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Enhanced angiogenesis and growth of collaterals by in vivo administration of recombinant basic fibroblast growth factor in a rabbit model of acute lower limb ischemia: dose-response effect of basic fibroblast growth factor.

The purpose of this study was to evaluate the effects of exogenous recombinant basic fibroblast growth factor (bFGF) on angiogenesis in severely ischemic tissue beds. We used a two-stage procedure to produce severe ischemia of the hindlimb of 34 New Zealand rabbits. The ischemic hindlimb received intramuscular injection of saline (group A), 1 microgram bFGF (group B), or 3 micrograms bFGF (group C), daily for 2 weeks. Tissue perfusion, skeletal muscle infarction, angiogenesis, and collateral growth were assessed by angiography, transcutaneous oximetry (TcPO2), quantitative spectrophotometric assay of triphenyltetrazolium chloride reduction in muscle, capillary density (capillaries per square millimeter), and capillary per muscle fiber ratio. There were no significant differences in baseline TcPO2 among the three groups for both thigh and calf measurements. Angiography revealed extensive perfusion of the left hindlimb in all the assessed bFGF treated animals. Both thigh and calf TcPO2 values showed a significant increase in all groups over the 14 days ischemia was induced (p less than 0.0001), but the two treatment groups exhibited a much more rapid rise in TcPO2 than the control group (p less than 0.0001). The capillaries per square millimeter and capillaries per muscle fiber ratios were significantly increased in all posttreatment measurements for all animals that received bFGF. The treatment groups with bFGF had a significant (p = 0.025) increase in thigh muscle viability compared with controls based on triphenyltetrazolium chloride reduction. Whereas there was evidence of muscle infarction in both the thighs of groups A and B, there was none in group C.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

[Effects of reconstructive human acidic fibroblast growth factor and wild type acidic fibroblast growth factor on skin cell proliferation].

OBJECTIVE: To investigate the effects of reconstructive human acidic fibroblast growth factor (aFGF) and wild type aFGF on skin cell proliferation in rat. METHODS: Neonatal rat skin (area of 2 mmx2 mm) was cultured in Dulbecco's modification of Eagle's medium containing reconstructive human aFGF and wild type aFGF, respectively. The concentrations of aFGF were 1 microg/L, 10 microg/L, and 100 microg/L. After being cultured for 4 days, the area of skin was measured. RESULTS: After treatment with two different growth factors in three different concentrations (1 microg/L, 10 microg/L and 100 microg/L) for 4 days, the areas of skin in three reconstructive human aFGF groups were 1.4, 1.5 and 1.3 fold of that of control, respectively and the areas of three wild type aFGF groups were 1.5, 3.2 and 1.6 fold of that of control, respectively, while the area of skin in the control group was (2.96+/-1.12) mm(2). In comparison with those of other groups, the skin area of 10 microg/L wild type aFGF group was significantly increased (P<0.05). CONCLUSION: Reconstructive human aFGF confers less impact on cutaneous cell growth. The capability of wild type aFGF to induce cutaneous cell proliferation is much greater than that of reconstructive human aFGF.

Animals↗

Fibroblast-like synoviocytes from patients with rheumatoid arthritis are more sensitive to apoptosis induced by the viral protein, apoptin, than fibroblast-like synoviocytes from trauma patients.

OBJECTIVE: Fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA) show characteristics of transformation. Because the chicken anemia virus protein, apoptin, induces apoptosis solely in transformed cells, it was investigated whether FLS from patients were more sensitive to apoptin-induced apoptosis than FLS from normal joints obtained from trauma patients. METHODS: FLS were transduced with maltose-binding protein (MBP)-apoptin recombinant protein or MBP as a control protein by microinjection. After 24 hours, cells were fixed and stained with immunofluorescence to detect apoptin or MBP and the number of dead cells was assessed. Furthermore, phosphorylation of apoptin was analysed in FLS from patients with RA and from trauma patients by in vitro kinase assay. RESULTS: FLS from patients with RA were significantly more sensitive to apoptin-induced apoptosis than FLS from trauma patients (p = 0.0263). Furthermore, MBP-apoptin induced more apoptosis than MBP in RA FLS (p = 0.004). No phosphorylation of apoptin was observed in FLS from patients with RA. DISCUSSION: FLS from patients with RA are more sensitive to apoptin-induced apoptosis than normal FLS, which is consistent with a transformed phenotype of these cells. However, given the lack of phosphorylation of apoptin in RA FLS the mechanism of action of apoptin seems to differ between tumour cells and RA FLS. This study indicates that apoptin may help to identify a new therapeutic pathway against hyperplasia of the synovium and joint destruction in RA.

