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Chong SJ, Seah BZ, Jailani RI, Angeles DC, Chong XY, Lee JH. Assessment of COVID-19 Positive Rates Amongst COVID-19 Close Contacts Through the Health Risk Warning System. J Med Syst 2023; 47:54. [PMID: 37129753 PMCID: PMC10152438 DOI: 10.1007/s10916-023-01948-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 04/15/2023] [Indexed: 05/03/2023]
Abstract
From 6 Jan 22 to 17 Feb 22, a total of 729,367 close contacts classified into four distinct groups (i.e., household, social, school and nursing/ welfare home contacts) were managed by the Health Risk Warning system. High COVID-19-positive rates were demonstrated amongst household contacts, i.e., 10.9% (37,220/342,302) were detected via antigen rapid test kits and 56.5% (4,952/8,767) were detected via polymerase chain reaction testing. Household contacts represent the highest risk of being infected by virtue of the sustained close-proximity interactions in the household setting. Social, school and nursing/ welfare home contacts continue to remain at-risk groups for close monitoring. At a population level, household and symptomatic close contacts should be the groups of focus in the early phases of the pandemic, including future potential waves involving COVID-19 variants of concern.
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Affiliation(s)
- Si Jack Chong
- Medical Operations and Policy Centre, Ministry of Health, 1 Maritime Square #11-18 HarbourFront Centre, Singapore, 099253, Singapore
- Health Alert Task Group, Ministry of Health, Singapore, Singapore
| | - Benjamin Zq Seah
- Medical Operations and Policy Centre, Ministry of Health, 1 Maritime Square #11-18 HarbourFront Centre, Singapore, 099253, Singapore.
| | - Rehmen I Jailani
- Health Alert Task Group, Ministry of Health, Singapore, Singapore
| | - Dario C Angeles
- Medical Operations and Policy Centre, Ministry of Health, 1 Maritime Square #11-18 HarbourFront Centre, Singapore, 099253, Singapore
| | | | - Joan Hin Lee
- Health Alert Task Group, Ministry of Health, Singapore, Singapore
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Chen ZC, Zhang W, Chua LL, Chai C, Li R, Lin L, Cao Z, Angeles DC, Stanton LW, Peng JH, Zhou ZD, Lim KL, Zeng L, Tan EK. Phosphorylation of amyloid precursor protein by mutant LRRK2 promotes AICD activity and neurotoxicity in Parkinson's disease. Sci Signal 2017; 10:10/488/eaam6790. [PMID: 28720718 DOI: 10.1126/scisignal.aam6790] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Mutations in LRRK2, which encodes leucine-rich repeat kinase 2, are the most common genetic cause of familial and sporadic Parkinson's disease (PD), a degenerative disease of the central nervous system that causes impaired motor function and, in advanced stages, dementia. Dementia is a common symptom of another neurodegenerative disease, Alzheimer's disease, and research suggests that there may be pathophysiological and genetic links between the two diseases. Aggregates of β amyloid [a protein produced through cleavage of amyloid precursor protein (APP)] are seen in both diseases and in PD patients carrying G2019S-mutant LRRK2. Using patient-derived cells, brain tissue, and PD model mice, we found that LRRK2 interacted with and phosphorylated APP at Thr668 within its intracellular domain (AICD). Phosphorylation of APP at Thr668 promoted AICD transcriptional activity and correlated with increased nuclear abundance of AICD and decreased abundance of a dopaminergic neuron marker in cultures and brain tissue. The AICD regulates the transcription of genes involved in cytoskeletal dynamics and apoptosis. Overexpression of AICD, but not a phosphodeficient mutant (AICDT668A), increased the loss of dopaminergic neurons in older mice expressing LRRK2G2019S Moreover, the amount of Thr668-phosphorylated APP was substantially greater in postmortem brain tissue and dopaminergic neurons (generated by reprogramming skin cells) from LRRK2G2019S patients than in those from healthy individuals. LRRK2 inhibitors reduced the phosphorylation of APP at Thr668 in the patient-derived dopaminergic neurons and in the midbrains of LRRK2G2019S mice. Thus, APP is a substrate of LRRK2, and its phosphorylation promotes AICD function and neurotoxicity in PD.
