基因芯片技术研究原发性干燥综合征患者唇腺基因表达

目的应用基因芯片技术筛选原发性干燥综合征（SS）患者与健康对照唇腺组织中的差异表达基因，探讨其可能的发病机制。方法实验组和对照组各3例，分别制成eRNA探针，与基因芯片杂交，筛选出差异表达基因。结果实验组与对照组显著差异表达基因181个，其中上调表达128个，下调表达53个。涉及细胞因子及受体相关基因、凋亡相关基因等。结论SS的发生发展受多种基因调控，差异基因表达谱的建立较全面地反映了SS的分子生物学概貌。     

肿瘤坏死因子超家族基因在慢性心力衰竭外周血单核细胞的表达

目的:应用基因芯片技术分析比较慢性心力衰竭（CHF）患者和健康对照组外周血单核细胞（PBMC）中细胞因子和其它炎症相关基因表达差异,以识别CHF细胞因子网络的不平衡。方法:分别抽提CHF和健康对照组PBMC总RNA并纯化mRNA,反转录合成单链、双链cDNA后,体外转录合成cRNA。分别用cy3-dCTP和cy5-dCTP标记对照和CHF组cRNA。将基因芯片和杂交探针变性后杂交、洗涤。用基因芯片扫描仪进行图像扫描,Im aGene3.0软件分析cy3、cy5两种荧光信号的强度和比值。结果:cDNA表达谱芯片中含365个炎性细胞因子相关基因,其中CHF组上调34个基因,下调2个。上调基因包括肿瘤坏死因子（TNF）超家族成员,趋化因子/趋化因子受体,转化生长因子超家族成员等。TNF超家族成员中,淋巴毒素（LTB）、TNF超家族成员5、7、10,TNF受体超家族成员13b,TNF相关凋亡诱导配体受体4（TRAIL-R4）在CHF组均上调。而TNF受体超家族成员10C（TRAIL-R3）在CHF显著下调。结论:CHF与正常人PBMC细胞因子相关基因的表达有显著差异,CHF存在细胞因子网络的不平衡;尤其是多个TNF超家族基因的高表达可能在CHF发生发展中起着重要作用。     

U230A芯片动态观察非酒精性脂肪性肝病大鼠肝脏基因表达

目的探讨大鼠非酒精性脂肪性肝病（NAFLD）发生过程中肝脏基因表达谱的改变。方法通过持续24周高脂饮食诱导大鼠NAFLD模型，应用U230A芯片检测不同造模时期肝脏基因表达，并设普通饮食饲养大鼠作对照。结果与对照大鼠相比，造模4周和8周时差异表达基因数分别为426条和540条，上调基因主要为细胞内磷酸化酶基因、代谢酶基因、脂肪酸结合蛋白基因，细胞色素P450基因以及细胞转录和分化基因等，下调基因主要为离子通道基因、激素受体基因、细胞黏附基因以及细胞骨架基因等；12周时差异表达基因有501条，其中表达上调352条，除上述基因外，还包括白细胞介素，Toll样受体4等炎症和凋亡相关基因；16周时差异表达的基因有665条，其中上调基因430条，炎症和凋亡相关基因表达进一步增加，且Ⅰ型胶原等纤维化相关基因出现表达上调，而细胞再生相关基因表达下调；24周时差异表达的基因有663条，其中上调基因512条，除上述基因表达差异外，主要包括成纤维细胞生长因子，转化生长因子和胰岛素样生长因子等纤维化相关基因。在所有表达差异的基因中，随着时间进展表达持续上调的基因共128条，其中成脂相关基因10条，代谢酶基因46条，炎症相关基因15条、凋亡相关基因10条，纤维化相关基因16条；持续下调的基因有52条，包括激素受体相关基因6条，细胞再生相关基因5条，电子转运基因11条等。结论高脂饮食大鼠肝脏基因谱呈动态改变，并与NAFLD的组织学进展一致。     

基因芯片技术对哮喘病人相关基因的筛选和分析

目的 利用基因芯片技术寻找哮喘病患者与正常人外周血单核细胞之间差异表达基因,拟为哮喘的早期诊断及预防提供分子标记.方法 用淋巴细胞分离液分别提取16例哮喘病患者与16例正常人外周血单核细胞,用QIAGEN Rneasy Kit提取纯化样本总RNA,并合成用荧光标记的cRNA,分别与含有41 000条基因序列的全基因芯片杂交,以基因表达倍数值≥2.0和基因表达倍数值≤-2.0为阈值来确定差异表达基因,然后用Genespring软件利用生物信息学方法对差异表达基因进行功能分类分析.结果 按P＜0.05差异显著性标准,从34 183条表达基因谱中,筛选出哮喘患者与正常对照差异表达2倍以上的基因有4177条,差异表达2倍以上已知与哮喘相关的基因有19条.经代谢途径分析发现这些差异基因主要涉及到炎症反应、免疫反应、防御反应、创伤反应、外部刺激反应等8大功能分类.结论 哮喘的发生涉及众多基因表达的改变,芯片技术可以有效地筛选出哮喘患者与正常对照的差异表达基因,对进一步探索哮喘的发病机制、有效的干预或逆转哮喘具有重要意义.     

