TGF-β1受体1和2在TGF-β1调节细胞增殖中的作用

转化生长因子β1(transforming growth factor-β1,TGF-β1)是一种多功能细胞因子,在细胞增殖、分化、伤口愈合和肿瘤生成转移等过程中均发挥重要调控作用。TGF-β1对细胞增殖的调节可因细胞类型、刺激剂量不同而不同,但其差异调节的机制还不清楚。现普遍认为,TGF-β1在TGFBR2/TGFBR1二聚体参与下通过经典的Smad信号通路抑制增殖,而通过非Smad信号通路促进细胞周期,但是机体是如何调控这种不同增殖调节作用转化的还不明确。TGFBR1和TGFBR2在细胞中的分布和比例变化可能是TGF-β1差异性调控细胞增殖作用的一个重要机制。

Cytokine receptor-like factor 1(CRLF1)promotes cardiac fibrosis via ERK1/2 signaling pathway

Cardiac fibrosis is a cause of morbidity and mortality in people with heart disease.Anti-fibrosis treatment is a significant therapy for heart disease,but there is still no thorough understanding of fibrotic mechanisms.This study was carried out to ascertain the functions of cytokine receptor-like factor 1(CRLF1)in cardiac fibrosis and clarify its regulatory mechanisms.We found that CRLF1 was expressed predominantly in cardiac fibroblasts.Its expression was up-regulated not only in a mouse heart fibrotic model induced by myocardial infarction,but also in mouse and human cardiac fibroblasts provoked by transforming growth factor-β1(TGF-β1).Gain-and loss-of-function experiments of CRLF1 were carried out in neonatal mice cardiac fibroblasts(NMCFs)with or without TGF-β1 stimulation.CRLF1 overexpression increased cell viability,collagen production,cell proliferation capacity,and myofibroblast transformation of NMCFs with or without TGF-β1 stimulation,while silencing of CRLF1 had the opposite effects.An inhibitor of the extracellular signal-regulated kinase 1/2(ERK1/2)signaling pathway and different inhibitors of TGF-β1 signaling cascades,comprising mothers against decapentaplegic homolog(SMAD)-dependent and SMAD-independent pathways,were applied to investigate the mechanisms involved.CRLF1 exerted its functions by activating the ERK1/2 signaling pathway.Furthermore,the SMAD-dependent pathway,not the SMAD-independent pathway,was responsible for CRLF1 up-regulation in NMCFs treated with TGF-β1.In summary,activation of the TGF-β1/SMAD signaling pathway in cardiac fibrosis increased CRLF1 expression.CRLF1 then aggravated cardiac fibrosis by activating the ERK1/2 signaling pathway.CRLF1 could become a novel potential target for intervention and remedy of cardiac fibrosis.

Association of overexpression of TIF1γ with colorectal carcinogenesis and advanced colorectal adenocarcinoma

AIM:To determine the expression and clinical significance of transcriptional intermediary factor 1 gamma (TIF1γ),Smad4 and transforming growth factor-beta (TGFβR) across a spectrum representing colorectal cancer (CRC) development.METHODS:Tissue microarrays were prepared from archival paraffin embedded tissue,including 51 colorectal carcinomas,25 tubular adenomas (TA) and 26 HPs,each with matched normal colonic epithelium.Immunohistochemistry was performed using antibodies against TIF1γ,Smad4 and TGFβ RⅡ.The levels of expression were scored semi-quantitatively (score 0-3 or loss and retention for Smad4).RESULTS:Overexpression of TIF1γ was detected in 5/26 (19%) HP;however,it was seen in a significantly higher proportion of neoplasms,15/25 (60%) TAs and 24/51 (47%) CRCs (P<0.05).Normal colonic mucosa,HP,and TAs showed strong Smad4 expression,while its expression was absent in 22/51 (43%) CRCs.Over-expression of TGFβ RⅡ was more commonly seen in neoplasms,13/25 (52%) TAs and 29/51 (57%) CRCs compared to 9/26 (35%) HP (P<0.05).Furthermore,there was a correlation between TIF1γ overexpression and Smad4 loss in CRC (Kendall tau rank correlation value=0.35,P<0.05).The levels of TIF1γ overexpression were significantly higher in stage Ⅲ than in stage Ⅰ and Ⅱ CRC (P<0.05).CONCLUSION:The findings suggest that over-expression of TIF1γ occurs in early stages of colorectal carcinogenesis,is inversely related with Smad4 loss,and may be a prognostic indicator for poor outcome.

