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Generation and identification of endothelial-specific Hrh2 knockout mice. Transgenic Res 2021; 30:251-261. [PMID: 33786748 DOI: 10.1007/s11248-021-00244-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/13/2021] [Indexed: 12/11/2022]
Abstract
Histamine H2 receptor (HRH2) is closely associated with the development of cardiovascular and cerebrovascular diseases. However, systematic Hrh2 knockout mice did not exactly reflect the HRH2 function in specific cell or tissue types. To better understand the physiological and pathophysiological functions of endothelial HRH2, this study constructed a targeting vector that contained loxp sites flanking the ATG start codon located in Hrh2 exon 2 upstream and a neomycin (Neo) resistance gene flanked by self-deletion anchor sites within the mouse Hrh2 allele. The targeting vector was then electroporated into C57BL/6J embryonic stem (ES) cells, and positively targeted ES cell clones were micoinjected into C57BL/6J blastocysts, which were implanted into pseudopregnant females to obtain chimeric mice. The F1 generation of Hrh2flox/+ mice was generated via crossing chimeric mice with wild-type mice to excise Neo. We also successfully generated endothelial cell-specific knockout (ECKO) mice by crossing Hrh2flox/+ mice with Cdh5-Cre mice that specifically express Cre in endothelial cells and identified that Hrh2 deletion was only observed in endothelial cells. Hrh2flox/+ and Hrh2ECKO mice were normal, healthy and fertile and did not display any obvious abnormalities. These novel animal models will create new prospects for exploring roles of HRH2 during the development and treatment of related diseases.
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Ichikawa H, Sugimoto M, Sakao Y, Sahara S, Ohashi N, Sano K, Tadokoro S, Azekura H, Shimomura A, Yamashita F, Sugiyama D, Fukuta K, Furuta T, Kato A, Sugimoto K, Yasuda H. Eradication therapy for Helicobacter pylori infection improves nutrition status in Japanese hemodialysis patients: a pilot study. J Clin Biochem Nutr 2018; 64:91-95. [PMID: 30705518 PMCID: PMC6348417 DOI: 10.3164/jcbn.18-61] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 06/25/2018] [Indexed: 12/28/2022] Open
Abstract
Plasma ghrelin level is influenced by Helicobacter pylori (H. pylori) status and the severity of gastric mucosal atrophy, and the ghrelin level is associated with nutrition status in hemodialysis patients. Here, we investigated the efficacy of H. pylori eradication therapy in improving nutrition status in relation to the ghrelin level in H. pylori-positive hemodialysis patients. Of H. pylori-positive patients receiving hemodialysis at 8 dialysis center, 21 patients underwent gastroduodenoscopy for evaluation of the severity of gastric atrophy, and nutrition markers and plasma ghrelin levels before and 1 year after H. pylori eradication therapy were evaluated. Serum cholinesterase level was significantly increased after H. pylori eradication compared with the level before eradication (303.2 ± 76.0 vs 287.3 ± 68.1 IU/L, p = 0.029). In particular, cholesterol (before, 196.6 ± 23.2 mg/dl; after, 206.1 ± 25.9 mg/dl, p = 0.042) and cholinesterase levels (before, 296.9 ± 70.8 IU/L; after, 316.4 ± 73.8 IU/L, p = 0.049) increased more strongly in patients with mild–moderate atrophy than those with severe atrophy, irrespective of improvement of plasma acyl-ghrelin and desacyl-ghrelin levels after eradication therapy. In conclusion, H. pylori eradication may improve nutrition status by increasing serum cholinesterase and cholesterol levels in hemodialysis patients, especially those with mild and moderate gastric mucosal atrophy.
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Affiliation(s)
- Hitomi Ichikawa
- First Department of Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Mitsushige Sugimoto
- Division of Digestive Endoscopy, Shiga University of Medical Science Hospital, Seta, Tsukinowa-cho, Otsu, Shiga 520-2192, Japan
| | - Yukitoshi Sakao
- Hamana Clinic, 235-1 Numa, Hamakita-ku, Hamamatsu, Shizuoka 434-0037, Japan
| | - Shu Sahara
- First Department of Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Naro Ohashi
- First Department of Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Koji Sano
- Sano Clinic, 1818 Tennou-cho, Higashi-ku, Hamamatsu, Shizuoka 435-0052, Japan
| | - Shigeru Tadokoro
- Tadokoro Clinic, 1239 Uchino, Hamakita-ku, Hamamatsu, Shizuoka 434-0044, Japan
| | - Hisanori Azekura
- Sanaru Sun Clinic, 2-14-39 Higashiiba, Naka-ku, Hamamatsu, Shizuoka 432-8036, Japan
| | - Akira Shimomura
- Sanarudai Asahi Clinic, 5-20-10 Sanarudai, Naka-ku, Hamamatsu, Shizuoka 432-8021, Japan
| | - Fuyuki Yamashita
- Yamashita Clinic, 2-1-5 Nakaizumi, Iwata, Shizuoka 438-0078, Japan
| | - Daiki Sugiyama
- Satsuki no Mori Clinic, 1665-2 Nakase, Hamakita-ku, Hamamatsu, Shizuoka 434-0012, Japan
| | - Ken Fukuta
- Hiryu Clinic, 304-9 Akura, Futamata-cho, Tenryu-ku, Hamamatsu, Shizuoka 431-3311, Japan
| | - Takahisa Furuta
- Center for Clinical Research, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Akihiko Kato
- Blood Purification Unit, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Ken Sugimoto
- First Department of Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Hideo Yasuda
- First Department of Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
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Yang CG, Liao ZF, Qiu WC, Yan J, Wang ZG. Function of ghrelin and ghrelin receptors in the network regulation of gastric motility. Mol Med Rep 2014; 10:2453-8. [PMID: 25230765 DOI: 10.3892/mmr.2014.2571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 05/21/2014] [Indexed: 12/23/2022] Open
Abstract
