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.

EFFECTS OF RAPAMYCIN ON INTRACELLULAR CHOLESTEROL HOMEOSTASIS OF GLOMERULAR MESANGIAL CELL IN THE PRESENCE OF INTERLEUKIN-1β

Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β（1L-1β）-induced mRNA and protein changes of low-density lipoprotein receptor （LDLR） and ATP-binding cassette transporter Al （ABCAl） were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin （mTOR）, including mTOR-WT （wild type）, mTOR-RR （rapamycin resistant, with kinase activity）, and mTOR-RR-KD （rapamycin resistant, without kinase activity）, were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR.

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.

Effects of Zao Huang Mixture (藻黄合剂) on the Expressions of TGF-β1 and Col IV in Human Glomerular Mesangial Cells Cultured in High Glucose Environment

Objective: To investigate the effect of Zao Huang Mixture (藻黄合剂ZHM) on expressions of growth factor-β1 (TGF-β1) and collagen IV (Col IV) in human glomerular mesangial cells (GMC) cultured in high-glucose environment. Methods: After primary culture of GMC, in vitro culture was carried out in normal group, high glucose group and high glucose medium with ZHM of different concentrations, and the expressions of TGF-β1 and Col IV in the GMC group and in ZHM group were detected at 24 and 48 h respectively. Results: Compared with the normal group, expressions of TGF-β1 and Col IV significantly increased at 24 h, 48 h in the high glucose group (all P<0.01); Compared with the high glucose group, the expressions of TGF-β1 and Col IV in all the ZHM groups significantly decreased at 24 h, 48 h (P<0.05 or P<0.01). Conclusion: ZHM may modulate the process of diabetic nephropathy by changing the expression of TGF-β1 and Col IV in glomerular mesangial cells.

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

THE LOCALIZATION OF ADRENOMEDULLIN IN RAT KIDNEY TISSUE AND ITS INHIBITORY EFFECT ON THE GROWTH OF CULTURED RAT MESANGIAL CELLS

OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by our laboratory was used to detect the localization of AM protein in rat kidney tissue by avidin-biotin complex immunohistochemistry. The expressions of AM and its receptor CRLR mRNA on cultured glomerular epithelial cells (GEC) and MsC were investigated by Northern blot assay, and the possible effect of AM secreted by GEC on MsC proliferation was observed using [3H]thymidine incorporation as an index. RESULTS: A specific monoclonal antibody against AM was succesfully developed. AM was immunohistochemically localized mainly in glomeruli (GEC and endothelial cells), some cortical proximal tubules, medullary collecting duct cells, interstitial cells, vascular smooth muscle cells and endothelial cells. Northern blot assay showed that AM mRNA was expressed only on cultured GEC, but not on MsC, however, AM receptor CRLR mRNA was only expressed on MsC. GEC conditioned medium containing AM can inhibit MsC growth and AM receptor blocker CGRP8-37 may partially decreased this inhibitory effect. CONCLUSION: AM produced by GEC inhibits the proliferation of MsC, which suggests that AM as an important regulator is involved in glomerular normal physiological functions and pathologic processes.

Porphyromonas gingivalis Induces Chronic Kidney Disease through Crosstalk between the NF-κB/NLRP3 Pathway and Ferroptosis in GMCs

Objective Porphyromonas gingivalis(P.gingivalis)is a gram-negative bacterium found in the human oral cavity and is a recognized pathogenic bacterium associated with chronic periodontitis and systemic diseases,including chronic kidney disease(CKD),but the roles and molecular mechanism of P.gingivalis in CKD pathogenesis are unclear.Methods In this study,an animal model of oral P.gingivalis administration and glomerular mesangial cells(GMCs)cocultured with M1-polarized macrophages and P.gingivalis supernatant were constructed.After seven weeks of P.gingivalis gavaged,peripheral blood was collected to detect the changes in renal function.By collecting the teeth and kidneys of mice,H&E staining and IHC were used to analyze the expression of periodontal inflammatory factors in mice,PAS staining was used to analyze glomerular lesions.The supernatant of macrophages was treated with 5%P.gingivalis supernatant.H&E staining,IHC,Western blot and RT-PCR were applied to analyze renal inflammatory factors,macrophage M1 polarization,NF-κB,NLRP3 and ferroptosis changes in vitro.Results We found that oral P.gingivalis administration induced CKD in mice.P.gingivalis supernatant induced macrophage polarization and inflammatory factor upregulation,which triggered the activation of the NF-κB/NLRP3 pathway and ferroptosis in GMCs.By inhibiting the NF-κB/NLRP3 pathway and ferroptosis in GMCs,cell viability and the inflammatory response were partially alleviated in vitro.Conclusion We demonstrated that P.gingivalis induced CKD in mice by triggering crosstalk between the NFκB/NLRP3 pathway and ferroptosis in GMCs.Overall,our study suggested that periodontitis can promote the pathogenesis of CKD in mice,which provides evidence of the importance of periodontitis therapy in the prevention and treatment of CKD.

