OBJECTIVE: To analysis the biological characteristics of human fibroblasts transfected by human telomerase reverse transcriptase (hTERT) eucaryotic expression plasmid pGRN145. METHODS: Fibroblasts from children’s foreskin were isolated and cultured in vitro, and the fibroblasts were transfected by pGRN145 with Lipofec-tAMINE PLUS Reagent. After strict screening of hygromycin B, the positive clones were subcultured. The telomerase activity was detected by RT-PCR and TRAP-PCR technique. The cell generation cycle and apoptosis rate were detected by flow cytometry to investigate the proliferative characteristics after transfection, and the chromosome karyotype of transformed cells was analyzed. The collagen secreted by transformed cells was detected by immunohistochemical staining. RESULTS: The morphological properties of fibroblasts did not change obviously after transfection. There were telomerase activity in transfected fibroblasts, while it could not be detected in pre-transfection fibroblasts. The cell generation cycle had no obvious changes between pre-transfection and post-transfection. However, the apoptosis rate of transfected fibroblasts were decreased compared with that of pre-transfection. The fibroblasts transfected by pGRN145 maintained the normal diploid karyotype, as well as the cells could normally secret type I and III collagen. CONCLUSION: The human fibroblasts transfected by pGRN145 has telomerase activity with prolonged life span of culture, which preliminarily proves the availability of establishing standard seeding cell lines of tissue engineering by hTERT plasmid transfection techniques.
Objective To study the effects of dermal template on the biological behaviors of fibroblasts during wound healing. Methods A total of 120 rats were made fullthickness wound modes on the dorsum and divided into 4 groups,in group 1, the wounds were allowed to heal by contraction（ConT）；in group2, the wounds covered with fullthickness skin grafts( FTSG); in group 3, the wounds were with split thickness skin grafts (STSG); and ingroup 4, the wounds were covered by dermal regeneration template with overlying thin splitthickness autograft (ADMT).The specimens were obtained at one week, two weeks, four weeks, six weeks,and twelve weeks respectively. The expressions of α smooth muscle actin(αSMA，characteristic of MFB）,fibronectin(FN),integrin α2,β1 and transforming growth factor β1(TGF-β1) were examined by immunohistochemical analysis. Results Positive expression of α-SMA、FN、integrin α2β1 and TGF-β1 in ADMT groups was significantly lower than that in STSG group and ConT group, but higher than that in FTSG group（P＜0.05）. Conclusion Dermal regeneration template can inhibit the transformation of FB to MFB and restrain the expressionof FN,integrin α2,β1,and TGF-β1 in fibroblasts which might reduce thepossibility of hypertrophyic scaring, and improve wound healing.
Objective To construct a mammalian expression vector ofbasic fibroblast growth factor (bFGF) and to investigate the expression of bFGFin vitro and in vivo. Methods A mammalian expression vector pcDNA3.1/myc-His(-)C-bFGF was constructed with gene cloning technique. The mammalian expression system was prepared and purified. The expression of bFGF cDNAin cultured transfected cells was examined by RT-PCR and cell immunohistochemistry. The recombinant plasmids, pcDNA3.1/myc-His(-)C-bFGF and pCD2-VEGF121, were transferred into rabbit cervical muscle by direct injection of plasmid following electric pulses in vivo. The transferred gene expression and the biological effect were measured by use of histochemistry and immunohistochemistry analysis. Results The eukaryon expression system pcDNA3.1/myc-His(-)C-bFGF could express the target protein bFGF in vitro. The recombinant plasmids, pcDNA3.1/myc-His(-)C-bFGF and pCD2-VEGF121 were transferred into muscles flap in vivo successfully. The active proteins bFGF and VEGF121were expressed at high levels. Blood vessels increased significantly in the muscles, and blood circulation was improved by local angiogenesis. Conclusion Theeukaryon expression vector of bFGF is constructed and can be expressed successfully in vitro and in vivo. That is a primary preparation for the research on tissue transplantation and tissue engineering with bFGF gene therapy.
