scholarly journals Distinct functional properties of native somatostatin receptor subtype 5 compared with subtype 2 in the regulation of ACTH release by corticotroph tumor cells

2005 ◽  
Vol 289 (2) ◽  
pp. E278-E287 ◽  
Author(s):  
Joost van der Hoek ◽  
Marlijn Waaijers ◽  
Peter M. van Koetsveld ◽  
Diana Sprij-Mooij ◽  
Richard A. Feelders ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Binding Affinity ◽  
Binding Capacity ◽  
Somatostatin Receptor ◽  
Inhibitory Effect ◽  
Pcr Analysis ◽  
Receptor Subtype ◽  
Mrna Levels ◽  
Acth Release

In a series of human corticotroph adenomas, we recently found predominant mRNA expression of somatostatin (SS) receptor subtype 5 (sst5). After 72 h, the multiligand SS analog SOM230, which has a very high sst5 binding affinity, but not Octreotide (OCT), significantly inhibited basal ACTH release. To further explore the role of sst5 in the regulation of ACTH release, we conducted additional studies with mouse AtT-20 cells. SOM230 showed a 7-fold higher ligand binding affinity and a 19-fold higher potency in stimulating guanosine 5′- O-(3-thiotriphosphate) binding in AtT-20 cell membranes compared with OCT. SOM230 potently suppressed CRH-induced ACTH release, which was not affected by 48-h dexamethasone (DEX) pretreatment. However, DEX attenuated the inhibitory effects of OCT on ACTH release, whereas it increased the inhibitory potency of BIM-23268, an sst5-specific analog, on ACTH release. Quantitative PCR analysis showed that DEX lowered sst2A+2B mRNA expression significantly after 24 and 48 h, whereas sst5 mRNA levels were not significantly affected by DEX treatment. Moreover, Scatchard analyses showed that DEX suppressed maximum binding capacity (Bmax) by 72% when 125I-Tyr3-labeled OCT was used as radioligand, whereas Bmax declined only by 17% when AtT-20 cells were treated with [125I-Tyr11]SS-14. These data suggest that the sst5 protein, compared with sst2, is more resistant to glucocorticoids. Finally, after SS analog preincubation, compared with OCT both SOM230 and BIM-23268 showed a significantly higher inhibitory effect on CRH-induced ACTH release. In conclusion, our data support the concept that the sst5 receptor might be a target for new therapeutic agents to treat Cushing’s disease.

scholarly journals Negative Regulation of Pancreatic and Duodenal Homeobox-1 by Somatostatin Receptor Subtype 5

2012 ◽  
Vol 26 (7) ◽  
pp. 1225-1234 ◽  
Author(s):  
Guisheng Zhou ◽  
Shi-He Liu ◽  
Kelly M. Shahi ◽  
Hua Wang ◽  
Xueyan Duan ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mrna Expression ◽  
Somatostatin Receptor ◽  
Negative Regulator ◽  
Nuclear Antigen ◽  
Pcr Analysis ◽  
Receptor Subtype ◽  
Human Embryonic Kidney ◽  
Insulin Expression ◽  
293 Cells

Abstract Somatostatin receptor subtype 5 (SSTR5) mediates the inhibitory effect of somatostatin and its analogs on insulin expression/secretion and islet cell proliferation. We provide biochemical and genetic evidence that SSTR5 exerted its physiological actions via down-regulating pancreatic and duodenal homeobox-1 (PDX-1), a β-cell-specific homeodomain-containing transcription factor. Cotransfection of SSTR5 with PDX-1 resulted in dose-dependent inhibition of PDX-1 expression in human embryonic kidney 293 cells. SSTR5 agonist RPL-1980 inhibited PDX-1 expression and abolished glucagon-like peptide 1-stimulated PDX-1 expression in mouse insulinoma β-TC-6 cells. SSTR5 knockdown by short hairpin RNA led to increased PDX-1 expression that was accompanied by enhanced insulin secretion stimulated by high glucose in β-TC6 cells and alternated expressions of cell cycle proteins that favor cell proliferation in mouse insulinoma MIN6 cells. Quantitative RT-PCR analysis showed that cotransfected SSTR5 inhibited PDX-1 mRNA expression, whereas knockdown of SSTR5 increased PDX-1 mRNA expression. In addition, we found that cotransfected wild-type SSTR5 increased PDX-1 ubiquitination in human embryonic kidney 293 cells, whereas SSTR5 P335L, a hypofunctional single nucleotide polymorphism of SSTR5, inhibited PDX-1 ubiquitination. SSTR5 knockout resulted in increased expression of PDX-1, insulin, and proliferating cell nuclear antigen in the islets of sstr−/− mice. Immunohistochemistry analysis showed that SSTR5 P335L was associated with elevated expression of PDX-1 in human pancreatic neuroendocrine tumor. Taken together, our studies demonstrated that SSTR5 is a negative regulator for PDX-1 expression and that SSTR5 may mediate the inhibitory effects of somatostatin and its analogs on insulin expression/secretion and cell proliferation via down-regulating PDX-1 at both transcriptional and posttranslational levels.

