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.

Interference of Y-27632 on the signal transduction of transforming growth factor beta type 1 in ocular Tenon capsule fibroblasts

AIM: To investigate the interfering effect of Y-27632, a ROCK-I selective inhibitor, on the signal transduction pathway of transforming growth factor-beta 1 (TGF-beta 1) in ocular Tenon capsule fibroblasts (OTFS) in vitro. METHODS: After OTFS from passages 4 to 6 47 vitro were induced by TGF-beta 1 and then treated by Y-27632, the changes of the OTFS cell cycles were analyzed via flow cytometry, and the proteins expression of the alpha -smooth muscular actin (alpha -SMA), connective tissue growth factor (CTGF), collagen I were calculated by Western blot. After OTFS treated by the different concentrations of Y-27632, the expression levels of the alpha -SMA, CTGF and collagen I mRNA were assayed by RT-PCR. RESULTS: Y-27632 had no markedly effect on the OTFS cell cycles. After treated by TGF-beta 1, OTFS in G1 period significantly increased. The cell cycles distribution by both TGF-beta 1 and Y-27632 had no remarkable difference from that in control group. Y-27632 significantly inhibited the proteins expressions of both alpha -SMA and CTGF, while to some extent inhibited that of collagen I. TGF-beta 1 significantly promoted the proteins expressions of alpha -SMA, CTGF and collagen I. After OTFS treated by both TGF-beta 1 and Y-27632, of alpha -SMA, the protein expression was similar with that in control group (P=0.066>0.05), but the protein expression of CTGF or collagen I, respectively, was significantly different from that in control group (P=0.000<0.01). The differences of expressions of the alpha -SMA, CTGF and collagen I mRNA in 30, 150, 750 mu mol/L Y-27632 group were statistically significant, compared with those in control group, respectively (alpha -SMA, P=0.002, 0.000, 0.000; CTGF, P=0.014, 0.002, 0.001; collagen I,P=0.003, 0.002, 0.000). CONCLUSION: Blocking the Rho/ROCK signaling pathway by using of Y-27632 could inhibit the cellular proliferation and the expression of both CTGF and alpha -SMA whatever OTFS induced by TGF-beta 1 or not. Y-27632 suppressed the expression of collagen I mRNA without induction.

Effects of RNA interference targeting transforming growth factor-beta 1 on immune hepatic fibrosis induced by Concanavalin A in mice

BACKGROUND: Previous studies have shown that transforming growth factor-beta 1 (TGF-beta 1) is the most potent means of stimulating liver fibrogenesis by myofibroblast-like cells derived from hepatic stellate cells. Thus, TGF-beta 1 could be a target for treating hepatic fibrosis. This study aimed to investigate the inhibitory effects of specific TGF-beta 1 small interference RNA (siRNA) on immune hepatic fibrosis induced by Concanavalin A (Con A) in mice. METHODS: Three short hairpin RNAs targeting different positions of TGF-beta 1 were designed and cloned to the plasmid pGenesil-1 to obtain three recombinant expression vectors (pGenesil-TGF-beta 1-ml, pGenesil-TGF-beta 1-m2 and pGenesil-TGF-beta 1-m3). Thirty male Kunming mice were randomly divided into 6 groups: normal, model, control, and three treatment groups. The immune hepatic fibrosis models were constructed by injecting Con A via the tail vein at 8 mg/kg per week for 6 weeks. At weeks 2, 4 and 6, pGenesil-TGF-beta 1-ml, pGenesil-TGF-beta 1-m2 or pGenesi1-TGF-beta 1-m3 was injected by a hydrodynamics-based transfection method via the tail vein at 0.8 ml/10 g within 24 hours after injection of Con A in each of the three treatment groups. The mice in the control group were injected with control plasmid pGenesil-HK at the same dose. All mice were sacrificed at week 7. The levels of hydroxyproline in liver tissue were determined by biochemistry. Liver histopathology was assessed by Van Gieson staining. The expression levels and localization of TGF-beta 1, Smad3, and Smad7 in liver tissue were detected by immunohistochemistry. The expression of TGF-beta 1, Smad3, Smad7 and alpha-smooth muscle actin (alpha-SMA) mRNAs in the liver were assessed by semi-quantitative RT-PCR. RESULTS: The levels of hydroxyproline in the liver tissue of the treatment groups were lower than those of the model group (P<0.01). Histopathologic assay showed that liver fibrogenesis was clearly improved in the treatment groups compared with the model group. The expression levels of TGF-beta 1 and Smad3 of liver tissue were also markedly lower in the treatment groups than in the model group (P<0.01), while the levels of Smad7 were higher in the treatment groups than in the model group (P<0.01). RT-PCR further showed that the expression of TGF-beta 1, Smad3 and alpha-SMA mRNA was significantly inhibited in the treatment groups compared with the model group, while the levels of Smad7 were increased. There was no difference in the above parameters among the three treatment groups or between the control and model groups (P>0.05), but the inhibitory effect of pGenesil-TGF-beta 1-ml was the highest among the treatment groups. CONCLUSIONS: Specific siRNA targeting of TGF-beta 1 markedly inhibited the fibrogenesis of immune hepatic fibrosis induced by Con A in mice. The anti-fibrosis mechanisms of siRNAs may be associated with the down-regulation of TGF-beta 1, Smad3 and alpha-SMA expression and up-regulation of Smad7 expression in liver tissue, which resulted in suppressing the activation of hepatic stellate cells. (Hepatobiliary Pancreat Dis Int 2009; 8: 300-308)

