Autoantibodies to histone, DNA and nucleosome antigens in canine systemic lupus erythematosus.

Dogs can develop systemic lupus erythematosus syndromes that are clinically similar to those seen in humans. In contrast, previous observations suggest differences in their autoantibody reactivity patterns against histones and DNA which are components of the nucleosome in chromatin. The objective of this study was to assess comprehensively the levels of autoantibodies against histone, DNA and nucleosome antigens in a population of lupus dogs. The specificities of antibodies in lupus and control dog sera were determined using IgM- and IgG-specific reagents in an ELISA against a variety of chromatin antigens. When compared with control sera, IgG antibodies to individual histones H1, H2A, H3 and H4 were significantly higher in the lupus group. In contrast, we did not detect IgG antibodies specific for H2B, H2A-H2B, DNA, H2A-H2B-DNA or nucleosome in lupus dogs. There was no significant increase in any of the IgM specificities tested. Therefore, the reactivity pattern to nucleosome antigens in canine lupus is restricted to IgG antibodies against individual histones H1, H2A, H3 and H4. This stands in contrast with human and murine lupus, where autoantibodies are directed against a wide variety of nucleosomal determinants, suggesting that unique mechanisms lead to the expansion of anti-histone antibody clones in canine lupus. The high incidence of glomerulonephritis in dog lupus suggests that anti-DNA antibodies are not required for the development of this complication, whereas IgG anti-histone antibodies may be relevant to its pathogenesis.     

血清抗果蝇唾腺染色体抗体测定及临床意义探讨

以果蝇唾腺作为基质,用间接免疫荧光法检测血清抗果蝇唾腺染色体抗体[简称抗染色体抗体(Anti—chromosome antibody AchrA)]。正常人及其它风湿性疾病患者共151例,均为阴性,而系统性红斑狼疮(SLE)患者44例,AchrA阳性者占16例(36.4%)。揭示AchrA对SLE有高度特异性及一定的敏感性。对比SLE患者的AchrA及抗核抗体(ANA),双阳性占15例(34.1%),提示与两种抗体起反应的核成分不尽相同。     

IL-12 inhibits in vitro immunoglobulin production by human lupus peripheral blood mononuclear cells (PBMC)

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by polyclonal B cell activation and by the production of anti-double-stranded (ds) DNA antibodies. Given the inhibitory effects of IL-12 on humoral immune responses, we investigated whether IL-12 displayed such an activity on in vitro immunoglobulin production by SLE PBMC. Spontaneous IgG, IgG1, IgG2, IgG3 and IgM antibody production was dramatically reduced by addition of IL-12. These results were confirmed by Elispot assays detecting IgG- and anti-dsDNA-secreting cells. While IL-6 and TNF titres measured in PBMC supernatants were not modified by addition of IL-12, interferon-gamma (IFN-γ) titres were up-regulated and IL-10 production down-regulated. Since addition of IFN-γ did not down-regulate immunoglobulin production and since the inhibitory activity of IL-12 on immunoglobulin synthesis was not suppressed by anti-IFN-γ antibody, we concluded that the effect of IL-12 on immunoglobulin production was not mediated through IFN-γ. Our data also argue against the possibility that down-regulation of endogenous IL-10 production was responsible for the effect of IL-12. Thus, inhibition of IL-10 production by IFN-γ was not accompanied by inhibition of immunoglobulin production, and conversely, restoration of IL-10 production by anti-IFN-γ antibody did not suppress the inhibitory activity exerted by IL-12 on immunoglobulin production. Taken together, our data indicate that reduction of excessive immunoglobulin and anti-dsDNA antibody production by lupus PBMC can be achieved in vitro by IL-12, independently of IFN-γ and IL-10 modulation.     

Association analyses of DNA methyltransferase-1 (<Emphasis Type="Italic">DNMT1</Emphasis>) polymorphisms with systemic lupus erythematosus

The etiology of systemic lupus erythematosus (SLE) is very complex, and genetic factors appear to play a significant role in susceptibility to SLE, in determining the disease expression, and in the autoantibody profiles of individuals with SLE. DNA methyltransferase-1 (DNMT1) is a major enzyme that determines genomic methylation patterns and both maintains methyltransferase and exhibits de novo DNA methylation activity in vivo. In order to clarify the association of DNMT1 polymorphisms with SLE, we scrutinized the genetic polymorphisms in exons and their boundaries of DNMT1, including the –1,500 bp promoter region, by direct sequencing in 24 Korean individuals. Twenty-nine sequence variants were identified: two in 5UTR, six in exons, and 21 in introns. Eight of these polymorphisms were selected for a larger-scale genotyping (n=680) by considering their allele frequencies, haplotype-tagging status, and linkage disequilibrium coefficiencies (LDs) among polymorphisms. The associations between DNMT1 polymorphisms and the clinical profiles of SLE were analyzed. No significant associations with the risk of SLE were detected. However, further analyses of association with autoantibody production among SLE patients revealed that one nonsynonymous SNP, +14463G>C (V120L) in exon 4, was weakly associated with an increased risk of anti-La antibody production (P=0.04), although the significance could not be retained after correction of multiple tests. The DNMT1 variations and haplotypes clarified in this study would provide valuable information for future genetic studies of other autoimmune diseases.     