皮肤基底细胞癌和鳞状细胞癌皮损中Smad 7、Smurf 1和Smurf 2的表达

目的探讨Smad 7、Smurf 1和Smurf 2在基底细胞癌和鳞状细胞癌皮损中表达水平的变化及其意义。方法采用实时定量聚合酶链反应和免疫组化技术分别检测基底细胞癌、鳞状细胞癌及正常人对照皮肤中Smad 7、Smurf 1和Smurf 2的表达。结果Smad 7、Smurf 1和Smurf 2在基底细胞癌和鳞状细胞癌中的表达较正常表皮显著升高。结论基底细胞癌和鳞状细胞癌皮损中Smad 7、Smurf 1和Smurf 2的表达增强可能干扰转化生长因子β(TGFβ)信号转导通路的多个环节,使TGFβ抑制上皮增生的作用不能有效发挥,从而有助于上述表皮肿瘤的异常增殖。

Qingxuan Jiangya Decoction(清眩降压汤) Prevents Blood Pressure Elevation and Ameliorates Vascular Structural Remodeling via Modulating TGF-β 1/Smad Pathway in Spontaneously Hypertensive Rats

Objective:To elevate the effects of Qingxuan Jiangya Decoction(清眩降压汤,QXJYD)on hypertension and vascular structural remodeling(VSR)in spontaneously hypertensive rats(SHRs),and investigate the underlying mechanisms.Methods:SHRs(n=8)were given intra-gastric administration with 60 mg/kg of QXJYD or saline,daily for 8 weeks,while rats in SHR-control(n=8)and WKY(n=8)groups were received equal volumes of saline solution.Systolic blood pressures(SBP),diastolic blood pressures(DBP)and mean blood pressures(MBP)were measured once a week.The levels of angiotensinⅡ(AngⅡ),endothelin 1(ET-1)and plasma renin activity(PRA)were tested by enzyme-linked immunosorbent assay(ELISA)and radioimmunoassay,respectively.The effect of QXJYD on VSR was determined by examining the media thickness and the ex vivo contractility of thoracic aortic.The proliferation and fibrosis of vascular smooth muscle cells(VSMCs)were examined via immunohistochemical(IHC)staining for proliferating cell nuclear antigen(PCNA),collagen Ⅰ and collagen Ⅲ,respectively.The mRNA and protein expressions of transforming growth factor β1(TGF-β1),Smad3 and phosphorylation of Smad3 in thoracic aorta tissues were determined by real-time polymerase chain reaction(PCR)and Western blot assay,respectively.Results:QXJYD treatment led to a significant decrease of the elevation of blood pressure in SHRs and reduced the levels of AngⅡ,ET-1 and PRA in the serum(P<0.05).In addition,QXJYD treatment remarkably ameliorated VSR and vascular function in SHRs.Moreover,QXJYD inhibited VSMC proliferation and fibrosis by suppressing the expression of PCNA,collagen Ⅰ and collagen Ⅲ in thoracic aortic.Furthermore,QXJYD inhibited the expression of TGF-β1,Smad3 and the phosphorylation of Smad3,respectively(P<0.05).Conclusion:QXJYD reversed VSR by inhibiting VSMC proliferation and collagen deposition via regulation of TGF-β1/Smad signaling pathway,which may,in part,illuminate its anti-hypertensive activities.

