Intestinal glucagon-like peptide-1:A new player associated with impaired counterregulatory responses to hypoglycaemia in type 1 diabetic mice

BACKGROUND Impaired hypoglycaemic counterregulation has emerged as a critical concern for diabetic patients who may be hesitant to medically lower their blood glucose levels due to the fear of potential hypoglycaemic reactions.However,the pathogenesis of hypoglycaemic counterregulation is still unclear.Glucagon-like peptide-1(GLP-1)and its analogues have been used as adjunctive therapies for type 1 diabetes mellitus(T1DM).The role of GLP-1 in counterregulatory dysfunction during hypoglycaemia in patients with T1DM has not been reported.AIM To explore the impact of intestinal GLP-1 on impaired hypoglycaemic counterregulation in type 1 diabetic mice.METHODS T1DM was induced in C57BL/6J mice using streptozotocin,followed by intraperitoneal insulin injections to create T1DM models with either a single episode of hypoglycaemia or recurrent episodes of hypoglycaemia(DH5).Immunofluorescence,Western blot,and enzyme-linked immunosorbent assay were employed to evaluate the influence of intestinal GLP-1 on the sympathetic-adrenal reflex and glucagon(GCG)secretion.The GLP-1 receptor agonist GLP-1(7-36)or the antagonist exendin(9-39)were infused into the terminal ileum or injected intraperitoneally to further investigate the role of intestinal GLP-1 in hypoglycaemic counterregulation in the model mice.RESULTS The expression levels of intestinal GLP-1 and its receptor(GLP-1R)were significantly increased in DH5 mice.Consecutive instances of excess of intestinal GLP-1 weakens the sympathetic-adrenal reflex,leading to dysfunction of adrenal counterregulation during hypoglycaemia.DH5 mice showed increased pancreaticδ-cell mass,cAMP levels inδcells,and plasma somatostatin concentrations,while cAMP levels in pancreaticαcells and plasma GCG levels decreased.Furthermore,GLP-1R expression in islet cells and plasma active GLP-1 levels were significantly increased in the DH5 group.Further experiments involving terminal ileal infusion and intraperitoneal injection in the model mice demonstrated that intestinal GLP-1 during recurrent hypoglycaemia hindered the secretion of the counterregulatory hormone GCG via the endocrine pathway.CONCLUSION Excessive intestinal GLP-1 is strongly associated with impaired counterregulatory responses to hypoglycaemia,leading to reduced appetite and compromised secretion of adrenaline,noradrenaline,and GCG during hypoglycaemia.

The role of intestinal flora on tumorigenesis,progression,and the efficacy of PD-1/PD-L1 antibodies in colorectal cancer

Intestinal flora affects the maturation of the host immune system,serves as a biomarker and efficacy predictor in the immunotherapy of several cancers,and has an important role in the development of colorectal cancer(CRC).Anti-PD-1/PD-L1 antibodies have shown satisfactory results in MSI-H/d MMR CRC but performed poorly in patients with MSS/p MMR CRC.In recent years an increasing number of studies have shown that intestinal flora has an important impact on anti-PD-1/PD-L1 antibody efficacy in CRC patients.Preclinical and clinical evidence have suggested that anti-PD-1/PD-L1 antibody efficacy can be improved by altering the composition of the intestinal flora in CRC.Herein,we summarize the studies related to the influence of intestinal flora on anti-PD-1/PD-L1 antibody efficacy in CRC and discuss the potential underlying mechanism(s).We have focused on the impact of the intestinal flora on the efficacy and safety of anti-PD-1/PD-L1 antibodies in CRC and how to better utilize the intestinal flora as an adjuvant to improve the efficacy of anti-PD-1/PD-L1 antibodies.In addition,we have provided a basis for the potential of the intestinal flora as a new treatment modality and indicator for determining patient prognosis.

Role of intestinal glucagon-like peptide-1 in hypoglycemia response impairment in type 1 diabetes

This study critically examines the novel findings presented by Jin et al,which explores the role of intestinal glucagon-like peptide-1(GLP-1)in impaired counterregulatory responses to hypoglycemia in mice with type 1 diabetes.The study identifies intestinal GLP-1 as a significant determinant in the physiological responses to hypoglycemia,offering new insights into its potential implications for diabetes management.The editorial synthesizes these findings,discusses their relevance in the context of current diabetes research,and outlines potential avenues for future investigation of intestinal GLP-1 as a therapeutic target.This analysis underscores the need for continued research into the complex mechanisms underlying impaired hypoglycemia responses and highlights the potential of targeting intestinal GLP-1 pathways in therapeutic strategies for type 1 diabetes.

