Isolation and Purification of Polysaccharides from Cordyceps minlitaris and Its Inhibition on the Proliferation of Rat Glomerular Mesangial Cells

The crude polysaccharide was obtained by means of the decolorization of porphyrized Cordyceps minlitaris stroma with organic solvent, extraction with hot water, precipitation in 80% ethanol, and protein removal with the Sevag method. After purification with Sephadex G-75, two of its components, CMP-1 and CMP-2, were obtained. Through the assay of gel chromatography and polarimetry, CMP-1 was identified as pure polysaccharide. The results demonstrated that CMP-1 had favorable oxidation resistance activity, which could scavenge not only oxygen-free radicals in the self-oxidation system of pyrogallic acid, but also the hydroxide-free radicals in the Fenton system. The study focused on the effects of low, medium, and high dosages of CMP-1 in rat blood serum on the proliferation of glomerular mesangial cells in vitro. Through MTT Colorimetric analysis, the activities were compared among the blank control group and the Niaoduqing positive control group CMP-1 and CMP-2. The results shows that CMP-1 was able to inhibit the proliferation of rat glomerular mesangial cells effectively. Therefore, CMP-1, one component of polysaccharides of Cordyceps minlitaris, was certainly a potential remedy for hyperplastic glomerular nephritis, whose antioxidant activity could slow down the process of chronic renal failure（CRF） to some extent.

Effects of emodin on the proliferation of the glomerular mesangial cell and correlative cytokines in rats

Objective：To investigate the effects of emodin（EMD） on cell proliferation and correlative cytokines secretion of glomerular mesangial in rats. Methods：The effects of EMD on cell proliferation and IL-6, TGF-β1 secretion of glomerular mesangial in rats were observed. Cell proliferation was measured by MTT method. IL-6 and TGF-β1 secretion was detected with ELISA. Results：EMD was able to inhibit the cell proliferation and down-regulate the IL-6 and TGF-β 1 secretion of glomerular mesangial, as compared to the model group in rats （P 〈 0.05）. Conclusion：EMD could significantly inhibit the cell proliferation, and reduce the creation of extracellular matrix（ECM）, this indicated that it could play an important role in alleviation and prevention of glomerular sclerosis. The mechanism may be that EMD can reduce the IL-6 and TGF-β1 secretion ofglomerular mesangial cell in rats.

TSP-1 promotes glomerular mesangial cell proliferation and extracellular matrix secretion in Thy-1 nephritis rats

The proliferation of glomerular mesangial cells （GMC） and secretion of the extracellular matrix （ECM） in rat with Thy-1 nephritis （Thy-lN） resembling human mesangioproliferative glomerulonephritis have been explored for many years; however, the molecular mechanisms of GMC proliferation and ECM production remain unclear. Our previous studies have demonstrated that the thrombospondin-1 （TSP-1） gene was involved in mediating rat GMC proliferation and ECM synthesis induced by sublytic C5b-9 in vitro. 111 the present study, the roles of the TSP-1 gene in GMC proliferation, ECM production, and urinary protein secretion in Thy-lN rats were determined by using TSP-1 small hairpin RNA, and the results revealed that silencing of the TSP-1 gene in rat renal tissues could diminish GMC proliferation （P 〈 0.01） and ECM secretion （P 〈 0.01） as well as urinary protein secretion （P 〈 0.05） in Thy-lN rats. Together, the current findings suggested that TSP-1 gene expression was required for GMC proliferation and ECM production in Thy-lN rats.

