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Chen BW, Chen SZ, Fang JQ, Jing XH. [Research progress and problems of neurobiological mechanisms of acupuncture underlying improvement of irritable bowel syndrome]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2021; 46:885-92. [PMID: 34698465 DOI: 10.13702/j.1000-0607.201262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In recent years, many studies have confirmed the positive effect of acupuncture and moxibustion in the treatment of irritable bowel syndrome (IBS), and a lot of researches have been made to explore its neurobiological mechanisms. The neurobiological mechanisms include two aspects 1) remission of visceral hypersensitivity via peripheral and central pathways (spinal cord and brain), and 2) improvement of intestinal motility via vagus nerve and enteric nervous system (ENS)- interstitial cells of Cajal (ICC)-smooth muscle cells (ENS-ICC-SMC) network, and 5-HT, vasoactive intestinal peptide (VIP), neuropeptide Y, etc.. At the same time, we also discussed the existing problems in the research of the underlying neurobiological mechanisms of acupuncture and moxibustion for IBS. The existing problems in this field mainly include 1) fragmentization or lack of integrity in researches, and 2) limitation of the reductionism method. For this reason, we should draw lessons from the research methods of systematic science to study the neurobiological mechanisms of acupuncture and moxibustion in the treatment of IBS, including the detailed links of peripheral and central nervous transmission of acupoint stimulation signals, and the interactive action modes (two-way benign regulation, multi-target regulation, saturation regulation, etc.).
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Videlock EJ, Chang L. Latest Insights on the Pathogenesis of Irritable Bowel Syndrome. Gastroenterol Clin North Am 2021; 50:505-522. [PMID: 34304785 DOI: 10.1016/j.gtc.2021.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The pathogenesis of irritable bowel syndrome is multifactorial and complex. Our understanding of its pathophysiology has evolved, but remains incompletely understood. Symptoms result from a dysregulation of brain-gut interactions. Evidence has identified alterations in central and peripheral (gut) mechanisms in irritable bowel syndrome and the bidirectional communication between the brain and the gut. Pertinent mechanisms include disturbed gut motility, visceral hypersensitivity, altered mucosal and immune function, altered gut microbiota, and altered central nervous system processing. This review addresses factors that increase the risk of irritable bowel syndrome and the central and peripheral mechanisms thought to underlie its symptoms.
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Wang T, Li L, Li S, Zhao H, Qu J, Xia Y, Li Y. Clostridium butyricum relieve the visceral hypersensitivity in mice induced by Citrobacter rodentium infection with chronic stress. PeerJ 2021; 9:e11585. [PMID: 34221718 PMCID: PMC8223894 DOI: 10.7717/peerj.11585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/20/2021] [Indexed: 12/13/2022] Open
Abstract
Background Visceral hypersensitivity is a common symptom in patients with post-infectious irritable bowel syndrome (PI-IBS), and change of the microbiota is a vital etiological factor of it. Clostridium butyricum (C. butyricum) is one of the probiotics which is reported as the active components in the treatment of IBS, especially IBS with diarrhea. Citrobacter rodentium (C. rodentium) is an enteropathogenic bacteria which can produce self-limiting colitis in mice, which have been used to produce a PI-IBS-like mice model. Whether C. butyricum could influence the visceral hypersensitivity and gut microbiota of PI-IBS is still unknown. Our study aimed to examine whether the intervention of C. butyricum or antibiotics could affect the etiology of visceral hypersensitivity. Methods C57BL/6 male mice were gavaged with the C. rodentium to induce a infective colitis. The C. butyricum and antibiotic compound were used to intervene the infected mice 3 days later. A 9-day chronic water avoidance stress (WAS) process was implemented to help induce the visceral hypersensitivity. The abdominal withdrawal reflex (AWR) score was assayed to indicate the visceral hypersensitivity of different groups. On the 7th, 14th, and 30th days after infection, mice feces were collected and high-throughput sequencing was carried out to analyze their gut microbiota. Results Combined, the C. rodentium infection plus chronic stress (WAS) could induce the visceral hypersensitivity in mice. Treatment of the C. butyricum after C. rodentium infection could relieve visceral hypersensitivity of mice, while no difference was observed in the antibiotic treatment group. The gut microbiota diversity of C. rodentium infected mice was similar to the uninfected mice, while there were different microbial communities structure between them. The Shannon and Chao indexes significantly decreased in the antibiotic treatment group compared to other groups at 7th, 14th, and 30th days post-infection, while treatment of C. butyricum could maintain the indexes within normal range. At day 14 after infection, the structure of microbiota headed towards normality after the C. butyricum treatment. After the WAS, the Shannon and Chao indexes of the control group decreased and the structure of microbiota changed. The C. butyricum treatment could prevent these changes of the gut microbiota induced by WAS. Conclusion C. butyricum could relieve the visceral hypersensitivity in mice induced by C. rodentium infection plus chronic stress. It could also remodel the microbiota change caused by the infection and chronic stress. It may be a more effective treatment strategy for PI-IBS than antibiotics.
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Chen Y, Zhao Y, Wang L, Yao JP, Li Y, Zhou SY. [Involvement of Pirt /TRPV1 signaling in acupuncture-induced reduction of visceral hypersensitivity in diarrhea-predominant irritable bowel syndrome rats]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2021; 46:278-83. [PMID: 33931991 DOI: 10.13702/j.1000-0607.200442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE To observe the effect of electroacupuncture (EA) on the expression of Pirt (a regulator of TRPV1) in the dorsal root ganglia (DRG) and transient receptor potential vanilloid 1 (TRPV1, a molecular sensor of noxious heat and capsaicin) in the colonic mucosa in rats suffering from diarrhea-predominant irritable bowel syndrome (IBS-D), so as to explore its mechanisms underlying alleviation of visceral hypersensitivity of IBS-D. METHODS Forty SD rats (half male and half female) were randomly assigned to control, model, EA, and medication groups by lottery, with 10 rats in each group. The IBS-D model was established by chronic unpredictable mild stress (CUMS) and gavage of senna soaking fluid. Rats in the EA group received EA (2 Hz/15 Hz,0.1-1 mA) stimulation of unilateral "Tianshu"(ST25), "Zusanli" (ST36), "Sanyinjiao"(SP6) and "Taichong"(LR3) for 15 min once a day for 14 days, and rats of the medication group received intragastric administration of pinave-rium bromide (10 mL/kg, 2.7 mg/mL) once daily for 14 days. The visceral pain threshold (VPT) was measured by using abdominal wall withdrawal reflex (AWR) test. The diarrhea index (loose stool rate [total number of loose stool/total number of defecation] X mean loose degree [0-4 grades according to the filter paper stain diameter] in 6 h/d) was used to assess the severity of diarrhea. The expression of Pirt in the DRG and TRPV1 in the colonic mucosa tissue was detected using immunohistochemistry. RESULTS After modeling, the VPT was obviously reduced (P<0.01), while the diarrhea index, mean optical density of Pirt and TRPV1 were remarkably increased in the model group relevant to the control group (P<0.01). After the interventions, the VPT was obviously increased while the diarrhea index, and the mean optical density of Pirt and TRPV1 was noticeably decreased in both EA and the medicine groups in contrast to the model group (P<0.01). No significant differences were found between the EA and medicine groups in up-regulating VPT and down-regulating the diarrhea index, and Pirt and TRPV1 expression (P>0.05). CONCLUSION EA can effectively alleviate visceral hypersensitivity in IBS-D rats, which may be related to its effect in down-regulating the expression level of DRG Pirt and colonic TRPV1.