scholarly journals Antiinflammatory Steroid Action in Human Ovarian Surface Epithelial Cells

2004 ◽  
Vol 89 (9) ◽  
pp. 4538-4544 ◽  
Author(s):  
Michael T. Rae ◽  
Deborah Niven ◽  
Hilary O. D. Critchley ◽  
Christopher R. Harlow ◽  
Stephen G. Hillier
Keyword(s):  
Glucocorticoid Receptor ◽  
Mrna Expression ◽  
Mrna Level ◽  
Inhibitory Effect ◽  
Surface Epithelium ◽  
Pcr Analysis ◽  
Mrna Levels ◽  
Cell Monolayers ◽  
Ovarian Surface ◽  
Cox 2

The human ovarian surface epithelium (OSE) is subject to serial injury and repair during ovulation, which is a natural inflammatory event. We asked whether there is a compensatory antiinflammatory component to this process, involving steroid hormones produced locally at the time of ovulation. Quantitative RT-PCR analysis of total RNA from cultured human OSE cell monolayers showed that exposure to proinflammatory IL1α (500 pg/ml) increased mRNA levels of cyclooxygenase-2 (COX-2) (P < 0.01) at 48 h. The COX-2 mRNA response to IL1α was associated with an approximate 18-fold (P < 0.01) increase in mRNA levels of 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), encoding the steroid dehydrogenase that reversibly reduces cortisone to antiinflammatory cortisol. Addition of cortisol to OSE cell culture medium dose-dependently suppressed the COX-2 mRNA response to IL1α (P < 0.01) but reciprocally enhanced the 11βHSD1 mRNA response (P < 0.05), with both effects strongest at 1 μm cortisol. Presence of glucocorticoid receptor-α mRNA and protein was established in OSE cell monolayers and treatment with IL1α shown to significantly up-regulate the glucocorticoid receptor-α mRNA level (P < 0.05). Glucocorticoid receptor antagonist (RU486, 10 μm) fully reversed the inhibitory effect of 1 μm cortisol on IL1α-stimulated COX-2 mRNA expression. Progesterone also suppressed IL1α-induced COX-2 mRNA expression but had no significant effect on IL1α-stimulated 11βHSD1 expression. These data provide direct evidence for antiinflammatory actions of cortisol and progesterone in human OSE cells.

DDR1 methylation is associated with bipolar disorder and the isoform expression and methylation of myelin genes

Epigenomics ◽  
2021 ◽  
Author(s):  
Beatriz Garcia-Ruiz ◽  
Manuel Castro de Moura ◽  
Gerard Muntané ◽  
Lourdes Martorell ◽  
Elena Bosch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Bipolar Disorder ◽  
Mrna Expression ◽  
Gene Expression Analysis ◽  
Mrna Levels ◽  
Healthy Controls ◽  
Genome Wide ◽  
Isoform Expression

Aim: To investigate DDR1 methylation in the brains of bipolar disorder (BD) patients and its association with DDR1 mRNA levels and comethylation with myelin genes. Materials & methods: Genome-wide profiling of DNA methylation (Infinium MethylationEPIC BeadChip) corrected for glial composition and DDR1 gene expression analysis in the occipital cortices of individuals with BD (n = 15) and healthy controls (n = 15) were conducted. Results: DDR1 5-methylcytosine levels were increased and directly associated with DDR1b mRNA expression in the brains of BD patients. We also observed that DDR1 was comethylated with a group of myelin genes. Conclusion: DDR1 is hypermethylated in BD brain tissue and is associated with isoform expression. Additionally, DDR1 comethylation with myelin genes supports the role of this receptor in myelination.

Microinjection of exogenous somatostatin in the dorsal vagal complex inhibits pancreatic secretion via somatostatin receptor-2 in rats

2007 ◽  
Vol 292 (3) ◽  
pp. G746-G752 ◽  
Author(s):  
Zhuan Liao ◽  
Zhao-Shen Li ◽  
Yan Lu ◽  
Wei-Zhong Wang
Keyword(s):  
Pancreatic Secretion ◽  
Exocrine Pancreas ◽  
Feedback Inhibition ◽  
Somatostatin Receptor ◽  
Inhibitory Effect ◽  
Receptor Subtype ◽  
Dependent Manner ◽  
Dorsal Vagal Complex ◽  
Somatostatin Receptor Antagonist ◽  
Dose Dependent

