An optimized growth factor cocktail for ovine mesenchymal stem cells

Growth factors that regulate proliferation, migration, and invasion of ovine mesenchymal stem cells (oMSCs) are not well defined. In this study, we have evaluated five growth factors for their ability to initiate and support in vitro proliferation, migration, and invasion of oMSCs. oMSCs were exposed to different doses and combinations of the growth factors: basic fibroblast growth factor (bFGF), transforming growth factor-β (TGF-β), epidermal growth factor (EGF), insulin growth factor-I (IGF-I), connective tissue growth factor, and platelet-derived growth factor-AB (PDGF-AB). Cellular proliferation, motility, and invasiveness were assayed. The most proliferative stimulating growth factors are PDGF-AB+TGF-β and PDGF-AB+IGF-I. Combinations EGF+bFGF and EGF+bFGF+PDGF-AB demonstrated the greatest ability to stimulate migration. Moreover, the triple cocktail EGF+bFGF+TGF-β has the most significant effect on invasion. Different growth factor cocktails are required to enhance proliferation, migration, and invasion. These results may be useful for the development of a tissue-engineered heart valve by stimulating cellular repopulation.     

Regulation of Migration of Human Colonic Myofibroblasts

Background and Aim: The migration of mesenchymal cells to areas of mucosal or submucosal tissue damage is an essential factor for wound healing in the intestine. Thus far, neither migration inducing factors nor signal transduction cascades involved in the migration of colonic myofibroblasts (CMF) have been studied in detail. Methods: Primary CMF were isolated from the mucosa of surgical specimens or endoscopic biopsies. Migration assays of CMF were performed in the modified 48-well Boyden chamber. Secreted growth factors were quantified by ELISA. Results: CMF secrete autocrine or paracrine migration stimulating factors. Culture supernatant of CMF collected after 24, 48, and 72 h (=conditioned media) stimulated the migration of CMF ( 48.9 &#45 4.5; 60.3 &#45 5.3 and 67.8 &#45 6.4 cells/hpf, respectively). Heating of conditioned media to 95°C or addition of cycloheximide during the conditioning period abolished migration. Addition of PDGF-AB (2.5-50 ng/ml) or IGF-I (10-300 ng/ml) to CMF conditioned media further increased the migration of CMF to a maximum of 177 and 160%, respectively, when compared to the migration induced by conditioned medium alone. Addition of EGF (2.5-50 ng/ml) or TGF- &#103 1 (1-50 pg/ml) caused an increased CMF migration up to 139 and 128%, respectively. MCP-1 (5-50 ng/ml) and bFGF (10-200 ng/ml) had no effect on CMF migration. Conclusion: The growth factors PDGF-AB, IGF-I, EGF and TGF- &#103 1 stimulate the migration of CMF. However, factors secreted by CMF are essential for their ability to migrate in response to these growth factors. The identification of physiologically relevant migration inducing factors may help to elucidate the network of interactions and the complex mechanisms involved in intestinal wound healing or fibrosis.     

Modulation of Transforming Growth Factor-β Actions in Rat Osteoblast-like Cells: The Effects of bFGF and EGF

Abstract

The present study examines how the mitogenic and differentiation functions of transforming growth factor-β (TGF-β) are modulated by basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) in primary cultures of rat osteoblast-like (ROB) cells. TGF-β, bFGF, and EGF individually stimulated [³H]thymidine incorporation and cell proliferation in a dose range of 0.01-10 ng/ml. When studied in combination, high doses of bFGF and EGF were additive to low doses of TGF-β. The additive effects of bFGF and EGF on mitogenesis diminished with increasing doses of TGF-β. These three factors also decreased alkaline phosphatase activity individually within the same dose range. When cells were treated with the combined factors, only high doses of bFGF and EGF were additive to the TGF-β inhibition. We were unable to detect any change in collagen synthesis with each individual factor or in combined treatments. In addition, TGF-β or bFGF alone or in combination did not affect fibronectin synthesis. Our studies showed that the biological functions of TGF-β can be modulated by bFGF and EGF in ROB cells. The pattern of modulation is varied depending on the specific function examined.     

