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

OBJECTIVETo explore the mechanism of the protective effects of Panax notoginseng saponins (PNS) on kidney in diabetic rats.

METHODSDiabetic rat model was obtained by intravenous injection of alloxan, and the rats were divided into model, PNS-100 mg/(kg day) and PNS-200 mg/(kg day) groups, 10 each. Another 10 rats injected with saline were served as control. Periodic acid-Schiff staining and immunological histological chemistry were used to observe histomorphology and tissue expression of bone morphogenetic protein-7 (BMP-7). Silent information regulator 1 (SIRT1) was silenced in rat mesangial cells by RNA interference. The mRNA expressions of SIRT-1, monocyte chemoattractant protein-1 (MCP-1), transforming growth factor β1 (TGF-β1) and plasminogen activator inhibitor-1 (PAI-1) were analyzed by reverse transcription polymerase chain reaction. The protein expressions of SIRT1 and the acetylation of nuclear factor κB (NF-κB) P65 were determined by western blotting. The concentration of MCP-1, TGF-β1 and malondialdehyde (MDA) in culture supernatant were detected by enzyme-linked immuno sorbent assay. The activity of superoxide dismutase (SOD) was detected by the classical method of nitrogen and blue four.

RESULTSIn diabetic model rats, PNS could not only reduce blood glucose and lipid (P<0.01), but also increase protein level of BMP-7 and inhibit PAI-1 expression for suppressing fibrosis of the kidney. In rat mesangial cells, PNS could up-regulate the expression of SIRT1 (P<0.01) and in turn suppress the transcription of TGF-β1 (P<0.05) and MCP-1 (P<0.05). PNS could also reverse the increased acetylation of NF-κB p65 by high glucose. In addition, redox regulation factor MDA was down-regulated (P<0.05) and SOD was up-regulated (P<0.01), which were both induced by SIRT1 up-regulation.

CONCLUSIONSPNS could protect kidney from diabetes with the possible mechanism of up-regulating SIRT1, therefore inhibiting inflammation through decreasing the induction of inflammatory cytokines and TGF-β1, as well as activating antioxidant proteins.

Acetylation ; drug effects ; Animals ; Antioxidants ; metabolism ; Blood Glucose ; metabolism ; Bone Morphogenetic Protein 7 ; metabolism ; Chemokine CCL2 ; metabolism ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; genetics ; physiopathology ; Gene Knockdown Techniques ; Immunohistochemistry ; Kidney ; drug effects ; pathology ; Kidney Function Tests ; Lipids ; blood ; Male ; Malondialdehyde ; metabolism ; Mesangial Cells ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Panax notoginseng ; chemistry ; Plasminogen Activator Inhibitor 1 ; genetics ; metabolism ; Protective Agents ; pharmacology ; therapeutic use ; Rats, Sprague-Dawley ; Saponins ; pharmacology ; therapeutic use ; Sirtuin 1 ; genetics ; Superoxide Dismutase ; metabolism ; Transcription Factor RelA ; metabolism ; Transcription, Genetic ; drug effects ; Transforming Growth Factor beta1 ; metabolism ; Up-Regulation ; drug effects

OBJECTIVETo investigate the effect of Xuezhikang (, XZK) on renal cell apoptosis in diabetic rats and the possible mechanism.

METHODSSixty-six rats were randomly divided into 3 groups: the normal, model and XZK groups. In each group, the rats were further randomly divided into 3-month and 6-month subgroups, respectively. Diabetes of rats was induced by a single intraperitoneal injection of 1% streptozocin at 60 mg/kg body weight. Rats in the XZK group received gastric perfusion of XZK (1200 mg/kg body weight) everyday for 3 or 6 months, while rats in the normal and model groups received equal volume of saline. Twenty-four hours' urine was collected for urinary albumin excretion (UAE) measurement. Periodic acid-Schiff (PAS) and Masson's trichrome staining were used for saccharides and collagen detection. Cell apoptosis of renal cortex was investigated by TdT-mediated dUTP nick end labeling (TUNEL) staining. Bax and Bcl-2 expressions were detected by immunohistochemistry and Western blot, respectively. Cytochrome C (Cyt C) and caspase-9 concentration were detected by Western blot.

