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 determine whether the transforminggrowth factor β1 (TGF-β1) is a key regulatory molecule required for an increase or a balance of extracellular matrix (ECM) and DNA synthesis in the goat passaged nucleus pulposus (NP) cells. Methods The NP cells isolated from the goat intervertebral discs were cultured in vitro for a serial of passages and transfected with the replicationincompetent adenoviral vectors carrying the human TGF-β1 (hTGF-β1) or lacZ genes. Then, they were cultured in monolayer or alginate bead 3dimensional (3-D) systems for 10 days.The changes in the production and the molecular components of ECM that occurredin the NP cells transfected with Ad/hTGF-β1 or the controls were evaluated by Westernblot and absorbance of glycosaminoglycan (GAG)-Alcian Blue complexes. Differences of DNA synthesis in the variant cells and culture systems were assessed by fluorometric analysis of the DNA content. ResultsA quantitation in the variant culture systems indicated that in monolayers the NP cells at Passage 3 transfected with Ad/hTGF-β1 had a much higher cell viability and more DNA synthesis(P＜0.05); however, in the alginate 3-D culture system, the NP cells transfected with Ad/hTGF-β1 did not have any significant difference from the controls(P＞0.05). The Western blotting analysis ofthe protein sample isolated from the variant cells for TGF-β1, type Ⅱ collagen, and Aggrecan expression indicated that in the monolayers and alginate 3-D culture systems the NP cells at Passage 3 transfected with Ad/hTGF-β1 revealed much higher protein levels than the controls(P＜0.05)； whereas the type Ⅰcollagen content was much lower than the controls (P＜0.05), but a significatly increased ratio of type Ⅱ/type Ⅰ collagen was found in both of the cell culture systems(P＜0.05). The GAG quantification also showed a positive result in both the cell culture systems and the NP cells at Passage 3 transfected with Ad/hTGF-β1 had a much higher GAG content than the controls(P＜0.05). Conclusion To a greaterextent, hTGF-β1 can play a key role in maintaining the phenotype of the NP cells and can still have an effect of the phenotypic modulation after a serial of the cell passages. The NP cells that are genetically manipulated to express hTGF-β1 have a promising effect on the restoration of the intervertebral disc defects. The NP cells transfected with Ad/hTGF-β1 cultured in the 3-D alginate bead systems can show a nearly native phenotype.
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.
Objective To evaluate the cell biological features and the effect of transplantation of transforming growth factor β3 (TGF-β3) gene-modified nucleus pulposus (NP) cells on the degeneration of lumbar intervertebral discs in vitro. Methods NP cells at passage 2 were infected by recombinant adenovirus carrying TGF-β3 (Ad-TGF-β3) gene (Ad-TGF-β3 group), and then the cell biological features were observed by cell vital ity assay, the expression of the TGF-β3 protein was determined by Western blot, the expression of collagen type II in logarithmic growth phase was determined by immunocytochemistry. The cells with adenovirus-transfected (Adv group) and the un-transfected cells (blank group) were used as controls. The model of lumbar disc degeneration was establ ished by needl ing L3, 4, L4, 5, and L5, 6 in 30 New Zealand rabbits (weighing 3.2-3.5 kg, male or female). Then Ad-TGF-β3-transfected rabbit degenerative nucleus pulposus cells (100 μL, 1 × 105/ mL, group A, n=12), no gene-modified nucleus pulposus cells (100 μL, 1 × 105/mL, group B, n=12), and phosphatebuffered sal ine (PBS, 100 μL, group C, n=6) were injected into degenerative lumbar intervertebral discs, respectively. L3, 4, L4, 5, and L5, 6 disc were harvested from the rabbits (4 in groups A and B, 2 in group C) at 6, 10, and 14 weeks respectively to perform histological observation and detect the expression of collagen type II and proteoglycan by RT-PCR. Results The viabil ity of nucleus pulposus cells was obviously improved after transfected by recombinant Ad-TGF-β3 gene. At 3, 7, and 14 days after transfected, TGF-β3 expression gradually increased in nucleus pulposus cells. The positive staining of collagen type II was seen in Ad-TGF-β3 group, and the positive rate was significantly higher than that of Adv group and blank group (P lt; 0.05). The disc degeneration in group A was sl ighter than that in groups B and C. The expressions of collagen type II mRNA and proteoglycan mRNA in group A were significantly higher than those in groups B and C at 6, 10, and 14 weeks (P lt; 0.05). Conclusion TGF-β3 can improve the biological activity of NP cells and promote the biosynthesis of collagen type II and proteoglycan in intervertebral discs, alleviate the degeneration of intervertebral discs after transplantation.
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 construct recombinant adenovirus vector containing human transforming growth factor beta 3 (TGF-β3), which was transfected into marrow mesenchymal stem cells(MSCs) and to observe its expression. Methods The cDNA TGF-β3 was intergraded into the shuttle vector of pAdTrack-CMV and recombinated with adenovirus skeleton vector pAdEasy-1 by homologous recombination. Then the product was transfected into package cell HEK293 by lipofedtamine and the recombinant adenovirus expressing the TGF-β3genewas generated. The rabbit’s MSCs were isolated, cultivated, purified, and then transfected with recombinant adenovirus containing the TGF-β3 gene. The green fluorescence protein expression was observed after 10 days, and the TGF-β3 expression was observed in MSCs transfected by recombinated adenovirus with TGF-β3 gene after 4 days. Results PCR showed that TGF-β3 cDNA was inserted into the recombinantadenoviral plasmid. The recombinant virus vectors with TGF-β3 gene were collected by the packaging HEK293 cells. The fusion rate of MSCs was 70%-80% with an intensive adhesion and uninform shape after the cultured 10th day. Fluorescent microscopy and immunocytochemistry demonstrated that TGF-β3 was expressed in MSCs. Conclusion Successful construction of human TGF-β3 recombinant adenovirus and its expression in MSCs provide a basis of research for the gene therapy of wound healing.
