Acetylome in Human Fibroblasts From Parkinson's Disease Patients

Parkinson's disease (PD) is a multifactorial neurodegenerative disorder. The pathogenesis of this disease is associated with gene and environmental factors. Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most frequent genetic cause of familial and sporadic PD. Moreover, posttranslational modifications, including protein acetylation, are involved in the molecular mechanism of PD. Acetylation of lysine proteins is a dynamic process that is modulated in PD. In this descriptive study, we characterized the acetylated proteins and peptides in primary fibroblasts from idiopathic PD (IPD) and genetic PD harboring G2019S or R1441G LRRK2 mutations. Identified acetylated peptides are modulated between individuals' groups. Although acetylated nuclear proteins are the most represented in cells, they are hypoacetylated in IPD. Results display that the level of hyperacetylated and hypoacetylated peptides are, respectively, enhanced in genetic PD and in IPD cells

Loss of KEAP1 causes an accumulation of nondegradative organelles

KEAP1 is a cytoplasmic protein that functions as an adaptor for the Cullin-3-based ubiquitin E3 ligase system, which regulates the degradation of many proteins, including NFE2L2/NRF2 and p62/SQSTM1. Loss of KEAP1 leads to an accumulation of protein ubiquitin aggregates and defective autophagy. To better understand the role of KEAP1 in the degradation machinery, we investigated whether Keap1 deficiency affects the endosome-lysosomal pathway. We used KEAP1-deficient mouse embryonic fibroblasts (MEFs) and combined Western blot analysis and fluorescence microscopy with fluorometric and pulse chase assays to analyze the levels of lysosomal-endosomal proteins, lysosomal function, and autophagy activity. We found that the loss of keap1 downregulated the protein levels and activity of the cathepsin D enzyme. Moreover, KEAP1 deficiency caused lysosomal alterations accompanied by an accumulation of autophagosomes. Our study demonstrates that KEAP1 deficiency increases nondegradative lysosomes and identifies a new role for KEAP1 in lysosomal function that may have therapeutic implications

Changes in Liver Lipidomic Profile in G2019S- LRRK2 Mouse Model of Parkinson's Disease

15 páginas, 4 figurasThe identification of Parkinson's disease (PD) biomarkers has become a main goal for the diagnosis of this neurodegenerative disorder. PD has not only been intrinsically related to neurological problems, but also to a series of alterations in peripheral metabolism. The purpose of this study was to identify metabolic changes in the liver in mouse models of PD with the scope of finding new peripheral biomarkers for PD diagnosis. To achieve this goal, we used mass spectrometry technology to determine the complete metabolomic profile of liver and striatal tissue samples from WT mice, 6-hydroxydopamine-treated mice (idiopathic model) and mice affected by the G2019S-LRRK2 mutation in LRRK2/PARK8 gene (genetic model). This analysis revealed that the metabolism of carbohydrates, nucleotides and nucleosides was similarly altered in the liver from the two PD mouse models. However, long-chain fatty acids, phosphatidylcholine and other related lipid metabolites were only altered in hepatocytes from G2019S-LRRK2 mice. In summary, these results reveal specific differences, mainly in lipid metabolism, between idiopathic and genetic PD models in peripheral tissues and open up new possibilities to better understand the etiology of this neurological disorder.This research was supported by “Instituto de Salud Carlos III”, “Fondo de Investigaciones Sanitarias” (PI15/0034), “CIBERNED-ISCIII” (CB06/05/0041 and 2015/03), and partially supported by “European Regional Development Fund (ERDF)” from the European Union. J.M.B.-S.P. is funded by “Ramon y Cajal Program” (RYC-2018-025099-I) and supported by Spain’s Ministerio de Ciencia e Innovación (PID2019-108827RA-I00). Y.C.N. and L.M.G. are funded by Community of Madrid (CT5/21/PEJ-2020-TL/BMD-17685 and CT36/22-41-UCM-INV respectively). S.M.S.Y.-D. was supported by CIBERNED-ISCIII. P.M.-C. is funded by the MINECO Spanish Ministry (FPI grant, PRE2020-092668). M.N.-S. was funded by “Ramon y Cajal Program” (RYC-2016-20883). E.U.-C. and S.C.-C. were supported by an FPU predoctoral fellowship (FPU16/00684) and FPU19/04435), respectively, from “Ministerio de Educación, Cultura y Deporte”. M.P-B was funded by a University of Extremadura fellowship. E.A-C was supported by a Grant (IB18048) from Junta de Extremadura, Spain. J.M.F. received research support from the “Instituto de Salud Carlos III”; “Fondo de Investigaciones Sanitarias” (PI15/0034) and CIBERNED-ISCIII (CB06/05/0041 and 2015/03). A.P.-C. was supported by MINECO (SAF2014-52940-R and SAF2017-85199-P). J.P.-T. received funding from CIBERNED-ISCIII (CB06/05/1123 and 2015/03). G.K. is supported by the Ligue contre le Cancer (équipe labellisée); Agence National de la Recherche (ANR)—Projets blancs; ANR under the frame of E-Rare-2, the ERANet for Research on Rare Diseases; AMMICa US/CNRS UMS3655; Association pour la recherche sur le cancer (ARC); Association “Le Cancer du Sein, Parlons-en!”; Cancéropôle Ile de-France; Chancelerie des universités de Paris (Legs Poix), Fondation pour la Recherche Médicale (FRM); a donation by Elior; European Research Area Network on Cardiovascular Diseases (ERA-CVD, MINOTAUR); Gustave Roussy Odyssea, the European Union Horizon 2020 Project Oncobiome; Fondation Carrefour; High-end Foreign Expert Program in China (GDW20171100085), Institut National du Cancer (INCa); Inserm (HTE); Institut Universitaire de France; LeDucq Foundation; the LabEx Immuno-Oncology (ANR-18-IDEX-0001); the RHU Torino Lumière; the Seerave Foundation; the SIRIC Stratified Oncology Cell DNA Repair and Tumor Immune Elimination (SOCRATE); and the SIRIC Cancer Research and Personalized Medicine (CARPEM).Peer reviewe

