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Biomedical subjects

E Vuorio

Publications and source records attributed to E Vuorio.

At least 127 records · Page 7Linked to original sources
PubMed1989

13-cis retinoic acid and dexamethasone modulate the gene expression of epidermal growth factor receptor and fibroblast proteoglycan 40 core protein in human skin fibroblasts.

The effects of 13-cis retinoic acid (RA) and dexamethasone on the levels of epidermal growth factor (EGF) receptor and fibroblast derived proteoglycan core protein (PG40) mRNAs were studied in human skin fibroblasts. The EGF receptor is involved in the regulation of cellular proliferation and the synthesis of matrix proteins, and proteoglycan 40 is important for cell attachment and interaction with collagen and fibronectin. 13-cis-RA at a concentration of 10(-7) M markedly reduced the levels of the EGF receptor and PG40 mRNAs, the decreases being 33 and 56%, respectively. Dexamethasone reduced these mRNAs markedly less. Simultaneous treatment of the fibroblasts with 13-cis-RA and dexamethasone resulted in similar decreases in EGF receptor and PG40 mRNAs as with 13-cis-RA alone. Surprisingly, the proliferation rate of the fibroblasts was increased in the presence of dexamethasone under conditions similar to those which caused slight decrease in the EGF receptor mRNA levels. This indicates that glucocorticoids also affect the cellular growth by mechanisms which do not involve EGF receptors.

Aggrecans↗
PubMed1989

In situ localization of collagen production by chondrocytes and osteoblasts in fracture callus.

An experimental model of fracture-healing was used to study the production of types-I and II collagen by in situ hybridization. The distribution of cartilage matrix in callus was determined by histochemical staining. Messenger RNA (mRNA) for cartilage-specific type-II collagen was detectable as early as the fifth day in a small number of cells that had acquired a chondrocyte phenotype but that also contained type-I collagen mRNA, suggesting an ongoing change in the expression of collagen genes. The location of the first chondrocytes, which were adjacent to cortical bone, suggested that they originated from cells that had derived from the periosteum by differentiation. On the seventh day of callus formation, the presence of both type-I and type-II collagen mRNA in chondrocytes of expanding cartilage suggested that most growth occurred by differentiation of mesenchymal cells and less by proliferation of differentiated chondrocytes. Expansion continued until the tenth to fourteenth day, after which the cartilage was replaced by woven bone. This was characterized by the presence of osteoblasts that were active in the synthesis of type-I collagen.

Animals↗
PubMed1988

Expression of the c-Ha-ras and neu oncogenes in DMBA-induced, anti-estrogen-treated rat mammary tumors.

Dimethylbenzanthracene (DMBA)-induced rat mammary tumors were analyzed for the structure and expression of the oncogenes c-Ha-ras and neu and the effects of anti-estrogen treatment. Tumor samples were divided into 3 groups, the first consisting of untreated tumors, the second of anti-estrogen (toremifene)-treated unresponsive (growing) tumors, and the third of toremifene-treated responsive (regressing) tumors. DNA and RNA derived from normal tissues of the same experimental animals were also analyzed. In Southern blot analysis of genomic DNAs, 2 tumors out of 23 contained a new Xbal site in the Ha-ras gene, indicating a point mutation in the second nucleotide of codon 61. Both of these tumors belonged to the group that had not received toremifene. No amplifications of the Ha-ras or the neu genes were observed. Although greatly variable, the levels of Ha-ras mRNA were highest in untreated tumors, lower in toremifene-treated, unresponsive tumors and even lower in toremifene-treated, regressing tumors, corresponding approximately to the levels detected in normal liver and uterus of untreated animals. Expression of the neu mRNA was variable and considerably lower than that of Ha-ras mRNA. It was similar in all 3 groups and somewhat elevated than in several non-malignant control tissues. Localization of c-Ha-ras expression by in situ hybridization revealed a relatively even distribution of the mRNA throughout the mammary tissue. The results suggest that mechanisms other than activation of the c-Ha-ras or neu genes are important for progression and regression of DMBA-induced rat mammary carcinomas.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1988

The small dermatan sulphate proteoglycans synthesized by fibroblasts derived from skin, synovium and gingiva show tissue-related heterogeneity.

