Effect and Mechanism of Dicliptera chinensis Polysaccharide on miR-141/AMPK/SIRT1 Signaling Pathway in Rats with NAFLD

[Objectives]Non-alcoholic fatty liver disease(NAFLD)rat model was established by feeding high-fat and high-sugar fodder to rats,and the protective effect of Dicliptera chinensis polysaccharide(DCP)on NAFLD rats was studied to explore its potential mechanism.[Methods]45 SD rats were randomly divided into 4 groups:normal control group,model control group and DCP treatment groups(100 and 300 mg/kg).The rats in the normal control group were fed with ordinary fodder,and the rats in other groups were fed with high-fat and high-sugar diet for 14 weeks to establish NAFLD model.From the 9^(th)week,the rats in the DCP treatment groups were given different doses of DCP by intragastric administration(5 mL/kg)for 6 weeks.After the last intragastric administration,the rats fasted for 16 h,and the serum and liver of rats were collected for detection.Hematoxylin-eosin(HE)staining was conducted to observe the histopathological changes of rat liver,and alanine aminotransferase(ALT),aspartate aminotransferase(AST),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondialdehyde(MDA),triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C),and high density lipoprotein cholesterol(HDL-C)were detected by biochemical method.Interleukin-6(IL-6),interleukin-1β(IL-1β),tumor necrosis factor(TNF-α)and micrornA-141(micro RNA-141)were detected by reverse transcription-polymerase chain reaction(RT-PCR).The expression of SIRT1 and adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)in rat liver was detected by western blot.[Results]Compared with the model control group,the inflammatory damage and steatodegeneration of rats in the DCP groups were relieved to varying degrees,and the number of lipid vacuoles significantly reduced.The ALT,AST,TC,TG and LDL-C content in the serum and MDA content in the liver tissue decreased to varying degrees,while the HDL-C,SOD and GSH-Px content increased.The expression of SIRT1 and AMPK increased,while the expression of miR-141,TNF-α,IL-6 and IL-1βdeclined,and the DCP 300 mg/kg treatment group had better improvement effect.[Conclusions]DCP had a certain protective effect on NAFLD rats,which may be related to the regulation of miR-141/AMPK/SIRT1 signaling pathway.

miR-146a-5p affects inflammation response of trophoblast by inhibiting TRAF6/NF-кB signaling pathway

Objective:To investigate the association of Micro-rna(miR)-146a-5p expression with preeclampsia,and further explore the potential mechanism involved.Methods:Compared with the blank control group,the expressions of miR-146a-5p and TRAF6 were detected in lipopolysaccharide(LPS)-induced JEG-3 cells.Chorionic carcinoma cell JEG-3 in vitro culture are divided into control,miR-146a-5p mimic+lipopolysaccharide(lps),miR-146a-5p mimic and miR-146a-5p inhibitor groups.qRT-PCR analysis were used to detect the mRNA of miR-146a-5p,IL-1β,IL-6,IL-8 and TNF-α.Western blot assays were carried out to determine the protein expression of TRAF6/NF-кB pathway related proteins.Results:1.miR-146a expression in miR-146a mimic group were significantly higher than the other three groups(P<0.05).2.Compared with the control group,the expression level of miR-146a-5p in JEG-3 cells induced by LPS was significantly increased,and the expression level of TRAF6 was significantly reduced(P<0.05).3.Compared with the control group,the mRNA expression levels of IL-1β,IL-6,IL-8,and TNF-αdecreased significantly after using miR-146a mimic(P<0.05).After adding miR-146a inhibitor,the mRNA expression levels of IL-1β,IL-6,IL-8,and TNF-αwere significantly increased(P<0.05).However,compared with the mimic+LPS group,the difference was not statistically significant(all P>0.05).The results of Western Blot showed that the expression of TRAF6 and NF-κB protein in JEG-3 cells decreased significantly after adding miR-146a mimic and increased after adding miR-146a inhibitor.Conclusion:MiR-146-5p can affect the inflammation response of Maternal-fetal interface by inhibiting TRAF6/NF-кB signaling pathway in preeclampsia.

