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1.
Hum Mol Genet ; 32(18): 2808-2821, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37384414

RESUMO

Mutations in the Leucine-Rich Repeat Kinase 2 (LRRK2) gene have been identified as one of the most common genetic causes of Parkinson's disease (PD). The LRRK2 PD-associated mutations LRRK2G2019S and LRRK2R1441C, located in the kinase domain and in the ROC-COR domain, respectively, have been demonstrated to impair mitochondrial function. Here, we sought to further our understanding of mitochondrial health and mitophagy by integrating data from LRRK2R1441C rat primary cortical and human induced pluripotent stem cell-derived dopamine (iPSC-DA) neuronal cultures as models of PD. We found that LRRK2R1441C neurons exhibit decreased mitochondrial membrane potential, impaired mitochondrial function and decreased basal mitophagy levels. Mitochondrial morphology was altered in LRRK2R1441C iPSC-DA but not in cortical neuronal cultures or aged striatal tissue, indicating a cell-type-specific phenotype. Additionally, LRRK2R1441C but not LRRK2G2019S neurons demonstrated decreased levels of the mitophagy marker pS65Ub in response to mitochondrial damage, which could disrupt degradation of damaged mitochondria. This impaired mitophagy activation and mitochondrial function were not corrected by the LRRK2 inhibitor MLi-2 in LRRK2R1441C iPSC-DA neuronal cultures. Furthermore, we demonstrate LRRK2 interaction with MIRO1, a protein necessary to stabilize and to anchor mitochondria for transport, occurs at mitochondria, in a genotype-independent manner. Despite this, we found that degradation of MIRO1 was impaired in LRRK2R1441C cultures upon induced mitochondrial damage, suggesting a divergent mechanism from the LRRK2G2019S mutation.


Assuntos
Células-Tronco Pluripotentes Induzidas , Doença de Parkinson , Humanos , Ratos , Animais , Idoso , Doença de Parkinson/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Mitofagia , Células-Tronco Pluripotentes Induzidas/metabolismo , Mutação , Mitocôndrias/metabolismo
2.
Hum Mol Genet ; 28(21): 3584-3599, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31642482

RESUMO

A common pathological hallmark of amyotrophic lateral sclerosis (ALS) and the related neurodegenerative disorder frontotemporal dementia, is the cellular mislocalization of transactive response DNA-binding protein 43 kDa (TDP-43). Additionally, multiple mutations in the TARDBP gene (encoding TDP-43) are associated with familial forms of ALS. While the exact role for TDP-43 in the onset and progression of ALS remains unclear, the identification of factors that can prevent aberrant TDP-43 localization and function could be clinically beneficial. Previously, we discovered that the oxidation resistance 1 (Oxr1) protein could alleviate cellular mislocalization phenotypes associated with TDP-43 mutations, and that over-expression of Oxr1 was able to delay neuromuscular abnormalities in the hSOD1G93A ALS mouse model. Here, to determine whether Oxr1 can protect against TDP-43-associated phenotypes in vitro and in vivo, we used the same genetic approach in a newly described transgenic mouse expressing the human TDP-43 locus harbouring an ALS disease mutation (TDP-43M337V). We show in primary motor neurons from TDP-43M337V mice that genetically-driven Oxr1 over-expression significantly alleviates cytoplasmic mislocalization of mutant TDP-43. We also further quantified newly-identified, late-onset neuromuscular phenotypes of this mutant line, and demonstrate that neuronal Oxr1 over-expression causes a significant reduction in muscle denervation and neuromuscular junction degeneration in homozygous mutants in parallel with improved motor function and a reduction in neuroinflammation. Together these data support the application of Oxr1 as a viable and safe modifier of TDP-43-associated ALS phenotypes.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Mitocondriais/metabolismo , Neurônios Motores/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/prevenção & controle , Animais , Citoplasma/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Mitocondriais/genética , Denervação Muscular , Músculos/inervação , Mutação de Sentido Incorreto , Junção Neuromuscular/metabolismo , Transporte Proteico
3.
BMC Immunol ; 22(1): 78, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34920698

RESUMO

BACKGROUND: Phosphoinositide-3-kinase-delta (PI3Kδ) inhibition is a promising therapeutic approach for inflammatory conditions due to its role in leucocyte proliferation, migration and activation. However, the effect of PI3Kδ inhibition on group 2 innate lymphoid cells (ILC2s) and inflammatory eosinophils remains unknown. Using a murine model exhibiting persistent airway inflammation we sought to understand the effect of PI3Kδ inhibition, montelukast and anti-IL5 antibody treatment on IL33 expression, group-2-innate lymphoid cells, inflammatory eosinophils, and goblet cell metaplasia. RESULTS: Mice were sensitised to house dust mite and after allowing inflammation to resolve, were re-challenged with house dust mite to re-initiate airway inflammation. ILC2s were found to persist in the airways following house dust mite sensitisation and after re-challenge their numbers increased further along with accumulation of inflammatory eosinophils. In contrast to montelukast or anti-IL5 antibody treatment, PI3Kδ inhibition ablated IL33 expression and prevented group-2-innate lymphoid cell accumulation. Only PI3Kδ inhibition and IL5 neutralization reduced the infiltration of inflammatory eosinophils. Moreover, PI3Kδ inhibition reduced goblet cell metaplasia. CONCLUSIONS: Hence, we show that PI3Kδ inhibition dampens allergic inflammatory responses by ablating key cell types and cytokines involved in T-helper-2-driven inflammatory responses.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Eosinófilos/imunologia , Hipersensibilidade/imunologia , Inflamação/imunologia , Interleucina-33/metabolismo , Linfócitos/imunologia , Sistema Respiratório/imunologia , Acetatos/uso terapêutico , Animais , Antígenos de Dermatophagoides/imunologia , Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Ciclopropanos/uso terapêutico , Citocinas/metabolismo , Feminino , Células Caliciformes/efeitos dos fármacos , Células Caliciformes/patologia , Hipersensibilidade/tratamento farmacológico , Inflamação/tratamento farmacológico , Interleucina-5/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos BALB C , Pyroglyphidae , Quinolinas/uso terapêutico , Sulfetos/uso terapêutico , Células Th2/imunologia
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