Psoriasis-like skin disease and arthritis caused by inducible epidermal deletion of Jun proteins

Psoriasis is a frequent, inflammatory disease of skin and joints with considerable morbidity. Here we report that in psoriatic lesions, epidermal keratinocytes have decreased expression of JunB, a gene localized in the psoriasis susceptibility region PSORS6. Likewise, inducible epidermal deletion of JunB and its functional companion c-Jun in adult mice leads (within two weeks) to a phenotype resembling the histological and molecular hallmarks of psoriasis, including arthritic lesions. In contrast to the skin phenotype, the development of arthritic lesions requires T and B cells and signalling through tumour necrosis factor receptor 1 (TNFR1). Prior to the disease onset, two chemotactic proteins (S100A8 and S100A9) previously mapped to the psoriasis susceptibility region PSORS4, are strongly induced in mutant keratinocytes in vivo and in vitro. We propose that the abrogation of JunB/activator protein 1 (AP-1) in keratinocytes triggers chemokine/cytokine expression, which recruits neutrophils and macrophages to the epidermis thereby contributing to the phenotypic changes observed in psoriasis. Thus, these data support the hypothesis that epidermal alterations are sufficient to initiate both skin lesions and arthritis in psoriasis.     

Warm-coding deficits and aberrant inflammatory pain in mice lacking P2X3 receptors

ATP activates damage-sensing neurons (nociceptors) and can evoke a sensation of pain. The ATP receptor P2X3 is selectively expressed by nociceptors and is one of seven ATP-gated, cation-selective ion channels. Here we demonstrate that ablation of the P2X3 gene results in the loss of rapidly desensitizing ATP-gated cation currents in dorsal root ganglion neurons, and that the responses of nodose ganglion neurons to ATP show altered kinetics and pharmacology resulting from the loss of expression of P2X(2/3) heteromultimers. Null mutants have normal sensorimotor function. Behavioural responses to noxious mechanical and thermal stimuli are also normal, although formalin-induced pain behaviour is reduced. In contrast, deletion of the P2X3 receptor causes enhanced thermal hyperalgesia in chronic inflammation. Notably, although dorsal-horn neuronal responses to mechanical and noxious heat application are normal, P2X3-null mice are unable to code the intensity of non-noxious 'warming' stimuli.     

小鼠同种异基因皮肤移植模型的建立

目的：为移植免疫及药物免疫机理研究建立小鼠同种异基因皮肤移植动物模型。方法：受体BALB/c分为A～E共5组,即对照组,5．0、7．5、10、20mg／kg环孢菌素A(CsA)剂量组,通过背-背法进行C57BL／6的全厚皮皮片移植,以探求通过较小剂量CsA及优化实验条件和护理方式建立供免疫机理研究的动物试验平台。结果：5．0、7．5、10mg/kg组相对于对照组皮片排斥时间无明显差别,而20mg/kg组植皮能较长时间存活。结论：20mg／kg的CsA剂量可以经济,快速地建立小鼠同种异基因移植动物模型。     

淫羊藿甙对小鼠同种异基因皮片移植的影响

目的:研究淫羊藿甙(ICA)对小鼠同种异基因皮片移植的影响.方法:试验分为腹腔注射生理盐水、ICA、环孢素A(CsA)以及CsA与ICA联用4组,5 d后将C57BL/C小鼠的背部皮片移植到BALB/c小鼠的相同位置,用眼科缝合线缝合,观察皮片愈合情况并记录皮片外观性状、排斥时间,于第11天取移植皮片做病理石蜡切片,取淋巴结细胞和脾细胞做增殖实验(CFDA-SE染色).结果:CsA+ICA联用能够延长皮片排斥时间,使皮片愈合得更好,胸腺和脾脏指数均比单独CsA组高,切片显示浸润的炎症细胞也较少,其淋巴结细胞增殖能力明显降低.结论:CsA与ICA联合能抑制移植造成的免疫排斥反应,可能是通过抑制受体小鼠的反应性T细胞的活化增殖来降低细胞免疫反应.     

Bovine papillomavirus genome elicits skin tumours in transgenic mice

Transmission of the bovine papillomavirus-1 (BPV-1) genome through the mouse germ line results in the heritable formation of fibropapillomas of the skin, a tissue-specific phenotype analogous to that observed in natural BPV-1 infection of cattle. Oncogenesis is slow, with tumours first arising at 8-9 months of age, usually in areas prone to wounding. Extrachromosomal BPV-1 DNA is detected in all tumours, whereas normal tissues show only integrated DNA.     

Genetics and pathogenesis of inflammatory bowel disease

Recent advances have provided substantial insight into the maintenance of mucosal immunity and the pathogenesis of inflammatory bowel disease. Cellular programs responsible for intestinal homeostasis use diverse intracellular and intercellular networks to promote immune tolerance, inflammation or epithelial restitution. Complex interfaces integrate local host and microbial signals to activate appropriate effector programs selectively and even drive plasticity between these programs. In addition, genetic studies and mouse models have emphasized the role of genetic predispositions and how they affect interactions with microbial and environmental factors, leading to pro-colitogenic perturbations of the host-commensal relationship.     

