脓毒症的基因多态性研究

尽管脓毒症的诊断和治疗取得了长足进步,但严重脓毒症和脓毒性休克的病死率仍居高不下.社会人口统计学和临床风险因素预测模型不能完全解释为什么在遭受相似程度打击后,有些人群易于发生脓毒症和多器官功能障碍综合征,有的患者却病情较轻而易于恢复.近年来,人们认识到遗传因素会影响脓毒症的易感性和预后.随着人类基因组计划和国际人类基因组单体型图计划的完成,脓毒症的遗传易感基因研究成为当前国内外研究的热点和焦点.基因多态性研究可以加深对脓毒症的发生、发展机制的认识,提供更精确的个体化靶向治疗措施.本文就基因多态性研究的相关概念、方法和在脓毒症基因关联研究中的策略及存在的问题作简要概述.     

谷胱甘肽S-转移酶基因多态性与男性不育

男性不育的发生是遗传因素与环境因素相互作用的过程,机体对内外源性化学物质的代谢和解毒能力影响个体对男性不育的易感性。谷胱甘肽S-转移酶(GSTs)属于机体Ⅱ相解毒酶系统,其参与细胞对外源性化学物质和人工合成有机物质解毒的各个生理阶段。研究发现,GSTs基因多态性与男性不育有一定的相关性。在同一地区人群中,GSTs基因多态性对男性不育的易感性具有相似性,也存在不一致性;在不同地区人群中,GSTs基因多态性对男性不育的易感性不一致,也存在相似性。因此,GSTs基因多态性对男性不育患者的易感性在不同人群中存在差异。     

Toll-样受体4基因单核苷酸多态性与中国汉族患者脓毒症的相关性

目的 探讨Toll-样受体4(TLR4)基因单核苷酸多态性(SNP)与中国汉族患者脓毒症发生风险、严重程度以及预后的相关性.方法 103例术后发生脓毒症的患者作为脓毒症组,另取术后未发生脓毒症患者114例为对照组,汉族,性别不限,年龄18 ～ 80岁.采集患者外周静脉血样,EDTA抗凝,采用基质辅助激光解吸附电离飞行时间质谱法检测TLR4基因SNPs rs10759932、rs11536889和rs2737190的基因型.采用logistic回归分析校正性别、年龄、基础疾病和手术方式的影响,评价SNPs基因型与脓毒症发生、器官功能障碍、脓毒性休克和死亡的相关性,计算比值比(OR)及95％可信区间(CI).结果 与对照组比较,脓毒症组rs10759932基因型频率构成比差异有统计学意义(P＜0.05),其他2个SNPs基因型频率构成比差异无统计学意义(P＞0.05).rs10759932与脓毒症的发生相关,其突变等位基因型(TC+ CC基因型)增加脓毒症发生风险(OR为1.86,95％CI为1.17～2.97,P＜0.05).3个SNPs基因型与脓毒症相关器官功能障碍、脓毒性休克和死亡均无相关性(P＞0.05).结论 TLR4基因rs10759932突变等位基因与中国汉族患者术后发生脓毒症的风险增加相关.     

TLR4与糖尿病肾病关系的研究进展

Toll样受体家族(Toll-like receptors,TLRs)属于模式识别受体(pattern cognition receptots,PRRs),Toll样受体-4 (Toll-like receptor4,TLR4)是其中最重要的成员之一,在先天免疫系统中起着不可忽略的作用,可通过激活炎性信号通路在微生物分子模式合成的应答反应中起作用.TLR4在糖尿病(diabetes mellitus,DM)的发生发展中起着重要作用,并且与胰岛素抵抗(insulin resistance,IR)、代谢综合征(metabolic syndrome,MetS)以及肥胖的发生发展等糖尿病高危因素也有着紧密联系.TLR4与糖尿病肾病(diabetic nephropathy,DN)之间的关系在近年来的研究中取得了重大进展,大量研究结果提示TLR4在DN的病理发生过程中起着重要作用.     

