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.

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.

Spatial signalling mediated by the transforming growth factor-β signalling pathway during tooth formation

Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day （E） 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factor-β signalling pathway might play a role in this process.

miR-34a mediates oxaliplatin resistance of colorectal cancer cells by inhibiting macroautophagy via transforming growth factor-β/Smad4 pathway

To investigate whether microRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colorectal cancer (CRC) cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.METHODSmiR-34a expression levels were detected in CRC tissues and CRC cell lines by quantitative real-time polymerase chain reaction. Computational search, functional luciferase assay and western blotting were used to demonstrate the downstream target of miR-34a in CRC cells. Cell viability was measured with Cell Counting Kit-8. Apoptosis and macroautophagy of CRC cells were analyzed by flow cytometry and transmission electron microscopy, and expression of beclin I and LC3-II was detected by western blotting.RESULTSExpression of miR-34a was significantly reduced while expression of TGF-β and Smad4 was increased in CRC patients treated with OXA-based chemotherapy. OXA treatment also resulted in decreased miR-34a levels and increased TGF-β and Smad4 levels in both parental cells and the OXA-resistant CRC cells. Activation of macroautophagy contributed to OXA resistance in CRC cells. Expression levels of Smad4 and miR-34a in CRC patients had a significant inverse correlation and overexpressing miR-34a inhibited macroautophagy activation by directly targeting Smad4 through the TGF-β/Smad4 pathway. OXA-induced downregulation of miR-34a and increased drug resistance by activating macroautophagy in CRC cells.CONCLUSIONmiR-34a mediates OXA resistance of CRC by inhibiting macroautophagy via the TGF-β/Smad4 pathway.

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.

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.

Regulation of transforming growth factor-β signaling as a therapeutic approach to treating colorectal cancer

According to data from 2020,Slovakia has long been among the top five countries with the highest incidence rate of colorectal cancer(CRC)worldwide,and the rate is continuing to rise every year.In approximately 80%of CRC cases,allelic loss(loss of heterozygosity,LOH)occurs in the long arm of chromosome 18q.The most important genes that can be silenced by 18q LOH or mutations are small mothers against decapentaplegic homolog(SMAD)2 and SMAD4,which are intracellular mediators of transforming growth factor(TGF)-βsuperfamily signals.TGF-βplays an important role in the pro-oncogenic processes,including such properties as invasion,epithelial-mesenchymal transition(commonly known as EMT),promotion of angiogenesis,and immunomodulatory effects.Several recent studies have reported that activation of TGF-βsignaling is related to drug resistance in CRC.Because the mechanisms of drug resistance are different between patients in different stages of CRC,personalized treatment is more effective.Therefore,knowledge of the activation and inhibition of factors that affect the TGF-βsignaling pathway is very important.

Effects of the Nocth signaling pathway on expression of inflammatory factors and transforming growth factors in diabetic foot ulcers

Objective:persistent hyperinflammation is an important reason for the development of diabetic foot ulcer.Notch signaling is an important signaling pathway involved in the inflammatory response and cell proliferation in diabetic foot ulcer rats.This paper aims to explore the effect of Notch signaling on inflammatory factors,chemokines and growth factors through the intervention of Notch signaling in diabetic foot ulcer rats.Methods:the experimental model was made by using high-fat feed combined with streptozotocin(STZ)to cause diabetes,and the experimental model of diabetic foot ulcer was established by constant temperature and constant pressure scald apparatus.The normal ulcer model was used as a control.The intervention controls of the experimental model included normal saline,western medicine growth factor,Notch agonist Jagged1,Notch signaling inhibitor ly-411575,and the intervention of traditional Chinese medicine Zizhu ointment for 7 days.Serum il-1,il-6,TNF-radiation,and il-17 were detected by ELISA.Real-time PCR was used to detect the inflammatory factors,chemokines,and growth factors associated with Notch signaling in wound tissues:tnf-uum,il-1,il-6,il-17,interleukin-8,ip-10,McP-1,TGF-uum,TGF-livelihood.Results:serum levels of il-1,il-6,TNF-radiation and il-17 in diabetic foot ulcer rats were significantly higher than that in normal ulcer rats.The contents of il-1,il-6,TNF-radiation and il-17a in ly-411575 group and Zizhu ointment group were significantly reduced.Real-time PCR results of wound tissue showed that the levels of inflammatory cytokines il-1,il-6,TNF-radiation,il-17 and chemokines ip-10,il-8 and McP-1 in the wound tissue of diabetic foot ulcer rat model were significantly higher than that of normal ulcer model,and the levels of growth factor TGF-exposure were lower than that of normal ulcer model.LY-411575 significantly reduced il-1,il-6,TNF-maxima,il-17,and the chemokines ip-10,il-8,and McP-1 in diabetic foot ulcer rats,and reduced the expression of TGF-,TGF-earth.Jagged1 can increase the expression of TGF--,TGF---,suggesting that inhibition of the Notch signaling pathway can reduce the expression of the inflammatory factors il-1,il-6,TNF--,il-17a,il-8,and the growth factors TGF--,TGF---.Zizhu ointment can reduce the levels of il-1,il-6,TNF-benand,il-17,and the chemokines ip-10,il-8,and McP-1 on the wound surface of diabetic foot rats,and improve the expression of TGF-benand TGF-SUNS.Ly-411575 inhibited the expression of TGF-bento and TGF-promoting of Zizhu ointment.Conclusion:the expression of inflammatory cytokines and chemokines was higher and the expression of growth factors was lower in diabetic foot ulcer rats than in normal ulcer rats.Inhibition of Notch signaling pathway can reduce the expression of inflammatory factors,chemokines and growth factors in experimental model rats,and Notch signaling pathway can promote inflammation and cell proliferation.Zizhu ointment can reduce the levels of inflammatory cytokines and chemokines in diabetic foot ulcer rats,improve the expression of growth factors,and reduce wound inflammation,which may be related to the inhibition of Nocth signal expression.