MiR-146a-5p targeting SMAD4 and TRAF6 inhibits adipogenensis through TGF-β and AKT/mTORC1 signal pathways in porcine intramuscular preadipocytes

Background: Intramuscular fat(IMF) content is a vital parameter for assessing pork quality. Increasing evidence has shown that microRNAs(miRNAs) play an important role in regulating porcine IMF deposition. Here, a novel miRNA implicated in porcine IMF adipogenesis was found, and its effect and regulatory mechanism were further explored with respect to intramuscular preadipocyte proliferation and differentiation.Results: By porcine adipose tissue miRNA sequencing analysis, we found that miR-146a-5p is a potential regulator of porcine IMF adipogenesis. Further studies showed that miR-146a-5p mimics inhibited porcine intramuscular preadipocyte proliferation and differentiation, while the miR-146a-5p inhibitor promoted cell proliferation and adipogenic differentiation. Mechanistically, miR-146a-5p suppressed cell proliferation by directly targeting SMAD family member 4(SMAD4) to attenuate TGF-β signaling. Moreover, miR-146a-5p inhibited the differentiation of intramuscular preadipocytes by targeting TNF receptor-associated factor 6(TRAF6) to weaken the AKT/mTORC1 signaling downstream of the TRAF6 pathway.Conclusions: MiR-146a-5p targets SMAD4 and TRAF6 to inhibit porcine intramuscular adipogenesis by attenuating TGF-β and AKT/mTORC1 signaling, respectively. These findings provide a novel miRNA biomarker for regulating intramuscular adipogenesis to promote pork quality.

葛根芩连汤含药血清通过miR-146b/SIRT1信号通路改善HepG2细胞胰岛素抵抗的研究

目的:探讨葛根芩连汤含药血清改善HepG2细胞胰岛素抵抗的机制。方法:建立胰岛素抵抗HepG2细胞模型,用葛根芩连汤含药血清、吡格列酮干预,并设空白对照组和模型组。比色法检测细胞糖原合成能力,实时定量PCR检测miR-146b的表达,Western blot和实时定量PCR检测SIRT1/FoxO1通路中相关蛋白及mRNA的表达。结果:葛根芩连汤含药血清能逆转胰岛素抵抗HepG2细胞的糖原合成能力下降(P<0.01)。与对照组比较,模型组miR-146b表达显著升高(P<0.01),葛根芩连汤含药血清能显著抑制miR-146b的表达(P<0.01)。Western blot显示,与空白对照组比较,模型组SIRT1、PPARγ蛋白表达显著降低,acetyl-FoxO1蛋白表达显著升高(P<0.05或P<0.01);与模型组比较,葛根芩连汤含药血清组SIRT1、PPARγ蛋白表达显著升高,acetyl-FoxO1蛋白表达显著降低(P<0.05或P<0.01)。过表达的miR-146b能抑制SIRT1蛋白的表达,沉默miR-146b能增强SIRT1蛋白的表达(P<0.05或P<0.01)。结论:葛根芩连汤含药血清能改善棕榈酸诱导的HepG2胰岛素抵抗模型,其机制与调控miR-146b/SIRT1信号通路有关。

MicroRNA-23a reduces lipopolysaccharide-induced cellular apoptosis and inflammatory cytokine production through Rho-associated kinase 1/sirtuin-1/nuclear factor-kappa B crosstalk

