Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FIBROBLASTS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed1981

An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: II. Colchicine-treated fibroblasts.

Colchicine administered intravenously depolymerized microtubules and disrupted the normal organization of the Golgi apparatus in periodontal ligament fibroblasts. Radioautography with 3H-proline indicated that collagen secretion was completely inhibited during a period of approximately 4 hours following the onset of the colchicine effect. During this period of secretory inhibition, labeled collagen precursors were present within a variety of dense bodies, primarily located in a juxtanuclear location replacing the normal Golgi complex. The time course of 3H-proline labeling from 2 to 8 hours suggested that small, newly formed dense bodies fused to form larger dense bodies and pleomorphic structures (zebra bodies), within which collagen precursors appeared to undergo partial polymerization. Autophagosomes, many labeled with 3H-proline, also increased in number after colchicine administration. A gradual decline in 3H-proline label occurred from 4 to 24 hours, presumably due to exocytosis of dense bodies or by the digestion of labeled collagen precursors within autophagosomes. These results support the concept that an intact microtubular network is essential for the organized transport of collagen precursors, from the rough endoplasmic reticulum to the Golgi apparatus, and the eventual transport and exocytosis of collagen secretory granules.

Animals↗
PubMed1985

Highly purified fibroblast-derived growth factor, an SV40-transformed fibroblast-secreted mitogen, is closely related to platelet-derived growth factor.

Fibroblast-derived growth factor (FDGF), a polypeptide secreted by an SV40-transformed baby hamster kidney cell line (SV28), was purified approximately 1000-fold from SV28-conditioned medium. FDGF, which gave a single band on SDS-polyacrylamide gel electrophoresis, is a hydrophobic and cationic protein of apparent mol. wt. 31 000 containing disulphide-linked polypeptides. This factor is positive in Western blots using human platelet-derived growth factor (PDGF) anti-serum. FDGF is a potent mitogen for Swiss 3T3 cells; half-maximal stimulation of DNA synthesis was achieved at a concentration of approximately 1 nM, comparable with those for human and porcine PDGF. FDGF inhibits EGF binding to Swiss 3T3 cells, as does PDGF. The coincidence of the physical, biological and immunological characteristics of FDGF and PDGF strongly suggests that they are closely related in structure.

Animals↗
PubMed1983

Interaction of fibroblasts and polymer surfaces: relationship between surface free energy and fibroblast spreading.

Cell spreading and cell division rates of a transformed line of mouse lung fibroblasts were studied on various polymer surfaces in the presence of serum proteins. The bare polymer surfaces, as well as the protein-coated surfaces, were characterized by their polar (gamma ps) and dispersion (gamma ds) surface free energies. Cell spreading appeared to be dependent on the polar surface free energy. Cell spreading is low when the gamma ps of the bare surface is lower than 5 erg cm-2; marked spreading occurs when gamma ps is higher than 15 erg cm-2. A similar relationship was found between cell spreading and polarity of the protein-coated surfaces, although less pronounced than for the bare surfaces. Cell spreading appeared independent of the dispersion surface free energy. Cell division rate was the same on all surfaces tested.

Animals↗
PubMed1985

12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced gene sequences in human primary diploid fibroblasts and their expression in SV40-transformed fibroblasts.

We have isolated cDNA sequences from TPA-treated primary human fibroblasts, which indicate RNA species that are coordinately regulated after treatment of these cells with either ultraviolet light, mitomycin C, the UV-induced factor EPIF, or TPA. The levels of RNA are elevated in Bloom syndrome (cells of two out of three patients). After transformation with SV40 one of the sequences is overexpressed while another one is reduced. Both genes maintain their inducibility by the agents mentioned.

Bloom Syndrome↗
PubMed1976

Regulation of sugar transport in chick embryo fibroblasts and in fibroblasts transformed by a temperature-sensitive mutant of the Rous sarcoma virus.