Comprehensive analysis of chemotactic factors for bone marrow mesenchymal stem cells

To understand which growth factors/cytokines can affect migration of mesenchymal stem cells (MSCs) to injured tissues, we compared the effects of many (26) growth factors/cytokines on the migration activity of rabbit and human MSCs using a microchemotaxis chamber. Among them, platelet-derived growth factor (PDGF)-BB, PDGF-AB, epidermal growth factor (EGF), HB-EGF, transforming growth factor (TGF-alpha), insulin growth factor (IGF-I), hepatocyte growth factor (HGF), fibroblast growth factor (FGF-2), and thrombin consistently enhanced the migration of rabbit and human MSCs at appropriate concentrations. PDGF-BB showed the greatest effect on migration. Various combinations of these factors further enhanced the migration of MSCs, whereas combinations of factors that shared common cell-surface receptors did not induce the additive stimulation. On the other hand, some combinations, including that of FGF-2 or thrombin with PDGF-BB, suppressed the migration activity of MSCs. These findings suggest that combinations of growth factors are important to eliciting the maximal chemotactic effect. The factors that induced the migration of MSCs also enhanced their proliferation, suggesting that migration and proliferation can take place simultaneously. The above factors were also effective in stimulating the migration of fibroblasts, but thrombin alone selectively enhanced the migration of MSCs, suggesting that thrombin is useful to stimulate migration of MSCs without migration of fibroblasts.     

In vitro studies on clonal growth of chondrocytes in thanatophoric dysplasia

Thanatophoric dysplasia (TD) is characterized by a disorganized growth plate with markedly reduced proliferative and hypertrophic cartilage zones. Therefore, we studied in vitro the proliferation rates of articular chondrocytes from five TD patients and age-matched controls in response to bFGF, IGF-I, IGF-II, and TGF-β1. In human fetal controls bFGF was the most potent growth factor. Clonal growth of articular chondrocytes in response to bFGF was reduced in two of five TD patients and slightly below the range of controls in a third case. Stimulation of chondrocyte proliferation by IGF I and II was reduced in the patient whose response to bFGF was most markedly impaired. The effect of TGF-β1 ranged from normal to slightly elevated values in TD fetuses. These results indicate heterogeneity of the underlying defects in TD. Low proliferative responses of chondrocytes to bFGF and IGF-I/II are likely to play a key role in the pathogenesis of some cases. In two of five patients studied, the mechanisms of bFGF and IGF-signal transduction are candidates for the primary molecular defect. © 1996 Wiley-Liss, Inc.     

Immunohistochemical expression of growth factors in subacute thyroiditis and their effects on thyroid folliculogenesis and angiogenesis in collagen gel matrix culture

The inflammatory-mechanistic basis of subacute thyroiditis remains unclear. To elucidate the roles of vascular endothelial cell growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor-BB (PDGF), transforming growth factor-β1 (TGF-β1) and epidermal growth factor (EGF) in the inflammatory process, their immunoexpression was examined in biopsy specimens of ten cases. At the granulomatous stage, all cases expressed VEGF, bFGF, PDGF, and TGF-β1 in monocytes/macrophages infiltrating into follicle lumina, and in both epithelioid histiocytes and multinucleated giant cells of the granulomas. In fibroblasts and endothelial cells around the granulomas, all cases displayed VEGF, bFGF, and PDGF, but TGF-β1 was detected only in fibroblasts in two cases. No cases expressed EGF in any of the above cell types. At the regenerative stage, all cases expressed VEGF, bFGF, and EGF in regenerating thyrocytes, whereas three and no cases displayed PDGF and TGF-β1, respectively. Ten, seven and six cases expressed PDGF in fibroblasts, endothelial cells, and monocytes, respectively. In these cell types, all cases expressed VEGF and bFGF, whereas no cases displayed TGF-β1 and EGF. To estimate the roles of these growth factors in thyroid tissue regeneration, their effects on thyroid folliculogenesis and angiogenesis were examined using collagen gel culture of thyrocytes and endothelial cells, respectively. Cell proliferation was also studied by bromodeoxyuridine (BrdU) uptake. EGF decreased follicle formation and TGF-β1 drastically inhibited it, but the others had no effect. VEGF showed the greatest effect on vessel formation, although all of the others promoted it. EGF and VEGF or bFGF caused the highest BrdU uptake in thyrocytes and endothelial cells, respectively. The data suggest firstly, that at the granulomatous stage of subacute thyroiditis, growth factor-rich monocytes/macrophages infiltrating into follicle lumina trigger the granulomatous reaction, and VEGF, bFGF, PDGF, and TGF-β1 produced by the stromal cell types tested mediate the reaction; secondly, that at the regenerative stage, EGF serves follicle regeneration through its mitogenic effect on thyrocytes, although some cofactors with EGF are involved in folliculogenesis and the decreased expression of TGF-β1, a fibrogenic factor, contributes to thyroid tissue repair; and thirdly, that VEGF and bFGF are more responsible for the angiogenesis at both stages than the other factors studied. Copyright © 1999 John Wiley & Sons, Ltd.     