Inhibitory Effect of Resveratrol on LPS-induced Glomerular Mesangial Cells Proliferation and TGF-β1 Expression via Sphingosine Kinase 1 Pathway

Objective To elucidate the renoprotective effect of resveratrol(RSV)on sphingosine kinase 1(SphK1)signaling pathway and expression of its downstream molecules including activator protein 1(AP-1)and transformation growth factor-β1(TGF-β1)in lipopolysaccharide(LPS)-induced glomerular mesangial cells(GMCs).Methods The rat GMCs line(HBZY-1)were cultured and randomly divided into 5 groups,including control,LPS(100 ng/mL),and 5,10,20µmol/L RSV-treated groups.In addition,SphK1 inhibitor(SK-II)was used as positive control.GMCs were pretreated with RSV for 2 h and treated with LPS for another 24 h.GMCs proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)assay.The proteins expression of SphK1,p-c-Jun and TGF-β1 in GMCs were detected by Western blot,and DNA-binding activity of AP-1 was performed by electrophoretic mobility shift assay(EMSA).The binding activity between RSV and SphK1 protein was detected by AutoDock Vina and visualized by Discovery Studio 2016.Results LPS could obviously stimulate GMCs proliferation,elevate SphK1,p-c-Jun and TGF-β1 expression levels and increase the DNA-binding activity of AP-1(P<0.05 or P<0.01),whereas these effects were significantly blocked by RSV pretreatment.It was also suggested that the effect of RSV was similar to SK-II(P>0.05).Moreover,RSV exhibited good binding affinity towards SphK1,with docking scores of−8.1 kcal/moL and formed hydrogen bonds with ASP-178 and LEU-268 in SphK1.Conclusion RSV inhibited LPS-induced GMCs proliferation and TGF-β1 expression,which may be independent of its hypoglycemic effect on preventing the development of mesangial cell fibrosis and closely related to the direct inhibition of SphK1 pathway.

Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro

Background The renoprotective mechanisms of adenosine monophosphate （AMP）-activated protein kinase （AMPK） agonist-metformin have not been stated clearly.We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB （NF-κB）,monocyte chemoattractant protein-1 （MCP-1）,intercellular adhesion molecule-1 （ICAM-1） and transforming growth factor-beta 1 （TGF-β1） induced by high glucose （HG） in cultured rat glomerular mesangial cells （MCs）.Methods MCs were cultured in the medium with normal concentration glucose （group NG,5.6 mmol/L）,high concentration glucose （group HG,25 mmol/L） and different concentrations of metformin （group M1,M2,M3）.After 48-hour exposure,the supernatants and MCs were collected.The expression of NF-κB,MCP-1,ICAM-1,and TGF-β1 mRNA was analyzed by real time polymerase chain reaction.Westem blotting was used to detect the expression of AMPK,phospho-Thr-172 AMPK （p-AMPK）,NF-κB p65,MCP-1,ICAM-1,and TGF-β1 protein.Results After stimulated by HG,the expression of NF-κB,MCP-1,ICAM-1,TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG （P ＜0.05）.Both genes and protein expression of NF-κB,MCP-1,ICAM-1,TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner （P ＜0.05）.The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend,while the level of total-AMPK protein was unchanged with exposure to HG or metformin.Conlusion Metformin can suppress the expression of NF-κB,MCP-1,ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation,which may partlv contribute to its reno-protection.

Role of activating transcription factor 3 （ATF3） in sublytic C5b-9-induced glomerular mesangial cell apoptosis

Sublytic complement C5b-9 complexes can cause cell apoptosis, but the mechanism of glomerular mesangial cell （GMC） apoptosis mediated by these complexes has not been well defined. The activating transcription factor 3 （ATF3） gene is an immediate early gene for the cell to cope with a variety of stress signals and can promote apoptosis of some cells. In this study, ATF3 expression and cell apoptosis in GMCs induced by sublytic C5b-9 were measured, and then the effects of ATF3 gene over-expression or knockdown on GMC apoptosis induced by sublytic C5b-9 were examined at a fixed time. The results showed that both ATF3 expression and GMC apoptosis were markedly increased and ATF3 over-expression obviously increased sublytic C5b-9-induced GMC apoptosis, whereas ATF3 gene silencing had a significant opposite effect. Collectively, these findings indicate that upregulation of ATF3 gene expression is involved in regulating GMC apoptosis induced by sublytic C5b-9 complexes.

