Cinobufotalin prevents bone loss induced by ovariectomy in mice through the BMPs/SMAD and Wnt/β-catenin signaling pathways

Background:Osteoporosis is a chronic bone disease characterized by bone loss and decreased bone strength.However,current anti-resorptive drugs carry a risk of various complications.The deep learning-based efficacy prediction system(DLEPS)is a forecasting tool that can effectively compete in drug screening and prediction based on gene expression changes.This study aimed to explore the protective effect and potential mechanisms of cinobufotalin(CB),a traditional Chinese medicine(TCM),on bone loss.Methods:DLEPS was employed for screening anti-osteoporotic agents according to gene profile changes in primary osteoporosis.Micro-CT,histological and morphological analysis were applied for the bone protective detection of CB,and the osteogenic differentiation/function in human bone marrow mesenchymal stem cells(hBMMSCs)were also investigated.The underlying mechanism was verified using qRT-PCR,Western blot(WB),immunofluorescence(IF),etc.Results:A safe concentration(0.25mg/kg in vivo,0.05μM in vitro)of CB could effectively preserve bone mass in estrogen deficiency-induced bone loss and promote osteogenic differentiation/function of hBMMSCs.Both BMPs/SMAD and Wnt/β-catenin signaling pathways participated in CB-induced osteogenic differentiation,further regulating the expression of osteogenesis-associated factors,and ultimately promoting osteogenesis.Conclusion:Our study demonstrated that CB could significantly reverse estrogen deficiency-induced bone loss,further promoting osteogenic differentiation/function of hBMMSCs,with BMPs/SMAD and Wnt/β-catenin signaling pathways involved.

Electroacupuncture improves myocardial fibrosis in heart failure rats by attenuating ECM collagen deposition through modulation of TGF-β1/Smads signaling pathway

Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure treatment. Methods: Healthy male Sprague-Dawley rats were allocated into three groups: Sham group, Model group, and electroacupuncture (Model + EA) group, with each group comprising 8 rats. The model underwent a procedure involving the ligation of the left anterior descending coronary artery to induce a model of heart failure. The Model + EA group was used for 7 consecutive days for electroacupuncture of bilateral Shenmen (HT7) and Tongli (HT5), once a day for 30 min each time. Left ventricular parameters in rats were assessed using a small-animal ultrasound machine to analyze changes in left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. Serum interleukin-1β (IL-1β), cardiac troponin (cTn), and N-terminal brain natriuretic peptide precursor levels were measured using ELISA. Histopathological changes in rat myocardium were observed through HE staining, while collagen deposition in rat myocardial tissue was assessed using the Masson staining method. Picro sirius red staining, immunohistochemical staining, and RT-qPCR were utilized to distinguish between the various types of collagen deposition. The expression level of TGF-β1 and SMAD2/3/4/7 mRNA in rat myocardial tissues was determined using RT-qPCR. Additionally, western blot analysis was conducted to assess the protein expression levels of TGF-β1, SMAD3/7, and p-SMAD3 in rat myocardial tissues. Results: Compared with the Sham group, the left ventricular ejection fraction and left ventricular fractional shortening values of the Model group were significantly decreased (P < 0.01);the left ventricular end-diastolic volume and left ventricular end-systolic volume values were remarkably increased (P < 0.01);serum N-terminal brain natriuretic peptide precursor content was increased (P < 0.01);serum IL-1β and cTn levels were increased (P < 0.01);myocardial collagen volume fraction were increased (P < 0.01);and those of the expression of TGF-β1 and SMAD2/3/4 mRNA was increased (P < 0.01);the expression of SMAD7 mRNA was decreased (P < 0.01);the protein expression levels of TGF-β1, SMAD3, and p-Smad3 were increased (P < 0.01);the protein expression level of SMAD7 was decreased (P < 0.01) in the Model group. Compared to the Model group, the expression levels of the proteins TGF-β1, SMAD3, and p-Smad3 in myocardial tissue were found to be decreased (P < 0.01), and the expression level of the protein SMAD7 was found to be increased (P < 0.01) in the Model + EA group;the collagen volume fraction and deposition of type Ⅰ /Ⅲ collagen were decreased (P < 0.01) in the Model + EA group. Conclusion: Electroacupuncture alleviates myocardial fibrosis in rats with heart failure, and this effect is likely due to attributed to the modulation of the TGF-β1/Smads signaling pathway, which helps reduce collagen deposition in the extracellular matrix.