Effect of growth factors on nuclear and mitochondrial ADP-ribosylation processes during astroglial cell development and aging in culture.

Epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I) and insulin (INS) are powerful mitogens and may regulate gene expression in cultured astrocytes by ADP-ribosylation process. Nuclear poly-ADP ribose polymerase (PARP) and mitochondrial monoADP-ribosyltransferase (ADPRT) are the key enzymes involved in poly-ADP-ribosylation and mono ADP-ribosylation, respectively. In this investigation the effect of EGF, bFGF, IGF-I or INS on nuclear PARP and mitochondrial ADPRT activities were assessed in nuclei and mitochondria purified from developing (30 DIV) or aging (90 and 190 DIV) primary rat astrocyte cultures. A marked increase of PARP activity in bFGF or IGF-I treated astroglial cell cultures at 30 DIV was found. Nuclear PARP and mitochondrial ADPRT activities were greatly stimulated by treatment with EGF or INS alone or together in astrocyte cultures at 30 DIV. Nuclear PARP and mitochondrial ADPRT activities showed a more remarkable increase in control untreated astrocyte cultures at 190 DIV than at 90 DIV. These findings suggest that ADP-ribosylation process is involved in DNA damage and repair during cell differentiation and aging in culture. Twelve hours treatment with EGF, INS or bFGF significantly stimulated nuclear PARP and mitochondrial ADPRT activities in 190 DIV aging astrocyte cultures. The above results indicate that EGF, INS and bFGF may play a crucial role in the post-translational modification of chromosomal proteins including ADP-ribosylation process in in vitro models. This suggests that growth factors regulate genomic stability in glial cells during development and maturation, stimulating nuclear and mitochondrial ADP-ribosylation processes in developing or aging astrocyte cultures.     

Comparison of fibrin clots derived from peripheral blood and bone marrow

Background: Autologous fibrin clots derived from peripheral blood (pb-fibrin clot) and bone marrow (bm-fibrin clot) are thought to be effective for tissue regeneration. However, there is no report detailing the amount of growth factors in pb-/bm-fibrin clot. In this study we evaluated the amount of growth factors in human pb-/bm-fibrin clot, and prove the validity of fibrin clot for clinical use. Methods: Human pb-/bm-fibrin clots were obtained during surgery. In the first experiment, enzyme-linked immunosorbent assay (ELISA) was performed for detecting the amount of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor basic (bFGF), hepatocyte growth factor (HGF), transforming growth factor-beta (TGF-β), platelet derived-growth factors-AB (PDGF-AB), and stromal cell-derived factor-1 (SDF-1). In the second experiment, the efficacy of fibrin clot on the osteogenic differentiation and fibroblast proliferation was evaluated. Pb-/bm-fibrin clots were incubated in human osteoblast derived from mesenchymal stromal cells (MSCs) or human skin fibroblast. Alizarin red staining and real-time PCR (COL1A1, RUNX2) were performed for the detection of osteogenic potential. Cell-growth assay (WST-8) and real-time PCR (COL1A1) were also performed for the detection of the potential of fibroblast proliferation. Results: ELISA analysis revealed that the amount of VEGF, HGF, bFGF, IGF-1, and SDF-1 of bm-fibrin clot group is higher than that of pb-fibrin clot group with statistical differences. Besides, we confirmed that bm-fibrin clot has much potential for the osteogenic differentiation and fibroblast proliferation. Conclusion: The positive outcomes confirm the efficacy of pb-/bm-fibrin clot, and bm-fibrin clot was proved to have much potential for tissue regeneration compared with pb-fibrin clot. The current study showed the potential of a strategy for regenerative medicine using bm-fibrin clot.     