Previous studies have suggested that somatostatin inhibits pancreatic secretion at a central vagal site, and the dorsal vagal complex (DVC) is involved in central feedback inhibition of the exocrine pancreas. The aim of this study was to investigate the effect of exogenous somatostatin in the DVC on pancreatic secretion and the somatostatin receptor subtype(s) responsible for the effect. The effects of somatostatin microinjected into the DVC on pancreatic secretion stimulated by cholecystokinin octapeptide (CCK-8) or 2-deoxy-d-glucose (2-DG) were examined in anesthetized rats. To investigate the somatostatin inhibitory action site, a somatostatin receptor antagonist [SRA; cyclo(7-aminoheptanoyl-Phe-d-Trp-Lys-Thr)] was microinjected into the DVC before intravenous infusion of somatostatin and CCK-8/2-DG. The effects of injection of a somatostatin receptor-2 agonist (seglitide) and combined injection of somatostatin and a somatostatin receptor-2 antagonist (CYN 154806) in the DVC on the pancreatic secretion were also investigated. Somatostatin injected into the DVC significantly inhibited pancreatic secretion evoked by CCK-8 or 2-DG in a dose-dependent manner. SRA injected into the DVC completely reversed the inhibitory effect of intravenous administration of somatostatin. Seglitide injected into the DVC also inhibited CCK-8/2-DG-induced pancreatic protein secretion. However, combined injection of somatostatin and CYN 154806 did not affect the CCK-8/2-DG-induced pancreatic secretion. Somatostatin in the DVC inhibits pancreatic secretion via somatostatin receptor-2, and the DVC is the action site of somatostatin for its inhibitory effect.

Effect of gsp oncogene on somatostatin receptor subtype 1 and 2 mRNA levels in GHRH-responsive GH3 cells

Pituitary ◽  
2005 ◽  
Vol 8 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Eunhee Kim ◽  
Sookjin Sohn ◽  
Mina Lee ◽  
Cheolyoung Park ◽  
Jeechang Jung ◽  
...  
Keyword(s):  
Somatostatin Receptor ◽  
Gh3 Cells ◽  
Receptor Subtype ◽  
Mrna Levels ◽  
Gsp Oncogene

scholarly journals Analysis of somatostatin receptor subtype mRNA expression in human breast cancer

1997 ◽  
Vol 75 (6) ◽  
pp. 798-803 ◽  
Author(s):  
AA Evans ◽  
T Crook ◽  
SAM Laws ◽  
AC Gough ◽  
GT Royle ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mrna Expression ◽  
Human Breast Cancer ◽  
Somatostatin Receptor ◽  
Receptor Subtype ◽  
Human Breast

XIAP mRNA levels but not XAF1 or XIAP/XAF1 mRNA levels predict pathological response in bladder cancer patients treated with neoadjuvant chemotherapy

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20030-20030
Author(s):  
M. B. Pinho ◽  
J. Sellos ◽  
F. Costas ◽  
D. Herchenhorn ◽  
F. A. Peixoto ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Mrna Expression ◽  
Cancer Patients ◽  
Pathological Response ◽  
Negative Regulator ◽  
Inhibitor Of Apoptosis ◽  
Mrna Levels ◽  
Bivariate Correlation ◽  
Xiap Expression

20030 Background: The relation between apoptosis-related molecules and chemosensitivity has been extensively studied. In recent years, attention has shifted to a new family of inhibitor of apoptosis proteins (IAPs). XIAP (X- linked inhibitor of apoptosis) is the most versatile and potent member of the IAP family. To date, the overexpression of XIAP has been detected in various cancers. XAF1 (X-linked inhibitor of apoptosis associated factor 1) is a new protein identified for its ability to interact with XIAP. Neither XIAP nor XAF1 or XIAP/XAF1 mRNA expression have been studied in bladder cancer patients. Methods: The expression of XIAP and XAF1 mRNA was analyzed by a real time quantitative fluorogenic PCR method in a group of 17 patients with locally advanced bladder cancer treated with a combination of neoadjuvant Gemcitabine and Cisplatin. The prognostic significance of XIAP and XAF1 mRNA expression and the correlation with several clinicopathological variables was evaluated. Results: XIAP and XAF1 mRNA expression was detected in all 17 (100%) case samples. The levels of XIAP mRNA expression showed a moderate variation among samples. In contrast, XAF1 and XIAP/XAF1 mRNA levels showed significant variation among samples. Bivariate correlation analyses revealed a significant positive Spearman direct correlation coefficient between the XIAP expression and the pathological response. No significant correlation was found for XAF1 expression as well as for the XIAP/XAF1 ratio and clinical and pathological response. Conclusions: This is first study to address the role of XIAP, its negative regulator XAF1, and the XIAP/XAF1 ratio in bladder cancer patients. The positive correlation between the XIAP mRNA expression and the pathological response is in line with a previous study from our group in which a correlation was found between XIAP expression and survival. All these observations point to a complex role of XIAP in tumor biology. XAF1 mRNA expression in bladder carcinomas did not achieve significance as an independent predictive and prognostic factor in a bivariate analysis. Further studies are necessary in order to better assess a possible clinical value for XIAP and XAF1 as predictive and prognostic markers in cancer patients. No significant financial relationships to disclose.

