Effect of angiotensin-(1-7) on angiotensin II-induced rat renal interstitial fibroblast activation

AIM: To explore the influence of angiotensin-(1-7) on angiotension II (Ang II)-induced activation and extracellular matrix secretion in rat renal interstitial fibroblasts (NRK-49F cells). METHODS: The NRK-49F cells were maintained and sub-cultured, then the cells were divided into control group, Ang II group, Ang-(1-7) group and Ang II+Ang-(1-7) group. The expression of α-smooth muscle actin(α-SMA),transforming growth factor β₁ (TGF-β₁) and insulin-like growth factor I(IGF-I) was detected by the method of immunocytochemistry when the cells were cultured for 72 h. The content of TGF-β₁, IGF-I and collagen type I(Col I) in the cultured supernatants were measured by ELISA. RESULTS: In control group and Ang-(1-7) group, only basic expression of α-SMA and almost no expression of TGF-β₁, IGF-I and Col I were observed. Compared with control group, the expression of α-SMA, TGF-β₁, IGF-I and Col I was increased in Ang II group. Compared with Ang II group, the expression of α-SMA, TGF-β₁, IGF-I and Col I was significantly decreased in Ang II+Ang-(1-7) group.CONCLUSION: Ang-(1-7) inhibits the activation of renal interstitial fibroblasts and decreases the Ang II induced secretion of Col I by suppressing TGF-β₁ and IGF-I expression.     

Study on relationship between expression of PKCα in glomeruli and development of nephropathy in diabetic rats

AIM:To observe the dynamic changes of expression of PKCα, TGF-β₁ and α-SMA in glomeruli of diabetic rats induced by the alloxon and to invesitigate their roles in the diabetic nephropathy(DN).METHODS:Rats were randomly divided into four groups: normal control group (group A), diabetic group of one week (group B), diabetic group of one month (group C), diabetic group of two months (group D). Immunohistochemistry and Western blotting were used to detect the expression of PKCα, TGF-β₁ and α-SMA in renal tissue of all groups. Blood glucose, triglycerides, cholesterol, creatinine and urine protein were analysed by chemical methods. The morphological changes of renal tissue were checked through microscopy.RESULTS:The expression of PKCα and TGF-β₁ in renal tissue of diabetic groups were increased comparing with those of nomal control group(P<0.05). The mesangial cells expressed α-SMA in two months group. Chronologically the expression of PKCα, TGF-β₁ and α-SMA were positively correlative with each other and the impairment of kidney was also observed.CONCLUSIONS: During the DN process the expression of PKCα increased. PKCα raised GFR and the permeability of glomerular filtration membrane which enhanced urinary albumin excretion. PKCα also increased expression of TGF-β and therefore to induce the expression of α-SMA. The appearance of α-SMA was a marker of the phenotypic transform of renal cells.     

Effect of all-trans-retinoic acid on the proliferation and expression of α-SMA in human embryonic lung fibroblasts

AIM: To investigate the effects of all-trans-retinoic acid (ATRA) on the proliferation and differentiation of transforming growth factor β₁(TGF-β₁)-stimulated human embryonic lung fibroblasts (HFL-I).METHODS: The HFL-I cells were cultured in vitro and were pretreated with ATRA for 3 days at the concentrations of 0.1 μmol/L, 1 μmol/L and 10 μmol/L. The proliferation of HFL-1 cells was detected by MTT method. The mRNA expression of α-smooth muscle actin(α-SMA) in HFL-I cells stimulated with TGF-β₁ for 0 h, 6 h, 12 h, 24 h, 48 h and 72 h was detected by RT-PCR and the protein expression of α-SMA at the time points of 1,3 and 5 days was detected by Western blotting. The mRNA expression of α-SMA in HFL-I cells pretreated with different concentrations of ATRA for 24 h was detected the by RT-PCR and the protein expression at time point of 3rd day was detected by Western blotting. RESULTS: Different concentration of ATRA inhibited the proliferation of HFL-I in a dose-dependent manner (P<0.05). Both mRNA and protein expression of α-SMA in HFL-I cells pretreated with TGF-β₁ was up-regulated (P<0.05). ATRA down-regulated the mRNA and protein expression of α-SMA induced by TGF-β₁ in a dose-dependent manner (P<0.05). CONCLUSION: ATRA inhibits the proliferation and TGF-β₁-stimulated differentiation in HFL-I cells by down-regulating the mRNA and protein expression of α-SMA.     

