Microarray screening of suppression subtractive hybridization-PCR cDNA libraries identifies novel RNAs regulated by dehydration in the rat supraoptic nucleus

Ghorbel, Mohamed; Sharman, Greig; Hindmarch, Charles; Becker, Kevin G.; Barrett, Tanya; Murphy, David

doi:10.1152/physiolgenomics.00229.2005

Cited by 21 publications

(14 citation statements)

References 42 publications

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“…Hyperosmotic stimuli alters levels of mRNA, and protein in the magnocellular neurons (Meister et al, 1990). Microarray studies have shown that RNA expression in the SON changes because of dehydration (Ghorbel et al, 2006). Acute osmotic challenges have been shown to increase the expression of many immediate early genes like c-fos, junB, NGFI-A, and NGFI-B in both the PVN and the SON (Kawasaki et al, 2005).…”

Section: Discussion Nuclear Transportmentioning

confidence: 99%

Trafficking of tachykinin neurokinin 3 receptor to nuclei of neurons in the paraventricular nucleus of the hypothalamus following osmotic challenge

2008

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Tachykinin NK3 receptor (NK3R) is a g-protein coupled receptor that is heavily expressed by magnocellular neurons of the paraventricular nucleus of the hypothalamus (PVN). Osmotic challenge is reported to activate NK3R expressed by magnocellular neurons and cause the NK3R to be internalized to the cytoplasm and perhaps the cell nucleus. In this study we show using immunoelectron microscopy that isolated nuclei from neurons in the PVN of osmotic challenged animals show a robust labeling for the NK3R. NK3R immunoreactivity was detected by Western blot in isolated nuclei of PVN neurons following the 2 M NaCl injection. No nuclear NK3R immunoreactivity was detected in control animals. NK3R antibody specificity was confirmed by small interfering (SI) RNA technology. This study establishes that the NK3R is trafficked to the nucleus of PVN neurons following a peripheral osmotic challenge. KeywordsG-protein coupled receptor; Cell signaling; Electron microscopy; siRNA Magnocellular neurons of the hypothalamus synthesize and secrete two key hormones: vasopressin (VP) and oxytocin (OT). The release of these hormones is influenced by a number of transmitters and magnocellular neurons express a number of receptors. Noteworthy is the tachykinin, NK3 receptor (NK3R) which is heavily expressed by magnocellular neurons of the supraoptic (SON) and paraventricular nucleus (PVN) of the hypothalamus (Ding et al., 1999). NK3R expressed by magnocellular neurons appears to have a functional role in the release of vasopressin and oxytocin. Stimulation of NK3R results in an increase in Ca ++ conductance (Buell et al., 1992), induction of c-Fos expression in magnocellular neurons, and causes the systemic release of both hormones (Ding et al., 1999;Smith and Flynn, 2000;Bealer and Flynn, 2003). Furthermore, the release of the endogenous ligand, presumably neurokinin B (NKB), and binding to the NK3R results in the internalization of the peptide-receptor complex (Chawala et al., 1997;Colin et al., 2002;Lessard et al., 2004;Johnson et al., 2004) that can be tracked immunohistochemically. NK3R expressed by magnocellular neurons are membrane bound in control (isotonic saline treated) animals. After hyperosmotic or Direct correspondence to: Francis W. Flynn, 1000 E. University Ave., Dept 3166, Laramie, WY 82071, tel: 307-766-6446, e-mail: flynn@uwyo.edu. Section Editor: Dr. Miles Herkenham Systems Neuroscience, Bethesda, MD, USA Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuroscience. Author manuscript; available in PMC 2009 July 31. Published in final edi...

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Section: Discussion Nuclear Transportmentioning

confidence: 99%

Trafficking of tachykinin neurokinin 3 receptor to nuclei of neurons in the paraventricular nucleus of the hypothalamus following osmotic challenge

2008

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“…Our findings suggest that the expression of approximately equal numbers of miRNAs increases and decreases after saline intake by mice. These regulated miRNAs may have crucial roles in regulating genes whose expression levels change in the PVN and SON with changes in serum osmolality (33)(34)(35). We focused on miR-7b because it has one of the highest levels of expression, and a previous report suggested that the miR-7 family is specific to the hypothalamus and pituitary in humans (36).…”

Section: Discussionmentioning

confidence: 99%

“…Recently, microarray analyses have been used to profile gene expression in the hypothalamo-neurohypophyseal system (HNS) after hypoosmolar and hyperosmolar treatments (33)(34)(35). How those expression changes are controlled remains largely unknown.…”

Section: Discussionmentioning

confidence: 99%

miR-7b, a microRNA up-regulated in the hypothalamus after chronic hyperosmolar stimulation, inhibits Fos translation

Lee

Palkovits

Young

2006

Proc. Natl. Acad. Sci. U.S.A.

