Corticotropin-releasing Factor Expression Research Articles

Hyperactivity of Hypothalamic-Pituitary-Adrenal Axis Due to Dysfunction of the Hypothalamic Glucocorticoid Receptor in Sigma-1 Receptor Knockout Mice.

Sigma-1 receptor knockout (σ1R-KO) mice exhibit a depressive-like phenotype. Because σ1R is highly expressed in the neuronal cells of hypothalamic paraventricular nuclei (PVN), this study investigated the influence of σ1R deficiency on the regulation of the hypothalamic-pituitary-adrenocortical (HPA) axis. Here, we show that the levels of basal serum corticosterone (CORT), adrenocorticotropic hormone (ACTH) and corticotrophin releasing factor (CRF) as well as the level of CRF mRNA in PVN did not significantly differ between adult male σ1R-KO mice and wild-type (WT) mice. Acute mild restraint stress (AMRS) induced a higher and more sustainable increase in activity of HPA axis and CRF expression in σ1R-KO mice. Percentage of dexamethasone (Dex)-induced reduction in level of CORT was markedly attenuated in σ1R−/− mice. The levels of glucocorticoid receptor (GR) and protein kinase C (PKC) phosphorylation were reduced in the PVN of σ1R-KO mice and σ1R antagonist NE100-treated WT mice. The exposure to AMRS in σ1R-KO mice induced a stronger phosphorylation of cAMP-response element binding protein (CREB) in PVN than that in WT mice. Intracerebroventricular (i.c.v.) injection of PKC activator PMA for 3 days in σ1R-KO mice not only recovered the GR phosphorylation and the percentage of Dex-reduced CORT but also corrected the AMRS-induced hyperactivity of HPA axis and enhancement of CRF mRNA and CREB phosphorylation. Furthermore, the injection (i.c.v.) of PMA in σ1R-KO mice corrected the prolongation of immobility time in forced swim test (FST) and tail suspension test (TST). These results indicate that σ1R deficiency causes down-regulation of GR by reducing PKC phosphorylation, which attenuates GR-mediated feedback inhibition of HPA axis and facilitates the stress response of HPA axis leading to the production of depressive-like behaviors.

Contribution of amygdala CRF neurons to chronic pain

We investigated the role of amygdala corticotropin-releasing factor (CRF) neurons in the perturbations of descending pain inhibition caused by neuropathic pain. Forced swim increased the tail-flick response latency in uninjured mice, a phenomenon known as stress-induced analgesia (SIA) but did not change the tail-flick response latency in mice with neuropathic pain caused by sciatic nerve constriction. Neuropathic pain also increased the expression of CRF in the central amygdala (CeAmy) and ΔFosB in the dorsal horn of the spinal cord. Next, we injected the CeAmy of CRF-cre mice with cre activated AAV-DREADD (Designer Receptors Exclusively Activated by Designer Drugs) vectors. Activation of CRF neurons by DREADD/Gq did not affect the impaired SIA but inhibition of CRF neurons by DREADD/Gi restored SIA and decreased allodynia in mice with neuropathic pain. The possible downstream circuitry involved in the regulation of SIA was investigated by combined injections of retrograde cre-virus (CAV2-cre) into the locus ceruleus (LC) and cre activated AAV-diphtheria toxin (AAV-FLEX-DTX) virus into the CeAmy. The viral injections were followed by a sciatic nerve constriction ipsilateral or contralateral to the injections. Ablation of amygdala projections to the LC on the side of injury but not on the opposite side, completely restored SIA, decreased allodynia and decreased ΔFosB expression in the spinal cord in mice with neuropathic pain. The possible lateralization of SIA impairment to the side of injury was confirmed by an experiment in which unilateral inhibition of the LC decreased SIA even in uninjured mice.The current view in the field of pain research attributes the process of pain chronification to abnormal functioning of descending pain inhibition. Our results demonstrate that the continuous activity of CRF neurons brought about by persistent pain leads to impaired SIA, which is a symptom of dysregulation of descending pain inhibition. Therefore, an over-activation of amygdala CRF neurons is very likely an important contributing factor for pain chronification.

