- Collection:
- Atlanta University and Clark Atlanta University Theses and Dissertations
- Title:
- Pattern-related retinoic acid metabolism by limb-bud mesenchymal cells, 1999
- Creator:
- Applewite, Lisa Carline
- Date of Original:
- 1999-12-01
- Subject:
- Degrees, Academic
Dissertations, Academic - Location:
- United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
- Medium:
- theses
- Type:
- Text
- Format:
- application/pdf
- Description:
- Retinoic acid (RA) affects limb-skeletal pattern in vivo through specific interactions with DNA-binding, nuclear retinoid receptors (RARs and RXRs). RA activity is mediated via cytoplasmic retinoic-acid binding proteins (CRABPs). In serum- free cultures, wing mesenchyme cells show age- and region-dependent RA responsiveness not entirely accounted for by RAR and RXR expression patterns. The proximodistal expression pattern of CRABP may affect RA metabolism patterns and thus the retinoids encountered by the nuclear receptors within the wing mesenchyme during outgrowth. Mesenchymal cells, isolated from the proximal and distal regions of the wing, at different developmental stages, were incubated with physiologic or pharmacologic concentrations of all-trans-RA mixed with radiolabeled RA (3H-all-/mm-RA) in order to determine RA metabolism and identify RA metabolites along the proximodistal axis. Culture extracts, subjected to reverse phase HPLC and scintillation counting, revealed age- and region-dependent RA metabolism in terms of rate and metabolites produced. Western blots of non-denaturing gel electrophoresed proteins isolated from the proximal and distal regions showed corresponding differences in CRABP isoform expression. Greater CRABP II expression was noted in the distal mesenchyme, where RA metabolism is enhanced. CRABP I expression is prevalent in cells isolated from the proximal region. These results suggest that CRABP isoform distribution may account for patterns of RA responsiveness through their role in RA metabolism.
- External Identifiers:
- Metadata URL:
- http://hdl.handle.net/20.500.12322/cau.td:1999_applewite_lisa_carline
- Rights Holder:
- Clark Atlanta University
- Holding Institution:
- Atlanta University Center Robert W. Woodruff Library
- Rights:
-
