1
|
Abstract
Stress is an integral part of life. Activation of the hypothalamus-pituitary-adrenal (HPA) axis in the adult can be viewed as mostly adaptive to restore homeostasis in the short term. When stress occurs during development, and specifically during periods of vulnerability in maturing systems, it can significantly reprogram function, leading to pathologies in the adult. Thus, it is critical to understand how the HPA axis is regulated during developmental periods and what are the factors contributing to shape its activity and reactivity to environmental stressors. The HPA axis is not a passive system. It can actively participate in critical physiological regulation, inducing parturition in the sheep for instance or being a center stage actor in the preparation of the fetus to aerobic life (lung maturation). It is also a major player in orchestrating mental function, metabolic, and cardiovascular function often reprogrammed by stressors even prior to conception through epigenetic modifications of gametes. In this review, we review the ontogeny of the HPA axis with an emphasis on two species that have been widely studied-sheep and rodents-because they each share many similar regulatory mechanism applicable to our understanding of the human HPA axis. The studies discussed in this review should ultimately inform us about windows of susceptibility in the developing brain and the crucial importance of early preconception, prenatal, and postnatal interventions designed to improve parental competence and offspring outcome. Only through informed studies will our public health system be able to curb the expansion of many stress-related or stress-induced pathologies and forge a better future for upcoming generations.
Collapse
Affiliation(s)
- Charles E Wood
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Claire-Dominique Walker
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
2
|
GUO H, FANG Q, HUO Y, ZHANG Y, ZHANG J. Social dominance-related major urinary proteins and the regulatory mechanism in mice. Integr Zool 2015; 10:543-54. [DOI: 10.1111/1749-4877.12165] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Huifen GUO
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture; Institute of Zoology, Chinese Academy of Sciences; Beijing China
| | - Qi FANG
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture; Institute of Zoology, Chinese Academy of Sciences; Beijing China
| | - Ying HUO
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture; Institute of Zoology, Chinese Academy of Sciences; Beijing China
| | - Yaohua ZHANG
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture; Institute of Zoology, Chinese Academy of Sciences; Beijing China
| | - Jianxu ZHANG
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture; Institute of Zoology, Chinese Academy of Sciences; Beijing China
| |
Collapse
|
3
|
Kolasa M, Faron-Górecka A, Kuśmider M, Szafran-Pilch K, Solich J, Żurawek D, Gruca P, Papp M, Dziedzicka-Wasylewska M. Differential stress response in rats subjected to chronic mild stress is accompanied by changes in CRH-family gene expression at the pituitary level. Peptides 2014; 61:98-106. [PMID: 25236411 DOI: 10.1016/j.peptides.2014.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 12/23/2022]
Abstract
The purpose of this study was to examine molecular markers of the stress response at the pituitary and peripheral levels in animals that responded differently to chronic mild stress (CMS). Rats were subjected to 2-weeks CMS and symptoms of anhedonia was measured by the consumption of 1% sucrose solution. mRNA levels of CRH-family neuropeptides (Crh-corticotropin-releasing hormone, Ucn1-urocortin 1, Ucn2-urocortin 2, Ucn3-urocortin 3), CRH receptors (Crhr1-corticotropin-releasing hormone receptor 1, Crhr2-corticotropin-releasing hormone receptor 2) and Crhbp (corticotropin-releasing factor binding protein) in the pituitaries of rats were determined with real-time PCR. Plasma levels of ACTH (adrenocorticotropin), CRH and urocortins were measured with ELISA assays. CMS procedure led to the development of anhedonia manifested by the decreased sucrose consumption (stress-reactive, SR, stress-susceptible group). Additionally, the group of animals not exhibiting any signs of anhedonia (stress non-reactive, SNR, stress-resilient group) and the group characterized by the increased sucrose consumption (stress invert-reactive group SIR) were selected. The significant increases in ACTH plasma level accompanied by the decreases in the pituitary gene expression of the Crh, Ucn2 and Ucn3 in both stress non-reactive and stress invert-reactive groups were observed. The only molecular change observed in stress-reactive group was the increase in UCN2 plasma level. The differentiated behavioral stress responses were reflected by gene expression changes in the pituitary. Alterations in the mRNA levels of Crh, Ucn2 and Ucn3 in the pituitary might confirm the paracrine and/or autocrine effects of these peptides in stress response. The opposite behavioral effect between SNR vs. SIR groups and the surprising similarity at gene expression and plasma ACTH levels in these two groups may suggest the discrepancy between molecular and behavioral stress responses; however, there results might indicate to similarity underlying different ways to cope with stress conditions.
