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 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.
Abstract： Marfan syndrome （MFS） is a congenital and heritable autosomal dominant disorder of the connective tissue which is often passed down through families. Its clinical presentation typically involves the skeletal， cardiovascular and ocular systems with a high natural mortality. Aortic root aneurysm and consecutive acute aortic dissection represent the main cardiovascular manifestations and main causes of morbidity and mortality in MFS. At present， the predominant therapeutic method is surgery， but surgical outcomes are quite unsatisfactory. Recent studies demonstrate that losartan， a common antihypertensive agent， is useful to treat MFS， the mechanism of which may results from inhibiting overactivation of transforming growth factor β （TGF-β） signaling. This discovery will definitely promote the transition of traditional surgical treatment of MFS into pharmacotherapy. In this review， we focus on the molecular biological pathogenesis， traditional and new therapeutic strategies for MFS patients.
ObjectiveTo investigate the effect of dust fine particles on tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP), transforming growth factor-β1 (TGF-β1), and collagens in the lung tissue of rats.MethodsAccording to random number table method, 96 male Wistar rats were divided into an untreated control group, a treated control group and an experimental group, with 32 rats in each group. The experimental group was exposed to the wind tunnel simulation of sandstorm (5 days per week, 5 hours per day); the untreated control group was put in the standard living environment next to the wind tunnel; the treated control group was exposed to the same wind tunnel simulation of sandstorm for 5 hours every day, the speed of wind was the same as the experimental group, but without dust; On the 30th, 60th, 90th, and 120th day, the levels of TNF-α, MMP-2, MMP-9, TGF-β1, lung collagen type Ⅰ and Ⅲ in the lung tissue of rats were determined by enzyme linked immunosorbent assay.ResultsCompared with the untreated control group and the treated control group, the content of TNF-α was higher in the experimental group on 30th, 60th, 90th and 120th day (all P<0.05). The contents of MMP-9 and MMP-2 in the experimental group on 60th and 90th day were significantly higher than those in the untreated group and the treated control group, respectively (all P<0.05). On the 30th, 60th, 90th, and 120th day, the content of TGF-β1 in the experimental group was significantly higher compared with the two control groups (all P<0.05). The contents of lung collagen type Ⅰ and type Ⅲ were higher in the experimental group on 60th, 90th and 120th day, respectively, compared with the two control groups (all P<0.05).ConclusionsThe strong sandstorm environmental exposure to a certain period of time can promote lung interstitial collagen deposition in rat. With the prolonged exposure time, the deposition of collagen increases. TNF-α, MMP-2, MMP-9 and TGF-β1 may all participate and induce the process of pulmonary fibrosis.
Objective To validate the mechanism of effect of hepatic artery ischemia on biliary fibrosis after liver transplantation and the prevention method. Methods Eighteen male dogs were established into the concise auto orthotopic liver transplantation models and assigned into three groups randomly: hepatic artery ischemia (HAI) group, TBB group (transferred the blood by a bridge duct ) and control group, each group contained 6 dogs. After opening portal vein, the samples were cut from liver in each group at the time of 6 h, 3 d and 14 d. The pathological modifications of intrahepatic bile ducts were observed and expression of transforming growth factor-β1 (TGF-β1) were detected in the three times. Expressions of Smad3 and phosphate-Smad3 as well as mRNA of α-smooth muscle actin (α-SMA) in intrahepatic bile ducts were detected 14 d after opening portal vein.Results Compared with control group, the collagen deposition and lumens stenosis in biliary vessel wall were more obviously in HAI group. In TBB group, the pathological modifications were slighter compared with HAI group. The positive cell index of TGF-β1 reached peak on day 3 after opening portal vein, then decreased in TBB group, and which in HAI group kept increase and was significantly higher than that in TBB group （Plt;0.05）. The expression level of phosphate-Smad3 and transcriptional level of α-SMA mRNA were 1.04±0.13 and 1.12±0.55 in TBB group on day 14 after opening portal vein, which were significantly higher than those in control group (0.59±0.09 and 0.46±0.18) and lower than those in HAI group (1.82±0.18 and 1.86±0.73), the diversities among three groups were significant (Plt;0.05). There was not significant difference of expression of Smads among three groups (Pgt;0.05). Conclusions Hepatic artery ischemia could increase the deposition of collagen fibers and the transdifferentiation of myofibroblast in bile duct and result in the biliary fibrosis by activating the TGF-β1/Smads signaling pathway. The bridging bypass device could lessen the biliary fibrosis caused by hepatic artery ischemia by inhibiting the activation of TGF-β1/Smads signal transduction passageway.
