Objective:To provide the most up-to-date data on the burden of malignant mesothelioma(MM)and the projections through 2029 in China.Methods:Data on patients diagnosed with MM from China during 1990-2019 were obtained f...Objective:To provide the most up-to-date data on the burden of malignant mesothelioma(MM)and the projections through 2029 in China.Methods:Data on patients diagnosed with MM from China during 1990-2019 were obtained from the Global Burden of Disease(GBD)2019 database,including annual cases and deaths data and age-standardized rates of incidence,mortality,and disability-adjusted life-years(DALYs)associated with MM among different age groups.Temporal trends during 1990-2019 were analyzed by the Joinpoint regression models using 95%confidence interval(CI),while the projections through 2029 were calculated by the Bayesian age-period-cohort model.Data on the production and consumption of asbestos in China were obtained from the United States Geological Survey on Mineral Commodity Summaries during 1996-2023.Results:We observed a significant elevation in incident new cases and deaths over the last 3 decades,increasing from 1193 in 1990 to 2815 in 2019 for incident cases and from 1134 in 1990 to 2773 in 2019 for death cases.We found a roughly 6%increase in the proportion of incident cases for those aged>70 years(30%in 2019 versus 24%in 1990),while for the proportion of deaths similar elevation for those aged>70 years was found.Additionally,men had significantly higher DALYs due to MM across age groups compared with women.Asbestos consumption in China dramatically dropped since 2012 and reached the bottom in 2017 with 230 kilotons.By 2029,the projected age-standardized rate for incidence and mortality is expected to reach 1.2 per million for both.Conclusion:We found,for the first time using GBD data on the Chinese population,that the burden of MM has been significantly increasing in China over the last three decades and will continue to increase in the upcoming decade,suggesting an urgent need for a complete ban on chrysotile asbestos in China.展开更多
AIM:To compare the reliability of gastritis staging sys-tems in ranking gastritis-associated cancer risk in a large series of consecutive patients.METHODS:Gastric mucosal atrophy is the precancer-ous condition in whic...AIM:To compare the reliability of gastritis staging sys-tems in ranking gastritis-associated cancer risk in a large series of consecutive patients.METHODS:Gastric mucosal atrophy is the precancer-ous condition in which intestinal-type gastric cancer(GC)most frequently develops.The operative link for gas-tritis assessment(OLGA)staging system ranks the GC risk according to both the topography and the severity of gastric atrophy(as assessed histologically on the ba-sis of the Sydney protocol for gastric mucosal biopsy).Both cross-sectional and long-term follow-up trials have consistently associated OLGA stages Ⅲ-Ⅳ with a higher risk of GC.A recently-proposed modification of the OLGA staging system(OLGIM)basically incorporates the OLGA frame,but replaces the atrophy score with an assessment of intestinal metaplasia(IM)alone.A series of 4552 consecutive biopsy sets(2007-2009)was re-trieved and reassessed according to both the OLGA and the OLGIM staging systems.A set of at least 5 biopsy samples was available for all the cases considered.RESULTS:In 4460 of 4552 cases(98.0%),both the high-risk stages(Ⅲ + Ⅳ)and the low-risk stages(0 +Ⅰ + Ⅱ)were assessed applying the OLGA and OL-GIM criteria.Among the 243 OLGA high-risk stages,14(5.8%)were down-staged to a low risk using OLGIM.The 67(1.5%)incidentally-found neoplastic lesions(intraepithelial or invasive)were consistently associated with high-risk stages,as assessed by both OLGA and OLGIM(P < 0.001 for both).Two of 34 intestinal-type GCs coexisting with a high-risk OLGA stage(stage Ⅲ)were associated with a low-risk OLGIM stage(stage Ⅱ).CONCLUSION:Gastritis staging systems(both OLGA and OLGIM)convey prognostically important informa-tion on the gastritis-associated cancer risk.Because of its clinical impact,the stage of gastritis should be included as a conclusive message in the gastritis histol-ogy report.Since it focuses on IM alone,OLGIM staging is less sensitive than OLGA staging in the identif ication of patients at high risk of gastric cancer.展开更多
