Reinitiation of gonocyte mitosis and movement of gonocytes to the basement membrane in testes of newborn rats in vivo and in vitro

1992 ◽  
Vol 233 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Michael P. McGuinness ◽  
Joanne M. Orth
Keyword(s):  
Basement Membrane ◽  
Newborn Rats

scholarly journals Origin of the glomerular basement membrane visualized after in vivo labeling of laminin in newborn rat kidneys.

1985 ◽  
Vol 100 (6) ◽  
pp. 1988-2000 ◽  
Author(s):  
D R Abrahamson
Keyword(s):  
Basement Membrane ◽  
Developmental Stages ◽  
Cell Types ◽  
Basement Membranes ◽  
Newborn Rats ◽  
Mature Adult ◽  
Capillary Loop ◽  
Double Label

To examine the origin and assembly of glomerular basement membranes (GBMs), affinity purified anti-laminin IgG was directly coupled to horseradish peroxidase (HRP) and intravenously injected into newborn rats. Kidneys were then processed for peroxidase histochemistry and microscopy. Within 1 h after injection, anti-laminin bound to basement membranes of nephrons in all developmental stages (vesicle, comma, S-shaped, developing capillary loop, and maturing glomeruli). In S-shaped and capillary loop glomeruli, anti-laminin-HRP labeled a double basal lamina between the endothelium and epithelium. Sections incubated with anti-laminin in vitro showed labeling within the rough endoplasmic reticulum of endothelium and epithelium, indicating that both cell types synthesized laminin for the double basement membrane. In maturing glomeruli, injected anti-laminin-HRP bound throughout the GBMs, and double basement membranes were rarely observed. At this stage, however, numerous knobs or outpockets of basement membrane material extending far into the epithelial side of the capillary wall were identified and these were also labeled throughout their full thickness. No such outpockets were found in the endothelial cell layer of newborn rats (and they normally are completely absent in fully mature, adult glomeruli). In contrast with these results, in kidneys fixed 4-6 d after anti-laminin IgG-HRP injection, basement membranes of vesicle, comma, and S-shaped nephrons were unlabeled, indicating that they were assembled after injection. GBM labeling was seen in maturing glomeruli, however. In addition, the outpockets of basement membrane extending into the epithelium were often completely unlabeled whereas GBMs lying immediately beneath them were labeled intensely, which indicates that the outpockets were probably assembled by the epithelium. Injections of sheep anti-laminin IgG followed 8 d later with injections of biotin-rabbit anti-laminin IgG and double-label immunofluorescence microscopy confirmed that GBM formation continued during individual capillary loop expansion. GBM assembly therefore occurs by at least two different processes at separate times in development: (a) fusion of endothelial and epithelial basement membranes followed by (b) addition of new basement membrane from the epithelium into existing GBMs.

Interactions between mesoderm cells and the extracellular matrix following gastrulation in the chick embryo

1991 ◽  
Vol 99 (2) ◽  
pp. 431-441
Author(s):  
A.J. Brown ◽  
E.J. Sanders
Keyword(s):  
Extracellular Matrix ◽  
Chick Embryo ◽  
Basement Membrane ◽  
Primitive Streak ◽  
Cell Binding ◽  
Fab Fragment ◽  
Fibronectin Receptor ◽  
In Vitro Methods