应用基因芯片技术研究甲状腺乳头状癌的基因表达

目的　应用基因芯片技术研究甲状腺乳头状癌 (PTC)和正常成人甲状腺组织基因的差异表达。方法　分别用Cy5和Cy3两种不同的荧光染料通过逆转录反应将PTC组和对照组甲状腺组织的mRNA分别标记成探针 ,并与载有一组靶基因的基因表达谱芯片进行杂交。通过扫描荧光强度 ,计算机软件分析 ,寻找两组差异表达基因 ,并用RT PCR、免疫组化对其中两条基因进行验证。结果　共有 65条差异表达基因 ,其中表达增加的有 48条 (2 .0倍以上 ) ,表达降低的有 17条 (0 .5倍以下 )。RT PCR、免疫组化结果与芯片扫描结果一致。结论　基因芯片是筛选PTC与正常成人甲状腺组织差异表达基因的有效方法。通过筛选所得差异基因提示 ,PTC的发病涉及细胞外基质、细胞因子、受体信号转导等多个方面。     

老年大鼠海马炎性衰老相关基因表达及淫羊藿苷对其影响

目的 探讨炎性衰老的炎性细胞因子网络机制，及淫羊藿苷（Icariin，Ica）干预的效果与机制。方法清洁级健康雄性SD大鼠30只，随机等分为4月龄（4m）、24月龄（24m）和24月龄加Ica干预（24m＋Ica）三组。自21月龄满开始，24m＋Ica组予Ica灌胃，24m组给予等量蒸馏水灌胃，均连续90d。取各组大鼠海马组织，应用炎症细胞因子与受体基因芯片进行基因表达检测，绘制基因表达谱，筛选有表达差异的基因。海马组织匀浆，离心取上清液，运用酶联免疫吸附法检测上清液中炎性细胞因子TNF-α、IL-6和IL-10蛋白表达。结果在海马组织中，与4m组相比，24m组表达卜调的促炎性反应细胞因子与受体基因有9个，表达下调的抗炎细胞因子与受体基因有6个。与24m组比较，24m＋Ica组中表达上调的抗炎细胞凶子与受体基因有6个，下调的促炎细胞因子与受体基因有9个。24m组海马组织中TNF-α和IL-6蛋白水平都显著高于4m组（P〈0，01）；与24m组比较，24m＋Ica组中TNF-α和IL-6蛋白水平都明显降低，IL-1蛋白水平显著升高（P〈0．01）。与4m组相比，24m组海马组织上清液中TNF-α／IL-10和IL-6／IL-10比值均显著升高（P〈0．01）；24m＋Ica组TNF-α／IL-10和IL-6／IL-10比值均比24m组显著降低（P〈0．01）。结论 老年大鼠海马存在促炎性细胞因子基闪表达上调，导致促航炎性细胞因子网络和促-抗炎反应体系平衡失调，这可能是炎性衰老中出现高促炎性反应状态的原因和炎性衰老发生的新机制；Ica可能通过下调促炎性细胞因子基因表达和上调抗炎性细胞因子基因表达，重塑促-抗炎性细胞因子网络和促-抗炎性反应体系新的平衡来干预炎性衰老。     

基因芯片在肝细胞癌相关基因筛选中的初步研究

目的探讨基因表达谱芯片技术在筛查肝细胞癌相关基因群表达中的作用。方法采用美国Affymetrix公司的U133A2．0基因表达谱芯片，按一步法抽提肝细胞癌及正常肝脏组织总RNA，分离纯化两种组织的mRNA；经逆转录合成掺人生物素标记的cDNA合成探针，与芯片杂交和严格洗片后，用荧光扫描仪扫描芯片荧光信号图像，分析肝细胞癌及正常肝组织中差异表达的基因。结果在18400条基因中，肝细胞癌组织与正常肝脏组织间有2756条（14．98％）存在差异表达的基因，其中上调基因1772条和下调基因984条，对2756条差异表达基因作了初步功能分类，这些基因与肝细胞癌的发病机制存在相关性。结论基因表达谱芯片技术可以筛选出肝细胞癌表达异常的相关基因群，对其进一步研究有助于认识肝细胞癌的发病机制。     

