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cAMP stimulation by Ucn-II and Ucn-III in neonatal cardiomyocytes . Cardiomyocytes were exposed to doses of peptides ranging from 30 pM to 300 nM for 20 min at 37 C. Intracellular cAMP was extracted and measured from triplicate wells by RIA. The mean values and SEM were determined from three independent experiments.
Source publication
Corticotropin-releasing factor (CRF) receptor type 2beta (CRFR2beta) is expressed in the heart. Urocortin (Ucn)-I activation of CRFR2beta is cardioprotective against ischemic reperfusion (I/R) injury by stimulation of the ERKs1/2 p42, 44. However, by binding CRF receptor type 1, Ucn-I can also activate the hypothalamic stress axis. Ucn-II/stresscop...
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Although the murine late pregnant (LP) heart is speculated to be a better functioning heart during physiological conditions, the susceptibility of LP hearts to I/R injury is still unknown. The aims of this study were to investigate the cardiac vulnerability of LP rodents to ischemia/reperfusion (I/R) injury and to explore its underlying mechanisms....
The aim of this study was to elucidate the signalling pathways implicated in the modulation of cardiac L-type Ca(2+) channels by urocortin (Ucn) in ventricular myocytes.
Adult rat ventricular myocytes were stimulated in vitro with Ucn for 20-40 min. L-type calcium currents (I(CaL)) were measured with the patch-clamp technique, whereas quantificatio...
The cytokine cardiotrophin-1 (CT-1) has previously been shown to protect cultured cardiocytes from cell death induced by serum removal or hypoxia when administered prior to the damaging stimulus. We wished to test whether a similar protective effect could be observed if CT-1 was added after the ischaemic period and to investigate the signalling pat...
Activated protein C (APC) is known to be beneficial on ischemia reperfusion injury in myocardium. However, the protection mechanism of APC is not fully understood. The purpose of this study was to investigate the effects and possible mechanisms of APC on myocardial ischemic damage. Artificially ventilated anaesthetized Sprague-Dawley rats were subj...
In most target cells, activation of the type 1 CRH receptor (CRH-R1) by CRH or urocortin (UCN I) leads to stimulation of the Gs-protein/adenylyl cyclase/protein kinase A cascade. Signal transduction of CRH-R1 also involves alternative pathways such as phosphorylation of ERK1/2 and p38 MAPK, two members of the MAPK family that mediate important path...
Citations
... This finding indicated a divergence in the positions they play roles, which might be attributable to the WGD3 event. Compared to tiCRHR1a and tiCRHR1b, tiCRHR2 was found to be ubiquitously expressed in peripheral tissues, in accordance with previous findings in other vertebrates (Bale et al., 2003Brar et al., 2004;Lovejoy et al., 2014;Wiley and Davenport, 2004), suggesting its broad functional significance in the organism. In this study, we found that tiCRHR1a and tiCRHR2 mRNA were expressed in the liver and kidney, clearly indicating their potential to influence the digestive and circulatory systems. ...
... In neuronal cells the activating phosphorylation of the MAP kinase cascade through CRF receptors occurs by the stimulation of the cAMP/PKA pathway [21], while in mouse cardiomyocytes and Chinese hamster ovary cells MAPK activation is PKA-independent [20], indicating a cell-typespecific process. Other proteins could also be involved in the activation of ERK1/2 MAPK, such as PKB/ Akt, PKC, and Raf-1 [22]. In human pregnant myometrial cells, urocortin stimulates the phosphorylation of ERK1/2 MAP kinase, but the activating phosphorylation can be prevented in the presence of the MEK inhibitor U0126 [23]. ...
... described in our previous work [15] in MCF7 breast cancer cells and is supported by the present study likewise. Urocortin also protects the isolated rat heart against ischaemic and reperfusion injury in a MAPK-dependent manner [21] by activating the phosphorylation of ERK1/2 [22]. Others have reported that urocortins (1, 2, and 3) can protect the rat heart from reperfusion injury not only in vitro but also in vivo via upregulation of the MAPK EKR1/2 signaling pathway [24,25]. ...