The mode of induction of sugar transport by serum-stimulation of growth and hexose-starvation in chick embryo fibroblasts (CEF) has been studied using metabolic inhibitors. We have concluded from these studies that the sugar transport increases induced by serum-stimulation are regulated by post-transcriptional mechanisms while sugar transport increases induced by hexose-starvation are regulated by a transcriptional mechanism. CEF infected with a temperature-sensitive mutant of the Rous sarcoma virus. Ts68 and incubated at the nonpermissive temperature for transformation, 41 degrees, retain the capacity to regulate sugar transport in a manner similar to uninfected CEF. However, Ts68-infected CEF maintained at the permissive temperature for transformation, 37 degrees, have lost the ability to regulate sugar transport at the post-transcriptional and post-translational levels.

Animals↗
PubMed1990

Fibroblast growth factor-dependent mitogenic signal transduction pathway in chemically transformed mouse fibroblasts is similar to but distinct from that initiated by phorbol esters.

Treatment of the quiescent, chemically transformed Balb/c mouse 3T3 cells (BP-A31) with fibroblast growth factor (FGF) leads to reinitiation of the cell division cycle in a large proportion of the cells. The characteristics of the mitogenic action of FGF closely resemble those of phorbol esters (activators of protein kinases type C) and differ from those of insulin (mediated by insulin-like growth factor 1 receptors). In particular, the effects of FGF as well as of phorbol-2-myristate-13-acetate (PMA), unlike the effects of insulin, are prevented by a low concentration (7.5 nM) of staurosporin (an efficient inhibitor of protein kinase C) as well as by 3-isobutyl-1-methyl xanthin (IBMX). Both FGF and PMA are good inducers of the accumulation of c-fos and c-jun mRNAs, whereas insulin has little effect. However, FGF was fully active (both as a mitogen and as inducer of c-fos mRNA accumulation) also in cells where the protein kinase C-mediated pathway had been downregulated by a long exposure to phorbol dibutyrate. We propose that the mitogenic effect of FGF does not require activation of protein kinase C, but that the subsequent events in the transduction pathways initiated by FGF and PMA, respectively, are (in part) coincident.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Suppression of the transformed phenotype in hybrids of human T-cell leukemia virus type I tax-transformed rat fibroblasts and normal human fibroblasts.

We have isolated and characterized hybrid cell lines derived from Rat-2 cells transformed by the human T-cell leukemia virus type-I (HTLV-I) Tax protein fused with WI-38 normal human fibroblasts. These hybrid cells (designated as RTW cells) showed contact inhibition after growing to confluency, loss of anchorage-independent growth in 0.33% soft agar, and inability to form tumors in athymic mice. Assays of transcription from the HTLV-I long terminal repeat (LTR) demonstrated that Tax-mediated trans-activation of its own promoter was fully maintained in RTW cells, implying that functional Tax is expressed in these cells. Our results indicate that WI-38 cells contain a suppressor gene(s) which can block Tax-mediated cell transformation without interfering its trans-activation of the HTLV-I LTR.

Animals↗
PubMed1983

Expression of the fragile site Xq27 in fibroblasts. I. Detection of fra(X)(q27) in fibroblast clones from males with X-linked mental retardation.

Twelve fibroblast clones from two males with X-linked mental retardation expressed the fragile site Xq27 in 3%-38% of metaphases analyzed. The number of in vitro doublings during the cloning procedure had no evident influence on the induction of fragile X expression. The variability of fragile X expression seems to depend on cell properties acquired during culture rather than on properties originally inherent in the cells.

Chromosome Fragile Sites↗
PubMed1987

Effects of fibroblastic growth factor on protein degradation, the migration of non-histone proteins to the nucleus and DNA synthesis in diploid fibroblasts.

Stimulation of resting WI38 cells, prelabeled with [3H]leucine, with fibroblastic growth factor (FGF) or serum, caused increased nuclear translocation of [3H]non-histone proteins [( 3H]NHP) and DNA synthesis, and a parallel decrease of proteolysis. [3H]NHP migration was independent of protein synthesis. Fractionation of the nuclear proteins in a pH gradient of 2.5-6.5 showed that [3H]NHP fractions with high degradation rates in resting cells corresponded to the [3H]NHP fractions with high migration rates in stimulated cells, suggesting that degradation and migration of [3H]NHP are linked. FGF inhibited cellular uptake of [3H]chloroquine, suggesting that FGF inhibits NHP degradation via lysosomes. The lysosomotropic amine eserine had similar effects as FGF. It is proposed that FGF induces NHP migration to the nucleus by inhibiting their lysosomal degradation. FGF also caused migration of [3H]histones, however, the mechanism is not clear.

