【Abstract】 Objective To explore the preventing effects of TGF-β1 antibody (TGF-β1Ab) compounded with fibringlue (FG) on postoperative adhesions of flexor tendon. Methods Seventy-two Leghorn chickens were randomly divided into 4 groups (groups A, B, C and D), 18 chickens for each group, and the long flexor tendons of the 3rd and 4th toes in zone Ⅱ of all chickens were transversed and sutured with the 4-strand cruciate repair technique to make defect models. In group A, 0.2 mL TGF-β1 Ab was appl ied at repair site. In group B, 0.2 mL FG was appl ied at repair site. In group C, 0.2 mL TGF-β1Ab and FG was appl ied at repair site. In group D, 0.2 mL normal sodium was appl ied at repair site. At 1, 3 and 8 weeks after operation, the tendons of 6 chickens in each group were harvested for morphological and histological evaluation. Six specimens of each group were obtained for biomechanical test at 3 and 8 weeks. Results The gross observation showed that the differences ingrading of tendon adhesion were not significant among 4 groups at 1 week after operation (P gt; 0.05), but the differences were significant between groups A, B, D and group C at 3 and 8 weeks after operation (P lt; 0.05). Histological observation showed that collagen fibers arranged irregularly in groups A, B and D, but arranged regularly in group C at 3 and 8 weeks after operation. At 3 weeks after operation the gl iding excursion ratio of the tendon in groups A, B, C and D were 0.45 ± 0.05, 0.40 ± 0.10, 0.79 ± 0.09 and 0.25 ± 0.07 respectively ; the simulated active flexion ratio were 0.61 ± 0.02, 0.67 ± 0.03, 0.91 ± 0.03 and 0.53 ± 0.04 respectively; the work of flexion were(18.00 ± 0.77), (17.80 ± 1.13), (27.60 ± 1.73) and (15.60 ± 1.27)?/N respectively. There were significant differences between group C and other three groups (P lt; 0.05). The tendon anastomosis breaking strengthwere (14.2 ± 1.9), (15.2 ± 2.2), (16.0 ± 2.2) and (14.7 ± 2.7) N, showing no significant differences among 4 groups (P gt; 0.05).At 8 weeks after operation, the gl iding excursion ratio of the tendon in groups A, B, C and D were 0.45 ± 0.07, 0.43 ± 0.08, 0.80 ± 0.09 and 0.29 ± 0.05 respectively; the simulated active flexion ratio were 0.61 ± 0.02, 0.63 ± 0.03, 0.92 ± 0.03 and 0.53 ± 0.03 respectively, the work of flexion were (18.30 ± 0.84), (18.60 ± 0.80), (27.90 ± 1.24) and (15.30 ± 0.75) ?/N respectively. There were significant differences between group C and other three groups (P lt; 0.05). The tendon anastomosis breaking strength were(51.9 ± 3.0), (51.4 ± 1.4), (53.3 ± 1.3) and (52.3 ± 2.2) N, showing no significant differences among 4 groups (P gt; 0.05). Conclusion TGF- β1Ab compounded with FG could significantly prohibit the formation of fibrous adhesions without interfering with the heal ing process.
Objective To compare the molecular phenotype of human intervertebral disc cells and articular chondrocytes and to analyze whether hBMSCs can differentiate into both chondrocytes and nucleus pulposus cells after combined induction of TGF-β3 and BMP-7 in vitro. Methods The cells with the characteristics of hBMSCs were isolated from marrow aspirates of the volunteer donors’ il iac crest. Human bone marrow was removed and fractionated, and adherent cell cultures were establ ished. The 4th passage cells were then translated into an aggregate culture system in a serum-free medium. The pellet cultures of hBMSCs were divided into four groups: 10 ng/mL TGF-β3 group (group A), 200 ng/mL BMP-7 group (group B), combination group of TGF-β3 and BMP-7 (group C) and blank group as the control (group D). Histological observation, RT-PCR and RQ-PCR were appl ied to measure the expressions of collagen type I, II, X, aggrecan and SOX9 on the 4th and 21st day after cell induction, respectively. Results As was shown by histological observation, the induced cells expressed the feature of chondrocytes in morphology and ECM in groups A and C on the 21st day after the culture. And the collagen type II was positive after staining in groups A and C. The cell morphology of the induced cells in groups B and C had no obviouly changed. PCR detection showed that the expressions of SOX9, aggrecan, collagen type I, II in groups A and C at 21st day were more increased than those at 4th day (P lt; 0.05). The only expressions of collagen type I in groups B and D at 21st day were more increased than those at 4th day (P lt; 0.05). The expressions of collagen type X only was positive in group A. Conclusion Combination of TGF-β3 and BMP-7 can make the differentiated cells from hBMSCs much closer to intervertebral disc cells, so it perhaps could provide seed cells for intervertebral disc tissue engineering.