Effects of altering the ratio of C16:0 and cis-9 C18:1 in rumen bypass fat on growth performance, lipid metabolism, intestinal barrier, cecal microbiota, and inflammation in fattening bulls

Background C16:0 and cis-9 C18:1 may have different effects on animal growth and health due to unique metabolism in vivo.This study was investigated to explore the different effects of altering the ratio of C16:0 and cis-9 C18:1 in fat supplements on growth performance,lipid metabolism,intestinal barrier,cecal microbiota,and inflammation in fattening bulls.Thirty finishing Angus bulls(626±69 kg,21±0.5 months)were divided into 3 treatments according to the randomized block design:(1)control diet without additional fat(CON),(2)CON+2.5%palmitic acid calcium salt(PA,90%C16:0),and(3)CON+2.5%mixed fatty acid calcium salt(MA,60%C16:0+30%cis-9 C18:1).The experiment lasted for 104 d,after which all the bulls were slaughtered and sampled for analysis.Results MA tended to reduce 0–52 d dry matter intake compared to PA(DMI,P=0.052).Compared with CON and MA,PA significantly increased 0–52 d average daily gain(ADG,P=0.027).PA tended to improve the 0–52 d feed conversion rate compared with CON(FCR,P=0.088).Both PA and MA had no significant effect on 52–104 days of DMI,ADG and FCR(P>0.05).PA tended to improve plasma triglycerides compared with MA(P=0.077),significantly increased plasma cholesterol(P=0.002)and tended to improve subcutaneous adipose weight(P=0.066)when compared with CON and MA.Both PA and MA increased visceral adipose weight compared with CON(P=0.021).Only PA increased the colonization of Rikenellaceae,Ruminococcus and Proteobacteria in the cecum,and MA increased Akkermansia abundance(P<0.05).Compared with CON,both PA and MA down-regulated the m RNA expression of Claudin-1 in the jejunum(P<0.001),increased plasma diamine oxidase(DAO,P<0.001)and lipopolysaccharide(LPS,P=0.045).Compared with CON and MA,PA down-regulated the ZO-1 in the jejunum(P<0.001)and increased plasma LPS-binding protein(LBP,P<0.001).Compared with CON,only PA down-regulated the Occludin in the jejunum(P=0.013).Compared with CON,PA and MA significantly up-regulated the expression of TLR-4 and NF-κB in the visceral adipose(P<0.001)and increased plasma IL-6(P<0.001).Compared with CON,only PA up-regulated the TNF-αin the visceral adipose(P=0.01).Compared with CON and MA,PA up-regulated IL-6 in the visceral adipose(P<0.001),increased plasma TNF-α(P<0.001),and reduced the Ig G content in plasma(P=0.035).Compared with CON,PA and MA increased C16:0 in subcutaneous fat and longissimus dorsi muscle(P<0.05),while more C16:0 was also deposited by extension and desaturation into C18:0 and cis-9 C18:1.However,neither PA nor MA affected the content of cis-9 C18:1 in longissimus dorsi muscle compared with CON(P>0.05).Conclusions MA containing 30%cis-9 C18:1 reduced the risk of high C16:0 dietary fat induced subcutaneous fat obesity,adipose tissue and systemic low-grade inflammation by accelerating fatty acid oxidative utilization,improving colonization of Akkermansia,reducing intestinal barrier damage,and down-regulating NF-κB activation.

Link between mutations in ACVRL1 and PLA2G4A genes and chronic intestinal ulcers:A case report and review of literature

BACKGROUND Genetic factors of chronic intestinal ulcers are increasingly garnering attention.We present a case of chronic intestinal ulcers and bleeding associated with mu-tations of the activin A receptor type II-like 1(ACVRL1)and phospholipase A2 group IVA(PLA2G4A)genes and review the available relevant literature.CASE SUMMARY A 20-year-old man was admitted to our center with a 6-year history of recurrent abdominal pain,diarrhea,and dark stools.At the onset 6 years ago,the patient had received treatment at a local hospital for abdominal pain persisting for 7 d,under the diagnosis of diffuse peritonitis,acute gangrenous appendicitis with perforation,adhesive intestinal obstruction,and pelvic abscess.The surgical treat-ment included exploratory laparotomy,appendectomy,intestinal adhesiolysis,and pelvic abscess removal.The patient’s condition improved and he was dis-charged.However,the recurrent episodes of abdominal pain and passage of black stools started again one year after discharge.On the basis of these features and results of subsequent colonoscopy,the clinical diagnosis was established as in-flammatory bowel disease(IBD).Accordingly,aminosalicylic acid,immunotherapy,and related symptomatic treatment were administered,but the symptoms of the patient did not improve significantly.Further investigations revealed mutations in the ACVRL1 and PLA2G4A genes.ACVRL1 and PLA2G4A are involved in angiogenesis and coagulation,respectively.This suggests that the chronic intestinal ulcers and bleeding in this case may be linked to mutations in the ACVRL1 and PLA2G4A genes.Oral Kangfuxin liquid was administered to promote healing of the intestinal mucosa and effectively manage clinical symptoms.CONCLUSION Mutations in the ACVRL1 and PLA2G4A genes may be one of the causes of chronic intestinal ulcers and bleeding in IBD.Orally administered Kangfuxin liquid may have therapeutic potential.

