青藤碱对炎症性肠病中肠道免疫炎症影响的研究进展

炎症性肠病(IBD)患者肠道免疫炎症反应异常,影响和调控肠道免疫炎性反应是其治疗方法之一.现已证明青藤碱(SN)可以通过抑制淋巴细胞增殖,影响免疫细胞功能,减少炎症介质生成,平衡细胞因子的分泌等多个环节来抑制机体免疫炎症反应.本文从IBD免疫发病机制入手,总结了目前SN对机体免疫功能影响方面的研究进展,为寻求SN调控肠道免疫炎症来治疗IBD提供参考.     

血管内皮细胞与炎症性肠病发生发展的关系

炎症性肠病(inflammatory bowel disease,IBD)是一组以肠道慢性炎症为主要表现的慢性复发性肠道自身免疫性疾病,包括克罗恩病(Crohn’s disease,CD)和溃疡性结肠炎(ulcerative colitis,UC).在IBD的发病过程中,引起肠道炎症持续存在的重要原因和特征是黏膜组织中的炎细胞集聚和释放各种炎症因子,其中各种免疫细胞及肠微血管内皮细胞的功能变化对黏膜免疫和胃肠道生理改变发挥了十分重要的作用.这些改变中微血管内皮细胞的结构和功能改变能影响免疫细胞的迁移、组织的血供及内环境的稳定.新生血管通过血管内皮细胞调节炎症性细胞的招募、炎症介质和维持炎症反应进而引起组织损伤.     

生长激素释放肽用于炎症性肠病治疗的研究进展

炎症性肠病(IBD)是一种病因尚不十分清楚的慢性非特异性肠道炎症性疾病,主要包括溃疡性结肠炎(UC)和克罗恩病(CD)。其发病主要是在遗传易感基础上环境因素、肠道菌群及免疫反应共同作用的结果。免疫介导的炎症反应是黏膜受损的主要机理,因此对IBD的治疗主要针对炎症的控制,包括糖皮质激素、氨基水杨酸、免疫抑制剂及抗肿瘤坏死因子单     

炎症性肠病分子病理机制及治疗进展

近年炎症性肠病(IBD)分子病理学机制及临床治疗方面有很大进展,IBD可能是遗传和环境因素共同作用导致肠道粘膜对肠道正常菌群免疫反应失常而引起的慢性炎症,NOD2的发现首次证实了IBD发病的遗传因素.针对免疫反应中各种炎症因子的干预治疗是近年IBD治疗进展最快的领域,抗TNF单克隆抗体(Infliximab)已成功地用于IBD治疗.肠道益生菌和基因治疗值得进一步开拓、深入研究.随着IBD分子发病机制的阐明,将会出现更多IBD治疗靶点.     

肠黏膜屏障在炎症性肠病中作用机制的研究进展

炎症性肠病(inflammatory bowel disease,IBD)是肠道慢性非特异性炎症,黏膜屏障与IBD的关系密切.正常的肠黏膜屏障能维持肠道内菌群的稳定、防止肠道内细菌及毒素的移位以及对微生物进行适当的免疫防御反应起重要作用.而当发生IBD时存在肠黏膜屏障功能的障碍.本文就肠黏膜屏障功能在IBD中作用机制的研究进展作一综述.     

调节性T细胞与炎症性肠病

炎症性肠病(IBD)的病因和发病机制尚未完全明确,肠道黏膜免疫系统对肠道非致病抗原的异常反应所导致的炎症过程在发病中起重要作用.调节性T细胞(Treg)有抑制自身免疫的功能,是维持肠道免疫稳态的重要因素.Treg功能紊乱致免疫耐受被打破可能是导致人类IBD的原因之一.此文就目前国内外关于Treg在IBD的发病机制中的研...     

树突状细胞与炎症性肠病

树突状细胞(DC)是体内功能最强的专职抗原提呈细胞,既能启动免疫应答,又能诱导免疫耐受。炎症性肠病可能是遗传和环境因素共同作用导致肠道黏膜对肠道正常菌群免疫反应失常引起的慢性非特异性炎症。DC可能参与了IBD的发生,对DC功能的进一步深入研究,有助于发现新的IBD治疗靶点。     

炎症性肠病的治疗进展

炎症性肠病（inflammatory bowel diseases，IBD）主要包括溃疡性结肠炎（ulcerative colitis，UC）和克罗恩病（crohn’s disease，CD），是一组慢性复发性疾病，病因未明，与肠道免疫机制有关，遗传和环境因素在IBD的发病中起重要作用。随着生活方式的改变，近年来IBD有增多趋势，对IBD发病机制的深入了解，发现分子和细胞介质在肠道免疫炎症过程中起重要作用，出现了环孢菌素、粘膜保护剂、抗肿瘤坏死因子抗体和白细胞去除术等新方法。本文就IBD的治疗进展作一综述。     