Calcitriol attenuates liver fibrosis through hepatitis C virus nonstructural protein 3-transactivated protein 1-mediated TGF β1/Smad3 and NF-κB signaling pathways

BACKGROUND Hepatic fibrosis is a serious condition,and the development of hepatic fibrosis can lead to a series of complications.However,the pathogenesis of hepatic fibrosis remains unclear,and effective therapy options are still lacking.Our group identified hepatitis C virus nonstructural protein 3-transactivated protein 1(NS3TP1) by suppressive subtractive hybridization and bioinformatics analysis,but its role in diseases including hepatic fibrosis remains undefined.Therefore,additional studies on the function of NS3TP1 in hepatic fibrosis are urgently needed to provide new targets for treatment.AIM To elucidate the mechanism of NS3TP1 in hepatic fibrosis and the regulatory effects of calcitriol on NS3TP1.METHODS Twenty-four male C57BL/6 mice were randomized and separated into three groups,comprising the normal,fibrosis,and calcitriol treatment groups,and liver fibrosis was modeled by carbon tetrachloride(CCl4).To evaluate the level of hepatic fibrosis in every group,serological and pathological examinations of the liver were conducted.TGF-β1 was administered to boost the in vitro cultivation of LX-2 cells.NS3TP1,α-smooth muscle actin(α-SMA),collagen I,and collagen Ⅲ in every group were examined using a Western blot and real-time quantitative polymerase chain reaction.The activity of the transforming growth factor beta 1(TGFβ1)/Smad3 and NF-κB signaling pathways in each group of cells transfected with pcDNA-NS3TP1 or siRNA-NS3TP1 was detected.The statistical analysis of the data was performed using the Student’s t test.RESULTS NS3TP1 promoted the activation,proliferation,and differentiation of hepatic stellate cells(HSCs)and enhanced hepatic fibrosis via the TGFβ1/Smad3 and NF-κB signaling pathways,as evidenced by the presence of α-SMA,collagen I,collagen Ⅲ,p-smad3,and p-p65 in LX-2 cells,which were upregulated after NS3TP1 overexpression and downregulated after NS3TP1 interference.The proliferation of HSCs was lowered after NS3TP1 interference and elevated after NS3TP1 overexpression,as shown by the luciferase assay.NS3TP1 inhibited the apoptosis of HSCs.Moreover,both Smad3 and p65 could bind to NS3TP1,and p65 increased the promoter activity of NS3TP1,while NS3TP1 increased the promoter activity of TGFβ1 receptor I,as indicated by coimmunoprecipitation and luciferase assay results.Both in vivo and in vitro,treatment with calcitriol dramatically reduced the expression of NS3TP1.Calcitriol therapy-controlled HSCs activation,proliferation,and differentiation and substantially suppressed CCl4-induced hepatic fibrosis in mice.Furthermore,calcitriol modulated the activities of the above signaling pathways via downregulation of NS3TP1.CONCLUSION Our results suggest that calcitriol may be employed as an adjuvant therapy for hepatic fibrosis and that NS3TP1 is a unique,prospective therapeutic target in hepatic fibrosis.

基于TGF-β/BMP/Smad信号通路治疗激素性股骨头坏死中医药研究进展

激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SIONFH)是由于糖皮质激素使用不当或过度而引起的髋关节疾病,发病机制尚未统一,临床疗效亦不佳。当前,没有效果明确的药物可以延缓疾病进程,而中医药治疗SIONFH在临床上取得一定疗效。即便如此,仍未能完整的从分子生物及细胞生物学角度阐明中药治疗SIONFH的作用机制。转化生长因子-β(TGF-β)/骨形态发生蛋白(BMP)/Smad信号通路的转导是防治SIONFH的研究热点之一,故该文阐明了该信号通路的转导机制以及与SIONFH的联系,检索了基于该通路治疗SIONFH的全部中药及复方并阐述其影响机制。基于中医对SIONFH的认识,现临床上使用补肝肾强筋骨以及活血祛瘀通络类的方药治疗SIONFH,且具有良好的疗效。中药通过调控该通路,可刺激骨髓间充质干细胞成骨分化,降低破骨细胞含量,减少脂肪生成,改善微循环,抗氧化损伤,促进股骨头内血管新生,从而促进股骨头损伤的修复。现基于TGF-β/BMP/Smad信号通路对中医药治疗SIONFH的研究进展做一综述,期许为中医药治疗SIONFH提供理论依据及参考。

