类风湿关节炎治疗药物的分子作用机制研究进展

类风湿关节炎是慢性自体免疫性疾病,文章从作用于细胞因子及其受体、针对T淋巴细胞的清除、影响G蛋白偶联受体信号转导和Ras-丝裂原激活的蛋白激酶信号转导四个方面阐述了消炎免疫药物治疗类风湿性关节炎的分子作用机制。     

Evidence for the effects of a superantigen in rheumatoid arthritis

While studying the alpha beta T cell receptor repertoire in rheumatoid arthritis (RA) patients, we found that the frequency of V beta 14+ T cells was significantly higher in the synovial fluid of affected joints than in the peripheral blood. In fact, V beta 14+ T cells were virtually undetectable in the peripheral blood of a majority of these RA patients. beta-chain sequences indicated that one or a few clones dominated the V beta 14+ population in the synovial fluid of individual RA patients, whereas oligoclonality was less marked for other V beta's and for V beta 14 in other types of inflammatory arthritis. These results implicate V beta 14-bearing T cells in the pathology of RA. They also suggest that the etiology of RA may involve initial activation of V beta 14+ T cells by a V beta 14-specific superantigen with subsequent recruitment of a few activated autoreactive v beta 14+ T cell clones to the joints while the majority of other V beta 14+ T cells disappear.     

Induction of self-tolerance in T cells but not B cells of transgenic mice expressing little self antigen

Self-tolerance to a transgene-encoded protein, hen egg lysozyme, was examined in the T and B cell repertoires of a series of lines of transgenic mice that expressed different serum concentrations of soluble lysozyme. T cells were tolerant in all lines in which lysozyme was expressed irrespective of the antigen concentration, whereas B cell tolerance did not occur when the serum lysozyme concentration was less than 1.5 nanograms per milliliter (0.1 nM). Induction of elevated transgene expression could restore B cell tolerance. These findings support the hypothesis that autoimmune disease may in some instances arise through a bypass of T cell tolerance.     

The growth factor progranulin binds to TNF receptors and is therapeutic against inflammatory arthritis in mice

The growth factor progranulin (PGRN) has been implicated in embryonic development, tissue repair, tumorigenesis, and inflammation, but its receptors remain unidentified. We report that PGRN bound directly to tumor necrosis factor receptors (TNFRs) and disturbed the TNFα-TNFR interaction. PGRN-deficient mice were susceptible to collagen-induced arthritis, and administration of PGRN reversed inflammatory arthritis. Atsttrin, an engineered protein composed of three PGRN fragments, exhibited selective TNFR binding. PGRN and Atsttrin prevented inflammation in multiple arthritis mouse models and inhibited TNFα-activated intracellular signaling. Collectively, these findings demonstrate that PGRN is a ligand of TNFR, an antagonist of TNFα signaling, and plays a critical role in the pathogenesis of inflammatory arthritis in mice. They also suggest new potential therapeutic interventions for various TNFα-mediated pathologies and conditions, including rheumatoid arthritis.     

Human sickle hemoglobin in transgenic mice

DNA molecules that contain the human alpha- and beta s-globin genes inserted downstream of erythroid-specific, deoxyribonuclease I super-hypersensitive sites were coinjected into fertilized mouse eggs and a transgenic mouse line was established that synthesizes human sickle hemoglobin (Hb S). These animals were bred to beta-thalassemic mice to reduce endogenous mouse globin levels. When erythrocytes from these mice were deoxygenated, greater than 90 percent of the cells displayed the same characteristic sickled shapes as erythrocytes from humans with sickle cell disease. Compared to controls the mice have decreased hematocrits, elevated reticulocyte counts, lower hemoglobin concentrations, and splenomegaly, which are all indications of the anemia associated with human sickle cell disease.     