OBJECTIVE: To investigate the effects of basic fibroblast growth factor (bFGF) on the promoter activities of human alpha 1(I) procollagen gene and the interaction between bFGF and transforming growth factor-beta 1 (TGF-beta 1). METHODS: Fibroblasts of the hypertrophic scar and normal skin from a 3-year-old patient were primarily cultured and subcultured in vitro. Both of the fibroblasts were transient transfected with phCOL 2.5, containing -2.5 kb of 5’f lank sequence of human alpha 1(I) procollagen gene and CAT reporter gene by FuGENE transfection reagent; and treated thereafter by 16 ng/ml bFGF, 2 ng/ml TGF-beta 1 and 16 ng/ml bFGF + 2 ng/ml TGF beta 1 for 24 hours. The relative CAT expression values were determined by CAT-ELISA. RESULTS: TGF-beta 1 bly induced the CAT expression level, however, bFGF not only inhibited the basal CAT expression but also reduced the CAT expression up-regulated by TGF-beta 1 in normal skin and hypertrophic scar fibroblasts (P lt; 0.05). CONCLUSION: bFGF can reduce the promoter activities of human alpha 1(I) procollagen gene and antagonize the role of TGF-beta 1 in up-regulating the promoter activities of human alpha 1(I) procollagen gene in normal skin and hyertrophic scar fibroblasts.
This study is aimed to investigate the effects of mechanical stretch on the expression of transforming growth factor-β1 (TGF-β1) and fibroblast growth factor-2 (FGF-2), and the signaling pathway in human bronchial epithelioid (16HBE) cells under mechanical stretch. Using loading device with flexible substrate (FX-4000T) to stretch 16HBE cells, we found that the stretching elongation was 15%, at frequency of 1 Hz, stretching for 0.5 h, 1 h, 1.5 h and 2 h. Choosing the higher expression of TGF-β1, FGF-2 and Ca2+ group to carry out intervention experiments, we used the cells pretreated with canonical transient receptor potential 1 (TRPC1) channel antagonist SKF96365, protein kinase C (PKC) inhibitor HA-100, and thereafter mechanical stretch to interpose. Compared with those in the blank control group, TGF-β1 and FGF-2' protein and mRNA, intracellular Ca2+ fluorescence intensity were higher, and the differences were statistically significant (P < 0.05) at the 4 time points, 0.5 h, 1 h, 1.5 h and 2 h. At 0.5 h, the increasing rate was the highest. TGF-β1 protein and mRNA, FGF-2 protein and mRNA, intracellular Ca2+ luorescence intensity in the stretch+SKF96365 and stretch+HA-100 intervented group were decreased, the differences were statistically significant than those in 0.5 h stretch group (P < 0.05) without intervention. The expression of TGF-β1, FGF-2 was up-regulated in 16HBE cells under mechanical stretch, PKC, TRPC1, and Ca2+ may participate in the signal path.
OBJECTIVE: To study the effect of overexpression of truncated type II TGF-beta receptor on transforming growth factor-beta 1(TGF-beta 1) autoproduction in normal dermal fibroblasts. METHODS: In vitro cultured dermal fibroblasts were treated with recombinant human TGF-beta 1(rhTGF-beta 1) (5 ng/ml) or recombinant adenovirus containing truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-beta 1 were observed with Northern blotting. RESULTS: rhTGF-beta 1 up-regulated the gene expression of TGF-beta 1 and type I procollagen. Overexpression of truncated receptor II down-regulated the gene expression of TGF-beta 1. CONCLUSION: Overexpression of the truncated TGF-beta receptor II decreases TGF-beta 1 autoproduction via blocking TGF-beta receptor signal. The results may provided a new strategy for scar gene therapy.
OBJECTIVE: To explore the molecular mechanisms involved in the increased collagen synthesis by platelet-derived wound healing factors (PDWHF) during wound healing in alloxan-induced diabetic rats. METHODS: Thirty-three male SD rats were divided into two groups, the normal (n = 9) (group A) and the diabetic group (n = 24). Two pieces of full-thickness skin with diameter of 1.8 cm were removed from the dorsal site of diabetic rats. PDWHF (100 micrograms/wound) was topically applied to one side of the diabetic wounds (group B) on the operation day and then once a day in the next successive 6 days. Meanwhile, bovine serum albumin (100 micrograms/wound) was applied to the other side of diabetic wound as control group (group C) in the same way. Levels of transforming growth factor-beta 1 (TGF-beta 1) and procollagen I mRNA in wound tissue were inspected by dot blotting. RESULTS: TGF-beta 1 mRNA levels in group B were 4 folds and 5.6 folds compared with those in group C after 5 and 7 days (P lt; 0.01), however, still significantly lower than those of group A (P lt; 0.05). There was no significance difference among three groups on the 10th day after wounding. The levels for procollagen I mRNA in group B amounted to 2.1, 1.8 and 2.3 folds of those in group C after 5, 7, and 10 days (P lt; 0.01), respectively. Compared with those in the group A, procollagen I mRNA levels in the group B were significantly lower after 5 and 7 days (P lt; 0.05), and no significant difference was observed between group B and A after 10 days. CONCLUSION: One important way for PDWHF to enhance the collagen synthesis in diabetic wound healing is to increase the gene expression of endogenous TGF-beta 1.