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1.
Int J Mol Sci ; 25(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38542193

RESUMO

Due to the high comorbidity of Parkinson's disease (PD) with major depressive disorder (MDD) and the involvement of sphingolipids in both conditions, we investigated the peripheral expression levels of three primarily PD-associated genes: α-synuclein (SNCA), lysosomal enzyme ß-glucocerebrosidase (GBA1), and UDP-glucose ceramide glucosyltransferase (UGCG) in a sex-balanced MDD cohort. Normalized gene expression was determined by quantitative PCR in patients suffering from MDD (unmedicated n = 63, medicated n = 66) and controls (remitted MDD n = 39, healthy subjects n = 61). We observed that expression levels of SNCA (p = 0.036), GBA1 (p = 0.014), and UGCG (p = 0.0002) were higher in currently depressed patients compared to controls and remitted patients, and expression of GBA1 and UGCG decreased in medicated patients during three weeks of therapy. Additionally, in subgroups, expression was positively correlated with the severity of depression and anxiety. Furthermore, we identified correlations between the gene expression levels and PD-related laboratory parameters. Our findings suggest that SNCA, GBA1, and UGCG analysis could be instrumental in the search for biomarkers of MDD and in understanding the overlapping pathological mechanisms underlying neuro-psychiatric diseases.


Assuntos
Transtorno Depressivo Maior , Glucosiltransferases , Doença de Parkinson , Humanos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Depressão , Transtorno Depressivo Maior/genética , Expressão Gênica , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Mutação , Doença de Parkinson/metabolismo , Regulação para Cima
2.
Hum Mol Genet ; 29(7): 1180-1191, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32160287

RESUMO

Parkinson's disease (PD) is a neurodegenerative disorder characterized by protein inclusions mostly composed of aggregated forms of α-synuclein (α-Syn) and by the progressive degeneration of midbrain dopaminergic neurons (mDANs), resulting in motor symptoms. While other brain regions also undergo pathologic changes in PD, the relevance of α-Syn aggregation for the preferential loss of mDANs in PD pathology is not completely understood yet. To elucidate the mechanisms of the brain region-specific neuronal vulnerability in PD, we modeled human PD using human-induced pluripotent stem cells (iPSCs) from familial PD cases with a duplication (Dupl) of the α-Syn gene (SNCA) locus. Human iPSCs from PD Dupl patients and a control individual were differentiated into mDANs and cortical projection neurons (CPNs). SNCA dosage increase did not influence the differentiation efficiency of mDANs and CPNs. However, elevated α-Syn pathology, as revealed by enhanced α-Syn insolubility and phosphorylation, was determined in PD-derived mDANs compared with PD CPNs. PD-derived mDANs exhibited higher levels of reactive oxygen species and protein nitration levels compared with CPNs, which might underlie elevated α-Syn pathology observed in mDANs. Finally, increased neuronal death was observed in PD-derived mDANs compared to PD CPNs and to control mDANs and CPNs. Our results reveal, for the first time, a higher α-Syn pathology, oxidative stress level, and neuronal death rate in human PD mDANs compared with PD CPNs from the same patient. The finding implies the contribution of pathogenic α-Syn, probably induced by oxidative stress, to selective vulnerability of substantia nigra dopaminergic neurons in human PD.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Estresse Oxidativo/genética , Doença de Parkinson/genética , alfa-Sinucleína/genética , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Encéfalo/patologia , Morte Celular/genética , Diferenciação Celular/genética , Linhagem Celular , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/transplante , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Neuritos/metabolismo , Neuritos/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/terapia , Substância Negra/metabolismo , Substância Negra/patologia
3.
Proc Natl Acad Sci U S A ; 115(30): 7813-7818, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-29991596

RESUMO

α-Synuclein (α-Syn) aggregation, proceeding from oligomers to fibrils, is one central hallmark of neurodegeneration in synucleinopathies. α-Syn oligomers are toxic by triggering neurodegenerative processes in in vitro and in vivo models. However, the precise contribution of α-Syn oligomers to neurite pathology in human neurons and the underlying mechanisms remain unclear. Here, we demonstrate the formation of oligomeric α-Syn intermediates and reduced axonal mitochondrial transport in human neurons derived from induced pluripotent stem cells (iPSC) from a Parkinson's disease patient carrying an α-Syn gene duplication. We further show that increased levels of α-Syn oligomers disrupt axonal integrity in human neurons. We apply an α-Syn oligomerization model by expressing α-Syn oligomer-forming mutants (E46K and E57K) and wild-type α-Syn in human iPSC-derived neurons. Pronounced α-Syn oligomerization led to impaired anterograde axonal transport of mitochondria, which can be restored by the inhibition of α-Syn oligomer formation. Furthermore, α-Syn oligomers were associated with a subcellular relocation of transport-regulating proteins Miro1, KLC1, and Tau as well as reduced ATP levels, underlying axonal transport deficits. Consequently, reduced axonal density and structural synaptic degeneration were observed in human neurons in the presence of high levels of α-Syn oligomers. Together, increased dosage of α-Syn resulting in α-Syn oligomerization causes axonal transport disruption and energy deficits, leading to synapse loss in human neurons. This study identifies α-Syn oligomers as the critical species triggering early axonal dysfunction in synucleinopathies.


Assuntos
Transporte Axonal , Axônios/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Modelos Biológicos , Doenças Neurodegenerativas/metabolismo , Multimerização Proteica , Axônios/patologia , Linhagem Celular , Metabolismo Energético/genética , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Cinesinas , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Mutação de Sentido Incorreto , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , alfa-Sinucleína , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo
4.
Behav Sci (Basel) ; 14(3)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38540540

RESUMO

Self-induced bloodletting (SBL) is a very rare form of self-injury (SI) seen primarily in adolescents and young adults with personality and eating disorders. It can result in complications like malaise, fatigue, or iron-deficiency anemia (Lasthénie de Ferjol syndrome, LFS), and poses a risk of accidental death or suicide. The condition often goes undetected due to patient concealment. There is no specific treatment established, and pharmacological strategies remain uncertain. We discuss the case of a 22-year-old female patient treated at our Psychiatry and Psychotherapy Department following a suicide attempt via SBL. She self-administered a venous cannula, losing 1.5 L of blood. Diagnosed with iron-deficiency anemia (LFS), she was initially treated with mirtazapine, risperidone, lithium, and later off-label high-dose clomipramine (300 mg/d). Clomipramine significantly reduced her SBL and suicidal thoughts, and her hemoglobin levels re-normalized under iron-substitution therapy. Despite improvement and later discharge, she attempted suicide by SBL again three months later, having stopped clomipramine due to adverse side effects. High-dose escitalopram was administered, leading to a decrease and eventual cessation of her SBL urges. This case demonstrates that patients with SBL/LFS can benefit from high-dose clomipramine or escitalopram. Despite its rarity, the consideration of high-dose serotonergic antidepressants is crucial in psychiatric diagnostics and treatment for patients affected by SBL/LFS.

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