Heat shock response enhanced by cell culture treatment in mouse embryonic stem cell-derived proliferating neural stem cells.

Cells have a regulatory mechanism known as heat shock (HS) response, which induces the expression of HS genes and proteins in response to heat and other cellular stresses. Exposure to moderate HS results in beneficial effects, such as thermotolerance and promotes survival, whereas excessive HS causes cell death. The effect of HS on cells depends on both exogenous factors, including the temperature and duration of heat application, and endogenous factors, such as the degree of cell differentiation.

Inhibition of epidermal growth factor receptor stimulates prolactin expression in primary culture of the mouse pituitary gland.

The roles of epidermal growth factor (EGF) in the regulation of prolactin (PRL) gene expression in the normal pituitary gland remain poorly understood. In the present study, the effects of EGF and an inhibitor of the EGF receptor, erlotinib, on PRL gene expression were examined both in the pituitary tumour cell line GH3 and in a primary culture of the mouse pituitary gland under similar experimental conditions. The results showed that EGF stimulated PRL expression in GH3 cells, but not in normal cells.

Estradiol and corticosterone stimulate the proliferation of a GH cell line, MtT/S: Proliferation of growth hormone cells.

Objectives: Estrogens are known as a potent growth-stimulator of the anterior pituitary cells such as prolactin cells and somatomammotroph cell lines, while glucocorticoids often inhibit cellular proliferation in the pituitary gland as well as in the extra-pituitary tissues. In this study, the involvement of these steroid hormones in the regulation of proliferation was examined in the MtT/S cells, secreting growth hormone (GH).

Design: Effects of estrogens and glucocorticoids were examined in MtT/S cells grown in the medium containing dextran-coated charcoal treated serum.

Presentation of noise during acute restraint stress attenuates expression of immediate early genes and arginine vasopressin in the hypothalamic paraventricular nucleus but not corticosterone secretion in rats.

The present study investigated the effect of acoustic stimulation on the activation of the hypothalamic-pituitary-adrenal (HPA) axis in rats submitted to acute restraint stress, through semi-quantitative histochemical analysis of expression of immediate early gene products (c-Fos, JunB and phosphorylated c-Jun) and arginine vasopressin (AVP) hnRNA in the paraventricular nucleus (PVN). Simultaneous presentation of white or pink noise with restraint resulted in a significant attenuation of stress-induced c-Fos and JunB expression in the dorsal body of dorsal medial parvicellular subdivision (mpdd) of the PVN, as compared with restraint without noise. However, this presentation did not change phosphorylation of c-Jun and the plasma corticosterone level.

Novel Bernard-Soulier syndrome variants caused by compound heterozygous mutations (case I) or a cytoplasmic tail truncation (case II) of GPIbα.

A defective platelet glycoprotein (GP) Ib/IX/V complex [von Willebrand factor (VWF) receptor] results in Bernard-Soulier syndrome (BSS), which is characterized by macrothrombocytopenia and impaired ristocetin- and thrombin-induced platelet aggregation. We found 2 independent BSS-variant families: Case I [compound heterozygous mutations, p.Glu331X and a frame shift by a deletion at c.

Voluntary resistance running with short distance enhances spatial memory related to hippocampal BDNF signaling.

Although voluntary running has beneficial effects on hippocampal cognitive functions if done abundantly, it is still uncertain whether resistance running would be the same. For this purpose, voluntary resistance wheel running (RWR) with a load is a suitable model, since it allows increased work levels and resultant muscular adaptation in fast-twitch muscle. Here, we examined whether RWR would have potential effects on hippocampal cognitive functions with enhanced hippocampal brain-derived neurotrophic factor (BDNF), as does wheel running without a load (WR).

A rhythmic change of vesicular glutamate transporter (VGLUT) 2 expression in the rat pineal gland.

The pineal gland secretes melatonin under circadian control via nocturnal noradrenergic stimulation, and expresses vesicular glutamate transporter (VGLUT) 1, VGLUT2 and a VGLUT1 splice variant (VGLUT1v). Although we previously reported that VGLUT2 mRNA level of rat pineal gland at postnatal day 21 is higher in the nighttime than in daytime, questions remained as to the time of postnatal onset of this phenomenon and a 24-h change in the mRNA or protein level at postnatal days. The day-night difference in VGLUT2 mRNA level was evident 14 days after birth.

