Transforming growth factor-beta 1 enhances discharge activity of cortical neurons

Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system diseases.The neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may depend on the pathological process and cell types involved.Voltage-gated sodium channels(VGSCs)are essential ion channels for the generation of action potentials in neurons,and are involved in various neuroexcitation-related diseases.However,the effects of TGF-β1 on the functional properties of VGSCs and firing properties in cortical neurons remain unclear.In this study,we investigated the effects of TGF-β1 on VGSC function and firing properties in primary cortical neurons from mice.We found that TGF-β1 increased VGSC current density in a dose-and time-dependent manner,which was attributable to the upregulation of Nav1.3 expression.Increased VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase(PD98059),p38 mitogen-activated protein kinase(SB203580),and Jun NH2-terminal kinase 1/2 inhibitor(SP600125).Interestingly,TGF-β1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical neurons.These findings suggest that TGF-β1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway,which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological conditions.Thus,this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.

Role of transforming growth factor-βin peripheral nerve regeneration

Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.

Telencephalic stab wound injury induces regenerative angiogenesis and neurogenesis in zebrafish:unveiling the role of vascular endothelial growth factor signaling and microglia

After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact are not well understood.In this work,we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury.To this end,we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms.First,using the Tg(fli1:EGFP×mpeg1.1:mCherry)zebrafish line,which enables visualization of blood vessels and microglia respectively,we analyzed regenerative angiogenesis from 1 to 21 days post-lesion.In parallel,we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry.We found that after brain damage,the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor(vegfaa and vegfbb)were increased.At the same time,neural stem cell proliferation was also increased,peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis,along with the recruitment of microglia.Then,through pharmacological manipulation by injecting an anti-angiogenic drug(Tivozanib)or Vegf at the lesion site,we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes,as well as microglial recruitment.Finally,we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis,as previously described,as well as injury-induced angiogenesis.In conclusion,we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process.In addition,we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes.This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.

Transforming growth factor-β1 and vascular endothelial growth factor levels in senile acute myeloid leukemia and correlation with prognosis

BACKGROUND Acute myeloid leukemia(AML)is a disease in which immature hematopoietic cells accumulate in the bone marrow and continuously expand,inhibiting hematopoiesis.The treatment and prognosis of this disease have always been unsatisfactory.AIM To investigate the correlation between vascular endothelial growth factor(VEGF)and transforming growth factor-β1(TGFβ1)expression and prognosis in older adults with AML.METHODS This study enrolled 80 patients with AML(AML group),including 36 with complete response(AML-CR),23 with partial response(AML-PR),and 21 with no response(AML-NR).The expression levels of VEGF and TGFβ1 were detected by reverse transcription polymerase chain reaction in bone marrow mononuclear cells isolated from 56 healthy controls.Kaplan-Meier analysis was performed to assess overall survival(OS)and progression-or disease-free survival(DFS).Prognostic risk factors were analyzed using a Cox proportional hazards model.RESULTS The AML group showed a VEGF level of 2.68±0.16.VEGF expression was lower in patients with AML-CR than those with AML-PR or AML-NR(P<0.05).TGFβ1 expression in the AML group was 0.33±0.05.Patients with AML-CR showed a higher TGFβ1 expression than those with AML-PR or AML-NR(P<0.05).VEGF and TGFβ1 expression in patients with AML was significantly correlated with the counts of leukocytes,platelets,hemoglobin,and peripheral blood immature cells(P<0.05);Kaplan-Meier survival analysis revealed that patients with high TGFβ1 expression had better OS and DFS than those with low TGFβ1 expression(P<0.05),whereas patients with low VEGF levels showed better OS and DFS than those with high VEGF levels(P<0.05).VEGF,TGFβ1,and platelet count were identified by the Cox proportional hazards model as independent risk factors for OS(P<0.05),while VEGF,TGFβ1,and white blood cell count were independent risk factors for DFS(P<0.05).CONCLUSION Decreased VEGF expression and increased TGFβ1 expression in patients with AML provide valuable references for determining and individualizing clinical treatment strategies.

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.