Pre-ischemia electro-acupuncture potentiates the expression of Bcl-2 and transforming growth factor-beta 1 in rat brains

The expression of the anti-apoptotic molecules Bcl-2 and transforming growth factor-beta 1 is known to confer protective effects on the cerebral ischemia-reperfusion injury.The current study investigated the expression levels of Bcl-2 and transforming growth factor-beta 1 in response to multiple pre-ischemia electro-acupuncture at acupoints Zusanli（ST36）and Fengchi（GB20） stimulation.Rats were divided into five groups：uninjured,control,non-acupoint,GB20 and ST36. Rats in the non-acupoint,GB20 and ST36 groups received 30 minutes（3 times or 18 times）of electro-acupuncture stimulation before experimental cerebral ischemia was induced.Bcl-2 and transforming growth factor-beta 1 were found to be significantly increased in the ST36 groups with either 3 or 18 electro-acupuncture treatments（P〈0.05）.The production was higher with 18 electro-acupuncture treatments in the ST36 groups（P〈0.05）.In the GB20 groups,significant increase was only observed in transforming growth factor-beta 1 with 18 electro-acupuncture treatments（P〈0.05）.No significant elevation of the level of transforming growth factor-beta 1 was observed in the non-acupoint groups.However,the production of Bcl-2 increased with 18 treatments in the non-acupoint groups（P〈0.05）.The data suggest that multiple pre-ischemia electro-acupuncture at ST36 was effective in conferring neuroprotective effect on the brain by means of upregulation of Bcl-2 and transforming growth factor-beta 1 and the effect was increase with the number of treatment.

Correlation between expression of two transforming growth factor-beta 1 receptors and microvascular density in a rat model of cerebral ischemia and reperfusion injury

The effects of transforming growth factor-β1 （TGF-β1） are currently controversial. Whether TGF-β1 promotes or inhibits revascularization under different conditions remains poorly understood. Based on previous studies, the current experiment established rat models of cerebral ischemia and reperfusion injury （IRI）, and demonstrated that pathological and functional damage was also increased after IRI. The most serious damage was observed at 3 days after reperfusion, at which time microvascular density fell to its lowest level. Soon afterwards, microvascular density increased, new collateral circulation was gradually established at 4 to 7 days after reperfusion, and pathological damage and neurological deficits were improved. TGF-β1, activin receptor-like kinase 5 （ALK5） mRNA and protein expression levels increased gradually over time. In contrast, ALK1 mRNA and protein expression decreased over the same period. A significant negative correlation was detected between microvascular density and expression of the ALK5 gene transcript. There was no correlation between microvascular density and ALK1 gene transcriptional expression following cerebral IRI in a rat model. These findings suggest that ALK5, rather than ALK1, is the critical receptor in the TGF-β1 signal pathways after cerebral IRI.

Plasma Levels of Transforming Growth Factor-Beta 1 in Women with Pelvic Organ Prolapse

Objective: In women with pelvic organ prolapse (POP), decreased expression of transforming growth factor-beta 1 (TGF-β1) has been shown in POP tissues. However, no studies have evaluated plasma TGF-β1 levels in patients with POP, so it is unknown whether they are also changed or not. Therefore, we compared plasma TGF-β1 levels in women with and without POP. Methods: Participants were 49 women with POP and 23 healthy control women. All participants were postmenopausal. We measured plasma TGF-β1 and compared data between patients with POP and controls, and between patients with uterine prolapse (UP, n = 19) and those with a cystocele (CC, n = 30). In addition, in patients, we assessed the POP quantification system (POP-Q) stage. Results: Plasma TGF-β1 levels were significantly lower in patients than in healthy controls. POP-Q stage was not significantly different between the UP and CC subgroups, but POP-Q stage IV was diagnosed in 63% of patients with UP and 7% of those with CC. Plasma TGF-β1 levels were significantly lower in the CC subgroup than in the UP subgroup. Conclusion: Plasma TGF-β1 is decreased in POP. It remains unclear whether the lower levels indicate a reduction in systemic TGF-β1 activity, but they can be assumed to reflect reduced TGF-β1 expression in POP tissues.

