Leucine-rich α-2-glycoprotein promotes TGFβ1-mediated growth suppression in the Lewis lung carcinoma cell lines

Leucine-rich α2-glycoprotein (LRG) is an approximately 50-kDa glycoprotein that has been found to be elevated in the sera of patients with several types of cancer. LRG directly binds to transforming growth factor beta 1 (TGFβ1) and modulates TGFβ1 signaling in endothelial cells; however, the precise function of LRG in cancer remains unclear. This study aimed to investigate the role of LRG in cancer. Lewis lung carcinoma (LLC) cells hardly expressed LRG. The growth of LLC tumors allografted in the LRG knockout (KO) mice was significantly increased compared with wild-type (WT) mice. Conversely, overexpression of LRG significantly inhibited the growth of LLC tumors in WT mice. In the presence of LRG, TGFβ1 significantly inhibited the proliferation of LLC cells and human hepatocellular carcinoma Hep3B cells in vitro by inducing apoptosis via the potent activation of smad2 and its downstream signaling pathway. Furthermore, administration of a TGFβR1 inhibitor (SB431542) significantly enhanced the growth of LLC tumors in WT mice compared with LRG KO mice via inhibition of apoptosis. We propose that LRG potentiates the effect of TGFβ1 in cancer cells whose growth is suppressed in the presence of TGFβ1.     

尿Smad1与2型糖尿病肾病早期诊断及病情进展关系的探讨

目的  探讨尿Smad1与2型糖尿病肾病早期诊断及病情进展之间的关系。方法  选取广州中医药大学第一附属医院内分泌科和暨南大学第一附属医院内分泌科166例2型糖尿病患者。按尿微量白蛋白与肌酐比值分为正常白蛋白尿组、微量白蛋白尿组和大量白蛋白尿组。并以80例健康体检者作为对照组。采用酶联免疫吸附法检测尿标本中Smad1浓度,并以尿Smad1与尿肌酐（SCR）作为标准数值,SCR取对数值。结果  正常白蛋白尿组SCR与对照组比较差异无统计学意义（P >0.05）;微量白蛋白尿组SCR较正常白蛋白尿组高（P <0.05）;大量白蛋白尿组SCR较微量白蛋白尿高（P <0.05）。Pearson相关分析显示,SCR与HbA1c、病程、视网膜病变呈线性正相关（r =0.384、0.413和0.325,P =0.000、0.005和0.021）;ROC曲线显示,尿Smad1是诊断2型糖尿病肾病的较好指标。结论  尿Smad1可作为2型糖尿病肾病早期诊断的新型指标,并可反映糖尿病肾病病情进展。

     

纤愈方对CCL4诱导的大鼠肝纤维化疗效研究

目的：观察纤愈方对四氯化碳（CCL4）诱导的大鼠肝纤维化的治疗效果,并探讨其可能的机制。方法：45只大鼠用四氯化碳（CCL4）诱导致肝纤维化,随机分成3组（模型组、纤愈方治疗组、IFN-γ治疗组）,连续用药12周,观察肝功能、肝组织病理、血清透明质酸（Hyaluronic Acid,HA）、血清转化生长因子β1（Transforming Growth Factor beta 1,TGF-β1）、肝组织切片中TGF-β1、转化生长因子βⅠ型受体（Transforming Growth FactorβReceptor,TβR-Ⅰ）、Smad2/3的表达。结果：1肝组织病理：与正常组比较,模型组大鼠肝组织都有不同程度的炎症和纤维化产生。模型组纤维化程度较正常对照组明显,差异有显著性意义（P〈0.05）;各治疗组纤维化程度较模型组显著改善,差异有显著性意义（P〈0.05）;纤愈方治疗组与IFN-γ治疗组间差异无显著性统计学意义（P〉0.05）;2肝功能、肝纤维化指标（HA、TGF-β1）：各组大鼠血清丙氨酸转氨酶（Alamine Aminotransferase,ALT）较正常对照组均有升高（P〈0.01）,白蛋白（Albumin,ALB）、总蛋白（Total protein,TP）、白球蛋白比例（A/G）较正常对照组均有降低（P〈0.01）,但以模型组差异最明显;各治疗组及模型组间ALT、ALB、TP、A/G无明显差异（P〉0.05）;各治疗组大鼠HA较模型组都有不同程度的降低（P〈0.05或0.01）,纤愈方治疗组和IFN-γ治疗组差异无显著性意义（P〉0.05）;各治疗组大鼠TGF-β1较模型组都有不同程度的降低（P〈0.05或0.01）,其中纤愈方治疗组与IFN-γ治疗组TGF-β1差异无显著性意义（P〉0.05）。TGF-β1/Smad基因蛋白：免疫组织化学检测显示,与模型组相比,各治疗组大鼠肝脏中TGF-β1、转化生长因子βⅠ型受体（Transforming Growth FactorβReceptor,TβR-Ⅰ）和Smad2/3蛋白表达均显著减弱（P〈0.01）。纤愈方治疗组和IFN-γ治疗组差异无显著性意义（P〉0.05）。结论：纤愈方组具     

