Pub Date : 2024-08-01Epub Date: 2024-07-02DOI: 10.1152/ajpgi.00123.2024
You-Min Lin, Ke Zhang, Ramasatyaveni Geesala, Kenneth E Lipson, Suimin Qiu, Don W Powell, Steven Cohn, Xuan-Zheng Shi
Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well understood. Transmural inflammation is associated with inflammatory cell infiltration, stenosis, and distention, which present mechanical stress (MS) to the bowel wall. We hypothesize that MS induces gene expression of profibrotic mediators such as connective tissue growth factor (CTGF), which may contribute to fibrosis in CD. A rodent model of CD was induced by intracolonic instillation of TNBS to the distal colon. TNBS instillation induced a localized transmural inflammation (site I), with a distended colon segment (site P) proximal to site I. We detected significant fibrosis and collagen content not only in site I but also in site P in CD rats by day 7. CTGF expression increased significantly in sites P and I, but not in the segment distal to the inflammation site. Increased CTGF expression was detected mainly in the smooth muscle cells (SMCs). When rats were fed exclusively with clear liquid diet to prevent mechanical distention in colitis, expression of CTGF in sites P and I was blocked. Direct stretch led to robust expression of CTGF in colonic SMC. Treatment of CD rats with anti-CTGF antibody FG-3149 reduced fibrosis and collagen content in both sites P and I and exhibited consistent trends toward normalizing expression of collagen mRNAs. In conclusion, our studies suggest that mechanical stress, by upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.NEW & NOTEWORTHY We found that CTGF expression increased significantly not only in the inflammation site but in the distended segment proximal to inflammation in a rodent model of CD-like colitis. Release of mechanical distention prevented CTGF expression in CD rats, whereas direct stretch induced CTGF expression. Treatment with anti-CTGF antibody reduced fibrosis and collagen contents in CD rats. Thus, mechanical stress, via upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.
克罗恩病(CD)是一种以跨膜炎症和肠纤维化为特征的炎症性肠病。克罗恩病纤维化的机制尚不十分清楚。跨壁炎症与炎症细胞浸润、狭窄和膨胀有关,这些因素对肠壁产生了机械应力(MS)。我们假设 MS 会诱导促纤维化介质(如结缔组织生长因子 (CTGF))的基因表达,这可能会导致 CD 的纤维化。我们通过向远端结肠灌注 TNBS 来诱导啮齿动物 CD 模型。TNBS 的灌注诱发了局部的跨膜炎症(部位 I),在部位 I 的近端有一个膨胀的结肠段(部位 P)。P部位和I部位的CTGF表达量明显增加,但炎症部位远端区段的CTGF表达量却没有增加。CTGF 表达的增加主要是在平滑肌细胞(SMC)中检测到的。当大鼠只吃清流食以防止结肠炎时的机械膨胀时,P 和 I 区段 CTGF 的表达受阻。直接拉伸导致 CTGF 在结肠 SMC 中大量表达。用抗 CTGF 抗体 FG-3149 治疗 CD 大鼠可减少 P 和 I 位点的纤维化和胶原含量,并显示出胶原 mRNA 表达正常化的一致趋势。总之,我们的研究表明,机械应力通过上调促纤维化介质(即 CTGF),可能在 CD 的纤维化过程中起到关键作用。
{"title":"Mechanical stress-induced connective tissue growth factor plays a critical role in intestinal fibrosis in Crohn's-like colitis.","authors":"You-Min Lin, Ke Zhang, Ramasatyaveni Geesala, Kenneth E Lipson, Suimin Qiu, Don W Powell, Steven Cohn, Xuan-Zheng Shi","doi":"10.1152/ajpgi.00123.2024","DOIUrl":"10.1152/ajpgi.00123.2024","url":null,"abstract":"<p><p>Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well understood. Transmural inflammation is associated with inflammatory cell infiltration, stenosis, and distention, which present mechanical stress (MS) to the bowel wall. We hypothesize that MS induces gene expression of profibrotic mediators such as connective tissue growth factor (CTGF), which may contribute to fibrosis in CD. A rodent model of CD was induced by intracolonic instillation of TNBS to the distal colon. TNBS instillation induced a localized transmural inflammation (<i>site I</i>), with a distended colon segment (<i>site P</i>) proximal to <i>site I</i>. We detected significant fibrosis and collagen content not only in <i>site I</i> but also in <i>site P</i> in CD rats by <i>day 7</i>. CTGF expression increased significantly in <i>sites P</i> and <i>I</i>, but not in the segment distal to the inflammation site. Increased CTGF expression was detected mainly in the smooth muscle cells (SMCs). When rats were fed exclusively with clear liquid diet to prevent mechanical distention in colitis, expression of CTGF in <i>sites P</i> and <i>I</i> was blocked. Direct stretch led to robust expression of CTGF in colonic SMC. Treatment of CD rats with anti-CTGF antibody FG-3149 reduced fibrosis and collagen content in both <i>sites P</i> and <i>I</i> and exhibited consistent trends toward normalizing expression of collagen mRNAs. In conclusion, our studies suggest that mechanical stress, by upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.<b>NEW & NOTEWORTHY</b> We found that CTGF expression increased significantly not only in the inflammation site but in the distended segment proximal to inflammation in a rodent model of CD-like colitis. Release of mechanical distention prevented CTGF expression in CD rats, whereas direct stretch induced CTGF expression. Treatment with anti-CTGF antibody reduced fibrosis and collagen contents in CD rats. Thus, mechanical stress, via upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141490604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-05-21DOI: 10.1152/ajpgi.00260.2023
Kristina Pravoverov, Iram Fatima, Susmita Barman, Frank Jühling, Mark Primeaux, Thomas F Baumert, Amar B Singh, Punita Dhawan
Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as an oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic colorectal cancer and colitis-associated cancer (CAC). CAC is one of the most severe complications of chronic inflammatory bowel disease (IBD), but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL levels in patients with IBD and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from patients with late-stage ulcerative colitis compared with controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, which facilitates IL-22-mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Furthermore, CAIX associates with and stabilizes MASTL in response to IL-22 stimulation.NEW & NOTEWORTHY MASTL is upregulated in colorectal cancer; however, its role in colitis and colitis-associated cancer is poorly understood. This study is the first to draw a link between MASTL and IL-22, a proinflammatory/intestinal epithelial recovery-promoting cytokine that is also implicated in colon tumorigenesis. We propose that IL-22 increases MASTL protein stability by promoting its association with CAIX potentially via AKT signaling to promote cell survival and proliferation.
{"title":"IL-22 regulates MASTL expression in intestinal epithelial cells.","authors":"Kristina Pravoverov, Iram Fatima, Susmita Barman, Frank Jühling, Mark Primeaux, Thomas F Baumert, Amar B Singh, Punita Dhawan","doi":"10.1152/ajpgi.00260.2023","DOIUrl":"10.1152/ajpgi.00260.2023","url":null,"abstract":"<p><p>Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as an oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic colorectal cancer and colitis-associated cancer (CAC). CAC is one of the most severe complications of chronic inflammatory bowel disease (IBD), but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL levels in patients with IBD and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from patients with late-stage ulcerative colitis compared with controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, which facilitates IL-22-mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Furthermore, CAIX associates with and stabilizes MASTL in response to IL-22 stimulation.<b>NEW & NOTEWORTHY</b> MASTL is upregulated in colorectal cancer; however, its role in colitis and colitis-associated cancer is poorly understood. This study is the first to draw a link between MASTL and IL-22, a proinflammatory/intestinal epithelial recovery-promoting cytokine that is also implicated in colon tumorigenesis. We propose that IL-22 increases MASTL protein stability by promoting its association with CAIX potentially via AKT signaling to promote cell survival and proliferation.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-25DOI: 10.1152/ajpgi.00080.2024
Javier Aguilera-Lizarraga, Anne Ritoux, David C Bulmer, Ewan St John Smith
The intestinal barrier plays a crucial role in homeostasis by both facilitating the absorption of nutrients and fluids and providing a tight shield to prevent the invasion by either pathogen or commensal microorganisms. Intestinal barrier malfunction is associated with systemic inflammation, oxidative stress, and decreased insulin sensitivity, which may lead to the dysregulation of other tissues. Therefore, a deeper understanding of physiological aspects related to an enhanced barrier function is of significant scientific and clinical relevance. The naked mole-rat has many unusual biological features, including attenuated colonic neuron sensitivity to acid and bradykinin and resistance to chemical-induced intestinal damage. However, insight into their intestinal barrier physiology is scarce. Here, we observed notable macroscopic and microscopic differences in intestinal tissue structure between naked mole-rats and mice. Moreover, naked mole-rats showed increased number of larger goblet cells and elevated mucus content. In measuring gut permeability, naked mole-rats showed reduced permeability compared with mice, measured as transepithelial electrical resistance, especially in ileum. Furthermore, intestinal ion secretion induced by serotonin, bradykinin, histamine, and capsaicin was significantly reduced in naked mole-rats compared with mice, despite the expression of receptors for all these agonists. In addition, naked mole-rats exhibited reduced prosecretory responses to the nonselective adenylate cyclase activator forskolin. Collectively, these findings indicate that naked mole-rats possess a robust and hard-to-penetrate gastrointestinal barrier that is resistant to environmental and endogenous irritants. Naked mole-rats may therefore provide valuable insights into the physiology of the intestinal barrier and set the stage for the development of innovative and effective therapies.NEW & NOTEWORTHY This is the first study to characterize the intestinal function of naked mole-rats. We found that these animals show a robust gut tissue structure, displaying thicker intestinal layers, longer villi, and larger crypts. Naked mole-rats showed more and larger goblet cells, with increased mucus content. Intestinal permeability, especially in the ileum, was substantially lower than that of mice. Finally, naked mole-rats showed reduced intestinal anion secretion in response to serotonin, bradykinin, histamine, capsaicin, and forskolin.