Dihydroergotamine ameliorates liver fibrosis by targeting transforming growth factor β type Ⅱ receptor

BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.

Transforming growth factor-β and fibrosis

Transforming growth factor-β （TGF-β）, a prototype of multifunctional cytokine, is a key regulator of extracellular matrix （ECM） assembly and remodeling. Specifically, TGF-β isoforms have the ability to induce the expression of ECM proteins in mesenchymal cells, and to stimulate the production of protease inhibitors that prevent enzymatic breakdown of the ECM. Elevated TGF-β expression in affected organs, and subsequent deregulation of TGF-β functions, correlates with the abnormal connective tissue deposition observed during the onset of fibrotic diseases. During the last few years, tremendous progress has been made in the understanding of the molecular aspects of intracellular signaling downstream of the TGF-β receptors. In particular, Smad proteins, TGF-β receptor kinase substrates that translocate into the cell nucleus to act as transcription factors, have been studied extensively. The role of Smad3 in the transcriptional regulation of type I collagen gene expression and in the development of fibrosis, demonstrated both/n vitro and in animal models with a targeted deletion of Smad3, is of critical importance because it may lead to novel therapeutic strategies against these diseases. This review focuses on the mechanisms underlying Smad modulation of fibrillar collagen expression and how it relates to fibrotic processes.

Cross-talk between microRNA-let7c and transforming growth factor-β2 during epithelial-to-mesenchymal transition of retinal pigment epithelial cells

AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS: Retinal pigment epithelial(ARPE-19) cells were cultured with no serum for 12 h, and then with recombinant human TGF-β2 for different lengths of time. ARPE-19 cells were transfected with 1×106 TU/mL miR-let7 c mimcs(miR-let7 cM), miR-let7 c mimcs negative control(miR-let7cMNC) and miR-let7 c inhibitor(miR-let7 cI) using the transfection reagent. The expression of keratin-18, vimentin, N-cadherin, IKB alpha, p65 were detected by Western blot, quantitative polymerase chain reaction and immunofluorescence. RESULTS: The expression of miR-let7c was dramatically reduced and the nuclear factor-kappa B(NF-κB) signaling pathway was activated after induction by TGF-β2(P<0.05). In turn, overexpressed miR-let7 c significantly inhibited TGF-β2-induced EMT(P<0.05). However, miR-let7 c was unable to inhibit TGF-β2-induced EMT when the NF-κB signaling pathway was inhibited by BAY11-7082(P<0.01). CONCLUSION: The miR-let7 c regulates TGF-β2-induced EMT through the NF-κB signaling pathway in ARPE-19 cells.

Activation of phospholipase D activity in transforming growth factor-beta-induced cell growth inhibition

Cells regulate phospholipase D (PLD) activity in response to numerous extracellular signals. Here, we investigated the involvement of PLD activity in transforming growth factor-β(TGF-β1)-mediated growth inhibition of epithelial cells. TGFβ1 inhibits the growth of MDCK, Mv1Lu, and A-549 cells. In the presence of 0.4 % butanol, TGF-β1 induces an increase in the formation of phosp hat idylbutanol, a unique product catalyzed by PLD. TGF-β1 also induces an increase in phosphatidic acid (PA) level in A-549 and MDCK cells. TGF-β1 induces an increase in the levels of DAG labeled with [~3H]-myristic acid in A-549 and MDCK cells but not in Mv1Lu cells- No increase of DAG was observed in cells prelabeled with [~3H]-arachidonic acid.The data presented suggest that PLD activation is involved in the TGF-β1-induced cell growth inhibition.

