Basement membrane and interstitial matrix components form separate matrices in heterokaryons of PYS-2 cells and fibroblasts

1993 ◽  
Vol 104 (1) ◽  
pp. 59-68
Author(s):  
P. Laurila ◽  
I. Leivo
Keyword(s):  
Basement Membrane ◽  
Matrix Protein ◽  
Spatial Organization ◽  
Gene Dosage ◽  
Parental Cell ◽  
Cell Nuclei ◽  
Fibronectin Matrix ◽  
Basement Membrane Protein ◽  
The Matrix

In order to gain further understanding of the spatial organization of interstitial and basement membrane matrices, we studied the expression of the interstitial matrix protein, fibronectin, and the basement membrane protein, laminin, in heterokaryons formed by the fusion of normal fibroblasts and teratocarcinoma-derived epithelial PYS-2 cells. These heterokaryons showed various distributions of the matrix proteins depending on the proportions of the different parental cell nuclei within the cytoplasm of the cell. Heterokaryons containing equal numbers of fibroblast and PYS-2 cell nuclei showed an abundant laminin matrix subcellularly and only minor amounts of fibronectin matrix at the periphery of the cells. Similar results were obtained in heterokaryons containing an excess of epithelial cell nuclei. In heterokaryons containing an excess of fibroblast nuclei, on the other hand, laminin matrix was reduced and a fibrillar fibronectin matrix was seen also on top of the cell body. The results suggest a gene dosage-type of effect on the expression of these proteins. Furthermore, extracellular laminin and fibronectin matrices did not codistribute around the heterokaryons but the two proteins were assembled into separate structures. The lack of codistribution of fibronectin and laminin matrices in heterokaryons suggests that the molecular interactions, which determine the assembly of basement membrane and interstitial matrices in these cells are highly type-specific. Similar mechanisms may also operate in the assembly of extracellular matrices in vivo.

scholarly journals In vivo evidence for the unique kinetics of evoked dopamine release in the patch and matrix compartments of the striatum

2021 ◽  
Author(s):  
Andrea Jaquins-Gerstl ◽  
Kathryn M. Nesbitt ◽  
Adrian C. Michael
Keyword(s):  
Dopamine Release ◽  
Spatial Organization ◽  
Dorsal Striatum ◽  
Immunohistochemical Analysis ◽  
Extensive Literature ◽  
Fast Scan Cyclic Voltammetry ◽  
Medial Dorsal ◽  
The Matrix ◽  
Slow Kinetic

AbstractThe neurochemical transmitter dopamine (DA) is implicated in a number of diseases states, including Parkinson’s disease, schizophrenia, and drug abuse. DA terminal fields in the dorsal striatum and core region of the nucleus accumbens in the rat brain are organized as heterogeneous domains exhibiting fast and slow kinetic of DA release. The rates of dopamine release are significantly and substantially faster in the fast domains relative to the slow domains. The striatum is composed of a mosaic of spatial compartments known as the striosomes (patches) and the matrix. Extensive literature exists on the spatial organization of the patch and matrix compartments and their functions. However, little is known about these compartments as they relate to fast and slow kinetic DA domains observed by fast scan cyclic voltammetry (FSCV). Thus, we combined high spatial resolution of FSCV with detailed immunohistochemical analysis of these architectural compartments (patch and matrix) using fluorescence microscopy. Our findings demonstrated a direct correlation between patch compartments with fast domain DA kinetics and matrix compartments to slow domain DA kinetics. We also investigated the kinetic domains in two very distinct sub-regions in the striatum, the lateral dorsal striatum (LDS) and the medial dorsal striatum (MDS). The lateral dorsal striatum as opposed to the medial dorsal striatum is mainly governed by fast kinetic DA domains. These finding are highly relevant as they may hold key promise in unraveling the fast and slow kinetic DA domains and their physiological significance. Graphical abstract

scholarly journals Matrix and Envelope Coevolution Revealed in a Patient Monitored since Primary Infection with Human Immunodeficiency Virus Type 1

2009 ◽  
Vol 83 (19) ◽  
pp. 9875-9889 ◽  
Author(s):  
Elodie Beaumont ◽  
Daniela Vendrame ◽  
Bernard Verrier ◽  
Emmanuelle Roch ◽  
François Biron ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Matrix Protein ◽  
Immunodeficiency Virus ◽  
The Matrix ◽  
Hiv 1