Collapse
Affiliation(s)
- Magdalena Kolasa
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Agata Faron-Górecka
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
| | - Maciej Kuśmider
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Kinga Szafran-Pilch
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Joanna Solich
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Dariusz Żurawek
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Piotr Gruca
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Mariusz Papp
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | | |
Collapse
|
4
|
Corticotrophin-Releasing Factor (CRF) and the urocortins are potent regulators of the inflammatory phenotype of human and mouse white adipocytes and the differentiation of mouse 3T3L1 pre-adipocytes. PLoS One 2014; 9:e97060. [PMID: 24835211 PMCID: PMC4024041 DOI: 10.1371/journal.pone.0097060] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
Abstract
Chronic activation of innate immunity takes place in obesity and initiated by the hypertrophic adipocytes which obtain a pro-inflammatory phenotype. The corticotrophin-releasing factor (CRF) family of neuropeptides and their receptors (CRF1 and CRF2) affect stress response and innate immunity. Adipose tissue expresses a complete CRF system. The aim of this study was to examine the role of CRF neuropeptides in the immune phenotype of adipocytes assessed by their expression of the toll-like receptor-4 (TLR4), the production of inflammatory cytokines IL-6, TNF-α and IL-1β, chemokines IL-8, monocyte attractant protein-1 (MCP-1) and of the adipokines adiponectin, resistin and leptin. Our data are as follows: (a) CRF, UCN2 and UCN3 are expressed in human white adipocytes as well as CRFR1a, CRFR2a and CRFR2b but not CRFR2c. 3T3L1 pre-adipocytes and differentiated adipocytes expressed both CRF1 and CRF2 receptors and UCN3, while UCN2 was detected only in differentiated adipocytes. CRF2 was up-regulated in mouse mature adipocytes. (b) CRF1 agonists suppressed media- and LPS-induced pre-adipocyte differentiation while CRF2 receptor agonists had no effect. (c) In mouse pre-adipocytes, CRF2 agonists suppressed TLR4 expression and the production of IL-6, CXCL1 and adiponectin while CRF1 agonists had no effect. (d) In mature mouse adipocytes LPS induced IL-6 and CXCL1 production and suppressed leptin. (e) In human visceral adipocytes LPS induced IL-6, TNF-α, IL-8, MCP-1 and leptin production and suppressed adiponectin and resistin. (f) In mouse mature adipocytes CRF1 and CRF2 agonists suppressed basal and LPS-induced production of inflammatory cytokines, TLR4 expression and adiponectin production, while in human visceral adipocytes CRF and UCN1 suppressed basal and LPS-induced IL-6, TNF-α, IL-8 and MCP-1 production. In conclusion, the effects of the activation of CRF1 and CRF2 may be significant in ameliorating the pro-inflammatory activity of adipocytes in obesity.
Collapse
|
5
|
Urocortin affects migration of hepatic cancer cell lines via differential regulation of cPLA2 and iPLA2. Cell Signal 2014; 26:1125-34. [PMID: 24518041 DOI: 10.1016/j.cellsig.2014.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 02/01/2014] [Indexed: 12/14/2022]
Abstract
Urocortin (UCN) is a member of corticotrophin-releasing factor (CRF) family, which has been reported to play a role in many biological processes, including inflammation and cancer development. Growing evidence shows that PLA2 (phospholipase A2) enzymes also participate in inflammation and tumor development. The primary aim of the present study was to identify a novel signaling pathway of CRF receptor activation leading to migration of two kinds of hepatoma carcinoma cell lines, HepG2 and SMMC-7721, linking the stimulation of PLA2 expression by UCN to UCN-induced tumor cell migration. Pharmacological inhibitors and genetic approaches (such as stable transfection and siRNAs) were used in this study. Unlike HepG2 cells which express both CRF receptors themselves, SMMC-7721 cells which hardly express these two CRF receptors needed stable transfection with CRFR1 or CRFR2 to observe the effect of UCN. Two types of PLA2 enzymes, cPLA2 and iPLA2, were found to be regulated by UCN. Our data showed that UCN raised cPLA2 expression but lowered iPLA2 expression. Moreover, UCN was found to act on the certain region of iPLA2 promoter to reduce its transcription. UCN promoted tumor cell migration by up-regulating cPLA2 expression via CRFR1 whereas it suppressed tumor cell migration by down-regulating iPLA2 expression via CRFR2. These results indicate the dual roles for UCN in the hepatoma carcinoma cell migration, which involve the regulation of both cPLA2and iPLA2.
