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Parathyroid hormone-related protein (PTHrP) and its receptor type 1 (PTH1 R) are extensively expressed in the kidney,where they are able to modulate renal function.Animal and human studies have shown that PTHrP acts as an important mediator of diabetic renal cell hypertrophy by a meehanism which involves the modulation of cell cycle regulatory proteins and TGF-β1.Furthermore,angiotensin Ⅱ (Ang Ⅱ) appears to be responsible for PTHrP upregulation in these conditions.These findings provide novel insights into the well-known protective effects of Ang Ⅱ antagonists in renal diseases,paving the wav for new therapeutic approaches.
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Acute kidney injury(AKI) has emerged as a major public health problem that leads to decreased survival.In AKI,cell hyperplasia,hypertrophy and apoptosis are related to the cell cycle control.Two supervisory restriction points,G1/S and G2/M checkpoints,are responsible for cell-cycle control.Furthermore,cell cycle regulatory proteins are also involved in the regulation of the cell cycle in AKI.This review focuses on the cell cycle regulation mechanism of AKI.
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Objective To investigate the radiosensitization of artesunate on nude mouse transplanted with HeLa cells,and to explore its possible mechanisms.Methods HeLa cells were inoculated into the nude mice to establish tumor model.Mice were randomly divided into 4 groups as blank control,artesunate group,radiation group and artesunate + radiation group when average volume of tumor were about 5 mm × 5 mm× 5 mm.During the term of treatment,the volume of tumors were measured every 2days.After 14 days treatment,the mice were killed and tumor tissues were harvested for flow cytometry to detect the alteration of cell cycle.Meanwhile,the pathological change of the tumor tissue was observed with HE staining method,and the change of expression of cycle regulatory protein Cyclin B1,Cdc2 and Wee1 were detected by Western blot.Results The growth of tumor was significantly inhibited by artesunate combined with radiation and its inhibition rate was 72.34％.Flow cytometry results showed that the percent of cells in G1 phase increased and G2 phase decreased in the artesunate + radiation group compared with those in irradiation group ( t =4.41,4.12,P ＜ 0.05 ).The expression level of Cyclin B1 was obviously increased while that of Wee1 decreased in the artesunate + radiation compared with irradiation group.There was no difference in the expression of Cdc2 among the four groups.Conclusions Artesunate can dramatically increase the radiosensitivity of transplanted tumor of HeLa cells.The possible mechanism might be related to the decreasing G2 phase by regulating the expression of Cyclin B1 and Wee1.
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Aim To investigate the effect of taurine(Tau)on the cardiac fibroblast(CFb)cell cycle and its regulatory protein expression,and to explore the underlying mechanism of Tau-inhibiting the proliferation of CFb.Methods The proliferation of cultured neonatal rat CFb was induced by Angiotensin Ⅱ and detected by the thiazole blue(MTT)colorimetric assay.Hydroxyproline measurement was carried out to detect the collagen quantification.The expression of cell cycle regulatory protein cyclin D and p27 were determined by the combination of immunocytochemical staining and image analysis software.Cell cycle and p27 were assessed via flow cytometry.Results CFb proliferation and hydroxyproline content in culture medium were markedly inhibited when CFb were treated with taurine at concentrations of 40,80 and 160 mmol?L-1 for 24 hours(P
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catechin plus dexamethasone-treated group. Compared with nephrotic group, the renal pathologic score were significantly different among the nephrotic group and the catechin-treated group (6 80?0 84,P
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BACKGROUND AND OBJECTIVE: AT-1 cells have been derived from the left atrial tissue in which the ANF promoter targeted SV40 large T antigen expression. When cultured, clusters of spontaneously contracting cells were observed after 4-5 days and contiguous sheets of synchronously beating cardiomyocytes were formed after 10 days. In this study, expression of several cell cycle regulatory genes were monitored through Northern blot analyses in AT-1 cells during beating and after formation of beating sheets (BS). MATERIALS AND METHOD: AT-1 RNAs were obtained in 3 days after plating, during beating and after formation of BS, and used for Northern blot analyses. RESULTS: alpha-Cardiac myosin heavy chain expression was prominent in beating cells, as would be expected for this contractile protein isoform but ANF was decreased after beating. Gax was not expressed in cultured AT-1 cells but in AT-1 tumor and murine heart. p53 and p21 were decreased after beating which indicate transcription level of p53 and p21 correlated well in AT-1 cells. In contrast, pRB and p107 were increased after beating but p68 (2.4 kb) which arose by alternative splicing of p107 and lacks the pocket domain B was decreased in beating cells. pTCS2, murine tuberous sclerosis gene, represented similar levels during beating but a little was decreased after formation of BS. mRAD50, the murine homologue of yeast DNA recombinational repair gene RAD50, was increased in beating cells, a similar pattern to p107 and pRB. But the p50 arose by alternative splicing of mRAD50 and has 3' half of mRAD50 had unexpectedly appeared and maintained after beating. CONCLUSION: The expression of cell cycle regulatory genes after beating and formation of BS in AT-1 cells showed gene-specific pattern and the p50 which has homology to the mRAD50 may participate in differentiation of cardiomyocytes.
