1.JNK-c-Jun signal pathway induces tubular epithelial-myofibroblast transition via downregulation of connexin 43 expression
Xiaoxia HUANG ; Changbin KE ; Shoujun BAI
Chinese Journal of Nephrology 2011;27(12):928-932
ObjectiveTo explore the effect of JNK-c-Jun signal pathwayon connexin 43 (Cx43) expression and its role in renal tubular epithelial-myofibroblast transition (TEMT) induced by TGF-β1.Methods Normal rat kidney tubular epithelial cells(NRK-52E) were cultured in Dulbecco's modified eagle medium(DMEM) with 10% fetal bovine serum,then were randomly divided into 3 groups: control group,TGF-β1 group (treated with TGF-β1 10 μg/L),and TGF-β1+SP600125 (selective JNK inhibitor,50 μmol/L) group. The protein expressions of JNK,c-Jun,α-SMA,Cx43 and E-cadherin were assayed by immunocytochemistry and Western blotting.The Cx43mRNA was assayed by RT-PCR.Gap junction intercellular communication(CJIC) was measured by fluorescence recovery after photobleaching assay(FRAP).Results TGF-β1increased the expressions of JNK,c-Jun and α-SMA(P<0.05),reduced the expressions of Cx43 and E-cadherin (P<0.05),and inhibited GJIC of NRK-52E(P <0.05).SP600125 could alleviate the above expressions changes and enhanced GJIC induced by TGF-β1.Conclusion JNK-c-Jun signal pathway induces TEMT ofNRK-52E treated with TGF-β1 viadown-regulation of connexin 43expression and inhibition of GJIC.
2.Effect of intermedin pretreatment on repair and regeneration process of renal ischemia reperfusion injury
Guozheng FENG ; Rongshan LI ; Xi QIAO ; Xiuli SUN
Chinese Journal of Nephrology 2011;27(12):917-922
ObjectiveTo explore the effect of intermedin pretreatment on repair and regeneration process of renal ischemia reperfusion (IR) injury.Methods Male Wistar rats were randomly divided into four groups: sham group,IR group,empty plasmid group and IMD group.One week after removing the right kidney,eukaryotic expression vector encoding rat IMD gene was transfected into the left kidney using an ultrasound-microbubble-mediated system,and transfection effect was detected by Western blotting and RT-PCR.After successful transfection,renal IR injury model was induced by clamping left renal arteries for 45 minutes followed by reperfusion.BUN and Scr were tested.Renal pathology was observed by PAS and HE staining.The proliferation of tubular epithelial cells was detected by SABC immunohistochemical method.Results (1)The expression of IMD protein and mRNA in IMD group was significantly up-regulated compared to empty plasmid group(P<0.05),reaching the peak at day 7,and the difference was not significant with that at day 4.(2)Compared with sham group,BUN and Scr were obviously increased at day 1and 2 in IR group(P<0.05).However,compared with IR group,BUN and Scr in IMD group decreased obviously(P<0.05).Differences between IR group and empty plasmid group were not significant(P>0.05).(3)Kidney tubules in IR group,IMD group and empty plasmid group were injuryed,but the injury in IMD group was less serious compared with that in IR group and empty plasmid group.The injury in three groups was the most severe at day 2 after reperfusion.(4)The number of PCNA positive cells evidently increased at day 7 in IR group and empty plasmid group,but the number of PCNA positive cell evidently increased at day 3 in IMD group.Compared with IR group 1 to 4 days after perfusion,PCNA positive cells in IMD group increased obviously (P<0.05).Compared with IR group day 7,PCNA expression in IMD group 7 d was obviously decreased(P< 0.05).Conclusion IMD pretreatment can induce tubular epithelial cells proliferative and accelerate the repair and regeneration progress in IR injury kidneys.
3.Effect of angiotensin 1-7 on human renal proximal tubular epithelial cell transdifferentiation induced by high glucose and its mechanism
Xiangyou LI ; Guohua DING ; Fengqi HU ; Wei LIANG ; Zhilong REN
Chinese Journal of Nephrology 2011;27(12):903-906
Objective To investigate the effect of angiotensin 1-7(Ang 1-7) on renal proximal tubular epithelial cell(HK-2) transdifferentiation induced by high glucose.Methods All the raised HK-2 cells were divided into 5 groups: normal control group,high glucose group,high glucose with Ang1-7 group,high glucose with Ang1-7 and A779 group,high glucose with pioglitazone group.Expression of peroxisome proliferator activated receptor-γ(PPAR-γ) and α-smooth muscle actin(α-SMA) was detected by Western blotting,real-time PCR and immunofluorescence.Results The levels of PPAR-γ protein and mRNA in HK-2 cells were significantly increased after treatment with high glucose and Ang 1-7.Expression of α-SMA protein and mRNA was inhibited remarkably after treatment with high glucose and Ang 1-7.These effects of Ang 1-7 on HK-2 cells could be reversed by Mas receptor antagonist A779.Conclusion Ang 1-7 inhibits high glucose-induced expression of o-SMA in HK-2 cells,which is in part through the Mas.
