Role Of Corticotropin-releasing Hormone Research Articles

Hypothalamic Corticotropin-Releasing Hormone Contributes to Hypertension in Spontaneously Hypertensive Rats.

Corticotropin-releasing hormone (CRH) is a neuropeptide regulating neuroendocrine and autonomic function. CRH mRNA and protein levels in the hypothalamic paraventricular nucleus (PVN) are increased in primary hypertension. However, the role of CRH in elevated sympathetic outflow in primary hypertension remains unclear. CRHR1 proteins were distributed in retrogradely labeled PVN presympathetic neurons with an increased level in the PVN tissue in adult spontaneously hypertensive rats (SHRs) compared with age-matched male Wistar-Kyoto (WKY) rats. CRH induced a more significant increase in the firing rate of PVN-rostral ventrolateral medulla (RVLM) neurons and sympathoexcitatory response in SHRs than in WKY rats, an effect that was blocked by preapplication of NMDA receptors (NMDARs) antagonist AP5 and PSD-95 inhibitor, Tat-N-dimer. Blocking CRHRs with astressin or CRHR1 with NBI35965 significantly decreased the firing rate of PVN-RVLM output neurons and reduced arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) in SHRs but not in WKY, whereas blocking CRHR2 with antisauvagine-30 did not. Furthermore, Immunocytochemistry staining revealed that CRHR1 colocalized with NMDARs in PVN presympathetic neurons. Blocking CRHRs significantly decreased the NMDA currents in labeled PVN neurons. PSD-95-bound CRHR1 and PSD-95-bound GluN2A in the PVN were increased in SHRs. These data suggested that the upregulation of CRHR1 in the PVN is critically involved in the hyperactivity of PVN presympathetic neurons and elevated sympathetic outflow in primary hypertension.SIGNIFICANCE STATEMENT Our study found that corticotropin-releasing hormone receptor (CRHR)1 protein levels were increased in the paraventricular nucleus (PVN), and CRHR1 interacts with NMDA receptors (NMDARs) through postsynaptic density protein (PSD)-95 in the PVN neurons in primary hypertension. The increased CRHR1 and CRHR1-NMDAR-PSD-95 complex in the PVN contribute to the hyperactivity of the PVN presympathetic neurons and elevated sympathetic vasomotor tone in hypertension in SHRs. Thus, the antagonism of CRHR1 decreases sympathetic outflow and blood pressure in hypertension. These findings determine a novel role of CRHR1 in elevated sympathetic vasomotor tone in hypertension, which is useful for developing novel therapeutics targeting CRHR1 to treat elevated sympathetic outflow in primary hypertension. The CRHR1 receptor antagonists, which are used to treat health consequences resulting from chronic stress, are candidates to treat primary hypertension.

A Review Article of Corticotrophin-Releasing Hormone and Preterm Birth: A Placental Clock

Preterm Birth is one of the main causes of infant mortality and morbidity worldwide. An estimated 15 million preterm births are birthed each year. Preterm Birth is not a single disease but a complex syndrome. The placenta's production of Corticotrophin-Releasing Hormone (CRH) is one theory for Preterm Birth. The peptide hormone CRH, which levels rise exponentially during pregnancy, has been linked to preterm Birth due to its endocrine, autocrine, and paracrine functions. It has been suggested that CRH functions as a component of the placental clock, with preterm Birth occurring when the placental clock is activated too early. In this review article, we will discuss Preterm Birth and the role of CRH in Preterm Birth. Keywords: Preterm Birth, Corticotrophin-Releasing Hormone (CRH), Placental clock

Placental CRH as a Signal of Pregnancy Adversity and Impact on Fetal Neurodevelopment.