TGF-β-induced fibroblast activation protein expression, fibroblast activation protein expression increases the proliferation, adhesion, and migration of HO-8910PM

Several studies recognize cancer-stromal fibroblasts' role in cancer-cell invasion and metastasis. Through paracrine signaling molecules, TGF-β and IL-1β, cancer cells activate stromal fibroblasts and induce the expression of fibroblast activation protein (FAP). FAP, in turn, affects the proliferation, invasion and migration of the cancer cells. We report that TGF-β and IL-1β are important factors in inducing differentiation of myofibroblasts and expression of functional markers, notably α-SMA. We discover that TGF-β is the dominant factor in promoting FAPα protein expression. This study also examines FAP's function in vitro by assaying the proliferation, migration and invasion of ovarian cancer cell line HO-8910PM.     

Quantification of Thrombocyte Growth Factors in Platelet Concentrates Produced by Discontinuous Cell Separation

Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers. All the blood samples (237 in total) were analysed using Quantikine ELISA kits (R and D). The mean &#45 SD platelet count in whole blood from these donors was 262,000 &#45 58,000/ &#119 l, while in PC produced by discontinuous cell separation it was 1,419,000 &#45 333,000/ &#119 l. The mean growth factor concentrations in PC preparations in ng/ml were as follows: PDGF-AB 125 &#45 55 ng/ml; TGF- &#103 1 221 &#45 92 ng/ml; IGF-I 85 &#45 25 ng/ml; PDGF-BB 14 &#45 9 ng/ml; TGF- &#103 2 0.4 &#45 0.3 ng/ml. These growth factor concentrations typically covered a 3-10 fold range: PDGF-AB 29-277 ng/ml; PDGF-BB 2-33 ng/ml; TGF- &#103 1 32-397 ng/ml; TGF- &#103 2 0.1-1.2 ng/ml; IGF-I 40-138 ng/ml. Platelet counts in PC were slightly higher for women (Mann-Whitney Test all p <0.001 ) than for men, while the concentrations of growth factors in PC exhibited no gender-related difference of any statistical significance.     

The effect of growth factor treatment on meniscal chondrocyte proliferation and differentiation on polyglycolic acid scaffolds

The aim of this investigation was to determine the effect of growth factor treatment on ovine meniscal chondrocyte (OMC) proliferation in vitro and on the production of matrix proteins by OMCs grown within a polyglycolic acid (PGA) scaffold. Analysis of 72-h monolayer cultures using the mean transit time (MTT) assay revealed a greater increase in OMC numbers in the presence of platelet-derived growth factor (PDGF)-AB, PDGF-BB, insulin-like growth factor (IGF)-I, transforming growth factor-beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) than in untreated controls. In contrast, IGF-II and bone morphogenetic protein-2 had no effect on OMC proliferation at the concentrations tested. The growth factors that elicited the greatest proliferative response (PDGF-AB, PDGF-BB, TGF-beta1, and IGF-I) were subsequently tested for their ability to enhance OMC proliferation and differentiation within PGA scaffolds. Biochemical analysis revealed less glycosaminoglycan (GAG) production in the presence of all growth factors tested compared to untreated control samples. In contrast, all of the growth factors increased collagen type I production by OMCs within the scaffolds at day 20, and all except PDGF-BB resulted in an increase at day 39, when compared to appropriate control samples. With the exception of IGF-I, none of the growth factors tested had any significant effect on collagen type II production. Histological staining of sections from OMC-PGA scaffolds did not reveal any difference in GAG or collagen production between the treatment groups. However, immunohistochemical analysis demonstrated an increase in collagen type I expression and a decrease in collagen type II at day 39 in all growth factortreated constructs, concomitant with a high infiltration of cells. This suggests that PDGF-AB, PDGF-BB, TGF-beta1, and IGF-1 may be useful in future tissue engineering studies for promoting meniscal cell proliferation and differentiation within scaffolds.     

Messenger RNA Expression for Growth Factors in Glomeruli from Focal Glomerular Sclerosis