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Affiliation(s)
- Zhong-Can Chen
- Neural Stem Cell Research Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore
| | - Wei Zhang
- Neural Stem Cell Research Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore
| | - Ling-Ling Chua
- Research Department, National Neuroscience Institute, Singapore General Hospital (SGH) Campus, Singapore 169856, Singapore
| | - Chou Chai
- Neurodegeneration Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore
| | - Rong Li
- Analytical Mass Spectrometry Laboratory, Experimental Therapeutics Centre, Agency of Science, Technology and Research (A*STAR), Singapore 138669, Singapore
| | - Lin Lin
- Stem Cell and Developmental Biology Group, Genome Institute of Singapore, A*STAR, Singapore 138672, Singapore.,National University of Singapore (NUS) Graduate School for Integrative Sciences and Engineering, NUS, Singapore 117456, Singapore
| | - Zhen Cao
- Neural Stem Cell Research Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore
| | - Dario C Angeles
- Research Department, National Neuroscience Institute, Singapore General Hospital (SGH) Campus, Singapore 169856, Singapore
| | - Lawrence W Stanton
- Stem Cell and Developmental Biology Group, Genome Institute of Singapore, A*STAR, Singapore 138672, Singapore
| | - Jian-He Peng
- Analytical Mass Spectrometry Laboratory, Experimental Therapeutics Centre, Agency of Science, Technology and Research (A*STAR), Singapore 138669, Singapore
| | - Zhi-Dong Zhou
- Research Department, National Neuroscience Institute, Singapore General Hospital (SGH) Campus, Singapore 169856, Singapore.,Neuroscience and Behavioral Disorders Program, DUKE-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Kah-Leong Lim
- Neurodegeneration Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore.,Neuroscience and Behavioral Disorders Program, DUKE-NUS Graduate Medical School, Singapore 169857, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, NUS, Singapore 117597, Singapore
| | - Li Zeng
- Neural Stem Cell Research Laboratory, Research Department, National Neuroscience Institute, Singapore 308433, Singapore. .,Neuroscience and Behavioral Disorders Program, DUKE-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Eng-King Tan
- Research Department, National Neuroscience Institute, Singapore General Hospital (SGH) Campus, Singapore 169856, Singapore. .,Neuroscience and Behavioral Disorders Program, DUKE-NUS Graduate Medical School, Singapore 169857, Singapore.,Department of Neurology, National Neuroscience Institute, SGH Campus, Singapore 169856, Singapore
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Zhou ZD, Sathiyamoorthy S, Angeles DC, Tan EK. Linking F-box protein 7 and parkin to neuronal degeneration in Parkinson's disease (PD). Mol Brain 2016; 9:41. [PMID: 27090516 PMCID: PMC4835861 DOI: 10.1186/s13041-016-0218-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/06/2016] [Indexed: 02/01/2023] Open
Abstract
Mutations of F-box protein 7 (FBXO7) and Parkin, two proteins in ubiquitin-proteasome system (UPS), are both implicated in pathogenesis of dopamine (DA) neuron degeneration in Parkinson's disease (PD). Parkin is a HECT/RING hybrid ligase that physically receives ubiquitin on its catalytic centre and passes ubiquitin onto its substrates, whereas FBXO7 is an adaptor protein in Skp-Cullin-F-box (SCF) SCF(FBXO7) ubiquitin E3 ligase complex to recognize substrates and mediate substrates ubiquitination by SCF(FBXO7) E3 ligase. Here, we discuss the overlapping pathophysiologic mechanisms and clinical features linking Parkin and FBXO7 with autosomal recessive PD. Both proteins play an important role in neuroprotective mitophagy to clear away impaired mitochondria. Parkin can be recruited to impaired mitochondria whereas cellular stress can promote FBXO7 mitochondrial translocation. PD-linked FBXO7 can recruit Parkin into damaged mitochondria and facilitate its aggregation. WT FBXO7, but not PD-linked FBXO7 mutants can rescue DA neuron degeneration in Parkin null Drosophila. A better understanding of the common pathophysiologic mechanisms of these two proteins could unravel specific pathways for targeted therapy in PD.
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Affiliation(s)
- Zhi Dong Zhou
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. .,Signature Research Program in Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, 169857, Singapore.
| | - Sushmitha Sathiyamoorthy
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Dario C Angeles
- Department of Neurology, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Eng King Tan
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. .,Department of Neurology, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore. .,Signature Research Program in Neuroscience and Behavioural Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, 169857, Singapore.
