Gga-miRNA-181-5p family facilitates chicken myogenesis via targeting TGFBR1 to block TGF-βsignaling

MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two chicken(Gallus gallus;Gga)miR-181-5p family members widely expressed in various tissues,specifically miR-181a-5p and miR-181b-5p.Besides,the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers.Functionally,miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including myogenin(MyoG),myogenic differentiation 1(MyoD1),and myosin heavy chain(MyHC),meanwhile accelerating the myotube formation of skeletal muscle satellite cells(SMSCs).Mechanistically,miR-181a-5p and miR-181b-5p directly bind to the 3′untranslated region(UTR)of the transforming growth factor beta receptor 1(TGFBR1)mRNA,further reducing the expression of TGFBR1.TGFBR1 is a key Transforming growth factor beta(TGF-β)signaling transduction receptor and had a negative function in muscle cell differentiation.Furthermore,knockdown of TGFBR1 facilitated the expression of chicken myogenic factors,boosted myotube formation,and decreased the SMAD family member 2/3(SMAD2/3)phosphorylation in chicken SMSCs.SMAD2/3 are downstream of TGF-βsignaling,and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation.Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-βsignaling transduction,which resulted in promoting chicken skeletal muscle development.

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.

Effects of Cigu Xiaozhi Formula on miR-378a-3p Expression and Hh Signaling Pathway in TGF-β1 Induced LX2 Cells

[Objectives]To observe the effects of Cigu Xiaozhi Formula on miR-378a-3p expression and Hh signaling pathway in TGF-β1 induced and activated LX2 cells.[Methods]Cells were divided into control group,induction group,drug-containing serum group,miR-378a-3p inhibitor group,and miR inhibitor NC group.CCK-8 method was used to detect the cell viability of each group,and flow cytometry was used to detect the apoptosis rate of each group.RT-qPCR was used to detect the expression of miR-378a-3p in each group s cells,and RT-qPCR and Western blot were used to detect mRNA and protein expression of Shh,Gli1,Gli2,Col-I,andα-SMA in each group s cells.[Results]Compared with the control group,the cell viability and expression of Shh,Gli1,Gli2,Col-I,andα-SMA mRNA and protein in induction group increased(P<0.01),while the expression of miR-378a-3p decreased(P<0.01).Compared with the induction group,the cell viability and expression of Shh,Gli1,Gli2,Col-I,α-SMA mRNA andα-SMA and Gli2 protein decreased in drug-containing serum group(P<0.05),while cell apoptosis rate and miR-378a-3p expression increased(P<0.01).In miR-378a-3p inhibitor group,cell viability and the expression of Shh,Gli1,Gli2,Col-I,α-SMA mRNA and Gli1,Gli2,α-SMA protein increased(P<0.05,P<0.01),while the apoptosis rate and miR-378a-3p expression decreased(P<0.05,P<0.01).[Conclusions]Cigu Xiaozhi Formula containing serum can upregulate miR-378a-3p expression and downregulate the expression of Gli2 andα-SMA in TGF-β1 induced LX2 cells,thereby inhibiting the activation of LX2 cells and exerting the effects of anti liver fibrosis.

Inhibition of colorectal cancer by ursolic acid via noncanonical Hedgehog signaling pathway