Early life is a period of considerable plasticity and vulnerability and insults during that period can disrupt the homeostatic equilibrium of the developing organism, resulting in adverse developmental programming and enhanced susceptibility to disease. Fetal exposure to prenatal stress can impede optimum brain development and deranged mother’s hypothalamic–pituitary–adrenal axis (HPA axis) stress responses can alter the neurodevelopmental trajectories of the offspring. Corticotropin-releasing hormone (CRH) and glucocorticoids, regulate fetal neurogenesis and while CRH exerts neuroprotective actions, increased levels of stress hormones have been associated with fetal brain structural alterations such as reduced cortical volume, impoverishment of neuronal density in the limbic brain areas and alterations in neuronal circuitry, synaptic plasticity, neurotransmission and G-protein coupled receptor (GPCR) signalling. Emerging evidence highlight the role of epigenetic changes in fetal brain programming, as stress-induced methylation of genes encoding molecules that are implicated in HPA axis and major neurodevelopmental processes. These serve as molecular memories and have been associated with long term modifications of the offspring’s stress regulatory system and increased susceptibility to psychosomatic disorders later in life. This review summarises our current understanding on the roles of CRH and other mediators of stress responses on fetal neurodevelopment.

The role of corticotropin-releasing hormone (CRH) family in tumor

The corticotropin-releasing hormone (CRH) family is widely distributed among the central nervous system and peripheral tissues, such as the digestive, cardiovascular, immune, reproductive, endocrine systems. The CRH family members are widely involved in the regulation of human cell biological processes, immune response, and regulation of inflammatory processes that can affect the occurrence and development of tumors. At present, CRH family members and their receptors can be detected in many tumor tissues, and some people think that members of the CRH family may be potential tumor treatment targets as they can affect cellular processes, such as proliferation, migration, invasion, and apoptosis. However currently, there is no systematic introduction to the relationship between the CRH family and various tumors. This review introduces the molecular regulation of the CRH family in tumor formation and seeks further targeted therapy.

The Role of Corticotropin-Releasing Hormone at Peripheral Nociceptors: Implications for Pain Modulation.

Peripheral nociceptors and their synaptic partners utilize neuropeptides for signal transmission. Such communication tunes the excitatory and inhibitory function of nociceptor-based circuits, eventually contributing to pain modulation. Corticotropin-releasing hormone (CRH) is the initiator hormone for the conventional hypothalamic-pituitary-adrenal axis, preparing our body for stress insults. Although knowledge of the expression and functional profiles of CRH and its receptors and the outcomes of their interactions has been actively accumulating for many brain regions, those for nociceptors are still under gradual investigation. Currently, based on the evidence of their expressions in nociceptors and their neighboring components, several hypotheses for possible pain modulations are emerging. Here we overview the historical attention to CRH and its receptors on the peripheral nociception and the recent increases in information regarding their roles in tuning pain signals. We also briefly contemplate the possibility that the stress-response paradigm can be locally intrapolated into intercellular communication that is driven by nociceptor neurons. Such endeavors may contribute to a more precise view of local peptidergic mechanisms of peripheral pain modulation.

Role of corticotropin-releasing hormone in the impact of chronic stress during pregnancy on inducing depression in male offspring mice

Role of corticotropin-releasing hormone in the impact of chronic stress during pregnancy on inducing depression in male offspring mice

Sleep in pituitary insufficient patients compared to patients with depression and healthy controls at baseline and after challenge with CRH

Sleep disturbances are prevalent in both patients with pituitary insufficiency and with depression. The role of corticotropin releasing hormone (CRH), involved in sleep regulation, has not been fully clarified. Pituitary insufficiency is an ideal model for studying sleep-endocrine effects since no consecutive hormone releases and feedback effects occur after hormone administration. 11 male patients with a chronic insufficiency of the anterior pituitary gland (PI) and under stable hormonal substitution were studied during three consecutive nights in the sleep laboratory. The first night served for adapting to laboratory setting, during the second night placebo was administered and during the third night 4 × 50 μg CRH were injected in pulsatile fashion. Sleep parameters were additionally compared with those of 15 healthy male controls (C) and 15 male patients with depression (D). CRH administration was associated with a numerical increase of wake time (115 ± 15 to 131 ± 13 min) and a decrease of REM sleep (89 ± 8 to 80 ± 8 min), REM latency (69 ± 14 to 55 ± 9 min) and slow wave sleep (66 ± 16 to 57 ± 15 min). Yet, none of these changes reached statistical significance. PI showed a worse sleep profile as compared to both control groups, e.g. indicated by a significantly lower sleep efficiency index (PI:0.80 ± 0.03 vs. C:0.94 ± 0.01 vs. D:0.87 ± 0.03). In conclusion sleep-EEG changes after CRH in PI patients resemble those found in in part in patients with depression. Sleep in anterior pituitary insufficiency was impaired despite full hormonal substitution possibly suggesting an alteration of the receptor organisation of brain structures involved in sleep regulation.

