Roles of transforming growth factor-βsignaling in liver disease

In this editorial we expand the discussion on the article by Zhang et al published in the recent issue of the World Journal of Hepatology.We focus on the diagnostic and therapeutic targets identified on the basis of the current understanding of the molecular mechanisms of liver disease.Transforming growth factor-β(TGF-β)belongs to a structurally related cytokine super family.The family members display different time-and tissue-specific expression patterns associated with autoimmunity,inflammation,fibrosis,and tumorigenesis;and,they participate in the pathogenesis of many diseases.TGF-βand its related signaling pathways have been shown to participate in the progression of liver diseases,such as injury,inflammation,fibrosis,cirrhosis,and cancer.The often studied TGF-β/Smad signaling pathway has been shown to promote or inhibit liver fibrosis under different circumstances.Similarly,the early immature TGF-βmolecule functions as a tumor suppressor,inducing apoptosis;but,its interaction with the mitogenic molecule epidermal growth factor alters this effect,activating anti-apoptotic signals that promote liver cancer development.Overall,TGF-βsignaling displays contradictory effects in different liver disease stages.Therefore,the use of TGF-βand related signaling pathway molecules for diagnosis and treatment of liver diseases remains a challenge and needs further study.In this editorial,we aim to review the evidence for the use of TGF-βsignaling pathway molecules as diagnostic or therapeutic targets for different liver disease stages.

Effect of Tuina along“bladder meridian”alleviating intervertebral disc degeneration by regulating the transforming growth factor-β1/Smad signaling pathway in a rabbit model

OBJECTIVE:The aim of this study was to investigate the protective effects of Tuina(a traditional Chinese massage therapy)on intervertebral disc(IVD)degeneration and the regulatory mechanisms of the transforming growth factor-β1(TGF-β1)/small mothers against decapentaplegic(Smad)signaling pathway.METHODS:Thirty New Zealand white rabbits were randomized into five groups:the control group,model group,model+Tuina group(Tuina group),model+TGF-β1 group(TGF-β1 group),and model+TGF-β1 inhibitor SB431542 group(SB431542 group).The model was established by posterolateral annulus fibrosus puncturing(AFP).Recombinant TGF-β1 and inhibitor SB431542 was injected into the TGF-β1 group and SB431542 group with a microsyringe,respectively.The rabbits in the Tuina group received Tuina treatment along the bladder meridian for 4 weeks.Magnetic resonance imaging(MRI)was performed on rabbits before AFP and after 4 weeks of intervention.Lumbar IVDs(L2-L3 to L4-L5)were harvested after intervention.Histopathological changes in the IVDs were measured by hematoxylin and eosin(HE)staining.Type I collagen was analyzed by immunohistochemistry detection.The expression level of matrix metalloproteinase-3(MMP3)was determined by enzyme-linked immunosorbent assay.Cell apoptosis was evaluated by terminal deoxynucleotidyl transferasemediated nick end labeling and Western blotting.Realtime polymerase chain reaction and Western blotting were used to analyze the expression of TGF-β1 and Smad2/3/4 and a disintegrin and metalloproteinase with thrombospondin motifs 5.RESULTS:Posterolateral AFP induced IVD degeneration in rabbits with histopathological damage and noticeable changes in MRI images.Tuina alleviated histopathological changes and reversed the expression of extracellular matrix degeneration-related molecules and apoptosis-related proteins.Furthermore,AFP induced the activation of TGF-β1 and Smad2/3/4,whereas Tuina therapy markedly reduced the protein expression of Smad2/3 and the gene expression of TGF-β1 and Smad2/3/4.Additionally,the TGF-β1/Smad signaling pathway was activated in the TGF-β1 group,while the TGF-β1/Smad signaling pathway was inhibited in the SB431542 group.CONCLUSION:Posterolateral AFP induced disc degeneration as determined by MRI assessment and histological analysis.Tuina alleviated disc degeneration,possibly by inhibiting the fibrotic response mediated by the TGF-β1/Smad pathway,thus alleviating extracellular matrix degeneration and reducing cell apoptosis.