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Ma J, Wang FY, Xu L, Wang YF, Tang XD. Mechanism of mast cell-mediated COX2-PGE2-Eps signaling pathway in visceral hypersensitivity in irritable bowel syndrome. Shijie Huaren Xiaohua Zazhi 2021; 29:306-311. [DOI: 10.11569/wcjd.v29.i6.306] [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] [Indexed: 02/06/2023] Open
Abstract
Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder (FGID) whose pathophysiological mechanism is complex, involving genetic factors, psychosocial factors, low-grade mucosal inflammation, changes in the intestinal barrier, bacterial flora disorder, neuroimmune abnormalities, and high visceral sensitivity. In recent years, the mechanism of visceral hypersensitivity in IBS has become a hot research topic. Mast cells (MCs) are a group of immune cells that are distributed in the central nervous system and digestive system. The COX2-PGE2-Eps signaling pathway plays a major role in the visceral hypersensitivity in IBS, from peripheral sensitization to central sensitization, which provides a new idea for further clarifying the pathological mechanism of IBS.
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Chen Z, Zhou T, Zhang Y, Dong H, Jin W. Mast cells in the paraventricular nucleus participate in visceral hypersensitivity induced by neonatal maternal separation. Behav Brain Res 2021; 402:113113. [PMID: 33412227 DOI: 10.1016/j.bbr.2020.113113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/11/2020] [Accepted: 12/28/2020] [Indexed: 02/08/2023]
Abstract
Early-life stress (ELS) is a high-risk factor for the development of chronic visceral pain in adulthood. Emerging evidence suggests that mast cells play a key role in the development of visceral hypersensitivity through interaction with neurons. The sensitization of corticotropin-releasing factor (CRF) neurons in the hypothalamic paraventricular nucleus (PVN) plays a pivotal role in the pathogenesis of visceral pain. However, the precise mechanism by which mast cells and CRF neurons interact in the PVN in the pathogenesis of visceral hypersensitivity remains elusive. In the present study, we used neonatal maternal separation (MS), an ELS model, and observed that neonatal MS induced visceral hypersensitivity and triggered PVN mast cell activation in adult rats, which was repressed by intra-PVN infusion of the mast cell stabilizer disodium cromoglycate (cromolyn). Wild-type (WT) mice but not mast cell-deficient KitW-sh/W-sh mice that had experienced neonatal MS exhibited chronic visceral hypersensitivity. MS was associated with an increase in the expression of proinflammatory mediators, the number of CRF+ cells and CRF protein in the PVN, which was prevented by intra-PVN infusion of cromolyn. Furthermore, we demonstrated that intra-PVN infusion of the mast degranulator compound 48/80 significantly induced mast cell activation, resulting in proinflammatory mediator release, CRF neuronal sensitization, and visceral hypersensitivity, which was suppressed by cromolyn. Overall, our findings demonstrated that neonatal MS induces the activation of PVN mast cells, which secrete numerous proinflammatory mediators that may participate in neighboring CRF neuronal activity, ultimately directly inducing visceral hypersensitivity in adulthood.
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Lin Z, Wang Y, Lin S, Liu D, Mo G, Zhang H, Dou Y. Identification of potential biomarkers for abdominal pain in IBS patients by bioinformatics approach. BMC Gastroenterol 2021; 21:48. [PMID: 33530940 PMCID: PMC7852366 DOI: 10.1186/s12876-021-01626-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 01/25/2021] [Indexed: 12/30/2022] Open
Abstract
Background Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disease characterized by chronic abdominal discomfort and pain. The mechanisms of abdominal pain, as a relevant symptom, in IBS are still unclear. We aimed to explore the key genes and neurobiological changes specially involved in abdominal pain in IBS. Methods Gene expression data (GSE36701) was downloaded from Gene Expression Omnibus database. Fifty-three rectal mucosa samples from 27 irritable bowel syndrome with diarrhea (IBS-D) patients and 40 samples from 21 healthy volunteers as controls were included. Differentially expressed genes (DEGs) between two groups were identified using the GEO2R online tool. Functional enrichment analysis of DEGs was performed on the DAVID database. Then a protein–protein interaction network was constructed and visualized using STRING database and Cytoscape. Results The microarray analysis demonstrated a subset of genes (CCKBR, CCL13, ACPP, BDKRB2, GRPR, SLC1A2, NPFF, P2RX4, TRPA1, CCKBR, TLX2, MRGPRX3, PAX2, CXCR1) specially involved in pain transmission. Among these genes, we identified GRPR, NPFF and TRPA1 genes as potential biomarkers for irritating abdominal pain of IBS patients. Conclusions Overexpression of certain pain-related genes (GRPR, NPFF and TRPA1) may contribute to chronic visceral hypersensitivity, therefore be partly responsible for recurrent abdominal pain or discomfort in IBS patients. Several synapses modification and biological process of psychological distress may be risk factors of IBS.