Regional distribution and ontogeny of the first exon variants of the rat growth hormone receptor mRNA in the brain and the pituitary gland.

Expression of the first exon variants of the rat growth hormone receptor mRNA was studied in the brain and the pituitary gland. Four of the five different variant mRNA previously identified in the liver were detected in the cerebral cortex by a conventional reverse-transcription polymerase chain reaction, and, unlike the data reported previously, a quantitative analysis revealed that approximately 90% of the total growth hormone receptor mRNA in the cerebral cortex is V1 form. The present results suggest that the V1 was also a dominant transcript in other brain areas and the pituitary gland, not only in adult but also in fetal and postnatal period.

Hormonal regulation of prolactin cell development in the fetal pituitary gland of the mouse.

The developmental process of prolactin (PRL) cells in the fetal pituitary gland was studied in mice. Although PRL cells were hardly detectable in the pituitary gland of intact fetuses, a treatment with 17beta-estradiol (E(2)) in vitro induced a number of PRL cells that varied drastically in number depending on the stage of gestation with a peak at embryonic d 15. This effect was specific to E(2), with epidermal growth factor, insulin, and forskolin failing to induce PRL cells.

Functional maturation of growth hormone cells in the anterior pituitary gland of the fetus.

Recent studies have disclosed the molecular mechanisms responsible for the phenotype determination of the anterior pituitary cell types. However, as far as growth hormone (GH) cells are concerned, particular extra-cellular cues are required for the initiation of GH and GH-releasing hormone (GHRH)-receptor gene production in addition to the expression of the cell type specific transcription factor, pit-1. The glucocorticoids play a principal role in the functional maturation of nascent GH cells in the fetal pituitary glands in rodents, inducing GH and GHRH-receptor gene expression, and establish the GH secretory system regulated by the brain in late gestation.

Upregulated expression of neuropeptide Y in hypothalamic-pituitary system of rats by chronic dexamethasone administration.

To study the effect of adrenal steroids on neuropeptide Y (NPY) synthesis in the hypothalamic-pituitary system, we examined NPY expression in rats treated with dexamethasone (a synthetic glucocorticoid) by in situ hybridization and immunohistochemistry. Rats were injected daily with dexamethasone (0.2mg/100g/day for 10 days, sc) or sesame oil (vehicle control), or non-injected (intact control).

Cajal-Retzius cells and subplate neurons differentially express vesicular glutamate transporters 1 and 2 during development of mouse cortex.

In the light of the various neurobiological effects of glutamate in brain development, although some embryonic cells are a probable source of glutamate involved in the development of precursor cells and/or immature neurons, little is known about when and where glutamate plays its crucial roles during corticogenesis. To investigate these roles, we focused on the developmental expression of vesicular glutamate transporter (VGLUT)1 and VGLUT2, which are regarded as the best markers for verifying glutamatergic neuron identity, especially the spatiotemporal distributions of their transcripts and proteins in the developing mouse cortex and hippocampus. In situ hybridization studies revealed that VGLUT1 mRNA is expressed in preplate and marginal zone cells at embryonic day (E)10 and in subplate cells by E13, whereas VGLUT2 mRNA is expressed in preplate and marginal zone cells at E10 and in cells of the subventricular zone by E13.

Regulation of 5'-promoter activity of the rat growth hormone and growth hormone-releasing hormone receptor genes in the MtT/S and MtT/E cells.

The MtT/E and MtT/S cells have been established from a mammotrophic pituitary tumor, and postulated to be progenitor and premature growth hormone (GH) cells, respectively. The difference in the regulation of GH and GH-releasing hormone (GHRH) receptor gene transcription in relation to the developmental stage of GH cells were examined in these two cell lines. In MtT/S cells, triiodothyronine (T3), all-trans retinoic acid (RA) and 9-cis retinoic acid (9cRA) stimulated GH promoter activity but dexamethasone (DEX) did not.

Developmentally-regulated expression of tissue-specific splice variant of rat vesicular glutamate transporter 1 in retina and pineal gland.

