P38MAPK Involve In ?-synuclein A53T-induced Mitochondrial Homeostasis Impairment In SN4741 Cells

BackgroundParkinson's disease(PD)is one of the most common neurodegenerative diseases,and its incidence is second only to Alzheimer's disease(AD).The typical pathological feature of PD is degenerative death of dopaminergic neurons in the substantia nigra.The number of patients suffering from PD ranks first in the world,and increases at an annual rate of 100,000 patients.Due to the limited treatment methods and effects of this disease,PD has brought enormous challenges to public health in China.More and more studies have shown that abnormal aggregation of a-synuclein and mitochondrial dysfunction are related to the pathogenesis of PD,but the specific mechanism is still unclear.The serine/threonine kinase p38MAPK affects multiple cellular processes in the cell by regulating the signal transduction of various cellular signaling pathways.Studies have shown that activation of p38MAPK is associated with intracellular mitochondrial dysfunction,but the specific mechanism is still unclear.Mitochondrial fission is essential for maintaining mitochondrial homeostasis and mitochondrial function.Mitochondrial fission is mediated by dynamin-related protein(Drp1),which is a large guanosine triphosphatases(GTPse).Many studies have shown that activation of Drpl leads to abnormal mitochondrial fission in PD,resulting in mitochondria and cell dysfunction.Drpl is regulated by a variety of kinases,and the relationship between p38MAPK and Drpl has not been reported.The aim of this study was to elucidate the relationship between p38MAPK,Drpl and mitochondrial homeostasis in PD and the specific regulatory mechanisms,providing a theoretical basis and new ideas for the treatment strategy of Parkinson's disease.Purpose1 To explore the effects on mitochondria and cell induced by a-synuclein A53T.2 To clarify whether p38MAPK is involved in mitochondria dysfunction induced by ?-synuclein A53T.3 To clarify whether Drpl is involved in mitochondria dysfunction induced by a-synuclein A53T.4 To determine whether p38MAPK is involved in the regulation of Drpl.Methods1 Fluorescent staining of mitochondrial with Mito tracker Red2 JC-1 to measure the mitochondrial membrane potential of SN4741 cells3 Flow cytometry to detect cell apoptosis4 Plasmid transformation and plasmid transfection5 Immunoblotting to detect protein level in the cell6 Mitochondrial protein extraction to detect the distribution of protein in cells7 The co-immuneprecipitation(Co-IP)to detect the interaction between proteins in cellsResults1 a-synuclein A53T induces mitochondrial homeostasis impairment and apoptosis in SN4741 cells.2 a-synuclein A53T activates p38MAPK,and inhibition of p38MAPK restores mitochondrial homeostasis impairment and reduce cell apoptosis.3 ?-synuclein A53T activates Drpl,which leads to Drpl phosphorylation and mitochondrial translocation,and inhibition of Drpl restores mitochondrial function and reduces cell apoptosis.4 Inhibition of p38MAPK can inhibit the activation of Drpl,resulting in decreased phosphorylation and mitochondrial translocation of Drpl.5 p38MAPK interacts with DRP1 and inhibition of p38MAPK can reduce this interaction.Conclusion?-synuclein A53T induces activation of p38MAPK in SN4741 cells.Activation of p38MAPK activates Drpl by inducing Drpl phosphorylation and mitochondrial translocation,which leads to abnormal mitochondrial fission,resulting in mitochondrial dysfunction and neuronal death.Inhibition of both Drpl and p38MAPK restored mitochondrial function and reduced neuronal death.