TLR-3启动子区功能性基因多态性与骨关节炎的相关性：两阶段病例对照研究

骨关节炎（osteoarthritis,OA）被认为是多因素疾病,目前有关其遗传因素的研究涉及了遗传方式及基因组的潜在突变位置等。最近的报道显示,Toll样受体（toll-like receptor,TLR）家族与OA的发生发展关系密切。单核苷酸多态性（single nucleotide polymorphisms,SNPs）在TLR基因中普遍存在,并对TLR功能产生影响。前期研究证实,TLR-9基因的（-1486T/C）启动子多态性与末期膝OA有关,而作为同属于核内体TLR、均以病原相关分子方式来识别病毒和细菌核酸的TLR-3,7,8,其功能性基因多态性是否与中国汉族人群膝OA有关,是本研究的主要目的。     

P2X7基因多态性与结核病易感性关系的研究进展

目前结核病仍然是全世界最致命的传染病之一,其发生是多种环境因素和遗传因素共同作用的结果。近年来,对嘌呤受体P2X7基因与结核病易感性的研究报道较多。本文介绍P2X7受体在机体抗结核免疫反应中的作用机制,总结目前研究已明确的与结核病易感性相关的P2X7基因多态性位点(1513、946、1729、-762和489五个位点)对结核病易感性的影响。     

前列腺癌根治术后生化复发与 p53 codon 72 的相关性

p53 codon 72多态性与肺癌、食管癌、肝癌、宫颈癌、卵巢癌、乳腺癌、结直肠癌等多种恶性肿瘤相关,而鼠双微基因2( MDM2)309多态性与食管癌、肺癌、贲门癌、鼻咽癌易感性相关.Morote等[1]研究结果显示KLK2、硫酸转移酶-A1(SULT1A1)和Toll样受体4(TLR4)基因多态性可以用于前列腺根治术后生化复发的预测.本研究旨在观察这些基因多态性对前列腺癌根治术后的生化复发是否有潜在的预测作用.     

代谢酶基因多态性与胰腺癌易感性研究进展

代谢酶基因多态性与肿瘤的关系是近来国内外研究的热点。代谢酶基因多态性使酶的活性发生改变,是胰腺癌遗传易感性的重要机制。现综述了与胰腺癌癌变过程中有关的代谢酶基因多态性与其易感性的关系。     

生精障碍相关基因单核苷酸多态性研究进展

生精相关基因遗传多态性是生精障碍的一个重要的遗传病因.通过基因敲除技术现已鉴定出大量与精子发生密切相关基因.此类生精障碍基因包括表达酶类、受体类、细胞凋亡类、转录调控类等基因.上述基因的遗传易感性、感染和环境等因素共同作用导致男性非梗阻性无精子症和少精子症.生精障碍相关基因单核苷酸多态性(SNP)分析可从分子水平上阐述...     

单核苷酸多态性与原发性肝癌的研究进展

原发性肝癌的发生是一个多因素的复杂的生物学过程,在其发生发展机制的研究中,对宿主遗传易感性的研究越来越受到重视.作为第三代分子遗传标记的单核苷酸多态性,是目前原发性肝癌研究中的一个热点.本文对原发性肝癌易感相关基因的单核苷酸多态性与原发性肝癌的易感相关关系的研究进展进行综述.     

Toll样受体2、4与全身性感染研究进展

全身性感染是由感染所致的临床综合征,是一种高发率和高病死率疾病,目前仍然是一项严重的临床问题。尽管在全身性感染治疗方面,人们已经取得了长足的进步,但是迄今为止,仍然没有有效的病因学治疗方法应用在全身性感染患者身上。这很可能是由于全身性感染的免疫病理学发病机制没有得到完全阐明。近来,TLR在全身性感染免疫机制中所起到的作,用在多种动物体内得到验证,TLR、TLR4在其中的作用尤为关键。TLR导致的体内信号传导,使炎症反应级联放大。此外,TLR还能诱发机体免疫功能紊乱．致使机体对病原体清除效率降低。这些原因都可以导致全身性感染的病情的进一步进展。所以阻断TLR传导道路可能会抑制全身性感染发生和发展的进程。这也为临床医生最终攻克全身性感染提供了崭新的思路和临床治疗靶点。     