Focal glomerular sclerosis was induced in rats by chronic injections of puromycin aminonucleoside (PAN) on Days 0, 27, 34, and 41 and by unilateral nephrectomy on Day 22. Rats were sacrificed on Days 0, 8, and 20 (acute phase) and on Days 48, 60, and 80 (sclerotic phase). The percentage of sclerosing glomeruli was 16.6% on Day 48 and increased significantly to 72.8% on Day 80. We examined glomerular mRNA levels for proliferating cell nuclear antigen (PCNA), platelet-derived growth factor (PDGF)-A and B chains, transforming growth factor (TGF)-β, epidermal growth factor (EGF), insulin-like growth factor (IGF)-I, and basic fibroblast growth factor (bFGF) on Days 0, 8, 20, 48, 60, and 80. Although these growth factor mRNA levels showed little change in glomeruli until Day 20, all growth factor mRNA levels increased in glomeruli during the sclerotic phase of PAN nephrosis as glomerular sclerosis progressed. On Day 80, mRNA levels for PCNA, PDGF-A and B chains, TGF-β, EGF, IGF-I, and bFGF increased 12-, 10-, 12-, 15-, 2-, 2-, and 8-fold, respectively, in the glomeruli of PAN-treated rats with marked glomerular sclerosis when compared with control rats. Unilateral nephrectomy without PAN administration did not cause glomerular sclerosis up to Day 80 and mRNA levels for PCNA, PDGF-A and -B chains, TGF-β, EGF, IGF-I, and bFGF in this group were almost the same as those in the normal sham-operated group. These data suggest that changes in growth factor mRNA levels in glomeruli may contribute to the development of PAN-induced glomerular sclerosis.     

A parallel and quantitative cell migration assay using a novel multi-well-based device

Cell migration assays for different chemical environments are important for both scientists and clinicians searching for new therapeutics. In this study, we developed a multi-well-based microfluidic chip that has multiple units for different conditions. In each unit, cells can be patterned and then released to observe their migration. Automatic image analysis and model-based data processing were developed to describe the integrated cell migration assay precisely and quickly. As a demonstration, the migration behaviors of two types of cells in eight chemical conditions were studied. The results showed that supplementation with transforming growth factor-β(TGF-β) significantly promoted the migration of MCF-7 and MCF-10 A cells compared to several growth factors, such as Epidermal Growth Factor(EGF) and basic fibroblast growth factor(bFGF), as well as a control sample. Cells can migrate particularly fast with two or more mixed supplementary factors, such as TGF-β + bFGF + EGF, which indicated a synergy effect. Thus, this chip could be used to quantitatively observe cancer cell migration and demonstrated great potential for use in quantitative migration studies and chemical screening.     

Platelet-rich plasma preparation using three devices: Implications for platelet activation and platelet growth factor release

Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured.

Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to prepare PRP. Furthermore, an autologous growth factor filter was used to concentrate PRP fractionated by the blood cell separator. PRP was subsequently activated with autologously produced thrombin to degranulate the platelets to measure platelet-derived growth factor-AB (PDGF-AB), transforming growth factor-beta (TGF-β), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF).

Results: PRP contained significantly higher platelet counts compared with baseline values (p < 0.001). PDGF-AB concentrations were increased more than 18-fold in the platelet gel supernatant when the cell-separator and GPS were used, whereas only a 3-fold increase was seen with the AGF.

Conclusion: The three PRP devices enable the preparation of PRP for the release of high concentrations of platelet growth factor, but showed different harvesting capacities for the collection of concentrated platelets. The administration of thrombin for PRP activation resulted in the release of high concentrations of PDGF-AB and TGF-β but only when PRP had not been activated during the preparation process in vitro.     

Hypoxia augments cytokine (transforming growth factor-beta (TGF-β) and IL-1)-induced vascular endothelial growth factor secretion by human synovial fibroblasts

Vascular endothelial growth factor (VEGF) is abundant in synovium and synovial fluids, where it probably contributes to vascular permeability and angiogenesis in arthritic joints. To investigate the probable sources of VEGF in synovium, we compared the ability of several cytokines (TGF-β, platelet-derived growth factor (PDGF), IL-1, tumour necrosis factor (TNF), basic fibroblast growth factor (bFGF) that are associated with arthritis and angiogenesis, to stimulate secretion of VEGF protein by human synovial fibroblasts. TGF-β was the strongest inducer of VEGF secretion; six times more VEGF was secreted when cells were stimulated by TGF-β than when stimulated by PDGF or IL-1 for 24 h. TNF-α and bFGF did not stimulate any secretion of VEGF. The stimulatory effects of TGF-β and IL-1 on VEGF secretion were additive. Hypoxic culture alone also stimulated VEGF secretion, but more importantly, hypoxic culture conditions doubled the rate of VEGF secretion stimulated by the cytokines TGF-β and IL-1. When dermal and synovial fibroblasts were stimulated identically by hypoxia and cytokines (TGF-β and IL-1), synovial fibroblasts secreted four times more VEGF than did dermal fibroblasts. Thus in rheumatoid arthritis, the capacity of synovial fibroblasts in the hypoxic environment to secrete large amounts of VEGF in response to cytokines such as TGF-β probably contributes significantly to angiogenesis in the synovium.     

