Accelerated ageing profile in inflammatory arthritis is unique and tissue compartment specific.

ABSTRACT

Rheumatoid arthritis is prevalent in more than 1% of the global population, with the highest occurrence between ages 35 and 50, which places a huge burden on the economy. Drug discovery for the prevention of this chronic disease is; therefore, a priority. It is known that subclinical progression of many chronic non-communicable diseases is exacerbated via accelerated ageing, a pro-inflammatory phenotype shift. However, rheumatoid arthritis additionally has significant humoral immune activation, inflammatory signalling-and thus the accelerated ageing profile-may differ from other chronic inflammatory diseases. The current study simulated inflammatory arthritis onset in a collagen-induced arthritis (CIA) rodent model, to characterise the redox and inflammatory profile at the onset of clinical symptoms, in different tissues, in the presence and absence of preventative antioxidant treatment. The data illustrate that an increased free radical level are evident already very early on in RA disease progression. Furthermore, oxidative stress seems to somewhat precede a significant pro-inflammatory state, perhaps due to humoral immune activation. Our data across different compartments further suggest that the compensatory increase in endogenous antioxidant activity is gradually exhausted at a different pace, with the liver showing the first signs of oxidant damage, even before significant evidence exist in circulation. The current data further suggest that preventative antioxidant intervention may have a sparing effect on endogenous antioxidant mechanisms and preserve telomere length to delay disease progression-or at least the accelerated ageing known to exacerbate RA symptoms-although it did not seem to have a significant direct effect on the autoimmune activity.