Oncogenesis of the lens in transgenic mice

Neoplastic tumors of the ocular lens of vertebrates do not naturally occur. Transgenic mice carrying a hybrid gene comprising the murine alpha A-crystallin promoter (-366 to +46) fused to the coding sequence of the SV40 T antigens developed lens tumors, which obliterated the eye cavity and even invaded neighboring tissue, thus establishing that the lens is not refractive to oncogenesis. Large-T antigen was detected early in lens development; it elicited morphological changes and specifically interfered with differentiation of lens fiber cells. Both alpha- and beta-crystallins persisted in many of the lens tumor cells, while gamma-crystallin was selectively reduced. Accessibility, characteristic morphology, and defined protein markers make this transparent epithelial eye tissue a potentially useful system for testing tumorigenicity of oncogenes and for studying malignant transformation from its inception until death of the animal.     

Blood sugar level following intravenous glucose in rheumatoid arthritis

Since the majority of patients with rheumatoid arthritis show a slower fall in the blood sugar level after the intravenous injection of glucose than do the normal controls, the alteration cannot be explained on the basis of gastrointestinal dysfunction. Differences in the renal threshold of glucose do not explain the altered glucose tolerance, since approximately the same amount of glucose is lost in the urine in both groups. Blood samples taken at 3 and 5 minutes following the injection of the glucose showed the height of the blood sugar level to be approximately the same in the patients with rheumatoid arthritis and in normals. The slower fall in the blood sugar level of the former is therefore not a simple function of a greater rise following the intravenous administration of the glucose. Although the patients with severe poliomyelitis had as much or more atrophy than the rheumatoid arthritic patients, there was no delay in rate of fall of the blood sugar level after the intravenous administration of glucose. In view of the fact that the hepatic homeostatic control regulates the blood sugar level, faulty utilization of glucose by extrahepatic tissues cannot be considered the primary factor responsible for the alteration of the glucose tolerance. The altered glucose tolerance in rheumatoid arthritis is explainable on the basis of an altered threshold of the hepatic homeostatic control of the blood sugar. Additional studies must be done to determine whether this derangement emanates directly from extrahepatic influences.     

Synthesis of functional human hemoglobin in transgenic mice

Human alpha- and beta-globin genes were separately fused downstream of two erythroid-specific deoxyribonuclease (DNase) I super-hypersensitive sites that are normally located 50 kilobases upstream of the human beta-globin gene. These two constructs were coinjected into fertilized mouse eggs, and expression was analyzed in transgenic animals that developed. Mice that had intact copies of the transgenes expressed high levels of correctly initiated human alpha- and beta-globin messenger RNA specifically in erythroid tissue. An authentic human hemoglobin was formed in adult erythrocytes that when purified had an oxygen equilibrium curve identical to the curve of native human hemoglobin A (Hb A). Thus, functional human hemoglobin can be synthesized in transgenic mice. This provides a foundation for production of mouse models of human hemoglobinopathies such as sickle cell disease.     

硒的生物学作用

目的研究正反杂交对少花龙葵(Solanum photeinocarpum) F₁代生理特性及富硒能力的影响,为富硒少花龙葵的杂交选育提供参考。方法以农田生态型和矿山生态型少花龙葵为亲本,通过硒含量为10 mg/kg的土壤盆栽试验,研究正反杂交对少花龙葵F₁代的生物量、光合色素含量、抗氧化酶活性以及硒积累量的影响。结果与自交F₁代相比,正反杂交显著提高了少花龙葵F₁代叶片的SOD活性、CAT活性以及可溶性蛋白含量(P<0.05)。2种生态型少花龙葵的正反杂交F₁代的根系和地上部分的生物量、硒积累量均显著高于其自交F₁代(P<0.05),并且以农田生态型少花龙葵为母本、矿山生态型少花龙葵为父本的杂交后代的生长和富硒能力更强。结论以农田生态型和矿山生态型少花龙葵为亲本杂交,可使其F₁代的生长、抗逆性以及硒积累等性状表现出超亲优势。     

转β-甘露聚糖酶基因manA小鼠的制备

为了获得β-甘露聚糖酶基因manA的转基因小鼠,从黑曲霉中克隆得到β-甘露聚糖酶基因manA,进行体外表达检测甘露聚糖酶活性后,将此基因插入到含有猪腮腺分泌蛋白(PSP)基因启动子的表达载体pPSPBGPneo中,得到在腮腺组织特异表达β-甘露聚糖酶基因manA的载体pPSP-manA,总长为16.3 kb,将其进行线性化后回收得到高质量DNA片段,通过显微注射得到17只原代小鼠,进行PCR和Southern blot检测发现有6只阳性转基因小鼠,表明转β-甘露聚糖酶基因manA小鼠制备成功.     