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Lingpeng P, Jingzhu S, Wei L, Enqi W, Yaqin L. Effect of water extracts from Cynanchum thesioides (Freyn) K. Schum. on visceral hypersensitivity and gut microbiota profile in maternally separated rats. JOURNAL OF ETHNOPHARMACOLOGY 2021; 264:113352. [PMID: 32891821 DOI: 10.1016/j.jep.2020.113352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Irritable bowel syndrome (IBS) is a chronic, stress-related, functional gastrointestinal disorder characterized by abdominal discomfort and altered bowel habits; the manipulation of the microbiota is emerging as a promising therapeutic option for IBS. Cynanchum thesioides (CT) is an herb of traditional Mongolian medicine that has been employed in treating abdominal pain and diarrhea for hundreds of years. Phytochemical studies of this plant showed the presence of various flavonoids with antibacterial and anti-inflammatory activities. We hypothesized that Cynanchum thesioides manipulates the gut mycobiome and reverses visceral hypersensitivity in IBS rat model. PURPOSE OF THE STUDY The aims of this study were to prove the in vivo efficacy of Cynanchum thesioides on improving visceral hypersensitivity in IBS rat model and to examine its effect on gut bacterial communities, focusing on the potential interrelationships among microbiota and visceral hypersensitivity. MATERIALS AND METHODS We induced visceral hypersensitivity rat models by maternal separation (MS) of Sprague-Dawley rats, and administered CT water extracts to MS rats for 10 consecutive days. The abdominal withdrawal reflex score and threshold of colorectal distention were employed to assess visceral sensitivity. We then used the Illumina HiSeq platform to analyze bacterial 16S rRNA gene. RESULTS Treatment with CT improved visceral hypersensitivity in MS rats, and this was accompanied by alterations in the structure and composition of the gut microbiota. The extent of the stability of the gut microbiota was improved after treatment with CT. The genera Pseudomonas, Lachnospiracea_incertae_sedis, and Clostridium XlVa (which were more prevalent in MS rats) were significantly decreased, whereas the abundance of some genera were less prevalent in MS rats-for example, Clostridium IV, Elusimicrobium, Clostridium_sensu_stricto, and Acetatifactor were significantly enriched after treatment with CT. CONCLUSION Water-extracted CT was beneficial against visceral hypersensitivity in IBS and favorably affected the structure, composition, and functionality of gut microbiota. CT is therefore a promising agent in therapy of IBS.
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Wei W, Wang HF, Zhang Y, Zhang YL, Niu BY, Yao SK. Altered metabolism of bile acids correlates with clinical parameters and the gut microbiota in patients with diarrhea-predominant irritable bowel syndrome. World J Gastroenterol 2020; 26:7153-7172. [PMID: 33362374 PMCID: PMC7723672 DOI: 10.3748/wjg.v26.i45.7153] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/21/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bile acids (BAs) have attracted attention in the research of irritable bowel syndrome with predominant diarrhea (IBS-D) due to their ability to modulate bowel function and their tight connection with the gut microbiota. The composition of the fecal BA pool in IBS-D patients is reportedly different from that in healthy populations. We hypothesized that BAs may participate in the pathogenesis of IBS-D and the altered BA profile may be correlated with the gut microbiome. AIM To investigate the role of BAs in the pathogenesis of IBS-D and the correlation between fecal BAs and gut microbiota. METHODS Fifty-five IBS-D patients diagnosed according to the Rome IV criteria and twenty-eight age-, sex-, and body mass index-matched healthy controls (HCs) were enrolled in this study at the gastroenterology department of China-Japan Friendship Hospital. First, clinical manifestations were assessed with standardized questionnaires, and visceral sensitivity was evaluated via the rectal distension test using a high-resolution manometry system. Fecal primary BAs including cholic acid (CA) and chenodeoxycholic acid (CDCA), secondary BAs including deoxycholic acid (DCA), lithocholic acid (LCA), and ursodeoxycholic acid (UDCA) as well as the corresponding tauro- and glyco-BAs were examined by ultraperformance liquid chromatography coupled to tandem mass spectrometry. The gut microbiota was analyzed using 16S rRNA gene sequencing. Correlations between fecal BAs with clinical features and gut microbiota were explored. RESULTS Fecal CA (IBS-D: 3037.66 [282.82, 6917.47] nmol/g, HC: 20.19 [5.03, 1304.28] nmol/g; P < 0.001) and CDCA (IBS-D: 1721.86 [352.80, 2613.83] nmol/g, HC: 57.16 [13.76, 1639.92] nmol/g; P < 0.001) were significantly increased, while LCA (IBS-D: 1621.65 [58.99, 2396.49] nmol/g, HC: 2339.24 [1737.09, 2782.40]; P = 0.002] and UDCA (IBS-D: 8.92 [2.33, 23.93] nmol/g, HC: 17.21 [8.76, 33.48] nmol/g; P = 0.025) were significantly decreased in IBS-D patients compared to HCs. Defecation frequency was positively associated with CA (r = 0.294, P = 0.030) and CDCA (r = 0.290, P = 0.032) and negatively associated with DCA (r = -0.332, P = 0.013) and LCA (r = -0.326, P = 0.015) in IBS-D patients. In total, 23 of 55 IBS-D patients and 15 of 28 HCs participated in the visceral sensitivity test. The first sensation threshold was negatively correlated with CDCA (r = -0.459, P = 0.028) in IBS-D patients. Furthermore, the relative abundance of the family Ruminococcaceae was significantly decreased in IBS-D patients (P < 0.001), and 12 genera were significantly lower in IBS-D patients than in HCs (P < 0.05), with 6 belonging to Ruminococcaceae. Eleven of these genera were negatively correlated with primary BAs and positively correlated with secondary BAs in all subjects. CONCLUSION The altered metabolism of BAs in the gut of IBS-D patients was associated with diarrhea and visceral hypersensitivity and might be ascribed to dysbiosis, especially the reduction of genera in Ruminococcaceae.
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Zhang Z, Engel MA, Koch E, Reeh PW, Khalil M. Menthacarin induces calcium ion influx in sensory neurons, macrophages and colonic organoids of mice. Life Sci 2020; 264:118682. [PMID: 33127519 DOI: 10.1016/j.lfs.2020.118682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/19/2020] [Accepted: 10/24/2020] [Indexed: 02/08/2023]
Abstract
AIMS Menthacarin is a herbal combination that is clinically used for the treatment of functional gastrointestinal disorders (FGIDs). In several clinical studies, Menthacarin reduced visceral hypersensitivity-related symptoms. Pathogenesis of visceral hypersensitivity is multifactorial. This involves several cell types and different transient receptor potential ion channels (TRPs); these ion channels are highly conductive for calcium ions. Since transient changes in cytosolic calcium levels are crucial for many functions of living cells, we investigated if Menthacarin can induce calcium influx in sensory, largely nociceptive, neurons from dorsal root ganglia (DRG), peritoneal macrophages (PMs) and colonic organoids. MAIN METHODS We employed the calcium imaging technique on sensory neurons from DRG, PMs and colonic organoids isolated from mice. All cells were superfused by Menthacarin at several concentrations (600, 1200, 1800 μg/ml) during the experiments, followed by calcium ionophor ionomycin (Iono., 1 μM) as a positive control. KEY FINDINGS Menthacarin induced concentration-dependent calcium ion influx in all investigated cell types. Furthermore, repeated applications of Menthacarin induced tachyphylaxis (desensitisation) of calcium responses in sensory neurons and colonic organoids. SIGNIFICANCE Menthacarin-induced calcium influx into sensory neurons, macrophages and colonic organoids is probably related to its clinical desensitising effects in patients with FGIDs.
