AIM: To investigate the effects of moxibustion on down-regulation of the colonic epithelial cell apoptosis and repair of the tight junctions in rats with Crohn's disease (CD). METHODS: Sixty male Sprague-Dawley ra...AIM: To investigate the effects of moxibustion on down-regulation of the colonic epithelial cell apoptosis and repair of the tight junctions in rats with Crohn's disease (CD). METHODS: Sixty male Sprague-Dawley rats were randomly divided into a normal control (NC) group, a model control (MC) group, an herbs-partitioned moxibustion (HPM) group, a mild-warm moxibustion (MWM) group and a salicylazosulphapyridine (SASP) group, with 12 rats in each group. The CD model rats were treated with trinitrobenzene sulphonic acid to induce intestinal inflammation. The rats in the HPM and MWM groups were treated at the Tianshu (ST25) and Qihai (CV6) acupoints once daily for 14 d, and the SASP group was fed SASP twice daily for 14 d. No additional treatment was given to the MC and NC groups. Themicrostructure of the colonic epithelium was observed under a transmission electron microscope, the transepithelial resistance was measured using a shortcircuit current, colonic epithelial cell apoptosis was determined by terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labelling assay, and the expression of occludin, claudin-1 and zonula occludens-l (ZO-1) in the colonic epithelial junction was determined by Western blotting and immunofluorescence staining. RESULTS: Compared with the MC group, the microstructure of the colonic epithelial barrier was signifi-cantly improved in rats treated with HPM, MWM or SASP, meanwhile, the current flow was reduced signifi-cantly, with values of 168.20 ± 6.14 vs 99.70 ± 3.13, 99.10 ± 4.28 and 120.30 ± 3.65 mA, respectively (P = 0.001). However, the HPM and MWM groups had higher current flow rates than the SASP group (99.70 ± 3.13, 99.10 ± 4.28 vs 120.30 ± 3.65 mA, P = 0.001). The number of the apoptotic colonic epithelial cells in HPM, MWM and SASP groups was largely reduced (61.5 ± 16.91 vs 15.5 ± 8.89, 14.8 ± 6.27 and 24.7 ± 9.68, respectively (P = 0.001); and the expression of occlu- din, claudin-1 and ZO-1 in the MWM and HPM groups was signifi cantly enhanced (0.48 ± 0展开更多
Irritable bowel syndrome(IBS) is a common, sometimes debilitating, gastrointestinal disorder worldwide. While altered gut motility and sensation, as well as aberrant brain perception of visceral events, are thought to...Irritable bowel syndrome(IBS) is a common, sometimes debilitating, gastrointestinal disorder worldwide. While altered gut motility and sensation, as well as aberrant brain perception of visceral events, are thought to contribute to the genesis of symptoms in IBS, a search for an underlying aetiology has, to date, proven unsuccessful. Recently, attention has been focused on the microbiota as a possible factor in the pathogenesis of IBS. Prompted by a number of clinical observations, such as the recognition of the de novo development of IBS following enteric infections, as well as descriptions of changes in colonic bacterial populations in IBS and supported by clinical responses to interventions, such as antibiotics and probiotics, that modify the microbiota, various approaches have been taken to investigating the microbiota-host response in IBS, as well as in animal models thereof. From such studies a considerable body of evidence has accumulated to indicate the activation or upregulation of both factors involved in bacterial engagement with the host as well host defence mechanisms against bacteria. Alterations in gut barrier function, occurring in response, or in parallel, to changes in the microbiota, have also been widely described and can be seen to play a pivotal role in generating and sustaining host immune responses both within and beyond the gut. In this manner a plausible hypothesis, based on an altered microbiota and/or an aberrant host response, for the pathogenesis, of at least some instances of IBS, can be generated.展开更多
