Exogenous hydrogen sulfide attenuates obstructive kidney injury in mice

AIM:To investigate the protective effect of exogenous hydrogen sulfide (H₂S) on obstructive renal injury in mice, and to explore the possible potential mechanisms involved in this animal model. METHODS:Male C57BL/6 mice (8 weeks old) were randomly divided into sham group, operation group and H₂S group, with 5 rats in each group. The model of obstructive renal injury was induced by unilateral ureteral obstruction (UUO). The mice in H₂S group were intraperitoneally injected with NaHS daily, while the mice in sham group and operation group were administered with the same volume of saline intraperitoneally. After 7 d, the mice were executed and the renal tissues were taken out for experiments. RNA was extracted to detect the mRNA expression of H₂S catalytic enzymes in the mice of 3 groups. HE staining was performed to observe the structural changes of renal tissues in the mice. Renal fibrosis in the mice of 3 groups was evaluated by Masson staining. The content of cystatin C in the plasma was detected to reflect glomerular filtration ability. The protein expression of LC3, beclin-1 and fibronectin (FN) in the mice of 3 groups was determined by Western blot. RESULTS:Compared with sham group, the mRNA expression of cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) in operation group decreased significantly. The collagen fiber content in operation group was increased significantly, while collagen fiber content in H₂S group was decreased significantly as compared with operation group. Compared with sham group, the protein expression of FN in operation group was increased significantly, while the protein expression of FN in H₂S group was decreased significantly as compared with operation group. Compared with sham group, the protein expression of LC-Ⅱ and beclin-1 in operation group was increased significantly, while the protein expression of LC-Ⅱ and beclin-1 in H₂S group was increased significantly as compared with the operation group. CONCLUSION:Exogenous H₂S possibly mitigates renal fibrosis in UUO mice by up-regulating autophagy.     

Increased fucosyltransferase 8 expression in rat kidney with unilateral ureteral obstruction

AIM: To investigate the effect of fucosyltransferase 8 (FUT8) on rat renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO). METHODS: Ninety male Wistar rats were randomly divided into normal control group (control), sham operation group (sham) and UUO group, and sacrificed on day 1, 3, 7, 14 and 21 after operation. Serum creatinine and urea nitrogen were detected to assess renal function. PAS and Masson staining were used to observe histological changes of the rat kidneys. The time-correlated expression of FUT8 in the kidney was monitored by RT-PCR and Western blotting. The protein expression levels of FUT8 and activin receptor-like kinase 5(ALK5) were determined by immunofluorescence double-staining. Immunohistochemical staining was also used to assess the protein expression of fibronectin (FN), type I collagen (Col I) and α-smooth muscle actin (α-SMA). RESULTS: Compared with control group, serum creatinine and urea nitrogen in UUO group elevated on day 3 after operation (P<0.05) and reached the peak value on day 21 after operation (P<0.01). Renal tubule atrophy and renal interstitial fibrosis were observed in UUO group 7 and 14 days after operation. The mRNA and protein expression levels of FUT8 increased markedly in UUO group on day 3 (P<0.05) and reached its peak value on day 14 and 21 after operation (P<0.01). The results of immunofluorescence and immunohistochemistry showed that FUT8 and ALK5 were coexpressed in renal tubulointestitium. FN, Col I and α-SMA were significantly elevated in UUO group (P<0.05), and were positively correlated with the expression of FUT8 (P<0.05).CONCLUSION: The expression of FUT8 influences the progress of renal interstitial fibrosis, tubule atrophy and inflammatory cell infiltration in the kidney.     

p38MAPK expression and apoptosis in the rat unilateral ureteral obstruction model

