Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Human dermal 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 109 records · Page 6Linked to original sources
PubMed2000

Inhibition of human dermal fibroblast proliferation by removal of dermatan sulfate.

In the current study, a glycosaminoglycan lyase, chondroitinase B, was used to study the role of dermatan sulfate proteoglycans on human dermal fibroblast proliferation. Pretreatment with chondroitinase B significantly decreased fibroblast proliferative responses to serum (20% to 55%). In contrast, heparinase III and chondroitinase AC were less effective in inhibiting fibroblast proliferation to serum. Analysis of glycosaminoglycans on chondroitinase B-treated fibroblasts confirmed that dermatan sulfate was removed from fibroblasts by this enzyme. Chondroitinase B treatment also decreased proliferation to basic fibroblast growth factor (bFGF) by 20% and reduced receptor binding by 25%. Heparinase III inhibited bFGF binding by 73%, but decreased proliferation to bFGF by only 21%. Chondroitinase AC had no effect on bFGF proliferation or binding. These data suggest that dermatan sulfate proteoglycans play a significant role in the control of human dermal fibroblast proliferation.

Cell Adhesion↗
PubMed1991

Hypoxia upregulates the synthesis of TGF-beta 1 by human dermal fibroblasts.

In this report, we have investigated the secretion and synthesis of transforming growth factor-beta 1 (TGF-beta 1) by human dermal fibroblast cultures in response to hypoxia (2% oxygen), and have compared it to standard oxygen culture conditions (15% oxygen at the cell surface). Sandwich enzyme-linked immunosorbent assay (SELISA) showed a selective and progressive increase in secretion of the TGF-beta 1 isoform in response to hypoxia, up to ninefold after cultures were exposed to low oxygen for 72 h; TGF-beta 2 peptide levels were not increased. We then investigated the transcriptional regulation of the TGF-beta 1 gene in response to low and standard oxygen tensions. In the first 24-48 h, TGF-beta 1 mRNA levels decreased steadily in both oxygen environments. This mRNA decline continued for up to 72 h in standard oxygen but not in cultures exposed to low oxygen tension. At 72 h, steady-state TGF-beta 1 mRNA levels were 8 times greater in low compared to standard oxygen, and this increase was reversible upon re-exposure of fibroblast cultures to standard oxygen tension for 24 h. Elevated TGF-beta 1 m-RNA levels in both low and standard oxygen declined steadily and with the same half-life after the addition of actinomycin D, suggesting that hypoxia increased TGF-beta 1 transcription rather than mRNA stability. We conclude that low oxygen tension upregulates the synthesis of TGF-beta 1 by human dermal fibroblasts, and leads to increased secretion of this peptide.

Cell Hypoxia↗
PubMed2005

Regulation of fibrogenic/fibrolytic genes by platelet-derived growth factor C, a novel growth factor, in human dermal fibroblasts.

Platelet-derived growth factor (PDGF) is a potent mitogenic and chemotactic cytokine, and PDGF-C is a novel growth factor belonging to the PDGF family. In this study, to determine whether this growth factor can contribute to fibrosis and tissue remodeling, we examined the effect of PDGF-CC on the expression of fibrogenic/fibrolytic genes such as type I collagen, fibronectin (FN), matrix metalloproteinases (MMPs), and their inhibitors (TIMPs) in normal human dermal fibroblasts in vitro. PDGF elevated the levels of MMP-1 or TIMP-1 protein as well as mRNA, whereas this cytokine had no influence on the expression of type I collagen, FN, or TIMP-2. PDGF-CC also increased the levels of MMP-1 catalytic activity in the cultured media and mRNA expression, which was paralleled that on the levels of promoter activation. Additionally, PDGF-CC induced the mitogenic and migratory activity of human dermal fibroblasts in a dose-dependent manner. On the other hand, we also determined the specificity of the inhibitory effect of monoclonal antibodies against PDGF-CC generated by immunizing balb/c mice with recombinant human PDGF-CC. This antibody could inhibit the regulatory effects of MMP-1 or TIMP-1 synthesis as well as the mitogenic effects on human dermal fibroblasts induced by PDGF-CC, whereas this antibody did not affect those induced by other PDGF forms such as PDGF-AA, -AB, or -BB. These results suggest that this cytokine plays a role in the tissue remodeling.

