Objective To investigate the effects of sodium ferulate on lung mRNA expression of TGF-β1 signal transduction molecule in rats with pulmonary fibrosis，and explore the mechanism of sodium ferulate on pulmonary fibrosis.Methods A rat model of pulmonary fibrosis was induced by intratracheal injection of bleomycin (5 mg/kg).Thirty SD rats were randomly divided into three groups (n=10 in each group)，ie.a control group，a pulmonary fibrosis model group，and a sodium ferulate group.The lung histopathology and the expression of collagen was examined by HE staining and collagen fibril staining respectively.The expressions of TGF-βRII and Smad4 mRNA in the lung tissue were detected by situ hybridization.And the expression of TGF-β1 mRNA was detected by real-time fluorescence-quantification RT-PCR.Results Collagen fibril staining indicated that the expression of pulmonary collagen in the model group was significantly higher than that in the control group and sodium ferulate group (Plt;0.001).The mRNA expressions of pulmonary TGF-β1，TGF-βRII and Smad4 were significantly higher in the model group than those in the control group (all Plt;0.01)，and were significantly lower in the sodium ferulate group than those in the model group (all Plt;0.05).Conclusions Sodium ferulate can effectively reduce pulmonary fibrosis through inhibition of the mRNA expression of TGF-β1，TGF-βRII and Smad4 in the lung tissue，thus influence the TGF-β1/Smad4 signal transduction way and inhibit the target gene activation.
Abstract： Objective To explore the association between transforming growth factor-β receptor typeⅡ (TGFBR2) gene rs6785358 and rs764522 polymorphisms and rheumatic heart disease (RHD) in Chinese Han People. Methods The research design was a case-control study. A total of 207 patients who were hospitalized in Nanjing First Hospital Affiliated to Nanjing Medical University between October 2008 and January 2011 with RHD served as RHD group while 225 age and gender matched healthy adults as control group. Polymerase chain reaction-restriction length polymorphism (PCR-RFLP) technique was used to determine TGFBR2 gene rs6785358 and rs764522 polymorphisms. Results The frequencies of genotype AA, AG and GG of rs6785358 in RHD group and control group were 72.0%, 25.1%, 2.9% and 68.9％, 28.0％, 3.1％,respectively. There was no significant difference in the distribution of genotype frequencies for rs6785358 between RHD group and control group（χ2=0.50，P=0.78）. The frequencies of allele A and G of rs6785358 in RHD group and control group were 84.5％, 15.5％ and 82.9％, 17.1％,respectively. There was no significant difference in the distribution of allele frequencies for rs6785358 between RHD group and control group（χ2=0.43，P=0.51）. The frequencies of genotype CC, CG and GG of rs764522 in RHD group and control group were 77.3%, 21.3%, 1.4% and 75.6％, 21.3％, 3.1％, respectively. There was no significant difference in the distribution of genotype frequencies for rs764522 between RHD group and control group（χ2=1.33，P=0.51）. The frequencies of allele C and G of rs764522 in RHD group and control group were 87.9％, 12.1％ and 86.2％, 13.8％,respectively. There was no significant difference in the distribution of allele frequencies for rs764522 between RHD group and control group（χ2=0.55，P=0.46）. Further analysis by sex stratification showed that no statistical significance was detected in the distribution of genotype and allele frequencies for rs6785358 or rs764522 between RHD patients and controls. Conclusion TGFBR2 gene rs6785358 and rs764522 polymorphisms are not associated with RHD in Chinese Han people.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
ObjectiveTo summarize the research advancement of peroxisome proliferator-activated receptor γ (PPARγ) agonists inhibiting transforming growth factor-β (TGF-β)-induced organ fibrosis. MethodsThe related literatures on PPARγ agonists inhibiting TGF-β-induced organ fibrosis were reviewed. ResultsTGF-β was a major fibrosispromoting cytokine, which could promote a variety of organ fibrosis. PPARγ agonists could effectively block TGFβ signal transduction, and then suppressed organ fibrosis well. ConclusionsThe main antifibrotic mechanism of PPARγ agonists is to inhibit TGF-β signal transduction. The studies on this mechanism will help promoting the clinical application of PPARγ agonists, and provide a new way of the treatment for organ fibrosis.
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 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 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 effect of transforming growth factor-β1 (TGF-β1) gene transfer on the biological characteristics of osteoblasts. Methods The expression of TGF-β1 in the transfected osteoblasts was detected by in situ hybridization and assay of TGF-β1 activity in the supernatant (minklung epithelium cell growth -inhibition test). The effects of gene transfer andsupernatant of the transfected osteoblasts on the proliferation and alkaline phosphatase(ALP) activity of osteoblasts were detected by 3 H-TdR and MTT. Results The results of in situ hybridization analysis suggested that the osteoblasts transfected by TGF-β1 gene could express TGF-β1 obviously. The complex medium, which was the mixture of serum-free DMEM and the activated supernatant according to 1∶1, 1∶2, 1∶4, could inhibit growth of Mv-1-Lu evidently and the ratios ofinhibition were 16.3%, 22.7%, 28.2% respectively. TGF-β1 gene transfer hadno effect on the biological characteristics of osteoblasts, but the activated supernatant of transfected osteoblasts stimulated proliferation and inhibited ALPactivity of osteoblasts. Conclusion TGF-β1 gene transfer promotes the expression of TGF-β1 and the biological characteristics of trasfected osteoblasts are stable, which is helpful for gene therapy of bone defects in vivo.
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．