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 study the clinicopathologic features of collagen III glomerulopathy and its cause, pathogenesis and prognosis.

METHODSFive cases of collagen III glomerulopathy that collected from 2005 to 2014 were observed by renal biopsy. The morphologic characteristics were studied by light microscopy, immunofluorescence, immunohistochemical and electron microscopy.

RESULTSThe glomerular mesangium became expansion but no hypercellularity, basement membrane appeared thickened. The glomeruli showed collagen type III deposit by immunohistochemistry method, and collagen fibers increased by electron microscopy. The patients often show serious proteinuria, nephrotic syndrome and renal function damage.

CONCLUSIONSCollagen III glomerulopathy is an idiopathic glomerular disease, characterized by massive accumulation of collagen type III within the glomerular mesangial areas and basement membrane. Collagen III glomerulopathy is extremely rare. The etiology and pathogenesis may relate to the abnormality of collagen III gene. There is no specific treatment for it and its prognosis is poor.

Basement Membrane ; metabolism ; Biopsy ; Collagen Type III ; genetics ; metabolism ; Female ; Fluorescent Antibody Technique ; Glomerular Mesangium ; metabolism ; Humans ; Immunohistochemistry ; Kidney Diseases ; etiology ; pathology ; Kidney Glomerulus ; pathology ; Microscopy, Electron ; Prognosis ; Proteinuria ; diagnosis

OBJECTIVETo explore effects of beraprost sodium (BPS) on the metabolism of extracellular matrix (ECM) in rat mesangial cells cultured in the presence of high glucose and the possible mechanism.

METHODSRat mesangial cells were cultured in the presence of high glucose with or without BPS for 24 or 48 h. The levels of transforming growth factor β1 (TGFβ1), fibronectin (FN) and matrix metalloproteinase-2 (MMP-2) protein in the culture supernatants were measured by enzyme-linked immunosorbent assay, and photoshop-Smad3 was detected by Western blotting.

RESULTSCompared with the cells in normal glucose, the cells cultured in the presence of high glucose for 24 and 48 h showed significantly increased TGFβ 1 and FN protein expression and lowered MMP-2 protein expression (P<0.01). Compared with the cells cultured in high glucose, BPS exposure at the concentration of 1, 2, and 5 µmol/L for 24 and 48 h significantly lowered TGFβ 1 protein expression (P<0.01), and at 2 and 5 µmol/L, BPS significantly decreased FN protein expression and increased MMP-2 protein expression in high glucose-induced cells (P<0.05). High glucose exposure also significantly increased the expression phosphorylated Smad3 (P<0.01), which was lowered by BPS treatment at 2 and 5 µmol/L (P<0.01).

CONCLUSIONBPS can regulate ECM metabolism in rat mesangial cells cultured in high glucose by inhibiting TGFβ 1/Smad3 pathway, suggesting the beneficial effects of BPS in preventing and treating diabetic nephropathy.

Animals ; Cell Line ; Cells, Cultured ; Diabetic Nephropathies ; Enzyme-Linked Immunosorbent Assay ; Epoprostenol ; analogs & derivatives ; pharmacology ; Extracellular Matrix ; metabolism ; Fibronectins ; metabolism ; Glomerular Mesangium ; cytology ; Glucose ; Matrix Metalloproteinase 2 ; metabolism ; Mesangial Cells ; drug effects ; Rats ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo study the effects and possible underlying mechanism of Qufeng Tongluo Prescription (, QFTL) on the regulation of mesangial cells (MCs) proliferation and apoptosis.

METHODSThe MCs used in this experiment have undergone five passages induced by lipopolysaccharide (LPS). Changes in the proliferation, apoptosis, cell cycle regulatory proteins and mRNA expression levels of the MCs after administration of Benazepril or QFTL were measured by methyl thiazolyl tetrazolium (MTT) reduction assay, flow cytometry, Western blot and quantitative real-time polymerase chain reaction (qRT-PCR), respectively.

RESULTSThe addition of Benazepril or QFTL serum inhibited LPS-induced MC proliferation after treatment for 24, 48 and 72 h, respectively (P<0.05 or P<0.01). Moreover, the inhibitory effect is more significant in the QFTL group at 48 h (P<0.05). Compared with the control group, LPS-induced cell proliferation decreased the number of cells in G1 phase versus cells in S and G2/M phases, while the addition of QFTL and Benazepril serum increased the ratio of cells at G1 phase (P<0.05 or P<0.01) to cells at S phase (P<0.01), implicating the cell cycle inhibition effect exerted by QFTL. LPS decreased the level of MC apoptosis, compared with the control group (P<0.05), while QFTL and Benazepril serum increased the level of MC apoptosis (P<0.01). Moreover, the difference between the QFTL group and the Benazepril group was statistically significant (P<0.01). Compared with the control group, the protein and mRNA expression levels of cylinD1, cyclin dependent kinase 2 (CDK2) and p21 were significantly increased (P<0.05 or P<0.01), p27 was decreased but with no statistical significance (P>0.05); After being treated with QFTL and Benazepril serum, the protein and mRNA expression levels of cylinD1, CDK2, p21 were decreased and p27 increased significantly (P<0.05 or P<0.01); Compared with the Benazepril group, QFTL show better effects on protein and mRNA expression levels of cylinD1, CDK2 (P<0.05 or P<0.01) and p21 protein expression (P<0.05).

