Differential Regulation of GHRH-Receptor and GHS-Receptor Expression by Long-Term In Vitro Treatment of Ovine Pituitary Cells with GHRP-2 and GHRH

Endocrine ◽  
2006 ◽  
Vol 30 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Sang-Gun Roh ◽  
Maria Doconto ◽  
Dan Dan Feng ◽  
Chen Chen
Keyword(s):  
Differential Regulation ◽  
Receptor Expression ◽  
Pituitary Cells ◽  
Ghrh Receptor ◽  
Ghs Receptor ◽  
In Vitro Treatment

scholarly journals Long-term In Vitro Treatment of Human Glioblastoma Cells with Temozolomide Increases Resistance In Vivo through Up-regulation of GLUT Transporter and Aldo-Keto Reductase Enzyme AKR1C Expression

Neoplasia ◽  
2010 ◽  
Vol 12 (9) ◽  
pp. 727-739 ◽  
Author(s):  
Benjamin Le Calvé ◽  
Michal Rynkowski ◽  
Marie Le Mercier ◽  
Céline Bruyère ◽  
Caroline Lonez ◽  
...  
Keyword(s):  
Glioblastoma Cells ◽  
Human Glioblastoma ◽  
Human Glioblastoma Cells ◽  
In Vitro Treatment

Abstract 281: Long-term Exposure of PM2.5 Causes Hypertension by Impaired Renal D1 Receptor Mediated Sodium Excretion via Up-regulation of GRK4 Expression in SD rats

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Xi Lu ◽  
Ken Chen ◽  
Jing Zeng ◽  
Hongmei Ren ◽  
Chunyu Zeng
Keyword(s):  
Sodium Excretion ◽  
D1 Receptor ◽  
Receptor Expression ◽  
Sd Rats ◽  
Induced Hypertension ◽  
Pm2.5 Exposure ◽  
And Function

Introduction: Epidemiological evidence supports an important association between PM2.5 exposure and hypertension. There are reports that PM2.5 induced hypertension with impaired sodium excretion, however, the mechanisms are not clear. Hypothesis: We hypothesize that PM2.5, via increased ROS levels, increased GRK4 expression, consequently impaired renal D1 receptor function, and lead to hypertension. Methods: We used Sprague-Dawley (SD) rats with in-vivo PM2.5 exposure, and immortalized renal proximal tubule (RPT) cells from Wistar-Kyoto (WKY) rats in-vitro, which behave similarly to freshly obtained RPT cells. Results: Our present study found that long-term exposure of PM2.5 caused hypertension and impaired renal sodium excretion, which might be ascribed to lower D1 receptor expression and higher D1 receptor phosphorylation, accompanied with higher GRK4 expression. The in-vivo results were confirmed in in-vitro study, i.e. PM2.5 increased basal Na+-K+ ATPase activity, decreased D1 receptor mediated inhibitory effect on Na+-K+ ATPase activity, decreased D1 receptor expression and increased D1 receptor phosphorylation in RPT cells. The downregulation of D1 receptor expression and function might be due to higher GRK4 expression, because down-regulation of GRK4 by siRNA reversed the D1 receptor expression and function. Due to the role of ROS on D1 receptor dysfunction, we checked ROS levels, and found plasma ROS levels were higher in PM2.5 treated SD rats. Inhibition of ROS by tempol reduced blood pressure and increased sodium excretion in PM2.5 treated SD rats, accompanied by increased the lower D1 receptor expression, and decreased the hyperphosphorylated D1 receptor and GRK4 expression. Conclusions: Long-term exposure of PM2.5 increases blood pressure by decreased D1 receptor expression and function; ROS, via regulation of GRK4 expression, is taken part in the pathogenesis of PM2.5-induced hypertension.

Effect of long-term corticosteroid administration on rat pituitary growth hormone and prolactin

1985 ◽  
Vol 108 (4) ◽  
pp. 475-478 ◽  
Author(s):  
R. Oosterom ◽  
T. Verleun ◽  
J. Zuiderwijk ◽  
P. Uitterlinden ◽  
S. W. J. Lamberts
Keyword(s):  
Pituitary Cells ◽  
Corticosteroid Administration ◽  
Pituitary Growth Hormone ◽  
Significant Stimulation ◽  
Rat Pituitary ◽  
Hydrocortisone Administration ◽  
Plasma Gh

