Objective To investigate the effects of exogenous bone morphogenetic protein(BMP) and transforming growth factor-β(TGF-β) on biomechanical property for ulna of fracture healing.Methods Thirty-six adult rabbits were made the model of right ulnar fracture and treated locally with TGF-β/PLA, BMP/PLA，TGF-β+BMP/PLA or PLA(as control group). Fracture healing was evaluated by measurement of the mechanical parameters and geometric parameters.Results As compared with control group, the geometric parameters, the bending broken load, the ultimatebending strength, the bending elastic modulus, the ultimate flexural strength, the flexural elastic modulus, the ultimate compressing strength, the compressingelastic modulus, and the ultimate tensile strength for ulna of fracture healingincreased significantly in the treatment groups(P＜0.01). These parameters were higher in TGF-β+BMP/PLA group than in TGF-β/PLA group or in BMP/PLA group andin TGF-β/PLA group than in BMP/PLA group(P＜0.05). There was no significant difference in bone density between the treatment groups and control group. Conclusion Local application of exogenous TGF-β and BMP canincrease the callus formation and enhance biomechanical strength of bone after fracture healing. A combination of TGF-β and BMP has synergetic effect in enhancing fracture healing.
Objective To observe the differences in protein contents of three transforming growth factorbeta(TGF-β) isoforms, β1, β2, β3 andtheir receptor(I) in hypertrophic scar and normal skin and to explore their influence on scar formation. Methods Eight cases of hypertrophic scar and their corresponding normal skin were detected to compare the expression and distribution of TGF-β1, β2, β3 and receptor(I) with immunohistochemistry and common pathological methods. Results Positive signals of TGF-β1, β2, and β3 could all be deteted in normal skin, mainly in the cytoplasm and extracellular matrix of epidermal cells; in addition, those factors could also be found in interfollicular keratinocytes and sweat gland cells; and the positive particles of TGF-β R(I) were mostly located in the membrane of keratinocytes and some fibroblasts. In hypertrophic scar, TGF-β1 and β3 could be detected in epidermal basal cells; TGFβ2 chiefly distributed in epidermal cells and some fibroblast cells; the protein contents of TGF-β1 and β3 were significantly lower than that of normal skin, while the change of TGF-β2 content was undistinguished when compared withnormalskin. In two kinds of tissues, the distribution and the content of TGF-β R(I) hadno obviously difference. ConclusionThe different expression and distribution of TGF-β1, β2 andβ3 between hypertrophic scar and normal skin may beassociated with the mechanism controlling scar formation, in which the role of the TGF-βR (I) and downstream signal factors need to be further studied.
Objective To investigate the mechanismof lung injury caused by paraquat poisoning by observing the changes of fibrogenic cytokines in acute paraquat poisoned rats and the effects of pyrrolidine dithiocarbamate ( PDTC) . Methods Sprague-Dawley rats were randomly divided into three groups, ie. acontrol group ( n =6) , a PDTC group ( n =36) , a paraquat group ( n = 36) , and a paraquat + PDTC group( n =36) . The rats in the PDTC group, the paraquat group, and the paraquat + PDTC group were subdivided into 6 subgroups sacrificed respectively on 1st, 3rd,7th,14th, 28th and 56th day after the treatment. The levels of transforming growth factor-β1( TGF-β1 ) , platelet-derived growth factor ( PDGF) , insulin-like growthfactor-1 ( IGF-1) in serum were measured. Meanwhile the expression of connective tissue growth factor ( CTGF) and hydroxyproline in lung tissues were detected. The relationship of above cytokines with hydroxyproline was analyzed. Results The destructive phase in early ( 1 ～7 d) was characterized by hemorrhage, alveolar edema, and inflammatory cell infiltration. The proliferous phase in later stage ( 14 ～56 d) was characterized by diffused alveolar collapse with fibroblast proliferation and patchy distribution of collagen fibers. Compared with the control group, the level of TGF-β1 on all time points, the level of PDGF from7th to 56th day, the level of IGF-1 from3rd to 56th day in the paraquat group all significantly increased ( P lt;0. 01) . Immunohistochemistry results showed CTGF positive cells mainly located in aleolar epithelialcells, endothelial cells,macrophages in early stage, and fibroblasts were main positive cells on the 28th and the 56th day. The expression of CTGF in the paraquat group increased gradually compared with the control group on different time points ( P lt; 0. 05 or P lt; 0. 01) . Meanwhile, the levels of above cytokines were positively correlated with the level of hydroxyproline. Noteworthy, PDTC treatment led to significant decreases of above cytokines compared with the paraquat group in corresponding time points ( P lt;0. 05 or P lt;0. 01) .Conclusions Over expressions of IGF-1, TGF-β1 , PDGF, IGF-1 and CTGF may play important roles in lung fibrosis of paraquat poisoned rats. PDTC, as a b NF-κB inhibitor, may inhibits NF-κB activity and further significantly decreases expressions of cytokines, leading to significantly attenuated pulmonary inflammation and fibrosis. However, the mechanisms of PDTC intervention still remain to be explored.
