The glial cells missing-1 protein is essential for branching morphogenesis in the chorioallantoic placenta

ABSTRACT Hepatocyte growth factor activator inhibitor type 1 (HAI-1) is a membrane-associated Kunitz-type serine proteinase inhibitor that was initially identified as a potent inhibitor of hepatocyte growth factor activator. HAI-1 is also a cognate inhibitor of matriptase, a membrane-associated serine proteinase. HAI-1 is expressed predominantly in epithelial cells in the human body. Its mRNA is also abundant in human placenta, with HAI-1 specifically expressed by villous cytotrophoblasts. In order to address the precise roles of HAI-1 in vivo, we generated HAI-1 mutant mice by homozygous recombination. Heterozygous HAI-1 +/− mice underwent normal organ development. However, homozygous HAI-1 −/− mice experienced embryonic lethality which became evident at embryonic day 10.5 postcoitum (E10.5). As early as E9.5, HAI-1 −/− embryos showed growth retardation that did not reflect impaired cell proliferation but resulted instead from failed placental development and function. Histological analysis revealed severely impaired formation of the labyrinth layer, in contrast all other placental layers, such as the spongiotrophoblast layer and giant cell layer, which were formed. Our results indicate that mouse HAI-1 is essential for branching morphogenesis in the chorioallantoic placenta and lack of HAI-1 function may result in placental failure.

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Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050743 ◽

1974 ◽

Vol 32 ◽

pp. 146-147

Author(s):

William P. Jollie

Keyword(s):

Osmium Tetroxide ◽

Uranyl Acetate ◽

Capillary Endothelium ◽

En Bloc ◽

Aldehyde Fixation ◽

Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

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Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083874 ◽

1978 ◽

Vol 36 (2) ◽

pp. 600-601

Author(s):

Wiktor Djaczenko ◽

Carmen Calenda Cimmino

Keyword(s):

Nervous System ◽

Glial Cells ◽

Early Period ◽

Postembryonic Development ◽

Ruthenium Red ◽

The Body ◽

Tubifex Tubifex ◽

Growth Stages ◽

Cell Processes ◽

Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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High-voltage electron microscopy of subretinal scar formation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122836 ◽

1992 ◽

Vol 50 (1) ◽

pp. 486-487

Author(s):

G.E. Korte ◽

M. Marko ◽

G. Hageman

Keyword(s):

Electron Microscopy ◽

Monoclonal Antibody ◽

Retinal Pigment Epithelium ◽

Glial Cells ◽

High Voltage ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Sodium Iodate ◽

High Voltage Electron Microscopy ◽

Voltage Electron

Sodium iodate iv. damages the retinal pigment epithelium (RPE) in rabbits. Where RPE does not regenerate (e.g., 1,2) Muller glial cells (MC) forma subretinal scar that replaces RPE. The MC response was studied by HVEM in 3D computer reconstructions of serial thick sections, made using the STEREC0N program (3), and the HVEM at the NYS Dept. of Health in Albany, NY. Tissue was processed for HVEM or immunofluorescence localization of a monoclonal antibody recognizing MG microvilli (4).

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Ultrasturcture of cerebellar cells and neuropil in rats subjected to partial global cerebral ischemia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014227x ◽

1986 ◽

Vol 44 ◽

pp. 126-127

Author(s):

R.V.W. Dimlich ◽

M.H. Biros

Keyword(s):

Purkinje Cells ◽

Glial Cells ◽

Granule Cells ◽

Molecular Layer ◽

Cell Types ◽

Primary Objective ◽

Global Cerebral Ischemia ◽

Forebrain Ischemia ◽

Substantial Evidence ◽

Cerebellar Cells

Although a previous study in this laboratory determined that Purkinje cells of the rat cerebellum did not appear to be damaged following 30 min of forebrain ischemia followed by 30 min of reperfusion, it was suggested that an increase in rough endoplasmic reticulum (RER) and/or polysomes had occurred in these cells. The primary objective of the present study was to morphometrically determine whether or not this increase had occurred. In addition, since there is substantial evidence that glial cells may be affected by ischemia earlier than other cell types, glial cells also were examined. To ascertain possible effects on other cerebellar components, granule cells and neuropil near Purkinje cells as well as neuropil in the molecular layer also were evaluated in this investigation.

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Extracellular filaments in the perineurium of the florida lobster, Panulirus argus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128237 ◽

1987 ◽

Vol 45 ◽

pp. 784-785

Author(s):

Roy J. Baerwald ◽

Lura C. Williamson

Keyword(s):

Blood Brain Barrier ◽

Glial Cells ◽

Tannic Acid ◽

Nerve Cord ◽

Ventral Nerve Cord ◽

Florida Keys ◽

Panulirus Argus ◽

Brain Barrier ◽

Cacodylate Buffer ◽

Nerve Cords

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.

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