Glycine Attenuates Myocardial Fibrosis in Myocardial Infarction in Rats Partly through Modulating Signal Transducer and Activator of Transcription 3/Nuclear Factor-κB/Transforming Growth Factor-β axis

Objective: Inflammation and fibrosis are strongly associated with each other. Glycine is present in various traditional Chinese medicines and exhibits anti-inflammatory activity. However, the effects of glycine on myocardial fibrosis(MF) in rats with myocardial infarction(MI) have not been reported. The purpose of this study is to investigate the effects of glycine therapy on MF and comprehend its underlying mechanisms. Materials and Methods: Left anterior descending artery ligation-induced MI in Sprague Dawley rats was leveraged to assess the therapeutic effects of Glycine. Rats received either normal saline or glycine(0.5 mg/g bodyweight) for 7 days. Results: Glycine upregulated cardiac ejection fraction and fractional shortening to improve cardiac function, as evaluated by echocardiography. Histological and immunohistochemical analyses demonstrated that glycine could decrease inflammatory cell infiltration and alleviate collagen deposition. Western blotting revealed that nuclear factor-κB(NF-κB)-mediated inflammatory signaling was also downregulated by glycine treatment. The expression of signal transducer and activator of transcription 3(STAT3), tumor necrosis factor-α, and transforming growth factor-β(TGF-β) was decreased significantly in the glycine-treated group compared to the model group. Thus, glycine plays a protective role against myocardial ischemia and subsequent MF. Conclusion: The protective effects of glycine were achieved partly through STAT3/NF-κB/TGF-β signaling pathway.

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。

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。

Targeting key signalling pathways in oesophageal adenocarcinoma:A reality for personalised medicine?

Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a result of tumor recurrence.We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways.There are many trials underway with the aim of improving survival in oesophageal cancer.Currently,phase 2 and 3 trials are focused on MAP kinase inhibition,either through inhibition of growth factor receptors or signal transducer proteins.In order to avoid tumor resistance,it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas.This may be achievable in the future with the advent of gene signatures and a combinatorial approach.

圣草酚对TGF-β1诱导的人皮肤成纤维细胞增殖、氧化应激反应及TGF-β1/Smad信号通路活化的影响

目的 探讨圣草酚对转化生长因子β1(TGF-β1)诱导的人皮肤成纤维细胞(HSF)的增殖、氧化应激反应及TGF-β1/Smad信号通路活化的影响。方法 将HSF分为对照组、模型组、圣草酚低剂量组、圣草酚中剂量组、圣草酚高剂量组、SB-431542组。对照组不做任何处理,模型组用5.0 ng/mL TGF-β1干预24 h,圣草酚低剂量组、圣草酚中剂量组、圣草酚高剂量组分别用40μmol/L、80μmol/L、160μmol/L圣草酚和5.0 ng/mL TGF-β1同时干预24 h,SB-431542组用10μmol/L SB-431542和5.0 ng/mL TGF-β1同时干预24 h。检测各组HSF细胞活力、α平滑肌肌动蛋白(α-SMA)蛋白表达水平、活性氧簇(ROS)含量、超氧化物歧化酶(SOD)活性,TGF-β1、α-SMA、Ⅰ型胶原蛋白(ColⅠ)、Ⅲ型胶原蛋白(Co lⅢ)、基质金属蛋白酶2(MMP2)的mRNA表达量及TGF-β1的蛋白表达水平。检测对照组、模型组、圣草酚中剂量组HSF的Smad2、Smad3、磷酸化Smad2 (p-Smad2)、磷酸化Smad3 (p-Smad3)蛋白表达水平。结果 与对照组相比,模型组的HSF细胞活力及α-SMA蛋白表达水平增加,ROS含量增加而SOD活性降低,TGF-β1、α-SMA、ColⅠ、Co lⅢ和MMP2 mRNA表达量上调,TGF-β1、Smad2、Smad3、p-Smad2、p-Smad3的蛋白表达量亦上调(P<0.05)。与模型组相比,圣草酚各剂量组和SB-431542组HSF细胞活力降低、ROS含量降低、SOD活性增强,且α-SMA、ColⅠ、Co lⅢ、MMP2的mRNA表达量和TGF-β1蛋白表达量下调,圣草酚中剂量组、圣草酚高剂量组和SB-431542组HSF细胞中α-SMA蛋白表达水平降低,圣草酚中剂量组及SB-431542组Smad2、Smad3、p-Smad2、p-Smad3蛋白表达量下调(P<0.05)。圣草酚低剂量组、圣草酚中剂量组、圣草酚高剂量组HSF细胞活力、α-SMA蛋白表达水平、ROS含量依次降低,SOD活性依次增强,α-SMA、ColⅠ、Co lⅢmRNA表达量依次降低(P<0.05)。结论 圣草酚可能通过抑制氧化应激反应及TGF-β1/Smad通路的活化,从而剂量依赖性地抑制TGF-β1诱导的HSF细胞纤维化。

