Sinkihwan-gamibang ameliorates puromycin aminonucleoside-induced nephrotic syndrome / 中国天然药物

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.

Effect of astragaloside IV combined with glucocorticoids on puromycin aminonucleoside-induced rat nephropathy model and the associated mechanism / 中华肾脏病杂志

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.

Effect of Tacrolimus on the eXpression of α-actinin-4 in podocytes induced by Puromycin aminonucleoside / 中华实用儿科临床杂志

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.

Protective effect of extractum trametes robiniophila murr on puromycin aminonucleoside-induced podocyte injury in vitro of mice and its mechanism / 吉林大学学报(医学版)

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.

Effect of Tacrolimus on the expression of α-actinin-4 in podocytes induced by Puromycin aminonucleoside / 中华实用儿科临床杂志

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.

Puromycin aminonucleoside triggers apoptosis in podocytes by inducing endoplasmic reticulum stress

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.

Salvia przewalskii extract of total phenolic acids against puromycin aminonucleoside-induced oxidative stress in podocytes in vitro and in vivo / 第二军医大学学报

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.

Effect of Puromycin Aminonucleoside on Podocyte P-Cadherin

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.

Comparison of two nephrotic syndrome rat models / 中华肾脏病杂志

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.

Puromycin aminonucleoside modulates p130Cas of podocytes / 소아과

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.

Fluvastatin attenuates the down-regulation of β1 integrin expression in PAN-treated podocytes by inhibiting ROS / 中华肾脏病杂志

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.

The Change of Podocyte beta-Catenin by Puromycin Aminonucleoside

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.

Changes in Endothelin Receptor Type B and Neuronal Nitric Oxide Synthase in Puromycin Aminonucleoside-Induced Nephrotic Syndrome

The collecting duct endothelin (ET) system, which involves ET-1 and its two receptors, may play a role in the regulation of renal sodium in association with the nitric oxide synthase (NOS) system. We determined whether sodium retention is associated with changes in the endothelin and NOS systems at different stages (i.e., a sodium retaining stage and a compensatory stage) of nephrotic syndromes. On day 7 after puromycin aminonucleoside (PAN) injection, urinary sodium excretion was decreased, ascites had developed, and there was a positive sodium balance. ET-1 mRNA expression was increased in the inner medulla of the kidney, whereas protein expression of ET receptor type B (ET(B)R) was unchanged. The expression of neuronal NOS (nNOS) was decreased in the inner medulla. On day 14, urinary sodium excretion was unchanged compared with controls. The expression of ET(B)R increased, while nNOS expression in the inner medulla was comparable to controls. These findings suggest that decreased nNOS plays a role in the development of sodium retention in the nephrotic syndrome. Recovery of nNOS and increased renal ET(B)R synthesis may promote sodium excretion in later stages of the nephrotic syndrome (on day 14).

Effects of Celecoxib and Nordihydroguaiaretic Acid on Puromycin Aminonucleoside-Induced Nephrosis in the Rat

The selective cyclooxygenase-2 (COX-2) and 5-lipoxygenase (LOX) inhibitors might inhibit prostaglandin synthesis and reduce proteinuria. The present study was designed to investigate the anti-proteinuric effects of nordihydroguaiaretic acid (NDGA) as compared with celecoxib in puromycin aminonucleoside (PAN) nephrosis rats. Fifty five male Sprague-Dawley rats were divided into 4 groups; A, normal control; B, PAN group; C, PAN+COX-2 inhibitor (celecoxib) group; and D, PAN+5-LOX inhibitor (NDGA) group. After induction of PAN nephrosis through repeated injections of PAN (7.5 and 15 mg/100 g body weight), rats were treated with celecoxib, NDGA, or vehicle for 2 weeks. Twenty four hour urine protein excretions were significantly lower in PAN+celecoxib and PAN+NDGA groups than in PAN group. Serum creatinine (SCr) concentrations and 24 hr urine creatinine clearances (CCr) were not significantly different in the four groups. Electron microscopy showed that podocyte morphology was changed after the induction of PAN nephrosis and was recovered after celecoxib or NDGA administration. Celecoxib significantly recovered the expressions of nephrin, CD2AP, COX-2, and TGF-beta. NDGA also recovered TGF-betaexpression, but did not alter the expressions of nephrin, CD2AP and COX-2. The present study suggested that celecoxib and NDGA might effectively reduce proteinuria in nephrotic syndrome without impairing renal function.

Effect of Down-regulation of TRPC6 on the Puromycin Aminonucleoside-induced Apoptosis of Mouse Podocytes / 华中科技大学学报（医学）（英德文版）

poptosis induced by PAN.