In the gastrulating chick embryo, the mesoderm cells arise from the epiblast layer by ingression through the linear accumulation of cells called the primitive streak. The mesoderm cells emerge from the streak with a fibroblastic morphology and proceed to move away from the mid-line of the embryo using, as a substratum, the basement membrane of the overlying epiblast and the extracellular matrix. We have investigated the roles of fibronectin and laminin as putative substrata for mesoderm cells using complementary in vivo and in vitro methods. We have microinjected agents into the tissue space adjacent to the primitive streak of living embryos and, after further incubation, we have examined the embryos for perturbation of the mesoderm tissue. These agents were: cell-binding regions from fibronectin (RGDS) and laminin (YIGSR), antibodies to these glycoproteins, and a Fab' fragment of the antibody to fibronectin. We find that RGDS, antibody to fibronectin, and the Fab' fragment cause a decrease in the number of mesoderm cells spread on the basement membrane, and a perturbation of cell shape suggesting locomotory impairment. No such influence was seen with YIGSR or antibodies to laminin. These results were extended using in vitro methods in which mesoderm cells were cultured in fibronectin-free medium on fibronectin or laminin in the presence of various agents. These agents were: RGDS; YIGSR; antibodies to fibronectin, fibronectin receptor, laminin and vitronectin; and a Fab' fragment of the fibronectin antiserum. We find that cell attachment and spreading on fibronectin is impaired by RGDS, antiserum to fibronectin, the Fab' fragment of fibronectin antiserum, and antiserum to fibronectin receptor. The results suggest that although the RGDS site in fibronectin is important, it is probably not the only fibronectin cell-binding site involved in mediating the behaviour of the mesoderm cells. Cells growing on laminin were perturbed by YIGSR, RGDS and antibodies to laminin, suggesting that mesoderm cells are able to recognise at least two sites in the laminin molecule. We conclude that the in vivo dependence of mesoderm cells on fibronectin is confirmed, but that although these cells have the ability to recognise sites in laminin as mediators of attachment and spreading, the in vivo role of this molecule in mesoderm morphogenesis is not yet certain.

Analysis of elongating morphogenesis of quail anterior submaxillary gland: absence of localized cell proliferation

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 229-239
Author(s):  
Hiroyuki Nogawa
Keyword(s):  
Cell Proliferation ◽  
Basement Membrane ◽  
Regional Differences ◽  
Submaxillary Gland ◽  
Mesenchymal Cells ◽  
Submaxillary Glands ◽  
Parallel Direction ◽  
Recombination Experiments

Quail anterior submaxillary glands elongated extensively without branching (more than sevenfold) from 8 to 10 incubation days. Investigation of mitotic activity of the rudiments in vivo showed no localized cell proliferation throughout the rudiments, and recombination experiments in vitro to examine regional differences in mitogenic activity of the surrounding mesenchyme also showed that no mesenchymal region specifically stimulates the epithelial cell proliferation. Histological observation of the rudiments showed that epithelial cells did not lengthen in a parallel direction to the long axis of the rudiment, and that mesenchymal cells encircled the epithelial cord perpendicularly to its axis. The basement membrane was obscure in the distal end of the rudiments, while it was easily detected in the other part of the rudiments. These results suggest that the elongating morphogenesis of the anterior submaxillary rudiments is not achieved by localized cell proliferation but by almost uniformly distributed cell proliferation, and mesenchymal cells surrounding the rudiment or the basement membrane may be involved in the controlling mechanisms of the elongating morphogenesis.

scholarly journals Perturbations in the fibrinolytic pathway abolish cyst formation but not capillary-like organization of cultured murine endothelial cells

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3206-3217 ◽  
Author(s):  
N Dubois-Stringfellow ◽  
A Jonczyk ◽  
VL Bautch
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Basement Membrane ◽  
Organizational Behavior ◽  
Cell Lines ◽  
Primary Cultures ◽  
Cyst Formation ◽  
Fibrin Gels

Abstract Fibrinolytic activity and its relation to morphogenesis was investigated in several transformed murine endothelial cell lines and primary cultures of endothelial cells. Two in vitro systems, fibrin gels and Matrigel (Collaborative Research, Bedford, MA), were used. Fibrin gels model a fibrin-rich extracellular matrix that frequently supports neovascularization in vivo, and Matrigel models the basement membrane surrounding quiescent endothelial cells in vivo. The transformed endothelial cell lines have higher levels of plasminogen activator (PA) mRNA than primary cultures of endothelial cells, and an increased PA-mediated proteolytic activity was correlated with formation of cysts in fibrin gels. Addition of neutralizing anti- urokinase antibodies, plasminogen depletion, or addition of a plasmin inhibitor prevented cyst formation. Addition of plasminogen restored the ability to form cysts in the plasminogen-depleted system. Normal endothelial cells organized into capillary-like structures in fibrin gels regardless of manipulations affecting the fibrinolytic pathway. In Matrigel, both transformed and primary cultures of endothelial cells rapidly formed a capillary-like network that was not affected by plasminogen depletion or addition of plasmin inhibitors. Thus, elements of the fibrinolytic pathway necessary for cyst formation are not critical in capillary-like structure formation on a reconstituted basement membrane. These results suggest that plasmin is essential for hemangioma formation but is not critical to the organizational behavior of normal endothelial cells.