炎性衰老机制与干预的实验研究

目的 运用基因芯片筛选与炎性衰老相关的炎性细胞因子与受体特征基因,探讨其炎性细胞因子网络调控机制;观察淫羊藿总黄酮(EF)和淫羊藿苷(Ica)对该网络的干预效果与机制.方法 SD大鼠分为4月龄(4 m)、24 m、24 m+EF和24 m+Ica组,每组10只.分别取各组大鼠海马和肺组织,用炎症细胞因子与受体基因芯片对各组组织分别进行基因表达检测.结果 (1)海马组织:24 m组与4 m组比较,促炎症细胞因子表达上调;同时抗炎症细胞因子下调.24 m+EF组、24 m+Ica组与24 m组比较,可见大量抗炎症细胞因子上调而促炎症细胞因子下调.(2)肺组织:24 m组与4 m组比较,促炎症细胞因子上调,同时抗炎症细胞因子下调.24 m+EF组、24 m+Ica组与24 m组比较,发现大量抗炎症细胞因子上调而促炎症细胞因子下调.结论 老年大鼠存在促炎性细胞因子基因表达上调和抗炎性因子表达下调,导致促-抗炎性细胞因子网络平衡失调;EF和Ica可能通过下调促炎性细胞因子基因表达和上调抗炎性细胞因子基因表达,重塑促-抗炎性细胞因子网络平衡而干预炎性衰老.     

应用基因芯片技术对系统性红斑狼疮患者外周血基因表达谱的初步研究

目的 研究系统性红斑狼疮（SLE）患者与正常对照外周血的基因表达谱的改变，以探讨SLE发病机制，诊断及鉴别诊断，以及基因功能的研究。方法 首先从外周血提取总RNA，反转录合成单链，双链cDNA后，体外转录合成生物素标记的cRNA与基因芯片进行杂交，再通过抗原抗体反应机制标记上荧光染料Cy3后，使用芯片扫描仪进行图像扫描。使用分析软件进行表达差异和聚类分析。结果 在3000多个基因点中，与正常对照相比较，鉴定出94个基因存在表达差异相关基因，其中有33个基因表达上调，61个基因表达下调。这些表达差异基因有细胞因子及受体，转录相关基因，凋亡相关基因，生长分化相关基因，信号转导相关基因，细胞周期相关基因，电子传递和氧化相关基因，转移酶相关, 酶相关基因等。聚类分析结果显示不同的疾病以及不同临床表面的同一疾病其外周血的基因表达谱是有差异的，可以用于疾病的诊断和鉴别诊断。基因聚类发现，根据表达谱聚类在一起的基因存在功能上的相似性，可以用来发现已知基因的免疫相关功能。结论 该基因芯片技术方法有较高的重复性和稳定性，能有效地进行SLE致病基因的筛选，更好地理解SLE发生的分子机制，诊断及鉴别诊断，以及基因功能的研究。     

老年大鼠下丘脑-垂体-肾上腺轴炎性衰老相关基因表达特征

目的探讨炎性衰老的炎性细胞因子网络机制。方法清洁级健康雄性SD大鼠分为4月龄（4m）和24月龄（24m）二组,每组各10只。分别取各组大鼠下丘脑、垂体和肾上腺组织,应用炎症细胞因子与受体基因芯片进行基因表达检测,绘制基冈表达谱,筛选有表达差异的基因。结果与4m组相比,24m组下丘脑、垂体和肾上腺组织中表达上调的促炎性反应细胞因子与受体基因分别有6个、7个和9个,表达下调的抗炎细胞因子与受体基因分别有3个、4个和3个（P〈0．05）。三种组织中表达都上调的促炎性反应细胞因子与受体基因有白介素、肿瘤坏死因子和趋化因子。结论老年大鼠下丘脑－垂体－肾上腺轴组织存在促炎性细胞因子基因表达上调,导致促－抗炎性细胞因子网络和促－抗炎性反应体系平衡失调,这可能是炎性衰老中出现高促炎性反应状态的原因和炎性衰老发生的新机制。     

In vivo therapy with monoclonal anti-I-A antibody suppresses immune responses to acetylcholine receptor

A monoclonal antibody to I-A gene products of the immune response gene complex attenuates both humoral and cellular responses to acetylcholine receptor and appears to suppress clinical manifestations of experimental autoimmune myasthenia gravis. This demonstrates that use of antibodies against immune response gene products that are associated with susceptibility to disease may be feasible for therapy in autoimmune conditions such as myasthenia gravis.     

