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Experimental Eye Research Jun 2024Aging changes the responsiveness of our immune defense, and this decline in immune reactivity plays an important role in the increased susceptibility to infections that...
Aging changes the responsiveness of our immune defense, and this decline in immune reactivity plays an important role in the increased susceptibility to infections that marks progressing age. Aging is also the most pronounced risk factor for development of age-related macular degeneration (AMD), a disease that is characterized by dysfunctional retinal pigment epithelial (RPE) cells and loss of central vision. We have previously shown that acute systemic viral infection has a large impact on the retina in young mice, leading to upregulation of chemokines in the RPE/choroid (RPE/c) and influx of CD8 T cells in the neuroretina. In this study, we sought to investigate the impact of systemic infection on the RPE/c in aged mice to evaluate whether infection in old age could play a role in the pathogenesis of AMD. We found that systemic infection in mice led to upregulation of genes from the crystallin family in the RPE/c from aged mice, but not in the RPE/c from young mice. Crystallin alpha A (CRYAA) was the most upregulated gene, and increased amounts of CRYAA protein were also detected in the aged RPE/c. Increased CRYAA gene and protein expression has previously been found in drusen and choroid from AMD patients, and this protein has also been linked to neovascularization. Since both drusen and neovascularization are important hallmarks of advanced AMD, it is interesting to speculate if upregulation of crystallins in response to infection in old age could be relevant for the pathogenesis of AMD.
PubMed: 38945517
DOI: 10.1016/j.exer.2024.109984 -
Neurobiology of Disease Jun 2024The temporal component of episodic memory has been recognized as a sensitive behavioral marker in early stage of Alzheimer's disease (AD) patients. However, parallel...
The temporal component of episodic memory has been recognized as a sensitive behavioral marker in early stage of Alzheimer's disease (AD) patients. However, parallel studies in AD animals are currently lacking, and the underlying neural circuit mechanisms remain poorly understood. Using a novel App knock-in (APP-KI) rat model, the developmental changes of temporal order memory (TOM) and the relationship with medial prefrontal cortex and perirhinal cortex (mPFC-PRH) circuit were determined through in vivo electrophysiology and microimaging technique. We observed a deficit in TOM performance during the object temporal order memory task (OTOMT) in APP-KI rats at 6 month old, which was not evident at 3 or 4 months of age. Alongside behavioral changes, we identified a gradually extensive and aggravated regional activation and functional alterations in the mPFC and PRH during the performance of OTOMT, which occurred prior to the onset of TOM deficits. Moreover, coherence analysis showed that the functional connectivity between the mPFC and PRH could predict the extent of future behavioral performance. Further analysis revealed that the aberrant mPFC-PRH interaction mainly attributed to the progressive deterioration of synaptic transmission, information flow and network coordination from mPFC to PRH, suggesting the mPFC dysfunction maybe the key area of origin underlying the early changes of TOM. These findings identify a pivotal role of the mPFC-PRH circuit in mediating the TOM deficits in the early stage of AD, which holds promising clinical translational value and offers potential early biological markers for predicting AD memory progression.
PubMed: 38945496
DOI: 10.1016/j.nbd.2024.106584 -
Translational Research : the Journal of... Jun 2024Renal aging and the subsequent rise in kidney-related diseases are attributed to senescence in renal tubular epithelial cells (RTECs). Our study revealed that the...