The soluble tumor necrosis factor receptor I is an early predictor of local infective complications after colorectal surgery

The clinical implications of increased cytokine levels after major surgery remain unclear. In this study, systemic concentration of a spectrum of cytokines, including interleukins IL-6, IL-8, IL-10, IL-1ra, and soluble tumor necrosis factor receptor-I (sTNF-RI) was examined in patients with and without postoperative septic complications following colorectal surgery. Although there were no significant changes in IL-1, TNF-, and IL-8 serum levels during the observation period, there was a significant rise in IL-6, IL-1ra, and sTNF-RI concentrations in the entire group of patients between postoperative day 1 and 14. There were no differences between the group without and with local complications when IL-6, IL-1ra, and IL-10 were examined. The serum levels of sTNF-RI, IL-1ra, and IL-6 were found to be sensitive indicators of the pro- and anti-inflammatory response to the surgical trauma, but only sTNF-RI turned out to be a sensitive early marker of local septic postoperative complications in patients with colorectal carcinoma.     

The B-cell activation pathway in human systemic lupus erythematosus: Imbalancedin vitro production of lymphokines and association with serum analytical findings

Recent knowledge of B-lymphocyte physiology has clarified the role of T cell-derived lymphokines in clonal proliferation and differentiation of B-cell responses. Lymphokine production was analyzed in 19 systemic lupus erythematosus (SLE) patients and sex- and age-matched controls in relation to clinical activity and steroid treatment. Whenin vitro production of interleukin-2 (IL-2) and B-cell growth factor (BCGF) was tested, both activities were found to be diminished in the group of patients (P<0.01), while B-cell differentiation factor (BCDF) activity was higher in this group with respect to normal controls (P<0.01). Interestingly enough, thisin vitro BCDF synthesis was positively correlated with clinical activity regardless of low-dose steroid treatment. A correlation was also found between BCDF production and the levels of IgG (r=0.64,P<0.01), anti-DNA antibodies (r=0.52,P<0.05), and the IgG/IgM ratio (r=0.7,P<0.01) in serum. Implications of these abnormal T-lymphocyte functions in SLE with respect toin vivo B-cell function are discussed.     

Increased expression and release of functional tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) by T cells from lupus patients with active disease

Increased expression of TRAIL in membrane-bound and soluble form in patients with systemic lupus erythematosus (SLE) has been previously reported. In this study, we characterized the upregulation of T-cell-associated and soluble TRAIL (sTRAIL) in vivo and the modulation of TRAIL expression and soluble protein release in vitro following T cell activation and IFNalpha exposure. The expression of membrane-bound TRAIL as determined by flow cytometry was higher on CD4(+) and CD8(+) T cells from lupus patients compared to controls, particularly on activated CD69(+)CD8(+) T cells. Similarly, sTRAIL levels determined by ELISA were significantly elevated in serum from patients with active SLE and correlated with levels of IFNalpha. In vitro, both T-cell-associated and sTRAIL were maximally induced by T cell activation plus IFNalpha in patients and controls. By Western blot analysis, sTRAIL was detected in sera in both the monomeric and multimeric, functional form. Both forms of TRAIL were functional in vitro as determined by Annexin V staining and (51)Cr release assay but the apoptotic activity of membrane TRAIL was 2.5-fold higher compared to that of sTRAIL. These results indicate that IFNalpha-induced enhancement of TRAIL expression and of TRAIL-mediated apoptosis may amplify the abnormal apoptotic process in SLE.     

Intramembranous fine deposit disease associated with collagen disorders: a new morphological entity?

Summary A distinct, hitherto unknown renal histopathological appearance, consisting of diffuse thickening of the glomerular basement membrane (GBM) with fine intramembranous electron-dense deposits, was observed in the renal biopsies from three patients with collagen diseases. In each case, proteinuria was mild with normal urinary sediment. On light microscopy there were no particular abnormalities but a mild thickening of the glomerular capillary wall. Immunofluorescence studies revealed faint linear or extremely fine granular IgG deposition along the capillary wall. On electron microscopy, the GBM was diffusely thickened with fine intramembranous electron-dense deposits without spike formation. No other deposits were seen in the glomerulus. These histological features resembled those of membranous glomerulonephritis (MGN), although the possibility of the early change of MGN is excluded by specific findings in these cases. Other GBM-thickening diseases such as diabetic glomerulosclerosis were ruled out clinically and histologically. Our cases have a singular renal histopathology which differs from any of the previously established classifications of glomerular lesions. It may be a specific change associated with some type of collagen disease.     

PBX1基因剪切体表达与SLE的相关研究

了解PBX1基因各种剪切体的表达在SLE患者和正常人中是否存在差异 ,探讨PBX1的表达与SLE发病的相关性。通过PCR扩增及毛细管芯片电泳 ,确证剪切体h、k、l存在于人体 ;通过实时荧光定量PCR技术 ,对剪切体h、k、l分别进行SLE患者组和正常组的mRNA表达定量比较。结果发现这 3种剪切体在患者组中的表达较正常人明显降低 ,正常人的表达是SLE的 9～ 12倍。重度患者的k、l剪切体与轻中度的病人相比表达明显降低 ,并发狼疮性肾炎的病人k剪切体的表达较无肾累及的病人显著降低。说明PBX1基因剪切体h、k、l在SLE患者中mRNA表达水平下降 ,并与SLE活动度及肾累及有关。提示机体通过PBX1的表达量的调节可能参与SLE的发病     

Power spectral analysis of the electroencephalographic and hemodynamic correlates of propofol anesthesia in the rat: Intravenous infusion

Based on the tail-flick response to noxious thermal stimuli, we determined in the present study that effective antinociception could be achieved in adult male Sprague-Dawley rats 15 min after intravenous infusion of propofol at 60 mg/kg/h. Simultaneous power spectral analysis of the electroencephalographic (EEG) and systemic arterial pressure signals further revealed a concomitant depression of the activity of all EEG frequency bands (δ, θ, , β), alongside hypotension, negative inotropic and chronotropic actions, and attenuated baroreceptor reflex and vasomotor activity. These effects were congruent with a plasma concentration of propofol in the arterial blood of 1.70 ± 0.13 μg/ml, as determined by high-performance liquid chromatography.