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Puromycin-sensitive aminopeptidase (PSAP) belongs to the M1 family of aminopeptidases, characterized by the N-terminal substrate binding sequence GAMEN, the enzyme activity center HEXXH(X)18E motif, and the C-terminal ERAP-1-like superfamily structural domain. Encoded by the gene NPEPPS located at 17q21.32, PSAP consists of 919 amino acids and is widely distributed throughout the human body, with the highest expression in the brain, followed by the heart and skeletal muscle. It is also found in the liver, renal tubular epithelium, small intestine, large intestine epithelium, and gastric epithelial cells. PSAP primarily relies on its aminopeptidase hydrolytic activity to remove toxic protein aggregates such as Tau, poly Q, and Cu, Zn-superoxide dismutase 1, making it an important factor in the development of diseases such as Alzheimer's disease, Huntington's chorea, and tumors. Existing PSAP inhibitors include bestatin, amastatin, leuhistin, actinonin, and purinomycin, some of which are already available or in clinical trials. This review provides an overview of the structural and biological functions of M1 family aminopeptidases, with a focus on PSAP, to facilitate further research and targeted drug development.
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Nephrotic syndrome (NS) is a kidney disease characterized by hypertriglyceridemia, massive proteinuria, hypo-albuminemia and peripheral edema. Sinkihwan-gamibang (SKHGMB) was recorded in a traditional Chinese medical book named "Bangyakhappyeon ()" and its three prescriptions Sinkihwan, Geumgwe-sinkihwan, and Jesaeng-sinkihwan belong to Gamibang. This study confirmed the effect of SKHGMB on renal dysfunction in an NS model induced by puromycin aminonucleoside (PAN). The experimental NS model was induced in male Sprague Dawley (SD) rats through injection of PAN (50 mg·kg-1)via the femoral vein. SKHGMB not only reduced the size of the kidneys increased due to PAN-induced NS, but also decreased proteinuria and ascites. In addition, SKHGMB significantly ameliorated creatinine clearance, creatinine, and blood urea nitrogen. SKHGMB relieved glomeruli dilation and tubules fibrosis in the glomeruli of the NS model. SKHGMB inhibited the protein and mRNA levels of the NLRP3 inflammasome including NLRP3, ASC, and pro-caspase-1 in NS rats. SKHGMB reduced the protein and mRNA levels of fibrosis regulators in NS rats. The results indicated that SKHGMB exerts protective effects against renal dysfunction by inhibiting of renal inflammation and fibrosis in NS rats.
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Animals , Male , Rats , Kidney , Nephrotic Syndrome/drug therapy , Proteinuria/metabolism , Puromycin Aminonucleoside/toxicity , Rats, Sprague-DawleyABSTRACT
Objective:To investigate the effect and mechanism of astragaloside IV (AS-IV) combined with glucocorticoids in the treatment of puromycin aminonucleoside (PAN) rat nephropathy model.Methods:Forty specific pathogen-free healthy male Wistar rats (150-180 g) were randomly divided into 5 groups: control group, PAN group, AS-IV treatment group (PAN+AS-IV group), methylprednisone (MP) treatment group (PAN+MP group), and AS-IV+MP treatment group (PAN+AS-IV+MP group). The model was established by a single tail vein injection of PAN (50 mg/kg body weight). The treatment groups were given 40 mg·kg -1·d -1 AS-IV by intragastric administration and 15 mg·kg -1·d -1 MP by intraperitoneal injection for 10 consecutive days at the same time of modeling. Urine sample was collected on the 11th day of the experiment. The urine protein, urine creatinine and blood albumin were detected by biochemical analyzer. The changes of nephrin and synaptopodin in renal tissues were detected by immunofluorescence assay, and the expressions of nephrin, RhoA and Rac/Cdc42 proteins were detected by Western blotting. Results:Compared with the control group, urine protein creatinine ratio (uPCR) was significantly increased, serum albumin (Alb) was significantly decreased in the PAN group, nephrin expression was significantly down-regulated, and the expressions of RhoA and Rac/Cdc42 were significantly up-regulated in the renal tissue of the PAN group (all P<0.01). Compared with PAN group, serum Alb levels in PAN+AS-IV group and PAN+AS-IV+MP group were significantly increased (both P<0.01), and the uPCR levels in PAN+MP group ( P<0.05) and PAN+AS-IV+MP group ( P<0.01) were significantly decreased (all P<0.05). Compared with the PAN group, the relative expressions of nephrin in renal tissue of all drug intervention group (PAN+AS-IV group, PAN+MP group and PAN+AS-IV+MP group) were significantly increased, while the relative expressions of RhoA and Rac/Cdc42 were significantly decreased (all P<0.01). The immunofluorescence results suggested that the expressions of nephrin and synaptopodin in renal tissue of PAN group were significantly down-regulated compared with the control group, which were reversed in all treatment groups, and the reversion was most pronounced in the PAN+AS-IV+MP group. Conclusion:Both AS-IV and glucocorticoid can improve PAN-induced podocyte injury, and the combination of the two has synergistic action, which may be related to inhibiting the activation of Rho family signaling pathway.
