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, 20 µmol/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.
Animals ; Rats ; Lipopolysaccharides/pharmacology* ; Mesangial Cells ; Resveratrol/pharmacology* ; Transcription Factor AP-1 ; Transforming Growth Factor beta1 ; Intercellular Signaling Peptides and Proteins ; Cell Proliferation ; DNA ; Cells, Cultured

OBJECTIVE: To investigate the effect of miR-324-5p on the proliferation of rat glomerular mesangial (HBZY-1) cells and the role of Syk/Ras/c-fos signaling pathway in mediating this effect. METHODS: HBZY-1 cells cultured in vitro were transiently transfected with miR-324-5p mimics or miR-324-5p-mimics-NC followed by treatment with lipopolysaccharide (LPS). MTT assay was used to detect the proliferation activity of HBZY-1 cells, and RT-qPCR was used to detect the expressions of miR-324-5p and the mRNA expressions of Syk, Ras, MEK1/2, ERK1/2 and c-fos mRNA. The protein expressions of p-Syk, Ras, p-MEK1/2, p-ERK1/2 and c-Fos were detected by Western blotting and immunofluorescence assay. RESULTS: MTT assay showed that exposure to LPS significantly enhanced the proliferative activity of HBZY-1 cells. Compared with the cells treated with LPS and LPS + mimics NC, the cells transfected with miR-324-5p mimics prior to LPS exposure exhibited significantly lowered proliferative activity. Transfection with miR-324-5p mimics significantly lowered the mRNA expressions of Syk, Ras, MEK1/2, ERK1/2 and c-fos and the protein expressions of p-Syk, Ras, MEK1/2, ERK1/2 and c-Fos ( CONCLUSIONS miR-324-5p can inhibit the proliferation of rat chronic glomerulonephritis cells induced by LPS by inhibiting Syk/Ras/c-fos signaling pathway and may potentially serve as a diagnostic indicator and a therapeutic target for chronic glomerulonephritis.
Animals ; Cell Proliferation ; Lipopolysaccharides ; Mesangial Cells ; MicroRNAs/genetics* ; Proto-Oncogene Proteins c-fos ; Rats ; Receptor Protein-Tyrosine Kinases ; Signal Transduction ; ras Proteins

Systemic lupus erythematosus (SLE), an autoimmune disease of unknown etiology, is characterized by the production of autoantibodies and end-organ damage. Lupus nephritis affects up to 70% of patients with SLE and is the most critical predictor of morbidity and mortality. The immunopathogenesis of SLE is complex and most clinical trials of biologics targeting immune cells or their mediators have failed to show efficacy in SLE patients. It has therefore become increasingly clear that additional, local factors give rise to the inflammation and organ damage. In this review, we describe recent advances in the role of renal resident cells, including podocytes, mesangial cells, and epithelial cells, in the pathogenesis of lupus nephritis.
Autoantibodies ; Autoimmune Diseases ; Biological Products ; Epithelial Cells ; Humans ; Inflammation ; Lupus Erythematosus, Systemic ; Lupus Nephritis* ; Mesangial Cells ; Mortality ; Podocytes