Corticotropin-releasing factor (CRF) stimulates adrenocorticotropic hormone (ACTH) secretion from the pituitary gland and is an essential regulator of the hypothalamic-pituitary-adrenocortical axis. Isoforms of CRF receptor are known to mediate the effects of urocortin stress ligands on regulation of stress responses, anxiety, and feeding behavior; however, urocortin stress ligands also influence cell proliferation. In view of the tumor-promoting capacity of prolonged stress, here we investigated (i) the effect of urocortin on cell proliferative signaling via Extracellular Signal Regulated Kinase1/2, (ii) the expression and cellular distribution of the specific CRF receptor isoforms, and (iii) the intracellular localization of phosphorylated ERK1/2 in HeLa cells. Stimulation of cell proliferation was observed in the presence of 10 nM urocortin. Our data also suggest that MAP Kinase Kinase MEK, the transcription factors E2F-1 and p53, and PKB/Akt are involved in this process. These findings may have therapeutic relevance for targeted treatment of various malignancies.
... Other studies have shown that the cardioprotective effects promoted by Ucn1 and Ucn2 are associated with ERK1/2 stimulation [91,92]. Brar et al. [93] have reported that astressin-2B, the selective antagonist of the CRF2R receptor, as well as the pharmacological inhibition of ERK1/2, abolished the cardioprotective effect promoted by Ucn2 and Ucn3. Although the underlying mechanisms involved in the role of ERK1/2 in controlling muscle mass and function are still focus of investigation, it is possible to speculate that such signaling is necessary for the force magnitude in Ucn2-transfected muscles. ...
Objective
Although it is well established that urocortin 2 (Ucn2), a peptide member of the corticotrophin releasing factor (CRF) family, and its specific corticotrophin-releasing factor 2 receptor (CRF2R) are highly expressed in skeletal muscle, the role of this peptide in the regulation of skeletal muscle mass and protein metabolism remains elusive.
Methods
To elucidate the mechanisms how Ucn2 directly controls protein metabolism in skeletal muscles of normal mice, we carried out genetic tools, physiological and molecular analyses of muscles in vivo and in vitro.
Results
Here, we demonstrated that Ucn2 overexpression activated cAMP signaling and promoted an expressive muscle hypertrophy associated with higher rates of protein synthesis and activation of Akt/mTOR and ERK1/2 signaling pathways. Furthermore, Ucn2 induced a decrease in mRNA levels of atrogin-1 and in autophagic flux inferred by an increase in the protein content of LC3-I, LC3-II and p62. Accordingly, Ucn2 reduced both the transcriptional activity of FoxO in vivo and the overall protein degradation in vitro through an inhibition of lysosomal proteolytic activity. In addition, we demonstrated that Ucn2 induced a fast-to-slow fiber type shift and improved fatigue muscle resistance, an effect that was completely blocked in muscles co-transfected with mitogen-activated protein kinase phosphatase 1 (MKP-1), but not with dominant-negative Akt mutant (Aktmt).
Conclusions
These data suggest that Ucn2 triggers an anabolic and anti-catabolic response in skeletal muscle of normal mice probably through the activation of cAMP cascade and participation of Akt and ERK1/2 signaling. These findings open new perspectives in the development of therapeutic strategies to cope with the loss of muscle mass.
... Despite the different roles for each of these peptides and their receptors in metabolic pathways (9), previous studies have indicated beneficial effects of overexpression or treatment with some of these neuropeptides, such as the administration of UCN1-protected cardiomyocytes (10). Similar cardioprotective effects were reported for UCN2 and UCN3 (11). Moreover, UCN3 overexpression protected rodents from metabolic dysregulation induced by a high-fat diet (HFD) (6). ...
Objective:
The corticotropin-releasing factor neuropeptides (corticotropin-releasing hormone [CRH] and urocortin [UCN]-1,2,3) and spexin contribute to the regulation of energy balance and inhibit food intake in mammals. However, the status of these neuropeptides in children with overweight has yet to be elucidated. This study investigated the effect of increased body weight on the circulating levels of these neuropeptides.
Methods:
A total of 120 children with a mean age of 12 years were enrolled in the study. Blood samples were collected to assess the circulating levels of neuropeptides and were correlated with various anthropometric, clinical, and metabolic markers.
Results:
Plasma levels of UCNs were altered in children with overweight but less so in those with obesity. Furthermore, the expression pattern of UCN1 was opposite to that of UCN2 and UCN3, which suggests a compensatory effect. However, no significant effect of overweight and obesity was observed on CRH and spexin levels. Finally, UCN3 independently associated with circulating zinc-alpha-2-glycoprotein and UCN2 levels, whereas UCN1 was strongly predicted by TNFα levels.