AIM: To investigate the expression of p38 mitogen-activated protein kinase (p38MAPK) in the kidney after unilateral ureteral obstruction (UUO) in rats and the functional role of it on apoptosis and fibrosis.METHODS: Eighteen Wistar rats underwent UUO were killed at 3, 7, 14 days. Additional 7 rats were sham operated. Histological changes were observed by HE and Masson staining. Immunohistochemistry study was performed on renal tissue for proliferating cell nuclear antigen (PCNA). Apoptotic cells were determined by terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling (TUNEL) and the electrophoresis analysis of genomic DNA. Western blotting of cysteinyl aspartate specific proteinase-3 (caspase-3), p38MAPK and p-p38MAPK were measured.RESULTS: UUO induced a significant increase in renal tubular and interstitial cell apoptosis, immunohistochemistry of PCNA and Western blotting of caspase-3, p-p38MAPK as well as severe morphology changes. However, there was no significant difference between UUO and the control in Western blotting of p38MAPK.CONCLUSION: An in vivo model of renal fibrosis after UUO demonstrates that activated or phosphorylated p38MAPK plays a role in apoptosis of renal tubulointerstitial cells.     

Role of hypoxia stimulated expression of connective tissue growth factor in renal interstitial fibrosis

AIM: To study the expression of connective tissue growth factor (CTGF) induced by hypoxia, and the role and mechanism of hypoxia on promoting renal interstitial fibrosis. METHODS: Renal interstitial fibrosis was induced by unilateral ureteral obstruction (UUO) in rat animal model for 9 days as in vivo studies; marker of hypoxia-HIF-1α mRNA and protein, the expression of CTGF in the obstructed kidneys were assessed by RT-PCR, immunohistochemistry and Western blotting respectively. In vitro, normal rat kidney interstitial fibroblast cells (NRK-49F) were exposed to hypoxia (1%O2) for up to 6 hours, hypoxia was confirmed by detecting the expression of HIF-1α protein in cells, cellular level of CTGF mRNA and protein were assessed by RT-PCR and Western blotting respectively. RESULTS: Neither HIF-1α mRNA nor HIF-1α protein was expressed in the kidney from sham-operated group of rats. High level of HIF-1α mRNA were occurred, and strongly HIF-1α positive immunostaining were seen in the tubular and interstitial cells in kidney from UUO rats. Expression and location of CTGF protein were paralleled and relevant with the expression of HIF-1α protein in kidney of UUO rats. In cultured NRK-49F cell line, subjected to hypoxia even for 6 hours stimulated the expression of CTGF mRNA and protein. CONCLUSION: Our results indicated that hypoxia could stimulate the expression of CTGF mRNA and protein in kidney from UUO rats, which may in turn contribute to renal interstitial fibrosis.     

Effect of Qiliqiangxin granule on apoptosis of renal tissues in rats with cardiorenal syndrome

AIM: To investigate the effect of Qiliqiangxin granule on the apoptosis of renal tissues in rats with cardiorenal syndrome (CRS) and its possible mechanism. METHODS: A rat model of CRS was established by ligation of the left anterior descending coronary artery and acute renal ischemia/reperfusion injury. After operation, the rats were divided into 6 groups:2-week sham operation (2w sham) group, 2-week model (2w CRS) group, 2-week drug (2w CRS-Q) group, 4-week sham operation (4w sham) group, 4-week model (4w CRS) group and 4-week drug (4w CRS-Q) group. The rats in 2w CRS-Q group and 4w CRS-Q group were given Qiliqiangxin granule (4 g·kg^-1·d^-1) by gavage for 2 weeks and 4 weeks, respectively. The levels of serum cystatin C (Cys-C), plasma angiotensin Ⅱ (Ang Ⅱ), urine neutrophil gelatinase-associated lipocalin (NGAL) and urine microalbumin (UMA) were measured by ELISA. The serum level of creatinine (Cre) was detected by sarcosine oxidase method. The renal histopathological changes were observed by HE staining. The mRNA and protein expression levels of Ang Ⅱ, Bcl-2 and Bax were evaluated by RT-qPCR and Western blot, respectively. The apoptosis rate of renal cells was assessed by TUNEL staining. RESULTS: The levels of serum Cys-C, serum Cre, plasma Ang Ⅱ, urine NGAL and UMA were significantly increased in 2w CRS group and 4w CRS group compared with 2w sham group and 4w sham group after modeling (P<0.05). The mRNA and protein expression levels of Bax and Ang Ⅱ in the renal tissues of CRS rats were significantly up-regulated (P<0.05), while Bcl-2 was significantly down-regulated (P<0.05) compared with 2w sham group and 4w sham group. Compared with 2w sham group and 4w sham group, the damage of renal tissues in 2w CRS and 4w CRS group was severe, and the apoptotic rates of renal cells were significantly increased. Compared with 2w CRS group and 4w CRS group, Qiliqiangxin granule greatly decreased the levels of Cys-C, Cre, Ang Ⅱ, NGAL and UMA, down-regulated the mRNA and protein expression levels of Bax and Ang Ⅱ in the renal tissues, and up-regulated the expression of Bcl-2 at mRNA and protein levels at 2 and 4 weeks. In addition, Qiliqiangxin granule also greatly attenuated the damage and apoptosis of the renal tissues. CONCLUSION: Qiliqiangxin granule significantly inhibits the apoptosis of renal tissues and improves the renal function of CRS rats, and its mechanism may be related to the inhibition of Ang Ⅱ expression.     