TAK1 regulates fibrosis of renal tubular epithelial cells by regulating p38 MAPK signaling pathway

AIM:To investigate the effect of transforming growth factor-β (TGF-β) activated kinase 1(TAK1) on renal tubular epithelial fibrosis. METHODS:The renal tubular epithelial cell line HK-2 was used as the research object. After induced by TGF-β1, real-time PCR and Western blot were used to detect the expression of TAK1 in the HK-2 cells. TAK1 shRNA lentivirus was used to infect HK-2 cells, real-time PCR and Western blot were used to determine the interference effect on TAK1 expression in the HK-2 cells with TGF-β1 stimulation. Under the condition of treating with p38 MAPK activator anisomycin, the levels of type I collagen and type Ⅲ collagen in the supernatant, and the protein levels of α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF) and p-p38MAPK^{Thr 180/Tyr 182} in the HK-2 cells with TAK1 knock-down were determined by ELISA and Western blot, respectively. RESULTS:TGF-β1 significantly increased the expression of TAK1 in the HK-2 cells(P<0.05). TAK1 shRNA significantly decreased the expression of TAK1 in the HK-2 cells with TGF-β1 stimulation. Type I collagen and type Ⅲ collagen secreted by the HK-2 cells after treatment with TGF-β1 were increased, the protein levels of α-SMA, CTGF and p-p38MAPK^{Thr 180/Tyr 182} were also increased(P<0.05). Knock-down of TAK1 expression significantly inhibited the secretion of type I and type Ⅲ collagen, reduced the protein levels of α-SMA, CTGF and p-p38MAPK^{Thr 180/Tyr 182} in the TGF-β1-induced HK-2 cells(P<0.05). Treatment with p38 MAPK activator reversed the inhibitory effect of TAK1 knock-down on the secretion of type I and type Ⅲ collagens, and the protein levels of α-SMA, CTGF and p-p38 MAPK^{Thr 180/Tyr 182} in the HK-2 cells(P<0.05). CONCLUSION:Knock-down of TAK1 expression attenuates the TGF-β1 induced fibrosis of renal tubular epithelial cells by inhibiting p38 MAPK signaling pathway.     

Inhibitory effect of metformin on alveolar epithelial-mesenchymal transition in lung tissue of rats with pulmonary fibrosis

AIM: To study the inhibitory effect of metformin on alveolar epithelial-mesenchymal transition (EMT) in rats with pulmonary fibrosis and the possible mechanism. METHODS: SD rats (n=48) were used, 12 of which were set up as normal control group, and 36 of which were induced by bleomycin (5 mg/kg) by tracheal instillation to establish pulmonary fibrosis. The pulmonary fibrosis rats were randomly divided into bleomycin group, low dose (100 mg/kg) of metformin group, and high dose (300 mg/kg) of metformin group. The rats in metformin groups were given the corresponding dose of metformin daily for 4 weeks. HE staining and Masson staining were used to observe the changes of lung histopathology and collagen deposition. Real-time PCR, Western blot and innunohistochemical staining were used to detect the mRNA and protein expression of α-smooth muscle actin (α-SMA), E-cadherin, vimentin, zonula occludens-1 (ZO-1), collagen I, collagen III and transforming growth factor-β₁ (TGF-β₁), and the protein phosphorylation levels of Smad2/3 and extracellular signal-regulated kinase 1/2 (ERK1/2) were also determined. RESULTS: Metformin up-regulated the expression of E-cadherin and ZO-1, down-regulated the expression of α-SMA, vimentin, collagen I and collagen III, and the protein phosphorylation levels of Smad2/3 and ERK1/2 were also decreased (P<0.05). CONCLUSION: Metformin inhibits alveolar EMT in the rats with pulmonary fibrosis, and its mechanism may be related to the inhibition of TGF-β₁ signal transduction pathway.     