Chronic traumatic stress impairs memory in mice: Potential roles of acetylcholine, neuroinflammation and corticotropin releasing factor expression in the hippocampus

Chronic stress in humans can result in multiple adverse psychiatric and neurobiological outcomes, including memory deficits. These adverse outcomes can be more severe if each episode of stress is very traumatic. When compared to acute or short term stress relatively little is known about the effects of chronic traumatic stress on memory and molecular changes in hippocampus, a brain area involved in memory processing. Here we studied the effects of chronic traumatic stress in mice by exposing them to adult Long Evan rats for 28 consecutive days and subsequently analyzing behavioral outcomes and the changes in the hippocampus. Results show that stressed mice developed memory deficits when assayed with radial arm maze tasks. However, chronic traumatic stress did not induce anxiety, locomotor hyperactivity or anhedonia. In the hippocampus of stressed mice interleukin-1β protein expression was increased along with decreased corticotropin releasing hormone (CRH) gene expression. Furthermore, there was a reduction in acetylcholine levels in the hippocampus of stressed mice. There were no changes in brain derived neurotrophic factor (BDNF) or nerve growth factor (NGF) levels in the hippocampus of stressed mice. Gene expression of immediate early genes (Zif268, Arc, C-Fos) as well as glucocorticoid and mineralocorticoid receptors were also not affected by chronic stress. These data demonstrate that chronic traumatic stress followed by a recovery period might lead to development of resilience resulting in the development of selected, most vulnerable behavioral alterations and molecular changes in the hippocampus.

Asparagine preserves intestinal barrier function from LPS-induced injury and regulates CRF/CRFR signaling pathway.

Stress causes intestinal inflammation and barrier dysfunction. Corticotrophin-releasing factor (CRF)/CRF receptor (CRFR) signaling pathway has been shown to be important for stress-induced intestinal mucosal alteration. L-Asparagine (ASN) is a powerful stimulator of ornithine decarboxylase and cell proliferation in a variety of cell types, including colonic cells. In the present study, we investigated whether dietary ASN supplementation could alleviate the damage of intestinal barrier function caused by LPS through modulation of CRF/CRFR signaling pathway. Twenty-four weaned pigs were randomly divided into one of four treatments: (1) non-challenged control; (2) Escherichia coli LPS challenged control; (3) LPS + 0.5% ASN; (4) LPS + 1.0% ASN. LPS stress induced villous atrophy, intestinal morphology disruption and decreased claudin-1 expression. ASN supplementation increased intestinal claudin-1 protein expression and alleviated villous atrophy and intestinal morphology impairment caused by LPS stress. In addition, ASN supplementation increased the number of intestinal intraepithelial lymphocytes and reversed the elevations of intestinal mast cell number and neutrophil number induced by LPS stress. Moreover, ASN decreased the mRNA expression of intestinal CRF, glucocorticoid receptors and tryptase. These results indicate that ASN attenuates intestinal barrier dysfunction induced by LPS stress, and regulates CRF/CRFR1 signaling pathway and mast cell activation.

MP82-04 TRANSCRIPTIONAL REGULATION OF CORTICOTROPIN RELEASING FACTOR

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology II1 Apr 2017MP82-04 TRANSCRIPTIONAL REGULATION OF CORTICOTROPIN RELEASING FACTOR Lizath Aguiniga, Anthony Schaeffer, and David Klumpp Lizath AguinigaLizath Aguiniga More articles by this author , Anthony SchaefferAnthony Schaeffer More articles by this author , and David KlumppDavid Klumpp More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2551AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Interstitial cystitis (IC) patients suffer from chronic pelvic pain and bladder dysfunction. IC patients have altered cortisol levels suggesting dysregulation of the hypothalamic-pituitary adrenal (HPA) axis and suffer from exacerbated symptoms in response to high stress. Corticotropin-releasing factor (CRF) is the initiator of the HPA axis and mediates stress responses and voiding control, where increased CRF levels in Barrington's nucleus induce bladder dysfunction. Arachidonic acid (AA) metabolites have been shown to induce CRF expression, however the transcriptional mediators of this modulation are unknown. Here we identify transcription factors that mediate AA-induced CRF gene expression. METHODS We used MIRAGE software to identify candidate transcription factor binding sites in a 1kb region of the human CRF gene promoter. We identified a peroxisome proliferator activated hormone response element (PPRE) and two Xenobiotic Responsive Element (XRE) sites as candidate mediators of AA-dependent CRF induction. Site-directed mutations of the PPRE and XRE sites were generated in a CRF-luciferase reporter plasmid to evaluate responses to AA and the impact of AhR and PPAR gamma expressed in HEK 293T cells. The hypothalamic neuronal cell line N42 was used to evaluate the role of AhR and PPAR gamma in native promoter regulation by RT PCR. We also generated mice that have PPAR gamma and AhR knocked-out in CRF-expressing cells and characterized voiding activity. RESULTS AA induction in the PPRE mutant resulted in increased CRF promoter activity compared to WT, whereas XRE1 had decreased activity. The mutation of both XRE1 and XRE2 resulted in decreased responsiveness to AA. Over-expression of PPAR gamma alone showed no change, while over-expression of AhR alone showed a significant increase in AA-induced CRF expression; this was inhibited by over-expression of both AhR and PPAR gamma in HEK 293T cells. Over-expression of AhR in N42 cells resulted in increased CRF mRNA in response to AA induction. AhR conditional knockout mice showed increased voiding frequency. CONCLUSIONS These results suggest AhR binding to the XRE sites modulates AA-dependent CRF gene expression. PPAR gamma inhibits AA-dependent CRF gene expression. Continued studies will use mouse models to examine the in vivo role of AhR and PPAR gamma inhibitors to modulate voiding activity. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1098 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Lizath Aguiniga More articles by this author Anthony Schaeffer More articles by this author David Klumpp More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Electroacupuncture ameliorates abnormal defaecation and regulates corticotrophin-releasing factor in a rat model of stress.