Effect of Kang Xianling decoction on TGF-β1-Smad pathway in a unilateral ureteral obstruction rat model

AIM: To study the effect of Kang Xianling decoction,comprised of dahuang,danshen,taoren,niuxi and danggui,on TGF-β₁-Smad pathway in unilateral ureteral obstruction rat model.METHODS: Eighteen male SD rats were divided into 3 groups,sham group,model group and model group treated with Kang Xianling decoction randomly.Renal interstitial fibrosis model was established in rats by unilateral ureteral obstruction (UUO).After treatment for additional 14 d,parameters of hydroxyproline in obstructed kidney from 3 groups were analyzed.Rats were sacrificed and the pathological statuses of their kidneys were checked by HE staining and electron microscopy.Transforming growth factor-β₁ (TGF-β₁) mRNA in kidney tissue was determined by RT-PCR.TGF-β₁ receptor Ⅰ (TβRⅠ),TGF-β₁ receptorⅡ (TβRⅡ),phosphorylated Smad2 and Smad2 protein were determined by Western blotting.RESULTS: Parameters of hydroxyproline in animals of model group were significantly increased than those in sham operation group (P<0.05).The mRNA expression of TGF-β₁ and the protein expression of TβRⅠ,TβRⅡ,phosphorylated Smad2 and Smad2 in kidney tissue of animals in model group were significantly up-regulated.After intervention with Kang Xianling decoction,the above-mentioned up-regulated parameters,except TGF-β₁,were all significantly inhibited.Compared to model group,the pathological changes in renal tissues in treatment group were remarkable improved.CONCLUSION: Kang Xianling decoction inhibits the TGF-β₁-Smad pathway and the protein expression of TβRⅠ,TβRⅡ,phosphorylated Smad2 and Smad2,so as to decrease the level of collagen in obstructed kidney and to alleviate the renal interstitial fibrosis in UUO rats.     

PAI-1,TIMP-1 gene expression in renal tubulointerstitial fibrosis of ureteral obstruction and the interfering effects of HGF treatment

AIM: The aim of this study was to determine the relationship between PAI-1,TIMP-1 gene expression and renal tubulointerstitial fibrosis(TIF) of ureteral obstruction ,and the interfering effects of hepatocyte growth factor (HGF) treatment. METHODS: Sixty rats were divided into normal control, sham operation,unilateral ureteral obstruction(UUO),and rhHGF treated groups (received 0.5 mg·kg^-1·d^-1 HGF for twenty-one days), and were sacrificed at postoperative day 3, 7, 14, 21. The levels of PAI-1, TIMP-1 mRNA were measured by RT-PCR. MMP2 and MMP9 activities were detected by substrate zymography, and renal fibrosis was assessed by measuring tissue hydroxyproline. RESULTS: Compared to controls, expression levels of PAI-1,TIMP-1 mRNA were significantly increased in UUO rats, and this was accompanied by decreased activities of MMP2 and MMP9 and increase in tissue hydroxyproline content. HGF treatment significantly decreased expressions of PAI-1, TIMP-1 mRNA, increased MMP2 and MMP9 activities,and decreased tissue hydroxyproline content in the obstructive kidney. CONCLUSIONS: These results indicate that the increases in PAI-1, TIMP-1 mRNA expression may be the major cause of sustained decreased matrix degradation during the development of tubulointerstitial fibrosis after unilateral ureteral obstruction. rhHGF efficiently ameliorates renal tubulointerstitial injury by the reduction of PAI-1,TIMP-1 mRNA expression, and increasing MMP2, MMP9 activities.     