The aim of this paper was to explore the effects and possible mechanisms in vitro of tea polyphenols (TP) delaying human glomerular mesangial cells (HGMCs) senescence induced by high glucose (HG). HGMCs were cultured in vitro and divided into the normal group (N, 5.5 mmol·L⁻¹ glucose), the mannitol group(MNT, 5.5 mmol·L⁻¹ glucose plus 24.5 mmol·L⁻¹ mannitol), the high dose of D-glucose group (HG, 30 mmol·L⁻¹ glucose), the low dose of TP group (L-TP, 30 mmol·L⁻¹ glucose plus 5 mg·L⁻¹ TP) and the high dose of TP group (H-TP, 30 mmol·L⁻¹ glucose plus 20 mg·L⁻¹ TP), which were cultured in 5% CO₂ at 37 °C, respectively. Firstly, the effects of TP on the cell morphology of HGMCs were observed after 72 h-intervention. Secondly, the cell cycle, the positive rate of senescence-associated-β-galactosidase (SA-β-gal) staining and the telomere length were detected, respectively. Finally, the protein expressions of p53, p21 and Rb in the p53-p21-Rb signaling pathway were investigated, respectively. And the expressions of p-STAT3 and miR-126 were examined severally. The results indicated that HG not only arrested the cell cycle in G₁ phase but also increased the positive rate of SA-β-gal staining, and shortened the telomere length. HG led to the protein over-expressions of p53, p21 and Rb and HGMCs senescence by activating the p53-p21-Rb signaling pathway. In addition, L-TP delayed HGMCs senescence by improving the cell cycle G₁ arrest, reducing SA-β-gal staining positive rate and lengthening the telomere length. L-TP reduced the protein over-expressions of p53, P21 and Rb induced by HG and inhibited the telomere-p53-p21-Rb signaling pathway. Moreover, the expression of p-STAT3 was increased and the expression of miR-126 was decreased in HGMCs induced by HG. L-TP reduced the expression of p-STAT3 and increased the expression of miR-126 in HGMCs. In conclusion, HG could induce HGMCs senescence by activating the telomere-p53-p21-Rb signaling pathway in vitro. L-TP could delay HGMCs senescence through regulating STAT3/miR-126 expressions and inhibiting the telomere-p53-p21-Rb signaling pathway activation. These findings could provide the effective interventions in clinic for preventing and treating renal cell senescence in diabetic kidney disease.
Cells, Cultured ; Cellular Senescence ; Cyclin-Dependent Kinase Inhibitor p21 ; Glucose ; Humans ; Mesangial Cells ; MicroRNAs ; Polyphenols ; STAT3 Transcription Factor ; Tea ; Telomere ; Tumor Suppressor Protein p53

OBJECTIVE: To study the effects of astragaloside-IV (As-IV) on the expression of inflammatory factor and proliferation of glomerular mesangial cells (GMCs) induced by angiotensin Ⅱ(AngⅡ). METHODS: The model of diabetic nephropathy(DN) was mimic by angiotensin Ⅱ (10mol/L)inducing GMCs injury. Then the GMCs were treated with As-IV at different concentrations(25,50,100 μmol/L)for 48 hours. The proliferation of GMCs was detected by MTT. The level of reactive oxidative species (ROS) was measured by flow cytometry. The expression of monocyte chemoattractant protein-1(MCP-1) protein in supernatant was detected by enzyme- linked immunosorbent assay (ELISA). The expression of transforming growth factor-β1(TGF-β1) in GMCs was measured by Western blot. RESULTS: Compared with model group, the proliferation of GMCs was inhibited in As-IV group. As-IV decreased the level of intercellular ROS, down-regulated the secretion of MCP-1 and the expression of TGF-β1 proteins. CONCLUSIONS As-IV could inhibit cell proliferation and inflammatory factors expression on GMCs induced by AngⅡ.
Angiotensin II ; Blotting, Western ; Cell Proliferation ; Cells, Cultured ; Diabetic Nephropathies ; Humans ; Mesangial Cells ; Transforming Growth Factor beta1

