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ObjectiveTo explore the underlying mechanism of modified Zhenwutang in delaying renal interstitial fibrosis in chronic renal failure （CRF） by observing the effects of modified Zhenwutang on the expression of angiotensin Ⅱ （Ang Ⅱ）， angiotensin Ⅱ type 1 receptor （AT1R）， nicotinamide adenine dinucleotide phosphate （NADPH） oxidase 4 （NOX4）， transforming growth factor-β1 （TGF-β1）， type I collagen （COL1A1）， and type Ⅲ collagen （COL3A1） in the serum and renal tissues of adenine-induced CRF rats. MethodFifty male SPF-grade SD rats were randomly divided into a normal group （n=10） and an experimental group （n=40） using a random number table. After one week of adaptive feeding， the experimental CRF model was established in rats by administering adenine at 150 mg·kg-1·d-1 orally. Three rats from each group were randomly selected to evaluate the model induction. After successful modeling， rats in the experimental group were randomly divided into a model group， low-， medium， and high-dose modified Zhenwutang groups， and a benazepril hydrochloride group， with six rats in each group. The rats were orally administered the corresponding drugs once daily for four weeks. At the end of the first week， 13th week， and 17th week of the experiment， 24 hour urinary protein quantification （24 h-UTP） was measured. At the end of the 17th week， the rats were euthanized， and blood samples were collected from the abdominal aorta for the measurement of total protein （TP）， albumin （ALB）， creatinine （Cr）， and blood urea nitrogen （BUN） in the serum. Enzyme-linked immunosorbent assay （ELISA） was used to measure the expression levels of serum Ang Ⅱ. Hematoxylin-eosin （HE） staining and Masson's trichrome staining were performed to observe the pathological changes in renal tissues. Immunohistochemistry （IHC） was performed to observe the expression of AT1R， NOX4， TGF-β1， COL1A1， and COL3A1. Real-time fluorescence-based quantitative polymerase chain reaction （Real-time PCR） was used to observe the mRNA expression levels of AT1R， NOX4， and TGF-β1. Western blot was conducted to measure the protein expression levels of AT1R， NOX4， and TGF-β1. Result① Compared with the normal group， the model group showed a significant increase in 24 h-UTP （P<0.01）. The levels of Cr and BUN in the model group were significantly higher （P<0.01）， while the levels of TP and ALB were significantly lower （P<0.01）. The serum Ang Ⅱ level in the model group was significantly elevated （P<0.01）. The model group exhibited widening of the renal glomerular mesangial space， necrotic glomeruli， increased interstitial width with extensive inflammatory cell infiltration， brownish precipitates blocking the renal tubular lumens， irregular renal tubules， and significant deposition of collagen fibers in the renal interstitium. Additionally， the collagen fibers around the renal vessels， outside the parietal layer of the renal sacs， glomerular basement membrane， and tubular basement membrane increased significantly. The expression of AT1R and NOX4 in the glomeruli and renal tubules of the model group was significantly enhanced， and TGF-β1 expression also significantly increased in the renal tubules. The expression of COL1A1 and COL3A1 in the renal interstitium significantly increased. The mRNA expression of AT1R and TGF-β1 in the model group significantly increased （P<0.01）， while NOX4 mRNA expression significantly decreased （P<0.01）. The protein expression of AT1R， NOX4， and TGF-β1 was significantly enhanced （P<0.01）. ② Compared with the model group， modified Zhenwutang significantly reduced 24h-UTP （P<0.01）， decreased levels of Cr and BUN （P<0.01）， increased levels of TP and ALB （P<0.01）， reduced serum Ang Ⅱ level （P<0.01）， alleviated renal pathological damage， reduced expression of AT1R， NOX4， TGF-β1， COL1A1， and COL3A1 in the glomeruli， renal tubules， and renal interstitium， reduced mRNA expression of AT1R and TGF-β1 （P<0.01）， increased NOX4 mRNA expression （P<0.01）， and weakened protein expression of AT1R， NOX4， and TGF-β1 （P<0.01）. The modified Zhenwutang groups showed a significant dose-effect trend. ConclusionModified Zhenwutang may delay renal interstitial fibrosis in CRF rats by reducing the expression of Ang Ⅱ， AT1R， NOX4， and TGF-β1 in the serum and renal tissues， thereby alleviating renal pathological damage， reducing proteinuria， protecting renal function， and delaying the progression of CRF. The modified Zhenwutang group exhibited a dose-effect trend.