LOW DOSE PIRFENIDONE SUPPRESSES TRANSFORMING GROWTH FACTOR BETA-1 AND TISSUE INHIBITOR OF METALLOPROTEINASE-1, AND PROTECTS RATS FROM LUNG FIBROSIS INDUCED BY BLEOMYCIN

Objective To investigate the optimal dosage of pirfenidone for the treatment of pulmonary fibrosis induced by bleomycin in Wistar rats, and the alteration of expressions of transforming growth factor beta-1 （ TGF-β1 ）, tissue inhibitor of metalloproteinase-1 （ TIMP-1 ）, and matrix metalloproteinase-13 （ MMP-13 ） in lung tissue. Methods Male Wistar rats were endotracheally instilled with bleomycin or normal saline. Pirfenidone （25-800 mg · kg^-l · d^-1 ）, dexamethasone （3 mg/kg）, or 1% carboxymethylcellulose sodium were given daily by feed 2 days before instillation of bleomycin. Groups T7 and T14 were fed pirfenidone 50 mg · kg^-1 · d^-1 at 7 days or 14 daYs after bleomycin instillation. Lungs were harvested at 28 days after bleomycin instillation. Patholological changes in luffg tissues were evaluated with HE staining. Lung collagen was stained by sirius red and measured by content of hydroxypro- line. Expression of proteins of TGF-β1 TIMP-1, and MMP-13 were detected by Western blotting. Results At doses of 25, 50, and 100 mg· kg^- 1 · d ^- 1, pirfenidone had significant anti-fibrotic effects for bleomy- cin-induced rat pulmonary fibrosis, and these effects were most significantly attenuated at the dosage of 50 mg · kg^-1 ·d^ -1（ HE： P 〈 0. 01, P 〈 0.01, and P = 0.064; sirius red： P 〈0.05, P 〈 0.01, and P 〈 0.05 ; hydroxyproline： P = 0.595, P 〈 0.01, and P = 0.976）. Pirfenidone at a dosage of 50 mg · kg^- l · d^-1 inhibited protein expression of TGF-131 and TIMP-1 in lung tissue in the early phase （0.79 and 0.75 times of control group）, but had no effect on ex- nr^eelnn nf MMP-13. Conclusion Low dose pirfenidone, especially at dosage of 50 mg · kg^-1 · d^-1, has significant anti-fibrotic effects on bleomycin-induced rat pulmonary fibrosis. Pirfenidone partially inhibits the enhancement of the expression of TGF-131 and TIMP-β1 in lung tissue.

Quantitative analysis of transforming growth factor beta 1 mRNA in patients with alcoholic liver disease

AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics were grouped by clinical findings into four groups: alcohol abusers without liver impairment (n =22), alcoholic steatosis (n =30); alcoholic hepatitis (n=31); and alcoholic cirrhosis(n=24). Using peripheral blood mononuclear cells (PBMC) as samples the gene expression of TGF-beta 1 was examined quantitatively by reverse transcription polymerase chain reaction (RT-PCR) and dot blot. There are 34 healthy subjects served as control. RESULTS: The expression of TGF-beta 1 from all ALD patients was significantly greater than that in controls (1.320 +/- 1.162 vs 0.808 +/- 0.276, P【0.001). The differences of the expressions were significant between the patients from each groups (alcoholic steatosis, alcoholic hepatitis and alcoholic cirrhosis) and the controls (1.168 +/- 0.852, 1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.808 +/- 0.276, P【0.050). No significant differences of TGF -beta 1 mRNA expression were observed between alcohol abusers without liver impairment and controls. The expressions in patients with alcoholic hepatitis and alcoholic cirrhosis were significantly greater than that in alcohol abusers respectively (1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.841 +/- 0.706, P【0.050). No significant differences of TGF-beta 1 mRNA expression were observed between alcoholic fatty liver men and alcohol abusers. CONCLUSION: TGF-beta 1 expression level can be a risk factor for alcoholic liver disease and might be related to the inflammatory activity and fibrosis of the liver in patients.