Transforming growth factor-β1 and vascular endothelial growth factor levels in senile acute myeloid leukemia and correlation with prognosis

BACKGROUND Acute myeloid leukemia(AML)is a disease in which immature hematopoietic cells accumulate in the bone marrow and continuously expand,inhibiting hematopoiesis.The treatment and prognosis of this disease have always been unsatisfactory.AIM To investigate the correlation between vascular endothelial growth factor(VEGF)and transforming growth factor-β1(TGFβ1)expression and prognosis in older adults with AML.METHODS This study enrolled 80 patients with AML(AML group),including 36 with complete response(AML-CR),23 with partial response(AML-PR),and 21 with no response(AML-NR).The expression levels of VEGF and TGFβ1 were detected by reverse transcription polymerase chain reaction in bone marrow mononuclear cells isolated from 56 healthy controls.Kaplan-Meier analysis was performed to assess overall survival(OS)and progression-or disease-free survival(DFS).Prognostic risk factors were analyzed using a Cox proportional hazards model.RESULTS The AML group showed a VEGF level of 2.68±0.16.VEGF expression was lower in patients with AML-CR than those with AML-PR or AML-NR(P<0.05).TGFβ1 expression in the AML group was 0.33±0.05.Patients with AML-CR showed a higher TGFβ1 expression than those with AML-PR or AML-NR(P<0.05).VEGF and TGFβ1 expression in patients with AML was significantly correlated with the counts of leukocytes,platelets,hemoglobin,and peripheral blood immature cells(P<0.05);Kaplan-Meier survival analysis revealed that patients with high TGFβ1 expression had better OS and DFS than those with low TGFβ1 expression(P<0.05),whereas patients with low VEGF levels showed better OS and DFS than those with high VEGF levels(P<0.05).VEGF,TGFβ1,and platelet count were identified by the Cox proportional hazards model as independent risk factors for OS(P<0.05),while VEGF,TGFβ1,and white blood cell count were independent risk factors for DFS(P<0.05).CONCLUSION Decreased VEGF expression and increased TGFβ1 expression in patients with AML provide valuable references for determining and individualizing clinical treatment strategies.

TRANSFORMING GROWTH FACTOR-β1 AND SMAD4 SIGNALING PATHWAY DOWN-REGULATES RENAL EXTRACELLULAR MATRIX DEGRADATION IN DIABETIC RATS

Objective To investigate the role of transforming growth factor-131 （TGF-β1）/Smad4 pathway in development of renal fibrosis in streptozotocin （STZ）-induced diabetic nephropathy （DN） rats and explore its possible mechanism. Methods Male Wistar rats weighing 180-220 g were divided into 5 groups： group A （ normal control）, group B [ diabetes mellitus （DM） 2 weeks ], group C （ DM 4 weeks）, group D （ DM 8 weeks）, and group E （ DM 16 weeks）. Except for the normal control group, other groups were induced DM by single injection of STZ （55 mg/kg） respectively. Blood glucose level, serum creatinine, and 24-hour urine protein were examined. Expressions of TGF-β1 and Smad4 protein and mRNA in kidney were detected using immunohistochemical technique, Western blot, and real-time PCR. mRNA expressions of stromelysin-1 （ MMP-3 ）, tissue inhibitor of metalloproteinase-1 （ TIMP-1 ）, and collagen Ⅲ in kidney were also detected by real-time PCR. Results The levels of blood glucose, serum creatinine, and 24-hour urine protein in rats of group B, C, D, and E were higher than those of the control group. With the progression of renal fibrosis, the expressions of TGF-β1 and Smad4 protein and mRNA in kidney of diabetic rats elevated. In addition, the renal MMP-3 mRNA expression diminished in diabetic rats, while TIMP-1 and collagen Ⅲ mRNA increased. Conclusions In STZ-induced diabetic rats, the TGF-β1/Smad4 appears to play an important role in renal fibrosis of DN. The increased expression of TGF-β1 and Smad4 might result in the transcriptional regulation of downstream target genes of TGF-β1/Smad4 pathway, which contributes to the progression of renal fibrosis in diabetic rats.

