D-Psicose intake exacerbates dextran sulfate sodium-induced colitis in mice through alteration in the gut microbiota and dysfunction of mucosal barrier

D-Psicose,as a low-calorie rare sugar,has attracted a lot of attention in recent years for alternating to sucrose.The anti-obesity effect of D-psicose has been extensively confirmed in previous studies,however,the impact of D-psicose on colitis remains vague.Here,we firstly evaluated the effect of the D-psicose prophylactic intervention on dextran sulfate sodium-induced colitis in C57BL/6 mice.The pathological symptoms,inflammatory cytokines levels,gut microbiota composition,short chain fatty acids(SCFAs)production and colonic barrier integrity were comprehensively evaluated.The results confirmed that D-psicose intervention aggravated colitis,characterized by the exacerbation of colon shortening,increase of colonic inflammatory infiltration,and marked exaltation of disease activity indices and IL-6,IL-1βand TNF-αlevels.Further,the dysfunction of gut microbiota was identified in the psicose group.The abundance of pro-inflammatory bacteria Lachnospiraceae_NK4A136_group was significantly up-regulated while the abundance of probiotics Akkermansia and Lactobacillus were significantly down-regulated in the psicose group compared to the model group.Moreover,the production of SCFAs was suppressed in the psicose group,accompanied by a decrease in the level of mucin 2(Muc-2).Collectively,the underlying mechanism of the exacerbation of colitis by D-psicose intervention might be attributed to microbiota dysfunction accompanied by the reduction of SCFAs,which leads to the damage of the mucosal barrier and the intensifi cation of inflammatory invasion.

Progress on immuno-microenvironment and immune-related therapies in patients with pseudomyxoma peritonei

Pseudomyxoma peritonei(PMP) is an indolent malignant syndrome. The standard treatment for PMP is cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy(CRS + HIPEC). However, the high recurrence rate and latent clinical symptoms and signs are major obstacles to further improving clinical outcomes. Moreover, patients in advanced stages receive little benefit from CRS + HIPEC due to widespread intraperitoneal metastases. Another challenge in PMP treatment involves the progressive sclerosis of PMP cell-secreted mucus, which is often increased due to activating mutations in the gene coding for guanine nucleotide-binding protein alpha subunit(GNAS). Consequently, the development of other PMP therapies is urgently needed. Several immune-related therapies have shown promise, including the use of bacterium-derived non-specific immunogenic agents, radioimmunotherapeutic agents, and tumor cell-derived neoantigens, but a well-recognized immunotherapy has not been established. In this review the roles of GNAS mutations in the promotion of mucin secretion and disease development are discussed. In addition, the immunologic features of the PMP microenvironment and immune-associated treatments are discussed to summarize the current understanding of key features of the disease and to facilitate the development of immunotherapies.

犬去黏膜回肠输尿管新生黏膜上皮性质鉴定

目的检测比格犬去黏膜回肠输尿管术后3、6、12月新生黏膜中CK7、CK20、UPK2和MUC2的表达,鉴别新生黏膜的组织类型。方法购买9只比格犬,建立去黏膜回肠代输尿管模型,建模过程中留取部分正常回肠作为阳性对照组,留取部分黏膜层剥脱回肠作为阴性对照组,于术后3、6、12月各选取3只比格犬,留取去黏膜回肠输尿管样本作为实验组,按取材月份将实验组样本分为术后3、6、12月组;用HE染色观察对照组及实验组样本管壁结构、免疫荧光检测阳性对照组及各实验组中CK7、CK20、UPK2和MUC2的表达,比较各组差异。结果术后3、6、12月见新生黏膜长出;免疫荧光示阳性对照组与各实验组CK7、UPK2阴性表达;与阳性对照组相比,术后3月组CK20表达明显降低,具有统计学意义(P<0.05),术后6、12月组CK20表达量未见明显差异,无统计学意义(P>0.05);与阳性对照组相比,术后3月组MUC2表达明显降低,具有统计学意义(P<0.05),术后6、12月组MUC2表达量未见明显差异,无统计学意义(P>0.05)。结论犬裁剪去黏膜回肠输尿管术后3月可见新生黏膜长出,6月后新生黏膜稳定与正常回肠组织MUC2、CK20的表达无明显统计学差异,新生黏膜为肠黏膜上皮。