Roles of gap junction in TGF-β1-induced proliferation of vascular smooth muscle cells from spontaneous hypertensive rats

AIM: To investigate whether gap junction participates in transforming growth factor β₁(TGF-β₁)-induced proliferation of spontaneous hypertensive rat (SHR) vascular smooth muscle cells (VSMCs). METHODS: The thoracic aorta of the rats were sampled. The primary SHR VSMCs were isolated and cultured in vitro. The cells were divided into 4 groups: control group, TGF-β₁ group,18α-glycyrrhetinic acid(18α-GA) group and TGF-β₁+18α-GA group. The proliferation of SHR VSMCs was observed by the methods of MTT and flow cytometry. The protein expression and co-localization of connexin(Cx)43 and Cx40 in SHR VSMCs were detected by immunofluorescence staining. The protein levels of Cx43 and Cx40 in the cells were also measured by Western blotting. The method of molecular dye transfer (scrape dye transfer method) was applied to detect the function of gap junction in SHR VSMCs. RESULTS: The protein expression of Cx43 and Cx40 in SHR VSMCs was positive and co-localized in the cytoplasm. Compared with control group, the percentage of S-phase detected by cell cycle and A value detected by MTT in TGF-β₁ group were obviously increased (P<0.05), indicating that the proliferation of the cells was enhanced. However, the proliferation of the cells decreased in 18α-GA group (P<0.05). Compared with TGF-β₁ group, the percentage of S-phase and A value in TGF-β₁+18α-GA group were both significantly decreased (P<0.05), indicating that the proliferation of the cells decreased. Compared with control group, the protein expression of Cx43 in TGF-β₁ group was increased (P<0.05), whereas the protein expression of Cx40 was not changed (P>0.05), and the protein expression of Cx43 and Cx40 in 18α-GA group were decreased (P<0.05). Compared with TGF-β₁ group, the expression of Cx43 in TGF-β₁+18α-GA group was significantly decreased (P<0.05),but no difference of the Cx40 protein levels between the two groups was observed. Compared with control group, the function of gap junction detected by scrape dye transfer method in TGF-β₁ group was enhanced (P<0.05), and weakened in 18α-GA group (P<0.05). Compared with the TGF-β₁ group, the function of gap junction in TGF-β₁+18α-GA group was significantly attenuated (P<0.05). CONCLUSION: TGF-β₁ enhances the function of gap junction to stimulate the proliferation of SHR VSMCs through the expression of Cx43 protein. The expression of Cx40 protein may not play a major role in this process.     

Inhibitory effect of oxymatrine on high glucose-induced rat renal tubular epithelial-mesenchymal transition

AIM:To investigate the inhibitory effect of oxymatrine (OM) on high glucose-induced rat renal tubular epithelial-mesenchymal transition (EMT). METHODS:The rat renal tubular epithelial NRK52E cells were cultured in vitro. The cells were divided into control group, high glucose group, high glucose+different concentrations of OM groups and high glucose+0.50 g/L OM dynamic observation group. The expression of TGF-β1, Smad7, α-SMA and E-cadherin at mRNA and protein levels was detected by real-time PCR and Western blotting. The viability of NRK52E cells was determined by MTT assay. RESULTS:(1) Compared with control group, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose group gradually increased, and Smad7 protein and E-cadherin mRNA and protein gradually reduced, but the mRNA expression of Smad7 gradually increased. (2) Compared with high glucose group, as increases in OM doses, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose+different concentrations of OM groups gradually reduced, and Smad7 protein and E-cadherin mRNA and protein gradually increased, but the mRNA expression of Smad7 had no significant change. (3) Compared with high glucose group, the expression of TGF-β1 and α-SMA at mRNA and protein levels was significantly reduced, the expression of E-cadherin at mRNA and protein levels significantly increased, and the protein expression of Smad7 significantly increased, but the mRNA expression of Smad7 had no significant change in high glucose+0.50 g/L OM dynamic observation group. CONCLUSION: In NRK52E cells, oxymatrine inhibits high glucose induced EMT by down-regulating TGF-β1 and up-regulating Smad7, thus preventing the fibrosis effect of TGF-β1/Smads signaling.     