Collapse
|
6
|
Zhao Y, Wang MY, Hao K, Chen XQ, Du JZ. CRHR1 mediates p53 transcription induced by high altitude hypoxia through ERK 1/2 signaling in rat hepatic cells. Peptides 2013; 44:8-14. [PMID: 23538210 DOI: 10.1016/j.peptides.2013.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 01/14/2023]
Abstract
We have previously reported that hypoxia activates corticotrophin-releasing hormone (CRH) and the expression of its type-1 receptor (CRHR1) and induces disorders of the brain-endocrine-immune network. p53 is activated by hypoxia and involved in tumorigenesis and apoptosis. Whether CRHR1 regulates p53 transactivation to further influence apoptotic genes remains unclear. Here, we showed that hypoxia at a simulated altitude of 5km or 7km for 8 and 24h increased p53 protein and mRNA, and reduced apoptotic bax and IGFBP3 gene expression while upregulating the cell-arrest gene p21 for 8h in rat liver cells. The upregulation of p53 mRNA and downregulation of bax mRNA induced by hypoxia were blocked by pretreatment with the specific CRHR1 antagonist CP-154,526, but the downregulation of IGFBP3 and upregulation of p21 mRNA were not. Furthermore, CRH stimulated p53 mRNA via the ERK 1/2 pathway in the BRL-3A cell line and this was blocked by the ERK 1/2 antagonist U0126. These data provide novel evidence that the CRHR1-triggered ERK 1/2 pathway is involved in the activation of p53 and suppression of the apoptotic bax gene by hypoxia in rat liver.
Collapse
Affiliation(s)
- Yang Zhao
- Division of Neurobiology and Physiology, Department of Basic Medical Sciences, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | | | | | | | | |
Collapse
|
7
|
Sherlock L, McKeegan DEF, Cheng Z, Wathes CM, Wathes DC. Effects of contact dermatitis on hepatic gene expression in broilers. Br Poult Sci 2013; 53:439-52. [PMID: 23130578 DOI: 10.1080/00071668.2012.707310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
1. Severe foot and hock dermatitis in broiler chickens can reduce growth rate and increase susceptibility to bacterial infection, affecting both profitability and welfare. However, little is known about the underlying physiological changes associated with foot and hock lesions. 2. This study compared global hepatic gene expression in control birds and those with ammonia-induced foot and hock lesions using Agilent 44 K chicken oligonucleotide microarrays (8 birds per group). 3. In total, 417 genes were differentially expressed of which 174 could be mapped onto the genome. Genes associated with energy metabolism, thyroid hormone activity and cellular control were affected, while there was also evidence of an up-regulation of genes linked to a pro-inflammatory response. 4. It is conceivable that pain is the underlying cause for the observed changes in energy metabolism genes. 5. Changes in hepatic gene expression provide new information on how a chicken's physiological mechanisms alter to cope with foot and hock lesions. The findings support other data indicating that birds with increased severity of lesions are likely to be in pain and that growth will be compromised. Reduction of the incidence of dermatitis by improved husbandry should therefore benefit both welfare and commercial performance.
Collapse
Affiliation(s)
- L Sherlock
- Royal Veterinary College, University of London, Hatfield, AL9 7TA.
| | | | | | | | | |
Collapse
|
8
|
Chatzaki E, Anton PA, Million M, Lambropoulou M, Constantinidis T, Kolios G, Taché Y, Grigoriadis DE. Corticotropin-releasing factor receptor subtype 2 in human colonic mucosa: Down-regulation in ulcerative colitis. World J Gastroenterol 2013; 19:1416-1423. [PMID: 23539366 PMCID: PMC3602501 DOI: 10.3748/wjg.v19.i9.1416] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 12/05/2012] [Accepted: 12/20/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess corticotropin-releasing factor receptor 2 (CRF2) expression in the colon of healthy subjects and patients with ulcerative colitis (UC).
