Collagenase gene expression in cutis laxa fibroblasts is upregulated by transcriptional activation of the promoter gene through a 12-0-tetradecanoyl-phorbol-13-acetate (TPA)-responsive element

Our previous work demonstrated that collagenase mRNA levels are increased in fibroblasts derived from patients with cutis laxa (CL). To pursue the mechanism of the upregulation of collagenase expression, we investigated transcriptional levels of the collagenase gene in CL fibroblasts. Fibroblasts cultured from the skin of three congenital CL patients were studied. Northern blot hybridization revealed 2.8- to 7.3-fold increases in collagenase mRNA levels in CL fibroblasts compared with normal cells. Nuclear run-off experiments demonstrated that the transcription rate of the collagenase gene in nuclei isolated from the same cells was 5.1- to 10.2-fold higher in the CL fibroblasts than in the controls. Transient transfection of a normal collagenase promoter-CAT construct into the cells further showed significantly enhanced transcriptional activity in CL but not in normal fibroblasts. Experiments of transient transfection of deleted or small substituted collagenase promoter-CAT constructs indicated that collagenase transcription in CL fibroblasts was activated the TPA-responsive element site of the collagenase promoter gene. Although the levels of Jun and Fos gene expression did not differ from those observed in normal fibroblasts, AP-1-binding activity, as measured by the ability to bind to an oligonucleotide containing a TPA-responsive element, was significantly elevated in CL fibroblasts as compared with normal fibroblasts. These data suggest that collagenase expression is upregulated at the transcriptional level by endogenous activation of DNA binding of AP-1 in CL fibroblasts [corrected].

Increased expression of type VI collagen genes in cutis laxa fibroblasts

Type VI collagen gene expression in cutis laxa was studied by measuring messenger RNA (mRNA) and protein production levels in four fibroblast strains from patients with congenital cutis laxa and comparing them with those in fibroblasts obtained from age-matched healthy subjects. Levels of type VI collagen mRNA were increased in all cutis laxa fibroblast strains and the levels of alpha 1 (VI) and alpha 3 (VI) chain mRNAs increased in parallel. Increases in type VI collagen mRNAs correlated well with production levels of the corresponding proteins, as determined by immunological assay. These results suggest that increased type VI collagen gene expression is one of the characteristics of cutis laxa dermal fibroblasts and that this abnormality may be related to the skin changes in cutis laxa.

Congenital psoriasiform erythrokeratodermia with cleidocranial dysplasia, urogenital anomalies and atresia ani

We describe two siblings with unique psoriasiform erythrokeratodermia associated with cleidocranial dysplasia, urogenital anomalies and atresia ani. The skin lesions were characterized by demarcated psoriasiform erythema with scaling. A skin biopsy revealed small abscesses containing polymorphonuclear leukocytes in the parakeratotic horny layer, elongation of the rete ridges and dermal papillae, and other findings consistent with psoriasis. A reverse-transcription polymerase chain reaction analysis disclosed increased expression of transforming growth factor alpha in the affected skin lesion of one of the siblings as well as in the skin of a patient with psoriasis. It is suggested that these cases are a variant of a congenital form of psoriasiform erythrokeratodermia.

Effects of tretinoin tocoferil on gene expression of the extracellular matrix components in human dermal fibroblasts in vitro

Recently, it has been reported that tretinoin tocoferil (TT), a synthesized ester-bond compound of all-trans-retinoic acid and alpha-tocopherol, accelerates the formation of granuloma and is effective in promoting experimental open skin wound healing. To investigate whether TT affects the gene expression of extracellular matrix components of human dermal fibroblasts, we measured the mRNA levels of various extracellular matrix components of fibroblasts incubated with TT using specific cDNA probes. The mRNA levels of elastin increased up to 30% of the controls and those of collagen III and VI up to 60%. The mRNA levels of collagen I and fibronectin remarkably increased up to 90% of the controls. These results suggest that the stimulatory effect of TT on the gene expression of many extracellular matrix components might be one of the mechanisms of its promotion of wound healing.

