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Biomedical subjects

E Vuorio

Publications and source records attributed to E Vuorio.

At least 109 records · Page 6Linked to original sources
PubMed1991

Comparative effects of interleukin-1 and tumor necrosis factor-alpha on collagen production and corresponding procollagen mRNA levels in human dermal fibroblasts.

The effects of recombinant human Interleukin-1 alpha (IL-1 alpha), Interleukin-1 beta (IL-1 beta), and Tumor Necrosis Factor-alpha (TNF-alpha) on collagen biosynthesis were studied in vitro using dermal fibroblast cultures. Both forms of IL-1 and TNF-alpha induced a dose-dependent inhibition of both types I and III collagen synthesis, as measured by radioimmunoassay, gel electrophoresis, or collagenase-sensitive material. This effect was accompanied by a significant release of prostaglandin E2 into the culture medium. However, indomethacin, a potent inhibitor of prostaglandin synthesis, could not prevent the inhibitory effect of the three cytokines on collagen synthesis. Measurement of type I and type III procollagen mRNA levels in IL-1 treated cells revealed that both IL-1 alpha and IL-1 beta were potent enhancers of procollagen gene expression at pretranslational level. On the other hand, TNF-alpha was found to reduce the steady-state levels of type I and III procollagen mRNA in a dose-dependent manner. Quantitation of IL-1 beta and TNF-alpha transcripts following TNF-alpha treatment of fibroblasts indicated that this cytokine can induce IL-1 beta gene expression in these cells. By contrast, TNF-alpha mRNA remained at a constant level after TNF-alpha exposure. These data suggest that IL-1 and TNF-alpha, two cytokines that share several biologic activities, modulate collagen deposition in dermal fibroblasts by mechanisms that are clearly different: TNF-alpha appears to act at a transcriptional level to inhibit collagen synthesis, whereas IL-1 inhibitory action involves important translational regulation, still unknown, that counterbalances its stimulatory effect on procollagen mRNA levels. Moreover, our data suggest the existence of local fibroblastic cytokine production that may be involved in the modulation of extracellular matrix deposition.

Adult↗
PubMed1991

Localization of type I and III collagen and fibronectin production in injured gastrocnemius muscle.

The healing of muscle rupture consists of two simultaneous processes, regeneration of disrupted muscle fibers and production of connective tissue scar. These two processes are at the same time supportive to and competitive with each other. Their balanced progression is necessary for optimal healing. Synthesis of three connective tissue proteins, collagen types I and III and fibronectin, was analyzed during the regeneration process from 2 days to 3 weeks by Northern blot and in situ hybridization and immunohistochemistry. For this purpose a partial standard rupture of the gastrocnemius muscle was induced in 56 rats by a strike with a blunt spring-loaded hammer. Northern blot analysis of the specific mRNAs during the healing process revealed distinctly different expression patterns for fibronection and type I and III collagens. During the early stages (days 2 and 3) fibronectin, derived mainly from plasma, was abundant in the traumatized area, but local production of fibronectin mRNA by fibroblasts had also already started by day 2, closely followed by that of type III collagen. This early active synthesis of type III collagen and fibronectin was followed by a decrease after 1 week. The production of type I collagen mRNAs was activated somewhat later and remained elevated for at least 3 weeks. The muscle cells did not contain procollagen mRNAs. The observed sequence of connective tissue proteins reflects the particular function that each carries out during muscle wound healing (e.g., fibronectin in fibroblast trapping, type III collagen in plasticity/flexibility, and type I collagen in tensile strength).

Animals↗
PubMed1991

Synthesis of laminin and type IV collagen by trophoblastic cells and fibroblastic stromal cells in the early human placenta.

In situ hybridization was used on both routinely processed paraffin embedded tissue sections and cryosections to study the synthesis of the basement membrane (BM) proteins laminin and type IV collagen in early human placentas from 8 to 11 weeks of gestation. Complementary DNA and RNA probes coding for the pro alpha 1 (IV) chain of human type IV collagen and the B1 chain of human laminin were used to detect respective mRNA. The clusters of cytotrophoblastic cells (i.e., cytotrophoblastic cell columns) contained cells that expressed both laminin and type IV collagen mRNA. Nearly all the stromal cells of developing villi also expressed mRNA for these proteins, type IV collagen mRNA levels being more pronounced than those of laminin. Conversely, the cytotrophoblastic cells of the villous trophoblastic epithelium synthesized mRNA for laminin more actively than that for type IV collagen. Decidual cells, endometrial stromal cells, and cells in the wall of spiral arteries all expressed mRNA for both laminin and type IV collagen. The results of in situ hybridization were found to correlate well with immunohistochemical stainings with specific antibodies to laminin and type IV collagen. The trophoblastic cells of the columns and the stromal fibroblasts are shown to contribute significantly to BM protein synthesis in the developing human placenta. The abundance of BM proteins may indicate their significance in guiding tissue organization in the placenta.