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Adult Stress Promotes Purinergic Signaling to Induce Visceral Pain in Rats with Neonatal Maternal Deprivation. Neurosci Bull 2020; 36:1271-1280. [PMID: 32909219 PMCID: PMC7674540 DOI: 10.1007/s12264-020-00575-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/08/2020] [Indexed: 12/17/2022] Open
Abstract
Chronic visceral pain is one of the primary symptoms of patients with irritable bowel syndrome (IBS), which affects up to 15% of the population world-wide. The detailed mechanisms of visceral pain remain largely unclear. Our previous studies have shown that neonatal maternal deprivation (NMD) followed by adult multiple stress (AMS) advances the occurrence of visceral pain, likely due to enhanced norepinephrine (NE)-β2 adrenergic signaling. This study was designed to explore the roles of P2X3 receptors (P2X3Rs) in the chronic visceral pain induced by combined stress. Here, we showed that P2X3Rs were co-expressed in β2 adrenergic receptor (β2-AR)-positive dorsal root ganglion neurons and that NE significantly enhanced ATP-induced Ca2+ signals. NMD and AMS not only significantly increased the protein expression of P2X3Rs, but also greatly enhanced the ATP-evoked current density, number of action potentials, and intracellular Ca2+ concentration of colon-related DRG neurons. Intrathecal injection of the P2X3R inhibitor A317491 greatly attenuated the visceral pain and the ATP-induced Ca2+ signals in NMD and AMS rats. Furthermore, the β2-AR antagonist butoxamine significantly reversed the expression of P2X3Rs, the ATP-induced current density, and the number of action potentials of DRG neurons. Overall, our data demonstrate that NMD followed by AMS leads to P2X3R activation, which is most likely mediated by upregulation of β2 adrenergic signaling in primary sensory neurons, thus contributing to visceral hypersensitivity.
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Tong L, Wu LB, Li N, Cheng HL, Cai RL, Chu HR. [Moxibustion relieves abdominal hypersensitivity and diarrhea by regulating colonic 5-hydroxytryptamine signaling pathway in rats with diarrhea type irritable bowel syndrome]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2020; 45:535-540. [PMID: 32705826 DOI: 10.13702/j.1000-0607.190857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
OBJECTIVE To observe the effect of moxibustion on visceral pain, diarrhea, colonic 5-hydroxytryptamine (5-HT) content, and expression of tryptophan hydroxylase 1 (TPH1), serotonin reup take transporter (SERT) and 5-hydroxytryptamine receptor 3 (5-HT3R) in colon tissue of rats with diarrhea irritable bowel syndrome (IBS-D), so as to reveal its underlying mechanisms in treating IBS-D. METHODS Thirty male SD rats were randomly divided into blank control, model and moxibustion groups (n=10 rats in each group). The IBS-D model was established by chronic restraint combined with gavage of Senna leaf solution. Moxibustion was applied to bilateral "Tianshu" (ST25) and "Shangjuxu" (ST37) for 30 min, once a day for 7 days. After the treatment, the loose stool rate (number of loose stool/total number of feces granules X100%) and the minimum volume threshold of abdominal reflex (abdominal pain threshold) induced by rectal dilatation were observed. The content of colonic 5-HT was detected by using ELISA, and the expression of TPH1, SERT and 5-HT3R mRNAs and proteins were detected by using quantitative real time-PCR and Western blot, respectively. RESULTS Compared with the blank control group, the minimum volume threshold of abdominal retraction reflex and the relative expression of SERT protein and mRNA were significantly decreased (P<0.01), and the loose stool rate, colonic 5-HT content, and relative expression of TPH1 and 5-HT3R proteins and mRNAs were notably increased in the model group (P<0.01). After moxibustion, both the decrease of minimum volume threshold and SERT protein and mRNA expressions and the increase of loose stool rate, colonic 5-HT content and TPH1 and 5-HT3R protein and mRNA expressions were reversed (P<0.01). CONCLUSION Moxibustion of ST25 and ST37 can relieve abdominal hypersensitivity and diarrhea in IBS-D model rats, which is related to its effects in down-regulating colonic 5-HT content and expression of TPH1 and 5-HT3R proteins and mRNAs and in up-regulating expression of SERT protein and mRNA (regulating 5-HT/5-HT3R signaling)..
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Roudsari NM, Lashgari NA, Zandi N, Pazoki B, Momtaz S, Sahebkar A, Abdolghaffari AH. PPARγ: A turning point for irritable bowel syndrome treatment. Life Sci 2020; 257:118103. [PMID: 32681913 DOI: 10.1016/j.lfs.2020.118103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/05/2020] [Accepted: 07/12/2020] [Indexed: 02/06/2023]
Abstract
Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal (GI) disorder with negative impacts on quality of life of patients. Although the etiology of the disease is still unclear, there are a set of mechanisms and factors involved in IBS pathogenesis. Visceral hypersensitivity, impaired gut barrier, along with minor inflammation and oxidative stress are the most important triggers for IBS induction. Activation of peroxisome proliferator activated receptor-γ (PPAR-γ) has been shown to improve gut barrier, downregulate pro-inflammatory cytokines, reduce free radical production through antioxidative mechanisms, and exert anti-nociceptive effects against somatic pain. An electronic search in PubMed, Google Scholar, Scopus, and Cochrane library was performed and relevant clinical, in vivo and in vitro articles published between 2004 and June 2020 were collected. Search terms included "Irritable Bowel Syndrome" OR "IBS" OR "visceral hypersensitivity" OR "motility dysfunction" AND "peroxisome proliferator activated receptors" OR "PPAR". Herein, the efficacy of PPARγ signaling as a potential target for IBS treatment is reviewed.
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Song Y, Meng QX, Wu K, Hua R, Song ZJ, Song Y, Qin X, Cao JL, Zhang YM. Disinhibition of PVN-projecting GABAergic neurons in AV region in BNST participates in visceral hypersensitivity in rats. Psychoneuroendocrinology 2020; 117:104690. [PMID: 32417623 DOI: 10.1016/j.psyneuen.2020.104690] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/09/2020] [Accepted: 04/13/2020] [Indexed: 02/08/2023]
Abstract
Ample evidence suggests that early life stress (ELS) is a high-risk factor for the development of visceral pain disorders, whereas the mechanism underlying neuronal circuit remains elusive. Herein, we employed neonatal colorectal distension (CRD) to induce visceral hypersensitivity in rats. A combination of electrophysiology, pharmacology, behavioral test, molecular biology, chemogenetics and optogenetics confirmed that CRD in neonatal rats could predispose the elevated firing frequency of the parvocellular corticotropin-releasing hormone (CRH) neurons in the paraventricular nucleus of hypothalamus (PVN) in adulthood, with the CRH neurons activated and the frequency of spontaneous inhibitory postsynaptic currents (sIPSC) diminished, both contributing to chronic visceral hypersensitivity. Moreover, following administration of exogenous GABA (300 mM/0.5 μL) and GABAA receptor agonist muscimol (3 mM/0.5 μL) in PVN, visceral hyperalgesia was abrogated. In addition, the PVN-projecting GABAergic neurons were mainly distributed in the anterior ventral (AV) region in the bed nucleus of stria terminalis (BNST), and the excitability of these GABAergic neurons was weakened in visceral hypersensitivity. Specific depletion of the GABAergic neurons in AV region precipitated visceral hyperalgesia. Moreover, chemogenetic activation of the PVN-projecting neurons alleviated the visceral hypersensitivity. Photoactivation of PVN-projecting GABAergic neurons abated the visceral hypersensitivity in neonatal-CRD rats, whereas photoinhibition evoked visceral hyperalgesia in naïve rats. Our findings demonstrated that disinhibition of the PVN-projecting GABAergic neurons in AV region contributed to the excitation of CRH neurons, thereby mediating visceral hypersensitivity. Our study might provide a novel insight into the neuronal circuits involved in the ELS-induced visceral hypersensitivity.