Analysis of large datasets for identifying molecular targets in intestinal polyps and metabolic disorders

Background:The interrelation between intestinal polyps,metabolic syndrome(MetS),and colorectal cancer(CRC)is a critical area of study.This research focuses on pinpointing potential molecular targets to understand the link between intestinal polyp formation,metabolic irregularities,and CRC progression.Methods:We examined clinical samples from patients with intestinal polyps coexisting with MetS and compared them with samples from patients with standard intestinal polyps.Transcriptome sequencing and public database analysis were employed to identify significant pathways and genes.These targets were then validated through immunohistochemistry(IHC).Following the RNA interference of key target expression,a series of experiments,including the cell counting kit-8 assay,colony formation,wound healing,and Transwell assays,were conducted.Results:Comparative analysis revealed 75 up-regulated and 61 down-regulated differentially expressed genes(DEGs)in the MetS polyp group vs.the control.Kyoto encyclopedia of genes and genomes(KEGG)pathway enrichment suggested these DEGs were primarily associated with cell cycle and mitosis.Integration with comparative toxicogenomics database(CTD)and the cancer genome atlas(TCGA)databases highlighted 44 key CRC-related genes.Protein interaction networks indicated connections of purkinje cell protein 4(PCP4),olfactomedin 1(OLFM1),fibronectin 1(FN1),and transforming growth factor beta 3(TGF-β3)with the mitogen-activated protein kinase(MAPK)pathway.Tumor correlation studies suggested higher risk associations with FN1,PCP4,and TGF-β3,while OLFM1 was identified as a lower risk gene.Immunohistochemical analysis revealed a decrease in OLFM1 in MetS-associated intestinal polyps.Upon interference with OLFM1 in polyp epithelial cells,there was a significant enhancement in cell proliferation,colony formation,and cell migration and invasion capabilities.Conclusion:Our study highlights a significant decrease in OLFM1 expression in MetS-associated intestinal polyps.And,this reduction in OLFM1 is associated with enhanced cell proliferation,colony formation,and increased cell migration and invasion capabilities.These findings underscore the reduced OLFM1 expression in MetS-associated intestinal polyps may play a crucial role in promoting tumorigenic processes in colorectal pathology.Further research on OLFM1 may provide valuable insights into understanding and targeting MetS-associated intestinal polyps.

Dexmedetomidine ameliorates diabetic intestinal injury by promoting the polarization of M2 macrophages through the MMP23B pathway

BACKGROUND Diabetes is often associated with gastrointestinal dysfunctions,which can lead to hypoglycemia.Dexmedetomidine(DEX)is a commonly used sedative in perioperative diabetic patients and may affect gastrointestinal function.AIM To investigate whether sedative doses of DEX alleviate diabetes-caused intestinal dysfunction.METHODS Sedation/anesthesia scores and vital signs of streptozotocin(STZ)-induced diabetic mice under DEX sedation were observed.Diabetic mice were divided into saline and DEX groups.After injecting sedatives intraperitoneally,tight junctions(TJs)and apoptotic levels were evaluated 24 hours later to assess the intestinal barrier function.The role of DEX was validated using Villin-MMP23B flox/flox mice with intestinal epithelial deletion.In vitro,high glucose and hyperosmolarity were used to culture Caco-2 monolayer cells with STZ intervention.Immunofluorescence techniques were used to monitor the barrier and mitochondrial functions.RESULTS MMP23B protein levels in the intestinal tissue of STZ-induced diabetic mice were significantly higher than those in the intestinal tissue of control mice,with the DEX group displaying decreased MMP23B levels.Diabetes-mediated TJ disruption,increased intestinal mucosal permeability,and systemic inflammation in wild-type mice might be reversed by DEX.In Caco-2 cells,MMP23B was associated with increased reactive oxygen species accumulation,mitochondrial membrane potential depolarization,and TJ disruption.CONCLUSION DEX reduces MMP23B,which may potentially contribute to STZ-induced intestinal barrier dysfunction,affecting TJ modification through mitochondrial dysfunction.

GLP-1RA及SGLT-2i对糖尿病患者的血尿酸的影响如何?

