scholarly journals Heads or tails? Stressor-specific expression of corticotropin-releasing factor and urotensin I in the preoptic area and caudal neurosecretory system of rainbow trout

2007 ◽  
Vol 196 (3) ◽  
pp. 637-648 ◽  
Author(s):  
Nicholas J Bernier ◽  
Sarah L Alderman ◽  
Erin N Bristow
Keyword(s):  
Rainbow Trout ◽  
Stress Response ◽  
Preoptic Area ◽  
Corticotropin Releasing Factor ◽  
Neurosecretory System ◽  
Mrna Levels ◽  
Specific Expression ◽  
Caudal Neurosecretory System ◽  
Social Challenges ◽  
Positive Correlations

Corticotropin-releasing factor (CRF)- and urotensin I (UI)-expressing cells of the preoptic area (POA) and caudal neurosecretory system (CNSS) are considered key contributors to the regulation of the stress response in fish; however, the expression pattern of these neurons to environmental and social challenges have not been compared in a single study. Therefore, we characterized in rainbow trout (Oncorhynchus mykiss) the central distribution of CRF and UI expression and quantified the POA and CNSS mRNA levels of both transcripts in response to hyperammonemia, hypoxia, isolation, or subordination. The tissue distribution demonstrated that the POA and the CNSS are dominant sites of CRF and UI expression. Comparison of the plasma cortisol levels in response to the diverse treatments showed that subordination was the most severe stressor followed by hyperammonemia, isolation, and hypoxia. In the POA, with the exception of subordination that had no effect on UI expression, all stressors resulted in increase in CRF and UI mRNA levels. In the CNSS, while hyperammonemia was associated with increase in CRF and UI mRNA levels, and hypoxia induced an increase in CRF expression, isolation caused a decrease in the expression of both transcripts, and subordination had no effect. Independent of the stressor, we found strong positive correlations between CRF and UI expression in the POA and the CNSS, and no correlation in the expression of either gene between regions. Overall, the results demonstrate that the contribution of POA and CNSS CRF and UI neurons to the stress response in rainbow trout is stressor-, time-, and region-specific.

scholarly journals Differential Increase in Forebrain and Caudal Neurosecretory System Corticotropin-Releasing Factor and Urotensin I Gene Expression Associated with Seawater Transfer in Rainbow Trout

Endocrinology ◽  
2005 ◽  
Vol 146 (9) ◽  
pp. 3851-3860 ◽  
Author(s):  
Paul M. Craig ◽  
Haider Al-Timimi ◽  
Nicholas J. Bernier
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Preoptic Area ◽  
Plasma Osmolality ◽  
Corticotropin Releasing Factor ◽  
Neurosecretory System ◽  
Mrna Levels ◽  
Caudal Neurosecretory System ◽  
Differential Increase ◽  
Crf System

Abstract Transfer to seawater (SW) in rainbow trout elicits an increase in plasma cortisol and a bout of anorexia. Although the corticotropin-releasing factor (CRF) system has known hypophysiotropic and anorexigenic properties, it is not known whether CRF-related peptides originating from either the forebrain or the caudal neurosecretory system (CNSS) play a role during SW acclimation. Therefore, we examined the effects of SW transfer on food intake, plasma osmolality, hypothalamic-pituitary-interrenal axis activity, and the expression of CRF and urotensin I (UI) in the forebrain and the CNSS. While SW transfer chronically suppressed food intake over a 2-wk period, it transiently increased plasma osmolality, ACTH, and cortisol. Similarly, 24 h after SW transfer, hypothalamic and preoptic area CRF mRNA levels were significantly increased but recovered to pretransfer levels within 7 d. Conversely, SW transfer elicited a delayed increase in hypothalamic UI mRNA levels and had no effect on preoptic area UI expression. In the CNSS, SW exposure was associated with parallel increases in CRF and UI mRNA levels from 24 h post transfer through 7 d. Finally, in situ hybridization demonstrated an extensive and overlapping pattern of CNSS CRF and UI expression. These results differentially implicate specific neuronal populations of the CRF system in the acute and chronic responses to a hyperosmotic stress and suggest that forebrain and CNSS CRF-related peptides have different roles in the coordinated response to fluid balance disturbances.