【Abstract】 Objective To investigate the secretion of target gene and differentiation of BMSCs transfected by TGF-β1 and IGF-1 gene alone and together into chondrocytes and to provide a new method for culturing seed cells in cartilage tissue engineering. Methods The plasmids pcDNA3.1-IGF-1 and pcDNA3.1-TGF-β1 were ampl ified and extracted, then cut by enzymes, electrophoresed and analyzed its sequence. BMSCs of Wistar rats were separated and purificated by the density gradient centrifugation and adherent separation. The morphologic changes of primary and passaged cells were observed by inverted phase contrast microscope and cell surface markers were detected by immunofluorescence method. According to the transfect situation, the BMSCs were divided into 5 groups, the non-transfected group (Group A), the group transfected by empty vector (Group B), the group transfected by TGF-β1 (Group C), the group transfected by IGF-1 (Group D) and the group transfected both by TGF-β1 and IGF-1 (Group E). After being transfected, the cells were selected, then the prol iferation activity was tested by MTT and expression levels were tested by RT-PCR and Western blot. Results The result of electrophoresis showedthat sequence of two bands of the target genes, IGF-1 and TGF-β1, was identical with the sequence of GeneBank cDNA. A few adherent cells appeared after 24 hours culture, typical cluster formed on the forth or fifth days, and 80%-90% of the cells fused with each other on the ninth or tenth days. The morphology of the cells became similar after passaging. The immunofluorescence method showed that BMSCs were positive for CD29 and CD44, but negative for CD34 and CD45. A few cells died after 24 hoursof transfection, cell clone formed at 3 weeks after selection, and the cells could be passaged at the forth week, most cells became polygonal. The boundary of some cells was obscure. The cells were round and their nucleus were asymmetry with the particles which were around the nucleus obviously. The absorbency values of the cells tested by MTT at the wavelength of 490 nm were0.432 ± 0.038 in group A, 0.428 ± 0.041 in group B, 0.664 ± 0.086 in group C, 0.655 ± 0.045 in group D and 0.833 ± 0.103 in group E. The differences between groups A, B and groups C, D, E were significant (P lt; 0.01). The differences between groups A and B or between C, D and E were not significant (P gt; 0.05)。RT-PCR and Western blot was served to detect the expression of the target gene and protein. TGF-β1 was the highest in group C, 0.925 0 ± 0.022 0, 124.341 7 ± 2.982 0, followed by group E, 0.771 7 ± 0.012 0, 101.766 7 ± 1.241 0（P lt; 0.01）; The expression of IGF-1 was the highest in group E, 1.020 0 ± 0.026 0, 128.171 7 ± 9.152 0, followed by group D, 0.465 0 ± 0.042 0, 111.045 0 ± 6.248 0 （P lt; 0.01）. And the expression of collagen II was the hignest in group E, 0.980 0 ± 0.034 0, 120.355 0 ± 12.550 0, followed by group C, 0.720 0 ± 0.026 0, 72.246 7 ± 7.364 0（P lt; 0.01）. Conclusion The repairment of cartilage defects by BMSCs transfected with TGF-β1 and IGF-1 gene together hasa good prospect and important significance of cl inic appl ication in cartilage tissue engineering.