Dab2 attenuates brain injury in APP/PS1 mice via targeting transforming growth factor-beta/SMAD signaling

Transforming growth factor-beta （TGF-β） type II receptor （TβRⅡ） levels are extremely low in the brain tissue of patients with Alzheimer＇s disease. This receptor inhibits TGF-β1/SMAD signaling and thereby aggravates amyolid-beta deposition and neuronal injury. Dab2, a specific adapter protein, protects T RII from degradation and ensures the effective conduction of TGF-β 1/SMAD signaling. In this study, we used an adenoviral vector to overexpress the Dab2 gene in the mouse hippocampus and investigated the regulatory effect of Dab2 protein on TGF-β1/SMAD signaling in a mouse model of Alzheimer＇s disease, and the potential neuroprotective effect. The results showed that the TβRⅡ level was lower.in APP/PS1 mouse hippocampus than in normal mouse hippocampus. After Dab2 expression, hippocampal TβRⅡ and p-SMAD2/3 levels were signifi- cantly increased, while amyloid-beta deposition, microglia activation, tumor necrosis factor- and interleulin-6 levels and neuronal loss were significantly attenuated in APP/PS1 mouse brain tissue. These results suggest that Dab2 can exhibit neuroprotective effects in Alzheimer＇s disease by regulating TGF-β1/SMAD signaling.

Wulong Xiaozheng Wan medicated serum inhibits epithelial-mesenchymal transition in human gastric carcinoma cell line BGC823 by modulation of transforming growth factor-β1/Smad signaling

OBJECTIVE:To evaluate the effect of Wulong Xiaozheng Wan medicated serum on the epithelial-mesenchymal transition (EMT) of BGC823 cell induced by transforming growth factor-β,(TGF-β,) and to explore its mechanism.METHODS:EMT model of BGC823 was stimulated by TGF-β1.Wulong Xiaozheng Wan medicated serum and LY-364947 were used as intervention.The proliferation and adhesion of BGC823 were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry was used to detect the apoptosis.The invasion and migration were detected by Transwell.The level of matrix metalloproteins was detected by enzyme-linked immunosorbent assay.The expressions of related proteins and mRNA of EMT marker and TGF-β1/Smad signal pathway were detected by Western blot and reverse transcription-polymerase chain reaction.RESULTS:Compared with the TGF-β1 group,Wulong Xiaozheng Wan medicated serum could inhibit the ability of proliferation,heterogeneous adhesion,invasion,and migration.It also promotes apoptosis and homotypic adhesion in BGC823,with a dose-dependent manner.Meanwhile,Wulong Xiaozheng Wan medicated serum could regulate the expression of related proteins and mRNA of TGF-β1/Smad signaling pathway,and inhibit the expressions of EMT transcription factors and EMT markers.CONCLUSION:Wulong Xiaozheng Wan medicated serum inhibited epithelial-mesenchymal transition by down-regulated the expression of TβRI and the activation of TGF-β1/Smad signaling pathway.

Shugan Huoxue Huayu Fang(疏肝活血化瘀方)attenuates carbon tetrachloride-induced hepatic fibrosis in rats by inhibiting transforming growth factor-β1/Smad signaling

OBJECTIVE:To investigate the potential mechanism by which Shugan Huoxue Huayu Fang(疏肝活血化瘀方,SGHXHYF)ameliorates liver fibrosis.METHODS:Liver fibrosis was induced in rats by intraperitoneal injection of carbon tetrachloride(CCl_(4))in peanut oil solution(40%,3 m L/kg body weight)twice a week for 8 weeks.A normal control group received the same volume of peanut oil alone.During weeks 5-8,the CCl_(4)-injected rat groups were administered saline(vehicle control),colchicine(0.1 mg/mL,1 mg/kg,positive control),or SGHXHYF(0.1 mg/mL;0.3,0.6 and 1.2 mg/kg)once daily by oral gavage.Rats were sacrificed 24 h after the last treatment.Blood samples were collected for measurement of serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),albumin(ALB),collagenⅠ,and collagenⅢlevels.Liver samples were analyzed by histopathological staining,Masson's staining of extracellular matrix proteins,and immune-ohistochemical staining ofα-smooth muscle actin(α-SMA).TGF-β1/Smad protein and mRNA levels were analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction analysis,respectively.In vitro experiments were also performed using rat hepatic stellate cells(HSCs).RESULTS:Compared with the control animals,CCl_(4)-exposed rats exhibited elevated serum levels of ALT,AST,ALP,collagenⅠ,and collagenⅢ;reduced serum levels of ALB;and increased collagen deposition andα-SMA expression in liver sections,reflecting liver fibrosis.CCl_(4) also increased expression of TGF-β1 and the activated(phosphorylated)forms of Smad2 and Smad3 but reduced expression of the negative regulator Smad7 in the liver.Notably,concomitant administration of SGHXHYF to CCl_(4)-exposed rats was found to significantly reverse or abolish the pro-fibrotic effects of CCl_(4) in the liver and reduced serum transferase levels.Analysis of HSCs in vitro confirmed that,mechanistically,SGHXHYF inhibited activation of the TGF-β1/Smad signaling pathway by downregulating phosphorylated Smad2 and Smad3 and upregulating Smad7 levels.CONCLUSION:SGHXHYF ameliorated CCl_(4)-induced liver fibrosis by inhibiting the TGF-β1/Smad signaling pathway.These findings suggest that SGHXHYF may have clinical utility for the treatment or prevention of liver fibrosis.