基于TGF‐β1/Smads信号通路探讨红花抗硬皮病小鼠皮肤纤维化的作用机制

目的探讨红花抗硬皮病小鼠皮肤纤维化的作用及对转化生长因子β1(TGF-β1)/Smads信号通路的影响。方法将64只雌性BALB/c小鼠分为对照组(16只)、模型组(16只)、泼尼松组(8只)、红花前干预组(16只)和红花后干预组(8只)。除对照组外,其他4组小鼠采用皮下注射博来霉素诱导硬皮病小鼠模型。造模当天给予泼尼松组小鼠灌胃0.45 mg/mL醋酸泼尼松混悬液,给予红花前干预组小鼠灌胃0.15 g/mL红花水提液,给予对照组、模型组小鼠灌胃生理盐水,造模第15天给予红花后干预组小鼠灌胃0.15 g/mL红花水提液,以上各组小鼠均连续灌胃4周(0.2 mL/d)。干预4周后,观察各组小鼠皮肤外观变化及皮肤病理组织学改变,比较各组小鼠的真皮厚度,采用免疫组化法检测各组小鼠皮肤组织Ⅰ型胶原蛋白(COLⅠ)、α-平滑肌肌动蛋白(α-SMA)的蛋白表达水平,采用实时荧光定量PCR检测各组小鼠皮肤组织COLⅠ-a1、COLⅠ-a2、α-SMA、TGF-β1、Smad2、Smad3的mRNA表达水平,采用Western blot检测各组小鼠皮肤组织TGF-β1、Smad2、Smad3、磷酸化Smad2、磷酸化Smad3的蛋白表达情况。结果(1)模型组小鼠背部未见新生毛发,皮肤硬化明显、有粘连,不易被提起,真皮厚度增厚,各药物干预组皮肤症状较模型组改善,真皮厚度变薄,以泼尼松组、红花前干预组改善最明显。(2)与对照组比较,模型组小鼠皮肤组织COLⅠ、α-SMA的蛋白表达水平,以及COLⅠ-a1、COLⅠ-a2、α-SMA的mRNA表达水平升高(P<0.05);与模型组比较,红花前干预组、红花后干预组和泼尼松组小鼠皮肤组织COLⅠ、α-SMA的蛋白表达水平,以及COLⅠ-a1、COLⅠ-a2、α-SMA的mRNA表达水平下降,且泼尼松组、红花前干预组小鼠皮肤组织COLⅠ、α-SMA的蛋白表达水平低于红花后干预组,红花前干预组小鼠皮肤组织COLⅠ-a1、COLⅠ-a2的mRNA表达水平低于红花后干预组(P<0.05)。(3)与对照组比较,模型组小鼠皮肤组织TGF-β1、Smad2、Smad3的蛋白及mRNA,以及磷酸化Smad2、磷酸化Smad3的蛋白表达水平升高,红花前干预组小鼠皮肤组织TGF-β1、Smad3的mRNA表达水平降低,Smad2的mRNA表达水平升高(P<0.05);与模型组比较,红花前干预组小鼠皮肤组织TGF-β1、Smad2、Smad3的蛋白及mRNA,以及磷酸化Smad2、磷酸化Smad3的蛋白表达水平降低(P<0.05)。结论红花可以抑制肌成纤维细胞的激活,减少细胞外基质的生成与堆积,从而发挥抗硬皮病小鼠皮肤纤维化的作用,其机制可能与下调硬皮病小鼠皮肤组织TGF-β1/Smads信号通路相关蛋白的表达有关。

Interaction between insulin-like growth factor binding protein-related protein 1 and transforming growth factor beta 1 in primary hepatic stellate cells

BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGF beta 1 in primary hepatic stellate cells (HSCs). METHODS: We overexpressed TGF beta 1 or IGFBPrP1 and inhibited TGF beta 1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of a-smooth muscle actin (alpha-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3). RESULTS: We found that the adenovirus vector encoding the TGF beta 1 gene (AdTGF beta 1) induced IGFBPrP1 expression while that of alpha-SMA, collagen I, fibronectin, and TGF beta 1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGF beta 1, alpha-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGF beta 1 expression reduced the IGFBPrP1-stimulated expression of alpha-SMA, collagen I, fibronectin, and p-Smad2/3. CONCLUSIONS: These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGF beta 1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGF beta 1-depedent manner, and may act as an upstream regulatory factor of TGF beta 1 in the Smad pathway.