Publications by authors named "Martin Ingelsson"

148 Publications

Impact of risk factors for major cardiovascular diseases: a comparison of life-time observational and Mendelian randomisation findings.

Open Heart 2021 09;8(2)

School of Health and Social Studies, Dalarna University, Falun, Sweden.

Background: This study compared the strength and causality of associations between major risk factors for cardiovascular disease (CVD) and the four major CVDs: myocardial infarction, ischaemic stroke, heart failure and atrial fibrillation. Both a long-term follow-up in an observational cohort and Mendelian randomisation (MR) were used for this aim.

Methods: In the Uppsala Longitudinal Study of Adult Men study, 2322 men, all aged 50 years, were assessed for CVD risk factors and then followed for four decades regarding incident CVDs. The two-sample MR part used public available Genome-Wide Association Study (GWAS) data.

Results: In multivariate analyses, systolic blood pressure was overall by far the most important risk factor, since it was related to all four CVDs, both in observational and MR analyses. Body mass index was the second most overall important risk factor, being linked to all four CVDs, except ischaemic stroke, both in observational and MR analyses. Smoking was an important risk factor for ischaemic stroke and heart failure, both in observational and MR analyses, while low-density lipoprotein-cholesterol mainly was related to myocardial infarction. Diabetes was mainly a causal risk factor for incident myocardial infarction and heart failure. Neither HDL-cholesterol nor triglycerides were of major importance as risk factors in these multivariable models.

Conclusion: By combining long-term observational data with genetic data, we show that the impact and causal role of specific established cardiovascular risk factors varies between different major CVDs. Systolic blood pressure was causally related to all four cardiovascular outcomes and was therefore, overall, the most important risk factor.
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http://dx.doi.org/10.1136/openhrt-2021-001735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8438838PMC
September 2021

The deletion causes early onset autosomal dominant Alzheimer's disease by altering APP processing and increasing amyloid β fibril formation.

Sci Transl Med 2021 08;13(606)

Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, 75185 Uppsala, Sweden.

Point mutations in the amyloid precursor protein gene () cause familial Alzheimer's disease (AD) by increasing generation or altering conformation of amyloid β (Aβ). Here, we describe the mutation (Δ690-695), the first reported deletion causing autosomal dominant AD. Affected individuals have an age at symptom onset in their early forties and suffer from a rapidly progressing disease course. Symptoms and biomarkers are typical of AD, with the exception of normal cerebrospinal fluid (CSF) Aβ42 and only slightly pathological amyloid-positron emission tomography signals. Mass spectrometry and Western blot analyses of patient CSF and media from experimental cell cultures indicate that the mutation alters APP processing by increasing β-secretase cleavage and affecting α-secretase cleavage. Furthermore, in vitro aggregation studies and analyses of patient brain tissue samples indicate that the longer form of mutated Aβ, AβUpp1-42, accelerates the formation of fibrils with unique polymorphs and their deposition into amyloid plaques in the affected brain.
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http://dx.doi.org/10.1126/scitranslmed.abc6184DOI Listing
August 2021

Leukocytes with chromosome Y loss have reduced abundance of the cell surface immunoprotein CD99.

Sci Rep 2021 07 26;11(1):15160. Epub 2021 Jul 26.

Department of Immunology, Genetics and Pathology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.

Mosaic loss of chromosome Y (LOY) in immune cells is a male-specific mutation associated with increased risk for morbidity and mortality. The CD99 gene, positioned in the pseudoautosomal regions of chromosomes X and Y, encodes a cell surface protein essential for several key properties of leukocytes and immune system functions. Here we used CITE-seq for simultaneous quantification of CD99 derived mRNA and cell surface CD99 protein abundance in relation to LOY in single cells. The abundance of CD99 molecules was lower on the surfaces of LOY cells compared with cells without this aneuploidy in all six types of leukocytes studied, while the abundance of CD proteins encoded by genes located on autosomal chromosomes were independent from LOY. These results connect LOY in single cells with immune related cellular properties at the protein level, providing mechanistic insight regarding disease vulnerability in men affected with mosaic chromosome Y loss in blood leukocytes.
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http://dx.doi.org/10.1038/s41598-021-94588-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8313698PMC
July 2021

Visualization of early oligomeric α-synuclein pathology and its impact on the dopaminergic system in the (Thy-1)-h[A30P]α-syn transgenic mouse model.

J Neurosci Res 2021 Jul 22. Epub 2021 Jul 22.

Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.

Aggregation of alpha-synuclein (α-syn) into Lewy bodies and Lewy neurites is a pathological hallmark in the Parkinson´s disease (PD) brain. The formation of α-syn oligomers is believed to be an early pathogenic event and the A30P mutation in the gene encoding α-syn, causing familial PD, has been shown to cause an accelerated oligomerization. Due to the problem of preserving antigen conformation on tissue surfaces, α-syn oligomers are difficult to detect ex vivo using conventional immunohistochemistry with oligomer-selective antibodies. Herein, we have instead employed the previously reported α-syn oligomer proximity ligation assay (ASO-PLA), along with a wide variety of biochemical assays, to discern the pathological progression of α-syn oligomers and their impact on the dopaminergic system in male and female (Thy-1)-h[A30P]α-syn transgenic (A30P-tg) mice. Our results reveal a previously undetected abundance of α-syn oligomers in midbrain of young mice, whereas phosphorylated (pS129) and proteinase k-resistant α-syn species were observed to a larger extent in aged mice. Although we did not detect loss of dopaminergic neurons in A30P-tg mice, a dysregulation in the monoaminergic system was recorded in older mice. Taken together, ASO-PLA should be a useful method for the detection of early changes in α-syn aggregation on brain tissue, from experimental mouse models in addition to post mortem PD cases.
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http://dx.doi.org/10.1002/jnr.24927DOI Listing
July 2021

In vivo imaging of synaptic density with [C]UCB-J PET in two mouse models of neurodegenerative disease.

