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Shen R, Li Z, Wang H, Wang Y, Li X, Yang Q, Fu Y, Li M, Gao LN. Chinese Materia Medica in Treating Depression: The Role of Intestinal Microenvironment. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2023; 51:1927-1955. [PMID: 37930334 DOI: 10.1142/s0192415x23500854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Depression is a highly heterogeneous mental illness. Drug treatment is currently the main therapeutic strategy used in the clinic, but its efficacy is limited by the modulation of a single target, slow onset, and side effects. The gut-brain axis is of increasing interest because intestinal microenvironment disorders increase susceptibility to depression. In turn, depression affects intestinal microenvironment homeostasis by altering intestinal tissue structure, flora abundance and metabolism, hormone secretion, neurotransmitter transmission, and immune balance. Depression falls into the category of "stagnation syndrome" according to Traditional Chinese Medicine (TCM), which further specifies that "the heart governs the spirit and is exterior-interior with the small intestine". However, the exact mechanisms of the means by which the disordered intestinal microenvironment affects depression are still unclear. Here, we present an overview of how the Chinese materia medica (CMM) protects against depression by repairing intestinal microenvironment homeostasis. We review the past five years of research progress in classical antidepressant TCM formulae and single CMMs on regulating the intestinal microenvironment for the treatment of depression. We then analyze and clarify the multitarget functions of CMM in repairing intestinal homeostasis and aim to provide a new theoretical basis for CMM clinical application in the treatment of depression.
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Affiliation(s)
- Ruhui Shen
- College of Pharmacy, Binzhou Medical University, Yantai, Shandong 264003, P. R. China
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
| | - Zhipeng Li
- College of Pharmacy, Binzhou Medical University, Yantai, Shandong 264003, P. R. China
| | - Huiyun Wang
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
- Shandong Collaborative Innovation Center for Diagnosis, Treatment and Behavioral Interventions of Mental Disorders, Institute of Mental Health, Jining Medical University, Jining, Shandong 272067, P. R. China
| | - Yongchao Wang
- Rizhao Hospital of Traditional Chinese Medicine, Rizhao, Shandong 276800, P. R. China
| | - Xiaofang Li
- Rizhao Hospital of Traditional Chinese Medicine, Rizhao, Shandong 276800, P. R. China
| | - Qian Yang
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
| | - Yingjie Fu
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
| | - Ming Li
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
| | - Li-Na Gao
- College of Pharmacy, Jining Medical University, Rizhao, Shandong 276800, P. R. China
- Shandong Collaborative Innovation Center for Diagnosis, Treatment and Behavioral Interventions of Mental Disorders, Institute of Mental Health, Jining Medical University, Jining, Shandong 272067, P. R. China
- Jining Key Laboratory of Depression Prevention and Treatment, Jining Medical University, Jining, Shandong 272067, P. R. China
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Qiu P, Li D, Xiao C, Xu F, Chen X, Chang Y, Liu L, Zhang L, Zhao Q, Chen Y. The Eph/ephrin system symphony of gut inflammation. Pharmacol Res 2023; 197:106976. [PMID: 38032293 DOI: 10.1016/j.phrs.2023.106976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/15/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023]
Abstract
The extent of gut inflammation depends largely on the gut barrier's integrity and enteric neuroimmune interactions. However, the factors and molecular mechanisms that regulate inflammation-related changes in the enteric nervous system (ENS) remain largely unexplored. Eph/ephrin signaling is critical for inflammatory response, neuronal activation, and synaptic plasticity in the brain, but its presence and function in the ENS have been largely unknown to date. This review discusses the critical role of Eph/ephrin in regulating gut homeostasis, inflammation, neuroimmune interactions, and pain pathways. Targeting the Eph/ephrin system offers innovative treatments for gut inflammation disorders, offering hope for enhanced patient prognosis, pain management, and overall quality of life.
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Affiliation(s)
- Peishan Qiu
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Daojiang Li
- Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Cong Xiao
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Fei Xu
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Xiaoyu Chen
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Ying Chang
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Lan Liu
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China
| | - Lei Zhang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Qiu Zhao
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China.
| | - Yuhua Chen
- Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Hubei Clinical Center & Key Lab of Intestinal & Colorectal Diseases, Wuhan 430071, China.
