Location-based prediction model for Crohn’s disease regarding a novel serological marker,anti-chitinase 3-like 1 autoantibodies

BACKGROUND Defective neutrophil regulation in inflammatory bowel disease(IBD)is thought to play an important role in the onset or manifestation of IBD,as it could lead to damage of the intestinal mucosal barrier by the infiltration of neutrophils in the inflamed mucosa and the accumulation of pathogens.Like neutrophils in the context of innate immune responses,immunoglobulin A(IgA)as an acquired immune response partakes in the defense of the intestinal epithelium.Under normal conditions,IgA contributes to the elimination of microbes,but in connection with the loss of tolerance to chitinase 3-like 1(CHI3L1)in IBD,IgA could participate in CHI3L1-mediated improved adhesion and invasion of potentially pathogenic microorganisms.The tolerance brake to CHI3L1 and the occurrence of IgA autoantibodies to this particular target,the exact role and underlying mechanisms of CHI3L1 in the pathogenesis of IBD are still unclear.AIM To determine the predictive potential of Ig subtypes of a novel serological marker,anti-CHI3L1 autoantibodies(aCHI3L1)in determining the disease phenotype,therapeutic strategy and long-term disease course in a prospective referral cohort of adult IBD patients.METHODS Sera of 257 Crohn’s disease(CD)and 180 ulcerative colitis(UC)patients from a tertiary IBD referral center of Hungary(Division of Gastroenterology,Department of Internal Medicine,Faculty of Medicine,University of Debrecen)were assayed for IgG,IgA,and secretory IgA(sIgA)type aCHI3L1 by enzyme-linked immunosorbent assay using recombinant CHI3L1,along with 86 healthy controls(HCONT).RESULTS The IgA type was more prevalent in CD than in UC(29.2%vs 11.1%)or HCONT(2.83%;P<0.0001 for both).However,sIgA subtype aCHI3L1 positivity was higher in both CD and UC patients than in HCONT(39.3%and 32.8%vs 4.65%,respectively;P<0.0001).The presence of both IgA and sIgA aCHI3L1 antibodies was associated with colonic involvement(P<0.0001 and P=0.038,respectively)in patients with CD.Complicated disease behavior at sample procurement was associated with aCHI3L1 sIgA positivity(57.1%vs 36.0%,P=0.009).IgA type aCH3L1 was more prevalent in patients with frequent relapse during the disease course in the CD group(46.9%vs 25.7%,P=0.005).In a group of patients with concomitant presence of pure inflammatory luminal disease and colon involvement at the time of diagnosis,positivity for IgA or sIgA type aCH3L1 predicted faster progression towards a complicated disease course in time-dependent models.This association disappeared after merging subgroups of different disease locations.CONCLUSION CHI3L1 is a novel neutrophil autoantigenic target in IBD.The consideration of antibody classes along with location-based prediction may transform the future of serology in IBD.

Interaction of the major inflammatory bowel disease susceptibility alleles in Crohn’s disease patients

AIM:To investigate the interaction of interleukin-23 receptor(IL23R)(rs1004819 and rs2201841),autophagy-related 16-like 1(ATG16L1)(rs2241880), caspase recruitment domain-containing protein 15 (CARD15)genes,and IBD5 locus in Crohn's disease(CD) patients. METHODS:A total of 315 unrelated subjects with CD and 314 healthy controls were genotyped.Interactions and specific genotype combinations of a total of eight variants were tested.The variants of IBD5locus(IGR2198a_1 rs11739135 and IGR2096a_1 rs12521868),CARD15(R702W rs2066845 and L1007fs rs2066847),ATG16L1(rs2241880)and IL23R (rs1004819,rs2201841)genes were genotyped by PCR-RFLP,the G908R(rs2066844)in CARD15 was determined by direct sequencing. RESULTS:The association of ATG16L1 T300A with CD was confirmed[P=0.004,odds ratio(OR)=1.69, 95%CI:1.19-2.41],and both IL23R variants were found to represent significant risk for the disease(P= 0.008,OR=2.05,95%CI:1.20-3.50 for rs1004819 AA;P<0.001,OR=2.97,95%CI:1.65-5.33 for rs2201841 CC).Logistic regression analysis of pairwise interaction of the inflammatory bowel disease (IBD)loci indicated that IL23R,ATG16L1,CARD15 and IBD5(IGR2198a_1)contribute independently to disease risk.We also analysed the specific combina- tions by pair of individual ATG16L1,IL23R rs1004819, rs2201841,IGR2198a_1,IGR2096a_1 and CARD15 genotypes for disease risk influence.In almost all cases,the combined risk of susceptibility pairs was higher in patients carrying two different risk-associated gene variants together than individuals with just one polymorphism.The highest OR was found for IL23R rs2201841 homozygous genotype with combination of positive CARD15 status(P<0.001,OR=9.15,95% CI:2.05-40.74). CONCLUSION:The present study suggests a cumulative effect of individual IBD susceptibility loci.