Neuroimage 2021 10 23;239:118302. Epub 2021 Jun 23.

Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden. Electronic address:

The positron emission tomography (PET) radioligand [C]UCB-J binds to synaptic vesicle protein 2A (SV2A) and is used to investigate synaptic density in the living brain. Clinical studies have indicated reduced [C]UCB-J binding in Alzheimer's disease (AD) and Parkinson's disease (PD) brains compared to healthy controls. Still, it is unknown whether [C]UCB-J PET can visualise synaptic loss in mouse models of these disorders. Such models are essential for understanding disease pathology and for evaluating the effects of novel disease-modifying drug candidates. In the present study, synaptic density in transgenic models of AD (ArcSwe) and PD (L61) was studied using [C]UCB-J PET. Data were acquired during 60 min after injection, and time-activity curves (TACs) in different brain regions and the left ventricle of the heart were generated based on the dynamic PET images. The [C]UCB-J brain concentrations were expressed as standardised uptake value (SUV) over time. The area under the SUV curve (AUC), the ratio of AUC in the brain to that in the heart (AUC), and the volume of distribution (V) obtained by kinetic modelling using the heart TAC as input were compared between transgenic and age-matched wild type (WT) mice. The L61 mice displayed 11-13% lower AUC ratio and brain V generated by kinetic modeling compared to the control WT mice. In general, also transgenic ArcSwe mice tended to show lower [C]UCB-J brain exposure than age-matched WT controls, but variation within the different animal groups was high. Older WT mice (18-20 months) showed lower [C]UCB-J brain exposure than younger WT mice (8-9 months). Together, these data imply that [C]UCB-J PET reflects synaptic density in mouse models of neurodegeneration and that inter-subject variation is large. In addition, the study suggested that model-independent AUC ratio can be used to evaluate [C]UCB-J binding as an alternative to full pharmacokinetic modelling.
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http://dx.doi.org/10.1016/j.neuroimage.2021.118302DOI Listing
October 2021

Multi-cohort profiling reveals elevated CSF levels of brain-enriched proteins in Alzheimer's disease.

Ann Clin Transl Neurol 2021 07 15;8(7):1456-1470. Epub 2021 Jun 15.

Division of Affinity Proteomics, Department of Protein Science, SciLifeLab, KTH Royal Institute of Technology, Stockholm, Sweden.

Objective: Decreased amyloid beta (Aβ) 42 together with increased tau and phospho-tau in cerebrospinal fluid (CSF) is indicative of Alzheimer's disease (AD). However, the molecular pathophysiology underlying the slowly progressive cognitive decline observed in AD is not fully understood and it is not known what other CSF biomarkers may be altered in early disease stages.

Methods: We utilized an antibody-based suspension bead array to analyze levels of 216 proteins in CSF from AD patients, patients with mild cognitive impairment (MCI), and controls from two independent cohorts collected within the AETIONOMY consortium. Two additional cohorts from Sweden were used for biological verification.

Results: Six proteins, amphiphysin (AMPH), aquaporin 4 (AQP4), cAMP-regulated phosphoprotein 21 (ARPP21), growth-associated protein 43 (GAP43), neurofilament medium polypeptide (NEFM), and synuclein beta (SNCB) were found at increased levels in CSF from AD patients compared with controls. Next, we used CSF levels of Aβ42 and tau for the stratification of the MCI patients and observed increased levels of AMPH, AQP4, ARPP21, GAP43, and SNCB in the MCI subgroups with abnormal tau levels compared with controls. Further characterization revealed strong to moderate correlations between these five proteins and tau concentrations.

Interpretation: In conclusion, we report six extensively replicated candidate biomarkers with the potential to reflect disease development. Continued evaluation of these proteins will determine to what extent they can aid in the discrimination of MCI patients with and without an underlying AD etiology, and if they have the potential to contribute to a better understanding of the AD continuum.
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http://dx.doi.org/10.1002/acn3.51402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8283172PMC
July 2021

Common variants in Alzheimer's disease and risk stratification by polygenic risk scores.

Nat Commun 2021 06 7;12(1):3417. Epub 2021 Jun 7.

Servei de Neurologia, Hospital Universitari i Politècnic La Fe, Valencia, Spain.

Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease.
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http://dx.doi.org/10.1038/s41467-021-22491-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8184987PMC
June 2021

Crosstalk between astrocytes and microglia results in increased degradation of α-synuclein and amyloid-β aggregates.

J Neuroinflammation 2021 Jun 3;18(1):124. Epub 2021 Jun 3.

Molecular Geriatrics, Rudbeck Laboratory, Department of Public Health & Caring Sciences/, Uppsala University, Uppsala, Sweden.

Background: Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by brain accumulation of aggregated amyloid-beta (Aβ) and alpha-synuclein (αSYN), respectively. In order to develop effective therapies, it is crucial to understand how the Aβ/αSYN aggregates can be cleared. Compelling data indicate that neuroinflammatory cells, including astrocytes and microglia, play a central role in the pathogenesis of AD and PD. However, how the interplay between the two cell types affects their clearing capacity and consequently the disease progression remains unclear.

Methods: The aim of the present study was to investigate in which way glial crosstalk influences αSYN and Aβ pathology, focusing on accumulation and degradation. For this purpose, human-induced pluripotent cell (hiPSC)-derived astrocytes and microglia were exposed to sonicated fibrils of αSYN or Aβ and analyzed over time. The capacity of the two cell types to clear extracellular and intracellular protein aggregates when either cultured separately or in co-culture was studied using immunocytochemistry and ELISA. Moreover, the capacity of cells to interact with and process protein aggregates was tracked using time-lapse microscopy and a customized "close-culture" chamber, in which the apical surfaces of astrocyte and microglia monocultures were separated by a <1 mm space.