Antisense Elements (Genetics)↗
PubMed1991

Expression of osteonectin, decorin, and transforming growth factor-beta 1 genes in fibroblasts cultured from patients with systemic sclerosis and morphea.

A characteristic feature of fibroblasts cultured from affected skin areas of patients with systemic sclerosis (SSc) and localized scleroderma (morphea) is excessive activation of collagen biosynthesis. To elucidate the nature of fibroblast activation in scleroderma we have studied the expression of 3 noncollagenous connective tissue components, osteonectin, small dermatan sulfate proteoglycan (proteoglycan II, decorin), and transforming growth factor-beta 1 (TGF-beta 1), by measuring their mRNA levels in fibroblast cultures from 6 patients with SSc and 3 with morphea. A clear correlation was observed between the increase in type I collagen and osteonectin mRNA in these cell lines. The apparent overproduction of osteonectin by scleroderma fibroblasts is in accordance with the suggested activation of osteonectin expression during tissue remodeling. The levels of decorin mRNA showed marked variation in the cell lines, but were in no correlation with collagen or osteonectin mRNA. The levels of TGF-beta 1 mRNA were found to be slightly elevated in fibroblasts grown from affected scleroderma skin. This may suggest that this potent activator of collagen production has a role during the initial activation of dermal fibroblasts both in SSc and morphea.

Adolescent↗
PubMed1990

Growth-dependent modulation of type I collagen production and mRNA levels in cultured human skin fibroblasts.

Five human skin fibroblast lines were studied for type I collagen production and type I procollagen mRNA levels through the different growth phases. The cells were plated at low density and followed for 11 days at daily intervals through the stages of rapid growth and visual confluency until the cultures reached stationary growth phase. Each day one culture flask was labeled with [3H]proline for 24 h, and analyzed for production of radiolabeled type I collagen into culture medium. The cell layers were counted and subjected to isolation of cytoplasmic RNA and determination of type I procollagen mRNA levels. The results revealed an approx. 2-fold increase in procollagen production and mRNA levels when the cells reached visual confluency. Thereafter the synthesis rates and mRNA levels remained relatively constant, although a decreasing tendency of both parameters was observed upon further culturing. The results confirm that determination of cell density is important when cell cultures are used for measurement of collagen synthesis or mRNA levels. For determination of pro alpha 2(I) collagen mRNA an 1193 bp cDNA clone was constructed using RNA extracted from human fetal calvaria. Sequencing of the clone revealed some nucleotide and amino acid differences between the previously published sequences. This suggests the presence of more individual variation in procollagen coding sequences than expected.

Amino Acid Sequence↗
PubMed1990

Expression of the myc proto-oncogenes in developing human fetal brain.

We have analysed c-myc, N-myc and L-myc gene expression in developing human fetal brain by Northern hybridization, RNAase protection and in situ hybridization. The unique zonal organization of the developing fetal brain allows a particularly good assessment of the coupling of myc gene expression to cell proliferation and differentiation in vivo. By Northern and in situ hybridization, L-myc as well as c-myc and N-myc transcripts in the brain were found in the post-mitotic cortical and intermediate layers, as well as in the mitotically active layers containing the neuroepithelial precursor cells. Consistent results were also obtained for L-myc using RNAase protection analysis. Both the 3.6 and 3.8kb forms of the L-myc mRNA, resulting from alternative splicing of intron I, were detected in layers of neuroectodermal origin, but not in the meninges or choroid plexus. We also extended L-myc expression and splicing analyses to other developing human fetal tissues. L-myc mRNA was expressed in several other fetal tissues, particularly in fetal skin. Predominantly intron I containing L-myc mRNA was observed in fetal striated and cardiac muscle. Thus, L-myc is expressed in a wider spectrum of developing tissues than previously known. Our findings also, show that L-myc as well as N-myc and c-myc expression is uncoupled from cell division in developing brain.