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Objective: To isolate, culture and identify rabbit bone mesenchymal stem cells (BMSCs) so as to explore the optimal conditions for lentiviral vector-mediated enhanced green fluorescent protein (eGFP) infection in rabbit BMSCs and screen stable transfected BMSCs in rabbits. Methods: BMSCs were obtained by whole bone marrow adherence method. The osteogenic, chondrogenic and adipogenic differentiation of BMSCs was made by alizarin red, toluidine blue and oil red O staining, respectively. The expressions of CD44 and CD90 were detected by immunofluorescence. The concentration of puromycin was used to screen the minimum lethal concentration of BMSCs; the lentiviral vector with multiplicity of infection (MOI) of 50, 100, 150 and 200 mediated eGFP BMSCs were infected; the fluorescence expression was observed under an inverted microscope, and the stable transformation system was screened with puromycin. Results: When MOI was 150, lentiviral vector-mediated eGFP infection of rabbit BMSCs was the most efficient. The optimum concentration of puromycin for stable transfection of rabbit BMSCs was 1.0 μg/mL. Conclusion: Rabbit BMSCs were successfully cultured in this experiment. The stem cells were labeled with lentivirus-mediated GFP and stable transfected rabbit BMSCs were screened. A simple and effective stem cell labeling method was established to label BMSCs in vivo.
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Objective: To investigate the effects of extractum trametes robiniophila murr on the filtration rate, motility and cytoskeleton rearrangement of the podocytes invitro of the puromycin aminonucleoside (PAN) - treated mice, and to clarify the protective effect of extractum trametes robiniophila murr on the podocyte injury and its mechanism. Methods: The podocytes cultured in vitro were randomly divided into control group, model group and test group. The podocytess in model group were treated with 50 mg · L-1 PAN for 24 h; the podocytess in test group were treated with 10 g · L-1 extraction trametes robiniophila murr for 1 h and then treated with 50 mg · L-1 PAN for 24 h. The filtration rate of podocytes to FITC-BSA was measured by two-compartment diffusion system; the scratch repair rate of podocytes was detected by cell scratch test, and the number of podocytes passing through the membrane was measured by Transwell cell migration test. Laser confocal microscope was used to observe the cytoskeleton rearrangement of podocyte cytoskeleton protein F-actin labeled with Invitrogen phalloidin directly. Results: Compared with control group, the FITC-BSA filtration rate of the podocytes in model group was increased significantly (P<0. 01); compared with model group, the FITC-BSA filtration rate of the podocytes in test group was decreased significantly (P<0. 01). Compared with control group, the scratch repair rate of podocytes and the number of transmembrane cells in model group were transmembrane (P<0. 05); compared with model group, the scratch repair rate of podocytes and the number of migration migration cells in test group were decreased significantly (P<0. 05). Compared with control group, the expression level of F-actin in the podocytes in model group was decreased significantly (P<0. 01), the rearrangement rate of F-actin was increased signifiantly (P< 0.01), and the structure of podocyte cytoskeleton was disordered; compared with model group, the expression level of F-actin in the podocytes in test group was increased significantly (P<0. 01), the rearrangement rate of F-actin was decreased significantly (P < 0. 01), and the skeleton rearrangement was alleviated obviously. Conclusion: Extractum trametes robiniophila murr could reduce the filtration rate of podocytes to BSA invitro under the pathological condition, and its possible mechanism is that extractum trametes robiniophila murr reduces the motility of podocytes and improve the rearrangement of podocyte cytoskeleton in vitro.