Animals↗
PubMed1985

Hemadsorption focus assay for growth of influenza and parainfluenza viruses in human dermal fibroblasts.

An assay for virus-induced hemadsorption foci in cultures of human dermal fibroblasts is described. The assay allows determination of activity of species-specific as well as nonspecific antiviral agents or biological factors, such as interferons. The assay may be used for abortive (e.g., influenza virus) and productive (e.g., parainfluenza virus) infections of human fibroblasts.

Fibroblasts↗
PubMed1992

Inflammatory cytokines stimulate glucose uptake and glycolysis but reduce glucose oxidation in human dermal fibroblasts in vitro.

Interleukin-1 alpha (IL-1 alpha) produced alterations in human dermal fibroblast glucose metabolism in vitro of the type seen in severe sepsis in man. Glycolysis and glucose uptake were increased but the oxidation of glucose within the tricarboxylic acid (TCA) cycle was reduced. The combined addition of tumour necrosis factor alpha (TNF alpha) with interferon-gamma (IFN-gamma) similarly increased the dependency for cellular energy provision from an oxidative to the glycolytic state. These cytokine-induced changes in glucose metabolism were unaffected when prostaglandin production was inhibited with a cyclo-oxygenase inhibitor, but were significantly reduced by the steroid dexamethasone. Thus, the inflammatory cytokines IL-1 and TNF alpha reportedly detected in the circulation during severe sepsis may directly affect not only glucose uptake but also its subsequent metabolism within tissue fibroblasts.

Biological Transport↗
PubMed1999

Cytokine modulation of type XV collagen gene expression in human dermal fibroblast cultures.

The expression of type XV collagen was studied in cultured human dermal fibroblasts exposed to transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha) or interleukin-1beta (IL-1beta), cytokines which have been shown previously to alter the expression of several extracellular matrix genes. TGF-beta enhanced the expression of the type XV collagen gene (COL15A1) in a time-dependent manner, up to 4.3-fold after 24 h of incubation, whereas TNF-alpha and IL-1beta reduced the mRNA steady-state levels by 32 and 80%, respectively. When TGF-beta and TNF-alpha were added together to the cultures, the stimulatory effect of TGF-beta on type XV collagen gene expression was abrogated, indicating antagonistic modulation by these 2 cytokines. These data suggest that the cytokines tested in this study may contribute to the regulation of type XV collagen synthesis in a variety of tissues which have recently been shown to express this particular collagen gene.

Cells, Cultured↗
PubMed1998

Mast cell tryptase stimulates both human dermal fibroblast proliferation and type I collagen production.

BACKGROUND: Mast cell tryptase has been shown to be mitogenic for fibroblasts, however, it still remains unknown whether mast cell tryptase stimulates collagen production by human derrmal fibroblasts. OBJECTIVE: We have investigated the effect of mast cell tryptase on type I collagen production by human dermal fibroblasts as well as the proliferation of the fibroblasts. METHODS: Tryptase isolated from human lung tissue was added to the culture of fibroblasts from normal dermis, and the fibroblast proliferation and the activity of type I collagen synthesis in the supernatants were assayed, respectively. RESULTS: Fibroblast proliferation was increased with tryptase in a concentration-dependent manner, and a significant increase was observed in the presence of tryptase at concentrations from 0.01 to 10 microg/mL. The increase of fibroblast proliferation with 3 microg/mL tryptase was significantly reduced by 15 microg/mL antitryptase IgG antibody, which was demonstrated to inhibit fibrinogenolysis of tryptase. On the other hand, the production of type I collagen by the fibroblasts was significantly increased with tryptase at a concentration of 10 microg/mL. The collagen production in the presence of 10 microg/mL tryptase was significantly inhibited by 50 microg/mL antitryptase IgG antibody. CONCLUSION: Tryptase increases not only the proliferation of human dermal fibroblasts but also type I collagen production.

