Jeremic 2019 MiP2019

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Marija Jeremic
Neurotoxic effect of extracellular alpha-synuclein can be alleviated by AMPK and autophagy.

Link: MiP2019

Jeremic M, Jovanovic M, Tovilovic Kovacevic G, Zogovic N, Harhaji Trajkovic LJ, Vukojevic M, Kostic V, Markovic I, Trajkovic V (2019)

Event: MiP2019

COST Action MitoEAGLE

Alpha-synuclein (ASYN) is regarded as one of the key culprits in pathogenesis of synucleinopathies, including Parkinson's disease, and impaired regulation of autophagy is associated with the ASYN aggregation. Autophagy is regulated by complex mechanisms, including AMP activated protein kinase (AMPK), a key energy sensor regulating cellular metabolism to maintain energy homeostasis. The aim of our study was to investigate the role of AMPK and autophagy in neurotoxic effect of secreted ASYN, as well as dopamine-modified and nitrated recombinant wild-type ASYN oligomers, on retinoic acid (RA)-differentiated SH-SY5Y cells.

The culture supernatant from neuroblastoma cells stably expressing wt ASYN was collected and used as conditioned medium (CM). The presence of wt ASYN in CM was confirmed by immunoblot, following lyophilisation.

The CM, as well as recombinant dopamine-modified or nitrated ASYN, all reduced viability in differentiated SH-SY5Y cells. This decrease in viability was accompanied by reduced AMPK activation, increased conversion of LC3-I to LC3-II and increase in Beclin-1 level, as demonstrated by immunoblot. Pharmacological activators of AMPK and autophagy (metformin and AICAR) significantly increased the cells’ viability in the presence of CM and modified ASYN forms. Level of AMPK-activated pULK was reduced in presence of CM, but pharmacological activators of AMPK reversed that effect. Pharmacological inhibitors of autophagy (chloroqine, bafilomycin A1 and ammonium-chloride), further reduced cell viability in the presence of extracellular ASYN. The shRNA-mediated LC3 downregulation, as well as the RNA interference-mediated knockdown of ATG7 gene, both important for autophagosome biogenesis/maturation, increased sensitivity of SH-SY5Y cells to the extracellular ASYN-induced toxicity.

These data demonstrate the protective role of AMPK and autophagy against the toxicity of extracellular ASYN, suggesting that their modulation may be a promising neuroprotective strategy in Parkinson's disease.


Bioblast editor: Plangger M, Tindle-Solomon L


Labels: MiParea: Pharmacology;toxicology  Pathology: Parkinson's 

Organism: Human  Tissue;cell: Neuroblastoma 





Affiliations

Jeremić M(1), Jovanović M(1), Tovilović Kovačević G(2), Zogović N(3), Harhaji Trajković LJ(3), Vukojevic M(1), Kostic V(4), Marković I(1), Trajković V(5)
  1. Inst Medical Clinical Biochemistry, School Medicine,
  2. Dept Biochemistry, Inst Biological Research "Sinisa Stankovic"
  3. Dept Neurophysiology, Inst Biological Research "Sinisa Stankovic"
  4. Clinic Neurology, Clinical Center Serbia, Biochemistry, School Medicine
  5. Inst Microbiology Immunology, School Medicine; Univ Belgrade, Belgrade, Serbia. - marijaj26@yahoo.com