BMP/Smad信号通路与先天性马蹄内翻足模型大鼠足踝部的软骨发育

背景:先天性马蹄内翻足主要表现为骨本身异常及软骨发育异常,BMP/Smad信号通路可以指导胚胎期骨和软骨的发育,但其在马蹄内翻足病因领域发挥的作用尚无动物实验证实。目的:探讨BMP/Smad信号通路参与调控先天性马蹄内翻足模型大鼠足踝部软骨发育异常的机制。方法:将生长状况相同的孕10 d的SD大鼠随机分为实验组和对照组。实验组采用135 mg/kg维甲酸灌胃制作马蹄内翻足模型,对照组采用等量植物油灌胃;孕21 d后剖腹取出胎鼠,实验组孕鼠产下胎鼠41只中出现马蹄足畸形27只,畸型率65.9%;对照组获得胎鼠36只,均未出现畸形。分离胎鼠足踝部组织进行苏木精-伊红染色,并采用Western blot、RT-qPCR、免疫组化检测BMP/Smad信号通路核心蛋白Smad5、P-Smad5、通路下游蛋白SP7以及Sox9的表达水平。结果与结论:①与对照组相比,苏木精-伊红染色可见实验组大鼠足踝部组织中软骨基质增多,骨间缝隙增大;②免疫组化显示实验组Smad5与SP7表达水平下降,而Sox9基因表达增高;③RT-qPCR结果显示实验组大鼠足踝部组织中Smad5、SP7的mRNA表达水平下降,Sox9 mRNA表达水平升高;④Western blot结果显示实验组大鼠足踝部软骨组织中P-Smad5/Smad5及SP7表达降低,Sox9表达升高;⑤结果说明,先天性马蹄内翻足模型大鼠足踝部软骨异常的发生与BMP/Smad信号通路传导障碍有关。

BMP⁃2/Smad信号通路探讨金匮肾气丸对BMSCs成骨分化的影响

目的观察金匮肾气丸含药血清对大鼠骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)成骨分化的影响并探讨其发生的作用机制。方法制备金匮肾气丸含药血清,CCK⁃8法筛选出最佳浓度的金匮肾气丸含药血清对BMSCs向成骨分化的影响。将BMSCs分为空白组(control组)、成骨诱导组(OIS)、空白血清组(ROIS组)及含药血清组(JKSQ⁃OIS),分别对各组BMSCs进行成骨诱导。连续干预14 d及21 d后,分别进行碱性磷酸酶(ALP)染色和茜素红染色镜下观察各组碱性磷酸酶活性和成骨矿化水平;连续干预14 d后,实时荧光定量PCR(q⁃PCR)和蛋白免疫印迹法(Western blot)分别检测各组BMSCs中骨形态发生蛋白2(BMP⁃2)、Smad1、ALP、Runt相关转录因子2(runt⁃related transcription factor 2,Runx2)及成骨细胞特异性转录因子(Osterix,OSX)mRNA和蛋白的相对表达量。结果与control组相比,OIS组与ROIS组出现点状矿化结节,ALP染色轻微变深,ALP和Runx2 mRNA及蛋白的表达上升(P<0.05,P<0.01),OSX的表达上升但不明显(P>0.05);与OIS组相比,JKSQ⁃OIS组矿化结节成片分布,ALP染色明显加深,BMP⁃2、Smad1、ALP和Runx2 mRNA及蛋白的表达上升(P<0.05,P<0.01),OSX mRNA及蛋白表达有上升趋势(P>0.05)。结论金匮肾气丸含药血清可能通过调控BMP⁃2/Smad信号通路,上调ALP、Runx2和OSX的表达,促进BMSCs向成骨分化,改善OP。

