Serine 129 Phosphorylation of α-Synuclein Cross-Links with Tissue Transglutaminase to Form Lewy Body-Like Inclusion Bodies

Exploration of the α-syn/T199678/miR-519-3p/KLF9 pathway in a PD-related α-syn pathology

BACKGROUND

Kruppel-like factor 9 (KLF9) plays a key role as an inducer of cellular oxidative stress in the modulation of cell death and in oxidant-dependent tissue injury. Our previous study indicated that lncRNA-T199678 (T199678) affected the expression of KLF9 in an α-synuclein (α-syn) induced cellular model. However, the roles of interactions among α-syn, T199678, KLF9 and related microRNAs (miRNAs) in the Parkinson's disease (PD)-related α-syn pathology are unclear and were therefore investigated in this study.

METHODS

An α-syn-injected mouse model and an α-syn exposed SY-SH5Y cellular model were used in this study. We confirmed the utility of these established models with morphological and behavioral methods. We checked how expression of T199678 and KLF9 were affected by α-syn and demonstrated their interaction by fluorescence in situ hybridization (FISH) staining and western blots. We analyzed expression in ROS+ cells by immunohistochemistry. Finally, we obtained seven miRNAs through bioinformatic analysis simultaneously affected by T199678 and α-syn and verified these with RT-PCR.

RESULTS

We found that expression of KLF9 was regulated by T199678, whereas expression of T199678 was not affected by KLF9 in the α-syn exposed SY-SH5Y cells. These findings suggest that KLF9 is the downstream gene regulated by T199678, whereas miR-519-3p may play a contributing role. We also confirmed that α-syn injection upregulated the expression of ROS, which could be downregulated by upregulation of T199678, indicating an anti-oxidative role of T199678 in the α-syn-related mechanisms.

CONCLUSIONS

Our results indicate the existence of a potential α-syn/T199678/miR-519-3p /KLF9 pathway in PD-related α-syn pathology. This pathway might explain oxidative stress processes in α-syn-related mechanisms, which requires further verification.

Lycium barbarum Polysaccharide Promotes Nigrostriatal Dopamine Function by Modulating PTEN/AKT/mTOR Pathway in a Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) Murine Model of Parkinson's Disease

To investigate the effects of Lycium barbarum polysaccharide (LBP) on pathological symptoms and behavioral deficits in a Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mouse model. The therapeutic effects of LBP were monitored with an Open field test, a Rotarod test and a Morris water maze test. We also investigated the mechanisms with qRT-PCR and Western blotting analyses. After a relatively short-term LBP treatment, the total distance and walking time of PD mice significantly increased. The staying duration on the rod of PD mice increased in the Rotarod test. LBP can up-regulate levels of SOD2, CAT and GPX1 and inhibit the abnormal aggregation of α-synuclein induced by MPTP. LBP treatment can also up-regulate the phosphorylation of AKT and mTOR, and may play its protective role by activating the PTEN/AKT/mTOR signaling axis. These results suggest that LBP can effectively alleviate the degeneration in the nigrostriatal system induced by MPTP treatment. It may be a potential candidate for the treatment of Parkinson's disease.