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The transcription factor activator protein 1 (AP-1) is formed through the dimerization of immediate-early genes Fos and Jun family members. Activator protein 1 is known as a pivotal regulator of major biological events such as cell proliferation, differentiation, organogenesis, memory formation, and apoptosis. During a search for microRNAs (miRNAs; small, endogenous, noncoding RNAs that repress gene expression of target mRNAs in animals posttranscriptionally) that are differentially expressed in the mouse paraventricular and supraoptic nuclei after 10 days of drinking 2% saline, one candidate microRNA that is relatively highly expressed, mmumiR-7b (miR-7b), was studied further because sequence analysis suggested a likely interaction with the 3 untranslated region of Fos mRNA. We show that miR-7b expression inhibits Fos translation in vitro and that it and its host gene are prominently expressed in the PVN and other brain areas, including the suprachiasmatic nucleus. No effect on Fos mRNA levels was observed. Normally, Fos is expressed at low to undetectable levels in cells, but it shows rapid induction and decay after acute stimuli. Various pathways have been identified through which Fos family proteins are degraded; our results indicate a significant additional mechanism by which Fos protein and activity may be regulated.AP-1 ͉ hyperosmolality ͉ microarray ͉ paraventricular nucleus ͉ suprachiasmatic

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“…Numerous genes are up regulated in SON during dehydration [21,27,105]. The concurrent decrease in ERβ, a potentially inhibitory transcription factor, identifies genes up-regulated by dehydration as candidates for ERβ inhibition.…”

Section: Conclusion and Future Researchmentioning

confidence: 99%

Estrogen receptors: Their roles in regulation of vasopressin release for maintenance of fluid and electrolyte homeostasis

Sladek

Somponpun

2008

Frontiers in Neuroendocrinology

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Long standing interest in the impact of gonadal steroid hormones on fluid and electrolyte balance has led to a body of literature filled with conflicting reports about gender differences, the effects of gonadectomy, hormone replacement, and reproductive cycles on plasma vasopressin (VP), VP secretion, and VP gene expression. This reflects the complexity of gonadal steroid hormone actions in the body resulting from multiple sites of action that impact fluid and electrolyte balance (e.g. VP target organs, afferent pathways regulating the VP neurons, and the VP secreting neurons themselves). It also reflects involvement of multiple types of estrogen receptors (ER) in these diverse sites including ERs that act as transcription factors regulating gene expression (i.e. the classic ERα as well as the more recently discovered ERβ) and potentially G-protein coupled, membrane localized ERs that mediate rapid non-genomic actions of estrogen. Furthermore, altered expression of these receptors in physiologically diverse conditions of fluid and electrolyte balance contributes to the difficulty of using simplistic approaches such as gender comparisons, gonadectomy, and hormone replacement to assess the role of gonadal steroids in regulation of VP secretion for maintenance of fluid and electrolyte homeostasis. This review catalogs these inconsistencies and provides a frame work for understanding them by describing: 1) the effect of gonadal steroids on target organ responsiveness to VP; 2) the expression of multiple types of estrogen receptors in the VP neurons and in brain regions monitoring feedback signals from the periphery; and 3) the impact of dehydration and hyponatremia on expression of these receptors.

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Microarray screening of suppression subtractive hybridization-PCR cDNA libraries identifies novel RNAs regulated by dehydration in the rat supraoptic nucleus

Cited by 21 publications

References 42 publications

Trafficking of tachykinin neurokinin 3 receptor to nuclei of neurons in the paraventricular nucleus of the hypothalamus following osmotic challenge

Trafficking of tachykinin neurokinin 3 receptor to nuclei of neurons in the paraventricular nucleus of the hypothalamus following osmotic challenge

miR-7b, a microRNA up-regulated in the hypothalamus after chronic hyperosmolar stimulation, inhibits Fos translation

Estrogen receptors: Their roles in regulation of vasopressin release for maintenance of fluid and electrolyte homeostasis

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