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Regulation of Na,K-ATPase expression by endothelin-1 in transformed human ciliary non-pigmented epithelial (HNPE) cells
- Source :
- Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics. 19(5)
- Publication Year :
- 2003
-
Abstract
- Endothelin-1 (ET-1) (1-100 nM) decreases the activity of Na,K-ATPase, a key enzyme responsible for aqueous humor formation, in transformed human non-pigmented ciliary epithelial (HNPE) cells. The present study sought to determine if ET-1 alters the expression of the catalytically active alpha subunit of Na,K-ATPase in HNPE cells and identify mechanisms underlying these effects. We report that acute (15 and 30 min) treatment with ET-1 results in an increase in mRNA expression of the alpha 1 subunit of Na,K-ATPase. Similar to ET-1's effects, ouabain (100 microM), a selective inhibitor of Na,K-ATPase, and monensin (10 microM), a sodium ionophore, also increased Na,K-ATPase expression in HNPE cells. The increase in Na,K-ATPase expression by short-term treatment with ouabain and monensin was dependent on their ability to elevate intracellular sodium concentrations. However, acute ET-1 treatment mediated increase in Na,K-ATPase expression was independent of changes in intracellular sodium. A prolonged (24 hr) ET-1 treatment results in an increase in both mRNA and protein levels of the alpha 1 subunit of Na,K-ATPase. These observations suggest that ET-1 could play a homeostatic role in modulating aqueous humor formation by having differential effects on the activity and expression of Na,K-ATPase by the ciliary epithelium in the eye.
- Subjects :
- medicine.medical_specialty
Sodium
ATPase
chemistry.chemical_element
Ouabain
Gene Expression Regulation, Enzymologic
chemistry.chemical_compound
Ciliary body
Internal medicine
medicine
Humans
Pharmacology (medical)
RNA, Messenger
Na+/K+-ATPase
G alpha subunit
Cell Line, Transformed
Pharmacology
biology
Dose-Response Relationship, Drug
Endothelin-1
Chemistry
Monensin
Ciliary Body
Infant
Epithelial Cells
Endothelin 1
Cell biology
Ophthalmology
Endocrinology
medicine.anatomical_structure
biology.protein
Sodium-Potassium-Exchanging ATPase
medicine.drug
Subjects
Details
- ISSN :
- 10807683
- Volume :
- 19
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics
- Accession number :
- edsair.doi.dedup.....d8e15197e4e24384d96e78cb65dd6180