Renal aging and the subsequent rise in kidney-related diseases are attributed to senescence in renal tubular epithelial cells (RTECs). Our study revealed that the abnormal expression of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), a reader of RNA N6-methyladenosine, is critically involved in cisplatin-induced renal tubular senescence. In cisplatin-induced senescence of RTECs, the promoter activity and transcription of IGF2BP3 is markedly suppressed. It was due to the down regulation of MYC proto-oncogene (MYC), which regulates IGF2BP3 transcription by binding to the putative site at 1852 to 1863 of the IGF2BP3 promoter. Overexpression of IGF2BP3 ameliorated cisplatin-induced renal tubular senescence in vitro. Mechanistic studies revealed that IGF2BP3 inhibits cellular senescence in RTECs by enhancing cyclin-dependent kinase 6 (CDK6) mRNA stability and increasing its expression. The inhibition effect of IGF2BP3 on tubular senescence is partially reversed by the knockdown of CDK6. Further, IGF2BP3 recruits nuclear cap binding protein subunit 1 (NCBP1) and inhibits CDK6 mRNA decay, by recognizing mA modification. Specifically, IGF2BP3 recognizes mA motif "GGACU" at nucleotides 110-114 in the 5' untranslated region (UTR) field of CDK6 mRNA. The involvement of IGF2BP3/CDK6 in alleviating tubular senescence was confirmed in a cisplatin-induced acute kidney injury (AKI)-to-chronic kidney disease (CKD) model. Clinical data also suggests an age-related decrease in IGF2BP3 and CDK6 levels in renal tissue or serum samples from patients. These findings suggest that IGF2BP3/CDK6 may be a promising target in cisplatin-induced tubular senescence and renal failure.
PubMed: 38945255
DOI: 10.1016/j.trsl.2024.06.004 -
Journal of the American Medical... Jun 2024Loneliness and social isolation are associated with adverse health outcomes, especially within the elderly population, underlining the need for effective interventions.... (Review)
Review
OBJECTIVES
Loneliness and social isolation are associated with adverse health outcomes, especially within the elderly population, underlining the need for effective interventions. This systematic review and meta-analysis aims to summarize all available evidence regarding the effectiveness of interventions for loneliness and social isolation, to map out their working mechanisms, and to give implications for policy and practice.
DESIGN
Systematic literature review and meta-analysis.
SETTING AND PARTICIPANTS
Older adults (≥65 years).
METHODS
A systematic search was conducted in MEDLINE, PsycINFO, and CINAHL for studies quantitively or qualitatively assessing effects of interventions for loneliness and social isolation in older adults, following predefined selection criteria. Risk of bias as well as small study effects were assessed and, wherever appropriate, information about effect sizes of individual studies pooled using random-effects meta-analyses. Sources for between-study heterogeneity were explored using meta-regression.
RESULTS
Of n = 2223 identified articles, n = 67 were eventually included for narrative synthesis. Significant intervention effects were reported for a proportion of studies (55.9% and 50.0% for loneliness and social isolation, respectively) and 57.6% of studies including a follow-up measure (n = 29) reported sustained intervention effects. Meta-analysis of n = 27 studies, representing n = 1756 participants, suggested a medium overall effect of loneliness interventions (d = -0.47; 95% CI, -0.62 to -0.32). Between-study heterogeneity was substantial and could not be explained by differences in study design, year of publication, outcome measures, intervention length, participant demographics, setting, baseline level of loneliness, or geographic location. However, non-technology-based interventions reported larger effect sizes on average (Δd = -0.35; 95% CI, -0.66 to -0.04; P = .029) and were more often significant. Qualitative assessment of potential intervention mechanisms resulted in 3 clusters of effective components: "promoting social contact," "transferring knowledge and skills," and "addressing social cognition".
CONCLUSIONS AND IMPLICATIONS
Interventions for loneliness and social isolation can generally be effective, although some unexplained between-study heterogeneity remains. Further research is needed regarding the applicability of interventions across different settings and countries, also considering their cost-effectiveness.
PubMed: 38945174
DOI: 10.1016/j.jamda.2024.105110 -
Journal of the American Medical... Jun 2024Although the cardiac benefits of maintaining a lifelong exercise routine are undisputed, to what extent late-in-life exercise training can ameliorate cardiac aging...
OBJECTIVE
Although the cardiac benefits of maintaining a lifelong exercise routine are undisputed, to what extent late-in-life exercise training can ameliorate cardiac aging remains unclear. We examined the impact of a 12-month exercise training program on cardiac reserve, static cardiac structure, and cardiac function in older adults.
DESIGN
This study was a single-center, randomized trial using Zelen design. Participants in the center-based exercise (CBE) group underwent an individualized multicomponent exercise training program.
