ObjectiveTo study the effect of transforming growth factor β3 (TGF-β3), bone morphogenetic protein 2 (BMP-2), and dexamethasone (DEX) on the chondrogenic differentiation of rabbit synovial mesenchymal stem cells (SMSCs).
MethodsSMSCs were isolated from the knee joints of 5 rabbits (weighing, 1.8-2.5 kg), and were identified by morphogenetic observation, flow cytometry detection for cell surface antigen, and adipogenic and osteogenic differentiations. The SMSCs were cultured in the PELLET system for chondrogenic differentiation. The cell pellets were divided into 8 groups: TGF-β3 was added in group A, BMP-2 in group B, DEX in group C, TGF-β3+BMP-2 in group C, TGF-β3+DEX in group E, BMP-2+DEX in group F, and TGF-β3+BMP-2+DEX in group G; group H served as control group. The diameter, weight, collagen type II (immuohistochemistry staining), proteoglycan (toluidine blue staining), and expression of cartilage related genes [real time quantitative PCR (RT-qPCR) technique] were compared to evaluate the effect of cytokines on the chondrogenic differentiation of SMSCs. Meanwhile, the DNA content of cell pellets was tested to assess the relationship between the increase weight of cell pellets and the cell proliferation.
ResultsSMSCs were isolated from the knee joints of rabbits successfully and the findings indicated that the rabbit synovium-derived cells had characteristics of mesenchymal stem cells. The diameter, weight, collagen type II, proteoglycan, and expression of cartilage related genes of pellets in groups A-F were significantly lower than those of group G (P<0.05). RT-qPCR detection results showed that the relative expressions of cartilage related genes (SOX-9, Aggrecan, collagen type II, collagen type X, and BMP receptor II) in group G were significantly higher than those in the other groups (P<0.01). Meanwhile, with the increase of the volume of pellet, the DNA content reduced about 70% at 7 days, about 80% at 14 days, and about 88% at 21 days.
ConclusionThe combination of TGF-β3, BMP-2, and DEX can make the capacity of chondrogenesis of SMSCs maximized. The increase of the pellet volume is caused by the extracellular matrix rather than by cell proliferation.
Objective To construct the recombinant adenovirus bearing human transforming growth factor β1(TGF-β1) and bone morphogenetic protein 7 (BMP-7) genes, and investigate its co-expression in the marrow stromalstemcells (MSCs) and bioactivity effect. Methods Using the replication defective adenovirus AdEasy as a carrier, MSCs were infected by the high-titer-level recombinant adenovirus taking TGF-β1 and BMP-7 genes. Immunocytochemistry, in situ hybridization，reverse transcription-polymerase chain reaction (RT-PCR), and hexuronic acid level test were used to detect the coexpression of the exogenous genes and to analyze their effect transfection on directive differentiation of MSCs. Results The immunocytochemistry staining showed that the brown coarse grains were situated in the cytoplasm of the most MSCs 72 h after infection. Procollagen ⅡmRNA in the cells was detected by the in situ hybridization, and the content of hexuronic acid in the culture mediumwas significantly increased 10 days after infection compared with the level before infecton (Plt;0.01). Conclusion The recombinant adenovirus bearing human TGF-β1 and BMP-7 genes can be constructed, and the exogenous gene can be coexpressed in MSCs, which may offer a novel approach to thelocal combination gene therapy for repairing joint cartilage defects.
ObjectiveTo discuss whether human amniotic mesenchymal stem cells (hAMSCs) possesses the characteristic of mesenchymal stem cells, and could differentiate into ligament cells in vitro after induction.
MethodsThe hAMSCs were separated through enzyme digestion, and the phenotypic characteristics of hAMSCs were tested through flow cytometry. The cells at passage 3 were cultured with L-DMEM/F12 medium containing transforming growth factor β1 (TGF-β1)+basic fibroblast growth factor (bFGF) (group A), containing hyaluronic acid (HA) (group B), containing TGF-β1+bFGF+HA (group C), and simple L-DMEM/F12 medium (group D) as control group. The morphology changes of cells in each group were observed by inverted phase contrast microscope at 21 days after induction; the cellular activities and proliferation were examined by sulforhodamine (SRB) colorimetric method; and specific mRNA and protein expressions of ligament including collagen type I, collagen type III, and tenascin C (TNC) were measured by real-time fluorescence quantitative PCR and immunohistochemical staining.