ObjectiveTo examine the effect of electroacupuncture (EA) treatment on abnormal defaecation in a rat model of chronic heterotypic stress (CHS) and investigate the underlying mechanisms.Methods20 male Sprague-Dawley rats were randomly divided into three groups: normal (n=6), CHS (n=7), and CHS+EA (n=7). Rats in the CHS group and CHS+EA groups received four different types of stressors for 7 days. For rats in the CHS+EA group, EA was applied at ST36 in the bilateral hind legs for 30 min before each stress-loading session. Rats in the normal group did not receive stressors or EA treatment. The faecal pellets of each rat were collected and weighed at a fixed time every day. Protein expression of corticotrophin-releasing factor (CRF) in the hypothalamus and colorectal tissues was measured by Western blotting at the end of the experiment on the 7th day.ResultsAfter 7 consecutive days of CHS, the number of faecal pellets, faecal wet weight, and faecal water content were significantly increased in the CHS group compared with the normal group (p=0.035, p=0.008 and p=0.008, respectively). All three parameters were significantly decreased in CHS+EA versus CHS groups (p=0.030, p=0.011 and p=0.006, respectively). Stress significantly increased CRF expression in both the hypothalamus and colorectal tissues. The excessive CRF responses seen following CHS were significantly suppressed by EA treatment.ConclusionsEA treatment can ameliorate stress loading induced abnormal defaecation in rats and decrease protein expression of CRF centrally (hypothalamus) and peripherally (colorectal tissues), suggesting a potentially therapeutic role for EA in stress-related responses.

Effects of baldrinal of Valeriana jatamansi on expression of CRF, TPH1 mRNA and 5-HT in rats with irritable bowel syndrome

This study aimed to investigate the effects of baldrinal of Valeriana jatamansi on the expression of corticotropin releasing factor (CRF) and tryptophan hydroxylase 1 (TPH1) mRNA and levels of 5-hydroxytryptamine (5-HT) in colon of rats with irritable bowel syndrome (IBS), and to explain its therapeutic mechanism on IBS through 5-HT pathway. Fifty-four male SD rats were randomly divided into 6 groups: blank group, model group, baldrinal high, medium and low dose groups, and pinaverium bromide group, n=9 in each group. The IBS rat models were established by using unpredictable chronic stress for 3 weeks followed by 1-hour acute restraint stress (CAS) after 7 days of rest and independent feeding. CRF expression was detected by IHC-P; TPH1 mRNA expression was detected by using RT-PCR and the 5-HT level was measured by high performance liquid chromatography(HPLC). The results indicated that the method of chronic stress with acute restrain stress method and independent feeding could lead to the increase in expressions of CRF and TPH1 mRNA and levels of 5-HT in IBS rats(P<0.05). The expressions of CRF, TPH1 mRNA and 5-HT in baldrinal groups were significantly lower than those in model group(P<0.05). The experimental results showed that IBS could result in increase in the expressions of CRF, TPH1 mRNA and levels of 5-HT, and the baldrinal of V. jatamansi could improve the symptoms of IBS by reducing the expressions of CRF, TPH1 mRNA and levels of 5-HT in colon of rats.

Chinese herb cinobufagin-reduced cancer pain is associated with increased peripheral opioids by invaded CD3/4/8 lymphocytes.