scholarly journals mRNA expression profiles for corticotrophin-releasing hormone, urocortin, CRH-binding protein and CRH receptors in human term gestational tissues determined by real-time quantitative RT-PCR

2004 ◽  
Vol 32 (2) ◽  
pp. 339-348 ◽  
Author(s):  
B Sehringer ◽  
HP Zahradnik ◽  
M Simon ◽  
R Ziegler ◽  
C Noethling ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Real Time ◽  
Binding Protein ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Releasing Hormone ◽  
Gestational Tissues ◽  
Crh Receptors

Increasing maternal plasma levels of corticotrophin-releasing hormone (CRH) during the last weeks of pregnancy suggest that this stress hormone plays an important role in the control of human parturition. Little is known about the quantitative contribution of gestational tissues (other than placenta) to intrauterine formation of CRH, urocortin and CRH-binding protein (CRH-BP), or about the distribution of CRH receptors within the uterus. We have investigated the mRNA expression of CRH, urocortin, CRH-BP and CRH receptors 1 and 2 (CRH-R1 and -R2) in gestational tissues by real-time RT-PCR. Placenta, myometrium and choriodecidua were collected after uncomplicated pregnancies at term, before the onset of labour. Distribution of CRH-R1 and CRH-R2 protein was also investigated by immunostaining with receptor subtype-specific antibodies. The placenta was identified as the main site of CRH and CRH-BP mRNA expression, displaying mRNA levels >1000 and >20 times higher than those found in the myometrium and choriodecidua respectively (P<0.05 in each case). mRNA expression of urocortin was low in all tissues investigated. Myometrium and choriodecidua expressed relevant amounts of both receptor subtypes, whereas the CRH receptor population in placenta consisted mainly of CRH-R2. The high expression of CRH in placenta and the substantial expression of CRH receptors in choriodecidua and myometrium suggested that CRH derived from placenta exerts direct or indirect actions on these tissues. Neither CRH produced by myometrium or choriodecidua nor urocortin from other intrauterine sources seem to play a major role in the control of labour.

scholarly journals Interleukin 2 induction of pore-forming protein gene expression in human peripheral blood CD8+ T cells.

1990 ◽  
Vol 171 (4) ◽  
pp. 1269-1281 ◽  
Author(s):  
M J Smyth ◽  
J R Ortaldo ◽  
Y Shinkai ◽  
H Yagita ◽  
M Nakata ◽  
...  
Keyword(s):  
T Cells ◽  
Mrna Expression ◽  
Cd8 T Cells ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cytotoxic Lymphocytes ◽  
Mrna Levels ◽  
Cytotoxic Potential

Our studies have analyzed pore-forming protein (PFP) mRNA expression in resting and stimulated human peripheral blood CD3- large granular lymphocytes (LGL), CD3+ T cells, and their CD4+ or CD8+ subsets. Signals that stimulate T cells to develop cytotoxic activity (i.e., IL-2 or OKT-3 mAb) led to the induction of PFP mRNA in T cells. The data indicated that IL-2 directly increased PFP mRNA in the CD8+ subset of T cells, in the absence of new DNA or protein synthesis. Abrogation of IL-2-induced PFP mRNA expression and cytotoxic potential of T cells by the anti-p75 IL-2 receptor mAb suggested that low numbers of p75 IL-2 receptors on CD8+ T cells were capable of transducing signals responsible for these IL-2-induced effects. The induction of T cell PFP mRNA via CD3, using OKT-3 mAb, was less rapid but greater than that caused by IL-2; however, a combination of PMA and ionomycin, which bypasses crosslinking of the TCR/CD3 complex, could not mimic this increase in PFP mRNA levels in T cells. The role of second messenger systems in regulating PFP mRNA expression remains to be determined. In contrast, high constitutive PFP mRNA expression was observed in CD3- LGL and these mRNA levels could not be enhanced by stimulation with IL-2. The cytotoxic potential of peripheral blood T cells and LGL induced in response to IL-2 correlated with IL-2-induced PFP mRNA levels in these cells and was consistent with PFP being one of several important molecules involved in the effector function of cytotoxic lymphocytes.

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