Abstract. In vitro corticosteroids stimulate GH synthesis by pituitary cells, while in vivo they suppress stimulated plasma GH levels. In this study we investigated in rats the effect of hydrocortisone administration for 2–4 weeks on pituitary GH content. Hydrocortisone added to the drinking water (100 mg/l) resulted in a marked stimulation of pituitary GH content after 3 and 4 weeks of treatment. No significant stimulation, however, was observed on basal GH release by the pituitary gland incubated in vitro. Further, we found that both Prl content and release were inhibited by hydrocortisone administration.

scholarly journals Sodium Fluoride In Vitro Treatment Affects the Expression of Gonadotropin and Steroid Hormone Receptors in Chicken Embryonic Gonads

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 943
Author(s):  
Agnieszka Karolina Grzegorzewska ◽  
Ewa Grot ◽  
Andrzej Sechman
Keyword(s):  
Progesterone Receptor ◽  
Sodium Fluoride ◽  
Hormone Receptor ◽  
Receptor Expression ◽  
Luteinizing Hormone Receptor ◽  
Steroid Hormone Receptors ◽  
Mrna Levels ◽  
Dependent Manner ◽  
In Vitro Treatment

Sodium fluoride (NaF), in addition to preventing dental decay may negatively affect the body. The aim of this study was to examine the effect of a 6 h in vitro treatment of gonads isolated from 14-day-old chicken embryos with NaF at doses of 1.7 (D1), 3.5 (D2), 7.1 (D3), and 14.2 mM (D4). The mRNA expression of luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR), estrogen receptors (ESR1 and ESR2), progesterone receptor (PGR), and the immunolocalization of progesterone receptors were examined in the tissue. In the ovary, the expression of FSHR and LHR increased following the NaF treatment. In the case of FSHR the highest stimulatory effect was noticed in the D2 group, while the expression of LHR increased in a dose-dependent manner. A gradual increase in ESR1 and PGR mRNA levels was also observed in the ovary following the NaF treatment, but only up to the D3 dose of NaF. The highest ESR2 level was also found in the D3 group. In the testes, the lowest dose of NaF significantly decreased the expression of FSHR, ESR1, ESR2, and PGR. On the other hand, an increase in PGR expression was observed in the D3 group. The expression of LHR in the testes was not affected by the NaF treatment. Immunohistochemical analysis showed that NaF exposure increased progesterone receptor expression in the ovarian cortex, while it decreased its expression in the testes. These results reveal that NaF may disturb the chicken embryonic development and different mechanisms of this toxicant action exist within the females and males.

scholarly journals Exocytotic protein components in rat pituitary gland after long-term estrogen administration

1999 ◽  
Vol 161 (2) ◽  
pp. 323-331 ◽  
Author(s):  
G Majo ◽  
MJ Lorenzo ◽  
J Blasi ◽  
F Aguado
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Pituitary Cells ◽  
Fischer 344 Rats ◽  
Fischer 344 ◽  
Anterior Pituitary Cells ◽  
Pituitary Glands ◽  
Protein Components

Recently, a set of proteins involved in the docking and fusion machinery of secretory organelles has been identified in anterior pituitary cells. In this study we analyzed, by Western blotting and immunocytochemistry, the expression of several proteins involved in exocytosis after long-term administration of 17beta-estradiol (E2) in Fischer 344 rats. No differences were observed in the amount of synaptosomal-associated protein of 25 kDa, synaptobrevin 2, syntaxin 1, synaptotagmin I and Rab3a in total brain homogenates from treated rats after E2 administration. In striking contrast, the levels of all of these exocytotic proteins, including cellubrevin, were notably decreased in pituitary glands of E2-treated rats. In addition, no differences were observed in the in vitro basal and 8-Br-cAMP-induced prolactin (PRL) release between pituitary cells from control and E2-treated rats, whereas TRH-induced PRL release in anterior pituitary cells from E2-treated animals was higher than in control donors. In conclusion, this study shows that protein components of the exocytotic machinery are specifically down-regulated in the pituitary gland of E2-treated Fischer 344 rats.

The Bone Marrow "Mystery Population" of Stem Cells 20 Years Later - a Puzzle Solved?

