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Hirota K, Hirashima T, Horikawa K, Yasoda A, Matsuda M. C-type Natriuretic Peptide-induced PKA Activation Promotes Endochondral Bone Formation in Hypertrophic Chondrocytes. Endocrinology 2022; 163:6511000. [PMID: 35041746 PMCID: PMC8826897 DOI: 10.1210/endocr/bqac005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Indexed: 11/28/2022]
Abstract
Longitudinal bone growth is achieved by a tightly controlled process termed endochondral bone formation. C-type natriuretic peptide (CNP) stimulates endochondral bone formation through binding to its specific receptor, guanylyl cyclase (GC)-B. However, CNP/GC-B signaling dynamics in different stages of endochondral bone formation have not been fully clarified, especially in terms of the interaction between the cyclic guanine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) pathways. Here, we demonstrated that CNP activates the cAMP/protein kinase A (PKA) pathway and that this activation contributed to the elongation of the hypertrophic zone in the growth plate. Cells of the chondrogenic line ATDC5 were transfected with Förster resonance energy transfer (FRET)-based cGMP and PKA biosensors. Dual-FRET imaging revealed that CNP increased intracellular cGMP levels and PKA activities in chondrocytes. Further, CNP-induced PKA activation was enhanced following differentiation of ATDC5 cells. Live imaging of the fetal growth plate of transgenic mice, expressing a FRET biosensor for PKA, PKAchu mice, showed that CNP predominantly activates the PKA in the hypertrophic chondrocytes. Additionally, histological analysis of the growth plate of PKAchu mice demonstrated that CNP increased the length of the growth plate, but coadministration of a PKA inhibitor, H89, inhibited the growth-promoting effect of CNP only in the hypertrophic zone. In summary, we revealed that CNP-induced cGMP elevation activated the cAMP/PKA pathway, and clarified that this PKA activation contributed to the bone growth-promoting effect of CNP in hypertrophic chondrocytes. These results provide insights regarding the cross-talk between cGMP and cAMP signaling in endochondral bone formation and in the physiological role of the CNP/GC-B system.
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Affiliation(s)
- Keisho Hirota
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Correspondence: Keisho Hirota, Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-Cho, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Tsuyoshi Hirashima
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- The Hakubi Center, Kyoto University, Kyoto, Japan
- Science and Technology Agency, PRESTO, Kawaguchi, Japan
| | - Kazuki Horikawa
- Department of Optical Imaging, Advanced Research Promotion Center, Tokushima University Graduate School, Tokushima, Japan
| | - Akihiro Yasoda
- Clinical Research Center, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
| | - Michiyuki Matsuda
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan
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Lian HM, Guo JY, Sun Y, Zhang MH, Piao LH, Jin Z, Cai YL. Mechanism of CNP-mediated DG-PKC and IP4 signaling pathway in diabetic rats with gastric motility disorder. Mol Biol Rep 2019; 47:141-149. [PMID: 31583569 DOI: 10.1007/s11033-019-05115-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/26/2019] [Indexed: 11/26/2022]
Abstract
In the precedent research conducted by the same team, it concluded that the activities in C-type natriuretic peptide (CNP)/cyclic guanosine monophosphate (cGMP)/cyclic adenosine monophosphate (cAMP)/β-type phospholipase C (PLCβ) pathways of rat antral smooth muscle were changed due to diabetes, which was the key pathogenetic mechanism for diabetic gastric dysmotility. As the follow-on step, this study was designed to probe into the downstream signaling pathway of CNP/PLCβ. The results showed that level of α-type protein kinase C (PKCα),cell membrane to cytoplasm ratio of PKCα, cell membrane to cytoplasmic ratio of βI-type protein kinase C (PKCβI) and level of Phosphor-PKCα (P-PKCα) were significantly reduced in diabetes rat antral smooth muscle samples. The content of tetraphosphate inositol (IP4) in gastric antral smooth muscle of diabetic rats reduced, and the content of diacyl-glycerol (DG) was unchanged. CNP significantly decreased the content of IP4 and DG, this effect was more obvious in diabetic rats. Subsequent to the addition of protein kinase A (PKA) blocker N-[2- (p-Bromocin-namylamino)ethyl]-5 -isoquinolinesulfonamide dihydrochloride (H-89) before CNP treatment, the inhibitory effect of CNP was reduced; subsequent to the addition of protein kinase G (PKG) blocker KT5823 before CNP treatment, the inhibitory effect of CNP was also reduced. With the addition of the combination of H-89 and KT5823 before CNP treatment, the inhibition by CNP could be offset. These results were concluded that CNP inhibited the activity of PKC family in rat smooth muscle and reduced the levels of IP4 and DG through the PKG/PKA-PLCβ pathways, causing inhibited muscular contractions, which may be a key pathogenetic factor for diabetic gastroparesis.