{"title":"Intestinal barrier function in the naked mole-rat: an emergent model for gastrointestinal insights.","authors":"Javier Aguilera-Lizarraga, Anne Ritoux, David C Bulmer, Ewan St John Smith","doi":"10.1152/ajpgi.00080.2024","DOIUrl":"10.1152/ajpgi.00080.2024","url":null,"abstract":"<p><p>The intestinal barrier plays a crucial role in homeostasis by both facilitating the absorption of nutrients and fluids and providing a tight shield to prevent the invasion by either pathogen or commensal microorganisms. Intestinal barrier malfunction is associated with systemic inflammation, oxidative stress, and decreased insulin sensitivity, which may lead to the dysregulation of other tissues. Therefore, a deeper understanding of physiological aspects related to an enhanced barrier function is of significant scientific and clinical relevance. The naked mole-rat has many unusual biological features, including attenuated colonic neuron sensitivity to acid and bradykinin and resistance to chemical-induced intestinal damage. However, insight into their intestinal barrier physiology is scarce. Here, we observed notable macroscopic and microscopic differences in intestinal tissue structure between naked mole-rats and mice. Moreover, naked mole-rats showed increased number of larger goblet cells and elevated mucus content. In measuring gut permeability, naked mole-rats showed reduced permeability compared with mice, measured as transepithelial electrical resistance, especially in ileum. Furthermore, intestinal ion secretion induced by serotonin, bradykinin, histamine, and capsaicin was significantly reduced in naked mole-rats compared with mice, despite the expression of receptors for all these agonists. In addition, naked mole-rats exhibited reduced prosecretory responses to the nonselective adenylate cyclase activator forskolin. Collectively, these findings indicate that naked mole-rats possess a robust and hard-to-penetrate gastrointestinal barrier that is resistant to environmental and endogenous irritants. Naked mole-rats may therefore provide valuable insights into the physiology of the intestinal barrier and set the stage for the development of innovative and effective therapies.<b>NEW & NOTEWORTHY</b> This is the first study to characterize the intestinal function of naked mole-rats. We found that these animals show a robust gut tissue structure, displaying thicker intestinal layers, longer villi, and larger crypts. Naked mole-rats showed more and larger goblet cells, with increased mucus content. Intestinal permeability, especially in the ileum, was substantially lower than that of mice. Finally, naked mole-rats showed reduced intestinal anion secretion in response to serotonin, bradykinin, histamine, capsaicin, and forskolin.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Data are limited regarding gastrointestinal motility disturbance in disorders of gut-brain interaction (DGBI). This study aimed to characterize antroduodenal motor alterations in patients with high-resolution antroduodenal manometry (HR-ADM). HR-ADM was performed in patients with severe DGBI and compared with healthy volunteers (HV). HR-ADM used a commercially available probe composed of 36 electronic sensors spaced 1 cm apart and positioned across the pylorus. Antral and duodenal motor high-resolution profiles were analyzed, based on the frequency, amplitude, and contractile integral/sensor (CI/s) calculated for each phase of the migrating motor complex (MMC). Eighteen HV and 64 patients were investigated, 10 with irritable bowel syndrome (IBS), 24 with functional dyspepsia (FD), 15 with overlap IBS-FD, and 15 with other DGBI. Compared with HV, patients had a lower frequency of phase II duodenal contractions (27 vs. 51 per hour; P = 0.002) and a lower duodenal phase II contraction amplitude (70 vs. 100 mmHg; P = 0.01), resulting in a lower CI/s of phase II (833 vs. 1,901 mmHg·cm·s; P < 0.001) in the duodenum. In addition, the frequency of phase II propagated antroduodenal contractions was lower (5 vs. 11 per hour; P < 0.001) in patients compared with HV. Interestingly, the antral CI/s of phase III was decreased in FD patients but not in IBS patients. Patients with severe DGBI display alterations in antral and intestinal motility assessed by commercially available HR-ADM. Whether these alterations may explain symptom profiles in such patients remains to be confirmed (NCT04918329 and NCT01519180).NEW & NOTEWORTHY Gastrointestinal dysmotility has been assessed poorly in disorders of gut-brain interaction (DGBI), especially with high-resolution antroduodenal manometry. Plots of DGBI patients showed lower duodenal contractions during phase II regarding amplitude, frequency, and contractile integral/sensor (CI/s) compared with healthy volunteers. A lower frequency of propagated antroduodenal contractions was also reported. Finally, antral CI/s was lower in patients with functional dyspepsia during phase III. Further studies are needed to assess the clinical significance of these alterations.
