Browsing by Subject "Laminin"
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- PublicationOpen AccessEffect of rehabilitation protocols on muscle function and morphology following hindlimb disuse in weanling rats(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Leite Nogut, Keite i; Bianchi, Eduardo; Chesca Simões, Deise Lúcia; Mattiello-Sverzut, Ana Claudia; de Moura-Jucá, Renata Viana BrígidoBackground: Primary or secondary disorders in developing skeletal muscles are prevalent in physical therapy practice. Assessment of gait functional changes and morphological aspects of hindlimb muscles of weanling rats have not been reported simultaneously in the literature. Rehabilitation by active (eccentric training) and passive (stretching) exercises after hypomobility needs to be investigated. Methods: After ten days of immobilisation in a plantar flexion-shortened position, animals underwent eccentric training on treadmills, intermittent (a single series of ten exercises of 30 seconds each, with a 30-s interval) or continuous stretching protocols for 40 minutes, or had free cage activity for three days. Analysis of gait variables and muscle morphology (immunohistochemical staining of soleus and plantar muscles for fibronectin and types I and III collagen and immunofluorescence staining for dystrophin, laminin, Pax-7, and CD68) were performed. Results: On the third day, the rehabilitated animals touched the ground surface with their toes, except for the group undergoing continuous stretching. The total amount of extracellular macrophages was higher in the rehabilitated animals. The number of satellite cells was not significantly different between groups. Conclusion: Three days of active training (eccentric exercise) showed greater effectiveness compared to the other rehabilitation programs. Weanling rats seem to respond differently to external stimuli such as disuse and remobilisation.
- PublicationOpen AccessLaminin isoforms in atherosclerotic arteries from mice and man(F. Hernández y J.F. Madrid. Murcia: Universidad de Murcia, Departamento de Biología Celular e Histología., 2011) Rauch, Uwe; Saxena, Amit; Lorkowski, Stefan; Rauterberg, Jürgen; Björkbacka, Harry; Durbeej, Madeleine; Hultgårdh-Nilsson, AnnaThe properties of the arterial vasculature depend to a large extent on the activities of smooth muscle cells, which, in turn, are determined by their extracellular environment. During pathological conditions, such as atherosclerosis, this interaction is altered. In close proximity to medial smooth muscle cells are basement membrane components, such as different isoforms of laminin. These proteins can have great impact on cellular function via interaction with cell surface integrins. However, knowledge of laminins in smooth muscle cell basement membranes during normal and pathological conditions is scarce. Therefore, we have analyzed the presence of laminin isoforms in atherosclerotic lesions of apolipoprotein E (ApoE)-deficient mice. Our study revealed that the laminin chain isotype composition within atherosclerotic plaque tissue was different from the chain composition in the media. In addition, obvious differences in laminin chain composition could be observed in areas of the media, which were or were not associated with plaque tissue. Our major findings demonstrate that laminin gamma3 was exclusively present in media associated with plaque tissue. Laminin alpha2 was also enriched in these medial areas. Plaque tissue was predominantly enriched in laminin alpha5 chains. This general distribution applied to lesions both with and without a fibrous cap-like structure. The differential distribution of laminin chains were partially accompanied by changes in the presence of the integrin alpha subunits 7 and V. The distribution of laminin chains in human atherosclerotic arteries, with different size and morphology, grossly resembled their distribution in mouse arteries.
- PublicationOpen AccessLaminin matrix formation and S-1 00 protein andlor desmin-positive cells in malignant fibrous histiocytoma MFH(Murcia : F. Hernández, 1993) Kosmehl, H.; Langbein, L.; Katenkamp, D.; Vogel, W.; Berndt, A.16/30 human storiform-pleomorphic malignant fibrous histiocytomas (MFH) showed a focal pericellular immunostaining for laminin. 14/16 of these laminin-positive tumours additionally revealed an atypical cellular differentiation (desmin- andlor S- 100 protein-positive cells). The significance of focal laminin positivity along with atypical, non-entity specific differentiated cells is discussed before the background of laminin as being an indicator and promoter of differentiation in MFH. The limited value of a laminin detection in MFH for solving differential diagnostic questions (MFH versus other poorly differentiated sarcomas with basement membrane formation) has been pointed out.