METHODS: We examined CRF2 gene and protein expression in the distal/sigmoid colonic mucosal biopsies from healthy subjects and patients with UC (active or disease in remission), human immunodeficiency virus (HIV) and functional bowel disease (FBD) by reverse transcription-polymerase chain reaction and immunofluorescence.
RESULTS: Gene expression of CRF2 was demonstrated in the normal human colonic biopsies, but not in the human colorectal adenocarcinoma cell line Caco2. Receptor protein localization showed immunoreactive CRF2 receptors in the lamina propria and in the epithelial cells of the distal/sigmoid biopsy samples. Interestingly, CRF2 immunoreactivity was no longer observed in epithelial cells of patients with mild-moderately active UC and disease in remission, while receptor protein expression did not change in the lamina propria. No differences in CRF2 expression profile were observed in distal/sigmoid intestinal biopsies from HIV infection and FBD patients, showing no signs of inflammation.
CONCLUSION: The down-regulation of the CRF2 receptor in the distal/sigmoid biopsies of UC patients is indicative of change in CRF2 signalling associated with the process of inflammation.
Collapse
|
9
|
Nemoto T, Mano A, Shibasaki T. Increased expression of miR-325-3p by urocortin 2 and its involvement in stress-induced suppression of LH secretion in rat pituitary. Am J Physiol Endocrinol Metab 2012; 302:E781-7. [PMID: 22252941 DOI: 10.1152/ajpendo.00616.2011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Urocortin 2 (Ucn2) is a member of the corticotropin releasing factor (CRF) peptide family, which binds to CRF type 2 receptor. We previously reported on expression of Ucn2 in proopiomelanocortin cells of rat pituitary and its inhibitory action on LH secretion. We also demonstrated that Ucn2 is involved in the mechanism underlying immobilization-induced suppression of LH secretion; the details remain unclear. Here, we found that Ucn2 increased the expression of miR-325-3p, one of three microRNAs with predicted sequence for binding to LH β-subunit 3'-untranslated region (3'-UTR) in monolayer cultured rat anterior pituitary cells, and that miR-325-3p was expressed in LH cells of the anterior pituitary. Immobilization also increased miR-325-3p expression in the anterior pituitary, and its increase was blocked by pretreatment with anti-Ucn2 IgG. Overexpression of miR-325-3p in cultured pituitary cells significantly suppressed intracellular contents and secretion of LH, while miR-325-3p knockdown blocked Ucn2-induced suppression of intracellular contents and secretion of LH. Coexpression of miR-325-3p with LH β-subunit 3'-UTR-fused luciferase vector significantly suppressed luciferase activity compared with that of mock transfectants. These results suggest that miR-325-3p is involved in immobilization-induced suppression of LH translation and secretion and that Ucn2 plays a role in the increase in miR-325-3p expression.
Collapse
Affiliation(s)
- Takahiro Nemoto
- Department of Physiology, Nippon Medical School, Tokyo, Japan.
| | | | | |
Collapse
|
10
|
Paschos KA, Charsou C, Constantinidis TC, Anagnostoulis S, Lambropoulou M, Papachristou F, Simopoulos K, Chatzaki E. Corticotropin-releasing hormone receptors mediate opposing effects in cholestasis-induced liver cell apoptosis. Endocrinology 2010; 151:1704-12. [PMID: 20189999 DOI: 10.1210/en.2009-1208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
CRH receptors are expressed in human and rat liver. The current study investigated the biological role of the CRH system in the hepatocellular apoptotic process and aimed to reveal the responsible molecular mechanisms. Using a rat experimental model of common bile duct surgical ligation leading to obstructive jaundice and cholestasis, liver apoptosis was induced in the hepatic parenchyma as confirmed by the elevated expression of the early apoptotic neoepitope M30. This effect was reversed by administration of the nonselective CRH antagonist astressin but not by the selective CRH(2) antagonist astressin2B, suggesting that antagonism of the endogenous CRH(1) blocked the cholestasis-induced apoptotic mechanism. No effect was observed in the noncholestasis controls. In our experimental model, early and late apoptosis-preventing markers were induced in parallel to apoptosis; elevated gene transcript levels of the anti-apoptotic bcl-2 were found by real-time PCR in the first postoperative day and increased serum hepatocyte growth factor levels were measured by ELISA in the third postoperative day. Selective CRH(2) antagonism reversed the elevated expression of bcl-2 and hepatocyte growth factor, suggesting that this receptor type mediated antiapoptotic actions of the endogenous CRH system, opposing the preapoptotic ones mediated by CRH(1). In conclusion, the present study indicated that the CRH neuroendocrine system regulates cholestasis-induced apoptosis in the hepatic parenchyma via receptor-specific pathways. These data may contribute to better understanding of the CRH biology and its pathophysiological significance in the periphery.
