A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major ...A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.展开更多
Background Asthma is a chronic inflammatory disease characterized by reversible bronchial constriction, pulmonary inflammation and airway remodeling. Current standard therapies for asthma provide symptomatic control, ...Background Asthma is a chronic inflammatory disease characterized by reversible bronchial constriction, pulmonary inflammation and airway remodeling. Current standard therapies for asthma provide symptomatic control, but fail to target the underlying disease pathology. Furthermore, no therapeutic agent is effective in preventing airway remodeling. A substantial amount of evidence suggests that statins have anti-inflammatory properties and immunomodulatory activity. In this study, we investigated the effect of rosuvastatin on airway inflammation and its inhibitory mechanism in mucus hypersecretion in a murine model of chronic asthma. Methods BALB/c mice were sensitized and challenged by ovalbumin to induce asthma. The recruitment of inflammatory cells into bronchoalveolar lavage fluid （BALF） and the lung tissues were measured by Diff-Quik staining and hematoxylin and eosin （H＆E） staining. ELISA was used for measuring the levels of IL-4, IL-5, IL-13 and TNF-a in BALE Periodic acid-Schiff （PAS） staining was used for mucus secretion. Gamma-aminobutyric acid type A receptor （GABAAR） β2 expression was measured by means of immunohistochemistry, reverse transcription-polymerase chain reaction （RT-PCR） and Western blotting. Results Rosuvastatin reduced the number of total inflammatory cells, lymphocytes, macrophages, neutrophils, and eosinophils recruited into BALF, the levels of IL-4, IL-5, IL-13 and TNF-a in BALF, along with the histological mucus index （HMI） and GABAAR 132 expression. Changes occurred in a dose-dependent manner. Conclusions Based on its ability to reduce the inflammatory response and mucus hypersecretion by regulating GABAAR activity in a murine model of chronic asthma, rosuvastatin may be a useful therapeutic agent for treatment of asthma.展开更多
The intestinal tract is inhabited by a tremendous number of microorganisms,termed the gut microbiota.These microorganisms live in a mutualistic relationship with their host and assist in the degradation of complex car...The intestinal tract is inhabited by a tremendous number of microorganisms,termed the gut microbiota.These microorganisms live in a mutualistic relationship with their host and assist in the degradation of complex carbohydrates.Although the gut microbiota is generally considered beneficial,the vast number of microbial cells also form a permanent threat to the host.Thus,the intestinal epithelium is covered with a dense layer of mucus to prevent translocation of the gut microbiota into underlying tissues.Intestinal mucus is an organized glycoprotein network with a host-specific glycan structure.While the mucus layer has long been considered a passive,host-designed barrier,recent studies showed that maturation and function of the mucus layer are strongly influenced by the gut microbiota.In return,the glycan repertoire of mucins can select for distinct mucosa-associated bacteria that are able to bind or degrade specific mucin glycans as a nutrient source.Because the intestinal mucus layer is at the crucial interface between host and microbes,its breakdown leads to gut bacterial encroachment that can eventually cause inflammation and infection.Accordingly,a dysfunctional mucus layer has been observed in colitis in mice and humans.Moreover,the increased consumption of a low-fiber Western-style diet in our modern society has recently been demonstrated to cause bacteria-mediated defects of the intestinal mucus layer.Here,I will review current knowledge on the interaction between gut bacteria and the intestinal mucus layer in health and disease.Understanding the molecular details of this host–microbe interaction may contribute to the development of novel treatment options for diseases involving a dysfunctional mucus layer,such as ulcerative colitis.展开更多