Three distinct subtypes of vesicular glutamate transporters (VGLUTs) have been identified to date that are expressed basically in a cell type-specific manner. We have found a splice variant of VGLUT1 mRNA that is expressed almost exclusively in photosensitive tissues, i.e.

Particular subpopulations of midbrain and hypothalamic dopamine neurons express vesicular glutamate transporter 2 in the rat brain.

Vesicular glutamate transporters (VGLUT1, -2, and -3) mediate the accumulation of transmitter glutamate into synaptic vesicles in glutamatergic neurons. VGLUT1 and VGLUT2 are more reliable glutamatergic neuron markers, since VGLUT3 also exists in other neuron types. To study whether the dopaminergic neuron uses glutamate as a cotransmitter, we analyzed VGLUTs expression in dopamine neurons of adult male rats by in situ hybridization and immunohistochemistry.

VGLUT2 expression is up-regulated in neurohypophysial vasopressin neurons of the rat after osmotic stimulation.

A second vesicular glutamate transporter (VGLUT2) is detected in magnocellular neurons in the rat hypothalamus. The present study revealed what phenotype of neurons express VGLUT2 mRNA by the histological method. We found that most vasopressin (VP) neurons and several oxytocin (OT) neurons express VGLUT2 mRNA.

The role of pit-1 in the regulation of the rat growth hormone-releasing hormone receptor gene transcription by glucocorticoids.

Glucocorticoids are involved in the regulation of the rat growth hormone-releasing hormone (GHRH) receptor gene expression, but they act only in the presence of the pituitary specific transcription factor, pit-1. In this study, the role of pit-1 in the glucocorticoid stimulation of the GHRH-receptor gene transcription was examined. The results suggest the presence of a silencer element in the promoter and it is postulated that pit-1 permits glucocorticoid action through suppressing the inhibitory effect of an as yet unknown factor that binds to this element.

Up-regulation of VGLUT2 expression in hypothalamic-neurohypophysial neurons of the rat following osmotic challenge.

A second vesicular glutamate transporter (VGLUT2) has been reported to be expressed in neurosecretory neurons of the hypothalamic-neurohypophysial system. To study its role in the neurosecretory neurons, we evaluated the expression of the VGLUT2 gene in the paraventricular (PVN) and supraoptic (SON) nuclei as well as the immunoreactivity in the neurohypophysis under euhydrated and chronic hyperosmotic conditions with in situ hybridization and immunohistochemistry. The intensity of hybridization signals in the PVN, SON and thalamus of rats subjected to water deprivation for 7 days, or drinking 2% NaCl for 4 or 7 days, was compared with that of euhydrated rats (control).

Expression of inorganic phosphate/vesicular glutamate transporters (BNPI/VGLUT1 and DNPI/VGLUT2) in the cerebellum and precerebellar nuclei of the rat.

Expression of inorganic phosphate/vesicular glutamate transporters (BNPI/VGLUT1 and DNPI/VGLUT2) was studied in the cerebellum and precerebellar nuclei of rats using immunohistochemistry and in situ hybridization. DNPI/VGLUT2-stained mossy fibers were principally seen in the vermis (lobules I and VIII-X) and flocculus, whereas BNPI/VGLUT1-stained mossy fibers were localized throughout the cortex. Some vermal and floccular mossy fibers were stained for both transporters.

Differential expression of two distinct vesicular glutamate transporters in the rat retina.

Expression and cellular localization of vesicular glutamate transporters (BNPI and DNPI) were studied in the rat retina. RT-PCR showed expression of both transporter mRNAs. hybridization demonstrated BNPI mRNA signals in the inner segments of photoreceptors and the inner nuclear layer, whereas DNPI mRNA signals were confined to the ganglion cell layer.

A composite hormone response element regulates transcription of the rat GHRH receptor gene.

To further elucidate the molecular mechanisms underlying the transcriptional regulation of the GHRH receptor (GHRH-R) gene, hormonal regulation of the promoter activity of this gene was examined. An approximately 3-kb genomic fragment spanning the promoter region of the gene was sequenced and the transcription start site was determined by RT-PCR and RNase protection assay. A major start site was localized at -105 (relative to the translation initiation codon, ATG), and a pit-1 binding sequence characteristic of pituitary specific genes was found at -155 to -146.

Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): a review.

Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action.