The role of toll-like receptor-4 in the development of multi-organ failure following traumatic haemorrhagic shock and resuscitation

Haemorrhagic shock and resuscitation (HS/R) following major trauma results in a global ischaemia and reperfusion injury that may lead to multiple organ dysfunction syndrome (MODS). Systemic activation of the immune system is fundamental to the development of MODS in this context, and shares many features in common with the systemic inflammatory response syndrome (SIRS) that complicates sepsis. An important advancement in the understanding of the innate response to infection involved the identification of mammalian toll-like receptors (TLRs) expressed on cells of the immune system. Ten TLR homologues have been identified in humans and toll-like receptor-4 (TLR4) has been studied most intensively. Initially found to recognise bacterial lipopolysaccharide (LPS), it has also recently been discovered that TLR4 is capable of activation by endogenous 'danger signal' molecules released following cellular injury; this has since implicated TLR4 in several non-infectious pathophysiologic processes, including HS/R. The exact events leading to multi-organ dysfunction following HS/R have not yet been clearly defined, although TLR4 is believed to play a central role as has been shown to be expressed at sites including the liver, lungs and myocardium following HS/R. Multi-organ dysfunction syndrome remains an important cause of morbidity and mortality in trauma patients, and current therapy is based on supportive care. Understanding the pathophysiology of HS/R will allow for the development of targeted therapeutic strategies aimed at minimising organ dysfunction and improving patient outcomes following traumatic haemorrhage. A review of the pathogenesis of haemorrhagic shock is presented, and the complex, yet critical role of TLR4 as both a key mediator and therapeutic target is discussed.     

Genetic variants in TNFA,LTA, TLR2 and TLR4 genes and risk of sepsis in patients with severe trauma: nested case-control study in a level-1 trauma centre in SERBIA

Introduction: Single nucleotide variants (SNVs) represent important genetic risk factors for susceptibility to posttraumatic sepsis and a potential target for immunotherapy. We aimed to evaluate the association between 8 different SNVs within tumor necrosis factor alpha (TNFA), lymphotoxin alpha (LTA) and Toll-like receptor (TLR2 and TLR4) genes and the risk of posttraumatic sepsis.Methods: Nested case-control study was conducted in the emergency department of the Clinical Centre of Serbia including 228 traumatized patients (44 with sepsis and 184 without sepsis). To compare the results of trauma subjects with the data from the general population, a control group of 101 healthy persons was included in the study. Genotyping of TNFA (rs1800629 and rs361525), LTA (rs909253), TLR2 (rs3804099, rs4696480 and rs3804100), and TLR4 (rs4986790 and rs4986791) was performed for all patients within all three groups using the real-time PCR method. MutationTaster database and in silico software SIFT were used to predict the variant pathogenic effect.Results: Carriage of the G allele of the TNFA rs1800629 gene variant (OR 2.1, 95%CI 1.06-4.16) and T allele-carriage of the TLR4 rs4986791 genetic variant (OR 3.02, 95%CI 1.31-6.57) were associated with significantly higher risk of sepsis in trauma patients when compared to the general population prone to sepsis and traumatized patients without developing a sepsis, respectively. Of these two variants, only variant in TLR4 gene (rs4986791) has been labeled as disease causing by both the MutationTaster database and the in-silico software SIFT, which further supports the role of this variant in various pathologies including sepsis. For the remaining six variants no significant association with the susceptibility to sepsis was detected.Conclusions: Carriage of the G allele of the TNFA rs1800629 gene variant and T allele-carriage of the TLR4 rs4986791 genetic variant confer significant risk of posttraumatic sepsis. TLR4 gene variants (rs4986790 and rs4986791) has been labelled as disease causing.     