The involvement of p38 MAPK in transforming growth factor β1-induced apoptosis in murine hepatocytes

We reported in this manuscript that TGF-beta1 induces apoptosis in AML12 murine hepatocytes, which is associated with the activation of p38 MAPK signaling pathway. SB202190, a specific inhibitor of p38 MAPK, strongly inhibited the TGF-beta1-induced apoptosis and PAI-1 promoter activity. Treatment of cells with TGF-beta1 activates p38. Furthermore, over-expression of dominant negative mutant p38 also reduced the TGF-beta1-induced apoptosis. The data indicate that the activation of p38 is involved in TGF-beta1-mediated gene expression and apoptosis.

Metformin attenuates angiotensin II induced cardiac fibrosis and transforming growth factor-β1 production through the inhibition of hepatocyte nuclear factor4

Aim In diabetic patients, metformin appears to provide cardiovascular protection that cannot be attribu- ted only to its antihyperglycemic effects. Metformin is also known as the AMP-activated protein kinase （AMPK） ac- tivator. Our previous study suggested that metformin inhibits transforming growth factor-β1 （TGF-β1） production in a mouse heart failure model of pressure overload. TGF-β1 is a key factor in cardiac fibrosis and is usually induced by Angiotensin Ⅱ （Ang Ⅱ ） in the pressure overload mouse models. This study investigated the effect of metformin on cardiac fibrosis and TGF-β production induced by AngII and the underlying mechanisms. Methods C57/BL6 wild-type and AMPKα2 knockout mice were used. AngII （3 mg · kg-1 · d-1） was infused subcutaneously into mice for 7 days. Adult mouse cardiac fibroblasts were isolated and treated with AngII （ 1 μmol · L-1） and/or met- formin （1 mmol · L-l）. Results In C57/BL6 mice, metformin inhibits AngII-induced cardiac fibrosis. In cardi-ac fibroblasts, metformin inhibits TGF-β1 expression and production induced by AngII. AMPK inhibitor, com- pound C, reversed the effects of metformin. In vivo, AMPKα2 deficiency further increases AngII-induced TGF-β1 production. In cardiac fibroblasts, metformin inhibited AngII induced hepatocyte nuclear factor4 （HNF4ot protein level increase and HNF4α binding with TGF-β1 promoter using chromatin immunoprecipitation assay. In vivo, AMPKα2 deficiency further increased AngII-induced HNF4α protein level. Using HNF4α adenovirus, overexpress- ing HNF4α led to a 1.5-fold increase in TGF-β1 mRNA expression. HNF4a siRNA blocked AngII induced TGF- β1 production. Luciferase reporter with deleted HNF4a binding sites showed decreased TGFbl transcriptional activ- ity induced by AngII. In AMPK or2-/- heart, the inhibition of metformin on HNF4a protein was attenuated. Con- clusion Metformin inhibits AngII induced cardiac fibrosis and TGF-β1 production through AMPK activation. The underlying mechanism is that AMPK activation inhibits AngII induced HNF4α and then decreases TGF-β1 expres- sion.

Transforming growth factor-β and toll-like receptor-4 polymorphisms are not associated with fibrosis in haemochromatosis

AIM:To investigate the role of genetic polymorphisms in the progression of hepatic fibrosis in hereditary haemochromatosis.METHODS:A cohort of 245 well-characterised C282Y homozygous patients with haemochromatosis was studied,with all subjects having liver biopsy data and DNA available for testing.This study assessed the association of eight single nucleotide polymorphisms(SNPs)in a total of six genes including toll-like receptor 4(TLR4),transforming growth factor-beta(TGF-β),oxoguanine DNA glycosylase,monocyte chemoattractant protein 1,chemokine C-C motif receptor 2 and interleukin-10 with liver disease severity.Genotyping was performed using high resolution melt analysis and sequencing.The results were analysed in relation to the stage of hepatic fibrosis in multivariate analysis incorporating other cofactors including alcohol consumption and hepatic iron concentration.RESULTS:There were significant associations between the cofactors of male gender(P=0.0001),increasing age(P=0.006),alcohol consumption(P=0.0001),steatosis(P=0.03),hepatic iron concentration(P<0.0001)and the presence of hepatic fibrosis.Of the candidate gene polymorphisms studied,none showed a significant association with hepatic fibrosis in univariate or multivariate analysis incorporating cofactors.We also specifically studied patients with hepatic iron loading above threshold levels for cirrhosis and compared the genetic polymorphisms between those with no fibrosis vs cirrhosis however there was no significant effect from any of the candidate genes studied.Importantly,in this large,well characterised cohort of patients there was no association between SNPs for TGF-βor TLR4and the presence of fibrosis,cirrhosis or increasing fibrosis stage in multivariate analysis.CONCLUSION:In our large,well characterised group of haemochromatosis subjects we did not demonstrate any relationship between candidate gene polymorphisms and hepatic fibrosis or cirrhosis.