Colorectal cancer(CRC)is a global problem affecting millions of people worldwide.This disease is unique because of its slow progress that makes it preventable and often curable.CRC symptoms usually emerge only at adva...Colorectal cancer(CRC)is a global problem affecting millions of people worldwide.This disease is unique because of its slow progress that makes it preventable and often curable.CRC symptoms usually emerge only at advanced stages of the disease,consequently its early detection can be achieved only through active population screening,which markedly reduces mortality due to this cancer.CRC screening tests that employ non-invasively detectable biomarkers are currently being actively developed and,in most cases,samples of either stool or blood are used.However,alternative biological substances that can be collected non-invasively(colorectal mucus,urine,saliva,exhaled air)have now emerged as new sources of diagnostic biomarkers.The main categories of currently explored CRC biomarkers are:(1)Proteins(comprising widely used haemoglobin);(2)DNA(including mutations and methylation markers);(3)RNA(in particular microRNAs);(4)Low molecular weight metabolites(comprising volatile organic compounds)detectable by metabolomic techniques;and(5)Shifts in gut microbiome composition.Numerous tests for early CRC detection employing such non-invasive biomarkers have been proposed and clinically studied.While some of these studies generated promising early results,very few of the proposed tests have been transformed into clinically validated diagnostic/screening techniques.Such DNA-based tests as Food and Drug Administration-approved multitarget stool test(marketed as Cologuard®)or blood test for methylated septin 9(marketed as Epi proColon®2.0 CE)show good diagnostic performance but remain too expensive and technically complex to become effective CRC screening tools.It can be concluded that,despite its deficiencies,the protein(haemoglobin)detection-based faecal immunochemical test(FIT)today presents the most cost-effective option for non-invasive CRC screening.The combination of non-invasive FIT and confirmatory invasive colonoscopy is the current strategy of choice for CRC screening.However,continuing intense research in the area pr展开更多
Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to ...Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to examine the effect and mechanisms of simvastatin on airway mucus hypersecretion in rats treated with lipopolysaccharide （LPS）. Methods Mucus hypersecretion in rat airways was induced by intra-tracheal instillation of LPS. Rats treated with or without LPS were administered intra-peritoneally simvastatin （5 and 20 mg/kg） for 4 days. Expression of Muc5ac, RhoA and mitogen-activated protein kinases （MAPK） p38 in lung were detected by real-time polymerase chain reaction （PCR）, immunohistochemistry or Western blotting. Tumor necrosis factor （TNF）-α and IL-8 in bronchoalveolar lavage fluid （BALF） were assayed by an enzyme-linked lectin assay and enzyme linked immunosorbent assay （ELISA）. Results Simvastatin attenuated LPS-induced goblet cell hyperplasia in bronchial epithelium and Muc5ac hypersecretion at both the gene and protein levels in lung （P 〈0.05）. Moreover, simvastatin inhibited neutrophil accumulation and the increased concentration of TNF-α and IL-8 in BALF follows LPS stimulation （P 〈0.05）. The higher dose of simvastatin was associated with a more significant reduction in Muc5ac mRNA expression, neutrophil accumulation and inflammatory cytokine release. Simultaneously, the increased expression of RhoA and p38 MAPK were observed in LPS-treated lung （P 〈0.05）. Simvastatin inhibited the expression of RhoA and p38 phosphorylation in lung following LPS stimulation （P 〈0.05）. However, the increased expression of p38 protein in LPS-treated lung was not affected by simvastatin administration. Conclusions Simvastatin attenuates airway mucus hypersecretion and pulmonary inflammatory damage induced by LPS. The inhibitory effect of simvastatin on airway mucus hypersecretion may be through, at least in part, the suppression of neutrophil accumulation and 展开更多
AIM:To assess the mucosa-associated bacterial microflora and mucus layer in adolescents with inflammatory bowel disease(IBD) .METHODS:Sixty-one adolescents(mean age 15 years,SD ± 4.13) were included in the study....AIM:To assess the mucosa-associated bacterial microflora and mucus layer in adolescents with inflammatory bowel disease(IBD) .METHODS:Sixty-one adolescents(mean age 15 years,SD ± 4.13) were included in the study.Intestinal biopsies from inflamed and non-inflamed mucosa of IBD patients and from controls with functional abdominal pain were cultured under aerobic and anaerobic conditions.The number of microbes belonging to the same group was calculated per weight of collected tissue.The mucus thickness in frozen samples was measured under a fluorescent microscope.RESULTS:The ratios of different bacterial groups in inflamed and non-inflamed mucosa of IBD patients and controls were specific for particular diseases.Streptococcus spp.were predominant in the inflamed mucosa of Crohn's disease(CD) patients(80% of all bacteria) ,and Lactobacillus spp.were predominant in ulcerative colitis patients(90%) .The differences were statistically significant(P = 0.01-0.001) .Lower number of bifidobacteria was observed in the whole IBD group.A relation was also found between clinical and endoscopic severity and decreased numbers of Lactobacillus and,to a lesser extent,of Streptococcus in biopsies from CD patients.The mucus layer in the inflamed sites was significantly thinner as compared to controls(P = 0.0033) and to non-inflamed areas in IBD patients(P = 0.031) .CONCLUSION:The significantly thinner mucosa of IBD patients showed a predominance of some aerobes specific for particular diseases,their numbers decreased in relation to higher clinical and endoscopic activity of the disease.展开更多