Compelling evidence indicates sex and gender differences in epidemiology, symptomatology, pathophysiology, and treatment outcome in irritable bowel syndrome (IBS). Based on the female predominance as well as the corre...Compelling evidence indicates sex and gender differences in epidemiology, symptomatology, pathophysiology, and treatment outcome in irritable bowel syndrome (IBS). Based on the female predominance as well as the correlation between IBS symptoms and hormonal status, several models have been proposed to examine the role of sex hormones in gastrointestinal (GI) function including differences in GI symptoms expression in distinct phases of the menstrual cycle, in pre- and post-menopausal women, during pregnancy, hormonal treatment or after oophorectomy. Sex hormones may influence peripheral and central regulatory mechanisms of the brain-gut axis involved in the pathophysiology of IBS contributing to the alterations in visceral sensitivity, motility, intestinal barrier function, and immune activation of intestinal mucosa. Sex differences in stress response of the hypothalamic-pituitary-adrenal axis and autonomic nervous system, neuroimmune interactions triggered by stress, as well as estrogen interactions with serotonin and corticotropin-releasing factor signaling systems are being increasingly recognized. A concept of “microgenderome” related to the potential role of sex hormone modulation of the gut microbiota is also emerging. Significant differences between IBS female and male patients regarding symptomatology and comorbidity with other chronic pain syndromes and psychiatric disorders, together with differences in efficacy of serotonergic medications in IBS patients confirm the necessity for more sex-tailored therapeutic approach in this disorder.展开更多
AIM: We have previously demonstrated that cholangiocytes, the epithelial cells lining intrahepatic bile ducts,encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile a...AIM: We have previously demonstrated that cholangiocytes, the epithelial cells lining intrahepatic bile ducts,encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile acid vectorial transport. Cholangiocytes possess ASBT,an apical sodium-dependent bile acid transporter to take up bile acids,and t-ASBT,a basolateral alternatively spliced and truncated form of ASBT to efflux bile acids.Though hepatocyte and ileal bile acid transporters are in part regulated by the flux of bile acids, the effect of alterations in bile acid flux on the expression of t-ASBT in terminal ileocytes remains undear.Thus,we tested the hypothesis that expression of ASBT and t-ASBT in cholangiocytes and ileocytes was regulated by bile acid flux. METHODS: Expression of ASBT and t-ASBT message and protein in cholangiocytes and ileocytes isolated from pair- fed rats given control (C) and 1% taurocholate (TCA) or 5% cholestyramine (CY) enriched diets,were assessed by both quantitative RNase protection assays and quantitative immunoblotting.The data obtained from each of the control groups were pooled to reflect the changes observed following TCA and CY treatments with respect to the control diets. Cholangiocyte taurocholate uptake was determined using a novel microperfusion technique on intrahepatic bile duct units (IBDUs) derived from C,TCA and CY fed rats. RESULTS: In cholangiocytes,both ASBT and t-ASBT message RNA and protein were significantly decreased in response to TCA feeding compared to C diet.In contrast, message and protein of both bile acid transporters significantly increased following CY feeding compared to C diet.In the ileum,TCA feeding significantly up-regulated both ASBT and t-ASBT message and protein compared to C diet,while CY feeding significantly down-regulated message and protein of both bile acid transporters compared to C diet.As anticipated from alterations in cholangiocyte ASBT expression,the uptake of taurocholate in microperfused IBDUs derived from rats on TCA diet decreased 2.7-fold,whereas it increased 1.7-fold in those on CY diet compared to C diet fed groups. CONCLUSION: These data demonstrate that expression of ASBT and t-ASBT in cholangiocytes is regulated by a negative feedback loop while the expression of these transporters in terminal ileum is modified via positive feedback.Thus, while transcriptional regulatory mechanisms in response to alterations in bile acid pool size are operative in both cholangiocytes and ileocytes,each cell type responds differently to bile acid supplementation and depletion.展开更多
