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.

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.

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

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

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.

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.

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.

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.

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.

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.

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.

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.

Expression of Transforming Growth Factor β_(1) in Mesenchymal Stem Cells: Potential Utility in Molecular Tissue Engineering for Osteochondral Repair

The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor(TGF)-β_(1)genes in bone marrow-derived mesenchymal stem cells(MSCs)in vitro.The full-length rat TGF-β_(1)cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418,a synthetic neomycin analog.The transient and stable expression of TGF-β_(1)by MSCs was detected by using immunohistochemical staining.The lipofectamine-mediated gene therapy efficiently transfected MSCs in vitro with the TGF-β_(1)gene causing a marked up-regulation in TGF-β_(1)expression as compared with the vector-transfected control groups,and the increased expression persisted for at least 4 weeks after selected with G418.It was suggested that bone marrow-derived MSCs were susceptible to in vitro lipofectamine mediated TGF-β_(1)gene transfer and that transgene expression persisted for at least 4 weeks.Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology,an innovative concept,i.e.molecular tissue engineering,are put forward for the first time.As a new branch of tissue engineering,it represents both a new area and an important trend in research.Using this technique,we have a new powerful tool with which:(1)to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and(2)to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis.

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.

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.

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

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

Effects of transforming growth factor β2 and connective tissue growth factor on induction of epithelial mesenchymal transition and extracellular matrix synthesis in human lens epithelial cells

AIM:To Investigate the effects of transforming growth factorβ2(TGF-β2)and connective tissue growth factor(CTGF)on transdifferentiation of human lens epithelial cells(HLECs)cultured in vitro and synthesis of extracellular matrix(ECM).METHODS:HLECs were treated with TGF-β2(0,0.5,1.0,5,10μg/L)and CTGF(0,15,30,60,100μg/L)for different times(0,24,48,72h)in vitro and the expression ofα-smooth muscle actin(α-SMA),the main component of the extracellular matrix typeⅠcollagen(Col-1)and fibronectin(Fn)were measured by using real-time polymerase chain reaction(PCR)and western-blot.RESULTS:TGF-β2 and CTGF significantly increased expression ofα-SMA mRNA and protein(P【0.05,P【0.001),Fn mRNA and protein(P【0.001),Col-1 mRNA and protein(P【0.001).TGF-β2 could induce HLECs expression of CTGF mRNA and protein in dosedependent manner(P【0.05,P【0.001).TGF-β2 and CTGF could induce HLECs to expressα-SMA,Fn and Col-1 in time-dependent manner.Each time of TGF-β2and CTGF induced HELCs expression ofα-SMA,Fn,Col-1 mRNA and protein was significant increase compared with control(P【0.05,P【0.001).CONCLUSION:TGF-β2 and CTGF could induce HLECs epithelial mesenchymal transition and ECM synthesis.

ROLE OF TRANSFORMING GROWTH FACTOR β(TGF-β)IN REPAIRING OF BONE DEFECTS

TGF-β is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repair. A rabbit radial bone defect model was used to evaluate the effect of TGF-β, which was extracted and purified from bovine blood platelets, on the healing of a large segmental osteoperiosteal defect. A 1. 5-centimeter segmental defect was created in the mid-upper part of the radial shaft of adult rabbits. The defect was filled with implant containing TGF-β that consisted of carrier and bovine TGF-β. Limbs served as controls received carrier alone. The defectswere examined radiographically and histologically at 4, 8,12 , 16 and 20 weeks after implantation. The results showed that in TGF-β implant group . the defect areas at 12 weeks post operation were bridged by uniform new bone and the cut ends of cortex could not be seen;while in control group, the defects remained clear. Only a small amount of new bone formed as a cap on the cut bone ends. In the experimental group, new lamellar and woven bone formed in continuity with the cut ends of the cortex. An early medullar canal appears to be forming and contained normal-appearancing marrow elements; while the control group displayed entirely fibrous tissue within the defect site. Remnants of the cancellous bone carrier were observed in the control specimen. These data demonstrate that exogenous TGF-β initiate osteogenesis and stimulate the bone defects repair in animal model.