Subject(s)
Alternative Splicing , Antigens, Viral, Tumor , Atrial Natriuretic Factor , Blotting, Northern , Cell Cycle , Genes, Regulator , Heart , Myocytes, Cardiac , Myosin Heavy Chains , Recombinational DNA Repair , RNA , Tuberous Sclerosis , YeastsABSTRACT
Objective To examine the expression of cell cycle regulatory protiens in renal tubulointerstitial cells of human glomerulonephritis. Methods Immunohisochemieal studies were performed on 19 specimen from renal biopsy to detect cyclin Dl, cyclin A, p21 and proliferating nuclear antigen (PCNA) . Results Cyclin Dl, cyclin A and p21 were positive in some of tubulointerstitial cells, and showed significant correlations with positive PCNA cells. The numbers of tubular positive cells in both groupsofⅠand Ⅱ degree of histopathological change were more than those of other groups. The numbers of interstitialpositive cells showed significant correlations with the degree of tubulointerstitial histopathological change and the value of urine NAG. Conclusion Cell cycle regulatory proteins regulate the proliferation of tubular and interstitial cells, and correlate with the interstitial fibrosis.
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Objective Our study aimed at the role of p27 on the hypertrophy of mesangial cell (MC) cultured in high glucose. Methods The p27 protein of MC lysate was detected with western blotting analysis. The degree of cultured MC hypertrophy was estimated through [3H]-thymidine incorporation and [3H]-leucine incorporation. The effect of reducing p27 expression on cell hypertrophy was analysed with p27 antisense oligodeoxynucleotide (ODN) phosphorothioate. Results in MC cultured in high glucose (450mg/dl) serum-free DMEM compared with MC cultured in normal glucose (100mg/dl) serum-free DMEM, p27 increased, [3H]-leucine incorporation increased and[3H]-thymidine incorporation decreased;p27 antisense ODN transfection reduced [3H]leucine incorporation, increased [3H] thymidine incorporation of MC cultured in high glucose senumfree DMEM. Increasing medium osmolarity with D-mannitol failed to induce p27 expression of MC. Conclusion p27 protein increased in MC cultured in high glucose. High level of p27 played an important role in MC hypertrophy induced by high glucose. Because the cell cycle is controlled by the interaction between the positive cell cycle regulatory proteins(CCRP) and negative CCRP, further research is needed to study the expression of the positive and negative CCRP in MC in order to better understand the role of CCRP in MC hypertrophy.
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Objective To observe the effects of myriocin(ISP-1) on improvement of glomerular messangial cell(GMC) apoptosis and on gene expression profiles of cell cycle regulatory proteins in GMC.Methods Rat GMC was cultured with 100 ?mol/L ISP-1 for 6,12,24,and 48 h,apoptosis was evaluated through flow cytometry,Hoechst33258/PI fluorescence stainig and DNA fragmentation analysis was carried out under Sepharose electrophoresis to observe the changes of apoptosis and DNA fragmentation.Gene expression profiles of cell cycle regulatory proteins were detected by SuperArray Real-Time PCR microarray analysis.The expression of Bax and Bcl-2 proteins was investigated by Western blotting.Results ISP-1 could significantly induce GMC apoptosis in a time-dependent manner,which was the most significant after 48 h.Apoptosis bodys of GMC were observed by Hoechst/PI fluorescence staining,and a typical ladder pattern was identified in DNA electrophoresis.SuperArray Real-Time PCR microarray analysis revealed that ISP-1 could up-regulate the expression of genes involved in DNA damage,apoptosis and cell cycle regulation,such as Rad51,Atm,Brcal,caspases,cyclinA2,cyclinC,chek1,cyclinB1,cyclinB2,cyclinD2,cyclinF,Cdc25a,and P27.Western blotting showed that ISP-1 could significantly up-regulate Bax protein expression and down-regulate Bcl-2 protein expression,respectively.ConclusionISP-1 could induce GMC apoptosis in a time-dependent manner,propabably through influencing gene expression of cell cycle regulatory proteins and apoptosis proteins.
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Objective To determine whether the anti-proliferation effect of L-arginine is due to inhibiting the expression of cyclin dependent kinase-2 (CDK2)、 CyclinE and proliferation cell nuclear antigen (PCNA) in blood vessel after balloon injury. Methods Rats were randomized into three groups: Group S (sham operation group), Group C (balloon injury control group) and Group L (balloon injury + L-arginine group). After 14 days, blood samples were collected for biochemical studies, and the thoracic aortas were harvested for immunohistochemistry. The expression of CDK2、 CyclinE and PCNA were measured by means of computer image analayzer. Results The levels of plasma nitric oxide (NO) in group C were significantly lower than those in group S. Compared with group C, the levels of plasma NO increased (P
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Objective: To investigate the role of cyclin kinase inhibitor P27 on the proliferation of mesangial cell(MC) in Thy1 glomerulonephritis(GN) rats. Methods: The Thy1 model of experimental mesangial proliferative glomerulonephritis was induced by intravenous injection of rabbit anti-thymocyte plasma. The P27 protein of glomerular lysate was detected with Western blotting analysis. The P27 mRNA was determined with RT-PCR. The extracellular matrix (ECM) protein (fibronectin and type Ⅳ collagen) of glomerular lysate was examined with ELISA. Results: Glomerular P27 protein of Thy1 model rat decreased compared with that of normal rat. The level of P27 was associated with the degree of MC proliferation:P27 began to decrease on day 1 in Thy1 model, then reached the lowest on day 3 when MC proliferation was maximal, then returned to 60% of the baseline level on day 5 when MC proliferation began to resolute. Glomeruar P27 mRNA remained constant in Thy1 GN(3 d) rats. Glomerular fibronectin(Fn) and type Ⅳ collagen increased in Thy1 model: They reached the highest on day 3(P