UNASSIGNED: During the course of adulthood and aging, white matter (WM) structure and organization are characterized by slow degradation processes such as demyelination and shrinkage. An acceleration of such aging processes has been linked to the development of a range of diseases. Thus, an accurate description of healthy brain maturation, particularly in terms of WM features, is fundamental to the understanding of aging.
UNASSIGNED: We used longitudinal diffusion magnetic resonance imaging to provide an overview of WM changes at different spatial and temporal scales in the UK Biobank (UKB) (n = 2678; agescan 1 = 62.38 ± 7.23 years; agescan 2 = 64.81 ± 7.1 years). To examine the genetic overlap between WM structure and common clinical conditions, we tested the associations between WM structure and polygenic risk scores for the most common neurodegenerative disorder, Alzheimer\'s disease, and common psychiatric disorders (unipolar and bipolar depression, anxiety, obsessive-compulsive disorder, autism, schizophrenia, attention-deficit/hyperactivity disorder) in longitudinal (n = 2329) and cross-sectional (n = 31,056) UKB validation data.
UNASSIGNED: Our findings indicate spatially distributed WM changes across the brain, as well as distributed associations of polygenic risk scores with WM. Importantly, brain longitudinal changes reflected genetic risk for disorder development better than the utilized cross-sectional measures, with regional differences giving more specific insights into gene-brain change associations than global averages.
UNASSIGNED: We extend recent findings by providing a detailed overview of WM microstructure degeneration on different spatial levels, helping to understand fundamental brain aging processes. Further longitudinal research is warranted to examine aging-related gene-brain associations.
In their study, Korbmacher et al. benchmark healthy aging processes in the brain’s white matter. Findings of degrading white matter at higher ages were consistent with recent cross-sectional and longitudinal findings, particularly outlining changes in ventricle-near and cerebellar white matter. Degenerative processes were also found to accelerate at a higher age. Finally, the polygenic risk to develop psychiatric and neurodegenerative disorders was weakly associated with the white matter change in the otherwise healthily aging participants.

UNASSIGNED: It is unclear to what extent lifestyle and genetic factors affect the incidence of chronic liver disease (CLD) in the general population and if lifestyle affects CLD independently of underlying cardiometabolic perturbations and genetic predisposition.
UNASSIGNED: We examined 27,991 men and women aged 44-73 years from the Malmö Diet and Cancer Study recruited between 1991-1996 and followed until the end of 2020 using registry linkage (median follow-up time 25.1 years; 382 incident first-time CLD events). Associations between cardiometabolic factors, polygenic risk scores (PRSs), and lifestyle factors in relation to CLD were examined using multivariable Cox proportional hazards regression models.
UNASSIGNED: The incidence of CLD increased with number of cardiometabolic risk factors (the hazard ratio per each additional cardiometabolic risk factor was 1.33; 95% CI 1.21-1.45; p = 5.1 x 10-10). Two novel PRSs for metabolic dysfunction-associated steatotic liver disease and a PRS for cirrhosis were associated with higher risk of CLD but provided marginal predictive utility on top of other risk factors and compared to the PNPLA3 rs738409 genetic variant. An unhealthy lifestyle (high alcohol intake, current smoking, physical inactivity and unhealthy diet) markedly increased the risk of CLD (hazard ratio 3.97, 95% CI 2.59-6.10). Observed associations between examined lifestyle factors and CLD were largely independent of cardiometabolic perturbations and polygenic risk.
UNASSIGNED: We confirmed the importance of cardiometabolic dysfunction in relation to risk of CLD in the general population. Lifestyle risk factors were shown to be independently associated with CLD and added predictive information on top of cardiometabolic risk factors. Information on the polygenic risk of liver disease does not currently improve the prediction of CLD in the general population.
UNASSIGNED: This large population-based prospective study suggests largely independent roles of cardiometabolic, lifestyle, and genetic risk factors in the development of chronic liver disease. Findings strengthen the evidence base for a beneficial effect of modification of high-risk lifestyle behaviors in the primary prevention of chronic liver disease in the general population.