Unravelling the pathogenesis of inflammatory bowel disease

Recently, substantial advances in the understanding of the molecular pathogenesis of inflammatory bowel disease (IBD) have been made owing to three related lines of investigation. First, IBD has been found to be the most tractable of complex disorders for discovering susceptibility genes, and these have shown the importance of epithelial barrier function, and innate and adaptive immunity in disease pathogenesis. Second, efforts directed towards the identification of environmental factors implicate commensal bacteria (or their products), rather than conventional pathogens, as drivers of dysregulated immunity and IBD. Third, murine models, which exhibit many of the features of ulcerative colitis and seem to be bacteria-driven, have helped unravel the pathogenesis/mucosal immunopathology of IBD.     

Intestinal homeostasis and its breakdown in inflammatory bowel disease

Intestinal homeostasis depends on complex interactions between the microbiota, the intestinal epithelium and the host immune system. Diverse regulatory mechanisms cooperate to maintain intestinal homeostasis, and a breakdown in these pathways may precipitate the chronic inflammatory pathology found in inflammatory bowel disease. It is now evident that immune effector modules that drive intestinal inflammation are conserved across innate and adaptive leukocytes and can be controlled by host regulatory cells. Recent evidence suggests that several factors may tip the balance between homeostasis and intestinal inflammation, presenting future challenges for the development of new therapies for inflammatory bowel disease.     

Tolerance in T-cell-receptor transgenic mice involves deletion of nonmature CD4+8+ thymocytes

The mechanism of self-tolerance is studied in T-cell-receptor transgenic mice expressing a receptor in many of their T cells for the male (H-Y) antigen in the context of class I H-2Db MHC antigens. Autospecific T cells are deleted in male mice. The deletion affects only transgene-expressing cells with a relatively high surface-density of CD8 molecules, including nonmature CD4+ CD8+ thymocytes, and is not caused by anti-idiotype cells.     

图多彩染色中的2度点删除问题

对整数r0,图G的一个r-多彩染色是一个从顶点集V(G)到数集{1,2,…,k}的映射c,使得:(C1)相邻点获得的颜色不同;(C2)︱c(N(v))︱≥min{N(v),r}(其中N(v)代表v的邻点集)。使图G有一个正常的(k,r)-染色的最小k值称为G的多彩色数χ_r(G)。本文主要研究在图G中删掉任意一个2度点后多彩色数的变化。     

Resistance to therapy caused by intragenic deletion in BRCA2

Cells with loss of BRCA2 function are defective in homologous recombination (HR) and are highly sensitive to inhibitors of poly(ADP-ribose) polymerase (PARP), which provides the basis for a new therapeutic approach. Here we show that resistance to PARP inhibition can be acquired by deletion of a mutation in BRCA2. We derived PARP-inhibitor-resistant (PIR) clones from the human CAPAN1 pancreatic cancer cell line, which carries the protein-truncating c.6174delT frameshift mutation. PIR clones could form DNA-damage-induced RAD51 nuclear foci and were able to limit genotoxin-induced genomic instability, both hallmarks of a competent HR pathway. New BRCA2 isoforms were expressed in the resistant lines as a result of intragenic deletion of the c.6174delT mutation and restoration of the open reading frame (ORF). Reconstitution of BRCA2-deficient cells with these revertant BRCA2 alleles rescued PARP inhibitor sensitivity and HR deficiency. Most of the deletions in BRCA2 were associated with small tracts of homology, and possibly arose from error-prone repair caused by BRCA2 deficiency. Similar ORF-restoring mutations were present in carboplatin-resistant ovarian tumours from c.6174delT mutation carriers. These observations have implications for understanding drug resistance in BRCA mutation carriers as well as in defining functionally important domains within BRCA2.     

RDP-p53融合蛋白对小鼠炎症细胞因子的影响

研究不同剂量RDP-p53融合蛋白对小鼠炎症细胞因子的影响。通过大肠杆菌Rosetta表达蛋白并纯化,SDS-PAGE确定RDP-p53融合蛋白准确性。同时,将昆明小鼠分为空白对照组和RDP-p53融合蛋白高、中、低剂量组,经腹腔注射给药,摘眼球取血,用酶联免疫吸附法(ELISA)测定血清中白细胞介素1β(IL-1β)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)的含量。RDP-p53融合蛋白在上清和沉淀中均获得表达。ELISA测定结果表明,与对照组比较,低、中剂量组小鼠血清炎症因子水平没有明显变化(P0.05),高剂量组的IL-1β和TNF-α含量显著升高(P0.05)。成功制备RDP-P53融合蛋白,并为进一步研究RDP-p53融合蛋白抗神经胶质瘤药理作用时给药剂量的确定提供了实验依据。