OBJECTIVE: To explore the effect of Fas/Apo-1 and Bcl-2 gene expression on mechanism of scar formation. METHODS: Immunohistochemical method was applied to defect the expression of Fas and Bcl-2 protein in fibroblasts from 10 cases with normal skin, 10 cases with hypertrophic scar and 10 cases with keloid. RESULTS: The positive expression rate of Bcl-2 protein in keloid was 83.2%, significantly higher than that in hypertrophic scar (38.6%), (P lt; 0.01), and the positive expression rate in hypertrophic scar and keloid was higher than that in normal skin (6.78%), (P lt; 0.01). But the positive expression rate of Fas/Apo-1 protein was 78.4% in normal skin 80.4% in hypertrophic scar, 84.4% in keloid respectively, which showed no significant difference among them (P gt; 0.05). CONCLUSION: Bcl-2 gene but Fas gene may take part in the formation of pathologic scar.
ObjectiveTo investigate relationship between ultrastructural changes and expression of basic fibroblast growth factor of diabetic retinopathy in rats.MethodsDiabetes was induced in rats with a single injection of streptozotocin (STZ) and divided into normal control group and 1- , 3- and 5- month diabetes group. The paraffin slide was observed by in-situ hybridization and immunohistochemistry, and retinal ultrastructure was examined by transmission electron microscopy.ResultsNo change of retinal ultrastructure was found in the control group. Different degrees of ultrastructure lesion were found in 1-month diabetic rats with fragmental increase of thickness of basement membrane, swelling of endothelial cells and obvions fingerlike processes in the capillary cavity, disconcentration of heterochromatin both in endothelium and pericyte, and swelling and degeneration of mitochondrion. The edema of endothelial cells of 3-month diabetic rats was more serious than that of 1month ones, and the capillary cavity was nearly occluded. In 5-month diabetic rats, the basement membrane was unevenly thickened, or obviously split. The positive rate of in-situ hybridization in 3-month diabetic rats was 77.8% while the positive rate of immunohistochemical stain was 55.6%, which increased to 88.9% in 5-month diabetic rats.ConclusionsThe occurrence of the ultrastructural changes in STZ rats with diabetic retinopathy is earlier than that of the expression of bFGF.(Chin J Ocul Fundus Dis, 2003,19:348-351)
OBJECTIVE To study the early protective effects of basic fibroblast growth factor(bFGF) on the experimental acute spinal cord injury. METHODS Thirty-four SD rats were randomly divided into three groups, and were subjected to contusion of thoracolumbar spinal cord. A thin plastic tube was placed in subarachnoid space below the injury level for perfusion. The bFGF-treated rats were received 20 microliters bFGF(containing bFGF 100 U) at once, 30 min, 1, 2, 3, 4, 6, 12, 24 and 48 hours after injury, and an equal volume of normal saline was given to the control group at the same time. The injured spinal cord was detected by morphological observation and biochemical index after injury. RESULTS The degree of ionic disorder in bFGF-treated rats was significantly ameliorated and the contents of H2O were also markedly decreased. The morphological finding showed that the damages of gray and white matter in bFGF-treated rats were slighter than those of saline-treated rats. CONCLUSION bFGF has some protective effects on the secondary lesion of early spinal cord injury in rats.
This study is aimed to investigate the effects of mechanical stretch on the expression of transforming growth factor-β1 (TGF-β1) and fibroblast growth factor-2 (FGF-2), and the signaling pathway in human bronchial epithelioid (16HBE) cells under mechanical stretch. Using loading device with flexible substrate (FX-4000T) to stretch 16HBE cells, we found that the stretching elongation was 15%, at frequency of 1 Hz, stretching for 0.5 h, 1 h, 1.5 h and 2 h. Choosing the higher expression of TGF-β1, FGF-2 and Ca2+ group to carry out intervention experiments, we used the cells pretreated with canonical transient receptor potential 1 (TRPC1) channel antagonist SKF96365, protein kinase C (PKC) inhibitor HA-100, and thereafter mechanical stretch to interpose. Compared with those in the blank control group, TGF-β1 and FGF-2' protein and mRNA, intracellular Ca2+ fluorescence intensity were higher, and the differences were statistically significant (P < 0.05) at the 4 time points, 0.5 h, 1 h, 1.5 h and 2 h. At 0.5 h, the increasing rate was the highest. TGF-β1 protein and mRNA, FGF-2 protein and mRNA, intracellular Ca2+ luorescence intensity in the stretch+SKF96365 and stretch+HA-100 intervented group were decreased, the differences were statistically significant than those in 0.5 h stretch group (P < 0.05) without intervention. The expression of TGF-β1, FGF-2 was up-regulated in 16HBE cells under mechanical stretch, PKC, TRPC1, and Ca2+ may participate in the signal path.
