新疆地区汉族及维吾尔族居民巯嘌呤甲基转移酶基因多态性研究

目的 研究新疆地区巯嘌呤甲基转移酶基因型分布及新疆地区汉族与维吾尔族基因突变频率的差异.方法 采用等位基因特异性的聚合酶链反应(allele specific-PCR,AS-PCR)方法和聚合酶链反应-限制性片段长度多态性(PCR-restrition fragment length polymophism,PCR-RFLP)方法检测新疆地区健康人群4种常见TPMT突变等位基因TPMT*2(G238C) 、TPMT* 3A (A719G/G460A)、TPMT*3B(G460A)和TPMT* 3C(A719G)进行检测.结果 192名新疆地区人群中发现8例TPMT*3C(A719G)杂合子,其中汉族5人,维吾尔族3人,没有发现TPMT*2、TPMT*3A、TPMT*3B.新疆地区人群中杂合子TPMT*3C的基因突变频率为2.08％.结论 TPMT*3C是新疆地区主要的突变类型,其等位基因频率2.08％;新疆地区汉族和维吾尔族人群中TPMT等位基因的频率差异无统计学意义.     

广西京族硫嘌呤甲基转移酶突变基因研究

目的 对广西京族硫嘌呤甲基转移酶(thiopurine S—methyltransferase，TPMT)突变基因进行研究。方法 用聚合酶链反应—单链构象多态性技术对京族标本TPMT基因第5、7、10外显子进行检测。结果 在103名京族中发现了两例TPMT*3C(A719G)杂合子，没有发现TPMT*2(G238C)、TPMT*3A(A719G／G460A)、TPMT*3B(G460A)和其他有害突变基因；发现了27例沉默突变TPMT*1S(T474C)，其中纯合子5例、杂合子22例。结论 建立的聚合酶链反应—单链构象多态性技术灵敏可靠，可以用予TPMT突变基因多态性的检测；TPMT*3C突变基因在广西京族中的发生频率较低(1.0％)，它可能是京族唯一的TPMT基因有害突变类型。     

核糖体18S rRNA m6A甲基转移酶METTL5的研究进展

<正>N⁶-甲基腺嘌呤(N⁶-methyladenosine, m⁶A)即在腺苷酸的第6位氮原子处发生甲基化,是真核生物核糖核酸(ribonucleic acid, RNA)普遍的表观遗传修饰之一,存在于多种类型的RNA分子上,参与生物发生、稳定性调节、半衰期控制和前体信使RNA(messenger RNA, mRNA)剪接、输出及翻译等诸多关键细胞过程。m⁶A甲基化修饰是一种动态可逆的过程,涉及到甲基化、去甲基化和甲基化修饰位点的识别,分别由m⁶A甲基转移酶、m⁶A去甲基化酶和m⁶A甲基化阅读蛋白介导^[1-3]。     

胆红素在炎性肠病中作用的研究进展

胆红素在炎性肠病中的作用不仅仅局限于抗氧化、抗炎作用,还有免疫调节、抗血小板聚集、抑制消化蛋白酶、调节肠道菌群等作用。血清胆红素水平与疾病的活动性、严重程度相关,是炎性肠病潜在的血清标志物,有助于临床炎性肠病诊治。     

炎性肠病中菌群与肠道免疫关系的研究进展

炎性肠病(IBD)是一类由异常免疫介导的肠道炎症.肠道免疫系统由多种免疫细胞组成,其中T、B淋巴细胞分别代表机体的细胞免疫和体液免疫水平,巨噬细胞和树突状细胞(DC)选择性地吞噬和递呈抗原,从而维持肠道稳态.研究表明IBD患者肠道菌群和免疫机能发生显著变化,但在IBD状态下,二者间的相互作用是否可以影响IBD的发展与治...     