Adult↗

[Human fibroblast interferon therapy alone and human fibroblast interferon combined with thymostimulin in genital papillomavirus infection associated with cervical intraepithelial neoplasia].

Eighteen patients suffering for HPV infections associated with CIN were treated using human fibroblast interferon, via an intramuscular route, with positive results. Five cases of recurrent HPV within nine months of treatment received thymostimulin therapy, via an intramuscular route, with positive results.

Adult↗

Structure of proteoheparan sulfates from fibroblasts. Confluent and proliferating fibroblasts produce at least three types of proteoheparan sulfates with functionally different core proteins.

[3H]Leucine- and [35S]sulfate-labeled proteoheparan sulfates were isolated from postconfluent or proliferating cultures of human skin fibroblasts. Cell layers were solubilized by Triton X-100, and transferrin-binding macromolecules were isolated by affinity chromatography. Proteoglycans with no affinity for transferrin were purified by using ion-exchange and gel permeation chromatography. Postconfluent cells synthesize a proteoheparan sulfate of Mr 350,000 (as determined by gel permeation chromatography) which has affinity for transferrin as well as for octyl-Sepharose. Its core protein (Mr 180,000) consists of two disulfide-bonded polypeptides of Mr 90,000. This species was not detected in cultures of proliferating cells. Proliferating and confluent cells also synthesize other forms of proteoheparan sulfates (Mr 200,000-400,000) which have no affinity for transferrin. However, most of them have affinity for octyl-Sepharose. The core protein of proteoheparan sulfates made by proliferating cells has Mr 50,000. A smaller form (Mr 250,000) of this proteoglycan was solubilized by Triton X-100, whereas a larger form (Mr 400,000) remained associated with the pericellular matrix. A third type of proteoheparan sulfate (Mr 200,000) without affinity for transferrin nor octyl-Sepharose was associated with postconfluent cell layers but not with proliferating ones. Its core protein has Mr 35,000. Heparan sulfate oligosaccharides (Mr 6,000 or higher) were found in proliferating cells but not in postconfluent ones.

Cell Division↗

Characterization of recombinant human acidic fibroblast growth factor: comparative studies with bovine acidic fibroblast growth factor.

Recombinant human acidic fibroblast growth factor (haFGF) was purified from E. coli lysate by heparin-sepharose affinity chromatography. The purified haFGF exhibited potent mitogenic activity in stimulating DNA synthesis in 3T3 cells and this activity could be significantly increased by heparin. By analysis of mitogenic activity and immunological properties, a marked difference was found between haFGF and bovine aFGF (baFGF). The main difference was that the heparin-dependence of haFGF was stronger than that of baFGF.

3T3 Cells↗

Induction of basic fibroblast growth factor mRNA by basic fibroblast growth factor in Müller cells.