- PublicationOpen Accesslmmunocytochemistry of perinatal rat livers with a special reference to the roles of mesenchymal cells in hepatic differentiation(Murcia : F. Hernández, 1996) Hayashida, T.; Nagata, Kengo; Doi, Y.; Ozaka, T.; Itoh, HiroyukiTo investigate the roles of extracellular matrix produced by hepatic mesenchymal cells in the organization of hepatic cell cords, perinatal rat livers were examined with immunocytochemistry of fibronectin (FN) and larninin (LM). Some hepatocytes in a free state at prenatal day 15 actively produced FN and LM in the rough endoplasmic reticulum but lost this synthetic activity when such cells were incorporated into hepatic cell cords. On the other hand, hepatic mesenchymal cells, especially those associated with the perisinusoidal space, retained this synthetic activity throughout the stages examined. In the differentiating hepatic cell cords, positive imrnunoreactions for FN and LM were preferentially seen on the cell surface facing both sinusoidal space and differentiating bile canaiiculus concomitant with the expression of the tight junction protein, ZO-1, from prenatal day 17. Since such hepatocytes have lost or reduced their synthetic activities of both glycoproteins in the rER, the immunoreactions appear to be mainly due to hepatic mesenchymal cells which seem to play a role in the formation of the hepatic cell cords and the bile canaliculi.
PublicationRestrictedMuscular dystrophy by merosin deficiency decreases acetylcholinesterase activity in thymus of Lama2dy mice(WILEY, 2005-08-31) Vidal Moreno, Cecilio Jesús; Nieto Cerón, Susana; Campoy Menéndez, Francisco Javier; Muñoz Delgado, Encarnación; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular AHalf of congenital muscular dystrophy cases arise from laminin alpha 2 (merosin) deficiency, and merosin-deficient mice (Lama2dy) exhibit a dystrophic phenotype. The abnormal development of thymus in Lama2dy mice, the occurrence of acetylcholinesterase (AChE) in the gland and the impaired distribution of AChE molecules in skeletal muscle of the mouse mutant prompted us to compare the levels of AChE mRNAs and enzyme species in thymus of control and Lama2dy mice. AChE activity in normal thymus (mean +/- SD 1.42 +/- 0.28 mu mol acetylthiocholine/h/mg protein, U/mg) was decreased by similar to 50% in dystrophic thymus (0.77 +/- 0.23 U/mg) (p = 0.007), whereas butyrylcholinesterase activity was little affected. RT-PCR assays revealed variable levels of R, H and T AChE mRNAs in thymus, bone marrow and spinal cord. Control thymus contained amphiphilic AChE dimers (G(2)(A), 64%) and monomers (G(1)(A), 19%), as well as hydrophilic tetramers (G(4)(H), 9%) and monomers (G(1)(H), 8%). The dimers consisted of glycosylphosphatidylinositol-anchored H subunits. Western blot assays with anti-AChE antibodies suggested the occurrence of inactive AChE in mouse thymus. Despite the decrease in AChE activity in Lama2dy thymus, no differences between thymuses from control and dystrophic mice were observed in the distribution of AChE forms, phosphatidylinositol-specific phospholipase C sensitivity, binding to lectins and size of AChE subunits.- PublicationOpen AccessPresence of laminin and 67KDa laminin-receptor on endothelial surface of lung capillaries. An immunocytochemical study(Murcia : F. Hernández, 1996) Hilario, E.; Unda, F.; Perez-Yarza, G.; Álvarez, A.; Garcia-Sanz, M.; Aliño, S.F.The existence of cell surface-associated molecules has been claimed to play a major role in cellular recognition and interaction. In this respect, different tumor cell lines express laminin and its receptor, and this expression has been correlated with metastatic potential. In the present work, we have studied, by electron microscopic immunolabeling methods, the presence of laminin and 67KDa lamininreceptor on the surface of endothelial cells of lung blood capillaries. To label these molecules, we have developed an easy method in which the labeling is carried out "in situ", in previously excised lungs. The presence of both molecules was observed on the luminal surface of endothelial capillaries and, in many cases, gold particles were associated to small open vesicles of the endothelial cells. The results suggest that these molecules, traditionally associated to extracellular matrix, are also expressed in cellular surface of the lung vascular bed.