TL1A Promotes Fibrogenesis in Colonic Fibroblasts via the TGF-β1/Smad3 Signaling Pathway

Objective Intestinal fibrosis is a refractory complication of inflammatory bowel disease(IBD).Tumor necrosis factor ligand-related molecule-1A(TL1A)is important for IBD-related intestinal fibrosis in a dextran sodium sulfate(DSS)-induced experimental colitis model.This study aimed to explore the effects of TL1A on human colonic fibroblasts.Methods A trinitrobenzene sulfonic acid(TNBS)-induced experimental colitis model of LCK-CD2-TL1A-GFP transgenic(Tg)or wild-type(WT)mice was established to determine the effect and mechanism of TL1A on intestinal fibrosis.The human colonic fibroblast CCD-18Co cell line was treated concurrently with TL1A and human peripheral blood mononuclear cell(PBMC)supernatant.The proliferation and activation of CCD-18Co cells were detected by BrdU assays,flow cytometry,immunocytochemistry and Western blotting.Collagen metabolism was tested by Western blotting and real-time quantitative polymerase chain reaction(RT-qPCR).Results The level of collagen metabolism in the TNBS+ethyl alcohol(EtOH)/Tg group was greater than that in the TNBS+EtOH/WT group.Transforming growth factor-β1(TGF-β1)and p-Smad3 in the TNBS+EtOH/Tg group were upregulated as compared with those in the TNBS+EtOH/WT group.The proliferation of CCD-18Co cells was promoted by the addition of human PBMC supernatant supplemented with 20 ng/mL TL1A,and the addition of human PBMC supernatant and TL1A increased CCD-18Co proliferation by 24.4%at 24 h.TL1A promoted cell activation and increased the levels of COL1A2,COL3A1,and TIMP-1 in CCD-18Co cells.Treatment of CCD-18Co cells with TL1A increased the expression of TGF-β1 and p-Smad3.Conclusion TL1A promotes TGF-β1-mediated intestinal fibroblast activation,proliferation,and collagen deposition and is likely related to an increase in the TGF-β1/Smad3 signaling pathway.

Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-β1 signaling in Crohn's disease intestinal fibrosis

AIM To explore the role and mechanism of total flavone of Abelmoschus manihot(TFA) on epithelial-mesenchymal transition(EMT) progress of Crohn's disease(CD) intestinal fibrosis.METHODS First,CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial(IEC-6) cells and select the optimal concentrations of TFA for our further studies.Then cell morphology,wound healing and transwell assays were performed to examine the effect of TFA on morphology,migration and invasion of IEC-6 cells treated with TGF-β1.In addition,immunofluorescence,real-time PCR analysis(q RT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress.Moreover,western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways.Further,the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by q RTPCR,western blotting,morphology,wound healing andtranswell assays.RESULTS In this study,TFA promoted transforming growth factor-β1(TGF-β1)-induced(IEC-6) morphological change,migration and invasion,and increased the expression of epithelial markers and reduced the levels of mesenchymal markers,along with the inactivation of Smad and MAPK signaling pathways.Moreover,we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-β1-induced EMT in IEC-6 cells.Importantly,co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-β1-induced EMT in IEC-6 cells than either one of them.CONCLUSION These findings could provide new insight into the molecular mechanisms of TFA on TGF-β1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis.

Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling

AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro.METHODS: HSCs were isolated from rats by in situperfusion of liver and 18% Nycodenz gradient centrifugation, and primarily cultured on uncoated plastic plates for 24 hwith DMEM containing 20% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1,2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscleα-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲprocollagen (PCⅢ) in supernatants were determined byradioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively.RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2%(control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P＜0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCⅢ to 84.6%, 81.5%,75.7% or 80.7% respectively (P＜0.05 vs control), with no significant difference among tetrandrine groups. RTPCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r= -0.755, P＜0.01), and both were significantly correlated with α-SMA protein expression (r = -0.938, P＜0.01;r = 0.938, P＜0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L)was confirmed by Western blotting as well.CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.

Role of transforming growth factor-beta signaling pathway in pathogenesis of benign biliary stricture

AIM: To characterize the expression of members of the transforming growth factor-beta (TGF-β)/Smad/ connective tissue growth factor (CTGF) signaling pathway in the tissue of benign biliary stricture, and to investigate the effect of TGF-β signaling pathway in the pathogenesis of benign biliary stricture. METHODS: Paraffin embedded materials from 23 cases of benign biliary stricture were analyzed for members of the TGF-β/Smad/CTGF signaling pathway. TGF-β_1, TβRⅠ, TβRⅡ, Smad4, Smad7 and CTGF protein were detected by immunohistochemical strepto-advidinbiotin complex method, and CTGF mRNA was evaluated by hybridization in situ, while 6 cases of normal bile duct served as controls. The percentages of positive cells were counted. The correlation between TGF-β_1, Smad4 and CTGF was analyzed. RESULTS: The positive expression ratios of TGF-β_1, TβRⅠ , TβRⅡ , Smad4, CTGF and CTGF mRNA in 23 cases with benign biliary stricture were 91.3%, 82.6%, 87.0%, 78.3%, 82.6% and 65.2%, respectively, signifi cantly higher than that in 6 cases of normal bile duct respectively (vs 33.3%, 16.7%, 50.0%, 33.3%, 50.0%, 16.7%, respectively, P < 0.05). The positiveexpression ratio of Smad7 in cases with benign biliary stricture was 70.0%, higher than that in normal bile duct, but this difference is not statistically signifi cant 70.0% vs 50%, P > 0.05). There was a positive correlation between positive expression of TGF-β_1, Smad4 and CTGF in cases with benign biliary stricture. CONCLUSION: The high expression of TGF-β/Smad/ CTGF signaling pathway plays an important role in the pathogenesis of benign biliary stricture.

Roles of Smad3 and Smad7 in rat pancreatic stellate cells activated by transforming growth factor-beta 1

BACKGROUND: Pancreatic stellate cells (PSCs) play a major role in promoting pancreatic fibrosis. Transforming growth factor beta 1 (TGF-beta 1) is a critical mediator of this process. This study aimed to determine the expression of the Smad3 and Smad7 genes in the process of PSC activation, and explore the mechanisms of chronic pancreatitis. METHODS: The expressions of Smad3 and Smad7 in PSCs before and after TGF-beta 1 treatment were detected by reverse transcription-polymerase chain reaction and Western blotting analysis. Smad3 expression was detected in PSCs after treatment with 5 ng/ml of TGF-beta 1 for 24 hours. RESULTS: Smad7 expression was decreased in TGF-beta 1 -activated PSCs (P<0.05) in a dose-dependent manner. When TGF-beta 1 concentration reached 10 ng/ml, the expression of p-Smad3, Smad3, and Smad7 was inhibited (P<0.05). CONCLUSIONS: TGF-beta 1 promotes the expression of Smad3 and inhibits the expression of Smad7 during the activation of PSCs. In contrast, high-dose TGF-beta 1 downregulates the expression of Smad3 in completely activated PSCs.