Blotting, Northern↗
PubMed1990

Differential localization of type I and type III procollagen messenger ribonucleic acids in inflamed periodontal and periapical connective tissues by in situ hybridization.

Inflammatory lesions of periodontal and periapical connective tissue were studied by in situ hybridization to detect cells responsible for type I and type III collagen production. Formalin-fixed and paraffin-embedded tissue specimens from patients with oral lesions of various stages of inflammation were hybridized with cDNA probes specific for human pro alpha 1(I) and pro alpha 1(III) collagen mRNAs, and with bacteriophage lambda DNA as a control probe. This technique permitted us to localize fibroblasts active in type I collagen synthesis in the vicinity of inflammatory infiltrates in all the samples studied. Cells containing high levels of type III collagen mRNA were seen in early abscess formation and they were particularly abundant in pyogenic granuloma and irritation fibroma. Type I collagen mRNA was prominent in gingival fibrosis. In the infrabony lesions with active inflammatory infiltrations the production of collagen was confined mostly to the periphery of the lesions. These findings give indirect evidence that cytokines liberated during the early stages of the inflammatory process stimulate expression of the type III collagen gene by fibroblasts. In chronic lesions a gradual switch from type III to type I collagen gene expression occurs. The change in collagen types appears to underlie the observed isolation of the inflammation by a collagenous capsule. In all the samples studied fibroblasts exhibited marked variation in their levels of procollagen mRNAs, supporting previous views about their heterogeneity in connective tissues. The approach presented here offers new possibilities to study cellular interactions and metabolic activities in inflammatory lesions.

Adolescent↗
PubMed1989

Expression of mRNAs for collagens and other matrix components in dedifferentiating and redifferentiating human chondrocytes in culture.

Cell cultures were initiated from epiphyseal cartilages, diaphyseal periosteum, and muscle of 16-week human fetuses. Total RNAs isolated from these cultures were analyzed for the levels of mRNAs for major fibrillar collagens, two proteoglycan core proteins and osteonectin. In standard monolayer cultures the differentiated chondrocyte phenotype was replaced by a dedifferentiated one: the mRNA levels of cartilage-specific type II collagen decreased upon subculturing, while those of types I and III collagen, and the core proteins increased. When the cells were transferred to grow in agarose, redifferentiation (reappearance of type II collagen mRNA) occurred. Fibroblasts grown from periosteum and muscle were found to contain mRNAs for types I and III collagen and proteoglycan cores. When these cells were transferred to agarose they acquired a shape indistinguishable from chondrocytes, but no type II collagen mRNA was observed.

Aggrecans↗
PubMed1989

Predisposition to familial osteoarthrosis linked to type II collagen gene.

The genetic background of two families, in whom a predisposition to primary osteoarthrosis is inherited as a dominant trait, was investigated. Use of restriction fragment length polymorphisms within and around the type II collagen gene on chromosome 12 revealed a linkage between this cartilage-specific gene and primary osteoarthrosis.

Adult↗
PubMed1989

Comparison of the effects of dexamethasone and 13-cis-retinoic acid on connective tissue biosynthesis in human skin fibroblasts.

The effects of glucocorticoids and retinoids on connective tissue biosynthesis were studied in cultured human skin fibroblasts (HSFs). More specifically attention was paid to the effects of dexamethasone and 13-cis-retinoic acid (RA) on total protein and collagen synthesis and on collagen and fibronectin mRNA levels. The results indicated that dexamethasone reduced the relative collagen synthesis and collagen mRNA levels in HSFs and increased the total incorporation of proline into proteins, the latter effect being due to increased activity in the intracellular proline pool. 13-cis-RA did not affect collagen synthesis at the concentration studied (10(-7) M) but it did reduce the corresponding mRNA levels. Simultaneous addition of both dexamethasone and 13-cis-RA or etretinate resulted in the largest decrease in type I and type III procollagen mRNA levels, indicating that retinoids do not oppose the effect of glucocorticoids on collagen synthesis in cultured HSFs. For comparison the effects of dexamethasone and 13-cis-RA on the mRNA levels of another extracellular matrix component, fibronectin, and of a constitutive enzyme, glyceraldehyde-3-phosphate dehydrogenase, were also studied. The results indicated, that dexamethasone treatment did not alter fibronectin mRNA levels in HSFs, while 13-cis-RA did so to a marked extent. Both dexamethasone and 13-cis-RA also reduced the mRNA level of glyceraldehyde-3-phosphate dehydrogenase, indicating that glucocorticoids and retinoids have both similar and different effects on gene expression in HSF.

