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Biomedical subjects

E Vuorio

Publications and source records attributed to E Vuorio.

154 records · Page 9Linked to original sources

Effects of sodium aurothiomalate on hyaluronic acid synthesis in normal and rheumatoid synovial fibroblast cultures.

In studies with normal and rheumatoid synovial fibroblast cultures the effects of sodium aurothiomalate on the quantity and quality of hyaluronic acid were tested. This gold compound produced one clear effect: the molecular weight of hyaluronate produced by rheumatoid fibroblasts was increased (shifted towards normal) whereas the effects on the amounts of hyaluronic acid synthesized were small in both rheumatoid and control cultures. The importance of this finding in relation to the known beneficial effects of gold preparations in clinical medicine is discussed.

Adolescent↗

Effects of cortisol on glycosaminoglycans synthesized by normal and rheumatoid synovial fibroblasts in vitro.

Cultivated rheumatoid synovial fibroblasts synthesize hyaluronic acid which has a changed molecular weight distribution in Sepharose 2B gel chromatography, when compared with normal synovial fibroblasts. Cortisol has no effect on the molecular weight distribution of either normal or rheumatoid hyaluronate. However, it does reduce the hyaluronic acid synthesis, by more than 50% in both cell types at low, near physiological plasma concentrations of the steroid.

Adult↗

Plasma membranes from experimental granulation tissue.

1. A procedure was developed for the preparation of plasma membranes from experimental granulation tissue of the rat without the addition of enzymes. The yield is better than 20% and the purification at least tenfold. 2. Values are given for the activities of 5'-nucleotidase, Na-+, k-+-activated Mg-2+dependent adenosine triphosphatase and leucine beta-naphthylamidase, for lipid composition, and for the gel-electrophoretic patterns of proteins and glycoporteins in the membrane preparations. 3. The plasma membranes from the mature granulation tissue contain proportionally more protein in the lipid phase, but the specific activities of 5'-nucleotidase and Na-+,K-+-activated Mg-2+-dependent adenosine triphosphatase are smaller than in the proliferating tissue. Certain differences were repeatedly observed in the gel-electrophoretic patterns of the developmental phases. 4. The plasma membranes from the granulation tissue were compared with those from rat peritoneal macrophages and from embryonic-chick tendon cells.

Adenosine Triphosphatases↗

Syndecan-1 expression is upregulated in degenerating articular cartilage in a transgenic mouse model for osteoarthritis.

OBJECTIVE: Mice heterozygous for the Del1 transgene locus with a short deletion mutation in the type II collagen gene develop early-onset degenerative changes in the knee joints that progress to end-stage osteoarthritis by the age of 12-15 months. This study focuses on the expression and distribution of syndecan-1, a cell-surface heparan sulfate proteoglycan, during the development of osteoarthritic cartilage degeneration, to better understand its role in this disease. METHODS: Northern analyses of total RNA extracted from knee joints of transgenic Del1 mice and their nontransgenic controls were used to monitor changes in syndecan-1 mRNA levels during development, growth, ageing, and cartilage degeneration. Immunohistochemistry was used to study the distribution of syndecan-1 in the knee joints at different stages of cartilage degeneration. RESULTS: Syndecan-1 mRNA was present in knee joints throughout life, with the highest mRNA levels in ageing knee joints. In Del1 mice, a transient upregulation of syndecan-1 mRNA synthesis was observed at the age of 6 months coinciding with early stages of cartilage degeneration and a period of attempted repair. Immunostaining for syndecan-1 was most intense in chondrocytes of superficial and intermediate zones of articular cartilage adjacent to defect areas. Chondrocyte clusters also stained strongly for syndecan-1. CONCLUSION: The present temporospatial expression data on upregulation of syndecan-1 in articular cartilage during early stages of cartilage degeneration suggest that this molecule is involved in the attempted repair of cartilage fibrillations. Combined with the known role of syndecan-1 during skeletal development and wound healing, this interesting finding warrants further validation.

Animals↗

Expression of Sox9 and type IIA procollagen during ocular development and aging in transgenic Del1 mice with a mutation in the type II collagen gene.