碱茅(Puccinellia tenuiflora)MYBAS1-like基因的克隆与功能分析

为了研究碱茅（Puccinellia tenuiflora）转录因子Put MYBAS1-like的功能及其在非生物胁迫下的表达特性。本研究利用差异显示法,从Na HCO3逆境胁迫下的碱茅（Puccinellia tenuiflora）c DNA文库中克隆得到MYB基因片段。利用实时荧光定量PCR、RACE技术克隆得到Put MYBAS1-like的全长序列。生物信息学表明：该基因序列中存在522 bp的开放阅读框,编码173个氨基酸,预测蛋白分子量为19.68 k D,其N端含有一个约45个氨基酸组成的MYB特征结构域。因与二穗短柄草（Brachypodium distachyon）MYBAS1-like基因同源性较高,命名为Put MYBAS1-like（Alternative splicing MYB transcription factor）。本研究还采用了实时荧光定量PCR的方法分析Put MYBAS1-like基因在几种非生物胁迫下表达的情况,通过酵母单杂交实验验证其转录活性以及分析其转录激活区,同时构建Put MYBAS1-like基因的植物过表达载体,为后续分析Put MYBAS1-like基因功能特性研究提供理论依据。

Cerebrospinal fluid phosphorylated tau,visinin-like protein-1,and chitinase-3-like protein 1 in mild cognitive impairment and Alzheimer’s disease

Background:Visinin-like protein-1(VILIP-1)and chitinase-3-like protein 1(CHI3L1 or YKL-40)in cerebrospinal fluid(CSF)are newly discovered markers indicating neuronal damage and microglial activation,respectively.Phosphorylated tau(p-tau)reflects the neuropathology of Alzheimer’s disease(AD)and is useful as diagnostic markers for AD.However,it is unknown whether these biomarkers have similar or complementary information in AD.Methods:We stratified 121 participants from the Alzheimer’s Disease Neuroimaging Initiative(ADNI)database into cognitively normal(CN),stable mild cognitive impairment(sMCI),progressive MCI(pMCI),and dementia due to AD.Analysis of covariance(ANOVA)and chi-square analyses,Spearman correlation,and logistic regression models were performed to test the demographic,associations between biomarkers,and diagnostic accuracies,respectively.Linear mixed-effects models were used to evaluate the effects of CSF amyloid-β(Aβ)on above biomarkers within diagnostic groups,the combination of diagnostic group and Aβstatus as predictor,and CSF biomarkers as predictors of AD features,including cognition measured by Mini–Mental State Examination(MMSE)and brain structure and white matter hyperintensity(WMH)measured by magnetic resonance imaging(MRI).Results:P-tau,VILIP-1,and YKL-40 were all predictors of AD diagnosis,but combinations of biomarkers did not improve the diagnostic accuracy(AUC 0.924 for p-tau,VILIP-1,and YKL-40)compared to p-tau(AUC 0.922).P-tau and VILIP-1 were highly correlated(r=0.639,p<0.001)and strongly associated with Aβpathology across clinical stages of AD,while YKL-40 was correlated with Aβpathology in CN and AD groups.VILIP-1 was associated with acceleration of cognitive decline,hippocampal atrophy,and expansion of ventricles in longitudinal analyses.YKL-40 was associated with hippocampal atrophy at baseline and follow-up,while p-tau was only associated with worsening WMH at baseline.Conclusions:CSF levels of p-tau,VILIP-1,and YKL-40 may have utility for discriminating between cognitively normal subjects and patients with AD.Increased levels of both VILIP-1 and YKL-40 may be associated with disease degeneration.These CSF biomarkers should be considered for future assessment in the characterization of the natural history of AD.