Cell Division↗
PubMedDate not supplied

Wound healing mediator production by human dermal fibroblasts grown within a collagen-GAG matrix for skin repair in humans.

Cell and tissue therapy applications in humans are being used increasingly, particularly for tissue repair. Several reconstructed skin models have been proposed. Wound healing involves overlapping steps of inflammation, cell migration and proliferation, neovascularisation, extracellular matrix production and remodelling. This is regulated by numerous cytokines and other soluble mediators. We have prepared dermal substitutes (DS) consisting of a collagen-GAG, three-dimensional matrix colonized by human dermal fibroblasts (HDF), isolated by skin explant or enzymatic digestion of the skin for potential therapeutic use in humans. To test the functionality of these DS, we measured (ELISA) the stimulatory effect on HDF in the matrix, of serial dilutions of human serum (HS) on the production of wound healing mediators: interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1). We observed: 1). a stimulatory effect of HS on HDF production of the different mediators tested, with a dose-dependent effect in the case of IL-8 and VEGF. 2). A matrix-potentiating effect on the production of the different mediators by HDF. 3). A decrease in the production of IL-8 and VEGF when HDF isolated by enzymatic digestion was used to colonize the matrix as compared with HDF isolated by skin explant. We conclude: 1). that the production by HDF, in a collagen-GAG matrix, of mediators involved in cutaneous wound healing is decreased when HDF are isolated by enzymatic skin digestion rather than by skin explant. 2). That measurement of the production of cytokines or other mediators could be a useful quality control to test the functionality of tissue-engineered DS for tissue repair therapy in humans and more generally of cells prepared for cell therapy.

Adult↗
PubMed1997

Effect of reactive oxygen species on the elastin mRNA expression in cultured human dermal fibroblasts.

The effects of ultraviolet A (UVA) and reactive oxygen species (ROS), generated by a xanthine and xanthine oxidase (XOD) system, on the mRNA expression of elastin, were investigated using cultured human dermal fibroblasts. Total RNA was isolated and subjected to Northern blot analysis using synthesized 530 base cDNA probe for elastin with primers derived from exon 10 and 1 of human elastin. UVA irradiation did not affect elastin mRNA expression. In contrast, ROS resulted in a dose-related increase in the level of elastin mRNA up to 1.8-fold in cultured human dermal fibroblasts. Catalase, used as scavenger, essentially prevented the ROS induced alterations in elastin mRNA levels. These results suggest that ROS produced in the dermis may contribute to elastin deposition observed in photoaging skin.

Blotting, Northern↗
PubMed1994

Tumor necrosis factor alpha stimulates production of leukemia inhibitory factor in human dermal fibroblast cultures.

Leukemia inhibitory factor (LIF) is a recently described cytokine with a variety of actions including a possible involvement in immune responses. We determined whether human dermal fibroblast cultures could produce LIF after they were treated with tumor necrosis factor alpha (TNF alpha), a cytokine that is produced as an early inflammatory response of activated monocytes. We found that treatment of the cultures with as little as 0.5 units/ml (1.5 pM) caused a detectable increase in both LIF message and protein as measured by Northern blot assay and ELISA, respectively. Furthermore, increasing concentrations of TNF alpha produced a dose-dependent increase in both steady-state LIF mRNA and protein levels up to a maximum response with 500 units/ml (1.5 nM). Increases in LIF mRNA levels were rapid and could be detected 1 hr after treatment with 500 units/ml of TNF alpha. However, this effect was transient. It reached a maximum at 2 hr and returned almost to baseline at 24 hr. In contrast, levels of LIF protein in the conditioned media of the cultures increased progressively over 24 hr. The LIF produced by these cultures was biologically active and was inhibited by a polyclonal antibody to human LIF in a bioassay. These results demonstrate that LIF is produced by human dermal fibroblasts in response to treatment with TNF alpha, a mediator of acute inflammation. Furthermore, they suggest that production of LIF by these cells may be involved in the development of both the local and generalized immune response.

Cells, Cultured↗
PubMed1996

Human dermal fibroblasts produce nitric oxide and express both constitutive and inducible nitric oxide synthase isoforms.

