Abstract Background Mutations in LRRK2 are a common genetic cause of Parkinson's disease (PD). LRRK2 interacts with and phosphorylates a subset of Rab proteins including Rab8a, a protein which has been implicated in various centrosome-related events. However, the cellular consequences of such phosphorylation remain elusive. Methods Human neuroblastoma SH-SY5Y cells stably expressing wildtype or pathogenic LRRK2 were used to test for polarity defects in the context of centrosomal positioning. Centrosomal cohesion deficits were analyzed from transiently transfected HEK293T cells, as well as from two distinct peripheral cell types derived from LRRK2-PD patients. Kinase assays, coimmunoprecipitation and GTP binding/retention assays were used to address Rab8a phosphorylation by LRRK2 and its effects in vitro. Transient transfections and siRNA experiments were performed to probe for the implication of Rab8a and its phosphorylated form in the centrosomal deficits caused by pathogenic LRRK2. Results Here, we show that pathogenic LRRK2 causes deficits in centrosomal positioning with effects on neurite outgrowth, cell polarization and directed migration. Pathogenic LRRK2 also causes deficits in centrosome cohesion which can be detected in peripheral cells derived from LRRK2-PD patients as compared to healthy controls, and which are reversed upon LRRK2 kinase inhibition. The centrosomal cohesion and polarity deficits can be mimicked when co-expressing wildtype LRRK2 with wildtype but not phospho-deficient Rab8a. The centrosomal defects induced by pathogenic LRRK2 are associated with a kinase activity-dependent increase in the centrosomal localization of phosphorylated Rab8a, and are prominently reduced upon RNAi of Rab8a. Conclusions Our findings reveal a new function of LRRK2 mediated by Rab8a phosphorylation and related to various centrosomal defects. ; S.H. was supported by the Michael J. Fox Foundation, the BBVA Foundation, FEDER, and the Spanish Ministry of Economy and Competitiveness (SAF2014–58653-R). E.G. was funded by the Michael J. Fox Foundation. J-M.T. and M.-C. C.-H. were funded by the Michael J. Fox Foundation, and M.-C.C.-H. was supported by Inserm, CHU de Lille, Lille University and the Ministère de la Recherche et de la Santé (PHRC Convergence). We gratefully acknowledge funding from the European Union's Horizon 2020 research and innovation programme (Marie Sklodowska-Curie Action Individual Fellowship to J.-M.T.). A.C.N. was supported by the Dept. of the Army (USAMRAA W23RYX-9049-N610) and NIH (DA10044). This research was supported in part by the Intramural Research Program of the NIH, National Institute on Aging (to M.R.C.).
Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation. Objective: To identify the genetic variants associated with juvenile ALS. Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism. Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members. Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway. Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.
CurePSP Foundation, the Peebler PSP Research Foundation, and National Institutes on Health (NIH) grants R37 AG 11762, R01 PAS-03-092, P50 NS72187, P01 AG17216 [National Institute on Aging(NIA)/NIH], MH057881 and MH077930 [National Institute of Mental Health (NIMH)]. Work was also supported in part by the NIA Intramural Research Program, the German National Genome Research Network (01GS08136-4) and the Deutsche Forschungsgemeinschaft (HO 2402/6-1), Prinses Beatrix Fonds (JCvS, 01–0128), the Reta Lila Weston Trust and the UK Medical Research Council (RdS: G0501560). The Newcastle Brain Tissue Resource provided tissue and is funded in part by a grant from the UK Medical Research Council (G0400074), by the Newcastle NIHR Biomedical Research Centre in Ageing and Age Related Diseases to the Newcastle upon Tyne Hospitals NHS