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Objective To investigate the effects of Tacrolimus( FK506 )and Puromycin aminonucleoside ( PAN)on apoptosis and expression of α-actinin-4 mRNA and protein in mouse glomerular podocytes in order to ex-plore the protective effect of FK506 on podocytes. Methods Mouse glomerular podocytes were cultured in υitro,and the control group,PAN group and FK506 group were established. After 8 h,24 h and 48 h of treatment,the cell mor-phology was observed and the apoptosis rate was detected. The cells were collected by real-time PCR and Western blot was used to detect the mRNA and protein expression of α-actinin-4. Results The cell body area of the PAN group was significantly smaller than that of the control group,and the cell area of the FK506 group was larger than that of the PAN group. There was no significant difference in the rate of podocyte apoptosis between those groups at 8 h( all P>0. 05). At 24 h and 48 h,the apoptotic rate of podocytes in PAN group[(8. 21 ± 0. 41)%,(16. 32 ± 0. 17)%]were significantly higher than those in the control group[(4. 28 ± 0. 35)%,(6. 27 ± 0. 28)%],and the differences were significant(all P<0. 05). The apoptosis rate of podocytes in FK506 group[(6. 26 ± 0. 24)%,(13. 32 ± 0. 24)%] were significantly lower than those in PAN group,and the differences were significant(all P<0. 05). At 8 h,there was no significant difference in the expression of α -actinin -4 mRNA and protein( all P >0. 05 ). The expression of mRNA(2. 42 ± 0. 21,3. 78 ± 0. 25)and protein(0. 77 ± 0. 04,1. 22 ± 0. 10)in the PAN group was significantly higher than mRNA(1. 50 ± 0. 22,2. 15 ± 0. 15)and protein(0. 44 ± 0. 03,0. 83 ± 0. 07)in the control group at 24 h and 48 h,and the differences were significant(all P<0. 01). The expression of mRNA(1. 65 ± 0. 24,1. 70 ± 0. 32)and protein(0. 52 ± 0. 05,0. 56 ± 0. 07)in FK506 group was significantly lower than that of PAN group,and the differ-ences were significant(all P<0. 05). Conclusions FK506 can effectively inhibit the damage of PAN on podocytes and stabilize the expression of α-actinin-4,which provides a basis for the clinical application of FK506 in the treat-ment of glomerular diseases.
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Objective@#To investigate the effects of Tacrolimus(FK506) and Puromycin aminonucleoside(PAN) on apoptosis and expression of α-actinin-4 mRNA and protein in mouse glomerular podocytes in order to explore the protective effect of FK506 on podocytes.@*Methods@#Mouse glomerular podocytes were cultured in vitro, and the control group, PAN group and FK506 group were established.After 8 h, 24 h and 48 h of treatment, the cell morphology was observed and the apoptosis rate was detected.The cells were collected by real-time PCR and Western blot was used to detect the mRNA and protein expression of α-actinin-4.@*Results@#The cell body area of the PAN group was significantly smaller than that of the control group, and the cell area of the FK506 group was larger than that of the PAN group.There was no significant difference in the rate of podocyte apoptosis between those groups at 8 h (all P>0.05). At 24 h and 48 h, the apoptotic rate of podocytes in PAN group[(8.21±0.41)%, (16.32±0.17)%] were significantly higher than those in the control group[(4.28±0.35)%, (6.27±0.28)%], and the differences were significant (all P<0.05). The apoptosis rate of podocytes in FK506 group[(6.26±0.24)%, (13.32±0.24)%] were significantly lower than those in PAN group, and the differences were significant (all P<0.05). At 8 h, there was no significant difference in the expression of α-actinin-4 mRNA and protein(all P>0.05). The expression of mRNA (2.42±0.21, 3.78±0.25) and protein(0.77±0.04, 1.22±0.10) in the PAN group was significantly higher than mRNA(1.50±0.22, 2.15±0.15) and protein(0.44±0.03, 0.83±0.07) in the control group at 24 h and 48 h, and the differences were significant (all P<0.01). The expression of mRNA (1.65±0.24, 1.70±0.32) and protein (0.52±0.05, 0.56±0.07) in FK506 group was significantly lower than that of PAN group, and the differences were significant (all P<0.05).@*Conclusions@#FK506 can effectively inhibit the damage of PAN on podocytes and stabilize the expression of α-actinin-4, which provides a basis for the clinical application of FK506 in the treatment of glomerular diseases.