接骨七厘胶囊通过激活BMP/Smad信号通路促进大鼠桡骨骨折愈合

【目的】探讨接骨七厘胶囊通过激活骨形态发生蛋白(BMP)/Smad信号通路对大鼠桡骨骨折愈合的改善作用。【方法】(1)构建大鼠桡骨骨折模型,检测大鼠血清中碱性磷酸酶(ALP)、钙(Ca)和磷的含量,观察骨折间隙的病理学变化。(2)培养人骨肉瘤细胞SaOS-2,检测ALP活性、矿化水平,实时定量聚合酶链反应(qRT-PCR)法检测细胞成骨相关基因ALP、胶原Ⅰ(COL-Ⅰ)、鸟氨酸转氨酶(OTC)、Osterix、骨桥蛋白(OPN)、Runt相关转录因子2(RUNX2)、BMP2表达,Western Blot法检测细胞BMP/Smad信号通路中关键蛋白的表达。【结果】接骨七厘胶囊促进大鼠桡骨骨折愈合,增强ALP活性,增加钙和磷含量。接骨七厘胶囊刺激SaOS-2细胞矿化结节的形成,并以剂量依赖的方式促进SaOS-2细胞中COL-I、OTC、Osterix、BMP2和OPN的表达水平。接骨七厘胶囊处理可上调SaOS-2细胞BMP/Smad信号通路Smad1/5磷酸化水平以及BMP2和RUNX2的水平。BMP/Smad信号通路的抑制剂Noggin抑制接骨七厘胶囊诱导的SaOS-2细胞成骨分化。【结论】接骨七厘胶囊可通过激活BMP/Smad信号通路,提高成骨相关基因的表达,从而促进骨折愈合。

Signaling cross-talk between TGF-β/BMP and other pathways

Transforming growth factor-beta （TGF-β）/bone morphogenic protein （BMP） signaling is involved in the vast majority of cellular processes and is fundamentally important during the entire life of all metazoans. Deregulation of TGF-β/ BMP activity almost invariably leads to developmental defects and/or diseases, including cancer. The proper functioning of the TGF-β/BMP pathway depends on its constitutive and extensive communication with other signaling pathways, leading to synergistic or antagonistic effects and eventually desirable biological outcomes. The nature of such signaling cross-talk is overwhelmingly complex and highly context-dependent. Here we review the different modes of cross-talk between TGF-β/BMP and the signaling pathways of Mitogen-activated protein kinase, phosphatidylinositol-3 kinase/ Akt, Wnt, Hedgehog, Notch, and the interleukin/interferon-gamma/tumor necrosis factor-alpha cytokines, with an emphasis on the underlying molecular mechanisms.

Xinfuli Granule improves post-myocardial infarction ventricular remodelingand myocardial fibrosis in rats by regulating TGF-β/Smads signaling pathway

Recent clinical and experimental studies have confirmed the effects of Xinfuli Granule (XG), a compound Chinese medicine in the prevention and treatment of heart failure (HF). This study aimed to investigate the effects and the mechanisms of XG on ventricular reconstruction in rats with acute myocardial infarction (AMI).MethodsSprague-Dawley rats were subjected to left anterior descending branch ligation. The rats that survived 24 h were randomly assigned to five groups: medium-dose of XG group (MI+XGM), high-dose of XG group (MI+XGH), carvedilol group (MI+C), medium-dose of XG + carvedilol group (MI+C+XGM). Fourteen rats underwent identical surgical procedures without artery ligation, serving as sham controls. At 28 days, left ventricular weight to body weight (LVW/BW) and heart weight to body weight (HW/BW) were calculated; left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVFS), left ventricular internal diameter at systole (LVIDS) were measured by ultrasound; HE staining, Masson staining, and Sirius red staining were used to assess the myocardial pathological and physiological changes as well as myocardial fibrosis area and non-infarct zone I/III collagen ratio. Expression of Smad3 were detected and analyzed by Western blot, immunohistochemistry and immunofluorescence. P-Smad3, Smad2 and Smad7 in the TGF-β/Smads signaling pathway were also analyzed by Western blot.ResultsThe LVIDS (P < 0.01), HW/BW (P < 0.05), type I/III collagen ratio (P < 0.01) and myocardial collagen (P < 0.01) decreased significantly while the LVW/BW, LVFS (P < 0.05) increased significantly in MI+XGM group as compared with those in other groups. The expression of key signal molecules of the TGF-β/Smads signaling pathway, including Smad3, P-Smad3 and Smad2 protein were decreased, while the expression of Smad7 increased in both XG and carvedilol treatment groups as compared to those of the MI group (all P < 0.01). Immunohistochemistry and immunofluorescence further confirmed the down-regulated Smad3 expression.ConclusionXG can improve ventricular reconstruction and inhibit myocardial fibrosis in rats with AMI by regulating TGF-β/Smads signaling pathway.

