Smad-3 as a mediator of the fibrotic response

Introduction Smad‐3, a key cytoplasmic mediator of transforming growth factor‐β (TGF‐β) signalling, mediates many of its inflammatory and fibrotic effects in vivo ( Roberts et al. 2001 ). Smad‐3 null mice are protected against cutaneous injury induced by ionizing irradiation ( Flanders et al. 2002 ). Here, we report on our continuing studies on radioprotection as well as protection against tubulointerstitial fibrosis following unilateral ureteral obstruction (UUO) in Smad‐3 null mice. Methods For radioprotection studies, the flank skin of Smad‐3^+/+ wild‐type (WT) and Smad‐3^–/– knockout (KO) mice was exposed to 30 Gy of localized γ‐irradiation and analysed for histology and gene expression at various times post irradiation. In the UUO model, the right proximal ureter of WT and KO mice was ligated, and 1–2 weeks later kidneys were analysed for inflammation, fibrosis and gene expression. Results Six weeks after exposure to irradiation, skin from KO mice shows less epidermal acanthosis and influx of mast cells, macrophages and neutrophils than skin of WT mice. Paradoxically, at 6–8 h post irradiation, KO skin shows a significantly greater number of neutrophils. Irradiated KO skin also exhibits less immunoreactive TGF‐β, fewer myofibroblasts and less scarring than does WT. Smad‐3 null dermal fibroblasts do not respond to the chemotactic effects of TGF‐β and show less induction of fibrogenic cytokines when treated with irradiation plus TGF‐β compared to WT cells. Following UUO, normal kidney architecture is preserved in KO mice, while kidneys from WT mice are enlarged with an influx of mononuclear cells and increased expression of collagen and TGF‐β1. Additionally, renal tubules in obstructed kidneys of KO mice remain positive for E‐cadherin without expression of α‐smooth muscle actin, while the opposite expression pattern is seen in obstructed kidneys of WT mice. TGF‐β treatment of primary cultures of WT renal tubular epithelial cells results in a phenotypic change from a cobblestone pattern to a spindle‐shaped fibroblastic appearance, while KO cells treated with TGF‐β maintain their original appearance. Conclusion Smad‐3 plays an important role in mediating pathogenic inflammation and fibrosis in several model systems and is also essential for TGF‐β1‐induced epithelial–mesenchymal transition in renal tubular epithelial cells. Inhibitors of the Smad‐3 pathway may have clinical applications in the treatment of a number of fibrotic conditions.     

Smad2/3与Smad7在大鼠化疗性卵巢早衰卵泡中的表达和意义

目的 探讨顺铂对大鼠卵巢结构和功能损伤的影响及其可能的分子机制。方法 3月龄SD 雌性大鼠随机分为对照组（C组,5只）和化疗组（H组,5只）。H组给予每只大鼠腹腔注射顺铂2 mg/（kg.d）,C组给予腹腔注射等体积生理盐水,连续注射7 d后检测大鼠卵巢指数（卵巢湿重/体重）;酶联免疫吸附法检测血清雌二醇（E₂）和促卵泡刺激素（FSH）水平;苏木素-伊红染色观察卵泡发育并计数各级卵泡;免疫组织化学和Real-time PCR法检测各组Smad2、磷酸化Smad2（p-Smad2）、Smad3、磷酸化Smad3（p-Smad3）、Smad4和Smad7的蛋白和mRNA表达。结果 与C组相比,H组大鼠卵巢体积减小,生长卵泡数明显减少（P<0.05）,大鼠卵巢指数下降（P<0.05）,血清中E2水平降低和FSH水平上升（P<0.05）。免疫组织化学和Real-time PCR结果显示,Smad2（p-Smad2）、Smad3（p-Smad3）、Smad4和Smad7蛋白在卵巢各级卵泡均有表达,H组Smad2蛋白和mRNA表达增加（P<0.05）,Smad2磷酸化水平（p-Smad2）表达增高（P<0.05）;Smad3、Smad4和Smad7蛋白和mRNA表达减少（P<0.05）,p-Smad3 表达降低（P<0.05）。结论 顺铂诱导大鼠卵泡损伤并促进卵巢早衰,引起卵泡细胞内Smad2表达增加,Smad3、Smad7表达降低,Smad细胞内信号通路参与了化疗性卵巢损伤的过程。     