O6-MG-DNA-甲基转移酶基因表达调控及其与肿瘤耐药性的研究进展

DNA损伤修复在基因突变、肿瘤发生及细胞死亡等过程中起重要作用,烷化类损伤主要由O6-甲基鸟嘌呤-DNA-甲基转移酶（O6-methylguanine-DNA methyltransferase,MGMT）修复。细胞内MGMT活性高低是肿瘤对替莫唑胺（temozolomide,TMZ）等烷化剂类化疗药产生耐药性的原因之一,其启动子甲基化与肿瘤患病风险及预后相关。研究MGMT基因表达调控对DNA损伤修复理论研究及克服肿瘤耐药均有重要意义。MGMT的表达调控机制主要包括启动子甲基化及组蛋白乙酰化、转录水平调控、转录后水平调控。     

中性粒细胞在炎性肠病中的作用

中性粒细胞是固有免疫抵抗微生物的主要执行者, 因此中性粒细胞对于维持肠道环境内稳态非常重要。当机体受到外来微生物入侵时, 局部组织发生感染, 中性粒细胞被激活并募集到感染部位, 通过吞噬、脱颗粒、NADPH氧化酶依赖性杀菌等功能发挥作用。有研究表明, 在炎症发生的早期, 中性粒细胞起着重要的抗感染作用, 而在炎症晚期, 中性粒细胞持续存在, 由于细胞凋亡, 细胞内毒素释放入感染部位, 对感染组织持续损伤。然而, 中性粒细胞在炎性肠病(inflammatory bowel disease, IBD)中的相关作用机制目前并不明确。文章总结了近年来中性粒细胞在IBD中的相关研究, 阐述了其在机体发生免疫应答时的作用。     

N6-甲基腺苷(m6A)RNA修饰在生殖系统疾病中作用的研究进展

N6-甲基腺苷(m6A)RNA修饰是发生在RNA腺嘌呤第6位N原子上的一种转录后的甲基化修饰,调控mRNA的结构、稳定性、剪接、输出、转译和衰变等,进而广泛影响各种生物的生命过程.本文总结了在生殖系统疾病及乳腺癌发生发展过程中各种m6A甲基化酶的作用及机制,旨在为生殖系统疾病及乳腺癌早期诊断、治疗及预后判断提供新的依据...     

5-氮杂-2'-脱氧胞苷对肝癌DNA甲基转移酶1及上皮钙黏附素表达的影响

目的:研究5-氮杂-2-脱氧胞苷(5-Aza-CdR)对肝癌细胞中DNA甲基转移酶1(DNMT1)及上皮钙黏附素(E-cadherin)表达的影响.方法:免疫组织化学检测上皮钙黏附素在肝癌(26例)及癌旁组织(20例)中的表达.用终浓度10μmol/L的5-Aza-CdR处理培养的肝癌细胞株GQY-7703作为实验组,未处理细胞为对照组;DNMT1基因和上皮钙黏附素基因(CDH1)的转录产物及表达蛋白分别使用半定量RT-PCR和免疫印迹法检测;CDH1的甲基化状态使用甲基化特异性PCR(MSP)检测.结果:相比较癌旁组织,肝癌组织中上皮钙黏附素表达显著下调.5-Aza-CdR降低了GQY-7703细胞中DNMT1在转录水平和翻译水平的表达CDH1 CpG岛的甲基化水平降低;上皮钙黏附素mRNA和蛋白表达量明显增高,对电泳条带的半定量分析显示实验组和对照组之间的差异具有统计学意义.结论:5-Aza-CdR通过抑制DNMT1的表达,改变了CDH1基因的异常甲基化状态,进而恢复上皮钙黏附素的表达.     

6-羟多巴胺诱导的Parkinson’s病模型

本研究应用6-OHDA诱导Parkinson’s病动物模型,腹腔注射Apomorphine诱发旋转,并测定模型鼠血中超氧化物歧化酶(SOD)的活性.结果显示,6-OHDA诱导的PD模型与文献报道一致,SOD活性高于正常组,提示抗氧化系统缺陷和内源性氧自由基堆积与PD发病有密切关系.     