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Objective To investigate the effect of Puromycin(PAN)and Tacrolimus(FK506)on the expre-ssion of podocin in podocytes,and discuss the mechanism of FK506 in improving proteinuria caused by the damage of glomerular podocytes.Methods Mouse podocyte were cultured and divided into 3 groups,which were control group, PAN group and FK506 group,respectively.The changes of each group after 8 hours,24 hours and 48 hours of treatment were detected by using phase-contrast microscope,and the expression and distribution of protein and mRNA were tested by adopting Western blot,quantitative real-time PCR and immunofluorescence technique.Results Compared with the control group(8.54 ± 0.25,8.27 ± 0.07,7.45 ± 0.13)at each time point(8 hours,24 hours and 48 hours),the soma size of the PAN group(6.41 ± 0.22,4.96 ± 0.09,3.76 ± 0.16)was reduced.But in the FK506 group(7.67 ± 0.06, 6.62 ± 0.04,5.57 ± 0.27),it was increased at each time point(8 hours,24 hours and 48 hours)compared with the PAN group.The podocytic process and the intercellular connection disappeared,and the distribution was significantly scattered.The mRNA(0.87 ± 0.15,0.78 ± 0.15,0.58 ± 0.12)and protein(0.82 ± 0.02,0.62 ± 0.03,0.50 ± 0.02) expressions of podocin increased in FK506 group and mRNA(0.63 ± 0.12,0.56 ± 0.01,0.48 ± 0.02),protein (0.71 ± 0.03,0.46 ± 0.01,0.34 ± 0.02)were observably reduced in PAN group at each time point(8 hours,24 hours and 48 hours)and showed abnormal distribution in PAN group,compared with the control group[podocin mRNA (1.22 ± 0.15,1.18 ± 0.06,0.87 ± 0.30),protein(0.86 ± 0.03,0.87 ± 0.03,0.61 ± 0.07)].Conclusions PAN attenuates the mRNA and protein expression of podocin by damaging podocytes,inversely,while FK506 protects poto-cyte injury by stabilizing the mRNA and protein expression of podocin,which maybe involve inhibition of proteinuria.It can be used as a target for the study and treatment of kidney diseases.
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BACKGROUND: Puromycin aminonucleoside (PAN) is a known podocytotoxin. PAN-induced nephrosis is a widely used animal model for studying human idiopathic nephrotic syndrome. Abnormal protein accumulation associated with podocyte-specific endoplasmic reticulum (ER) stress damages cells structurally and functionally, which in turn induces apoptosis and severe proteinuria. In the present study, we investigated the effect of PAN on ER stress and apoptosis in podocytes in vitro. METHODS: Mouse podocytes were cultured and treated with various concentrations of PAN. ER stress markers were then evaluated by western blotting, and apoptosis was evaluated by fluorescence-activated cell sorting (FACS) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. RESULTS: PAN treatment increased ER stress markers such as activating transcription factor (ATF) 6α and caspase-12 in a dose-dependent manner at 12 and 24 hours, respectively. These markers were reduced by chemical chaperones, such as sodium 4-phenylbutyric acid and tauroursodeoxycholic acid. PAN treatment also increased 78 kD glucose-regulated protein (GRP78)/binding immunoglobulin protein (BiP) at the earlier stage of 12 hours. PAN significantly induced podocyte apoptosis in concentration- and time-dependent manners, as seen using FACS and TUNEL assays. This result was improved by Nox4 siRNA, ATF6 siRNA, and chemical chaperones. LY294002, a PI3-kinase inhibitor, significantly boosted ER stress and apoptosis. PAN-induced ER stress increased oxidative stress and subsequently induced apoptosis, and could be mitigated by inhibition of PI3-kinase signaling. CONCLUSION: Our findings suggest that PAN induces ER stress in podocytes mainly through the GRP78/BiP, ATF6α, and caspase-12 pathways, which trigger apoptosis via induction of oxidative stress. This stress is mitigated by inhibiting PI3-kinase signaling.
