Distinct serum proteome profiles associated with collagen‐induced arthritis and complete Freund's adjuvant‐induced inflammation in CD38−/− mice: The discriminative power of protein species or proteoforms

Collagen‐type‐II‐induced arthritis (CIA) is an autoimmune disease, which involves a complex host systemic response including inflammatory and autoimmune reactions. CIA is milder in CD38^?/? than in wild‐type (WT) mice. ProteoMiner‐equalized serum samples were subjected to 2D‐DiGE and MS‐MALDI‐TOF/TOF analyses to identify proteins that changed in their relative abundances in CD38^?/? versus WT mice either with arthritis (CIA⁺), with no arthritis (CIA^?), or with inflammation (complete Freund's adjuvant (CFA)‐treated mice). Multivariate analyses revealed that a multiprotein signature (n = 28) was able to discriminate CIA⁺ from CIA^? mice, and WT from CD38^?/? mice within each condition. Likewise, a distinct multiprotein signature (n = 16) was identified which differentiated CIA⁺ CD38^?/? mice from CIA⁺ WT mice, and lastly, a third multiprotein signature (n = 18) indicated that CD38^?/? and WT mice could be segregated in response to CFA treatment. Further analyses showed that the discriminative power to distinguish these groups was reached at protein species level and not at the protein level. Hence, the need to identify and quantify proteins at protein species level to better correlate proteome changes with disease processes. It is crucial for plasma proteomics at the low‐abundance protein species level to apply the ProteoMiner enrichment. All MS data have been deposited in the ProteomeXchange with identifiers PXD001788, PXD001799 and PXD002071 ( http://proteomecentral.proteomexchange.org/dataset/PXD001788 , http://proteomecentral.proteomexchange.org/dataset/PXD001799 and http://proteomecentral.proteomexchange.org/dataset/PXD002071 ).     

寄生虫治疗类风湿关节炎研究进展

在西方国家自身免疫性疾病的发病率增高,这可能是因为卫生条件改善,儿童时期感染的几率下降(卫生假说)。目前寄生虫感染是预防还是促进自身免疫性疾病还在讨论中。多种寄生虫用于不同的动物模型显示了其在多种疾病中限制疾病活动的能力,包括炎性肠病、多发硬化、1型糖尿病、类风湿关节炎和系统性红斑狼疮。目前大多数研究还在动物实验阶段,然而已经有一些临床试验在进行中。因此本文回顾了评估寄生虫的抗炎作用的几个临床试验及针对类风湿关节炎的动物实验。寄生虫诱导免疫调节的主要途径是抑制IFN-γ和IL-17产生,促进IL-4、IL-10和TGF-β释放,诱导CD4+T细胞Fox P3表达及调节性巨噬细胞细胞、树突状细胞和B细胞产生,然而寄生虫调节自身免疫性疾病的机制尚不完全清楚。目前寄生虫治疗类风湿关节炎在动物实验方面已经取得一定进展,进一步的研究是针对寄生虫调节免疫反应的有效成分模拟的人造类似物。     

Biochemical analysis of matrix metalloproteinase activation of chemokines CCL15 and CCL23 and increased glycosaminoglycan binding of CCL16

Leukocyte migration and activation is orchestrated by chemokines, the cleavage of which modulates their activity and glycosaminoglycan binding and thus their roles in inflammation and immunity. Early research identified proteolysis as a means of both activating or inactivating CXC chemokines and inactivating CC chemokines. Recent evidence has shown activating cleavages of the monocyte chemoattractants CCL15 and CCL23 by incubation with synovial fluid, although the responsible proteases could not be identified. Herein we show that CCL15 is processed in human synovial fluid by matrix metalloproteinases (MMPs) and serine proteases. Furthermore, a family-wide investigation of MMP processing of all 14 monocyte-directed CC chemokines revealed that each is precisely cleaved by one or more MMPs. By MALDI-TOF-MS, 149 cleavage sites were sequenced including the first reported instance of CCL1, CCL16, and CCL17 proteolysis. Full-length CCL15-(1-92) and CCL23-(1-99) were cleaved within their unique 31 and 32-amino acid residue extended amino termini, respectively. Unlike other CCL chemokines that lose activity and become receptor antagonists upon MMP cleavage, the prominent MMP-processed products CCL15-(25-92, 28-92) and CCL23-(26-99) are stronger agonists in calcium flux and Transwell CC receptor transfectant and monocytic THP-1 migration assays. MMP processing of CCL16-(1-97) in its extended carboxyl terminus yields two products, CCL16-(8-77) and CCL16-(8-85), with both showing unexpected enhanced glycosaminoglycan binding. Hence, our study reveals for the first time that MMPs activate the long amino-terminal chemokines CCL15 and CCL23 to potent forms that have potential to increase monocyte recruitment during inflammation.     