ResultsThe flow cytometry result indicated that hAMSCs expressed mesenchymal stem cell phenotype. After 21 days of induction, the cells in groups A, B, and C grew like spindle-shaped fibroblasts under inverted phase contrast microscope, and cells showed single shape, obvious directivity, and compact arrangement in group C. The SRB result indicated that the cells in each group reached the peak of growth curve at 6 days; the cellular activities of groups A, B, and C were significantly higher than that of group D at 6 days after induction. Also, the immunohistochemical staining results showed that no expressions of TNC were detected in 4 groups at 7 days; expressions of collagen type I in groups A, B, and C were significantly higher than that in group D at 7, 14, and 21 days (P<0.001); the expressions of collagen type III in groups A, B, and C were significantly higher than that in group D at 14 and 21 days (P<0.001). There was an increasing tendency with time in collagen type I of group B, in collagen type III and TNC of groups A and C, showing significant difference among different time points (P<0.001). The real-time fluorescence quantitative PCR results revealed that the mRNA expressions of collagen type I and TNC in group C were significantly higher than those in groups A and B (P<0.05), and the mRNA expression of collagen type III in group B were significantly higher than that in groups A and C at 21 days (P<0.05). The mRNA expressions of collagen type I and TNC in groups A and C and mRNA expression of collagen type III in group C had an increasing tendency with time, showing significant difference among different time points (P<0.001).
ConclusionThe hAMSCs possesses the characteristics of mesenchymal stem cells and excellent proliferation capacity. After in vitro induction, the expressions of ligament specific genes can be up-regulated and the synthesis of ligament specific proteins can be also strengthened. As a result, it can be used as one of ligament tissue engineering seed cell sources.
Objective To observe the influence of the transforming growth factor β1(TGF-β1) on the denervated mouse musclederived stem cells（MDSCs） producing the connective tissue growth factor（CTGF）at different time points in vitro. Methods MDSCs from the primarycultureof the denervated mouse skeletal muscle were isolated and purified by the preplate technique, and they were identified before the culture and after the culturein vitro with TGF-β1 (10 ng/ml) for 24 hours. Then, MDSCs were randomlydivided into 6 groups (Groups A, B, C, D, E and F) according to the different time points, and were cultured in vitro with TGF-β1 (10 ng/ml) for 0, 3, 6, 12, 24 and 48 hours, respectively. The levels of CTGF mRNA in MDSCs were measured by the real time RT-PCR and the expression of CTGF protein was detected by the CTGF Western blot. Results The immunohistochemistry revealed that before the adding of TGF-β1, MDSCs highly expressed Sca-1, with a positivityrate of 96%; however, after the adding of TGF-β1, the positive expression of Sca-1 decreased greatly, with a negativity rate gt;99%. The Western blot test showed that the ratios of CTGF to the average absorbance of βactin in Groups A-F were 0.788±0.123, 1.063±0.143, 2.154±0.153, 2.997±0.136, 3.796±0.153 and 3.802±0.175, respectively. In Groups AD，the absorbance increased gradually, with a significant difference between the abovementioned groups (Plt;0.05). However, in Groups D-F, there was no significant difference between the groups as the promotive tendency became less significant (P＞0.05). The RT-PCR test showed that the △Ct values in GroupsA-F were 1.659±0.215, 1.897±0.134, 2.188±0.259, 2.814±0.263,2.903±0.125 and 3.101±0.186, respectively. In Groups A-D, the increase in the △Ct value was gradual, but the differences were significant between the groups (Plt;0.05). But in Groups E and F, the promotive tendency became less significant（Pgt;0.05）. Conclusion TGF-β1 can promote the production of CTGF inthe mouse MDSCs cultured in vitro and the time-dependent relation exists for 3-12 hours.
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.
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.
Objective To explore an experimental method of transfecting the marrow stromal stem cells (MSCs) with the reconstructed PGL3-t ransforming growth factor-β1 (TGF-β1) gene and to evaluate the feasibility of selfinduction of MSCs to the chondrocytes in vitro so as to provide a scientific and experimental basis for a further “gene enhanced tissue engineering” research. Methods The rabbit MSCs was transfected with the reconstructed PGL3-TGF-β1gene by the Liposo mesMethod, the growth of the cells were observed, and the growth curve was drawn. The living activity of the transfected cells in the experimental group was evalua ted by MTT, and the result was significantly different when compared with that in the control group. By the immunohistochemistry method (SABC), the antigens of TGF-β1 and collagen Ⅱ were examined at 2 and 7 days of the cell culture afte r transfe ction with PGL3-TGF-β1gene. The pictures of the immunohistochemistry slice were analyzed with the analysis instrument, and the statistical analysis was perfor med with the software of the SPSS 11.0, compared with the control group and the blank group. Results Transfection of the cultured rabbit MSCs in vitro with the reconstructed PGL3-TGF-β1gene by the Liposomes Method achie ved a success, with a detection of the Luceraferase activity. The result was significantly different from that in the control group (Plt;0.01). Tested by MTT, the living acti vity of the transfected cells was proved to be significantly decreased (Plt;0.01 vs. the control group). By the immunohistochemistry method (SABC) to study TGF-β1 positive particles were detected in the experimental group，but there were no positive particles in the control and the blank groups. There was a significant difference between the two groups of the experiment and the control group based on the analysis of the ttest (Plt;0.01). By the immunohistochemistry me thod (SABC) to study collagen Ⅱ, there were more positive particles in the transfected cells in t he experimental group than in the control and the blank groups, and there was a significant difference between the experimental group and the two other groups based on the t-test (Plt;0.01). Conclusion Transfection of the rabbit MSCs with the reconstructed PGL3-TGF-β1 gene by the Liposomes Method is successful. There may be some damage to the cells when transfection is performed. The transfecte d BMS cells with PGL3-TGF-β1 gene can express and excrete TGF-β1when cultured in vitro. The transfected MSCs that secret TGF-β1 can be self-induced into the chondrocytes after being infected for 7 days when cultured in vitro.