OBJECTIVES: Stably expressed transforming growth factor -beta 1(TGF-β1)MCs were obtained and the effects of centellaasiatica (CA) granule on the expressions of Smad 2/3, Smad 7 and collagen Ⅳ and the level of Smad 2/3 phosphorylation were observed. METHODS: Lipofectin method was used to transfect TGF-β1 vector into MC, and the stably expressed TGF-β1 cell lines were selected by G418. The cells were divided into three groups. Control group:normal MC + RPMI 1640 + 10% normal rat serum; TGF-β1 group:stably expressed TGF-β1 MC + RPMI 1640 + 10% normal rat serum; CA group:stably expressed TGF-β1 MC + RPMI 1640 + 10% rat serum containing high CA. The experiments were repeated for five times. The contents of TGF-β1 and collagen Ⅳ in the culture medium were detected with ELISA, the expressions of mRNA and protein of TGF-β1, Smad 2/3, Smad 7 and the level of Smad 2/3 phosphorylation were detected by using real time quantitative polymerase chain reaction and Western blot. RESULTS: The contents of TGF-β1 and collagen Ⅳ in the culture medium of stably-expressed TGF-β1 MC were increased significantly, and the CA could reverse the effects of TGF-β1. The expressions of mRNA and protein of TGF-β1, Smad 2/3 and the level of Smad 2/3 phosphorylation were increased significantly in TGF-β1 transfected MC, and CA could dramatically reduce the expressions of mRNA and protein of TGF-β1, Smad 2/3 and the level of Smad 2/3 phosphorylation. The high expression of TGF-β1 decreased the expression of Smad 7 mRNA and protein, and the CA could antagonize the effect of mRNA expression. CONCLUSIONS The MCs stably-expressed TGF-β1 can activate the TGF-β1/Smad signal pathway and increase the expression of collagen Ⅳ. CA can decrease the occurrence of diabetic nephropathy(DN) by reducing the production of collagen Ⅳ through inhibiting the TGF-β1/Smad signal pathway.
Animals ; Cells, Cultured ; Centella ; chemistry ; Collagen Type IV ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Mesangial Cells ; drug effects ; metabolism ; Rats ; Signal Transduction ; Smad Proteins ; metabolism ; Smad2 Protein ; metabolism ; Smad3 Protein ; metabolism ; Smad7 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism

BACKGROUND: Renal tubulointerstitial fibrosis is a common feature of the final stage of nearly all cause types of chronic kidney disease. Although classic peroxisome proliferator-activated receptor γ (PPARγ) agonists have a protective effect on diabetic nephropathy, much less is known about their direct effects in renal fibrosis. This study aimed to investigate possible beneficial effects of lobeglitazone, a novel PPARγ agonist, on renal fibrosis in mice. METHODS: We examined the effects of lobeglitazone on renal tubulointerstitial fibrosis in unilateral ureteral obstruction (UUO) induced renal fibrosis mice. We further defined the role of lobeglitazone on transforming growth factor (TGF)-signaling pathways in renal tubulointerstitial fibrosis through in vivo and in vitro study. RESULTS: Through hematoxylin/eosin and sirius red staining, we observed that lobeglitazone effectively attenuates UUO-induced renal atrophy and fibrosis. Immunohistochemical analysis in conjunction with quantitative reverse transcription polymerase chain reaction and Western blot analysis revealed that lobeglitazone treatment inhibited UUO-induced upregulation of renal Smad-3 phosphorylation, α-smooth muscle actin, plasminogen activator inhibitor 1, and type 1 collagen. In vitro experiments with rat mesangial cells and NRK-49F renal fibroblast cells suggested that the effects of lobeglitazone on UUO-induced renal fibrosis are mediated by inhibition of the TGF-β/Smad signaling pathway. CONCLUSION: The present study demonstrates that lobeglitazone has a protective effect on UUO-induced renal fibrosis, suggesting that its clinical applications could extend to the treatment of non-diabetic origin renal disease.
Actins ; Animals ; Atrophy ; Blotting, Western ; Collagen Type I ; Diabetic Nephropathies ; Fibroblasts ; Fibrosis* ; In Vitro Techniques ; Mesangial Cells ; Mice* ; Peroxisomes* ; Phosphorylation ; Plasminogen Activator Inhibitor 1 ; Polymerase Chain Reaction ; Rats ; Renal Insufficiency, Chronic ; Reverse Transcription ; Transforming Growth Factor beta ; Transforming Growth Factors ; Up-Regulation ; Ureter* ; Ureteral Obstruction*