Promoter polymorphism (T‐1486C) of TLR‐9 gene is associated with knee osteoarthritis in a Turkish population

In this study, we aimed to determine whether TLR‐9 T‐1486C SNP was associated with susceptibility to OA in the Turkish population. The study group comprised 272 patients with Grade 2‐3‐4 knee OA according to the Kellgren‐Lawrence scoring system and the control group was formed of 296 individuals with Grade 0–1. The TLR‐9 genotype were assessed by real‐time polymerase chain reaction. An analysis of TLR‐9 promoter −1486T/C polymorphism revealed that the −1486CC genotype appeared to have a higher risk for OA and −1486TT and −1486CT genotypes have a protective effect against the development of OA (crude OR = 0.473, 95% CI = 0.297–0.754, p = 0.002, adjusted OR = 0.531, 95% CI = 0.326–0.864, p = 0.011). This study indicate that there is a correlation of TLR‐9 T‐1486C gene polymorphism with advanced knee OA in a Turkish population. Changed in TLR expression due to different allelles may cause osteoarthrith development outcome cartilage degeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2484–2489, 2017.

     

Sepsis-induced organ failure is mediated by different pathways in the kidney and liver: acute renal failure is dependent on MyD88 but not renal cell apoptosis

Toll-like receptors (TLRs) are important in sepsis. Myeloid differentiation factor 88 (MyD88) is a key molecule involved in signal transduction by multiple TLRs. The objective of this study was to investigate the contribution of TLR4 and MyD88 to acute renal failure (ARF) induced by polymicrobial sepsis. Liver dysfunction and apoptosis in the spleen contribute to sepsis severity after cecal ligation and puncture (CLP). Therefore, we also investigated liver injury and splenic apoptosis. We used a mouse model of sepsis-induced ARF using CLP to generate polymicrobial sepsis. Despite fluid and antibiotic resuscitation the mice developed multi-organ failure, including ARF, which resembles human sepsis. We investigated the role of the TLR4 receptor by comparing C3H/HeJ mice (which lack TLR4) with C3H/He0UJ normal controls. The role of MyD88 was investigated by comparing MyD88 knockout mice (MyD88(-/-)) with wild-type controls. Following CLP, mice lacking TLR4 and wild-type mice both developed comparable ARF. However, MyD88(-/-) mice did not develop ARF compared to wild-type controls. In contrast, MyD88(-/-) mice developed liver injury comparable to wild type. After CLP, MyD88(-/-) mice had significantly reduced apoptosis in the spleen compared with wild type. Apoptosis was not detected in the kidney of wild-type or MyD88(-/-) mice after CLP. In summary, ARF induced by polymicrobial sepsis is dependent on MyD88, but not TLR4. The absence of MyD88 dissociates ARF from liver injury; liver injury is MyD88-independent. There was MyD88-dependent apoptosis in the spleen, but no apoptosis in the kidney. MyD88 may be a good drug target for some, but not all, organ dysfunctions following sepsis.     

TLR4 influences the humoral and cellular immune response during polymicrobial sepsis

As part of the innate immune system, Toll-like receptors (TLRs) react rapidly on a pathogen challenge without prior exposure. Although it is well known that TLR4 is associated with the receptor for lipopolysaccharide (LPS), its role during sepsis has not yet been clearly defined. To study this, polymicrobial sepsis was induced in male C3H/HeN (TLR4 wild type) and C3H/HeJ (TLR4 mutant) mice by caecal ligation and puncture (CLP).A total of 48 h following the surgical procedure, the mice were sacrificed and plasma was collected. Kupffer cells were isolated and ex vivo cytokine production and plasma levels were determined. Lung neutrophil influx was investigated by myeloperoxidase (MPO) content and immunohistochemistry. T-cell subtypes in blood and spleen were determined by flow cytometry.Mice with intact TLR4 (wild type) had increased Kupffer cell IL-6 production and increased plasma levels as compared with C3H/HeJ mice following sepsis. Furthermore, wild type mice showed increased neutrophil influx in lungs and lower percentages of CD8⁺ splenocytes. This was accompanied with less activity, increased weight loss and decreased core temperature.We conclude that TLR4 influences the humoral and cellular response during the course of sepsis and lack of TLR4 reduces markers of the systemic inflammatory response as well as distant organ damage. Therefore, TLR4 could act as a future therapeutic target modulating the immune response during sepsis.     