Conclusions:
Significant changes in neuropeptide levels were primarily observed in children with overweight and were attenuated with increased obesity. This suggests the presence of a compensatory mechanism for neuropeptides to curb the progression of obesity.
... They are concomitantly expressed in the brain and peripheral organs, such as the heart, pancreas, skeletal muscle, and adipose tissue [6][7][8] suggest multiple sites of interaction of central neurochemistry circuitry. UCN1, 2, and 3 exhibit cardioprotective effects [9,10] and are able to modulate feeding behavior by reducing food intake and body weight gain in rodents [11]. Although UCN3 overexpression protects against high-fat diet (HFD)-induced metabolic dysregulation [6] and increased energy expenditure [12], decreased food intake and insulin sensitivity were observed in UCN3-null rodents [13]. ...
The corticotropin-releasing hormone (CRH) and urocortins (UCNs) have been implicated in energy homeostasis and the cellular stress response. However, the expression of these neuropeptides in children remains unclear. Therefore, we determined the impact of obesity on their expression in 40 children who were normal weight, overweight, and had obesity. Peripheral blood mononuclear cells (PBMCs) and plasma were used to assess the expression of neuropeptides. THP1 cells were treated with 25 mM glucose and 200 µM palmitate, and gene expression was measured by real-time polymerase chain reaction (RT-PCR). Transcript levels of neuropeptides were decreased in PBMCs from children with increased body mass index as indicated by a significant decrease in UCN1, UCN3, and CRH mRNA in overweight and obese children. UCN3 mRNA expression was strongly correlated with UCN1, UCN2, and CRH. Exposure of THP1 cells to palmitate or a combination of high glucose and palmitate for 24 h increased CRH, UCN2, and UCN3 mRNA expression with concomitant increased levels of inflammatory and endoplasmic reticulum stress markers, suggesting a crosstalk between these neuropeptides and the cellular stress response. The differential impairment of the transcript levels of CRH and UCNs in PBMCs from overweight and obese children highlights their involvement in obesity-related metabolic and cellular stress.
... In the last two decades, Urocortin (Ucn) isoforms, peptides related to stress, arose as potential therapeutic drugs to improve performances of heart in I/R and under HF [16,17]. This review aims to highlight Ucn's role in IHD and discusses the available clinical evidence of Ucn isoforms' therapeutic feature in HF. ...
Despite the considerable progress in strategies of myocardial protection, ischemic heart diseases (IHD) and consequent heart failure (HF) remain the main cause of mortality worldwide. Several procedures are used routinely to guarantee the prompt and successful reestablishment of blood flow to preserve the myocardial viability of infarcted hearts from ischemia injuries. However, ischemic heart reperfusion/revascularization triggers additional damages that occur when oxygen-rich blood re-enters the vulnerable myocardial tissue, which is a phenomenon known as ischemia and reperfusion (I/R) syndrome. Complications of I/R injuries provoke the adverse cardiac remodeling, involving inflammation, mishandling of Ca2+ homeostasis, apoptotic genes activation, cardiac myocytes loss, etc., which often progress toward HF. Therefore, there is an urgent need to develop new cardioprotective therapies for IHD and HF. Compelling evidence from animal studies and pilot clinical trials in HF patients suggest that urocortin (Ucn) isoforms, which are peptides associated with stress and belonging to the corticotropin releasing factor family, have promising potential to improve cardiovascular functions by targeting many signaling pathways at different molecular levels. This review highlights the current knowledge on the role of urocortin isoforms in cardioprotection, focusing on its acute and long-term effects.
... Along that line are findings, showing that UCN2 and UCN3 inhibit apoptosis in cardiomyocytes during hypoxia-reoxygenation. Mechanistically, these effects were mediated by the p42/44 mitogen-activated protein kinase and protein kinase B/Akt pathway [16,17]. Together, UCNs appear to be important regulators of metabolism and to respond to hypoxia. ...
Hypoxia controls metabolism at several levels, e.g., via mitochondrial ATP production, glucose uptake and glycolysis. Hence it is likely that hypoxia also affects the action and/or production of many peptide hormones linked to food intake and appetite control. Many of those are produced in the gastrointestinal tract, endocrine pancreas, adipose tissue, and selective areas in the brain which modulate and concert their actions. However, the complexity of the hypoxia response and the links to peptides/hormones involved in food intake and appetite control in the different organs are not well known. This review summarizes the role of the hypoxia response and its effects on major peptides linked to appetite regulation, nutrition and metabolism.