P38-MAPK pathway is activated in retinopathy of microvascular disease of STZ-induced diabetic rat model.

To investigate the role of corticotropin releasing hormone (CRH) in diabetic retinopathy of microvascular disease and the potential mechanism. The diabetic rat model was constructed by a single intraperitoneal injection of streptozotocin (STZ). The expression of CRH in the retina of diabetic rats and wild-type rats was detected by Real-Time Polymerase Chain Reaction (RT-PCR). CRH shRNA or Scr shRNA adenovirus was injected into the eyes of diabetic rats and wild-type rats, respectively. The effect of down-regulated CRH on visual electrophysiology in rats was evaluated. Protein expressions of vascular endothelial growth factor (VEGF) and inflammatory factors that were related to the microvascular lesion after CRH downregulation were detected by Western blot. Furthermore, p38 expression was detected by Western blot to explore whether mitogen-activated protein kinase (MAPK) signaling pathway was involved in the function of retinal endothelial cells regulated by CRH. The expression of CRH was significantly up-regulated in the retina of diabetic rats. RT-PCR results showed that the mRNA level of CRH in the retina of diabetic rats injected with CRH shRNA was decreased. However, no significant change in CRH level was observed in rats injected with Scr shRNA adenovirus. The down-regulated CRH could improve the diabetes-induced visual impairment and retinal inflammatory response. Moreover, the down-regulated CRH led to a decreased phosphorylation level of p38. CRH improves the diabetic retinopathy of microvascular disease via the p38-MAPK pathway, which is expected to be a new target for the treatment of diabetic microangiopathy.

Endometrial CRH and implantation: from bench to bedside.

Endometrial corticotropin-releasing hormone (CRH) has been described as a mediator of decidualisation and as a contributor of maternal-fetal immunotolerance. Deregulation of the CRH expression pattern has been associated with unfavourable reproductive outcomes as well as chronic endometrium-derived inflammatory disorders, such as endometriosis and adenomyosis. The current review summarises the evidence produced regarding the role of CRH in endometrial physiology and pathophysiology and highlights recent clinical data regarding the role of CRH in improving clinical pregnancy rates in women with repeated implantation failures following in vitro fertilisation and embryo transfer.

454 The role of corticotropin releasing hormone on connective tissue type and mucosal type mast cells biology

454 The role of corticotropin releasing hormone on connective tissue type and mucosal type mast cells biology

CRH Affects the Phenotypic Expression of Sepsis-Associated Virulence Factors by Streptococcus pneumoniae Serotype 1 In vitro.

Sepsis is a life-threatening health condition caused by infectious pathogens of the respiratory tract, and accounts for 28–50% of annual deaths in the US alone. Current treatment regimen advocates the use of corticosteroids as adjunct treatment with antibiotics, for their broad inhibitory effect on the activity and production of pro-inflammatory mediators. However, despite their use, corticosteroids have not proven to be able to reverse the death incidence among septic patients. We have previously demonstrated the potential for neuroendocrine factors to directly influence Streptococcus pneumoniae virulence, which may in turn mediate disease outcome leading to sepsis and septic shock. The current study investigated the role of Corticotropin-releasing hormone (CRH) in mediating key markers of pneumococcal virulence as important phenotypic determinants of sepsis and septic shock risks. In vitro cultures of serotype 1 pneumococcal strain with CRH promoted growth rate, increased capsule thickness and penicillin resistance, as well as induced pneumolysin gene expression. These results thus provide significant insights of CRH–pathogen interactions useful in understanding the underlying mechanisms of neuroendocrine factor's role in the onset of community acquired pneumonias (CAP), sepsis and septic shock.

Intermittent Access to Ethanol Induces Escalated Alcohol Consumption in Primates.