Background:MicroRNAs are closely associated with the progression and outcomes of multiple human diseases,including sepsis.In this study,we examined the role of miR-23a in septic injury.Methods Lipopolysaccharide(LPS)was used to induce sepsis in a rat model and H9C2 and HK-2 cells.miR-23a expression was evaluated in rat myocardial and kidney tissues,as well as H9C2 and HK-2 cells.A miR-23a mimic was introduced into cells to identify the role of miR-23a in cell viability,apoptosis,and the secretion of inflammatory cytokines.Furthermore,the effect of Rho-associated kinase 1(ROCK1),a miR-23a target,on cell damage was evaluated,and molecules involved in the underlying mechanism were identified.Results:In the rat model,miR-23a was poorly expressed in myocardial(sham vs.sepsis 1.00±0.06 vs.0.27±0.03,P<0.01)and kidney tissues(sham vs.sepsis 0.27±0.03 vs.1.00±0.06,P<0.01).Artificial overexpression of miR-23a resulted in increased proliferative activity(DNA replication rate:Control vs.LPS vs.LPS+Mock vs.LPS+miR-23a:H9C2 cells:34.13±3.12 vs.12.94±1.21 vs.13.31±1.43 vs.22.94±2.26,P<0.05;HK-2 cells:15.17±1.43 vs.34.52±3.46 vs.35.19±3.12 vs.19.87±1.52,P<0.05),decreased cell apoptosis(Control vs.LPS vs.LPS+Mock vs.LPS+miR-23a:H9C2 cells:11.39±1.04 vs.32.57±2.29 vs.33.08±3.12 vs.21.63±2.35,P<0.05;HK-2 cells:15.17±1.43 vs.34.52±3.46 vs.35.19±3.12 vs.19.87±1.52,P<0.05),and decreased production of inflammatory cytokines,including interleukin-6(Control vs.LPS vs.LPS+Mock vs.LPS+miR-23a:H9C2 cells:59.61±5.14 vs.113.54±12.30 vs.116.51±10.69 vs.87.69±2.97 ng/mL;P<0.05,F=12.67,HK-2 cells:68.12±6.44 vs.139.65±16.62 vs.143.51±13.64 vs.100.82±9.74 ng/mL,P<0.05,F=9.83)and tumor necrosis factor-α(Control vs.LPS vs.LPS+Mock vs.LPS+miR-23a:H9C2 cells:103.20±10.31 vs.169.67±18.84 vs.173.61±15.91 vs.133.36±12.32 ng/mL,P<0.05,F=12.67,HK-2 cells:132.51±13.37 vs.187.47±16.74 vs.143.51±13.64 vs.155.79±15.31 ng/mL,P<0.05,F=9.83)in cells.However,ROCK1 was identified as a miR-23a target,and further up-regulation of ROCK1 mitigated the protective function of miR-23a in LPS-treated H9C2 and HK-2 cells.Moreover,ROCK1 suppressed sirtuin-1(SIRT1)expression to promote the phosphorylation of nuclear factor-kappa B(NF-κB)p65,indicating the possible involvement of this signaling pathway in miR-23a-mediated events.Conclusion:Our results indicate that miR-23a could suppress LPS-induced cell damage and inflammatory cytokine secretion by binding to ROCK1,mediated through the potential participation of the SIRT1/NF-κB signaling pathway.

The functional analysis of transiently upregulated miR-101 suggests a “braking” regulatory mechanism during myogenesis

Skeletal muscle differentiation is a highly coordinated process that involves many cellular signaling pathways and microRNAs(miRNAs).A group of muscle-specific miRNAs has been reported to promote myogenesis by suppressing key signaling pathways for cell growth.However,the functional role and regulatory mechanism of most non-muscle-specific miRNAs with stage-specific changes during differentiation are largely unclear.Here,we describe the functional characterization of miR-101a/b,a pair of non-muscle-specific miRNAs that show the largest change among a group of transiently upregulated miRNAs during myogenesis in C2C12 cells.The overexpression of miR-101a/b inhibits myoblast differentiation by suppressing the p38/MAPK,Interferon Gamma,and Wnt pathways and enhancing the C/EBP pathway.Mef2a,a key protein in the p38/MAPK pathway,was identified as a direct target of miR-101a/b.Interestingly,we found that the long non-coding RNA(lncRNA)Malat1,which promotes muscle differentiation,interacts with miR-101a/b,and this interaction competes with Mef2a mRNA to relieve the inhibition of the p38/MAPK pathway during myogenesis.These results uncovered a“braking”role in differentiation of transiently upregulated miRNAs and provided new insights into the competing endogenous RNA(ceRNA)regulatory mechanism in myoblast differentiation and myogenesis.