... Further, this research was extended by Chanalaris et al. and Brar et al. where they found that Ucn II and Ucn III also have the potential in cardio-protection both ex-vivo and in-vivo (Chanalaris et al., 2003;Brar et al., 2004). Now, it is well recognized that Ucn and its homology can protect the heart from IR injury, but the mechanism of their action is not well understood. ...
A proper balance between cell proliferation and cell death plays a critical role in organ development and maintaining the integrity of structural elements. Failure to regulate apoptosis, leads to the development of several diseases, such as cancer, neurodegenerative diseases, and autoimmune disorders. In this aspect, the study of complex networks of regulatory factors involved in cell proliferation and its death has gained significant importance. Consequently, therapeutic agents, modulating the key molecules of apoptosis are currently been implemented to devise a more effective and rational therapy. In the past decade, substantial advances have been achieved in the development of novel therapeutics targeting apoptosis. Numerous novel approaches are already underway, that employ gene therapy, antisense strategies, and inhibition or activation of second messengers involved in apoptosis. This chapter outlines the recent advances made in the field of apoptosis-modulating therapies together with its clinical success for the management of different disease conditions.
... Similarly, our discovery that exogenous CRF has pro-survival properties in an isolated larval zebrafish brain raises questions about the role of endogenous CRF in brain resilience, i.e. in the capacity of the brain to withstand environmental insults. Despite the evolution of four CRF-related peptides in fish and mammals, all have cytoprotective properties under various conditions (Facci et al., 2003;Brar et al., 2004;Williams et al., 2017a). The fact that this role has escaped subfunctionalization within the vertebrate lineage since the last common ancestor of fish and mammals suggests a strong and vital role for cytoprotection by CRF-related peptides. ...
The physiological roles of corticotropin-releasing factor (CRF) have recently been extended to cytoprotection. Here, to determine whether CRF is neuroprotective in fish, the effects of CRF against high environmental ammonia (HEA)-mediated neurogenic impairment and cell death were investigated in zebrafish. In vivo, exposure of 1 day post-fertilization (dpf) embryos to HEA only reduced the expression of the determined neuron marker, neurod1 In contrast, in 5 dpf larvae, HEA increased the expression of nes and sox2, neural progenitor cell markers, and reduced the expression of neurog1, gfap and mbpa, proneuronal cell, radial glia and oligodendrocyte markers, respectively, and neurod1 The N-methyl-D-aspartate (NMDA) receptor inhibitor MK801 rescued the HEA-induced reduction in neurod1 in 5 dpf larvae but did not affect the HEA-induced transcriptional changes in other neural cell types, suggesting that hyperactivation of NMDA receptors specifically contributes to the deleterious effects of HEA in determined neurons. As observed in vivo, HEA exposure elicited marked changes in the expression of cell-type specific markers in isolated 5 dpf larval brains. The addition of CRF reversed the in vitro effects of HEA on neurod1 expression and prevented an HEA-induced increase in cell death. Finally, the protective effects of CRF against HEA-mediated neurogenic impairment and cell death were prevented by the CRF type 1 receptor selective antagonist, antalarmin. Together, these results provide novel evidence that HEA has developmental time- and cell type-specific neurotoxic effects, that NMDA receptor hyperactivation contributes to HEA-mediated impairment of determined neurons, and that CRF has neuroprotective properties in the larval zebrafish brain.
... These findings suggest that cellular background may also govern the ability of PKA or PKC pathways to regulate CRF 1 R ERK1/2 signaling similar to its possible role in mediating CRF 1 R selective activation of a specific MAP kinase cascade. MEK1/2-mediated phosphorylation of ERK1/2 at Thr 202 and Tyr 204 during CRF 1 R and CRF 2 R signaling in various cell lines has been confirmed by inhibiting ERK1/2 activation with PD98059 (2,9,12,13,19). Inhibiting C-Raf function by pretreatment with R1-K1 inhibitor or blocking Ras activation by transfection with the dominant-negative mutant RasS17N inhibited Ucn1-stimulated ERK1/2 phosphorylation in CRF 1 Rexpressing CHO and HEK293 cells (5,12). CRF 2 R activation by urocortin 2 (Ucn2) and urocortin 3 (Ucn3) has also been shown to signal via the Ras→C-Raf→MEK1/2 cascade in rat cardiomyocytes, based on the ability of manumycin A (a Ras inhibitor) and R1-K1 to abolish ERK1/2 phosphorylation (19). ...