Smad7而非Smad6基因可抑制TGF-β诱导肾小管上皮-间充质转分化

目的:观察Smad6和Smad7基因能否抑制TGF-β诱导肾小管上皮-间充质转分化.方法:构建产生表达Smad6和Smad7基因的无辅毒腺相关病毒载体, 再将病毒颗粒分别转染入人肾小管上皮细胞(HKC), 细胞随机分为正常对照、 TGF-β1组、 Smad7 组、 LacZ组、 TGF-β1 Smad7或Smad6组、 TGF-β1 LacZ组.10 μg/L TGF-β1添加入培养液孵育15、 30、 60、 120 min和3 d.Western blot测定TGF-β1和Smad6或Smad7基因转染对细胞p-Smad2、 E-cadherin、α-smooth muscle actin(α-SMA)表达的影响, ELISA法测定培养上清羟脯氨酸的含量的变化, 倒置显微镜观察细胞形态变化.结果:与未加TGF-β1细胞相比, 添加TGF-β1后15、 30、 60、 120 min胞内Smad2磷酸化水平明显增加, 30 min时表现最大.10 μg/L TGF-β1与HKC孵育72 h后, 细胞α-SMA和羟脯氨酸量合成增加, E-cadherin表达减少;细胞形态变长, 呈纺锤状细胞, 失去鹅卵石样的形状.Smad7基因转染可抑制TGF-β1诱导Smad2磷酸化, 抑制细胞α-SMA和羟脯氨酸合成, 增加E-cadherin表达, 维持培养细胞的上皮样形态, 相反, Smad6没有这样的作用.结论:Smad7而不是Smad6基因转染能抑制TGF-β1诱导肾小管上皮-间充质转分化, 这些作用可能与Smad7阻断Smad2磷酸化有关.     

Smad3基因敲除小鼠肾Smad2和p-Smad2表达的变化

目的:观察Smad3基因敲除小鼠肾Smad2和p-Smad2表达的变化,探讨Smad3基因敲除小鼠肾是否有Smad2和p-Smad2代偿性增加.方法:4只Smad3基因敲除小鼠,10只野生型小鼠,应用免疫组织化学显色技术,检测Smad2和p-Smad2蛋白的定位和表达情况,并用Motic病理图像分析系统对图像进行半定量分析.结果:野生型小鼠肾Smad2蛋白在肾远端小管和肾集合管细胞胞质中有广泛弱表达,p-Smad2蛋白在肾远端小管和肾集合管细胞胞质、胞核中也有弱表达,而Smad3基因敲除小鼠的Smad2和p-Smad2的表达比野生型小鼠有显著升高.结论:Smad3基因敲除能引起小鼠肾Smad2和p-Smad2表达的代偿性增加.     

Smad7过度表达抑制3T3细胞增殖和TGF-β1基因表达

研究Smad7过度表达对TGF β1基因表达的调控和对 3T3细胞增殖的影响。实验将Smad7质粒 ,通过脂质体介导转染NIH3T3细胞 ,应用RT PCR方法鉴定转染结果和检测TGF β1mRNA的表达 ,以及用免疫细胞化学检测TGF β1蛋白的表达情况 ,并观察基因转染对细胞增殖的影响。结果显示转染Smad7后 ,NIH3T3细胞中TGF β1mRNA的表达显著减少 (P <0 0 5 ) ,TGF β1蛋白的表达下降 ,细胞增殖明显减缓 (P <0 0 5 )。提示Smad7过度表达能够抑制 3T3细胞的增殖和TGF β1基因的表达 ,可以通过阻断TGF β细胞内信号传导来调控TGF β1的生物学行为。     