GLP-1RA及SGLT-2i是ADA和中华医学会糖尿病学分会推荐的新型降糖药物,具有低血糖风险小、兼具心血管保护及降低体重等代谢获益的特点。高尿酸血症是2型糖尿病的独立危险因素,在临床实践中,人们一直在关注预防SUA的升高。据估计,患者SUA每升高1 mg/dl,发生T2DM的风险就会增加17%。国内外学者研究结果提示SGLT-2i能兼顾降糖的同时降低SUA水平;最近国外研究显示GLP-1RA还可以降低SUA水平,但仍存在矛盾。国内学者对此研究报告甚少。还需要更多的研究填补此领域的空白,为更好地预防2型糖尿的发生及发展作出贡献。GLP-1RA and SGLT-2i are new hypoglycemic drugs recommended by ADA and Diabetes Branch of Chinese Medical Association, which have the characteristics of low risk of hypoglycemia, metabolic benefits such as cardiovascular protection and weight reduction. Hyperuricemia is an independent risk factor for type 2 diabetes, and much attention has been paid to the prevention of elevated SUA in clinical practice. It is estimated that every 1 mg/dl elevation of patient SUA causes a 17% increase in the risk of developing T2DM. The results of domestic and foreign scholars suggest that SGLT-2i can reduce SUA level while lowering glucose;recent foreign studies show that GLP-1RA can also reduce SUA level, but there are still contradictions. Domestic scholars have few reports on this. More studies are needed to fill the gap in this field to contribute to better prevention of the occurrence and development of type 2 diabetes mellitus.

Chlorogenic Acid Maintains Glucose Homeostasis through Modulating the Expression of SGLT-1,GLUT-2,and PLG in Different Intestinal Segments of Sprague-Dawley Rats Fed a High-Fat Diet

Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.

葛根芩连汤通过IRS-1/PI3K/AKT通路对胃肠湿热型2型糖尿病大鼠糖脂代谢的影响

目的探究葛根芩连汤通过胰岛素受体底物-1(IRS-1)/磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)通路对胃肠湿热型2型糖尿病大鼠糖脂代谢的影响。方法将40只SD大鼠随机分为正常组(2 mL生理盐水灌胃)、造模组(2 mL生理盐水灌胃)、二甲双胍组(4.17 mg/100 g二甲双胍灌胃)和葛根芩连汤组(1 g/100 g葛根芩连汤灌胃),每组10只。采用高脂高糖饲料加腹腔注射链脲佐菌素(STZ)构建2型糖尿病大鼠模型,随后喂食油脂、42°白酒及蜂蜜水构建胃肠湿热型2型糖尿病大鼠模型。测量各组大鼠不同时间节点体质量,血糖仪测定空腹血糖(FBG);ELISA检测空腹胰岛素(FINS)、三酰甘油(TG)、总胆固醇(TC)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平变化、计算胰岛素抵抗指数(HOMA-IR);HE染色检测肝组织病理学变化;检测肝组织过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)及丙二醛(MDA)含量变化。Western blot检测肝组织IRS-1、PI3K、p-PI3K、AKT及p-AKT蛋白变化。结果与正常组比较,造模组大鼠体质量、FBG、FINS及HOMA-IR、GSH-Px、CAT、SOD、IRS-1、p-PI3K/PI3K及p-AKT/AKT水平均明显下降(P<0.05)、TG、TC、IL-6、TNF-α及MDA含量均显著升高(P<0.05),可见局灶性肝实质损失。与造模组比较,二甲双胍组及葛根芩连汤组大鼠体质量、FBG、FINS及HOMA-IR、GSH-Px、CAT、SOD、IRS-1、p-PI3K/PI3K及p-AKT/AKT水平均明显升高(P<0.05)、TG、TC、IL-6、TNF-α及MDA含量均显著降低(P<0.05),显示正常的肝实质。结论葛根芩连汤可明显改善胃肠湿热型2型糖尿病糖脂紊乱,可能是通过IRS-1/PI3K/AKT通路发挥作用。