Activation of Rac1-PI3K/Akt is required for epidermal growth factorinduced PAK1 activation and cell migration in MDA-MB-231 breast cancer cells

Epidermal growth factor （EGF） may increase cell motility, an event implicated in cancer cell invasion and metastasis. However, the underlying mechanisms for EGF-induced cell motility remain elusive. In this study, we found that EGF treatment could activate Ras-related C3 botulinum toxin substrate 1 （Racl）, PI3K/Akt and p21- actived kinase （PAK1） along with cell migration. Ectopic expression of PAK1 K299R, a dominant negative PAK1 mutant, could largely abolish EGF-induced cell migration. Blocking PI3K/Akt signalling with LY294002 or Akt siRNA remarkably inhibited both EGF-induced PAK1 activation and cell migration. Furthermore, expression of dominant-negative Racl （T17N） could largely block EGF-induced PI3K/Akt-PAK1 activation and cell migration. Interestingly, EGF could induce a significant production of ROS, and N-acetyl-L-cysteine, a scavenger of ROS which abolished the EGF-induced ROS generation, cell migration, as well as activation of PI3K/Akt and PAK, but not Racl. Our study demonstrated that EGF-induced cell migration involves a cascade of signalling events, including activation of Racl, generation of ROS and subsequent activation of PI3K/Akt and PAK1.

儿童慢性粒细胞白血病慢性期红细胞参数及血清bFGF、TGF-β1、VEGF表达变化分析

目的探究儿童慢性粒细胞白血病(CML)慢性期红细胞参数及血清碱性成纤维细胞生长因子(bFGF)、转化生长因子β1(TGF-β1)及血管内皮生长因子(VEGF)表达变化。方法前瞻性选取2020年1月至2023年1月在首都医科大学附属北京儿童医院进行治疗的54例CML慢性期患儿为研究组,另随机抽取46名同期在本院进行体检的健康儿童为健康对照组。研究组给予酪氨酸激酶抑制剂治疗。比较两组间红细胞参数及血清bFGF、TGF-β1、VEGF表达变化,并比较研究组治疗前后红细胞参数及血清bFGF、TGF-β1、VEGF表达水平。结果研究组的RBC、血红蛋白、红细胞压积(HCT)及平均红细胞血红蛋白浓度(MCHC)水平分别为(3.45±0.04)×10^(12)/L、(102.33±1.15)g/L、(32.03±0.61)%、322.15±2.58,均显著低于对照组[(4.98±0.03)×10^(12)/L、(149.78±1.88)g/L、(44.33±0.31)%、334.12±0.77],平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)及红细胞体积分布宽度(RDW)水平分别为(91.44±0.77)fL、(33.15±2.55)pg、(17.55±0.12)%,均显著高于对照组[(89.88±0.34)fL、(30.24±0.16)pg、(12.66±0.11)%],差异均有统计学意义(P<0.05)。研究组的血清bFGF、VEGF水平分别为(30.66±9.66)、(128.68±30.58)pg/mL,均显著高于对照组[(5.26±1.54)、(70.66±11.26)pg/mL],TGF-β1水平为(38.22±8.06)μg/L,显著低于对照组[(78.66±8.13)μg/L],差异均有统计学意义(P<0.05)。治疗后,研究组患儿的RBC、血红蛋白、HCT、MCV及MCH水平均较治疗前显著降低,MCHC及RDW水平均较治疗前显著升高,差异均有统计学意义(P<0.05)。研究组治疗后的血清bFGF、VEGF水平均较治疗前显著降低,TGF-β1水平较治疗前显著升高,差异均有统计学意义(P<0.05)。结论在儿童CML慢性期患儿中可见血细胞参数明显异常,血清bFGF、VEGF水平显著升高,TGF-β1水平显著降低。酪氨酸激酶抑制剂治疗CML慢性期能有效改善患儿红细胞形态及功能,抑制肿瘤细胞生长,临床疗效显著,值得临床推广使用。

血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6在结核性胸膜炎胸膜纤维化患者中的变化及临床意义

目的探讨血清和胸腔积液纤溶酶原激活剂抑制物-1(PAI-1)、转化生长因子-β(TGF-β)、血管内皮生长因子(VEGF)、白细胞介素-6(IL-6)在结核性胸膜炎胸膜纤维化患者中的变化及临床意义。方法选取2020年7月至2023年7月该院收治的103例结核性胸膜炎胸膜纤维化患者作为研究对象,治疗2周后,根据糖皮质激素治疗疗效将其分为显效组、非显效组。比较两组治疗前及治疗1、2周后血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平。采用Spearman相关分析血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平与疗效的相关性。治疗2周后血清PAI-1、TGF-β、VEGF、IL-6水平与胸腔积液中该指标水平之间进行Pearson相关分析。绘制受试者工作特征曲线分析治疗1、2周后血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平对结核性胸膜炎胸膜纤维化患者疗效的预测价值。结果两组治疗1、2周后血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平低于治疗前,显效组治疗1、2周后血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平低于非显效组,差异有统计学意义(P<0.05)。治疗1、2周后血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平与疗效呈负相关(P<0.05)。治疗2周后血清PAI-1、TGF-β、VEGF、IL-6水平和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平呈正相关(r=0.761、0.783、0.812、0.741,均P<0.05)。治疗1、2周后血清和胸腔积液各指标联合检测的曲线下面积(AUC)大于其单独指标的AUC(P<0.05)。结论结核性胸膜炎胸膜纤维化患者血清和胸腔积液PAI-1、TGF-β、VEGF、IL-6水平与疗效有关,血清及胸腔积液PAI-1、TGF-β、VEGF、IL-6联合检测的预测价值较好,能够为临床干预提供参考依据。