Citometría de flujo

La siembra celular se hace en placas de 6 pocillos (130184, Biolite) o de 24 pocillos (3524,Corning). A continuación, se aplican los tratamientos según corresponda en tiempo y concentración. El marcaje y análisis permiten recuperar las células con tripsina y se añaden junto a las que se encuentran en suspensión a tubos de citometría (1 por pocillo). Después, se centrifugan a 1.230 xg durante 5 min y se elimina el sobrenadante. Según el análisis a realizar, resuspender el pellet en diferentes tampones.Cell seeding is done in 6-well plates (130184, Biolite) or 24-well plates (3524, Corning). Treatments are then applied according to time and concentration. Cells are trypsin labelled and analysed and recovered and added together with the cells in suspension to cytometry tubes (1 per well). They are then centrifuged at 1230 xg for 5 min and the supernatant is removed. Depending on the analysis to be performed, resuspend the pellet in different buffers

Mitochondrial Dysfunction in Repeat Expansion Diseases

Repeat expansion diseases are a group of neuromuscular and neurodegenerative disorders characterized by expansions of several successive repeated DNA sequences. Currently, more than 50 repeat expansion diseases have been described. These disorders involve diverse pathogenic mechanisms, including loss-of-function mechanisms, toxicity associated with repeat RNA, or repeat-associated non-ATG (RAN) products, resulting in impairments of cellular processes and damaged organelles. Mitochondria, double membrane organelles, play a crucial role in cell energy production, metabolic processes, calcium regulation, redox balance, and apoptosis regulation. Its dysfunction has been implicated in the pathogenesis of repeat expansion diseases. In this review, we provide an overview of the signaling pathways or proteins involved in mitochondrial functioning described in these disorders. The focus of this review will be on the analysis of published data related to three representative repeat expansion diseases: Huntington’s disease, C9orf72-frontotemporal dementia/amyotrophic lateral sclerosis, and myotonic dystrophy type 1. We will discuss the common effects observed in all three repeat expansion disorders and their differences. Additionally, we will address the current gaps in knowledge and propose possible new lines of research. Importantly, this group of disorders exhibit alterations in mitochondrial dynamics and biogenesis, with specific proteins involved in these processes having been identified. Understanding the underlying mechanisms of mitochondrial alterations in these disorders can potentially lead to the development of neuroprotective strategies

Microscopia electrónica

Protocolo de procesamiento de muestras de cultivos celulares en microscopia electrónica. Se aplica a la investigación de enfermedades neurodegenerativas en un laboratorio de neurociencias.Protocol for processing cell culture samples in electron microscopy. Applied to the investigation of neurodegenerative diseases in a neuroscience laboratory

Is the Modulation of Autophagy the Future in the Treatment of Neurodegenerative Diseases?