AIM: To determine if novel bile acid transporters may be expressed in human tissues. METHODS: SLC10A1 (NTCP) was used as a probe to search the NCBI database for homology to previously uncharacterized ESTs. The homolog...AIM: To determine if novel bile acid transporters may be expressed in human tissues. METHODS: SLC10A1 (NTCP) was used as a probe to search the NCBI database for homology to previously uncharacterized ESTs. The homology search identified an EST (termed SLC10A4) that shares sequence identity with SLC10A1 and SLC10A2 (ASBT). We performed Northern blot analysis and RT-PCR to determine the tissue distribution of SLC10A4. SLC10A4 was cloned in frame with an epitope tag and overexpressed in CHO cells to determine cellular localization and functional analysis of bile acid uptake. RESULTS: Northern analysis revealed that SLC10A4 mRNA is ubiquitously expressed in human tissues with the highest levels of mRNA expression in brain, placenta, and liver. In SLC10A4-transfected CHO cells, immunoblotting analysis and immunofluorescence staining demonstrated a 49-kDa protein that is expressed at the plasma membrane and intracellular compartments. Functional analysis of SLC10A4 showed no significant taurocholate uptake in the presence of sodium when compared to untransfected CHO cells. CONCLUSION: To date, we have shown that this protein has no capacity to transport taurocholate relative to SLC10A1; however, given its ubiquitous tissue distribution, it may play a more active role in transporting other endogenous organic anions.展开更多
AIM: To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a nove...AIM: To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a novel surgery-free method of solid-state manometry.METHODS: Male Wistar rats fed a standard diet with or without 4% enzyme-treated rice fiber (ERF) for 5 wk were subjected to rWAS (1 h daily x 10 d) or no stress. The VMR to graded phasic CRD was assessed by intraluminal colonic pressure recording on days 0 (base-line), 1 and 10 (45 min) and 11 (24 h) after rWAS and expressed as percentage change from baseline. Cecal content of short chain fatty acids and distal colonic histology were assessed on day 11. RESULTS: WAS on day 1 reduced the VMR to CRD at 40 and 60 mmHg similarly by 28.9% ± 6.6% in both diet groups. On day 10, rWAS-induced reduction of VMR occurred only at 40 mmHg in the standard diet group (36.2% ± 17.8%) while in the ERF group VMR was lowered at 20, 40 and 60 mmHg by 64.9% ± 20.9%, 49.3% ± 11.6% and 38.9% ± 7.3% respectively. The visceral analgesia was still observed on day 11 in ERF-but not in standard diet-fed rats. By contrast the non-stressed groups (standard or ERF diet) exhibited no changes in VMR to CRD. In standard diet-fed rats, rWAS induced mild colonic histological changes that were absent in ERF-fed rats exposed to stress compared to non-stressed rats. The reduction of cecal content of isobutyrate and total butyrate, but not butyrate alone, was correlated with lower visceral pain response. Additionally, ERF diet increased rWAS-induced defecation by 26% and 75% during the first 0-15 min and last 15-60 min, respectively, compared to standard diet, and reduced rats' body weight gain by 1.3 fold independently of their stress status. CONCLUSION: These data provide the first evidence of psychological stress-related visceral analgesia in rats that was enhanced by chronic intake of ERF prebiotic.展开更多