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Objective:To observe the influence of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) 4 inhibitors on epithelial-mesenchymal transition (EMT) of human retinal pigment epithelial (RPE) cells induced by bevacizumab.Methods:The cultured ARPE-19 cells were divided into blank control group, bevacizumab group, bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group.Cells were cultured with 0.25 g/L bevacizumab, 0.25 g/L bevacizumab plus 3 μmol/L VAS2870 (a NOX4 inhibitor), 0.25 g/L bevaczumab plus 20 μmol/L GKT137831 (a NOX4 inhibitor) for 72 hours according to grouping.No intervention was administered to the blank control group.The mRNA and protein expression levels of NOX4 and EMT markers including fibronectin (FN), vimentin, α-smooth muscle actin (α-SMA) and tight junction related protein zonula occludens-1 (ZO-1) were measured by real-time PCR and Western blot assay, and the expression levels in different intervention groups were compared.The expressions of NOX4 and EMT markers were verified by immunofluorescence staining.Results:There were statistically significant differences in the relative mRNA and protein expression levels of FN, vimentin, α-SMA, ZO-1 and NOX4 among blank control group, bevacizumab group, bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group (mRNA: F=97.07, 195.40, 722.40, 38.56, 70.81; all at P<0.001.Protein: F=23.09, 64.58, 58.19, 26.97, 63.19; all at P<0.001). The relative mRNA and protein expression levels of FN, vimentin, α-SMA and NOX4 were significantly higher and the relative mRNA and protein expression level of ZO-1 was significantly lower in bevacizumab group than those in blank control group (all at P<0.05). The relative mRNA and protein expression levels of FN, vimentin, α-SMA and NOX4 were significantly lower and the relative mRNA and protein expression levels of ZO-1 were significantly higher in bevacizumab+ VAS2870 and bevacizumab+ GKT137831 groups than those in bevacizumab group (all at P<0.05). The immunofluorescence intensity of FN, vimentin and α-SMA was stronger and the immunofluorescence intensity of ZO-1 was weaker in bevacizumab group than blank control group.The immunofluorescence intensity of FN, vimentin and α-SMA were weaker and the immunofluorescence intensity of ZO-1 was stronger in bevacizumab+ VAS2870 group and bevacizumab+ GKT137831 group than those in bevacizumab group. Conclusions:NOX4 is involved in the bevacizumab-induced EMT of human RPE cells, the degree of which can be reduced by NOX4 inhibitors.
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Objective:From a new perspective，to explore therapeutic effect of Huidouba (HDB) on alleviating kidney oxidative damage in rats with diabetic nephropathy (DN) and provide a scientific basis for developing HDB as a potential Tibetan medicine for treatment of DN. Method:Rats were fed with high-fat diet (HFD) and injected with streptozocin (STZ, 65 mg·kg-1) intraperitoneally to induce DN model, while rats in Blank group were injected with an equal volume of vehicle and fed with normal chow. The successfully modeling DN rats were randomly divided into three groups, 8 rats per group, DN model group (10 mL·kg-1·d-1), Metformin group (0.045 g·kg-1·d-1) and HDB group (0.18 g·kg-1·d-1). Monitor body weight (BW) and fasting blood glucose (FBG) weekly, and collect 24 hours urine before and after medication to examine microalbuminuria (mAlb). Calculate kidney index (KI) after sacrificing, analyze mAlb, serum creatinine (SCr) and blood urea nitrogen (BUN) with a fully automatic biochemical analyzer. Histopathology of kidney was observed by Masson staining. Lipid peroxidation malondialdehyde (MDA) assay kit was used to examine MDA content in kidney tissue. Nox4, as a subtype of triphosphopyridine nucleotide (NADPH) oxidase family was determined by Western blot and immunofluorescence assay of kidney tissue. Result:Compared with blank group, levels of FBG, 24 h mAlb, SCr, BUN and MDA in DN model group were increased (P<0.01), tissue damage was obvious and Nox4 expression in glumeruli was increased significantly (P<0.01). Compared with DN model group, levels of FBG, 24 h mAlb, SCr, BUN and MDA in drug administration groups were decreased (P<0.01), kidney injury was alleviated and Nox4 expression was down-regulated（P<0.01）. Conclusion:HDB as a Yiqiyangyin Tibetan medicine, could ease oxidative stress injury of kidney and reduce proteinuria in DN rats, thus prevent the development of DN. Its mechanism is closely related to down-regulating Nox4 expression of kidney tissue in DN rats.