ABSTRACT Lentiviruses, including human immunodeficiency virus type 1 (HIV-1), typically encode envelope glycoproteins (Env) with long cytoplasmic tails (CTs). The strong conservation of CT length in primary isolates of HIV-1 suggests that this factor plays a key role in viral replication and persistence in infected patients. However, we report here the emergence and dominance of a primary HIV-1 variant carrying a natural 20-amino-acid truncation of the CT in vivo. We demonstrated that this truncation was deleterious for viral replication in cell culture. We then identified a compensatory amino acid substitution in the matrix protein that reversed the negative effects of CT truncation. The loss or rescue of infectivity depended on the level of Env incorporation into virus particles. Interestingly, we found that a virus mutant with defective Env incorporation was able to spread by cell-to-cell transfer. The effects on viral infectivity of compensation between the CT and the matrix protein have been suggested by in vitro studies based on T-cell laboratory-adapted virus mutants, but we provide here the first demonstration of the natural occurrence of similar mechanisms in an infected patient. Our findings provide insight into the potential of HIV-1 to evolve in vivo and its ability to overcome major structural alterations.

Activation of Epac stimulates integrin-dependent homing of progenitor cells

Blood ◽  
2008 ◽  
Vol 111 (5) ◽  
pp. 2640-2646 ◽  
Author(s):  
Guillaume Carmona ◽  
Emmanouil Chavakis ◽  
Ulrike Koehl ◽  
Andreas M. Zeiher ◽  
Stefanie Dimmeler
Keyword(s):  
Progenitor Cells ◽  
Progenitor Cell ◽  
Matrix Protein ◽  
Therapeutic Potential ◽  
Limb Ischemia ◽  
Β1 Integrin ◽  
Nucleotide Exchange ◽  
Β2 Integrin ◽  
The Matrix

Cell therapy is a novel promising option for treatment of ischemic diseases. Administered endothelial progenitor cells (EPCs) are recruited to ischemic regions and improve neovascularization. However, the number of cells that home to ischemic tissues is restricted. The GTPase Rap1 plays an important role in the regulation of adhesion and chemotaxis. We investigated whether pharmacologic activation of Epac1, a nucleotide exchange protein for Rap1, which is directly activated by cAMP, can improve the adhesive and migratory capacity of distinct progenitor cell populations. Stimulation of Epac by a cAMP-analog increased Rap1 activity and stimulated the adhesion of human EPCs, CD34+ hematopoietic progenitor cells, and mesenchymal stem cells (MSCs). Specifically, short-term stimulation with a specific Epac activator increased the β2-integrin–dependent adhesion of EPCs to endothelial cell monolayers, and of EPC and CD34+ cells to ICAM-1. Furthermore, the Epac activator enhanced the β1-integrin–dependent adhesion of EPCs and MSCs to the matrix protein fibronectin. In addition, Epac1 activation induced the β1- and β2-integrin–dependent migration of EPCs on fibronectin and fibrinogen. Interestingly, activation of Epac rapidly increased lateral mobility of β1- and β2-integrins, thereby inducing integrin polarization, and stimulated β1-integrin affinity, whereas the β2-integrin affinity was not increased. Furthermore, prestimulation of EPCs with the Epac activator increased homing to ischemic muscles and neovascularization-promoting capacity of intravenously injected EPCs in the model of hind limb ischemia. These data demonstrate that activation of Epac1 increases integrin activity and integrin-dependent homing functions of progenitor cells and enhances their in vivo therapeutic potential. These results may provide a platform for the development of novel therapeutic approaches to improve progenitor cell homing.

scholarly journals AUTOIMMUNE DISEASE IN NZB/BL MICE

1965 ◽  
Vol 122 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Robert C. Mellors
Keyword(s):  
Basement Membrane ◽  
Membranous Glomerulonephritis ◽  
Histological Change ◽  
Cellular Level ◽  
Red Cells ◽  
Cell Nuclei ◽  
Main Site ◽  
Capillary Basement Membrane