Successful Azathioprine Treatment with Metabolite Monitoring in a Pediatric Inflammatory Bowel Disease Patient Homozygous for TPMT*3C

Thiopurine S-methyltransferase (TPMT) methylates purine analogues, showing TPMT activity in inverse relation to concentrations of active metabolites such as 6-thioguanine nucleotide (6-TGN). With conventional dosing of thiopurines, patients with homozygous variant TPMT alleles consistently suffer from severe myelosuppression. Here, we report a patient with TPMT^*3C/^*3C who managed successfully with monitoring of thiopurine metabolites. The patient was an 18-year-old male diagnosed with Crohn''s disease. The standard dose of azathioprine (AZA) (1.8 mg/kg/day) with mesalazine (55.6 mg/kg/day) was prescribed. Two weeks after starting AZA treatment, the patient developed leukopenia. The DNA sequence analysis of TPMT identified a homozygous missense variation ({"type":"entrez-nucleotide","attrs":{"text":"NM_000367.2","term_id":"62953142","term_text":"NM_000367.2"}}NM_000367.2: c.719A>G; p.Tyr240Cys), TPMT^*3C/^*3C. He was treated with adjusted doses of azathioprine (0.1-0.2 mg/kg/day) and his metabolites were closely monitored. Leukopenia did not reoccur during the follow-up period of 24 months. To our knowledge, this is the first case of a patient homozygous for TPMT^*3C successfully treated with azathioprine in Korea. While a TPMT genotyping test may be helpful to determine a safe starting dose, it may not completely prevent myelosuppression. Monitoring metabolites as well as routine laboratory tests can contribute to assessing drug metabolism and optimizing drug dosing with minimized drug-induced toxicity.     

Review of Saccharomyces boulardii as a treatment option in IBD

Abstract

Context: Review of the yeast Saccharomyces boulardii as a treatment option for the inflammatory bowel diseases (IBD) ulcerative colitis and Crohn’s disease.

Objective: IBD is caused by an inappropriate immune response to gut microbiota. Treatment options could therefore be prebiotics, probiotics, antibiotics and/or fecal transplant. In this review, we have looked at the evidence for the yeast S. boulardii as a treatment option.

Material and methods: Searches in PubMed and the Cochrane Library with the MeSH words ‘Saccharomyces boulardii AND IBD’, ‘Saccharomyces boulardii AND Inflammatory Bowel Disease’, ‘Saccharomyces boulardii AND ulcerative colitis’ and ‘Saccharomyces boulardii AND Crohn’s disease’ gave total a total of 80 articles. After exclusions because of irrelevance, articles in other languages and some articles that were not available, 16 articles were included in this review.

Results: Three of the clinical trials showed a positive effect of S. boulardii in IBD patients (two Crohn’s disease, one ulcerative colitis), while there was one trial that didn’t prove any effect (Crohn’s disease). Included Animal trials and cell assays describes different anti-inflammatory mechanisms of S. boulardii supporting a possible effect when treating IBD patients.

Discussion: The number of studies of S. boulardii as treatment for IBD is limited. Furthermore, the existing trials have small populations and short duration.

Conclusion: We do not have enough evidence to prove the effect of S. boulardii in IBD. Saccharomyces boulardii is, however, a plausible treatment option in the future, but more placebo-controlled clinical studies on both patients with ulcerative colitis and Crohn’s disease are needed.     

NUDT15基因多态性与巯基嘌呤所致肝功能异常的相关性分析CSCD

Objective To investigate the association between single nucleotide polymorphism of NUDT15 gene (SNP rs116855232) and hepatotoxicity in children with acute lymphocytic leukemia (ALL).Methods A total of 135 children with ALL in Shandong Province were recruited in this study, and patients were divided into two groups based on the presence of liver injury.Genotypes of each patient were detected using PCR and Sanger sequencing.Clinical data and the average dose of 6-mercaptopurine (6-MP) were collected and analyzed by SPSS 19.0 software.Results Respectively, 99 patients were found with CC genotype, 32 patients with CT genotype and 4 patients with TT genotype.Compared with ALL patients without hepatotoxicity, there was a difference in genotypes between the two groups in the initial stage of chemotherapy for leukemia (χ2=7.583, P=0.023).In maintenance therapy stage there was also a difference between the two groups (χ2=10.591, P=0.005), and T allele was a risk factor for hepatotoxicity.Conclusion The polymorphism of rs116855232 in NUDT15 gene was associated with hepatotoxicity induced by 6-mercaptopurine in children with ALL, and ALL patients with TT genotype should take a lower dose of 6-MP to avoided hepatotoxicity. © 2021 West China University of Medical Sciences. All rights reserved.     