UNASSIGNED: Heterozygous familial hypercholesterolemia (HeFH) is a monogenic disorder characterized by increased circulating low-density lipoprotein cholesterol and accelerated atherosclerosis. Even among this high-risk group, prior studies note considerable variability in risk of coronary artery disease (CAD).
UNASSIGNED: The purpose of this study was to evaluate the cumulative impact of many common DNA variants-as quantified by a polygenic score-on incident CAD among individuals carrying a HeFH variant.
UNASSIGNED: We analyzed data from a prospective cohort study of 1,315 individuals who carried a HeFH variant and 1,315 matched family noncarriers derived from a nationwide screening program in the Netherlands, with subsequent replication in 151,009 participants of the UK Biobank.
UNASSIGNED: Despite identification and lipid management within the Dutch screening program, 84 (6.4%) of HeFH variant carriers developed CAD as compared to 45 (3.4%) of matched family members (median follow-up 10.2 years, HR 1.88, 95% CI: 1.31-2.70). Among HeFH variant carriers, a polygenic score was associated with CAD with an effect size similar to low-density lipoprotein cholesterol - HR of 1.35 (95% CI: 1.07-1.70) and 1.41 (95% CI: 1.17-1.70) per standard deviation increase, respectively. When compared to noncarriers, CAD risk increased from 1.24-fold (95% CI: 0.64-2.34) to 3.37-fold (95% CI: 2.11-5.36) across quintiles of the polygenic score. A similar risk gradient, 1.36-fold (95% CI: 0.65-2.85) to 2.88-fold (95% CI: 1.59-5.20), was observed in 429 carriers in the UK Biobank.
UNASSIGNED: In 2 cohort studies involving 1,744 individuals with genetically confirmed HeFH - the largest study to date - risk of CAD varied according to polygenic background, in some cases approaching the risk observed in noncarriers.

Alzheimer\'s disease typically progresses in stages, which have been defined by the presence of disease-specific biomarkers: amyloid (A), tau (T) and neurodegeneration (N). This progression of biomarkers has been condensed into the ATN framework, in which each of the biomarkers can be either positive (+) or negative (-). Over the past decades, genome-wide association studies have implicated ∼90 different loci involved with the development of late-onset Alzheimer\'s disease. Here, we investigate whether genetic risk for Alzheimer\'s disease contributes equally to the progression in different disease stages or whether it exhibits a stage-dependent effect. Amyloid (A) and tau (T) status was defined using a combination of available PET and CSF biomarkers in the Alzheimer\'s Disease Neuroimaging Initiative cohort. In 312 participants with biomarker-confirmed A-T- status, we used Cox proportional hazards models to estimate the contribution of APOE and polygenic risk scores (beyond APOE) to convert to A+T- status (65 conversions). Furthermore, we repeated the analysis in 290 participants with A+T- status and investigated the genetic contribution to conversion to A+T+ (45 conversions). Both survival analyses were adjusted for age, sex and years of education. For progression from A-T- to A+T-, APOE-e4 burden showed a significant effect [hazard ratio (HR) = 2.88; 95% confidence interval (CI): 1.70-4.89; P < 0.001], whereas polygenic risk did not (HR = 1.09; 95% CI: 0.84-1.42; P = 0.53). Conversely, for the transition from A+T- to A+T+, the contribution of APOE-e4 burden was reduced (HR = 1.62; 95% CI: 1.05-2.51; P = 0.031), whereas the polygenic risk showed an increased contribution (HR = 1.73; 95% CI: 1.27-2.36; P < 0.001). The marginal APOE effect was driven by e4 homozygotes (HR = 2.58; 95% CI: 1.05-6.35; P = 0.039) as opposed to e4 heterozygotes (HR = 1.74; 95% CI: 0.87-3.49; P = 0.12). The genetic risk for late-onset Alzheimer\'s disease unfolds in a disease stage-dependent fashion. A better understanding of the interplay between disease stage and genetic risk can lead to a more mechanistic understanding of the transition between ATN stages and a better understanding of the molecular processes leading to Alzheimer\'s disease, in addition to opening therapeutic windows for targeted interventions.