Dermatan sulphate proteoglycans (DSPGs) synthesized in the presence of 35SO4 were characterized in culture media of fibroblast lines obtained from skin, synovium, and gingiva. The molecular mass of DSPG varied from 95-130 kDa as estimated by SDS/polyacrylamide-gel electrophoresis. Gingival fibroblasts constantly produced larger DSPGs than skin fibroblasts. This was due to the larger dermatan sulphate (DS) chains, which also showed tissue-related heterogeneity in the distribution of 4- and 6-sulphated disaccharide units. The N-glycosylated cores (44 and 47 kDa) obtained following chondroitinase ABC treatment were of identical size in all tissues. The cores from the different tissues were also of the same size (38 kDa) when addition of the N-linked oligosaccharides was inhibited by tunicamycin or when they were removed by N-glycanase treatment. No evidence for low-molecular-mass sulphated oligosaccharides was found. All tissues contained two mRNA species (1.6 and 1.9 kb) for the DSPG core protein. These data suggest that the pattern of transferase activities involved in the construction of DS chains differs from one tissue to another. This variation may modulate the functions of DSPG in the extracellular matrix.

Blotting, Northern↗
PubMed1988

Interferon-alpha and interferon-gamma reduce excessive collagen synthesis and procollagen mRNA levels of scleroderma fibroblasts in culture.

The effects of interferon-alpha and interferon-gamma on collagen synthesis and mRNA levels of type I and type III procollagens were studied in skin fibroblasts cultured from affected and unaffected skin sites of two patients with localized scleroderma (morphea). Both scleroderma cell lines exhibited elevated type I and type III procollagen mRNA levels to account for the increased procollagen synthesis, when compared to the unaffected controls. Interferon-gamma treatment resulted in a dose-dependent reduction in collagen synthesis and procollagen mRNA levels in scleroderma fibroblasts. A 72-h exposure to interferon-gamma reduced procollagen mRNA levels in the scleroderma fibroblast lines to the levels exhibited by the unaffected control fibroblasts. The suppressive effect of interferon-alpha on procollagen mRNA levels was somewhat weaker than that of interferon-gamma. The results suggest potential use of interferon-gamma in treatment and prevention of human fibrotic conditions.

Cells, Cultured↗
PubMed1988

Arthritis-associated changes in flow cytometric characteristics of cultured synovial fibroblasts.

Synovial fibroblasts cultured from patients with rheumatoid or reactive arthritis and from controls were studied by flow cytometry, spectroscopy, and electron microscopy. Analysis of 29 cell lines revealed consistent differences between arthritic and normal fibroblasts. Cells cultured from inflamed synovial tissue exhibited higher autofluorescence than did control fibroblasts, and displayed exceptional light scatter properties in flow cytometry, indicating changes in cytoplasmic structures. Electron microscopic examination of the fibroblasts from arthritic synovial tissue revealed large numbers of round, swollen, laminated, mitochondrion-like bodies, which were not observed in the control fibroblasts. The changes observed by flow cytometry (light scatter and autofluorescence) coincided with the presence of the mitochondrion-like organelles. The strong autofluorescence observed in the arthritic fibroblasts resembled the fluorescence spectrum of mitochondrial flavoproteins. These data suggest that persistent metabolic and structural changes have occurred in the mitochondria of synovial fibroblasts and inflammatory synovial tissue. The usefulness of flow cytometry in identifying such cells is described.

Arthritis↗
PubMed1988

Localization of the expression of types I, III, and IV collagen, TGF-beta 1 and c-fos genes in developing human calvarial bones.