Objective To study the relation between expressions of transforming growth factor β1 （TGF-β1）, transforming growth factor receptor type Ⅰ (TβRⅠ) and cell proliferation, cell cycle in gallbladder carcinomas, to disclose the mechanism of TGF-β1 and TβRⅠin the gallbladder carcinogenesis，and to evaluate their values in the prognosis of gallbladder carcinomas. Methods Thirty five gallbladder carcinomas 〔age （57.94± 4.61） years, 14 male cases and 21 female cases〕 comprised 32 adenocarcinomas, 2 adenosquamous carcinoma and 1 squamous cell carcinomas. Formalin fixed, paraffin embedded sections from gallbladder carcinomas were immunostained with TGF-β1, TβRⅠ, PCNA, cyclin E antibodies by immunochemical assays. Gallbladder adenoma and chronic cholecystitis were collected as non-malignant controls. Patients of gallbladder carcinomas were followed up. Results Positive immunostaining rate of TGF-β1 was 57.14% in gallbladder carcinomas, which was significantly higher than that in gallbladder adenomas and chronic cholecystitis (P＜0.01, respectively). Expression of TGF-β1 was associated with Nevin stage, lymph nodes and distant metastasis (P＜0.05, P＜0.01, respectively). Expression of TGF-β1 was positively correlated with expression of PCNA LI and cyclin E (r=0.523 2, P=0.001 3; r=0.406 5, P=0.015 4), and 34.29% of gallbladder carcinomas were immunostained positively for TβRⅠ. Expression of TβRⅠwas significantly lower in gallbladder carcinomas than that in gallbladder adenomas and cholecystitis (P＜0.05, respectively). It was significantly lower in gallbladder carcinomas patients with lymph nodes and distant metastases than in those without (P＜0.05). Expression of TβRⅠwas negatively correlated with PCNA LI (r=-0.402 4, P=0.016 6). Patients with negative expression of TGF-β1 and/or positive expression of TβRⅠ had significant longer survival rates than those with positive expression of TGF-β1 and/or negative expression of TβRⅠ(P＜0.01, P＜0.05, respectively). Expressions of TGF-β1 and TβRⅠ correlated with prognosis of gallbladder carcinomas closely. Conclusion TGF-β1 and TβRⅠ have close correlation with cell proliferation, cell cycle of gallbladder carcinomas and are important biological markers of carcinogenesis and progress of gallbladder carcinomas. The escape of growth inhibition of TGF-β1 due to low expression of TβRⅠand carcinogenesis of TGF-β1 may play an important role in gallbladder carcinogenesis. TGF-β1 and TβRⅠare valuable indices for judging the prognosis of gallbladder carcinoma.
Objective To investigate the role of transforming growth factorβ3 (TGF-β3) on the amylase secretion of rat submandibular gland cells(RSGCs).Methods The RSGCs were cultured and identified. The expressions of CK 8.13, S100 and Vimentin in the RSGCs were examined by immunohistochemical staining. The experimental group was divided into 5 groups according to differentconcentrations of TGF-β3 (0.5, 1.0, 5.0, 10.0 and 25.0 ng/ml) and no TGF-β3 culture was used as control group. The effects ofTGF-β3 on the cell proliferation and amylase secretion were examined at the24th, the 48th, the 72nd and the 96th hour. MTT colorimetric method was used to estimate vital force of culture cells. Amylase protein was assayed by autobiochemistry equipment and Western blotting.Results The RSGCs were stained positively for CK 8.13 and S-100, but negatively for Vimentin. There were no significant differences in absorbency between the experimental groups and the control group(Pgt;0.05). Compared with the control group,TGF-β3 at concentrations of 0.5-10.0 ng/ml significantly stimulated the amylase secretion of RSGCs after 72 and 96 hours(Plt;0.01). But high concentration of TGF-β3 (25.0ng/ml) showed no stimulation. Western blotting demonstrated that the cultured RSGCs and submandibular gland had the same band of amylase electrophoresis.Conclusion TGF-β3 can stimulate RSGCs to differentiate and to secrete amylase, but TGF-β3 has no effect on proliferation ofRSGCs.
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 To review the progress of the relation between transforming growth factor beta (TGF-beta) and repair of tissue injury. METHODS The recent articles about TGF-beta and tissue reconstruction were extensively reviewed. The gene identification, production, activation of TGF-beta and its role in the repair course of tissue injury were investigated. RESULTS TGF-beta belongs to a family of multifunctional polypeptides, its gene structure is highly conservative. Many animal models about TGF-beta and tissue injury have been established. The research mainly focuses on the classification, distribution of TGF-beta receptors and their signal pathway. CONCLUSION TGF-beta plays an important roles in the regulation of repair of tissue injury.