心房颤动患者血清脂蛋白a、Apelin-13、转化生长因子β1水平与左心房内径的关系

目的 探讨心房颤动(AF)患者血清脂蛋白a[Lp(a)]、Apelin-13、转化生长因子β1(TGF-β1)及左心房内径(LAD)间的关系。方法 2022年12月至2024年1月,选择在滁州市第一人民医院心内科住院患者100例,按照是否发生AF分为2组,AF组50例,非AF(NAF)组50例。检测2组患者血清Lp(a)、Apelin-13、TGF-β1水平,采用经胸超声心动图检查左心房内径并进行相关性分析。结果 AF组Lp(a)、TGF-β1水平及LAD升高,Apelin-13水平降低,与NAF组比较差异均有统计学意义(P<0.05)。多因素logistic回归分析显示,Lp(a)、TGF-β1、舒张压及LAD为AF的危险因素,Apelin-13为AF的保护因素(P<0.05),且Lp(a)、TGF-β1、LAD及Apelin-13对AF具有预测价值(P<0.05)。线性回归结果显示,Lp(a)、TGF-β1、Apelin-13对LAD的回归系数分别为0.01(P>0.05)、-0.04(P>0.05)、-1.22(P<0.05)。结论 Lp(a)、TGF-β1及LAD为AF的独立危险因素;但Lp(a)、TGF-β1与LAD无明确相关性;Apelin-13作为AF独立保护因素,与LAD呈负相关。

IGF-1介导MAPKs通路在C3H10T1/2细胞成骨分化中的作用

目的探究胰岛素样生长因子1(IGF-1)介导丝裂原活化蛋白激酶(MAPKs)信号通路在C3H10T1/2细胞成骨分化中的调控作用及机制。方法不同浓度IGF-1(0、5、10、20 ng/mL)培养C3H10T1/2细胞,碱性磷酸酶(ALP)与茜素红(ARS)染色检测ALP活性、钙盐沉积情况,qRT-PCR法检测成骨特性因子核心结合因子α-1(RUNX2)、成骨分化特异性因子骨桥蛋白(OPN)、骨钙蛋白(OCN)mRNA表达水平,Western Blot法检测MAPK通路蛋白磷酸化表达水平。对数期细胞分为空白组、IGF-1组、ERK通路抑制剂(PD98059)组、PD+IGF-1组、p38通路抑制剂(SB202192)组、SB+IGF-1组,qRT-PCR法检测成骨特性因子RUNX2、成骨分化特异性因子骨桥蛋白(OPN)、骨钙蛋白(OCN)mRNA表达水平。结果不同浓度IGF-1组ALP显色加深,ALP活性升高,钙盐结节形成增多,RUNX2、OPN、OCN mRNA表达水平升高,磷酸化ERK、p38、JNK蛋白表达增加,具有剂量效应(P<0.05)。与空白组比较,PD组、SB组C3H10T1/2细胞RUNX2、OPN、OCN mRNA表达水平明显降低(P<0.05),PD+IGF-1组、SB+IGF-1组C3H10T1/2细胞RUNX2、OPN、OCN mRNA表达水平明显升高(P<0.05);但与IGF-1组比较,PD+IGF-1组、SB+IGF-1组C3H10T1/2细胞RUNX2、OPN、OCN mRNA表达水平明显降低(P<0.05)。结论IGF-1促进C3H10T1/2细胞成骨分化,其作用机制可能与激活ERK信号通路和p38 MAPK信号通路有关。

