c-Rel and p65 trans-activate the monocyte chemoattractant protein-1 gene in interleukin-1 stimulated mesangial cells

c-Rel and p65 trans-activate the monocyte chemoattractant protein-1 gene in interleukin-1 stimulated mesangial cells.BackgroundThe chemokine monocyte chemoattractant protein-1 (MCP-1) is secreted by human glomerular mesangial cells in response to interleukin-1 (IL-1) and has a central role in amplifying the inflammatory response during glomerulonephritis. However, the mechanism by which IL-1 regulates its transcription is not understood. Specific members of the nuclear factor κB/rel (NF-κB) proteins may regulate MCP-1 expression in a stimulus- and tissue-specific manner.MethodsElectrophoretic mobility shift assays and Western blot analysis characterized the members of the NF-κB family that bound the two NF-κB sites of the MCP-1 enhancer (A1 and A2) in vitro. Trans-activation of the MCP-1 gene was investigated by transfer of the MCP-1 enhancer DNA to mesangial cells.ResultsPrimary human mesangial cells contained in addition to p50 (NF-κB1) and p65 (Rel A) NF-κB proteins, the oncoprotein c-rel, and Rel B, but not p52 (NF-κB2). IL-1 induced c-rel to form a complex with p65, which bound the MCP-1 A2 site but not the A1 or IL-6 NF-κB sites in vitro. IL-1 up-regulated transfected MCP-1 enhancer activity. Cotransfer of the MCP-1 enhancer together with individual members of the NF-κB family showed that the heterodimer c-relp65 or (p65)2 can selectively trans-activate the MCP-1 gene via its A1 and A2 sites in mesangial cells.ConclusionsThis study demonstrates for the first time that the c-rel oncoprotein can enhance MCP-1 transcription in mesangial cells and suggests that it may have an important role in amplifying gene expression in the inflamed glomerulus

Increased serum HO-1 in hemophagocytic syndrome and adult-onset Still's disease: use in the differential diagnosis of hyperferritinemia

Heme oxygenase-1 (HO-1), an inducible heme-degrading enzyme, is expressed by macrophages and endothelial cells in response to various stresses. Because ferritin synthesis is stimulated by Fe(2+), which is a product of heme degradation, we examined the relation between HO-1 and ferritin levels in the serum of patients with hemophagocytic syndrome (HPS), adult-onset Still's disease (ASD), and other diseases that may cause hyperferritinemia. Seven patients with HPS, 10 with ASD, 73 with other rheumatic diseases, 20 with liver diseases, 10 recipients of repeated blood transfusion because of hematological disorders, and 22 healthy volunteers were enrolled. Serum HO-1 and ferritin levels were determined by ELISA. Expression of HO-1 mRNA and protein by peripheral blood mononuclear cells (PBMCs) was determined by real-time PCR and immunocytochemical techniques, respectively. Serum levels of HO-1 were significantly higher in patients with active HPS and ASD than in the other groups (P < 0.01). HO-1 levels were not elevated in patients with other causes of hyperferritinemia but were moderately elevated in patients with dermatomyositis/polymyositis. Among patients with HPS and ASD, serum HO-1 levels correlated closely with serum ferritin levels, and the levels of both returned to normal after therapy had induced remission. Increased expression of HO-1 mRNA was confirmed in PBMCs from some patients with HPS and ASD. Hyperferritinemia correlated closely with increased serum HO-1 in patients with HPS and ASD but not other conditions, indicating that measurement of serum HO-1 and ferritin levels would be useful in the differential diagnosis of hyperferritinemia and perhaps also in monitoring disease activity in HPS and ASD

Armadillo Repeat Containing 8α Binds to HRS and Promotes HRS Interaction with Ubiquitinated Proteins

Recently, we reported that a complex with an essential role in the degradation of Fructose-1,6-bisphosphatase in yeast is well conserved in mammalian cells; we named this mammalian complex C-terminal to the Lissencephaly type-1-like homology (CTLH) complex. Although the function of the CTLH complex remains unclear, here we used yeast two-hybrid screening to isolate Hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) as a protein binding to a key component of CTLH complex, Armadillo repeat containing 8 (ARMc8) α. The association was confirmed by a yeast two-hybrid assay and a co-immunoprecipitation assay. The proline-rich domain of HRS was essential for the association. As demonstrated through immunofluorescence microscopy, ARMc8α co-localized with HRS. ARMc8α promoted the interaction of HRS with various ubiquitinated proteins through the ubiquitin-interacting motif. These findings suggest that HRS mediates protein endosomal trafficking partly through its interaction with ARMc8α

Power Doppler ultrasonography is useful for assessing disease activity and predicting joint destruction in rheumatoid arthritis patients receiving tocilizumab—preliminary data

To evaluate the responsiveness of power Doppler ultrasonography (PDUS) in comparison with conventional measures of disease activity and structural damage in rheumatoid arthritis (RA) patients receiving tocilizumab (TCZ). Seven RA patients with active arthritis were enrolled in the study and prospectively monitored for 12 months. They were treated with TCZ (8 mg/kg) every 4 weeks as monotherapy or in combination with disease-modifying antirheumatic drugs (DMARDs). Clinical, laboratory, and ultrasound examinations were conducted at baseline, 1, 3, 6, 9, and 12 months. Power Doppler (PD) signals were graded from 0 to 3 in 24 joints, and total PD score was calculated as the sum of scores of individual joints. One-year radiographic progression of the hands was estimated by using Genant-modified Sharp scoring. The averages of the clinical parameters rapidly improved, and all patients achieved good response within 6 months based on standard 28-joint Disease Activity Score (DAS28). Although the average total PD score declined in parallel with clinical improvement, radiography of the hands showed progression of destruction in the joints where PD signals remained, even among clinical responders. ΔSharp score correlated with the time-integrated value (TIV) of total PD scores (Δtotal Sharp score: r = 0.77, P = 0.04; Δerosion: r = 0.78, P = 0.04; Δjoint-space narrowing (JSN): r = 0.75, P = 0.05), but not with TIVs of clinical parameters including DAS28. PDUS can independently evaluate disease activity in RA patients receiving TCZ and is superior to DAS28, especially in predicting joint destruction

Clinical and Pathological Roles of Ro/SSA Autoantibody System

Anti-Ro/SSA antibodies are among the most frequently detected autoantibodies against extractable nuclear antigens and have been associated with systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). Although the presence of these autoantibodies is one of the criteria for the diagnosis and classification of SS, they are also sometimes seen in other systemic autoimmune diseases. In the last few decades, the knowledge of the prevalence of anti-Ro/SSA antibodies in various autoimmune diseases and symptoms has been expanded, and the clinical importance of these antibodies is increasing. Nonetheless, the pathological role of the antibodies is still poorly understood. In this paper, we summarize the milestones of the anti-Ro/SSA autoantibody system and provide new insights into the association between the autoantibodies and the pathogenesis of autoimmune diseases