Dexamethasone inhibits puromycin aminonucleoside-induced injury of mouse glomerular podocytes via stabilizing the expression and distribution of podocin in vitro / 中华肾脏病杂志

Objective To observe the effects of puromycin aminonucleoside (PAN) and dexamethasone (DEX) on the expression and distribution of pedocin in vitro, and to explore the possible mechanism of DEX in improving proteinuria. Methods Mouse podecyte cells (MPCs) in control group were cultured with RPMI-1640 plus 0.02% DMSO, and were subjected to PAN treatment alone (PAN group) or PAN plus DEX (DEX group) for 8, 24,48 hours respectively. The pedocyte morphology was observed by phase-contrast microscope, and was analyzed by Image J. The distribution, mRNA and protein expression of podocin were detected by indirect immunocytofluorescence, semi-quantitative RT-PCR and Western blot, respectively. Results The well-developed arborization and interconnection of podocytes were found in control group. PAN treatment led to significant shrinkage of pedocytes with decreased distribution at 43% of control group at 8 h, 10% at 24 h and 5.7% at 48 h (P<0.01), respectively, together with podocyte foot process retraction as well as effacement and loss of cell contact. RT-PCR revealed podoein mRNA expression prone to decrease. Western blot showed podoein protein expression was significantly decreased and immunocytochemistry revealed podoein expression was disappeared in the cellular membrane after PAN treatment. DEX significantly prevented the shrinkage of podcytes, with decreased area at 43.9% of control at 8 h, 26.2% at 24 h and 29.6% at 48 h (P<0.05), respectively, and up-regulated the mRNA and protein expression of podocin at 48 h (P<0.05). The abnormal distribution of podocin was also alleviated by DEX. Conclusion DEX exerts a direct action on podocyte via stabilizing mRNA, protein expression and distribution of podocin, which may be associated with the improvement of proteinuria.

Changes of Atrial Natriuretic Peptide System in Rats with Puromycin Aminonucleoside-Induced Nephrotic Syndrome

Sodium retention is a hallmark of nephrotic syndrome. We investigated whether sodium retention is associated with changes of natriuretic peptide system at different stages (i.e., a sodium retaining stage and a compensatory stage) of nephrotic syndrome. At day 7 after PAN (puromycin aminonucleoside) injection, the urinary excretion of sodium was decreased, along with the development of ascites and positive sodium balance. The plasma and urinary ANP (atrial natriuretic peptide) immunoreactivities were increased. ANP mRNA expression was increased in the heart and kidney, whereas that of NPR (natriuretic peptide receptor)-A and NPR-C mRNA was decreased in the kidney. The expression of NEP was decreased in the kidney. At day 14, urinary excretion of sodium did not differ from the control. The plasma ANP level and heart ANP mRNA expression returned to their control values. The expression of ANP mRNA in the kidney was increased in association with increased urinary ANP immunoreactivities. The expression of NPR-A in the kidney became normal, whereas that of NPR-C kept decreased. The expression of NEP (neutral endopeptidase) remained decreased. These findings suggest that the increased renal ANP synthesis in association with decreased metabolism via NEP and NPR-C may play a compensatory role against the development of sodium retention in nephrotic syndrome. The decreased of NPR-A expression in the kidney may contribute to the ANP resistance at day 7. The subsequent recovery of NPR-A expression may play a role in promoting sodium excretion in later stage (at day 14).

Down-regulation of nestin expression in the glomeruli with foot process effacement and its correlation with the degree of proteinuria / 中华肾脏病杂志

Objective To investigate the expression of nestin, a type Ⅵ intermediate filament protein in the glomeruli with foot process effacement and the potential relationship between nestin expression in the kidney and the degree of proteinuria. Method Immunohistochemistry was used to determine the localization of nestin in the kidney samples obtained from needle biopsies of normal human and patients with minimal change disease (MCD). Puromycin aminonucleoside (PAN) nephrosis rat models were established by a single intraperitoneal injection of PAN. Both real time quatitative reverse PCR and Western blot methods were applied to evaluate the levels of nestin expression at day 1, 4, 10 and 20 after PAN injection. Results Immunohistochemistry showed that the expression of nestin in glomeruli of MCD patients was significantly reduced compared with normal samples (0.93±0.08 vs 1.65±0.12, P<0.05) . The mRNA and protein expressions of nestin in the rat kidney were transitorily increased by 1.23 folds and 1.48 folds of control group (NC) after 1 day of PAN injection (P<0.05), then decreased quickly in the following days. The mRNA levels of nestin in the kidney were 35.8% and 12.1% of NC after 4 days and 10 days of PAN injection, respectively, (P<0.01) as determined by real time PCR. After 20 days of PAN injury, nestin mRNA expression partly recovered to 65.8% of NC (P< 0.05 ). The protein levels of nestin detected by Western blot presented the similar trend, which were 77.0%, 58.0% and 83.4% of NC after 4 days, 10 days and 20 days of PAN injection, respectively (P<0.05). The degree of proteinuria in puromycin aminonucleoside nephrosis rats was negatively correlated with both mRNA and protein levels of nestin in the kidney(r=-0.667,P<0.05 and r=-0.621 ,P<0.05, respectively). Conclusions The expression of intermediate filament protein nestin is down-regnlated in the kidney characterized with foot process effacement and negatively correlated with the degree of proteinuria in puromycin aminonucleoside nephrosis rats. Nestin may play a potential role in modulating the structure and function of podocyte.

