A method for treating and / or preventing osteoarthritis includes administering to a subject in need thereof a pharmaceutical composition comprising a PEDF-derived short peptide (PDSP) or a variant of the PDSP, wherein the PDSP comprises residues 93-106 of human pigmented epithelium-derived factor (PEDF), and wherein the variant of the PDSP contains serine-93, alanine-96, glutamine-98, isoleucine-103, isoleucine-104, and arginine 106 of the PDSP and contains one or more amino acid substitutions at other positions, wherein residue location numbers are based on those in the human PEDF.