siRNA沉默Smad3对人KFB细胞增殖、凋亡及合成MMP3的影响

目的 研究siRNA特异性沉默Smad3基因对人瘢痕疙瘩成纤维细胞(keloid fibroblast,KFB)增殖、凋亡及合成基质金属蛋白酶3(matrix metalloproteinase3,MMP3)的影响.方法 设计合成3对Smad3特异性siRNA片段(Smad3-siRNA-Y1,Y2,Y3)和1对无关干扰片段,转染人KFB细胞,RT-PCR和Western blot方法检测Smad3-siRNA片段对Smad3基因的特异性沉默效果,MTT法检测其对细胞增殖的影响,流式细胞仪检测细胞周期及细胞凋亡的变化,免疫细胞化学法检测MMP-3表达量的变化.结果 75 nmol/L Smad3-siRNA-Y1处理KFB细胞48小时后可特异并有效地抑制Smad3基因的表达;抑制细胞增殖,使S期细胞减少,G0/G1幅期细胞增多;凋亡指数增加;细胞表达MMP-3增加.结论 Smad3-siRNA可特异性抑制KFB细胞中Smad3基因表达,明显抑制细胞增殖,诱导细胞凋亡,并加快其合成MMP3.     

siRNA沉默Smad3对肝星状细胞增殖与凋亡的影响及其机制研究

目的: 观察 Smad3 小干扰RNA(siRNA-Smad3)沉默肝星状细胞(HSCs) Smad3 基因对肝星状细胞增殖、凋亡的影响,并探讨其可能机制。方法: 肝星状细胞株HSCs-T6分为3组:空白对照组、阴性对照组、siRNA-Smad3转染组。siRNA-Smad3转染HSCs细胞株,转染不同时间后,CCK-8检测HSCs增殖的变化,流式细胞术检测HSCs凋亡的变化,免疫细胞化学法检测HSCs凋亡相关蛋白P53和Bcl-2表达的变化。结果: (1)24 h、48 h、72 h siRNA-Smad3转染组HSCs增殖受到显著抑制且凋亡明显增多(P<0.01)。(2)转染48 h后,siRNA-Smad3转染组P53蛋白表达显著增多,Bcl-2蛋白表达显著减少(P<0.01)。结论: siRNA-Smad3沉默Smad3基因可以在一定时间内显著抑制HSCs的增殖并诱导其凋亡,其可能通过上调凋亡相关蛋白P53表达、下调Bcl-2的表达来发挥诱导凋亡的作用;Smad3沉默有望成为抗肝纤维化治疗的一个新途径。     

Smad4/Smad7 balance: A role of tumorigenesis in gastric cancer

Smad signaling pathway plays an important role in tumorigenesis and progression in cancer (Halder, S.K., Rachakonda, G., Deane, N.G., Datta, P.K., 2008. Smad7 induces hepatic metastasis in colorectal cancer. Br. J. Cancer 99, 957-965). The protein level of Smad is associated with growth, inhibition, and metastasis in different cancers. It is unclear if the differentiation, metastasis and apoptosis are reduced by Smad expression pattern in gastric cancer. To determine the effect of Smad on gastric cancer cells, we investigated the relationship of Smad4/Smad7 expression, and differentiation, metastasis, and apoptosis in different gastric cancer. The results show that Smad4 expression in the gastric cancer tissue was dramatically lower than that in the peritumoral tissue. A lower expression of Samd4 was significantly lower in the poorly differentiated tissue than that in the well and middle differentiated tissues (P < 0.01). In contrast, Smad7 expression in gastric cancer tissues was significantly higher than that in the peritumoral tissue. Smad7 was overexpressed in poorly differentiated tissue, also higher than those in the middle, and well differentiated tissues (P < 0.05). The Smad4 or Smad7 expression obviously related with the lymphatic metastasis in gastric cancer. There were 45 cases with lymphatic metastasis in all 78 patients. Smad4 expression in the cases with lymphatic metastasis was lower than the cases without metastasis (P < 0.01), whereas Smad7 expression in the cases with lymphatic metastasis was much higher than the case without metastasis (P < 0.01). To better understand the mechanisms involved in tumorigenesis of gastric cancer, we established SGC7901 gastric cancer cell lines transduced with Smad4 or Smad7 plasmid DNA. Apoptosis and survival of cancer cells was induced after Smad4 and Smad7 transduction. This effect is concentration and time dependent. Thus, this study provides a mechanism by which a balance between Smad4 and Smad7 in human gastric cancer is critical for differentiation, metastasis, and apoptosis of tumor cells.     