Total RNA extracted from developing calvarial bones of 15- to 18-week human fetuses was studied by Northern hybridization: in addition to high levels of type I collagen mRNAs, the presence of mRNAs for type III and type IV collagen, TGF-beta and c-fos was observed. In situ hybridization of sections containing calvarial bone, overlying connective tissues, and skin was employed to identify the cells containing these mRNAs. Considerable variation was observed in the distribution of pro alpha 1(I) collagen mRNA in osteoblasts: the amount of the mRNA in cells at or near the upper surface of calvarial bone was distinctly greater than that in cells at the lower surface, indicating the direction of bone growth. High levels of type I collagen mRNAs were also detected in fibroblasts of periosteum, dura mater, and skin. Type III collagen mRNA revealed a considerably different distribution: the highest levels were detected in upper dermis, lower levels were seen in fibroblasts of the periosteum and the fibrous mesenchyme between bone spiculas, and none was seen in osteoblasts. Type IV collagen mRNAs were only observed in the endothelial cells of blood capillaries. Immunohistochemical localization of type III and IV collagens agreed well with these observations. The distribution of TGF-beta mRNA resembled that of type I collagen mRNA. In addition, high levels of TGF-beta mRNA were observed in osteoclasts of the calvarial bone. These cells, responsible for bone resorption, were also found to contain high levels of c-fos mRNA. Production of TGF-beta by osteoclasts and its activation by the acidic environment could form a link between bone resorption and new matrix formation.

Blotting, Northern↗
PubMed1988

Localization of protamine 1 mRNA in different stages of the cycle of the rat seminiferous epithelium.

A mouse protamine 1 cDNA probe was used to study P1 protamine gene expression during the cycle of the seminiferous epithelium in the rat. In situ hybridization experiments showed that transcription of the P1 protamine mRNA starts in the middle of step 7 of spermiogenesis during substage VIIc. The mRNA levels stay high in steps 7-14 spermatids but decrease during steps 15-16 and are virtually undetectable in steps 17-19 spermatids. Northern blot analyses of RNAs isolated from microdissected pools of seminiferous tubules show high P1 protamine mRNA concentrations during stages VIIc-XIV-III of the cycle and lower levels during stages IV-VIIb. Owing to a post-transcriptional shortening of the poly(A) tail by 130 bases, a decrease in the size of protamine 1 mRNA from approximately 580 to 450 nucleotides was observed in stages XIII-XIV suggesting an initiation of protamine 1 synthesis in step 13-14 spermatids. In stages II-VI (steps 16-18 spermatids), only the smaller size protamine 1 mRNA was detectable. The expression of protamine 1 mRNAs has been localized in the very last phase of the haploid gene activity. Although the in situ hybridization suggests a disappearance of protamine 1 mRNA after step 16 of spermiogenesis, Northern blot analysis shows that low levels of mRNA are present during the period of final condensation of the chromatin, reflecting the association of protamine with DNA.

Animals↗
PubMed1988

Abnormal mitochondria in cultured synovial fibroblasts in rheumatoid and reactive arthritis?

This paper summarizes our recent studies on synovial fibroblast cultures started from patients with rheumatoid or reactive arthritis and from healthy controls. Analysis of these cultures by flow cytometry, spectroscopy and electron microscopy revealed consistent differences between arthritic and normal fibroblasts. Increased autofluorescence, exceptional light scatter properties, rhodamine-123 staining and electron microscopic findings of fibroblasts from arthritis patients suggest involvement of mitochondria in the disease process. Conditioned media of activated monocytes induced in the mitochondria of normal synovial fibroblasts changes similar to those observed in the fibroblasts originating from patients with rheumatoid or reactive arthritis.

Arthritis, Rheumatoid↗
PubMed1988

Identification of fibroblasts responsible for increased collagen production in localized scleroderma by in situ hybridization.