ObjectivesTo investigate the mechanism of cinobufagin-reduced cancer pain in mouse cancer pain model and in vitro cell co-culture system.MethodsFemale Kunming mice were randomly divided into 4 groups. One group of animals was set as normal control without any treatment. Other three groups of animals received H22 hepatoma cell inoculation in right hind paw. At day 9 after inoculation, mice in other three groups were injected intraperitoneally once a day for 8 days with the solvent, morphine or cinobufagin, respectively. The pain behavior was recorded daily. On the last day, all mice were sacrificed and xenograft tissues homogenate and plasma levels of β-endorphin (β-END), corticotropin-releasing factor (CRF) and interleukin-1β (IL-1β) were assessed by ELISA assay. Immunohistochemistry was performed to determine the expression of β-END, pro-opiomelanocortin (POMC) and the μ-opioid receptor (μ-OR) in the xenograft tissues. Immunofluorescence was used to localize lymphocytes with expression of CD3+, CD4+ and CD8+ in xenograft tumors and adjacent tissues. Mice splenic lymphocytes and H22 hepatoma carcinoma ascites cells were prepared for co-culture. β-END and CRF were detected in co-culture supernatants. The MTT assay and cytometry were used to assess cell proliferation. RT-PCR was conducted to determine the gene expression of POMC and Cathepsin L (CTSL). Chemotaxis was examined using a transwell-based migration assay.ResultsCompared to the model group, the thermal and mechanical pain thresholds were increased in mice after cinobufagin treatment. The expression of β-END and CRF in the plasma and tumor tissues of cinobufagin group were much higher than that of the model group mice, but the expression of IL-1β in the plasma and tumor tissues was much lower than that in the model group mice. Meanwhile, the expression of β-END, POMC and μ-OR proteins was significantly increased in the xenograft tissues from cinobufagin group. Lymphocyte population of CD3+, CD4+, CD8+ were also elevated in xenograft tumors and adjacent tissues. In the cell co-culture assays, the content of β-END in the supernatant was significantly increased by cinobufagin in a dose-dependent manner. Cinobufagin also largely increased the proliferation of immune cells and inhibited H22 hepatoma carcinoma cell proliferation in single or co-culture cell assays. Gene expression of POMC and CTSL in cinobufagin group was significantly up-regulated comparing to the control group. Finally, cinobufagin addition enhanced the migration of immune cells in transwell assay.ConclusionsCinobufagin-induced local analgesic effect might be associated with increased activity of POMC/β-END/μ-OR pathway released from invaded CD3/4/8 lymphocytes in cancer tissues.

Amygdala-mediated mechanisms regulate visceral hypersensitivity in adult females following early life stress: importance of the glucocorticoid receptor and corticotropin-releasing factor.

Alterations in amygdala activity are apparent in women who report a history of early life stress (ELS) and those diagnosed with chronic pain disorders. Chronic stress in adulthood induces visceral hypersensitivity by alterations in glucocorticoid receptor (GR) and corticotropin-releasing factor (CRF) expression within the central amygdala (CeA). Here, we hypothesized that unpredictable ELS, previously shown to induce visceral hypersensitivity in adult female rats, alters GR and CRF expression in the CeA. After neonatal ELS, visceral sensitivity and GR and CRF gene expression were quantified in adult female rats. After unpredictable ELS, adult female rats exhibited visceral hypersensitivity and increased expression of GR and CRF in the CeA. After predictable ELS, adult female rats demonstrated normosensitive behavioral pain responses and upregulation of GR but not CRF in the CeA. After the ELS paradigms, visceral sensitivity and gene expression within the CeA were unaffected in adult male rats. The role of GR and CRF in modulating visceral sensitivity in adult female rats after ELS was investigated using oligodeoxynucleotide sequences targeted to the CeA for knockdown of GR or CRF. Knockdown of GR increased visceral sensitivity in all rats but revealed an exaggerated visceral hypersensitivity in females with a history of predictable or unpredictable ELS compared with that of controls. Knockdown of CRF expression or antagonism of CRF1R in the CeA attenuated visceral hypersensitivity after unpredictable ELS. This study highlights a shift in GR and CRF regulation within the CeA after ELS that underlies the development of visceral hypersensitivity in adulthood.

Cardiac CRFR1 Expression Is Elevated in Human Heart Failure and Modulated by Genetic Variation and Alternative Splicing.