4.Investigation of chronic pain in maintenance hemodialysis patients
Fang GAO ; Gongjian LIU ; Dong SUN
Chinese Journal of Nephrology 2011;27(12):896-898
ObjectiveTo investigate the incidence and the cause of chronic pain in maintenance hemodialysis(MHD) patients,and the effect of chronic pain on quality of life.Methods Seventy MHD patients in dialysis centre of our hospital were enrolled in the study and divided into 2 groups according to pain symptoms.There were 32 patients with chronic pain in pain group,and 38 patients without chronic pain in painless group.Pain degree was evaluated by numerical rating scale (NRS,1 to 10) in pain group.Parathyroid hormone (PTH),β2-microglobulin (β2-MG) and bone mineral density(BMD) of all the patients were measured.Depression and insomnia degrees were examined by Beck depression index (BDI) and Pittsburgh sleep quality index (PSQI) respectively.Correlations were performed among parameters.Results The incidence of chronic pain in MHD patients was 45.7% and the mean pain intensity of NRS was 5.71±1.86(95% CI,5.04-6.38).There were significant differences of PTH,BMD,β2-MG,BDI score and PSQI score between two groups(all P<0.01).The painful degree was positively correlated with levels of PTH and β2-MG,and the scores of PSQI and BDI,and was negatively correlated with BMD in pain group.Conclusion Chronic pain is common in MHD patients with different location and moderate degree,which can aggravate the depression and insomnia and may be associated with the changes of PTH,β2-MG and BMD.
5.Clinicopathological features of polyomavirus-associated nephropathy
Shicong YANG ; Gang HUANG ; Yongdong LIU ; Wenfang CHEN
Chinese Journal of Nephrology 2011;27(12):884-889
Objective To interpret the clinicopathological features and the key factors for diagnosis of polyomavirus-associated nephropathy (PVAN).Methods Clinicopathological data of 13casesof polyomavirus-associatednephropathyduring2008-2011inour hospitalwere retrospectively analyzed.Three cases received repeat biopsy.The clinicopathological features were analyzed according to thelight microscopicsceneandSV40-Timmunochemicalexpression.Results Recipients had a peak incidence of PVAN in 12 to 18 months period after renal transplantation,accompanied by elevated serum creatinine.Due to the progression of the disease,3patterns of histological findings could be identified.The early lesion was confined to the collected ducts,with slightly inflammatory infiltration in medullary interstitium,viral inclusions were not necessarily seen.The only findings could be enlarged nuclear and irregular arrangement of the tubular epithelial cells.At the developing stage,prominent tubulointerstitial nephritis was detected,and the involved tubules extended to other segments of renal tubule,even the parietal epithelial cells of Bowman's capsule could be compromised.The epithelial cells shed off,leading the tubular basement membrane exposed.Typical intra-nuclear inclusions as well as variable nuclear changes were found.At the end stage,the allograft showed notable chronic tubulointersititial change,with diffuse tubular atrophy and interstitial fibrosis.Although in this period,typical viral inclusions were rare, stillIHCshowedpositiveexpression of SV40-T. After immunosuppressantreductionor exchange,2 cases developed renal failure,4 cases showed sustained increment in serum creatinine,while 7 cases had a stabilized serum creatinine level.Conclusions Polyomavirus-associated nephropathy can display uneven pathological changes,as well as the morphology of the infected epithelial cells.Segments of the involved tubule are associated with the course of disease.Reduction of immunosuppressant at the early stage has a favorable effect.A prompt renal biopsy should be done in renal transplant recipient if who shows increased serum creatinine,and a routine polyomavirus immunohistochemical staining should be applied as well.