The pathogenesis of neurodegenerative diseases involves altered activity of proteolytic systems and accumulation of protein aggregates. Autophagy is an intracellular process in which damaged organelles and long-lived proteins are degraded and recycled for maintaining normal cellular homeostasis. Disruption of autophagic activity in neurons leads to modify the cellular homeostasis, causing deficient elimination of abnormal and toxic protein aggregates that promotes cellular stress and death. Therefore, induction of autophagy has been proposed as a reasonable strategy to help neurons to clear abnormal protein aggregates and survive. This review aims to give an overview of some of the main modulators of autophagy that are currently being studied as possible alternatives in the search of therapies that slow the progression of neurodegenerative diseases, which are incurable to date

Mitophagy in human astrocytes treated with the antiretroviral drug Efavirenz: Lack of evidence or evidence of the lack

Efavirenz (EFV), a first generation non-nucleoside analogue reverse transcriptase inhibitor widely employed in combination antiretroviral therapy regimens over the last 20 years, has been associated with a wide range of neuropsychiatric effects and has also been linked with HIV-associated neurocognitive disorder (HAND). EFV has been reported to alter mitochondrial dysfunction and bioenergetics in different cell types, including astrocytes. Here, we analyzed whether this mitochondrial effect is associated with alterations in autophagy and, more specifically, mitophagy. U251-MG cells were exposed to EFV (10 and 25 μM; 24 h) and the effect was compared with that of CCCP - an uncoupler of the mitochondrial membrane potential and widely-employed in vitro inducer of mitophagy – and those of the known pharmacological stressors rotenone and thapsigargin, selected due to reported similarities with EFV. EFV induces autophagy with functional autophagic flux despite the accumulated p62/SQSTM1. However, it fails to activate canonical mitophagy (according to mitochondrial mass and expression of mitophagy-related proteins). The fact that EFV-exposed cells display decreased levels of TOM20, an outer mitochondrial membrane protein, together with the association of TOM20 with autophagosomes (LC3), points to an alternative form of mitochondrial degradation. Moreover, the perinuclear mitochondrial cluster in EFV-treated cells differs from that displayed with CCCP. Also, in EFV-treated cells, p62 was associated with mitochondria, which may be related to the mito-protective function of this autophagic protein. In conclusion, these findings add to the existing knowledge of the EFV-triggered mitochondrial interference, a mechanism that may be implicated in the adverse CNS events observed in the clinics.Sin financiación4.101 JCR (2019) Q1, 56/270 Pharmacology & Pharmacy; Q2, 11/37 Virology1.596 SJR (2019) Q1, 16/71 Virology, 33/331 PharmacologyNo data IDR 2019UE

Toxicity of Necrostatin-1 in Parkinson’s Disease Models

Parkinson’s disease (PD) is a neurodegenerative disorder that is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. This neuronal loss, inherent to age, is related to exposure to environmental toxins and/or a genetic predisposition. PD-induced cell death has been studied thoroughly, but its characterization remains elusive. To date, several types of cell death, including apoptosis, autophagy-induced cell death, and necrosis, have been implicated in PD progression. In this study, we evaluated necroptosis, which is a programmed type of necrosis, in primary fibroblasts from PD patients with and without the G2019S leucine-rich repeat kinase 2 (LRRK2) mutation and in rotenone-treated cells (SH-SY5Y and fibroblasts). The results showed that programmed necrosis was not activated in the cells of PD patients, but it was activated in cells exposed to rotenone. Necrostatin-1 (Nec-1), an inhibitor of the necroptosis pathway, prevented rotenone-induced necroptosis in PD models. However, Nec-1 affected mitochondrial morphology and failed to protect mitochondria against rotenone toxicity. Therefore, despite the inhibition of rotenone-mediated necroptosis, PD models were susceptible to the effects of both Nec-1 and rotenone

PINK1 deficiency enhances autophagy and mitophagy induction

Parkinson's disease (PD) is a neurodegenerative disorder with poorly understood etiology. Increasing evidence suggests that age-dependent compromise of the maintenance of mitochondrial function is a key risk factor. Several proteins encoded by PD-related genes are associated with mitochondria including PTEN-induced putative kinase 1 (PINK1), which was first identified as a gene that is upregulated by PTEN. Loss-of-function PINK1 mutations induce mitochondrial dysfunction and, ultimately, neuronal cell death. To mitigate the negative effects of altered cellular functions cells possess a degradation mechanism called autophagy for recycling damaged components; selective elimination of dysfunctional mitochondria by autophagy is termed mitophagy. Our study indicates that autophagy and mitophagy are upregulated in PINK1-deficient cells, and is the first report to demonstrate efficient fluxes by one-step analysis. We propose that autophagy is induced to maintain cellular homeostasis under conditions of non-regulated mitochondrial quality control