... Inhibiting C-Raf function by pretreatment with R1-K1 inhibitor or blocking Ras activation by transfection with the dominant-negative mutant RasS17N inhibited Ucn1-stimulated ERK1/2 phosphorylation in CRF 1 Rexpressing CHO and HEK293 cells (5,12). CRF 2 R activation by urocortin 2 (Ucn2) and urocortin 3 (Ucn3) has also been shown to signal via the Ras→C-Raf→MEK1/2 cascade in rat cardiomyocytes, based on the ability of manumycin A (a Ras inhibitor) and R1-K1 to abolish ERK1/2 phosphorylation (19). Other research has provided evidence for a phosphoinositide 3-kinase (PI3K)-dependent mechanism contributing to CRF 1 Rand CRF 2 R-mediated ERK1/2 activation in HEK293, CHO, A7r5, and CATH.a cells (5,9,12). ...
... Earlier studies have implicated a PI3K-dependent mechanism in CRF 1 R ERK1/2 signaling based on the observation that pretreatment with PI3K inhibitors attenuated sauvagineand Ucn1-stimulated ERK1/2 phosphorylation in CRF 1 Rexpressing CHO and HEK293 cells (5,9,12). PI3K is also involved in CRF 2(b) R-stimulated ERK1/2 activation in CHO, A7r5, and mouse neonatal cardiomyocyte cells (12,19). However, the activation sequence of PI3K, EGFR, and ERK1/2 during CRF 1 R signaling has not been fully elucidated. ...
In the present study, we determined the cellular regulators of ERK1/2 and Akt signaling pathways in response to human CRF1 receptor (CRF1R) activation in transfected COS-7 cells. We found that Pertussis Toxin (PTX) treatment or sequestering Gβγ reduced CRF1R-mediated activation of ERK1/2, suggesting the involvement of a Gi-linked cascade. Neither Gs/PKA nor Gq/PKC were associated with ERK1/2 activation. Besides, CRF induced EGF receptor (EGFR) phosphorylation at Tyr1068, and selective inhibition of EGFR kinase activity by AG1478 strongly inhibited the CRF1R-mediated phosphorylation of ERK1/2, indicating the participation of EGFR transactivation. Furthermore, CRF-induced ERK1/2 phosphorylation was not altered by pretreatment with batimastat, GM6001, or an HB-EGF antibody indicating that metalloproteinase processing of HB-EGF ligands is not required for the CRF-mediated EGFR transactivation. We also observed that CRF induced Src and PYK2 phosphorylation in a Gβγ-dependent manner. Additionally, using the specific Src kinase inhibitor PP2 and the dominant-negative-SrcYF-KM, it was revealed that CRF-stimulated ERK1/2 phosphorylation depends on Src activation. PP2 also blocked the effect of CRF on Src and EGFR (Tyr845) phosphorylation, further demonstrating the centrality of Src. We identified the formation of a protein complex consisting of CRF1R, Src, and EGFR facilitates EGFR transactivation and CRF1R-mediated signaling. CRF stimulated Akt phosphorylation, which was dependent on Gi/βγ subunits, and Src activation, however, was only slightly dependent on EGFR transactivation. Moreover, PI3K inhibitors were able to inhibit not only the CRF-induced phosphorylation of Akt, as expected, but also ERK1/2 activation by CRF suggesting a PI3K dependency in the CRF1R ERK signaling. Finally, CRF-stimulated ERK1/2 activation was similar in the wild-type CRF1R and the phosphorylation-deficient CRF1R-Δ386 mutant, which has impaired agonist-dependent β-arrestin-2 recruitment; however, this situation may have resulted from the low β-arrestin expression in the COS-7 cells. When β-arrestin-2 was overexpressed in COS-7 cells, CRF-stimulated ERK1/2 phosphorylation was markedly upregulated. These findings indicate that on the base of a constitutive CRF1R/EGFR interaction, the Gi/βγ subunits upstream activation of Src, PYK2, PI3K, and transactivation of the EGFR are required for CRF1R signaling via the ERK1/2-MAP kinase pathway. In contrast, Akt activation via CRF1R is mediated by the Src/PI3K pathway with little contribution of EGFR transactivation.