Stage-specific localization of transforming growth factor β1 and β3 and their receptors during spermatogenesis in men

Aim: To investigate the stage-specific localization of transforming growth factor (TGF) β1 and β3 during spermatogenesis in adult human testis. Methods: The localization of TGFβ1 and β3 was investigated by immunohis tochemical staining method employing specific polyclonal antibodies. Results: Both TGFβ1 and β3 and their recep tors were preponderant in the Leydig celis. TGFβ1 could not be detected in the seminiferous tubules. TGFβ3 and TGFβ-Receptor (R) I were mainly seen in the elongated spermatids, while TGFβ-RⅡ in the pachytene spermatocytes and weak in the spermatogonia, spermatids and Sertoli celis. Only TGFβ-RⅡ was detected in the Sertoli celis. TGFβ3, TGFβ-RⅠ and TGFβ-RⅡ showed a staining pattern dependent upon the stages of the seminiferous epithelium cycle. Conclusion: TGFβ isoforms and their receptors are present in the somatic and germ celis of the adult human testis, suggesting their involvement in the regulation of spermatogenesis.

Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and transdifferentiation

AIM: To explore different roles of TGF-β (transforming growth factor beta) and bone morphogenetic proteins (BMPs)in hepatic stellate cell proliferation and trans-differentiation.METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA).RESULTS: The results indicated that TGF-β1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGFβ1 and BMPs. However, BMPs was more potent at transdifferentiation of hepatic stellate cells than TGF-β1. In addition, we observed that TGF-β1 transient reduced the abundance of SMA in hepatic stellate cells.CONCLUSION: TGF-β may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell transdifferentiation.

PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

Transforming growth factor-β1 induces intestinal myofibroblast differentiation and modulates their migration

AIM： To investigate the effects of transforming growth factor β1 （TGF-β1） on the differentiation of colonic lamina propria fibroblasts （CLPF） into myofibroblasts in vitro.METHODS： Primary CLPF cultures were incubated with TGF-β1 and analyzed for production of m-smooth muscle actin （α-SMA）, fibronectin （FN） and FN isoforms. Migration assays were performed in a modified 48-well Boyden chamber. Levels of total and phosphorylated focal adhesion kinase （FAK） in CLPF were analyzed after induction of migration.did not change α-SMA levels, while TGF-β1 treatment for 6 d significantly increased α-SIVlA production. Short term incubation （6 h） with TGF-β1 enhanced CLPF migration, while long term treatment （6 d） of CLPF with TGF-β1 reduced migration to 15%-37% compared to untreated cells. FN and FN isoform mRNA expression were increased after short term incubation with TGF-β1 （2 d） in contrast to long term incubation with TGF-β1 for 6 d. After induction of migration, TGF-β1-preincubated CLPF showed higher amounts of FN and its isoforms and lower levels of total and phosphorylated FAK than untreated cells.CONCLUSION： Long term incubation of CLPF with TGF-β1 induced differentiation into myofibroblasts with enhanced α-SMA, reduced migratory potential and FAK phosphorylation, and increased FN production. In contrast, short term contact （6 h） of fibroblasts with TGF-β1 induced a dose-dependent increase of cell migration and FAK phosphorylation without induction of α-SMA production.

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway

AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

Roles of Smad3 and Smad7 in rat pancreatic stellate cells activated by transforming growth factor-beta 1

BACKGROUND: Pancreatic stellate cells (PSCs) play a major role in promoting pancreatic fibrosis. Transforming growth factor beta 1 (TGF-beta 1) is a critical mediator of this process. This study aimed to determine the expression of the Smad3 and Smad7 genes in the process of PSC activation, and explore the mechanisms of chronic pancreatitis. METHODS: The expressions of Smad3 and Smad7 in PSCs before and after TGF-beta 1 treatment were detected by reverse transcription-polymerase chain reaction and Western blotting analysis. Smad3 expression was detected in PSCs after treatment with 5 ng/ml of TGF-beta 1 for 24 hours. RESULTS: Smad7 expression was decreased in TGF-beta 1 -activated PSCs (P<0.05) in a dose-dependent manner. When TGF-beta 1 concentration reached 10 ng/ml, the expression of p-Smad3, Smad3, and Smad7 was inhibited (P<0.05). CONCLUSIONS: TGF-beta 1 promotes the expression of Smad3 and inhibits the expression of Smad7 during the activation of PSCs. In contrast, high-dose TGF-beta 1 downregulates the expression of Smad3 in completely activated PSCs.