CRF-related peptides contribute to stress response and regulation of appetite in hypoxic rainbow trout

2005 ◽  
Vol 289 (4) ◽  
pp. R982-R990 ◽  
Author(s):  
Nicholas J. Bernier ◽  
Paul M. Craig
Keyword(s):  
Rainbow Trout ◽  
Food Intake ◽  
Plasma Cortisol ◽  
Preoptic Area ◽  
Physiological Role ◽  
Corticotropin Releasing Factor ◽  
Stress Axis ◽  
Mrna Levels ◽  
Hypoxic Conditions ◽  
Hpi Axis

Hypoxia stress suppresses appetite in a variety of fish species, but the mechanisms mediating this response are not known. Therefore, given their anorexigenic and hypophysiotropic properties, we investigated the contribution of forebrain corticotropin-releasing factor (CRF) and urotensin I (UI) to the regulation of food intake and the hypothalamic-pituitary-interrenal (HPI) stress axis in hypoxic rainbow trout. Exposure to 50 and 35% O2 saturation for 24 h decreased food intake by 28 and 48%, respectively. The 35% O2 treatment also increased forebrain CRF and UI mRNA levels, plasma cortisol, and lactate. Exposure for 72 h to the same conditions resulted in similar reductions in food intake, increases in plasma cortisol proportional to the hypoxia severity, and increases in forebrain CRF and UI mRNA levels in the 50% O2 treatment. Relative to saline-infused fish, chronic intracranial infusion of the CRF receptor antagonist α-helical CRF(9–41) reduced the appetite-suppressing effects of 24-h exposure to 35% O2 and blocked the hypoxia-induced increase in plasma cortisol. Finally, forebrain microdissection revealed that 50 and 35% O2 exposure for 24 h specifically increases preoptic area CRF and UI mRNA levels in proportion to the severity of the hypoxic challenge and either has no effect or elicits small decreases in other forebrain regions. These results show that CRF-related peptides play a physiological role in regulating the HPI axis and in mediating at least a portion of the reduction in food intake under hypoxic conditions in rainbow trout and demonstrate that the response of forebrain CRF and UI neurons to this stressor is region specific.

scholarly journals Stress elevates corticotropin-releasing factor (CRF) and CRF-binding protein mRNA levels in rainbow trout (Oncorhynchus mykiss)

2005 ◽  
Vol 186 (1) ◽  
pp. 123-130 ◽  
Author(s):  
C Doyon ◽  
V L Trudeau ◽  
T W Moon
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Plasma Cortisol ◽  
Preoptic Area ◽  
Binding Protein ◽  
Corticotropin Releasing Factor ◽  
Stress Axis ◽  
Control Group ◽  
Mrna Levels ◽  
Cortisol Levels

The objectives of this study were to characterize rainbow trout (Oncorhynchus mykiss) corticotropin-releasing factor (CRF)-binding protein (CRF-BP) cDNA and to examine the variations in CRF-BP and CRF mRNA levels in response to different intensities of stress. Trout were physically disturbed by a single or three consecutive periods of chasing until exhaustion followed by 2 h of recovery. The pituitary CRF-BP and preoptic area CRF1 mRNA contents were significantly increased only after repeated chasing events. Physical disturbance increased plasma cortisol levels with the largest change occurring in the group of trout that were exposed to repeated chasing events. Trout were also individually isolated in 120 l tanks or confined to 1.5 l boxes for 4, 24 or 72 h. CRF-BP mRNA levels in confined fish were greater than those of isolated fish at 72 h although there were no differences compared with the control group. CRF1 mRNA levels in the preoptic area were greater and remained elevated for a longer period in confined compared with isolated trout. Isolation led to a transient increase in plasma cortisol levels, but the higher cortisol values developed in the confined fish suggest that this treatment was more stressful than isolation. These results demonstrate that the intensity and duration of stress are important factors regulating CRF and CRF-BP mRNA levels in rainbow trout. We hypothesize that pituitary CRF-BP is involved in regulating the activity of the stress axis, possibly by reducing access to CRF1 receptors in the corticotropes.