OBJECTIVE To identify the inhibitory effect of ursolic acid on the colorectal cancer HCT116 cells in vitro and in vivo,and to explore the underlying mechanism.METHODS The smoothened(SMO)gene-silenced human colorectal cancer HCT116^(hSMO)cell line was established by transfection with the lentivirus carrying SMO shRNA.The cytotoxic effect of ursolic acid on HCT116^(hSMO)cells was determined by MTT assay.The effect of ursolic acid on the migration of HCT116^(hSMO)cells was studied by wound healing assay.The effect of ursolic acid on apoptosis of HCT116^(hSMO)cells was explored by Hoechst33342/PI double staining and flow cytometry.The effects of ursolic acid on the expressions of apoptotic marker gene Bcl-2,Bax,caspase-3 and caspase-9 were measured by real-time quantitative RT-PCR(RT-qPCR)and Western blotting(WB)analysis.RT-qPCR and WB were used to examine the relationship between GLI1,c-Myc expression and PI3K/Akt pathway to further investigate the mechanism of GLI1 activation in HCT116^(hSMO)cells.The effects of ursolic acid on the expressions of GLI1,p-Akt,Akt,c-Myc,SHH and SUFU of noncanonical Hedgehog pathway were evaluated by RT-qPCR and WB assays.Xenograft nude mouse model bearing HCT116^(hSMO)cells was established and intraperitoneally treated with ursolic acid to investigate the effect on tumor growth in vivo.The body weight and tumor size of mice were assessed regularly every 2 d.The effect of ursolic acid on the apoptosis of tumor tissue was determined by TUNEL assay.The expressions of Bcl-2,Bax,GLI1,p-Akt,Akt,c-Myc,SHH,SUFU mRNA and proteins were measured by RT-qPCR and WB.The levels of Bcl-2,Bax,GLI1,p-Akt,c-Myc and SHH proteins in tumor tissues were also evaluated by immunohistochemistry.RESULTS Ursolic acid significantly inhibited the growth and migration of HCT116^(hSMO)cells in vitro,compared with the control(P<0.05).Meanwhile,ursolic acid also induced apoptosis of HCT116^(hSMO)cells in vitro(P<0.05).Furthermore,SC79(Akt activator)enhanced the expressions of p-Akt,GLI1 and c-Myc,which could be abolished by ursolic acid,and the effect was equal to Akt inhibitor LY294002.The expressions of Bcl-2,GLI1,p-Akt,c-Myc,SHH mRNA and proteins were reduced by ursolic acid,while the levels of Bax and SUFU were increased.Ursolic acid could inhibit the growth and induce the apoptosis of colorectal cancer xenograft in vivo.Similarly,lower levels of Bcl-2,GLI1,p-Akt,c-Myc and SHH,and higher expression of Bax and SUFU were noted in ursolic acid-treated mice.CONCLUSION Ursolic acid can inhibit the growth and induce apoptosis of HCT116^(hSMO)cells both in vitro and in vivo.And the mechanism is related to the suppression of PI3K/Akt-mediated noncanonical Hedgehog signaling pathway.

Ski and SnoN, potent negative regulators of TGF-β signaling

Ski and the closely related SnoN were discovered as oncogenes by their ability to transform chicken embryo fibroblasts upon overexpression. While elevated expressions of Ski and SnoN have also been reported in many human cancer cells and tissues, consistent with their pro-oncogenic activity, emerging evidence also suggests a potential anti-oncogenic activity for both. In addition, Ski and SnoN have been implicated in regulation of cell differentiation, especially in the muscle and neuronal lineages. Multiple cellular partners of Ski and SnoN have been identifed in an effort to understand the molecular mechanisms underlying the complex roles of Ski and SnoN. In this review, we summarize recent findings on the biological functions of Ski and SnoN, their mechanisms of action and how their levels of expression are regulated.

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.

Phospho-control of TGF-β superfamily signaling

Members of the transforming growth factor-β （TGF-β） family control a broad range of cellular responses in metazoan organisms via autocrine, paracrine, and endocrine modes. Thus, aberrant TGF-β signaling can play a key role in the pathogenesis of several diseases, including cancer. TGF-β signaling pathways are activated by a short phospho-cascade, from receptor phosphorylation to the subsequent phosphorylation and activation of downstream signal transducers called R-Smads. R-Smad phosphorylation state determines Smad complex assembly/disassembly, nuclear import/export, transcriptional activity and stability, and is thus the most critical event in TGF-β signaling. Dephosphorylation of R-Smads by specific phosphatases prevents or terminates TGF-β signaling, highlighting the need to consider Smad （de）phosphorylation as a tightly controlled and dynamic event. This article illustrates the es- sential roles of reversible phosphorylation in controlling the strength and duration of TGF-β signaling and the ensu- ing physiological responses.

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.