Escalation of voluntary alcohol drinking is characteristic of alcohol addiction and can be induced in rodents using intermittent access to alcohol. This model has been used to evaluate candidate therapeutics, but key systems involved in the transition into alcohol addiction, such as CRF, differ in their organization between rodents and primates. We examined the ability of an intermittent access schedule to induce escalation of voluntary alcohol drinking in non-human primates and used this model to assess the role of corticotropin releasing hormone (CRF) signaling in this process. Four young adult male rhesus macaques were given access to an 8.4% alcohol solution every other weekday (EOD; M, W, F), while four other young adult males were given the same solution every weekday (ED; M-F). Subjects were then administered a CRF1 antagonist, antalarmin. EOD increased alcohol intake by up to 50% over baseline, with a more pronounced increase immediately following reintroduction of alcohol. For the morning/daytime sessions, EOD subjects increased their consumption by 83% over baseline. Differences between ED and EOD schedules emerged quickly, and EOD-induced escalation resulted in pharmacologically active BAC's. EOD-induced alcohol consumption was insensitive to CRFR1 blockade by antalarmin, but subjects with high CSF levels of CRF were more responsive. Similar to what has been observed in rodents, intermittent access results in an escalation of voluntary alcohol drinking in non-human primates. In contrast to findings in rats, recruitment of the CRF system does not seem to be involved in the escalated alcohol drinking observed under these conditions, though individual differences in CRF system activity may play a role.

AB0185 Increased Corticotropin-Releasing Hormone (CRH) Expression in Cutaneous Lupus Lesions

BackgroundCorticotropin-releasing hormone (CRH) and the pro-opiomelanocortin (POMC) axis activation leads to the production of several bioactive hormones such as adrenocorticotrophic hormone (ACTH) and the neuropeptide α-melanocyte stimulating hormone (α-MSH). In...

Abstract 340: Psychological Stress Impairs Both Endothelial Function and Insulin Sensitivity via Activation of Inflammation and ER Stress Pathways Mediated by Corticotropin-Releasing Hormone

Background: Psychological stress may contribute to atherogenesis, although the underlying mechanism is poorly understood yet. We studied the role of corticotropin-releasing hormone (CRH) in the pathogenesis of stress-induced endothelial dysfunction and insulin resistance with specific focus on inflammation and ER stress pathways. Methods and Results: Immobilization stress (IS) was applied (2 hr/d) for 14 d to male 8-wk OLETF rats, whereas control groups comprised of rats without IS (n≥7 for each). 14d-IS decreased acetylcholine (Ach)-induced NO production, measured by direct NO electrochemical microsensor, from the aorta along with decreased expression of eNOS mRNA compared with control group. 14d-IS did not significantly change plasma glucose, but increased plasma insulin (342.5±6.3 vs. 496.0±51.6 pg/ml, p<0.05) and HOMA-IR (3.1±0.2 vs.4.7±0.5 mmol/LxμIU/mL, p<0.05) compared with control group. IS increased phosphorylation of both IRS1 serine and ERK, and increased expression of ER stress marker BiP. IS also increased translocation of NF-kB subunit p65 into nucleal fraction, and increased mRNA expression of both TNF-α and MCP-1 in the liver. Real-time RT-qPCR study showed that 1d IS increased expression of CRH mRNA and urocortin 2 mRNA in the hypothalamus by 2.5 folds and expression of CRH receptor type 2 mRNA in the aorta by 7.8 folds compared with control group. In cultured monocyte U937 cells, CRH induced translocation of NF-kB subunit p65 into nuclear fraction, and increased expression of BiP, phosphorylated inositol requiring enzyme 1, and MCP-1 mRNA. In cultured HUVECs, CRH pretreatment inhibited insulin-stimulated eNOS phosphorylation at Ser 1177 . Conclusions: Psychological stress impairs both endothelial function and insulin sensitivity probably via activation of NF-kB-mediated inflammation and ER stress pathways by CRH.

Tu1717 Role of Corticotropin-Releasing Hormone 2 in Mucosal Healing During Colitis

Tu1717 Role of Corticotropin-Releasing Hormone 2 in Mucosal Healing During Colitis

Stress-Induced Corticotropin-Releasing Hormone-Mediated NLRP6 Inflammasome Inhibition and Transmissible Enteritis in Mice

