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Expression and cellular localization of the transcription factor N euro D 1 in the developing and adult rat pineal gland
Author(s) -
Castro Analía E.,
Benitez Sergio G.,
Farias Altamirano Luz E.,
Savastano Luis E.,
Patterson Sean I.,
Muñoz Estela M.
Publication year - 2015
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/jpi.12228
Subject(s) - biology , pineal gland , pinealocyte , transcription factor , microbiology and biotechnology , melatonin , circadian rhythm , medicine , endocrinology , genetics , gene
Abstract Circadian rhythms govern many aspects of mammalian physiology. The daily pattern of melatonin synthesis and secretion is one of the classic examples of circadian oscillations. It is mediated by a class of neuroendocrine cells known as pinealocytes which are not yet fully defined. An established method to evaluate functional and cytological characters is through the expression of lineage‐specific transcriptional regulators. NeuroD1 is a basic helix‐loop‐helix transcription factor involved in the specification and maintenance of both endocrine and neuronal phenotypes. We have previously described developmental and adult regulation of NeuroD1 m RNA in the rodent pineal gland. However, the transcript levels were not influenced by the elimination of sympathetic input, suggesting that any rhythmicity of NeuroD1 might be found downstream of transcription. Here, we describe NeuroD1 protein expression and cellular localization in the rat pineal gland during development and the daily cycle. In embryonic and perinatal stages, protein expression follows the m RNA pattern and is predominantly nuclear. Thereafter, NeuroD1 is mostly found in pinealocyte nuclei in the early part of the night and in cytoplasm during the day, a rhythm maintained into adulthood. Additionally, nocturnal nuclear NeuroD1 levels are reduced after sympathetic disruption, an effect mimicked by the in vivo administration of α ‐ and β ‐adrenoceptor blockers. NeuroD1 phosphorylation at two sites, Ser 274 and Ser 336 , associates with nuclear localization in pinealocytes. These data suggest that NeuroD1 influences pineal phenotype both during development and adulthood, in an autonomic and phosphorylation‐dependent manner.