Subject(s)
Animals , Humans , Mice , Apoptosis , Blotting, Western , Caspase 12 , DNA Nucleotidylexotransferase , Endoplasmic Reticulum Stress , Endoplasmic Reticulum , Flow Cytometry , Immunoglobulins , In Situ Nick-End Labeling , In Vitro Techniques , Models, Animal , Nephrosis , Nephrotic Syndrome , Oxidative Stress , Phosphatidylinositol 3-Kinases , Podocytes , Proteinuria , Puromycin Aminonucleoside , Puromycin , RNA, Small Interfering , Sodium , Transcription FactorsABSTRACT
Objective:To explore the protective effect of rapamycin and the role of autophagy on podocyte injury induced by pu-romycin amino nucleoside.Methods:The mice podocytes cell 5(MPC5)were randomly divided into four groups:Control group,PAN group(50 μg/ml PAN);rapamycin group(RAP group,100 ng/ml,200 ng/ml,300 ng/ml rapamycin)and PAN+rapamycin group (PAN+RAP group,treated with rapamycin before PAN).The apoptosis of podocytes were detected by Annexin V/PI.Transmission electronic microscopy was used to observe the formation of autophagosome.The expression of autophagic markers,LC3,p62,and 4EBP1,P70S6K,mTOR were detected by Western blot.Results: The podocyte apoptotic rate was significantly decreased when the podocytes were treated with rapamycin compared with PAN group.Further,more autophagosomes appeared in cytoplasm of podocytes in RAP and PAN+RAP group compared with PAN group.And the expression of LC3Ⅱ was significantly increased in rapamycin treated podocytes,whereas the expression of p62 was decreased markedly.Phosphorylation of mTOR,4EBP1 and P70S6K was decreased rapamycin treated groups.Conclusion: Podocyte autophagy was inhibited by PAN, and the apoptosis of podocytes was promoted.Rapamycin protect puromycin amino nucleoside induced podocyte injury by upregulating autophagy and it may be concerned with mTOR 4EBP1 and P70S6K signaling pathway.
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Objective To construct mitochondrial antiviral-signaling protein ( MAVS ) knockout ZR-751 breast neoplasms cells using CRISPR/Cas9 genome engineering technology , and study the effect of MAVS on cell proliferation . Methods Small guide RNA ( sgRNA ) was designed by targeting the first exon of MAVS gene and the pX 459-sgRNA recombinant eukaryotic expressional plasmid was constructed .Puromycin was used to screen monoclonal cells which stably knocked out MAVS gene .The knockout effect was measured by Western blotting .Cellular proliferation rates were detected by colony-forming assay when MAVS gene was knockout .The MTS assay was designed to detect the effect of MAVS on cell proliferation under DFX stimulus .Results The result of Western blotting suggested that no MAVS protein was detected in the MAVS gene knockout stable ZR-751 cells,showing that MAVS gene was knocked out completely .Proliferation became faster when MAVS was knocked out .MAVS promoted cell death under DFX stimulus .Conclusion The MAVS knockout ZR-751 stable cells have been constructed using CRISPR/Cas9 system.The preliminary experimental results show that MAVS inhibits breast cancer cell proliferation , which will facilitate studies on the function of MAVS in tumors in the future .
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Objective To construct mitochondrial antiviral-signaling protein ( MAVS ) knockout ZR-751 breast neoplasms cells using CRISPR/Cas9 genome engineering technology , and study the effect of MAVS on cell proliferation . Methods Small guide RNA ( sgRNA ) was designed by targeting the first exon of MAVS gene and the pX 459-sgRNA recombinant eukaryotic expressional plasmid was constructed .Puromycin was used to screen monoclonal cells which stably knocked out MAVS gene .The knockout effect was measured by Western blotting .Cellular proliferation rates were detected by colony-forming assay when MAVS gene was knockout .The MTS assay was designed to detect the effect of MAVS on cell proliferation under DFX stimulus .Results The result of Western blotting suggested that no MAVS protein was detected in the MAVS gene knockout stable ZR-751 cells,showing that MAVS gene was knocked out completely .Proliferation became faster when MAVS was knocked out .MAVS promoted cell death under DFX stimulus .Conclusion The MAVS knockout ZR-751 stable cells have been constructed using CRISPR/Cas9 system.The preliminary experimental results show that MAVS inhibits breast cancer cell proliferation , which will facilitate studies on the function of MAVS in tumors in the future .