诱导性免疫共刺激分子转基因小鼠模型的建立

利用RT—PCR方法从人扁桃体的激活T细胞mRNA中扩增出诱导性免疫共刺激分子(ICOS)cDNA,继而将ICOS基因插入到pEGFP—N3中得到含ICOS和GFP融合蛋白的pEGFP—ICOS。将外源基因pEGF、P—ICOS注射至FVB小鼠原核中,其胚胎移植到同期发情的假孕受体产出后代,经PCR和Southern检测获得阳性转基因小鼠。试验共注射移植胚胎117枚,出生小鼠43只,检出阳性小鼠2只,该转基因已稳定遗传至F3代,说明建立了ICOS转基因小鼠模型。     

Induction of tumors in mice by genomic hypomethylation

Genome-wide DNA hypomethylation occurs in many human cancers, but whether this epigenetic change is a cause or consequence of tumorigenesis has been unclear. To explore this phenomenon, we generated mice carrying a hypomorphic DNA methyltransferase 1 (Dnmt1) allele, which reduces Dnmt1 expression to 10% of wild-type levels and results in substantial genome-wide hypomethylation in all tissues. The mutant mice were runted at birth, and at 4 to 8 months of age they developed aggressive T cell lymphomas that displayed a high frequency of chromosome 15 trisomy. These results indicate that DNA hypomethylation plays a causal role in tumor formation, possibly by promoting chromosomal instability.     

人胰岛素原基因在转基因小鼠乳汁中的表达

将构建的绵羊 β-乳球蛋白基因 ( BLG)调控人胰岛素原基因的重组基因通过显微注射生产转基因小鼠。共移植 888枚注射 BLG-胰岛素原基因的小鼠卵 ,移植受体 31只 ,怀孕 1 4只 ,产仔 53只。PCR检测 51只 ,有 5只为阳性 ,并均为雌性 ,其中 2只小鼠泌乳 ,经放免检测小鼠乳汁中人胰岛素原的质量浓度分别为 37.44mg/L和 39.99mg/L。另外 3只异常消瘦而不孕 ,其中 1只极度衰竭而死亡     

麻黄加术汤对大鼠类风湿性关节炎模型作用机制的研究

目的探讨麻黄加术汤对类风湿性关节炎的作用机制。方法运用Ⅱ型胶原法建立Wistar大鼠类风湿性关节炎模型,采用麻黄加术汤给予干预,以甲氨喋呤片为阳性对照药。将大鼠随机分为空白组、模型组、甲氨喋呤组、麻黄加术汤组。检测大鼠血清炎性细胞因子IL-1β、TNF-α浓度,观察大鼠膝关节滑膜组织病理改变。结果麻黄加术汤可显著降低大鼠血清炎性细胞因子IL-1β、TNF-α的含量,差异具有统计学意义(P<0.01),对CIA大鼠滑膜组织的炎性细胞浸润、纤维组织增生和巨噬样A型细胞有明显抑制作用,差异具有统计学意义(P<0.01)。结论麻黄加术汤治疗类风湿性关节炎的机制可能与降低炎性因子IL-1β、TNF-α的水平,抑制炎性细胞浸润、纤维组织增生和巨噬样A型细胞增生有关。 更多还原     

Spontaneous neurodegeneration in transgenic mice with mutant prion protein

Transgenic mice were created to assess genetic linkage between Gerstmann-Str?ussler-Scheinker syndrome and a leucine substitution at codon 102 of the human prion protein gene. Spontaneous neurologic disease with spongiform degeneration and gliosis similar to that in mouse scrapie developed at a mean age of 166 days in 35 mice expressing mouse prion protein with the leucine substitution. Thus, many of the clinical and pathological features of Gerstmann-Str?ussler-Scheinker syndrome are reproduced in transgenic mice containing a prion protein with a single amino acid substitution, illustrating that a neurodegenerative process similar to a human disease can be genetically modeled in animals.     