{"title":"Alterations in gastrointestinal motility assessed by high-resolution antroduodenal manometry in patients with severe disorders of gut-brain interaction.","authors":"Heithem Soliman, Fabien Wuestenberghs, Charlotte Desprez, Anne-Marie Leroi, Chloé Melchior, Guillaume Gourcerol","doi":"10.1152/ajpgi.00039.2024","DOIUrl":"10.1152/ajpgi.00039.2024","url":null,"abstract":"<p><p>Data are limited regarding gastrointestinal motility disturbance in disorders of gut-brain interaction (DGBI). This study aimed to characterize antroduodenal motor alterations in patients with high-resolution antroduodenal manometry (HR-ADM). HR-ADM was performed in patients with severe DGBI and compared with healthy volunteers (HV). HR-ADM used a commercially available probe composed of 36 electronic sensors spaced 1 cm apart and positioned across the pylorus. Antral and duodenal motor high-resolution profiles were analyzed, based on the frequency, amplitude, and contractile integral/sensor (CI/s) calculated for each phase of the migrating motor complex (MMC). Eighteen HV and 64 patients were investigated, 10 with irritable bowel syndrome (IBS), 24 with functional dyspepsia (FD), 15 with overlap IBS-FD, and 15 with other DGBI. Compared with HV, patients had a lower frequency of phase II duodenal contractions (27 vs. 51 per hour; <i>P</i> = 0.002) and a lower duodenal phase II contraction amplitude (70 vs. 100 mmHg; <i>P</i> = 0.01), resulting in a lower CI/s of phase II (833 vs. 1,901 mmHg·cm·s; <i>P</i> < 0.001) in the duodenum. In addition, the frequency of phase II propagated antroduodenal contractions was lower (5 vs. 11 per hour; <i>P</i> < 0.001) in patients compared with HV. Interestingly, the antral CI/s of phase III was decreased in FD patients but not in IBS patients. Patients with severe DGBI display alterations in antral and intestinal motility assessed by commercially available HR-ADM. Whether these alterations may explain symptom profiles in such patients remains to be confirmed (NCT04918329 and NCT01519180).<b>NEW & NOTEWORTHY</b> Gastrointestinal dysmotility has been assessed poorly in disorders of gut-brain interaction (DGBI), especially with high-resolution antroduodenal manometry. Plots of DGBI patients showed lower duodenal contractions during phase II regarding amplitude, frequency, and contractile integral/sensor (CI/s) compared with healthy volunteers. A lower frequency of propagated antroduodenal contractions was also reported. Finally, antral CI/s was lower in patients with functional dyspepsia during phase III. Further studies are needed to assess the clinical significance of these alterations.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141299831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-04-02DOI: 10.1152/ajpgi.00274.2023
E L Garcia-Villatoro, A Ufondu, E S Callaway, K F Allred, S H Safe, R S Chapkin, A Jayaraman, C D Allred
After birth, the development of secondary lymphoid tissues (SLTs) in the colon is dependent on the expression of the aryl hydrocarbon receptor (AhR) in immune cells as a response to the availability of AhR ligands. However, little is known about how AhR activity from intestinal epithelial cells (IECs) may influence the development of tertiary lymphoid tissues (TLTs). As organized structures that develop at sites of inflammation or infection during adulthood, TLTs serve as localized centers of adaptive immune responses, and their presence has been associated with the resolution of inflammation and tumorigenesis in the colon. Here, we investigated the effect of the conditional loss of AhR activity in IECs in the formation and immune cell composition of TLTs in a model of acute inflammation. In females, loss of AhR activity in IECs reduced the formation of TLTs without significantly changing disease outcomes or immune cell composition within TLTs. In males lacking AhR expression in IECs, increased disease activity index, lower expression of functional-IEC genes, increased number of TLTs, increased T-cell density, and lower B- to T-cell ratio were observed. These findings may represent an unfavorable prognosis when exposed to dextran sodium sulfate (DSS)-induced epithelial damage compared with females. Sex and loss of IEC AhR also resulted in changes in microbial populations in the gut. Collectively, these data suggest that the formation of TLTs in the colon is influenced by sex and AhR expression in IECs.NEW & NOTEWORTHY This is the first research of its kind to demonstrate a clear connection between biological sex and the development of tertiary lymphoid tissues (TLT) in the colon. In addition, the research finds that in a preclinical model of inflammatory bowel disease, the expression of the aryl hydrocarbon receptor (AhR) influences the development of these structures in a sex-specific manner.
