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

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

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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Uncovering the profile of mutations of transforming growth factor beta-induced gene in Chinese corneal dystrophy patients

AIM： To uncover the mutations profile of transforming growth factor beta-induced （TGFBI） gene in Chinese corneal dystrophy patients and further investigate the characteristics of genotype-phenotype correlations. METHODS： Forty-two subjects （6 unrelated families including 15 patients and 8 unaffected members, and 19 sporadic patients） of Chinese origin were subjected to phenotypic and genotypic characterization. The corneal phenotypes of patients were documented by slit lamp photography. Mutation screening of the coding regions of TGFBI was performed by direct sequencing. RESULTS： We detected four corneal dystrophy types. The most frequent phenotypes were granular corneal dystrophy （GCD） （including 3 families and 8 sporadic patients） and lattice corneal dystrophy （LCD） （including 2 families and 9 sporadic patients）. The next phenotypes were corneal dystrophy of Bowman layer （CDB） （1 family and 1 sporadic patient） and epithelial basement membrane dystrophy （EBMD） （1 sporadic patient）. Six distinct mutations responsible for TGFBI corneal dystrophies were identified in 30 individuals with corneal dystrophies. Those were, p.R124H mutation in 1 family and 2 sporadic patients with GCD, p.R555W mutation in 2 families and 3 sporadic patients with GCD, p.R124C mutation in 2 families and 7 sporadic patients with LCD, p.A620D mutation in 1 sporadic patient with LCD, p.H626R mutation in 1 sporadic patient with LCD, and p.R555Q in 1 family and 1 sporadic patient with CDB. No mutation was detected in the remaining 3 atypical GCD patients and 1 EBMD patient, CONCLUSION： GCD and LCD are the most frequent phenotypes in Chinese population. R555W was the most common mutation for GCD; R124C was the most common mutation for LCD, Our findings extend the mutational spectrum of TFGBI , and this is the extensively delineated TGFBI mutation profile associated with the various corneal dystrophies in the Chinese population.

Cloning and Expression of Rat Transforming Growth Factor β1 cDNA in Osteoblasts

Summary: Rat transforming growth factor β1 (rTGFβ1) cDNA from rat lymphocytes was cloned by RT-PCR and inserted into pcDNA3 to construct an eukaryotic expression vector, which was named pcDNA3-TGFβ1. The cloned gene was confirmed to code rat TGFβ1 by restriction enzyme analysis. pcDNA3-TGFβ1 plasmid was transfected into rat osteoblasts by using liposome-mediated gene transfer technique and the expression of TGFβ1 was detected by using irnmunohistochemical staining assay. It was found that the rat TGFβ1 expression product was obviously detectable in the transfected osteoblasts in 48 h. High expression of TGFβ1 was obtained in the rat osteoblasts in which the constructed TGFβ1 expression vector was transfected.

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.

Role of Transforming Growth Factor-β1 in the Process of Fibrosis of Denervated Skeletal Muscle

In order to investigate the biological function of transforming growth factor-β1（TGF-β1） during fibrosis in denervated skeletal muscle,we recruited sciatic nerve injury model of SD rats in which denervated gastrocnemius was isolated for analysis.At different time points after operation,denervated muscle was examined by several methods.Masson trichrome staining showed morphological changes of denervated skeletal muscle.Quantitative RT-PCR detected the rapid increase of TGF-β1 expression at mRNA level after nerve injury.It was found that a peak of TGF-β1 mRNA expression appeared one week post-operation.The expression of collagen Ⅰ（COL Ⅰ） mRNA was up-regulated in the nerve injury model as well,and reached highest level two weeks post-injury.Immunoblot revealed similar expression pattern of TGF-β1 and COL Ⅰ in denervated muscles at protein level.In addition,we found that the area of the gastrocnemius muscle fiber was decreased gradually along with increased interstitital fibrosis.Interestingly,this pathological change could be prevented,at least partly,by local injection of TGF-β1 antibodies,which could be contributed to the reduced production of COL Ⅰ by inhibiting function of TGF-β1.Taken together,in this study,we demonstrated that the expression of TGF-β1 was increased significantly in denervated skeletal muscle,which might play a crucial role during muscle fibrosis after nerve transection.

Effect of matrine on transforming growth factor β1 and hepatocyte growth factor in rat liver fibrosis model

Objective:To observe the preventive and control effect of matrine on transforming growth factor(TCF- β1) and hepatocyte.growth factor(HCF) of liver fibrosis tissue in rals.Methods:A total of48 SD rats were randomly divided into A,B,C,D groups with 12 in each,group A as the normal control group and groups B.C,D as liver fibrosis models using composite modulus method with carbon tetrachloride(CCL_4).Group B was the model group,group C adopted γ— interferon lavage therapy in the second day of modeling,and group D adopted matrine lavage treatment,at 4 and8 weeks after treatment.Six rats were executed for detection of TGF- β1 and HGF,liver tissue histology and comparison fibrosis degree changes of rat liver tissue between groups.Results:Croups B,C,D showed a more significantly increased TCF- β1 at each time point compared with group A(P<0.05);Group B showed a more significantly increased TGF- β1 than groups C and D at weeks 4 and 8(P<0.05);group D showed a lowest level of TGF-β1,followed by groups C and B.HGF of group B decreased more significantly than A group at weeks 4 and 8(P<0.05);HGF of groups C and D was significantly elevated at 4 and 8 weeks than groups A and B(P<0.05),in which the group D showed the highest level of HGF.According to tissue histologic observation,rat liver tissue structure of group A was clear and normal,tissue structure of group B was destroyed with obvious fibrous tissue hyperplasia and fatty change of hepatic cells;groups C and D showed a slighter liver tissue damage,cell necrosis and connective tissue hyperplasia in collect abbacy than group B with a trend of obvious improvement.Conclusions:Matrine can reduce TGF- β1expression and enhance the activity of HGF,so as to realize the inhibition effect on liver fibrosis in rats.

Vascular endothelial growth factor A, secreted in response to transforming growth factor-β1 under hypoxic conditions, induces autocrine effects on migration of prostate cancer cells

Hypoxia and transforming growth factor-β1 （TGF-β1） increase vascular endothelial growth factor A （VEGFA） expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines （HPV7 and RWPE1） and prostate cancer cell lines （DU 145 and PC3）. Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor （ALK5） kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor （VEGFR） 1 （Fit-l） and 2 （FIk-I/KDR）. Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERKI/2） in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.