Expression of Sonic hedgehog pathway-related genes in kidney tissues of rats with unilateral ureteral obstruction

AIM: To investigate the role of Sonic hedgehog (Shh) signaling pathway in renal interstitial fibrosis in the rats with unilateral ureteral obstruction (UUO). METHODS: Forty-eight male Sprague-Dawley rats were divided randomly into sham operation group and UUO model group with 24 rats each. The kidneys were excised on day 3, 7, and 14, and the deposition of collagen fiber in the kidneys was detected with HE and Masson staining. Immunohistochemical analysis was performed to evaluate the expression of Shh signaling pathway-related proteins, including Shh, Smo,Ptch1 and Gli1. The contents of TGF-β₁ and Shh in the kidney tissues were determined by ELISA. Real-time RT-PCR was used to detect the mRNA expression of TGF-β₁, Col I, Col III and Shh signaling-related genes.RESULTS: Fibrosis observed with HE and Masson staining was obviously increased in UUO kidneys, and aggravated as time prolonged. The contents of TGF-β₁, Col I and Col III were also increased. In addition, the expression of Shh, Smo and Gli1 was markedly increased in obstructive kidneys, and the expression of Ptch1 was decreased (P<0.01), suggesting that Shh signaling was activated. The level of Shh in UUO rats was associated with the content of TGF-β₁. CONCLUSION: Shh signaling is activated in the progress of renal interstitial fibrosis in UUO rats, and the possible mechanism triggering the fibrogenic response is that Shh signaling promotes the expression of TGF-β₁.     

Role of miR-219 and TGFBR2 in pathogenesis of renal fibrosis

AIM:To study the role of microRNA-219 (miR-219) in regulation of transforming growth factor-β receptor type 2 (TGFBR2) in renal fibrosis. METHODS:The renal fibrosis patients (n=70) were selected in this stu-dy, and 20 cases of healthy people were selected as control group. RT-qPCR was used to detect the expression of miR-219 in the serum of the patients with renal fibrosis and control group, and the expression of miR-219 in NRK49F cells after stimulation with angiotensin Ⅱ(AngⅡ) was detected. The protein expression of α-smooth muscle actin (α-SMA) in the NRK49F cells transfected with miR-219 mimics after stimulation with AngⅡ was determined by Western blot. The potential target gene TGFBR2 of miR-219 was screened and verified by the method of luciferase reporter gene. RT-qPCR and Western blot were used to detected the effect of miR-219 mimics on the expression of TGFBR2 at mRNA and protein levels, and the mRNA expression of α-SMA, connective tissue growth factor (CTGF), type I collagen α1 (COL1A1) and COL3A1 in the NRK49F cells was also detected, respectively. The unilateral ureteral occlusion (UUO) mouse model was established and the expression of miR-219 in the renal tissue was monitored. The morphological change of renal fibrosis was observed in the UUO mice after injection of miR-219, and the mRNA expression levels of COL1A1 and COL3A1 were detected. RESULTS:The expression level of miR-219 in the patients with renal fibrosis was significantly lower than that in control group, and the expression of miR-219 in the UUO mice was decreased significantly (P<0.01). The expression level of miR-219 was significantly decreased in the NRK49F cells after AngⅡ stimulation, and miR-219 mimics inhibited the protein expression of α-SMA(P<0.01). miR-219 mimics had a targeted regulatory effect on TGFBR2 gene, which inhibited the mRNA and protein expression of TGFBR2. miR-219 mimics inhibited the mRNA expression of α-SMA, CTGF, COL1A1 and COL3A1. miR-219 also down-regulated the mRNA expression of COL1A1 and COL3A1 in the UUO mice and inhibited the process of renal fibrosis. CONCLUSION:miR-219 inhibits the development of renal fibrosis by inhibiting the expression of TGFBR2, which may become a new target for the diagnosis and treatment of renal fibrosis.     