Effect of c-SKI on coronary endothelial cell proliferation and endothelial-mesenchymal transition

AIM: To investigate the effect of cellular Sloan-Kettering Institute (c-SKI) on the proliferation and endothelial-mesenchymal transition of human coronary artery endothelial cells (HCAECs). METHODS: HCAECs were treated with transforming growth factor-β1 (TGF-β1) at varying concentrations for different time points. Western blot was used to test the expression of c-SKI and mesenchymal markers such as α-smooth muscle actin (α-SMA) and vimentin. Meanwhile, the endothelial marker E-cadherin was also detected. HCAECs were transfected with c-ski gene mediated by lentivirus (LV), the efficiency of LV-SKI transfection was detected by RT-qPCR. The HCAECs were divided into 4 groups:control group, TGF-β1 (5 μg/L) group, LV-SKI+ TGF-β1 group, LV-NC+ TGF-β1 group. The cell viability and colony formation were measured by MTT assay and colony formation assay. The protein levels of vimentin, α-SMA, E-cadherin, Smad2, Smad3, p-Smad2 and p-Smad3 were determined by Western blot. RESULTS: The expression of c-SKI was down-regulated in the HCAECs treated with TGF-β1 (P<0.01). Over-expression of c-SKI inhibited the proliferation of HCAECs (P<0.01). Compared with LV-NC group, over-expression of c-SKI down-regulated the expression of α-SMA and vimentin (P<0.01), up-regulated the expression of E-cadherin (P<0.01), and inhibited the protein phosphorylation of Smad2 and Smad3 (P<0.01), reversed the endothelial-mesenchymal transition induced by TGF-β1. CONCLUSION: The expression of c-SKI in the HCAECs is down-regulated in the process of endothelial-mesenchymal transition. Over-expression of c-SKI inhibits proliferation and endothelial-mesenchymal transition of HCAECs, the mechanism may be related to regulation of the TGF-β1/Smad signaling pathway.     

Mollugin inhibits viability and collagen synthesis of rat CFSC-2G cells

AIM: To investigate the effects of mollugin on the viability and collagen synthesis of rat hepatic stellate cell line CFSC-2G. METHODS: The activation of CFSC-2G cells was induced with low concentration (10 μmol/L) of hydrogen peroxide (H₂O₂) for 30 min in the experiment. The viability of the CFSC-2G cells after exposed to mollugin at different concentrations (0, 20, 40, 60 and 120 μmol/L) was detected by MTT assay. The mRNA and protein expression levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), nuclear factor-κB (NF-κB) p65, Bcl-2, Bcl-xL, Bax, and hepatic stellate cell activation markers α-smooth muscle actin (α-SMA) and collagen type I (Col Ⅰ) were detected by real-time PCR and Western blot. The phosphorylation level of p38 mitogen-activated protein kinase (p38 MAPK) was determined by Western blot. RESULTS: Mollugin significantly inhibited the viability and collagen synthesis of activated CSFC-2G cells induced by H₂O₂. The expression of Nrf2, HO-1 and Bax at mRNA and protein levels, and the phosphorylation level of p38 MAPK were promoted, while the levels of NF-κB p65, Bcl-2, Bcl-xL, α-SMA and ColⅠwere inhibited by mollugin (P<0.05). CONCLUSION: Mollugin may inhibit H₂O₂-induced viability and collagen synthesis of the CSFC-2G cells by activating Nrf2 and HO-1, and blocking the NF-κB p65 and Bcl-2 expression.     