Gut microbes are closely related with human health,but remain much to learn.Clostridium symbiosum is a conditionally pathogenic human gut bacterium and regarded as a potential biomarker for early diagnosis of intestin...Gut microbes are closely related with human health,but remain much to learn.Clostridium symbiosum is a conditionally pathogenic human gut bacterium and regarded as a potential biomarker for early diagnosis of intestinal tumors.However,the absence of an efficient toolbox that allows diverse genetic manipulations of this bacterium limits its in-depth studies.Here,we obtained the complete genome sequence of C.symbiosum ATCC 14940,a representative strain of C.symbiosum.On this basis,we further developed a series of genetic manipulation methods for this bacterium.Firstly,following the identification of a functional replicon pBP1 in C.symbiosum ATCC 14940,a highly efficient conjugative DNA transfer method was established,enabling the rapid introduction of exogenous plasmids into cells.Next,we constructed a dual-plasmid CRISPR/Cas12a system for genome editing in this bacterium,reaching over 60% repression for most of the chosen genes as well as efficient deletion(>90%)of three target genes.Finally,this toolbox was used for the identification of crucial functional genes,involving growth,synthesis of important metabolites,and virulence of C.symbiosum ATCC 14940.Our work has effectively established and optimized genome editing methods in intestinal C.symbiosum,thereby providing strong support for further basic and application research in this bacterium.展开更多
The gut microbiota plays a key role in host health and disease,particularly through their interactions with the immune system.Intestinal homeostasis is dependent on the symbiotic relationships between the host and the...The gut microbiota plays a key role in host health and disease,particularly through their interactions with the immune system.Intestinal homeostasis is dependent on the symbiotic relationships between the host and the diverse gut microbiota,which is influenced by the highly co-evolved immune-microbiota interactions.The first step of the interaction between the host and the gut microbiota is the sensing of the gut microbes by the host immune system.In this review,we describe the cells of the host immune system and the proteins that sense the components and metabolites of the gut microbes.We further highlight the essential roles of pattern recognition receptors(PRRs),the G protein-coupled receptors(GPCRs),aryl hydrocarbon receptor(AHR)and the nuclear receptors expressed in the intestinal epithelial cells(IECs)and the intestine-resident immune cells.We also discuss the mechanisms by which the disruption of microbial sensing because of genetic or environmental factors causes human diseases such as the inflammatory bowel disease(IBD).展开更多
基金supported by grants from Zhejiang Provincial Ten-Thousand Talents Plan(grant number:2021R52020)the Horizon 2020 Program of the European Union(grant number:856620).
文摘Objective:To provide the most up-to-date data on the burden of malignant mesothelioma(MM)and the projections through 2029 in China.Methods:Data on patients diagnosed with MM from China during 1990-2019 were obtained from the Global Burden of Disease(GBD)2019 database,including annual cases and deaths data and age-standardized rates of incidence,mortality,and disability-adjusted life-years(DALYs)associated with MM among different age groups.Temporal trends during 1990-2019 were analyzed by the Joinpoint regression models using 95%confidence interval(CI),while the projections through 2029 were calculated by the Bayesian age-period-cohort model.Data on the production and consumption of asbestos in China were obtained from the United States Geological Survey on Mineral Commodity Summaries during 1996-2023.Results:We observed a significant elevation in incident new cases and deaths over the last 3 decades,increasing from 1193 in 1990 to 2815 in 2019 for incident cases and from 1134 in 1990 to 2773 in 2019 for death cases.We found a roughly 6%increase in the proportion of incident cases for those aged>70 years(30%in 2019 versus 24%in 1990),while for the proportion of deaths similar elevation for those aged>70 years was found.Additionally,men had significantly higher DALYs due to MM across age groups compared with women.Asbestos consumption in China dramatically dropped since 2012 and reached the bottom in 2017 with 230 kilotons.By 2029,the projected age-standardized rate for incidence and mortality is expected to reach 1.2 per million for both.Conclusion:We found,for the first time using GBD data on the Chinese population,that the burden of MM has been significantly increasing in China over the last three decades and will continue to increase in the upcoming decade,suggesting an urgent need for a complete ban on chrysotile asbestos in China.