Stress alters brain-gut interactions and could exacerbate intestinal disorders, including irritable bowel syndrome. Alterations in the intestinal microbiota have been associated with irritable bowel syndrome. Maintenance of healthy microbiota requires nucleotide-binding oligomerization domain protein-like receptors, pyrin-domain containing (NLRP)-6 inflammasomes. We investigated the involvement of NLRP6 in water-avoidance stress (WAS)-induced intestinal disorders in mice. B57BL6 mice were subjected to WAS for 1 hour each day for 10 days; body weights and intestinal inflammation and permeability were analyzed. We investigated signaling via the NLRP3 and NLRP6 inflammasomes, and the role of corticotropin-releasing hormone (CRH) in WAS-associated inflammation and NLRP6 inhibition. Mice that were not exposed to stress were co-housed with mice subjected to WAS to determine the effects of WAS-induced dysbiosis, measured by sequencing bacterial 16S ribosomal RNA. We also assessed the effects of a peroxisome proliferator-activated receptor-γ agonist and probiotics. WAS-induced small-bowel inflammation (enteritis) was associated with inhibition of NLRP6, but not NLRP3, and was prevented by a peroxisome proliferator-activated receptor-γ agonist, which induced epithelial expression of NLRP6. CRH was released during WAS and inhibited NLRP6 expression. WAS induced alterations in the gut microbiota of mice; co-housed nonstressed mice developed enteritis associated with increased CRH and decreased levels of NLRP6. Probiotic therapy reduced intestinal inflammation in mice with WAS-induced enteritis. Exposure of mice to stress inhibits NLRP6 and alters the composition of the gut microbiota, leading to intestinal inflammation. These findings might explain the benefits of probiotics for patients with stress-associated gastrointestinal disorders.

Corticotropin-releasing hormone regulates common target genes with divergent functions in corticotrope and neuronal cells

As a key regulator of the neuroendocrine stress axis and as a neuromodulator in the brain, the neuropeptide corticotropin-releasing hormone (CRH) plays an important role in various diseases of the central nervous system. Its cognate receptor CRH receptor type 1 (CRHR1) is a potential novel target for the therapeutic intervention in major depressive disorder. Therefore, a more precise understanding of involved intracellular signaling mechanisms is essential. The objective of this project was to identify specific target genes of CRHR1-mediated signaling pathways in the corticotrope cell line AtT-20 and in the neuronal cell line HN9 using microarray technology and qRT-PCR, respectively. In addition, we assessed the capacity of validated target genes to directly impact on CRHR1-dependent signaling using reporter assays. Thereby, we identified a set of CRHR1 downstream targets with diverging and cell type-specific roles which strengthen the role of CRH and CRHR1 as dynamic modulators of a variety of signal transduction mechanisms and cellular processes.

784 Impaired Resolution of Inflammation and Tissue Regeneration in Corticotropin Releasing Hormone (CRH)- Deficient Mice Following DSS-Colitis

Inflammatory bowel disease (IBD) is a chronic, relapsing disease owing its development on complex interactions between genetic and environmental factors. It is currently accepted that innate immunity and indigenous pathogens play a critical role in the pathophysiology of IBD by compromising the function of the epithelial barrier. In previous studies we have demonstrated immunomodulatory actions of Corticotropin Releasing Hormone, or Factor, (CRH or CRF), a neuropeptide acting as the major mediator of the stress response, in intestinal inflammation in rodents. CRH and its receptors are expressed in a variety of tissues in humans and rodents including the intestine. Using an experimental model of innate immunity-dependent ulcerative colitis, the DSS model, we have recently shown that Crh deficiency is associated with increased susceptibility to disease development, indicating new roles for CRH in innate immune responses. To extend our understanding on the role of CRH in experimental IBD, we followed the course of DSS-colitis during the phase of repair of the tissue injury. To our surprise the disease was progressed in the Crh-/mice 5 days following cessation of DSS treatment resulting in their severely compromised survival, while all wild-type mice recovered. The progressive disease in the Crh-/mice was characterized by significant body weight loss, lack of regeneration of the epithelial barrier, and signs of increased fibrosis. Preliminary findings suggest that recovery of the vascularization and the innervation of the injured tissue follow an abnormal pattern. Thus, we identified prominent expression of beta III tubulin, a neuron specific cytoskeletal protein, and synaptophysin, a major synaptic vesicle protein, during the early phase of the disease unlike the late expression in the normal mice. The significance of these findings for the adverse course of the disease in the Crh-/mice, given recent reports on the significant correlation between gut innervation and inflammation, is under investigation. Our findings demonstrate the requirement of CRH for the intestinal epithelial repair in colitis and raise the hypothesis of the critical contribution of “appropriate” tissue stress response for the resolution of inflammation and return to tissue homeostasis in the gut.