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Qin G, Zhang Y, Yao SK. Serotonin transporter and cholecystokinin in diarrhea-predominant irritable bowel syndrome: Associations with abdominal pain, visceral hypersensitivity and psychological performance. World J Clin Cases 2020; 8:1632-1641. [PMID: 32432141 PMCID: PMC7211531 DOI: 10.12998/wjcc.v8.i9.1632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/21/2020] [Accepted: 04/04/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Visceral hypersensitivity and psychological performance are the main pathophysiological mechanisms of irritable bowel syndrome (IBS). Previous studies have found that cholecystokinin (CCK) can enhance colon movement and that serotonin transporter (SERT) is a transmembrane transport protein with high affinity for 5-hydroxytryptamine, which can rapidly reuptake 5-hydroxytryptamine and then regulate its action time and intensity. We speculate that SERT and CCK might play a role in the pathogenesis of diarrhea-predominant IBS (IBS-D) by affecting visceral sensitivity and the brain-gut axis. AIM To determine SERT and CCK levels in IBS-D patients diagnosed using Rome IV criteria and to analyze their associations with abdominal pain, visceral hypersensitivity and psychological performance. METHODS This study collected data from 40 patients with IBS-D at the China-Japan Friendship Hospital from September 2017 to April 2018 and 18 healthy controls. The severity of abdominal pain, visceral sensitivity and psychological performance were evaluated in IBS-D patients and healthy controls, the levels of SERT and CCK in plasma and colonic mucosa were evaluated, and the correlations between them were analyzed. RESULTS There were significant differences in the initial sensation threshold (31.00 ± 8.41 mL vs 52.22 ± 8.09 mL, P < 0.001), defecating sensation threshold (51.75 ± 13.57 mL vs 89.44 ± 8.73 mL, P < 0.001) and maximum tolerable threshold (97.25 ± 23.64 mL vs 171.11 ± 20.83 mL, P < 0.001) between the two groups. IBS-D patients had more severe anxiety (7.78 ± 2.62 vs 2.89 ± 1.02, P < 0.001) and depressive (6.38 ± 2.43 vs 2.06 ± 0.73, P < 0.001) symptoms than healthy controls. Significant differences were also found in mucosal CCK (2.29 ± 0.30 vs 1.66 ± 0.17, P < 0.001) and SERT (1.90 ± 0.51 vs 3.03 ± 0.23, P < 0.001) between the two groups. There was a significant positive correlation between pain scores and mucosal CCK (r = 0.96, 0.93, 0.94, P < 0.001). Significant negative correlations between anxiety (r = -0.98; P < 0.001), depression (r = -0.99; P < 0.001), pain evaluation (r = -0.96, -0.93, -0.95, P < 0.001) and mucosal SERT were observed. CONCLUSION IBS-D patients had psychosomatic disorders and visceral hypersensitivity. SERT and CCK might be involved in the pathogenesis of IBS-D by regulating the brain-gut axis and affecting visceral sensitivity. This provides a new potential method for identifying a more specific and effective therapeutic target.
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El-Salhy M, Hatlebakk JG, Hausken T. Possible role of peptide YY (PYY) in the pathophysiology of irritable bowel syndrome (IBS). Neuropeptides 2020; 79:101973. [PMID: 31727345 DOI: 10.1016/j.npep.2019.101973] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/15/2019] [Accepted: 09/18/2019] [Indexed: 12/19/2022]
Abstract
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder of unknown aetiology for which there is no effective treatment. Although IBS does not increase mortality, it reduces the quality of life and is an economic burden to both the patients themselves and society as a whole. Peptide YY (PYY) is localized in endocrine cells located in the ileum, colon and rectum. The concentration of PYY and the density of PYY cells are decreased in both the colon and rectum but unchanged in the ileum of patients with IBS. The low density of PYY cells in the large intestine may be caused by a decreased number of stem cells and their progeny toward endocrine cells. PYY regulates the intestinal motility, secretion and absorption as well as visceral sensitivity via modulating serotonin release. An abnormality in PYY may therefore contribute to the intestinal dysmotility and visceral hypersensitivity seen in IBS patients. Diet management involving consuming a low-FODMAP diet restores the density of PYY cells in the large intestine and improves abdominal symptoms in patients with IBS. This review shows that diet management appears to be a valuable tool for correcting the PYY abnormalities in the large intestine of IBS patients in the clinic.