Expression of connective tissue growth factor in the renal tissue of rats with unilateral ureteral obstruction

AIM: To detect the expression of connective tissue growth factor (CTGF), transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in rat unilateral ureteral obstructive (UUO) nephropathy animal model, and to observe the kinetic changes at different stages of firosis. METHODS: Male SD rats were subjected to either left ureteral ligation or sham operation, then killed at 3, 7, 14, 21 or 28 days after UUO or sham operation (n=6 at each time point). HE, Masson or PAS staining were applied to the renal tissue sections. The extent of tubulointerstitial injury was determined by Banff classification. RESULTS: The extent of tubulinterstitial fibrosis became serious with the time of obstruction. Tubules were mostly atropic and replaced by proliferative fibrous tissue at day 28. The expression of CTGF and α-SMA were consistent with the damage of tubulointerstitial. The positive correlation among CTGF or α-SMA and the tubulointerstitial injury scores were significant. The expression of TGF-β1 came to peak at day 7 to 14, and gradually decreased at day 21 and 28. CONCLUSION: These results indicate that the expression of CTGF may be upregulated by TGF-β in UUO rats, and CTGF may be involved in tubulointerstitial fibrosis through the development of myofibroblasts.     

Effect of Yiqi Huayu Huatan decoction on expression of KLF15, HMGB1, NF-κB and its downstream inflammatory factors in rats with UUO-induced renal interstitial fibrosis

AIM: To observe the effect of Yiqi Huayu Huatan decoction (YHHD) on unilaterral ureteral obstruction (UUO)-induced renal interstitial fibrosis in rats, and to investigate the possible mechanism. METHODS: Female SD rats (n=48) were randomly divided into sham group, model group, telmisartan group, and low-, middle-and high-dose YHHD groups, with 8 rats in each group. The UUO model rats was established by ligating left ureter. The rats in sham group and model group were treated with equal volume of normal saline, others were treated with the corresponding drugs daily. After 12 weeks, the rats were sacrificed. The serum samples were collected for determining the concentrations of cystatin C (Cys-C) and uric acid (UA). The morphological changes of the renal tissue were observed by PAS staining. The collagen fiber was observed by Masson staining. The mRNA expression of Krüppel-like factor 15 (KLF15), high-mo-bility group box protein 1 (HMGB1), nuclear factor-κB (NF-κB), IκB, monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), fibronectin (FN), collagen type I (Col I) and Col-Ⅳ was detected by real-time PCR. The protein expression of KLF15, HMGB1 and NF-κB was detected by Western blot. The protein expression of MCP-1 was determined by the method of immunohistochemistry. RESULTS: Compared with sham group, the deposition rate of collagen fibers and the concentration of Cys-C in model group were significantly increased (P<0.05), the mRNA and protein expression of KLF15 was significantly down-regulated (P<0.05), while the mRNA expression of HMGB1, NF-κB, IκB, MCP-1, IL-1β, TNF-α, FN, Col I and Col Ⅳ and the protein expression of HMGB1, NF-κB and MCP-1 were significantly up-regulated (P<0.05). Compared with model group, the deposition rates of collagen fibers in middle-and high-dose YHHD groups and telmisartan group were significantly decreased (P<0.05), with down-regulated protein expression of HMGB1 and NF-κB and mRNA expression of IL-1β and TNF-α (P<0.05). The protein expression of KLF15 was significantly up-regulated in high-dose YHHD group and telmisartan group (P<0.05), while the protein expression of MCP-1 and the mRNA expression of FN were significantly down-regulated (P<0.05). The mRNA expression of KLF15 was significantly up-regulated in high-dose YHHD group (P<0.05), while the mRNA expression of MCP-1, Col I and Col IV was significantly down-regulated (P<0.05). The mRNA expression of NF-κB and IκB was significantly down-regulated and the concentration of Cys-C was significantly decreased in each dose of YHHD groups and telmisartan group (P<0.05). No significant difference of UA level among the groups was observed. CONCLUSION: YHHD alleviates renal interstitial fibrosis in a dose-dependent manner, and YHHD at high dose shows the most obvious effect. The mechanism may be associated with the up-regulation of KLF15 and the down-regulation of HMGB1, NF-κB and its downstream inflammation-related factors in the renal tissue.     