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Objective To determine the effect of Salvia przewalskii extract of total phenolic acids (SPE) on puromycin aminonucleoside (PAN)-induced oxidative stress in podocytes of rats in vivo and the effect of SPE on PAN-induced oxidative stress in podocytes of mice in vitro. Methods (1) Nephropathy rat model was established by PAN and was given intervention with SPE and tacrolimus. The renal tissue samples were obtained for WT1 staining to calculate the number of podocytes on the 5th# 10th# 15th and 21st day. The intensities of 8-hydroxy-27-deoxyguanine (8-OHdG) were evaluated by immunofluorescence. (2)The podocytes of mice were exposed to PAN for 24 h in vitro#, and then SPE# salvianolic acid B (SalB) # rosmarinic acid (RA) or tacrolimus were added for 6# 12# 24# and 48 h culture. Then the cytoskeleton distribution of podocytes, indicated by F-actin# was observed by fluorescence microscopy, and the intracellular reactive oxygen species (ROS) production was measured by flow cytometry. Results (1) Decrease of podocytes per glomerular volume as measured by counting WT1-positive cells was started on day 5 in each group except normal control (NC) group# and on day 15 glomerular podocytes in PAN group was significantly less than that in the NC group ([14. 4 + 0. 7]/glomerular volume vs [37. 2 + 1. 5]/glomerular volume# P<0. 05). The numbers of glomerular podocytes in SPE group and positive group (tacrolimus group) were more than that in PAN group at all time points. The glomerular podocyte count of high-dose SPE group was similar to that of positive group on day 15 ([21. 7 + 1. 0]/glomerular volume vs [23. 6 + 1. 2]/glomerular volume# P<0. 05). After injection of PAN# 8-OHdG intensities were increased in each group except normal control group on day 5; and the intensities peaked on day 10 and then began to decrease# but still higher than that of the normal control group on day 15. The intensities of 8-OHdG in renal tissue was decreased after intervention# and those of the tacrolimus and high-dose SPE groups were similar. (2) In vitro study found that F-actin of podocytes was almost completely disrupted 24 h after PAN treatment# with disrupted filamentous structure. After the treatment with tacrolimus, SPE, SalB and RA# the PAN induced injury of podocytes was lessened# with reappeared polarity distribution of intracellular microfilaments. Compared with NC group# the ROS production in podocytes was significantly increased in PAN group (P<0. 05). After treatment of podocyte with drugs# the ROS production was decreased. The cellular ROS production of positive control group was similar to those in tacrolimus group, low-dose SPE group, high-dose SalB group and RA group at 24 h. Compared with RA,SalB had a better efficacy in reducing ROS# and the reducing effect had a positive relation with drug dose. Conclusion Our study suggests that SPE can protect podocytes from PAN-induced oxidant stress in vivo and in vitro.
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Objective To observe the expression and distribution of α-actin-4 mRNA through puromycin aminonueleoside(PAN) injury podocyte,and discuss the relation between α-actin-4 and podocyte damage.Methods Podocytes were cultured in vitro,and 2 groups were set up:control group and PAN stimulation group.The control group was cultured with concentration of 100 mL/L FBS RPMI 1640 nutrient solution culture,while the PAN group was cultivated to PAN(50 mg/L) treatment,and cell morphology,extraction of total RNA of α-actin-4 were observed in 8 h,24 h and 48 h.The podocyte morphology was observed and pictures were taken through phase-contrast microscope,then the differences of morphology and areas between the 2 groups were analyzed.The distribution and mRNA expression of α-actin-4 were detected by indirect immunocyto-fluorescence and real-time quantitative PCR,respectively.Results The well-developed podocyte arborization was formed after the in vitro induction,and the PAN treatment led to the podocyte foot process retraction and effacement together with the mouse podocyte cell line shrinkage and the loss of cell contact.The above time point α-actin-4 mRNA expressions between the 2 groups were compared,and there was no significant difference in 8 h (P ＞ 0.05),but significant difference was found in 24 h,48 h,α-actin-4 higher mRNA expression,with statistical significance(all P ＜0.01).α-actin-4 in the control group had thin filaments evenly distributed in the cytoplasm,but a radioactive distribution in foot process.In the experimental group,α-actin-4 pressure silk fiber was shorter,with disordered arrangement,and PAN stimulus after 24 h,α-actin-4 distribution in cytoplasm was decreased significantly,while cytoplasmic distribution was missing after 48 h.Conclusions The abnormal of distribution and mRNA expression of α-actin-4 is time-related to the PAN injury podocyte,and α-actin-4 is an important part of podocyte damage mechanism.