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Affiliation(s)
- Hui-Ming Lian
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Jun-Yu Guo
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Yan Sun
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Mo-Han Zhang
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Li-Hua Piao
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Zheng Jin
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China
| | - Ying-Lan Cai
- Department of Histology and Embryology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji, 133002, China.
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An J, Li Y, Song S, Liu S. Electroacupuncture promotes the gastrointestinal motility of diabetic mice by CNP/NPR-B-cGMP and PDE3A-cGMP signaling. Neurogastroenterol Motil 2019; 31:e13539. [PMID: 30672071 DOI: 10.1111/nmo.13539] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/03/2018] [Accepted: 12/11/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Electroacupuncture (EA) can promote gastrointestinal (GI) motility of diabetic mice, but the mechanism is not clearly elucidated. Natriuretic peptides (NPs) were related to the diabetes-induced gut dysfunction of mice, which may be associated with ICC (interstitial cells of cajal). Besides, EA could increase the ICC of diabetic mice. Our aim was to explore whether EA can promote the gut motility by CNP/NPR-B-cGMP and PDE3A-cGMP signaling in diabetic mice, and the relationship between NPs and ICC. METHODS Wild C57BL/6 male mice were divided into five groups: control group, diabetic mellitus (DM group), diabetic mellitus plus sham EA group (SEA), diabetic mellitus plus low-frequency EA group (LEA), and diabetic mellitus plus high-frequency group (HEA). Gastrointestinal motility was assessed by gastric emptying and GI transit test. Immunofluorescence staining was applied to assess the expression level of CNP, NPR-B, and c-Kit. Western blot, PCR, and ELISA were used to detect the level of CNP, NPR-B, PDE2A, PDE3A, c-Kit, mSCF, and cGMP content. The correlativity between NPR-B and mSCF was evaluated by Pearson's correlation and linear regression analyses. KEY RESULTS (a) EA could improve the GI dysfunction of diabetic mice. (b) CNP, NPR-B, and cGMP contents were decreased, but the level of PDE3A, c-Kit, and mSCF was increased in the EA groups. (c) There was a negative correlation between NPR-B and mSCF among the groups. CONCLUSIONS AND INFERENCES Electroacupuncture promotes the GI function by CNP/NPR-B-cGMP and PDE3A-cGMP signaling in diabetic mice; up-regulated mSCF/c-Kit signaling by EA may be mediated partially via down-regulation of CNP/NPR-B signaling.