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2392-2392
Author(s):  
Malwina Suszynska ◽  
Daniel Pedziwiatr ◽  
Magdalena J Kucia ◽  
Mariusz Z Ratajczak ◽  
Janina Ratajczak
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Receptor Expression ◽  
Stem Cell Population ◽  
Hematopoietic Stem ◽  
Murine Bone Marrow ◽  
Low Levels

Abstract Background . Almost 20 years ago, a "mystery" population of small stem cells with many of the phenotypic characteristics attributed to resting hematopoietic stem cells was identified in murine bone marrow (BM) (Stem Cells 1998, 16, 38-48). These cells expressed high levels of Sca-1, H-2K, and CD38 and low levels of Thy-1.1; they expressed CD45 antigen but were lineage-negative (lin-) for other hematopoietic markers. These cells incorporated only low levels of Rh123 and were resistant to the cytotoxic effects of 5-fluorouracil. The only phenotypic characteristic that distinguishes these cells from Sca-1+, Lin-, CD45+ Thy-1.1low long-term-reconstituting hematopoietic stem cell population is the lack of c-kit expression. In sum, this "mystery" population of small Sca-1+, lin-, c-kit- but CD45+ stem cells do not respond to hematopoietic growth factors in vitro, form in vivo spleen colonies, or reconstitute lethally irradiated mice. With our discovery of Sca-1+ Lin- CD45- very small embryonic-like stem cells (VSELs) in murine bone marrow (BM) (Leukemia 2006, 20, 857-869), we became interested in this "mystery" population of stem cells. VSELs, like the "mystery" population, are c-kit - and, if freshly isolated from BM, do not show any hematopoietic activity in standard in vitro and in vivo assays. In order to become specified to hematopoiesis, they need to be expanded over an OP-9 stromal support (Exp Hematol 2011;39:225-237). Hypothesis. Since (1) very small CD45- VSELs can be specified in OP-9 co-cultures into long-term reconstituting CD45+ HSCs, (2) the size of the "mystery" population is intermediate between VSELs and HSCs, and (3) VSELs and HSCs differ in cell surface receptor expression, we hypothesized that the "mystery" population is a missing developmental intermediate between VSELs and HSCs. Materials and Methods . Multicolor FACS analysis was employed to compare size and expression of surface markers between murine BM HSCs, the unknown population of stem cells, and VSELs. Next, the populations of small Sca-1+ H2-K+ lin- c-kit+ CD38+/- CD45+ cells (HSCs), smaller Sca-1+ H-2K+ lin- c-kit- CD38+ CD45+ cells (the "mystery" population), and very small in size Sca-1+ H-2K+ lin- c-kit- CD38+/- CD45- cells (VSELs) were purified by FACS from BM (Figure 1) and tested for in vitro colony formation. All these cell populations were primed/expanded over OP-9 support and subsequently evaluated for their hematopoietic potential after passaging in consecutive methylocellulose cultures (passages 1-4). RQ-PCR analysis was employed for detection of pluripotency marker expression as well as hematopoietic gene expression. Results . We found that, in contrast to HSCs, neither freshly sorted stem cells from the "mystery" BM population nor, as expected, VSELs grew hematopoietic colonies in standard methylcellulose cultures. This was also an important step in excluding contamination of our sorted populations with clonogenic cells. We also found that, while VSELs highly expressed Oct-4, this transcription factor was expressed at very low levels in the "mystery" population and was not detectable in HSCs. The most important observation was that the "mystery" population of stem cells became specified in OP-9-supported cultures into clonogenic HSPCs, and this specification occurred faster than the delayed specification of VSELs. VSELs first became enriched for HSPCs after acquiring CD45 antigen expression. Conclusions . Based on the results presented, we propose that the "mystery" population in murine BM is a population of stem cells intermediate between the most primitive population of BM-residing stem cells (VSELs) and the population of stem cells already specified to lympho-hematopoietic development (HSCs). Disclosures No relevant conflicts of interest to declare.

scholarly journals Epigenetic Suppression of Interferon Lambda Receptor Expression Leads to Enhanced Human Norovirus Replication In Vitro

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Sabastine E. Arthur ◽  
Frédéric Sorgeloos ◽  
Myra Hosmillo ◽  
Ian G. Goodfellow
Keyword(s):  
Dna Methyltransferase ◽  
Ectopic Expression ◽  
Epigenetic Reprogramming ◽  
Receptor Expression ◽  
Human Norovirus ◽  
Type Iii ◽  
Interferon Lambda ◽  
Type Iii Ifn