- PublicationOpen AccessThe glomerular distribution of laminin and fibronectin in glomerulonephritis(Murcia : F. Hernández, 1993) Nakopoulou, Lydia; Stefanak, K.; Zeis, P.M.; Papadakis, J.; Boletis, J.; Vosnidis, G.; Davaris, P.Laminin (LAM) and fibronectin (FI) are regarded as major components of the glomerular extracellular matrix The aim of this study was to define the distribution of LAM and F1 in primary glomerulonephritis (GN) and GN of systemic lupus erythematosus (SLE) and to correlate the type of glomerular disorders with possible changes in the expression of these components. Normal portions of kidney tissue from 10 patients with renal tumors and sixty-six renal biopsies obtained from patients with GN were studied by the immunoperoxidase- antiperoxidase (PAP) method for the detection of LAM and FI. Twelve patients had membranous GN (MGN), 8 mesangiocapillary GN (MCGN), 2 1 mesangioproliferative GN (MPGN), including I l cases of IgA nephropathy, 11 focal segmental glomerulosclerosis (FSGS) and 14 had SLE. In MGN, LAM was detected more intensely than F1 along the glomerular basement membranes (GBM), in subepithelial GBM protrusions and in the newly-formed GBM. On the contrary, F1 was intensely expressed in the mesangium. LAM and FI expression was pronounced in stages I1 and 111 of MGN. In MCGN, LAM and F1 were diffusely expressed along the GBM and in the mesangium. The distribution of the two antigens in MPGN and FSGS was similar to that seen in normal glomeruli. However, the F1 staining reaction was more intense in severe mesangioproliferative lesions, mainly observed in the cases of IgA-nephropathy, There were no differences in the distribution of LAM and F1 between primary and SLE GN. The antigen staining pattern was pronounced in the membranous and mesangiocapillary lesions of SLE GN. The crescents observed in 7 cases contained increased amounts of both LAM and FI, while the adhesions with Bowman's capsule seen in 9 cases demonstrated increased amounts of LAM. In contrast, the large adhesions observed in 2 cases and the sclerotic lesions in 4 cases contained only small amounts of LAM. Offprint requests to: Dr. Lydia Nakopoulou. Department of Pathology. Medical School, University of Athens, 138-140 Grigoriou Afxediou, Alhens 15772, Greece In conclusion, the increased LAM and F1 glomerular expression mainly in MGN and MCGN, and the F1 overexpression in severe mesangioproliferative lesions of IgA nephropathy suggest that the disturbance of extracellular glomerular matrix is probably due to the damage of glomerular cells or the involvement of the above components in immune-complex formation.
- PublicationOpen AccessThe role of dystroglycan, a novel receptor of laminin and agrin, in cell differentiation(Murcia : F. Hernández, 1997) Matsumura, K.; Yamada, H.; Saito, F.; Sunada, Y.; Shimizu, T.Dystroglycan was originally identified as the extracellular and transmembrane constituents of a large oligomeric complex of sarcolemmal proteins associated with dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene. During the last few years, dystroglycan has been demonstrated to be a novel receptor of not only laminin but also agrin, two major proteins of the extracellular matrix having distinct biological effects. The fact that the drastic reduction of dystroglycan in the sarcolemma, caused by the absence of dystrophin, leads to muscle cell death in DMD patients and mdx mice indicates that, as a laminin receptor, dystroglycan contributes to sarcolemmal stabilization during contraction and stretch of striated muscle cells. Dystroglycan is also expressed in the neuromuscular junction and non-muscle tissues such as kidney, brain and peripheral nerve, and, as a receptor of lamininlagrin, has been implicated in such diverse and specific developmental processes as epithelial morphogenesis, synaptogenesis and myelinogenesis. These findings point to the fundamental role of dystroglycan in the cellular differentiation process shared by many different cell types. In this paper, we review the recent publications on the biological functions of dystroglycan and discuss its roles in cell differentiation.
- PublicationOpen AccessThe ultrastructural composition of basement membranes in vivo(Murcia : F. Hernández, 2001) Miosge, NicolaiThe ultrastructure of basement membranes has a homogeneous appearance. The enormous cell biological importance of basement membranes and their components f o r c e l l proliferation, migration and differentiation implies that their composition is more complex than their structure suggests. To elucidate the molecular composition of basement membranes it1 vivo, we optimised immunogold histochemistry to allow the determination of the molecular arrangement of matrix molecules. Basically, we apply a mild fixation and embed the tissues in the hydrophilic L R - G O ~T~h~is .p reserves the basement membrane with a quality similar to freeze substitution. The application of two antibodies directed toward the C- and N-terminal ends of a molecule and coupled to gold particles of different sizes allows determination of the orientation of a molecule within the basement membrane. We were able to demonstrate that the molecular orientation of the laminin-l molecule changes in the basement membrane according to cell biological needs. We also showed that ultrastructurally identical basement membranes like the ones of the proximal and distal tubules of the kidney have a differing molecular arrangement. Integrin a7 influences the molecular composition of the basement membranes at the myotendinous junction. With the help of double labelling at the ultrastructural level we could show that nidogen-l is CO-localised with laminin-l and only found in fully developed, mature basement membranes. In general, laminin-l, nidogen-l and collagen type IV are localised over the entire width of basement membranes, with laminin-l and nidogen-l CO-localised, in accordance with the current basement membrane models. Incidentally, our investigations warn us, that not every matrix protein found at the light microscopic level as a linear staining pattern underneath an epithelium (basement membrane zone) is a real basement membrane component when investigated at the ultrastructural level. Instead, one and the same molecule, e.g. endostatin, can be a basement membrane component in one organ and a matrix molecule in another.