Corticotropin-releasing factor (CRF) and the CRF-related peptides, urocortin (Ucn)-1, Ucn2, and Ucn3 signal through receptors CRFR1 and CRFR2 to restore homeostasis in response to stress. The Ucns exert potent cardioprotective effects and may have clinical utility in heart failure. To explore the activity of this system in the heart, we measured the levels of myocardial gene expression of the CRF/Ucn family of ligands/receptors and investigated genetic variation and alternative splicing of CRFR1 in 110 heart failure patients and 108 heart donors. Using quantitative real-time PCR, we detected CRFR1, CRFR2, CRF, Ucn1, Ucn2, and Ucn3 in all samples. CRFR2α was the most abundant receptor and Ucn3 the most abundant ligand, both in patients and donors. Compared with donors, cardiac expression of CRFR1, CRF, and Ucn3 was higher (P < .001) and CRFR2α lower (P = .012) in patients. In patients and donors, genetic variation within CRFR1, represented by the chromosome 17q21.31 inversion polymorphism, was associated with markedly higher CRFR1 expression (P < .001), making CRFR1 and CRFR2α expression almost equivalent in some patients. A novel, truncated splice variant of CRFR1, designated CRFR1j, was identified and shown to exert a dominant-negative effect on CRFR1 signaling in vitro. The novel variant was expressed in a greater proportion of patients (60%) than donors (3%, P < .001). In summary, cardiac expression of CRFR1, CRF, and Ucn3 genes is elevated in heart failure and may contribute to the activation of the CRF/Ucn system in these patients. A common variant within the CRFR1 gene and a novel CRFR1 splice variant may modulate CRFR1 expression and signaling.

Stress differentially regulates brain expression of corticotropin-releasing factor in binge-like eating prone and resistant female rats

The expression of corticotropin-releasing factor (CRF), a neuropeptide that regulates endocrine and behavioral responses to stress, was assessed in the brain in rats prone or resistant to stress-induced binge-like eating of sucrose. Female Sprague-Dawley rats were subjected to unpredictable intermittent 1-h access to sucrose in non-stressful conditions or after exposure to three foot shock stress sessions. Experimental sessions were performed at metestrus, diestrus, and proestrus. The rats were assigned to the binge-like eating prone (BEP) or the binge-like eating resistant (BER) phenotypes according to the rats' persistently high or low sucrose intake following three stress sessions. The BEP rats displayed elevated consumption of sucrose in non-stressful conditions and an additional significant increase in sucrose intake in response to stress. Conversely, the BER rats showed lower sucrose intake in non-stressful conditions, and stress did not increase sucrose intake in this phenotype. The brain expression of CRF mRNA and plasma corticosterone levels were assessed 30 min after the last stress session at the diestrous phase of the estrous cycle. Stress triggered a significant increase in plasma corticosterone levels and strongly increased CRF mRNA expression in the paraventricular hypothalamic nucleus in the BER but not in the BEP rats. However, the BEP but not the BER rats demonstrated a significant increase in CRF mRNA expression in the bed nucleus of the stria terminalis (BNST) after stress. Hyporeactivity of the hypothalamic-pituitary-adrenal axis and the higher CRF expression in the BNST in BEP rats may contribute to stress-induced binge-like sucrose eating in the BEP phenotype.

Sex‐specific effects of relaxin‐3 on food intake and body weight gain

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.