Biological Transport↗
PubMed1993

Induction of phosphatidic acid by fibroblast growth factor in cultured baby hamster kidney fibroblasts.

Basic fibroblast growth factor (bFGF/FGF-2) is a strong mitogenic inducer of cultured baby hamster kidney (BHK) cells. When cultured BHK cells were stimulated with FGF-2, phosphatidic acid (PA) was induced within 2 min, peaked at 5 min and gradually decreased. Phospholipase D (PLD) was also mitogenic for cultured BHK cells and this effect was mediated via PA. The possibility that PA induction by FGF-2 is an essential signaling step for BHK cell proliferation is discussed.

Animals↗
PubMed1991

Basic fibroblast growth factor induces 3T3 fibroblasts to synthesize and secrete a cyclophilin-like protein and beta 2-microglobulin.

When stimulated by fibroblast growth factor (FGF) BALB/c 3T3 cells synthesize and secrete elevated amounts of five proteins called the 'superinducible proteins', or SIPs. The expression of these proteins is greatly enhanced if the cells are treated with cycloheximide during induction. The 24 kDa protein (SIP24) has been purified and antiserum raised against it. This protein is N-glycosylated and probably structurally constrained by one or more intramolecular disulfide bonds. The amino acid sequences of three of four peptides show significant identity with cyclophilin, an abundant cytoplasmic protein believed to mediate the immunosuppressive effects of cyclosporin A. Several members of the cyclophilin family have been identified, and cDNA clones of two cyclophilin-like proteins with signal sequences have been reported. Here we show that at least one cyclophilin-like protein is secreted and that its expression is regulated by growth factors. The 12.5 kDa protein (SIP12.5) was found to be immunoprecipitated by an antiserum raised to human beta 2-microglobulin. This protein is strongly induced by interferon, which is a characteristic of the beta 2-microglobulin gene. Thus, FGF stimulates mouse embryo 3T3 cells to produce two proteins related to immune regulatory molecules. This may reflect an interaction between immune cells and nonimmune cells that occurs in vivo during processes such as wound healing when growth factors are released locally.

3T3 Cells↗
PubMed1980

Differential susceptibility of fibroblastic and non-fibroblastic surface fibronectins to periodate-borohydride labelling and enzymic treatment.

Surface labelling of liver epithelioid cells permits the detection of a 230,000 dalton component reactive with antifibronectin serum, when tritiated borohydride labelling is preceded by oxidation of sugar residues with galactose oxidase but not with sodium periodate. Similar experiments with liver fibroblasts lead to the labelling of a similar 230,000 dalton component both when sugar oxidation is carried out with galactose oxidase or periodate. Neuraminidase treatment prior to surface labelling lead to an increased labelling in both cell types, although a decreased labelling in the fibronectin region was apparent in the epithelioid cells.

Animals↗
PubMed1990

Growth stimulation by androgens, glucocorticoids or fibroblast growth factors and the blocking of the stimulated growth by antibody against basic fibroblast growth factor in protein-free culture of Shionogi carcinoma 115 cells.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. We have established an androgen-dependent cloned cell line (SC-3) from a SC115 tumor. In a serum-free medium, testosterone (T) or fibroblast growth factors (FGFs) markedly stimulate the growth of SC-3 cells, and the T-induced growth was shown to be mediated through FGF-like peptide(s) in an autocrine mechanism. Since we used the serum-free culture including 0.1% bovine serum albumin (BSA), a partially serum-containing condition, putative roles of BSA- or serum-borne growth factors in growth stimulation of autocrine production of FGF-like peptide(s) could not be excluded. This paper reports findings performed in a protein-free medium including plating [Ham's F-12:MEM (1:1; v/v)]. In the protein-free culture, the growth of SC-3 cells was significantly stimulated by the addition of greater than or equal to 10(-10) M T (up to 20-fold), greater than or equal to 10(-7) M dexamethasone (Dex; up to 7-fold) or greater than or equal to 1 ng/ml basic (b) or acidic FGF (up to 10-fold); other various growth factors had no such effects. Furthermore, DNA synthesis of SC-3 cells induced by T, Dex or bFGF was similarly and markedly inhibited by bFGF neutralizing antibody IgG. Therefore, the present findings seem to demonstrate that androgens or high levels of glucocorticoids induce the production and secretion of FGF-like peptide(s) from SC-3 cells for their growth even in the absence of additional support by other factors.