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Angeles DC, Ho P, Dymock BW, Lim KL, Zhou ZD, Tan EK. Antioxidants inhibit neuronal toxicity in Parkinson's disease-linked LRRK2. Ann Clin Transl Neurol 2016; 3:288-94. [PMID: 27081659 PMCID: PMC4818746 DOI: 10.1002/acn3.282] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 10/28/2015] [Accepted: 11/24/2015] [Indexed: 12/12/2022] Open
Abstract
Mutations in leucine‐rich repeat kinase‐2 are the most common cause of familial Parkinson's disease. The prevalent G2019S mutation increase oxidative, kinase and toxic activity and inhibit endogenous peroxidases. We initially screened a library of 84 antioxidants and identified seven phenolic compounds that inhibited kinase activity on leucine‐rich repeat kinase‐2 substrates. The representative antioxidants (piceatannol, thymoquinone, and esculetin) with strong kinase inhibitor activity, reduced loss in dopaminergic neurons, oxidative dysfunction, and locomotor defects in G2019S‐expressing neuronal and Drosophila models compared to weak inhibitors. We provide proof of principle that natural antioxidants with dual antioxidant and kinase inhibitor properties could be useful for leucine‐rich repeat kinase‐2‐linked Parkinson's disease.
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Affiliation(s)
- Dario C Angeles
- Department of Neurology Singapore General Hospital 20 College Rd The Academia Discovery Tower Singapore 169856; Departments of Psychology and Pediatrics National University of Singapore Singapore
| | - Patrick Ho
- National Neuroscience Institute 11 Tan Tock Seng Singapore 308433
| | - Brian W Dymock
- Department of Pharmacy National University of Singapore 21 Lower Kent Ridge Singapore 119077
| | - Kah-Leong Lim
- National Neuroscience Institute 11 Tan Tock Seng Singapore 308433; Department of Physiology National University of Singapore 21 Lower Kent Ridge Singapore 119077; Duke-NUS Graduate Medical School 8 College Rd Singapore 169857
| | - Zhi-Dong Zhou
- Department of Neurology Singapore General Hospital 20 College Rd The Academia Discovery Tower Singapore 169856
| | - Eng-King Tan
- Department of Neurology Singapore General Hospital 20 College Rd The Academia Discovery Tower Singapore 169856; National Neuroscience Institute 11 Tan Tock Seng Singapore 308433; Duke-NUS Graduate Medical School 8 College Rd Singapore 169857
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Sharan P, Angeles DC, Ho P, Dymock BW, Lim KL, Tan EK. Antioxidant kinase inhibitors for LRRK2 Parkinson's disease. Parkinsonism Relat Disord 2016. [DOI: 10.1016/j.parkreldis.2015.10.403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Zhou ZD, Xie SP, Sathiyamoorthy S, Saw WT, Sing TY, Ng SH, Chua HPH, Tang AMY, Shaffra F, Li Z, Wang H, Ho PGH, Lai MKP, Angeles DC, Lim TM, Tan EK. F-box protein 7 mutations promote protein aggregation in mitochondria and inhibit mitophagy. Hum Mol Genet 2015; 24:6314-30. [PMID: 26310625 DOI: 10.1093/hmg/ddv340] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/17/2015] [Indexed: 11/14/2022] Open
Abstract
The mutations of F-box protein 7 (FBXO7) gene (T22M, R378G and R498X) are associated with a severe form of autosomal recessive juvenile-onset Parkinson's disease (PD) (PARK 15). Here we demonstrated that wild-type (WT) FBXO7 is a stress response protein and it can play both cytoprotective and neurotoxic roles. The WT FBXO7 protein is vital to cell mitophagy and can facilitate mitophagy to protect cells, whereas mutant FBXO7 inhibits mitophagy. Upon stress, the endogenous WT FBXO7 gets up-regulated, concentrates into mitochondria and forms FBXO7 aggregates in mitochondria. However, FBXO7 mutations aggravate deleterious FBXO7 aggregation in mitochondria. The FBXO7 aggregation and toxicity can be alleviated by Proline, glutathione (GSH) and coenzyme Q10, whereas deleterious FBXO7 aggregation in mitochondria can be aggravated by prohibitin 1 (PHB1), a mitochondrial protease inhibitor. The overexpression of WT FBXO7 could lead to FBXO7 protein aggregation and dopamine neuron degeneration in transgenic Drosophila heads. The elevated FBXO7 expression and aggregation were identified in human fibroblast cells from PD patients. FBXO7 can also form aggregates in brains of PD and Alzheimer's disease. Our study provides novel pathophysiologic insights and suggests that FBXO7 may be a potential therapeutic target in FBXO7-linked neuron degeneration in PD.