大鼠心肌肥厚过程中信号蛋白Smad3的变化

为研究SMAD信号通路在大鼠心肌肥厚中的作用 ,结扎大鼠腹主动脉复制心肌肥厚模型 ,在不同时间点检测左心室重量指数 (leftvertricularmassindex,LVMI) ,RT -PCR法检测肥大心肌组织中胚胎抗原心房利钠因子 (atrialna triureticfactor,ANF)的mRNA表达、转化生长因子β1(transforminggrowthfactor β1,TGF β1)及Smad3的mRNA表达 ,West ernblotting检测Smad3的蛋白表达。结果术后 3天LVMI开始上升并持续至 4周 ,肥大心肌组织中ANF、TGF β1、Smad3的mRNA表达水平以及Smad3的蛋白表达术后 3天开始上升 ,持续至 4周 ,术后 2周为表达高峰 (P <0 0 1)。提示信号蛋白Smad3参与了腹主动脉结扎诱导的大鼠心肌肥厚病理过程     

跨种属研究Smad3在肝癌组织中的表达及意义

 目的：研究Smad3在人、大鼠、树鼩等不同种属的肝癌、癌旁及正常肝组织中的表达和意义,进一步验证跨种属筛选肝癌关键蛋白研究策略的可行性。方法：采用实时荧光定量PCR和Western blotting技术分别检测人、大鼠和树鼩的肝癌及其相应癌旁组织以及正常肝组织中Smad3 mRNA和蛋白表达水平。结果：Smad3 mRNA在人、大鼠和树鼩的肝癌中表达水平均低于其相应的癌旁组织（均P<0.05）;在大鼠肝癌组织中的表达低于正常肝组织（P<0.05）;在树鼩癌旁组织中的表达高于正常肝组织（P<0.05）;其余各组织间mRNA表达水平的差别无统计学意义（均P>0.05）。Smad3蛋白在人和大鼠的肝癌组织中的表达水平均低于其相应的癌旁组织及正常肝组织（均P<0.05）;在树鼩肝癌组织中的表达水平也低于相应的癌旁组织和正常肝组织,但差别无统计学意义（均P>0.05）;3个种属的癌旁组织与正常肝组织比较,差别无统计学意义（均P>0.05）。结论：Smad3在人、大鼠和树鼩3个种属的肝癌组织中的mRNA和蛋白表达水平均下调,提示该蛋白表达水平的改变可能在肝癌发生发展中起重要作用,有可能成为防治肝癌的靶分子。     

Significance of pSmad2/3 and Smad4 in hepatitis C virus‐related liver fibrosis and hepatocellular carcinoma

Chronic hepatitis C (CHC) is a major public health problem, especially in Egypt. Risk of hepatocellular carcinoma (HCC) development increases as hepatitis C virus (HCV)‐related liver diseases progress. Smads act as substrates for the transforming growth factor‐beta (TGF‐β) family of receptors. This study aims to assess hepatic expression of pSmad2/3 and Smad4 in CHC with different stages of fibrosis and grades of necro‐inflammation as well as in HCC on top of CHC. This study was done on 33 core liver biopsies from patients with CHC (15 with early fibrosis and 18 with late fibrosis), 15 liver specimens from HCC cases on top of CHC, as well as five normal controls. pSmad2/3 and Smad4 show more immunopositivity, higher percentage of positive hepatocytes and stronger staining intensity in CHC with late fibrosis compared to early fibrosis. pSmad2/3 shows increase of the previous parameters in CHC with high grade activity than those with low activity. Smad4 shows increase of the previous parameters in HCC compared to CHC cases. pSmad2/3 and Smad4 can be used as diagnostic and/or prognostic markers for progression of HCV‐related fibrosis to cirrhosis and further progression to HCC.     

Paeonol alleviates CCl4-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-β/Smad3 signaling

Objective: Paeonol is a natural phenolic component isolated from the root bark of peony with multiple pharmacological activities. We investigated the anti-fibrotic effect and underlying mechanism of paeonol.

