title: Up-regulation of the alpha-secretase ADAM10 by retinoic acid receptors and acitretin.
abstract: Late-onset Alzheimer's disease is often connected with nutritional misbalance, such as enhanced cholesterol intake, deficiency in polyunsaturated fatty acids, or hypovitaminosis. The alpha-secretase ADAM10 has been found to be regulated by retinoic acid, the bioreactive metabolite of vitamin A. Here we show that retinoids induce gene expression of ADAM10 and alpha-secretase activity by nonpermissive retinoid acid receptor/retinoid X receptor (RAR/RXR) heterodimers, whereby alpha- and beta-isotypes of RAR play a major role. However, ligands of other RXR binding partners, such as the vitamin D receptor, do not stimulate alpha-secretase activity. On the basis of these findings, we examined the effect of synthetic retinoids and found a strong enhancement of nonamyloidogenic processing of the amyloid precursor protein by the vitamin A analog acitretin: it stimulated ADAM10 promoter activity with an EC(50) of 1.5 microM and led to an increase of mature ADAM10 protein that resulted in a two- to three-fold increase of the ratio between alpha- and beta-secretase activity in neuroblastoma cells. The alpha-secretase stimulation by acitretin was completely inhibited by the ADAM10-specific inhibitor GI254023X. Intracerebral injection of acitretin in APP/PS1-21 transgenic mice led to a reduction of Abeta(40) and Abeta(42). The results of this study may have clinical relevance because acitretin has been approved for the treatment of psoriasis since 1997 and found generally safe for long-term use in humans.
authors.affiliation: Institute of Biochemistry, University of Mainz, Becherweg 30, D-55099 Mainz, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Tippmann
authors.forename: Jana
authors.initials: J
authors.lastname: Hundt
authors.forename: Anja
authors.initials: A
authors.lastname: Schneider
authors.forename: Kristina
authors.initials: K
authors.lastname: Endres
authors.forename: Falk
authors.initials: F
authors.lastname: Fahrenholz
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072197:ADAM10 Protein; D017255:Acitretin / Q000737:chemistry / Q000378:metabolism*; D000544:Alzheimer Disease / Q000378:metabolism; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007641:Keratolytic Agents / Q000378:metabolism*; D000071518:Liver X Receptors; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D015394:Molecular Structure; D057093:Orphan Nuclear Receptors; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism*; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism; D047488:Retinoid X Receptors / Q000235:genetics / Q000378:metabolism*; D014212:Tretinoin / Q000737:chemistry / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016564:Amyloid beta-Protein Precursor; D004268:DNA-Binding Proteins; D007641:Keratolytic Agents; D000071518:Liver X Receptors; D008565:Membrane Proteins; D057093:Orphan Nuclear Receptors; D047495:PPAR gamma; D018167:Receptors, Calcitriol; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D047488:Retinoid X Receptors; D014212:Tretinoin; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; C491234:Adam10 protein, mouse; D017255:Acitretin