非小细胞肺癌患者抗PD-1/PD-L1治疗疗效及其肠道菌群特征分析

目的分析非小细胞肺癌(NSCLC)患者抗程序性死亡受体1(PD-1)/程序性死亡配体1(PD-L1)治疗疗效及其肠道菌群特征。方法将2020年1月至2022年1月新疆维吾尔自治区人民医院收治的81例NSCLC患者作为研究对象,根据患者免疫治疗应答情况,将患者分为无应答组及应答组,比较两组患者临床资料及肠道菌群分布差异,并采用Spearman相关性分析患者无进展生存期(PFS)与肠道菌群α多样性指标之间的相关性。结果应答组吸烟患者比例显著低于无应答组,差异有统计学意义(χ^(2)=4.648,P=0.031)。无应答组Chao1指数、ACE指数及香农-威纳指数患者低于应答组,辛普森多样性指数高于应答组,差异有统计学意义(P<0.05)。Chao1指数、ACE指数及香农-威纳指数与PFS呈正相关(r=0.526、0.579、0.539,均P<0.05),而辛普森多样性指数与PFS呈负相关(r=-0.867,P<0.001)。采用主坐标分析对肠道菌群β多样性结构进行分析,第一主成分贡献率为70.36%,第二主成分贡献率为16.63%。结论NSCLC患者肠道菌群多样性及分布与抗PD-1/PD-L1治疗有关,患者肠道菌群多样性越高,抗PD-1/PD-L1治疗越敏感。

Sirtuin 1 alleviates endoplasmic reticulum stress-mediated apoptosis of intestinal epithelial cells in ulcerative colitis

BACKGROUND Sirtuin 1(SIRT1)is a nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase that is involved in various diseases,including cancers,metabolic diseases,and inflammation-associated diseases.However,the role of SIRT1 in ulcerative colitis(UC)is still confusing.AIM To investigate the role of SIRT1 in intestinal epithelial cells(IECs)in UC and further explore the underlying mechanisms.METHODS We developed a coculture model using macrophages and Caco-2 cells.After treatment with the SIRT1 activator SRT1720 or inhibitor nicotinamide(NAM),the expression of occludin and zona occludens 1(ZO-1)was assessed by Western blot analysis.Annexin V-APC/7-AAD assays were performed to evaluate Caco-2 apoptosis.Dextran sodium sulfate(DSS)-induced colitis mice were exposed to SRT1720 or NAM for 7 d.Transferase-mediated dUTP nick-end labeling(TUNEL)assays were conducted to assess apoptosis in colon tissues.The expression levels of glucose-regulated protein 78(GRP78),CCAAT/enhancerbinding protein homologous protein(CHOP),caspase-12,caspase-9,and caspase-3 in Caco-2 cells and the colon tissues of treated mice were examined by quantitative real-time PCR and Western blot.RESULTS SRT1720 treatment increased the protein levels of occludin and ZO-1 and inhibited Caco-2 apoptosis,whereas NAM administration caused the opposite effects.DSS-induced colitis mice treated with SRT1720 had a lower disease activity index(P<0.01),histological score(P<0.001),inflammatory cytokine levels(P<0.01),and apoptotic cell rate(P<0.01),while exposure to NAM caused the opposite effects.Moreover,SIRT1 activation reduced the expression levels of GRP78,CHOP,cleaved caspase-12,cleaved caspase-9,and cleaved caspase-3 in Caco-2 cells and the colon tissues of treated mice.CONCLUSION SIRT1 activation reduces apoptosis of IECs via the suppression of endoplasmic reticulum stress-mediated apoptosis-associated molecules CHOP and caspase-12.SIRT1 activation may be a potential therapeutic strategy for UC.

Bone-marrow mesenchymal stem cells reduce rat intestinal ischemia-reperfusion injury, ZO-1 downregulation and tight junction disruption via a TNF-α-regulated mechanism

AIM: To investigate the effect of bone-marrow mesenchymal stem cells (BM MSCs) on the intestinal mucosa barrier in ischemia/reperfusion (I/R) injury. METHODS: BM MSCs were isolated from male Sprague-Dawley rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. I/R injury was induced by occlusion of the superior mesenteric artery for 30 min. Rats were treated with saline, BM MSCs (via intramucosal injection) or tumor necrosis factor (TNF)-α blocking antibodies (via the tail vein). I/R injury was assessed using transmission electron microscopy, hematoxylin and eosin (HE) staining, immunohistochemistry, western blotting and enzyme linked immunosorbent assay.RESULTS: Intestinal permeability increased, tight junctions (TJs) were disrupted, and zona occludens 1 (ZO-1) was downregulated after I/R injury. BM MSCs reduced intestinal mucosal barrier destruction, ZO-1 downregulation, and TJ disruption. The morphological abnormalities after intestinal I/R injury positively correlated with serum TNF-α levels. Administration of anti-TNF-α IgG or anti-TNF-α receptor 1 antibodies attenuated the intestinal ultrastructural changes, ZO-1 downregulation, and TJ disruption. CONCLUSION: Altered serum TNF-α levels play an important role in the ability of BM MSCs to protect against intestinal I/R injury.