S&T-31 TRANSCRIPTIONAL REGULATION OF CORTICOTROPIN RELEASING FACTOR

You have accessJournal of UrologyScience & Technology Posters1 Apr 2016S&T-31 TRANSCRIPTIONAL REGULATION OF CORTICOTROPIN RELEASING FACTOR Lizath Aguiniga, Anthony Schaeffer, and David Klumpp Lizath AguinigaLizath Aguiniga More articles by this author , Anthony SchaefferAnthony Schaeffer More articles by this author , and David KlumppDavid Klumpp More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2860AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Interstitial cystitis (IC) patients suffer from chronic pelvic pain and bladder dysfunction. IC patients have altered cortisol levels suggesting dysregulation of the hypothalamic-pituitary adrenal (HPA) axis and suffer from exacerbated symptoms in response to high stress. Corticotropin-releasing factor (CRF) is the initiator of the HPA axis and mediates stress responses and voiding control, where increased CRF levels in Barrington′s nucleus induce bladder dysfunction. Arachidonic acid (AA) metabolites have been shown to induce CRF expression, however the transcriptional mediators of this modulation are unknown. We are investigating which transcription factors mediate AA-induced CRF gene expression. METHODS We used MIRAGE software to identify candidate transcription factor binding sites in a 1kb region of the human CRF gene promoter. We identified a peroxisome proliferator activated hormone response element (PPRE) and two Xenobiotic Responsive Element (XRE) sites as candidate mediators of AA-dependent CRF induction. Site directed mutations of the PPRE and XRE sites were generated in a CRF luciferase reporter plasmid. We evaluated the WT CRF promoter and the mutants for their responses to AA. We also over-expressed transcription factors AhR and PPAR gamma and evaluated AA-induced CRF expression in HEK 293T cells. We used the hypothalamic cell line N42, which has functional CRF expression to assess the role of AhR. We over-expressed AhR, induced with AA and used RT PCR to quantify CRF expression. RESULTS AA induction in the PPRE mutant resulted in increased CRF promoter activity compared to WT, whereas XRE1 had decreased activity. The mutation of both XRE1 and XRE2 resulted in decreased responsiveness to AA. Over expression of PPAR gamma alone showed no change, while over expression of AhR alone showed a significant increase in AA-induced CRF expression; this was inhibited by over-expression of both AhR and PPAR gamma in HEK 293T cells. Over expression of AhR in N42 cells resulted in increased CRF mRNA in response to AA induction. CONCLUSIONS These results suggest AhR binding to the XRE sites modulates AA-dependent CRF gene expression. PPAR gamma inhibits AA-dependent CRF gene expression. Continued studies will use mouse models to examine the in vivo role of AhR and PPAR gamma in modulating voiding in response to stress. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e321 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Lizath Aguiniga More articles by this author Anthony Schaeffer More articles by this author David Klumpp More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Effects of ZnO nanoparticles on perfluorooctane sulfonate induced thyroid-disrupting on zebrafish larvae

Perfluorooctane sulfonate (PFOS) and ZnO nanoparticles (nano-ZnO) are widely distributed in the environment. However, the potential toxicity of co-exposure to PFOS and nano-ZnO remains to be fully elucidated. The test investigated the effects of co-exposure to PFOS and nano-ZnO on the hypothalamic–pituitary–thyroid (HPT) axis in zebrafish. Zebrafish embryos were exposed to a combination of PFOS (0.2, 0.4, 0.8mg/L) and nano-ZnO (50mg/L) from their early stages of life (0–14days). The whole-body content of TH and the expression of genes and proteins related to the HPT axis were analyzed. The co-exposure decreased the body length and increased the malformation rates compared with exposure to PFOS alone. Co-exposure also increased the triiodothyronine (T3) levels, whereas the thyroxine (T4) content remained unchanged. Compared with the exposure to PFOS alone, exposure to both PFOS (0.8mg/L) and nano-ZnO (50mg/L) significantly up-regulated the expression of corticotropin-releasing factor, sodium/iodidesymporter, iodothyronine deiodinases and thyroid receptors and significantly down-regulated the expression of thyroid-stimulating hormone, thyroglobulin (TG), transthyretin (TTR) and thyroid receptors. The protein expression levels of TG and TTR were also significantly down-regulated in the co-exposure groups. In addition, the expression of the thyroid peroxidase gene was unchanged in all groups. The results demonstrated that PFOS and nano-ZnO co-exposure could cause more serious thyroid-disrupting effects in zebrafish than exposure to PFOS alone. Our results also provide insight into the mechanism of disruption of the thyroid status by PFOS and nano-ZnO.

Corticotropin-releasing factor augments LPS-induced immune/inflammatory responses in JAWSII cells.

The effect of corticotropin-releasing factor (CRF) on gastrointestinal tract inflammation via modulation of the immune system cells such as dendritic cells (DCs) is not known. We investigated the expression of CRF and its receptors CRFR1 and CRFR2 in a colonic DC model (JAWSII cells) in a pro-inflammatory and anti-inflammatory milieu. The mRNA expression of CRF and protein expression of CRFR1 and CRFR2 was assessed, and lipopolysaccharide (LPS) was used to induce the maturation of JAWSII cells. JAWSII cells were divided into four groups: control, CRF, LPS, and LPS + CRF. The levels of secreted cytokines IL-6, IL-4, TNF-α, and MIP-1α were determined, both in JAWSII cells and in the culture supernatant, by qRT-PCR and ELISA. The expression of CRFR1 and CRFR2 in JAWSII cells was accompanied by a low CRF expression. Compared with control group, CRF group did not affect the expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and MIP-1α, but LPS treatment significantly increased the expression of these cytokines, indicating maturation of JAWSII cells. CRF further augmented the production of IL-6, TNF-α, and MIP-1α in mature JAWSII cells, with no increase in TNF-α mRNA expression. However, the expression of anti-inflammatory factor IL-4 did not change after LPS treatment. CRF treatment decreased the expression of IL-4 in both mature and immature JAWSII cells. JAWSII cells produce low level of CRF and express CRFR1 and CRFR2 surface receptors. CRF promotes immune/inflammatory responses in mature JAWSII cells when induced by LPS treatment.