Results: Our data show that intracellular deposits of αSYN and Aβ are significantly reduced in co-cultures of astrocytes and microglia, compared to monocultures of either cell type. Analysis of conditioned medium and imaging data from the "close-culture" chamber experiments indicate that astrocytes secrete a high proportion of their internalized protein aggregates, while microglia do not. Moreover, co-cultured astrocytes and microglia are in constant contact with each other via tunneling nanotubes and other membrane structures. Notably, our live cell imaging data demonstrate that microglia, when attached to the cell membrane of an astrocyte, can attract and clear intracellular protein deposits from the astrocyte.

Conclusions: Taken together, our data demonstrate the importance of astrocyte and microglia interactions in Aβ/αSYN clearance, highlighting the relevance of glial cellular crosstalk in the progression of AD- and PD-related brain pathology.
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http://dx.doi.org/10.1186/s12974-021-02158-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8173980PMC
June 2021

Astroglial tracer BU99008 detects multiple binding sites in Alzheimer's disease brain.

Mol Psychiatry 2021 Apr 23. Epub 2021 Apr 23.

Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.

With reactive astrogliosis being established as one of the hallmarks of Alzheimer's disease (AD), there is high interest in developing novel positron emission tomography (PET) tracers to detect early astrocyte reactivity. BU99008, a novel astrocytic PET ligand targeting imidazoline-2 binding sites (IBS) on astrocytes, might be a suitable candidate. Here we demonstrate for the first time that BU99008 could visualise reactive astrogliosis in postmortem AD brains and propose a multiple binding site [Super-high-affinity (SH), High-affinity (HA) and Low-affinity (LA)] model for BU99008, IBS specific ligands (2-BFI and BU224) and deprenyl in AD and control (CN) brains. The proportion (%) and affinities of these sites varied significantly between the BU99008, 2-BFI, BU224 and deprenyl in AD and CN brains. Regional binding studies demonstrated significantly higher H-BU99008 binding in AD brain regions compared to CN. Comparative autoradiography studies reinforced these findings, showing higher specific binding for H-BU99008 than H-Deprenyl in sporadic AD brain compared to CN, implying that they might have different targets. The data clearly shows that BU99008 could detect IBS expressing reactive astrocytes with good selectivity and specificity and hence be a potential attractive clinical astrocytic PET tracer for gaining further insight into the role of reactive astrogliosis in AD.
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http://dx.doi.org/10.1038/s41380-021-01101-5DOI Listing
April 2021

Immune cells lacking Y chromosome show dysregulation of autosomal gene expression.

Cell Mol Life Sci 2021 Apr 10;78(8):4019-4033. Epub 2021 Apr 10.

Department of Immunology, Genetics and Pathology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.

Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer's disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a "genetic wasteland", and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.
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http://dx.doi.org/10.1007/s00018-021-03822-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8106578PMC
April 2021

Different Inflammatory Signatures in Alzheimer's Disease and Frontotemporal Dementia Cerebrospinal Fluid.

J Alzheimers Dis 2021 ;81(2):629-640

Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, Uppsala, Sweden.

Background: Neuroinflammatory processes are common in neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD), but current knowledge is limited as to whether cerebrospinal fluid (CSF) levels of neuroinflammatory proteins are altered in these diseases.

Objective: To identify and characterize neuroinflammatory signatures in CSF from patients with AD, mild cognitive impairment (MCI), and FTD.

Methods: We used proximity extension assay and ANOVA to measure and compare levels of 92 inflammatory proteins in CSF from 42 patients with AD, 29 with MCI due to AD (MCI/AD), 22 with stable MCI, 42 with FTD, and 49 control subjects, correcting for age, gender, collection unit, and multiple testing.

Results: Levels of matrix metalloproteinase-10 (MMP-10) were increased in AD, MCI/AD, and FTD compared with controls (AD: fold change [FC] = 1.32, 95% confidence interval [CI] 1.14-1.53, q = 0.018; MCI/AD: FC = 1.53, 95% CI 1.20-1.94, q = 0.045; and FTD: FC = 1.42, 95% CI 1.10-1.83, q = 0.020). MMP-10 and eleven additional proteins were increased in MCI/AD, compared with MCI (q < 0.05). In FTD, 36 proteins were decreased, while none was decreased in AD or MCI/AD, compared with controls (q < 0.05).

Conclusion: In this cross-sectional multi-center study, we found distinct patterns of CSF inflammatory marker levels in FTD and in both early and established AD, suggesting differing neuroinflammatory processes in the two disorders.
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http://dx.doi.org/10.3233/JAD-201565DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8203220PMC
September 2021

Accumulation of alpha-synuclein within the liver, potential role in the clearance of brain pathology associated with Parkinson's disease.

Acta Neuropathol Commun 2021 03 20;9(1):46. Epub 2021 Mar 20.

Department of Biomedical and Clinical Sciences (BKV), Linköping University, 581 85, Linköping, Sweden.