CONCLUSIONQFTL inhibits MCs proliferation, promotes MCs apoptosis through an underlying mechanism of down-regulating the protein and mRNA expression levels of cylinD1, CDK2, p21 and up-regulation of the expression level of p27.

Animals ; Apoptosis ; drug effects ; Base Sequence ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; genetics ; metabolism ; Cell Proliferation ; drug effects ; DNA Primers ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Glomerular Mesangium ; cytology ; drug effects ; metabolism ; Male ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the effect of exendin-4 on the expression of monocyte chemoattractant protein-1 (MCP-1) and fibronectin (FN) in rat glomerular mesangial cells in vitro.

METHODSRat glomerular mesangial cells were divided into 5 groups, namely control group, tumor necrosis factor-α (TNF-α) group (10 ng/ml), TNF-α (10 ng/ml)+E1 (1 nmol/L exendin-4) group, TNF-α (10 ng/ml)+E5 (5 nmol/L exendin-4) group, and TNF-α (10 ng/ml)+E10 (10 nmol/L exendin-4) group. After cultured 24 h or 48 h, RNA were extracted to determine the expression of MCP-1 with real-time PCR, the supernatant were collected to determine the expression of MCP-1 and FN with ELISA.

RESULTSCompared with control group, the cells treated with TNF-α for 24 h showed significantly increase the expression of MCP-1 and FN (P<0.01), exendin-4 significantly reduced the expression of MCP-1 and FN in TNF-α+E5 group and TNF-α+E10 group (P<0.05). After 48h incubation, the expression of MCP-1 and FN increased significantly in TNF-α group (P<0.01), which was lowered by exendin-4 in TNF-α+E1,TNF-α+E5 and TNF-α+E10 groups (P<0.05).

CONCLUSIONExendin-4 has an intrinsic capability to concentration- and time-dependently inhibit TNF-α-induced expression of MCP-1 and FN in rat mesangial cells, suggesting the beneficial effect of exendin-4 in preventing and treating diabetic nephropathy.

Animals ; Cells, Cultured ; Chemokine CCL2 ; metabolism ; Diabetic Nephropathies ; metabolism ; Glomerular Mesangium ; cytology ; Mesangial Cells ; drug effects ; metabolism ; Peptides ; pharmacology ; Rats ; Tumor Necrosis Factor-alpha ; pharmacology ; Venoms ; pharmacology

OBJECTIVETo investigate whether FTY720 inhibits rat mesangial proliferation and extracellular matrix expansion through suppression of transforming growth factor β1-connective tissue growth factor (TGFβ1-CTGF) pathway, and to explore experimental evidence for its effect on mesangial proliferative glomerulonephritis.

METHODSA rat model of anti-Thy-1 mesangial proliferative glomerulonephritis was established and FTY720 intervention was performed. Periphery blood lymphocyte count, urine protein excretion, glomerular mesangial proliferation, protein and gene expression of TGFβ1 and CTGF and extracellular matrix protein including fibronectin, laminin and collagen IV in isolated glomeruli were documented at 1, 3 and 7 days after injection of anti-Thy-1 antibody.

RESULTSThe model group developed proteinuria at 1, 3 and 7 days after injection of anti-Thy-1 antibody, which were significantly higher [(27.9 ± 7.3), (63.5 ± 18.8) and (52.4 ± 15.4)mg/d, respectively] than those in the control group [(8.4 ± 2.4), (8.4 ± 2.1) and (10.4 ± 3.2) mg/d; respectively, P < 0.01]. FTY720 intervention group showed significantly decreased proteinuria at 3 and 7 days after injection [(31.4 ± 7.0), (25.5 ± 7.7) mg/d, respectively] than model group (P < 0.01), although higher than the control group (P < 0.01). After intervention for 3 and 7 days, FTY720 significantly down-regulated both TGFβ1 and CTGF gene and protein expression in cultured glomeruli, and suppressed the production of glomerular extracellular matrix protein secretion, leading to attenuated mesangial cell proliferation and extracellular matrix expansion in rat anti-Thy-1 mesangial proliferative glomerulonephritis.

