SUN-LB007 The Mouse AgRP Gene Has Three Promoters: Differential Regulation by Nutritional States
| Autor: | Shun-Mei Liu, Bruno Ifebi, Streamson C. Chua |
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| Rok vydání: | 2019 |
| Předmět: |
How Genetics and Development Impact the Endocrine System
nervous system Endocrinology Diabetes and Metabolism digestive oral and skin physiology Promoter Differential regulation Computational biology Biology Gene hormones hormone substitutes and hormone antagonists Genetics and Development (including Gene Regulation) |
| Zdroj: | Journal of the Endocrine Society |
| ISSN: | 2472-1972 |
| Popis: | Diabetes and obesity are metabolic indicators of an energy imbalance in the melanocortin system. Agouti related protein (AgRP) neurons in the arcuate nucleus of the hypothalamus regulate energy through the release of its neuropeptide- AgRP, along with Neuropeptide Y and GABA. AgRP acts on melanocortin 4 receptor (MC4-R) by stimulating appetite and decreasing energy expenditure. Overexpression of AgRP is known to contribute to the development of diabetes and obesity. Expression of the Agrp gene is regulated by weight loss, presumably via leptin. We found that the Ensembl database specifies that for the mouse Agrp gene there are three AgRP transcripts which differ in their 5’ untranslated regions and share the same coding exons. To determine if the AgRP mRNA isoforms are relevant for weight control, we collected tissue samples from adult mouse hypothalamus, and designed a quantitative PCR assay for each of the three AgRP mRNA isoforms. After establishing the presence of each isoform in the hypothalamus, we used these assays to determine the influence of fasting on the expression levels of the three different AgRP transcripts. We also sought to determine whether the sequences upstream of each of the three isoforms could function as promoters to drive gene expression. To determine if each upstream region can act as a promoter, we cloned the upstream regions into a reporter plasmid expressing FLAG-tagged red fluorescent protein. Each promoter construct was transfected into a neuronal cell line established from NPY/AgRP-GFP neurons. We found that all three AgRP mRNA isoforms are expressed in the adult mouse hypothalamus. While fasting caused an induction of the total AgRP mRNA (fed=1.00, fasted= 6.29; p |
| Databáze: | OpenAIRE |
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