Buserelin treatment to rats causes enteric neurodegeneration with moderate effects on CRF-immunoreactive neurons and Enterobacteriaceae in colon, and in acetylcholine-mediated permeability in ileum.

BackgroundThe gonadotropin-releasing hormone (GnRH) analog buserelin causes enteric neuronal loss. Acute stress or injection of corticotropin-releasing factor (CRF) affects motility, secretion, and barrier function of the gastrointestinal tract. The aim of the study was to characterize the CRF immunoreactivity in enteric neurons after buserelin treatment, and to evaluate possible effects of enteric neuropathy on gut microbiota, intestinal permeability, and stress response behavior.ResultsSixty rats were given buserelin (20 μg) or saline subcutaneously for 5 days, repeated four times with 3 weeks in-between. At the study end, enteric neuronal density, enteric expression of CRF, gut microbial composition, and plasma levels of adrenocorticotropic hormone (ACTH) and CRF were analyzed. Intestinal permeability was examined in Ussing chambers and the reaction to stressful events was measured by behavior tests. Buserelin treatment reduced the number of neurons along the entire gastrointestinal tract, with increased relative numbers of CRF-immunoreactive submucosal and myenteric neurons in colon (p < 0.05 and p < 0.01, respectively). The overall microbial diversity and relative abundance did not differ between groups, but Enterobacteriaceae was decreased in colon in buserelin-treated rats (p = 0.020). Basal intestinal permeability did not differ between groups, whereas carbachol stimulation increased ileum permeability in controls (p < 0.05), but not in buserelin-treated rats. Buserelin did not affect stress behavior.ConclusionsAlthough buserelin treatment leads to enteric neuronal loss along the gastrointestinal tract with an increased percentage of CRF-immunoreactive neurons in colon, the physiology is well preserved, with modest effects on colon microbiota and absence of carbachol-induced permeability in ileum as the only observed changes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1800-x) contains supplementary material, which is available to authorized users.

Endogenous CRF in rat large intestine mediates motor and secretory responses to stress.

Corticotropin-releasing factor (CRF) mediates our body's overall responses to stress. The role of central CRF in stress-stimulated colonic motility is well characterized. We hypothesized that transient perturbation in expression of enteric CRF is sufficient to change stress-induced colonic motor and secretory responses. Sprague-Dawley rats (adult, male) were subjected to 1-h partial restraint stress (PRS) and euthanized at 0, 4, 8, and 24h. CRF mRNA and peptide levels in the colon were quantified by real-time RT-PCR, enzyme immuno-assay and immunohistochemistry. Double-stranded RNA (dsRNA) designed to target CRF (dsCRF) was injected into the colonic wall to attain RNA interference-mediated inhibition of CRF mRNA expression. DsRNA for β-globin was used as a control (dsControl). Four days after dsRNA injection, rats were subjected to 1-h PRS. Fecal output was measured. Ussing chamber techniques were used to assess colonic mucosal ion secretion and transepithelial tissue conductance. Exposure to PRS elevated CRF expression and increased CRF release in the rat colon. Injection of dsCRF inhibited basal CRF expression and prevented the PRS-induced increase in CRF expression, whereas CRF expression in dsControl-injected colons remained high after PRS. In rats treated with dsControl, PRS caused a significant increase in fecal pellet output, colonic baseline ion secretion, and transepithelial tissue conductance. Inhibition of CRF expression in the colon prevented PRS-induced increase in fecal output, baseline ion secretion, and transepithelial tissue conductance. These results provide direct evidence that transient perturbation in peripherally expressed CRF prevents colonic responses to stress.