Intestinal microecology is the main component of human microecology.Intestinal microecology consists of intestinal microbiota,intestinal epithelial cells,and intestinal mucosal immune system.These components are inter...Intestinal microecology is the main component of human microecology.Intestinal microecology consists of intestinal microbiota,intestinal epithelial cells,and intestinal mucosal immune system.These components are interdependent and establish a complex interaction network that restricts each other.According to the impact on the human body,there are three categories of symbiotic bacteria,opportunistic pathogens,and pathogenic bacteria.The intestinal microecology participates in digestion and absorption,and material metabolism,and inhibits the growth of pathogenic microorganisms.It also acts as the body’s natural immune barrier,regulates the innate immunity of the intestine,controls the mucosal barrier function,and also participates in the intestinal epithelial cells’physiological activities such as hyperplasia or apoptosis.When the steady-state balance of the intestinal microecology is disturbed,the existing core intestinal microbiota network changes and leads to obesity,diabetes,and many other diseases,especially irritable bowel syndrome,inflammatory bowel disease(IBD),and colorectal malignancy.Intestinal diseases,including tumors,are particularly closely related to intestinal microecology.This article systematically discusses the research progress on the relationship between IBD and intestinal microecology from the pathogenesis,treatment methods of IBD,and the changes in intestinal microbiota.展开更多
AIM： To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-α （TNF-α） on intestinal epithelial cells. METHODS： Caco-2 cells were incubated with TNF-α alone or i...AIM： To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-α （TNF-α） on intestinal epithelial cells. METHODS： Caco-2 cells were incubated with TNF-α alone or in the presence of L. plantarum. Transepithelial electrical resistance was used to measure epithelial barrier function. Interleukin 8 （IL-8） secretion by intestinal epithelial cells was measured using an ELISA. Cellular lysate proteins were immunoblotted using the anti-extracellular regulated kinase （ERK）, anti-phospho- ERK and anti-IκB-α. RESULTS： A TNF-α-induced decrease in transepithelial electrical resistance was inhibited by L. plantarum. TNF- α-induced IL-8 secretion was reduced by L. plantarum. L. plantarum inhibited the activation of ERK and the degradation of IκB-α in TNF-a-treated Caco-2 cells. CONCLUSION： Induction of epithelial barrier dysfunction and IL-8 secretion by TNF-α is inhibited byL. plantarum. Probiotics may preserve epithelial barrier function and inhibit the inflammatory response by altering the signal transduction pathway.展开更多
The intestinal epithelium constitutes a physical and functional barrier between the external environment and the host organism. It is formed by a continuous monolayer of intestinal epithelial cells maintained together...The intestinal epithelium constitutes a physical and functional barrier between the external environment and the host organism. It is formed by a continuous monolayer of intestinal epithelial cells maintained together by intercellular junctional complex, limiting access of pathogens, toxins and xenobiotics to host tissues. Once this barrier integrity is disrupted, inflammatory disorders and tissue injury are initiated and perpetuated. Beneath the intestinal epithelial cells lies a population of astrocyte-like cells that are known as enteric glia. The morphological characteristics and expression markers of these enteric glia cells were identical to the astrocytes of the central nervous system. In the past few years, enteric glia have been demonstrated to have a trophic and supporting relationship with intestinal epithelial cells. Enteric glia lesions and/or functional defects can be involved in the barrier dysfunction. Besides, factors secreted by enteric glia are important for the regulation of gut barrier function. Moreover, enteric glia have an important impact on epithelial cell transcriptome and induce a shift in epithelial cell phenotype towards increased cell adhesion and cell differentiation.Enteric glia can also preserve epithelial barrier against intestinal bacteria insult. In this review, we will describe the current body of evidence supporting functional roles of enteric glia on intestinal barrier.展开更多