Skin biopsies from seven patients with localized scleroderma (morphea) and from two healthy individuals were studied by in situ hybridization to localize the cells responsible for increased procollagen production. In scleroderma lesions, high levels of pro alpha 1 (I) and pro alpha 1 (III) collagen mRNAs were detected in some but not all fibroblasts, suggesting the presence of a subpopulation responsible for the increased collagen production. The levels of pro alpha 1 (I) and pro alpha 1 (III) collagen mRNAs in these fibroblasts were clearly elevated compared to control skin specimens hybridized at the same time under identical conditions. Most of the scleroderma samples represented intermediate stages where the fibroblasts containing elevated levels of type I and type III procollagen mRNAs were located in the papillary and upper reticular layer of the dermis. One of the scleroderma samples from an early inflammatory stage of the disease was found to contain activated fibroblasts in all dermal layers and also in aggregates adjacent to inflammatory cell infiltrates. In situ analyses were also performed on cell cultures from affected and unaffected skin of one scleroderma patient. These experiments revealed a homogeneous population of activated fibroblasts in cultures producing high levels of collagen. The results suggest that development of fibrosis in scleroderma could evolve through activation of a certain fibroblast subpopulation. During cell culturing, however, cell selection or uncharacterized regulatory mechanisms appear to modulate the behavior of these cells with respect to collagen production.

Autoradiography↗
PubMed1988

Polymorphic restriction sites of type II collagen gene: their location and frequencies in the Finnish population.

Restriction fragment length polymorphism (RFLP) of the cartilage-specific type II collagen gene has been studied in the Finnish population. Two high-frequency alleles, also reported in other populations, were detected. The HindIII allele had a frequency of 0.33, and that detected with PvuII a frequency of 0.46. Both of these frequencies resembled the ones reported for other populations. Also one BamHI allele, not earlier reported, was found at a low frequency. Two other previously reported polymorphisms for BamHI and EcoRI were not detected in the Finnish population. The RFLPs showed a fair agreement with the Hardy-Weinberg equilibrium. A linkage disequilibrium was found between PvuII and HindIII markers. The alpha 1(II) collagen gene seems to be more conserved in populations of various origins than the alpha 2(I) collagen gene. These polymorphic collagen markers would be useful in linkage studies of various inherited cartilage disorders.

Alleles↗
PubMed1988

Flow cytometry of fibroblasts cultured from skin of patients with localized scleroderma.

Fibroblast cultures were initiated from affected and unaffected skin sites of 6 patients with localized scleroderma. Two of the affected cell lines exhibited more than threefold increases in procollagen production and mRNA levels. All the cell lines were analyzed by flow cytometry to detect a possible heterogeneity of scleroderma fibroblast cultures which could explain the production of excessive amounts of collagen. No evidence of a subpopulation responsible for elevated collagen production was detected using cytoplasmic dot hybridization of cells fractionated by flow cytometry. When compared with the nonaffected controls, all the cell lines from affected skin areas of scleroderma patients were found to exhibit a lower level of cellular autofluorescence, suggesting an alteration in metabolic activity. The results show that the heterogeneity of scleroderma fibroblasts that was found in vivo is lost when the cells are cultured.

Adolescent↗
PubMed1988

Enhanced expression of TGF-beta and c-fos mRNAs in the growth plates of developing human long bones.

The expression of mRNAs for type I and type II procollagens, transforming growth factor-beta (TGF-beta) and c-fos was studied in developing human long bones by Northern blotting and in situ hybridization. The cells producing bone and cartilage matrix were identified by hybridizations using cDNA probes for types I and II collagen, respectively. Northern blotting revealed that the highest levels of TGF-beta mRNA were associated with the growth plates. By in situ hybridization, this mRNA was localized predominantly in the osteoblasts and osteoclasts of the developing bone, in periosteal fibroblasts and in individual bone marrow cells. These findings are consistent with the view that TGF-beta may have a role in stimulation of type I collagen production and bone formation. Only a low level of TGF-beta mRNA was detected in cartilage where type II collagen mRNA is abundant. In Northern hybridization, the highest levels of c-fos mRNA were detected in epiphyseal cartilage. In situ hybridization revealed two cell types with high levels of c-fos expression: the chondrocytes bordering the joint space and the osteoclasts of developing bone. These differential expression patterns suggest specific roles for TGF-beta and c-fos in osseochondral development.