Allergic bronchopulmonary aspergillosis(ABPA) is a complex hypersensitivity syndrome triggered against antigens of Aspergillus fumigatus,a fungus that most commonly colonizes the airways of patients with bronchial ast...Allergic bronchopulmonary aspergillosis(ABPA) is a complex hypersensitivity syndrome triggered against antigens of Aspergillus fumigatus,a fungus that most commonly colonizes the airways of patients with bronchial asthma and cystic fibrosis.It presents clinically with refractory asthma,hemoptysis and systemic manifestations including fever,malaise and weight loss.Radiologically,it presents with central bronchiectasis and recurrent episodes of mucus plugging.The mucus plugs in ABPA are generally hypodense but in up to 20% of patients the mucus can be hyperdense on computed tomography.This paper reviews the literature on the clinical significance of hyperattenuated mucus in patients with ABPA.展开更多
To reduce medication for patients with ulcerative colitis(UC),we need to establish the etiology of UC.The intestinal microbiota of patients with inflammatory bowel disease(IBD)has been shown to differ from that of hea...To reduce medication for patients with ulcerative colitis(UC),we need to establish the etiology of UC.The intestinal microbiota of patients with inflammatory bowel disease(IBD)has been shown to differ from that of healthy controls and abundant data indicate that it changes in both composition and localization.Small intestinal bacterial overgrowth is significantly higher in IBD patients compared with controls.Probiotics have been investigated for their capacity to reduce the severity of UC.The luminal surfaces of the gastrointestinal tract are covered by a mucus layer.This normally acts as a barrier that does not allow bacteria to reach the epithelial cells and thus limits the direct contact between the host and the bacteria.The mucus layer in the colon comprises an inner layer that is firmly adherent to the intestinal mucosa,and an outer layer that can be washed off with minimal rinsing.Some bacteria can dissolve the protective inner mucus layer.Defects in renewal and formation of the inner mucus layer allow bacteria to reach the epithelium and have implications for the causes of colitis.In this review,important elements of UC pathology are thought to be the intestinal bacteria,gut mucus,and the mucosa-associated immune system.展开更多
基金Supported by Robert Bosch Foundation,Stuttgart,Germany
文摘A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.
基金This study was partially supported by the National Natural Science Foundation of China （No. 30971303）.
文摘Background Asthma is a chronic inflammatory disease characterized by reversible bronchial constriction, pulmonary inflammation and airway remodeling. Current standard therapies for asthma provide symptomatic control, but fail to target the underlying disease pathology. Furthermore, no therapeutic agent is effective in preventing airway remodeling. A substantial amount of evidence suggests that statins have anti-inflammatory properties and immunomodulatory activity. In this study, we investigated the effect of rosuvastatin on airway inflammation and its inhibitory mechanism in mucus hypersecretion in a murine model of chronic asthma. Methods BALB/c mice were sensitized and challenged by ovalbumin to induce asthma. The recruitment of inflammatory cells into bronchoalveolar lavage fluid （BALF） and the lung tissues were measured by Diff-Quik staining and hematoxylin and eosin （H＆E） staining. ELISA was used for measuring the levels of IL-4, IL-5, IL-13 and TNF-a in BALE Periodic acid-Schiff （PAS） staining was used for mucus secretion. Gamma-aminobutyric acid type A receptor （GABAAR） β2 expression was measured by means of immunohistochemistry, reverse transcription-polymerase chain reaction （RT-PCR） and Western blotting. Results Rosuvastatin reduced the number of total inflammatory cells, lymphocytes, macrophages, neutrophils, and eosinophils recruited into BALF, the levels of IL-4, IL-5, IL-13 and TNF-a in BALF, along with the histological mucus index （HMI） and GABAAR 132 expression. Changes occurred in a dose-dependent manner. Conclusions Based on its ability to reduce the inflammatory response and mucus hypersecretion by regulating GABAAR activity in a murine model of chronic asthma, rosuvastatin may be a useful therapeutic agent for treatment of asthma.