AIM: To investigate the effect of emodin on expression of claudin4, claudin5 and occludin, as well as the alveolar epithelial barrier in rats with pancreatitis induced by sodium taurocholate. METHODS: Experimental pan...AIM: To investigate the effect of emodin on expression of claudin4, claudin5 and occludin, as well as the alveolar epithelial barrier in rats with pancreatitis induced by sodium taurocholate. METHODS: Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Emodin was injected via the external jugular vein 3 h after induction of acute pancreatitis. Rats from sham operation group and acute pancreatitis group were injected with normal saline (an equivalent volume as emodin) at the same time point. Samples of lung and serum were obtained 6 h after drug administration. Pulmonary morphology was examined with HE staining. Pulmonary edema was estimated by measuring water content in lung tissue samples. Tumor necrosis factorα (TNFα) and interleukin6 (IL6) level were measured by enzymelinked immunospecific assay. Serum amylase and pulmonary myeloperoxidase (MPO) activity were detected by spectrophotometry. Alveolar epithelial barrier was assessed by pulmonary dye extravasation. Expression of claudin4, claudin5 and occludin in lung tissue samples was examined by immunohistology, quantitative realtime reverse transcription polymerase chain reaction and Western blotting analysis, respectively.RESULTS: Pancreatitis-associated lung injury was char-acterized by pulmonary edema, leukocyte infiltration, alveolar collapse, and elevated serum amylase level. The pulmonary damage, pulmonary pathological scores, serum amylase and MPO activity, TNF-α and IL-6 levels, and wet/dry ratio were decreased in rats after treatment with emodin. Immunostaining of claudin-4, claudin-5 and occludin was detected in lung tissue samples from rats in sham operation group, which was distributed in alveolar epithelium, vascular endothelium, and bron-chial epithelium, respectively. The mRNA and protein expression levels of claudin-4, claudin-5 and occludin in lung tissue samples were markedly decreased, the expression level of claudin-4, claudin-5 and occluding was increased, and the pulmon展开更多
The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important ...The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important element is represented by the intestinal barrier, a complex system formed mostly by intestinal epithelial cells (IECs). IECs have an active role in producing mucus and regulating its composition; they provide a physical barrier capable of controlling antigen traff ic through the intestinal mucosa. At the same time, they are able to play the role of non-professional antigen presenting cells, by processing and presenting antigens directly to the cells of the intestinal immune system. On the other hand, immune cells regulate epithelial growth and differentiation, producing a continuous bi-directional cross-talk within the barrier. Several alterations of the barrier function have been identif ied in IBD, starting from mucus features up to its components, from epithelial junctions up to the Toll-like receptors, and altered immune responses. It remains to be understood whether these defects are primary causes of epithelial damage or secondary effects. We review the possible role of the epithelial barrier and particularly describe the role of IECs in the pathogenesis of IBD.展开更多
Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,...Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,gallic acid,and flavonols),which are thought to contribute to the health benefits of tea.High intake of tea polyphenols has been described to prevent and/or attenuate a variety of chronic pathological conditions like cardiovascular diseases,neurodegenerative diseases,diabetes,and cancer.This review focuses on established antioxidant and anti-inflammatory properties of tea polyphenols and underlying mechanisms of their involvement in inflammatory bowel diseases(IBD).Tea polyphenols act as efficient antioxidants by inducing an endogenous antioxidant defense system and maintaining intracellular redox homeostasis.Tea polyphenols also regulate signaling pathways such as nuclear factor-κB,activator protein 1,signal transducer and activator of transcriptions,and nuclear factor E2-related factor 2,which are associated with IBD development.Accumulating pieces of evidence have indicated that tea polyphenols enhance epithelial barrier function and improve gut microbial dysbiosis,contributing to the management of inflammatory colitis.Therefore,this study suggests that supplementation of tea polyphenols could prevent inflammatory conditions and improve the outcome of patients with IBD.展开更多
AIM: To investigate the effect of the probiotic combination Lactibiane Tolerance<sup>®</sup> (LT) on epithelial barrier function in vitro and in vivo.