ABSTRACT Human norovirus (HuNoV) is the main cause of gastroenteritis worldwide, yet no therapeutics are currently available. Here, we utilize a human norovirus replicon in human gastric tumor (HGT) cells to identify host factors involved in promoting or inhibiting HuNoV replication. We observed that an interferon (IFN)-cured population of replicon-harboring HGT cells (HGT-Cured) was enhanced in their ability to replicate transfected HuNoV RNA compared to parental HGT cells, suggesting that differential gene expression in HGT-Cured cells created an environment favoring norovirus replication. Microarrays were used to identify genes differentially regulated in HGT-NV and HGT-Cured compared to parental cells. We found that IFN lambda receptor (IFNLR1) expression was highly reduced in HGT-NV and HGT-Cured cells. While all three cell lines responded to exogenous IFN-β by inducing interferon-stimulated genes, HGT-NV and HGT-Cured cells failed to respond to exogenous IFN-λ. Methylation-sensitive PCR showed that an increased methylation of the IFNLR1 promoter and inhibition of DNA methyltransferase activity partially reactivated IFNLR1 expression in HGT-NV and HGT-Cured cells, indicating that host adaptation occurred via epigenetic reprogramming. Moreover, IFNLR1 ectopic expression rescued response to IFN-λ and restricted HuNoV replication in HGT-NV cells. We conclude that type III IFN is important in inhibiting HuNoV replication in vitro and that the loss of IFNLR1 enhances replication of HuNoV. This study unravels for the first time epigenetic reprogramming of the interferon lambda receptor as a new mechanism of cellular adaptation during long-term RNA virus replication and shows that an endogenous level of interferon lambda signaling is able to control human norovirus replication. IMPORTANCE Noroviruses are one of the most widespread causes of gastroenteritis, yet no suitable therapeutics are available for their control. Moreover, to date, knowledge of the precise cellular processes that control the replication of the human norovirus remains ill defined. Recent work has highlighted the importance of type III interferon (IFN) responses in the restriction of viruses that infect the intestine. Here, we analyzed the adaptive changes required to support long-term replication of noroviruses in cell culture and found that the receptor for type III IFN is decreased in its expression. We confirmed that this decreased expression was driven by epigenetic modifications and that cells lacking the type III IFN receptor are more permissive for norovirus replication. This work provides new insights into key host-virus interactions required for the control of noroviruses and opens potential novel avenues for their therapeutic control.

scholarly journals GHRH excess and blockade in X-LAG syndrome

2015 ◽  
Vol 23 (3) ◽  
pp. 161-170 ◽  
Author(s):  
Adrian F Daly ◽  
Philippe A Lysy ◽  
Céline Desfilles ◽  
Liliya Rostomyan ◽  
Amira Mohamed ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Young Female ◽  
Prolactin Secretion ◽  
Pituitary Cells ◽  
Therapeutic Blockade ◽  
Ghrelin Receptor ◽  
Gh Secretion ◽  
Ghrh Receptor ◽  
Ghrelin Receptor Agonist

X-linked acrogigantism (X-LAG) syndrome is a newly described form of inheritable pituitary gigantism that begins in early childhood and is usually associated with markedly elevated GH and prolactin secretion by mixed pituitary adenomas/hyperplasia. Microduplications on chromosome Xq26.3 including the GPR101 gene cause X-LAG syndrome. In individual cases random GHRH levels have been elevated. We performed a series of hormonal profiles in a young female sporadic X-LAG syndrome patient and subsequently undertook in vitro studies of primary pituitary tumor culture following neurosurgical resection. The patient demonstrated consistently elevated circulating GHRH levels throughout preoperative testing, which was accompanied by marked GH and prolactin hypersecretion; GH demonstrated a paradoxical increase following TRH administration. In vitro, the pituitary cells showed baseline GH and prolactin release that was further stimulated by GHRH administration. Co-incubation with GHRH and the GHRH receptor antagonist, acetyl-(d-Arg2)-GHRH (1-29) amide, blocked the GHRH-induced GH stimulation; the GHRH receptor antagonist alone significantly reduced GH release. Pasireotide, but not octreotide, inhibited GH secretion. A ghrelin receptor agonist and an inverse agonist led to modest, statistically significant increases and decreases in GH secretion, respectively. GHRH hypersecretion can accompany the pituitary abnormalities seen in X-LAG syndrome. These data suggest that the pathology of X-LAG syndrome may include hypothalamic dysregulation of GHRH secretion, which is in keeping with localization of GPR101 in the hypothalamus. Therapeutic blockade of GHRH secretion could represent a way to target the marked hormonal hypersecretion and overgrowth that characterizes X-LAG syndrome.

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