{"title":"Aryl hydrocarbon receptor activity in intestinal epithelial cells in the formation of colonic tertiary lymphoid tissues.","authors":"E L Garcia-Villatoro, A Ufondu, E S Callaway, K F Allred, S H Safe, R S Chapkin, A Jayaraman, C D Allred","doi":"10.1152/ajpgi.00274.2023","DOIUrl":"10.1152/ajpgi.00274.2023","url":null,"abstract":"<p><p>After birth, the development of secondary lymphoid tissues (SLTs) in the colon is dependent on the expression of the aryl hydrocarbon receptor (AhR) in immune cells as a response to the availability of AhR ligands. However, little is known about how AhR activity from intestinal epithelial cells (IECs) may influence the development of tertiary lymphoid tissues (TLTs). As organized structures that develop at sites of inflammation or infection during adulthood, TLTs serve as localized centers of adaptive immune responses, and their presence has been associated with the resolution of inflammation and tumorigenesis in the colon. Here, we investigated the effect of the conditional loss of AhR activity in IECs in the formation and immune cell composition of TLTs in a model of acute inflammation. In females, loss of AhR activity in IECs reduced the formation of TLTs without significantly changing disease outcomes or immune cell composition within TLTs. In males lacking AhR expression in IECs, increased disease activity index, lower expression of functional-IEC genes, increased number of TLTs, increased T-cell density, and lower B- to T-cell ratio were observed. These findings may represent an unfavorable prognosis when exposed to dextran sodium sulfate (DSS)-induced epithelial damage compared with females. Sex and loss of IEC AhR also resulted in changes in microbial populations in the gut. Collectively, these data suggest that the formation of TLTs in the colon is influenced by sex and AhR expression in IECs.<b>NEW & NOTEWORTHY</b> This is the first research of its kind to demonstrate a clear connection between biological sex and the development of tertiary lymphoid tissues (TLT) in the colon. In addition, the research finds that in a preclinical model of inflammatory bowel disease, the expression of the aryl hydrocarbon receptor (AhR) influences the development of these structures in a sex-specific manner.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140334432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-05-23DOI: 10.1152/ajpgi.00022.2024
Emelie Öhnstedt, Cristian Doñas, Kristel Parv, Yanhong Pang, Hava Lofton Tomenius, Macarena Carrasco López, Venkata Ram Gannavarapu, Jacueline Choi, Maria Ovezik, Peter Frank, Margareth Jorvid, Stefan Roos, Evelina Vågesjö, Mia Phillipson
Treatments of colitis, inflammation of the intestine, rely on induction of immune suppression associated with systemic adverse events, including recurrent infections. This treatment strategy is specifically problematic in the increasing population of patients with cancer with immune checkpoint inhibitor (ICI)-induced colitis, as immune suppression also interferes with the ICI-treatment response. Thus, there is a need for local-acting treatments that reduce inflammation and enhance intestinal healing. Here, we investigated the effect and safety of bacterial delivery of short-lived immunomodulating chemokines to the inflamed intestine in mice with colitis. Colitis was induced by dextran sulfate sodium (DSS) alone or in combination with ICI (anti-PD1 and anti-CTLA-4), and Limosilactobacillus reuteri R2LC (L. reuteri R2LC) genetically modified to express the chemokine CXCL12-1α (R2LC_CXCL12, emilimogene sigulactibac) was given perorally. In addition, the pharmacology and safety of the formulated drug candidate, ILP100-Oral, were evaluated in rabbits. Peroral CXCL12-producing L. reuteri R2LC significantly improved colitis symptoms already after 2 days in mice with overt DSS and ICI-induced colitis, which in benchmarking experiments was demonstrated to be superior to treatments with anti-TNF-α, anti-α4β7, and corticosteroids. The mechanism of action involved chemokine delivery to Peyer's patches (PPs), confirmed by local CXCR4 signaling, and increased numbers of colonic, regulatory immune cells expressing IL-10 and TGF-β1. No systemic exposure or engraftment could be detected in mice, and product feasibility, pharmacology, and safety were confirmed in rabbits. In conclusion, peroral CXCL12-producing L. reuteri R2LC efficiently ameliorates colitis, enhances mucosal healing, and has a favorable safety profile.NEW & NOTEWORTHY Colitis symptoms are efficiently reduced by peroral administration of probiotic bacteria genetically modified to deliver CXCL12 locally to the inflamed intestine in several mouse models.