基金B.O.S.is supported by a Long-Term Fellowship from the Human Frontier Science Program(LT000109/2014).
文摘The intestinal tract is inhabited by a tremendous number of microorganisms,termed the gut microbiota.These microorganisms live in a mutualistic relationship with their host and assist in the degradation of complex carbohydrates.Although the gut microbiota is generally considered beneficial,the vast number of microbial cells also form a permanent threat to the host.Thus,the intestinal epithelium is covered with a dense layer of mucus to prevent translocation of the gut microbiota into underlying tissues.Intestinal mucus is an organized glycoprotein network with a host-specific glycan structure.While the mucus layer has long been considered a passive,host-designed barrier,recent studies showed that maturation and function of the mucus layer are strongly influenced by the gut microbiota.In return,the glycan repertoire of mucins can select for distinct mucosa-associated bacteria that are able to bind or degrade specific mucin glycans as a nutrient source.Because the intestinal mucus layer is at the crucial interface between host and microbes,its breakdown leads to gut bacterial encroachment that can eventually cause inflammation and infection.Accordingly,a dysfunctional mucus layer has been observed in colitis in mice and humans.Moreover,the increased consumption of a low-fiber Western-style diet in our modern society has recently been demonstrated to cause bacteria-mediated defects of the intestinal mucus layer.Here,I will review current knowledge on the interaction between gut bacteria and the intestinal mucus layer in health and disease.Understanding the molecular details of this host–microbe interaction may contribute to the development of novel treatment options for diseases involving a dysfunctional mucus layer,such as ulcerative colitis.
文摘Colorectal cancer(CRC)is a global problem affecting millions of people worldwide.This disease is unique because of its slow progress that makes it preventable and often curable.CRC symptoms usually emerge only at advanced stages of the disease,consequently its early detection can be achieved only through active population screening,which markedly reduces mortality due to this cancer.CRC screening tests that employ non-invasively detectable biomarkers are currently being actively developed and,in most cases,samples of either stool or blood are used.However,alternative biological substances that can be collected non-invasively(colorectal mucus,urine,saliva,exhaled air)have now emerged as new sources of diagnostic biomarkers.The main categories of currently explored CRC biomarkers are:(1)Proteins(comprising widely used haemoglobin);(2)DNA(including mutations and methylation markers);(3)RNA(in particular microRNAs);(4)Low molecular weight metabolites(comprising volatile organic compounds)detectable by metabolomic techniques;and(5)Shifts in gut microbiome composition.Numerous tests for early CRC detection employing such non-invasive biomarkers have been proposed and clinically studied.While some of these studies generated promising early results,very few of the proposed tests have been transformed into clinically validated diagnostic/screening techniques.Such DNA-based tests as Food and Drug Administration-approved multitarget stool test(marketed as Cologuard®)or blood test for methylated septin 9(marketed as Epi proColon®2.0 CE)show good diagnostic performance but remain too expensive and technically complex to become effective CRC screening tools.It can be concluded that,despite its deficiencies,the protein(haemoglobin)detection-based faecal immunochemical test(FIT)today presents the most cost-effective option for non-invasive CRC screening.The combination of non-invasive FIT and confirmatory invasive colonoscopy is the current strategy of choice for CRC screening.However,continuing intense research in the area pr
基金This study was supported by grants from National Natural Science Foundation of China to Dr. WEN Fu-qing （No. 30425007, 30370627, 30670921） and from China Medical Board of New York to Dr. WEN Fu-qiang （No. 0-722）.