基金Supported by An AIRC grant from the Veneto Regional Authorities,2009the"Guido Berlucchi"Foundation+1 种基金the"Morgagni"Association for Oncological Research (PadovaPD)
文摘AIM:To compare the reliability of gastritis staging sys-tems in ranking gastritis-associated cancer risk in a large series of consecutive patients.METHODS:Gastric mucosal atrophy is the precancer-ous condition in which intestinal-type gastric cancer(GC)most frequently develops.The operative link for gas-tritis assessment(OLGA)staging system ranks the GC risk according to both the topography and the severity of gastric atrophy(as assessed histologically on the ba-sis of the Sydney protocol for gastric mucosal biopsy).Both cross-sectional and long-term follow-up trials have consistently associated OLGA stages Ⅲ-Ⅳ with a higher risk of GC.A recently-proposed modification of the OLGA staging system(OLGIM)basically incorporates the OLGA frame,but replaces the atrophy score with an assessment of intestinal metaplasia(IM)alone.A series of 4552 consecutive biopsy sets(2007-2009)was re-trieved and reassessed according to both the OLGA and the OLGIM staging systems.A set of at least 5 biopsy samples was available for all the cases considered.RESULTS:In 4460 of 4552 cases(98.0%),both the high-risk stages(Ⅲ + Ⅳ)and the low-risk stages(0 +Ⅰ + Ⅱ)were assessed applying the OLGA and OL-GIM criteria.Among the 243 OLGA high-risk stages,14(5.8%)were down-staged to a low risk using OLGIM.The 67(1.5%)incidentally-found neoplastic lesions(intraepithelial or invasive)were consistently associated with high-risk stages,as assessed by both OLGA and OLGIM(P < 0.001 for both).Two of 34 intestinal-type GCs coexisting with a high-risk OLGA stage(stage Ⅲ)were associated with a low-risk OLGIM stage(stage Ⅱ).CONCLUSION:Gastritis staging systems(both OLGA and OLGIM)convey prognostically important informa-tion on the gastritis-associated cancer risk.Because of its clinical impact,the stage of gastritis should be included as a conclusive message in the gastritis histol-ogy report.Since it focuses on IM alone,OLGIM staging is less sensitive than OLGA staging in the identif ication of patients at high risk of gastric cancer.
基金Supported by The Veterans Administration Research Career Scientist Award(to TachéY)National Institute of Health grants No.P50 DK-64539(to TachéY)No.K01-DK088937(to Larauche M)
文摘Compelling evidence indicates sex and gender differences in epidemiology, symptomatology, pathophysiology, and treatment outcome in irritable bowel syndrome (IBS). Based on the female predominance as well as the correlation between IBS symptoms and hormonal status, several models have been proposed to examine the role of sex hormones in gastrointestinal (GI) function including differences in GI symptoms expression in distinct phases of the menstrual cycle, in pre- and post-menopausal women, during pregnancy, hormonal treatment or after oophorectomy. Sex hormones may influence peripheral and central regulatory mechanisms of the brain-gut axis involved in the pathophysiology of IBS contributing to the alterations in visceral sensitivity, motility, intestinal barrier function, and immune activation of intestinal mucosa. Sex differences in stress response of the hypothalamic-pituitary-adrenal axis and autonomic nervous system, neuroimmune interactions triggered by stress, as well as estrogen interactions with serotonin and corticotropin-releasing factor signaling systems are being increasingly recognized. A concept of “microgenderome” related to the potential role of sex hormone modulation of the gut microbiota is also emerging. Significant differences between IBS female and male patients regarding symptomatology and comorbidity with other chronic pain syndromes and psychiatric disorders, together with differences in efficacy of serotonergic medications in IBS patients confirm the necessity for more sex-tailored therapeutic approach in this disorder.
