Provided are a pharmaceutical composition for preventing or treating neurodegenerative diseases including an agent capable of suppressing expression or activity of SHP-1/-2 or FcγRIIB, a method of preventing or treating neurodegenerative diseases by administering the pharmaceutical composition, a method of screening for a therapeutic agent for neurodegenerative diseases, a diagnostic composition for neurodegenerative diseases, a diagnostic kit for neurodegenerative diseases including the diagnostic composition, and a method of providing information for the diagnosis of neurodegenerative diseases by using the diagnostic composition or kit.The agent capable of suppressing expression or activity of SHP-1/-2 or FcγRIIB according to the present invention inhibits signal transduction caused by propagation of α-synuclein to neighboring cells, thereby reducing cytotoxicity of α-synuclein to neighboring cells and thus being usefully applied to a therapeutic agent for neurodegenerative diseases. Furthermore, the agent capable of suppressing expression or activity of SHP-1/-2 or FcγRIIB according to the present invention may be an important clue to elucidate the pathogenesis of neurodegenerative diseases, and therefore, contributes to fundamental cure, thereby overcoming neurodegenerative diseases.