Alpha-synuclein (α-syn) aggregation is the hallmark pathological lesion in brains of patients with Parkinson's disease (PD) and related neurological disorders characterized as synucleinopathies. Accumulating evidence now indicates that α-syn deposition is also present within the gut and other peripheral organs outside the central nervous system (CNS). In the current study, we demonstrate for the first time that α-syn pathology also accumulates within the liver, the main organ responsible for substance clearance and detoxification. We further demonstrate that cultured human hepatocytes readily internalize oligomeric α-syn assemblies mediated, at least in part, by the gap junction protein connexin-32 (Cx32). Moreover, we identified a time-dependent accumulation of α-syn within the liver of three different transgenic (tg) mouse models expressing human α-syn under CNS-specific promoters, despite the lack of α-syn mRNA expression within the liver. Such a brain-to-liver transmission route could be further corroborated by detection of α-syn pathology within the liver of wild type mice one month after a single striatal α-syn injection. In contrast to the synucleinopathy models, aged mice modeling AD rarely show any amyloid-beta (Aß) deposition within the liver. In human post-mortem liver tissue, we identified cases with neuropathologically confirmed α-syn pathology containing α-syn within hepatocellular structures to a higher degree (75%) than control subjects without α-syn accumulation in the brain (57%). Our results reveal that α-syn accumulates within the liver and may be derived from the brain or other peripheral sources. Collectively, our findings indicate that the liver may play a role in the clearance and detoxification of pathological proteins in PD and related synucleinopathies.
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http://dx.doi.org/10.1186/s40478-021-01136-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7980682PMC
March 2021

Age-related increase of alpha-synuclein oligomers is associated with motor disturbances in L61 transgenic mice.

Neurobiol Aging 2021 05 28;101:207-220. Epub 2021 Jan 28.

Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden. Electronic address:

The pathogenesis of Parkinson's disease involves fibrillization and deposition of alpha-synuclein (α-syn) into Lewy bodies. Accumulating evidence suggests that α-syn oligomers are particularly neurotoxic. Transgenic (tg) mice overexpressing wild-type human α-syn under the Thy-1 promoter (L61) reproduce many Parkinson's disease features, but the pathogenetic relevance of α-syn oligomers in this mouse model has not been studied in detail. Here, we report an age progressive increase of α-syn oligomers in the brain of L61 tg mice. Interestingly, more profound motor symptoms were observed in animals with higher levels of membrane-bound oligomers. As this tg model is X-linked, we also performed subset analyses, indicating that both sexes display a similar age-related increase in α-syn oligomers. However, compared with females, males featured increased brain levels of oligomers from an earlier age, in addition to a more severe behavioral phenotype with hyperactivity and thigmotaxis in the open field test. Taken together, our data indicate that α-syn oligomers are central to the development of brain pathology and behavioral deficits in the L61 tg α-syn mouse model.
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http://dx.doi.org/10.1016/j.neurobiolaging.2021.01.010DOI Listing
May 2021

Life-Time Covariation of Major Cardiovascular Diseases: A 40-Year Longitudinal Study and Genetic Studies.

Circ Genom Precis Med 2021 04 26;14(2):e002963. Epub 2021 Feb 26.

Uppsala Clinical Research Centre (UCR) (E.L.), Uppsala University, Sweden.

Background: It is known that certain cardiovascular diseases (CVD) are associated, like atrial fibrillation and stroke. However, for other CVDs, the links and temporal trends are less studied. In this longitudinal study, we have investigated temporal epidemiological and genetic associations between different CVDs.

Methods: The ULSAM (Uppsala Longitudinal Study of Adult Men; 2322 men aged 50 years) has been followed for 40 years regarding 4 major CVDs (incident myocardial infarction, ischemic stroke, heart failure, and atrial fibrillation). For the genetic analyses, publicly available data were used.

Results: Using multistate modeling, significant relationships were seen between pairs of all of the 4 investigated CVDs. However, the risk of obtaining one additional CVD differed substantially both between different CVDs and between their temporal order. The relationship between heart failure and atrial fibrillation showed a high risk ratio (risk ratios, 24-26) regardless of the temporal order. A consistent association was seen also for myocardial infarction and atrial fibrillation but with a lower relative risk (risk ratios, 4-5). In contrast, the risk of receiving a diagnosis of heart failure following a myocardial infarction was almost twice as high as for the reverse temporal order (risk ratios, 16 versus 9). Genetic loci linked to traditional risk factors could partly explain the observed associations between the CVDs, but pathway analyses disclosed also other pathophysiological links.

Conclusions: During 40 years, all of the 4 investigated CVDs were pairwise associated with each other regardless of the temporal order of occurrence, but the risk magnitude differed between different CVDs and their temporal order. Genetic analyses disclosed new pathophysiological links between CVDs.
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http://dx.doi.org/10.1161/CIRCGEN.120.002963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8284356PMC
April 2021

Differential DNA Methylation of the Genes for Amyloid Precursor Protein, Tau, and Neurofilaments in Human Traumatic Brain Injury.

J Neurotrauma 2021 Jun 8;38(12):1679-1688. Epub 2021 Jan 8.

Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skåne University Hospital, Lund, Sweden.

Traumatic brain injury (TBI) is an established risk factor for neurodegenerative disorders and dementias. Epigenetic modifications, such as DNA methylation, may alter the expression of genes without altering the DNA sequence in response to environmental factors. We hypothesized that DNA methylation changes may occur in the injured human brain and be implicated in the neurodegenerative aftermath of TBI. The DNA methylation status of genes related to neurodegeneration; for example, amyloid beta precursor protein (), microtubule associated protein tau (), neurofilament heavy (), neurofilament medium (), and neurofilament light (), was analyzed in fresh, surgically resected human brain tissue from 17 severe TBI patients and compared with brain biopsy samples from 19 patients with idiopathic normal pressure hydrocephalus (iNPH). We also performed an epigenome-wide association study (EWAS) comparing TBI patients with iNPH controls. Thirty-eight CpG sites in the , , , and genes were differentially methylated by TBI. Among the top 20 differentially methylated CpG sites, 11 were in the gene. In addition, the EWAS evaluating 828,888 CpG sites revealed 308 differentially methylated CpG sites in genes related to cellular/anatomical structure development, cell differentiation, and anatomical morphogenesis. These preliminary findings provide the first evidence of an altered DNA methylome in the injured human brain, and may have implications for the neurodegenerative disorders associated with TBI.
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http://dx.doi.org/10.1089/neu.2020.7283DOI Listing
June 2021

Extracellular vesicles from amyloid-β exposed cell cultures induce severe dysfunction in cortical neurons.