PURPOSE: To investigate the induction of basic fibroblast growth factor (bFGF) gene expression in cultured rat Müller cells by bFGF and to study the mechanism of induction. METHODS: Müller cells from 1- to 3-day-old Sprague-Dawley rats were isolated and cultured with Dulbecco's modified Eagle's medium with 10% fetal calf serum. Cultured cells were identified by immunocytochemistry using antibodies against vimentin, carbonic anhydrase II, and glutamine synthetase. Cells of passages 1 through 4 were treated with bFGF, the protein kinase C (PKC) inhibitor, H-7; calphostin C, or the PKC activator, PMA; and protein kinase A (PKA) inhibitor, H-89; as well as the adenylate cylase activator, forskolin; or the adenylate cyclase inhibitor, SQ22536. Northern blot analysis was performed to determine the mRNA expression of bFGF, ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF). RESULTS: Addition of bFGF to culture medium induced bFGF gene expression in a dose- and time-dependent manner. Induction of bFCF mRNA started at a bFGF concentration of 0.1 ng/ml. The bFGF mRNA level was elevated by 2-fold at 1 ng/ml of bFGF, 2.8-fold at 5 ng/ml, and reached a peak of 4-fold at 10 ng/ml and 3.7-fold at 50 ng/ml. At 10 ng/ml of bFGF, induction of bFGF mRNA was observed as early as 2 hours (2-fold) after treatment. The bFGF mRNA level continued to increase to 3.7-fold by 4 hours, and reached a maximum of 4.4-fold by 8 hours. A slow decline of the bFGF mRNA level was observed after 8 hours of bFGF treatment (3.5-fold by 12 hours, and 3-fold by 24 hours). This induction of bFGF gene expression was blocked by PKC inhibitors H-7 (30 microM). The PKC activator PMA (0.1 microM) also upregulated bFGF gene expression, but the effects of bFGF and PMA were not additive. An adenylate cyclase inhibitor, SQ22536 (100 microM), did not inhibit bFGF-induced bFGF gene expression. Although forskolin (5 microM), an adenylate cyclase activator, also upregulated the level of bFGF mRNA, the effects of forskolin and bFGF were additive. In addition, no inhibitory effect on bFGF-induced expression of bFGF mRNA was found using H-89 (1 microM). Exogenous bFGF did not alter the mRNA levels of CNTF and BDNF. CONCLUSIONS: These results indicate that bFGF induces bFGF gene expression in cultured rat Müller cells through PKC activation. The authors' findings raise the possibility that Müller cells in vivo also respond to available bFGF (for example, that released from the endogenous reservoirs in the case of injury) or to exogenous bFGF by producing more bFGF, which could in turn promote photoreceptor survival.

Animals↗

Effects of fibroblast growth factor 8, fibroblast growth factor 9 and keratinocyte growth factor on multiplication and locomotion in human teratocarcinoma cells in vitro.

BACKGROUND: The effects of three members of the heparin binding growth factor family, FGF-8, FGF-9 and KGF, on the human embryonal carcinoma-derived cells line tera 2 were examined. MATERIALS AND METHODS: Cell numbers as well as cell migration was examined at clonal level by microscopy. RESULTS: It was found that each of these factors promoted Tera 2 cell multiplication, albeit with different efficacy. Whereas a dramatic effect on cell numbers was observed after the addition of 1-10 micrograms FGF-9/ml, a lesser effect could be achieved by FGF-8 or KGF. In contrast, KGF expressed the most potent effect on cell locomotion at a higher concentration (100 micrograms/ml). Even though high concentrations of FGF-8 and FGF-9 did stimulate cell locomotion, this effect was substantially smaller than that of KGF. CONCLUSION: All three FGFs exert a dual effect on Tera 2 cell survival and locomotion.

Cell Division↗

Heparinase treatment of bovine smooth muscle cells inhibits fibroblast growth factor-2 binding to fibroblast growth factor receptor but not FGF-2 mediated cellular proliferation.

On the surface of smooth muscle cells there are two types of receptors for the mitogenic and angiogenic growth factor fibroblast growth factor-2 (FGF-2); a high affinity tyrosine kinase FGF receptor (FGFR1) and low affinity heparin./heparan-like glycosaminoglycan (HLGAG) component of surface expressed proteoglycans. It is believed that all three components; FGFR1, FGF-2, and the HLGAG chains, must form a ternary complex for maximal cellular stimulation. To carefully examine the role surface HLGAGs play in FGF-2-mediated proliferation of SMCs we have utilized HLGAG degrading enzymes heparinase I, II and III. We report that heparinase treatment of bovine smooth muscle cells inhibits the binding of (125)I-FGF-2 to FGFR1, but does not inhibit FGF-2 induced cellular proliferation. Through the use of both sodium chlorate and FGF-2 mutants with deficient HLGAG-binding capabilities, we show the FGF-2-HLGAG interaction is important for FGF-2's ability to induce SMC proliferation. Finally, we report conditioned media from heparinase treated SMCs is capable of supporting FGF-2 induced proliferation in an HLGAG-free lymphoid F32 cells, suggesting that the heparinase generated fragments are responsible for the proliferative response. The data presented here suggest FGF-2 is capable of stimulating smooth muscle cell proliferation through an FGFR independent, HLGAG dependent mechanism.

Journal Article↗

Most iodinatable fibroblast surface proteins accompany the cytoplast membrane during cytochalasin B-mediated enucleation of chick embryo fibroblasts.