Berberine Attenuates Cigarette Smoke Extract-induced Airway Inflammation in Mice:Involvement of TGF-β1/Smads Signaling Pathway

Although several studies confirmed that berberine may attenuate airway inflammation in mice with chronic obstructive pulmonary disease(COPD),its underlying mechanisms were not clear until now.We aimed to establish an experiment mouse model for COPD and to investigate the effects of berberine on airway inflammation and its possible mechanism in COPD model mice induced by cigarette smoke extract(CSE).Twenty SPF C57BL/6 mice were randomly divided into PBS control group,COPD model group,low-dose berberine group and high-dose berberine group,5 mice in each group.The neutrophils and macrophages were examined by Wright's staining.The levels of inflammatory cytokines TNF-α and IL-6 in bronchoalveolar lavage fluid(BALF)were detennined by enzyme-linked immunosorbent assay.The expression levels of TGF-β1,Smad2 and Smad3 mRNA and proteins in lung tissues were respectively detected by quantitative real-time polymerase chain reaction and Western blotting.It was found that CSE increased the number of inflammation cells in BALF,elevated lung inflammation scores,and enhanced the TGF-β1/Smads signaling activity in mice.High-dose berberine restrained the alterations in the COPD mice induced by CSE.It was concluded that high-dose berberine ameliorated CSE-induced airway inflammation in COPD mice.TGF-β1/Smads signaling pathway might be involved in the mechanism.These findings suggested a therapeutic potential of high-dose berberine on the CSE-induced airway inflammation.

Cetirizine regulates scleroderma skin fibrosis in mice via the TGF-β1/Smad3 signaling pathway

Objective:To investigate the effect of cetirizine on the fibrosis of skin tissue in systemic sclerosis(SSc)mice and its mechanism of action.Methods:Thirty-two BALB/C mice were randomly divided into a blank group,a model group,a cetirizine low-dose group,and a cetirizine high-dose group,with eight in each group.The blank group was injected with normal saline on the back,and the other three groups were injected with bleomycin on the back to prepare SSc mouse models.The mice were injected once a day for 28 consecutive days,while the normal group and the model group were given saline.The dose group was administrated intragastrically at 2 mg/kg and 5 mg/kg,respectively,for 28 consecutive days.Detect the thickness of the dermis by taking the skin tissue in the back injection area of each group.Hematoxylin-eosin staining(HE)and Masson staining.Sample hydrolysis method to detect hydroxyproline(HYP)content in skin tissue.Immunohistochemical detection ofα-smooth muscle actin(α-SMA)expression in skin tissues.Enzyme-linked immunosorbent assay(ELISA)to detect serum interleukin(IL-6,IL-10)and transforming growth factor(TGF-αand TGF-β1).Quantitative real-time PCR(qRT-PCR)was used to detect the expression levels of collagen type I(COL1A1),type III collagen(COL3A1),Smad homolog 3(Smad3),and TGF-β1 mRNA.Western blot was used to detect the expression levels of COL1A1,COL3A1 and p-Smad3.Results:Compared with the blank group,the dermis thickness and HYP content of the model group increased,the skin tissue lesions and fibrosis were more severe,theα-SMA positive expression intensity in the skin tissue was higher,and the serum IL-6,IL-10,TGF-α,TGF-β1 content increased,COL1A1,COL3A1,Smad3,TGF-β1 mRNA expression levels increased in skin tissues,COL1A1,COL3A1,p-Smad3 protein expression increased,the differences were statistically significant(P<0.05).Compared with the model group,the dermal thickness and HYP content of the low and high dose cetirizine groups were reduced,the degree of skin tissue lesions and fibrosis was improved,the expression ofα-SMA in skin tissues was weakened,the levels of IL-6,IL-10,TGF-α,TGF-β1 in serum were reduced,the expression levels of COL1A1,COL3A1,Smad3 and TGF-β1 in skin tissues were reduced,and the expression levels of COL1A1,COL3A1,and p-Smad3 proteins were reduced,the decrease in the high-dose group was more significant,and the differences were statistically significant(P<0.05).Conclusion:Cetirizine can improve the degree of fibrosis of skin tissue in SSc mice and reduce the immune inflammation response.The mechanism of action is related to the TGF-β1/Smad3 signaling pathway.