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Objective To compared two classical rat models of nephrotic syndrome and to provide some reference data to researchers.Methods Thirty male SD rats were randomly divided into control group,puromycin aminonucleoside-induced nephrotic syndrome (PAN) group and adriamycininduced nephrotic syndrome (ADR) group.The body weight,twenty four hour proteinuria level,serum albumin concentration,cholesterol concentration,creatinine and urea concentration were measured.The renal pathology change was evaluated.The drug toxic effects,administration methods and the costs were also compared.Results There was no significant difference in body weight and hair color between control group and PAN group.Compared to control group,the body weight of the rats significantly decreased at day 15 and day 21 in ADR group (P ＜ 0.01),accompanied by epilation and diarrhea.Compared to control group,the 24-hour urinary protein levels increased significantly at day 10 (P ＜ 0.01),day 15 (P ＜ 0.01),and reached the peak level at day 15 (P ＜ 0.01),day 21 (P ＜ 0.01) in PAN group and ADR group respectively.Compared to control group,the serum albumin concentration decreased significantly at day 10 (P＜0.01),and return to normal level at day 15.The serum cholesterol concentration was increased significantly at day 10 (P ＜ 0.01) and return to normal at day 15 in PAN group.Compared to control group,the serum albumin concentration was decreased significantly at day 15 (P＜0.05) and return to normal at day 21 in ADR group.No significant difference of serum creatinine and serum urea nitrogen levels were found among three groups.Compared to control group,the width of foot process increased significantly at day10 (P ＜ 0.01) and day 15 (P ＜ 0.05) in PAN group and ADR group respectively.To successfully induce a nephrotic rat model (per 100 g),the cost of PAN group was 3.1 times of ADR group (578.10 yuan vs 186.94 yuan).Conclusions Nephrotic syndrome can be induced by both PAN and ADR.The administration of PAN via intraperitoneal injection is more convenient as compared to ADR via tail intravenous injection.Compared to ADR,PAN can induce nephrotic syndrome model more rapidly,with more consistent detection index,and less toxic effects,but its cost is more expensive.
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PURPOSE: To test whether the expression of P-cadherin, a component of slit diaphragms between podocyte foot processes, would be altered by puromycin aminonucleoside (PAN) in a cultured podocyte in vitro. METHODS: Rat glomerular epithelial cells (GEpC) were cultured with various concentrations of PAN. The distribution of P-cadherin was examined with a confocal microscope. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the change in P-cadherin expression. RESULTS: This study found that P-cadherin was concentrated in the inner and peripheral cytoplasm with high concentrations of PAN under immunofluorescence views. Western blotting of GEpC revealed that PAN induced a decrease of P-cadherin in dose- and time-dependent manners. A high dose (50 microg/mL) of PAN decreased P-cadherin expression by 21.9% at 24 h (P<0.05) and 31.9% at 48 h (P<0.01) compared to those without PAN. In RT-PCR, high concentrations (50 microg/mL) of PAN also decreased P-cadherin mRNA expression, similar to protein suppression, by 23.5% at 48 h (P<0.05). CONCLUSION: Podocytes exposed to PAN in vitro concentrated P-cadherin internally, and reduced P-cadherin mRNA and protein expression. This could explain the development of proteinuria in experimental PAN-induced nephropathy.
Subject(s)
Animals , Rats , Ascorbic Acid , Blotting, Western , Cadherins , Cytoplasm , Diaphragm , Epithelial Cells , Fluorescent Antibody Technique , Foot , Glycyrrhetinic Acid , Podocytes , Proteinuria , Puromycin Aminonucleoside , Puromycin , RNA, MessengerABSTRACT
Objective To investigate the effect of fluvastatin (FLV) on the expression of β1 integrin in puromycin aminonucleoside (PAN)-treated podocytes and its mechanism.Methods Cultured human podocytes were divided into PAN,different concentrations of fluvastatin (1 × 10-8 to 1 × 10-5 mol/L),SOD,H2O21 groups respectively.Expressions of β1 integrin and reactive oxygen species (ROS) in podocytes were detected by Western blotting and DCFHDA (2' 7'-Dichlorofluoresecein 3' 6'-diacetate) respectively.The viability of podocyte was determined by MTT colorimetry.Results PAN and H2O2 significantly decreased the expression of β1 integrin and increased the synthesis of ROS in podocytes (P＜0.05respectively).Lower concentration fluvastatin or SOD treatment up-regulated β1 integrin and downregulated ROS of podocytes induced by PAN (P＜0.05 respectively).MTT revealed that lower podocyte viability was found in higher concentration fluvastatin,PAN and H2O2 groups.Lower concentration fluvastatin and SOD could protect podocytes against PAN.Conclusion Fluvastatin attenuates the injury of podocyte induced by PAN and increases the expression of β1 integrin,whose mechanism may be associated with the inhibition of the ROS activity.