RESULTSCompared with the model group, XZK treatment could significantly decrease the kidney hypertrophy index, 24 h UAE, renal cell apoptosis, cytoplasmic Cyt C level and active caspase-9 level, as well as suppress the increment of Bax and up-regulate the expression of Bcl-2, leading to the suppression of Bax/Bcl-2 ratio at 3 and 6 months (P<0.05 or P<0.01). Moreover, XZK treatment could alleviate the deposition of PAS-stained saccharides and Masson's trichromestained collagen to different extent.

CONCLUSIONSRenal cell apoptosis was observed in diabetic kidney, in which mitochondrial apoptotic pathway might be involved. XZK treatment could attenuate pathological changes in diabetic kidney and reduce renal cell apoptosis, probably via the suppression of Bax/Bcl-2 ratio, which lead to inhibition of Cyt C release and following caspase-9 activation.

Albuminuria ; blood ; complications ; Animals ; Apoptosis ; drug effects ; Blood Glucose ; metabolism ; Caspase 9 ; metabolism ; Cytochromes c ; metabolism ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; metabolism ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hypertrophy ; In Situ Nick-End Labeling ; Kidney ; drug effects ; pathology ; Kidney Glomerulus ; pathology ; Lipids ; blood ; Male ; Mesangial Cells ; drug effects ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats, Sprague-Dawley ; Streptozocin ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo explore effects of exendin-4 on the metabolism of extracellular matrix (ECM) in human mesangial cells (HMC) cultured in the presence of high glucose and explore the possible mechanism.

METHODSHuman mesangial cells (HMC) were treated with exendin-4 under high glucose conditions. The cell proliferation was observed using CCK8 assay, and the expressions of collagen type I, fibronectin, transforming growth factor-β1 (TGFβ1) expression and extracellular signal- regulated kinase (ERK) signaling pathway activity were assessed using Western blotting.

RESULTSExendin-4 inhibited cell proliferation and the expressions of collagen type I, fibronectin and TGFβ1 and reversed ERK phosphorylation in high glucose-induced HMC.

CONCLUSIONExendin-4 can regulate ECM metabolism in HMC cultured in high glucose by inhibiting TGFβ1/ERK pathway, suggesting the beneficial effects of exendin-4 in preventing and treating diabetic nephropathy.

Cell Proliferation ; Cells, Cultured ; Collagen Type I ; metabolism ; Culture Media ; chemistry ; Diabetic Nephropathies ; Extracellular Matrix ; metabolism ; Fibronectins ; metabolism ; Glucose ; chemistry ; Humans ; MAP Kinase Signaling System ; Mesangial Cells ; drug effects ; Peptides ; pharmacology ; Phosphorylation ; Signal Transduction ; Transforming Growth Factor beta1 ; metabolism ; Venoms ; pharmacology

OBJECTIVETo explore the effect of Modified Hangqi Chifeng Decoction (MHCD) on levels of collagen type IV (Col IV), 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.

METHODSNormal serum and telmisartan, high, medium, low dose MHCD containing serums were prepared by using serum pharmacology method. GMCs were cultured in vitro. The proliferation of mesangial cells were induced using LPS as stimulating factor. GMCs were divided into six groups, i.e., the normal group, the model group, the telmisartan group, high, medium and low dose MHCD groups. Col IV content in the supernatant of mesangial cells was detected using ELISA. Protein expressions of MMP-2 and TIMP-2 were detected using Western blot.

RESULTSCompared with the normal group, Col IV content obviously increased in the model group after 72-h LPS stimulation; protein expressions of MMP-2 and TIMP-2 were obviously up-regulated, and MMP-2/TIMP-2 ratio was down-regulated in the model group (P < 0.01). Compared with the model group, Col IV content obviously decreased in high and medium dose MHCD groups and the telmisartan group (P < 0.01); protein expressions of MMP-2 were obviously down-regulated in medium and low dose MHCD groups (P < 0.01, P < 0.05); the protein expression of TIMP-2 was obviously down-regulated in high, medium, low dose MHCD groups and the telmisartan group (P < 0.01). The pro- tein expression of TIMP-2 was obviously lower in the high dose MHCD group than in the low dose MHCD group (P < 0.01). MMP-2/TIMP-2 ratio was obviously up-regulated in the telmisartan group, high and medium dose MHCD groups (P < 0.01).