Role of TGF-βl Signaling in Heart Valve Calcification Induced by Abnormal Mechanical Stimulation in a Tissue Engineering Model

A tissue engineering model of heart valve calcification induced in a bio-reactor was established to evaluate the calcification induced by abnormal mechanical stimulation and explore the underlying molecular mechanisms.Polyethylene glycol (PEG)-modified decellularized porcine aortic leaflets seeded with human valve interstitial cells (huVICs)were mounted on a Ti-Ni alloy frame to fabricate two-leaflet and three-leaflet tissue engineered valves.The two-leaflet model valves were exposed to abnormal pulsatile flow stimulation with null (group A),low (1000mL/min,group B),medium (2000mL/min,group C),and high velocity (3000mL/min,group D)for 14 days. Morphology and calcification were assessed by yon Kossa staining,alkaline phosphatase (ALP)content,and Runx2 immunostaining.Leaflet calcification and mRNA and protein expression of transforming growth factor (TGF)-β1,bone morphogenetic protein 2 (BMP2),Smadl,and MSX2 were measured at different time points.ALP content was examined in two-leaflet valves seeded with BMP2 shRNA plasmid-infected huVICs and exposed to the same stimulation conditions.The results showed that during 14 days of flow stimulation,huVICs on the leaflet surface proliferated to generate normal monolayer coverage in groups A,B,and C.Under mechanical stimulation,huVICs showed a parallel growth pattern in the direction of the fluid flow,but huVICs exhibited disordered growth in the high-velocity flow environment,yon Kossa staining,ALP measurement,and immunohistochemical staining for Runx2 confirmed the lack of obvious calcification in group A and significant calcification in group D.Expression levels of TGF-β1,BMP2, and MSX2 mRNA and protein were increased under fluid stimulation.ALP production by BMP2 shRNA plasmid-infected huVICs on model leaflets was significantly reduced.In conclusion,abnormal mechanical stimulation in a bioreactor induced calcification in the tissue engineering valve model.The extent of calcification correlated positively with the flow velocity,as did the mRNA and protein levels of TGF-β1,BMP2,and MSX2.These findings indicate that TGF-β1/BMP2 signaling is involved in valve calcification induced bv abnormal mechanical stimulation.

Canonical and noncanonical Wnt signaling: Multilayered mediators, signaling mechanisms and major signaling crosstalk

Wnt signaling plays a major role in regulating cell proliferation and differentiation.The Wnt ligands are a family of 19 secreted glycoproteins that mediate their signaling effects via binding to Frizzled receptors and LRP5/6 coreceptors and transducing the signal either throughβ-catenin in the canonical pathway or through a series of other proteins in the nonca-nonical pathway.Many of the individual components of both canonical and noncanonical Wnt signaling have additional functions throughout the body,establishing the complex interplay between Wnt signaling and other signaling pathways.This crosstalk between Wnt signaling and other pathways gives Wnt signaling a vital role in many cellular and organ processes.Dys-regulation of this system has been implicated in many diseases affecting a wide array of organ systems,including cancer and embryological defects,and can even cause embryonic lethality.The complexity of this system and its interacting proteins have made Wnt signaling a target for many therapeutic treatments.However,both stimulatory and inhibitory treatments come with potential risks that need to be addressed.This review synthesized much of the current knowl-edge on the Wnt signaling pathway,beginning with the history of Wnt signaling.It thoroughly described the different variants of Wnt signaling,including canonical,noncanonical Wnt/PCP,and the noncanonical Wnt/Ca2+pathway.Further description involved each of its components and their involvement in other cellular processes.Finally,this review explained the various other pathways and processes that crosstalk with Wnt signaling.

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.

Regulation Mechanism of TFP on TGF-β1/STAT3 Signaling Pathway in Immune-mediated Liver Injury in Mice

