Suppression of MAPK attenuates neuronal cell death induced by activated glia-conditioned medium in alpha-synuclein overexpressing SH-SY5Y cells.
BACKGROUND
Parkinson's disease (PD) is a neurodegenerative disease with characteristics and symptoms that are well defined. Nevertheless, its aetiology remains unknown. PD is characterized by the presence of Lewy bodies inside neurons. α-Synuclein (α-syn) is a soluble protein present in the pre-synaptic terminal of neurons. Evidence suggests that α-syn has a fundamental role in PD pathogenesis, given that it is an important component of Lewy bodies localized in the dopaminergic neurons of PD patients.


METHODS
In the present study, we investigated the influence of wild type (WT) and A30P α-syn overexpression on neuroblastoma SH-SY5Y toxicity induced by the conditioned medium (CM) from primary cultures of glia challenged with lipopolysaccharide (LPS) from Escherichia coli.


RESULTS
We observed that SH-SY5Y cells transduced with α-syn (WT or A30P) and treated with CM from LPS-activated glia cells show evidence of cell death, which is not reverted by NF-κB inhibition by sodium salicylate or by blockage of P50 (NF-κB subunit). Furthermore, the expression of A30P α-syn in neuroblastoma SH-SY5Y decreases the cell death triggered by the CM of activated glia versus WT α-syn or control group. This effect of A30P α-syn may be due to the low MAPK42/44 phosphorylation. This finding is substantiated by MEK1 inhibition by PD98059, decreasing LDH release by CM in SH-SY5Y cells.


CONCLUSIONS
Our results suggest that SH-SY5Y cells transduced with α-syn (WT or A30P) and treated with CM from LPS-activated glia cells show cell death, which is not reverted by NF-κB blockage. Additionally, the expression of A30P α-syn on neuroblastoma SH-SY5Y leads to decreased cell death triggered by the CM of activated glia, when compared to WT α-syn or control group. The mechanism underlying this process remains to be completely elucidated, but the present data suggest that MAPK42/44 phosphorylation plays an important role in this process.


BACKGROUND

CRD42015020829.
Department of Pharmacology, Molecular Neuropharmacology Laboratory, Institute of Biomedical Science ICB-1, University of São Paulo, Avenida Professor Lineu Prestes, 1524, São Paulo, 05508-900, Brazil. lidiays@yahoo.com.
Lidia M
LM
Yshii
Department of Pharmacology, Section of Experimental Endocrinology, Federal University of São Paulo, São Paulo, Brazil. aledenadai@hotmail.com.
Alexandre
A
Denadai-Souza
Department of Pharmacology, Molecular Neuropharmacology Laboratory, Institute of Biomedical Science ICB-1, University of São Paulo, Avenida Professor Lineu Prestes, 1524, São Paulo, 05508-900, Brazil. andrea.vasconcelos@gmail.com.
Andrea R
AR
Vasconcelos
Department of Pharmacology, Section of Experimental Endocrinology, Federal University of São Paulo, São Paulo, Brazil. mcwavellar@gmail.com.
Maria Christina W
MC
Avellar
Department of Pharmacology, Molecular Neuropharmacology Laboratory, Institute of Biomedical Science ICB-1, University of São Paulo, Avenida Professor Lineu Prestes, 1524, São Paulo, 05508-900, Brazil. cristoforo.scavone@gmail.com.
Cristoforo
C
Scavone
D000818:Animals; D000831:Animals, Newborn; D016923:Cell Death / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism; D042844:L-Lactate Dehydrogenase (Cytochrome) / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D009154:Mutation; D009447:Neuroblastoma / Q000473:pathology; D009457:Neuroglia / Q000737:chemistry* / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*
D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D005419:Flavonoids; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D051844:alpha-Synuclein; D042844:L-Lactate Dehydrogenase (Cytochrome); C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one