The intestinal barrier is important in preventing translocation of bacteria, toxins and antigens from the lumen of the gut into the body. Enhanced permeability, or gut leakiness, has been associated with different dis...The intestinal barrier is important in preventing translocation of bacteria, toxins and antigens from the lumen of the gut into the body. Enhanced permeability, or gut leakiness, has been associated with different diseases. Probiotics can, strain-specifically, improve the epithelial barrier function. However, so far most researches have used cell lines or animal models due to the difficulty of measuring the effects of products on the epithelial barrier function in vivo in humans. Here a systematic literature search was performed to find articles addressing the effects of probiotics on the barrier function in human trials. The Pubmed database was searched (January 2013) to identify human in vivo studies with probiotic products in which parameters for epithelial barrier function were measured. In total 29 studies were identified, but patients, bacterial characteristics and methods to measure intestinal barrier function caused large heterogeneity among these studies. About half of the studies showed positive results of probiotics on the epithelial barrier function, indicating a clear potential of probiotics in this field. In a case series of 14 patients using Ecologica825, a probiotic food supplement with known effect on epithelial barrier function, different markers of intestinal integrity improved significantly. Further studies in this field should consider strain(s), dose and duration of the probiotic supplementation as well as the markers used to measure epithelial barrier function. Besides the lactulose/mannitol test, zonulin and α1-antitrypsin might be valuable markers to measure epithelial barrier function in future experiments.展开更多
The disruption of epithelial barrier integrity is an important factor in the pathogenesis of various immune disorders. However, the restitution of the compromised barrier functions is difficult. This study investigate...The disruption of epithelial barrier integrity is an important factor in the pathogenesis of various immune disorders. However, the restitution of the compromised barrier functions is difficult. This study investigates the regulation of TWIK-related potassium channel-1 （Trek1） in the restitution of intestinal epithelial barrier functions. The human colon epithelial cell line T84 was cultured in monolayers and used to observe epithelial barrier functions in vitro. An intestinal allergy mouse model was created. Cytokine levels were determined by enzyme-linked immunosorbent assay and western blotting. The results showed that Trek1 deficiency induced T84 monolayer barrier disruption. Allergic responses markedly suppressed the expression of Trek1 in the intestinal epithelia via activating the mitogen-activated protein kinase pathways and increasing the expression of histone deacetylase-1. The inhibition of histone deacetylase-1 by sodium butyrate or the administration of a butyrate-producing probiotic （Clostridium butyricum） restored the intestinal epithelial barrier functions and markedly enhanced the effect of antigen-specific immunotherapy. The data suggest that Trek1 is required for the maintenance of intestinal epithelial barrier integrity. Allergic responses induce an insufficiency of Trek1 expression in the intestinal epithelia. Trek1 expression facilitates the restoration of intestinal epithelial barrier functions in an allergic environment.展开更多
A number of digestive and extra-digestive disorders,including inflammatory bowel diseases,irritable bowel syndrome,intestinal infections,metabolic syndrome and neuropsychiatric disorders,share a set of clinical featur...A number of digestive and extra-digestive disorders,including inflammatory bowel diseases,irritable bowel syndrome,intestinal infections,metabolic syndrome and neuropsychiatric disorders,share a set of clinical features at gastrointestinal level,such as infrequent bowel movements,abdominal distension,constipation and secretory dysfunctions.Several lines of evidence indicate that morphological and molecular changes in intestinal epithelial barrier and enteric neuromuscular compartment contribute to alterations of both bowel motor and secretory functions in digestive and extra-digestive diseases.The present review has been conceived to provide a comprehensive and critical overview of the available knowledge on the morphological and molecular changes occurring in intestinal epithelial barrier and enteric neuromuscular compartment in both digestive and extra-digestive diseases.In addition,our intent was to highlight whether these morphological and molecular alterations could represent a common path(or share some common features)driving the pathophysiology of bowel motor dysfunctions and related symptoms associated with digestive and extra-digestive disorders.This assessment might help to identify novel targets of potential usefulness to develop original pharmacological approaches for the therapeutic management of such disturbances.展开更多
Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases(IBD),yet the mechanism(s)in which this complex microbial community initiates or perpetua...Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases(IBD),yet the mechanism(s)in which this complex microbial community initiates or perpetuates inflammation remains unclear.The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD.We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system.Additionally,we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors,ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD.Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria.Although not classified as traditional virulence factors,proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability.Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD.A better understanding of these pathways and characterization of the enteric bacteria involved,their proteases,and protease receptors may pave the way for new therapeutic approaches for these diseases.展开更多
基金Supported by National Natural Science Foundation of China,No. 30772831National Basic Research Program of China, 973program, No. 2009CB522900Shanghai Leading Discipline Project, No. S30304
文摘AIM: To investigate the effects of moxibustion on down-regulation of the colonic epithelial cell apoptosis and repair of the tight junctions in rats with Crohn's disease (CD). METHODS: Sixty male Sprague-Dawley rats were randomly divided into a normal control (NC) group, a model control (MC) group, an herbs-partitioned moxibustion (HPM) group, a mild-warm moxibustion (MWM) group and a salicylazosulphapyridine (SASP) group, with 12 rats in each group. The CD model rats were treated with trinitrobenzene sulphonic acid to induce intestinal inflammation. The rats in the HPM and MWM groups were treated at the Tianshu (ST25) and Qihai (CV6) acupoints once daily for 14 d, and the SASP group was fed SASP twice daily for 14 d. No additional treatment was given to the MC and NC groups. Themicrostructure of the colonic epithelium was observed under a transmission electron microscope, the transepithelial resistance was measured using a shortcircuit current, colonic epithelial cell apoptosis was determined by terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labelling assay, and the expression of occludin, claudin-1 and zonula occludens-l (ZO-1) in the colonic epithelial junction was determined by Western blotting and immunofluorescence staining. RESULTS: Compared with the MC group, the microstructure of the colonic epithelial barrier was signifi-cantly improved in rats treated with HPM, MWM or SASP, meanwhile, the current flow was reduced signifi-cantly, with values of 168.20 ± 6.14 vs 99.70 ± 3.13, 99.10 ± 4.28 and 120.30 ± 3.65 mA, respectively (P = 0.001). However, the HPM and MWM groups had higher current flow rates than the SASP group (99.70 ± 3.13, 99.10 ± 4.28 vs 120.30 ± 3.65 mA, P = 0.001). The number of the apoptotic colonic epithelial cells in HPM, MWM and SASP groups was largely reduced (61.5 ± 16.91 vs 15.5 ± 8.89, 14.8 ± 6.27 and 24.7 ± 9.68, respectively (P = 0.001); and the expression of occlu- din, claudin-1 and ZO-1 in the MWM and HPM groups was signifi cantly enhanced (0.48 ± 0
文摘Irritable bowel syndrome(IBS) is a common, sometimes debilitating, gastrointestinal disorder worldwide. While altered gut motility and sensation, as well as aberrant brain perception of visceral events, are thought to contribute to the genesis of symptoms in IBS, a search for an underlying aetiology has, to date, proven unsuccessful. Recently, attention has been focused on the microbiota as a possible factor in the pathogenesis of IBS. Prompted by a number of clinical observations, such as the recognition of the de novo development of IBS following enteric infections, as well as descriptions of changes in colonic bacterial populations in IBS and supported by clinical responses to interventions, such as antibiotics and probiotics, that modify the microbiota, various approaches have been taken to investigating the microbiota-host response in IBS, as well as in animal models thereof. From such studies a considerable body of evidence has accumulated to indicate the activation or upregulation of both factors involved in bacterial engagement with the host as well host defence mechanisms against bacteria. Alterations in gut barrier function, occurring in response, or in parallel, to changes in the microbiota, have also been widely described and can be seen to play a pivotal role in generating and sustaining host immune responses both within and beyond the gut. In this manner a plausible hypothesis, based on an altered microbiota and/or an aberrant host response, for the pathogenesis, of at least some instances of IBS, can be generated.
基金supported by the National Natural Science Foundation of China(grant no.81774449).