Corticotropin-releasing factor and neuropeptide Y mRNA levels are elevated in the preoptic area of socially subordinate rainbow trout

2003 ◽  
Vol 133 (2) ◽  
pp. 260-271 ◽  
Author(s):  
C Doyon ◽  
K.M Gilmour ◽  
V.L Trudeau ◽  
T.W Moon
Keyword(s):  
Rainbow Trout ◽  
Neuropeptide Y ◽  
Preoptic Area ◽  
Corticotropin Releasing Factor ◽  
Mrna Levels

Corticotropin-releasing factor and neuropeptide Y mRNA levels are modified by glucocorticoids in rainbow trout, Oncorhynchus mykiss

2006 ◽  
Vol 146 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Christian Doyon ◽  
Jason Leclair ◽  
Vance L. Trudeau ◽  
Thomas W. Moon
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Neuropeptide Y ◽  
Corticotropin Releasing Factor ◽  
Mrna Levels ◽  
Rainbow Trout Oncorhynchus Mykiss

scholarly journals Molecular cloning and expression analysis of rainbow trout (Oncorhynchus mykiss) CCAAT/enhancer binding protein genes and their responses to induction by GH in vitro and in vivo

2007 ◽  
Vol 194 (2) ◽  
pp. 393-406 ◽  
Author(s):  
Jay H Lo ◽  
Pinwen Peter Chiou ◽  
C M Lin ◽  
Thomas T Chen
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cloning And Expression ◽  
Mrna Levels ◽  
Specific Expression ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Enhancer Binding Protein ◽  
Previous Hypothesis

CCAAT/enhancer-binding proteins (C/EBPs) are transcription factors consisting of six isoforms and play diverse physiological roles in vertebrates. In rainbow trout (Oncorhynchus mykiss), in addition to the reported C/EBPβ1, we have isolated cDNA of four other isoforms, C/EBPα, C/EBPβ2, C/EBPδ1, C/EBPδ2, from the liver. Comparison of the deduced amino acid sequence of rainbow trout C/EBPs with those of other vertebrates revealed that C/EBP isoforms are highly conserved. The profiles of tissue-specific expression of individual C/EBP isoform mRNA, determined by quantitative real-time (RT)-PCR showed distinct patterns. Furthermore, injection of bovine GH into yearling rainbow trout resulted in a significant increase of mRNA levels of C/EBPβ1, C/EBPβ2, and C/EBPδ2 but not C/EBPα and C/EBPδ1 in the liver. GH-dependent increase of mRNA levels of C/EBPβ1, C/EBPβ2, C/EBPδ2, and IGF-II were also confirmed by treating rainbow trout hepatoma cells expressing a goldfish GH receptor with bGH. Together with our previous findings, the results presented in this paper strengthen our previous hypothesis that GH may regulate the expression of the IGF-II gene via mediating the expression of C/EBPβ1, C/EBPβ2, and C/EBPδ2 mRNA.

scholarly journals Alternative Splice Variants of the Rainbow Trout Leptin Receptor Encode Multiple Circulating Leptin-Binding Proteins

Endocrinology ◽  
2013 ◽  
Vol 154 (7) ◽  
pp. 2331-2340 ◽  
Author(s):  
Ningping Gong ◽  
Ingibjörg E. Einarsdottir ◽  
Marcus Johansson ◽  
Björn Thrandur Björnsson
Keyword(s):  
Rainbow Trout ◽  
Binding Proteins ◽  
Leptin Receptor ◽  
Splice Variants ◽  
Size Exclusion ◽  
Mrna Levels ◽  
Specific Expression ◽  
Competitive Binding Assay ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Exclusion Chromatography

Abstract In mammals, leptin (Lep) binding proteins (LepBPs) derived from Lep receptor (LepR) gene or protein bind most of the circulating Lep, but to date, information on LepBPs in nonmammalian vertebrate classes is lacking. This study details the characterization of multiple LepBPs in rainbow trout (Oncorhynchus mykiss), an early poikilothermic vertebrate, and presents the complete coding sequences for 3 of them. Size-exclusion chromatography and cross-linking assay identified plasma proteins bound to Lep ranging from 70 to 100 kDa. LepBPs were isolated from plasma by affinity chromatography, and their binding specificity was assessed by a competitive binding assay. A RIA for LepBPs indicates that plasma LepBP levels decline after fasting for 3 weeks. Immunoblotting of LepBPs using antibodies against different LepR epitopes shows that the LepBPs are indeed LepR isoforms. The alternatively spliced LepR transcripts (LepRS1–3) that include only the extracellular segment transcribe the 90-kDa LepBP1, the 80-kDa LepBP2, and the 70-kDa LepBP3, respectively. LepRS1 generally has lower expression than the long-form LepR in most tissues. LepRS2 is primarily expressed in adipose tissue, whereas LepRS3 is expressed abundantly in brain and spleen, and moderately in liver and gills. The mRNA levels of hepatic LepRS3 increase after 2 weeks of fasting. This study demonstrates a mechanism in fish for the generation of LepBPs that differs from that seen in mammals and indicates that the physiologic action of Lep in these poikilothermic vertebrates can be modulated, both centrally and peripherally, by the differentiated, tissue-specific expression of multiple LepBPs.