CONCLUSIONMHCD could regulate disordered MMP-2/TIMP-2 ratio in LPS induced ECM, inhibit excessive production of Col IV in ECM, promote the degradation of ECM, reduce the accumulation of ECM, thereby, delaying the process of glomerular sclerosis.

Animals ; Cells, Cultured ; Collagen Type IV ; metabolism ; Extracellular Matrix ; metabolism ; Kidney Glomerulus ; cytology ; Matrix Metalloproteinase 2 ; metabolism ; Mesangial Cells ; drug effects ; Mice ; RNA, Messenger ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism

OBJECTIVETo study the effects of p38 MAPK signaling pathway and aldose reductase (AR) on the transforming growth factor (TGF)-β1-induced expression of fibronectin (FN).

METHODSHuman mesangial cells (HMCs) were cultured, and transfected with pCDNA3-AR. AR gene silencing was induced by small interfering RNA (siRNA). AR expression in HMCs was examined by immunofluorescence analysis. RT-PCR and real-time PCR were performed to detect the mRNA expression of AR in the HMCs and Western blotting was used to detect the protein expression of AR, FN and p38. AR inhibitors (ARIs), Sorbinil and Zopolrestat were added and co-incubated, followed by addition of TGF-β1. Western blotting was used to document protein expression of FN and p38 mitogen-activated protein kinases (p38 MAPKs) in the HMCs.

RESULTSImmunofluorescence analysis showed a stronger expression of AR in HMCs transfected with AR than that of normal HMCs and HMCs transfected with blank vector. In comparison with normal HMCs and those transfected with blank vector, HMCs transfected with AR showed stronger protein expression of FN (P<0.05). After incubation of ARIs, protein expression of FN decreased in HMCs transfected with AR (P<0.05). After stimulation of TGF-β1, FN protein expression increased in both normal HMCs and those transfected with AR (P<0.05). After preincubation with ARI, FN protein expression in HMCs transfected decreased significantly (P<0.05). After stimulation of TGF-β1, naïve HMCs showed increased expression of phosphor-p38. In contrast, HMCs preincubated with ARIs showed reduced expression of phosphor-p38, and HMCs transfected with AR showed increased expression of phosphor-p38 (P<0.05).

CONCLUSIONSAR regulates the expression of FN through the stimulation of TGF-β1, which may involve the activation of p38-MAPK signaling pathway. AR may play a role in the pathogenesis of glomerulosclerosis.

Aldehyde Reductase ; metabolism ; Cells, Cultured ; Fibronectins ; metabolism ; Humans ; MAP Kinase Signaling System ; Mesangial Cells ; metabolism ; RNA, Small Interfering ; Real-Time Polymerase Chain Reaction ; Transfection ; Transforming Growth Factor beta1 ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; metabolism

PURPOSE: The aim of this study was to examine the effects of all-trans retinoic acid (ATRA) on diabetic nephropathy. MATERIALS AND METHODS: We measured amounts of urinary albumin excretion (UAE) after administrating ATRA to Otsuka Long-Evans Tokushima Fatty (OLETF) rats. In order to understand the mechanism of action for ATRA, we administrated ATRA to examine its inhibitory action on the production of transforming growth factor-beta1 (TGF-beta1), protein kinase C (PKC), and reactive oxidative stress (ROS) in cultured rat mesangial cells (RMCs). RESULTS: After 16 weeks of treatment, UAE was lower in the ATRA-treated OLETF rats than in the non-treated OLETF rats (0.07+/-0.03 mg/mgCr vs. 0.17+/-0.15 mg/mgCr, p<0.01). After incubation of RMCs in media containing 30 or 5 mM of glucose, treatment with ATRA showed time- and dose-dependent decreases in TGF-beta1 levels and ROS. Moreover, ATRA treatment showed a dose-dependent decrease in PKC expression. CONCLUSION: ATRA treatment suppressed UAE and TGF-beta1 synthesis, which was mediated by significant reductions in PKC activity and ROS production. Our results suggest that ATRA has a potential therapeutic role for diabetic nephropathy.
Animals ; Diabetes Mellitus, Type 2/*complications ; Diabetic Nephropathies/*complications/*drug therapy/pathology ; Mesangial Cells/*metabolism ; Oxidative Stress/drug effects ; Rats ; Rats, Inbred OLETF ; Reactive Oxygen Species/metabolism ; Transforming Growth Factor beta1/analysis/pharmacology ; Tretinoin/*pharmacology/therapeutic use