Objective To observe the effects of cobalt chloride (CoCl2)-simulated hypoxia on VEGF and TGF-β1 expression and to provide theoretical basis for deci phering the molecular mechanism of cl inical distraction osteogenesis. Methods The mandibular osteoblasts were obtained from newborn Wistar rats within 24 hours and cultured and purified through modified enzymatic digestion. The morphological and histological changes of cells were evaluated by the HE staining,the histochemical staining for ALP, the collagen I immunohistochemistry staining and the calcified nodules staining, and the growth curves were drawn. The best cells of the 3rd-passage rats were treated with CoCl2, and then immunofluorescence was used to detect the expressions of VEGF and TGF-β1 at 0, 3, 6, 9, 12 and 24 hours after culture. Results The HE staining demonstrated that the cellular forms were diverse, triangular, polygonal, circular and scaly and so on. The prominence varied in length and extended outwards. The nucleus was clearly discernible. The cytoplasma was rich and pink, with the nucleus royal purple. Sometimes 2 cell nuclei were seen. At the crowded place, cellular form was not clear, the dividing l ine was indistinct, and just the great-circle nuclear cells could be seen. The ALP immunohistochemistry staining demonstrated that the cell butcher nature appeared black pellets, the cell nucleus outl ine was unclear, and at the cell compact district, massive mascul ine cells could be seen clearly. The collagen I immunohistochemistry staining demonstrated that mascul ine cells were seen evenly, cytoplasma appeared yellowish brown especially around the nucleus. However, yellowish brown pellets were not seen in negative cells. The osteoblast calcium tubercle staining demonstrated that the cells gathered in the opaque region with the shape of tubercle after15 days of culture. After al izarin red staining, the reddish orange pigmentation appeared. At various time points, weak VEGF fluorescence was seen in the cells in the control group under the laser confocal microscope. As the hypoxia time prolonged, VEGF fluorescence of cells in the experimental group intensified, and reached the peak 9 hours after peration, and then dropped to the normal level. At various time points, TGF-β1 fluorescence was found in both groups under the laser confocal microscope, and fluorescence intensity in the control group was sl ightly ber than that in the VEGF control group. In the experimental group, TGF-β1 expression had short-term increase 3 hours after hypoxia, and reduced gradually with the prolonging of hypoxia time. Conclusion The method of culturing osteoblast from Wistar rats mandibular is practicable. The cells can be used for further studies. Moderate hypoxia can affect bone synthesis and turnover in distraction osteogenesis and up-regulate the expressions of VEGF and TGF-β1.
To investigate the preventive effect of TGF-β1 neutral izing antibody on collagen production and adhesion formation of flexor tendon. Methods Tendon fibroblasts, epitenon tenocytes, and endotenon tenocytes were obtained from 6 New Zealand rabbit flexor tendons. Each cell culture was supplemented with 1 ng/mL of TGF-β along with increasing dose of TGF-β1 neutral izing antibody. Col I production was measured by enzyme-l inked immunoabsorbent assay after 3 days. Eighty-four adult New Zealand White rabbits forepaws underwent sharp transection of middle digit flexor digitorumprofundus and immediate repair. Then the rabbits were divided into three groups: the normal saline (NS group, n=36), 1.0 µg/ mL TGF-β1neutral izing antibody (1.0 µg/mL TGF-β1group, n=36) and 2.0 µg/mL TGF-β1 neutral izing antibody (2.0 µg/mL TGF-β1 group, n=12) were injected in tendon sheath respectively. Tendons were harvested at 4 and 8 weeks for biomechanics testing, histological evaluation and scanning electron microscope observation. Tendons were harvested at 1, 2, 4 and 8 weeks to determine the mRNA expression of TGF-β1 and Col I by in situ hybridization. Results ELISA exhibed that TGF-β1 enhanced Col I production and the neutral izing antibody significantly inhibited TGF-β1-induced Col I production in all 3 cell culture with a dose-dependent. At 4 and 8 weeks after operation the gl iding excursion of the tendon and the simulated active flexion in NS group were less than that of 1.0 µg/mL TGF-β1 group and 2.0 µ g/mL TGF-β1 group. There was significant difference between NS group and 1.0 µ g/mL TGF-β1 group, 2.0 µ g/mL TGF-β1 group (P lt; 0.05). The tendon anastomosis breaking strength showed no significant differences among three groups (P gt; 0.05). Scanning electron microscope and histological observation showed that collagen fibers arranged irregularly in NS group, but arranged regularly in 1.0 µ g/mL TGF-β1 group and 2.0 µ g/mL TGF-β1group at 4 and 8 weeks after operation. The in situ hybridization results revealed that TGF-β1 and Col I mRNA expression in 1.0 µ g/mL TGF-β1 group was lower than that in NS group at each time. There was significant difference between two groups (P lt; 0.05). Conclusion TGF-β1neutral izing antibody can inhibit the function of the TGF-β1 effectively and prevent adhesion formation after the flexor tendon injured and repaired.