Effects of Zuogui pill-medicated serum on proliferation and differentiation of MC3T3-E1 cells via ERK/TGF-β/Smads signaling cascade

AIM:To study the effects of Zuogui pill(ZG)-medicated serum on the proliferation and differentiation of MC3T3-E1 cells via ERK/TGF-β/Smads signaling pathway. METHODS:Using Premarin(conjugated estrogens tablets) as a positive control, the SD female rats were fed with high-, medium- or low-dose of ZG suspension. ZG-medicated serum was separated from abdominal aortic blood 7 d after feeding of ZG. MTT assay was applied to test the effect of ZG-medicated serum on the viability of MC3T3-E1 cells. The production of alkaline phosphatase(ALP) was detected by a modified calcium and cobalt dyeing method. The calcified nodules were observed by the method of alizarin red staining. The levels of core binding factor α1(Cbfα1) and collagen type I(Col I) protein were analyzed by Western blotting. The mRNA expression of TGF-β₁, Smad4 and Smad2 was measured by real-time RT-PCR. RESULTS:ZG-medicated serum promoted the proliferation of MC3T3-E1 cells in a dose-and time-dependent manner. Compared with other groups, treatment with 15% ZG(low dose) for 48 h increased the proliferation of MC3T3-E1 cells significantly. The protein levels of ALP, Cbfα1 and Col I,the calcified nodules, and the mRNA expression of TGF-β₁, Smad4 and Smad2 in MC3T3-E1 cells were all significantly increased after treatment with ZG-medicated serum. After the addition of PD98059(a specific blocker of ERK1/2 signaling pathway), all those were down-regulated except for mRNA expression of TGF-β₁. CONCLUSION:ZG regulates MC3T3-E1 cell proliferation and differentiation via the intervention of ERK/TGF-β/Smads signaling cascade, which may be one of the mechanisms that ZG effectively prevents and treats osteoporosis.     

Lentiviral vector CV072-mediated Mfn2 over-expression inhibits hepatic stellate cell activation

AIM:To construct a lentiviral vector carrying mitofusin 2 (Mfn2), and to investigate the inhibitory effect of Mfn2 on the activation of rat hepatic stellate cells and its mechanism of reducing the formation of hepatic fibrosis-related factors. METHODS:The lentiviral over-expression vector CV072-pCMV-Mfn2-EGFP containing Mfn2 was constructed and transfected into the hepatic stellate cells. The expression of green fluorescent protein was observed under fluorescence microscope, and the transfection efficiency was evaluated. The protein levels of Bax, Bcl-2, cleaved caspase-3, α-SMA, TGF-β1, Smad2 and Smad3 were detected by Western blot. The levels of type I collagen, type Ⅲ collagen and type IV collagen in the cell culture supernatants were determined by ELISA. RESULTS:Compared with control group, the apoptosis of the hepatic stellate cells transfected with lentivirus over-expression vector CV072-pCMV-Mfn2-EGFP was increased, and the protein levels of proapoptotic molecules Bax and cleaved caspase-3 were increased (P<0.01). TGF-β1/Smad pathway-related proteins TGF-β1, p-Smad2 and p-Smad3 were decreased, and the levels of fibrosis-related proteins α-SMA, type I collagen, type Ⅲ collagen and type IV collagen were decreased (P<0.01). CONCLUSION:Transfection of lentiviral over-expression vector CV072-pCMV-Mfn2-EGFP effectively inhibits hepatic stellate cell activation in vitro and may reduce the production of hepatic fibrosis-related factors by inhibiting TGF-β1/Smad pathway.     