BACKGROUND: The study of biological age acceleration may help identify at-risk individuals and reduce the rising global burden of age-related diseases. Using DNA methylation (DNAm) clocks, we investigated biological aging in schizophrenia (SCZ), a mental illness that is associated with an increased prevalence of age-related disabilities and morbidities. In a whole blood DNAm sample of 1090 SCZ cases and 1206 controls across four European cohorts, we performed a meta-analysis of differential aging using three DNAm clocks (i.e., Hannum, Horvath, and Levine). To dissect how DNAm aging contributes to SCZ, we integrated information on duration of illness and SCZ polygenic risk, as well as stratified our analyses by chronological age and biological sex.
RESULTS: We found that blood-based DNAm aging is significantly altered in SCZ independent from duration of the illness since onset. We observed sex-specific and nonlinear age effects that differed between clocks and point to possible distinct age windows of altered aging in SCZ. Most notably, intrinsic cellular age (Horvath clock) is decelerated in SCZ cases in young adulthood, while phenotypic age (Levine clock) is accelerated in later adulthood compared to controls. Accelerated phenotypic aging was most pronounced in women with SCZ carrying a high polygenic burden with an age acceleration of + 3.82 years (CI 2.02-5.61, P = 1.1E-03). Phenotypic aging and SCZ polygenic risk contributed additively to the illness and together explained up to 14.38% of the variance in disease status.
CONCLUSIONS: Our study contributes to the growing body of evidence of altered DNAm aging in SCZ and points to intrinsic age deceleration in younger adulthood and phenotypic age acceleration in later adulthood in SCZ. Since increased phenotypic age is associated with increased risk of all-cause mortality, our findings indicate that specific and identifiable patient groups are at increased mortality risk as measured by the Levine clock. Our study did not find that DNAm aging could be explained by the duration of illness of patients, but we did observe age- and sex-specific effects that warrant further investigation. Finally, our results show that combining genetic and epigenetic predictors can improve predictions of disease outcomes and may help with disease management in schizophrenia.

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Subjective cognitive decline (SCD) has been described as a probable early stage of dementia, as it has consistently appeared to precede the onset of objective cognitive impairment. SCD is related to many risk factors, including genetic predisposition for dementia. The Apolipoprotein (APOE) ε4 allele, which has been thoroughly studied, seems to explain genetic risk for SCD only partially. Therefore, we aimed to summarize existing data regarding genetic factors related to SCD, beyond APOE ε4, in order to improve our current understanding of SCD. We conducted a PRISMA systematic search in PubMed/MEDLINE and Embase databases using the keywords \"subjective cognitive decline\" and \"genetic predisposition\" with specific inclusion and exclusion criteria. From the 270 articles identified, 16 were finally included for the qualitative analysis. Family history of Alzheimer\'s disease (AD) in regard to SCD was explored in eight studies, with conflicting results. Other genes implicated in SCD, beyond APOE ε4, were investigated in six studies, which were not strong enough to provide clear conclusions. Very few data have been published regarding the association of polygenic risk for AD and SCD. Thus, many more genes related to AD must be studied, with polygenic risk scores appearing to be really promising for future investigation.