文摘AIM: We have previously demonstrated that cholangiocytes, the epithelial cells lining intrahepatic bile ducts,encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile acid vectorial transport. Cholangiocytes possess ASBT,an apical sodium-dependent bile acid transporter to take up bile acids,and t-ASBT,a basolateral alternatively spliced and truncated form of ASBT to efflux bile acids.Though hepatocyte and ileal bile acid transporters are in part regulated by the flux of bile acids, the effect of alterations in bile acid flux on the expression of t-ASBT in terminal ileocytes remains undear.Thus,we tested the hypothesis that expression of ASBT and t-ASBT in cholangiocytes and ileocytes was regulated by bile acid flux. METHODS: Expression of ASBT and t-ASBT message and protein in cholangiocytes and ileocytes isolated from pair- fed rats given control (C) and 1% taurocholate (TCA) or 5% cholestyramine (CY) enriched diets,were assessed by both quantitative RNase protection assays and quantitative immunoblotting.The data obtained from each of the control groups were pooled to reflect the changes observed following TCA and CY treatments with respect to the control diets. Cholangiocyte taurocholate uptake was determined using a novel microperfusion technique on intrahepatic bile duct units (IBDUs) derived from C,TCA and CY fed rats. RESULTS: In cholangiocytes,both ASBT and t-ASBT message RNA and protein were significantly decreased in response to TCA feeding compared to C diet.In contrast, message and protein of both bile acid transporters significantly increased following CY feeding compared to C diet.In the ileum,TCA feeding significantly up-regulated both ASBT and t-ASBT message and protein compared to C diet,while CY feeding significantly down-regulated message and protein of both bile acid transporters compared to C diet.As anticipated from alterations in cholangiocyte ASBT expression,the uptake of taurocholate in microperfused IBDUs derived from rats on TCA diet decreased 2.7-fold,whereas it increased 1.7-fold in those on CY diet compared to C diet fed groups. CONCLUSION: These data demonstrate that expression of ASBT and t-ASBT in cholangiocytes is regulated by a negative feedback loop while the expression of these transporters in terminal ileum is modified via positive feedback.Thus, while transcriptional regulatory mechanisms in response to alterations in bile acid pool size are operative in both cholangiocytes and ileocytes,each cell type responds differently to bile acid supplementation and depletion.
基金Supported by National Institutes of Health Grant DK24031 (to NF. L.) and by the Mayo Foundation
文摘AIM: To determine if novel bile acid transporters may be expressed in human tissues. METHODS: SLC10A1 (NTCP) was used as a probe to search the NCBI database for homology to previously uncharacterized ESTs. The homology search identified an EST (termed SLC10A4) that shares sequence identity with SLC10A1 and SLC10A2 (ASBT). We performed Northern blot analysis and RT-PCR to determine the tissue distribution of SLC10A4. SLC10A4 was cloned in frame with an epitope tag and overexpressed in CHO cells to determine cellular localization and functional analysis of bile acid uptake. RESULTS: Northern analysis revealed that SLC10A4 mRNA is ubiquitously expressed in human tissues with the highest levels of mRNA expression in brain, placenta, and liver. In SLC10A4-transfected CHO cells, immunoblotting analysis and immunofluorescence staining demonstrated a 49-kDa protein that is expressed at the plasma membrane and intracellular compartments. Functional analysis of SLC10A4 showed no significant taurocholate uptake in the presence of sodium when compared to untransfected CHO cells. CONCLUSION: To date, we have shown that this protein has no capacity to transport taurocholate relative to SLC10A1; however, given its ubiquitous tissue distribution, it may play a more active role in transporting other endogenous organic anions.