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Zhang WX, Zhang Y, Qin G, Li KM, Wei W, Li SY, Yao SK. Altered profiles of fecal metabolites correlate with visceral hypersensitivity and may contribute to symptom severity of diarrhea-predominant irritable bowel syndrome. World J Gastroenterol 2019; 25:6416-6429. [PMID: 31798278 PMCID: PMC6881512 DOI: 10.3748/wjg.v25.i43.6416] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/19/2019] [Accepted: 11/01/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Fecal metabolites are associated with gut visceral sensitivity, mucosal immune function and intestinal barrier function, all of which have critical roles in the pathogenesis of irritable bowel syndrome (IBS). However, the metabolic profile and pathophysiology of IBS are still unclear. We hypothesized that altered profiles of fecal metabolites might be involved in the pathogenesis of IBS with predominant diarrhea (IBS-D). AIM To investigate the fecal metabolite composition and the role of metabolites in IBS-D pathophysiology. METHODS Thirty IBS-D patients and 15 age- and sex-matched healthy controls (HCs) underwent clinical and psychological assessments, including the IBS Symptom Severity System (IBS-SSS), an Italian modified version of the Bowel Disease Questionnaire, the Bristol Stool Form Scale (BSFS), the Hospital Anxiety and Depression Scale, and the Visceral Sensitivity Index. Visceral sensitivity to rectal distension was tested using high-resolution manometry system by the same investigator. Fecal metabolites, including amino acids and organic acids, were measured by targeted metabolomics approaches. Correlation analyses between these parameters were performed. RESULTS The patients presented with increased stool water content, more psychological symptoms and increased visceral hypersensitivity compared with the controls. In fecal metabolites, His [IBS-D: 0.0642 (0.0388, 0.1484), HC: 0.2636 (0.0780, 0.3966), P = 0.012], Ala [IBS-D: 0.5095 (0.2826, 0.9183), HC: 1.0118 (0.6135, 1.4335), P = 0.041], Tyr [IBS-D: 0.1024 (0.0173, 0.4527), HC: 0.5665 (0.2436, 1.3447), P = 0.018], Phe [IBS-D: 0.1511 (0.0775, 0.3248), HC: 0.3967 (0.1388, 0.7550), P = 0.028], and Trp [IBS-D: 0.0323 (0.0001, 0.0826), HC: 0.0834 (0.0170, 0.1759), P = 0.046] were decreased in IBS-D patients, but isohexanoate [IBS-D: 0.0127 (0.0060, 0.0246), HC: 0.0070 (0.0023, 0.0106), P = 0.028] was significantly increased. Only Tyr was mildly correlated with BSFS scores in all subjects (r = -0.347, P = 0.019). A possible potential biomarker panel was identified to correlate with IBS-SSS score (R 2 Adjusted = 0.693, P < 0.001). In this regression model, the levels of Tyr, Val, hexanoate, fumarate, and pyruvate were significantly associated with the symptom severity of IBS-D. Furthermore, visceral sensation, including abdominal pain and visceral hypersensitivity, was correlated with isovalerate, valerate and isohexanoate. CONCLUSION Altered profiles of fecal metabolites may be one of the origins or exacerbating factors of symptoms in IBS-D via increasing visceral sensitivity.
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Bai Y, Chen YB, Qiu XT, Chen YB, Ma LT, Li YQ, Sun HK, Zhang MM, Zhang T, Chen T, Fan BY, Li H, Li YQ. Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats. World J Gastroenterol 2019; 25:6077-6093. [PMID: 31686764 PMCID: PMC6824279 DOI: 10.3748/wjg.v25.i40.6077] [Citation(s) in RCA: 10] [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: 07/17/2019] [Revised: 09/06/2019] [Accepted: 09/10/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP). We hypothesized that the nucleus tractus solitarius (NTS), a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn, plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.
AIM To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.
METHODS CP was induced by the intraductal injection of trinitrobenzene sulfonic acid (TNBS) in rats. Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay. Neural activation of the NTS was indicated by immunohistochemical staining for Fos. Basic synaptic transmission within the NTS was assessed by electrophysiological recordings. Expression of vesicular glutamate transporters (VGluTs), N-methyl-D-aspartate receptor subtype 2B (NR2B), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1 (GluR1) was analyzed by immunoblotting. Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy. The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats.
RESULTS TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS. The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats (frequency: 5.87 ± 1.12 Hz in CP rats vs 2.55 ± 0.44 Hz in sham rats, P < 0.01; amplitude: 19.60 ± 1.39 pA in CP rats vs 14.71 ± 1.07 pA in sham rats; P < 0.01). CP rats showed upregulated expression of VGluT2, and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS. Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats (abdominal withdraw threshold: 7.00 ± 1.02 g in CNQX group, 8.00 ± 0.81 g in AP-5 group and 1.10 ± 0.27 g in saline group, P < 0.001). Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia (abdominal withdraw threshold: 13.67 ± 2.55 g in Gi group, 2.00 ± 1.37 g in Gq group, and 2.36 ± 0.67 g in mCherry group, P < 0.01).
CONCLUSION Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents, which provide novel insights into the central sensitization of painful CP.
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Bao CH, Wang CY, Li GN, Yan YL, Wang D, Jin XM, Wu LY, Liu HR, Wang XM, Shi Z, Wu HG. Effect of mild moxibustion on intestinal microbiota and NLRP6 inflammasome signaling in rats with post-inflammatory irritable bowel syndrome. World J Gastroenterol 2019; 25:4696-4714. [PMID: 31528095 PMCID: PMC6718040 DOI: 10.3748/wjg.v25.i32.4696] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/27/2019] [Accepted: 07/05/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND About one-third of refractory irritable bowel syndrome (IBS) cases are caused by gastrointestinal (GI) infection/inflammation, known as post-infectious/post-inflammatory IBS (PI-IBS). Although it is known that intestinal microbiota and host NOD-like receptor family pyrin domain containing 6 (NLRP6) inflammsome signaling are closely related to PI-IBS and moxibustion has a therapeutic effect on PI-IBS, whether moxibustion regulates the intestinal flora and host NLRP6 events in PI-IBS remains unclear. AIM To examine the regulatory effect of moxibustion on intestinal microbiota and host NLRP6 inflammatory signaling in PI-IBS. METHODS Sprague-Dawley rats were divided into a normal control group, a model control group, a mild moxibustion group, and a sham mild moxibustion group. PI-IBS rats in the mild moxibustion group were treated with moxibusiton at bilateral Tianshu (ST 25) and Zusanli (ST36) for 7 consecutive days for 10 min each time. The sham group rats were given the same treatment as the mild moxibustion group except the moxa stick was not ignited. Abdominal withdrawal reflex (AWR) score was measured to assess the visceral sensitivity, and colon histopathology and ultrastructure, colonic myeloperoxidase (MPO) activity, and serum C-reactive protein (CRP) level were measured to evaluate low-grade colonic inflammation in rats. The relative abundance of selected intestinal bacteria in rat feces was detected by 16S rDNA PCR and the NLRP6 inflammsome signaling in the colon was detected by immunofluorescence, qRT-PCR, and Western blot. RESULTS The AWR score was significantly decreased and the low-grade intestinal inflammation reflected by serum CRP and colonic MPO levels was inhibited in the mild moxibustion group compared with the sham group. Mild moxibustion remarkably increased the relative DNA abundances of Lactobacillus, Bifidobacterium, and Faecalibacterium prausnitzii but decreased that of Escherichia coli in the gut of PI-IBS rats. Additionally, mild moxibustion induced mRNA and protein expression of intestine lectin 1 but inhibited the expression of IL-1β, IL-18, and resistance-like molecule β by promoting the NLRP6 and reducing the mRNA and protein expression of apoptosis-associated speck-like protein containing CARD (ASC) and cysteinyl-aspartate-specific proteinase 1 (Caspase-1). The relative DNA abundances of Lactobacillus, Bifidobacteria, Faecalibacterium prausnitzii, and Escherichia coli in each group were correlated with the mRNA and protein expression of NLRP6, ASC, and Caspase-1 in the colon. CONCLUSION These findings indicated that mild moxibustion can relieve low-grade GI inflammation and alleviate visceral hypersensitivity in PI-IBS by regulating intestinal microbes and controlling NLRP6 inflammasome signaling.