Six different proteins are found to be reproducibly exposed on the cell surface of chicken embryo fibroblasts (CEF) by the criterion of lactoperoxidase-catalyzed iodination (250,000, 185,000, 130,000, 100,000, 87,000, and 75,000 daltons). We wondered whether cell enucleation might lead to a differential partition of these surface proteins with the karyoplast or cytoplast membrane. We found that there is a marked enrichment of most iodinatable cell surface proteins in the cytoplast after cytochalasin-mediated enucleation of cell monolayers. Nearly all the iodinatable fibronectin remains with the cytoplast. Of the six labeled proteins, the karyoplast membrane contains a small amount of the 130 kdalton protein as well as trace levels of the 100-, 85-, and 75-kdalton proteins. Proteolysis or selective shedding of membrane proteins were not significant factors in the relative exclusion of iodinatable membrane proteins from the karyoplast. The cytoplast could replace some exposed membrane proteins after removal by trypsinization; however, fibronectin was not detectable within 10 h. That the karyoplast was not capable of membrane protein synthesis and/or insertion was suggested by the lack of any change in the labeling pattern of karyoplasts up to 8-h incubation after enucleation. A variety of control studies indicated that the surface proteins identified in this report were cell-derived and not adsorbed serum components. That some of the iodinatable proteins are intrinsic membrane proteins was suggested by their resistance to removal by conditions thought to extract extrinsic membrane proteins (i.e., low salt, high salt, and NaOH washes). lack of effect of cytoskeletal disrupting agents (preliminary evidence) suggests the nonrandom partition of membrane proteins may depend on anchoring of membrane proteins by a system(s) in the cytoplast other than intact microtubules and microfilaments.

Animals↗

Fibroblast growth factor signalling in the hair growth cycle: expression of the fibroblast growth factor receptor and ligand genes in the murine hair follicle.

Using RNA in situ hybridization analysis, we have characterized the expression domains of the four known members of the FGF receptor-tyrosine kinase gene family in the murine hair follicle at various stages of the hair growth cycle. During anagen, we detected Fgfr1 RNA in the dermal papilla, Fgfr2 RNA in hair matrix cells near the dermal papilla, Fgfr3 RNA in pre-cuticle cells in the periphery of the hair bulb, and Fgfr4 RNA in cells in the periphery of the hair bulb and also in the inner and outer root sheath in the lower half of the follicle neck. No RNA expression of these genes was detected during late catagen or telogen. We have previously shown that Fgf5 is expressed in the outer root sheath in the transient portion of the follicle (Hébert et al. [1994] Cell 78:1017-1025). In the present study we have also assayed for the expression of six other members of the FGF ligand gene family, Fgf3, Fgf4, Fgf6, Fgf7, Fgf8, and Fgf9. Among these FGF genes, only Fgf7 was found to be expressed in the hair follicle. Fgf7 RNA is localized to the dermal papilla during anagen, but expression is down-regulated by the late-anagen VI stage. We have also demonstrated that addition of FGF5 protein to the culture medium changes the behavior of dermal papilla cells in vitro, indicating that they are capable of responding to FGF5. Together with previously published data, these results provide a complete analysis of FGF ligand and FGF receptor-tyrosine kinase gene expression in the hair follicle, and suggest that FGF signalling may have several functions in the hair growth cycle.

Animals↗

Uptake and intracellular transport of acidic fibroblast growth factor: evidence for free and cytoskeleton-anchored fibroblast growth factor receptors.

Endocytic uptake and intracellular transport of acidic FGF was studied in cells transfected with FGF receptor 4 (FGFR4). Acidification of the cytosol to block endocytic uptake from coated pits did not inhibit endocytosis of the growth factor in COS cells transfected with FGFR4, indicating that it is to a large extent taken up by an alternative endocytic pathway. Fractionation of the cells demonstrated that part of the growth factor receptor was present in a low-density, caveolin-containing fraction, but we were unable to demonstrate binding to caveolin in immunoprecipitation studies. Upon treatment of the cells with acidic FGF, the activated receptor, together with the growth factor, moved to a juxtanuclear compartment, which was identified as the recycling endosome compartment. When the cells were lysed with Triton X-100, 3-([3-chloramidopropyl]dimethylammonio)-2-hydroxy-1-propanesulfona te, or 2-octyl glucoside, almost all surface-exposed and endocytosed FGFR4 was solubilized, but only a minor fraction of the total FGFR4 in the cells was found in the soluble fraction. The data indicate that the major part of FGFR4 is anchored to detergent-insoluble structures, presumably cytoskeletal elements associated with the recycling endosome compartment.

Animals↗