6.Clinical and pathological features of patients with anti-GBM disease lacking linear IgG deposition along GBM in kidney
Junliang CHEN ; Zhao CUI ; Zhen QU ; Gang LIU ; Wanzhong ZOU ; Minghui ZHAO
Chinese Journal of Nephrology 2011;27(12):871-876
ObjectiveTo investigate the clinical and pathological features of patients with anti-glomerular basement membrane(GBM) disease lacking linear IgG deposition along GBM on renal biopsy.Method Ninety-three patients with anti-GBM disease were collected in our hospital from 1991 to 2008,with 40 patients presenting negative linear IgG deposition along GBM on renal biopsy by direct immunofluorescence(group A) and 53 patients presenting classical linear IgG deposition along GBM(group B).The clinical manifestation,pathological presentation and prognosis were compared between two groups.Results Between two groups,there were no significant differences in gender,age,hemoptysis,oliguria or anuria,gross hematuria,proteinuria,anemia,ANCA positivity,level of circulating anti-GBM antibodies,the percentage of crescent formation in glomeruli and patient outcomes(P>0.05).Patients in group A were diagnosed significantly later than patients in group B(68 d vs 36 d,P=0.013) and serum creatinine was significantly lower at diagnosis(716.0 μmol/L vs 896.8 μmol/L,P=0.027).Direct immunofluorescence was performed on the paraffin-embedded renal sections from four patients in group A,and all of them revealed positive linear IgG deposition along GBM.Conclusions Patients with circulating anti-GBM antibodies but withont IgG deposition along GBM present slower progress of renal injury,but same clinical,pathological and prognostic features as those with classical anti-GBM disease.Serum anti-GBM antibodies should be prescribed earlier to the suspected patients,and the diagnosed patients should be treated with plasmapheresis and extensive immunosuppression to improve prognosis.
7.Role of HSP47 in renal tubulointerstitial fibrosis induced by transforming growth factor β1
Hongbo XIAO ; Jinlei LV ; Qinkai CHEN ; Ruihong LIU ; Guanghui LING
Chinese Journal of Nephrology 2011;27(12):923-927
ObjectiveTostudytheroleof hotshockprotein (HSP)47in tubulointerstitial fibrosis induced by transforming growth factor β1(TGF-β1),and to explore its possible mechanism.Methods Human proximal tubular epithelial cells(HK-2) were divided into threegroups:control,TGF-β1andHSP47siRNA. Theexpressionsof HSP47, collagenⅣ,fibronectin(FN),plasminogen activator inhibitor 1(PAI-1) mRNA and HSP47,collagen Ⅳ,FN protein were detected by RT-PCR and Western blotting respectively.PAl-1 protein was detected by ELISA. ResultsHK-2expressedHSP47innormalmedium. ThemRNAandprotein expressions of HSP47 up-regulated in concentration- and time-dependent manner in HK-2 cells induced with increasing concentrations of TGF-β1(0,2.5,5,10 μg/L) and with prolong times (12,24,48 h),and peaked at 10 μg/L TGF-β1 for 48 h.Similar phenomena was observed in the mRNA andproteinexpressionsof collagenⅣ, FN, PAI-1inHK-2 cellsinducedbyincreasing concentrations of TGF-β1 (0,2.5,5,10 μg/L) at different time points (12,24,48 h),and peaked at 10 μg/L TGF-β1 for 48 h.HSP47 siRNA could significantly reduce the up-regulation of mRNA and protein expressions of HSP47,collagen Ⅳ,FN,PAI-1 in HK-2 cells induced by TGF-β1.Conclusion HSP47 can promote renal tubulointerstitial fibrosis maybe through the regulation of the expressions of collagen Ⅳ,FN,PAI-1.
8.Effect of intermedin on the expressions of angiogenesis-related genes induced by renal ischemia reperfusion injury
Haihong ZHAO ; Rongshan LI ; Xi QIAO ; Li ZHAO ; Xinyan LIU ; Shan SHAO
Chinese Journal of Nephrology 2011;27(12):912-916
Objective To investigate the effect of intermedin (IMD) on the expressions of angiogenesis-related genes induced by renal ischemia reperfusion injury (IRI).Methods Wistar rats were randomly divided into four groups: control group,IRI group,empty plasmid group and IMD plasmid group.One week after removing the right kidney,eukaryotic expression vector encoding rat IMD gene was transfected into the left kidney using an ultrasound-microbubble mediated system.Renal IRI model was induced by clamping left renal arteries for 45 minutes followed by reperfusion for 1 d,2 d,3 d,4 d,7 d and 14 d.The expressions of hypoxia inducible factor-1α (HIF-1o),vascular endothelial growth factor (VEGF) and angiopoietin receptor Tie-2 were examined by RT-PCR and Western boltting.Results Compared with control group,an increase in HIF-1α,VEGF and Tie-2 was observed in the IRI group at d 1,d 2 and d 3 (allP<0.05).The expression of HIF-1o peaked at d 1 d(P<0.05),while VEGF and Tie-2 at d 2 (P<0.05),followed by a decrease that was similar to the control levels at d 4(P>0.05).Compared with the IRI group,the expressions of HIF-1α,VEGF and Tie-2 of IMD group were much higher and all reached the peak at d 1 (P<0.05),maintained at d 2-4 (P<0.05),followed by a decrease at d 7(P>0.05).The above indexes had no differences between empty plasmid group and IRI group(P>0.05).Conclusions IMD pretreatment may play an important role in the process of repair and regeneration after renal ischemia reperfusion injury byimproving the expressions of angiogenesis-related genes(HIF-1α,VEGF and Tie-2) induced by renal ischemia reperfusion injury.
