The transition of fibroblast-like synoviocytes (FLS) toward a proinflammatory phenotype is a hallmark of rheumatoid arthritis (RA), with proinflammatory RA-FLS exacerbating joint destruction via hyperproliferation, enhanced migration/invasion, and excessive inflammatory cytokine secretion. Extracellular ATP (eATP), a key damage-associated molecular pattern, is elevated in RA's inflammatory microenvironment and exerts proinflammatory effects on immune cells via P2X7 receptors (P2X7R), but its role in regulating RA-FLS' proinflammatory phenotype via P2X7R remains unclear. Using MH7A cells (a RA-FLS line), this study investigated eATP's effect on RA-FLS' proinflammatory transition and P2X7R's mediatory role to support FLS-targeted RA therapies. Methods included CCK-8 assays for optimal eATP/antagonist concentrations and metabolic activity, TranswellPlease check if the affiliations are captured correctly. assays for migration/invasion, q-PCR/Western blotting for P2X7R expression, ELISA for IL-1β/IL-6/TNF-α secretion, and Western blotting for NLRP3 (NOD-like receptor protein 3) inflammasome (NLRP3, pro-caspase-1, cleaved-caspase-1) activation. Results showed eATP enhanced MH7A migration/invasion, upregulated P2X7R, increased NLRP3 inflammasome activation, and elevated cytokine secretion, while P2X7R antagonist pretreatment abrogated these changes. Thus, eATP induces MH7A's proinflammatory transition by activating P2X7R, with targeting the eATP-P2X7R pathway representing a promising RA therapeutic target.