SETTING AND PARTICIPANTS
In total, 120 community-dwelling older adults aged 65-85 years were evenly divided into a CBE group and a control group.
METHODS
The primary outcome indicator was absolute change in peak oxygen uptake (peakVO) per kilogram from baseline to 12 months. The secondary outcome indicators were the absolute changes in other cardiopulmonary exercise test indices and cardiac magnetic resonance parameters. This study has been registered at the Chinese Clinical Trial Registry Network (ChiCTR XXXX).
RESULTS
In total, 47 older adults in the control group and 49 in the CBE group ultimately completed the 12-month follow-up and were analyzed. Of all participants, 52 (46.4%) were men, and the mean age was 71.22 ± 4.55 years. The absolute change in peakVO/kg was significantly different between the CBE and control groups by +3.32 mL/kg/min (95% CI 2.10-4.53; P < .001), and a sex-related difference was observed. Additionally, the right ventricular peak filling and ejection rate improved to a greater degree in the CBE than control group (+65.57 mL/s, P = .006; +56.39 mL/s, P = .026, respectively).
CONCLUSIONS AND IMPLICATIONS
A 12-month exercise training program started later in life was effective in improving cardiopulmonary reserve, and men showed a better response to training than women. The right ventricular function increased after late-in-life exercise training.
PubMed: 38945172
DOI: 10.1016/j.jamda.2024.105117 -
The Lancet. Healthy Longevity Jul 2024Little is known about ageing and frailty progression in low-income settings. We aimed to describe frailty changes over time in individuals living in rural Burkina Faso...
BACKGROUND
Little is known about ageing and frailty progression in low-income settings. We aimed to describe frailty changes over time in individuals living in rural Burkina Faso and to assess which sociodemographic, disability, and multimorbidity factors are associated with frailty progression and mortality.
METHODS
This longitudinal, population-based study was conducted at the Nouna Health and Demographic Surveillance Systems (HDSS) site in northwestern Burkina Faso. Eligible participants were aged 40 years or older and had been primarily resident in a household within the HDSS area for at least the past 6 months before the baseline survey and were selected from the 2015 HDSS household census using a stratified random sample of adults living in unique households within the area. Participants were interviewed in their homes in 2018 (baseline), 2021 (follow-up), or both. We derived the Fried frailty score for each participant at each timepoint using data on grip strength, gait speed, self-reported weight loss, self-reported exhaustion, and physical activity, and described changes in frailty status (no frailty, pre-frailty, or frailty) between 2018 and 2021. We used multivariate regression models to assess factors (ie, sex, age, marital status, educational attainment, wealth quintile, WHO Disability Assessment Schedule (WHODAS) score, and multimorbidity) associated with frailty progression (either worsening frailty status or dying, compared with frailty status remaining the same or improving) and with mortality, and developed sequential models: unadjusted, adjusting for sociodemographic factors (sex, age, marital status, educational attainment, and wealth quintile), and adjusting for sociodemographic factors, disability, and multimorbidity.
FINDINGS
Between May 25 and July 19, 2018, and between July 1 and Aug 22, 2021, 5952 individuals were invited to participate: 1709 (28·7%) did not consent, 1054 (17·8%) participated in 2018 only and were lost to follow-up, 1214 (20·4%) participated in 2021 only, and 1975 (33·2%) were included in both years or died between years. Of 1967 participants followed up with complete demographic data, 190 (9·7%) were frail or unable to complete the frailty assessment in 2018, compared with 77 (3·9%) in 2021. Between 2018 and 2021, frailty status improved in 567 (28·8%) participants and worsened in 327 (16·6%), and 101 (5·1%) participants died. The relative risk of frailty status worsening or of dying (compared with frailty impRoving or no change) increased with age and WHODAS score, whereas female sex appeared protective. After controlling for all sociodemographic factors, multimorbidity, and WHODAS score, odds of mortality were 1·07 (odds ratio 2·07, 95% CI 1·05-4·09) times higher among pre-frail individuals and 1·1 (2·21, 0·90-5·41) times higher among frail individuals than among non-frail individuals.
