Linked Life Data

16684131

Source:http://linkedlifedata.com/resource/pubmed/id/16684131

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-5-10
pubmed:abstractText
A remarkable feature of the seasonal adaptation displayed by the Siberian hamster (Phodopus sungorus) is the ability to decrease food intake and body weight (by up to 40%) in response to shortening photoperiod. The regulating neuroendocrine systems involved in this adaptation and their neuroanatomical and molecular bases are poorly understood. We investigated the effect of photoperiod on the expression of prohormone convertases 1 (PC1/3) and 2 (PC2) and the endoproteolytic processing of the neuropeptide precursor pro-opiomelanocortin (POMC) within key energy balance regulating centres of the hypothalamus. We compared mRNA levels and protein distribution of PC1/3, PC2, POMC, adrenocorticotrophic hormone (ACTH), alpha-melanocyte-stimulating hormone (MSH), beta-endorphin and orexin-A in selected hypothalamic areas of long day (LD, 16:8 h light:dark), short day (SD, 8:16 h light:dark) and natural-day (ND, photoperiod depending on time of the year) acclimated Siberian hamsters. The gene expression of PC2 was significantly higher within the arcuate nucleus (ARC, P < 0.01) in SD and in ND (versus LD), and is reflected in the day length profile between October and April in the latter. PC1/3 gene expression in the ARC and lateral hypothalamus was higher in ND but not in SD compared to the respective LD controls. The immunoreactivity of PC1/3 cleaved neuropeptide ACTH in the ARC and PC1/3-colocalised orexin-A in the lateral hypothalamus were not affected by photoperiod changes. However, increased levels of PC2 mRNA and protein were associated with higher abundance of the mature neuropeptides alpha-MSH and beta-endorphin (P < 0.01) in SD. This study provides a possible explanation for previous paradoxical findings showing lower food intake in SD associated with decreased POMC mRNA levels. Our results suggest that a major part of neuroendocrine body weight control in seasonal adaptation may be effected by post-translational processing mediated by the prohormone convertases PC1/3 and PC2, in addition to regulation of gene expression of neuropeptide precursors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0953-8194
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
413-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16684131-Adaptation, Physiological, pubmed-meshheading:16684131-Adrenocorticotropic Hormone, pubmed-meshheading:16684131-Animals, pubmed-meshheading:16684131-Body Weight, pubmed-meshheading:16684131-Cricetinae, pubmed-meshheading:16684131-Female, pubmed-meshheading:16684131-Gene Expression Regulation, Enzymologic, pubmed-meshheading:16684131-Hypothalamic Area, Lateral, pubmed-meshheading:16684131-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:16684131-Male, pubmed-meshheading:16684131-Neuropeptides, pubmed-meshheading:16684131-Phodopus, pubmed-meshheading:16684131-Photoperiod, pubmed-meshheading:16684131-Pro-Opiomelanocortin, pubmed-meshheading:16684131-Proprotein Convertase 1, pubmed-meshheading:16684131-Proprotein Convertase 2, pubmed-meshheading:16684131-Protein Precursors, pubmed-meshheading:16684131-Protein Processing, Post-Translational, pubmed-meshheading:16684131-RNA, Messenger, pubmed-meshheading:16684131-Seasons, pubmed-meshheading:16684131-alpha-MSH, pubmed-meshheading:16684131-beta-Endorphin
pubmed:year
2006
pubmed:articleTitle
PC1/3 and PC2 gene expression and post-translational endoproteolytic pro-opiomelanocortin processing is regulated by photoperiod in the seasonal Siberian hamster (Phodopus sungorus).
pubmed:affiliation
Molecular Endocrinology Group, Division of Obesity and Metabolic Health, Rowett Research Institute, Aberdeen Centre for Energy Regulation and Obesity, Aberdeen, UK. helwigmi@staff.uni-marburg.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't