Effects of peripheral blood mononuclear cells from idiopathic nephrotic childr en on cultured rat glomerular epithelial and mesangial cells

Objective To investigate the effect of immune cell from idiopathic nephrotic children on extracellular matrix (ECM) synthesis by cultured rat glomerular epithelial cell (GEC) and on the proliferation of mesangial cell (GMC). Methods Twenty-eight children with idiopathic nephrotic syndrome and 15 age-matched healthy children were randomly selected and divided into 4 groups: Group 1, untreated nephrotic children; Group 2, glucocorticoid treated nephrotic children; Group 3, children undergoing glucocorticoid treatment with negative proteinuria; and Group 4, normal control. The peripheral blood mononuclear cells (PBMC) were collected from these children and PBMC conditioned medium (PBMC-CM) were prepared. The PBMC-CM was co-cultured with GEC and GMC respectively. The concentrations of collagen, laminin, collagen Ⅲ and collagen Ⅳ in the GEC and PBMC-CM co-culture medium were investigated. The GMC proliferation was measured by the 3 H-thymidin incorporation method. Results The 3 H-proline incorporation coefficients of the GEC treated with the PBMC-CM of the 4 groups were 0.93, 1.24, 1.23, and 1.11, respectively. The laminin inhibitory coefficients of the 4 groups were 0.95, 1.02, 1.01, and 1.04, respectively. The inhibitory coefficients of collagen Ⅲ were 0.97, 1.00, 0.99, and 1.01, respectively, for the 4 groups. All these parameters showed a significant difference between Group 1 and the other 3 groups (P<0.05). However, there was no significant difference in the inhibitory coefficient of collagen Ⅳ between each two of the 4 groups (1.04, 1.05, 1.04, 1.08, P>0.05). The 3 H-thymidine incorporation coefficients of GMC responsive to PBMC-CM were 1.21, 1.53, 1.50, and 1.10, respectively, and no significant difference was found between the 4 groups (P>0.05). Conclusion The results suggested that the circulating immune cells from idiopathic nephrotic children have a direct effect on some ECM component synthesis in cultured rat GEC; the bio-activity of immune cells could be neutralized by administering glucocorticoid; and the circulating immune cells of nephrotic children have no direct effect on GMC proliferation.

TypeⅠinositol 1, 4, 5-triphosphate receptors increase in kidney of mice with fulminant hepatic failure

AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant hepatic failure （FHF）. METHODS： FHF was induced by lipopolysaccharide （LPS） in D-galactosamine （GAIN） sensitized BALB/c mice. There were 20 mice in normal saline （NS）-treated group, 20 mice in LPS-treated group, 20 mice in GaIN- treated group, and 60 mice in GalN/LPS-treated group （FHF group）. Liver and kidney tissues were obtained at 2, 6, and 9 h after administration. The liver and kidney specimens were stained with hematoxylin-eosin for studying morphological changes under light microscope. The expression of IP3R I in kidney tissue was tested by immunohistochemistry, Western blot and reverse transcription （RT）-PCR. RESULTS： Kidney tissues were morphologically normal at all time points in all groups. IP3R I proteins were found localized in the plasma region of glomerular mesangial cells （GMC） and vascular smooth muscle cells （VSMC） in kidney by immunohistochemical staining. In kidney of mice with FHF at 6 h and 9 h IP3R I staining was upregulated. Results from Western blot demonstrated consistent and significant increment of IP3R I expression in mice with FHF at 6 h and 9 h （t = 3.16, P 〈 0.05; t = 5.43, P 〈 0.01）. Furthermore, we evaluated IP3R I mRNA expression by RT-PCR and observed marked upregulation of IP3R I mRNA in FHF samples at 2 h, 6 h and 9 h compared to controls （t = 2.97, P 〈 0.05; t = 4.42, P 〈 0.01; t = 3.81, P 〈 0.01）. CONCLUSION： The expression of IP3R I protein increased in GMC and renal VSMC of mice with FHF, possibly caused by up-regulation of IP3R I mRNA.

High expression of type I inositol 1,4,5-trisphosphate receptor in the kidney of rats with hepatorenal syndrome

AIM To detect the expression of typeⅠ inositol 1,4,5-trisphosphate receptor(IP3 RI) in the kidney of rats with hepatorenal syndrome(HRS).METHODS One hundred and twenty-five Sprague-Dawley rats were randomly divided into four groups to receive an intravenous injection of D-galactosamine(D-Gal N) plus lipopolysaccharide(LPS; group G/L, n = 50), D-Gal N alone(group G, n = 25), LPS alone(group L, n = 25), and normal saline(group NS, n = 25), respectively.At 3, 6, 9, 12, and 24 h after injection, blood, liver, and kidney samples were collected. Hematoxylineosin staining of liver tissue was performed to assess hepatocyte necrosis. Electron microscopy was used to observe ultrastructural changes in the kidney. Western blot analysis and real-time PCR were performed to detect the expression of IP3 RI protein and m RNA in the kidney, respectively.RESULTS Hepatocyte necrosis was aggravated gradually, which was most significant at 12 h after treatment with D-galactosamine/lipopolysaccharide, and was characterized by massive hepatocyte necrosis. At the same time, serum levels of biochemical indicators including liver and kidney function indexes were all significantly changed. The structure of the renal glomerulus and tubules was normal at all time points. Western blot analysis indicated that IP3 RI protein expression began to rise at 3 h(P < 0.05) and peaked at 12 h(P < 0.01). Real-time PCR demonstrated that IP3 RI m RNA expression began to rise at 3 h(P < 0.05) and peaked at 9 h(P < 0.01).CONCLUSION IP3 RI protein expression is increased in the kidney of HRS rats, and may be regulated at the transcriptional level.

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.