Numerous previous studies have demonstrated that ghrelin promotes gastric motility when administered peripherally. This effect appears to be regulatory but not directly stimulatory, and therefore may involve a number of complex mechanisms. In the periphery, ghrelin may affect gastric motility through intercellular networks among interstitial cells of Cajal, myenteric nerve cells and smooth muscle cells. The aim of the present study was to investigate the effects and possible mechanisms underlying this hypothesis. The effects of ghrelin on the contraction force of gastric antrum smooth muscle strips of rats were studied in the presence or absence of carbachol (CCh), [D‑Lys3]‑GHRP‑6, atropine, tetrodotoxin (TTX) and nimodipine in vitro. The expression of ghrelin receptors (GHS‑Rs) on different cell types in gastric muscle layers was observed by means of immunofluorescence. Ghrelin enhanced smooth muscle strip contraction induced by CCh, but when CCh was absent, this effect was eliminated. Atropine and nimodipine eradicated the muscle strip contraction enhanced by ghrelin, while [D‑Lys3]‑GHRP‑6 was only able to partly block this effect and TTX had no effect on muscle strip contraction. It was identified that ghrelin had no effect on the contractive rhythm of the strips. GHS‑R1s were located differentially depending on the cell type, including myenteric nerve cells, interstitial cells of Cajal and smooth muscle cells. In conclusion the present study demonstrated that ghrelin may act as an adjuvant to regulate gastric smooth muscle contraction induced by CCh through GHS‑R1s, which are expressed on myenteric nerve cells, Cajal cells and smooth muscle cells. Ghrelin may exert its effects by influencing the functional status of different cell types in the gastric muscle layer to subsequently enhance the contractive effect of cholinergic neurotransmitters and enhance gastric motility.
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Affiliation(s)
- Cheng-Guang Yang
- Department of General Surgery, The Affiliated Tongren Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200336, P.R. China
| | - Zuo-Fu Liao
- Department of General Surgery, The Affiliated Tongren Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200336, P.R. China
| | - Wen-Cai Qiu
- Department of General Surgery, The Affiliated Sixth Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Jun Yan
- Department of General Surgery, The Affiliated Sixth Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Zhi-Gang Wang
- Department of General Surgery, The Affiliated Sixth Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200233, P.R. China
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Yang CG, Wang WG, Yan J, Fei J, Wang ZG, Zheng Q. Gastric motility in ghrelin receptor knockout mice. Mol Med Rep 2012; 7:83-8. [PMID: 23128468 DOI: 10.3892/mmr.2012.1157] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Accepted: 10/11/2012] [Indexed: 11/06/2022] Open
Abstract
The aim of this study was to investigate the effects and possible mechanisms of ghrelin receptor (GHS-R) deficiency on gastric motility in GHS-R deficient (Ghsr-/-) mice. Ghsr-/- and control (Ghsr+/+) mice were genotyped by PCR. The percentage of gastric emptying (GE%) was calculated following the intraperitoneal adminis-tration of ghrelin. In vitro, the contractile response of smooth muscle strips to ghrelin and electrical field stimulation (EFS) and the intraluminal pressure change of isolated stomach to carbachol were observed in an organ bath. The staining of nerve cells in the gastric muscle layer was performed by immunofluorescence. Delayed gastric emptying was observed in the Ghsr-/- mice; ghrelin enhanced the GE% in the Ghsr+/+ mice but had no effect on the GE% in the Ghsr-/- mice. In vitro, the response of the strips to ghrelin and EFS and the intraluminal pressure change to cabarchol was reduced in the Ghsr-/- mice. GHS-Rs were predominantly expressed on nerve cells in gastric muscle layers. The number of nerve cells was observed to be decreased in the Ghsr-/- mice. The delayed gastric emptying may relate to the loss of GHS-Rs and the reduction in the number of nerve cells in the gastric muscle layers of the GHS-R-deficient mice.
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Affiliation(s)
- Cheng-Guang Yang
- Department of General Surgery, The Affiliated Sixth Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200233, PR China
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Veldhuis JD, Bowers CY. Integrating GHS into the Ghrelin System. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010:879503. [PMID: 20798846 PMCID: PMC2925380 DOI: 10.1155/2010/879503] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/30/2009] [Indexed: 12/21/2022]
Abstract
Oligopeptide derivatives of metenkephalin were found to stimulate growth-hormone (GH) release directly by pituitary somatotrope cells in vitro in 1977. Members of this class of peptides and nonpeptidyl mimetics are referred to as GH secretagogues (GHSs). A specific guanosine triphosphatate-binding protein-associated heptahelical transmembrane receptor for GHS was cloned in 1996. An endogenous ligand for the GHS receptor, acylghrelin, was identified in 1999. Expression of ghrelin and homonymous receptor occurs in the brain, pituitary gland, stomach, endothelium/vascular smooth muscle, pancreas, placenta, intestine, heart, bone, and other tissues. Principal actions of this peptidergic system include stimulation of GH release via combined hypothalamopituitary mechanisms, orexigenesis (appetitive enhancement), insulinostasis (inhibition of insulin secretion), cardiovascular effects (decreased mean arterial pressure and vasodilation), stimulation of gastric motility and acid secretion, adipogenesis with repression of fat oxidation, and antiapoptosis (antagonism of endothelial, neuronal, and cardiomyocyte death). The array of known and proposed interactions of ghrelin with key metabolic signals makes ghrelin and its receptor prime targets for drug development.
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Affiliation(s)
- Johannes D. Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Cyril Y. Bowers
- Division of Endocrinology, Department of Internal Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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