Eruptions in life-threatening rheumatologic diseases

Clinical and autoantibody profile in male and female patients with systemic lupus erythematosus: A retrospective study in 603 Brazilian patients

OBJECTIVE

Sex and ethnic background may influence the clinical and autoantibody profile in systemic lupus erythematosus (SLE). This retrospective study aimed to compare the clinical and autoantibody profiles of male and female patients with SLE in a sample of Brazilian patients.

METHODS

This was a retrospective study of 603 patients (48 males and 555 females) from a single rheumatology center. Collected clinical data included clinical findings according to the definition of 2012 Systemic Lupus International Collaborating Clinics classification criteria, the presence of antiphospholipid antibody syndrome according to the Sydney classification criteria and autoantibody profile (anti-dsDNA, anti-Ro, anti-La, anti-Sm, anti-RNP, rheumatoid factor, anticardiolipin [aCl] IgG, aCl IgM, lupus anticoagulant, and direct antiglobulin test), and histological results of kidney biopsies.

RESULTS

It was found that females had higher age at disease onset (p=0.02), more oral ulcers (p=0.001), and presented more often with alopecia (p<0.0001) than males. Males had a higher prevalence of glomerulonephritis (OR=6.5; 95%CI=3.0-13.7) and anti-dsDNA (OR=2.59; 95%CI=1.38-4.85) than females, but no differences were found in the pattern of renal biopsies (p=0.46).

CONCLUSION

In this sample of Brazilian patients, the males had more renal involvement, fewer oral ulcers, and presented fewer times with alopecia than females.

Mst1 promotes mitochondrial dysfunction and apoptosis in oxidative stress-induced rheumatoid arthritis synoviocytes

In this study, we investigated the role of macrophage stimulating 1 (Mst1) and the AMPK-Sirt1 signaling pathway in the oxidative stress-induced mitochondrial dysfunction and apoptosis seen in rheumatoid arthritis-related fibroblast-like synoviocytes (RA-FLSs). Mst1 mRNA and protein expression was significantly higher in hydrogen peroxide (H₂O₂)-treated RA-FLSs than untreated controls. H₂O₂ treatment induced the mitochondrial apoptotic pathway by activating caspase3/9 and Bax in the RA-FLSs. Moreover, H₂O₂ treatment significantly reduced mitochondrial membrane potential and mitochondrial state-3 and state-4 respiration, but increased reactive oxygen species (ROS). Mst1 silencing significantly reduced oxidative stress-induced mitochondrial dysfunction and apoptosis in RA-FLSs. Sirt1 expression was significantly reduced in the H₂O₂-treated RA-FLSs, but was higher in the H₂O₂-treated Mst1-silenced RA-FLSs. Pretreatment with selisistat (Sirt1-specific inhibitor) or compound C (AMPK antagonist) significantly reduced the viability and mitochondrial function in H₂O₂-treated Mst1-silenced RA-FLSs by inhibiting Sirt1 function or Sirt1 expression, respectively. These findings demonstrate that oxidative stress-related upregulation and activation of Mst1 promotes mitochondrial dysfunction and apoptosis in RA-FLSs by inhibiting the AMPK-Sirt1 signaling pathway. This suggests the Mst1-AMPK-Sirt1 axis is a potential target for RA therapy.