Androgens↗
PubMed2004

Production of intracellular IL-1alpha, IL-1beta, and IL-1Ra isoforms by activated human dermal and synovial fibroblasts: phenotypic differences between human dermal and synovial fibroblasts.

We compared the production of IL-1alpha, IL-1beta, and of IL-1Ra isoforms by cultured human dermal (HDF) and synovial fibroblasts (HSF) in response to IL-1alpha, TNF-alpha, or direct T cell membrane contact. IL-1Ra was constitutively present in the cell lysates of cultured HDF and its synthesis increased in stimulated cells, whereas IL-1Ra was present in low amounts in the supernatants. Secreted IL-1Ra (sIL-1Ra) and intracellular IL-1Ra type 1 (icIL-1Ra1) mRNA levels followed the same pattern. In stimulated HDF, IL-1alpha and IL-1beta were increased intracellularly but remained undetectable in the supernatants. In HSF, IL-1Ra levels increased in both cell lysates and supernatants upon stimulation. IL-1beta was only present in HSF cell lysates after stimulation, whereas IL-1alpha was undetectable. Both sIL-1Ra and icIL-1Ra1 mRNAs were detected in stimulated HSF. icIL-1Ra1 was the predominant intracellular isoform in both cell types. In conclusion, stimulated HDF produce high amounts of intracellular IL-1Ra, IL-1alpha, and IL-1beta. In contrast, HSF synthesized both intracellular and secreted IL-1Ra, whereas IL-1beta was present only in cell lysates. The presence of high amounts of icIL-1Ra1 and intracellular IL-1alpha in HDF suggests that these cytokines may carry out important function inside cells.

Blotting, Western↗
PubMed1988

Alterations in levels of 5'-adenyl dinucleotides following DNA damage in normal human fibroblasts and fibroblasts derived from patients with xeroderma pigmentosum.

Levels of 5'-adenyl dinucleotides, measured as diadenosine-5',5'''-P1,P4-tetraphosphate (Ap4A), were found to accumulate in cultured human fibroblasts following treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), the radiomimetic drug bleomycin, and nitroquinoline-1-oxide (NQO) or UV-irradiation in the presence of cytosine arabinofuranoside (araC). In contrast, cells derived from patients with xeroderma pigmentosum complementation group A (XP-A) did not demonstrate an increase in DNA-strand breaks following UV irradiation or NQO in the presence of araC nor an increase in Ap4A levels. Ap4A accumulation did occur in XP-A cells following treatment with MNNG. Cells derived from patients characterized as XP variants, which are incision repair-proficient, accumulated 5'-dinucleotides following bleomycin, MNNG and UV or NQO in the presence of araC. Taken together, these data suggest that Ap4A accumulates as a response to DNA-strand breaks.

4-Nitroquinoline-1-oxide↗
PubMed1991

Characterization of human renal fibroblasts in health and disease: II. In vitro growth, differentiation, and collagen synthesis of fibroblasts from kidneys with interstitial fibrosis.