Cell Line↗
PubMed1989

Localization of osteonectin expression in human fetal skeletal tissues by in situ hybridization.

The expression of osteonectin gene was studied in developing human fetuses by Northern analysis and in situ hybridization. The highest levels of osteonectin mRNA were detected in RNA extracted from calvarial bones, growth plates, and skin. Low mRNA levels were present in several parenchymal tissues. In situ hybridization of developing long bones revealed three cell types with high osteonectin mRNA levels: osteoblasts, cells of the periosteum, and hypertrophic chondrocytes. Weaker signals were detected in osteocytes, fibroblasts of tendons, ligaments and skin, and in cells of the epidermis. Apart from the hypertrophic chondrocytes, only low osteonectin mRNA levels were seen in cartilage. The localization of osteonectin mRNA in fetal growth plates is consistent with the hypothesis that the protein plays a role in the mineralization of bone and cartilage matrices.

Bone and Bones↗
PubMed1989

Construction of a human pro alpha 1(III) collagen cDNA clone and localization of type III collagen expression in human fetal tissues.

A cDNA clone for human pro alpha 1(III) collagen mRNA was isolated from a cDNA library constructed for human fetal skin RNA. The clone, pHFS3, was identified by restriction mapping and sequencing. Comparison with previously published human type III collagen sequences revealed some differences which may reflect individual variation. The clone was used to study the expression of type III collagen mRNA in various fetal tissues in comparison to the expression of type I collagen mRNAs. In 15-18-week fetal skin the ratio of alpha 1(I) to alpha 1(III) collagen mRNAs was 0.8. Diaphyseal and calvarial bone contained high amounts of type I collagen mRNA and low levels of type III collagen mRNA, resulting in high type I/type III ratios. In situ hybridization of sections of skeletal tissues was employed to identify the cells containing the mRNAs for types I, II and III procollagens. The results revealed differential expression patterns for these three collagen types in various human fetal tissues. Lack of coordinate expression suggests that production of type I and type III collagens is under different regulatory mechanisms in developing skeletal tissues.

Amino Acid Sequence↗
PubMed1989

The N-myc proto-oncogene and IGF-II growth factor mRNAs are expressed by distinct cells in human fetal kidney and brain.

We studied the expression of the N-myc proto-oncogene and the insulin-like growth factor-II (IGF-II) gene in human fetuses of 16-19 gestational wk. Both genes have specific roles in the growth and differentiation of embryonic tissues, such as the kidney and neural tissue. Since continued expression of N-myc and IGF-II mRNAs is also a characteristic feature of Wilms' tumor, a childhood neoplasm of probable fetal kidney origin, we were particularly interested in the possibility that their expression might be linked or coordinately regulated in the developing kidney. Expression of N-myc mRNA was observed in the brain and in the kidney by Northern hybridization analysis. In in situ hybridization of the kidney, N-myc autoradiographic grains were primarily located over epithelially differentiating mesenchyme while most of the mesenchymal stromal cells showed only a background signal with the N-myc probe. N-myc mRNA was detectable throughout the developing brain with a slight accentuation in the intermediate zone cells in between the subependymal and cortical layers. Thus, even postmitotic neuroepithelial cells of the fetal cerebrum expressed N-myc mRNA. In Northern hybridization, IGF-II mRNA signal was abundant in the kidney but much weaker, though definite, in the brain. The regional distribution of IGF-II mRNA in the kidney was largely complementary to that of N-myc. IGF-II autoradiographic grains were located predominantly over the stromal and blastemal cells with a relative lack of hybridization over the epithelial structures. In the brain, IGF-II mRNA was about two- to threefold more abundant in the subependymal and intermediate layers than in the cortical plate and ependymal zone, respectively. The fetal expression patterns of the N-myc and IGF-II mRNAs are reflected by the types of tumors known to express the corresponding genes during postnatal life such as Wilms' tumor. However, the apparent coexpression of the IGF-II and N-myc genes in immature kidneys occurs largely in distinct cell types.

Autoradiography↗
PubMed1989

Expression of mRNAs coding for the alpha 1 chain of type XIII collagen in human fetal tissues: comparison with expression of mRNAs for collagen types I, II, and III.