Involvement of human muscle acetylcholine receptor alpha-subunit gene (CHRNA) in susceptibility to myasthenia gravis.

The muscle acetylcholine receptor is the major target of the autoimmune response in generalized myasthenia gravis. To investigate the role of the gene encoding the alpha subunit of the receptor (CHRNA), two stable polymorphic d[(GT).(CA)]dinucleotide repeats, designated HB and BB, were characterized within the first intron of CHRNA. The HB*14 allele conferred a relative risk for myasthenia gravis of 2.5 in 81 unrelated patients compared with 100 control subjects. Very significantly, family analysis based on haplotype segregation data indicated that parental haplotypes associated with HB*14 always segregated to the child with myasthenia gravis (P < 0.0002 for the comparison with the transmission of haplotypes not bearing HB*14), whereas their transmission to unaffected siblings was equilibrated. Myasthenia gravis patients also showed a high frequency of microsatellite variants unseen in controls. These findings implicate the CHRNA in susceptibility to myasthenia gravis.     

Acetylcholine receptors and myasthenia gravis

Recent years have seen considerable progress in understanding the nature of the molecular events involved in neuromuscular transmission. The acetylcholine receptor (AChR) has been purified to homogeneity and acetylcholine-induced ion transport has been reconstituted by incorporation of pure AChR into artificial membranes. Immunization against purified AChR induces a condition, clinically and physiologically similar to the human disease myasthenia gravis, which is due to circulating anti-AChR antibodies. This model, experimental autoimmune myasthenia gravis, is proving useful for investigating the role of genetic factors in determining the immune response to AChRs and for testing various experimental approaches to specific treatment. Myasthenia gravis is an autoimmune disease in which there is loss of acetylcholine receptors at the neuromuscular junction. Anti-AChR antibodies can be detected in the majority of patients and they cause loss of AChR by a variety of mechanisms. Anti-AChR antibody is heterogeneous and not restricted in idiotype. The role of the thymus in MG is still uncertain, but recent experiments implicate the presence of a cell type in MG thymus which may be involved in autosensitization to AChR.     

Immunological relationship between acetylcholine receptor and thymus: a possible significance in myasthenia gravis.

A defined immunological cross-reaction was observed between acetylcholine receptor fraction from the electric eel, Electrophorus electricus, and two calf thymus fractions. The cross-reaction was demonstrated on the cellular level by means of the lymphocyte transformation technique, and on the humoral level, by means of the microcomplement fixation assay. In the human disease myasthenia gravis both acetylcholine receptor at the neuromuscular junction and the thymus are affected, probably by an autoimmune mechanism. The immunological cross-reaction between acetylcholine receptor and thymic components may explain the association between endplate and thymus disorders in myasthenia gravis.     

THE THYMUS: EXPERIMENTAL PHYSIOLOGY,AND PATHOLOGY IN MAN

The thymus is an integral part of the immunological system. It is a site of intense lymphopoiesis, especially in early life. Neonatal thymectomy in mice causes runting and death due to gross immunological deficiencies. These deficiencies are determined by lymphopenia, and by lack of a lymphotrophic hormone secreted by the epithelial cells of the medulla; this hormone confers on lymphocytes the capacity to respond to antigenic stimulation. The thymus may be the main source of lymphoid cells carrying new or primary patterns of immune reactivity; it is thus “first-level” or “central” lymphoid tissue, which seeds cells to “second-level” or “peripheral” lymphoid tissues in the lymph nodes and spleen. Pathological lesions of the thymus in man include aplasia, hyperplasia, dysplasia and neoplasia. Gross aplasia characterizes the immunological deficiency diseases of infancy, including the lymphopenic type of congenital agammaglobulinæmia. Hyperplasia accompanies thyrotoxicosis. Dysplasia refers to the lymph follicle-germinal centre development in myasthenia gravis, probably an autoimmune disease, and to the proliferation in the medulla of spindle-epithelial cells in lupus erythematosus, an autoimmune disease. Neoplasia occurs as benign thymoma, which may be accompanied by extrathymic diseases which are possibly autoimmune in origin; these include myasthenia gravis, red cell aplasia, polymyositis, agammaglobulinæmia and lupus erythematosus. These diseases may in some way be caused by the thymoma; alternatively, the thymoma may represent the result of continuing hyperplasia of the thymus provoked by a primary autoimmune process. The place of thymectomy in the treatment of autoimmune disease is discussed. It is an established procedure in myasthenia gravis, and has been successful in two cases of autoimmune hæmolytic anæmia in infancy. We review our experience with thymectomy for three patients with systemic lupus erythematosus.     

