Objective To investigate the possible mechanism of the fibroblasts inducing the vascularization of dermal substitute. Methods Fibroblasts were seeded on the surface of acellular dermal matrix and cultivated in vitro to construct the living dermal substitute. The release of interleukin 8 (IL 8) and transfonming growth factor β 1(TGF β 1) in culture supernatants were assayed by enzyme linked immunosorbent assay, the mRNA expression of acid fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) were detected by RT-PCR. Then, the living substtute was sutured to fullth ickness excised wound on BALBouml;C m ice, and the fate of fibroblast w as observed by using in situ hybridizat ion. Results Fibroblasts cultured on acellular dermalmat rix p ro liferated and reached a single2layer confluence. Fibroblasts could secret IL 28 (192. 3±15. 9) pgouml;m l and TGF-B1 (1. 105±0. 051) pgouml;m l. There w as the mRNA exparession of aFGF and bFGF. Fibroblasts still survived and proliferated 3 weeks after graft ing. Conclusion Pept ides secreted by fibroblasts and its survival after graft ing may be relat ive to the vascularizat ion of the dermal subst itute.
OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
Objective To observe the effects of keratinocytes on proliferation and collagen secretion of fibroblasts. Methods The conditioned medium,collected from cultured keratinocytes, was added to the cultured fibroblasts as the tested groups(12.5％, 25% and 50％ groups) and DMEM as control group. The MTT, hydroxyproline coloricmetric method and flow cytometer were employed to measure the fibroblast proliferation, the collagen secretion andthe change of the cell cycle.Results In fibroblast proliferation, the absorbency(A) value of tested groups was significantly different from that of the control group (P＜0.01). A value increased as increasing concentration, there was statistically significant difference betweetheconcentrations of 25%,50% and the concentration of 12.5%(P＜0.01), but no statistically significant difference between the concentrations of 25% and 50%(P＞0.01). In collagen secretion, there was no statistically significant difference between the tested groups and the control group(P＞0.01), and between the tested groups(P＞0.01). In cell cycle, 50% of conditioned medium could make the fibroblast pass the limit of G1/S and S/G2 period, the cell rates of S,G2-M period increased. Conclusion The conditioned medium from keratinocytes can increase fibroblasts proliferation, have little effect on general collagen secretion.
Objective To determine whether fibroblasts can be used to promote endochondral bone formation in vivo by transfer of human bone morphogenetic protein-2(hBMP-2) into fibroblasts. Methods pcDNA3-hBMP-2 was constructed by use of gene clone and recombined technique.NIH3T3 fibroblasts were transfected with pcDNA3hBMP-2. The positive cell clones were selected with G418. In NIH3T3 fibroblaststransferred with pcDNA3-hBMP-2, the expression of hBMP-2 was determined by in situ hybridization and immunohistochemical analysis; alkaline phosphatase activity was measured. hBMP-2producing fibroblasts were implanted into nude mouse muscle to observe endochondral bone formation in vivo. Results pcDNA3-hBMP-2 was successfully constructed. In NIH3T3 fibroblasts transfected with -pcDNA3-hBMP-2,the BMP-2 expression was stable; alkaline phophatase activity was much higher than that in nontransfectedNIH3T3 cells. Endochondral bone formation invivo was observed at the site of implantation 4 weeks later.Conclusion Fibroblasts transfected by hBMP-2 gene can be used to promote endochondral bone formation in vivo.
OBJECTIVE :To investigale effect of subretinal fluld(SRF)on proliferalion of the cellular elements of PVR.
METHOD:The effect of SRF of 28 patients with rhegmatogenous retinal detachment proliferation of the cultured human retinal pigment epithelial cells(RPE),retinal glial cells (RG),and fibroblast (FB)was observed and detected by the methods of cell-counting and 3H-TdR in DNA synthesis.
RESULTS:The range of proliferatinn-stimulating activity was 52.5%~233.3%,
36.4% ~ 177.8%，55.4% ~277.8% above the baseline in 1:10 dilution of these 3 kinds ,of cellular elements,and there was no significant difference among them.
CONCLUSION ;The stimulating effect of SRF on the cellular proliferation was thougt to be due to the actions from certain growth factors.