Emodin alleviates intestinal mucosal injury in rats with severe acute pancreatitis via the caspase-1 inhibition

BACKGROUND: Emodin, a traditional Chinese medicine, has a therapeutic effect on severe acute pancreatitis (SAP), whereas the underlying mechanism is still unclear. Studies showed that the intestinal mucosa impairment, and subsequent release of endotoxin and proinflammatory cytokines such as IL-1 beta, which further leads to the dysfunction of multiple organs, is the potentially lethal mechanism of SAP. Caspase-1, an IL-1 beta converting enzyme, plays an important role in this cytokine cascade process. Investigation of the effect of emodin on regulating the caspase-1 expression and the release proinflammatory cytokines will help to reveal mechanism of emodin in treating SAP. METHODS: Eighty Sprague-Dawley rats were randomly divided into four groups (n=20 each group): SAP, sham-operated (SO), emodin-treated (EM) and caspase-1 inhibitor-treated (ICE-I) groups. SAP was induced by retrograde infusion of 3.5% sodium taurocholate into the pancreatic duct. Emodin and caspase-1 inhibitor were given 30 minutes before and 12 hours after SAP induction. Serum levels of IL-1 beta, IL-18 and endotoxin, histopathological alteration of pancreas tissues, intestinal mucosa, and the intestinal caspase-1 mRNA and protein expressions were assessed 24 hours after SAP induction. RESULTS: Rats in the SAP group had higher serum levels of IL-1 beta and IL-18 (P<0.05), pancreatic and gut pathological scores (P<0.05), and caspase-1 mRNA and protein expressions (P<0.05) compared with the SO group. Compared with the SAP group, rats in the EM and ICE-I groups had lower IL-1 beta and IL-18 levels (P<0.05), lower pancreatic and gut pathological scores (P<0.05), and decreased expression of intestine caspase-1 mRNA (P<0.05). Ultrastructural analysis by transmission electron microscopy found that rats in the SAP group had vaguer epithelial junctions, more disappeared intercellular joints, and more damaged intracellular organelles compared with those in the SO group or the EM and ICE-I groups. CONCLUSIONS: Emodin alleviated pancreatic and intestinal mucosa injury in experimental SAP. Its mechanism may partly be mediated by the inhibition of caspase-1 and its downstream inflammatory cytokines, including IL-1 beta and IL-18. Our animal data may be applicable in clinical practice.

通腑理肺汤对脓毒症肠屏障损伤大鼠肠黏膜组织闭锁小带蛋白-1、闭合蛋白mRNA及蛋白表达的影响

目的:探讨通腑理肺汤(TFL)对脓毒症肠屏障损伤大鼠肠黏膜组织闭锁小带蛋白-1(ZO-1)、闭合蛋白(Occludin)mRNA及蛋白表达影响的实验研究。方法:随机抽取纯种SD大鼠40只,依次分为假手术组、模型组、TFL低剂量组和TFL高剂量组,共四组,每组10只。应用盲肠结扎穿孔(CLP)的造模方式制作脓毒症肠屏障损伤大鼠模型;假手术组只暴露盲肠,不做穿孔处理。TFL低剂量组造模成功后给予3.6 g/kg体重TFL灌胃;TFL高剂量组采用相同方法造模后,按7.2 g/kg体重TFL进行灌胃处理;模型组和假手术组按蒸馏水10 ml/kg体重灌胃,以上各组均每天干预1次,共7 d。7 d后处死各组大鼠,分离肠黏膜组织,采用RT-qPCR法检测肠黏膜组织ZO-1、Occludin mRNA基因,Western blot检测ZO-1、Occludin蛋白表达;同时取出各组相同部位的肠黏膜组织,光镜及透射电镜下观察肠黏膜组织病理及超微结构变化。结果:模型组大鼠肠黏膜组织中ZO-1、Occludin mRNA基因及蛋白表达对比假手术组均显著降低(P<0.05)。TFL低剂量组、高剂量组大鼠肠黏膜组织中ZO-1、Occludin mRNA基因及蛋白表达对比模型组均显著升高(P<0.05)。光镜下观察肠黏膜组织病理显示TFL低剂量组及高剂量组肠黏膜上皮细胞水肿、肠黏膜绒毛受损以及基底层、固有层水肿、淋巴细胞及中性粒细胞浸润明显减轻。透射电镜下肠黏膜组织超微结构亦显示TFL低剂量组及高剂量组微绒毛密集且规则,肠细胞间呈锯齿状和互锁模式,线粒体清晰,紧密连接轻微受损。结论:脓毒症肠屏障损伤大鼠模型病理损害的减轻,可能是TFL上调了肠黏膜组织紧密连接ZO-1、Occludin mRNA基因及蛋白的表达,改善肠上皮细胞间的紧密连接作用来实现的。

Resveratrol inhibits collagen Ⅰ synthesis by suppressing IGF-1R activation in intestinal fibroblasts

AIM: To investigate whether resveratrol (3,4,5-trihydroxy-trans-stilbene) inhibits collagen&#x02005;I&#x02005;synthesis induced by insulin growth factor-1 (IGF-1) in intestinal fibroblasts, and to explore the possible molecular mechanisms.

