Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-2-12
pubmed:abstractText
The maintenance and differentiation of retinal progenitors take place in the context of the microenvironment in which they reside at a given time during retinal histogenesis. To understand the nature of the microenvironment in the developing retina, we have examined the influence of activities present during the early stage of retinal histogenesis on enriched retinal progenitors, using the neurosphere model. Early and late retinal progenitors, enriched as neurospheres from embryonic day 14 (E14) and E18 rat retina, respectively, were cultured in embryonic day 3 (E3) chick retinal conditioned medium, simulating the microenvironment present during early retinal histogenesis. Examination of the differentiation and proliferation of retinal progenitors revealed that the early microenvironment contains at least three regulatory activities, which are partitioned in different size fractions of the conditioned medium with different heat sensitivity. First, it is characterized by activities, present in heat stable <30 kDa fraction, that promote the differentiation of retinal ganglion cells (RGCs), the early born neurons. Second, it contains activities, present in heat-sensitive >30 kDa fraction, that regulate the number of early born neurons and maintain the pool of retinal progenitors. Third, it possesses activities, present in heat-sensitive <30 kDa fraction, that prevent the premature differentiation of early retinal progenitors into the late born neurons. Thus, our observations demonstrate the regulatory influence of microenvironment on the maintenance and differentiation of retinal progenitors and establish neurospheres as a viable model system for the examination of such influences.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-4835
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
577-90
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17227675-Animals, pubmed-meshheading:17227675-Cell Differentiation, pubmed-meshheading:17227675-Cell Division, pubmed-meshheading:17227675-Cells, Cultured, pubmed-meshheading:17227675-Coculture Techniques, pubmed-meshheading:17227675-Culture Media, Conditioned, pubmed-meshheading:17227675-Female, pubmed-meshheading:17227675-Gene Expression Regulation, Developmental, pubmed-meshheading:17227675-Immunohistochemistry, pubmed-meshheading:17227675-Models, Animal, pubmed-meshheading:17227675-Photoreceptor Cells, Vertebrate, pubmed-meshheading:17227675-Rats, pubmed-meshheading:17227675-Rats, Sprague-Dawley, pubmed-meshheading:17227675-Retina, pubmed-meshheading:17227675-Retinal Ganglion Cells, pubmed-meshheading:17227675-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:17227675-Stem Cells
pubmed:year
2007
pubmed:articleTitle
Characterization of early retinal progenitor microenvironment: presence of activities selective for the differentiation of retinal ganglion cells and maintenance of progenitors.
pubmed:affiliation
Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't