Leptin/OB-R signaling is elevated in mice with Sjögren's syndrome and is implicated in disease pathogenesis

Sjögren's syndrome (SjS) is a systemic autoimmune disease resulting in a severe dry mouth and dry eyes. Currently, care for patients with SjS is palliative, as no established therapeutics target the disease directly, and its pathogenetic mechanisms are uncertain. Leptin activates B cells to induce the secretion of proinflammatory and anti-inflammatory cytokines and is elevated in several autoimmune diseases. In this study, we found the expression of leptin and its receptor OB-R in mouse models of SjS are elevated both locally and systemically during SjS progression. Recombinant serotype 2 adeno-associated viral (rAAV2) vectors expressing either OB-R shRNA (rAAV2-shOB-R) or none (rAAV2-null) were injected into 4 or 16 week-old BALB/c NOD/LtJ (NOD) mice and resulted in a modest reduction in glandular inflammation in the SjS model. In conclusion, Leptin/OB-R signaling may be pathogenically involved in SjS and may serve as a new marker and a potential therapeutic target.