β_2肾上腺能受体与黏蛋白2在大鼠结肠黏膜的共存

目的探究去甲肾上腺素对大鼠结肠黏液分泌的影响以及肾上腺能β受体在大鼠结肠黏膜的分布。方法采用酶联免疫吸附测定法检测去甲肾上腺素(norepinephrine,NE)对结肠黏液分泌的影响;用免疫荧光组织化学方法观察黏蛋白2(mucin2,MUC2)及β肾上腺能受体在结肠黏膜的分布;实时定量PCR方法检测β肾上腺能受体在大肠结肠黏膜的表达;同时采用阿利新蓝/过碘酸雪夫染色方法检测黏液细胞在结肠黏膜的分布;使用激光共聚焦显微镜观察β2肾上腺能受体与MUC2在结肠黏液细胞的共存。结果去甲肾上腺素可刺激大鼠远端结肠黏膜的黏液释放增加,比对照组增加约247%。免疫荧光组织化学结果显示β1和β3肾上腺能受体在结肠黏膜有弱表达,β2肾上腺能受体为高表达。β1和β2肾上腺能受体mRNA表达相对量与免疫荧光组织化学一致。黏蛋白MUC2主要表达在结肠隐窝的黏液细胞内,且与β2肾上腺能受体有共存。结论β2肾上腺能受体与MUC2在结肠黏液细胞共存;去甲肾上腺素可促进结肠黏液分泌。

黏蛋白-2与肠黏膜屏障损伤的研究进展

黏蛋白-2(MUC2)是肠黏液层主要成分,覆盖于肠上皮细胞顶端,主要由杯状细胞分泌,在润滑肠道、为肠内抗菌蛋白及共生菌群提供黏附位点、抵御肠内致病菌及有害物质入侵等方面发挥着重要功能。近年来MUC2在肠道黏膜屏障损伤中的作用研究日趋受到学者重视,这也可能是肠黏膜屏障损伤的一个重要治疗突破口。

MUC1、MUC2与Met在下咽癌中的表达及其临床意义

目的:探讨MUC1、MUC2与Met在下咽癌中的表达及其临床意义。方法:采用免疫组化方法检测了59例下咽癌MUC1、MUC2和Met的表达。结果:59例下咽癌中MUC1高表达率为66.1%(39/59),MUC2高表达率为61.0%(36/59),Met高表达率为61.0%(36/59);MUC1低表达率为33.9%(20/59),MUC2低表达率39.0%(23/59),Met低表达率39.0%(23/59)。MUC1和MUC2均与Met的表达高低显著相关(P<0.01),MUC1与MUC2的表达不相关(P>0.05)。此三项指标的高表达组淋巴结转移的发生率均显著高于低表达组(P<0.01),而在肿瘤的不同分化程度组间差异无显著性(P>0.05)。MUC2蛋白的表达在肿瘤的不同T分级组间差异有显著性(P<0.01)。MUC1、MUC2、Met高表达组生存率均显著低于低表达组(P<0.01)。结论:MUC1、MUC2、Met的表达参与了下咽癌的发生发展,3项指标联合检测可更好地预测下咽癌的预后。

Diverse expression patterns of mucin 2 in colorectal cancer indicates its mechanism related to the intestinal mucosal barrier

BACKGROUND Abnormal expression patterns of mucin 2(MUC2)have been reported in a variety of malignant tumors and precancerous lesions.Reduced MUC2 expression in the intestinal mucosa,caused by various pathogenic factors,is related to mechanical dysfunction of the intestinal mucosa barrier and increased intestinal mucosal permeability.However,the relationship between MUC2 and the intestinal mucosal barrier in patients with colorectal cancer(CRC)is not clear.AIM To explore the relationship between MUC2 and intestinal mucosal barrier by characterizing the multiple expression patterns of MUC2 in CRC.METHODS Immunohistochemical staining was performed on intestinal tissue specimens from 100 CRC patients,including both cancer tissues and adjacent normal tissues.Enzyme-linked immunosorbent assays were performed on preoperative sera from 66 CRC patients and 20 normal sera to detect the serum levels of MUC2,diamine oxide(DAO),and D-lactate(D-LAC).The relationship between MUC2 expression and clinical parameters was calculated by theχ2 test or Fisher’s exact test.Prognostic value of MUC2 was evaluated by Kaplan-Meier curve and log-rank tests.RESULTS Immunohistochemical staining of 100 CRC tissues showed that the expression of MUC2 in cancer tissues was lower than that in normal tissues(54%vs 79%,P<0.05),and it was correlated with tumor-node-metastasis(TNM)stage and lymph node metastasis in CRC patients(P<0.05).However,the serum level of MUC2 in CRC patients was higher than that in normal controls,and was positively associated with serum levels of human DAO(χ2=3.957,P<0.05)and D-LAC(χ^(2)=7.236,P<0.05),which are the biomarkers of the functional status of the intestinal mucosal barrier.And the serum level of MUC2 was correlated with TNM stage,tumor type,and distant metastasis in CRC patients(P<0.05).Kaplan-Meier curves showed that decreased MUC2 expression in CRC tissues predicted a poor survival.CONCLUSION MUC2 in tissues may play a protective role by participating in the intestinal mucosal barrier and can be used as an indicator to evaluate the prognosis of CRC patients.