Up-regulation of miR-181a attenuates releases of CSE-induced pro-inflammatory factors and expression of collagen IV,fibronectin and α-SMA in human bronchial epithelial cells

AIM: To investigate the effect and potential mechanism of microRNA-181a (miR-181a) on cigarette smoke extract (CSE)-induced the productions of pro-inflammatory factors and the expression of collagen IV, fibronectin and α-smooth muscle actin (α-SMA) in human bronchial epithelial cells (HBECs). METHODS: CSE-induced miR-181a expression was detected by RT-qPCR in the HBECs. After tansfected with miR-181a mimic, the releases of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and transforming growth factor-β1 (TGF-β1) were measured by ELISA, the protein expression of collagen IV, fibronectin and α-SMA was determined by Western blot. The activation of NF-κB/TGF-β1/Smad3 pathway was also evaluated by Western blot. RESULTS: CSE increased the levels of TNF-α, IL-1β, IL-6 and TGF-β1 and the expression of collagen IV, fibronectin and α-SMA, and decreased the expression of miR-181a in the HBECs (P<0.05). However, transfected with miR-181a mimic partially prevented the releases of TNF-α, IL-1β, IL-6 and TGF-β1, and inhibited the expression of collagen IV, fibronectin and α-SMA (P<0.05). Additionally, the activation of NF-κB/TGF-β1/Smad3 evoked by CSE was attenuated after transfected with miR-181a mimic. CONCLUSION: Up-regulation of miR-181a prevents the releases of CSE-induced pro-inflammatory factors and expression of collagen IV, fibronectin and α-SMA in the HBECs, and its mechanism may be related to the inhibition of NF-κB/TGF-β1/Smad3 pathway.     

Blockage of core fucosylation contributes to inhibition of epithelial mesenchymal transition of renal tubular epithelial cells

AIM: To investigate the role of inhibiting core fucosylation in the process of epithelial mesenchymal transition (EMT) in HK-2 cells.METHODS: An EMT cell model with transforming growth factor-β₁(TGF-β₁) was established and RNAi technique was used to silence the expression of α-1,6-fucosyltransferase ( FUT8) gene which is responsible to catalysation of core fucose. The morphological changes of HK-2 cells were observed under light microscope. The epithelial cell marker E-cadherin and fibrotic cell markers N-cadherin, fibroblast-specific protein-1(FSP-1) and α-smooth muscle actin(α-SMA) were detected by Western blotting and immunocytochemistry. The apoptosis induced by TGF-β₁ was determined by flow cytometry. RESULTS: After incubated with TGF-β₁ at the concentration of 5 μg/L for 48 h, HK-2 cells lost epithelial morphology and showed fibrotic morphology. The expression of α-SMA, FSP-1 and N-cadherin was markedly increased, while E-cadherin was decreased. Meanwhile, the expression of FUT8 was up-regulated, and the apoptosis of the cells increased. However, pre-incubation of the cells with FUT8 siRNA inhibited these changes above.CONCLUSION: The core fucosylation involves in the process of EMT in HK-2 cells. Blockage of core fucosylation results in the inhibition of EMT in HK-2 cells.     

Changes of histone modification levels in rats with liver fibrosis

AIM: To observe the changes of histone modifications in the liver of rats with hepatic fibrosis and its possible role in the development of hepatic fibrosis. METHODS: Male Wistar rats (n=20) were randomly divided into liver fibrosis group and normal control group. The liver fibrosis model was established by hypodermic injection of CCl₄, and the rats in normal control group were injected with vegetable oils. At the end of the 8th week, all rats were killed. Liver function indexes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and liver fibrosis indexes including haluronic acid (HA), laminin (LN), collagen type IV (Col Ⅳ) and procollagen type Ⅲ (PCⅢ) were determined by biochemical and RIA methods. The liver index was analyzed, and the liver fibrosis degree and the morphological change of the liver were detected by HE and Masson staining. The levels of α-smooth muscle actin (α-SMA), collagen type Ⅰ (ColⅠ), H3K4me2, H3K9me2, acH3K9 and acH4K12 were detected by Western blot. RESULTS: After hypodermic injection of CCl₄ for 8 weeks, the liver index, ALT, AST, HA, LN, Col Ⅳ and PCⅢ of the rats in liver fibrosis group were higher than those in control group (P<0.05). Compared with control group, the level of acH4K12 was decreased (P<0.05), while acH3K9, H3K9me2, α-SMA and ColⅠ were increased (P<0.05), but H3K4me2 had no significant change.CONCLUSION: The levels of acH4K12, acH3K9 and H3K9me2 may play essential roles in the pathogenesis of liver fibrosis, and these histone modifications may regulate gene expression associated with extracellular matrix metabolism.     