Smad6信号干扰对MSCs骨向分化中Smad5及Smurf1基因表达的影响

目的研究在骨形态发生蛋白2(BMP-2)诱导的骨髓间充质干细胞(MSCs)骨向分化中Smad6信号干扰对Smad5、Smurf1基因表达的影响。方法培养小鼠骨髓MSCs,并分为3组:A组为对照细胞;B组细胞用携带绿色荧光蛋白(GFP)的空白载体病毒转染+BMP-2骨向诱导;C组细胞用Smad6重组RNA干扰载体转染+BMP-2诱导。结果病毒转染后GFP在MSCs中有效表达,病毒转染效率接近100%。与A组比较,BMP-2诱导24h显著提高了B组Smurf1 mRNA水平(P<0.01);而Smad6信号干扰在两个时间点则进一步提高了C组Smurf1 mRNA水平,并显著高于B组(P<0.01)。C组磷酸化的Smad5(pSmad5)和Smurf1水平在两个时间点也显著高于B组(P<0.01),而Smad5蛋白水平则未受影响。结论在BMP-2诱导的MSCs骨向分化中,Smad6 RNA干扰可促进Smad5磷酸化,并引起Smurf1基因表达代偿性增高。     

Transforming growth factor-beta type 1 receptor (ALK5) and Smad proteins mediate TIMP-1 and collagen synthesis in experimental intestinal fibrosis

Transforming growth factor β (TGF-β) is known to play a key role in intestinal fibrosis; however, the underlying mechanisms are not well understood. TGF-β signal transduction is through TGF-β receptors, including the TGF-β type 1 receptor. Most cell types contain a TGF-β type 1 receptor form known as activin receptor-like kinase 5 (ALK5), which propagates the signal to the nucleus through the phosphorylation of Smad2 and Smad3 proteins. Therefore, we assessed the effect of the disruption of TGF-β/ALK5/Smad signalling by an ALK5 inhibitor (SD-208) in two experimental animal models of intestinal fibrosis: anaerobic bacteria- and trinitrobenzensulphonic acid-induced colitis. In addition, isolated myofibroblasts were pretreated with SD-208 and exposed to recombinant TGF-β1. Finally, myofibroblasts were transfected with ALK5, Smad2, and Smad3-specific siRNA. Up-regulation of ALK5 and TIMP-1, phosphorylation of Smad2 and Smad3 proteins, and increased intestinal wall collagen deposition were found in both experimental animal models. These effects were decreased by SD-208. TGF-β1 treatment also induced phosphorylation of Smad2 and Smad3 and up-regulation of ALK5 protein, TIMP-1, and α2 type 1 collagen gene expression in isolated myofibroblasts. Again these effects were inhibited by SD-208. Also, ALK5, Smad2, and Smad3 siRNA abolished the induction of TIMP-1 and α2 type 1 collagen. Our findings provide evidence that the TGF-β/ALK5/Smad pathway participates in the pathogenesis of experimental intestinal fibrosis. These data show promise for the development of an effective therapeutic intervention in this condition.     

Modulation of bone morphogenetic protein activity by melatonin in ovarian steroidogenesis

Background

Melatonin regulates circadian and seasonal rhythms and the activities of hormones and cytokines that are expressed in various tissues, including the ovary, in which melatonin receptors are expressed. In the ovary, follicular growth occurs as a result of complex interactions between pituitary gonadotropins and autocrine and paracrine factors, including bone morphogenetic proteins (BMPs) that are expressed in the ovary.

Methods

The effects of melatonin and BMPs on steroidogenesis were examined by using the primary cultures of rat granulosa cells.

Main findings (Results)

It was shown that melatonin has antagonistic effects on BMP‐6 actions in the granulosa cells, suggesting that melatonin is likely to contribute to balancing the biological activity of endogenous BMPs that maintain progesterone production and luteinization in the growing follicles. Similar interactions between melatonin and BMP–smad signaling also were shown in the mechanism of controlling ovarian steroidogenesis by other ligands.

Conclusion

A new role of melatonin in the regulation of endocrine homeostasis in relation to BMP activity is introduced in this review.     