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Park KH, Lee H, Kim HC, Choi I, Han SB, Kang JS. VDUP1 Deficiency Promotes the Severity of DSS-Induced Colitis in Mice by Inducing Macrophage Infiltration. Int J Mol Sci 2023; 24:13584. [PMID: 37686390 PMCID: PMC10487977 DOI: 10.3390/ijms241713584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
The loss of vitamin D3 upregulated protein 1 (VDUP1) has been implicated in the pathogenesis of various inflammation-related diseases. Notably, reduced expression of VDUP1 has been observed in clinical specimens of ulcerative colitis (UC). However, the role of VDUP1 deficiency in colitis remains unclear. In this study, we investigated the role of VDUP1 in dextran sulfate sodium (DSS)-induced experimental colitis in mice. VDUP1-deficient mice were more susceptible to DSS-induced colitis than their wild-type (WT) littermates after 2% DSS administration. VDUP1-deficient mice exhibited an increased disease activity index (DAI) and histological scores, as well as significant colonic goblet cell loss and an increase in apoptotic cells. These changes were accompanied by a significant decrease in MUC2 mRNA expression and a marked increase in proinflammatory cytokines and chemokines within damaged tissues. Furthermore, phosphorylated NF-κB p65 expression was significantly upregulated in damaged tissues in the context of VDUP1 deficiency. VDUP1 deficiency also led to significant infiltration of macrophages into the site of ulceration. An in vitro chemotaxis assay confirmed that VDUP1 deficiency enhanced bone marrow-derived macrophage (BMDM) chemotaxis induced by CCL2. Overall, this study highlights VDUP1 as a regulator of UC pathogenesis and a potential target for the future development of therapeutic strategies.
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Affiliation(s)
- Ki Hwan Park
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji, Cheongwon, Cheongju 28116, Republic of Korea; (K.H.P.); (H.L.); (H.-C.K.)
| | - Hyunju Lee
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji, Cheongwon, Cheongju 28116, Republic of Korea; (K.H.P.); (H.L.); (H.-C.K.)
| | - Hyoung-Chin Kim
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji, Cheongwon, Cheongju 28116, Republic of Korea; (K.H.P.); (H.L.); (H.-C.K.)
| | - Inpyo Choi
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro Yuseoung-gu, Daejeon 34141, Republic of Korea;
| | - Sang-Bae Han
- College of Pharmacy, Chungbuk National University, 194-21 Osongsaengmyung-1-ro, Heungdeok-gu, Cheongju 28116, Republic of Korea;
| | - Jong Soon Kang
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji, Cheongwon, Cheongju 28116, Republic of Korea; (K.H.P.); (H.L.); (H.-C.K.)
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Mou Y, Bai X, Ma H, Li T, Zhao Y, Wu T, Zhang Y, Qu H, Kong H, Wang X, Zhao Y. Protective effect of carbon dots derived from scrambled Coptidis Rhizoma against ulcerative colitis in mice. Front Mol Biosci 2023; 10:1253195. [PMID: 37711388 PMCID: PMC10498776 DOI: 10.3389/fmolb.2023.1253195] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023] Open
Abstract
Introduction: Ulcerative colitis (UC) is a chronic and progressive inflammatory disease of the intestines. The primary symptoms, such as bloody diarrhea, can result in weight loss and significantly diminish the patient's quality of life. Despite considerable research endeavors, this disease remains incurable. The scrambled Coptidis Rhizoma (SCR) has a rich historical background in traditional Chinese medicine as a remedy for UC. Drawing from a wealth of substantial clinical practices, this study is focused on investigating the protective effects and underlying mechanisms of the active component of SCR, namely SCR-based carbon dots (SCR-CDs), in the treatment of UC. Methods: SCR-CDs were extracted and isolated from the decoction of SCR, followed by a comprehensive characterization of their morphological structure and functional groups. Subsequently, we investigated the effects of SCR-CDs on parameters such as colonic length, disease activity index, and histopathological architecture using the dextran sulfate sodium (DSS)-induced colitis mice model. Furthermore, we delved into the assessment of key aspects, including the expression of intestinal tight junction (TJ) proteins, inflammatory cytokines, oxidative stress markers, and gut microbial composition, to unravel the intricate mechanisms underpinning their therapeutic effects. Results: SCR-CDs displayed a consistent spherical morphology, featuring uniform dispersion and diameters ranging from 1.2 to 2.8 nm. These SCR-CDs also exhibited a diverse array of surface chemical functional groups. Importantly, the administration of SCR-CDs, particularly at higher dosage levels, exerted a noteworthy preventive influence on colonic shortening, elevation of the disease activity index and colonic tissue impairment caused by DSS. These observed effects may be closely associated with the hygroscopic capability and hemostatic bioactivity inherent to SCR-CDs. Concurrently, the application of SCR-CDs manifested an augmenting impact on the expression of intestinal TJ proteins, concomitantly leading to a significant reduction in inflammatory cell infiltration and amelioration of oxidative stress. Additionally, SCR-CDs treatment facilitated the restoration of perturbed gut microbial composition, potentially serving as a fundamental mechanism underlying their observed protective effects. Conclusion: This study demonstrates the significant therapeutic potential of SCR-CDs in UC and provides elucidation on some of their mechanisms. Furthermore, these findings hold paramount importance in guiding innovative drug discovery for anti-UC agents.
