Search results for "matrix"

Chromogranin A in the Mammalian Merkel Cell: Cellular and Subcellular Distribution

1989

Chromogranin-A (CGA), which accounts for more than half the soluble matrix protein in secretory granules of various neuroendocrine cells, has a wide spectrum of potential biological roles and is considered an important marker of the diffuse neuroendocrine system (DNES). Light and electron microscopic immunohistochemistry of mammalian skin revealed that Merkel cells are exclusively CGA-immunoreactive (ir) and that the immunoreaction is localized in the secretory granules. This finding supports the classification of the Merkel cell as a member of the DNES. The CGA immunoreactivity was restricted to Merkel cells of pigs and humans. In human embryonic skin, CGA was expressed in Merkel cells as …

Tenascin gene expression in rat liver and in rat liver cells. In vivo and in vitro studies.

1991

Tenascin is a major glycoprotein constituent of the extracellular matrix with a strong affinity to fibronectin; its distribution is believed to be temporarily and spatially limited. Tenascin gene expression is increased during wound healing processes. As repair mechanisms in chronic liver diseases resemble wound healing we studied tenascin gene expression in rat liver and in isolated rat liver cells. In normal rat liver a tenascin specific antiserum stains sinusoidal cells with fiber-like prolongations, which at the same time are desmin-positive (ITO-cells). In the CCl4-acutely-damaged liver a strong tenascin staining is detected in cells located among the mononuclear cells of the inflammat…

Human recombinant vasostatin-1 may interfere with cell-extracellular matrix interactions

2006

Vasostatin-1 (VS-1), the N-terminal fragment derived from the cleavage of chromogranin A (CgA), has been shown to exert several biological activities on several tissues and organs. Recently, it has been reported that human recombinant VS-1 (STA-CGA(1-78)) may alter myocardial contractility in eel, frog., and rat hearts. In this article we have explored if STA-CGA(1-78) can induce intracellular cascades interacting both with adhesion molecules and/or extracellular matrix (ECM), components, that is, involvement of the heat shock protein 90 (HSP90) and the endothelial NOS (eNOS), known to be implicated in signal transduction mechanisms affecting myocardial contractility. We used 3D cultured ad…

Long-term function of porcine islets and single cells embedded in barium-alginate matrix.

1993

The influence of alginate-embedding on the maintenance of functioning and morphological integrity in long-term culture of isolated porcine islets and islet cells was studied. Free-floating islets and islet cells served for control. Function was tested after the 1st, 2nd and 4th week. Basal and glucose-stimulated insulin secretion of embedded islets decreased slightly, but significantly after the first week (from 4.39 +/- 0.64 to 2.87 +/- 0.47 at normal and from 11.96 +/- 1.44 to 4.76 +/- 0.78 microU pro 24 h pro islet at elevated glucose concentration, p < 0.05 and < 0.01, resp.) and remained unchanged thereafter. Glucose-stimulation resulted in significant increases in insulin secretion at…

Application of endometrial extracellular matrix hydrogels developed from decellularized uterus in reproductive medicine.

2021

El endometrio es la capa del útero encargada de recibir al embrión en el momento de la implantación. Sin embargo, algunas enfermedades endometriales, como la atrofia endometrial y el síndrome de Asherman, pueden afectar negativamente a su función y provocar infertilidad. La matriz extracelular (del inglés extracellular matrix, ECM) es una red macromolecular en la que residen todas las células. La composición de la ECM es específica de cada tejido y sirve para sostener la estructura tisular, modular la función celular y contribuir a la curación después de una lesión. En las últimas décadas, los avances en las técnicas de bioingeniería y descelularización han permitido producir hidrogeles de …

Aligned microcontact printing of biomolecules on microelectronic device surfaces

2001

Microcontact printing (/spl mu/CP) of extracellular matrix proteins is a fascinating approach to control cell positioning and outgrowth, which is essential in the development of applications ranging from cellular biosensors to tissue engineering. Microelectronic devices can be used to detect the activity from a large number of recording sites over the long term. However, signals from cells can only be recorded at small sensitive spots. Here, the authors present an innovative setup to perform aligned /spl mu/CP of extracellular matrix proteins on microelectronic devices in order to guide the growth of electrogenic cells specifically to these sensitive spots. The authors' system is based on t…

Controlling micro-structure to enhance de novo extracellular matrix deposition in elastomeric scaffolds for cardiac tissue regeneration

2012

Extracellulare membrane vesicles as vehicles for cell-to-cell and cell-to-extracellular matrix functional interactions

2012

Unveiling neural stem cell quiescence: a crosstalk with the extracellular matrix niche

2023

Neural stem cells (NSCs) in the subependymal zone (SEZ) reside in a very specialized microenvironment that tightly regulates their activation state. Three NSC populations coexist in the niche, quiescent (qNSCs), primed and activated (aNSCs), which display unique, actively modulated, molecular identities. One of the specialized extrinsic properties that affect NSC quiescence-to-activation transitions is the extracellular matrix (ECM). The SEZ is the only region in the whole mouse brain that has two basement membrane (BM) structures: vascular and speckled BMs. Further, it displays higher stiffness compared to non-neurogenic areas, suggesting that both composition and ECM properties could part…

Comparison between the MHFEM formulation and a 2nd spatial order FV formulation of the linear groundwater flow problem

2008

Mixed and Mixed Hybrid Finite Elements (MHFE) methods have been widely used in the last decade for simulation of groundwater flow problem, petroleum reservoir problems, potential flow problems, etc. The main advantage of these methods is that, unlike the classical Galerkin approach, they guarantee local and global mass balance, as well the flux continuity between inter-element sides. The simple shape of the control volume, where the mass conservation is satisfied, makes also easier to couple this technique with a Finite Volume technique in the time splitting approach for the solution of advection-dispersion problems. In the present paper a new second spatial approximation order Finite Volum…