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Affiliation(s)
- Jing An
- Division of Gastroenterology, Union Hospital, Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
| | - YingLi Li
- Division of Gastroenterology, Union Hospital, Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
| | - ShuangNing Song
- Division of Gastroenterology, Union Hospital, Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
| | - Shi Liu
- Division of Gastroenterology, Union Hospital, Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
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Guo JY, Zhang MH, Jiang JZ, Piao LH, Fang XS, Jin Z, Cai YL. The role of CNP-mediated PKG/PKA-PLCβ pathway in diabetes-induced gastric motility disorder. Peptides 2018; 110:47-55. [PMID: 30391424 DOI: 10.1016/j.peptides.2018.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/30/2018] [Accepted: 10/30/2018] [Indexed: 12/18/2022]
Abstract
Our previous work demonstrated that the C-type natriuretic peptide (CNP)/cyclic guanosine monophosphate (cGMP)/cyclic adenosine monophosphate (cAMP) pathway in gastric antrum smooth muscle of rats with diabetes was upregulated and played an important role in the development of diabetic gastric dysmotility. Our goal for this study was to explore the downstream signaling pathways of CNP. We found that the expressions of protein kinase G (PKG) and protein kinase A (PKA) in gastric smooth muscle tissue of rats with diabetes were significantly upregulated. The expressions of β-type phospholipase C 3(PLCβ3) and β-type phospholipase C 1(PLCβ1) protein were reduced, whereas Phosphor-PLCβ3Ser1105 (P-PLCβ3Ser1105) was increased. The inhibitory effect of CNP on gastric antral smooth muscle in diabetic rats was significantly greater than in the normal group. The content of trisphosphate inositol (IP3) in the gastric antral smooth muscle of rats with diabetes was significantly lower than that of the normal group. After blocking PKA with N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H-89, a blockage PKA), the effect of CNP on the production of IP3 was decreased, while blocking PKG with KT5823 (a blockage PKG) simultaneously, and CNP can no longer reduce the IP3 production. CNP promoted the phosphorylation of PLCβ3Ser1105, thereby inhibiting the activity of PLCβ3 in gastric smooth muscle tissue of rats with diabetes; this effect can be abolished by blocking PKA and PKG. These results suggested that CNP can decrease IP3 level in gastric smooth muscle cells and thus inhibit gastric smooth muscle contraction through PKG/PKA-PLCβ pathway, which may play an important role in the development of diabetic gastroparesis.
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Affiliation(s)
- Jun-Yu Guo
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Mo-Han Zhang
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Jing-Zhi Jiang
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Li-Hua Piao
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Xue-Sen Fang
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Zheng Jin
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China
| | - Ying-Lan Cai
- Department of Physiology, Yanbian University School of Medicine, 977 Gongyuan, Road, Jilin, Yanji 133002, China.
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Meier S, Andressen KW, Aronsen JM, Sjaastad I, Hougen K, Skomedal T, Osnes JB, Qvigstad E, Levy FO, Moltzau LR. PDE3 inhibition by C-type natriuretic peptide-induced cGMP enhances cAMP-mediated signaling in both non-failing and failing hearts. Eur J Pharmacol 2017; 812:174-183. [PMID: 28697992 DOI: 10.1016/j.ejphar.2017.07.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 12/28/2022]
Abstract
We have previously shown that the natriuretic peptide receptor B (NPR-B) agonist C-type natriuretic peptide (CNP) enhances cyclic adenosine 3´,5´-monophosphate (cAMP)-mediated signaling in failing hearts, through cyclic guanosine 3´,5´-monophosphate (cGMP)-mediated phosphodiesterase (PDE) 3 inhibition. As several signaling pathways are importantly changed in failing hearts, it could not be taken for granted that this crosstalk would be the same in non-failing hearts. Thus, we wanted to clarify to which extent this effect of CNP occurred also in non-failing hearts. Inotropic and lusitropic responses were measured in muscle strips and cGMP levels, localized cAMP levels, cAMP-PDE activity and mRNA levels were analyzed in isolated cardiomyocytes from left ventricles of non-failing and failing rat hearts. CNP increased cGMP and enhanced β1- and β2-adrenoceptor-mediated inotropic and β1-adrenoceptor-mediated lusitropic responses, in non-failing and failing hearts. The NPR-A agonist brain natriuretic peptide (BNP) increased cGMP, but did not affect inotropic or lusitropic responses, indicating different compartmentation of cGMP from the two natriuretic peptide receptors. cAMP-PDE activity of PDE3 was concentration-dependently inhibited by cGMP with the same potency and to the same extent in non-failing and failing cardiomyocytes. CNP enhanced β1-adrenoceptor-induced cAMP increase in living cardiomyocytes in the absence, but not in the presence of a PDE3 inhibitor indicating involvement of PDE3. In summary, CNP sensitizes cAMP-mediated signaling in non-failing as in failing hearts, via NPR-B-mediated increase of cGMP that inhibits the cAMP-PDE activity of PDE3.