基于Traf6/TAK1通路探讨维生素D对甲状腺功能减退肾损伤幼鼠肾小管上皮细胞间充质转化的影响

目的探讨维生素D(VD)对甲状腺功能减退(HT)肾损伤幼鼠肾小管上皮细胞间充质转化(EMT)的影响,以及其对肿瘤坏死因子受体相关因子6(Traf6)/转化生长因子-β活化激酶1(TAK1)通路的调控机制。方法通过丙基硫尿嘧啶(PTU)灌胃构建幼鼠HT模型,以过表达TAK1(pc DNA3.1-TAK1)作功能挽救实验;50只SPF级雄性SD大鼠分为正常组、HT组、VD低剂量(HT+VD-L)组、VD高剂量(HT+VD-H)组、HT+VD-H+pc DNA3.1-TAK1(HT+VD-H+pc)组,每组10只。全自动生化仪检测各组大鼠血清血肌酐(Scr)和血尿素氮(BUN)的含量;脱氧核糖核苷酸末端转移酶介导的缺口末端标记法试剂盒(TUNEL)检测肾组织中的细胞凋亡;免疫组化检测肾组织中转化生长因子β1(TGF-β1)、α-平滑肌肌动蛋白(α-SMA)和上皮钙黏蛋白(E-cadherin)的表达;Western blot法检测肾组织中B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、Traf6、TAK1和磷酸化TAK1(p-TAK1)的表达。结果VD能明显降低HT幼鼠血清中Scr和BUN的含量,下调肾组织中的细胞凋亡率,降低肾组织中TGF-β1和α-SMA的表达,上调E-cadherin的表达;抑制肾组织中Traf6、p-TAK1和Bax的表达,升高肾组织中Bcl-2的表达,差异均具有统计学意义(均P<0.05)。结论维生素D能抑制HT幼鼠肾小管上皮细胞的EMT,降低肾组织中的细胞凋亡率,减轻肾组织的病理损伤,改善其肾功能,这与抑制Traf6/TAK1信号的激活有关。

鉴定LTBP1作为胃癌预后的生物标志物及其与肿瘤免疫微环境的相关性

目的探索潜在转化生长因子β结合蛋白1(latent transforming growth factor beta binding protein 1,LTBP1)在胃癌发生发展及免疫微环境中的生物学功能。方法在TCGA数据库中分析LTBP1在泛癌中的表达,然后通过胃癌组织和癌旁组织进行验证。通过回归比例分析法分析LTBP1表达与临床病理变量之间的相关性。Cox回归分析和Kaplan-Meier图用于评估LTBP1在胃癌中的预后价值。通过TIMER分析LTBP1的表达水平与胃癌中免疫细胞浸润之间的相关性。免疫组织化学染色检测LTBP1蛋白在胃癌组织及癌旁组织中的表达水平。结果与正常胃组织相比,胃癌组织中LTBP1表达显著上调。其表达与病理TNM分期显著相关。LTBP1高表达的胃癌患者的总体生存率(overall survival,OS)缩短。免疫组化结果显示,与癌旁组织相比,LTBP1在胃癌组织中显著高表达。TIMER检测发现LTBP1的表达与3种免疫细胞浸润呈正相关。结论LTBP1可能是胃癌预后的一个潜在生物标志物,并影响癌症的肿瘤免疫微环境。

Effects of retinoic acid on proliferation,phenotype and expression of cyclin-dependent kinase inhibitors in TGF-β1-stimulated rat hepatic stellate cells

AIM To study the molecular mechanisms ofretinoic acid(RA)on proliferation andexpression of cyclin-dependent kinase inhibitors(CKI),i.e.p16,p21 and p27 in cultured rathepatic stellate cells(HSC)stimulated withtransforming growth factor beta 1(TGF-β1).METHODS HSC were isolated from healthy ratlivers and cultured.After stimulated with1 mg/L TGF-β1,subcultured HSC were treatedwith or without 1 nmol/L RA.MTT assay,immunocytochemistry(ICC)for p16,p21,p27and α-smooth muscle actin(α-SMA)protein,insitu hybridization(ISH)for retinoic acidreceptor beta 2(RAR-β2)and p16,p21 and p27mRNA and quantitative image analysis(partially)were performed.RESULTS RA inhibited HSC proliferation(41.50%,P【0.05),decreased the protein levelof α-SMA(55.09%,P【0.05),and induced HSCto express RAR-β2 mRNA.In addition,RAincreased the protein level of p16(218.75%,P【0.05)and induced p21 protein expression;meanwhile,p27 was undetectable by ICC in bothcontrol and RA-treated HSC.However,RA hadno influence on the mRNA levels of p16,p21 orp27 as determined by ISH.CONCLISION Up-regulation of p16 and p21 on post-transcriptional level may contribule, in part to RA inhibition of TGF-β1-initiated rat HSC activation in vitro.

