Biomedical subjects

A Hatamochi

Publications and source records attributed to A Hatamochi.

At least 37 records · Page 2Linked to original sources

PubMed1997

Alopecia areata associated with myasthenia gravis and thymoma: a case of alopecia with marked improvement following thymectomy and high level prednisolone administration.

A 57-year-old Japanese woman who suffered from alopecia areata associated with myasthenia gravis (MG) and thymoma responded well to thymectomy and high doses of glucocorticosteroid administration. Several treatments for alopecia areata including administration of systemic prednisolone were attempted, but loss of hair on the scalp progressed. After thymectomy and high level glucocorticosteroid administration for MG, the lesions on the scalp improved within four weeks. Consequently, we suggest that this thymectomy and high level glucocorticosteroid administration assisted in improving the immune dysfunction causing the alopecic lesions in this patient.

Alopecia Areata↗

PubMed1996

The transcription of human alpha 1(I) procollagen gene (COL1A1) is suppressed by tumour necrosis factor-alpha through proximal short promoter elements: evidence for suppression mechanisms mediated by two nuclear-factorbinding sites.

Recent studies have demonstrated that tumour necrosis factor-alpha (TNF-alpha) decreases alpha 1(I) procollagen gene (COL1A1) expression in cultured human dermal fibroblasts. The purpose of this study was to analyse the transcriptional control of COL1A1 by TNF-alpha. Cultured human dermal fibroblasts were transiently transfected with plasmids containing 5' flanking sequences of COL1A1 fused to the chloramphenicol acetyltransferase (CAT) gene, and were incubated for 48 h in medium with or without TNF-alpha. TNF-alpha inhibited the CAT activity of fibroblasts transfected with plasmids containing 2.3 kb of 5' flanking sequences of COL1A1, whereas the activity of control plasmids containing the herpes simplex thymidine kinase promoter gene (pBLCAT) was unaltered. A series of deletion constructs of various small substitution mutations of the COL1A1 5' flanking region fused to the CAT gene were also transfected, and CAT activity was measured after incubation with TNF-alpha. TNF-alpha suppressed COL1A1 promoter activity through proximal short promoter elements containing only 107 bp. Short substitution mutations between -101 and -97 bp or between -46 and -38 bp abolished TNF-alpha suppression of COL1A1 promoter activity. DNA-protein complex formation was observed involving both sites in gel retardation assays. These results suggest that TNF-alpha suppressed COL1A1 promoter activity through elements located between -101 and -97 bp and between -46 and -38 bp of the COL1A1 promoter, and that the suppression involved DNA-protein interactions.

Base Sequence↗

PubMed1996

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.

Child, Preschool↗

PubMed1996

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].

Cells, Cultured↗

PubMed1996

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.

Adolescent↗

PubMed1996

Reduced collagenase gene expression in fibroblasts from hypertrophic scar tissue.

The major histopathological feature of hypertrophic scar lesions is fibrosis, characterized by excessive accumulation of collagen. The purpose of this study was to determine if there is not only increased expression of collagen but also decreased expression of collagenase in hypertrophic scar fibroblasts. We compared the expression of mRNA for alpha 1 (I) and alpha 1 (III) collagen, and collagenase in cultured fibroblasts from different portions of hypertrophic scars and normal dermis. In hypertrophic scar fibroblasts, increased levels of alpha 1 (I) and alpha 1 (III) collagen mRNAs were observed in fibroblasts from the edge and outside of scar tissue, while normal levels were noted in fibroblasts from the centre of this tissue. In contrast, decreased levels of collagenase mRNA were found in the hypertrophic scar fibroblasts. The reductions were: centre (25% of the control) greater than the edge (43% of the control) greater than the outside (84% of the control). The changes in the collagenase mRNA levels of the hypertrophic scar fibroblasts correlated well with decreased collagenolytic activity as determined by the degradation rate of fluorescein isothiocyanate-labelled type I collagen in fibroblast culture supernatant. These results suggest that decreased expression of collagenase in hypertrophic scar fibroblasts may be one possible cause for the excessive accumulation of collagen in the skin lesions of hypertrophic scars.

Adolescent↗

PubMed1994

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.

Animals↗

PubMed1994

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.

Actins↗

PubMed1994

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.

Adult↗

PubMed1994

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.

Adult↗

PubMed1993

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.

3T3 Cells↗

PubMed1993

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.

Adult↗

PubMed1993

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.

Adult↗

PubMed1992

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.

Actins↗

PubMed1991

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.

Actins↗

PubMed1991

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.

Actins↗

PubMed1991

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.

Cell Line, Transformed↗

PubMed1991

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.

Collagen↗