Enhanced expression of intracellular heme oxygenase-1 in deactivated monocytes from patients with severe systemic inflammatory response syndrome

BACKGROUND: Monocyte deactivation is an important contributor to infectious susceptibility in critically ill patients. However, the mechanism of monocyte deactivation has not been fully elucidated. Recently, intracellular heme oxygenese-1 (HO-1), an anti-inflammatory heat-shock protein, was reported to be activated by Toll-like receptors (TLRs), and to inhibit inflammatory cytokine production such as that of TNF-alpha. In the present study, we evaluated the expression of intracellular HO-1 and TLRs in monocytes from patients with severe systemic inflammatory response syndrome (SIRS) and examined the role of HO-1 in monocyte deactivation. PATIENTS: Twenty-seven patients who fulfilled the criteria for severe SIRS and had a serum C-reactive protein (CRP) level >10 mg/dL were included in this study. The cause of SIRS was sepsis in 16 patients, trauma in 7, and other in 4. Expression of intracellular HO-1, surface TLR2 and TLR4, and intracellular cytokines (TNF-alpha, Interleukin-6) stimulated via TLR activation were measured in circulating monocytes by flow cytometry. Intracellular HO-1 expression was evaluated in normal monocytes stimulated with patient serum. Serum cytokine levels were also measured. Patient data were compared with data from healthy volunteers (n = 16). RESULTS: Cytoplasmic HO-1 was clearly detected by fluorescence microscopy. Expression of HO-1, TLR2, and TLR4 in monocytes was significantly enhanced in patients with severe SIRS compared with that in healthy volunteers, whereas intracellular TNF-alpha expression with peptidoglycan was significantly decreased (p < 0.05) in patients compared with that in healthy volunteers. HO-1 expression was significantly enhanced in normal monocytes stimulated with patient serum. Intracellular HO-1 levels were positively related to serum TNF-alpha levels in patients (r = 0.46). CONCLUSIONS: Expression of intracellular HO-1 and of TLRs was enhanced in deactivated monocytes from patients with SIRS. Increased production of intracellular HO-1 in response to serum factors may play a role in monocyte deactivation after systemic inflammation.     

Relation of a TNF Gene Polymorphism to Severe Sepsis in Trauma Patients

OBJECTIVE: To investigate the relation of the biallelic Nco1 restriction fragment length polymorphism in the first intron of the tumor necrosis factor (TNF) beta gene with the development of severe sepsis in multiply injured patients. SUMMARY BACKGROUND DATA: The biallelic Nco1 polymorphism of the TNFbeta gene has been described to be associated with autoimmune diseases and with the mortality rate in severe sepsis. Therefore, the Nco1 polymorphism may be associated with the clinical finding that despite comparable risk factors, posttraumatic sepsis develops in some patients but not others. METHODS: The study group consisted of 110 patients with severe blunt trauma (Injury Severity Score > or = 17). Typing of each patient for the biallelic Nco1 polymorphism was performed by analyzing restriction fragments of an Nco1-digested DNA fragment obtained using polymerase chain reaction. Genotypes were then related to the occurrence of severe posttraumatic sepsis and TNFalpha serum concentrations. RESULTS: Fifty-seven patients showed an uncomplicated posttraumatic recovery, and severe sepsis developed in 53 patients. The overall allele frequency (TNFB1 0.29, TNFB2 0.71) and genotype distribution (TNFB1 homozygous 7.3%, TNFB1/TNFB2 42.7%, TNFB2 homozygous 50%) were in agreement with the distribution in healthy volunteers. Genotype distribution in patients with an uncomplicated clinical course was significantly different from that in patients with severe posttraumatic sepsis. Development of severe posttraumatic sepsis was significantly increased in patients homozygous for the allele TNFB2. In patients with severe posttraumatic sepsis, TNFalpha serum concentrations were significantly higher in TNFB2-homozygous individuals compared with heterozygous and TNFB1 -homozygous individuals. The age- and injury-matched odds ratio for the homozygous TNFB2 genotype compared with the heterozygous genotype was 5.22 (p = 0.007, 95% confidence interval 1.6 to 17.9). CONCLUSIONS: In multiply injured patients, the Nco1 polymorphism within the TNFbeta gene is associated with the development of severe posttraumatic sepsis and with increased TNFalpha serum levels when severe sepsis has occurred. This suggests a genetic determination of the individual inflammatory response after infection or tissue damage, which significantly influences susceptibility to severe nosocomial infections.     