Transforming growth factor beta 1, a cytokine with regenerative functions

We review the biology and role of transforming growth factor beta 1 （TGF-β1） in peripheral nerve injury and regeneration, as it relates to injuries to large nerve trunks （i.e., sciatic nerve, brachial plexus）, which often leads to suboptimal functional recovery. Experimental studies have suggested that the reason for the lack of functional recovery resides in the lack of sufficient mature axons reaching their targets, which is a result of the loss of the growth-supportive environment provided by the Schwann cells in the distal stump of injured nerves. Using an established chronic nerve injury and delayed repair animal model that accu- rately mimics chronic nerve injuries in humans, we summarize our key findings as well as others to better understand the pathophysiology of poor functional recovery. We demonstrated that 6 month TGF-β1 treat- ment for chronic nerve injury significantly improved Schwann cell capacity to support axonal regeneration. When combined with forskolin, the effect was additive, as evidenced by a near doubling of regenerated axons proximal to the repair site. We showed that in vivo application of TGF-β1 and forskolin directly onto chronically injured nerves reactivated chronically denervated Schwann cells, induced their proliferation, and upregulated the expression of regeneration-associated proteins. The effect of TGF-β1 and forskolin on old nerve injuries is quite impressive and the treatment regiment appears to mediate a growth-supportive milieu in the injured peripheral nerves. In summary, TGF-β1 and forskolin treatment reactivates chronical- ly denervated Schwann cells and could potentially be used to extend and prolong the regenerative responses to promote axonal regeneration.

Effect of intestinal ischemia-reperfusion on expressions of endogenous basic fibroblast growth factor and transforming growth factor β in lung and its relation with lung repair

AIM To study the changes of endogenoustransforming growth factor β(TGFβ)and basicfibroblast growth factor(bFGF)in lung followingintestinal ischemia and reperfusion injury andtheir effects on lung injury and repair.METHODS Sixty Wistar rats were divided intofive groups,which underwent sham-operation,ischemia(45 minutes),and reperfusion(6,24and 48 hours,respectively)after ischemia(45minutes).Immunohistochemical method wasused to observe the localization and amounts ofboth growth factors.RESULTS Positive signals of both growthfactors could be found in normal lung,mainly inalveolar cells and endothelial cells of vein.Afterischemia and reperfusion insult,expressions ofboth growth factors were increased and theiramounts at 6 hours were larger than those ofnormal control or of 24 and 48 hours after insult.CONCLUSION The endogenous bFGF and TGF βexpression appears to be up-regulated in thelung following intestinal ischemia andreperfusion,suggesting that both growth factorsmay be involved in the process of lung injury andrepair.

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

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

Aberrant activation of latent transforming growth factor-β initiates the onset of temporomandibular joint osteoarthritis

There is currently no effective medical treatment for temporomandibular joint osteoarthritis(TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transforming growth factor-β(TGF-β)signalling in the cartilage and subchondral bone of the TMJ using a temporomandibular joint disorder(TMD) rat model, an ageing mouse model and a Camurati–Engelmann disease(CED) mouse model. In the three animal models, the subchondral bone phenotypes in the mandibular condyles were evaluated by μCT, and changes in TMJ condyles were examined by TRAP staining and immunohistochemical analysis of Osterix and p-Smad2/3. Condyle degradation was confirmed by Safranin O staining, the Mankin and OARSI scoring systems and type X collagen(Col X), p-Smad2/3 a and Osterix immunohistochemical analyses. We found apparent histological phenotypes of TMJ-OA in the TMD, ageing and CED animal models, with abnormal activation of TGF-βsignalling in the condylar cartilage and subchondral bone. Moreover, inhibition of TGF-β receptor I attenuated TMJ-OA progression in the TMD models. Therefore, aberrant activation of TGF-β signalling could be a key player in TMJ-OA development.