scholarly journals The endothelial basement membrane acts as a checkpoint for entry of pathogenic T cells into the brain

2020 ◽  
Vol 217 (7) ◽  
Author(s):  
Xueli Zhang ◽  
Ying Wang ◽  
Jian Song ◽  
Hanna Gerwien ◽  
Omar Chuquisana ◽  
...  
Keyword(s):  
T Cells ◽  
Basement Membrane ◽  
Immune Cell ◽  
Cell Phenotype ◽  
T Cell Infiltration ◽  
And Migration ◽  
Endothelial Basement Membrane ◽  
Laminin 411

The endothelial cell basement membrane (BM) is a barrier to migrating leukocytes and a rich source of signaling molecules that can influence extravasating cells. Using mice lacking the major endothelial BM components, laminin 411 or 511, in murine experimental autoimmune encephalomyelitis (EAE), we show here that loss of endothelial laminin 511 results in enhanced disease severity due to increased T cell infiltration and altered polarization and pathogenicity of infiltrating T cells. In vitro adhesion and migration assays reveal higher binding to laminin 511 than laminin 411 but faster migration across laminin 411. In vivo and in vitro analyses suggest that integrin α6β1- and αvβ1-mediated binding to laminin 511–high sites not only holds T cells at such sites but also limits their differentiation to pathogenic Th17 cells. This highlights the importance of the interface between the endothelial monolayer and the underlying BM for modulation of immune cell phenotype.

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.

Functional significance of the dorsal respiratory group in adult and newborn rats: in vivo and in vitro studies

1990 ◽  
Vol 111 (1-2) ◽  
pp. 133-138 ◽  
Author(s):  
G. Hilaire ◽  
R. Monteau ◽  
P. Gauthier ◽  
P. Rega ◽  
D. Morin
Keyword(s):  
Functional Significance ◽  
In Vitro Studies ◽  
Newborn Rats ◽  
Dorsal Respiratory Group

scholarly journals Capillary endothelial cell cultures: phenotypic modulation by matrix components.

1983 ◽  
Vol 97 (1) ◽  
pp. 153-165 ◽  
Author(s):  
J A Madri ◽  
S K Williams
Keyword(s):  
Endothelial Cells ◽  
Basement Membrane ◽  
Membrane Surface ◽  
Phenotypic Expression ◽  
Aortic Endothelial Cells ◽  
Capillary Endothelial Cells ◽  
Endothelial Cell Cultures ◽  
Cell Densities

Capillary endothelial cells of rat epididymal fat pad were isolated and cultured in media conditioned by bovine aortic endothelial cells and substrata consisting of interstitial or basement membrane collagens. When these cells were grown on interstitial collagens they underwent proliferation, formed a continuous cell layer and, if cultured for long periods of time, formed occasional tubelike structures. In contrast, when these cells were grown on basement membrane collagens, they did not proliferate but did aggregate and form tubelike structures at early culture times. In addition, cells grown on basement membrane substrata expressed more basement membrane constituents as compared with cells grown on interstitial matrices when assayed by immunoperoxidase methods and quantitated by enzyme-linked immunosorbent inhibition assays. Furthermore, when cells were grown on either side of washed, acellular amnionic membranes their phenotypes were markedly different. On the basement membrane surface they adhered, spread, and formed tubelike structures but did not migrate through the basement membrane. In contrast, when seeded on the stromal surface, these cells were observed to proliferate and migrate into the stromal aspect of the amnion and ultimately formed tubelike structures at high cell densities at longer culture periods (21 d). Thus, connective tissue components play important roles in regulating the phenotypic expression of capillary endothelial cells in vitro, and similar roles of the collagenous components of the extracellular matrix may exist in vivo following injury and during angiogenesis. Furthermore, the culture systems outlined here may be of use in the further study of differentiated, organized capillary endothelial cells in culture.