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Affiliation(s)
- Zhi Dong Zhou
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore, Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, Singapore
| | - Shao Ping Xie
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | | | - Wuan Ting Saw
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Tan Ye Sing
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Shin Hui Ng
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Heidi Pek Hup Chua
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Alyssa Mei Yan Tang
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Fathima Shaffra
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Zeng Li
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Hongyan Wang
- Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, Singapore
| | - Patrick Ghim Hoe Ho
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore
| | - Mitchell Kim Peng Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Dario C Angeles
- Department of Neurology, Singapore General Hospital, Outram Road, Singapore, Singapore and
| | - Tit Meng Lim
- Department of Biological Science, National University of Singapore, 14 Science Drive 4, Singapore, Singapore
| | - Eng-King Tan
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, Singapore, Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, Singapore, Department of Neurology, Singapore General Hospital, Outram Road, Singapore, Singapore and
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Abstract
Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common cause of dominant and sporadic Parkinson’s disease (PD), a common neurodegenerative disorder. Yeast-two-hybrid screening using human LRRK2 kinase domain as bait identified microtubule associated protein 1B (MAP1B) as a LRRK2 interactor. The interacting domains were LRRK2 kinase and the light chain portion of MAP1B (LC1). LRRK2 + LC1 interaction resulted in LRRK2 kinase inhibition. LRRK2 mutants (R1441C, G2019S and I2020T) exhibited decreased endogenous LC1 expression and its co-expression with LC1 rescued LRRK2 mutant-mediated toxicity. This study presented the first data on the effects of LRRK2 + LC1 interaction and also suggested that LCI possibly rescued LRRK2 mutant-induced cytotoxicity by inhibiting LRRK2 kinase activity. Compounds that upregulate LC1 expression may therefore hold therapeutic potential for LRRK2-linked diseases.
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Affiliation(s)
- Sharon L Chan
- National Neuroscience Institute, SGH Campus, Singapore, Singapore.
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Angeles DC, Ho P, Chua LL, Wang C, Yap YW, Ng C, Zhou ZD, Lim KL, Wszolek ZK, Wang HY, Tan EK. Thiol peroxidases ameliorate LRRK2 mutant-induced mitochondrial and dopaminergic neuronal degeneration in Drosophila. Hum Mol Genet 2014; 23:3157-65. [PMID: 24459295 DOI: 10.1093/hmg/ddu026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in leucine-rich repeat kinase 2 (LRRK2) are common causes of familial Parkinson's disease (PD). LRRK2 has been shown to bind peroxiredoxin-3 (PRDX3), the most important scavenger of hydrogen peroxide in the mitochondria, in vitro. Here, we examined the interactions of LRRK2 and PRDX3 in Drosophila models by crossing transgenic LRRK2 and PRDX3 flies. As proof of principle experiments, we subsequently challenged LRRK2 and LRRK2/PRDX3 flies with a peroxidase mimic, Ebselen. We demonstrated that co-expression of PRDX3 with the LRRK2 kinase mutant G2019S in bigenic Drosophila ameliorated the G2019S mutant-induced reduction in peroxidase capacity, loss of dopaminergic neurons, shortened lifespan and mitochondrial defects of flight muscles in monogenic flies expressing the G2019S alone. Challenges with Ebselen recapitulated similar rescue of these phenotypic features in mutant-expressing Drosophila. The peroxidase mimic preserved neuronal and mitochondrial and neuronal integrity and improved mobility and survival in mutant-expressing Drosophila. Taken together, our study provides the first in vivo evidence to suggest that phosphoinhibition of endogenous peroxidases could be a mechanism in LRRK2-induced oxidant-mediated neurotoxicity. Our therapeutic experiments also highlight the potential of thiol peroxidases as neuroprotective agents in PD patients carrying LRRK2 mutations.