CONCLUSIONFTY720 significantly attenuates mesangial proliferation and extracellular matrix expansion through inhibition of TGFβ1-CTGF pathway in rat, and thus ameliorates the development of anti-Thy-1 mesangial proliferative glomerulonephritis.

Animals ; Cell Proliferation ; Connective Tissue Growth Factor ; genetics ; metabolism ; Down-Regulation ; Extracellular Matrix Proteins ; metabolism ; Fingolimod Hydrochloride ; Gene Expression ; Glomerular Mesangium ; metabolism ; pathology ; Glomerulonephritis, Membranoproliferative ; immunology ; metabolism ; pathology ; Immunosuppressive Agents ; pharmacology ; Isoantibodies ; immunology ; Kidney Glomerulus ; metabolism ; pathology ; Male ; Propylene Glycols ; pharmacology ; Proteinuria ; urine ; Rats ; Rats, Wistar ; Signal Transduction ; drug effects ; Sphingosine ; analogs & derivatives ; pharmacology ; Thy-1 Antigens ; immunology ; Transforming Growth Factor beta1 ; genetics ; metabolism

OBJECTIVETo investigate the effects of rapamycin and 3-methyladenine on autophagy impairment, oxidative stress and premature senescence induced by high-glucose in primarily cultured rat mesangial cells.

METHODSRat glomerular mesangial cells (GMCs) were isolated and cultured in normal glucose, high glucose, high glucose with 3-methyladenine (3-MA), or high glucose with rapamycin. At 24 h, 72 h and 10 days of culture, the cells were examined for expression levels of autophagy markers LC3 and p62/SQSTM1, malondialdehyde (MDA) and protein carbonyl, β-galactosidase (SA-β-gal) activity and heterochromatin foci (SAHF).

RESULTSCompared with those of normal cell culture, the cells exposed to high glucose for 72 h and 10 days showed down-regulated LC3 expression, up-regulated p62/SQSTM1 expression, elevated MDA and protein carbonyl levels, and increased SAHF formation and percentage of SA-β-gal-positive cells. These changes were reversed in GMCs exposed to high glucose and rapamycin for 72 h and 10 days, but exacerbated in cells incubated with 3-MA.

CONCLUSIONHigh glucose can suppress autophagic function of rat GMCs to result in oxidative damage and cell senescence. Rapamycin can attenuate autophagy impairment, oxidative damage and senescence induced by high glucose, whereas 3-MA can further aggravate high glucose-induced cell injuries in rat GMCs.

Animals ; Autophagy ; drug effects ; Cells, Cultured ; Cellular Senescence ; drug effects ; Glomerular Mesangium ; cytology ; Glucose ; adverse effects ; Male ; Mesangial Cells ; cytology ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Sirolimus ; pharmacology

OBJECTIVETo observe the effects of Shensu II Recipe on the renal function, mesangial extracellular matrix (ECM) accumulation, the expressions of transforming growth factor-beta1, (TGF-beta1), and plasminogen activator inhibitor-1 (PAI-1) in the focal segmental glomerulosclerosis (FSGS) rats.

METHODSFSGS SD rat model was induced by injecting adriamycin. They were randomly divided into the model group, the Western medicine group, and the Chinese medicine group according to body weight. Besides, another 12 rats was taken as the blank control group. Of them, benazepril (0.33 mg/100 g) was given to rats in the Western medicine group by gastrogavage, while Shensu II Recipe (3.5 g/100 g) was given to rats in the Chinese medicine group by gastrogavage. Normal saline was given to rats in the control group and the model group by gastrogavage. Six rats died during the experiment process, among which, one in the control group, two in the model group, one in the Western medicine group, and two in the Chinese medicine group. The changes of 24 h urinary protein (24 hU, pyrogallol red method), blood urea nitrogen (BUN, urease method), serum creatinine (SCr, enzymatic assay of creatinine), serum total protein (TP, biuret colorimetry), serum albumin (ALB, bromocresol green colormetry) were detected. The pathomorphological changes of the glomerulus were observed. Fibronection (FN), collagen IV (Col IV), glomerulus sclerosis index (GSI), ECM/glomerulus area (GA), expressions of TGF-beta1, and PAI-1 were determined by semi-quantitative analysis.