TLR4-HMGB1-, MyD88- and TRIF-dependent signaling in mouse intestinal ischemia/reperfusion injury

AIM: To characterize high-mobility group protein 1-toll-like receptor 4(HMGB1-TLR4) and downstream signaling pathways in intestinal ischemia/reperfusion(I/R) injury.METHODS: Forty specific-pathogen-free male C57BL/6 mice were randomly divided into five groups(n = 8 per group): sham, control, anti-HMGB1, anti-myeloid differentiation gene 88(My D88), and anti-translocatingchain-associating membrane protein(TRIF) antibody groups. Vehicle with the control Ig G antibody, antiHMGB1, anti-My D88, or anti-TRIF antibodies(all 1 mg/kg, 0.025%) were injected via the caudal vein 30 min prior to ischemia. After anesthetization, the abdominal wall was opened and the superior mesenteric artery was exposed, followed by 60 min mesenteric ischemia and then 60 min reperfusion. For the sham group, the abdominal wall was opened for 120 min without I/R. Levels of serum nuclear factor(NF)-κB p65, interleukin(IL)-6, and tumor necrosis factor(TNF)-α were measured, along with myeloperoxidase activity in the lung and liver. Inaddition,morphologic changes that occurred in the lung and intestinal tissues were evaluated. Levels of m RNA transcripts encoding HMGB1 and NF-κB were measured by real-time quantitative PCR, and levels of HMGB1 and NF-κB protein were measured by Western blot. Results were analyzed using one-way analysis of variance.RESULTS: Blocking HMGB 1, MyD 8 8, and TRIF expression by injecting anti-HMGB1, anti-My D88, or anti-TRIF antibodies prior to ischemia reduced the levels of inflammatory cytokines in serum; NF-κB p65: 104.64 ± 11.89, 228.53 ± 24.85, 145.00 ± 33.63, 191.12 ± 13.22, and 183.73 ± 10.81(P < 0.05); IL-6: 50.02 ± 6.33, 104.91 ± 31.18, 62.28 ± 6.73, 85.90 ± 17.37, and 78.14 ± 7.38(P < 0.05); TNF-α, 43.79 ± 4.18, 70.81 ± 6.97, 52.76 ± 5.71, 63.19 ± 5.47, and 59.70 ± 4.63(P < 0.05) for the sham, control, anti-HMGB1, anti-My D88, and anti-TRIF groups, respectively(all in pg/m L).Antibodies also alleviated tissue injury in the lung and small intestine compared with the control group in the mouse intestinal I/R model. The administration of antiHMGB1, anti-My D88, and anti-TRIF antibodies markedly reduced damage caused by I/R, for which anti-HMGB1 antibody had the most obvious effect.CONCLUSION: HMGB1 and its downstream signaling pathway play important roles in the mouse intestinal I/R injury, and the effect of the TRIF-dependent pathway is slightly greater.

Interleukin-22 receptor 1 is expressed in multinucleated giant cells:A study on intestinal tuberculosis and Crohn’s disease

BACKGROUND It is challenging to distinguish intestinal tuberculosis from Crohn’s disease due to dynamic changes in epidemiology and similar clinical characteristics. Recent studies have shown that polymorphisms in genes involved in the interleukin (IL)- 23/IL-17 axis may affect intestinal mucosal immunity by affecting the differentiation of Th17 cells. AIM To investigate the specific single-nucleotide polymorphisms (SNPs) in genes involved in the IL-23/IL-17 axis and possible pathways that affect susceptibility to intestinal tuberculosis and Crohn's disease. METHODS We analysed 133 patients with intestinal tuberculosis, 128 with Crohn’s disease, and 500 normal controls. DNA was extracted from paraffin-embedded specimens or whole blood. Four SNPs in the IL23/Th17 axis (IL22 rs2227473, IL1β rs1143627, TGFβ rs4803455, and IL17 rs8193036) were genotyped with TaqMan assays. The transcriptional activity levels of different genotypes of rs2227473 were detected by dual luciferase reporter gene assay. The expression of IL-22R1 in different intestinal diseases was detected by immunohistochemistry. RESULTS The A allele frequency of rs2227473 (P = 0.030, odds ratio = 0.60, 95% confidence interval: 0.37-0.95) showed an abnormal distribution between intestinal tuberculosis and healthy controls. The presence of the A allele was associated with a higher IL-22 transcriptional activity (P < 0.05). In addition, IL-22R1 was expressed in intestinal lymphoid tissues, especially under conditions of intestinal tuberculosis, and highly expressed in macrophage-derived Langhans giant cells. The results of immunohistochemistry showed that the expression of IL-22R1 in patients with Crohn's disease and intestinal tuberculosis was significantly higher than that in patients with intestinal polyps and colon cancer (P < 0.01). CONCLUSION High IL-22 expression seems to be a protective factor for intestinal tuberculosis. IL-22R1 is expressed in Langhans giant cells, suggesting that the IL-22/IL-22R1 system links adaptive and innate immunity.