Sci Rep 2020 11 12;10(1):19656. Epub 2020 Nov 12.

Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, 751 85, Uppsala, Sweden.

Alzheimer's disease (AD) is characterized by a substantial loss of neurons and synapses throughout the brain. The exact mechanism behind the neurodegeneration is still unclear, but recent data suggests that spreading of amyloid-β (Aβ) pathology via extracellular vesicles (EVs) may contribute to disease progression. We have previously shown that an incomplete degradation of Aβ protofibrils by astrocytes results in the release of EVs containing neurotoxic Aβ. Here, we describe the cellular mechanisms behind EV-associated neurotoxicity in detail. EVs were isolated from untreated and Aβ protofibril exposed neuroglial co-cultures, consisting mainly of astrocytes. The EVs were added to cortical neurons for 2 or 4 days and the neurodegenerative processes were followed with immunocytochemistry, time-lapse imaging and transmission electron microscopy (TEM). Addition of EVs from Aβ protofibril exposed co-cultures resulted in synaptic loss, severe mitochondrial impairment and apoptosis. TEM analysis demonstrated that the EVs induced axonal swelling and vacuolization of the neuronal cell bodies. Interestingly, EV exposed neurons also displayed pathological lamellar bodies of cholesterol deposits in lysosomal compartments. Taken together, our data show that the secretion of EVs from Aβ exposed cells induces neuronal dysfunction in several ways, indicating a central role for EVs in the progression of Aβ-induced pathology.
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http://dx.doi.org/10.1038/s41598-020-72355-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7661699PMC
November 2020

Dual-Task Tests Predict Conversion to Dementia-A Prospective Memory-Clinic-Based Cohort Study.

Int J Environ Res Public Health 2020 11 3;17(21). Epub 2020 Nov 3.

Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, SE-751 22 Uppsala, Sweden.

The aim of this study was to investigate whether Timed Up-and-Go (TUG) dual-task (TUGdt) tests predict dementia incidence among patients with subjective or mild cognitive impairment (SCI; MCI). Other study objectives were to determine whether TUGdt improves dementia prediction compared to a) demographic characteristics and standard cognitive tests alone; and b) TUG and Verbal Fluency performed separately. Patients (n = 172, age range 39-91 years, 78 women) with SCI or MCI performed TUGdt tests, including 1) naming animals and 2) reciting months backwards, and clinical cognitive tests at baseline. Diagnoses were identified at follow-up after 2.5 years. Logistic regression was used to predict dementia incidence, receiver operating characteristic (ROC) curves and c-statistics for predictive capacity. Analyses were stratified by age and gender. At follow-up, 51 patients had developed dementia. The TUGdt result "animals/10 s" was associated with dementia incidence (standardized odds ratio (OR) = 4.06, 95% confidence interval (CI) 2.28-7.23, < 0.001), more so among patients under the median age of 72 years (standardized OR = 19.4, 95% CI 3.53-106.17, p < 0.001). TUGdt "animals/10 s" improved dementia prediction compared to demographic characteristics and standard tests alone (c-statistics 0.88 to 0.94) and single-task tests (c-statistics 0.86 to 0.89), but only in the younger patient group. TUGdt has the potential to become a useful tool for dementia prediction.
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http://dx.doi.org/10.3390/ijerph17218129DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7662628PMC
November 2020

Self-reported difficulty initiating sleep and early morning awakenings are associated with nocturnal diastolic non-dipping in older white Swedish men.

Sci Rep 2020 08 7;10(1):13355. Epub 2020 Aug 7.

Department of Neuroscience, Uppsala University, Box 593, 751 24, Uppsala, Sweden.

Chronically blunted nocturnal blood pressure (BP) dipping has been shown to increase the future risk of cardiovascular diseases. In the present cross-sectional study, we investigated whether self-reported insomnia symptoms were associated with an altered 24-h BP profile and blunted nocturnal BP dipping (night-to-day BP ratio > 0.90) in older men. For the analysis, we used 24-h ambulatory blood pressure data and reports of insomnia symptoms (difficulty initiating sleep, DIS; and early morning awakenings, EMA) from 995 Swedish men (mean age: 71 years). Compared to men without DIS, those reporting DIS (10% of the cohort) had a higher odds ratio of diastolic non-dipping (1.85 [1.15, 2.98], P = 0.011). Similarly, men who reported EMA (19% of the cohort) had a higher odds ratio of diastolic non-dipping than those without EMA (1.57 [1.09, 2.26], P = 0.015). Despite a slightly higher nocturnal diastolic BP among men with EMA vs. those without EMA (+ 1.4 mmHg, P = 0.042), no other statistically significant differences in BP and heart rate were found between men with and those without insomnia symptoms. Our findings suggest that older men reporting difficulty initiating sleep or early morning awakenings may have a higher risk of nocturnal diastolic non-dipping. Our findings must be replicated in larger cohorts that also include women.
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http://dx.doi.org/10.1038/s41598-020-70399-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414842PMC
August 2020

The existence of Aβ strains and their potential for driving phenotypic heterogeneity in Alzheimer's disease.

Acta Neuropathol 2021 07 2;142(1):17-39. Epub 2020 Aug 2.

Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, Rm. 4KD481, 60 Leonard Ave., Toronto, ON, M5T 0S8, Canada.

