EGF mediated suppression of ROD photoreceptor differentiation is accompanied by a decrease in MASH-1 expression

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Abstract

PURPOSE: Mash-1 is acandidale transcription factor involved in the differentiation of the rod photoreceptor. Since Mash-1 and other members of bHLH class of transcription factors have been observed to be regulated in response to growth factors we tested the hypothesis that Mash-1 plays a role in the mediation of intracellular response during the specification of progenitors into rod photoreceptors. METHODS: The effect of EGF on retinal cell proliferation and differentiation was studied in culture of relinal explants obtained from E-18 embryos. The expiants were treated with EGF ( 10ng/ml) for three days. Cell-proliferation was assayed by tritiated thymidine incorporation. Immunocytochemical analyses were carried out using MashI and opsin antibodies. Mash-1 and opsin transcript levels were analyzed by RTPCR. RESULTS: Treatment of retinal expiants with EGF led to cell proliferation These proliferating cells were predominantly localized in the outer neuroblastic layer which harbors rod precursors. Mash-I positive cells, which are also preferentially localized in the outer neuroblastic layer in the E-18 retina, decreased in response to EGF treatment. The decrease in Mash-1 expression was accompanied by a decrease in opsin immunoreactivity and opsin transcript levels. Withdrawal of EGF from the culture led to an increase in Mash-l immunoreactivity and transcript levels. Similar increases in opsin immunoreactivity and transcript levels were observed following EGF withdrawal. CONCLUSIONS: In retinal explant culture, EOF promotes proliferation of progenitors at the expense of their differentiation into rod photoreceptors. The concomitant decrease in Mash-l and opsin expression in the presence of EGF and their increase following EGF withdrawal suggest that Mash-1 may be involved in the EGF mediated suppression of rod photoreceptur differentiation. Supported by NIH grant EY 10313. NONE.

Original languageEnglish (US)
Pages (from-to)S225
JournalInvestigative Ophthalmology and Visual Science
Volume38
Issue number4
StatePublished - Dec 1 1997

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Epidermal Growth Factor
Opsins
Retinal Rod Photoreceptor Cells
Cell Proliferation
Basic Helix-Loop-Helix Transcription Factors
Organized Financing
Thymidine
Retina
Cell Differentiation
Intercellular Signaling Peptides and Proteins
Transcription Factors
Embryonic Structures
Antibodies

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

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title = "EGF mediated suppression of ROD photoreceptor differentiation is accompanied by a decrease in MASH-1 expression",
abstract = "PURPOSE: Mash-1 is acandidale transcription factor involved in the differentiation of the rod photoreceptor. Since Mash-1 and other members of bHLH class of transcription factors have been observed to be regulated in response to growth factors we tested the hypothesis that Mash-1 plays a role in the mediation of intracellular response during the specification of progenitors into rod photoreceptors. METHODS: The effect of EGF on retinal cell proliferation and differentiation was studied in culture of relinal explants obtained from E-18 embryos. The expiants were treated with EGF ( 10ng/ml) for three days. Cell-proliferation was assayed by tritiated thymidine incorporation. Immunocytochemical analyses were carried out using MashI and opsin antibodies. Mash-1 and opsin transcript levels were analyzed by RTPCR. RESULTS: Treatment of retinal expiants with EGF led to cell proliferation These proliferating cells were predominantly localized in the outer neuroblastic layer which harbors rod precursors. Mash-I positive cells, which are also preferentially localized in the outer neuroblastic layer in the E-18 retina, decreased in response to EGF treatment. The decrease in Mash-1 expression was accompanied by a decrease in opsin immunoreactivity and opsin transcript levels. Withdrawal of EGF from the culture led to an increase in Mash-l immunoreactivity and transcript levels. Similar increases in opsin immunoreactivity and transcript levels were observed following EGF withdrawal. CONCLUSIONS: In retinal explant culture, EOF promotes proliferation of progenitors at the expense of their differentiation into rod photoreceptors. The concomitant decrease in Mash-l and opsin expression in the presence of EGF and their increase following EGF withdrawal suggest that Mash-1 may be involved in the EGF mediated suppression of rod photoreceptur differentiation. Supported by NIH grant EY 10313. NONE.",
author = "Iqbal Ahmad",
year = "1997",
month = "12",
day = "1",
language = "English (US)",
volume = "38",
pages = "S225",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
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number = "4",