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Affiliation(s)
- Silja Meier
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Kjetil Wessel Andressen
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jan Magnus Aronsen
- Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Institute for Experimental Medical Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Bjørknes College, Oslo, Norway
| | - Ivar Sjaastad
- Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Institute for Experimental Medical Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Karina Hougen
- Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Institute for Experimental Medical Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Tor Skomedal
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jan-Bjørn Osnes
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Eirik Qvigstad
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Finn Olav Levy
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.
| | - Lise Román Moltzau
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
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Holditch SJ, Schreiber CA, Harris PC, LaRusso NF, Ramirez-Alvarado M, Cataliotti A, Torres VE, Ikeda Y. B-type natriuretic peptide overexpression ameliorates hepatorenal fibrocystic disease in a rat model of polycystic kidney disease. Kidney Int 2017; 92:657-668. [PMID: 28416225 DOI: 10.1016/j.kint.2017.02.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 02/05/2017] [Accepted: 02/16/2017] [Indexed: 12/15/2022]
Abstract
Polycystic kidney disease (PKD) involves progressive hepatorenal cyst expansion and fibrosis, frequently leading to end-stage renal disease. Increased vasopressin and cAMP signaling, dysregulated calcium homeostasis, and hypertension play major roles in PKD progression. The guanylyl cyclase A agonist, B-type natriuretic peptide (BNP), stimulates cGMP and shows anti-fibrotic, anti-hypertensive, and vasopressin-suppressive effects, potentially counteracting PKD pathogenesis. Here, we assessed the impacts of guanylyl cyclase A activation on PKD progression in a rat model of PKD. Sustained BNP production significantly reduced kidney weight, renal cystic indexes and fibrosis, in concert with suppressed hepatic cystogenesis in vivo. In vitro, BNP decreased cystic epithelial cell proliferation, suppressed fibrotic gene expression, and increased intracellular calcium. Together, our data demonstrate multifaceted effects of sustained activation of guanylyl cyclase A on polycystic kidney and liver disease. Thus, targeting the guanylyl cyclase A-cGMP axis may provide a novel therapeutic strategy for hepatorenal fibrocystic diseases.
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Affiliation(s)
- Sara J Holditch
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Claire A Schreiber
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic Translational Polycystic Kidney Disease Center, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Alessandro Cataliotti
- Institute for Experimental Medical Research, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic Translational Polycystic Kidney Disease Center, Mayo Clinic, Rochester, Minnesota, USA
| | - Yasuhiro Ikeda
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA.