Nitric oxide (NO) is produced by a variety of human and animal cells and is involved in a broad array of physiological and pathophysiological processes. It can cause vasodilation, serve as a neurotransmitter, and have anti-neoplastic, anti-microbial, and anti-proliferative effects. In this study, we have demonstrated that fibroblasts derived from human skin spontaneously produce NO and that this production can be enhanced by stimulating the cells with interferon-gamma and lipopolysaccharide. The production of NO by human dermal fibroblasts can be blocked by NG-monomethyl-L-arginine (L-NMMA). The inhibitory effect of L-NMMA on NO production was restored by addition of L-arginine but not D-arginine. By measuring the rate of conversion of [14C]L-arginine to [14C]L-citrulline, we show that unstimulated cells expressed only Ca2+-dependent NO synthase (NOS) activity (1.36 +/- 0.57 pmol/mg/min; n = 4) whereas stimulated cells expressed both Ca2+-dependent (2.60 +/- 0.54 pmol/mg/min; n = 4) and -independent (1.59 +/- 0.14 pmol/mg/min; n = 4) NOS activities. With reverse transcription polymerase chain reaction (RT-PCR), the 422-bp RT-PCR product for human endothelial constitutive NOS and the 462-bp RT-PCR product for human hepatocyte inducible NOS were detected in proportion to the amount of mRNA-related RT-cDNA added to the reaction mixture. Further evidence by immunocytochemistry demonstrated that human dermal fibroblasts express both constitutive and inducible NOS proteins. These data collectively suggest that in addition to macrophages and other inflammatory cells, nitric oxide production by dermal fibroblasts could be important during the inflammatory stages of wound healing and possibly also in the later stages of proliferation and tissue remodeling after skin injury in humans.

Animals↗
PubMed2003

Inhibition of cytokine-induced fractalkine production by bacterial invasion of human-dermal fibroblasts.

Fractalkine (FKN/CX3CL1) is an atypical chemokine, for which a major biological function has not yet emerged. However, recent data suggest a role in immune responses in the skin. In this study, we analyzed fractalkine (FKN) secretion by human-dermal fibroblasts after exposure to pro-inflammatory cytokines or to invasive and noninvasive strains of Escherichia coli. Incubation of fibroblasts with TNF-alpha and IL-1beta induced a delayed expression of soluble FKN, compared with the rapid secretion of other chemokines including IL-8 (CXCL8), monocyte chemotactic protein-1 (CCL2), and RANTES (regulated upon activation, normal T cell expressed and secreted; CCL5). TNF-alpha and IFN-gamma gamma were more potent at inducing FKN secretion than was IL-1beta. Very little FKN was detected on the cell surface. FKN was not detected after incubation with the bacteria, regardless of the strain used. In contrast, both invasive and noninvasive E. coli triggered the release of IL-8 and monocyte chemotactic protein-1 in a dose-response manner, whereas RANTES was produced only in response to the invasive strain. Finally, incubation of fibroblasts with the invasive strain of E. coli inhibited TNF-alpha- and IFN-gamma-induced production of FKN. These results demonstrate for the first time that human-dermal fibroblasts express FKN, and that the characteristics of FKN secretion are distinct from those of other chemokines produced by these cells during immune responses in the dermis. In addition, our data indicate that bacterial invasion of dermal fibroblasts actively modulates FKN expression.

Cells, Cultured↗
PubMed1999

Ultraviolet-B induction of interstitial collagenase and stromelyin-1 occurs in human dermal fibroblasts via an autocrine interleukin-6-dependent loop.

Ultraviolet-B irradiation of human dermal fibroblasts has earlier been shown to induce matrix-degrading metalloproteinases, thus driving connective tissue degradation in photoaging and photocarcinogenesis. Herein, we report that Ultraviolet-B irradiation led to a dramatic increase in specific mRNA and protein levels of interstitial collagenase, stromelysin and interleukin-6. By contrast, the major tissue inhibitor of matrix-degrading metalloproteinases, TIMP-1, was unaffected. Monospecific neutralizing antibodies directed against human interleukin-6 significantly reduced the interstitial collagenase and stromelysin-1 protein levels. Taken together, our data provide the first evidence that Ultraviolet-B induction of interstitial collagenase and stromelysin-1 occurs via the synthesis and release of interleukin-6. Hence, this newly identified autocrine mechanism may contribute to dermal photodamage.

