Up-regulation of steroid biosynthesis by retinoid signaling: Implications for aging
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Accepted version
Author(s)
Type
Journal Article
Abstract
Retinoids (vitamin A and its derivatives) are critical for a spectrum of developmental and physiological processes, in which steroid hormones also play indispensable roles. The StAR protein predominantly regulates steroid biosynthesis in steroidogenic tissues. We have reported that regulation of retinoid, especially atRA and 9-cis RA, responsive StAR transcription is largely mediated by an LXR–RXR/RAR heterodimeric motif in the mouse StAR promoter. Herein we demonstrate that retinoids are capable of enhancing StAR protein, P-StAR, and steroid production in granulosa, adrenocortical, glial, and epidermal cells. Whereas transient expression of RARα and RXRα enhanced 9-cis RA induced StAR gene transcription, silencing of RXRα with siRNA, decreased StAR and steroid levels. An oligonucleotide probe encompassing an LXR–RXR/RAR motif bound to adrenocortical and epidermal keratinocyte nuclear proteins in EMSAs. ChIP studies revealed association of RARα and RXRα with the StAR proximal promoter. Further studies demonstrated that StAR mRNA levels decreased in diseased and elderly men and women skin tissues and that atRA could restore steroidogenesis in epidermal keratinocytes of aged individuals. These findings provide novel insights into the relevance of retinoid signaling in the up-regulation of steroid biosynthesis in various target tissues, and indicate that retinoid therapy may have important implications in age-related complications and diseases.
Date Issued
2015-08-21
Date Acceptance
2015-08-15
Citation
Mechanisms of Ageing and Development, 2015, 150, pp.74-82
ISSN
1872-6216
Publisher
Elsevier
Start Page
74
End Page
82
Journal / Book Title
Mechanisms of Ageing and Development
Volume
150
Copyright Statement
© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Science & Technology
Life Sciences & Biomedicine
Cell Biology
Geriatrics & Gerontology
Retinoids
RAR
RXR
cAMP/PKA
StAR expression
Steroid biosynthesis
Steroidogenic cells
MOUSE LEYDIG-CELLS
GONADOTROPIN-RELEASING-HORMONE
PROTEIN-KINASE-C
X-RECEPTOR-ALPHA
MOLECULAR-MECHANISMS
MEDIATED REGULATION
VITAMIN-A
LUTEINIZING-HORMONE
RESPONSIVE ELEMENT
CHOLESTEROL EFFLUX
Gerontology
1103 Clinical Sciences
Publication Status
Published