Activation of renal tubular epithelial cells by monocytes/macrophages and the relative mechanisms

AIM: To observe the direct effects of peripheral blood monocytes/macrophages (MO/MAC) on renal tubular epithelial cells (RTEC),and further probe into the possible mechanisms. METHODS: Conditioned medium(M-CM) of human peripheral blood MO/MAC was collected and added to HK-2,a human renal proximal tubular cell line.After incubation with M-CM for 24 hours,HK-2 cells were detected for DNA synthesis by [³H]-TdR incorporation,osteopontin (OPN) and α-smooth muscle actin (α-SMA) expression by Western blot,and fibronectin(FN) secretion by ELISA.Furthermore,anti-TGFβ₁ neutralizing antibody and interlukin-10(IL-10) were used separately to antagonize the effects of M-CM on HK-2 cells. RESULTS: ①DNA synthesis,α-SMA expression and FN secretion were all increased in HK-2 cells when incubated with M-CM.②When adding with anti-TGFβ₁ neutralizing antibody (5 mg/L) in the M-CM,the degree of upregulation of α-SMA and FN in HK-2 cells was much lower than that stimulated by M-CM alone.③M-CM added with IL-10 (20 μg/L) had a weaker ability to induce the increasing in α-SMA expression and FN excretion in HK-2 cells, compared with M-CM itself alone.M-CM from MO/MAC preincubated with IL-10 caused a lower upregulation of α-SMA expression in HK-2 cells than M-CM from non-preincubated MO/MAC. CONCLUSION: MO/MAC can directly induce proliferation,transdifferentiation and extracellular matrix secretion in RTEC.TGFβ₁ and proinflammatory cytokines secreted by MO/MAC might be involved in the aboveeffects.     

Alteration of p38 MAPK activity in lung tissue in diabetic rats

AIM: To observe the pathologic changes in lung and the role of p38 MAPKinase signal pathways in pulmonary alteration in diabetic rats. METHODS: Diabetic rats were induced by intraperitoneally injected streptozotozin (STZ). After 4 weeks, we observed the pathologic changes in lungs, tested protein kinase C (PKC) activities by isotope in lungs of model rats, tested transforming growth factor (TGF-β₁) by Western blotting and immunohistochemical analysis, and determined the expression of p38 MAPKinase mRNA using in situ hybridization.RESULTS: After STZ administration for 4 weeks, we observed thickened pulmonary capillary basal lamina and increased number of fibre in Diabetes mellitus (DM) rats. TGF-β₁ levels, PKC and p38 MAPK activities were also found increased. CONCLUSION: The increased activities of TGF-β₁ and p38 MAPK suggeste that TGF-β₁ may play an important role in diabetic lung, and hyperglycemia-PKC-p38 MAPK signal pathways may be involved in the pathogenesis of diabetes.     