黏液屏障在炎症性肠病中的研究进展

炎症性肠病(IBD)是一种慢性非特异性肠道炎症性疾病,主要包括溃疡性结肠炎(UC)和克罗恩病(CD)。IBD的发病原因尚未完全阐明,主要与基因、环境、免疫功能紊乱以及肠道黏膜屏障功能失调有关。黏液屏障作为肠道黏膜屏障的第一道防线,在IBD发生、发展中发挥重要作用。本文就黏液屏障在IBD中的研究进展作一综述。     

肠道菌群与肠道屏障互作在炎症性肠病中的作用研究进展

炎症性肠病(inflammatory bowel disease,IBD)是一种慢性非特异性肠道炎症性疾病,其发病机制复杂.IBD患者肠道菌群的组成与结构发生明显变化即肠道菌群失调.肠道屏障功能对维持人体肠道功能稳态发挥着重要调节作用.研究表明,在IBD中存在肠道屏障功能受损、肠道通透性增加.肠道菌群失调导致肠道屏障功...     

Potential roles of neutrophils in regulating intestinal mucosal inflammation of inflammatory bowel disease

Inflammatory bowel diseases (IBD), comprising of ulcerative colitis and Crohn's disease, are inflammatory disorders of the gastrointestinal tract characterized by chronically relapsing mucosal inflammation. Neutrophils, as the effector cells of acute inflammation, have long been reported to play a role in the maintenance of intestinal homeostasis and pathogenesis of IBD. At the early stage of mucosal inflammation in patients with IBD, neutrophils flood into intestinal mucosa, phagocytose pathogenic microbes, and promote mucosal healing and resolution of inflammation. However, large numbers of neutrophils infiltrating in the inflamed mucosa and accumulating in the epithelia cause damage of mucosal architecture, compromised epithelial barrier and production of inflammatory mediators. In this review we discuss the critical roles of neutrophils in modulating innate and adaptive immune responses in intestinal mucosa, and, importantly, clarify the potential roles of neutrophils related to their production of inflammatory mediators, transenthothelial and transepithelial migration into intestinal mucosa, and the underlying mechanisms in regulating mucosal inflammation of IBD. Moreover, we also describe a new subset of neutrophils (i.e., CD177⁺ neutrophils) and illustrate its protective role in modulating intestinal mucosal immune responses in IBD.     

A defect in epithelial barrier integrity is not required for a systemic response to bacterial antigens or intestinal injury in T cell receptor-alpha gene-deficient mice

BACKGROUND AND AIMS: Genetically induced disruption of the intestinal epithelial barrier leads to development of intestinal inflammation. In the interleukin-10 gene-deficient inflammatory bowel disease (IBD) mouse model, for instance, a primary defect in intestinal epithelial integrity occurs before the development of enterocolitis. In humans, a causal role for epithelial barrier disruption is still controversial. Although studies with first-degree relatives of IBD patients suggests an underlying role of impaired barrier function, a primary epithelial barrier defect in IBD patients has not been confirmed. The purpose of this article is to examine whether a primary epithelial barrier disruption is a prerequisite for the development of intestinal inflammation or whether intestinal inflammation can develop in the absence of epithelial disruption. We examined the intestinal epithelial integrity of the T cell receptor (TCR)-alpha gene-deficient mouse model of IBD. MATERIALS AND METHODS: In vivo colonic permeability, determined by mannitol transmural flux, was assessed in 6-week-, 12-week-, and 25-week-old TCR-alpha gene-deficient and wild-type control mice using a single-pass perfusion technique. Mice were scored for intestinal histological injury and intestinal cytokine levels measured in organ cultures. Systemic responses to bacterial antigens were determined through 48-h spleen cell cultures stimulated with sonicate derived from endogenous bacterial strains. RESULTS: In contrast with previous findings in the interleukin-10 gene-deficient IBD model, TCR-alpha gene-deficient mice did not demonstrate evidence of primary intestinal epithelial barrier disruption at any age, despite developing a moderate to severe colitis within 12 weeks. A rise in intestinal interferon (IFN)-gamma levels preceded the onset of mucosal inflammation and then correlated closely with the degree of intestinal inflammation and injury. Spleen cells from TCR-alpha gene-deficient mice released IFN-gamma in response to stimulation with endogenous luminal bacterial antigens, a finding that suggests that the systemic response to bacterial antigens occurred independently of epithelial barrier disruption. CONCLUSIONS: Intestinal inflammation and a systemic response to bacterial antigens can develop in the absence of a measurable disruption of intestinal permeability.     