Near-infrared imaging of flare-up arthritis with native fluorochrome Cy5.5 and albumin-bound Cy5.5

The aim of the study was to visualize chronic experimental arthritis with near-infrared fluorescence imaging (NIRF) in a murine experimental arthritis model of rheumatoid arthritis (RA) (flare-up arthritis). The flare-up arthritis model is a modification of the primary antigen-induced arthritis (AIA) model. NIRF was done for two preparations of the fluorochrome Cy5.5, one native and the other albumin conjugated. Histological features of flare-up arthritis were evaluated.AIA was induced in 16 mice (strain C57/Bl6); flare-up arthritis was induced in a subgroup of eight. On day 7 after induction of flare-up arthritis, four mice received 50 nmol/kg native dye and four mice equimolar concentrations of the dye as albumin-dye conjugate intravenously. NIRF imaging was performed immediately before injection (baseline) and until 72 h thereafter. Arthritis severity was evaluated histologically for primary AIA and flare-up arthritis mice.NIRF imaging revealed higher fluorochrome uptake in all inflamed knees compared to contralateral ones. The signal intensities induced by native Cy5.5 were higher than those generated by albumin-Cy5.5 conjugate. Histological evaluation of arthritic joints showed similar abnormalities in flare-up arthritis and in primary AIA joints.Imaging of flare-up arthritis in the near-infrared range was successful for both fluorochrome preparations, but albumin conjugation prior to injection does not improve the uptake of dye in arthritic joints. Flare-up arthritis is a feasible model of chronic relapse of arthritis in human RA.     

The Escherichia coli heat shock protease HtrA participates in defense against oxidative stress

The serine protease HtrA (DegP), which is indispensable for cell survival at elevated temperatures, is a peripheral membrane protein, localized on the periplasmic side of the inner membrane in Escherichia coli, and the biochemical and genetic evidence indicates that the physiological role of HtrA is to degrade denatured proteins formed in the cellular envelope during heat shock. The aim of this study was to find out if the HtrA protease contributes to protection of the cell against oxidative stress. We compared the influence of various oxidizing agents on htrA mutant cells with their effects on wild-type bacteria, and found that the htrA mutation did not increase sensitivity to hydrogen peroxide or paraquat but made the cell extremely sensitive to ferrous [Fe(II)] ions, which are known to enhance oxidation of proteins. Treatment with ferrous ions caused a larger increase in the level of protein carbonyl groups in the membrane fraction of the cell than in the periplasm and cytoplasm. Iron-induced oxidation of membrane proteins was enhanced in the htrA mutant relative to wild-type cells. Inhibition of the growth of the htrA mutant by iron could be alleviated more efficiently by a nitroxide antioxidant that localizes in the membranes (A-TEMPO) than by a derivative (4OH-TEMPO) that acts mainly in the soluble fraction of the cell. Inhibition of the growth of the htrA mutant was more pronounced following treatment with cumene hydroperoxide, which partitions into membranes, than with t-butyl hydroperoxide, which forms radical mainly in the cytosol. Both ferrous ions and cumene hydroperoxide, but not hydrogen peroxide, paraquat or t-butyl hydroperoxide, induced synthesis of HtrA. Our results show that HtrA plays a role in defense against oxidative shock and support the hypothesis that HtrA participates in the degradation of oxidatively damaged proteins localized in the cell envelope, especially those associated with the membranes. Received: 9 March 1999 / Accepted: 31 May 1999     

Successful genetic transduction in vivo into synovium by means of electroporation