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Affiliation(s)
- Yanfang Mou
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Xue Bai
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- Henan University of Chinese Medicine, Zhengzhou, China
| | - Huagen Ma
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Tingjie Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Yafang Zhao
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Tong Wu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Yue Zhang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Huihua Qu
- Center of Scientific Experiment, Beijing University of Chinese Medicine, Beijing, China
| | - Hui Kong
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Xueqian Wang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yan Zhao
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
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Giraudo A, Pallavicini M, Bolchi C. Small molecule ligands for α9* and α7 nicotinic receptors: a survey and an update, respectively. Pharmacol Res 2023; 193:106801. [PMID: 37236412 DOI: 10.1016/j.phrs.2023.106801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
The α9- and α7-containing nicotinic acetylcholine receptors (nAChRs) mediate numerous physiological and pathological processes by complex mechanisms that are currently the subject of intensive study and debate. In this regard, selective ligands serve as invaluable investigative tools and, in many cases, potential therapeutics for the treatment of various CNS disfunctions and diseases, neuropathic pain, inflammation, and cancer. However, the present scenario differs significantly between the two aforementioned nicotinic subtypes. Over the past few decades, a large number of selective α7-nAChR ligands, including full, partial and silent agonists, antagonists, and allosteric modulators, have been described and reviewed. Conversely, reports on selective α9-containing nAChR ligands are relatively scarce, also due to a more recent characterization of this receptor subtype, and hardly any focusing on small molecules. In this review, we focus on the latter, providing a comprehensive overview, while providing only an update over the last five years for α7-nAChR ligands.
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Affiliation(s)
- Alessandro Giraudo
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy
| | - Marco Pallavicini
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy
| | - Cristiano Bolchi
- Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133 Milano, Italy.
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Keever KR, Yakubenko VP, Hoover DB. Neuroimmune nexus in the pathophysiology and therapy of inflammatory disorders: role of α7 nicotinic acetylcholine receptors. Pharmacol Res 2023; 191:106758. [PMID: 37028776 DOI: 10.1016/j.phrs.2023.106758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 04/08/2023]
Abstract
The α7-nicotinic acetylcholine receptor (α7nAChR) is a key protein in the cholinergic anti-inflammatory pathway (CAP) that links the nervous and immune systems. Initially, the pathway was discovered based on the observation that vagal nerve stimulation (VNS) reduced the systemic inflammatory response in septic animals. Subsequent studies form a foundation for the leading hypothesis about the central role of the spleen in CAP activation. VNS evokes noradrenergic stimulation of ACh release from T cells in the spleen, which in turn activates α7nAChRs on the surface of macrophages. α7nAChR-mediated signaling in macrophages reduces inflammatory cytokine secretion and modifies apoptosis, proliferation, and macrophage polarization, eventually reducing the systemic inflammatory response. A protective role of the CAP has been demonstrated in preclinical studies for multiple diseases including sepsis, metabolic disease, cardiovascular diseases, arthritis, Crohn's disease, ulcerative colitis, endometriosis, and potentially COVID-19, sparking interest in using bioelectronic and pharmacological approaches to target α7nAChRs for treating inflammatory conditions in patients. Despite a keen interest, many aspects of the cholinergic pathway are still unknown. α7nAChRs are expressed on many other subsets of immune cells that can affect the development of inflammation differently. There are also other sources of ACh that modify immune cell functions. How the interplay of ACh and α7nAChR on different cells and in various tissues contributes to the anti-inflammatory responses requires additional study. This review provides an update on basic and translational studies of the CAP in inflammatory diseases, the relevant pharmacology of α7nAChR-activated drugs and raises some questions that require further investigation.