Deamidation enables pathogenic SMAD6 variants to activate the BMP signaling pathway

The BMP signaling pathway plays a crucial role in regulating early embryonic development and tissue homeostasis.SMAD6 encodes a negative regulator of BMP,and rare variants of SMAD6 are recurrently found in individuals with birth defects.However,we observed that a subset of rare pathogenic variants of SMAD6 consistently exhibited positive regulatory effects instead of the initial negative effects on the BMP signaling pathway.We sought to determine whether these SMAD6 variants have common pathogenic mechanisms.Here,we showed that pathogenic SMAD6 variants accompanying this functional reversal exhibit similar increases in deamidation.Mechanistically,increased deamidation of SMAD6 variants promotes the accumulation of the BMP receptor BMPR1A and the formation of new complexes,both of which lead to BMP signaling pathway activation.Specifically,two residues,N262 and N404,in SMAD6 were identified as the crucial sites of deamidation,which was catalyzed primarily by glutamine-fructose-6-phosphate transaminase 2(GFPT2).Additionally,treatment of cells harboring SMAD6 variants with a deamidase inhibitor restored the inhibitory effect of SMAD6 on the BMP signaling pathway.Conversely,when wild-type SMAD6 was manually simulated to mimic the deamidated state,the reversed function of activating BMP signaling was reproduced.Taken together,these findings show that deamidation of SMAD6 plays a crucial role in the functional reversal of BMP signaling activity,which can be induced by a subset of various SMAD6 variants.Our study reveals a common pathogenic mechanism shared by these variants and provides a potential strategy for preventing birth defects through deamidation regulation,which might prevent the off-target effects of gene editing.

BMP-7/Smads信号通路在胆总管结扎大鼠肝纤维化组织中的表达及意义

目的探讨BMP-7/Smads信号通路在胆总管结扎大鼠肝纤维化组织中的表达及意义。方法将雄性Wistar大鼠简单随机化分组成假手术组,胆总管结扎7天组、14天组、28天组、42天组,采用胆总管结扎方法制备大鼠胆汁淤积肝纤维化模型。苏木精-伊红染色、Msaaon染色观察各组大鼠肝组织形态及胶原沉积情况,实时荧光定量聚合酶链反应(real-time quantitative polymerase chain reaction,RT-qPCR)测各组大鼠肝脏中α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、纤连蛋白(fibronectin,FN)等肝纤维化指标mRNA的表达变化,免疫组化法明确肝脏胶原蛋白Ⅰ(collagenⅠ)沉积情况,Western blot法检测各组肝组织内FN、collagenⅠ、胶原蛋白Ⅲ(collagenⅢ)、α-SMA和金属基质蛋白酶组织抑制因子1(tissue inhibitor of matrix metalloproteinase,TIMP1)等蛋白的表达,同时用免疫组化法及Western blot法检测各组肝组织内BMP-7及p-Smad1/5/8蛋白定位及表达量的变化。结果与假手术组比较,胆总管结扎组随着胆总管结扎时间延长,肝纤维化程度逐渐加重,肝内胶原增生明显,形成粗大的纤维间隔,肝组织内FN、α-SMA、collagenⅠ、collagenⅢ及TIMP1蛋白的表达明显增多,且差异有统计学意义(P<0.05),在肝纤维化组织内,BMP-7及p-Smad1/5/8蛋白在肝纤维化早期显著升高,随着纤维化程度加重,其表达逐渐减少,与假手术组比较,差异有统计学意义(P<0.05)。结论BMP-7/Smads信号通路在大鼠肝纤维化早期明显激活,作为一种保护性措施发挥内源性保护作用,而随着肝纤维化的进展,BMP-7/Smads信号通路的激活程度逐渐减弱,这一作用逐渐被削弱。