Histone deacetylase inhibitor suberoylanilide hydroxamic acid alleviates liver fibrosis by suppressing the transforming growth factor-β1 signal pathway

Background: Histone deacetylases(HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylanilide hydroxamic acid(SAHA) by suppressing transforming growth factor-β1(TGF-β1) signaling. Methods: Male Sprague-Dawley rats were used to induce liver fibrosis with carbon tetrachloride(CCl 4) and LX2 cell(human hepatic stellate cell line) was stimulated by TGF-β1. Both animals and cells were treated with SAHA. The Smad7 and connective tissue growth factor(CTGF) mRNA levels were detected by real-time polymerase chain reaction(PCR). Western blotting was used to examine the protein levels of CTGF, Histone H3(H3), Smad7, Smad2/3, Acetyl-Histone H3(AH3), HDAC2, α-smooth muscle actin( α-SMA), HDAC6, p-Smad2/3 and HDAC8. In addition, the TGF-β1 and liver enzyme levels from rat serum were detected. Histopathological changes were examined by hematoxylin and eosin(HE), Sirius red and Masson trichrome staining. The α-SMA expression was detected by immumohistochemical staining. Results: Compared with control group, the TGF-β1 and liver enzyme levels from rat serum, together with the mRNA levels of CTGF and protein levels of CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were elevated in fibrotic rats( P < 0.01). But the Smad7 mRNA and AH3 protein levels were notably suppressed in the fibrotic rats( P < 0.01). Pathological examination showed the typical changes of liver fibrosis in the fibrotic rats. After the treatment with SAHA, the levels of liver enzymes, TGF-β1, CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were reduced( P < 0.01) and Smad7 and AH3 protein contents were elevated in liver fibrotic rats( P < 0.01). Moreover, immumohistochemistry showed that SAHA significantly suppressed the α-SMA protein content in fibrotic liver( P < 0.01). Conclusion: The HDAC inhibitor SAHA alleviated liver fibrosis by suppressing the TGF-β1 signaling.

Effects of Tanshinone ⅡA on Transforming Growth Factor β1-Smads Signal Pathway in Renal Interstitial Fibroblasts of Rats

The effects of tanshinone ⅡA （TSN） on transforming growth factor β1 （TGFβ1） signal transduction in renal interstitial fibroblasts of rats were studied in order to investigate its mechanism in prevention of renal interstitial fibrosis. Rat renal fibroblasts of the line NRK/49F were cultured in vitro, stimulated with 5 ng/mL TGFβ1 and pretreated with 10-6, 10-5, 10-4 mol/L TSN respectively. The mRNA levels of fibronectin （FN） were examined by RT-PCR. The protein expression of FN and Smads was detected by Western blot. TGFβ1 induced the expression of FN mRNA and Smads in a time-dependent manner in a certain range. Compared with pre-stimulation, the FN mRNA and protein levels were increased by 1.1 times and 1.5 times respectively （P〈0.01, P〈0.01）, and the protein expression of phosphorylated Smad2/3 （p-Smad2/3） increased by 7 times at the end of TGFβ1 stimulation （P〈0.01）. TSN pretreatment may down-regulate the FN and p-Smad2/3 expression in a dose-dependent manner. 10-6 mol/L TSN pretreatment had no effect on the FN and p-Smad2/3 expression （both P〉0.05）. After pretreatment with 10-5 and 10-4 mol/L TSN, the FN mRNA levels were decreased by 28.1% and 43.8% respectively （P〈0.05, P〈0.01）, the FN protein levels were decreased by 40% and 44% respectively （P〈0.05, P〈0.05）, and the p-Smad2/3 protein expression were decreased by 40% and 65% respectively （P〈0.05, P〈0.01）. The inhibitory effect of TSN on renal interstitial fibrosis may be related to its blocking effect on TGFβ1-Smads signal pathway in renal intersti- tial fibroblasts.

Expression of transforming growth factor-β_1 and its typeⅠ receptor in different phases of post-burn hypertrophic scars

Objective: To analyze and compare the expression pattern of the transforming growth factor-β1(TGF-β1) and its type I receptor (TGF-β RI ) in nounal human skin and various phases of post-burn hypertrophic scars (HTS). Method: The immunohistochemical ABC method was employed. Results: In nounal human skin, no evident immunoreactivity of TGF-β1 and TGF-β R I was observed. In activation phase of post-burn HTS, TGF-β R I and TGF-β1 were highly expressed in most dermal fibroblasts which seemed to be the same subset. However, in remission phase, no staining was seen in der mal fibroblasts. Conclusion: The formation of all may involve the increase of TGF-β responsiveness in fibroblasts The ac cumulation at the wound site and failure of apoptosis of over-resposive fibroblasts may contribute to the formation of HTS.