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Affiliation(s)
- Dario C Angeles
- Department of Neurology, Singapore General Hospital, Singapore, Singapore 169856
| | - Patrick Ho
- Department of Neurology, Singapore General Hospital, Singapore, Singapore 169856
| | - Ling Ling Chua
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, Singapore 308433
| | - Cheng Wang
- Duke-NUS Graduate Medical School, 8 College Road, Singapore, Singapore 169857
| | - Yan Wann Yap
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, Singapore 308433
| | - Cheehoe Ng
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, Singapore 308433
| | - Zhi dong Zhou
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, Singapore 308433
| | - Kah-Leong Lim
- Department of Physiology, National University of Singapore, Singapore, Singapore 117599
| | | | - Hong Y Wang
- Duke-NUS Graduate Medical School, 8 College Road, Singapore, Singapore 169857
| | - Eng King Tan
- Department of Neurology, Singapore General Hospital, Singapore, Singapore 169856 National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, Singapore 308433 Duke-NUS Graduate Medical School, 8 College Road, Singapore, Singapore 169857
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Angeles DC, Gan BH, Onstead L, Zhao Y, Lim KL, Dachsel J, Melrose H, Farrer M, Wszolek ZK, Dickson DW, Tan EK. Mutations in LRRK2 increase phosphorylation of peroxiredoxin 3 exacerbating oxidative stress-induced neuronal death. Hum Mutat 2011; 32:1390-7. [PMID: 21850687 DOI: 10.1002/humu.21582] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 07/10/2011] [Indexed: 12/31/2022]
Abstract
Mutations in the leucine rich repeat kinase 2 (LRRK2) gene are responsible for autosomal dominant and sporadic Parkinson disease (PD), possibly exerting their effects via a toxic gain of function. A common p.G2019S mutation (rs34637584:A>G) is responsible for up to 30-40% of PD cases in some ethnic populations. Here, we show that LRRK2 interacts with human peroxiredoxin 3 (PRDX3), a mitochondrial member of the antioxidant family of thioredoxin (Trx) peroxidases. Importantly, mutations in the LRRK2 kinase domain significantly increased phosphorylation of PRDX3 compared to wild-type. The increase in PRDX3 phosphorylation was associated with decreased peroxidase activity and increased death in LRRK2-expressing but not in LRRK2-depleted or vector-transfected neuronal cells. LRRK2 mutants stimulated mitochondrial factors involved in apoptosis and induced production of reactive oxygen species (ROS) and oxidative modification of macromolecules. Furthermore, immunoblot and immunohistochemical analysis of postmortem human PD patients carrying the p.G2019S mutation showed a marked increase in phosphorylated PRDX3 (p-PRDX3) relative to normal brain. We showed that LRRK2 mutations increase the inhibition of an endogenous peroxidase by phosphorylation promoting dysregulation of mitochondrial function and oxidative damage. Our findings provide a mechanistic link between the enhanced kinase activity of PD-linked LRRK2 and neuronal cell death.
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Affiliation(s)
- Dario C Angeles
- Neuroscience Laboratory, Singapore Health Services Research Facilities, Singapore
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Allison GE, Angeles DC, Huan PT, Verma NK. Morphology of temperate bacteriophage SfV and characterisation of the DNA packaging and capsid genes: the structural genes evolved from two different phage families. Virology 2003; 308:114-27. [PMID: 12706095 DOI: 10.1016/s0042-6822(03)00198-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The entire genome of SfV, a temperate serotype-converting bacteriophage of Shigella flexneri, has recently been sequenced (Allison, G.E., Angeles, D., Tran-Dinh, N., Verma, N.K. 2002, J. Bacteriol. 184, 1974-1987). Based on the sequence analysis, we further characterised the SfV virion structure and morphogenesis. Electron microscopy indicated that SfV belongs to the Myoviridae morphology family. Analysis of the proteins encoded by orf1, orf2, and orf3 revealed that they were homologous to small and large terminase subunits, and portal proteins, respectively; the protein encoded by orf5 showed homology to capsid proteins. Western immunoblot of the phage with anti-SfV sera revealed two antigenic proteins, and the N-terminal amino acid sequence of the 32-kDa protein corresponded to amino acids 116 to 125 of the ORF5 protein, suggesting that the capsid may be processed. Functional analysis of orf4 showed that it encodes the phage capsid protease. The proteins encoded by orfs1, 2, 3, 4, and 5 are homologous to similar proteins in the Siphoviridae phage family of both gram-positive and gram-negative origin. The capsid and morphogenesis genes are upstream and adjacent to the genes encoding Myoviridae (Mu-like) tail proteins. The organisation of the structural genes of SfV is therefore unique as the head and tail genes originate from different morphology groups.
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Affiliation(s)
- Gwen E Allison
- School of Biochemistry and Molecular Biology, Faculty of Science, The Australian National University, Canberra, ACT 0200, Australia
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