This study, based upon 528 laboratory examinations and 16 complete autopsies of NZB/Bl mice, deals with autoimmune manifestations (as shown by hypergammaglobulinemia, Coombs positive hemolytic anemia, and the occasional presence of lupus- and rheumatoid-like factors) and mainly with the pathology and the pathogenesis of glomerulonephritis in these mice, a model system of membranous glomerulonephritis with spontaneous and insidious onset, progression through chronic stages, and almost certainly induced by immunological, and autoimmune, mechanisms. The earliest and lasting histological change was hyaline thickening of the capillary walls and adjacent intercapillary regions of the glomerular tufts, corresponding in location to polysaccharide-rich capillary basement membrane and mesangial materials. Distributed focally and diffusely in the glomerular tuft and eventually sparing no glomerulus, hyaline, granular, and fibrillar ("spongy fiber") materials produced narrowing of capillary lumens by concentric or eccentric encroachment upon them. In the later stages hyaline lobulation and sclerosis of the glomerular tufts occurred. Thus the lesions corresponded to those seen in human focal and diffuse membranous, chronic lobular, and lastly (intracapillary) sclerosing glomerulonephritis. In all instances of glomerulonephritis the glomerular tufts contained selective localizations of mouse immunoglobulins corresponding in distribution to that of the hyaline and (PAS-positive) polysaccharide-rich materials in the focal and diffuse membranous and lobular lesions and in amounts increasing with the severity of glomerular disease. The mouse immunoglobulins were extracted from frozen sections of glomerulonephritic kidneys and were then capable of recombination with glomerular tufts in sections of autologous or isologous glomerulonephritic kidneys from which in vivo localized immunoglobulins had been extracted. The pattern of recombination with glomerular tufts was similar to that of in invo localized immunoglobulins. The extracted immunoglobulins did not show affinity for mouse red cells (in the indirect Coombs test) nor for autologous or isologous cell nuclei (in the immunofluorescence test). The serum of mice with severe glomerulonephritis contained immunoglobulins with in vitro affinity for extracted autologous or isologous glomerular tufts. Thus circulating as well as localized antibodies were demonstrated. The immunogenic materials (autoantigens) may have been formed in the glomerular tufts or accumulated in them from some other source, such as the circulating plasma; however they corresponded in location to polysaccharide-rich capillary basement membrane and mesangial materials. The spleen was identified at the cellular level as the main site of formation of autoantibodies to red cells, as well as the main site of red cell destruction. Some evidence was brought forth suggesting that these autoantibodies were "heavy" or γM-globulins. More studies are in progress.

scholarly journals CD98hc (SLC3A2) participates in fibronectin matrix assembly by mediating integrin signaling

2007 ◽  
Vol 178 (4) ◽  
pp. 701-711 ◽  
Author(s):  
Chloé C. Féral ◽  
Andries Zijlstra ◽  
Eugene Tkachenko ◽  
Gerald Prager ◽  
Margaret L. Gardel ◽  
...  
Keyword(s):  
Wound Healing ◽  
Membrane Protein ◽  
Small Gtpase ◽  
Integrin Signaling ◽  
Vertebrate Development ◽  
Matrix Assembly ◽  
Fibronectin Matrix ◽  
The Matrix

Integrin-dependent assembly of the fibronectin (Fn) matrix plays a central role in vertebrate development. We identify CD98hc, a membrane protein, as an important component of the matrix assembly machinery both in vitro and in vivo. CD98hc was not required for biosynthesis of cellular Fn or the maintenance of the repertoire or affinity of cellular Fn binding integrins, which are important contributors to Fn assembly. Instead, CD98hc was involved in the cell's ability to exert force on the matrix and did so by dint of its capacity to interact with integrins to support downstream signals that lead to activation of RhoA small GTPase. Thus, we identify CD98hc as a membrane protein that enables matrix assembly and establish that it functions by interacting with integrins to support RhoA-driven contractility. CD98hc expression can vary widely; our data show that these variations in CD98hc expression can control the capacity of cells to assemble an Fn matrix, a process important in development, wound healing, and tumorigenesis.

Integrin expression during human epidermal development in vivo and in vitro

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 193-206 ◽  
Author(s):  
M.D. Hertle ◽  
J.C. Adams ◽  
F.M. Watt
Keyword(s):  
Basement Membrane ◽  
Spatial Organization ◽  
Basal Layer ◽  
Subsequent Development ◽  
Sweat Glands ◽  
Collagen Type Iv ◽  
Integrin Expression ◽  
Basal Cells

In order to investigate the role of extracellular matrix receptors of the integrin family in establishing the spatial organization of epidermal kerotinocytes, we used immunofluorescence microscopy to examine the expression of a range of integrin subunits during development of human palm and sole skin. All of the integrins expressed during development were also present in mature epidermis and were largely confined to the basal layer of keratinocytes in a pericellular distribution. The alpha 3 and beta 1 subunits were expressed prior to the initiation of stratification and did not change in abundance or distribution during subsequent development. alpha 4 and beta 3 were not detected at any time in the epidermis. Every other subunit examined showed spatial or temporal changes in expression. Staining for alpha 1 was strong before stratification and until mid-development, but was greatly decreased in neonatal epidermis. alpha 2 was first detected in small patches of basal cells prior to stratification, and thereafter was found in the entire basal layer, with greater staining in developing sweat glands. alpha 5 was not expressed until mid-development, and then primarily in developing sweat glands, with faint expression in neonatal epidermis. alpha v was detected following stratification, in developing sweat glands, and occasionally in neonatal epidermis. alpha 6 and beta 4 were peribasally expressed before stratification, but thereafter became concentrated at the basal cell surface in contact with the basement membrane, co-localizing with hemidesmosomes as determined by staining with bullous pemphigoid antiserum. We also examined the distribution of three known ligands for keratinocyte integrins: laminin and collagen type IV were present in the basement membrane zone at all stages of development, whereas fibronectin was only evident there until about 13 weeks estimated gestational age. Finally, we found that the changes in integrin expression that occur on initiation of stratification in vivo could be reproduced in organ cultures of developing skin; such cultures therefore provided a useful experimental model for further studies of the role of integrins in epidermal stratification.

