Biomedical subjects

Noriko Mutsuga

Publications and source records attributed to Noriko Mutsuga.

4 recordsLinked to original sources

PubMed2005

APeg3, a novel paternally expressed gene 3 antisense RNA transcript specifically expressed in vasopressinergic magnocellular neurons in the rat supraoptic nucleus.

Vasopressin (VP) and oxytocin (OT) play critical roles in the regulation of salt and water balance, lactation, and various behaviors and are expressed at very high levels in specific magnocellular neurons (MCNs) in the hypothalamo-neurohypophysial system (HNS). In addition to the cell-specific expression of the VP and OT genes in these cells, there are other transcripts that are preferentially expressed in the VP or OT MCNs. One such gene, paternally expressed gene 3 (Peg3), is an imprinted gene expressed exclusively from the paternal allele that encodes a Kruppel-type zinc finger-containing protein involved in maternal behavior and is abundantly expressed in the VP-MCNs. We report here the robust expression in the VP-MCNs of an RNA, which we designate APeg3 that is transcribed in the antisense direction to the 3' untranslated region of the Peg3 gene. The APeg3 mRNA is about 1 kb in size, and the full-length sequence of APeg3, as determined by 5' and 3' RACE, contains an open reading frame that predicts a protein of 93 amino acids and is predominantly expressed in VP-MCNs. Both Peg3 and APeg3 gene expression in the VP-MCNs increase during systemic hyperosmolality in vivo, demonstrating that both of these genes are osmoregulated.

3' Untranslated Regions↗

PubMed2004

Regulation of gene expression in magnocellular neurons in rat supraoptic nucleus during sustained hypoosmolality.

Hypoosmolality produces a dramatic inhibition of vasopressin (VP) and oxytocin gene expression in the supraoptic nucleus (SON). This study examines the effect of sustained hypoosmolality on global gene expression in the oxytocin and VP magnocellular neurons of the hypothalamo-neurohypophysial system, to identify genes associated with the magnocellular neuron's adaptation to this physiological condition. Using laser microdissection of the SON, T7-based linear amplification of its RNA, and a 35,319-element cDNA microarray, we compare gene expression profiles between SONs in normoosmolar (control), 1-desamino-[8-D-arginine]-VP-treated normoosmolar, and hypoosmolar rats. We found 4959 genes with statistically significant differences in expression between normosmolar control and the hypoosmolar SONs, with 1564 of these differing in expression by more than 2-fold. These genes serve a wide variety of functions, and most were up-regulated in gene expression in hypoosmolar compared with control SONs. Of these, 90 were preferentially expressed in the SON, and 44 coded for transcription-related factors, of which 15 genes were down-regulated and 29 genes were up-regulated in the hypoosmolar rat SONs. None of these transcription-related factor genes significantly changed in expression after sustained 1-desamino-[8-D-arginine]-VP-treatment alone, indicating that these changes were associated with the hypoosmolar state and not due solely to a decreased activity in the SON. Quantitative in situ hybridization histochemistry was selectively used to confirm and extend these microarray observations. These results indicate that the hypoosmolar state is accompanied by a global, but selective, increase in expression of a wide variety of regulatory genes in the SON.

Animals↗

PubMed2004

Selective gene expression in magnocellular neurons in rat supraoptic nucleus.

Oxytocin- and vasopressin-producing magnocellular neurons (MCNs) of the hypothalamo-neurohypophysial system are the only neuronal phenotypes present in the rat supraoptic nucleus (SON). Laser microdissection of the SON, extraction and T7-based amplification of its RNAs, and analysis of the resulting cDNAs by hybridization on a 35, 319 element DNA microarray have provided a detailed composite view of the gene expression profile of the MCNs. The genes expressed in the SON were compared with those expressed in a reference tissue consisting of total hypothalamus, and this "expression ratio" indicated which genes were preferentially expressed in the SON. Of the 26,000 unique genes on the array, 1385 were found to be expressed in the SON at levels more than two times greater than in the hypothalamus as a whole. Of these, 123 were expressed > or =3.4-fold higher in the SON versus hypothalamus. Most of these preferentially expressed genes were not previously known to be expressed in the MCNs. Quantitative and double-label in situ hybridization histochemistry was used selectively to confirm a number of these microarray observations and to evaluate the osmotic regulation and cell-specific expression of these genes, respectively.

Animals↗

PubMed2003

Sodium bicarbonate infusion test: a new method for evaluating parathyroid function.

We have developed a new test for estimating the secretory capacity of parathyroid hormone (PTH) from the parathyroid gland. Sodium bicarbonate solution [8.4% (w/v); 35 ml/m(2) body surface area] was infused for 2 min, and blood samples for the determination of plasma ionized calcium, plasma PTH (intact, midregion, carboxy-terminus) and related parameters were serially obtained. In 8 healthy volunteers, the mean (+/-SE) plasma ionized calcium fell promptly and significantly (from 1.21 +/- 0.01 to 1.11 +/- 0.01 mmol/L) after the sodium bicarbonate infusion. The mean (+/-SE) plasma intact PTH increased promptly and significantly, by more than four fold (42.3 +/- 4.2 to 182.4 +/- 34.7 pg/ml), and then gradually returned to basal levels. In patients with partial hypoparathyroidism who have detectable basal plasma levels of PTH, the absolute increment in PTH levels was much less, and in the plasma obtained from patients with complete hypoparathyroidism, absolutely no response was observed. Plasma obtained from patients diagnosed with primary hyperparathyroidism (parathyroid adenoma or hyperplasia) has high basal PTH levels. The response to the sodium bicarbonate infusion in these patients was markedly blunted (less than a two-fold increase in all cases examined). No significant adverse effects were observed during the procedure. Therefore, the sodium bicarbonate infusion test is a simple and sensitive method to stimulate PTH release, and is clinically useful for evaluating parathyroid gland function.

Adult↗