Role of cytokines in controlling connective tissue gene expression

Recently, the role of cytokines in controlling gene expression of connective tissue components has been increasingly emphasized. Many cytokines have been shown to have specific effects on gene expression of connective tissue components, and the roles of cytokines in controlling connective tissue metabolism during wound healing and in fibrosis have increasingly been discussed. In this article, the effects of cytokines on regulation of gene expression of connective tissue components, especially of type I collagen were described. We analysed transcriptional control of the alpha 1(I) collagen gene by TNF-alpha by means of DNA mediated transfection experiments using recombinant plasmids in which the promoter region of the human alpha 1(I) collagen had been fused to the chloramphenicol acetyl-transferase (CAT) gene, in human dermal fibroblasts. It was found that TNF-alpha reduced alpha 1(I) collagen transcription through at least up to -107 bp upstream of the human alpha 1(I) collagen promoter gene in dermal fibroblasts.

Decreased collagenase expression in cultured systemic sclerosis fibroblasts

One cause of the excessive deposition of collagen in systemic sclerosis is thought to be abnormal functioning of fibroblasts. The purpose of this study is to determine whether there is decreased expression of collagenase in systemic sclerosis fibroblasts. In this study, we analyzed collagen and collagenase expression in dermal fibroblasts derived from eight patients with systemic sclerosis and compared the findings with those from nine sex- and age-matched healthy subjects. Increased collagen synthesis accompanying enhanced mRNA levels was observed in two of eight strains, whereas all eight strains showed remarkable decreases in collagenase activity and production. There were no differences in the levels of collagenase mRNA between the systemic sclerosis strains and the normal strains. Results suggest that decreased collagenase expression is a characteristic of systemic sclerosis fibroblasts, and both increased collagen expression and decreased collagenase expression in systemic sclerosis fibroblasts may result in the excessive accumulation of collagen in patients with systemic sclerosis. It is also suggested that decreased collagenase expression is altered at translational and/or post-translational levels.

Activation of fibroblast proliferation by Werner's syndrome fibroblast-conditioned medium

The effects of Werner's syndrome (WS) fibroblast-conditioned medium on cell proliferation and collagen production of normal fibroblasts were studied using four WS fibroblast strains. The conditioned medium from the WS fibroblasts brought about activation of normal fibroblast proliferation, whereas, that from late passage normal fibroblasts and fibroblasts from aged donors' skin did not. Collagen and non-collagenous protein synthesis in normal fibroblasts were increased by the addition of conditioned medium from the WS fibroblasts, but the relative rates of collagen synthesis and non-collagenous protein synthesis were unaltered. These results suggest that activation of fibroblast proliferation by conditioned medium is one of the characteristics of WS fibroblasts.

Purification of a novel factor which binds to the mouse alpha 2 (I) collagen promoter

We have identified and purified a DNA binding protein which specifically binds to a segment of the mouse alpha 2 (I) collagen promoter between -420 and -399 bp upstream of the start of transcription. Purification included heparin-agarose and sequence-specific DNA-affinity chromatography, followed by SDS-PAGE and renaturation of the DNA binding activity after elution from SDS-polyacrylamide gel. The DNA binding activity resides in two species of 42 kDa and 40 kDa, respectively. The levels of DNA binding activity of this factor, which has been tentatively designated as ColF1, are considerably higher in nuclear extracts of NIH-3T3 fibroblasts than in nuclear extracts from epidermal cells, lymphoid cells and transformed NIH-3T3 fibroblasts.

Decreased type VI collagen gene expression in cultured Werner's syndrome fibroblasts

Gene expression of collagens VI, I, and III in Werner's syndrome was studied by measuring messenger RNA (mRNA) and protein production levels in four fibroblast strains from patients with Werner's syndrome and comparing them with age-matched healthy subjects. Levels of type VI collagen mRNA were decreased in all Werner's syndrome fibroblast strains and the decreases were in parallel in all three chains (alpha 1, alpha 2, and alpha 3) of type VI collagen. A coordinate increase of the alpha 1(I) and alpha 1(III) collagen mRNA levels was observed in three of the four Werner's syndrome fibroblast strains. However, no qualitative abnormality of these mRNA transcripts in Werner's syndrome fibroblasts were found by Northern blot analysis. Changes in type VI and type I collagen mRNA correlated well with production levels of corresponding proteins, as determined by immunologic assays. These data suggest that there are changes in expression of multiple connective tissue constituents in Werner's syndrome fibroblasts.

