ABSTRACT
Microplastics (MPs) are ubiquitous in the environment, continuously undergo aging processes and release toxic chemical substances. Understanding the environmental behaviors of MPs is critical to accurately evaluate their long-term ecological risk. Generalized two-dimensional correlation spectroscopy (2D-COS) is a powerful tool for MPs studies, which can dig more comprehensive information hiding in the conventional one-dimensional spectra, such as infrared (IR) and Raman spectra. The recent applications of 2D-COS in analyzing the behaviors and fates of MPs in the environment, including their aging processes, and interactions with natural organic matter (NOM) or other chemical substances, were summarized systematically. The main requirements and limitations of current approaches for exploring these processes are discussed, and the corresponding strategies to address these limitations and drawbacks are proposed as well. Finally, new trends of 2D-COS are prospected for analyzing the properties and behaviors of MPs in both natural and artificial environmental processes.
Subject(s)
Environmental Monitoring , Microplastics , Microplastics/analysis , Environmental Monitoring/methods , Spectroscopy, Fourier Transform Infrared/methods , Water Pollutants, Chemical/analysisABSTRACT
Objetivo: identificar quais os instrumentos disponíveis para avaliação multidimensional da fragilidade em idosos com doença cardiovascular, potencialmente aplicáveis durante a realização do Processo de Enfermagem. Método: revisão sistemática conduzida em oito bases de dados/portais, para identificação de estudos que apresentassem instrumentos multidimensionais de avaliação de fragilidade em idosos com doença cardiovascular e que fossem aplicáveis ao processo de enfermagem. Resultados: foram incluídos 19 instrumentos multidimensionais. O Brief Frailty Index for Coronary Artery Disease foi desenvolvido para uso no cuidado cardiovascular de idosos. O Frailty Index for Adults e o Maastricht Frailty Screening Tool for Hospitalized Patients foram desenvolvidos para uso no Processo de Enfermagem. Conclusão: apesar de apenas um instrumento ter sido desenvolvido para o idosos com doença cardiovascular e apenas dois serem aplicáveis ao processo de enfermagem, a maioria deles tem potencial de adaptação e validação para uso nesta população durante a avaliação de enfermagem.
Objective: to identify which tools are available for multidimensional frailty assessment of older adult with cardiovascular disease and which are potentially applicable during the Nursing Process. Method: a systematic review conducted in eight databases/portals to identify studies that presented multidimensional frailty assessment tools for older adult with cardiovascular disease and that were applicable to the nursing process. Results: a total of 19 multidimensional tools were included. The Brief Frailty Index for Coronary Artery Disease was developed for use in the cardiovascular care of older adult. The Frailty Index for Adults and the Maastricht Frailty Screening Tool for Hospitalized Patients were developed for use in the Nursing Process. Conclusion: although only one tool was developed for older adults with cardiovascular disease and only two are applicable to the nursing process, most of them have the potential to be adapted and validated for use in this population during nursing assessment.
Objetivo: identificar qué instrumentos están disponibles para la evaluación multidimensional de la fragilidad en personas mayores con enfermedad cardiovascular, que se puedan aplicar en el Proceso de Enfermería. Método: revisión sistemática realizada en ocho bases de datos/portales, para identificar estudios que presentaran instrumentos multidimensionales para la evaluación de la fragilidad en adultos mayores con enfermedad cardiovascular y que fueran aplicables al proceso de enfermería. Resultados: se incluyeron 19 instrumentos multidimensionales. El Brief Frailty Index for Coronary Artery Disease se desarrolló para usarlo en el cuidado cardiovascular de las personas mayores. El Frailty Index for Adults y la Maastricht Frailty Screening Tool for Hospitalized Patients se elaboraron para ser usados en el Proceso de Enfermería. Conclusión: aunque sólo se elaboró un instrumento para adultos mayores con enfermedad cardiovascular y sólo dos son aplicables al proceso de enfermería, la mayoría de ellos tienen el potencial para ser adaptados y validados para ser usados en esa población en la evaluación de enfermería.
ABSTRACT
Epigenetic studies have provided new opportunities to better understand the biological effects of poverty and racial/ethnic minority status. However, little is known about sex differences in these processes. Methods: We used 15 years of follow up of 854 racially and ethnically diverse birth cohort who were followed from birth to age 15. Structural equation modeling (SEM) was used to examine the effects of race/ethnicity, maternal education, and family structure on poverty at birth, as well as the effects of poverty at birth on epigenetic changes at age 15. We also explored variations by sex. Results: Our findings indicate that Black and Latino families had lower maternal education and married family structure which in turn predicted poverty at birth. Poverty at birth then was predictive of epigenetic changes 15 years later when the index child was 15. This suggested that poverty at birth partially mediates the effects of race/ethnicity, maternal education, and family structure on epigenetic changes of youth at age 15. There was an effect of poverty status at birth on DNA methylation of male but not female youth at age 15. Thus, poverty at birth may have a more salient effect on long term epigenetic changes of male than female youth. Conclusions: Further studies are needed to understand the mechanisms underlying the observed sex differences in the effects of poverty as a mechanism that connects race/ethnicity, maternal education, and family structure to epigenetic changes later in life.