Structural determinants of glomerular hydraulic permeability

1994 ◽  
Vol 266 (1) ◽  
pp. F1-F12 ◽  
Author(s):  
M. C. Drumond ◽  
W. M. Deen
Keyword(s):  
Basement Membrane ◽  
Hydraulic Resistance ◽  
Structural Changes ◽  
Water Movement ◽  
Capillary Wall ◽  
Hydraulic Permeability ◽  
Structural Determinants ◽  
Membrane Area

To elucidate which structures determine the resistance to water movement, we used a computational fluid dynamics approach to determine velocity and pressure fields within the glomerular capillary wall. The model included representations of the endothelial fenestrae, basement membrane, and epithelial filtration slits with slit diaphragms. The input data included dimensions of the various structures from previous electron microscopy studies, as well as the hydraulic permeability recently measured for isolated films of glomerular basement membrane in vitro. The hydraulic resistance of the endothelium was predicted to be small, whereas the basement membrane and filtration slits were each found to contribute roughly one-half of the total hydraulic resistance of the capillary wall. It was calculated that, for a given filtrate flux, the pressure drop within basement membrane in vivo is roughly twice that of “bare” or isolated basement membrane, because of the small fraction of basement membrane area exposed. The dominant resistance in the filtration slit was found to be the slit diaphragm. Predicted values for the overall hydraulic permeability of the capillary wall were within the experimental range derived from micropuncture measurements in normal rats. The model should be a useful tool for analyzing the effects of various structural changes on glomerular hydraulic permeability. This is illustrated by applying the model to recent physiological and morphometric data in nephrotic rats.

scholarly journals Pivotal Role of Brain-Derived Neurotrophic Factor Secreted by Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage in Newborn Rats

2017 ◽  
Vol 26 (1) ◽  
pp. 145-156 ◽  
Author(s):  
So Yoon Ahn ◽  
Yun Sil Chang ◽  
Dong Kyung Sung ◽  
Se In Sung ◽  
Jee-Yin Ahn ◽  
...  
Keyword(s):  
Neurotrophic Factor ◽  
Intraventricular Hemorrhage ◽  
Brain Injuries ◽  
Brain Derived Neurotrophic Factor ◽  
Therapeutic Effects ◽  
Newborn Rats ◽  
Paracrine Factors ◽  
Posthemorrhagic Hydrocephalus

Mesenchymal stem cell (MSC) transplantation protects against neonatal severe intraventricular hemorrhage (IVH)-induced brain injury by a paracrine rather than regenerative mechanism; however, the paracrine factors involved and their roles have not yet been delineated. This study aimed to identify the paracrine mediator(s) and to determine their role in mediating the therapeutic effects of MSCs in severe IVH. We first identified significant upregulation of brain-derived neurotrophic factor (BDNF) in MSCs compared with fibroblasts, in both DNA and antibody microarrays, after thrombin exposure. We then knocked down BDNF in MSCs by transfection with small interfering (si)RNA specific for human BDNF. The therapeutic effects of MSCs with or without BDNF knockdown were evaluated in vitro in rat neuronal cells challenged with thrombin, and in vivo in newborn Sprague–Dawley rats by injecting 200 μl of blood on postnatal day 4 (P4), and transplanting MSCs (1 × 105 cells) intraventricularly on P6. siRNA-induced BDNF knockdown abolished the in vitro benefits of MSCs on thrombin-induced neuronal cell death. BDNF knockdown also abolished the in vivo protective effects against severe IVH-induced brain injuries such as the attenuation of posthemorrhagic hydrocephalus, impaired behavioral test performance, increased astrogliosis, increased number of TUNEL cells, ED-1+ cells, and inflammatory cytokines, and reduced myelin basic protein expression. Our data indicate that BDNF secreted by transplanted MSCs is one of the critical paracrine factors that play a seminal role in attenuating severe IVH-induced brain injuries in newborn rats.

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