Fibroblast cultures from normal human kidneys (NKF cells) and kidneys affected with interstitial fibrosis (FKIF cells) were analyzed for in vitro growth, differentiation dynamics, and collagen synthesis. FKIF cells are characterized by hyperproliferative growth, resulting in a prolonged mitotic lifespan, by an altered differentiation pattern, and by the expression of the FKIF cell-specific protein "fibrosin" (molecular weight 53 kd, isoelectric point [pi] 6.1). Furthermore, FKIF cells synthesize four to five times more total collagen per cell as compared with NKF cells, and the relative amounts of the collagen types produced (type I, III, and V) are significantly different from controls. Thus, the in vitro cell system of FKIF cells may help to elucidate the underlying mechanisms triggering the induction and progression of renal interstitial fibrosis in vivo.

Biopsy↗
PubMed1981

In vitro susceptibilities of normal human skin fibroblasts to oncoviruses, and the decreased susceptibility to HSV of fibroblasts from untreated Hodgkin's patients.

Fibroblast cultures established from the skin of 56 healthy controls and 15 untreated Stages I and II Hodgkin's patients (HD) were studied in their 3rd, 4th and 5th in vitro passage with respect to transformation with Simian sarcoma virus (SSV) and SV40 and with respect to replication of herpes simplex virus (HSV) Types 1 and 2, pox virus and interferon release. Susceptibility to the 5 viruses varied independently, except for an inverse correlation between susceptibility to SSV and HSV. HD cultures showed a depressed replication of both types of HSV. There was a borderline (P = 0.02) correlation between magnitude of HSV replication and presence of HL-A type B-w44, but this does not explain the HD control difference. Furthermore, the level of serum antibodies to HSV common antigen was not related to magnitude of in vitro replication. The results thus speak against generally enhanced cellular susceptibility to HSV as a reason for the high titres of serum antibodies to HSV in HD patients.

Adolescent↗
PubMed1979

Structure and metabolism of sulphated glycosaminoglycans in cultures of human fibroblasts. Structural characteristics of co-polymeric galactosaminoglycans in sequential extracts of fibroblasts during pulse-chase experiments.

1. Human embryonic lung and skin fibroblasts were allowed to incorporate 32SO42- or 35SO42- and D-[1-3H]glucosamine. After removal of the medium the monolayer was subjected to sequential extractions by using EDTA, brief trypsin digestion, extraction with dithiothreitol ofllowed by freeze--thawing and extraction with trichloroacetic acid. The heparan sulphate and galactosaminoglycan contents of the various extracts were estimated after deaminative cleavage of the former component. Heparan sulphate was the major component of the trypsin digest, whereas galactosaminoglycans were the dominant component of other fractions. 2. Galactosaminoglycans of the various fractions were subjected to chemical (periodate oxidation/alkaline elimination) and enzymic (chondroitinase-AC and -ABC, as well as testicular hyaluronidase) degradations. Galactosaminoglycans from the insoluble cell fraction and the dithiothreitol extract contained larger amounts of L-iduronic acid than did those of other fractions. 3. Pulse-chase experiments were performed with and without replating of the cells at the start of the chase period. Radioactive glycans were isolated from the various extracts during the chase period. The half-lives of glycans of the insoluble cell fraction and the dithioreitol extract were shorter (5--8h) than were those of the trypsin digest and the EDTA extract (22h and 11h respectively). After replating of the cells in chase medium, radioactive cell-associated glycans were secreted from the cells and could be recovered in the trypsin digest, the EDTA extract and the medium. Furthermore, 35S/3H ratios of glycans from all these fractions decreased during the chase period. The following conclusions were reached. The insoluble cell fraction contains the synthesis pool and some structural material, whereas the soluble cell fraction is the storage and degradation pool. The dithiothreitol extract appears to contain the immediate precursors of secreted material. The trypsin-released glycans comprise structural components as well as material destined for pinocytosis or secretion into the medium. The EDTA extract is considered to consist of glycans en route to the medium. 4. The two presumptive precursor pools were preferentially depleted of L-iduronic acid-rich galactosaminoglycans during the chase. Glycans recovered from the trypsin digest, the EDTA extract and the medium during the chase contained larger amounts of periodate-resistant uronic acid residues (D-glucuronic acid and/or L-iduronic acid O-sulphate) than did their precursors. It is proposed that polymer-level modifications of secreted glycans are partly responsible for the results.

Cells, Cultured↗