Methods: Twenty-four male C57BL/6J mice were divided into 4 groups (n?=?6 in each group), injected with CCl₄ to induce liver fibrosis and administrated with paeonol according to the regimen. The serum activity of ALT and AST, and H&E staining were to assess liver injury. Sirius and Masson staining, and hydroxyproline content were to evaluate the degree of liver fibrosis. TNF-α, IL-6, TGF-β, MDA, GSH-PX, SOD, and CAT were detected to reflect inflammation and oxidative stress. RT-qPCR and Western blot analysis to assess the activation of HSCs and TGF-β/Smad3 signaling.

Results: Paeonol ameliorated liver injury and liver fibrosis, reflected by the decrease of ALT, AST, less lesion in H&E staining, mitigated fibrosis in Sirius and Masson staining, lessened content of hydroxyproline. Paeonol attenuated the level of IL-6 and TNF-α, and elevated the activity of GSH-PX, SOD, and CAT with reducing the level of MDA. The expression of col 1a, α-SMA, vimentin, and desmin were down-regulated and TGF-β/Smad3 signaling pathway was inhibited.

Conclusion: These data demonstrated that paeonol could alleviate CCl₄-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-β/Smad3 signaling.     

上调表达Smad7显著抑制TGF-β介导的大鼠腹膜间皮细胞Smad2的表达

目的： 探讨外源性转入并上调表达抑制性信号蛋白Smad7对TGF-β₁作用下大鼠腹膜间皮细胞Smad2表达的影响。 方法： 通过脂质体介导的方法，将表达Smad7的重组质粒（PCDNA3-Smad7）转染培养的大鼠腹膜间皮细胞，分别培养于不同浓度TGF-β₁培养液(0、1.25、2.5和10 μg/L)，用RT-PCR及Western blotting的方法检测不同时间（0、5、15、30、60和120 min）Smad2、Smad7表达的水平。 结果： 正常间皮细胞Smad2 mRNA和蛋白在TGF-β₁刺激后5 min开始表达，呈时间依赖性，在30 min达到高峰，而后逐渐减弱；Smad7 mRNA和蛋白也在TGF-β₁刺激后5 min可见表达，但此后逐渐减弱，30 min达到最低，60 min又开始逐渐增强。Smad2 和Smad7 mRNA和蛋白，随TGF-β₁浓度的增高而表达增强。转染后大鼠腹膜间皮细胞可见Smad7 mRNA和蛋白表达显著上调，并可持续高表达。转染后的腹膜间皮细胞在TGF-β₁刺激下，Smad2 mRNA及蛋白的表达均低下，刺激0、5、15、30、60 和120 min后Smad2 mRNA表达分别低33%、56%、67%、71%、63%和57%（P<0.05）。Smad2蛋白表达分别低78%、89%、89%、88%和76%（P<0.05）。 结论： 上调表达抑制性信号蛋白Smad7可显著抑制腹膜间皮细胞中受体调控信号蛋白Smad2的表达和活性，提示Smad7可能对TGF-β₁起反向调控作用。     

Smad3促进大鼠卵巢颗粒细胞自噬

目的 探讨Smad3基因对大鼠卵巢颗粒细胞自噬的影响。方法 21d SD雌性大鼠腹腔注射孕马血清20 IU/只,48h后收集卵巢颗粒细胞进行原代培养。培养细胞分为3组：空白对照组：培养液中不加任何处理因素;敲低实验组：培养液中加入Smad3基因特异性的SiRNA及转染试剂RNAiMAX;过表达实验组：培养液中加入Smad3真核表达质粒及转染试剂Lipo 2000。免疫细胞化学方法鉴定培养细胞纯度;Western blotting方法检测Smad3蛋白表达变化,检测转染效率。Smad3基因敲低及过表达后,Western blotting方法检测自噬体膜形成标志蛋白LC3B及自噬调控相关蛋白Bcl-2的蛋白表达变化。 结果 Smad3敲低时,LC3B蛋白Ⅱ型与Ⅰ型的比值(LC3BⅡ/Ⅰ)变化不明显,Bcl-2蛋白表达明显降低;Smad3过表达时,LC3BⅡ/Ⅰ明显增加,Bcl-2蛋白表达明显增加。 结论 Smad3基因特异的SiRNA及真核表达质粒可以有效地转入大鼠卵巢颗粒细胞中,Smad3基因促进大鼠卵巢颗粒细胞自噬,其机制可能与Bcl-2蛋白相关。     