9.Effect of the pass of apelin-13 through ADMA-damaged endothelial monolayer on vascular smooth muscle cells
Liyan WANG ; Dongliang ZHANG ; Yu ZHANG ; Wenhu LIU
Chinese Journal of Nephrology 2011;27(12):907-911
Objective To study the effect of apelin-13 on myosin light chain (MLC)phosphorylation in vascular smooth muscle cells under the condition that the permeability of endothelial layer is changed by ADMA.Methods Human umbilical vein endothelial cell (HUVECs) were cultured in bottom of upper well of Transwell system to establish the endothelial monolayer barrier.The cells were cultured normally or incubated with ADMA.Some FITC-apelin-13was added to the upper well.After a period of leakage time,the amount of FITC-apelin-13 in the lower well was measured to evaluate Pa value,which reflected the permeability of endothelial monolayer. Thechangesofcytoskeletonandintercellularjunctionwereobservedby immunofluorescence.Subsequently,Transwell dishes were used to establish a co-culture system with HUVECs in the upper well and human umbilical vein smooth muscle cells(HUVSMCs) in the lower well.There were four groups: blank control group; ADMA group,stimulated by ADMA only;apelin group,apelin-13 used only; ADMA+apelin group,apelin-13 used after HUVECs stimulated by ADMA.Immunofluorescence and Western blotting were used to detect phosphorylation of MLC in HUVSMCs.Results ADMA induced changes of cytoskeleton and intercellular junction and increased endothelial permeability of apelin-13.The percentage of Pa between ADMA-stimulated and control groups varied during the period of apelin-13 pass and peaked at 20 minutes,which was significantly higher than that at 0 minutes [(176.3±9.2)% vs (100.3±1.5)%,P<0.05].In the co-culture system,Western blotting showed that p-MLC expression in ADMA +apelin group was significantly higher than that in apelin group(P<0.05).In ADMA group,a few p-MLC expression was found also.Phosphorylation of MLC in above 3 groups was significantly higher as compared to blank control group(P<0.05).Conclusions ADMA can increase endothelial permeability of apelin-13 by inducing changes of cytoskeleton and intercellular junction.Apelin-13 passes through the damaged endothelial barrier and directly acts on vascular smooth muscle cells to elevate phosphorylation of MLC,which may play an important role in hypertension of uremic patients.
10.Empiric initial therapy in peritoneal dialysis-related peritonitis
Huanqing YAN ; Yun LI ; Yongjun BAO ; Lin TANG ; Xin HUANG ; Guoxiu ZHOU ; Tongying ZHU
Chinese Journal of Nephrology 2011;27(12):899-902
Objective To investigate the pathogens,drug resistance and outcomes of continuous ambulatory peritoneal dialysis(CAPD) patients with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers. Method Data including clinical manifestations,pathogens,treatment,outcome of 93 CAPD cases with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers were retrospectively analyzed.Results Dialysate culture of 75cases was positive with a positive rate of 80.2%,including 45 cases of gram-positive cocci,21cases of gram-negative bacilli,2 cases of fungi and 5 cases of mixed infection.Coagulase-negative staphylococci were the most common gram-positive cocci.All the gram-positive cocci were sensitive to vancomycin,but the resistance rate to cefazolin was 60.0% with an increasing tendence year by year.Resistance rate of gram-negative bacilli to ceftazidime was 46.1%.All the gram-negative bacilli were sensitive to imipenem.The withdraw rate of CAPD was 17.2%(16/93) because of peritonitis. Noobviousside-effectofperitonealadministrationofvancomycinwasfound.Conclusions Gram-positive cocci are major pathogens in CAPD-related peritonitis.Now cefasolin is not suitable for the empiric initial treatment.Peritoneal administration of vancomycin should be recommended for peritonitis caused by gram-positive cocci.