文摘Background Mucus hypersecretion in the respiratory tract and goblet cell metaplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study aimed to examine the effect and mechanisms of simvastatin on airway mucus hypersecretion in rats treated with lipopolysaccharide （LPS）. Methods Mucus hypersecretion in rat airways was induced by intra-tracheal instillation of LPS. Rats treated with or without LPS were administered intra-peritoneally simvastatin （5 and 20 mg/kg） for 4 days. Expression of Muc5ac, RhoA and mitogen-activated protein kinases （MAPK） p38 in lung were detected by real-time polymerase chain reaction （PCR）, immunohistochemistry or Western blotting. Tumor necrosis factor （TNF）-α and IL-8 in bronchoalveolar lavage fluid （BALF） were assayed by an enzyme-linked lectin assay and enzyme linked immunosorbent assay （ELISA）. Results Simvastatin attenuated LPS-induced goblet cell hyperplasia in bronchial epithelium and Muc5ac hypersecretion at both the gene and protein levels in lung （P 〈0.05）. Moreover, simvastatin inhibited neutrophil accumulation and the increased concentration of TNF-α and IL-8 in BALF follows LPS stimulation （P 〈0.05）. The higher dose of simvastatin was associated with a more significant reduction in Muc5ac mRNA expression, neutrophil accumulation and inflammatory cytokine release. Simultaneously, the increased expression of RhoA and p38 MAPK were observed in LPS-treated lung （P 〈0.05）. Simvastatin inhibited the expression of RhoA and p38 phosphorylation in lung following LPS stimulation （P 〈0.05）. However, the increased expression of p38 protein in LPS-treated lung was not affected by simvastatin administration. Conclusions Simvastatin attenuates airway mucus hypersecretion and pulmonary inflammatory damage induced by LPS. The inhibitory effect of simvastatin on airway mucus hypersecretion may be through, at least in part, the suppression of neutrophil accumulation and
基金Supported by Polish Ministry of Science and Higher Education,Grant No.3PO5E09125
文摘AIM:To assess the mucosa-associated bacterial microflora and mucus layer in adolescents with inflammatory bowel disease(IBD) .METHODS:Sixty-one adolescents(mean age 15 years,SD ± 4.13) were included in the study.Intestinal biopsies from inflamed and non-inflamed mucosa of IBD patients and from controls with functional abdominal pain were cultured under aerobic and anaerobic conditions.The number of microbes belonging to the same group was calculated per weight of collected tissue.The mucus thickness in frozen samples was measured under a fluorescent microscope.RESULTS:The ratios of different bacterial groups in inflamed and non-inflamed mucosa of IBD patients and controls were specific for particular diseases.Streptococcus spp.were predominant in the inflamed mucosa of Crohn's disease(CD) patients(80% of all bacteria) ,and Lactobacillus spp.were predominant in ulcerative colitis patients(90%) .The differences were statistically significant(P = 0.01-0.001) .Lower number of bifidobacteria was observed in the whole IBD group.A relation was also found between clinical and endoscopic severity and decreased numbers of Lactobacillus and,to a lesser extent,of Streptococcus in biopsies from CD patients.The mucus layer in the inflamed sites was significantly thinner as compared to controls(P = 0.0033) and to non-inflamed areas in IBD patients(P = 0.031) .CONCLUSION:The significantly thinner mucosa of IBD patients showed a predominance of some aerobes specific for particular diseases,their numbers decreased in relation to higher clinical and endoscopic activity of the disease.
文摘Allergic bronchopulmonary aspergillosis(ABPA) is a complex hypersensitivity syndrome triggered against antigens of Aspergillus fumigatus,a fungus that most commonly colonizes the airways of patients with bronchial asthma and cystic fibrosis.It presents clinically with refractory asthma,hemoptysis and systemic manifestations including fever,malaise and weight loss.Radiologically,it presents with central bronchiectasis and recurrent episodes of mucus plugging.The mucus plugs in ABPA are generally hypodense but in up to 20% of patients the mucus can be hyperdense on computed tomography.This paper reviews the literature on the clinical significance of hyperattenuated mucus in patients with ABPA.
基金Supported by National Natural Science Foundation of China,No.81270471
文摘To reduce medication for patients with ulcerative colitis(UC),we need to establish the etiology of UC.The intestinal microbiota of patients with inflammatory bowel disease(IBD)has been shown to differ from that of healthy controls and abundant data indicate that it changes in both composition and localization.Small intestinal bacterial overgrowth is significantly higher in IBD patients compared with controls.Probiotics have been investigated for their capacity to reduce the severity of UC.The luminal surfaces of the gastrointestinal tract are covered by a mucus layer.This normally acts as a barrier that does not allow bacteria to reach the epithelial cells and thus limits the direct contact between the host and the bacteria.The mucus layer in the colon comprises an inner layer that is firmly adherent to the intestinal mucosa,and an outer layer that can be washed off with minimal rinsing.Some bacteria can dissolve the protective inner mucus layer.Defects in renewal and formation of the inner mucus layer allow bacteria to reach the epithelium and have implications for the causes of colitis.In this review,important elements of UC pathology are thought to be the intestinal bacteria,gut mucus,and the mucosa-associated immune system.
