Background:Parkinson’s disease(PD)is a common neurodegenerative disease,characterized by symptoms like tremors,muscle rigidity,and slowmovement.Themain cause of these symptoms is the loss of dopamineproducing neurons...Background:Parkinson’s disease(PD)is a common neurodegenerative disease,characterized by symptoms like tremors,muscle rigidity,and slowmovement.Themain cause of these symptoms is the loss of dopamineproducing neurons in a brain area called the substantia nigra.Various genetic and environmental factors contribute to this neuronal loss.Once symptoms of PD begin,they worsen with age,which also impacts several critical cellular processes.Leucine-rich repeat kinase 2(LRRK2)is a gene associated with PD.Certain mutations in LRRK2,such as G2019S,increase its activity,disrupting cellular mechanisms necessary for healthy neuron function,including autophagy and lysosomal activity.Exposure to rotenone(RTN)promotes LRRK2 activity in neurons and contributes to cellular senescence andα-syn accumulation.Methods:In this study,human dopaminergic progenitor cells were reprogrammed to study the effects of RTN with the co-treatment of LRRK2 inhibitor on cellular senescence.We measured the cellular senescence using quantifying proteins of senescence markers,such as p53,p21,Rb,phosphorylated Rb,andβ-galatocidase,and the enzymatic activity of senescence-associatedβ-galatocidase.And we estimated the levels of accumulatedα-synuclein(α-syn),which is increased via the impaired autophagy-lysosomal pathway by cellular senescence.Then,we evaluated the association of the G2019S LRRK2 mutation and senescence-associatedβ-galatocidase and the levels of accumulated or secretedα-syn,and the neuroinflammatory responses mediated by the secretedα-syn in rat primary microglia were determined using the release of pro-inflammatory cytokines.Results:RTN raised senescence markers and affected the phosphorylation of Rab10,a substrate of LRRK2.The inhibiting agent MLI2 reduced these senescence markers and Rab10 phosphorylations.Additionally,RTN increasedα-syn levels in the neurons,while MLI2 aided in degrading it.When focusing on cells from PD patients with the G2019S mutation,an increase in cellular senescence and release ofα-syn was observed,provoking neuroinflammation.Treatment with the LRRK2 inhibitor MLI2 decreased both cellular senescence andα-syn secretion,thereby mitigating inflammatory responses.Conclusion:Overall,inhibiting LRRK2 may provide a beneficial strategy formanaging PD.展开更多
基金supportedby a grant from the Korean Fundfor Regenerative Medicine(KFRM),which is funded by the Korean government’s Ministry of Science and ICT and the Ministry of Health&Welfare(23A0102L1 to Janghwan Kim)by KRIBB Research Initiative Program(KGM5362521 to Janghwan Kim)+1 种基金supported by a grant fromthe National Research Foundation of Korea(NRF)which is funded by theMinistry of Science and ICT(MSIT)of the Korean government(RS-2023-NR077070 to SungWoo Park).
文摘Background:Parkinson’s disease(PD)is a common neurodegenerative disease,characterized by symptoms like tremors,muscle rigidity,and slowmovement.Themain cause of these symptoms is the loss of dopamineproducing neurons in a brain area called the substantia nigra.Various genetic and environmental factors contribute to this neuronal loss.Once symptoms of PD begin,they worsen with age,which also impacts several critical cellular processes.Leucine-rich repeat kinase 2(LRRK2)is a gene associated with PD.Certain mutations in LRRK2,such as G2019S,increase its activity,disrupting cellular mechanisms necessary for healthy neuron function,including autophagy and lysosomal activity.Exposure to rotenone(RTN)promotes LRRK2 activity in neurons and contributes to cellular senescence andα-syn accumulation.Methods:In this study,human dopaminergic progenitor cells were reprogrammed to study the effects of RTN with the co-treatment of LRRK2 inhibitor on cellular senescence.We measured the cellular senescence using quantifying proteins of senescence markers,such as p53,p21,Rb,phosphorylated Rb,andβ-galatocidase,and the enzymatic activity of senescence-associatedβ-galatocidase.And we estimated the levels of accumulatedα-synuclein(α-syn),which is increased via the impaired autophagy-lysosomal pathway by cellular senescence.Then,we evaluated the association of the G2019S LRRK2 mutation and senescence-associatedβ-galatocidase and the levels of accumulated or secretedα-syn,and the neuroinflammatory responses mediated by the secretedα-syn in rat primary microglia were determined using the release of pro-inflammatory cytokines.Results:RTN raised senescence markers and affected the phosphorylation of Rab10,a substrate of LRRK2.The inhibiting agent MLI2 reduced these senescence markers and Rab10 phosphorylations.Additionally,RTN increasedα-syn levels in the neurons,while MLI2 aided in degrading it.When focusing on cells from PD patients with the G2019S mutation,an increase in cellular senescence and release ofα-syn was observed,provoking neuroinflammation.Treatment with the LRRK2 inhibitor MLI2 decreased both cellular senescence andα-syn secretion,thereby mitigating inflammatory responses.Conclusion:Overall,inhibiting LRRK2 may provide a beneficial strategy formanaging PD.