This present study aims at establishing a novel in vivo gene delivery system for intra-articular tissues. Plasmid DNA (pDNA) carrying the firefly luciferase or enhanced green fluorescent protein (EGFP) genes as markers was injected into a joint space and electric stimuli were given percutaneously with a pair of electrodes. Injection with naked pDNA alone did not induce any detectable level of luciferase activity, whereas electroporation at 25-500 V/0.7 cm resulted in a significant expression of the marker gene in the synovium. The expression level depended on the voltage, the optimum transfection being achieved at 150 V/0.7 cm. When the Epstein-Barr virus (EBV)-based plasmid vectors harboring the EBV nuclear antigen 1 (EBNA1) gene and oriP sequence were substituted for conventional pDNA, the transfection efficiency was increased approximately 5-10 times. Histological examination of the EGFP gene-transfected joints revealed that the marker gene was expressed in the synovial membrane while other intra-articular tissues such as articular cartilage were negative for the transgene product. Transgene-specific mRNA was demonstrated in synovium but not in other organs as estimated by RT-PCR analysis. The present results strongly suggest that in vivo electroporation is a quite simple, safe, and effective gene delivery method that could be applicable to gene therapy against articular diseases.     

Diffuse idiopathic skeletal hyperostosis in Meroitic Nubians from Semna South,Sudan

The paleopathological study of human osteological remains from the site of Semna South, of northern Sudan, revealed that about thirteen percent of this ancient Nubian population had diffuse idiopathic skeletal hyperostosis (DISH). As in modern cases, males were more affected than females. Two thousand years ago, ancient Nubian males had the same spinal problems elderly men have today. © 1993 Wiley-Liss, Inc.     

Solubilization and assay of an hepatic receptor for the haptoglobin-hemoglobin complex

Hemoglobin released into the bloodstream is tightly bound by haptoglobin. The resulting complex (HpHb) is promptly cleared from the circulation and accumulates in the liver. A binding protein with a high affinity for HpHb has been solubilized from an acetone powder of rat liver and freed from an endogenous inhibitor by passage over a column of immobilized hemoglobin. An assay procedure has been developed whereby the bound HpHb is selectively precipitated by polyethylene glycol 6000. Employing this assay, the binding reaction was shown to be linear and saturable with respect to the ligand. In contrast to several previously described receptors for glycoproteins, the carbohydrate moiety of haptoglobin did not appear to participate in the binding of HpHb by the soluble receptor.     

N-Acyl derivatives of glucosamine as acceptor substrates for galactosyltransferase from bone and cartilage cells

Glucosamine is commonly used as a nutraceutical by arthritis patients. However, its mode of action is still unknown, and there is controversy about its clinical efficacy. Synthetic N-acyl glucosamines (acyl group>2 carbons) comprise a new class of drugs. We examined these derivatives for their effect in bone and cartilage cells, and for their ability to serve as acceptor substrates for galactosyltransferase. With the exception of N-benzoylglucosamine, compounds of the series were good substrates for galactosyltransferases from bone and cartilage cells, and for purified enzyme from bovine milk. When N-butyrylglucosamine (GlcNBu) was added to the cell medium of primary bovine chondrocytes and human osteoblasts, small amounts were found to enter the cells and a radiolabeled metabolite appeared in the medium. However, GlcNBu did not appear to be incorporated directly into oligosaccharides. GlcNBu at 1 and 5mM concentrations in the glucose-free cell medium of primary human osteoblasts from osteoarthritis patients did not significantly alter cell proliferation or cell differentiation.     

Ncf1 (p47phox) polymorphism determines oxidative burst and the severity of arthritis in rats and mice

Identifying genes that regulate polygenic diseases influenced by the environment such as rheumatoid arthritis (RA), has so far proven to be difficult. By using an alternative approach, i.e., linkage analysis using relevant animal models we succeeded in finding the Ncf1 gene residing in the Pia4 quantitative trait locus to be responsible for the severity of pristane induced arthritis in rats. The influence of another mutation in the mouse Ncf1 gene showed the same association between decreased oxidative burst and enhanced arthritis. In this case the mutation affected a splice site giving a non-detectable oxidative burst response and enhanced collagen induced arthritis as well as myelin oligodendrocyte protein induced experimental autoimmune encephalomyelitis. These findings open up new possibilities for new treatments for autoimmune diseases, i.e., RA, targeting the NADPH oxidase pathway.