Collapse
Affiliation(s)
- Konstantinos A Paschos
- Department of Pharmacology, Democritus University of Thrace, Dragana, 68100 Alexandroupolis, Thrace, Greece
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Paschos KA, Kolios G, Chatzaki E. The corticotropin-releasing factor system in inflammatory bowel disease: prospects for new therapeutic approaches. Drug Discov Today 2009; 14:713-20. [PMID: 19379831 DOI: 10.1016/j.drudis.2009.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 04/01/2009] [Accepted: 04/06/2009] [Indexed: 12/16/2022]
Abstract
Mounting evidence suggests that stress is implicated in the development of inflammatory bowel disease (IBD), via initial nervous disturbance and subsequent immune dysfunction through brain-gut interactions. The corticotropin-releasing factor (CRF) system, being the principal neuroendocrine coordinator of stress responses, is involved in the inflammatory process within the gastrointestinal tract, via vagal and peripheral pathways, as implied by multiple reports reviewed here. Blocking of CRF receptors could theoretically exert beneficial anti-inflammatory effects in colonic tissues. The recently synthesised small-molecule CRF(1) antagonists or alternatively non-peptide CRF(2) antagonists when available, may become new reliable options in the treatment of IBD.
Collapse
Affiliation(s)
- Konstantinos A Paschos
- Laboratory of Pharmacology, Faculty of Medicine, Laboratory of Pharmacology, Democritus University of Thrace (DUTH), DUTH, Dragana, Alexandroupolis 68100, Thrace, Greece
| | | | | |
Collapse
|
12
|
Chae JI, Ju SK, Lee MK, Park JH, Yoon JH, Shim JH, Lee DS. cDNA cloning and analysis of tissue-specific gene expression of rat urocortin II. Mol Biol 2009. [DOI: 10.1134/s0026893309010117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
13
|
Li X, Hu J, Zhang R, Sun X, Zhang Q, Guan X, Chen J, Zhu Q, Li S. Urocortin ameliorates diabetic nephropathy in obese db/db mice. Br J Pharmacol 2008; 154:1025-34. [PMID: 18587447 DOI: 10.1038/bjp.2008.155] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Hyperglycaemia induces overproduction of mitochondrial reactive oxygen species (ROS) in endothelial cells, which is believed to be a major molecular mechanism underlying complications of diabetes, including diabetic nephropathy. Impairment of endothelium-dependent vasodilatation is found in type 2 diabetes. Urocortin is a 40 amino-acid peptide related to the corticotrophin-releasing factor (CRF) family, which suppresses production of ROS in endothelial cells and sustains endothelium-dependent relaxations of rat coronary artery. However, it is not clear if urocortin has any effect on diabetic nephropathy. EXPERIMENTAL APPROACH Possible mechanisms underlying the effects of urocortin on diabetic nephropathy were investigated in db/db mice and cultured rat mesangial cells. KEY RESULTS Urocortin decreased body weight, plasma levels of advanced glycation end-products, blood urea nitrogen and creatinine levels. However, food intake, plasma insulin and glucose levels remained unaffected. Superoxide dismutase activity was increased markedly, whereas malonaldehyde levels in kidney homogenate and sorbitol concentrations in red blood cells were decreased significantly in urocortin-treated mice. Urocortin significantly decreased glomerular extracellular matrix expansion and accumulation in kidney. Moreover, urocortin inhibited the overexpression of transforming growth factor-beta 1 and connective tissue growth factor in rat mesangial cells induced by 25 mM glucose. All the effects of urocortin, except sorbitol accumulation, were abolished by the non-selective CRF receptor blocker, astressin. CONCLUSION AND IMPLICATIONS Urocortin could significantly ameliorate diabetic nephropathy and this effect was mediated via the CRF receptor.
Collapse
Affiliation(s)
- X Li
- Department of Pharmacology, Nanjing Medical University, Nanjing, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|