scholarly journals Regulation of Proliferation, Differentiation and Functions of Osteoblasts by Runx2

2019 ◽  
Vol 20 (7) ◽  
pp. 1694 ◽  
Author(s):  
Toshihisa Komori
Keyword(s):  
Osteoblast Differentiation ◽  
Matrix Protein ◽  
Gene Dosage ◽  
Bone Matrix ◽  
Mesenchymal Cells ◽  
Heterozygous Mutation ◽  
Chondrocyte Maturation ◽  
Osteoblast Progenitors

Runx2 is essential for osteoblast differentiation and chondrocyte maturation. During osteoblast differentiation, Runx2 is weakly expressed in uncommitted mesenchymal cells, and its expression is upregulated in preosteoblasts, reaches the maximal level in immature osteoblasts, and is down-regulated in mature osteoblasts. Runx2 enhances the proliferation of osteoblast progenitors by directly regulating Fgfr2 and Fgfr3. Runx2 enhances the proliferation of suture mesenchymal cells and induces their commitment into osteoblast lineage cells through the direct regulation of hedgehog (Ihh, Gli1, and Ptch1), Fgf (Fgfr2 and Fgfr3), Wnt (Tcf7, Wnt10b, and Wnt1), and Pthlh (Pthr1) signaling pathway genes, and Dlx5. Runx2 heterozygous mutation causes open fontanelle and sutures because more than half of the Runx2 gene dosage is required for the induction of these genes in suture mesenchymal cells. Runx2 regulates the proliferation of osteoblast progenitors and their differentiation into osteoblasts via reciprocal regulation with hedgehog, Fgf, Wnt, and Pthlh signaling molecules, and transcription factors, including Dlx5 and Sp7. Runx2 induces the expression of major bone matrix protein genes, including Col1a1, Spp1, Ibsp, Bglap2, and Fn1, in vitro. However, the functions of Runx2 in differentiated osteoblasts in the expression of these genes in vivo require further investigation.

Proteins From Oyster Shell: Biomineralization Regulators and Commercial Polymer Analogs

1999 ◽  
Vol 599 ◽  
Author(s):  
A. P. Wheeler ◽  
C. S. Sikes
Keyword(s):  
Crystal Growth ◽  
Aspartic Acid ◽  
Large Scale ◽  
Matrix Protein ◽  
Gene Families ◽  
Eastern Oyster ◽  
Matrix Proteins ◽  
The Matrix

AbstractMolluscan shell is a composite made up of μm-sized CaCO3 crystals and an organic phase (matrix). This report outlines our studies on the structure and activities of matrix proteins isolated from the inner calcite layer of shell of the Eastern oyster, including their cellular origin and structure and their relationship to the crystalline mineral phase. In addition, we present results of the synthesis and commercialization of polypeptide polymers which are based on the structure and activities of the oyster proteins. Extracted shell proteins are polyanionic and range in size from relatively small soluble forms to those which are crosslinked and insoluble. The soluble forms are capable of adsorbing to calcite in vitro and in the process changing its growth habit and acting as threshold growth inhibitors. Their function in vivo is not understood, but they may serve to control shell crystal morphology. The insoluble protein forms gels readily and may serve to provide resiliency to the shell and, from in vitro and in situ observations, appears to serve as a site for nucleation of crystals. However, from studies in vitro, these gels do not lower the energy of activation for nucleation, as previously expected. Matrix protein aggregates are identifiable by AFM on the surface of crystals, but as such do not serve as nucleation sites for new crystal growth. If the aggregates are removed, then ectopic crystal growth proceeds readily revealing orientation of the underlying crystals. All the matrix proteins contain domains rich in aspartic acid, are heavily phosphorylated, crossreact in antibody studies and may belong to a limited number of gene families with individuals modified post-synthesis. The proteins are made by a specialized group of cells located primarily some distance from the growing edge of the shell and appear to be assembled into sheets soon after secretion. Soluble anti-scalants and crosslinked insoluble water absorbents have been developed based on the structure and activity of the matrix proteins. These are primarily poly(aspartates) which can be made in large scale via thermal polycondensation of aspartic acid. The soluble forms are commercially used as biodegradable water treatment chemicals among other applications.

Sign in / Sign up

Export Citation Format

Share Document