基金Supported by Central Labs for Frontier Technology Kirin Holdings Co., Ltd Japanthe National Institute of Health grants,P50 DK-64539 (to Taché Y and Larauche M)+2 种基金Center Grant DK-41301 (Animal Core, to Yvette Taché)R01 DK-33061 (to Yvette Taché) Veterans Administration Research Career Scientist Award
文摘AIM: To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a novel surgery-free method of solid-state manometry.METHODS: Male Wistar rats fed a standard diet with or without 4% enzyme-treated rice fiber (ERF) for 5 wk were subjected to rWAS (1 h daily x 10 d) or no stress. The VMR to graded phasic CRD was assessed by intraluminal colonic pressure recording on days 0 (base-line), 1 and 10 (45 min) and 11 (24 h) after rWAS and expressed as percentage change from baseline. Cecal content of short chain fatty acids and distal colonic histology were assessed on day 11. RESULTS: WAS on day 1 reduced the VMR to CRD at 40 and 60 mmHg similarly by 28.9% ± 6.6% in both diet groups. On day 10, rWAS-induced reduction of VMR occurred only at 40 mmHg in the standard diet group (36.2% ± 17.8%) while in the ERF group VMR was lowered at 20, 40 and 60 mmHg by 64.9% ± 20.9%, 49.3% ± 11.6% and 38.9% ± 7.3% respectively. The visceral analgesia was still observed on day 11 in ERF-but not in standard diet-fed rats. By contrast the non-stressed groups (standard or ERF diet) exhibited no changes in VMR to CRD. In standard diet-fed rats, rWAS induced mild colonic histological changes that were absent in ERF-fed rats exposed to stress compared to non-stressed rats. The reduction of cecal content of isobutyrate and total butyrate, but not butyrate alone, was correlated with lower visceral pain response. Additionally, ERF diet increased rWAS-induced defecation by 26% and 75% during the first 0-15 min and last 15-60 min, respectively, compared to standard diet, and reduced rats' body weight gain by 1.3 fold independently of their stress status. CONCLUSION: These data provide the first evidence of psychological stress-related visceral analgesia in rats that was enhanced by chronic intake of ERF prebiotic.
基金supported by the National Key R&D Program of China(2018YFA0901500)Science and Technology Commission of Shanghai Municipality(21DZ1209100)+1 种基金DNL Cooperation Fund,CAS(DNL202013)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-016).
文摘Gut microbes are closely related with human health,but remain much to learn.Clostridium symbiosum is a conditionally pathogenic human gut bacterium and regarded as a potential biomarker for early diagnosis of intestinal tumors.However,the absence of an efficient toolbox that allows diverse genetic manipulations of this bacterium limits its in-depth studies.Here,we obtained the complete genome sequence of C.symbiosum ATCC 14940,a representative strain of C.symbiosum.On this basis,we further developed a series of genetic manipulation methods for this bacterium.Firstly,following the identification of a functional replicon pBP1 in C.symbiosum ATCC 14940,a highly efficient conjugative DNA transfer method was established,enabling the rapid introduction of exogenous plasmids into cells.Next,we constructed a dual-plasmid CRISPR/Cas12a system for genome editing in this bacterium,reaching over 60% repression for most of the chosen genes as well as efficient deletion(>90%)of three target genes.Finally,this toolbox was used for the identification of crucial functional genes,involving growth,synthesis of important metabolites,and virulence of C.symbiosum ATCC 14940.Our work has effectively established and optimized genome editing methods in intestinal C.symbiosum,thereby providing strong support for further basic and application research in this bacterium.
基金We would like to thank W.Tao,H.Ma,and other members of Zhu laboratory and Z.Wei in Richard Flavell’s lab for helpful discussions.This work was supported by grants from the National Key R&D Program of China(Grant No.2018YFA0508000,S.Z.)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB29030101,S.Z.)+1 种基金the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-074,S.Z.)the National Natural Science Foundation of China(Grant No.82061148013,S.Z.).
文摘The gut microbiota plays a key role in host health and disease,particularly through their interactions with the immune system.Intestinal homeostasis is dependent on the symbiotic relationships between the host and the diverse gut microbiota,which is influenced by the highly co-evolved immune-microbiota interactions.The first step of the interaction between the host and the gut microbiota is the sensing of the gut microbes by the host immune system.In this review,we describe the cells of the host immune system and the proteins that sense the components and metabolites of the gut microbes.We further highlight the essential roles of pattern recognition receptors(PRRs),the G protein-coupled receptors(GPCRs),aryl hydrocarbon receptor(AHR)and the nuclear receptors expressed in the intestinal epithelial cells(IECs)and the intestine-resident immune cells.We also discuss the mechanisms by which the disruption of microbial sensing because of genetic or environmental factors causes human diseases such as the inflammatory bowel disease(IBD).