Association of a functional polymorphism in the promoter region of TLR‐3 with osteoarthritis: A two‐stage case–control study

Recent studies have suggested that polymorphisms in toll‐like receptor 9 (TLR‐9), an endosomal TLR, are associated with knee osteoarthritis (OA). TLR‐3, ‐7, and ‐8 are also found on the surface of endosomes and to investigate whether similar associations exist with polymorphisms in these TLR genes we performed a two‐stage case–control study and genotyped 11 TLR single nucleotide polymorphisms (SNPs) in 823 OA cases and 594 healthy controls by polymerase chain reaction restriction fragment length polymorphism assays. Real‐time PCR was performed to assess the functional expression of an identified promoter polymorphism in TLR‐3 following dexamethasone stimulation of articular chondrocytes. An association between TLR‐3 SNPs at rs3775296 and rs3775290 and OA was identified in both populations. In males the allelic frequencies of TLR‐7 rs179010 and TLR‐8 rs5744080 were significantly different between OA cases and healthy controls. The ATCA, CTCA, and CCTA haplotypes of TLR‐3 were associated with OA susceptibility. A significant difference in TLR‐3 gene expression following dexamethasone treatment was seen among the various genotypes of rs3775296 (p = 0.004). Our findings indicate that a SNP in the promoter region of TLR‐3 is associated with elevated TLR‐3 gene expression and susceptibility to knee OA in a Chinese Han population. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 680–685, 2013     

Influence of toll-like receptor 4, CD14, tumor necrosis factor, and interleukine-10 gene polymorphisms on clinical outcome in Japanese critically ill patients

The innate recognition of microbial components and subsequent activation of cytokine network are important in the pathophysiology of sepsis. Recently, functional gene polymorphisms in molecules associated with these responses were demonstrated. On the other hand, it has been claimed that there are ethnic differences in genetic polymorphisms. This study investigated toll-like receptor (TLR) 4, CD14, tumor necrosis factor (TNF)-alpha and -beta, and interleukin (IL)-10 gene polymorphisms in 197 Japanese critically ill patients and 214 healthy control subjects to evaluate the influence of these polymorphisms on clinical outcome. No Japanese participant carrying TLR4Asp299Gly or Thr399Ile was detected. No association of CD14-159C/T polymorphisms with genotype frequency or sepsis mortality was observed. Frequency of TNF-alpha-308 GA genotype was significantly higher in the sepsis group than in the control group and TNF-alpha-308GA and IL-10-592CC genotypes were related to poor outcome of sepsis. Ethnic differences in genetic variations are very important issues and the frequencies in this study differ from those previously reported in Caucasians. In conclusion, this study may indicate that TNF-alpha-308G/A and IL-10-592C/A polymorphisms involved in subsequent activation of cytokine network had a larger effect on clinical outcome in patients with sepsis than TLR4Asp299Gly, Thr399Ile, and CD14-159C/T polymorphisms associated with the initial host-microbial interaction.