Foundation Trust, and by a grant from the Alzheimer's Society and Alzheimer's Research Trust as part of the Brains for Dementia Resarch Project. We acknowledge the contribution of many tissue samples from the Harvard Brain Tissue Resource Center. We also acknowledge the 'Human Genetic Bank of Patients affected by Parkinson Disease and parkinsonism' (http://www.parkinson.it/dnabank.html) of the Telethon Genetic Biobank Network, supported by TELETHON Italy (project n. GTB07001) and by Fondazione Grigioni per il Morbo di Parkinson. The University of Toronto sample collection was supported by grants from Wellcome Trust, Howard Hughes Medical Institute, and the Canadian Institute of Health Research. Brain-Net-Germany is supported by BMBF (01GI0505). RdS, AJL and JAH are funded by the Reta Lila Weston Trust and the PSP (Europe) Association. RdS is funded by the UK Medical Research Council (Grant G0501560) and Cure PSP+. ZKW is partially supported by the NIH/NINDS 1RC2NS070276, NS057567, P50NS072187, Mayo Clinic Florida (MCF)Research Committee CR programs (MCF #90052030 and MCF #90052030), and the gift from Carl Edward Bolch, Jr., and Susan Bass Bolch (MCF #90052031/PAU #90052). The Mayo Clinic College of Medicine would like to acknowledge Matt Baker, Richard Crook, Mariely DeJesus-Hernandez and Nicola Rutherford for their preparation of samples. PP was supported by a grant from the Government of Navarra ("Ayudas para la Realización de Proyectos de Investigación" 2006–2007) and acknowledges the "Iberian Atypical Parkinsonism Study Group Researchers", i.e. Maria A. Pastor, Maria R. Luquin, Mario Riverol, Jose A. Obeso and Maria C Rodriguez-Oroz (Department of Neurology, Clínica Universitaria de Navarra, University of Navarra, Pamplona, Spain), Marta Blazquez (Neurology Department, Hospital Universitario Central de Asturias, Oviedo, Spain), Adolfo Lopez de Munain, Begoña Indakoetxea, Javier Olaskoaga, Javier Ruiz, José Félix Martí Massó (Servicio de Neurología, Hospital Donostia, San Sebastián, Spain), Victoria Alvarez (Genetics Department, Hospital Universitario Central de Asturias, Oviedo, Spain), Teresa Tuñon (Banco de Tejidos Neurologicos, CIBERNED, Hospital de Navarra, Navarra, Spain), Fermin Moreno (Servicio de Neurología, Hospital Ntra. Sra. de la Antigua, Zumarraga, Gipuzkoa, Spain), Ainhoa Alzualde (Neurogenétics Department, Hospital Donostia, San Sebastián, Spain).
IMPORTANCE: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation. OBJECTIVE: To identify the genetic variants associated with juvenile ALS. DESIGN, SETTING, AND PARTICIPANTS: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism. MAIN OUTCOMES AND MEASURES: De novo variants present only in the index case and not in unaffected family members. RESULTS: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway. CONCLUSIONS AND RELEVANCE: These data ...
In: Johnson , J O , Chia , R , Miller , D E , Li , R , Kumaran , R , Abramzon , Y , Alahmady , N , Renton , A E , Topp , S D , Gibbs , J R , Cookson , M R , Sabir , M S , Dalgard , C L , Troakes , C , Jones , A R , Shatunov , A , Iacoangeli , A , Al Khleifat , A , Ticozzi , N , Silani , V , Gellera , C , Blair , I P , Dobson-Stone , C , Kwok , J B , Bonkowski , E S , Palvadeau , R , Tienari , P J , Morrison , K E , Shaw , P J , Al-Chalabi , A , Brown , R H , Calvo , A , Mora , G , Al-Saif , H , Gotkine , M , Leigh , F , Chang , I J , Perlman , S J , Glass , I , Scott , A I , Shaw , C E , Basak , A N , Landers , J E , Chiò , A , Crawford , T O , Smith , B N , Traynor , B J , Smith , B N , Ticozzi , N , Fallini , C , Gkazi , A S , Topp , S D , Scotter , E L , Kenna , K P , Keagle , P , Tiloca , C , Vance , C , Troakes , C , Colombrita , C , King , A , Pensato , V , Castellotti , B , Baas , F , Ten Asbroek , A L M A , McKenna-Yasek , D , McLaughlin , R L , Polak , M , Asress , S , Esteban-Pérez , J , Stevic , Z , D'Alfonso , S , Mazzini , L , Comi , G P , Del Bo , R , Ceroni , M , Gagliardi , S , Querin , G , Bertolin , C , Van Rheenen , W , Rademakers , R , Van Blitterswijk , M , Lauria , G , Duga , S , Corti , S , Cereda , C , Corrado , L , Sorarù , G , Williams , K L , Nicholson , G A , Blair , I P , Leblond-Manry , C , Rouleau , G A , Hardiman , O , Morrison , K E , Veldink , J H , Van Den Berg , L H , Al-Chalabi , A , Pall , H , Shaw , P J , Turner , M R , Talbot , K , Taroni , F , García-Redondo , A , Wu , Z , Glass , J D , Gellera , C , Ratti , A , Brown , R H , Silani , V , Shaw , C E , Landers , J E , Dalgard , C L , Adeleye , A , Soltis , A R , Alba , C , Viollet , C , Bacikova , D , Hupalo , D N , Sukumar , G , Pollard , H B , Wilkerson , M D , Martinez , E M G , Abramzon , Y , Ahmed , S , Arepalli , S , Baloh , R H , Bowser , R , Brady , C B , Brice , A , Broach , J , Campbell , R H , Camu , W , Chia , R , Cooper-Knock , J , Ding , J , Drepper , C , Drory , V E , Dunckley , T L , Eicher , J D , England , B K , Faghri , F , Feldman , E , Floeter , M K , Fratta , P , Geiger , J T , Gerhard , G , Gibbs , J R , Gibson , S B , Glass , J D , Hardy , J , Harms , M B , Heiman-Patterson , T D , Hernandez , D G , Jansson , L , Kirby , J , Kowall , N W , Laaksovirta , H , Landeck , N , Landi , F , Le Ber , I , Lumbroso , S , Macgowan , D J L , Maragakis , N J , Mora , G , Mouzat , K , Murphy , N A , Myllykangas , L , Nalls , M A , Orrell , R W , Ostrow , L W , Pamphlett , R , Pickering-Brown , S , Pioro , E P , Pletnikova , O , Pliner , H A , Pulst , S M , Ravits , J M , Renton , A E , Rivera , A , Robberecht , W , Rogaeva , E , Rollinson , S , Rothstein , J D , Scholz , S W , Sendtner , M , Shaw , P J , Sidle , K C , Simmons , Z , Singleton , A B , Smith , N , Stone , D J , Tienari , P J , Troncoso , J C , Valori , M , Van Damme , P , Van Deerlin , V M , Van Den Bosch , L , Zinman , L , Landers , J E , Chiò , A , Traynor , B J , Angelocola , S M , Ausiello , F P , Barberis , M , Bartolomei , I , Battistini , S , Bersano , E , Bisogni , G , Borghero , G , Brunetti , M , Cabona , C , Calvo , A , Canale , F , Canosa , A , Cantisani , T A , Capasso , M , Caponnetto , C , Cardinali , P , Carrera , P , Casale , F , Chiò , A , Colletti , T , Conforti , F L , Conte , A , Conti , E , Corbo , M , Cuccu , S , Dalla Bella , E , D'Errico , E , Demarco , G , Dubbioso , R , Ferrarese , C , Ferraro , P M , Filippi , M , Fini , N , Floris , G , Fuda , G , Gallone , S , Gianferrari , G , Giannini , F , Grassano , M , Greco , L , Iazzolino , B , Introna , A , La Bella , V , Lattante , S , Lauria , G , Liguori , R , Logroscino , G , Logullo , F O , Lunetta , C , Mandich , P , Mandrioli , J , Manera , U , Manganelli , F , Marangi , G , Marinou , K , Marrosu , M G , Martinelli , I , Messina , S , Moglia , C , Mora , G , Mosca , L , Murru , M R , Origone , P , Passaniti , C , Petrelli , C , Petrucci , A , Pozzi , S , Pugliatti , M , Quattrini , A , Ricci , C , Riolo , G , Riva , N , Russo , M , Sabatelli , M , Salamone , P , Salivetto , M , Salvi , F , Santarelli , M , Sbaiz , L , Sideri , R , Simone , I , Simonini , C , Spataro , R , Tanel , R , Tedeschi , G , Ticca , A , Torriello , A , Tranquilli , S , Tremolizzo , L , Trojsi , F , Vasta , R , Vacchiano , V , Vita , G , Volanti , P , Zollino , M & Zucchi , E 2021 , ' Association of Variants in the SPTLC1 Gene with Juvenile Amyotrophic Lateral Sclerosis ' , JAMA neurology . https://doi.org/10.1001/jamaneurol.2021.2598
Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation. Objective: To identify the genetic variants associated with juvenile ALS. Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism. Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members. Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway. Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.