Podocyte apoptosis is suppressed by 1,25(OH)2D3 in puromycin aminonudeoside nephropathy rats / 中华肾脏病杂志

ObjectiveTo evaluate the effects of 1,25(OH)zD3 on podocyte apoptosis in kidney of puremyein aminonueleoside nephropathy (PAN) rats. Methods Seventy-two male Sprague-Dawley rats were randomly divided into three groups: PAN model group(PAN), 1,25 (OH)2D3 treated group (T, 0.2 μg·kg-1d-1 by garages) and normal control group (NC). PAN rat model was constructed by a single intravenous injection of 100 mg/kg body weight. Renal function and 24hour urinary protein were measured at day 3, 7, 14, 21 after PAN injection. The renal tissue morphology was observed by light and electron microscope. Podocyte apeptosis was evaluated by TUNEL. Protein expressions of nephrin, TGF-β1 and p-Smad2/3 were examined by immunofluoreacence, immunohistochemistry and Western blot, respectively. Results(1)The levels of serum creafinine, BUN and 24-h urinary protein [(20.26±4.87) mg vs (1.01±0.41) mg at day 7, P ＜0.01] were significantly higher and the number of glomerular pedocyte was significantly lower [(10.9±4.2)/glomerular volume vs (31.9±6.2)/glomerular volume at day 14, P＜0.01] in PAN group compared with NC group. T group rats had less urinary protein excretion [(9.95±3.82) mg/24 h, P＜0.01] and more glomerular podocytes compared with PAN group. (2) Distribution of nephrin expression was changed from linear to granular pattern in PAN rats on day 7, nephrin mRNA and protein expressions were markedly decreased(P＜0.01), while the number of apoptotic podocyte was increased in PAN group(P＜0.01). However, higher nephrin expression and less apoptotic podocytes were found in T group (P＜0.01). (3) Compared with NC group, the mRNA and protein expression of TGF-β1 and p-Smad2/3 were higher in PAN group (P＜0.01), while 1,25 (OH)2D3 treatment abrogated PAN-induced changes in the expression of TGF-β1 and p-Smad2/3 (P＜0.01). Conclusions 1,25 (OH)2D3 can significantly suppress PAN-induced podocyte apoptosis and ameliorate proteinnuria. The beneficial effect of 1,25(OH)2D3 on podocyte may contribute to direct suppression of TGF-β signaling.

The Effects of Selective Cyclooxygenase-2 Inhibition in Puromycin Aminonucleoside Nephropathy Rats / 대한신장학회잡지

BACKGROUND: It is known that non-steroidal antiinflammatory drugs (NSAIDs) reduce the amount of proteinuria in nephrotic syndrome. It is based on the facts that the NSAIDs block the production of prostaglandins. Therefore selective cyclooxygenase-2 (COX-2) inhibitor may be expected to play a role in reduction of the proteinuria in nephrotic syndrome. METHODS: Twenty-seven Sprague-Dawley rats were divided into 3 groups. After 3 to 5 days of adaptation, we gave puromycin aminonucleoside to groups A and B via intraperitoneal route. The third group C was a normal control group. Selective COX-2 inhibitor was orally given to group A for 2 weeks. Each group was divided again into 3 subgroups by the day of experiment: 1, 14 and 21-day subgroups. We checked the changes in the serum and urine creatinine, albumin concentrations, creatinine clearances, the amount of proteinuria and the pathologic findings. The differences between groups were tested by 2-way ANOVA and Dunnett T-test, and the changes of proteinuria were tested by Repeated measures ANOVA. RESULTS: The changes of 24-hour urine protein excretion were significantly different between three groups (p<0.01). Protein excretion of group A was significantly decreased, especially between 14 and 21 days (p<0.05). The changes of creatinine clearance were significantly different between three groups (p<0.05), between 1 and 21 days (p<0.05). Electron microscopy showed morphological recovery of foot processes after administration of selective COX-2 inhibitor in PAN nephropathy rats (group A). CONCLUSION: It is suggested that selective COX- 2 inhibitors may be effective in reducing proteinuria and protecting the renal function in nephrotic syndrome.