（Chin J Ocul Fundus Dis,1996,12: 233-235）
Objective To evaluated the role of wt-P53 protein in telomerase regulation in keloid fibroblasts(KFBs). Methods The fibroblasts were derived from humankeloid tissue which was proved by pathological diagnosis. KFBs were divided into 2 groups, the transfection group and the untransfection group. wt-p53 gene was transfected into the fibroblasts by adenovirus vectors in the transfection group. The KFBs untransfected with wt-p53 gene served as control (untransfection group). After 48 hours of transfection, the expression of wt-P53 protein was analyzed by both Western blotting and immunofluorescence method, respectively. The telomerase activity was evaluated by TRAP-ELISA after 1-7 days of transfection. Results All the KFBs from 2 groups expressed wt-P53 protein. But the expression level of wt-P53 protein in the transfection group was significantly higher than that in the untransfection group.At the same time of high expression of wt-P53 protein, the telomeraseactivity of KFBs in transfection group was significantly lower than that in theuntransfection group(P＜0.05). Conclusion High level expression of wt-P53 protein can transiently inhibit the telomerase activity of KFBs.
ObjectiveTo investigate the histological changes and vascularization of the porcine acellular dermal matrix (P-ADM) processed with matrix metalloproteinase 7 (MMP-7) (P-ADM-pm) after implanted into rats.
MethodsSixty-two pieces of porcine reticular layer dermis which were from the pig abdominal skin and obtained by using a mechanical method, were randomly divided into group A (n=31) and group B (n=31). The porcine reticular layer dermis in 2 groups were treated with decellularization (P-ADM), then the P-ADM in group B were treated with processing by MMP-7 (P-ADM-pm). Thirty adult male Wistar rats were selected. P-ADM (group A) and P-ADM-pm (group B) were subcutaneously transplanted into the left and right fascia lacuna, respectively. The implants were harvested from 6 rats at 3, 7, 14, 21, and 28 days after implantation, respectively. Gross, histochemical, and immunohistochemical observations, and scanning electron microscopy (SEM) examination were performed to observe host cells, microvessels infiltration and histological changes in the implants.
ResultsNo rat died in the experiment, incision healed well and no obvious inflammatory reaction was seen in all rats. Gross observation suggested that the implants of 2 groups were encapsulated by a thin layer of connective tissue at 7 days after implantation. With the time of implantation, the microvessels increased and coarsened, and the changes of group B were more obvious than those of group A. At 21 days, the microvessels of 2 groups decreased, and the implants of group B showed complete vascularization. The histochemical and immunohistochemical observations showed that group A had more severe inflammatory response than group B. Fibroblasts and microvessels in group B appeared in the superficial zone of implant at 3 and 7 days after implantation and they could be observed in the center zone of implant at 14 and 21 days. However, fibroblasts and microvessels in group A appeared in the superficial zone of implant at 3 and 14 days and they could not be observed in the center zone of implant at 28 days. Fibroblasts and microvessels of group B were significantly more than those of group A (P < 0.05). SEM examination showed that more fibroblasts and new collagen fibrils were observed in group B at 14 days.
ConclusionThe host response to P-ADM-pm is similar to normal wound healing, and P-ADM-pm as implantable scaffold material plays a good template conduction role.
Objective To investigate an effect of compressive stress on proliferation and apoptosis of human hyperplastic scar fibroblasts（HSFb） in vitro. Methods HSFb were obtained from a 20 year old female patient who developed a hyperplastic scar 3 months after operation for a largearea burn. HSFb were isolated, and were cultured in vitro with the simplified airpressure controlled cellculture instrument, and then they were randomly divided into the following 8 groups: the control group (no stress) and the 7 continuous compressive stress groups, which respectively underwent the 5, 10, 15, 25, 50, 100 and 150mmHg(1mmHg=0.133 kPa) pressure treatment for 4d ays. The absorbance (A) of the cell and the inhibition ratio (IR) of the cell proliferation were determined by the MTT assay, the cell growth cycle was determined by the flow cytometer, and the cell apoptosis was observed by the AnnexinV binding with PI labeling method. Results In the 5, 10, 15, 25, 50, 100 and 150mmHg pressure groups and the control group, the A values of the cells were 0.228±0.004, 0.226±0.003, 0.213±0.005, 0.180±0.005, 0.172±0.007, 0.165±0.004, 0.164±0.004 and 0.230±0.005, respectively; the IRs of the cell proliferation were 0.8%，2.0%，7.3%，21.7%，252%， 28.2% and 0, respectively;the ratios of the cells in G1 were 71.80％±0.44％, 72.32％±0.40％, 74.56％±1.01％, 82.82％±2.76％, 86.77％±2.06％, 88.23％±1.27％, 89.11％±1.74％ and 71.6％±0.49％,respectively; the cell apoptosis ratios were 4.22％±0.49％, 5.12％±0.74％ , 8.58％±0.79%, 19.28％±1.40%, 25.60％±1.21%, 3580％±2.39%, 36.18％±2.38% and 4.00％±0.36％, respectively. In the 5 and 10mmHggroups there were no statistically significant differences in all the above parameters when compared with those in the control group (P＞0.05); however, in the 15, 25,50, 100 and 150mmHg groups there were statistically significant differences in the above parameters when compared with those in the control group (P＜0.05). Furthermore, in the 10, 15, 25 and 50 mmHg groups, there were statistically significant differences in the Avalue of the cells and the ratios of the cells in G 1 when compared with each other (P＜0.01). By contrast, there were no statistically significant differences in the 50, 100 and 150 mmHg groups when compared witheach other (P＞0.05). In the 10, 15, 25, 50 and 100mmHg groups there werestatistically significant differences in the cell apoptosis ratio when comparedwith each other (P＜0.01). In the 100 and 150 mmHg groups there were no such statistically significant differences when compared with each other (P＞0.05).Conclusion A continuous compressive stress when given properly can have a combined effect of the proliferation inhibition and the apoptosis promotion on HSFb in vitro, and this kind of combined effects can becomeone of the important mechanisms for the pressure therapy in treating hyperplastic scar.