Association of HLA-DQA1*0101/2 and DQB1*0502 with Myasthenia Gravis in Southern Iranian Patients

Background: Myasthenia gravis is an autoimmune disorder of neuromuscular junction characterized by skeletal muscle weakness and fatigability. Different genes may control the induction and clinical presentation of this disease. Various HLA alleles are reported as predisposing or protective genetic elements in myasthenia gravis. Objective: The aim of this study was to investigate the probable association between HLA-DQ alleles and myasthenia gravis in southern Iranian patients. Methods: HLA-DQA1 and DQB1 alleles were determined in 104 sporadic patients with myasthenia gravis using polymerase chain reaction - restriction fragment length polymorphism method and the results were compared to 816 healthy controls. Results: HLA-DQA1*0101/2 (39.4%) and DQB1*0502 (21.6%) were the most frequent alleles in southern Iranian patients with myasthenia gravis. These alleles revealed positive associations with the disease with relative risks of 1.69 and 2.41, respectively. The most common haplotype was DQA1*0101/2-DQB1*0502 in these patients. Conclusion: According to the results of this study, DQA1*0101/2 and DQB1*0502 alleles might be considered as predisposing genetic factors to myasthenia gravis while DQA1*0501, DQB1*0301 and *0602/3 show protective roles against this disease.     

The thymic theme of acetylcholinesterase splice variants in myasthenia gravis

Cholinergic signaling and acetylcholinesterase (AChE) influence immune response and inflammation. Autoimmune myasthenia gravis (MG) is mediated by antibodies to the acetylcholine receptor and current therapy is based on anti-AChE drugs. MG is associated with thymic hyperplasia, showing signs of inflammation. The objectives of this study were to analyze the involvement of AChE variants in thymic hyperplasia. We found lower hydrolytic activities in the MG thymus compared with adult controls, accompanied by translocation of AChE-R from the cytoplasm to the membrane and increased expression of the signaling protein kinase PKC-betaII. To explore possible causal association of AChE-R changes with thymic composition and function, we used an AChE-R transgenic model and showed smaller thymic medulla compared with strain-matched controls, indicating that AChE-R overexpression interferes with thymic differentiation mechanisms. Interestingly, AChE-R transgenic mice showed increased numbers of CD4(+)CD8(+) cells that were considerably more resistant in vitro to apoptosis than normal thymocytes, suggesting possibly altered positive selection. We further analyzed microarray data of MG thymic hyperplasia compared with healthy controls and found continuous and discrete changes in AChE-annotated GO categories. Together, these findings show that modified AChE gene expression and properties are causally involved in thymic function and development.     

Myasthenia gravis

Myasthenia gravis is an autoimmune disease, which leads to load-dependent weakness of voluntary skeletal muscles with recovery of function after resting. The disease is caused by autoantibodies directed against the postsynaptic nicotinic acetylcholine receptors (AChR) leading to a reduction of neuromuscular transmission. Muscles and nerves are not affected. Disorders of the thymus play a role in the pathogenesis of AChR antibody-positive myasthenia. The clinical symptoms include exercise-induced fatigue either of the ocular muscles alone (ocular myasthenia) or striated skeletal muscle and the ocular, facial and bulbar musculature (generalized myasthenia). Treatment of myasthenia gravis involves administration of acetylcholine esterase inhibitors and immunosuppressive drugs. A myasthenic crisis is characterized by life-threatening complications with severe weakness, swallowing difficulties and respiratory failure, which requires intensive care treatment.     

Crohn's disease and myasthenia gravis: a possible role for thymectomy.

A female patient with a three year history of Crohn's disease of the colon developed myasthenia gravis. Despite diversion of the faecal stream by an ileostomy, and total colectomy, the patient had continuing problems with perineal and perianal abscesses and fistulas. Her myasthenia gravis became unresponsive to anti-cholinergics so a thymectomy was performed. The perineal and perianal disease improved subsequently. This case supports the theory that functional disturbances of the thymus may have a role in the pathogenesis of inflammatory bowel disease.     

Coexistence of Myasthenia Gravis and Hashimoto's Thyroiditis in a Chinese Woman

Summary: The coexistence of myasthenia gravis and Hashimoto's thyroiditis has rarely been described. A 64-year-old Chinese woman with myasthenia gravis and Hashimoto's thyroiditis is described. The literature on the occurrence of Hashimoto's thyroiditis and myasthenia gravis is briefly reviewed. The relationship between myasthenia gravis and thyroid dysfunction is outlined. It is suggested that the association of myasthenia gravis with Hashimoto's thyroiditis (a long-known autoimmune disease) provides further support to the hypothesis that myasthenia gravis may be an auto-immune disorder.