{"title":"Oral administration of CXCL12-expressing <i>Limosilactobacillus reuteri</i> improves colitis by local immunomodulatory actions in preclinical models.","authors":"Emelie Öhnstedt, Cristian Doñas, Kristel Parv, Yanhong Pang, Hava Lofton Tomenius, Macarena Carrasco López, Venkata Ram Gannavarapu, Jacueline Choi, Maria Ovezik, Peter Frank, Margareth Jorvid, Stefan Roos, Evelina Vågesjö, Mia Phillipson","doi":"10.1152/ajpgi.00022.2024","DOIUrl":"10.1152/ajpgi.00022.2024","url":null,"abstract":"<p><p>Treatments of colitis, inflammation of the intestine, rely on induction of immune suppression associated with systemic adverse events, including recurrent infections. This treatment strategy is specifically problematic in the increasing population of patients with cancer with immune checkpoint inhibitor (ICI)-induced colitis, as immune suppression also interferes with the ICI-treatment response. Thus, there is a need for local-acting treatments that reduce inflammation and enhance intestinal healing. Here, we investigated the effect and safety of bacterial delivery of short-lived immunomodulating chemokines to the inflamed intestine in mice with colitis. Colitis was induced by dextran sulfate sodium (DSS) alone or in combination with ICI (anti-PD1 and anti-CTLA-4), and <i>Limosilactobacillus reuteri</i> R2LC (<i>L. reuteri</i> R2LC) genetically modified to express the chemokine CXCL12-1α (R2LC_CXCL12, emilimogene sigulactibac) was given perorally. In addition, the pharmacology and safety of the formulated drug candidate, ILP100-Oral, were evaluated in rabbits. Peroral CXCL12-producing <i>L. reuteri</i> R2LC significantly improved colitis symptoms already after 2 days in mice with overt DSS and ICI-induced colitis, which in benchmarking experiments was demonstrated to be superior to treatments with anti-TNF-α, anti-α4β7, and corticosteroids. The mechanism of action involved chemokine delivery to Peyer's patches (PPs), confirmed by local CXCR4 signaling, and increased numbers of colonic, regulatory immune cells expressing IL-10 and TGF-β1. No systemic exposure or engraftment could be detected in mice, and product feasibility, pharmacology, and safety were confirmed in rabbits. In conclusion, peroral CXCL12-producing <i>L. reuteri</i> R2LC efficiently ameliorates colitis, enhances mucosal healing, and has a favorable safety profile.<b>NEW & NOTEWORTHY</b> Colitis symptoms are efficiently reduced by peroral administration of probiotic bacteria genetically modified to deliver CXCL12 locally to the inflamed intestine in several mouse models.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141080401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-11DOI: 10.1152/ajpgi.00090.2024
Xianghu Wang, Ningling Kang
{"title":"The transgenic BAC-Alb-FlpO mouse line: a new tool for liver disease research.","authors":"Xianghu Wang, Ningling Kang","doi":"10.1152/ajpgi.00090.2024","DOIUrl":"10.1152/ajpgi.00090.2024","url":null,"abstract":"","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141299837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-11DOI: 10.1152/ajpgi.00063.2024
MaKayla L O'Guinn, David A Handler, Jonathan J Hsieh, Michael U Mallicote, Karina Feliciano, Christopher P Gayer
Accumulating literature suggests that the farnesoid-X receptor (FXR), a nuclear bile acid receptor best known for its role in bile acid homeostasis, is also a potent context-dependent regulator of inflammation. FXR may thus be relevant to several intestinal disease states including inflammatory bowel disease, necrotizing enterocolitis, and sepsis. In this study, we tested the effects of FXR deletion on acute murine intestinal inflammation. We found that FXR knockout (KO) mice were protected from intestinal injury and barrier dysfunction induced by lipopolysaccharide (LPS) injection, dithizone (DI)/Klebsiella, and cecal ligation/puncture models. In the LPS model, RNA sequencing and qPCR analysis showed that this protection correlated with substantial reduction in LPS-induced proinflammatory gene expression, including lower tissue levels of Il1a, Il1b, and Tnf. Examining functional effects on the epithelium, we found that LPS-induced tight junctional disruption as assessed by internalization of ZO-1 and occludin was ameliorated in FXR KO animals. Taken together, these data suggest a role for FXR in the intestinal barrier during inflammatory injury.NEW & NOTEWORTHY Intestinal barrier failure is a hallmark in gut-origin sepsis. We demonstrate that the intestinal barriers of farnesoid-X receptor (FXR) knockout (KO) animals are protected from inflammatory insult using multiple models of acute intestinal inflammation. This protection is due to decreased inflammatory cytokine production and maintenance of tight junctional architecture seen within the KO animals. This is the first report of FXR deletion being protective to the intestinal barrier.
