Cortistatin

Cortistatin is a neuropeptide belonging to the somatostatin family, existing in three biologically active isoforms: CST-14, CST-17, and CST-29. It shares 11 of 14 amino acids with somatostatin-14 yet is encoded by a separate gene. Cortistatin binds all five somatostatin receptors and additionally activates the ghrelin receptor (GHSR1a) and MrgX2. It exerts potent anti-inflammatory effects in experimental colitis, arthritis, and sepsis models, distinguishing it from somatostatin by its broader receptor profile and immunomodulatory potency.

Cortistatin's anti-inflammatory actions are mediated through multiple converging pathways. Binding to somatostatin receptors (particularly SSTR2/3/5) suppresses cAMP, reducing inflammatory cytokine production (TNF-α, IL-1β, IL-6, IL-12, IFN-γ, IL-17). Activation of GHSR1a on macrophages and dendritic cells shifts cytokine balance toward anti-inflammatory profiles. Cortistatin also inhibits NF-κB activation, reduces leukocyte migration, and promotes regulatory T-cell differentiation. In arthritis models, it directly binds TNF-α receptors and protects cartilage from destruction. Central actions include modulation of slow-wave sleep and suppression of growth hormone secretion.

Preclinical evidence for cortistatin as an anti-inflammatory agent is robust. In experimental colitis models, cortistatin treatment dramatically reduced colonic inflammation, pro-inflammatory cytokine expression, and mucosal damage, improving survival. In collagen-induced arthritis, treatment completely abrogated joint swelling and cartilage/bone destruction. Cortistatin also reduces pain hypersensitivity in arthritis models through mechanisms independent of its anti-inflammatory action. A 2021 Nature Communications study reported structure-based design of a cortistatin analog with improved metabolic stability and efficacy in IBD models. Clinical translation is limited by cortistatin's short plasma half-life.