文摘Intestinal microecology is the main component of human microecology.Intestinal microecology consists of intestinal microbiota,intestinal epithelial cells,and intestinal mucosal immune system.These components are interdependent and establish a complex interaction network that restricts each other.According to the impact on the human body,there are three categories of symbiotic bacteria,opportunistic pathogens,and pathogenic bacteria.The intestinal microecology participates in digestion and absorption,and material metabolism,and inhibits the growth of pathogenic microorganisms.It also acts as the body’s natural immune barrier,regulates the innate immunity of the intestine,controls the mucosal barrier function,and also participates in the intestinal epithelial cells’physiological activities such as hyperplasia or apoptosis.When the steady-state balance of the intestinal microecology is disturbed,the existing core intestinal microbiota network changes and leads to obesity,diabetes,and many other diseases,especially irritable bowel syndrome,inflammatory bowel disease(IBD),and colorectal malignancy.Intestinal diseases,including tumors,are particularly closely related to intestinal microecology.This article systematically discusses the research progress on the relationship between IBD and intestinal microecology from the pathogenesis,treatment methods of IBD,and the changes in intestinal microbiota.
基金Supported by grant No. 0520050040 from the Seoul National University Hospital Research Fund and by KT&G Reserach Fund
文摘AIM： To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-α （TNF-α） on intestinal epithelial cells. METHODS： Caco-2 cells were incubated with TNF-α alone or in the presence of L. plantarum. Transepithelial electrical resistance was used to measure epithelial barrier function. Interleukin 8 （IL-8） secretion by intestinal epithelial cells was measured using an ELISA. Cellular lysate proteins were immunoblotted using the anti-extracellular regulated kinase （ERK）, anti-phospho- ERK and anti-IκB-α. RESULTS： A TNF-α-induced decrease in transepithelial electrical resistance was inhibited by L. plantarum. TNF- α-induced IL-8 secretion was reduced by L. plantarum. L. plantarum inhibited the activation of ERK and the degradation of IκB-α in TNF-a-treated Caco-2 cells. CONCLUSION： Induction of epithelial barrier dysfunction and IL-8 secretion by TNF-α is inhibited byL. plantarum. Probiotics may preserve epithelial barrier function and inhibit the inflammatory response by altering the signal transduction pathway.
基金Supported by the National Natural Science Foundation of China,NSFC,No.81200270the Scientific Research Foundation for Outstanding Young Scientist of Shandong Province,No.BS2012SW012
文摘The intestinal epithelium constitutes a physical and functional barrier between the external environment and the host organism. It is formed by a continuous monolayer of intestinal epithelial cells maintained together by intercellular junctional complex, limiting access of pathogens, toxins and xenobiotics to host tissues. Once this barrier integrity is disrupted, inflammatory disorders and tissue injury are initiated and perpetuated. Beneath the intestinal epithelial cells lies a population of astrocyte-like cells that are known as enteric glia. The morphological characteristics and expression markers of these enteric glia cells were identical to the astrocytes of the central nervous system. In the past few years, enteric glia have been demonstrated to have a trophic and supporting relationship with intestinal epithelial cells. Enteric glia lesions and/or functional defects can be involved in the barrier dysfunction. Besides, factors secreted by enteric glia are important for the regulation of gut barrier function. Moreover, enteric glia have an important impact on epithelial cell transcriptome and induce a shift in epithelial cell phenotype towards increased cell adhesion and cell differentiation.Enteric glia can also preserve epithelial barrier against intestinal bacteria insult. In this review, we will describe the current body of evidence supporting functional roles of enteric glia on intestinal barrier.