Effects of Heparin on Transforming Growth Factor-β_1 and Extracellular Matrix Components in the Glomeruli of Diabetic Rats

The effects of heparin on the expression of transforming growth factor-β 1 (TGF-β 1) and two extracellular matrix components laminin (LN) and fibronectin (FN) in diabetic rat glomeruli were investigated. Twenty-six rats were randomly divided into control group (C, n=8), diabetic group (D, n=9), and diabetes+heparin group (DH, n=9). After 8-week therapy of heparin (200 U once daily by abdominal injection), TGF-β 1, LN and FN expression in glomeruli was detected by immunohistochemical method. The results showed that the expression levels of TGF-β 1, LN and FN were higher in group D than in group C. It was found that heparin could reduce 24-h urinary albumin excretion and inhibit overexpression of TGF-β 1, LN and FN in glomeruli of diabetic rats. It suggested that the inhibitory effect of heparin on diabetic glomerular sclerosis was at least partly related with the inhibition of TGF-β 1 expression.

Expression of Mesenger RNA for Transforming Growth Factor-β_1 in Bovine Trabecular Meshwork

Purpose: To investigate the relationship between transforming growth factor-β1(TGF-β1) and primary open-angle glaucoma, we have determined whether trabec-ular tissues have the expression of messenger RNA for TGF-β1.Methods: Total RNA of 24 newborn bovine trabecular tissue were extracted byGuanidine isothiocyanate method. The TGF-β33 plasmid was brought into E. col-ibacillius HB101 and amplificated. After Bam HI endolase degradation and labelwith a-32p-dATP the RNA was hybridized with the cDNA (complementary DNA)probe and examined by autoradiography.Results: The presence of mRNA for TGF-β1 in bovine trabecular meshwork wasconfirmed.Conclusions: The TGF-β1 present in normal aqueous humor must be at least partlyderived from the trabecular meshwork. It offered a basis for understanding therelationship between abnormal synthesis, activation and clearance of TGF-β1 andthe pathogenesis of primary open-angle glaucoma (POAG) in molecular biology.Eye Science 1996; 12:1-4.

黄芪多糖通过TGF-β1/Smads通路对哮喘大鼠Th1/Th2免疫失衡的调节作用

目的:探讨黄芪多糖通过转化生长因子(TGF)-β1/Smads信号通路对哮喘大鼠辅助性T细胞(Th)l/Th2免疫失衡的调节作用。方法:选择雄性SD大鼠40只,分为对照组、模型组、黄芪多糖低、中、高剂量组,各8只。建立慢性哮喘大鼠模型,对照组和模型组大鼠尾静脉注射等体积0.9%氯化钠溶液,川芎嗪低、中、高剂量腹腔注射川芎嗪,各组均连续治疗14 d。干预后检测各组大鼠支气管黏膜受损面积和平滑肌厚度,收集各组大鼠支气管肺泡灌洗液(BALF),测定白细胞介素-4(IL-4)、干扰素-γ(IFN-γ)水平变化,苏木精-伊红(HE)染色观察肺组织结构变化,实时荧光定量PCR(qRT-PCR)和蛋白质免疫印迹(Western blot)对肺组织TGF-β1、Smad2、Smad3 mRNA和蛋白表达进行测定。结果:与对照组比较,模型组支气管黏膜受损面积、平滑肌厚度增加,与模型组比较,黄芪多糖各组均下降,且呈剂量依赖性(P<0.05)。与对照组比较,模型组BALF中IFN-γ水平降低,IL-4水平升高,与模型组比较,黄芪多糖各组BALF中IFN-γ水平均升高,IL-4水平均下降,且呈剂量依赖性(P<0.05)。模型组肺组织TGF-β1、Smad2、Smad3 mRNA和蛋白表达较对照组升高,黄芪多糖各组肺组织TGF-β1、Smad2、Smad3 mRNA和蛋白表达较模型组下降,且呈剂量依赖性(P<0.05)。结论:黄芪多糖通过抑制TGF-β1/Smads信号激活阻止哮喘大鼠气道炎症,调节Th1/Th2比值失衡,改善大鼠肺组织病理损伤。

