Therapeutic Potential Of Peptidomimetics of Suppressors Of Cytokine Signaling (SOCS) proteins In Rheumatic Disorders

Daniela Marasco^1*Alessia Cugudda²

• ¹University of Naples Federico II, Naples, Italy
• ²Universita degli Studi di Napoli Federico II, Naples, Italy

Dysregulation of the Janus Kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway is increasingly recognized as a central molecular hallmark in the pathogenesis of multiple rheumatic diseases. Suppressors of Cytokine Signaling (SOCS) proteins function as critical intracellular inhibitors of JAK/STAT signaling through a classical negative feedback mechanism. In Rheumatoid Arthritis (RA), aberrant upregulation of SOCS1 and SOCS3 has been documented in peripheral blood T lymphocytes, monocytes, and synovial tissues, with expression levels correlating with disease activity and progression. Notably, diminished basal expression of SOCS1 mRNA is associated with poor therapeutic response to methotrexate or rituximab, and specific SOCS1 polymorphisms have been genetically linked to RA susceptibility. In Ankylosing Spondylitis (AS), enhanced SOCS3 expression in Peripheral Blood Mononuclear Cells (PBMCs), CD4⁺ T cells, and monocytes show positive correlation with systemic inflammatory markers such as Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP), as well as with clinical indices of functional impairment. Conversely, SOCS1 expression is attenuated in T cells during phases of low-grade inflammation, suggesting context-dependent regulatory dynamics. In drug discovery for inflammatory diseases, recent advances have focused on the development of SOCS peptidomimetics, particularly those derived from the Kinase Inhibitory Region (KIR) of SOCS1, as novel immunomodulatory agents. Herein, we propose that peptidomimetics of SOCSs may represent a new frontier in the precise modulation of JAK/STAT signaling, offering a promising avenue toward personalized prevention and treatment of rheumatic pathologies.