基金Supported by National Natural Science Foundation of China, No. 30500688
文摘AIM: To investigate the effect of emodin on expression of claudin4, claudin5 and occludin, as well as the alveolar epithelial barrier in rats with pancreatitis induced by sodium taurocholate. METHODS: Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Emodin was injected via the external jugular vein 3 h after induction of acute pancreatitis. Rats from sham operation group and acute pancreatitis group were injected with normal saline (an equivalent volume as emodin) at the same time point. Samples of lung and serum were obtained 6 h after drug administration. Pulmonary morphology was examined with HE staining. Pulmonary edema was estimated by measuring water content in lung tissue samples. Tumor necrosis factorα (TNFα) and interleukin6 (IL6) level were measured by enzymelinked immunospecific assay. Serum amylase and pulmonary myeloperoxidase (MPO) activity were detected by spectrophotometry. Alveolar epithelial barrier was assessed by pulmonary dye extravasation. Expression of claudin4, claudin5 and occludin in lung tissue samples was examined by immunohistology, quantitative realtime reverse transcription polymerase chain reaction and Western blotting analysis, respectively.RESULTS: Pancreatitis-associated lung injury was char-acterized by pulmonary edema, leukocyte infiltration, alveolar collapse, and elevated serum amylase level. The pulmonary damage, pulmonary pathological scores, serum amylase and MPO activity, TNF-α and IL-6 levels, and wet/dry ratio were decreased in rats after treatment with emodin. Immunostaining of claudin-4, claudin-5 and occludin was detected in lung tissue samples from rats in sham operation group, which was distributed in alveolar epithelium, vascular endothelium, and bron-chial epithelium, respectively. The mRNA and protein expression levels of claudin-4, claudin-5 and occludin in lung tissue samples were markedly decreased, the expression level of claudin-4, claudin-5 and occluding was increased, and the pulmon
文摘The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important element is represented by the intestinal barrier, a complex system formed mostly by intestinal epithelial cells (IECs). IECs have an active role in producing mucus and regulating its composition; they provide a physical barrier capable of controlling antigen traff ic through the intestinal mucosa. At the same time, they are able to play the role of non-professional antigen presenting cells, by processing and presenting antigens directly to the cells of the intestinal immune system. On the other hand, immune cells regulate epithelial growth and differentiation, producing a continuous bi-directional cross-talk within the barrier. Several alterations of the barrier function have been identif ied in IBD, starting from mucus features up to its components, from epithelial junctions up to the Toll-like receptors, and altered immune responses. It remains to be understood whether these defects are primary causes of epithelial damage or secondary effects. We review the possible role of the epithelial barrier and particularly describe the role of IECs in the pathogenesis of IBD.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2020R1F1A1073595 and 2021R1A2C2006745)。
文摘Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,gallic acid,and flavonols),which are thought to contribute to the health benefits of tea.High intake of tea polyphenols has been described to prevent and/or attenuate a variety of chronic pathological conditions like cardiovascular diseases,neurodegenerative diseases,diabetes,and cancer.This review focuses on established antioxidant and anti-inflammatory properties of tea polyphenols and underlying mechanisms of their involvement in inflammatory bowel diseases(IBD).Tea polyphenols act as efficient antioxidants by inducing an endogenous antioxidant defense system and maintaining intracellular redox homeostasis.Tea polyphenols also regulate signaling pathways such as nuclear factor-κB,activator protein 1,signal transducer and activator of transcriptions,and nuclear factor E2-related factor 2,which are associated with IBD development.Accumulating pieces of evidence have indicated that tea polyphenols enhance epithelial barrier function and improve gut microbial dysbiosis,contributing to the management of inflammatory colitis.Therefore,this study suggests that supplementation of tea polyphenols could prevent inflammatory conditions and improve the outcome of patients with IBD.
基金Supported by PiLeJe,37,quai-de-Grenelle,batiment Pollux,75738 Paris cedex 15
文摘AIM: To investigate the effect of the probiotic combination Lactibiane Tolerance<sup>®</sup> (LT) on epithelial barrier function in vitro and in vivo.
文摘The intestinal barrier is important in preventing translocation of bacteria, toxins and antigens from the lumen of the gut into the body. Enhanced permeability, or gut leakiness, has been associated with different diseases. Probiotics can, strain-specifically, improve the epithelial barrier function. However, so far most researches have used cell lines or animal models due to the difficulty of measuring the effects of products on the epithelial barrier function in vivo in humans. Here a systematic literature search was performed to find articles addressing the effects of probiotics on the barrier function in human trials. The Pubmed database was searched (January 2013) to identify human in vivo studies with probiotic products in which parameters for epithelial barrier function were measured. In total 29 studies were identified, but patients, bacterial characteristics and methods to measure intestinal barrier function caused large heterogeneity among these studies. About half of the studies showed positive results of probiotics on the epithelial barrier function, indicating a clear potential of probiotics in this field. In a case series of 14 patients using Ecologica825, a probiotic food supplement with known effect on epithelial barrier function, different markers of intestinal integrity improved significantly. Further studies in this field should consider strain(s), dose and duration of the probiotic supplementation as well as the markers used to measure epithelial barrier function. Besides the lactulose/mannitol test, zonulin and α1-antitrypsin might be valuable markers to measure epithelial barrier function in future experiments.
