Inhibition of excessive autophagy and mitophagy mediates neuroprotective effects of URB597 against chronic cerebral hypoperfusion

• Published in: Cell death & disease Vol. 9; no. 7; pp. 733 - 14
• Main Authors: Su, Shao-Hua, Wu, Yi-Fang, Wang, Da-Peng, Hai, Jian
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28-06-2018; Springer Nature B.V
• Subjects: 101/28; 13/95; 82/1; Adenylate Kinase - metabolism; Animals; Antibodies; Autophagosomes - drug effects; Autophagosomes - metabolism; Autophagosomes - ultrastructure; Autophagy; Autophagy - drug effects; Bcl-2 protein; Beclin-1 - metabolism; Benzamides - pharmacology; Biochemistry; BNIP3 protein; Brain Ischemia - pathology; Carbamates - pharmacology; Cell Biology; Cell Culture; Cytoplasm; Disease management; Electron microscopy; Hippocampus - pathology; Immunofluorescence; Immunology; Immunoprecipitation; Life Sciences; Lysates; Lysosomes - drug effects; Lysosomes - metabolism; Male; Membrane Fusion - drug effects; Membrane potential; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondria - ultrastructure; Mitophagy; Mitophagy - drug effects; Neurons - drug effects; Neurons - metabolism; Neurons - ultrastructure; Neuroprotection; Neuroprotective Agents - pharmacology; Parkin protein; Phagocytosis; Phosphorylation - drug effects; Protein expression; Proteins; Proto-Oncogene Proteins c-akt - metabolism; Proto-Oncogene Proteins c-bcl-2 - metabolism; Rats, Sprague-Dawley; Synapses - drug effects; Synapses - pathology; Synapses - ultrastructure; TOR Serine-Threonine Kinases - metabolism; Western blotting
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-018-0755-y

URB597 (URB) has therapeutic potential for treating chronic cerebral hypoperfusion (CCH)-induced neuronal death. The present study investigated the protective effects of URB on autopahgy and mitophagy in a CCH model as well as the underlying mechanisms. The ultrastructural changes were examined by electron microscopy. The mitochondrial membrane potential was assessed by immunofluorescence. The expressions of autophagy-related proteins (beclin-1, p62, and LC3), lysosome-related proteins (CTSD and LAMP1), and mitophagy-related proteins (BNIP3, cyt C and parkin) were evaluated by western blotting, and the interaction of beclin-1 and Bcl-2 were determined by immunoprecipitation. CCH significantly decreased the protein expression of p62, CTSD, and LAMP1 and increased the protein expression of beclin-1, parkin, and BNIP3, the LC3-II to LC3-I ratio, and the release of cyt C from mitochondria to cytoplasm. Furthermore, CCH induced the accumulation of ubiquitinated proteins in PSDs. However, URB significantly reversed these results. Besides, URB significantly inhibited the beclin-1 from beclin-1/Bcl-2 complex to whole-cell lysates. The above results indicate that URB could inhibit impaired autophagy degradation and the disruption of beclin-1/Bcl-2 complex and subsequently cut off BNIP3-cyt C- and parkin-required mitophagy, finally preventing the abnormal excessive autophagy and mitophagy. These findings provide new insights that URB is a promising agent for therapeutic management of CCH.