A 2019 study published by NCBI discusses the active participation of autophagy impairment in alpha-synuclein accumulation and propagation, as well as alpha-synuclein-independent neurodegenerative processes in the field of synucleinopathy. There is genetic and post-mortem evidence suggesting that autophagy is involved in synucleinopathies. Also, studies demonstrate the role of autophagy in the pathology of synucleinopathy. α-syn is mainly degraded by both macroautophagy and chaperone-mediated autophagy. Thus, autophagy defects induce intracellular α-syn accumulation, participating in its aggregative state towards the formation of α-syn-positive intracytoplasmic inclusions. Plus, autophagy defects also increase the α-syn secretion by the non-autophagic exosomal pathway, leading to increased cell-to-cell transmission of the protein, and thus the propagation of the α-syn-linked pathology in different brain regions of the CNS. However, autophagy defects also cause detriment effects in cellular homeostasis: (i) lysosomal impairment through structural or functional defects leads to accumulation of non-degraded products and increased production of ROS; (ii) decreased mitophagy leads to neuronal bioenergetic imbalance, and (iii) defective cargo trafficking impairs the addressing of vesicles to lysosomal clearance. There is increasing evidence that inducing the autophagy pathways (by natural, chemical, or genetic approaches), has become a relevant therapeutic approach to counteract the deleterious effects of autophagy impairment in synucleinopathy.
Source: Autophagy in Synucleinopathy: The Overwhelmed and Defective Machinery