Reminiscent of the human prion diseases, there is considerable clinical and pathological variability in Alzheimer's disease, the most common human neurodegenerative condition. As in prion disorders, protein misfolding and aggregation is a hallmark feature of Alzheimer's disease, where the initiating event is thought to be the self-assembly of Aβ peptide into aggregates that deposit in the central nervous system. Emerging evidence suggests that Aβ, similar to the prion protein, can polymerize into a conformationally diverse spectrum of aggregate strains both in vitro and within the brain. Moreover, certain types of Aβ aggregates exhibit key hallmarks of prion strains including divergent biochemical attributes and the ability to induce distinct pathological phenotypes when intracerebrally injected into mouse models. In this review, we discuss the evidence demonstrating that Aβ can assemble into distinct strains of aggregates and how such strains may be primary drivers of the phenotypic heterogeneity in Alzheimer's disease.
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http://dx.doi.org/10.1007/s00401-020-02201-2DOI Listing
July 2021

Dual-task tests discriminate between dementia, mild cognitive impairment, subjective cognitive impairment, and healthy controls - a cross-sectional cohort study.

BMC Geriatr 2020 07 29;20(1):258. Epub 2020 Jul 29.

Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, Box 564, SE-751 22, Uppsala, Sweden.

Background: Discrimination between early-stage dementia and other cognitive impairment diagnoses is central to enable appropriate interventions. Previous studies indicate that dual-task testing may be useful in such differentiation. The objective of this study was to investigate whether dual-task test outcomes discriminate between groups of individuals with dementia disorder, mild cognitive impairment, subjective cognitive impairment, and healthy controls.

Methods: A total of 464 individuals (mean age 71 years, 47% women) were included in the study, of which 298 were patients undergoing memory assessment and 166 were cognitively healthy controls. Patients were grouped according to the diagnosis received: dementia disorder, mild cognitive impairment, or subjective cognitive impairment. Data collection included participants' demographic characteristics. The patients' cognitive test results and diagnoses were collected from their medical records. Healthy controls underwent the same cognitive tests as the patients. The mobility test Timed Up-and-Go (TUG single-task) and two dual-task tests including TUG (TUGdt) were carried out: TUGdt naming animals and TUGdt months backwards. The outcomes registered were: time scores for TUG single-task and both TUGdt tests, TUGdt costs (relative time difference between TUG single-task and TUGdt), number of different animals named, number of months recited in correct order, number of animals per 10 s, and number of months per 10 s. Logistic regression models examined associations between TUG outcomes pairwise between groups.

Results: The TUGdt outcomes "animals/10 s" and "months/10 s" discriminated significantly (p < 0.001) between individuals with an early-stage dementia diagnosis, mild cognitive impairment, subjective cognitive impairment, and healthy controls. The TUGdt outcome "animals/10 s" showed an odds ratio of 3.3 (95% confidence interval 2.0-5.4) for the groups dementia disorders vs. mild cognitive impairment. TUGdt cost outcomes, however, did not discriminate between any of the groups.

Conclusions: The novel TUGdt outcomes "words per time unit", i.e. "animals/10 s" and "months/10 s", demonstrate high levels of discrimination between all investigated groups. Thus, the TUGdt tests in the current study could be useful as complementary tools in diagnostic assessments. Future studies will be focused on the predictive value of TUGdt outcomes concerning dementia risk for individuals with mild cognitive impairment or subjective cognitive impairment.
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http://dx.doi.org/10.1186/s12877-020-01645-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7392684PMC
July 2020

Amyloid, tau, and astrocyte pathology in autosomal-dominant Alzheimer's disease variants: AβPParc and PSEN1DE9.

Mol Psychiatry 2020 Jun 25. Epub 2020 Jun 25.

Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.

Autosomal-dominant Alzheimer's disease (ADAD) may be associated with atypical amyloid beta deposits in the brain. In vivo amyloid imaging using C-Pittsburgh compound B (PiB) tracer has shown differences in binding between brains from ADAD and sporadic Alzheimer's disease (sAD) patients. To gain further insight into the various pathological characteristics of these genetic variants, we performed large frozen hemisphere autoradiography and brain homogenate binding assays with H-PiB, H-MK6240-H-THK5117, and H-deprenyl for detection of amyloid fibrils, tau depositions, and activated astrocytes, respectively, in two AβPParc mutation carriers, one PSEN1ΔE9 mutation carrier, and three sAD cases. The results were compared with Abeta 40, Abeta 42, AT8, and GFAP immunostaining, respectively, as well as with Congo red and Bielschowsky. PiB showed a very low binding in AβPParc. A high binding was observed in PSEN1ΔE9 and in sAD tissues but with different binding patterns. Comparable H-THK5117 and H-deprenyl brain homogenate binding was observed for AβPParc, PSEN1ΔE9, and sAD, respectively. Some differences were observed between H-MK6240 and H-THK5117 in ADAD. A positive correlation between H-deprenyl and H-THK5117 binding was observed in AβPParc, while no such correlation was found in PSEN1ΔE9 and sAD. Our study demonstrates differences in the properties of the amyloid plaques between two genetic variants of AD and sAD. Despite the lack of measurable amyloid fibrils by PiB in the AβPParc cases, high regional tau and astrocyte binding was observed. The lack of correlation between H-deprenyl and H-THK5117 binding in PSEN1ΔE9 and sAD in contrast of the positive correlation observed in the AβPParc cases suggest differences in the pathological cascade between variants of AD that warrant further exploration in vivo.
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http://dx.doi.org/10.1038/s41380-020-0817-2DOI Listing
June 2020

Altered levels of CSF proteins in patients with FTD, presymptomatic mutation carriers and non-carriers.

Transl Neurodegener 2020 06 23;9(1):27. Epub 2020 Jun 23.

Division of Affinity Proteomics, Department of Protein Science, KTH Royal Institute of Technology, SciLifeLab, Tomtebodavägen 23 A, Alpha 2, 171 65 Solna, Stockholm, Sweden.

