Peripheral blood mononuclear cells show markers of mitochondrial dysfunction in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Metabolic and mitochondrial dysregulation are critical causal factors in the pathogenesis and progression of RA. Mitochondrial dysfunction include abnormal energy metabolism, and excessive production of reactive oxygen species (ROS). This study aimed to investigate the adenosine triphosphate (ATP), mitochondrial membrane potential (ΔΨm), ROS, and mRNA expression level of ROMO1 (as ROS modulator) and OMA1 (as regulator mitochondrial dynamics) of peripheral blood mononuclear cells (PBMC) in RA patients. The study participants were 50 patients with RA and 50 sex- and age-matched healthy volunteers. PBMC of all participant were isolated by Ficoll-Paque. Alteration in ΔΨm and cellular ROS were measured using flow cytometry, ATP level was also assessed via luminometry, and ROMO1 and OMA1 mRNA expression via qRT-PCR assay. A significant decrease in ATP (p = .005) and ΔΨm (p < .001) was observed in the PBMC of RA compared to control. The ROS levels were significantly higher in the PBMC of RA compared to the control (p < .001). ROMO1 and OMA1 mRNA expression was also significantly increased in RA patients compared to control (p < .001). The decrease in ATP is strongly associated with ROS increasing in PBMC of RA patients, denoting an inverse and negative relationship between ATP and ROS production. Also, a decrease in ΔΨm was observed. It seems that in line with mitochondrial dysfunction in PBMC, increased expression of ROMO1 and OMA1 genes could also be involved in the development of RA.