PURPOSE: To investigate the influence of transforming growth factor-beta (TGF-beta;) on endotoxin-induced uveitis (EIU). METHODS: TGF- beta; was abstracted from humam platelets using Bio-gel P-60 chromatography. It was introduced either topically(drops) or intraperitoneally into the SD rats after footpad injection of lipopolysaccbaride(LPS). The inflammation in the anterior uvea was clinically evaluated with slitlamp every day. RESULTS :TGF-beta; obtained from Biogel P-60 chromatography displayed single band on SDS-PAGE,showing a molecular weight of 12 500 EIU occurs significantly earlier and more severe in the rats which only received LPS injection than in the TGF-beta; treated rats. The duration of the inflammation was also much longer in the untreated rats than in the treated rats (P＜0. 001). CONCLUSION: TGF-beta; purified from human platelets may partly prevent the development of EIU and effectively reduce the severity of the inflammation induced by LPS injection. （Chin J Ocul Fundus Dis,1996,12: 101-104)
Objective To investigate the mechanism of p38 mitogen activated protein kinase (MAPK) signaling pathway in regulating the hyperplasia and hypertrophy of human lumbar ligamentum flavum via transforming growth factor β1 (TGF-β1)/connective tissue growth factor (CTGF). Methods The lumbar ligamentum flavum tissue taken from patient with lumbar intervertebral disc herniation was isolated by collagenase-predigested explant cultures. The ligamentum flavum cells were treated with the extracellular regulated protein kinase pathway blocker PD98059, c-Jun N-terminal kinase pathway blocker SP600125, and p38 pathway blocker SB203580, and then the mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescence quantitative PCR (qRT-PCR). The ligamentum flavum cells were divided into 4 groups, and transfected with small interfering RNA (siRNA), p38 siRNA, siRNA+3 ng/mL TGF-β1, and p38 siRNA+3 ng/mL TGF-β1 in groups A, B, C, and D, respectively. After 24 hours of transfection, immunofluorescence staining was performed to observe the expressions of p38 and phosphorylation p38 (p-p38); the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ in each group were detected by qRT-PCR; the protein expression of CTGF in each group was detected by Western blot. Results p38 pathway blocker SB203580 could significantly reduce the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ (P<0.05). After 24 hours of transfection, immunofluorescence staining showed positive staining with p38 and p-p38 expressions in groups A, C, and D and negative staining in group B. Compared with group A, the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ and relative protein expression of CTGF in group B decreased significantly (P<0.05), while those in groups C and D increased significantly (P<0.05); and those indicators significantly increased in group C than in group D (P<0.05). Conclusion TGF-β1/CTGF based on the p38 MAPK signaling pathway play an important role in the occurance and development of hypertrophy of human lumbar ligamentum flavum.
Objective To verify the potential of the recombinant adeno-associated virus 2 (rAAV2) vector as a strategy for human transforming growth factor β1 (hTGF-β1) gene transfer in degenerative intervertebral discs of rabbit, to investigate the gene transduction efficacy and to quantify the biologic effects on the proteoglycan level after gene transferring. Methods Rabbit models of disc degeneration were established by injecting the 25 μL fibronectin fragment (Fn-f, 1 mmol/ L), 4 weeks later,saline with or without virus was injected directly into 96 lumbar discs of 24 mature New Zealand white rabbits (male or female and weighing 1.7-2.2 kg) which were divided into 3 groups (n=8). Group A received the 25 μL rAAV2-hTGF-β1 (1 × 1012 vg/mL); group B received rAAV2-enhanced green fluorescent protein (rAAV2-EGFP); and group C received PBS. Two rabbits of groups A, C were killed 1 week after injection, the immunohistochemical staining for hTGF-β1 was performed on the sl ices of nucleus pulposus (NP) tissues. At 4, 8, and 12 weeks after gene transferring, NP tissues were harvested and cultured to quantify the changes of the proteoglycan level using 35S-sulfate incorporation assay. The expression of EGFP in group B was observed 12 weeks after injection. Results Immunohistochemical staining showed that extensive and intense positive immunohisochemical staining for hTGF-β1 were seen in group A when compared with group C 1 week after gene transferring. The nucleus pulposus tissues from the group A exhibited an increased synthesis of proteoglycan, which was significantly more than that from groups B and C (P lt; 0.05), and no significant difference was observed between group B and group C. The expression of EGFP in group B was high at 12 weeks. Conclusion The discs injected with rAAV2-hTGF-β1 can highly expressed the therapeutic proteins for more than 12 weeks, it is suggested that rAAV2 should be an valid vector for transferring exogenous genes in the degenerative disc. The therapeutic factors hTGF-β1 can efficiently increase the proteoglycan synthesis of the degenerative NP cells.