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CNP-pGC-cGMP-PDE3-cAMP Signal Pathway Upregulated in Gastric Smooth Muscle of Diabetic Rats. Gastroenterol Res Pract 2015; 2015:305258. [PMID: 25883642 PMCID: PMC4390109 DOI: 10.1155/2015/305258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/01/2014] [Indexed: 12/26/2022] Open
Abstract
Our previous studies have shown that CNP-NPR-B/pGC-cGMP is upregulated in the diabetic rats. The present study was designed to determine whether the upregulation of CNP-NPR-B/pGC-cGMP signal pathway affects cGMP-PDE3-cAMP signal pathway in diabetic gastric smooth muscle. The gastric smooth muscle motility was observed by using isometric measurement. PDEs expressions in diabetic gastric smooth muscle tissue were observed by using immunohistochemistry, Western blotting, and RT-PCR methods. The results demonstrated that the inhibitory effect of CNP on the spontaneous contraction of gastric antral circular smooth muscle was potentiated in STZ-induced diabetic rat. CNP-induced increase of cGMP and cAMP was much higher in diabetic gastric smooth muscle tissue than in controls. The expression of PDE3 is downregulated while the levels of gene expression of PDE1, PDE2, PDE4, and PDE5 were not altered in the diabetic gastric smooth muscle tissue. The results suggest that the sensitivity of gastric smooth muscle to CNP is potentiated via activation of CNP-pGC-cGMP-PDE3-cAMP signal pathway in STZ-induced diabetic rats, which may be associated with diabetes-induced gastric motility disorder.
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Li P, Tang XD, Cai ZX, Qiu JJ, Lin XL, Zhu T, Owusu L, Guo HS. CNP signal pathway up-regulated in rectum of depressed rats and the interventional effect of Xiaoyaosan. World J Gastroenterol 2015; 21:1518-1530. [PMID: 25663771 PMCID: PMC4316094 DOI: 10.3748/wjg.v21.i5.1518] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 08/28/2014] [Accepted: 10/21/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the distribution and expression of C-type natriuretic peptide (CNP)/natriuretic peptide receptor B (NPR-B) in the rectum of a rodent depression model and the interventional effect of Xiaoyaosan (XYS).
METHODS: Male rats (n = 45) of clean grade (200 ± 20 g) were divided into five groups after one week of adaptive feeding: primary control, depression model, low dose XYS, middle dose XYS, and high dose XYS. The animal experiment continued for 3 wk. Primary controls were fed normally ad libitum. The rats of all other groups were raised in solitary and exposed to classic chronic mild unpredictable stimulation each day. XYS groups were perfused intragastrically with low dose, middle dose, and high dose XYS one hour before stimulation. Primary control and depression model groups were perfused intragastrically with normal saline under similar conditions as the XYS groups. Three weeks later, all rats were sacrificed, and the expression levels of CNP and NPR-B in rectum tissues were analyzed by immunohistochemistry, real-time polymerase chain reaction, and Western blotting.
RESULTS: CNP and NPR-B were both expressed in the rectum tissues of all rats. However, the expression levels of CNP and NPR-B at both gene and protein levels in the depression model group were significantly higher when compared to the primary control group (n = 9; P < 0.01). XYS intervention markedly inhibited the expression levels of CNP and NPR-B in depressed rats. The expression levels of CNP and NPR-B in the high dose XYS group did not significantly differ from the expression levels in the primary control group. Additionally, the high and middle dose XYS groups (but not the low dose group) significantly exhibited lower CNP and NPR-B expression levels in the rectum tissues of the respectively treated rats compared to the untreated depression model cohort (n = 9; P < 0.01).
CONCLUSION: The CNP/NPR-B pathway is upregulated in the rectum of depressed rats and may be one mechanism for depression-associated digestive disorders. XYS antagonizes this pathway at least partially.
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MESH Headings
- Animals
- Antidepressive Agents/pharmacology
- Behavior, Animal/drug effects
- Depression/drug therapy
- Depression/genetics
- Depression/metabolism
- Depression/psychology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drugs, Chinese Herbal/pharmacology
- Male
- Natriuretic Peptide, C-Type/genetics
- Natriuretic Peptide, C-Type/metabolism
- RNA, Messenger/metabolism
- Rats, Sprague-Dawley
- Receptors, Atrial Natriuretic Factor/drug effects
- Receptors, Atrial Natriuretic Factor/genetics
- Receptors, Atrial Natriuretic Factor/metabolism
- Rectum/drug effects
- Rectum/metabolism
- Signal Transduction/drug effects
- Time Factors
- Up-Regulation
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