联合检测类风湿因子、抗角蛋白抗体及抗环瓜氨酸多肽抗体对类风湿性关节炎的诊断价值

目的探讨类风湿因子（RF）、抗角蛋白抗体（AKA）及抗环瓜氨酸多肽（CCP）抗体联合检测对类风湿性关节炎（RA）的临床诊断价值。方法对83例RA和106例非RA患者用速率散射比浊法检测RF,间接免疫荧光染色法检测AKA,酶联免疫吸附法检测抗CCP抗体,并对3种指标检测进行比较分析。结果3种抗体单独检测对RA诊断的敏感性、特异性分别是：RF为71．1％、74．5％,AKA为49．4％、95．3％,抗CCP抗体为65．1％、94．3％;不同方式联合检测对RA诊断的敏感性、特异性分别是RF＋AKA为34．9％、97．2％,RF＋抗CCP抗体为45．8％、98．1％,RF＋AKA＋抗CCP抗体为28．9％、100％;RF在AKA、抗CCP抗体分别阴性的RA患者中检出率分别为28．6％和34．5％;AKA和抗CCP抗体在RF阴性的RA患者中分别有45．8％和62．5％的阳性率。结论单独检测RF对RA诊断的敏感性最高,特异性最高的是AKA,抗CCP抗体有较高的的敏感性及特异性,3种指标各有优点,可互为补充,联合检测RF、AKA及抗CCP抗体可提高对RA诊断的特异性,有助于早期RA的诊断。     

Induction of cachexia in mice by systemically administered myostatin

Mice and cattle with genetic deficiencies in myostatin exhibit dramatic increases in skeletal muscle mass, suggesting that myostatin normally suppresses muscle growth. Whether this increased muscling results from prenatal or postnatal lack of myostatin activity is unknown. Here we show that myostatin circulates in the blood of adult mice in a latent form that can be activated by acid treatment. Systemic overexpression of myostatin in adult mice was found to induce profound muscle and fat loss analogous to that seen in human cachexia syndromes. These data indicate that myostatin acts systemically in adult animals and may be a useful pharmacologic target in clinical settings such as cachexia, where muscle growth is desired.     

Substance P activation of rheumatoid synoviocytes: neural pathway in pathogenesis of arthritis

Several clinical features are consistent with nervous system involvement in the pathogenesis of rheumatoid arthritis. The neuropeptide substance P is one possible mediator of this interaction, since it can be released into joint tissues from primary sensory nerve fibers. The potential effects of the peptide on rheumatoid synoviocytes were examined. The results show that substance P stimulates prostaglandin E2 and collagenase release from synoviocytes. Furthermore, synoviocyte proliferation was increased in the presence of the neuropeptide. Similar effects were observed with a truncated form of substance P. Synoviocytes were sensitive to very small doses of the neuropeptide (10(-9) M), and its effects were inhibited by a specific antagonist. Thus, the specific stimulation of synoviocytes by the neuropeptide substance P represents a pathway by which the nervous system might be directly involved in the pathogenesis of rheumatoid arthritis.     

Gonadotroph-specific expression of metallothionein fusion genes in pituitaries of transgenic mice

Transgenic mice expressing a metallothionein-somatostatin fusion gene contain high concentrations of somatostatin in the anterior pituitary gland, a tissue that does not normally produce somatostatin. Immunoreactive somatostatin within the anterior pituitaries was found exclusively within gonadotrophs. Similarly, a metallothionein-human growth-hormone fusion gene was also expressed selectively in gonadotrophs. It is proposed that sequences common to the two fusion genes are responsible for the gonadotroph-specific expression.