Smad3基因促进大鼠卵巢颗粒细胞增殖

目的 探讨Smad3基因对大鼠卵巢颗粒细胞增殖功能的影响.方法 21d SD雌性大鼠,腹腔注射孕马血清20IU/只,48h后收集卵巢颗粒细胞进行原代培养,用Smad3 基因特异的siRNA基因沉默后,采用免疫细胞化学法检测颗粒细胞中Smad3蛋白表达的变化,以判定基因沉默效率,Smad3基因沉默后用免疫细胞化学法检测...     

Smad3 signalling plays an important role in keloid pathogenesis via epithelial-mesenchymal interactions

Smad signalling plays important roles in developmental and cancer biology as well as in fibropathogenesis. Its role in keloid biology is not known. Epithelial-mesenchymal interactions, originally described in normal skin, have recently been established to play a significant role in keloid pathogenesis, and demonstrate the important influence of keratinocyte paracrine factor signalling on fibroblast behaviour. The present study investigated the role of downstream Smad cascade induction in this interaction. Normal fibroblasts (NF) and keloid fibroblasts (KF) were co-cultured in serum-free medium with normal keratinocytes (NK) or keloid keratinocytes (KK) for 5 days, after which fibroblast cell lysates were subjected to western blot and immunoprecipitation analysis to quantify the levels of Smad and Smad2/3/4 binding complex. In another set of experiments, wild-type (wt), Smad2-null (Smad2-/-) and Smad3-null (Smad3-/-) mouse embryonic fibroblasts (MEF) were assayed for cell proliferation and collagen production after serum-free co-culture with KK or exposure to conditioned media collected from serum-free KK/KF co-culture. Compared to normal skin, keloids expressed high basal levels of TGFbetaR1 and TGFbetaR2, Smad2, 3 and 4 and phospho-Smad2. Upregulation of TGFbetaR1 and TGFbetaR2, Smad3 and p-Smad2 was observed in KF co-cultured with KK, together with enhanced Smad3 phosphorylation and Smad2/3/4 binding complex production. When MEF-wt, MEF-Smad2-/- or MEF-Smad3-/- were co-cultured with KK or exposed to KK/KF co-culture conditioned media, enhanced proliferation and collagen production were seen in MEF-wt and MEF-Smad2-/- but not in MEF-Smad3-/- cells. The activation of Smad signalling, importantly that of Smad3, appears to be one facet of the complex epithelial-mesenchymal interactions in keloid pathogenesis, resulting in active KF proliferation and collagen-ECM production in co-culture with KK. This finding suggests the suppression of Smad signalling as a novel approach in keloid therapy.     

Canine visceral leishmaniasis as a systemic fibrotic disease

We propose that canine visceral leishmaniasis (CVL) is a systemic fibrotic disease, as evidenced by the wide distribution of fibrosis that we have found in the dogs suffering from chronic condition. The inflammatory cells apparently direct fibrosis formation. Twenty‐four cases (symptomatic dogs) were identified from a total of one hundred and five cases that had been naturally infected with Leishmania chagasi and had been documented during an epidemiological survey of CVL carried out by the metropolitan area of the municipality of Belo Horizonte, MG, Brazil. The histological criterion was intralobular liver fibrosis, as has been described previously in dogs with visceral leishmaniasis. In addition to the findings in the liver, here we describe and quantify conspicuous and systemic deposition of collagen in other organs, including spleen, cervical lymph nodes, lung and kidney of all the infected symptomatic dogs. Thus we report that there is a systematic fibrotic picture in these animals, where inflammatory cells appear to direct fibrosis in all organs that have been studied. Therefore we propose that CVL is a systemic fibrotic disease.     