Adult and umbilical cord blood-derived platelet-rich plasma for mesenchymal stem cell proliferation, chemotaxis, and cryo-preservation

Platelet-rich plasma (PRP) was prepared from human adult peripheral blood and from human umbilical cord (uc) blood and the properties were compared in a series of in vitro bioassays. Quantification of growth factors in PRP and platelet-poor plasma (PPP) fractions revealed increased levels of mitogenic growth factors PDGF-AB, PDGF-BB, and FGF-2, the angiogenic agent VEGF and the chemokine RANTES in ucPRP compared to adult PRP (aPRP) and PPP. To compare the ability of the various PRP products to stimulate proliferation of human bone marrow (BM), rat BM and compact bone (CB)-derived mesenchymal stem cells (MSC), cells were cultured in serum-free media for 4 and 7 days with varying concentrations of PRP, PPP, or combinations of recombinant mitogens. It was found that while all forms of PRP and PPP were more mitogenic than fetal bovine serum, ucPRP resulted in significantly higher proliferation by 7 days than adult PRP and PPP. We observed that addition of as little as 0.1% ucPRP caused greater proliferation of MSC effects than the most potent combination of recombinant growth factors tested, namely PDGF-AB + PDGF-BB + FGF-2, each at 10 ng/mL. Similarly, in chemotaxis assays, ucPRP showed greater potency than adult PRP, PPP from either source, or indeed than combinations of either recombinant growth factors (PDGF, FGF, and TGF-β1) or chemokines previously shown to stimulate chemotactic migration of MSC. Lastly, we successfully demonstrated that PRP and PPP represented a viable alternative to FBS containing media for the cryo-preservation of MSC from human and rat BM.     

Effect of EGF and bFGF on Fibroblast Proliferation and Angiogenic Cytokine Production from Cultured Dermal Substitutes

Abstract

Growth factors accelerate wound healing but the underlying mechanisms remain poorly understood. The aim of this study was to investigate the effect of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on fibroblast proliferation and production of angiogenic factors from cultured dermal substitutes (CDS). In the first experiment, fibroblasts were seeded into a flask at a density of 1 × 10⁴ cells/cm².Cell proliferation was assessed after culturing in media containing EGF or bFGF at concentrations ranging from 2 to 50 μg. The number of fibroblasts increased significantly in the presence of EGF or bFGF, but fibroblasts detached from the flasks in the presence of 50 μg bFGF. In the second experiment, CDS were prepared by incorporating fibroblasts into collagen gels. To make a wound surface model, the CDS was elevated to the air–liquid interface, on which a spongy sheet of hyaluronic acid (HA) containing EGF or bFGF was placed. The amount of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) released from the CDS after 1 week of cultivation was measured by ELISA. When the CDS was covered with a HA sponge containing EGF (Group 1), fibroblasts released 3.5-times more VEGF compared with a HA-alone sponge (control group). When covered with a HA sponge containing bFGF (Group 2), 8.7-times more VEGF was released compared with the control group. Fibroblasts in Groups 1 and 2 released 9.6- and 9.3-times more HGF, respectively, compared with the control group. Thus, EGF stimulates fibroblasts to produce VEGF and HGF, in addition to its ability to enhance epidermal cell proliferation.     

胎儿巩膜碱性成纤维细胞生长因子和转化生长因子β表达的研究

目的 观察不同胎龄胎儿眼球巩膜碱性成纤维细胞生长因子(bFGF)和转化生长因子β(TGF-β)的表达情况,了解bFGF和TGF-β在正常眼球发育过程中的作用及变化规律.方法 收集12～20周米非司酮配伍米索前列醇或利凡诺羊膜腔注射引产的胎儿20例,其40只眼,立即摘除眼球,取4～5mm范围巩膜,用实时定量PCR方法检测巩膜bFGF和TGF-β的表达情况.结果 各胎龄阶段巩膜bFGF均有表达,胎龄12～14周时表达最高.以后逐渐下降并保持稳定水平,各胎龄阶段巩膜均有TGF-β表达,胎龄12周时表达较低,以后逐渐升高并保持稳定水平.结论 各胎龄阶段胎儿巩膜均有bFGF和TGF-β的表达,bFGF和TGF-β的表达水平随着胎龄的变化而变化.