OBJECTIVETo study the effect of Tangshenkang Granule (TG) containing serum on renal mesangial cells' (RMCs) proliferation and TGF-β1/Smad2/3 pathway in the high glucose condition.

METHODSTwelve SD rats were randomly divided into four groups, i.e., the low dose TG group, the middle dose TG group, the high dose TG group, and the blank control group, 3 in each group. After 7-day gastrogavage via portal vein blood, rats were sacrificed and their serum samples were collected. RMCs were cultured in common rat serum and TG containing serum respectively. The proliferation of mesangial cells was determined by methly thiazolyl tetrazolium (MTT) assay to determine the optimal TG containing serum concentration. Expression levels of TGF-β1 mRNA and protein were determined by real time quantitative PCR and ELISA. Smad2/3 protein expression and phosphorylation were determined by Western blot and immunofluorescence.

RESULTSTG containing serum at different doses could inhibit high glucose induced RMC cells' proliferation, TGF-β1 over-expression and Smad2/3 phosphorylation.

CONCLUSIONTG containing serum could inhibit high glucose induced RMC cells' proliferation, and its mechanism might be possibly associated with inhibiting TGF-β1/Smad2/3 signaling pathway.

Animals ; Cell Proliferation ; Drugs, Chinese Herbal ; pharmacology ; Glucose ; Mesangial Cells ; Phosphorylation ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Serum ; Signal Transduction ; Smad2 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism

BACKGROUNDThe 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).

METHODSMCs 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. Western 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.

RESULTSAfter 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 partly contribute to its reno-protection.

AMP-Activated Protein Kinases ; metabolism ; Animals ; Cells, Cultured ; Glomerular Mesangium ; cytology ; Glucose ; pharmacology ; Mesangial Cells ; drug effects ; metabolism ; Metformin ; pharmacology ; NF-kappa B ; metabolism ; Rats

OBJECTIVETo investigate the effects of advanced glycosylation end products (AGEs) modified bovine serum albumin (AGE-BSA) on the expression of reactive oxygen species (ROS) and monocyte chemoattractant protein-1 (MCP-1) in human renal mesangial cells (HRMCs).

METHODSHRMCs were cultured in vitro with medium containing different doses of AGE-BSA or BSA (50,100, 200, 400 mg/L) for 48 hours, or with AGE-BSA (200 mg/L) for different times (12, 24, 48, 72 h). Immunocytochemistry assay was used to estimate the protein level of RAGE. The ROS in cells were measured by flow cytometry and the mRNA expression of MCP-1 were analyzed by semi-quantiative reverse transcription-polymerase chain reaction (RT-PCR) after treatment with AGE-BSA or BSA.

RESULTSThe protein level of RAGE was upregulated in the HRMCs with AGE-BSA. The expression of ROS and MCP-1 significantly enhanced by incubation of AGE-BSA in a time- and dose-dependent manner. The effects of AGE-BSA-induced up-regulation of ROS and MCP-1 level was significantly blocked by neutralizing antibodies to RAGE, while the expression of ROS and MCP-1 stood nearly unchanged after cultured with huamn IgG.

CONCLUSIONThe expression of ROS and MCP-1 in HRMCs is induced by AGE-BSA through RAGE, which may have potential effects in the pathgenic mechanism of diabetic nephropathy.

Cells, Cultured ; Chemokine CCL2 ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans ; Mesangial Cells ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Serum Albumin, Bovine ; pharmacology