[Objectives]To study the effect of total flavonoids extracted from Polygonum perfoliatum L.(TFP)on immune-mediated liver injury induced by bacillus Calmette-Guerin plus lipopolysaccharide(BCG+LPS)in mice,and to explore its action mechanism.[Methods]60 Kunming mice were divided into normal group,model group,control group(bifendate)and TFP low,medium and high dose groups according to random number table method,with 10 mice in each group.On the first day of modeling,mice were injected with 0.2 mL of BCG solution(12.5 mg/mL)through the tail vein,and on the eleventh day,0.2 mL of LPS(37.5μg/mL)were injected into the tail vein to prepare a mouse model of immune-mediated liver injury;from the first day of modeling,the normal group and the model group were administered intragastrically with the corresponding volume of distilled water,and the bifendate group and the TFP high,medium,and low dose groups were administered intragastrically with the corresponding doses once a day for 11 d.After the last time administration,fasting but giving water for 16 h,took blood from eyes,then collected the liver tissue.The levels of alanine transaminase(ALT)and aspartate transaminase(AST)in serum were detected by biochemical method;transforming growth factor-β1(TGF-β1),intercellular adhesion molecule-1(ICAM-1),interleukin-6(IL-6)and interleukin-1β(IL-1β)expression levels in liver tissue were detected by enzyme-linked immunosorbent assay(ELISA);phosphorylated protein tyrosine kinase JAK-2(p-JAK2),phosphorylated signal transducer and activator of transcription 3(p-STAT3)protein expression levels were detected by Western Blot method;the degree of liver tissue lesions was detected by HE staining.[Results]Compared with the model group,the levels of ALT and AST in the serum of mice in each dose group of TFP(high dose 600 mg/kg,medium dose 400 mg/kg,and low dose 200 mg/kg)were reduced,and the activities of T-SOD and GSH-Px were increased;the content or expression ofβ1,ICAM-1,IL-6,IL-1βdecreased,and the expression of p-JAK2 and p-STAT3 protein decreased;pathological sections showed that the degree of inflammatory necrosis and the degree of lesions in the liver tissues of each dose group of TFP were reduced by varying degrees.[Conclusions]TFP has a protective effect on BCG+LPS-induced immune-mediated liver injury in mice.The mechanism may be related to regulating the phosphorylation level of JAK2 and inhibiting the inflammatory reaction,thereby regulating the TGF-β1/STAT3 signaling pathway and improving the immune-mediated liver injury.

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 signaling in mesenchymal stem cell differentiation and bone formation

Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.

Tea domain transcription factor TEAD4 mitigatesTGF-β signaling and hepatocellular carcinomaprogression independently of YAP

Tea domain transcription factor 4 (TEAD4) plays a pivotal role in tissue development and homeostasis by interacting with Yesassociated protein (YAP) in response to Hippo signaling inactivation. TEAD4 and YAP can also cooperate with transforminggrowth factor-β (TGF-β)-activated Smad proteins to regulate gene transcription. Yet, it remains unclear whether TEAD4 playsa YAP-independent role in TGF-β signaling. Here, we unveil a novel tumor suppressive function of TEAD4 in liver cancer viamitigating TGF-β signaling. Ectopic TEAD4 inhibited TGF-β-induced signal transduction, Smad transcriptional activity, and targetgene transcription, consequently suppressing hepatocellular carcinoma cell proliferation and migration in vitro and xenografttumorgrowth in mice. Consistently, depletion of endogenous TEAD4 by siRNAs enhanced TGF-β signaling in cancer cells. Mechanistically,TEAD4 associates with receptor-regulated Smads (Smad2/3) and Smad4 in the nucleus, thereby impairing the binding of Smad2/3to the histone acetyltransferase p300. Intriguingly, these negative effects of TEAD4 on TGF-β/Smad signaling are independent ofYAP, as impairing the TEAD4–YAP interaction through point mutagenesis or depletion of YAP and/or its paralog TAZ has little effect.Together, these results unravel a novel function of TEAD4 in fine tuning TGF-β signaling and liver cancer progression in a YAPindependent manner.

TGF-β-induced epithelial to mesenchymal transition

During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition （MET）. While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins （BMPs）, and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms.

Smad3 mediates immediate early induction of Idl by TGF-β

Idl is a member of the inhibitor of differentiation （Id） protein family that regulates a wide range of cell functions. Previous studies have shown that expression of the Idl gene is down-regulated by TGF-β in epithelial cells, whereas it is up-regulated by BMP in a variety of cell types. During our study of the biological function of TGF-β1, we found that Idl can be strongly up-regulated by TGF-β1 in the human mammary gland epithelial cell line MCF10A. Quantitative real-time RT-PCR has revealed as high as 7.5-fold induction ofldl mRNA by TGF-β1 in MCF10A cells after 1 h of TGF-β1 stimulation, and this induction does not require de novo protein synthesis. Using Smad knockdown and knockout approaches, we have identified Smad3 as the responsible R-Smad for mediating transcriptional activation of the Idl gene. Chromatin immunoprecipitation assay confirms that Smad3 and Smad4 bind to the upstream region of the Idl gene. Our results demonstrate that Smad3, but not Smad2, mediates TGF-β1-dependent early transcriptional induction of Idl.