Sublytic C5b-9 triggers glomerular mesangial cell apoptosis in rat Thy-1 nephritis via Gadd45 activation mediated by Egr-1 and p300-dependent ATF3 acetylation

The apoptosis of glomerular mesangial cells(GMCs)is considered to be an important contributor to the initiation and development of rat Thy-1 nephritis(Thy-1N)and is accompanied by sublytic C5b-9 deposition.However,the mechanism by which sublytic C5b-9 triggers GMC apoptosis has not been elucidated.In this study,functional and histological examinations were performed on GMCs treated with sublytic C5b-9(in vitro)and renal tissues of Thy-1N rats(in vivo).The in vitro studies found that sublytic C5b-9 could trigger GMC apoptosis through upregulating Egr-1,ATF3,and Gadd45 expression.Egr-1-mediated post-transcriptional modulation of ATF3,Egr-1/ATF3-enhanced Gadd45 promoter activity,and p300-mediated ATF3 acetylation were all involved in GMC apoptosis.More importantly,the effective binding elements for Egr-1 and ATF3 to Gadd45β/γpromoters and the ATF3 acetylation site were identified.In vivo,silencing renal p300,Egr-1,ATF3,and Gadd45β/γsignificantly decreased GMC apoptosis,secondary GMC proliferation,and urinary protein secretion in Thy-1N rats.Together,these findings implicate that sublytic C5b-9-induced activation of Egr-1/p300–ATF3/Gadd45 axis plays a critical role in GMC apoptosis in Thy-1N rats.

Effect of modified Hangqi Chifeng decoction containing serum on the expression of Col Ⅳ,MMP-2,and TIMP-2 in glomerular mesangial cells induced by LPS

Objective To explore the effect of Modified Hangqi Chifeng Decoction(MHCD)on levels of collagen typeⅣ(ColⅣ),matrix metalloproteinase-2(MMP-2),tissue inhibitor of metalloproteinase-2(TIMP-2)in extracellular matrix(ECM)of glomerular mesangial cells(GMCs)in LPS induced mice.Methods Normal serum and telmisartan,high,medium,low dose MHCD containing

Expression of Nrf2/ARE pathway in diabetic nephropathy and renal protection of Qihuang Bushen Xiezhuo Formula

Objective:To investigate the effect of Qihuang Bushen Xiezhuo Formula on the expression of the nuclear factor E2 related factor 2(Nrf2)/antioxidant response element(ARE)signaling pathway of human glomerular mesangial cells(HMC)in high glucose medium and its protective effect on oxidative stress.Methods:The HMC were cultured in vitro to prepare normal rat serum.The rats were intragastrically administered with irbesartan and Qihuang Bushen Xiezhuo Formula.The serum containing the drugs was prepared after the blood concentration was reached.The rats were divided into the control group,the high glucose group,the irbesartan group and the Qihuang Bushen Xiezhuo Formula group.The HMC of the control group was cultured with normal rat serum(10%serum concentration)medium,while that of the high glucose group was cultured with high glucose medium of rat serum(10%serum concentration).The irbesartan group and the Qihuang Bushen Xiezhuo Formula group were respectively treated with 10%irbesartan and 10%Qihuang Bushen Xiezhuo Formula in serum high glucose medium.After 48 h of culture,the relevant indicators were collected and detected.The mRNA expression levels of Nrf2,gamma-glutamylcysteine synthetase(γ-GCS)and superoxide dismutase(SOD)in each group were detected by real-time PCR.The expressions ofγ-GCS and SOD were detected by immunohistochemistry.The protein expressions ofγ-GCS and SOD in HMC of each group were observed by Western Blot.Results:The expressions of Nrf2,γ-GCS,SOD mRNA and protein in experimental cells of each group were low in the control group,while those in the high glucose group were decreased as compared with the control group(P<0.05).After interference of irbesartan and Qihuang Bushen Xiezhuo Formula the expressions were increased,and the increase in Qihuang Bushen Xiezhuo Formula group was more significant(P<0.05).Conclusion:Qihuang Bushen Xiezhuo Formula can improve HMC oxidative stress injury in high glucose culture,and its mechanism may be achieved by activating Nrf2 and its related downstream proteinsγ-GCS and SOD.