BACKGROUND: Theories of risk for suicidal thoughts and behaviors (STB) implicate both interpersonal and biological factors. Divorce/separation and aggregate genetic liability are robustly associated with STB, but have seldom been evaluated in conjunction with one another. Furthermore, whether these factors are effective predictors in high-risk populations is not clear.
METHODS: Analyses were conducted in a sample of Han Chinese women with severe recurrent major depressive disorder (maximum N = 4380). Logistic regressions were used to evaluate the associations between divorce/separation and polygenic scores (PGS) for suicidal ideation or behavior with STB. Where appropriate, additive interactions between divorce and PGS were tested.
RESULTS: Divorce/separation was significantly associated with increased risk of suicidal ideation, plans, and attempts (odds ratios = 1.28-1.61). PGS for suicidal ideation were not associated with STB, while PGS for suicidal behavior were associated with ideation and plans (odds ratios = 1.08-1.09). There were no significant interactions between divorce/separation and PGS.
CONCLUSIONS: Consistent with theories of suicidality, the disruption or end of an important interpersonal relationship is an indicator of risk for STB. Aggregate genetic liability for suicidal behavior more modestly contributes to risk, but does not exacerbate the negative impact of divorce. Thus, even within a high-risk sample, interpersonal and biological exposures distinguish between those who do and do not experience STB, and could motivate targeted screening. Further research is necessary to evaluate whether and how the context of divorce contributes to variation in its effect on STB risk.

Impairment of the ubiquitin-proteasome system (UPS) has been implicated in abnormal protein accumulation in Alzheimer\'s disease. It remains unclear if genetic variation affects the intrinsic properties of neurons that render some individuals more vulnerable to UPS impairment.
Induced pluripotent stem cell (iPSC)-derived neurons were generated from over 50 genetically variant and highly characterized participants of cohorts of aging. Proteomic profiling, proteasome activity assays, and Western blotting were employed to examine neurons at baseline and in response to UPS perturbation.
Neurons with lower basal UPS activity were more vulnerable to tau accumulation following mild UPS inhibition. Chronic reduction in proteasome activity in human neurons induced compensatory elevation of regulatory proteins involved in proteostasis and several proteasome subunits.
These findings reveal that genetic variation influences basal UPS activity in human neurons and differentially sensitizes them to external factors perturbing the UPS, leading to the accumulation of aggregation-prone proteins such as tau.
Polygenic risk score for AD is associated with the ubiquitin-proteasome system (UPS) in neurons. Basal proteasome activity correlates with aggregation-prone protein levels in neurons. Genetic variation affects the response to proteasome inhibition in neurons. Neuronal proteasome perturbation induces an elevation in specific proteins involved in proteostasis. Low basal proteasome activity leads to enhanced tau accumulation with UPS challenge.

Prostate cancer has high heritability. Healthy lifestyle has been associated with lower lethal prostate cancer risk among men at increased genetic susceptibility, but the role of healthy dietary patterns remains unknown. We prospectively followed 10,269 genotyped men in the Health Professionals Follow-up Study (1993-2019). Genetic risk was quantified using an established polygenic risk score (PRS). Five dietary patterns were investigated: healthy eating index, Mediterranean, diabetes risk-reducing, hyperinsulinemic and inflammatory diet. Overall and lethal prostate cancer rates (metastatic disease/prostate cancer-specific death) were analyzed using multivariable Cox proportional hazards models. During 26 years of follow-up, 2133 overall and 253 lethal prostate cancer events were documented. In the highest PRS quartile, higher adherence to a diabetes risk-reducing diet was associated with lower rates of overall (top vs. bottom quintile HR [95% CI], 0.74 [0.58-0.94]) and lethal prostate cancer (0.43 [0.21-0.88]). A low insulinemic diet was associated with similar lower rates (overall, 0.76 [0.60-0.95]; lethal, 0.46 [0.23-0.94]). Other dietary patterns showed weaker, but similar associations. In the highest PRS quartile, men with healthy lifestyles based on body weight, physical activity, and low insulinemic diet had a substantially lower rate (0.26 [0.13-0.49]) of lethal prostate cancer compared with men with unhealthy lifestyles, translating to a lifetime risk of 3.4% (95% CI, 2.3%-5.0%) among those with healthy lifestyles and 9.5% (5.3%-16.7%) among those with unhealthy lifestyles. Our findings indicate that lifestyle modifications lowering insulin resistance and chronic hyperinsulinemia could be relevant in preventing aggressive prostate cancer among men genetically predisposed to prostate cancer.