Browsing by Subject "Collagens"

Now showing 1 - 5 of 5
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    A micro-anatomical model of the distribution of myocardial endomysial collagen
    (Murcia : F. Hernández, 2002) Macchiarelli, G.; Ohtani, O.; Nottola, S.A.; Stallone, T.; Camboni, A.; Prado, I.M.; Motta, P.M.
    Myocardial connective tissue probably provides passive support for regulating heart tensile strength and stiffness and ultimately for controlling heart mechanics through its endomysial part. However, endomysial collagen micro-arrangement is still a matter of debate. In order to define the fine distribution of left ventricle endomysial collagen, we applied the NaOHscanning electron microscopy (SEM) maceration method (one of the techniques of choice for studying collagen micro-arrangement) to rabbit heart. Gomori-reticulum staining was used for correlated light microscopy (LM) observations. The SEM-NaOH method allowed isolation of collagen by removing other extracellular matrix components and cells and preserved collagen structure and position. Endomysial collagen appeared arranged in laminae that delimited the lacunae that were left empty by macerated myocytes and small vessels (mostly capillaries). These laminae were formed by reticular fibers, as confirmed by LM observations of Gomorireticulum- stained samples, and were organized in irregularly meshed networks made of thin (single) and thick (composed) filaments. In longitudinal views, collagen laminae extended the entire length of lacunae. In transversal views, the cut surface of the laminae appeared to be made of collagen bundles. These observations provide an updated microanatomical view of endomysial collagen distribution, which integrates previous studies. This model is based on the evidence that collagen laminae enveloped the surface of small vessels and myocytes. Thus, a type of myocyte-myocyte or capillary-myocyte "laminar connection" anchored to the entire cell length here is emphasized, rather than a type of "strut connection" anchored to defined loci, as usually described. This structure explains better how endomysium may provide the necessary support for heart compliance and protection against overstretch.
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    Extracellular matrix molecules associated with lymphatic vessels in health and disease
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Czarnowska, Elżbieta; Ratajska, Anna; Jankowska Steifer, Ewa; Flaht Zabost, Aleksandra; Niderla Bielińska, Justyna
    Lymphatic vessels (LyVs), responsible for fluid, solute, and immune cell homeostasis in the body, are closely associated with the adjacent extracellular matrix (ECM) molecules whose structural and functional impact on LyVs is currently more appreciated, albeit not entirely elucidated. These molecules, serving as a platform for various connective tissue cell activities and affecting LyV biology should be considered also as an integral part of the lymphatic system. Any alterations and changes in ECM molecules over the course of disease impair the function and structure of the LyV network. Remodeling of LyV cells, which are components of lymphatic vessel walls, also triggers alterations in ECM molecules and interstitial tissue composition. Therefore, in this review we aimed to present the current knowledge on ECM in tissues and particularly on molecules surrounding lymphatics in normal conditions and in disease
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    Immunolocalization of matrix proteins in different human cartilage subtypes
    (Murcia : F. Hernández, 2006) Wachsmuth, L.; Söder, S.; Fan, Z.; Finger, F.; Aigner, T.
    Cartilage exerts many functions in different tissues and parts of the body. Specific requirements presumably also account for a specific biochemical composition. In this study, we investigated the presence and distribution pattern of matrix components, in particular collagen types in the major human cartilages (hyaline, fibrous, and elastic cartilage) by histochemical and immunohistochemical means. Macroscopically normal articular cartilages, menisci, disci (lumbar spine), epiglottal, and tracheal tissues were obtained from donors at autopsy. Aurical and nasal cartilages were part of routine biopsy samples from tumor resection specimens. Conventional histology and immunohistochemical stainings with collagen types I, II, III, IV, V, VI, and X and S-100 protein antibodies were performed on paraformaldehyde-fixed and paraffinembedded specimens. The extracellular matrix is the functional component of all cartilages as indicated by the low cell densities. In particular major scaffold forming collagen types I (in fibrous cartilage) and II (in hyaline and elastic cartilages) as well as collagen type X (in the calcified layer of articular cartilages, the inner part of tracheal clips, and epiglottis cartilage) showed a specific distribution. In contrast, the "minor" collagen types III, V, and VI were found in all, collagen type IV in none of the cartilage subtypes. In this study, we present a biochemical profile of the major cartilage types of the human body which is important for understanding the physiology and the pathophysiology of cartilages.
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    lmmunohistochemical localization of collagens and fibronectin in human breast neoplasms
    (Murcia : F. Hernández, 1987) Al-Adnani, M. S.; Taylor, S.; Al-Bader, A.A.; Al-Zuhair, A.G.H.; McGee, James O`D.
    Forty four specimens from neoplastic, hyperplastic and normal human breast tissues were studied for localization of collagens and fibronectin. Affinity purified antihuman type I, I11 and IV collagens and antifibronectins were utilized by the indirect immunoperoxidase technique on fixed and paraffinembedded sections. 86% of the cell cytoplasm of infiltrating ductal and 83% of the lobular cancers were positively stained for collagen type I and 111. Collagen type IV, however, was detected in 100% of infiltrating ductal and 83% of lobular carcinomas. Focal cytoplasmic staining is a predominant feature for all antigens in the intraduct carcinoma while a diffuse pattern is encountered in the infiltrating types. Intact basement membranes in various lesions always stained for type IV collagen and showed variable staining for type I11 collagen and fibronectin. Epithelia of normal, benign, hyperplastic breast and most medullary carcinoma were negative for the three collagen types. Our results are in favour of the view that infiltrating breast carcinoma cells produce inappropriately the majority of collagens and inconsistently other proteins such as fibronectin.
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    Long-term type 1 diabetes alters the deposition of collagens and proteoglycans in the early pregnant myometrium of mice
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Favaro, Rodolfo R.; Raspantin, Priscila R.; Salgado, Renato M.; Forte, Zuleica B.; Zorn, Telma M.T.
    troduction: We have previously shown that long-term type 1 diabetes affects the structural organization, contractile apparatus and extracellular matrix (ECM) of the myometrium during early pregnancy in mice. Objective: This study aimed to identify which myometrial ECM components are affected by diabetes, including fibril-forming collagen types I, III and V, as well as proteoglycans, decorin, lumican, fibromodulin and biglycan. Methods: Alloxaninduced type 1 diabetic female mice were divided into subgroups D1 and D2, formed by females that bred 90- 100 and 100-110 days after diabetes induction, respectively. The deposition of ECM components in the myometrium was evaluated by immunohistochemistry/immunofluorescence. Results: The subgroup D1 showed decreased deposition of collagen types I and III in the external muscle layer (EML) and decreased collagen types III and V in the internal muscle layer (IML). Collagen types I and III were decreased in both muscle layers of the subgroup D2. In addition, increased deposition of collagen types I and III and lumican as well as decreased collagen type V were observed in the connective tissue between muscle layers of D2. Lumican was decreased in the EML of the subgroups D1 and D2. Fibromodulin was repressed in the IML and EML of both D1 and D2. In contrast, decorin deposition diminished only in muscle layers of D2. No changes were noticed for biglycan. Conclusions: Subgroups D1 and D2 showed distinct stages of progression of diabetic complications in the myometrium, characterized by both common and specific sets of changes in the ECM composition.