This paper describes the topographic distribution of the multiple mRNAs coding for a novel human short-chain collagen, the alpha 1 chain of type XIII collagen. To identify the tissues and cells expressing these mRNAs, human fetal tissues of 15-19 gestational wk were studied by Northern and in situ hybridizations. The distribution pattern of the type XIII collagen mRNAs was compared with that of fibrillar collagen types I, II, and III using specific human cDNA probes for each collagen type. Northern hybridization showed the bone, cartilage, intestine, skin, and striated muscle to contain mRNAs for type XIII collagen. An intense in situ hybridization signal was obtained with the type XIII collagen cDNAs in the epidermis, hair follicles, and nail root cells of the skin, whereas the fibrillar collagen mRNAs were detected in the dermis. Cells in the intestinal mucosal layer also appeared to contain high levels of alpha 1(XIII) collagen mRNAs, but contained none of the fibrillar collagen mRNAs. In the bone and striated muscle, alpha 1(XIII) collagen mRNAs were detected in the mesenchymal cells forming the reticulin fibers of the bone marrow and endomycium. The hybridization signal obtained with the alpha 1(XIII) collagen cDNA probe in cartilaginous areas of the growth plates was similar, but less intense, to that obtained with the type II collagen probe. A clear hybridization signal was also detected at the (pre)articular surfaces and at the margins of the epiphyses, whereas it was weaker in the resting chondrocytes in the middle of the epiphyses. The brain, heart, kidney, liver, lung, placenta, spleen, testis, tendon, and thymus did not appear to contain alpha 1(XIII) collagen mRNAs.

Blotting, Northern↗
PubMed1989

Altered distribution of type I collagen mRNA in periodontal disease.

Earlier studies on collagen metabolism in the periodontium have suggested that periodontal disease is associated with reduced amounts of type I collagen in the pocket walls, and with an overall increase in collagen synthesis. In this study we analyzed gingival biopsies of patients suffering from adult type chronic periodontal disease by in situ hybridization, which permitted localization of fibroblasts containing different amounts of proa(I) collagen mRNA. The results showed that expression of type I collagen mRNA is reduced in the vicinity of periodontal pockets and dental plaque. Deeper in the connective tissue, high levels of proa(I) collagen mRNA were observed particularly around inflammatory cell infiltrates which may contribute to the fibrotic reaction observed. In all areas studied the levels of type I collagen mRNA in periodontal fibroblasts varied considerably, supporting previous views about their heterogeneity.

Collagen↗
PubMed1989

Exclusion of the COL2A1 gene as the mutation site in diastrophic dysplasia.

The involvement of the cartilage specific type II collagen gene (COL2A1) was studied in nine patients with diastrophic dysplasia in the Finnish population, where the prevalence of this chondrodystrophy clearly exceeds that reported for other populations. COL2A1 was chosen as the candidate gene based on previous morphological and chemical studies which suggested abnormal structure of type II collagen in diastrophic dysplasia. Southern analysis of the patients' DNA showed no disease related differences in any of the restriction fragments covering the 30 kb COL2A1 gene. As a second approach, the nine patients and their 74 relatives were studied for the inheritance of the type II collagen gene. Three of the patients with diastrophic dysplasia were not homozygous for the intragenic RFLP markers, which suggests that the disease is not linked to the type II collagen gene. Multipoint linkage analysis gave a lod score of -2.95, which conclusively excluded the COL2A1 gene as the mutation site in diastrophic dysplasia in these families.

Adolescent↗
PubMed1989

Characterization of one phenotype of human periodontal granulation-tissue fibroblasts.

Human granulation-tissue fibroblasts were cultured from oral chronic inflammatory lesions and compared with fibroblasts of healthy gingival connective tissue with respect to cell-surface sialoglycoproteins, and the synthesis of extracellular matrix components. Granulation-tissue fibroblasts exhibited a slower growth rate and larger size than their controls. Their cell-surface sialoglycoproteins resembled those of the control cells, except that the relative amount of glycoproteins in the 140-kd region was lower. The ratio of mRNAs for pro alpha l (I) and pro alpha l (III) collagen chains was decreased in granulation-tissue fibroblasts, although electrophoretic fractionation of the proteins did not reveal consistent differences in type I/type III collagen ratio. Granulation-tissue fibroblasts secreted into the culture medium a dermatan sulfate proteoglycan with a lower molecular weight. After digestion with chondroitinase ABC, the molecular weight of the core protein appeared to be identical with that of the control fibroblasts, suggesting a difference in the glycosylation of the core protein. These results support the theory that granulation-tissue fibroblasts represent a distinct phenotype of fibroblastic cells.

Adolescent↗