Potential use of iloprost for asthma treatment

Inflammatory bowel disease in children can be marked by aggressive disease both at presentation and over time. Risk stratification of individual patients may help identify when early biologic therapy is justified. Currently, combination biologic and immunomodulator therapy for moderate-to-severe Crohn’s disease is the most effective treatment regimen. The clinician’s conundrum arises from the recent understanding that rare but serious adverse events do occur with use of these strong immune suppressive drugs and may be more prevalent with combination therapy. An understanding of the natural history of Crohn’s disease and ulcerative colitis and the benefits and risks of the current medical armamentarium is essential to provide optimal care for each child with inflammatory bowel disease.     

Use of immunomodulators and biologic therapies in children with inflammatory bowel disease

The immunomodulators (6-mercaptopurine, azathioprine and methotrexate) and biologics (infliximab, adalimumab, certolizumab and natalizumab) are medications essential in the management of pediatric inflammatory bowel disease. If properly utilized, these medications can control active disease, reduce corticosteroid exposure, induce remission, and promote normal growth and development. However, these medications also have significant toxicity and increase the risk of infections and lymphoma. This article provides information about the safety and efficacy of these medications in the treatment of children with Crohn’s disease and ulcerative colitis.     

Monitoring Thiopurine Metabolites in Korean Pediatric Patients with Inflammatory Bowel Disease

Purpose

This study aimed to assess the role of thiopurine S-methyltransferase (TPMT) and 6-thioguanine nucleotide (6-TGN) as predictors of clinical response and side effects to azathioprine (AZA), and estimate the optimal AZA dose in Korean pediatric inflammatory bowel disease (IBD) patients.

Materials and Methods

One hundred and nine pediatric IBD patients in whom AZA treatment was required were enrolled. Thiopurine metabolites were monitored since September 2010. Among them, 83 patients who had prescribed AZA for at least 3 months prior to September 2010 were enrolled and followed until October 2011 to evaluate optimal AZA dose, adverse effects and disease activity before and after thiopurine metabolite monitoring.

Results

The result of the TPMT genotype was that 102 patients were *1/*1 (wild type), four were *1/*3C, one was *1/*6, one was *1/*16 (heterozygote) and one was *3C/*3C (homozygote). Adverse effects happened in 31 patients pre-metabolite monitoring and in only nine patients post-metabolite monitoring. AZA dose was 1.4±0.31 mg/kg/day before monitoring and 1.1±0.46 mg/kg/day after monitoring (p<0.001). However, there were no statistical differences in disease activity during metabolite monitoring period (p=0.34). Adverse effects noticeably decreased although reduction of the AZA dose since monitoring.

Conclusion

TPMT genotype and thiopurine metabolite monitoring could be helpful to examine TPMT genotypes before administering AZA and to measure 6-TGN concentrations during prescribing AZA in IBD patients.     

Impaired B cell responses to orally administered antigens in lamina propria but not Peyer's patches of Galphai2-deficient mice prior to colitis

Despite numerous studies on the intestinal immune system in patients with inflammatory bowel disease (IBD) and animal models of IBD, very little is known about the immune reactivity of mucosal lymphocytes following oral immunizations under these circumstances. The reactivity of Peyer's patch (PP) and lamina propria (LP) T and B lymphocytes in inhibitory G-protein alpha2 subunit-deficient (Galphai2-/-) mice developing an IBD resembling ulcerative colitis was investigated following repeated oral immunizations with keyhole limpet haemocyanin (KLH), together with the adjuvant cholera toxin, prior to colitis. The antigen-specific B-cell response in the LP of both the small and the large intestines was significantly reduced in Galphai2-/- as compared to wild-type mice. In contrast, the frequency of KLH-specific immunoglobulin (Ig)-producing cells in the PP did not differ between Galphai2-/- and wild-type mice, whereas the total frequency of Ig-producing cells as well as the frequency of enteric flora-specific Ig-producing cells in the PP was significantly increased in Galphai2-/- as compared to wild-type mice. Analysis of T cell responses following restimulation ex vivo with KLH revealed a dramatic increase in the production of interferon-gamma in mesenteric lymph node, PP and LP lymphocytes from Galphai2-deficient as compared to wild-type mice, together with decreased production of interleukin-10 in all locations except the PP.     

