Hydrostatic pressure stimulates synthesis of elastin in cultured optic nerve head astrocytes

Hydrostatic pressure stimulates synthesis of elastin in cultured optic nerve head astrocytes Elastin is a major component of the extracellular matrix (ECM) of the lamina cribrosa in the optic nerve head in humans and nonhuman primates. The lamina cribrosa appears to be the site of damage to the retinal ganglion cell axons in glaucomatous optic neuropathy, characterized in many patients by elevated intraocular pressure (IOP). Type 1B astrocytes are the major cell type in the lamina, synthesize elastic fibers during development, express increased elastin mRNA, and synthesize abnormal elastin in glaucoma. In this study, we determined the effect of elevated hydrostatic pressure on the synthesis of elastin by type 1B astrocytes in culture. Type 1B astrocytes were exposed to gradients of hydrostatic pressure and tested for proliferation, morphology, synthesis, and deposition of elastin. Trichloroacetic acid (TCA) and immunoprecipitation of radiolabeled protein determined total new protein and elastin synthesis. Proteins from the conditioned media were analyzed by Western blot. Levels of elastin mRNA were determined by in situ hybridization. Cell proliferation increased ∼2‐fold after exposure to pressure for one day, ∼5‐fold after 3 and 5 days of exposure to pressure. Confocal and electron microscopic cytochemistry showed a marked increase in intracellular elastin in astrocytes exposed to pressure, as compared with controls. Intracellular elastin was associated with the RER‐Golgi region and with the cytoskeleton. Total protein and elastin synthesis increased significantly (P < 0.05) at 3‐ and 5‐day exposure to pressure, as well as the level of elastin mRNA. Elastin protein in the media increased with the level of pressure. These results indicate that hydrostatic pressure stimulates type 1B astrocytes to synthesize and secrete soluble elastin into the media. In glaucoma, type 1B astrocytes may respond to IOP‐related stress with increased expression of elastin and formation of elastotic fibers leading to loss of elasticity and tissue remodeling. GLIA 32:122–136, 2000. © 2000 Wiley‐Liss, Inc. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Glia Wiley

Hydrostatic pressure stimulates synthesis of elastin in cultured optic nerve head astrocytes

Loading next page...
 
/lp/wiley/hydrostatic-pressure-stimulates-synthesis-of-elastin-in-cultured-optic-KMXx2Pfw7E
Publisher
Wiley
Copyright
Copyright © 2000 Wiley‐Liss, Inc.
ISSN
0894-1491
eISSN
1098-1136
D.O.I.
10.1002/1098-1136(200011)32:2<122::AID-GLIA20>3.0.CO;2-J
Publisher site
See Article on Publisher Site

Abstract

Elastin is a major component of the extracellular matrix (ECM) of the lamina cribrosa in the optic nerve head in humans and nonhuman primates. The lamina cribrosa appears to be the site of damage to the retinal ganglion cell axons in glaucomatous optic neuropathy, characterized in many patients by elevated intraocular pressure (IOP). Type 1B astrocytes are the major cell type in the lamina, synthesize elastic fibers during development, express increased elastin mRNA, and synthesize abnormal elastin in glaucoma. In this study, we determined the effect of elevated hydrostatic pressure on the synthesis of elastin by type 1B astrocytes in culture. Type 1B astrocytes were exposed to gradients of hydrostatic pressure and tested for proliferation, morphology, synthesis, and deposition of elastin. Trichloroacetic acid (TCA) and immunoprecipitation of radiolabeled protein determined total new protein and elastin synthesis. Proteins from the conditioned media were analyzed by Western blot. Levels of elastin mRNA were determined by in situ hybridization. Cell proliferation increased ∼2‐fold after exposure to pressure for one day, ∼5‐fold after 3 and 5 days of exposure to pressure. Confocal and electron microscopic cytochemistry showed a marked increase in intracellular elastin in astrocytes exposed to pressure, as compared with controls. Intracellular elastin was associated with the RER‐Golgi region and with the cytoskeleton. Total protein and elastin synthesis increased significantly (P < 0.05) at 3‐ and 5‐day exposure to pressure, as well as the level of elastin mRNA. Elastin protein in the media increased with the level of pressure. These results indicate that hydrostatic pressure stimulates type 1B astrocytes to synthesize and secrete soluble elastin into the media. In glaucoma, type 1B astrocytes may respond to IOP‐related stress with increased expression of elastin and formation of elastotic fibers leading to loss of elasticity and tissue remodeling. GLIA 32:122–136, 2000. © 2000 Wiley‐Liss, Inc.

Journal

GliaWiley

Published: Nov 1, 2000

References

  • Morphological and proliferative responses of endothelial cells to hydrostatic pressure: role of fibroblast growth factor
    Acevedo, Acevedo; Bowser, Bowser; Gerritsen, Gerritsen; Bizios, Bizios
  • Effects of increased ambient pressure on colon cancer cell adhesion
    Basson, Basson; Yu, Yu; Herden‐Kirchoff, Herden‐Kirchoff; Ellermeier, Ellermeier; Sanders, Sanders; Merrell, Merrell; Sumpio, Sumpio
  • The optic nerve head in glaucoma: role of astrocytes in tissue remodeling
    Hernandez, Hernandez
  • Tensegrity: the architectural basis of cellular mechanotransduction
    Ingber, Ingber
  • Astrocytoma cell interaction with elastin substrates: implications for astrocytoma invasive potential
    Jung, Jung; Hinek, Hinek; Tsugu, Tsugu; Hubbard, Hubbard; Ackerley, Ackerley; Becker, Becker; Rutka, Rutka
  • Expression of neural cell adhesion molecule (NCAM) characterizes a subpopulation of type 1 astrocytes in human optic nerve head
    Kobayashi, Kobayashi; Vidal, Vidal; Pena, Pena; Hernandez, Hernandez
  • The transduction of very small hydrostatic pressures
    Macdonald, Macdonald; Fraser, Fraser
  • Influence of short‐term hydrostatic pressure on organization of stress fibers in cultured chondrocytes
    Parkkinen, Parkkinen; Lammi, Lammi; Inkinen, Inkinen; Jortikka, Jortikka; Tammi, Tammi; Virtanen, Virtanen; Helminen, Helminen
  • In vitro stimulation of articular chondrocyte mRNA and extracellular matrix synthesis by hydrostatic pressure
    Smith, Smith; Rusk, Rusk; Ellison, Ellison
  • Immunohistochemical study of human optic nerve head astroglia
    Trivino, Trivino; Ramirez, Ramirez; Salazar, Salazar; Ramirez, Ramirez; Garcia‐Sanchez, Garcia‐Sanchez

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create folders to
organize your research

Export folders, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off