Expression of transforming growth factors in hepatocellular carcinoma and its relations with clinicopathological parameters and prognosis

BACKGROUND: Transforming growth factors (TGF)-beta 1, TGF-beta R2 and Smad4 belong to the TGF family, and play important roles in carcinogenesis and the development of carcinoma, especially hepatocellular carcinoma (HCC). TGF-beta 1 is a multipotent polypeptide, which inhibits the growth of epithelial cells including hepatoma cell lines and hepatocytes by inducing apoptosis. TGF-beta R2 forms a heterodimeric complex upon binding to TGF-beta, and then generates the first step in the signal transduction pathway leading to growth inhibition in coordination with the type I receptor. Smad4 protein is an important mediator in the TGF-beta signaling pathway, and negatively regulates the growth of epithelial cells. This study aimed to detect the expression of TGF-beta 1, TGF-beta R2 and Smad4 in HCCs and their adjacent normal tissues, while assessing its relations with the clinicopathological parameters of HCC. METHODS: Forty-seven HCC specimens and their adjacent normal tissues were obtained surgically at the Affiliated Hospital of Medical College, Qingdao University. The expression of TGF-beta 1, TGF-beta R2 and Smad4 was separately detected by immunohistochemistry in all HCC specimens and their adjacent normal tissues, and its relations with the clinicopathological parameters of HCC were assessed. RESULTS: The positive expression of TGF-beta 1 was 72.34% in the HCC specimens, which was higher than that in the adjacent normal tissues (P < 0.001). The positive expression of Smad4 and TGF-beta R2 was 34.04% and 59.57% respectively in the carcinoma specimens. The expression of TGF-beta 1, TGF-beta R2 and Smad4 was significantly higher in groups with a tumor embolus of the portal vein, integrity of the amicula, and Edmondson's III-IV than that in other groups, but it was not related to tumor size (P < 0.05). CONCLUSIONS: TGF-beta 1 may play an important role in the occurrence and development of HCC. Combined detection of TGF-beta 1, TGF-beta R2 and Smad4 may be useful for the determination of the degree of malignancy and the prognosis of HCC.

Organ fibrosis inhibited by blocking transforming growth factor-β signaling via peroxisome proliferator-activated receptor γ agonists

BACKGROUND:Organ fibrosis has been viewed as one of the major medical problems, which can lead to progressive dysfunction of the liver, lung, kidney, skin, heart, and eventually death of patients. Fibrosis is initiated by a variety of pathological, physiological, biochemical, and physical factors. Regardless of their different etiologies, they all share a common pathogenetic process: excessive activation of the key profibrotic cytokine, transforming growth factor-β (TGF-β). Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated transcription factor of the nuclear receptor superfamily, has received particular attention in recent years, because the activation of PPARγ by both natural and synthetic agonists could effectively inhibit TGF-β-induced profibrotic effects in many organs. DATA SOURCES: The English-language medical databases, PubMed, Elsevier and SpringerLink were searched for articles on PPARγ, TGF-β, and fibrosis, and related topics. RESULTS: TGF-β is recognized as a key profibrotic cytokine. Excessive activation of TGF-β increases synthesis of extracellular matrix proteins and decreases their degradation, associated with a gradual destruction of normal tissue architecture and function, whereas PPARγ agonists inhibit TGF-β signal transduction and are effective antifibrogenic agents in many organs including the liver, lung, kidney, skin and heart. CONCLUSIONS: The main antifibrotic activity of PPARγ agonists is to suppress the TGF-β signaling pathway by so-called PPARγ-dependent effect. In addition, PPARγ agonists, especially 15d-PGJ2, also exert potentially antifibrotic activity independent of PPARγ activation. TGF-β1/Smads signaling not only plays many essential roles in multiple developmental processes, butalso forms cross-talk networks with other signal pathways, and their inhibition by PPARγ agonists certainly affects the cytokine networks and causes non-suspected side-effects. Anti-TGF-β therapies with PPARγ agonists may have to be carefully tailored to be tissue-and target gene-specific to minimize side-effects, indicating a great challenge to the medical research at present.

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

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