Objective To investigate the expression of vascular endothelial growth factor-A （VEGF-A） and the phenotypic transition after the activation of fibroblasts by the supernatant of cultured tumor cells．Methods The growth tendency of fibroblasts was tested by the MTT assay．The expressions of alpha-smooth muscle actin （α-SMA） and VEGF-A mRNA were tested by RT-PCR．The expressions of α-SMA and VEGF-A protein were tested by immunohistochemistry and Western blot．Results The MTT assay indicated that the conditional medium which contained tumor cells supernatant could obviously promote the growth of the fibroblasts． RT-PCR and Western blot manifested that α-SMA expressed by the fibroblasts which cultured by normal medium reached its peak on day 5，then decreased to a low level on day 7．When the medium contained 2 ng/ml transforming growth factor-β1 （TGF-β1），the fibroblasts could steadily express more α-SMA．But the above two mediums could not make the fibroblasts express the VEGF-A. When using the conditional medium，the α-SMA peak advanced on the third day and maintained at a high level，so as the expression of the VEGF-A．Conclusions The results suggested that fibroblasts can be activated to be myofibroblasts when using the conditional medium．The best activation time of the fibroblasts is consistent with the time of the VEGF-A expression at the highest level by the activated fibroblasts．The fibroblasts which activated at the best time are expected to become a kind of cells which can be used for promoting revascularization．
Objective To observe the expression and distribution of transforming growth factor-β1 (TGF-β1) in the healing process of bile duct and discuss its function and significance in the process of benign biliary stricture formation. Methods An injury to bile duct of dog was made and then repaired. The expression and distribution of TGF-β1 in the tissue at different time of the healing process were studied after operation with immunohistochemical SP staining. Results TGF-β1 staining was observed in the granulation tissue, fibroblasts and endothelial cells of blood vessels. High expression of TGF-β1 was observed in the healing process lasting for a long time. Conclusion The high expression of TGF-β1 is related closely with the fibroblast proliferating activity, extracellular matrix overdeposition and scar proliferation in the healing process of bile duct.
Objective To investigate the effects of bursopentin ( BP5) on expression of extracellular matrix in human lung fibroblasts ( HLFs) and its mechanism.Methods HLFs were cultured in vitro and divided into five groups. The cells in the control group were cultured in DMEMwithout TGF-β1 or BP5. The cells in TGB-β1 treatment group were cultured in DMEMcontaining 5 μg/L TGF-β1 . While in three TGF-β1 + BP5 treatment groups, the cells were cultured in DMEM containing 5 μg/L TGF-β1 and simultaneously intervened with BP5 at three different concentrations ( 2. 5 μg/mL, 5 μg/mL, and 10 μg/mL respectively) . The expression of α-SMA was detected using a fluorescent-labeling strategy. The expressions of Collagen-Ⅰ, p-Smad2/3, p-Smad3, and Smad7 proteins were measured by Western blot. Results The cells in the TGF-β1 treatment group showed positive expression of α-SMA, implying TGF-β1 had induced fibroblasts to differentiate into myofibroblasts. In the TGF-β1 treatment group, the expressions of collagen-Ⅰ( 1. 402 ±0. 158 vs. 0. 605 ±0. 367) , p-Smad2/3 ( 1. 457 ±0. 111 vs. 0. 815 ±0. 039) , and p-Smad3 ( 1. 320 ±0. 147 vs. 0. 623 ±0. 128) increased with statistical significance ( P lt; 0. 01) . Meanwhile the expression of Smad7 reduced ( 0. 614 ±0. 107 vs. 0. 865 ±0. 063, P lt;0. 05) . But in the TGF-β1 + BP5 treatment groups, over-expressions of collagen-Ⅰ, α-SMA, p-Smad2 and p-Smad3 induced by TGF-β1 were obviously inhibited by BP5, especially at the BP5 concentration of 10 μg/mL ( collagen-Ⅰ: 0. 718 ±0. 049 vs. 1. 402 ±0. 158; p-Smad2 /3: 0. 696 ±0. 031 vs. 1. 457 ±0. 111; p-Smad3: 0. 766 ±0. 006 vs. 1. 320 ±0. 147; all P lt; 0. 01) . Otherwise, the up-regulation of Smad7 ( 1. 237 ±0. 173 vs. 0. 614 ±0. 107) was found.Conclusions Bursopentin can reduce the expressions of collagen-Ⅰ and α-SMA protein of fibroblast stimulated by TGF-β1 , maybe through inhibiting TGF-β1 /Smads transduction pathway. It is suggested that bursopentin may have intervention effect on pulmonary fibrosis.
Objective To review the recent advances in transforming growth factor-β(TGF-β) super family study and its role in new bone formation. Methods The latest original articles related to this subject were retrieved extensively,especially the effect of TGF-β, bone morphogenetic proteins(BMPs) and activin(ACT) on distractionosteogenesis. Results TGF-β, BMPs and ACT play important roles in prompting new bone formation and each of them has different effects. Among them, TGF-β can stimulate the proliferation of osteoblast and synthesis ofextra cellular medium; BMPs can initiate the differentiation of interstitial cell toosteocyte; then ACT displays the combine effect of above two factors. Conclusion TGF-β superfamily can regulate new bone formation and thus shorten the course of mandibular distraction osteogenesis.