ObjectiveTo investigate the effect of Wnt5a derived from tumor-associated fibroblasts （CAFs） on the migration and invasion of gastric cancer cells. MethodsThe differentially expressed genes Wnt5a between CAFs and normal gastric fibroblasts (NGFs) in gastric cancer tissues and their corresponding normal gastric tissues using the GEO database GSE194261 dataset were screened. Immunohistochemical method was used to detect the expression of Wnt5a protein in tissue samples of clinical gastric cancer patients, and the relationship between Wnt5a protein expression and clinicopathological features of gastric cancer was analyzed. CAFs and NGFs were extracted from fresh surgical specimens of gastric cancer patients, and the expression of Wnt5a in CAFs was detected by real-time fluorescence quantitative-polymerase chain reaction and Western blot experiment. Transwell invasion and migration experiment was used to observe the effects of CAFs, inhibition of Wnt5a expression in CAFs and different concentrations of recombinant Wnt5a protein on the migration and invasion ability of gastric cancer MGC-803 and MKN-28 cell lines in vitro. ResultsThrough the screening of GEO database GSE194261 data set, it was found that Wnt5a was more expressed in CAFs than NGFs (P<0.05). Immunohistochemical results showed that the expression of Wnt5a protein in gastric cancer tissues was significantly stronger than that in normal gastric tissues (P<0.05), and the expression of Wnt5a protein was related to T stage of tumor (χ2=5.035, P<0.05), but not related to gender, age, degree of tumor differentiation, lymph node metastasis, vascular invasion and nerve invasion (P>0.05). Inhibiting Wnt5a derived from CAFs could inhibit the invasion and migration of gastric cancer cells. By stimulating gastric cancer cells with different concentrations of human recombinant Wnt5a protein, it was found that when the concentration of human recombinant Wnt5a protein was greater than 100 ng/mL, the invasion and migration abilities of MGC-803 and MKN-28 gastric cancer cells were significantly increased (P<0.05). ConclusionWnt5a is highly expressed in CAFs derived from the interstitial tissue of gastric cancer, which is related to the invasion depth of gastric cancer and can promote the invasion and migration of gastric cancer cells.
Porpose To investigate the optimal concentration of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on DNA synthesis and their synergism indensity arrested human retinal pigment epithelial (RPE) cells. Methods Growth factor effects in cultured human RPE of the 6th generation were assessed by [3 H]-thymidine incorporation and radioautography. Results EGF and bFGF were potent stimulators when used alone,and their optimal concentrations were 10ng/ml in DMEM and 1ng/ml in 2% serum DMEM.When used in combination (10ng/ml EGF and 10ng/ml bFGF),they caused a significant enhancement of [3 H]-thymidine incorporation about 2.96 times. Conclusion EGF and bFGF were potent stimulators in RPE cells,and demonstrated synergism in their action. (Chin J Ocul Fundus Dis,1998,14:98-100)
Objective To build artificial dermis by using the acellular dermis matrix(ADM), collagen membrane and collagen gel as scaffolds. Methods The fibroblasts were isolated by enzyme from infant skin and were cultivated in the DMEM medium. After 14 days when the fibroblasts were seeded into 3 different scaffolds, the autografts were detected by HE staining, transmission electron microscope and scanning electron microscope. Results ①The fibroblasts obtained from the fullskin by enzyme could be passaged in the Dulbecco’s modified Eagle’s medium 2high gluco se w ith 10% calf bovine serum. ②A layer of fibroblastsw ere found on the surface of th ree different scaffo lds, the fibroblasts could grow into the co llagen membrane and the co llagengel, but could no t be found in the inner of ADM. ③A rt ificial derm is cont racted slightly by inoculat ing fabricat ion on collagen membrane and ADM , and the fibroblasts on them w ere no t act ive in proliferat ing; but the art ificial derm is built by the collagen gel cont racted obviously. Conclus ion The art ificial dermis built by ADM , collagen membrane and collagen gel as scaffolds have a preferable structure for an ideal subst itute of sk n, and can beused as the graft in the next experiments.