INTERPRETATION
Frailty status was highly dynamic in this low-income setting and appears to be modifiable. Given the rapid increase in the numbers of older adults in low-income or middle-income countries, understanding the behaviour of frailty in these settings is of high importance for the development of policies and health systems to ensure the maintenance of health and wellbeing in ageing populations. Future work should focus on designing context-appropriate interventions to improve frailty status.
FUNDING
Alexander Von Humboldt Foundation, Institute for Global Innovation, University of Birmingham, and Wellcome Trust.
Topics: Humans; Male; Female; Longitudinal Studies; Aged; Middle Aged; Frailty; Burkina Faso; Rural Population; Adult; Disease Progression; Aged, 80 and over; Frail Elderly
PubMed: 38945131
DOI: 10.1016/S2666-7568(24)00096-5 -
The Lancet. Healthy Longevity Jul 2024Together with environmental factors, intrinsic capacity (the composite of all the physical and mental capacities of an individual) has been proposed as a marker of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Together with environmental factors, intrinsic capacity (the composite of all the physical and mental capacities of an individual) has been proposed as a marker of healthy ageing. However, whether intrinsic capacity predicts major clinical outcomes is unclear. We aimed to explore the association of intrinsic capacity with functional decline and mortality in older adults.
METHODS
In this systematic review and meta-analysis, we conducted a systematic search in MEDLINE (via PubMed), Scopus, and Web of Science from database inception to Feb 14, 2024, of observational longitudinal studies conducted in older adults (age ≥60 years) assessing the association of intrinsic capacity with impairment in basic activities of daily living (BADL) or instrumental activities of daily living (IADL) or risk of mortality. Estimates were extracted by two reviewers (JLS-S and W-HL) and were pooled using three-level meta-analytic models. The quality of each study was independently assessed by two authors (JLS-S and PLV) using the Newcastle-Ottawa Scale for longitudinal studies. Heterogeneity was evaluated using the I indicator at two levels: within-study (level 2) and between-study (level 3) variation. For associations between intrinsic capacity and IADL and BADL, we transformed data (standardised β coefficients and odds ratios [ORs]) into Pearson product moment correlation coefficients (r) using Pearson and Digby formulas to allow comparability across studies. For associations between intrinsic capacity and risk of mortality, hazard ratios (HRs) with 95% CIs were extracted from survival analyses. This study is registered with PROSPERO, CRD42023460482.
FINDINGS
We included 37 studies (206 693 participants; average age range 65·3-85·9 years) in the systematic review, of which 31 were included in the meta-analysis on the association between intrinsic capacity and outcomes; three studies (2935 participants) were included in the meta-analysis on the association between intrinsic capacity trajectories and longitudinal changes in BADL or IADL. Intrinsic capacity was inversely associated with longitudinal impairments in BADL (Pearson's r -0·12 [95% CI -0·19 to -0·04]) and IADL (-0·24 [-0·35 to -0·13]), as well as with mortality risk (hazard ratio 0·57 [95% CI 0·51 to 0·63]). An association was also found between intrinsic capacity trajectories and impairment in IADL (but not in BADL), with maintained or improved intrinsic capacity over time associated with a lower impairment in IADL (odds ratio 0·37 [95% CI 0·19 to 0·71]). There was no evidence of publication bias (Egger's test p>0·05) and there was low between-study heterogeneity (I=18·4%), though within-study (I=63·2%) heterogeneity was substantial.
INTERPRETATION
Intrinsic capacity is inversely associated with functional decline and mortality risk in older adults. These findings could support the use of intrinsic capacity as a marker of healthy ageing, although further research is needed to refine the structure and operationalisation of this construct across settings and populations.
FUNDING
None.
TRANSLATIONS
For the Spanish and French translations of the abstract see Supplementary Materials section.
