Conjugated linoleic acid prevents age-dependent neurodegeneration in a mouse model of neuropsychiatric lupus via the activation of an adaptive response

Abstract

Oxidative stress is a key mediator of autoimmune/neurodegenerative disorders. The antioxidant/anti-inflammatory effect of a synthetic conjugated linoleic acid (CLA) mixture in MRL/MpJ-Fas <i>^lpr</i> mice (MRL/<i>lpr</i>), an animal model of neuropsychiatric lupus, was previously associated with the improvement of nuclear factor-E2-related factor 2 (Nrf2) defenses in the spleen and liver. However, little is known about the neuroprotective ability of a CLA mixture. This study investigated the age-dependent progression of oxidative stress and the hyperactivation of redox-sensitive compensatory pathways (macroautophagy, Nrf2) in old/diseased MRL/<i>lpr</i> mice brains and examines the effect produced by dietary CLA supplementation. Disrupted redox homeostasis was evidenced in the blood, liver, and brain of 21- to 22-week-old MRL/<i>lpr</i> (Old) mice compared with 8- to 10-week-old MRL/<i>lpr</i> (Young) animals. This alteration was associated with significant hyperactivation of compensatory mechanisms (macroautophagy, Nrf2, and astrocyte activation) in the brains of Old mice. Five-week daily supplementation with CLA (650 mg/kg^-1 body weight) of 16-week-old (CLA+Old) mice diminished all the pathological hallmarks at a level comparable to Young mice or healthy controls (BALB/c). Such data demonstrated that MRL/<i>lpr</i> mice can serve as a valuable model for the evaluation of the effectiveness of neuroprotective drugs. Notably, the preventive effect provided by CLA supplementation against age-associated neuronal damage and hyperactivation of compensatory mechanisms suggests that the activation of an adaptive response is at least in part accountable for its neuroprotective ability.