Cells, Cultured↗
PubMed1990

Detection of neutrophil-activating peptide NAP/IL-8 and NAP/IL-8 mRNA in human recombinant IL-1 alpha- and human recombinant tumor necrosis factor-alpha-stimulated human dermal fibroblasts. An immunocytochemical and fluorescent in situ hybridization study.

A neutrophil-activating peptide (NAP)/IL-8 produced by LPS-stimulated human peripheral blood monocytes was biochemically purified and functionally characterized by different investigators. Work conducted in our laboratory showed that NAP/IL-8 as well as variants of this peptide are produced by a variety of cells (e.g., monocytes, T lymphocytes, endothelial cells) and that lesional psoriatic scales contain large amounts of biologically active NAP/IL-8. We now investigated human dermal fibroblasts for production of NAP/IL-8. The peptide was detected by immunocytochemistry by using the mAb 46E5. NAP/IL-8 mRNA was visualized by high resolutive fluorescent in situ hybridization with biotinylated antisense/sense RNA probes. Among the various stimuli used [human (h)rIL-1 alpha, hrTNF-alpha, hrIL-3, hr-granulocyte-macrophage-CSF, LPS, FMLP, and platelet-activating factor (PAF)] only hrIL-1 alpha (100 U/ml) and hrTNF-alpha (100 ng/ml) induced the transcription and translation of NAP/IL-8. In contrast to monocytes, LPS was without effect in cultured human dermal fibroblasts. Both NAP/IL-8 and NAP/IL-8 mRNA were found in the cytoplasm adjacent to the nucleus, but interestingly NAP/IL-8 mRNA was not restricted to the cytoplasm. In positive cells only two small bright spots were randomly distributed in the nucleus. Most likely these spots represent transcription sites where NAP/IL-8 mRNA is accumulated during gene expression. Our observations show that stimulation of dermal fibroblasts with the cytokines hrIL-1 alpha and hrTNF-alpha results in expression of IL-8.

Cell Compartmentation↗
PubMed2003

Matrix metalloproteinase expression in cytokine stimulated human dermal fibroblasts.

In this study, we investigated the effect of inflammatory cytokines on matrix metalloproteinase (MMP-1) and TIMP-1 production in human dermal fibroblasts, which play a pivotal role in wound healing, ranging from the synthesis and remodeling of extracellular matrix (ECM) to the synthesis of growth factors. The balance of MMPs and TIMPs is crucial in directing successful wound repair. Human adult dermal fibroblasts were seeded in six well plates (7.5 x 10(4) cells/ml) in complete media. Eighty to ninety percent confluent cells were treated with interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) (10 ng/ml) for 6h in serum free media with suitable controls run in triplicate. Supernatants were assayed for pro-MMP-1 & TIMP-1. Extracted total RNA was used for reverse transcription polymerase chain reaction (RT-PCR) with sequence specific primers for MMP-1, TIMP-1 and beta-actin. Signal intensity was normalized to the internal control (beta-actin). Statistical analysis used ANOVA. MMP-1 and TIMP-1 mRNA expression were markedly increased with IL-6 and TNF-alpha treatment and remains unchanged with IL-1beta. Pro-MMP-1 protein levels are unchanged with TNF-alpha and significantly increased with IL-1beta and IL-6 treatment. However, TNF-alpha significantly increases TIMP-1 protein levels. Data suggests differential regulation of MMP-1 and TIMP-1 protein levels by the cytokines found in stimulated dermal fibroblasts. Further characterization of this response will provide an understanding of the mechanisms of pathogenesis of extracellular matrix (ECM) and the potential role of metalloproteinases in tissue remodeling after injury.

Actins↗
PubMed2005

Stimulation of the proliferation of human dermal fibroblasts in vitro by a lipidocolloid dressing.