Circulating antiinflammatory cytokine IL-10 in patients with inflammatory bowel disease (IBD).

IBD is characterized by increased serum concentrations of different cytokines. IL-10 inhibits the production of proinflammatory cytokines such as IL-1, tumour necrosis factor-alpha (TNF-a), interferon-gamma (IFN-gamma) and IL-6 through inhibitory action on Th1 cells and macrophages, and it is thought to be a suppressor type cytokine. In the present study we determined serum concentrations of IL-10 in patients with ulcerative colitis (UC) and Crohn's disease (CD). We measured human IL-10 by our own newly established ELISA system using PharMingen antibodies. Serum antibodies were assessed in 44 patients with UC, 40 patients with CD, and in 30 healthy controls. Human IL-10 serum levels were significantly increased in patients with active UC (144 +/- 34 pg/ml (mean +/- s.e.m.), P < 0.001) and in active CD (132 +/- 32 pg/ml, P < 0.001) compared with healthy controls (44 +/- 9.5 pg/ml). Only patients with active CD and active UC presented with significantly increased IL-10 serum levels, while patients with inactive disease did not show any significant increase. There was no statistically significant difference between IL-10 serum levels in patients with CD or UC. Compared with clinical disease activity indices there was a significant correlation between IL-10 serum concentration and CDAI in patients with CD (r = 0.45, P < 0.01) and CAI in UC patients (r = 0.39, P < 0.05). Comparing IL-10 serum levels with serum concentrations of other proinflammatory cytokines there was a significant correlation to serum levels of sIL-2R (r = 0.417, P < 0.05) and IL-6 (r = 0.387, P < 0.05) in patients with CD. Serum cytokine levels in patients with UC did not show any significant correlation to IL-10 serum concentration. IL-10 is elevated in serum of patients with active CD and UC, suggesting that IL-10 acts as a naturally occurring damper in the acute inflammatory process of IBD.     

Epistatic interaction between FCRL3 and MHC in Spanish patients with IBD

Inflammatory bowel disease (IBD), which comprises ulcerative colitis (UC) and Crohn's disease (CD), shows a multifactorial origin, with genetic and environmental factors involved. Although the genetic influence is clear for both diseases, the genetics involved is complex and epistatic interactions with other genes probably exist. The Fc receptor-like 3 gene (FCRL3) maps to the human chromosome 1q21-22 and certain single nucleotide polymorphisms (SNPs) in its promoter have been associated with some autoimmune diseases. Our aim was to study the role of two promoter SNPs of the FCRL3 gene (-169A>G, rs7528684 and -110C>T, rs11264799) in patients with IBD and their interaction with HLA-DRB1 and CARD15 in patients with UC and CD, respectively. A case-control study with 311 patients with CD, 324 patients with UC and 497 healthy controls was performed. All the individuals were White Spaniards. No significant associations were found between any FCRL3 SNP and CD or UC, but the stratification in patients with UC by human leukocyte antigen (HLA) showed a significant increase in heterozygosity at the FCRL3 locus, especially -169 AG (AG vs AA+GG, P= 0.0027, odds ratio = 3.6, 95% confidence interval 1.4-2.9), when HLA-DRB1*0103 carrier patients were compared with HLA-DRB1*0103 noncarriers. Our data suggest an epistatic interaction between genes in chromosomes 6p21 and 1q21-22, marked, respectively, by HLA-DRB1*0103 and FCRL3-169 AG.