Background: The clinical presentations of frontotemporal dementia (FTD) are diverse and overlap with other neurological disorders. There are, as of today, no biomarkers in clinical practice for diagnosing the disorders. Here, we aimed to find protein markers in cerebrospinal fluid (CSF) from patients with FTD, presymptomatic mutation carriers and non-carriers.

Methods: Antibody suspension bead arrays were used to analyse 328 proteins in CSF from patients with behavioural variant FTD (bvFTD, n = 16) and progressive primary aphasia (PPA, n = 13), as well as presymptomatic mutation carriers (PMC, n = 16) and non-carriers (NC, n = 8). A total of 492 antibodies were used to measure protein levels by direct labelling of the CSF samples. The findings were further examined in an independent cohort including 13 FTD patients, 79 patients with Alzheimer's disease and 18 healthy controls.

Results: We found significantly altered protein levels in CSF from FTD patients compared to unaffected individuals (PMC and NC) for 26 proteins. The analysis show patterns of separation between unaffected individuals and FTD patients, especially for those with a clinical diagnosis of bvFTD. The most statistically significant differences in protein levels were found for VGF, TN-R, NPTXR, TMEM132D, PDYN and NF-M. Patients with FTD were found to have higher levels of TN-R and NF-M, and lower levels of VGF, NPTXR, TMEM132D and PDYN, compared to unaffected individuals. The main findings were reproduced in the independent cohort.

Conclusion: In this pilot study, we show a separation of FTD patients from unaffected individuals based on protein levels in CSF. Further investigation is required to explore the CSF profiles in larger cohorts, but the results presented here has the potential to enable future clinical utilization of these potential biomarkers within FTD.
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http://dx.doi.org/10.1186/s40035-020-00198-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310563PMC
June 2020

[Alzheimer's disease - the most common cause of dementia].

Lakartidningen 2020 03 9;117. Epub 2020 Mar 9.

Klinisk Neurokemi Lab - Inst. för Neurovetenskap och Fysiologi Mölndal, Sweden Klinisk Neurokemi Lab - Inst. för Neurovetenskap och Fysiologi Mölndal, Sweden.

Alzheimer's disease is the most common cause of dementia. As many as 250,000 people in Sweden will have a dementia disease in 2050. The »amyloid cascade hypothesis« is a common model which explains how β-amyloid affects the function of the nerve cells. Alzheimer's disease has a long-lasting course and can present in typical and atypical forms. CSF analyses for »core AD CSF biomarkers« and synaptic proteins have been available for clinical diagnostics. PET scanning can detect either β-amyloid or tau aggregates in the brain of living humans. Current Alzheimer's disease therapy is based on two classes of cognition-enhancing drugs: acetylcholinesterase inhibitor and NMDA-receptor antagonist, which delays cognitive decline in most patients. The latest clinical development of potential therapy for Alzheimer's is active or passive immunotherapy against brain β-amyloid and tau, where several studies have shown varying but promising treatment effects. Non-pharmacological interventions in patients with AD aim to delay the loss of mental abilities, helping people to be independent in everyday life for as long as possible, and to increase their well-being and quality of life.
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March 2020

Timed Up-and-Go Dual-Task Testing in the Assessment of Cognitive Function: A Mixed Methods Observational Study for Development of the UDDGait Protocol.

Int J Environ Res Public Health 2020 03 5;17(5). Epub 2020 Mar 5.

Department of Public Health and Caring Sciences, Geriatrics, Uppsala University, SE-75185 Uppsala, Sweden.

New methods to screen for and identify early-stage dementia disorders are highly sought after. The purpose of this pilot study is to develop a study protocol for a dual-task test aimed at aiding the early detection of dementia disorders. We used the Timed Up-and-Go (TUG) test, which is a mobility task involving starting in a sitting position, standing up, walking three meters to cross a line on the floor, turning around, walking back and sitting down again. We combined TUG with the verbal task of naming different animals. Pilot study participants were 43 individuals with and without established dementia diagnoses who attended a clinic for memory assessment. Video-recorded test performances were systematically analysed. Deviant test performances concerning the interplay between test administration and participants' responses to the assessment instructions were revealed and led to refinements being made to the final study protocol. Exploration of the dual-task test outcome measures in a sub-sample of 22 persons, ten with and twelve without dementia, indicated that step-length and number of named animals after the turning point of the dual-task test might constitute appropriate measures for examining this kind of sample. We concluded that the refined study protocol is feasible for testing individuals undergoing initial memory assessments and healthy controls. Follow-up studies with larger samples are being carried out and will bring new knowledge to this area of research. It may also provide an opportunity for further studies exploring possibilities for broad clinical implementation.
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http://dx.doi.org/10.3390/ijerph17051715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7084863PMC
March 2020

Torque teno virus viral load is related to age, CMV infection and HLA type but not to Alzheimer's disease.

PLoS One 2020 9;15(1):e0227670. Epub 2020 Jan 9.

Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.

Torque teno virus (TTV) is an unenveloped, circular, single stranded DNA virus with a genome size of approximately 3.8 kb. Previous studies have demonstrated varying grades of association between TTV DNA levels and immune deficiencies related to age, chronic infections and cancer. Alzheimer's disease (AD) has been related to persistent viral infections such as HSV-1 and CMV, but it is not known whether TTV viral load could serve as a functional biomarker of cellular immunity in this setting. Therefore, the objective of this study was to investigate whether TTV infection and viral load is related to AD status, CMV immunity, systemic inflammation or HLA types connected to anti-viral immunity. A total of 50 AD subjects and 51 non-demented controls were included in the study. AD subjects were diagnosed according to NINCDS-ADRDA and DSM-IV criteria and neuroradiologic findings were consistent with the diagnosis. TTV viral load was analyzed in plasma samples using a quantitative real-time PCR. Using a cut-off for TTV status at 200 copies/ml, 88% (89/101) of the study subjects were classified as TTV positive. TTV viral load significantly increased with age (beta 0.049 per year, p<0.001) but significantly decreased in relation to CMV IgG levels (beta -0.022 per 1000 units, p = 0.005) and HLA-B27 positivity (beta -0.53, p = 0.023). In conclusion, TTV immune control is not significantly affected by AD status, but appears related to age, CMV humoral immune response and HLA type.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227670PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6952092PMC
April 2020

α-Synuclein strains target distinct brain regions and cell types.