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TY - JOUR

T1 - EGF mediated suppression of ROD photoreceptor differentiation is accompanied by a decrease in MASH-1 expression

AU - Ahmad, Iqbal

PY - 1997/12/1

Y1 - 1997/12/1

N2 - PURPOSE: Mash-1 is acandidale transcription factor involved in the differentiation of the rod photoreceptor. Since Mash-1 and other members of bHLH class of transcription factors have been observed to be regulated in response to growth factors we tested the hypothesis that Mash-1 plays a role in the mediation of intracellular response during the specification of progenitors into rod photoreceptors. METHODS: The effect of EGF on retinal cell proliferation and differentiation was studied in culture of relinal explants obtained from E-18 embryos. The expiants were treated with EGF ( 10ng/ml) for three days. Cell-proliferation was assayed by tritiated thymidine incorporation. Immunocytochemical analyses were carried out using MashI and opsin antibodies. Mash-1 and opsin transcript levels were analyzed by RTPCR. RESULTS: Treatment of retinal expiants with EGF led to cell proliferation These proliferating cells were predominantly localized in the outer neuroblastic layer which harbors rod precursors. Mash-I positive cells, which are also preferentially localized in the outer neuroblastic layer in the E-18 retina, decreased in response to EGF treatment. The decrease in Mash-1 expression was accompanied by a decrease in opsin immunoreactivity and opsin transcript levels. Withdrawal of EGF from the culture led to an increase in Mash-l immunoreactivity and transcript levels. Similar increases in opsin immunoreactivity and transcript levels were observed following EGF withdrawal. CONCLUSIONS: In retinal explant culture, EOF promotes proliferation of progenitors at the expense of their differentiation into rod photoreceptors. The concomitant decrease in Mash-l and opsin expression in the presence of EGF and their increase following EGF withdrawal suggest that Mash-1 may be involved in the EGF mediated suppression of rod photoreceptur differentiation. Supported by NIH grant EY 10313. NONE.

AB - PURPOSE: Mash-1 is acandidale transcription factor involved in the differentiation of the rod photoreceptor. Since Mash-1 and other members of bHLH class of transcription factors have been observed to be regulated in response to growth factors we tested the hypothesis that Mash-1 plays a role in the mediation of intracellular response during the specification of progenitors into rod photoreceptors. METHODS: The effect of EGF on retinal cell proliferation and differentiation was studied in culture of relinal explants obtained from E-18 embryos. The expiants were treated with EGF ( 10ng/ml) for three days. Cell-proliferation was assayed by tritiated thymidine incorporation. Immunocytochemical analyses were carried out using MashI and opsin antibodies. Mash-1 and opsin transcript levels were analyzed by RTPCR. RESULTS: Treatment of retinal expiants with EGF led to cell proliferation These proliferating cells were predominantly localized in the outer neuroblastic layer which harbors rod precursors. Mash-I positive cells, which are also preferentially localized in the outer neuroblastic layer in the E-18 retina, decreased in response to EGF treatment. The decrease in Mash-1 expression was accompanied by a decrease in opsin immunoreactivity and opsin transcript levels. Withdrawal of EGF from the culture led to an increase in Mash-l immunoreactivity and transcript levels. Similar increases in opsin immunoreactivity and transcript levels were observed following EGF withdrawal. CONCLUSIONS: In retinal explant culture, EOF promotes proliferation of progenitors at the expense of their differentiation into rod photoreceptors. The concomitant decrease in Mash-l and opsin expression in the presence of EGF and their increase following EGF withdrawal suggest that Mash-1 may be involved in the EGF mediated suppression of rod photoreceptur differentiation. Supported by NIH grant EY 10313. NONE.

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