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 EndoMT in HHPH based on TGF-β/Smads signaling pathway and regulated by Yiqi-Wenyang-Huoxue-Huatan formula

AIM: To investigate the relationship between transforming growth factor-β (TGF-β)/Smads signaling pathway and pulmonary arterial endothelial-mesenchymal transition (EndoMT) in hypoxia-hypercapnia pulmonary hypertension (HHPH) process and the regulatory effect of Yiqi-Wenyang-Huoxue-Huatan formula (YWHHF). METHODS: Healthy male SD rats were randomly divided into 5 groups:normal control (N) group, hypoxia-hypercapnia (HH) group, high-dose YWHHF (YH) group, middle-dose YWHHF (YM) group and low-dose YWHHF (YL) group. The rats in N group was housed in normoxic environment, and the rats in the other 4 groups were housed in hypoxia-hypercapnia environment (9%~11% O₂ and 5%~6% CO₂) for 4 weeks, 8 h/d, 6 d/week. The excess water vapor was absorbed by anhydrous CaCl₂, and CO₂ was absorbed by sodium hydroxide. The rats in YWHHF groups were put into the oxygen chamber before the same volume of YWHHF at different concentrations were given (200 g/L for YH group, 100 g/L for YM group and 50 g/L for YL group). The average pulmonary artery pressure and the average carotid artery pressure were measured during the operation. After operation, the right ventricular free wall and left ventricle plus interventricular septum were collected for determining the right ventricular hypertrophy index. Moreover, the morphological changes of the lung tissues were observed under light microscope. The mRNA and protein levels of α-smooth muscle actin (α-SMA), CD31, TGF-β1 and Smad2/3, and the protein level of p-Smad2/3 were detected by RT-PCR and Western blot. RESULTS: Compared with N group, the pulmonary artery mean pressure, the mRNA and protein expression of α-SMA, TGF-β1 and Smad2/3, and the protein level of p-Smad2/3 were increased, the levels of CD31 were decreased (P<0.05), and the lung tissue damage was observed in the other 4 groups. Compared with HH group, the pulmonary artery mean pressure, the mRNA and protein expression of α-SMA, TGF-β1 and Smad2/3, and the protein level of p-Smad2/3 were decreased, while the mRNA and protein levels of CD31 were increased. Moreover, the lung tissue damage was reduced in YH, YM and YL groups. CONCLUSION: TGF-β/Smads pathway may be involved in the process of EndoMT under hypoxia and hypercapnia condition, and YWHHF may reduce EndoMT by inhibiting the expression of TGF-β/Smads pathway-related molecules.     

Dynamical observation of the expression of TGF-β1 and MAPK1/3 in the renal tubules of rats with diabetes

AIM: To observe the expression of transforming growth factor β₁ (TGF-β₁), MAPK_1/3 and fibronectin (FN) in the development of renal tubulointerstitial disease. METHODS: Wistar male rats were randomly divided into normal control group, diabetic group of 1week, 2 weeks, 4 weeks and 8 weeks. Diabetic model was induced by peritoneal injection of streptozotocin. Immunohistochemistry was employed to detect the expression of TGF-β₁, MAPK_1/3 and FN in the kidney. TGF-β₁ protein in the renal cortex was checked by Western blot. BG, Scr and UP were analysed by biochemical methods, and the morphological changes in renal tubulointerstitium were also examined under microscopy on sections stained with HE and PAS. RESULTS: The expression of MAPK_1/3 and FN was observed, but not the expression of TGF-β₁ in normal renal tissue. Positive staining of TGF-β₁ was observed in the renal tubulo-interstitium in 1-week diabetic group and thereafter it increased in the course of diabetes. A continuous increase in the expression of MAPK_1/3 and FN was also observed in two - week diabetic rats. Chronologically the expression of TGF-β₁,MAPK_1/3 and FN and the ratio of KW/BW were positively correlative with each other in diabetic animals except one -week diabetic rats. There was also a positive correlation between MAPK_1/3 and FN in l -week diabetic rats. CONCLUSION: Our data suggest that TGF-β₁ appears in the renal tubulointerstitium in early period of diabetes and then its signal is mediated by MAPK_1/3 cascades to accelerate production of FN ,and in turn leads to renal hypertrophy and tubulointerstitial fibrosis.