatty acid synthase(FAS), acetyl-CoA carboxylase(ACC), diacylglycerol acyltransferase-1(Dgat1), and diacylglycerol acyltransferase-2(Dgat2) involved in the SREBP-1/FAS signaling pathway were detected to evaluate the effect of DLT on lipid metabolism in diabetic mice. Real-time quantitative PCR was employed to determine the mRNA levels of galectin-3(Gal-3), interleukin-6(IL-6), and monocyte chemoattractant protein-1(MCP-1) in mouse liver to evaluate the effect of DLT on inflammatory response in diabetic mice. The results showed that DLT significantly reduced the blood glucose and lipid levels and alleviated the insulin resistance in diabetic mice. Compared with the MC group, DLT significantly up-regulated the protein levels of p-IRß, PI3 K, and IRS-1(P<0.05 or P<0.01), and down-regulated the protein level of SREBP-1 in liver tissues of diabetic mice(P<0.05). DLT lowered the mRNA levels of SREBP-1 c, FAS, ACC, Dgat1, and Dgat2 related to lipid metabolism as well as those of Gal-3, IL-6, and MCP-1 associated with inflammation in the livers of diabetic mice(P<0.05 or P<0.01). The findings of this study suggest that DLT may alleviate insulin resistance in diabetic mice by regulating IRS-1/PI3 K/Akt signaling pathway and SREBP-1/FAS signaling pathway to reduce lipid production and inhibit inflammatory response.

Novel antisense inhibition of diacylglycerol O-acyltransferase 2 for treatment of non-alcoholic fatty liver disease: a multicentre, double-blind, randomised, placebo-controlled phase 2 trial.

BACKGROUND: Diacylglycerol-O-acyltransferase 2 (DGAT2) is one of two enzyme isoforms that catalyse the final step in the synthesis of triglycerides. IONIS-DGAT2Rx is an antisense oligonucleotide inhibitor of DGAT2 that is under clinical investigation for the treatment of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The aim of this trial was to examine the safety, tolerability, and efficacy of IONIS-DGAT2Rx versus placebo in reducing liver fat in patients with type 2 diabetes and NAFLD. METHODS: This double-blind, randomised, placebo-controlled, phase 2 study consisted of a 2-week screening period, a run-in period of up to 4 weeks, a 13-week treatment period of once-weekly dosing, and a 13-week post-treatment follow-up period. The study was done at 16 clinical research sites in Canada, Poland, and Hungary. Eligible participants were aged 18-75 years, had a body-mass index at screening between 27 kg/m2 and 39 kg/m2, haemoglobin A1c (HbA1c) levels from 7·3% to 9·5%, and liver fat content 10% or greater before randomisation, and agreed to maintain a stable diet and exercise routine throughout the study. Enrolled participants were stratified on the basis of liver fat content during the run-in period (<20% or ≥20%) and then centrally randomised (2:1) to receive once weekly subcutaneous injection of 250 mg IONIS-DGAT2Rx or placebo for 13 weeks. Participants, investigators, funder personnel, and the clinical research organisation staff, including central readers of MRI scans, were all masked to treatment identity. The primary endpoints were the safety, tolerability, and pharmacodynamic effect of IONIS-DGAT2Rx on hepatic steatosis, according to absolute reduction from baseline in liver fat percentage as quantified by MRI-estimated proton density fat fraction and assessed in the per-protocol population. Pharmacodynamic performance was determined in the per-protocol population by the change in liver fat content from baseline to 2 weeks after the last dose. The per-protocol population included all randomised participants who received at least ten doses of study drug, with the first four doses administered in the first 5 weeks, did not miss more than three consecutive weekly doses, and who had no protocol deviations that might affect efficacy. All randomised participants who received at least one dose of study drug were included in the safety analysis. This study is registered with ClinicalTrials.gov, NCT03334214. FINDINGS: Between Nov 3, 2017, and Nov 28, 2018, we screened 173 people for eligibility. 44 were enrolled and randomly assigned to receive either IONIS-DGAT2Rx (29 participants) or placebo (15 participants). After 13 weeks of treatment, the mean absolute reduction from baseline was -5·2% (SD 5·4) in the IONIS-DGAT2Rx group compared with -0·6% (6·1) in the placebo group (treatment difference -4·2%, 95% CI -7·8 to -0·5, p=0·026). Reductions in liver fat were not accompanied by hyperlipidaemia, elevations in serum aminotransferases or plasma glucose, changes in bodyweight, or gastrointestinal side-effects compared with placebo. Six serious adverse events occurred in four patients treated with IONIS-DGAT2Rx. No serious adverse events were reported in the placebo group. One of four patients reported three serious adverse events: acute exacerbation of chronic obstructive pulmonary disease, cardiac arrest, and ischaemic cerebral infarction, each considered severe and not related to study drug. Three of four patients reported one serious adverse event of increased blood triglycerides (severe, unrelated to study drug), deep-vein thrombosis (severe, unlikely to be related to study drug), and acute pancreatitis (mild, unrelated to study drug). INTERPRETATION: Our results suggest that DGAT2 antisense inhibition could be a safe and efficacious strategy for treatment of NAFLD and support further investigation in patients with biopsy-proven NASH. Based on the pharmacological target, the response to treatment observed in this study population could extend to the broader population of patients with NAFLD. FUNDING: Ionis Pharmaceuticals.

Ghrelin deletion protects against age-associated hepatic steatosis by downregulating the C/EBPα-p300/DGAT1 pathway.

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. NAFLD usually begins as low-grade hepatic steatosis which further progresses in an age-dependent manner to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma in some patients. Ghrelin is a hormone known to promote adiposity in rodents and humans, but its potential role in hepatic steatosis is unknown. We hypothesized that genetic ghrelin deletion will protect against the development of age-related hepatic steatosis. To examine this hypothesis, we utilized ghrelin knockout (KO) mice. Although no different in young animals (3 months old), we found that at 20 months of age, ghrelin KO mice have significantly reduced hepatic steatosis compared to aged-matched wild-type (WT) mice. Examination of molecular pathways by which deletion of ghrelin reduces steatosis showed that the increase in expression of diacylglycerol O-acyltransferase-1 (DGAT1), one of the key enzymes of triglyceride (TG) synthesis, seen with age in WT mice, is not present in KO mice. This was due to the lack of activation of CCAAT/enhancer binding protein-alpha (C/EBPα) protein and subsequent reduction of C/EBPα-p300 complexes. These complexes were abundant in livers of old WT mice and were bound to and activated the DGAT1 promoter. However, the C/EBPα-p300 complexes were not detected on the DGAT1 promoter in livers of old KO mice resulting in lower levels of the enzyme. In conclusion, these studies demonstrate the mechanism by which ghrelin deletion prevents age-associated hepatic steatosis and suggest that targeting this pathway may offer therapeutic benefit for NAFLD.