Bone Development↗
PubMed1987

Determination of the single polyadenylation site of the human pro alpha 1(II) collagen gene.

Several cDNA clones for the human type II procollagen mRNA were isolated from a cartilage cDNA library. Six of the clones containing the longest inserts were subjected to restriction site mapping for alignment. All these six clones extended to the poly A tail. The longest clone, containing a 1470 bp insert, was named pHCAR3. Sequencing of pHCAR3 made it clear that neither of the two canonical AATAAA sequences of the human type II collagen gene is used as the polyadenylation signal. Two 60 bp stretches of high interspecies homology terminating in a hexanucleotide ATTAAA, located 23 nucleotides upstream of the poly A tail, apparently have an important role in determining the single polyadenylation signal for this gene. S1 protection experiments confirmed these observations.

Amino Acid Sequence↗
PubMed1987

Epidermal growth factor increases collagen production in granulation tissue by stimulation of fibroblast proliferation and not by activation of procollagen genes.

The effects of epidermal growth factor (EGF) on granulation-tissue formation and collagen-gene expression were studied in experimental sponge-induced granulomas in rats. After daily administration of 5 micrograms of EGF into the sponge, total RNA was extracted from the ingrown granulation tissue at days 4 and 7 and analysed by Northern hybridization for the contents of mRNAs for types I and III procollagens. EGF treatment increased procollagen mRNA, particularly at day 4. To determine whether this elevation was due to increased proliferation of collagen-producing fibroblasts or to activation of collagen-gene expression in these cells, fibroblast cultures were started from granulation tissue and treated with EGF. These experiments confirmed that EGF is a potent mitogen for granuloma fibroblasts in a dose-dependent manner. The effect of EGF treatment on radioactive hydroxyproline production in cultured cells was inhibitory. The decreased rate of collagen synthesis was also indicated by decreased amounts of procollagen mRNAs. The results suggest that the stimulation of wound healing and collagen production by EGF is due to increased fibroblast proliferation, and not to increased expression of type I and III procollagen genes.

Animals↗
PubMed1987

Interleukin-1 increases collagen production and mRNA levels in cultured skin fibroblasts.

In the present study we show that highly purified human interleukin-1 increases collagen production nearly 2-fold and mRNA levels of type I and III collagen over 2.5-fold in cultured normal human dermal fibroblasts. To minimize the effects of transient prostaglanding E2 production in fibroblasts treated with interleukin-1, the cell cultures were preincubated for 24 h before these measurements were made. The effects of interleukin-1 were also tested on scleroderma fibroblasts exhibiting increased collagen production. Although collagen synthesis was stimulated by interleukin-1 to some degree, the cells grown from both affected and unaffected skin areas were found to be relatively unresponsive to the effects of interleukin-1, suggesting a role for this monokine in the earlier stages of the disease process. The results also suggest that interleukin-1 has a role in stimulation of collagen synthesis under certain normal and pathological conditions in addition to stimulating fibroblast proliferation.

Cells, Cultured↗
PubMed1987

Elevated pro alpha 2(I) collagen mRNA levels in cultured scleroderma fibroblasts result from an increased transcription rate of the corresponding gene.

Fibroblasts cultured from affected and unaffected skin sites of three scleroderma patients were studied for the activation of type I collagen gene expression. Dot blot hybridizations with pro alpha 2(I) collagen specific cDNA probe revealed 2.9-4.8-fold increases in pro alpha 2(I) mRNA levels in the affected fibroblasts over the unaffected control cells. Transcription rate of the pro alpha 2(I) gene in the nuclei isolated from the same cells was 2.0-3.7-fold higher in the scleroderma fibroblasts than in the controls. The results show that scleroderma fibroblasts have undergone activation of collagen gene expression at the transcriptional level, which subsequently results in elevated procollagen mRNA levels, overproduction of collagen, and development of dermal fibrosis.

Adolescent↗