PURPOSE: To study the expression and distribution of transcription factor Sox9 and type IIA procollagen in the developing and aging eyes of normal and transgenic Dell mice carrying pro(alpha)1(II) collagen transgenes with a short deletion mutation, which cause ocular abnormalities in this mouse line. METHODS: The eyes of Del1 mice were studied on embryonic days E14.5, E16.5 and E18.5, and at the ages of 4 and nine months, using their nontransgenic littermates as controls. Sox9 and pro(alpha)1(IIA) collagen were detected by RNase protection assay and immunohistochemistry. RESULTS: RNase protection assay revealed Sox9 transcripts in the eyes of Del1 and control mice during development and aging. The mRNA for type IIA procollagen had a similar temporal expression pattern. On embryonic days E14.5, E16.5 and E18.5, Sox9 was located by immunohistochemistry in the nuclei and type IIA procollagen in the extracellular space of the developing retina. During growth and aging, the ocular expression of Sox9 mRNA and the immunohistochemical reaction for Sox9 antibody diminished, concomitant with the reduction in type II procollagen mRNA. However, at the age of nine months, levels of Sox9 and type IIA procollagen mRNAs were higher in the degenerating eyes of Del1 and control mice. CONCLUSIONS: The similarities in the temporo-spatial distribution of Sox9 and type IIA procollagen suggest that this transcription factor is involved in the activation of type II collagen expression in the eye, as has been demonstrated in prechondrogenic mesenchyme and immature cartilage. The increased production of Sox9 and type IIA procollagen in the aging retina and vitreous is analogous to degenerating articular cartilage where attempted tissue repair has also been observed.

Aging↗

Ocular abnormalities in transgenic mice harboring mutations in the type II collagen gene.

PURPOSE: To characterize the morphological changes in the eyes of transgenic mice harboring different mutations in type II collagen gene to elucidate the function of this collagen in the eye, and to find out whether these animals could function as models for the human arthro-ophthalmopathies of the Kniest, Stickler and Wagner types. METHODS: Three genetically engineered mouse lines representing two types of mutations in the triple-helical domain of type II collagen and their nontransgenic littermates used as controls were analyzed on day 18.5 embryonic development. After genotyping by polymerase chain reaction (PCR) and Southern hybridization the embryos were prepared for routine histology. Polarization microscopy was done on hyaluronidase-treated sections. RESULTS: Histological analysis revealed several genotype-dependent abnormalities in the eyes of the transgenic mice. Most striking changes were observed in the vitreous architecture; in one line of mice the vitreous was tightly packed in the posterior region of the vitreous space with thick fibrils, empty cavities and dense membrane-like material. The other mutation resulted in reduced filament density of the vitreous. In the most severely affected phenotype the internal limiting membrane was detached from the retinal layers and was markedly thickened, and the posterior lens capsule was thickened. The anterior chamber was shallow or absent in all transgenic lines but was well formed in the normal animals. Changes were also observed in the lens, corneal and scleral structures. CONCLUSIONS: The ocular changes observed in transgenic mice harboring mutations in type II collagen gene show similarities to the human ocular findings in Kniest dysplasia, and in Stickler and Wagner syndromes. We therefore propose that these animals could serve as models for systematic analysis of vitreoretinal degeneration and other abnormalities, as seen in these syndromes.

Abnormalities, Multiple↗

Abnormal craniofacial morphology and cartilage structure in transgenic mice harboring a Gly --> Cys mutation in the cartilage-specific type II collagen gene.

Gross morphology and histology of the craniofacial complex was studied in the offspring of two transgenic founder mice, Gly85-1 and Gly85-3, carrying several copies of a mouse type II collagen transgene that causes a single amino acid substitution (Gly-->Cys) at position 85 of the triple helix. The newborn transgenic mice had a short snout and mandible, a protruding tongue, a cleft of the secondary palate with the tongue situated between the shelves, and a doming cranial vault. Radiological examination revealed that the cranial base of the transgenic mice was shorter and its posterior part downward bent; in addition both the palate and the cribriform plate were less extended in relation to the cranial base than in the controls. Histologically the midline cartilaginous structures were composed of densely packed enlarged chondrocytes in a reduced extracellular matrix containing abnormally thick collagen fibrils. With the exception of the zone of hypertrophic chondrocytes the matrix also showed a loss of glycosaminoglycans. The cellular architecture of the basicranial synchondroses was disorganized, and the nasocerebrally oriented collagen fibrils formed unevenly distributed aggregates. The craniofacial morphology described here for the Gly85 mice shares features typical for other mouse mutations causing short limbed dwarfism. The observations indicate that defective cartilage production causes disproportionate craniofacial growth. Transgenic mice with specific mutations in cartilage-specific genes should therefore be useful for elucidating the complex mechanisms involved in determining the craniofacial growth.

Animals↗

Abnormalities in secondary cartilages in four lines of transgenic mice harboring two different types of mutations in the cartilage-specific type II collagen gene.

A histological analysis was performed on two secondary cartilages, the mandibular condyle and the medial end of clavicle, in transgenic mice harboring two different types of mutations in the cartilage-specific type II collagen gene. Considerable differences were observed in the maturation zone of the chondrocytes and the hypertrophic cells of the growth regions of the two secondary cartilages examined between the transgenic mice and their transgene-negative littermates, which served as controls. Looseness of the perichondrium/periosteum was a distinct feature seen in both mutations. However, phenotypic consequences of the mutations in secondary cartilages were less severe than those in primary cartilages. We propose that the differences between primary and secondary cartilages are due to differences in their origin, mode of growth, architecture and behavior under extrinsic factors.

Amino Acid Sequence↗