ObjectiveTo investigate the effect of transforming growth factor β1 (TGF-β1) induced proliferation of ligamentum flavum cells and ligamentum flavum hypertrophy and its effect on connective tissue growth factor (CTGF) expression.MethodsThe ligamentum flavum tissue in lumbar intervertebral disc herniation was extracted and the ligamentum flavum cells were isolated and cultured by collagenase pre-digestion method. Morphological observation, immunofluorescence staining observation, and MTT assay were used for cell identification. The 3rd generation ligamentum flavum cells were divided into 5 groups. The cells of groups A, B, C, and D were respectively sealed with 3 ng/mL TGF-β1, 50 ng/mL CTGF, 3 ng/mL TGF-β1+CTGF neutralizing antibody, and 50 ng/mL CTGF+CTGF neutralizing antibody. Serum free DMEM was added to group E as the control. MTT assay was used to detect the effects of TGF-β1 and CTGF on the proliferation of ligamentum flavum cells. Western blot was used to detect the expression of CTGF protein. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of collagen type Ⅰ, collagen type Ⅲ, and CTGF genes.ResultsThe morphological diversity of cultured ligamentum flavum cells showed typical phenotype of ligamentum flavum fibroblasts; all cells expressed collagen type Ⅰ and vimentin, and some cells expressed collagen type Ⅲ; MTT identification showed that with the prolongation of culture time, the absorbance (A) value of each generation of cells increased gradually, and the A value of the same generation of cells at each time point was significantly different (P<0.05), there was no significant difference in A value between the cells of each generation at the same time point (P>0.05). After cultured for 24 hours, MTT assay showed that the A value of cells in groups A and B was significantly higher than that of group E (P<0.05). After adding CTGF neutralizing antibody, the A value of cells in groups C and D decreased, but it was still higher than that of group E (P<0.05). There were also significant differences among groups A, C and groups B, D (P<0.05). Western blot analysis showed that the relative expression of CTGF protein in groups A and B was significantly higher than that in group E (P<0.05), while the relative expression of CTGF protein in groups C and D was significantly lower than that in group E (P<0.05), and the difference between groups A, C and groups B, D was also significant (P<0.05). qRT-PCR detection showed that the mRNA relative expression of CTGF, collagen type Ⅰ, and collagen type Ⅲ in group A was significantly higher than that in group E (P<0.05). After adding neutralizing antibody, the mRNA relative expression of genes in group C was inhibited and were significantly lower than that in group A, but still significantly higher than that in group E (P<0.05). The mRNA relative expressions of collagen type Ⅰ and collagen type Ⅲ in group B was significantly higher than that in group E (P<0.05), but the mRNA relative expression of CTGF was not significantly different from that in group E (P>0.05); after neutralizing antibody was added, the mRNA relative expression of collagen type Ⅰ and collagen type Ⅲ in group D was inhibited and was significantly lower than that in group B, but still significantly higher than that in group E (P<0.05); there was no significant difference in the mRNA relative expression of CTGF between group D and groups B, E (P>0.05).ConclusionTGF-β1 can promote CTGF, collagen typeⅠ, collagen type Ⅲ gene level and protein expression in ligamentum flavum cells, and TGF-β1 can synergistically promote proliferation of ligamentum flavum cells through CTGF.
ObjectiveTo observe transforming growth factor β3 (TGF-β3) gene expression and the chondrogenesis of bone marrow mesenchymal stem cells (BMSCs) after TGF-β3 gene is transfected into BMSCs of Diannan small-ear pig. MethodsRecombinant adenovirus 5 (rAd5) was extracted as gene vector and packed into recombinant adenovirus rAd5-TGF-β3, double enzyme digestion and PCR identification were performed. BMSCs were isolated and cultured from bone marrow of 2-month-old Diannan small-ear pigs (weighing, 12-15 kg), and the 2nd generation of BMSCs were harvested for experiments. The experiments were divided into 3 groups. BMSCs were transfected with rAd5-TGF-β3 as experimental group and with empty vector as control group, and non-transfected BMSCs were used as blank control group. The transfection efficiency of exogenous gene was identified by flow cytometry, TGF-β3 protein expression by immunofluorescence and Western blot. The cell morphology of experimental group was observed by inverted phase contrast microscope, and the expression of collagen type II in each group was detected by Western blot. ResultsThe rAd5-TGF-β3 recombinant adenovirus was successfully constructed and transfected into BMSCs. Green fluorescence was observed by immunofluorescence microscope. Flow cytometry test showed the best transfection at 72 hours (transfection efficiency of 84.86%). Immunofluorescence staining showed that the expression of TGF-β3 protein was obvious at 72 hours; Western blot showed that there was a TGF-β3 positive band with a relative molecular mass of 30×103, while the control group and blank control group had no positive band. Obvious chondrogenic differentiation was observed in the experimental group after transfection in vitro, while the control group and blank control group had no obvious chondrogenic differentiation. Western blot showed that there was collagen type II positive band with a relative molecular mass of 130×103 at 21 days after culture, while the control group and blank control group had no positive band. ConclusionrAd5-TGF-β3 gene can be successfully transfected into BMSCs via adenovirus vectors, and stable expression of TGF-β3 protein can be observed, enhancing BMSCs differentiation into chondrocytes, which may provide an experimental basis for gene therapy of joint cartilage defects.