Effects of tumor necrosis factor-alpha on connective tissue metabolism in normal and scleroderma fibroblast cultures

Recent studies have demonstrated that tumor necrosis factor-alpha (TNF-alpha) selectively decreases production of collagens I and III, the major types of collagen in the dermis, and increases production of collagenase in cultured dermal fibroblasts. The effects of TNF-alpha on collagens I, III and VI, fibronectin and collagenase gene expression by fibroblasts derived from normal individuals and patients with systemic sclerosis (SSc) were studied. SSc is characterized by excessive accumulation of collagen in the skin and in certain organs. TNF-alpha inhibited collagen production and mRNA levels of collagens I and III and of fibronectin, and stimulated collagenase activity and collagenase mRNA levels in SSs fibroblasts. Levels of mRNA for alpha 1 (VI) and alpha 3 (VI) collagen and for beta-actin were unaltered in SSc fibroblasts incubated with TNF-alpha. Similar results were observed for mRNA levels in normal fibroblasts incubated with TNF-alpha. These results suggest that TNF-alpha could be expected to be beneficial in the treatment of SSc. In addition, our results indicated that collagen-VI expression is regulated independently from expression of collagens I and III, and expression of fibronectin and collagens I and III are regulated in parallel in fibroblasts treated with TNF-alpha.

Analysis of collagen gene expression by cultured fibroblasts in morphoea

Collagen gene expression was studied in dermal fibroblasts derived from the inflammatory and sclerotic skin lesions of patients with localized or generalized morphoea. The levels of mRNA for type I collagen in early-passage fibroblasts derived from inflammatory lesions were higher than those obtained from the uninvolved skin, whereas those fibroblasts obtained from sclerotic lesions were unaltered. No alteration in type I collagen mRNA levels was observed in late-passage fibroblasts derived from the inflammatory lesions. The relative rate of collagen to total protein synthesis in early-passage fibroblasts derived from inflammatory lesions was higher than that of fibroblasts from uninvolved skin, while no alteration or a slight decrease was observed in fibroblasts from the sclerotic lesions. The data suggest that the inflammatory reactions induce increased collagen synthesis by fibroblasts in the skin in scleroderma.

Effect of histamine on collagen and collagen m-RNA production in human skin fibroblasts

Direct effects of histamine on collagenous and non-collagenous protein synthesis by human skin fibroblasts were studied. Fibroblasts derived from human skin were incubated with various concentrations of histamine. Collagen and non-collagenous protein synthesis were measured by incorporation of 3H-proline. Both collagen synthesis measured as protein-bound hydroxyproline and non-collagenous protein synthesis measured as protein-bound proline increased in the presence of histamine at concentrations of 10(1)-10(2) micrograms/ml. Total RNA was extracted and m-RNA levels of various proteins were estimated by dot blot analysis, and densitometrically quantified. The levels of alpha 1(I) collagen and beta-actin m-RNA were clearly increased at the same concentrations. m-RNA levels of alpha 1(III) collagen were also increased but the rate was lower than that of alpha 1(I) collagen. No alteration of beta-tubulin m-RNA level was observed at the same concentrations. These results demonstrate that stimulation of collagen synthesis by histamine is pretranslationally controlled.

Collagen metabolism in cutis laxa fibroblasts: increased collagenase gene expression associated with unaltered expression of type I and type III collagen

Collagen metabolism was studied in cutis laxa by analyzing collagen and collagenase gene expression in three dermal fibroblast strains from patients with congenital cutis laxa and comparing them with fibroblasts obtained from age-matched healthy subjects. Normal collagen synthetic activity was observed in the cutis laxa fibroblasts. An increased level of collagenase mRNA and unaltered levels of alpha 1(I) and alpha 1(III) collagen mRNA were found in all cutis laxa cell strains by dot blot hybridization. Reduced levels of elastin mRNA were also detected in these strains. However, no qualitative differences in these mRNA transcripts were detected between the control and cutis laxa fibroblasts by Northern blot analysis. Collagenase activity in fibroblast culture supernatants was then measured using fluorescein isothiocyanate (FITC)-labeled type I collagen. Increased collagenolytic activity in cutis laxa fibroblast culture supernatants was also found. These data suggest that increased collagenase expression of fibroblasts is related to the structural abnormality of dermal connective tissue in cutis laxa.