藤黄健骨丸调控BMP-2/Smad信号通路治疗绝经后骨质疏松症

目的观察藤黄健骨丸对绝经后骨质疏松症模型大鼠的治疗作用。方法将72只雌性大鼠随机分为6组,分别为假手术组(SHAM)、模型组(OVX)、仙灵骨葆胶囊组(XLGB)、藤黄健骨丸低剂量组(THJGW-L)、藤黄健骨丸中剂量组(THJGW-M)及藤黄健骨丸高剂量组(THJGW-H)。手术造模3 d后给药,除假手术组、模型组灌胃蒸馏水外,其余4组均按照相应剂量灌胃药物。连续灌胃8周后,分别检测大鼠术后各阶段体质量、子宫和肾脏重量、骨强度值,观察股骨病理变化。Western-blot法检测大鼠股骨中Runx2、BMP-2和Smad1蛋白表达水平。结果实验结果显示,藤黄健骨丸可以增加去卵巢大鼠的子宫和肾脏重量,能够提高去卵巢大鼠的股骨荷载力,改善骨微结构,增加钙离子沉积,增加骨细胞数量。Western-blot结果显示去势大鼠骨组织中Runx2、BMP-2和Smad1相对蛋白水平降低,经过藤黄健骨丸治疗后,Runx2、BMP-2和Smad1相对蛋白水平显著升高。结论藤黄健骨丸可以提高去势大鼠骨强度,改善骨组织形态,其作用机制可能与调控BMP-2/Smad信号通路来促进骨形成,对绝经后骨质疏松症有一定的治疗作用。

抑制BMP/Smad信号通路对水牛卵巢颗粒细胞生长和类固醇激素合成的影响

【目的】探究BMP/Smad信号通路对水牛卵巢颗粒细胞生长和类固醇激素合成的影响。【方法】利用脂质体转染的方法将合成的Smad 4基因的3对siRNAs(Smad4-siRNA1、Smad4-siRNA2和Smad4-siRNA3)和NC-siRNA(对照组)分别转染水牛颗粒细胞,通过实时荧光定量PCR检测Smad 4基因的表达水平,比较不同siRNA的干扰效率。然后利用筛选的干扰效率最高的siRNA,转染水牛卵巢颗粒细胞,通过CCK-8法检测对照组和干扰组细胞的增殖情况,实时荧光定量PCR检测上述两组细胞凋亡相关基因Bax和Bcl2,细胞周期相关调控基因CyclinD2和CDK4,以及类固醇激素合成相关基因Cyp19A1和Cyp11A1的表达水平,并通过ELISA检测雌二醇(E 2)和孕酮(P 4)的含量。【结果】基因干扰试验结果表明,3对siRNAs对Smad4基因的表达均具有极显著的干扰作用(P<0.01),其中Smad4-siRNA1的干扰效率最高,达到了64%。CCK-8检测结果显示,与对照组相比,干扰组细胞的增殖效率显著降低(P<0.05)。实时荧光定量PCR结果显示,与对照组相比,干扰组Bcl2、CyclinD2、CDK4和Cyp19A1基因的表达量均显著或极显著下调(P<0.05;P<0.01),而Cyp11A1基因的表达极显著上调(P<0.01),Bax基因的表达未受影响。ELISA检测结果表明,与对照组相比,干扰组雌二醇分泌量减少10.2%,孕酮的分泌量增加24.7%,差异均显著(P<0.05)。【结论】通过RNAi介导的Smad 4基因沉默对内源性BMP/Smad信号通路的中断不仅能够显著抑制水牛颗粒细胞的生长,而且能够诱导水牛颗粒细胞的凋亡,还会改变类固醇激素生成。BMP/Smad信号通路在调控水牛颗粒细胞生长和类固醇生成过程中具有重要的作用。

MiR-146a-5p targeting SMAD4 and TRAF6 inhibits adipogenensis through TGF-β and AKT/mTORC1 signal pathways in porcine intramuscular preadipocytes

Background: Intramuscular fat(IMF) content is a vital parameter for assessing pork quality. Increasing evidence has shown that microRNAs(miRNAs) play an important role in regulating porcine IMF deposition. Here, a novel miRNA implicated in porcine IMF adipogenesis was found, and its effect and regulatory mechanism were further explored with respect to intramuscular preadipocyte proliferation and differentiation.Results: By porcine adipose tissue miRNA sequencing analysis, we found that miR-146a-5p is a potential regulator of porcine IMF adipogenesis. Further studies showed that miR-146a-5p mimics inhibited porcine intramuscular preadipocyte proliferation and differentiation, while the miR-146a-5p inhibitor promoted cell proliferation and adipogenic differentiation. Mechanistically, miR-146a-5p suppressed cell proliferation by directly targeting SMAD family member 4(SMAD4) to attenuate TGF-β signaling. Moreover, miR-146a-5p inhibited the differentiation of intramuscular preadipocytes by targeting TNF receptor-associated factor 6(TRAF6) to weaken the AKT/mTORC1 signaling downstream of the TRAF6 pathway.Conclusions: MiR-146a-5p targets SMAD4 and TRAF6 to inhibit porcine intramuscular adipogenesis by attenuating TGF-β and AKT/mTORC1 signaling, respectively. These findings provide a novel miRNA biomarker for regulating intramuscular adipogenesis to promote pork quality.

