Browsing by Subject "Matrix metalloproteinase 9"

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    Diagnostic value of matrix metalloproteinase 9 and tissue inhibitor of matrix metalloproteinases 1 in cholesteatoma
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Olszewska, Ewa; Matulka, Marlena; Mroczko, Barbara; Pryczynicz, Anna
    Objectives: Matrix metalloproteinase 9 (MMP-9), able to degrade type IV collagen, plays a key role in inflammatory cell migration as well as in the destructive behaviour of cholesteatoma. The aim of our study was to compare the expression of MMP-9 and TIMP-1 in cholesteatoma tissue and in the concentrations in serum and plasma concentrations. Material and Methods: Twenty five adult patients suffering from cholesteatoma (a study group) were included in the study. A comparison group consisted of 25 adult patients admitted to hospital due to nasal septum deviation. MM-9 and TIMP-1 serum and plasma concentrations as well as proteins’ expressions in cholesteatoma tissues (study group) and normal retroauricular skin specimens (control group) were evaluated. MMP-9 and TIMP-1 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Cholesteatoma tissues and normal retroauricular skin specimens were evaluated immunohistochemically. Results: In the study and comparison groups, MMP9 and TIMP-1 concentrations were similar with no significant difference within the groups. In cholesteatoma tissues, the expression of the investigated enzyme and its inhibitor was higher than in normal skin specimens, limited mostly to cholesteatoma perimatrix. Conclusion: Cholesteatoma may be limited to the middle ear or parts of the temporal bones. Our findings suggest better clinical usefulness of MMP-9 and TIMP-1 expression in cholesteatoma tissues than either serum or plasma levels of these proteins. It might suggest that the higher the expression of MMP-9 the stronger the inflammation -accompanied cholesteatoma.
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    The hypertrophic chondrocyte: To be or not to be
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Hallett, Shawn A.; Ono, Wanida; Ono, Noriaki
    Hypertrophic chondrocytes are the master regulators of endochondral ossification; however, their ultimate cell fates cells remain largely elusive due to their transient nature. Historically, hypertrophic chondrocytes have been considered as the terminal state of growth plate chondrocytes, which are destined to meet their inevitable demise at the primary spongiosa. Chondrocyte hypertrophy is accompanied by increased organelle synthesis and rapid intracellular water uptake, which serve as the major drivers of longitudinal bone growth. This process is delicately regulated by major signaling pathways and their target genes, including growth hormone (GH), insulin growth factor-1 (IGF-1), indian hedgehog (Ihh), parathyroid hormone-related protein (PTHrP), bone morphogenetic proteins (BMPs), sex determining region Y-box 9 (Sox9), runt-related transcription factors (Runx) and fibroblast growth factor receptors (FGFRs). Hypertrophic chondrocytes orchestrate endochondral ossification by regulating osteogenic-angiogenic and osteogenic-osteoclastic coupling through the production of vascular endothelial growth factor (VEGF), receptor activator of nuclear factor kappa-B ligand (RANKL) and matrix metallopeptidases-9/13 (MMP-9/13). Hypertrophic chondrocytes also indirectly regulate resorption of the cartilaginous extracellular matrix, by controlling formation of a special subtype of osteoclasts termed "chondroclasts". Notably, hypertrophic chondrocytes may possess innate potential for plasticity, reentering the cell cycle and differentiating into osteoblasts and other types of mesenchymal cells in the marrow space. We may be able to harness this unique plasticity for therapeutic purposes, for a variety of skeletal abnormalities and injuries. In this review, we discuss the morphological and molecular properties of hypertrophic chondrocytes, which carry out important functions during skeletal growth and regeneration.