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PURPOSE: Puromycin aminonucleoside (PAN) specifically injures podocytes, leading to foot process effacement, actin cytoskeleton disorganization, and abnormal distribution of slit diaphragm proteins. p130Cas is a docking protein connecting F-actin fibers to the glomerular basement membrane (GBM) and adapter proteins in glomerular epithelial cells (GEpCs; podocytes). We investigated the changes in the p130Cas expression level in the PAN-induced pathological changes of podocytes in vitro. METHODS: We observed changes in the p130Cas expression in cultured rat GEpCs and mouse podocytes treated with various concentrations of PAN and antioxidants, including probucol, epigallocatechin gallate (EGCG), and vitamin C. The changes in the p130Cas expression level were analyzed using confocal immunofluorescence imaging, Western blotting, and polymerase chain reaction. RESULTS: In the immunofluorescence study, p130Cas showed a diffuse cytoplasmic distribution with accumulation at distinct sites visible as short stripes and colocalized with P-cadherin. The fluorescences of the p130Cas protein were internalized and became granular by PAN administration in a dose-dependent manner, which had been restored by antioxidants, EGCG and vitamin C. PAN also decreased the protein and mRNA expression levels of p130Cas at high doses and in a longer exposed duration, which had been also reversed by antioxidants. CONCLUSION: These findings suggest that PAN modulates the quantitative and distributional changes of podocyte p130Cas through oxidative stress resulting in podocyte dysfunction.
Subject(s)
Animals , Mice , Rats , Actin Cytoskeleton , Actins , Antioxidants , Ascorbic Acid , Blotting, Western , Cadherins , Catechin , Crk-Associated Substrate Protein , Cytoplasm , Cytoskeleton , Diaphragm , Epithelial Cells , Fluorescent Antibody Technique , Foot , Glomerular Basement Membrane , Oxidative Stress , Podocytes , Probucol , Proteins , Puromycin , Puromycin Aminonucleoside , RNA, MessengerABSTRACT
PURPOSE: To test whether the expression of beta-catenin, a component of podocyte as a filtration molecule, would be altered by puromycin aminonucleoside (PAN) in the cultured podocyte in vitro. METHODS: We cultured rat glomerular epithelial cells (GEpC) with various concentrations of PAN and examined the distribution of beta-catenin by confocal microscope and measured the change of beta-catenin expression by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: We found that beta-catenin relocalized from peripheral cytoplasm to inner cytoplasm, therefore, intercellular separations were seen in confluently cultured cells by high concentrations of PAN in immunofluorescence views. In Western blotting of GEpC, PAN (50 microg/mL) decreased beta-catenin expression by 34.9% at 24 hrs and 34.3% at 48 hrs, compared to those in without PAN condition (P<0.05). In RT-PCR, high concentrations (50 microg/mL) of PAN also decreased beta-catenin mRNA expression similar to protein suppression by 25.4% at 24 hrs and 51.8% at 48 hrs (P<0.05). CONCLUSION: Exposure of podocytes to PAN in vitro relocates beta-catenin internally and reduces beta-catenin mRNA and protein expression, which could explain the development of proteinuria in experimental PAN-induced nephropathy.
Subject(s)
Animals , Rats , Ascorbic Acid , beta Catenin , Blotting, Western , Cells, Cultured , Cytoplasm , Epithelial Cells , Filtration , Fluorescent Antibody Technique , Glycyrrhetinic Acid , Podocytes , Proteinuria , Puromycin , Puromycin Aminonucleoside , RNA, MessengerABSTRACT
Proteinuria is a major promoter that induces tubulointerstitial injury in glomerulopathy. Dietary salt restriction may reduce proteinuria, although the mechanism is not clear. We investigated the effects of dietary salt restriction on rat kidneys in an animal model of glomerular proteinuria. Male Sprague-Dawley rats were used and divided into 3 groups: vehicle-treated normal-salt controls, puromycin aminonucleoside (PA)-treated normal-salt rats, and PA-treated low-salt rats. PA was given at a dose of 150 mg/kg BW at time 0, followed by 50 mg/kg BW on days 28, 35, and 42. Sodium-deficient rodent diet with and without additional NaCl (0.5%) were provided for normal-salt rats and low-salt rats, respectively. On day 63, kidneys were harvested for histopathologic examination and immunohistochemistry. PA treatment produced overt proteinuria and renal damage. Dietary salt restriction insignificantly reduced proteinuria in PA-treated rats, and PA-treated low-salt rats had lower urine output and lower creatinine clearance than vehicle-treated normal-salt controls. When tubulointerstitial injury was semiquantitatively evaluated, it had a positive correlation with proteinuria. The tubulointerstitial injury score was significantly increased by PA treatment and relieved by low-salt diet. ED1-positive infiltrating cells and immunostaining for interstitial collagen III were significantly increased by PA treatment. These changes appeared to be less common in PA-treated low-salt rats, although the differences in PA-treated normal-salt versus low-salt rats did not reach statistical significance. Our results suggest that renal histopathology in PA nephrosis may potentially be improved by dietary salt restriction. Non-hemodynamic mechanisms induced by low-sodium diet might contribute to renoprotection.