Nat Neurosci 2020 01 2;23(1):21-31. Epub 2019 Dec 2.

Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.

The clinical and pathological differences between synucleinopathies such as Parkinson's disease and multiple system atrophy have been postulated to stem from unique strains of α-synuclein aggregates, akin to what occurs in prion diseases. Here we demonstrate that inoculation of transgenic mice with different strains of recombinant or brain-derived α-synuclein aggregates produces clinically and pathologically distinct diseases. Strain-specific differences were observed in the signs of neurological illness, time to disease onset, morphology of cerebral α-synuclein deposits and the conformational properties of the induced aggregates. Moreover, different strains targeted distinct cellular populations and cell types within the brain, recapitulating the selective targeting observed among human synucleinopathies. Strain-specific clinical, pathological and biochemical differences were faithfully maintained after serial passaging, which implies that α-synuclein propagates via prion-like conformational templating. Thus, pathogenic α-synuclein exhibits key hallmarks of prion strains, which provides evidence that disease heterogeneity among the synucleinopathies is caused by distinct α-synuclein strains.
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http://dx.doi.org/10.1038/s41593-019-0541-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6930851PMC
January 2020

Genetic predisposition to mosaic Y chromosome loss in blood.

Nature 2019 11 20;575(7784):652-657. Epub 2019 Nov 20.

Genetics of Complex Traits, University of Exeter Medical School, University of Exeter, Exeter, UK.

Mosaic loss of chromosome Y (LOY) in circulating white blood cells is the most common form of clonal mosaicism, yet our knowledge of the causes and consequences of this is limited. Here, using a computational approach, we estimate that 20% of the male population represented in the UK Biobank study (n = 205,011) has detectable LOY. We identify 156 autosomal genetic determinants of LOY, which we replicate in 757,114 men of European and Japanese ancestry. These loci highlight genes that are involved in cell-cycle regulation and cancer susceptibility, as well as somatic drivers of tumour growth and targets of cancer therapy. We demonstrate that genetic susceptibility to LOY is associated with non-haematological effects on health in both men and women, which supports the hypothesis that clonal haematopoiesis is a biomarker of genomic instability in other tissues. Single-cell RNA sequencing identifies dysregulated expression of autosomal genes in leukocytes with LOY and provides insights into why clonal expansion of these cells may occur. Collectively, these data highlight the value of studying clonal mosaicism to uncover fundamental mechanisms that underlie cancer and other ageing-related diseases.
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http://dx.doi.org/10.1038/s41586-019-1765-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6887549PMC
November 2019

Longitudinal changes in the frequency of mosaic chromosome Y loss in peripheral blood cells of aging men varies profoundly between individuals.

Eur J Hum Genet 2020 03 25;28(3):349-357. Epub 2019 Oct 25.

Department of Immunology, Genetics and Pathology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.

Mosaic loss of chromosome Y (LOY) is the most common somatic genetic aberration and is associated with increased risk for all-cause mortality, various forms of cancer and Alzheimer's disease, as well as other common human diseases. By tracking LOY frequencies in subjects from which blood samples have been serially collected up to five times during up to 22 years, we observed a pronounced intra-individual variation of changes in the frequency of LOY within individual men over time. We observed that in some individuals the frequency of LOY in blood clearly progressed over time and that in other men, the frequency was constant or showed other types of longitudinal development. The predominant method used for estimating LOY is calculation of the median Log R Ratio of probes located in the male specific part of chromosome Y (mLRRY) from intensity data generated by SNP-arrays, which is difficult to interpret due to its logarithmic and inversed scale. We present here a formula to transform mLRRY-values to percentage of LOY that is a more comprehensible unit. The formula was derived using measurements of LOY from matched samples analysed using SNP-array, whole genome sequencing and a new AMELX/AMELY-based assay for droplet digital PCR. The methods described could be applied for analyses of the vast amount of SNP-array data already generated in the scientific community, allowing further discoveries of LOY associated diseases and outcomes.
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http://dx.doi.org/10.1038/s41431-019-0533-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7028735PMC
March 2020

High levels of AAV vector integration into CRISPR-induced DNA breaks.

Nat Commun 2019 09 30;10(1):4439. Epub 2019 Sep 30.

Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA.

Adeno-associated virus (AAV) vectors have shown promising results in preclinical models, but the genomic consequences of transduction with AAV vectors encoding CRISPR-Cas nucleases is still being examined. In this study, we observe high levels of AAV integration (up to 47%) into Cas9-induced double-strand breaks (DSBs) in therapeutically relevant genes in cultured murine neurons, mouse brain, muscle and cochlea. Genome-wide AAV mapping in mouse brain shows no overall increase of AAV integration except at the CRISPR/Cas9 target site. To allow detailed characterization of integration events we engineer a miniature AAV encoding a 465 bp lambda bacteriophage DNA (AAV-λ465), enabling sequencing of the entire integrated vector genome. The integration profile of AAV-465λ in cultured cells display both full-length and fragmented AAV genomes at Cas9 on-target sites. Our data indicate that AAV integration should be recognized as a common outcome for applications that utilize AAV for genome editing.
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http://dx.doi.org/10.1038/s41467-019-12449-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769011PMC
September 2019
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