{"title":"FXR deletion attenuates intestinal barrier dysfunction in murine acute intestinal inflammation.","authors":"MaKayla L O'Guinn, David A Handler, Jonathan J Hsieh, Michael U Mallicote, Karina Feliciano, Christopher P Gayer","doi":"10.1152/ajpgi.00063.2024","DOIUrl":"10.1152/ajpgi.00063.2024","url":null,"abstract":"<p><p>Accumulating literature suggests that the farnesoid-X receptor (FXR), a nuclear bile acid receptor best known for its role in bile acid homeostasis, is also a potent context-dependent regulator of inflammation. FXR may thus be relevant to several intestinal disease states including inflammatory bowel disease, necrotizing enterocolitis, and sepsis. In this study, we tested the effects of FXR deletion on acute murine intestinal inflammation. We found that FXR knockout (KO) mice were protected from intestinal injury and barrier dysfunction induced by lipopolysaccharide (LPS) injection, dithizone (DI)/<i>Klebsiella</i>, and cecal ligation/puncture models. In the LPS model, RNA sequencing and qPCR analysis showed that this protection correlated with substantial reduction in LPS-induced proinflammatory gene expression, including lower tissue levels of <i>Il1a</i>, <i>Il1b</i>, and <i>Tnf</i>. Examining functional effects on the epithelium, we found that LPS-induced tight junctional disruption as assessed by internalization of ZO-1 and occludin was ameliorated in FXR KO animals. Taken together, these data suggest a role for FXR in the intestinal barrier during inflammatory injury.<b>NEW & NOTEWORTHY</b> Intestinal barrier failure is a hallmark in gut-origin sepsis. We demonstrate that the intestinal barriers of farnesoid-X receptor (FXR) knockout (KO) animals are protected from inflammatory insult using multiple models of acute intestinal inflammation. This protection is due to decreased inflammatory cytokine production and maintenance of tight junctional architecture seen within the KO animals. This is the first report of FXR deletion being protective to the intestinal barrier.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141299833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-25DOI: 10.1152/ajpgi.00135.2024
Rachel Edens, Alyssa Gutierrez, Melinda A Engevik
{"title":"Exploring the use of panaxynol from American ginseng to combat intestinal inflammation and colon cancer.","authors":"Rachel Edens, Alyssa Gutierrez, Melinda A Engevik","doi":"10.1152/ajpgi.00135.2024","DOIUrl":"10.1152/ajpgi.00135.2024","url":null,"abstract":"","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-11DOI: 10.1152/ajpgi.00069.2024
Omkar N Athavale, Madeleine R Di Natale, Recep Avci, Alys R Clark, John B Furness, Leo K Cheng, Peng Du
Rhythmic electrical events, termed slow waves, govern the timing and amplitude of phasic contractions of the gastric musculature. Extracellular multielectrode measurement of gastric slow waves can be a biomarker for phenotypes of motility dysfunction. However, a gastric slow-wave conduction pathway for the rat, a common animal model, is unestablished. In this study, the validity of extracellular recording was demonstrated in vitro with simultaneous intracellular and extracellular recordings and by pharmacological inhibition of slow waves. The conduction pathway was determined by in vivo extracellular recordings while considering the effect of motion. Slow-wave characteristics [means (SD)] varied regionally having higher amplitude in the antrum than the distal corpus [1.03 (0.12) mV vs. 0.75 (0.31) mV; n = 7; P = 0.025 paired t test] and faster propagation near the greater curvature than the lesser curvature [1.00 (0.14) mm·s-1 vs. 0.74 (0.14) mm·s-1; n = 9 GC, 7 LC; P = 0.003 unpaired t test]. Notably, in some subjects, separate wavefronts propagated near the lesser and greater curvatures with a loosely coupled region occurring in the area near the distal corpus midline at the interface of the two wavefronts. This region had either the greater or lesser curvature wavefront propagating through it in a time-varying manner. The conduction pattern suggests that slow waves in the rat stomach form annular wavefronts in the antrum and not the corpus. This study has implications for interpretation of the relationship between slow waves, the interstitial cells of Cajal network structure, smooth muscles, and gastric motility.NEW & NOTEWORTHY Mapping of rat gastric slow waves showed regional variations in their organization. In some subjects, separate wavefronts propagated near the lesser and greater curvatures with a loosely coupled region near the midline, between the wavefronts, having a varying slow-wave origin. Furthermore, simultaneous intracellular and extracellular recordings were concordant and independent of movement artifacts, indicating that extracellular recordings can be interpreted in terms of their intracellular counterparts when intracellular recording is not possible.