RESULTSAt the end of the 12th week, improvement was shown in the Chinese medicine group (24 hU: 38.55 +/- 2.49 mg; BUN:10.87 +/- 1.78 mmol/L; SCr: 51.70 +/- 1.50 micromol/L; TP: 68.28 +/- 2.31 g/L; and ALB: 42.43 +/- 1.95 g/L). The pathomorphological observation showed that the development of glomerulosclerosis (GS) was significantly slowed down. Semi-quantitative analysis showed significant difference when compared with the model group (GSI: 1.68 +/- 0.33 grade; ECM/GA: 7.11% +/- 2.46%; FN: 4.15% +/- 1.55%; Col IV:1.47% +/- 0.48%; TGF-beta1:19.70% +/- 5.05%; PAI-1: 22.57% +/- 10.65%) ( P < 0.05, P < 0.01).

CONCLUSIONShensu II Recipe could postpone the development of GS in FSGS rats possibly through inhibiting the expressions of TGF-beta1 and PAI-1, hindering the over-accumulation of mesangial matrix.

Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Extracellular Matrix ; drug effects ; Glomerular Mesangium ; drug effects ; Glomerulosclerosis, Focal Segmental ; drug therapy ; metabolism ; Male ; Plasminogen Activator Inhibitor 1 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism

The aim of this study was to investigate whether green tea extract (GTE) has the protective effects on excess L-arginine induced toxicity in human mesangial cell. Human mesangial cells treated with L-arginine were cultured on Dulbecco's modified eagle medium in the presence and absence of inducible nitric oxide synthase (iNOS) inhibitor and GTE. The cell proliferation was determined by 3 (4,5-dimethylthiazol- 2-yl)-2, 5-diphengltetrqzolium bromide, a tetrazole assay. The iNOS mRNA and its protein expression were detected by reverse transcription polymerase chain reaction and Western blot, respectively. The concentration of nitric oxide (NO) was measured by NO enzyme-linced immuno sorbent assay kit. L-arginine significantly inhibited the proliferation of human mesangial cells, and induced the secretion of NO to the media. NO production by L-arginine was significantly suppressed by GTE and iNOS inhibitor (p<0.01). The expression level of iNOS mRNA and its protein that was significantly increased by L-arginine was decreased by iNOS inhibitor but not by GTE. GTE protected the mesangial cells from the NO-mediated cytotoxicity by scavenging the NO rather than by iNOS gene expression. Therefore, we conclude that GTE has some protective effect for renal cells against oxidative injury possibly by polyphenols contained in GTE.
Antioxidants/metabolism ; Arginine/metabolism/pharmacology/*toxicity ; Cell Line ; Cell Proliferation ; Cell Survival ; Flavonoids/metabolism ; Glomerular Mesangium/cytology/metabolism ; Humans ; Mesangial Cells/*cytology/metabolism ; Nitric Oxide/chemistry/metabolism ; Nitric Oxide Synthase Type II/metabolism ; Phenols/metabolism ; RNA, Messenger/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tea

OBJECTIVETo study the clinicopathologic features of membranous nephropathy coexisting with IgA nephropathy.

METHODSThe renal biopsies performed in Peking University First Hospital during the period from January, 1998 to April, 2006 were retrospectively reviewed. The clinicopathologic features of 11 cases of membranous nephropathy coexisting with IgA nephropathy were studied. Electron microscopy with immunogold labeling for IgG and IgA were also performed.

RESULTSThe mean age of patients was 39.9 years. The male-to-female ratio was 1:2.9. The patients mainly presented with proteinuria. Proteinuria of nephrotic level was seen in 7 cases (63.6%). Seven cases also had associated microscopic hematuria. None of them showed evidence of renal insufficiency. Cases with secondary diseases, such as hepatitis virus infection and systemic lupus erythematosus, were excluded from the study. Histologically, vacuolation and thickening of glomerular basement membrane was seen. There was also mild mesangial hypercellularity and increase in mesangial matrix. Occasional glomeruli with crescent formation were identified in 2 cases. Immunofluorescence study showed granular staining for IgG and C3 along glomerular capillary walls, in addition to clumps of IgA deposits in mesangium. Electron microscopy revealed subepithelial and mesangial electron-dense deposits. Immunogold labeling showed IgG and IgA localized in the subepithelial and mesangial deposits respectively.

CONCLUSIONMembranous nephropathy coexisting with IgA nephropathy possesses the clinicopathologic features of both components. It might be caused by independent occurrence of the two entities.

Adult ; Female ; Glomerular Basement Membrane ; immunology ; pathology ; ultrastructure ; Glomerular Mesangium ; immunology ; pathology ; ultrastructure ; Glomerulonephritis, IGA ; complications ; immunology ; pathology ; Glomerulonephritis, Membranous ; complications ; immunology ; pathology ; Humans ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; metabolism ; Kidney Glomerulus ; immunology ; pathology ; ultrastructure ; Male ; Middle Aged ; Retrospective Studies