Role of transforming growth factor-beta1-smad signal transduction pathway in patients with hepatocellular carcinoma

AIM： To explore the role of transforming growth factorbeta1 （TGF-β1）-smad signal transduction pathway in patients with hepatocellular carcinoma. METHODS： Thirty-six hepatocellular carcinoma specimens were obtained from Qidong Liver Cancer Institute and Department of Pathology of the Second Affiliated Hospital of Nanjing Medical University. All primary antibodies （polyclonal antibodies） to TGF-β1, type H Transforming growth factor-beta receptor （TβR-Ⅱ）, nuclear factor-kappaB （NF-KB）, CD34, smad4 and smad7, secondary antibodies and immunohistochemical kit were purchased from Zhongshan Biotechnology Limited Company （Beijing, China）. The expressions of TGF-β1, TβR-Ⅱ, NF- KB, smad4 and smad7 proteins in 36 specimens of hepatocellular carcinoma （HCC） and its adjacent tissue were separately detected by immunohistochemistry to observe the relationship between TGF-β1 and TβR-Ⅱ, between NF-KB and TGF-β1, between smad4 and smad7 and between TGF-β1 or TβR-Ⅱ and microvessel density （MVD）. MVD was determined by labelling the vessel endothelial cells with CD34. RESULTS： The expression of TGF-β1, smad7 and MVD was higher in HCC tissue than in adjacent HCC tissue （P〈0.01, P〈0.05,P〈0.01 respectively）. The expression of TβR-Ⅱ and smad4 was lower in HCC tissue than in its adjacent tissue （P〈0.01, P〈0.05 respectively）. The expression of TGF-β1 protein and NF-KB protein was consistent in HCC tissue. The expression of TGF-β1 and MVD was also consistent in HCC tissue. The expression of TIER- Ⅱ was negatively correlated with that of MVD in HCC tissue. CONCLUSION： The expressions of TGF-IB1, TβR- Ⅱ, NF-KB, smad4 and smad7 in HCC tissue, which are major up and down stream factors of TGF-β1-smad signal transduction pathway, are abnormal. These factors are closely related with NVD and may play an important role in HCC angiogenesis. The inhibitory action of TGF-β1 is weakened in hepatic carcinoma cells because of abnormality of TGF-β1 receptors （such as TIBR- Ⅱ） and postreceptors （such as smad4 and smad7）. NF-KB may cause activation and production of TGF-β1.

Celastrol Protects TGF-β1-induced Endothelial-mesenchymal Transition

The endothelial-to-mesenchymal transition（End MT） in endothelial cells contributes to the development of cardiac fibrosis,ultimately leading to cardiac remodeling.In this study,the effects and molecular mechanisms of celastrol（CEL） on transforming growth factor-β1（TGF-β1）-induced End MT in human umbilical vein endothelial（HUVEC-12） cells were investigated.The presented data demonstrated that CEL significantly blocked the morphology change of HUVEC-12 cells induced by TGF-β1 without cell cytotoxicity.In accordance with these findings,CEL blocked TGF-β1-induced EndM T as evidenced by the inhibition of the mesenchymal markers,including collagen Ⅰ,Ⅲ,α-SMA,fibronectin m RNA expression,and the increase in the m RNA expression of endothelial cell marker CD31.These changes were also confirmed by double immunofluorescence staining of CD31 and vimentin.The in vitro scratch assay showed that CEL inhibited the migration capacity of the transitioned endothelial cells induced by TGF-β1.Further experiments showed that the beneficial effect of CEL on blocking the End MT in HUVEC-12 cells was associated with the suppression of the TGF-β1/Smads signalling pathway,which was also confirmed by the inhibition of its downstream transcription factor snail1,twist1,twist2,ZEB1 and ZEB2.These results indicate that CEL blocks TGF-β1-induced End MT through TGF-β1/Smads signalling pathway and suggest that it may be a feasible therapy for cardiac fibrosis diseases.