Effects of casein glycomacropeptide on the early development of primary colorectal cancer in rats

In this paper,we utilized dimethylhydrazine(DMH)-induced colorectal cancer(CC)model rats to explore the effects of casein glycomacropeptide(CGMP)on colorectal cancer.Rats with CC were orally administrated with 10,50,or 100 mg/kg bw d CGMP,or the same volume of phosphatebuffered saline for 15 weeks.The total numbers of aberrant crypt foci(ACF)and crypts per focus in colon were scored using a light microscope at low magnification after the colon was stained with methylene blue solutions.The methylation level of DNA extracted from colon was detected using methylation-specific PCR.The expression of p16 and mucin 2(MUC2)proteins were measured by immunohistochemistry.The results showed that although ACF were found in rats treated with CGMP,their number was significantly decreased compared to that of model rats.In addition,methylation and expression levels of p16 and MUC2 were also inhibited by CGMP,which were more obvious in rats treated with 50 mg/kg bw d CGMP.In conclusion,CGMP has potential application as nutritional therapy for preventing colorectal cancer.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Clinicopathological characteristics of human epidermal growth factor receptor 2-positive Barrett's adenocarcinoma

AIM:To compare the clinicopathological characteristics of human epidermal growth factor receptor 2 (HER2)-positive and HER2-negative Barrett's adenocarcinoma in Japan. METHODS:We performed immunohistochemical analysis of HER2 in 30 samples taken from patients with Barrett's adenocarcinoma and dual color in situ hybridization in cases showing 2+ reactions. We compared the clinicopathological characteristics of HER2-positive and HER2-negative patients.RESULTS:HER2 positivity was identified in 8 (27%) carcinoma samples. We found that HER2 expression was associated with p53 overexpression (100% vs 52.6% in pT1 tumor; 100% vs 54.5% in all stage tumor, P < 0.05) and protruding lesions at the early disease stage. There was no association between the mucin phenotype of the carcinomas and prognosis. HER2 expression and low clinical stage were unexpectedly different between Barrett's adenocarcinoma patients and gastric cancer patients, but the macroscopic features may be associated with earlier diagnosis in these patients. CONCLUSION:Our results suggest that HER2-positive Barrett's adenocarcinomas are associated with p53 overexpression and lesion protrusion at the early disease stage.

Abelmoschus manihot polysaccharide fortifies intestinal mucus barrier to alleviate intestinal inflammation by modulating Akkermansia muciniphila abundance

The intestinal mucus barrier is an important line of defense against gut pathogens.Damage to this barrier brings bacteria into close contact with the epithelium,leading to intestinal inflammation.Therefore,its restoration is a promising strategy for alleviating intestinal inflammation.This study showed that Abelmoschus manihot polysaccharide(AMP)fortifies the intestinal mucus barrier by increasing mucus production,which plays a crucial role in the AMP-mediated amelioration of colitis.IL-10-deficient mouse models demonstrated that the effect of AMP on mucus production is dependent on IL-10.Moreover,bacterial depletion and replenishment confirmed that the effects of AMP on IL-10 secretion and mucus production were mediated by Akkermansia muciniphila.These findings suggest that plant polysaccharides fortify the intestinal mucus barrier by maintaining homeostasis in the gut microbiota.This demonstrates that targeting mucus barrier is a promising strategy for treating intestinal inflammation.

Dietary iron regulates intestinal goblet cell function and alleviates Salmonella typhimurium invasion in mice

Iron is an important micronutrient that plays a vital role in host defenses and bacterial pathogenicity. As iron treatments increase the risk of infection by stimulating the growth and virulence of bacterial pathogens, their roles in anti-infection immunity have frequently been underestimated. To estimate whether adequate dietary iron intake would help defend against pathogenic bacterial infection, mice were fed iron-deficient(2 mg kg-1feed), iron-sufficient(35 mg kg-1feed), or iron-enriched diet(350 mg kg-1feed) for 12 weeks, followed by oral infection with Salmonella typhimurium. Our results revealed that dietary iron intake improved mucus layer function and decelerated the invasion of the pathogenic bacteria, Salmonella typhimurium. Positive correlations between serum iron and the number of goblet cells and mucin2 were found in response to total iron intake in mice.Unabsorbed iron in the intestinal tract affected the gut microbiota composition, and the abundance of Bacteroidales, family Muribaculaceae, was positively correlated with their mucin2 expression. However, the results from antibiotic-treated mice showed that the dietary iron-regulated mucin layer function was not microbial-dependent. Furthermore, in vitro studies revealed that ferric citrate directly induced mucin2 expression and promoted the proliferation of goblet cells in both ileal and colonic organoids. Thus, dietary iron intake improves serum iron levels, regulates goblet cell regeneration and mucin layer function, and plays a positive role in the prevention of pathogenic bacteria.