复黄生肌愈创油膏对大鼠糖尿病创面中smad3和smad7表达的影响

目的动态观察复黄生肌愈创油膏(简称复黄膏)对Wistar大鼠糖尿病创面中smad3s、mad7含量变化的影响。方法将雄性Wistar大鼠随机分为创面对照组、糖尿病模型组、复黄膏组。制备糖尿病合并皮肤创面模型,复黄膏组给予复黄膏外敷,糖尿病模型组给予生理盐水纱布外敷,1次/d。造模后分别于第3d和第11d分批处死动物,采用免疫组化和实时荧光定量PCR技术,观察不同时段创面中smad3s、mad7含量变化。结果 smad3 mRNA含量:在创面修复的第3d时,复黄膏组明显高于糖尿病模型组(P<0.05),但和创面对照组比较无统计学差异;11d时,复黄膏组明显低于创面对照组(P<0.05),但和糖尿病模型组比较无统计学差异。smad7 mRNA含量:3d时s,mad7含量三组比较无统计学差异。11d时,复黄膏组明显高于糖尿病模型组(P<0.05),虽然和创面对照组比较无统计学差异,但糖尿病模型组smad7mRNA含量明显高于创面对照组。结论 smad3在复黄膏组创面愈合早期基因表达上调,表明复黄膏通过促进创面生长因子的表达及其信号转导,从而起到促进创面愈合的作用;而在创面愈合晚期,复黄膏组smad3在基因表达下调,smad7表达上调,可能为复黄膏促进了创面愈合的负反馈机制,及时中止成纤维细胞过度生长,防止瘢痕形成。     

SnoN的基本特征、生物学功能及其在肝纤维化中的作用

SnoN是一种核转录共抑制因子,在细胞核和细胞浆中均能阻断TGFβ1/Smad信号转导,是该信号通路的重要负调控因子之一。SnoN在肝纤维化发生发展中的作用已有研究报道,并日益引起人们的关注。因此,本文回顾了有关SnoN方面的研究进展,对其基本特征、生物学功能及其在肝纤维化中的作用作一综述。     

养肝益水颗粒对自发性高血压大鼠肾脏Smad2、Smad3、Smad7表达的影响

目的观察养肝益水颗粒对自发性高血压大鼠（spontaneously hypertensive rat,SHR）肾脏smad2、smad3、smad7表达的影响,探讨养肝益水颗粒保护肾脏的机制。方法将40只12周雄性SHR大鼠随机分为模型组、贝拉普利组（每日1.8 mg/kg）、养肝益水颗粒低剂量组（每日5.4 g/kg）、养肝益水颗粒高剂量组（每日27 g/kg）,每组10只;并设Wista-rKyoto（WKY）大鼠10只作正常对照组;模型组和正常对照组给予等容积生理盐水灌胃,每天1次,共6周。采用免疫组织化学法检测各组大鼠肾脏smad2、smad3、smad7的表达水平。结果与正常组相比,模型组肾脏Smad2、Smad3的表达明显上调（P〈0.01）,Smad7的表达明显下调（P〈0.01）;各治疗组与模型组相比,肾脏Smad2、Smad3的表达明显下调（P〈0.01）,Smad7的表达明显上调（P〈0.01）,且养肝益水颗粒低剂量组与贝拉普利组相比疗效相近（P〉0.05）,养肝益水颗粒高剂量组疗效优于养肝益水颗粒低剂量组与贝拉普利组（P〈0.05,或P〈0.01）。结论养肝益水颗粒可能是通过下调肾脏Smad2、Smad3和上调肾脏Smad7的表达以阻断转化生长因子及其受体（transforming growth factor-transfor-ming growth factor receptor,TGF-β-TβR）-Smads信号转导通路而抗高血压肾脏纤维化。     

Smad4与P53在乳腺癌中的表达与其病理特征的相关性研究

目的研究smad4、P53在乳腺癌组织中的表达,与乳腺癌病理特征的关系及其临床意义。方法采用免疫组织化学的方法检测61例乳腺癌患者的癌组织,23例乳腺纤维腺瘤组织,15例正常乳腺组织中的smad4及P53的表达情况,结合临床表现做统计学分析。结果 61例乳腺癌的组织中有23例（37.7%）smad4基因呈现异常的表达;P53蛋白阳性表达的有31例（50.8%）。smad4基因、P53基因在乳腺癌组织中的表达情况均显著的与乳腺纤维腺瘤组和正常乳腺组不同（P〈0.05）;并且乳腺癌中smad4基因的低表达与P53蛋白的高表达具有显著的相关性（P〈0.05）。结论乳腺癌中smad4的突变或缺失、P53表达水平的上调,与乳腺癌的发生、发展及预后有关,其机制可能与野生型P53基因的突变有关,smad4的异常表达和P53蛋白的高表达可作为乳腺癌临床预后的一个指标。