All-trans Retinoic Acid Diminishes Collagen Production in a Hepatic Stellate Cell Line via Suppression of Active Protein-1 and c-Jun N-terminal Kinase Signal

Following acute and chronic liver injury,hepatic stellate cells (HSCs) become activated to undergo a phenotypic transformation into myofibroblast-like cells and lose their retinol content,but the mechanisms of retinoid loss and its potential roles in HSCs activation and liver fibrosis are not understood.The influence of retinoids on HSCs and hepatic fibrosis remains controversial.The purpose of this study was to evaluate the effects of all-trans retinoid acid (ATRA) on cell proliferation,mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),fibrolytic genes (MMP-3,MMP-13) and the upstream element (JNK and AP-1) in the rat hepatic stellate cell line (CFSC-2G).Cell proliferation was evaluated by measuring BrdU incorporation.The mRNA expression levels of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and fibrolytic genes (MMP-3,MMP-13) were quantitatively detected by using real-time PCR.The mRNA expression of JNK and AP-1 was quantified by RT-PCR.The results showed that ATRA inhibited HSCs proliferation and diminished the mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)] and profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly stimulated the mRNA expression of MMP-3 and MMP-13 in HSCs by suppressing the mRNA expression of JNK and AP-1.These findings suggested that ATRA could inhibit proliferation and collagen production of HSCs via the suppression of active protein-1 and c-Jun N-terminal kinase signal,then decrease the mRNAs expression of profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly induce the mRNA expression of MMP-3 and MMP-13.

Follistatin-Like 1 Promotes Bleomycin-lnduced Pulmonary Fibrosis through the Transforming Growth Factor Beta 1/Mitogen-Activated Protein Kinase Signaling Pathway

Background： Follistatin-like I （FSTL 1） is a novel profibrogenic factor that induces pulmonary fibrosis （PF） through the transforming growth factor-beta 1 （TGF-[B 1 ）/Smad signaling. Little is known about its effects on PF through the non-Smad signaling, like the mitogen-activated protein kinase （MAPK） pathway. Therefore, this study aimed to investigate the role ofFSTL 1 in PF through the MAPK signaling pathway and its mechanisms in lung fibrogenesis. Methods： PF was induced in Fstll~ and wild-type （WT） C57BL/6 mice with bleomycin. After 14 days, the mice were sacrificed, and lung tissues were stained with hematoxylin and eosin; the hydroxyproline content was measured to confirm PF. The mRNA and protein level of FSTLI and the change of MAPK phosphorylation were measured by quantitative polymerase chain reaction and Western blotting. The effect of Fst11 deficiency on fibroblasts differentiation was measured by Western blotting and cell immunofluorescence. MAPK signaling activation was measured by Western blotting in Fst11＋/ and WT fibroblasts treated with recombinant human FSTLI protein. We pretreated mouse lung fibroblast cells with inhibitors of the extracellular signal-regulated kinase （ERK）, p38, and Jun N-terminal kinase （JNK） signaling and analyzed their differentiation, proliferation, migration, and invasion by Western blotting, 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide analysis, and transwell assays. The Student＇s t-test was used to compare the differences between two groups. Results： Fstll deficiency attenuated phosphorylation of the ERK, p38, and JNK signaling in bleomycin-induced fibrotic lung tissue 14 days after injury （0.67 ± 0.05 vs. 1.22 ± 0.03, t = 14.92, P = 0.0001; 0.41 ± 0.01 vs. 1.15 ± 0.07; t = 11.19; P = 0.0004; and 0.41 ± 0.01 vs. 1.07± 0.07, t = 8.92, P = 0.0009; respectively）, compared with WT lungs at the same time and in primary lung fibroblasts （0.82 ± 0.01 vs. 1.01 ±0.04, t = 4.06, P = 0.0150; 1.04 ±0.03 vs. 1.24 ± 0.03, t= 4.44, P = 0.0100： and 0.76 ±0.05 vs. 0.99± 0.05, t = 4.48, P = 0.0100; respectively）, compared with TGF-β1-stimulated WT group. Recombinant human FSTLI protein in lung fibroblasts enhanced TG F-β1 -mediated phosphorylation of the ERK （ 1.19± 0.08 vs, 0.55 ± 0.04, t = 6.99, P = 0.0020）, p38 （ 1.18 ±0.04 vs. 0.66 ± 0.03, t = 11.20, P = 0.0020）, and .INK （ 1,11± 0.01 vs. 0.84 ± 0.04, t = 6.53, P = 0.0030）, compared with the TGF-β1-stimulated WT group. Fstll-deficient fibroblasts showed reduced alpha-smooth muscle actin （α-SMA） expression （0.70 ± 0.06 vs. 1.28 ±0.11, t = 4.65, P = 0.0035, compared with the untreated WT group; 1.40 ± 0.05 vs. 1.76± 0.02, t = 6.31, P = 0.0007; compared with the TGF-β1-treated WT group）. Compared with the corresponding condition in the control group, the TGF-β1/FSTL 1-mediated α-SMA expression was significantly suppressed by pretreatment with an inhibitor of p38 （0.73± 0.01 vs. 1.13 ± 0.10, t = 3.92, P = 0.0078） and JNK （0.78 ± 0.03 vs. 1.08 ± 0.06, t = 4.40,P = 0.0046） signaling. The proliferation of mouse lung fibroblast cells （MLgs） significantly decreased after treatment of an inhibitor of p38 （0.30 ±0.01 vs. 0.46 ±0.03, t = 4.64, P = 0.0009）, JNK （0.30 ± 0.01 vs. 0.49 ± 0.01, t = 12.84, P = 0.0001）, and Smad2/3 （0.18 ± 0.02 vs. 0.46 ±0.02, t = 12.69, P = 0.0001） signaling compared with the dimethylsulibxide group. The migration and invasion cells of MLgs significantly decreased in medium pretreated with an inhibitor of p38 （70.17 ±3.28 vs. 116.30 ± 7.11, t = 5.89, P = 0.0042 for the migratory cells; 19.87 ± 0.84 vs. 32.70 i 0.95, t =10.14, P = 0.0005 for the invasive cells）, JNK （72.30 ±3.85 vs. 116.30 ± 7.11, t = 5.44, P = 0.0056 for the migratory cells; 18.03 ± 0.94 vs. 32.70 ± 0.95, t = 11.00, P = 0.0004 for the invasive cells）, and Smad2/3 （64.76 ± 1.41 vs. 116.30 ± 7.11, t = 7.11, P = 0.0021 for the migratory cells; 18.03 ± 0.94 vs. 32.70 ±0.95, t = 13.29, P = 0.0002 for the invasive cells） signaling compared with the corresponding condition in the dimethylsulfoxide group. Conclusion： FSTL1 affects lung fibroblast differentiation, proliferation, migration, and invasion through p38 and JNK signaling, and in this way, it might influence the development of PF.