Chemokines in inflammatory bowel diseases

Uncontrolled activation of mucosal effector cells has been identified as the main pathogenic mechanism involved in the initiation and perpetuation of mucosal inflammation in inflammatory bowel diseases (IBD). The sustained activation of these cells leads to the aberrant production of various pro-inflammatory mediators, which co-ordinated action amplifies the inflammatory process. In this setting a network of tissue-specific chemoattractant cytokines (chemokines) and their corresponding receptors have been implicated as main contributors in the initiation and perpetuation of the inflammatory reaction in IBD. They are produced by a variety of inflammatory cells present in IBD lesions, as well as endothelial and epithelial cells. Chemokines not only control the multistep process of leukocyte adhesion to and migration across the endothelium, but also the release of lipid mediators and oxygen radicals from leukocytes, the modulation of tumorigenesis, release of matrix metalloproteinases and tissue fibrosis. Numerous data indicate that that intestinal chemokine expression is non-selectively up-regulated in IBD and correlates with disease activity. The development of selective inhibitors for chemokines or chemokine receptors, based on a more complete understanding of the immunopathogenic role of chemokines in intestinal inflammation, will be of great interest as potential novel therapeutic strategies in IBD.     

Role of the JNK signal transduction pathway in inflammatory bowel disease

The c-Jun NH2-terminal Kinase （JNK） pathway represents one sub-group of the mitogen-activated protein （MAP） kinases which plays an important role in various inflammatory diseases states, including inflammatory bowel disease （IBD）. Significant progress towards understanding the function of the JNK signaling pathway has been achieved during the past few years. Blockade of the JNK pathway with JNK inhibitors in animal models of IBD lead to resolution of intestinal inflammation. Current data suggest specific JNK inhibitors hold promise as novel therapies in IBD.     

The IL23 axis plays a key role in the pathogenesis of IBD

Exciting new results from a genetic study in humans and functional studies in mice have pinpointed interleukin 23 (IL23) and its receptor as a key pathway in the pathogenesis of inflammatory bowel disease (IBD). These findings reveal a hitherto unappreciated role for the IL23 axis in intestinal inflammation and may open new avenues for development of therapeutic strategies in IBD.     

Chemokines in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn’s disease (CD), collectively termed inflammatory bowel diseases (IBD), represent chronic relapsing and remitting inflammatory disorders of the gastrointestinal tract that are charcterized by leukocytic infiltration of the intestinal mucosa and submucosa. In CD, the inflammation is transmural and frequently associated with granuloma formation. Chemokines have emerged as the most important regulators of leukocyte trafficking during infection or inflammation and, therefore, have been implicated in the pathogenesis of IBD. In this review, recent advances on the role of chemokines and their receptors in mucosal immunity and inflammation are discussed, and the potential use of chemokine/chemokine-receptor antagonists as novel therapeutic targets for the treatment of human IBD is highlighted.     

The Interleukin-23 / Interleukin-17 axis in intestinal inflammation

Although the precise aetiology of inflammatory bowel disease (IBD) remains unclear, recent discoveries have led to an improved understanding of disease pathogenesis. Whilst these findings have underscored the central role of innate and adaptive immune responses in intestinal inflammation, they have also precipitated a paradigm shift in the key cytokine pathways that drive disease. The prevailing dogma that IBD was mediated by interleukin (IL)-12-driven T-helper (Th)1 CD4 T cell responses towards the bacterial flora has been largely dispelled by findings that the closely related cytokine IL-23 appears to be the key mediator of intestinal inflammation. IL-23 is associated with a novel subset of IL-17-secreting CD4 T cells termed Th17 cells and rodent studies have implicated the IL-23/IL-17 axis in autoimmune inflammation. Genome-wide association studies in IBD patients have confirmed the predominant role of the IL-23 pathway, indicating that this could represent an important future therapeutic target.     

Th17/Treg失衡与炎症性肠病的关系

炎症性肠病(inflammatory bowel disease.IBD)的病因和发病机制尚未完全明确,肠道黏膜免疫系统异常反应所导致的炎症过程在发病中起重要作用.辅助性T细胞17(T helper 17 cells,Th17)可介导慢性炎症和自身免疫性疾病的发生,调节性T细胞(regulatory T cell,Treg)有抑制自身免疫的功能,二者存在相互转化的关系.有研究表明Th17/Treg转化平衡是维持肠道免疫稳态的重要因素,这可能是导致人类IBD的原因之一.最近研究表明TGF-β,IL-6和维甲酸(retinoic acid,RA)可能是调控二者平衡关系的重要因素.肠道菌群(intestinal flora)与IBD的发生发展关系密切,益生菌(probiotics)对IBD的治疗作用成为研究的热点.深化对Th17/Treg转化调控关系的研究是当前重要的研究课题.