Circ_0000218 plays a carcinogenic role in laryngeal cancer through regulating microRNA-139-3p/Smad3 axis

BackgroundLaryngeal squamous cell carcinoma (LSCC) accounts for about 85%–90% of all cases of laryngeal cancer. So far, the role and molecular mechanism of circular RNA 0,000,218 (circ_0000218)/microRNA (miR)-139−3p in laryngeal cancer are not clear. The present study aimed to investigate the role and regulatory mechanism of circ_0000218/miR-139−3p in laryngeal cancerin vitro and in vivo.Methodsquantitative real time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ_0000218/miR-139−3p in LSCC cells. Dual luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to confirm binding sites between miR-139−3p and smad family member 3 (Smad3), and circ_0000218 and miR-139−3p. Cell Counting Kit-8 (CCK-8) and cell apoptosis analysis were used to detect cell viability and apoptosis. Xenograft experiment was performed to show in vivo effect of circ_0000218/miR-139−3p on the growth of LSCC.ResultsCirc_0000218 was highly expressed in LSCC cells. miR-139−3p, lower expressed in LSCC cells, was negatively regulated by circ_0000218 in LSCC cells. Besides, the findings suggested that circ_0000218 silencing inhibited the LSCC cell viability and promoted apoptosis by negatively regulating miR-139−3p expression. Furthermore, the data indicated that miR-139−3p inhibited the viability of LSCC cells and promoted apoptosis, and these effects were reversed by Smad3 over-expression. In addition, the in vivo effects of circ_0000218/miR-139−3p on LSCC were consistent with the in vitro study.Conclusionscirc_0000218 inhibition inhibited the growth of LSCC by targeting miR-139−3p/Smad3 axis. Our present study provided a new target for laryngeal cancer treatment.     

大黄酸通过抑制miR-21而干预TGF-β1/Smad通路并减轻博莱霉素所致大鼠肺纤维化

目的:观察大黄酸(rhein,RH)对博莱霉素所致肺纤维化大鼠微小RNA-21(miR-21)表达以及转化生长因子β1(TGF-β1)/Smad通路的影响。方法:博莱霉素一次性气管内注射复制大鼠肺纤维化模型,随机分为RH低、中、高剂量组及模型(model)组;正常对照组大鼠气管内注射生理盐水。用药28 d后,HE染色观察各组大鼠肺组织形态学的变化;测定肺系数、肺组织羟脯氨酸含量;real-time PCR检测肺组织中miR-21和TGF-β1/Smad7m RNA表达;Western blot法分析TGF-β1和Smad7蛋白的表达。结果:与model组相比,RH用药组大鼠的肺泡炎及肺纤维化程度有明显降低,肺系数及肺组织羟脯氨酸含量也显著减少,肺组织中miR-21表达下降,TGF-β1的m RNA和蛋白表达水平也明显下降,Smad7的mRNA及蛋白表达水平明显增高(P0.05)。结论:RH抗肺纤维化的作用可能与抑制miR-21的表达,从而干预TGF-β1/Smad信号通路,减少细胞外基质沉积有关。     

SnoN和Smad2/3信号蛋白与糖尿病大鼠肾小管-间质纤维化的关系

目的 观察核转录共抑制因子SnoN和Smad2/3信号蛋白在糖尿病（DM）大鼠肾组织中的动态表达,并初步探讨它们与糖尿病肾病（DN）肾小管-间质纤维化的关系。方法 尾静脉注射链尿佐菌素（STZ）复制DM大鼠模型,随机分为DM2、4、8、12、16和24周组,每组均设鼠龄匹配的正常对照组(n=6)。免疫组化及Western blotting法检测肾组织SnoN、转化生长因子β1（TGF-β1）、Smad2/3、α-平滑肌肌动蛋白（α-SMA）、纤连蛋白（FN）的蛋白表达;RT-PCR检测SnoN的mRNA;生化方法测血糖、血肌酐及24h尿蛋白量。结果 DM4周起肾组织中SnoN蛋白表达明显减少(P < 0.01),DM各组SnoN的mRNA表达无变化;TGF-β1、Smad2/3及FN的蛋白表达随DM病程进展逐渐增多;DM12周始肾小管上皮细胞可见α-SMA阳性表达。结论 SnoN蛋白表达减少与TGF-β1/Smad信号通路共同参与了DN的发生发展过程。