OBJECTIVE: The effect of Urgotul on normal human dermal fibroblast proliferation was studied in vitro and compared with that of two other dressings: Mepitel and Tulle Gras. METHOD: Proliferation was measured by the extent of thymidine incorporation into the replicating DNA of proliferative fibroblasts in contact with the complete dressing.Additional cell viability and metabolism were evaluated using MTT assay. Morphology and ultrastructure analysis were based on immunolabelling and confocal laser microscopy. RESULTS: Only Urgotul significantly stimulated thymidine incorporation, generally with a maximal proliferative effect at a contact time of 48 hours. This was confirmed by the observation of a greater number of dividing cells (mitotic cells) than in the control cultures. No cytotoxicity was observed following treatment with this dressing. Cells exhibited normal structural and ultrastructural features. CONCLUSION: Fibroblasts play a key role in dermal wound repair. The ability of Urgotul to promote fibroblast proliferation could explain its efficiency in the healing process of acute and chronic wounds. DECLARATION OF INTEREST: This study was supported by Urgo Laboratories.

Analysis of Variance↗
PubMed2000

Isolation and identification of psoralen plus ultraviolet A (PUVA)-induced genes in human dermal fibroblasts by polymerase chain reaction-based subtractive hybridization.

Premature aging of the skin is a prominent side-effect of psoralen photoactivation, a therapy used for a variety of skin disorders. Recently, we demonstrated that treatment of human dermal fibroblasts with 8-methoxypsoralen and ultraviolet A irradiation resulted in a permanent growth arrest with a switch of mitotic to postmitotic fibroblasts. Furthermore, an upregulation of matrix-degrading metalloproteinases and a high level of de novo expression of the senescence-associated beta-galactosidase was detected in the PUVA-treated postmitotic fibroblasts. The molecular basis for this PUVA-induced change in the functional and morphologic phenotype of fibroblasts resembling or mimicking replicative senescence is, however, unknown. Herein after, we have used a polymerase chain reaction-based subtractive hybridization protocol to identify human genes that are induced by PUVA treatment. Application of polymerase chain reaction-Select resulted in the cloning of four PUVA genes. Sequence analysis and homology searches identified three cDNA clones of known genes related to cell cycle regulation (p21waf1/cip1), stress response (ferritin H) and connective tissue metabolism (tissue inhibitor of metalloproteinases-3), whereas one cDNA clone represented a novel gene (no. 478). Northern blot analyses were performed to confirm a PUVA-dependent increase in specific mRNA levels in human dermal fibroblasts in vitro. This report on the identification of growth arrest related genes in PUVA-treated fibroblasts may stimulate further research addressing the causal role of these known and novel genes in extrinsic and intrinsic aging processes on a molecular and cellular level.

Cell Division↗
PubMedDate not supplied

Effect of activated human mast cells and mast cell-derived mediators on proliferation, type I collagen production and glycosaminoglycans synthesis by human dermal fibroblasts.

Although an increased number of mast cells in fibrotic tissues such as scleroderma, keloid or healing wound has been highlighted, it is still unclear whether or not mast cells are fibrogenic. The aim of the present study is to determine whether functionally active human mast cells can provide human dermal fibroblasts directly with fibrogenic properties. In order to examine the effects of IgE-mediated mast cell activation on fibroblast proliferation and synthesis of type I collagen, we utilized an in vitro defined system in which cultured human mast cells were co-cultured with human dermal fibroblasts. We also employed a three-dimensional fibroblast culture system using supplementation of L-ascorbic acid as an assay system to investigate the effects of mast cell-derived mediators on synthesis of glycosaminoglycans by human fibroblast. Fibroblast proliferation was actively stimulated with IgE-activated mast cells. However, this stimulatory effect was canceled in co-cultures with a higher number of IgE-activated mast cells. In the presence of a higher number of activated mast cells, the fibroblast cell layer was destroyed, in contrast to an intact cell layer in the presence of same number of the mast cells without activation. Type I collagen synthesis was unchanged in fibroblasts co-cultured with mast cells. The total amount of main disaccharide units, particularly DELTADi-HA, was increased when fibroblasts were exposed to histamine. Thus, we conclude that other factors, in addition to mast cells, are important in the development of human tissue fibrosis or sclerosis.

Cell Division↗