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Yu ZC, Cen YX, Wu BH, Wei C, Xiong F, Li DF, Liu TT, Luo MH, Guo LL, Li YX, Wang LS, Wang JY, Yao J. Berberine prevents stress-induced gut inflammation and visceral hypersensitivity and reduces intestinal motility in rats. World J Gastroenterol 2019; 25:3956-3971. [PMID: 31413530 PMCID: PMC6689801 DOI: 10.3748/wjg.v25.i29.3956] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/26/2019] [Accepted: 07/05/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is a common chronic non-organic disease of the digestive system. Berberine (BBR) has been used to treat patients with IBS, but the underlying therapeutic mechanism is little understood. We believe that BBR achieves its therapeutic effect on IBS by preventing stress intestinal inflammation and visceral hypersensitivity and reducing bowel motility.
AIM To test the hypothesis that BBR achieves its therapeutic effect on IBS by preventing subclinical inflammation of the intestinal mucosa and reducing visceral hypersensitivity and intestinal motility.
METHODS IBS was induced in rats via water avoidance stress (WAS). qRT-PCR and histological analyses were used to evaluate the levels of cytokines and mucosal inflammation, respectively. Modified ELISA and qRT-PCR were used to evaluate the nuclear factor kappa-B (NF-κB) signal transduction pathway. Colorectal distention test, gastrointestinal transit measurement, Western blot, and qRT-PCR were used to analyze visceral sensitivity, intestinal motility, the expression of C-kit (marker of Cajal mesenchymal cells), and the expression of brain derived neurotrophic factor (BDNF) and its receptor TrkB.
RESULTS WAS led to mucosal inflammation, visceral hyperalgesia, and high intestinal motility. Oral administration of BBR inhibited the NF-κB signal transduction pathway, reduced the expression of pro-inflammatory cytokines [interleukin (IL)-1β, IL-6, interferon-γ, and tumor necrosis factor-α], promoted the expression of anti-inflammatory cytokines (IL-10 and transforming growth factor-β), and improved the terminal ileum tissue inflammation. BBR inhibited the expression of BDNF, TrkB, and C-kit in IBS rats, leading to the reduction of intestinal motility and visceral hypersensitivity. The therapeutic effect of BBR at a high dose (100 mg/kg) was superior to than that of the low-dose (25 mg/kg) group.
CONCLUSION BBR reduces intestinal mucosal inflammation by inhibiting the intestinal NF-κB signal pathway in the IBS rats. BBR reduces the expression of BDNF, its receptor TrkB, and C-kit. BBR also reduces intestinal motility and visceral sensitivity to achieve its therapeutic effect on IBS.
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Huang CS, Sun YH, Wang YT, Pan YH, Huang YC, Hsu CM, Tsai YF. Repeated transcutaneous electrical nerve stimulation of nonspecific acupoints of the upper body attenuates stress-induced visceral hypersensitivity in rats. Auton Neurosci 2019; 220:102556. [PMID: 31331689 DOI: 10.1016/j.autneu.2019.102556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 02/08/2023]
Abstract
Irritable bowel syndrome (IBS) is a common stress-related gastrointestinal disorder and visceral hypersensitivity (VH) is characteristically found in IBS patients. Transcutaneous electrical nerve stimulation (TENS) applied to certain acupoints has been shown to benefit IBS patients. Here, we investigated whether nonspecific acupoint is involved in the efficacy of TENS treatment for IBS. Twenty-five male rats were randomly assigned to four experimental groups and one sham-control group. The four experimental groups were defined as TENS-RR, TENS-RL, TENS-LR, and TENS-LL based on the location of the two TENS patches [right (R) or left (L)]. The former and latter letter pairs indicate that the patch locations were the upper chest and upper back, respectively. The heterotypic intermittent stress (HIS) protocol was performed for 16 days. VH was assessed by electromyography to evaluate response to rectal distention (RD). Modulated medium-frequency TENS, sweep range 1-10 Hz, amplitude slightly above the supra motor threshold, was applied 30 min per day followed by RD every second day for the final 7 days of the 16-day HIS period. VH was induced after the rats had been subjected to HIS for 10 days. A significant reduction of VH was observed only in the TENS-LL group compared with that in the sham-control group. These data suggest that repeated TENS treatment can alleviate stress-induced VH in rats. Further, whether TENS patches are attached to the left or right side of the body, which are nonspecific acupoints for gastrointestinal functions, may be an important factor in the treatment of stress-associated gastrointestinal symptoms.
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Inhibition of Mast Cell Degranulation Relieves Visceral Hypersensitivity Induced by Pancreatic Carcinoma in Mice. J Mol Neurosci 2019; 69:235-245. [PMID: 31201657 PMCID: PMC6732154 DOI: 10.1007/s12031-019-01352-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 05/29/2019] [Indexed: 12/14/2022]
Abstract
Cancer pain induced by pancreatic carcinoma is one of the most common symptoms and is difficult to endure, especially in the advanced stage. Evidence suggests that mast cells are recruited and degranulate in enteric disease-related visceral hypersensitivity. However, whether mast cells promote the visceral pain induced by pancreatic carcinoma remains unclear. Here, using toluidine blue staining and western blotting, we observed that mast cells were dramatically recruited to tissues surrounding pancreatic carcinoma, but not inside the carcinoma in patients with severe visceral pain. The levels of mast cell degranulation products, including tryptase, histamine, and nerve growth factor, were significantly increased in pericarcinoma tissues relative to their levels in normal controls, as evidenced by enzyme-linked immunosorbent assay. We determined that systemic administration of mast cell secretagogue compound 48/80 exacerbated pancreatic carcinoma-induced visceral hypersensitivity in a male BALB/c nude mouse model as assessed by measuring the hunching behavior scores and mechanical withdrawal response frequency evoked by von Frey stimulation. In contrast, the mast cell stabilizer ketotifen dose-dependently alleviated pancreatic cancer pain. In addition, we observed incomplete development of abdominal mechanical hyperalgesia and hunching behavior in mast cell–deficient mice with pancreatic carcinoma. However, ketotifen did not further attenuate visceral hypersensitivity in mast cell–deficient mice with carcinoma. Finally, we confirmed that intraplantar injection of pericarcinoma supernatants from BALB/c nude mice but not mast cell–deficient mice caused acute somatic nociception. In conclusion, our findings suggest that mast cells contribute to pancreatic carcinoma-induced visceral hypersensitivity through enrichment and degranulation in pericarcinoma tissues. The inhibition of mast cell degranulation may be a potential strategy for the therapeutic treatment of pancreatic carcinoma-induced chronic visceral pain.