scholarly journals Longitudinal Expression of Testicular TAS1R3 from Prepuberty to Sexual Maturity in Congjiang Xiang Pigs

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 437
Author(s):  
Ting Gong ◽  
Weiyong Wang ◽  
Houqiang Xu ◽  
Yi Yang ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Cell Function ◽  
Expression Patterns ◽  
Taste Receptor ◽  
Receptor Type ◽  
Mrna Levels ◽  
Early Puberty ◽  
Specific Expression

Testicular expression of taste receptor type 1 subunit 3 (T1R3), a sweet/umami taste receptor, has been implicated in spermatogenesis and steroidogenesis in mice. We explored the role of testicular T1R3 in porcine postnatal development using the Congjiang Xiang pig, a rare Chinese miniature pig breed. Based on testicular weights, morphology, and testosterone levels, four key developmental stages were identified in the pig at postnatal days 15–180 (prepuberty: 30 day; early puberty: 60 day; late puberty: 90 day; sexual maturity: 120 day). During development, testicular T1R3 exhibited stage-dependent and cell-specific expression patterns. In particular, T1R3 levels increased significantly from prepuberty to puberty (p < 0.05), and expression remained high until sexual maturity (p < 0.05), similar to results for phospholipase Cβ2 (PLCβ2). The strong expressions of T1R3/PLCβ2 were observed at the cytoplasm of elongating/elongated spermatids and Leydig cells. In the eight-stage cycle of the seminiferous epithelium in pigs, T1R3/PLCβ2 levels were higher in the spermatogenic epithelium at stages II–VI than at the other stages, and the strong expressions were detected in elongating/elongated spermatids and residual bodies. The message RNA (mRNA) levels of taste receptor type 1 subunit 1 (T1R1) in the testis showed a similar trend to levels of T1R3. These data indicate a possible role of T1R3 in the regulation of spermatid differentiation and Leydig cell function.

scholarly journals The co-chaperone Fkbp5 shapes the acute stress response in the paraventricular nucleus of the hypothalamus of male mice

2021 ◽  
Author(s):  
Alexander S. Häusl ◽  
Lea M. Brix ◽  
Jakob Hartmann ◽  
Max L. Pöhlmann ◽  
Juan-Pablo Lopez ◽  
...  
Keyword(s):  
Stress Response ◽  
Hpa Axis ◽  
Paraventricular Nucleus ◽  
Acute Stress ◽  
Negative Regulator ◽  
Neuron Activity ◽  
Cell Type ◽  
Specific Expression ◽  
Acute Stress Response ◽  
Cell Type Specific

AbstractDisturbed activation or regulation of the stress response through the hypothalamic-pituitary-adrenal (HPA) axis is a fundamental component of multiple stress-related diseases, including psychiatric, metabolic, and immune disorders. The FK506 binding protein 51 (FKBP5) is a negative regulator of the glucocorticoid receptor (GR), the main driver of HPA axis regulation, and FKBP5 polymorphisms have been repeatedly linked to stress-related disorders in humans. However, the specific role of Fkbp5 in the paraventricular nucleus of the hypothalamus (PVN) in shaping HPA axis (re)activity remains to be elucidated. We here demonstrate that the deletion of Fkbp5 in Sim1+ neurons dampens the acute stress response and increases GR sensitivity. In contrast, Fkbp5 overexpression in the PVN results in a chronic HPA axis over-activation, and a PVN-specific rescue of Fkbp5 expression in full Fkbp5 KO mice normalizes the HPA axis phenotype. Single-cell RNA sequencing revealed the cell-type-specific expression pattern of Fkbp5 in the PVN and showed that Fkbp5 expression is specifically upregulated in Crh+ neurons after stress. Finally, Crh-specific Fkbp5 overexpression alters Crh neuron activity, but only partially recapitulates the PVN-specific Fkbp5 overexpression phenotype. Together, the data establish the central and cell-type-specific importance of Fkbp5 in the PVN in shaping HPA axis regulation and the acute stress response.

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