OBJECTIVE: To localize the distribution of basic fibroblast growth factor (bFGF) and transforming growth factor-beta(TGF-beta) in tissues from dermal chronic ulcer and hypertrophic scar and to explore their effects on tissue repair. METHODS: Twenty-one cases were detected to localize the distribution of bFGF and TGF-beta, among them, there were 8 cases with dermal chronic ulcers, 8 cases with hypertrophic scars, and 5 cases of normal skin. RESULTS: Positive signal of bFGF and TGF-beta could be found in normal skin, mainly in the keratinocytes. In dermal chronic ulcers, positive signal of bFGF and TGF-beta could be found in granulation tissues. bFGF was localized mainly in fibroblasts cells and endothelial cells and TGF-beta mainly in inflammatory cells. In hypertrophic scar, the localization and signal density of bFGF was similar with those in granulation tissues, but the staining of TGF-beta was negative. CONCLUSION: The different distribution of bFGF and TGF-beta in dermal chronic ulcer and hypertrophic scar may be the reason of different results of tissue repair. The pathogenesis of wound healing delay in a condition of high concentration of growth factors may come from the binding disorder of growth factors and their receptors. bFGF may be involved in all process of formation of hypertrophic scar, but TGF-beta may only play roles in the early stage.
Objective To explore the treatment effect of bone marrow mesenchymal stem cells( BMSCs)transplantation in ratmodel of bleomycin-induced pulmonary fibrosis. Methods BMSCs fromten-day-old SDmale rat were cultured and marked with 4, 6-diamidino-2-phenylindole( DAPI) . Seventy female SD rats were randomly divided into four groups. Group A( n = 21) was intratracheally injected with saline as control. Group B( n = 21)were intratracheally injected with BLMA5 to establish pulmonary fibrosis. Group C( n = 21) was injected with BLMA5 intratracheally and BMSCs intravenously via tail vein simultaneously. Group D( n = 7) was injected with BMSCs 14 days after BLMA5 injection. The rats were sacrificed on 7th, 14th and 28th day respectively( rats of group D were on28th) . HE and Masson stainings were performed to observe lung pathological changes. Fluorocyte marked with DAPI was analyzed by fluorescent microscope. Sex determining region Y( SRY) gene were detected by PCR. The lung levels of HYP, tumor necrosis factor-α( TNF-α) and transforming growth factor-β1 ( TGF-β1 ) were measured by ELISA. Results ( 1) In group C and D, BMSCs marked with DAPI were detected in lung frozen section on 7th, 14th and 28th day, and SRY gene of male rats were detected by PCR. ( 2) Alveolitis was most obvious on 7th day and pulmonary fibrosis was most severe on 28th day in group B compared to other three groups( P lt;0. 05 or 0. 01) . Alveolitis and pulmonary fibrosis in group C and D were significantly alleviated compared to group B( P lt; 0. 05) , but still more severe than group A( P lt; 0. 05 or 0. 01) , which in group D was more severe compared to group C( P lt;0. 05) . ( 3) HYP level in group B, coincided with fibrosis, began to increase on7th day and reached the peak on 28th day, significantly higher than other three groups( P lt;0.05 or 0. 01) . TNF-αlevel in group B was highest on 7th day, then descended, which was significantly higher than group A and C on 14th day and not obviously different from other three groups on 28th day. TGF-β1 level in group B was highest on 28th day which was different significantly fromother three groups. Conclusion BMSCs can colonize in the recipient lung tissue and effectively prevent the development of pulmonary fibrosis of rats induced by BLMA5, especially in the early stage.
ObjectiveTo investigate the effects of ezrin on transforming growth factor beta (TGF-β) mediated epithelial mesenchymal transition (EMT). MethodsHuman bronchial epithelial 16HBE cells were stimulated by TGF-β to induce EMT. The mRNA and protein levels were analyzed by RT-PCR and Western blot. Lentivirus (LV)-Ezrin-shRNA was employed to investigate the effects of ezrin deficiency on cell morphology and expressions of EMT associated biomarkers including E-cadherin, vimentin, and alpha smooth muscle actin (α-SMA). The effects of recombinant ezrin protein on 16HBE were also examined. ResultsThe expression of ezrin was down-regulated in 16HBE activated by TGF-β. Due to ezrin depletion, the cell morphology changed from a typical multilateral paving stone-like appearance to a mesenchymal-like fusiform appearance along with the decreased expression of epithelium biomarker E-cadherin and the increased mesenchymal cell markers, vimentin and α-SMA. Recombination protein ezrin increased the expression of E-cadherin whilst reducing vimentin and α-SMA. ConclusionTGF-β promotes EMT of 16HBE cells at least partly via inhibiting the expression of ezrin.