褐藻聚合酚下调TGF-β_(1)/Smads信号通路抑制大肠癌细胞增殖与侵袭

目的探讨褐藻聚合酚(PFFE-A)对大肠癌细胞增殖与侵袭的影响,以及其对转化生长因子β_(1)(TGF-β_(1))及母体抗生物皮肤生长因子同源物2/3(Smad2/3)通路的调控作用。方法细胞分组:依次以50、100、150μmol·L-1的小、中、大剂量的PFFE-A干预细胞,另设立正常对照组细胞。5-乙炔基-2'脱氧尿苷(EdU)染色检测细胞的增殖;Transwell小室检测细胞的侵袭能力;异种种植结肠癌裸鼠模型检测细胞的体内生长与转移能力;实时荧光定量聚合酶链反应(RT-qPCR)检测细胞中上皮间质转化(EMT)相关基因的表达;Western blotting检测细胞中TGF-β_(1)、p-Smad2/3的表达水平。结果与正常对照组比较,PFFE-A小、中、大剂量组细胞的增殖率、侵袭细胞数、肿瘤瘤体质量、病灶转移比例、神经型钙黏附蛋白(N-cadherin)的mRNA的表达、TGF-β_(1)和p-Smad2/3的表达明显下降(P<0.05),E-钙黏蛋白(E-cadherin)的mRNA的表达明显升高(P<0.05),具有明显的剂量依赖性(P<0.05)。结论PFFE-A能抑制肿瘤细胞的EMT过程,抑制大肠癌细胞HT29的体外增殖与侵袭能力,下调其体内生长与转移的能力,这可能是通过下调TGF-β_(1)/Smads信号实现的。

活血利水复方对自发性高血压大鼠转化生长因子-β1/SMAD家族蛋白信号通路介导下游结缔组织生长因子及Ⅰ、Ⅲ型胶原表达及血管重塑的影响

目的:基于转化生长因子-β1/SMAD家族蛋白信号通路探讨活血利水中药复方对自发性高血压大鼠血管重塑的保护作用及机制。方法:将自发性高血压大鼠随机分为模型组、卡托普利组、活血利水复方低剂量组、活血利水复方中剂量组、活血利水复方高剂量组,Wistar大鼠作为空白组,每组10只。给予相应药物灌胃,4周后采用酶联免疫吸附试验方法检测血清中C反应蛋白、肿瘤坏死因子-α、白细胞介素-6的含量;采用逆转录聚合酶链反应检测大鼠主动脉组织转化生长因子-β1、结缔组织生长因子及Ⅰ型胶原、Ⅲ型胶原mRNA表达,并取冠状动脉组织进行马松三色染色。结果:与空白组比较,模型组血清中C反应蛋白、肿瘤坏死因子-α、白细胞介素-6的含量显著升高(P<0.01);与模型组比较,各药物组大鼠干预后血清中C反应蛋白、肿瘤坏死因子-α、白细胞介素-6的含量不同程度降低(P<0.01)。其中,卡托普利组和活血利水复方高剂量组上述3项指标表达最低,与其他组的差异有统计学意义(P<0.05或P<0.01);卡托普利组和活血利水复方高剂量组比较,差异无统计学意义(P>0.05)。与空白组比较,模型组大鼠主动脉转化生长因子-β1、结缔组织生长因子及Ⅰ型胶原、Ⅲ型胶原mRNA表达显著升高(P<0.01);与模型组比较,卡托普利组及活血利水复方低剂量组、活血利水复方中剂量组、活血利水复方高剂量组大鼠主动脉组织转化生长因子-β1、结缔组织生长因子及Ⅰ型胶原、Ⅲ型胶原mRNA表达不同程度降低(P<0.05或P<0.01)。结论:活血利水中药复方可通过调控转化生长因子-β1/SMAD家族蛋白信号通路及下游结缔组织生长因子及Ⅰ型胶原、Ⅲ型胶原mRNA表达水平,降低C反应蛋白、肿瘤坏死因子-α、白细胞介素-6等炎症因子的表达,抑制炎症反应,从而改善高血压病炎症状态及血管重塑,其机制可能与降低转化生长因子-β1、结缔组织生长因子及Ⅰ型胶原、Ⅲ型胶原蛋白沉积有关。