Effects of Astragalus injection combined with puerarin injection on expression of BMP-7 and TGF-β1 in type 2 diabetic KKAy mouse kidney

AIM: To observe the effects of Astragalus injection combined with puerarin injection on the expression of transforming growth factor beta 1 (TGF-β₁) and bone morphogenetic protein 7 (BMP-7) in the kidney of type 2 diabetic KKA^y mouse. METHODS: The male KKA^y mice of 14 weeks old were randomly divided into model group and Astragalus injection combined with puerarin injection treatment (Astragalus+puerarin) group. The age-matched male C57BL/6J mice were selected as normal group. The general conditions and body weight of the mice were observed. Blood glucose (BG), triglyceride (TG), cholesterol (TC) and serum creatinine (SCr) were examined at the 20th, 24th and 28th week. The protein expression of renal TGF-β₁ was determined by immunohistochemical method. The mRNA expression of BMP-7 and TGF-β₁ was detected by RT-PCR. RESULTS: Compared with normal group, the body weight, BG, TG, TC and SCr increased significantly in model group. TGF-β₁ expression at protein and mRNA levels was increased, while mRNA expression of BMP-7 was decreased in KKA^y mice. Compared with model group, the body weight, BG, TG, TC and SCr reduced in Astragalus+puerarin group. The mRNA expression of BMP-7 in the renal tissues was higher, and TGF-β₁ expression at mRNA and protein levels was significantly lower in Astragalus+puerarin group than those in model group. CONCLUSION: Astragalus injection combined with puerarin injection has renal protective effects on type 2 diabetic KKA^y mice. The mechanism may be related to restoring BMP-7 expression and reducing the overexpression of TGF-β₁ in renal tissues.     

Effects of renal denervation on inflammatory factors in a rabbit model of early atherosclerosis

AIM: To evaluate the effects of renal denervation (RDN) on the expression of tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interleukin-6 (IL-6) in a rabbit model of early atherosclerosis. METHODS: New Zealand male rabbits were divided into control group, RDN+ high-fat diet (HFD) group (RDN group), sham+HFD group (sham group) and HFD group. The rabbits in later 3 groups were fed with 2% cholesterol for 8 weeks to establish an early atherosclerosis model. The blood samples were collected to test the levels of lipids, norepinephrine (NE), TNF-α, IL-1α and IL-6. The protein expression of angiotensin Ⅱ (Ang Ⅱ) was detected by the method of immunohistochemistry. The levels of nuclear factor-κB (NF-κB) and Ang II 1 type receptor (AT1R) were evaluated by Western blot. The mRNA expression of TNF-α, IL-1α and IL-6 was determined by real-time PCR. RESULTS: After 1 d of RDN procedure, the NE level was lower in RDN group than that in sham group (P<0.01). After 8 weeks, the NE level was lower in RDN group than that in sham group and HFD group (P<0.05), and triglyceride (TG) was lower in RDN group than that in HFD group (P<0.05). The protein expression of Ang II was decreased in RDN group compared with sham group and HFD group (P<0.01). The protein expression of NF-κB was lower in RDN group than that in sham group (P<0.05). The plasma levels of TNF-α and IL-1α were reduced in RDN group compared with sham group and HFD group (P<0.05). The mRNA expression of TNF-α, IL-1α and IL-6 was reduced in RDN group compared with sham group (P<0.05). CONCLUSION: RDN inhibits sympathetic activity, decreases the plasma level of TG, and alleviates inflammatory reactions in the rabbits with atherosclerosis.     