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Objective To detect the expression levels of collagen1 (colla-1),transforming growth factor-β1 (TGF-β1),a-smooth muscle actin (α-SMA) and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX-4) in mouse esophagus submitted to chronic restraint stress (CRS),in order to discuss stress-induced esophageal fibrosis and the role of oxidative stress.Methods 20 male Kunming mice were randomly divided into two groups,CRS and normal control (NC).The mice in CRS group were submitted to 2 h per day of restraint stress using home-made device for a period of 14 days,and the mice in both group were treated the same at rest of the time.Fibrotic changes of esophageal tissue were observed using Masson staining.The expression levels of NOX-4 and related fibrotic cytokines in esophageal tissues were detected by several methods such as immunohistochemistry,enzyme-linked immunosorbent assay (ELISA) and realtime polymerase chain reaction (qRT-PCR).Results Body weight in CRS group was significantly lower than NC group (8.75 ± 1.69 vs 12.69 ± 3.16),with statistically significant difference (t =3.11,P ＜ 0.05).Masson staining revealed that CRS mice showed distinct fibrosis of epithelial interstitium,while there was no distinct changes observed in NC mice.Immunohistochemical staining revealed intense staining for NOX-4 in epithelial,mucosal and submucosal layers of esophagi in CRS mice.ELISA showed that the serum level of NOX-4 in CRS mice was higher than NC mice (1.442 ± 0.05 vs 0.449 ± 0.08),with statistically significant difference (t =-27.32,P ＜ 0.01).Real-time PCR results showed that the expression of colla-1,TGF-β1,α-SMA and NOX-4 in CRS mice were as (2.443 ±0.36,2.78 ±0.13,2.244 ±0.18,2.448 ±0.440) times higher than NC mice,with statistically significant difference (t =-11.19,-38.86,-19.90,-10.37,P ＜ 0.01).Conclusions Fibrotic cytokines such as colla-1,TGF-β1 and α-SMA may participate in formation of stress induced esophageal fibrosis,and oxidative stress may play crucial role in the process of esophageal fibrosis.
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AIM:To investigate the regulatory effect of NADPH oxidase-4 (NOX-4) on PI3K signaling path-way in transforming growth factor-β1 (TGF-β1)-induced collagen type Ⅰ (collagen Ⅰ) synthesis from lung cancer cells and the mechanisms. METHODS:Human lung cancer A549 cells were cultured in vitro and stimulated with TGF-β1. The ex-pression of NOX family and collagen family at mRNA and protein levels as well as the PI3K class Ⅰ catalytic subunits and the activation of PI3K signaling pathway was measured. A549 cells were pre-treated with NOX-4 inhibitor diphenyleneiodo-nium (DPI), and the expression of collagen Ⅰ at mRNA level as well as the PI3K class Ⅰ catalytic subunits and the activa-tion of PI3K signaling pathway was measured upon TGF-β1 stimulation. RESULTS:TGF-β1 stimulated the expression of NOX-4 and collagen Ⅰ at mRNA and protein levels as well as the expression of PIK3CD and the activation of PI3K signaling pathway at a dose- and time-dependent manner. NOX-4 inhibitor DPI partly reversed TGF-β1-induced collagen Ⅰ expres-sion. Inhibition of NOX-4 down-regulated the degree of TGF-β1-stimulated activation of PI3K signaling pathway without effect on the expression of PIK3CD. CONCLUSION:NOX-4 participates in TGF-β1-induced collagen Ⅰ synthesis from lung cancer cells via regulating the activation of PI3K signaling pathway. TGF-β1/NOX-4/PI3K signaling pathway axis acts as a regulatory role in collagen Ⅰ synthesis from lung cancer cells.
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4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-β (TGF-β) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-β signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-β-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-β1-induced G1/G0 phase arrest and TGF-β1-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-β1-induced canonical pathway. We observed that ERK phosphorylation by TGF-β1 was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-β1-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-β1-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-β1-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-β1-induced cell cycle arrest.