Objective It is reported that transforming growth factor β1 (TGF-β1) has the protective effects on the articular cartilage in osteoarthritis (OA). To investigate the significance of the expressions of matrix metalloproteinase 9 (MMP-9), TGF-β1 mRNA and corresponding proteins in OA. Methods The specimens of articular cartilage and synovium were collected from voluntary donators, including 60 cases of OA (experimental group) and 20 cases of traumatic amputation,cruciate l igament rupture, discoid cartilage injury, and menisci injury (normal control group). The pathological changes were observed by HE staining. MMP-9 and TGF-β1 protein expressions were detected by immunohistochemical technique, and the mRNA expressions of MMP-9 and TGF-β1 were detected through in situ hybridization technique; and their correlation was analysed. Results HE staining showed: shrinkage, necrosis, and irregular arrange of the articular chondrocytes, extracellular matrix fracture, hypertrophy and hyperplasia synovium, infiltration of lymphoid and mononuclear cells and prol iferation of many small blood vessels in the experimental group; regular arrangement of the articular chondrocytes, the homogeneously staining matrix, and synovial tissue without chronic inflammation and significant prol iferation in the normal control group. The mRNA and protein expressions of MMP-9 and TGF-β1 were positive in 2 groups. The positive-stained cells included chondrocytes, synovial l ining cells, and vascular endothel ial cells, fibroblasts, and inflammatory infiltrated cells in subsynovial layer. The expressions of mRNA and corresponding protein of MMP-9 and TGF-β1 in the experimental group were significantly higher than those in the normal control group (P lt; 0.01). There was a positive correlation between MMP-9 mRNA and protein expression (r=0.924, P=0.000), and between TGF-β1 mRNA and protein expression (r=0.941, P=0.000) in the experimental group. There was a negative correlation between the expression of MMP-9 protein and TGF-β1 protein (r= — 0.762, P=0.000), and between the expression of MMP-9 mRNA and TGF-β1 mRNA (r= — 0.681, P=0.000) in the experimental group. Conclusion The higher expression of TGF-β1 can protect articular cartilage by down-regulating the expression of MMP-9 of chondrocytes and synoviocytes in OA, which may delay the biological behavior of OA such as occurrence and progress, etc.
Objective To construct recombinant lentiviral expression vectors of porcine transforming growth factor β1 (TGF-β1) gene and transfect bone marrow mesenchymal stem cells (BMSCs) so as to provide TGF-β1 gene-modified BMSCs for bone and cartilage tissue engineering. Methods The TGF-β1 cDNA was extracted and packed into lentiviral vector, and positive clones were identified by PCR and gene sequencing, then the virus titer was determined. BMSCs were isolated frombone marrow of the 2-month-old Bama miniature pigs (weighing 15 kg), and the 2nd and 3rd generations of BMSCs wereharvested for experiments. BMSCs were then transfected by TGF-β1 recombinant lentiviral vectors (TGF-β1 vector group)respectively at multi pl icity of infection (MOI) of 10, 50, 70, 100, and 150; then the effects of transfection were detected bylaser confocal microscope and Western blot was used to determine the optimal value of MOI. BMSCs transfected by empty vector (empty vector group) and non-transfected BMSCs (non-transfection group) were used as control group. RT-PCR, immunocytochemistry, and ELISA were performed to detect the expressions of TGF-β1 mRNA, TGF-β1 protein, and collagen type II. Results Successful construction of recombinant lentiviral vectors of porcine TGF-β1 gene was identified by PCR and gene sequencing, and BMSCs were successfully transfected by TGF-β1 recombinant lentiviral vectors. Green fluorescence was observed by laser confocal microscope. Western blot showed the optimal value of MOI was 70. The expression of TGF-β1 mRNA was significantly higher in TGF-β1 vector group than in empty vector group and non-transfection group (P lt; 0.05). Immunocytochemistry results revealed positive expression of TGF-β1 protein and collagen type II in BMSCs of TGF-β1 vector group, but negative expression in empty vector group and non-transfection group. At 21 days after transfection, high expression of TGF-β1 protein still could be detected by ELISA in TGF-β1 vector group. Conclusion TGF-β1 gene can be successfully transfected into BMSCs via lentiviral vectors, and long-term stable expression of TGF-β1 protein can be observed, prompting BMSCs differentiation into chondrocytes.
Objective\ To understand the effects of serum of patients with rheumatic heart disease and γ interferon on collagen synthesis by valvular fibroblast cultured in vitro, so as to investigate the possible role of transforming growth factor β in genesis of valvular fibrosis and the possibility of γ interferon used to prevent valvular fibrosis in patient with rheumatic heart disease.\ Methods\ Mitral and aortic valve fibroblasts from 5 patients with rheumatic heart disease were cultured in vitro, the cultured ...