BACKGROUND/AIMS:: We demonstrated the role of caveolin-1 involved in high glucose (HG)-induced glomerular mesangial cells (GMCs) senescence. METHODS:: HG was used to stimulate GMCs. The telomere lengths were analyzed by Southern blot. β-Galactosidase staining was determined. The expressions of caveolin-1 and P53 proteins were determined by Western blot. RESULTS:: Treatment with high concentrations of glucose induced GMC senescence accompanied by shortened telomere length and increase of β-galactosidase staining as well as P53 protein, which was abrogated after application of caveolin-1-siRNA. CONCLUSIONS:: This study proved that HG induced cell senescence in GMCs. The caveolin-1 is involved in HG-induced mesangial cell senescence, and blocking caveolin-1 significantly reduced cell senescence. The effect of caveolin-1 is mediated by P53 pathway.
Aging* ; Blotting, Southern ; Blotting, Western ; Caveolin 1* ; Cell Aging ; Glucose* ; Humans* ; Mesangial Cells* ; Telomere

The present study aimed to show that pro-inflammatory cytokines [tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-1β] synergistically induce the production of nitric oxide (NO) production in mouse mesangial cells, which play an important role in inflammatory glomerular injury. We also found that co-treatment with cytokines at low doses (TNF-α; 5 ng/ml, IFN-γ; 5 ng/ml, and IL-1β; 1.25 U/ml) synergistically induced NO production, whereas treatment with each cytokine alone did not increase NO production at doses up to 100 ng/ml or 50 U/ml. Silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), attenuates cytokine mixture (TNF-α, IFN-γ, and IL-1β)-induced NO production. Western blot and RT-PCR analyses showed that silymarin inhibits inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Silymarin also inhibited extracellular signal-regulated protein kinase-1 and -2 (ERK1/2) phosphorylation. Collectively, we have demonstrated that silymarin inhibits NO production in mouse mesangial cells, and may act as a useful anti-inflammatory agent.
Animals ; Blotting, Western ; Cytokines ; Interferons ; Interleukins ; Mesangial Cells* ; Mice* ; Milk Thistle ; Necrosis ; Nitric Oxide ; Nitric Oxide Synthase Type II ; Phosphorylation ; Silymarin*

Sodium butyrate (SB) has various metabolic actions. However, its effect on dipeptidyl peptidase 4 (DPP-4) needs to be studied further. We aimed to evaluate the metabolic actions of SB, considering its physiologically relevant concentration. We evaluated the effect of SB on regulation of DPP-4 and its other metabolic actions, both in vitro (HepG2 cells and mouse mesangial cells) and in vivo (high fat diet [HFD]-induced obese mice). Ten-week HFD-induced obese C57BL/6J mice were subjected to SB treatment by adding SB to HFD which was maintained for an additional 16 weeks. In HepG2 cells, SB suppressed DPP-4 activity and expression at sub-molar concentrations, whereas it increased DPP-4 activity at a concentration of 1,000 µM. In HFD-induced obese mice, SB decreased blood glucose, serum levels of insulin and IL-1β, and DPP-4 activity, and suppressed the increase in body weight. On the contrary, various tissues including liver, kidney, and peripheral blood cells showed variable responses of DPP-4 to SB. Especially in the kidney, although DPP-4 activity was decreased by SB in HFD-induced obese mice, it caused an increase in mRNA expression of TNF-α, IL-6, and IL-1β. The pro-inflammatory actions of SB in the kidney of HFD-induced obese mice were recapitulated by cultured mesangial cell experiments, in which SB stimulated the secretion of several cytokines from cells. Our results showed that SB has differential actions according to its treatment dose and the type of cells and tissues. Thus, further studies are required to evaluate its therapeutic relevance in metabolic diseases including diabetes and obesity.
Animals ; Blood Cells ; Blood Glucose ; Body Weight ; Butyric Acid* ; Cytokines ; Diet ; Dipeptidyl Peptidase 4 ; Hep G2 Cells ; In Vitro Techniques ; Insulin ; Interleukin-6 ; Kidney ; Liver ; Mesangial Cells ; Metabolic Diseases ; Mice ; Mice, Obese ; Obesity ; RNA, Messenger ; Sodium*