Flagellin of Pseudomonas aeruginosa induces transforming growth factor beta 1 expression in normal bronchial epithelial cells through mitogen activated protein kinase cascades

Background Acute lung infection due to Pseudomonas aeruginosa （P. Aeruginosa） is a serious problem, especially in patients with structural lung conditions or immune compromised hosts, leading to an overwhelming threat with a high risk of morbidity and mortality. As an outcome of infection, fibrosis can be linked with chronic lung diseases. But some fibrotic manifestations, such as an irreversible decrease of lung function and fibrous bands seen on chest imaging, have been found after an acute infection with P. Aeruginosa. Fibrogenesis/remodeling resulting from acute lung infection by P.aeruginosa is rarely reported. This study was designed to explore the relation between fibrogenesis/remodeling and acute infection by P. Aeruginosa in vitro. We used flagellin protein from P. Aeruginosa, a key initiator of acute P.aeruginosa lung infection, to elucidate mechanisms by which acute lung infection with P. Aeruginosa can cause fibrogenesis/remodeling.Methods We studied the effect of flagellin from P. Aeruginosa （flagellin for short） on the transforming growth factor beta 1 （TGF-β1） and interleukin-8 （IL-8） expression, and the possible involvement of the signaling pathway, tumor necrosis factor receptor-associated factor 6 （TRAF6）/mitogen activated protein kinase （MAPK） pathway. Flagellin was purified from the P. Aeruginosa standard strain, PAO1. Normal bronchial epithelial cells BEAS-2B were challenged with different concentrations of flagellin, and cell viability assessment was performed by cell counting kit-8. BEAS-2B cells were incubated with flagellin with the specific MAPK inhibitors or TRAF6 siRNA. Cell lysates and the cultured supernatant were collected. The level of TGF-β1 and IL-8 were detected by enzyme-linked immunosorbant assay （ELISA）. Western blotting was used to detect the protein levels of MAPK signal proteins p38, c-Jun NH2-terminal kinase （JNK） and extracellular regulated kinase （ERK）.Results Expression of TGF-β1 in BEAS-2B cells was elevated by flagellin vs. Control groups （（104.3±20.8） vs.（44.6±4.4） pg/ml （P 〈0.01）） and was ablated by either p38 or JNK inhibitors compared with flagellin treatment （（45.1±18.8）vs. （104.3±20.8） pg/ml and （48.1±20.8） vs. （104.3±20.8） pg/ml, respectively （P 〈0.05））. Flagellin also elevated the expression of IL-8 in BEAS-2B cells vs. The control groups （（554.9±57.7） vs. （51.4±2.2.9） pg/ml （P 〈0.01））, and p38 MAPK inhibitors weaken the expression by flagellin （（301.1 ±155.1） vs. （554.9±57.7） pg/ml （P 〈0.05））. Western blotting revealed that all three MAPK proteins, p38, JNK and ERK were activated by flagellin challenge in an early phase, respectively in 15 minutes （P 〈0.01）, 30 minutes （P 〈0.01） and 15 minutes （P 〈0.01）. TRAF6 siRNA which decreased expression of TRAF6, altered the activation of JNK, p38, and ERK following flagellin treatment, but its influence on the expression of TGF-β1 and IL-8 has no statistical significance.Conclusions Flagellin from P. Aeruginosa PAO1 induces TGF-β1 expression in normal bronchial epithelial cells,BEAS-2B, through the MAPK signal cascade in vitro. It suggests that the fibrogenesis/remodeling process may be initiated from an early stage of acute lung infection due to P. Aeruginosa.