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Li YJ, Dai C, Jiang M. Mechanisms of Probiotic VSL#3 in a Rat Model of Visceral Hypersensitivity Involves the Mast Cell-PAR2-TRPV1 Pathway. Dig Dis Sci 2019; 64:1182-1192. [PMID: 30560330 DOI: 10.1007/s10620-018-5416-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 12/06/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Mast cells (MCs), PAR2 and TRPV1, play a key role in the regulation of visceral pain. Several studies have found that probiotics regulate visceral sensitivity. AIMS The purpose of the current study was to explore the role of MC-PAR2-TRPV1 in VH and the mechanism of VSL#3 in a rat model of VH. METHODS A total of 64 rats were randomly divided into eight groups: Control VH, VH + ketotifen, VH + FSLLRY-NH2, VH + SB366791, VH + VSL#3, VH + VSL#3 + capsaicin, and VH + VSL#3 + SLIGRL-NH2. The rat model of VH was induced by acetic acid enema and the partial limb restraint method. VH was assessed by the abdominal withdrawal reflex score. MCs in colonic tissue were detected by the toluidine blue staining assay. The expression of PAR2 and TRPV1 in DRGs (L6-S1) was measured by immunohistochemistry and Western blotting. RESULTS The established VH was abolished by treatment with ketotifen, a mast cell stabilizer FSLLRY-NH2, a PAR2 antagonist SB366791 a TRPV1 antagonist, and probiotic VSL#3 in rats. The administration of ketotifen or probiotic VSL#3 caused a decrease in mast cell number in the colon and decreased PAR2 and TRPV1 expression in DRGs. Intrathecal injection of FSLLRY-NH2 or SB366791 caused decreased expression of PAR2 and/or TRPV1 in DRGs in VH rats. SLIGRL-NH2, a PAR2 agonist, and capsaicin, a TRPV1 agonist, blocked the effects of probiotic VSL#3. CONCLUSIONS The probiotic VSL#3 decreases VH in rat model of VH. The mechanism may be related with the mast cell-PAR2-TRPV1 signaling pathway.
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Zhang Y, Qin G, Liu DR, Wang Y, Yao SK. Increased expression of brain-derived neurotrophic factor is correlated with visceral hypersensitivity in patients with diarrhea-predominant irritable bowel syndrome. World J Gastroenterol 2019; 25:269-281. [PMID: 30670915 PMCID: PMC6337018 DOI: 10.3748/wjg.v25.i2.269] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Visceral hypersensitivity is considered to play a vital role in the pathogenesis of irritable bowel syndrome (IBS). Neurotrophins have drawn much attention in IBS recently. Brain-derived neurotrophic factor (BDNF) was found to mediate visceral hypersensitivity via facilitating sensory nerve growth in pre-clinical studies. We hypothesized that BDNF might play a role in the pathogenesis of diarrhea-predominant IBS (IBS-D).
AIM To investigate BDNF levels in IBS-D patients and its role in IBS-D pathophysiology.
METHODS Thirty-one IBS-D patients meeting the Rome IV diagnostic criteria and 20 age- and sex-matched healthy controls were recruited. Clinical and psychological assessments were first conducted using standardized questionnaires. Visceral sensitivity to rectal distension was tested using a high-resolution manometry system. Colonoscopic examination was performed and four mucosal pinch biopsies were taken from the rectosigmoid junction. Mucosal BDNF expression and nerve fiber density were analyzed using immunohistochemistry. Mucosal BDNF mRNA levels were quantified by quantitative real-time polymerase chain reaction. Correlations between these parameters were examined.
RESULTS The patients had a higher anxiety score [median (interquartile range), 6.0 (2.0-10.0) vs 3.0 (1.0-4.0), P = 0.003] and visceral sensitivity index score [54.0 (44.0-61.0) vs 21.0 (17.3-30.0), P < 0.001] than controls. The defecating sensation threshold [60.0 (44.0-80.0) vs 80.0 (61.0-100.0), P = 0.009], maximum tolerable threshold [103.0 (90.0-128.0) vs 182.0 (142.5-209.3), P < 0.001] and rectoanal inhibitory reflex threshold [30.0 (20.0-30.0) vs 30.0 (30.0-47.5), P = 0.032] were significantly lower in IBS-D patients. Intestinal mucosal BDNF protein [3.46E-2 (3.06E-2-4.44E-2) vs 3.07E-2 (2.91E-2-3.48E-2), P = 0.031] and mRNA [1.57 (1.31-2.61) vs 1.09 (0.74-1.42), P = 0.001] expression and nerve fiber density [4.12E-2 (3.07E-2-7.46E-2) vs 1.98E-2 (1.21E-2-4.25E-2), P = 0.002] were significantly elevated in the patients. Increased BDNF expression was positively correlated with abdominal pain and disease severity and negatively correlated with visceral sensitivity parameters.
CONCLUSION Elevated mucosal BDNF may participate in the pathogenesis of IBS-D via facilitating mucosal nerve growth and increasing visceral sensitivity.
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Chao G, Wang Y, Ye F, Zhang S. Regulation of Colonic Mucosal MicroRNA Expression via Multiple Targets in Visceral Hypersensitivity Rats by Tongxieyaofang. Yonsei Med J 2018; 59:945-950. [PMID: 30187701 PMCID: PMC6127421 DOI: 10.3349/ymj.2018.59.8.945] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/30/2018] [Accepted: 08/02/2018] [Indexed: 02/07/2023] Open
Abstract
PURPOSE This study aimed to screen for differentially expressed microRNAs (miRNAs) in the colons of rats with visceral hypersensitivity to build the expression profiles of miRNAs therein and to determine the mechanism of Tongxieyaofang use in the treatment of irritable bowel syndrome (IBS). MATERIALS AND METHODS Forty Sprague-Dawley rats were divided randomly into four groups: control group, model control group (induced by rectum stimulus and evaluated by abdominal withdraw reaction), treatment control group (normal saline), and Tongxieyaofang group (treated with Tongxieyaofang). We screened for differential expression of colonic mucosal miRNAs using liquid chip technology and verified the expression thereof using reverse transcription-PCR. RESULTS The visceral hypersensitivity rat model was successfully established. We found the expression of let-7f, let-7i, miR-130b, miR-29a, miR-132, miR-21, and miR-375 to be up-regulated (p<0.05), while the expression of miR-24, miR-31a, miR-192, miR-221, and miR-223 was down-regulated (p<0.05) in the visceral hypersensitivity rats. After treatment with Tongxieyaofang, the expression of let-7f, let-7i, miR-130b, miR-29a, miR-132, miR-21, and miR-375 was reduced (p<0.05), whereas the expression of miR-24, miR-31a, miR-192, miR-221, miR-223 was increased, compared to the treatment control group (p<0.05). CONCLUSION MiRNAs play a pivotal role in visceral hypersensitivity and might be targets in the treatment of IBS by Tongxieyaofang.
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