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Yang WJ, Han FH, Gu YP, Qu H, Liu J, Shen JH, Leng Y. TGR5 agonist inhibits intestinal epithelial cell apoptosis via cAMP/PKA/c-FLIP/JNK signaling pathway and ameliorates dextran sulfate sodium-induced ulcerative colitis. Acta Pharmacol Sin 2023:10.1038/s41401-023-01081-y. [PMID: 36997665 PMCID: PMC10374578 DOI: 10.1038/s41401-023-01081-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/15/2023] [Indexed: 04/01/2023] Open
Abstract
Excessive apoptosis of intestinal epithelial cell (IEC) is a crucial cause of disrupted epithelium homeostasis, leading to the pathogenesis of ulcerative colitis (UC). The regulation of Takeda G protein-coupled receptor-5 (TGR5) in IEC apoptosis and the underlying molecular mechanisms remained unclear, and the direct evidence from selective TGR5 agonists for the treatment of UC is also lacking. Here, we synthesized a potent and selective TGR5 agonist OM8 with high distribution in intestinal tract and investigated its effect on IEC apoptosis and UC treatment. We showed that OM8 potently activated hTGR5 and mTGR5 with EC50 values of 202 ± 55 nM and 74 ± 17 nM, respectively. After oral administration, a large amount of OM8 was maintained in intestinal tract with very low absorption into the blood. In DSS-induced colitis mice, oral administration of OM8 alleviated colitis symptoms, pathological changes and impaired tight junction proteins expression. In addition to enhancing intestinal stem cell (ISC) proliferation and differentiation, OM8 administration significantly reduced the rate of apoptotic cells in colonic epithelium in colitis mice. The direct inhibition by OM8 on IEC apoptosis was further demonstrated in HT-29 and Caco-2 cells in vitro. In HT-29 cells, we demonstrated that silencing TGR5, inhibition of adenylate cyclase or protein kinase A (PKA) all blocked the suppression of JNK phosphorylation induced by OM8, thus abolished its antagonizing effect against TNF-α induced apoptosis, suggesting that the inhibition by OM8 on IEC apoptosis was mediated via activation of TGR5 and cAMP/PKA signaling pathway. Further studies showed that OM8 upregulated cellular FLICE-inhibitory protein (c-FLIP) expression in a TGR5-dependent manner in HT-29 cells. Knockdown of c-FLIP blocked the inhibition by OM8 on TNF-α induced JNK phosphorylation and apoptosis, suggesting that c-FLIP was indispensable for the suppression of OM8 on IEC apoptosis induced by OM8. In conclusion, our study demonstrated a new mechanism of TGR5 agonist on inhibiting IEC apoptosis via cAMP/PKA/c-FLIP/JNK signaling pathway in vitro, and highlighted the value of TGR5 agonist as a novel therapeutic strategy for the treatment of UC.
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Affiliation(s)
- Wen-Ji Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fang-Hui Han
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yi-Pei Gu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hui Qu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jia Liu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jian-Hua Shen
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ying Leng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Dahlgren D, Nylander O, Sjöblom M. Hypotonicity-Induced Increase in Duodenal Mucosal Permeability Is Regulated by Cholinergic Receptors in Rats. Dig Dis Sci 2022; 68:1815-1823. [PMID: 36436156 PMCID: PMC10133373 DOI: 10.1007/s10620-022-07764-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 11/08/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND The role of cholinergic receptors in the regulation of duodenal mucosal permeability in vivo is currently not fully described. AIMS To elucidate the impact of nicotinic and muscarinic acetylcholine receptor signaling in response to luminal hypotonicity (50 mM NaCl) in the proximal small intestine of rat. METHODS The effect on duodenal blood-to-lumen clearance of 51Cr-EDTA (i.e., mucosal permeability) and motility was studied in the absence and presence of nicotinic and muscarinic receptor agonists and antagonists, a sodium channel blocker (tetrodotoxin), and after bilateral cervical vagotomy. RESULTS Rats with duodenal contractions responded to luminal hypotonicity by substantial increase in intestinal permeability. This response was absent in animals given a non-selective nicotinic receptor antagonist (mecamylamine) or agonist (epibatidine). Pretreatment with tetrodotoxin reduced the increase in mucosal permeability in response to luminal hypotonicity. Further, the non-selective muscarinic receptor antagonist (atropine) and agonist (bethanechol) reduced the hypotonicity-induced increase in mucosal permeability, while vagotomy was without an effect, suggesting that local enteric reflexes dominate. Finally, neither stimulating nor blocking the α7-nicotinic receptor had any significant effects on duodenal permeability in response to luminal hypotonicity, suggesting that this receptor is not involved in regulation of duodenal permeability. The effect of the different drugs on mucosal permeability was similar to the effect observed for duodenal motility. CONCLUSIONS A complex enteric intramural excitatory neural reflex involving both nicotinic and muscarinic receptor subtypes mediates an increase in mucosal permeability induced by luminal hypotonicity.
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Affiliation(s)
- David Dahlgren
- Department of Medical Cell Biology, Uppsala University, 751 23, Uppsala, Sweden.
| | - Olof Nylander
- Department of Medical Cell Biology, Uppsala University, 751 23, Uppsala, Sweden
| | - Markus Sjöblom
- Department of Medical Cell Biology, Uppsala University, 751 23, Uppsala, Sweden
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