Effects of the endogenous CRF on the biological phenotypes of mouse mesenteric lymph nodes den-dritic cells

Objective To investigate the expression of corticotropin-releasing factor (CRF) and its receptors including CRFR1 and CRFR2 on mouse mesenteric lymph nodes dendritic cells (MLNDC), and to analyze their effects on the biological phenotypes of intestinal dendritic cells. Methods The MLNDCs were isolated from C57BL/6 mice by using magnetic bead sorting. The purity of CD11c+ DCs was identified by flow cytometry. The double-labeling immunofluorescence and the reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to detect the expression of CRF, CRFR1 and CRFR2 on MLNDCs. The MLNDCs were exposed to CRF with or without the interference of CRFR1 and CRFR2 antagonists. Flow cytometry was used to measure the changes of surface molecules (MHCⅠ and MHCⅡ) and co-stimulatory molecules (CD80 and CD86). Results The CD11c+ DCs accounted for (80.12±6.34)% of the isolate cells with a high cell viability of more than 90%. The expression of CRF, CRFR1 and CRFR2 at mRNA level were detected in MLNDCs by RT-PCR. Results of the immunofluorescent staining assay indicated that both CRFR1 and CRFR2 were expressed on the surface of MLNDCs. The expression of CD86 on MLNDCs was inhibited by the treatment of MLNDCs with CRFR1 antagonist, but enhanced by the treatment with CRFR2 antagonist. Conclusion Both CRF and CRFRs were detected in the MLNDCs isolated from the C57BL/6 mice. The CRF could alter the biological phenotypes of MLNDCs through binding to different CRFRs (CRFR1 and CRFR2), which affected the phenotypes of MLNDCs in opposite ways. Key words: Corticotropin-releasing factor; Mesenteric lymph nodes; Dendritic cell

The central anorexigenic mechanism of adrenocorticotropic hormone involves the caudal hypothalamus in chicks

Adrenocorticotropic hormone (ACTH), consisting of 39 amino acids, is most well-known for its involvement in an organism's response to stress. It also participates in satiety, as exogenous ACTH causes decreased food intake in rats. However, its anorexigenic mechanism is not well understood in any species and its effect on appetite is not reported in the avian class. Thus, the present study was designed to evaluate central ACTH's effect on food intake and to elucidate the mechanism mediating this response using broiler chicks. Chicks that received intracerebroventricular (ICV) injection of 1, 2, or 4nmol of ACTH reduced food intake, under both ad libitum and 180min fasted conditions. Water intake was also reduced in ACTH-injected chicks under both feeding conditions, but when measured without access to feed it was not affected. Blood glucose was not affected in either feeding condition. Following ACTH injection, c-Fos immunoreactivity was quantified in key appetite-associated hypothalamic nuclei including the ventromedial hypothalamus (VMH), dorsomedial hypothalamus, lateral hypothalamus (LH), arcuate nucleus (ARC) and the parvo- and magno-cellular portions of the paraventricular nucleus. ACTH-injected chicks had increased c-Fos immunoreactivity in the VMH, LH, and ARC. Hypothalamus was collected at 1h post-injection, and real-time PCR performed to measure mRNA abundance of some appetite-associated factors. Neuropeptide Y, pro-opiomelanocortin, glutamate decarboxylase 1, melanocortin receptors 2–5, and urocortin 3 mRNA abundance was not affected by ACTH treatment. However, expression of corticotropin releasing factor (CRF), urotensin 2 (UT), agouti-related peptide (AgRP), and orexin (ORX), and melanocortin receptor 1 (MC1R) mRNA decreased in the hypothalamus of ACTH-injected chicks. In conclusion, ICV ACTH causes decreased food intake in chicks, and is associated with VMH, LH, and ARC activation, and a decrease in hypothalamic mRNA abundance of CRF, UT, AgRP, ORX and MC1R.

Corticotropin-releasing factor mediates bone cancer induced pain through neuronal activation in rat spinal cord

Corticotropin-releasing factor (CRF) serves as a neuromodulator in the hypothalamic-pituitary-adrenal axis, playing an essential role in depression, anxiety, and pain regulation. However, its biological role in bone cancer induced pain has not been investigated. In the present study, we aimed to elucidate the expression and distribution of CRF in spinal cord using a rodent model of bone cancer pain. Our study showed that implantation of Walker 256 mammary gland carcinoma cells into the tibia of rats significantly increased CRF expression in the spinal cord in a time-dependent manner. The upregulated expression of CRF mainly expressed in the superficial dorsal horn of spinal cord. Moreover, immunofluorescence double staining showed that CRF was extensively colocalized with neurons, but hardly with astrocytes or microglia. In addition, intrathecal injection of CRF receptor antagonist (α-helical-CRF) significantly inhibited heat hyperalgesia, mechanical allodynia, and the expression of c-Fos in spinal dorsal horn of bone cancer pain rats. In summary, our study demonstrates that CRF plays an important role in the development and maintenance of bone cancer pain via activation of neurons.