Topics: Humans; Aged; Longitudinal Studies; Activities of Daily Living; Mortality; Geriatric Assessment; Aged, 80 and over; Female; Male
PubMed: 38945130
DOI: 10.1016/S2666-7568(24)00092-8 -
The Lancet. Healthy Longevity Jul 2024Ageing hallmarks, characterising features of cellular ageing, have a role in the pathophysiology of many age-related diseases. We examined whether obesity is associated...
BACKGROUND
Ageing hallmarks, characterising features of cellular ageing, have a role in the pathophysiology of many age-related diseases. We examined whether obesity is associated with an increased risk of developing such hallmark-related diseases.
METHODS
In this multicohort study, we included people aged 38-72 years with data on weight, height, and waist circumference measured during a clinical examination at baseline between March 13, 2006, and Oct 1, 2010, from the UK Biobank with follow-up until Nov 12, 2021. To test reproducibility of the findings (replication analysis), we used data from people aged 40 years or older included in the Finnish Public Sector study and the Finnish Health and Social Support study who responded to the study surveys, had data on BMI, and were successfully linked to electronic health records from national registers up to Dec 31, 2016. Obesity and clinical characteristics were assessed at baseline. Via linkage to national health records, participants were followed up for 83 diseases related to nine ageing hallmarks (genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication). Outcomes were the first instance of hallmark-related disease, in addition to co-occurrence of three or more hallmark-related diseases and mortality.
FINDINGS
496 530 adults (mean age 57·0 years [SD 8·1]) from the UK Biobank were included in the primary analysis, and 83 249 (mean age 48·2 years [6·4]) adults from the Finnish cohorts were included in the replication analysis. Median follow-up was 12·7 years (IQR 12·0-13·4) in the UK Biobank and 14·0 years (8·0-15·0) in the Finnish cohorts. After adjusting for demographic characteristics, lifestyle factors, and depression, UK Biobank participants with obesity (BMI ≥30·0 kg/m) had a 1·40 (95% CI 1·38-1·41) times higher hazard ratio for the first hallmark-related disease than those with a healthy weight (BMI 18·5-24·9 kg/m). The corresponding hazard ratios for three co-occurring diseases were 2·92 (95% CI 2·64-3·22) for deregulated nutrient sensing, 2·73 (2·46-3·02) for telomere attrition, 2·33 (2·10-2·60) for epigenetic alterations, 2·30 (2·14-2·48) for mitochondrial dysfunction, 2·23 (2·04-2·45) for stem cell exhaustion, 2·02 (1·89-2·16) for altered intercellular communication, 2·01 (1·89-2·15) for cellular senescence, 1·83 (1·67-2·00) for loss of proteostasis, and 1·39 (1·27-1·52) for genomic instability. These findings were replicated in the Finnish cohorts. In both studies, the associations between other risk factors (low education, unhealthy dietary factors [available only in the UK Biobank], smoking, high alcohol consumption, physical inactivity, and depression) and hallmark-related diseases were weaker than those with obesity. 45-60% of the excess mortality in people with obesity was attributable to hallmark-related diseases.
INTERPRETATION
Obesity might have an important role in the development of diseases associated with cellular ageing. Tackling ageing mechanisms could potentially help to reduce the disease and mortality burden resulting from the obesity epidemic.
FUNDING
Wellcome Trust, UK Medical Research Council, US National Institute on Aging, Academy of Finland, and Finnish Foundation for Cardiovascular Research.
TRANSLATIONS
For the German and Finnish translations of the abstract see Supplementary Materials section.
Topics: Humans; Obesity; Middle Aged; Male; Female; Aged; Adult; Cellular Senescence; Finland; Cohort Studies; Risk Factors; Aging; United Kingdom; Body Mass Index
PubMed: 38945128
DOI: 10.1016/S2666-7568(24)00087-4 -
The Lancet. Healthy Longevity Jul 2024
Topics: Humans; Aging
PubMed: 38945126
DOI: 10.1016/S2666-7568(24)00111-9 -
The Lancet. Healthy Longevity Jul 2024
Topics: Humans; COVID-19
PubMed: 38945125
DOI: 10.1016/S2666-7568(24)00110-7