被称为慢波的节律性电事件控制着胃肌肉相位性收缩的时间和幅度。对胃慢波的细胞外多电极测量可作为运动功能障碍表型的生物标记。然而,大鼠这一常见动物模型的胃慢波传导途径尚未建立。本研究在体外同时进行细胞内和细胞外记录,并通过药物抑制慢波,证明了细胞外记录的有效性。体内细胞外记录确定了传导路径,同时考虑了运动的影响。慢波特征(平均值(标度))因区域而异,前腔的振幅高于远端冠状沟(1.03 (0.12) mV vs 0.75 (0.31) mV; n = 7; p = 0.025 成对 t 检验),大曲率附近的传播速度快于小曲率(1.00 (0.14) mm s-1 vs 0.74 (0.14) mm s-1;n = 9 GC,7 LC;p = 0.003 非成对 t 检验)。值得注意的是,在一些受试者中,小弯和大弯附近有单独的波阵面传播,在靠近远端冠状中线的区域,即两个波阵面的交界处有一个松散的耦合区域。该区域有大曲率波面或小曲率波面以随时间变化的方式传播通过。这种传导模式表明,大鼠胃中的慢波在胃窦而非胃冠形成环形波面。这项研究对解释慢波、卡雅尔间质细胞网络结构、平滑肌和胃运动之间的关系具有重要意义。
{"title":"Mapping the rat gastric slow-wave conduction pathway: bridging in vitro and in vivo methods, revealing a loosely coupled region in the distal stomach.","authors":"Omkar N Athavale, Madeleine R Di Natale, Recep Avci, Alys R Clark, John B Furness, Leo K Cheng, Peng Du","doi":"10.1152/ajpgi.00069.2024","DOIUrl":"10.1152/ajpgi.00069.2024","url":null,"abstract":"<p><p>Rhythmic electrical events, termed slow waves, govern the timing and amplitude of phasic contractions of the gastric musculature. Extracellular multielectrode measurement of gastric slow waves can be a biomarker for phenotypes of motility dysfunction. However, a gastric slow-wave conduction pathway for the rat, a common animal model, is unestablished. In this study, the validity of extracellular recording was demonstrated in vitro with simultaneous intracellular and extracellular recordings and by pharmacological inhibition of slow waves. The conduction pathway was determined by in vivo extracellular recordings while considering the effect of motion. Slow-wave characteristics [means (SD)] varied regionally having higher amplitude in the antrum than the distal corpus [1.03 (0.12) mV vs. 0.75 (0.31) mV; <i>n</i> = 7; <i>P</i> = 0.025 paired <i>t</i> test] and faster propagation near the greater curvature than the lesser curvature [1.00 (0.14) mm·s<sup>-1</sup> vs. 0.74 (0.14) mm·s<sup>-1</sup>; <i>n</i> = 9 GC, 7 LC; <i>P</i> = 0.003 unpaired <i>t</i> test]. Notably, in some subjects, separate wavefronts propagated near the lesser and greater curvatures with a loosely coupled region occurring in the area near the distal corpus midline at the interface of the two wavefronts. This region had either the greater or lesser curvature wavefront propagating through it in a time-varying manner. The conduction pattern suggests that slow waves in the rat stomach form annular wavefronts in the antrum and not the corpus. This study has implications for interpretation of the relationship between slow waves, the interstitial cells of Cajal network structure, smooth muscles, and gastric motility.<b>NEW & NOTEWORTHY</b> Mapping of rat gastric slow waves showed regional variations in their organization. In some subjects, separate wavefronts propagated near the lesser and greater curvatures with a loosely coupled region near the midline, between the wavefronts, having a varying slow-wave origin. Furthermore, simultaneous intracellular and extracellular recordings were concordant and independent of movement artifacts, indicating that extracellular recordings can be interpreted in terms of their intracellular counterparts when intracellular recording is not possible.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141299834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}