Effect of nuclear factor kappa B on intercellular adhesion molecule-1 expression and neutrophil infiltration in lung injury induced by intestinal ischemia/reperfusion in rats

AIM： To investigate the role of nuclear factor kappa B （NF-κB） in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion （I/R）, and its effect on intercellular adhesion molecule-1 （ICAM-1） expression and neutrophil infiltration. METHODS： Twenty-four Wistar rats were divided randomly into control, I/R and pyrrolidine dithiocarbamate （PDTC） treatment groups, n = 8 in each. I/R group and PDTC treatment group received superior mysenteric artery （SMA） occluding for 1 h and reperfusion for 2 h. PDTC group was administrated with intraperitoneal injection of 2% 100 mg/kg PDTC 1 h before surgery. Lung histology and bronchia alveolus lung fluid （BALF） protein were assayed. Serum IL-6, lung malondialdehyde （MDA） and myeloperoxidase （MPO） as well as the expression level of NF-κB and ICAM-1 were measured.RESULTS： Lung injury induced by intestinal I/R, was characterized by edema, hemorrhage and neutrophil infiltration as well as by the significant rising of BALF protein. Compared to control group, the levels of serum IL-6 and lung MDA and MPO increased significantly in I/R group （P=0.001）. Strong positive expression of NF-κB p65 and ICAM-1 was observed. After the administration of PDTC, the level of serum IL-6, lung MDA and MPO as well as NF-κB and ICAM-1 decreased significantly （P〈 0.05） when compared to I/R group.CONCLUSION： The activation of NF-κB plays an important role in the pathogenesis of lung injury induced by intestinal I/R through upregulating the neutrophil infiltration and lung ICAM-1 expression. PDTC as an inhibitor of NF-κB can prevent lung injury induced by intestinal I/R through inhibiting the activity of NF-κB.

Protective effect of heme oxygenase-1 on Wistar rats with heart failure through the inhibition of inflammation and amelioration of intestinal micro- circulation

Background Myocardial infarction （MI） has likely contributed to the increased prevalence of heart failure （HF）. As a result of re- duced cardiac function, splanchnic blood flow decreases, causing ischemia in villi and damage to the intestinal barrier. The induction of heme oxygenase-1 （HO-1） could prevent, or lessen the effects of stress and inflammation. Thus, the effect and mechanism thereof of HO-1 on the intestines of rats with HF was investigated. Methods Male Wistar rats with heart failure through ligation of the left coronary artery were identified with an left ventricular ejection fraction of 〈 45% through echocardiography and then divided into various experimental groups based on the type of peritoneal injection they received [MI： saline; MI ＋ Cobalt protoporphyrin （CoPP）： CoPP solution; and MI ＋ Tin mesoporphyrin IX dichloride （SnMP）： SnMP solution]. The control group was comprised of rats without coronary ligation. Echocardiogra- phy was performed before ligation for a baseline and eight weeks after ligation in order to evaluate the cardiac function of the rats. The bac- terial translocation （BT） incidence, mesenteric microcirculation, amount of endotoxins in the vein serum, ileum levels of HO- 1, carbon oxide （CO）, nitric oxide （NO）, intedeuldn （IL）-10, turnour necrosis factor-et （TNF-ct）, and the ileum morphology were determined eight weeks after the operation. Results The rats receiving MI ＋ CoPP injections exhibited a recovery in cardiac function, an amelioration of mesenteric microcirculation and change in morphology, a lower BT incidence, a reduction in serum and ileac NO and TNF-ct levels, and an elevation in ileac HO-1, CO, and interleukin-10 （[L-10） levels compared to the MI group （P 〈 0.05）. The rats that received the MI ＋ SnMP injections exhibited results inverse to the MI （P 〈 0.05） group. Conclusions HO-1 exerted a protective effect on the intestines of rats with HF by inhibiting the inflammation and amelioration of microcirculation through the CO pathway. This protective effect could be independent from the recovery of cardiac function.