LEDGF regulation of alcohol and aldehyde dehydrogenases in lens epithelial cells: stimulation of retinoic acid production and protection from ethanol toxicity.
Retinoic acid (RA) is required for the normal growth and maintenance of many cell types, including lens epithelial cells (LECs). Alcohol (ADH) and aldehyde (ALDH) dehydrogenases are implicated in cellular detoxification and conversion of vitamin A to RA. Lens epithelium-derived growth factor (LEDGF) provides cellular protection against stress by transactivating stress-associated genes. Here we show evidence that LEDGF binds and transactivates heat shock (nGAAn) and stress response (A/TGGGGA/T) elements in the promoters of ADH1, ADH4, and retinaldehyde 2 (RALDH2) genes. Electrophoretic mobility and supershift assays disclosed specific binding of LEDGF to nGAAn and A/TGGGGA/T elements in these gene promoters. Transfection experiments in LECs with promoters linked to a chloramphenicol acetyltransferase (CAT) reporter gene along with LEDGF cDNA revealed higher CAT activity. RT-PCR results confirmed that LECs overexpressing LEDGF contained increased levels of ADH1, ADH4, and RALDH2 mRNA. Notably, LECs displayed higher LEDGF mRNA and protein expression during ethanol stress. Cells overexpressing LEDGF typically exhibited elevated RA levels and survived well during ethanol stress. The present findings indicate that LEDGF is one of the transcriptional activators of these genes that facilitates cellular protection against ethanol stress and plays a role in RA production.
Fatma
Nigar
N
Department of Ophthalmology, 985840 Nebraska Medical Center, University of Nebraska Medical Center, Omaha, NE 68198-5840, USA.
Kubo
Eri
E
Chylack
Leo T
LT
Shinohara
Toshimichi
T
Akagi
Yoshio
Y
Singh
Dhirendra P
DP
D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000080924:Aldehyde Dehydrogenase 1 Family; D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002492:Central Nervous System Depressants / Q000633:toxicity; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology; D000431:Ethanol / Q000633:toxicity; D015971:Gene Expression Regulation, Enzymologic; D006360:Heat-Shock Proteins / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007908:Lens, Crystalline / Q000166:cytology*; D051379:Mice; D011401:Promoter Regions, Genetic / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D050697:Retinal Dehydrogenase; D014212:Tretinoin / Q000378:metabolism*
D002492:Central Nervous System Depressants; D006360:Heat-Shock Proteins; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D012333:RNA, Messenger; C119380:lens epithelium-derived growth factor; D000431:Ethanol; D014212:Tretinoin; D000426:Alcohol Dehydrogenase; C105552:alcohol dehydrogenase IV; D000445:Aldehyde Oxidoreductases; D000080924:Aldehyde Dehydrogenase 1 Family; D000444:Aldehyde Dehydrogenase; C515028:ALDH1A1 protein, mouse; D050697:Retinal Dehydrogenase