Relationship between peritubular capillary injury and renal interstitial fibrosis in mice with unilateral ureteral obstruction

AIM: To observe the injury of peritubular capillary (PTC), hypoxia and interstitial fibrosis after unilateral ureteral obstruction (UUO), and to explore the effects of PTC injury and hypoxia on interstitial fibrosis in mouse model of UUO. METHODS: Forty-eight male KM mice were randomly divided into control group and UUO group. On the 1st, 3rd, 7th and 14th days, 6 mice in each group were sacrificed. The changes of pathomorphism in the kidney were observed by HE and Masson staining. The expression levels of thrombospondin-1 (TSP-1), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α), and PTC density were detected by immunohistochemistry. The protein expression of VEGF was also determined by Western blotting. RESULTS: No histological abnormalities of the kidneys were observed in sham-operated mice. The expression of TSP-1 was increased 1 day after UUO, and significantly increased on the 3rd, 7th and 14th days(P<0.05). The expression of VEGF was obviously decreased(P<0.05). PTC density was gradually decreased. The expression of HIF-1α was gradually increased, and renal interstitial area was gradually expanded. PTC density was negatively correlated with the expression of TSP-1 and HIF-1α (r=-0.874 and r=-0.930, respectively). VEGF expression was positively correlated with PTC density (r=0.745). PTC density was negatively correlated with the area of renal fibrosis (r=-0.787). HIF-1α expression was positively correlated with the area of renal fibrosis (r=0.835, P<0.05). CONCLUSION: In mouse UUO model, the expression of TSP-1 is increased. The expression of VEGF is reduced. The peritubular capillary injury and tissue hypoxia are aggravated, and renal interstitial fibrosis area is expanded. Ischemia and hypoxia may play an important role in the progression of UUO.     

Effect of drug-containing serum of Fushen Jiangzhuo formula on anti-fibrosis factors HGF and BMP-7 in rat renal interstitial fibroblasts with renal tubulointerstitial lesion

AIM: To study the protective effects and mechanism of Fushen Jiangzhuo formula (FSJZ) on the rat renal interstitial fibroblasts with renal tubulointerstitial lesion. METHODS: The serum containing FSJZ and blank control serum were prepared. The rat model of mesangial proliferative glomerulonephritis (MsPGN) was established and extended the time of modeling to 20th weeks for developing tubulointerstitial lesion naturally. The rat renal interstitial fibroblasts at the end of 12, 16, 20 week of modeling were isolated and cultured. The effects of FSJZ on the expression of hepatocyte growth factor (HGF) and bone morphogenetic protein-7 (BMP-7) at mRNA and protein levels in the pathological renal interstitial fibroblasts were determined. RESULTS: The anti-fibrosis factors HGF and BMP-7 were changed in pathological renal interstitial fibroblasts. Renal tubulointerstitial lesion significantly down-regulated the expression of HGF and BMP-7, while the drug containing serum of FSJZ significantly up-regulated the expression of HGF and BMP-7. CONCLUSION: Drug containing serum of FSJZ has protective effect on pathological renal interstitial fibroblasts by regulating the mRNA and protein expression of HGF and BMP-7.     