Gardenia jasminoides attenuates hepatocellular injury and fibrosis in bile duct-ligated rats and human hepatic stellate cells

AIM:To investigate the anti-hepatofibrotic effects of Gardenia jasminoides in liver fibrosis.METHODS:Male Sprague-Dawley rats underwent common bile duct ligation(BDL) for 14 d and were treated with Gardenia jasminoides by gavage.The ef-fects of Gardenia jasminoides on liver fibrosis and the detailed molecular mechanisms were also assessed in human hepatic stellate cells(LX-2) in vitro.RESULTS:Treatment with Gardenia jasminoides decreased serum alanine aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,146.6 ± 15 U/L vs 77 ± 6.5 U/L,P = 0.0007) and aspartate aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,188 ± 35.2 U/L vs 128 ± 19 U/L,P = 0.005) as well as hydroxyproline(BDL vs BDL + 100 mg/kg Gardenia jasminoides,438 ± 40.2 μg/g vs 228 ± 10.3 μg/g liver tissue,P = 0.004) after BDL.Furthermore,Gardenia jasminoides significantly reduced liver mRNA and/or protein expression of transforming growth factor β1(TGF-β1),collagen type?Ⅰ?(Col?Ⅰ) and α-smooth muscle actin(α-SMA).Gardenia jasminoides significantly suppressed the upregulation of TGF-β1,Col?Ⅰand α-SMA in LX-2 exposed to recombinant TGF-β1.Moreover,Gardenia jasminoides inhibited TGF-β1-induced Smad2 phosphorylation in LX-2 cells.CONCLUSION:Gardenia jasminoides exerts antifibrotic effects in the liver fibrosis and may represent a novel antifibrotic agent.

Xueshuantong for Injection(Lyophilized,注射用血栓通)Alleviates Streptozotocin-Induced Diabetic Retinopathy in Rats

Objective To investigate the ameliorate effect and underlying mechanism of Xueshuantong for Injection(Lyophilized,注射用血栓通,XST)in streptozocin(STZ)-induced diabetic retinopathy(DR)rats.Methods Diabetes mellitus(DM)model was induced by intraperitoneal(i.p.)injection of STZ(60 mg/kg)in Sprague-Dawley rats.Diabetic rats were randomized into 3 groups(n=10)according to a random number table,including DM,XST50 and XST100 groups.XST treatment groups were daily i.p.injected with 50 or 100 mg/kg XST for 60 days,respectively.The control and DM groups were given i.p.injection with saline.Blood glucose level and body weight were recorded every week.Histological changes in the retina tissues were observed with hematoxylin-eosin staining.Apoptosis and inflammation related factors,including cleaved caspase-3,glial fifibrillary acidic protein(GFAP),tumor necrosis factor-α(TNF-α)and intercellular cell adhesion molecule-1(ICAM-1)were detected by Western blot or real-time polymerase chain reaction.Then,the levels of advanced glycation end product(AGE)and its receptor(RAGE)were investigated.Tight junctions proteins(Zonula occludens-1(ZO-1),Occludin and Claudin-5)of blood-retinal barrier were detected by Western blot.The levels of retinal fifibrosis,transforming growth factor-β1(TGF-β1)-Smad2/3 signaling pathway were evaluated at last.Results There was no signifificant difference in the body weight and blood glucose level between XST and DM groups(P>0.05).Compared with the DM group,XST treatment signifificantly increased the retinal thickness of rats(P<0.05 or P<0.01),and suppressed cleaved caspase-3 expression(P<0.01).XST increased the protein expressions of ZO-1,Occludin and Claudin-5 and decreased the mRNA expressions of matrix metalloproteinase 2(MMP-2)and MMP-9(P<0.05 or P<0.01).Moreover,XST signifificantly reduced the productions of AGE and RAGE proteins in the retina of rats(P<0.05 or P<0.01),suppressed the over-expression of TNF-α,and decreased the elevated level of ICAM-1 in retina of rats(P<0.05 or P<0.01).XST signifificantly reduced the levels ofα-smooth muscle actin(α-SMA),connective tissue growth factor(CTGF),TGF-β1 and phosphorylation of Smad2/3 protein in rats(P<0.05 or P<0.01).Conclusions XST had protective effects on DR with possible mechanisms of inhibiting the inflammation and apoptosis,up-regulating the expression of tight junction proteins,suppressing the productions of AGE and RAGE proteins,and blocking the TGF-β/Smad2/3 signaling pathway.XST treatment might play a role for the future therapeutic strategy against DR.