BMP-2/Smads/Osterix信号在氟化钠诱导大鼠成骨细胞增殖分化中的作用研究

目的探讨氟化钠对大鼠颅骨成骨细胞增殖分化的影响,并进一步研究BMP-2/Smads/Osterix信号的调控机制。方法选择新生SD大鼠(24 h以内)颅骨,分离大鼠颅骨中的成骨细胞,进行体外原代培养。分别用不同浓度的氟化钠作用于成骨细胞,用噻唑蓝(MTT)、碱性磷酸酶观察氟化钠对大鼠成骨细胞的影响,并用蛋白印迹法测定BMP-2蛋白、Smad1/5/9蛋白、Osterix蛋白的表达。结果与对照组相比,低剂量的氟化钠(0.25mmol/L、0.50 mmol/L)暴露于成骨细胞,成骨细胞增殖明显、碱性磷酸酶活性增强,而当高剂量的氟化钠(2.00mmol/L、4.00 mmol/L)刺激成骨细胞,成骨细胞的增殖明显受到抑制、碱性磷酸酶活性降低;与对照组比较,低剂量氟化钠浓度为0.50 mmol/L时,BMP-2蛋白、Smad1/5/9蛋白、Osterix蛋白的表达水平显著升高,差异有统计学意义(P<0.05)。结论低浓度氟化钠可通过BMP-2/Smads/Osterix信号促进大鼠成骨细胞的增殖和分化,高浓度氟化钠则抑制成骨细胞的增殖分化。

SPOC domain of mint protein induces hematopoietic differentiation via Bmp4/Smad5 pathway

Mint is a newly identified molecule that mediates signal transduction and modulates chromatin repression. Mint family members contain a highly conserved C-terminus SPOC domain (SpenParalog and OrthologsC-terminal domain) commonly associated with proliferation and related diseases (for example: cancer) due to its role in cell differentiation and apoptosis. In this study, we addressed the SPOC function using a tetracycline-inducible system to express the target domain in Ain V15 embryonic ES cells and bone marrow stem cells from SPOC transenic mice. In vitro differentiation of Ain V15 ES cells as a model of early hematopoietic development, we found expression of SPOC domain induces hematopoietic differentiation via up-regulation of transcription factors Bmp4 and Smad5, which induce the expression of hematopoietic factors Eklf1 and hematopoietic proliferation associated factor Gata2, the SPOC domain also plays the regulation function in the differentiation of hematopoitic progenitor by colony forming Unit (CFU) assays. Further, we determined SPOC expression enhances erythrocyte and granulocyte maturationusing bone marrow cells derived from tiSPOC chimeric mice. Finally, we identified that overexpression of full length Mint in ES cells drive Smad5 and Bmp4 up-regulation under culture conditions, and up-regulation of endogenous Mint when induceshematopoitic differentiation of EML, M1 and WT18 cells. In summary, our study reveals the conserved SPOC domain of Mint protein induces differentiation both in the stages of embryonic stem cells and hematopoietic progenitor cells.

Research status of E3 ubiquitin ligase Smurf2 and related signaling pathways in glioma

Glioma is the tumor with the highest incidence in the brain,and it is eager to seek new and efiective treatment.The interaction of ubiquitination and deubiquitination regulates many cell activities in organisms,and participates in tumor occurrence,development,migration,invasion and other processes.This article summarized the progress of E3 ubiquitination ligase smad ubiquitination regulatory factor 2(Smurf2)and glioma-related signaling pathways to assist clinical diagnosis and treatment of glioma.

BMP/Smad信号通路与哺乳动物卵泡发生

BMPs属于TGF-β超家族成员,在调节哺乳动物的生长、细胞增殖和分化等方面有很广泛的生物学功能。越来越多的证据显示,BMPs在雌性哺乳动物生殖,尤其在卵泡发生过程中发挥重要作用。Smads蛋白是BMP家族细胞内信号转导分子,可将BMPs胞外信号从细胞膜传递入细胞核。文章对BMPs、BMP/Smad信号通路和BMP如何被调节进行概述,并重点对BMP/Smad信号通路在卵泡发生过程中所起的调控作用进行综述。