Role of corticotropin-releasing hormone family peptides in androgen receptor and vitamin D receptor expression and translocation in human breast cancer MCF-7 cells

The presence of corticotropin-releasing hormone (CRH) in breast cancer biopsies suggests that it may play a role in the development of breast cancer. Here, the role of CRH in apoptosis and the relevant mechanisms were investigated. The CRH homologues, Urocortins, which have equal affinity for both corticotropin-releasing hormone receptor types 1 and 2, were secreted in MCF-7 breast cancer cells. CRH (receptor type 1 agonist) and Urocortin2 (receptor type 2 agonist) were used to substitute Urocortin to identify the differences between the two receptors. The results showed that both CRH and Urocortin2 promoted apoptosis of MCF-7 cells by regulating expressions and distributions of androgen receptor and vitamin D receptor. CRH down-regulated androgen receptor mRNA through inducing its decay while up-regulating androgen receptor protein expression and promoting nuclear transportation. Urocortin2 repressed the mRNA production of androgen receptor but had no significant impact on its protein expression. Both CRH and Urocortin2 time-dependently increased the protein expression of vitamin D receptor which translocated into the nuclei to realize its genic activity thereafter. The activity of CRH and Urocortin2 could be inhibited by Antalarmin and Antisauvagine-30, respectively. Additional analyses showed that CRH and Urocortin2 both phosphorylated heat shock protein 27, and this phosphorylation was associated with the nuclear transportation of vitamin D receptor. In conclusion, the results firstly revealed that CRH and Urocortin2 could induce breast cancer cell apoptosis via the two different receptors. The mechanisms involve phosphorylation of heat shock protein 27, the increment of androgen receptor and vitamin D receptor protein expression and their nuclear translocation.

New Aspects of the Immunoregulation by the Hypothalamo-Pituitary-Adrenal (HPA) Axis

One of the basic neuro-immune-endocrine interaction is the hypothalamo-pituitary-adrenal axis (HPA) to harmonize immune response to inflammatory stressors. Immune defense mechanisms mediated by cytokines and other humoral factors play particularly important roles in this communication. They are also potent activators in the CNS and factors of the HPA axis, like an increased secretion of glucocorticoids (GC). They can act as major feedback regulator of the vertebrate immune response via suppression of a wide range of cytokines, as well as interferons. Increases in systemic GC levels, however, often play dual role: do not suppress all cytokines since inhibition of a particular cytokine may result in elevated production of others. External stimuli/acute stress can compromise activation of the HPA axis and activate immune processes for defense, redirecting leukocytes from the circulation to the environment/organism interface. Overall it results in release of danger-associated molecular patterns (DAMPs) to activate cells of the innate immune system, which is resolved by neural, hormonal or immune mechanisms. The chronic stress leads to chronic immune arousal and subsequent sterile, low-grade inflammation, which has been identified in most stress-related or civilized disorders in humans. The role of pituitary-gonadal axis in the activation of HPA axis results in a gender difference in HPA response to immunological challenges: e.g. can be varied during the estrus cycle, pregnancy or lactation. That corresponds to the results of recent experimental data that reveals an important role of certain neurotramsitters (such as dopamine) in immune regulation. Internal constitutional-factors of neuro-immune-endocrine interaction, such as corticotropin-releasing hormone (CRH) and its receptors (CRF-R1 and CRF-R2), melanocortin peptides, glucocorticoids or pro-inflammatory cytokines can also act as an immunoregulator, since their receptors is present in lymphoid organs, also in peripheral blood and organs that are enhanced under inflammatory conditions. In spite of series experimental data, the role of CRH and other members of its family, as well as its receptors in inflammation are still controversial. This dual role may be due to different CRF receptors and altered functionality. There are several putative mechanisms or ports of entry, in which the cytokines may affect HPA activity and CRH release. Some influences of cytokines on the HPA axis may be exerted by an indirect way. The aim of our review was to summarize and outline of key interacting agents based upon recent experimental results.