ObjectiveTo investigate the antibacterial pretreatment protocol for primary fibroblast cell culture from transbronchial biopsies in patients with benign tracheal stenosis (BTS).
MethodsFifteen specimens of intratracheal hyperplastic granulation tissue were obtained from 14 BTS patients by transbronchial biopsies. The tissues were divided into 3 groups according to different antibacterial pretreatment with 5 specimens in each group. An usual concentration of antibiotics pretreatment group (group 1) was pretreated by washing with PBS contained 1%-2% penicillin/streptomycin. A high concentration of antibiotics pretreatment group (group 2) was pretreated by washing with PBS contained 6% penicillin/streptomycin. An alchohol and high concentration of antibiotics pretreatment group (group 3) was pretreated by washing with 75% alcohol 3-4 seconds firstly,then by washing with 6% penicillin/streptomycin. After different pretreatment,all tissues were cultured with tissue culture method in the same condition.
ResultsThe primary fibroblasts were successfully cultured from the tissue pretreated by method 2 and 3,but not cultured from the tissue pretreated by method 1 with large amount of bacteria. There were significant differences in the furthest radius of cell proliferation between different culture time points in three groups (P<0.01). The differences in the furthest radius of cell proliferation between three groups were not different at 24,48 or 72 h (P>0.05),but were significant between three groups at 96 h (P<0.05).
ConclusionAn pretreatment protocol with high concentration of antibiotics or 75% alcohol is feasible in human primary fibroblasts culture from small specimens obtained by transbronchial biopsy.
Objective To explore the osteogenic potential of cervical intervertebral disc fibroblasts in vitro, to investigate the regulatory factors of recombinant human bone morphogenetic protein 2(rhBMP-2) and tumor necrosis factor α(TNF-α) on osteogenic phenotype of fibroblasts and to discuss the condition that facilitates osteogenesis of fibroblasts. Methods Theannulus fibroblasts cell lines of experiment goats were established in vitro and the biologicspecificity was found. According to different medias, 4 groups were included in this experiment: control group, TNF-α group ( 50 U/ml TNF-α), rhBMP-2 group (0.1 μg/ml rhBMP-2) and TNF-α+rhBMP-2 group (50 U/ml TNF-α+0.1 μg/ml rhBMP-2). Thefibroblasts were incubated in the media for about 3 weeks,and then the markers for osteogenic features were investigated by biochemistry, histochemistry observations. Results rhBMP-2 and TNF-α had no effect on the proliferation of fibroblasts from the experiment goats. rhBMP-2 or TNF-α could stimulate fibroblasts to secrete alkaline phosphatase and collagen type Ⅰ. The combined use of rhBMP-2 and TNF-α or the single use of rhBMP-2 could make fibroblasts to secrete osteocalin and the morphological changes of the fibroblasts were very obvious. Histochemical study of the nodules with specific new bone labeler(Alizarin red S) revealed positive reaction, denoting that the nodules produced by the fibroblasts werebone tissues. There was statistically significant difference(Plt;0.05) inALP activity between 3 experimental groups and control group and in secretion of osteocalcin between rhBMP-2 group, TNF-α+rhBMP-2 group and control group. Conclusion The results point out clearly that rhBMP-2 can induce theosteogenic potential of annulus fibroblasts in vitro.