Effects of cyclosporin A on cell proliferation and collagen production by human skin fibroblasts

Cyclosporin A (CSA) is a potent immunosuppressive drug that has been used clinically for the treatment of organ rejection after transplantation as well as for patients with a wide variety of immune-mediated disorders. CSA has recently been reported to be effective in systemic sclerosis, which is a disease of the connective tissues leading to fibrosis of the skin and other involved organs. In this study, we investigated whether CSA affects the cell proliferation and collagen synthesis of human skin fibroblasts. CSA inhibited the DNA synthesis and cell growth of cultured fibroblasts at concentrations of 10(-8) M to 10(-5) M in a dose-dependent manner. The production of both collagen and non-collagenous protein at both the mRNA and protein levels was not affected by 10(-8) to 10(-6) M CSA, but was decreased in the presence of 10(-5) M CSA. These results suggest that CSA may inhibit the proliferation of fibroblasts, but not their synthesis of collagenous and non-collagenous proteins at therapeutic concentrations.

Regulation of collagen gene expression by transformed human fibroblasts: decreased type I and type III collagen RNA transcription

The regulation of collagen gene expression in normal diploid human fetal fibroblasts (KMS-6 cells), and fibroblasts immortally transformed by treatment of KMS-6 with Co-60 gamma rays (KMST-6 cells) was compared to that of ones tumorigenically transformed by treatment of KMST-6 cells with Harvey murine sarcoma virus (KMST-6-Ras cells). Synthesized collagenous protein decreased to approximately 30% of that of normal fetal fibroblasts in both transformed cell lines, and the relative rate of collagen synthesis to total protein synthesis decreased about sixfold in KMST-6 cells and twelvefold in KMST-6-Ras cells. The m-RNA levels of type I collagen in both of these cell lines decreased to approximately 20% of that of the control fibroblasts, whereas type III collagen m-RNA levels decreased to only 9% of that of the control. The copy number of the collagen gene in both transformed cell lines was unaltered. The transcriptional rates of collagen alpha 1(I) and collagen alpha 1(III) in both cell lines decreased to 20% and 7% respectively of that of control. These data indicate that collagen synthesis was reduced at the transcriptional level in these transformed human fibroblasts.

Analysis of methylation in the c-MYC gene in five human myeloma cell lines

Genomic alterations of the human c-MYC gene were analysed in five human myeloma cell lines established in Kawasaki Medical School and compared with those of normal lymphocytes, Raji cells from Burkitt's lymphoma, and an Epstein-Barr virus positive lymphoblastoid cell line (LCL). Although no structural chromosome aberrations at 8q24, the c-MYC locus, were distinct, the mRNA level of c-MYC in these myeloma cell lines was 30-50-fold that in normal peripheral blood lymphocytes. Regarding the methylation of c-MYC, DNAs of the myeloma cell lines were digested with MspI plus EcoRI or HpaII plus EcoRI, and hybridized with three genomic 32P-labelled probes; the first, second and third exons of the human c-MYC gene, respectively. The extent of methylation in cytosine at a single CCGG site in the third exon substantially decreased in these myeloma cell lines as compared with that in normal tonsillar B, LCL and Raji cells. No significant differences in hypomethylation between these myeloma, normal B, LCL and Raji cells was detected in the first and second exon of c-MYC. These results suggest that the hypomethylation in the third exon of c-MYC might be related to the enhanced expression of c-MYC in these human myeloma cell lines.

Increased collagen synthesis accompanying elevated m-RNA levels in cultured Werner's syndrome fibroblasts

Although Werner's syndrome (WS) is a premature aging disease and its fibroblasts typically grow poorly in culture, WS may cause abnormalities in connective tissue metabolism that are seldom seen in normal aging, such as scleroderma-like skin. In a preliminary report, we described increased collagen synthesis in fibroblasts derived from two WS patients. The present study was undertaken to determine the degree of the regulation of collagen gene expression in dermal fibroblasts from two other patients. Overproduction of collagenase sensitive protein was observed in WS fibroblasts. Collagen m-RNA levels, that were determined by hybridization of RNA blots with specific cDNA were about 2 times greater than those in the control cells. These results suggest that control of collagen synthesis in WS fibroblasts is altered at the transcriptional level.