黏蛋白(MUC1、MUC2、MUC5AC和MUC6)在乳腺浸润性导管癌中的表达及意义

目的检测黏蛋白(MUC1、MUC2、MUC5AC和MUC6)在乳腺浸润性导管癌中的表达,并探讨其临床病理学意义。方法收集207例乳腺浸润性导管癌标本,应用组织芯片以及免疫组化等技术对黏蛋白家族成员M UC1、M UC2、M UC5AC和M UC6进行检测,并对其与临床病理学特征的关系进行分析。结果 M UC1在89.4%的被检测病例中表达。MUC1高表达的乳腺癌病例更倾向于具有低组织学级别、雌激素受体(ER)阳性、无淋巴结转移等特点。MUC1的亚细胞定位,即胞浆伴胞膜表达与乳腺癌术后复发转移具有相关性。MUC2的阳性率很低,仅为4.3%。MUC5AC与MUC6在患者标本中的表达率分别是42.0%和22.2%。除了MUC5AC与低级别导管癌、ER阳性有关,以及MUC6与HER-2呈正相关外,与乳腺癌其他因素均无明显相关性。结论 MUC1在大多数乳腺浸润性导管癌中都有表达,而MUC2、MUC5AC及MUC6的表达率则相对较低。MUC1的异位表达可能是潜在的预后不良因素。

Leucine increases mucin 2 and occludin production in LS174T cells partially via PI3K-Akt-mTOR pathway

Mucin 2 and occludin play a crucial role in preserving the intestinal mucosal integrity. However, the role for leucine mediating intestinal mucin 2 and occludin expression has little been investigated. The current study was conducted to test the hypothesis that leucine treatment could increase mucin 2 and occludin levels in LS174 T cells. The LS174 T cells were incubated in the Dulbecco's Modified Eagle Medium(DMEM)supplementing 0, 0.5 and 5 mmol/L L-leucine for the various durations. Two hours after the leucine treatment, the inhibitor of mammalian target of rapamycin(mTOR) and protein kinase B(Akt) phosphorylation in LS174 T cells were significantly increased(P < 0.05), and the mucin 2 and occludin levels were also significantly enhanced(P < 0.05). However, the pretreatment of 10 nmol/L rapamycin, which was an mTOR inhibitor, or 1 μmol/L wortmanin, which was an inhibitor of phosphatidylinositol 3-kinase(PI3 K), completely inhibited leucine-induced mTOR or Akt phosphorylation(P < 0.05), and significantly reduced leucine-stimulated mucin 2 and occludin levels(P < 0.05). These results suggest that leucine treatment promotes the mucin 2 and occludin levels in LS174 T cells partially through the PI3 K-Akt-mTOR signaling pathway.

Structural Basis of Glycan Recognition in Globally Predominant Human P[8]Rotavirus

Rotavirus(RV)causes acute gastroenteritis in infants and children worldwide.Recent studies showed that glycans such as histo-blood group antigens(HBGAs)function as cell attachment factors affecting RV host susceptibility and prevalence.P[8]is the predominant RV genotype in humans,but the structural basis of how P[8]RVs interact with glycan ligands remains elusive.In this study,we characterized the interactions between P[8]VP8~*s and glycans which showed that VP8~*,the RV glycan binding domain,recognized both mucin core 2 and H type 1 antigens according to the ELISA-based oligosaccharide binding assays.Importantly,we determined the structural basis of P[8]RV-glycans interaction from the crystal structures of a Rotateq P[8]VP8~*in complex with core 2 and H type 1 glycans at 1.82.3?,respectively,revealing a common binding pocket and similar binding mode.Structural and sequence analysis demonstrated that the glycan binding site is conserved among RVs in the P[Ⅱ]genogroup,while genotype-specific amino acid variations determined different glycan binding preference.Our data elucidated the detailed structural basis of the interactions between human P[8]RVs and different host glycan factors,shedding light on RV infection,epidemiology,and development of anti-viral agents.