High glucose induces down-regulation of BMP-7 expression in renal tubular epithelial cells through p38 MAPK pathway

AIM: To observe the BMP-7 expression in primary renal tubular epithelial cells cultured with high glucose and to investigate the role of p38MAPK signaling pathway.METHODS: The primary renal tubular epithelial cells were randomly treated with normal glucose, high glucose, co-incubation of high glucose with specific p38MAPK inhibitor SB202190 or D-mannitol for 72 h. The protein expression of BMP-7 and fibronectin (FN) in all the cells was assessed by the method of immunocytochemistry. The protein expression of p38MAPK and p-p38MAPK was determined by Western blotting. The mRNA expression of BMP-7 and FN was detected by RT-PCR.RESULTS: In normal glucose group, BMP-7 was highly expressed in the cytoplasm of tubular epithelial cells, and only small amounts of p38MAPK and FN, but not p-p38MAPK, were observed. High glucose was able to activate p38MAPK, and therefore the protein of p-p38MAPK increased remarkably in high glucose-treated cells. High glucose also enhanced FN production. Meanwhile, the expression of BMP-7 decreased. Co-incubation of high glucose with SB202190 for 72 h reduced the activity of p38MAPK by 80% and the FN expression was also decreased, while the BMP-7 expression significantly increased. No significant difference of the BMP-7 or FN expression between control group and D-mannitol group was observed.CONCLUSION: The expression of BMP-7 at mRNA and protein levels in renal tubular epithelial cells is decreased under the condition of high-glucose cultivation. Suppression of p38MAPK signaling pathway stimulates endogenous BMP-7 expression, indicating that p38MAPK pathway may be involved in the down-regulation of BMP-7 in renal tubular epithelial cells by high glucose.     

Effect of fluvastatin on left ventricular remodeling and caspase-3 expression after myocardial infarction in rats

AIM: To observe the effect of fluvastatin (FV) on left ventricular remodeling and expression of caspase-3 after myocardial infarction (MI) in rats. METHODS: Rats were divided into 4 groups: group Ⅰ (sham), group Ⅱ (sham+FV), group Ⅲ (MI) and group Ⅳ (MI+FV). group Ⅱ and Ⅳ were treated with FV (10 mg·kg^-1·d^-1) for 4 weeks. The left ventricular structure, echocardiography and hydroxyproline were observed. The expression of caspase-3 was measured by immunohistochemistry and RT-PCR. RESULTS: Compared with MI group, there was a improvement of ultrastructure and index of left ventricular remodeling, and decrease in hydroxyproline in MI+FV group (all P<0.05). The number of caspase-3 positive cells also decreased in MI+FV group, and RT-PCR showed the level of caspase-3 mRNA expression was lower than that in MI group (P<0.05). CONCLUSION: Fluvastatin improves left ventricular remodeling after myocardial infarction, decreases the expression of caspase-3 and inhibits apoptosis.     

Effects of estrogens on BMP-4 gene expression during osteoporotic fracture healing

AIM: To study the effects of estrogens on expression of BMP-4 in osteoporotic fracture healing, and the pathogenesis of improvement of osteoporotic fracture healing by estrogen. METHODS: 144 female SD rats were divided randomly into ovariectomy group (OVX)， sham-operation group (sham) and estrogen replacement therapy group (OVXE). Closed fractures were produced manually in shaft of both tibias after intra-medullary fixation in all rats one month later. Calluses and soft tissue were collected at the date of 1st, 3rd, 5th, 7th, 14th, 28th, 56th, 112th day after fracture. The histological changes of calluses and the healing of trabecular bone with the structure changes of trabecular bone fiber were observed by microscope and activity of osteoblasts, osteoclasts by electron microscopy. The regularity of BMP-4 expression during osteoporotic fracture and the effect of estrogens on it were studied by in situ hybridization with BMP-4 cDNA probe. RESULTS: (1) Compared to OVXE group, the changes in callus density and arrange of trabecular bone, activity of osteoblasts and osteoclasts in OVX group were significantly different, and more remarkable changes were observed than that in sham group. (2) From 1 to 3 days after fracture, the signals of BMP-4 were positively detected and localized in the cells in parafractures hematoma and in the nearly appeared mesenchymal cells in the muscles adjacent to fracture site, and OVX>OVXE>sham (P<0.01). CONCLUSION: When estrogen deficient, bone turnover was enhanced with the increase in BMP-4 gene expression. Estrogens play an important role in fracture healing, estrogen replacement therapy may be effective.