ABSTRACT
Histone lysine methylation is thought to play a role in the pathogenesis of rheumatoid arthritis (RA). We previously reported aberrant expression of the gene encoding mixed-lineage leukemia 1 (MLL1), which catalyzes methylation of histone H3 lysine 4 (H3K4), in RA synovial fibroblasts (SFs). The aim of this study was to elucidate the involvement of MLL1 in the activated phenotype of RASFs. SFs were isolated from synovial tissues obtained from patients with RA or osteoarthritis (OA) during total knee joint replacement. MLL1 mRNA and protein levels were determined after stimulation with tumor necrosis factor α (TNFα). We also examined changes in trimethylation of H3K4 (H3K4me3) levels in the promoters of RA-associated genes (matrix-degrading enzymes, cytokines, and chemokines) and the mRNA levels upon small interfering RNA-mediated depletion of MLL1 in RASFs. We then determined the levels of H3K4me3 and mRNAs following treatment with the WD repeat domain 5 (WDR5)/MLL1 inhibitor MM-102. H3K4me3 levels in the gene promoters were also compared between RASFs and OASFs. After TNFα stimulation, MLL1 mRNA and protein levels were higher in RASFs than OASFs. Silencing of MLL1 significantly reduced H3K4me3 levels in the promoters of several cytokine (interleukin-6 [IL-6], IL-15) and chemokine (C-C motif chemokine ligand 2 [CCL2], CCL5, C-X-C motif chemokine ligand 9 [CXCL9], CXCL10, CXCL11, and C-X3-C motif chemokine ligand 1 [CX3CL1]) genes in RASFs. Correspondingly, the mRNA levels of these genes were significantly decreased. MM-102 significantly reduced the promoter H3K4me3 and mRNA levels of the CCL5, CXCL9, CXCL10, and CXCL11 genes in RASFs. In addition, H3K4me3 levels in the promoters of the IL-6, IL-15, CCL2, CCL5, CXCL9, CXCL10, CXCL11, and CX3CL1 genes were significantly higher in RASFs than OASFs. Our findings suggest that MLL1 regulates the expression of particular cytokines and chemokines in RASFs and is associated with the pathogenesis of RA. These results could lead to new therapies for RA.
Subject(s)
Arthritis, Rheumatoid , Histone-Lysine N-Methyltransferase , Myeloid-Lymphoid Leukemia Protein , Synovial Membrane , Aged , Female , Humans , Male , Middle Aged , Arthritis, Rheumatoid/metabolism , Arthritis, Rheumatoid/pathology , Arthritis, Rheumatoid/genetics , Cells, Cultured , Chemokines/metabolism , Chemokines/genetics , Cytokines/metabolism , Fibroblasts/metabolism , Gene Expression Regulation , Histone-Lysine N-Methyltransferase/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histones/metabolism , Myeloid-Lymphoid Leukemia Protein/metabolism , Myeloid-Lymphoid Leukemia Protein/genetics , Osteoarthritis/metabolism , Osteoarthritis/pathology , Osteoarthritis/genetics , Promoter Regions, Genetic , RNA, Messenger/metabolism , RNA, Messenger/genetics , Synovial Membrane/metabolism , Synovial Membrane/pathology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Malignant syphilis (MS) is a rare variant of secondary syphilis. Also known as rupioid syphilis, MS is characterized by the presence of multiple papules, papulopustules, black lamellate crust that may resemble an oyster shell, or nodules with ulceration lacking central clearing. MS is often associated with immunodeficiency and frequently co-occurs with HIV infection. We here report a case of MS in a patient with HIV infection. HIV infection can cause atypical clinical symptoms of syphilis. In this case, unlike previous cases, cutaneous lesions of MS were limited to the face, making the diagnosis challenging based on clinical findings alone. However, his laboratory findings, appearance of the Jarisch-Herxheimer reaction, and a dramatic response to antibiotic therapy are characteristic of MS, making the diagnosis even more certain. Our case suggests the importance of physicians considering the possibility of MS when observing black-crusted lesions.
ABSTRACT
Aims: Atrial fibrillation (AF) increases the risk of heart failure (HF); however, little is known regarding the risk stratification for incident HF in AF patients, especially with preserved left ventricular ejection fraction (LVEF). Methods and results: The Fushimi AF Registry is a community-based prospective survey of AF patients. From the registry, 3002 non-valvular AF patients with preserved LVEF and with the data of antero-posterior left atrial diameter (LAD) at enrolment were investigated. Patients were stratified by LAD (<40, 40-44, 45-49, and ≥50â mm) with backgrounds and HF hospitalization incidences compared between groups. Of 3002 patients [mean age, 73.5 ± 10.7 years; women, 1226 (41%); paroxysmal AF, 1579 (53%); and mean CHA2DS2-VASc score, 3.3 ± 1.7], the mean LAD was 43 ± 8â mm. Patients with larger LAD were older and less often paroxysmal AF, with a higher CHA2DS2-VASc score (all P < 0.001). Heart failure hospitalization occurred in 412 patients during the median follow-up period of 6.0 years. Larger LAD was independently associated with a higher HF hospitalization risk [LAD ≥ 50â mm: hazard ratio (HR), 2.36; 95% confidence interval (CI), 1.75-3.18; LAD 45-49â mm: HR, 1.84; 95% CI, 1.37-2.46; and LAD 40-44â mm: HR, 1.34; 95% CI, 1.01-1.78, compared with LAD < 40â mm) after adjustment by age, sex, AF type, and CHA2DS2-VASc score. These results were also consistent across major subgroups, showing no significant interaction. Conclusion: Left atrial diameter is significantly associated with the risk of incident HF in AF patients with preserved LVEF, suggesting the utility of LAD regarding HF risk stratification for these patients.