文摘The disruption of epithelial barrier integrity is an important factor in the pathogenesis of various immune disorders. However, the restitution of the compromised barrier functions is difficult. This study investigates the regulation of TWIK-related potassium channel-1 （Trek1） in the restitution of intestinal epithelial barrier functions. The human colon epithelial cell line T84 was cultured in monolayers and used to observe epithelial barrier functions in vitro. An intestinal allergy mouse model was created. Cytokine levels were determined by enzyme-linked immunosorbent assay and western blotting. The results showed that Trek1 deficiency induced T84 monolayer barrier disruption. Allergic responses markedly suppressed the expression of Trek1 in the intestinal epithelia via activating the mitogen-activated protein kinase pathways and increasing the expression of histone deacetylase-1. The inhibition of histone deacetylase-1 by sodium butyrate or the administration of a butyrate-producing probiotic （Clostridium butyricum） restored the intestinal epithelial barrier functions and markedly enhanced the effect of antigen-specific immunotherapy. The data suggest that Trek1 is required for the maintenance of intestinal epithelial barrier integrity. Allergic responses induce an insufficiency of Trek1 expression in the intestinal epithelia. Trek1 expression facilitates the restoration of intestinal epithelial barrier functions in an allergic environment.
文摘A number of digestive and extra-digestive disorders,including inflammatory bowel diseases,irritable bowel syndrome,intestinal infections,metabolic syndrome and neuropsychiatric disorders,share a set of clinical features at gastrointestinal level,such as infrequent bowel movements,abdominal distension,constipation and secretory dysfunctions.Several lines of evidence indicate that morphological and molecular changes in intestinal epithelial barrier and enteric neuromuscular compartment contribute to alterations of both bowel motor and secretory functions in digestive and extra-digestive diseases.The present review has been conceived to provide a comprehensive and critical overview of the available knowledge on the morphological and molecular changes occurring in intestinal epithelial barrier and enteric neuromuscular compartment in both digestive and extra-digestive diseases.In addition,our intent was to highlight whether these morphological and molecular alterations could represent a common path(or share some common features)driving the pathophysiology of bowel motor dysfunctions and related symptoms associated with digestive and extra-digestive disorders.This assessment might help to identify novel targets of potential usefulness to develop original pharmacological approaches for the therapeutic management of such disturbances.
基金Supported by The national institutes of health(DK092330)to Carroll IM
文摘Numerous reports have identified a dysbiosis in the intestinal microbiota in patients suffering from inflammatory bowel diseases(IBD),yet the mechanism(s)in which this complex microbial community initiates or perpetuates inflammation remains unclear.The purpose of this review is to present evidence for one such mechanism that implicates enteric microbial derived proteases in the pathogenesis of IBD.We highlight and discuss studies demonstrating that proteases and protease receptors are abundant in the digestive system.Additionally,we investigate studies demonstrating an association between increased luminal protease activity and activation of protease receptors,ultimately resulting in increased intestinal permeability and exacerbation of colitis in animal models as well as in human IBD.Proteases are essential for the normal functioning of bacteria and in some cases can serve as virulence factors for pathogenic bacteria.Although not classified as traditional virulence factors,proteases originating from commensal enteric bacteria also have a potential association with intestinal inflammation via increased enteric permeability.Reports of increased protease activity in stools from IBD patients support a possible mechanism for a dysbiotic enteric microbiota in IBD.A better understanding of these pathways and characterization of the enteric bacteria involved,their proteases,and protease receptors may pave the way for new therapeutic approaches for these diseases.