ABSTRACT
Purpose: Chronic obstructive pulmonary disease (COPD) is accompanied by increased inflammation, persistent lung function decline, and extensive lung injury. Klotho, a well-known antiaging protein, has anti-inflammatory and antioxidative effects. However, the effects of klotho on COPD have yet to be thoroughly elucidated. This study examined the association among COPD adults and their α-klotho level. Patients and methods: Data were collected from the 2007 to 2012 National Health and Nutrition Examination Survey (NHANES). A total of 676 participants were analyzed and divided into COPD (n = 403) and non-COPD (n = 273) groups. The two groups were compared with respect to clinical characteristics. Logistic regression analysis and a generalized additive model were used to estimate the association between COPD incidence and serum α-klotho concentration. All COPD participants were stratified according to the levels of α-klotho (Q1: <687 pg./mL; Q2: 687-900 pg./mL; Q3: ≥900 pg./mL), and clinical characteristics were compared. Results: Non-COPD individuals had higher α-klotho levels than did COPD individuals (863.09 ± 267.13 vs. 817.51 ± 302.20, p < 0.05). Logistic regression analysis revealed that the Q2 and Q3 layers had a lower risk of COPD than did the Q1 layer, with odds ratios (ORs) of 0.73 (0.50, 0.99) for Q2 and 0.58 (0.41, 0.86) for Q3 (p < 0.001). The generalized additive model showed that the risk of COPD gradually decreased with increasing α-klotho concentration when the α-klotho concentration < 1,500 pg./mL, while the risk of COPD increased as the α-klotho concentration increased to ≥1,500 pg./mL. Compared with individuals in the Q2 or Q3 groups, individuals with COPD in the Q1 group were more likely to be current smokers, have lower levels of erythrocytes, and have higher levels of creatinine and leukocytes. Conclusion: Increased α-klotho levels were negatively correlated with the risk of COPD in participants over 40 years old with α-klotho <1,500 pg./mL. When α-klotho was ≥1,500 pg./mL, the risk of COPD increased as α-klotho levels increased. Pulmonary ventilation function and the number of hemocytes differed among COPD patients with different levels of α-klotho.
ABSTRACT
The intersection of gerontology and public health is increasingly vital due to the global aging population and its implications for health systems. This scoping review aims to map existing literature on gerontology within public health, identify current perspectives, and evaluate interventions tailored to the needs of older adults. A systematic search was performed using predefined keywords across multiple databases, including PubMed, Google Scholar, Scopus, and Web of Science. The review included 42 studies that employed various designs, all focusing on public health interventions targeting the aging population. Key findings indicate a pressing need to integrate gerontological principles into public health practice, recognizing the heterogeneous nature of older adults and the significance of social determinants of health. Interventions ranged from preventive health measures and chronic disease management programs to health promotion activities and caregiver support, including the application of technology to improve health outcomes. However, there was a notable lack of research on diverse populations and mental health interventions. The review also uncovered critical gaps in the literature, such as economic barriers to care access and the necessity for comprehensive policies addressing the aging population's diverse needs. In conclusion, this review emphasizes the importance of a multidimensional approach to effectively addressing older adults' health needs. While several effective interventions exist, there is an urgent need to tackle identified gaps, particularly concerning diverse populations and mental health, to enhance overall health strategies for the aging demographic.
ABSTRACT
In this study, a new system was developed to carry out simultaneous near-infrared (NIR) and small-angle X-ray scattering (SAXS) measurements. Aged PP was examined with the NIR-SAXS system to demonstrate how it can be utilized to derive pertinent information about polymer structure. Pairs of SAXS profiles and NIR spectra of PP in its initial state and after aging were measured to derive an in-depth understanding of the aging phenomenon. The SAXS profiles of the PP samples showed a clear shift of the SAXS peak to the lower q direction induced by the thermal aging, indicating an increase in the length of the long-period structure. Two-trace two-dimensional (2T2D) asynchronous correlation spectra derived from NIR spectra clearly revealed that the aging treatment leads to the substantial increase in the spectral intensity of the regularity bands representing the longer helix present in a folded lamellar structure. In other words, it suggest that the long helix structure is more abundantly present than the short helix structure in the aged PP than in the initial PP. By combining the information derived from the SAXS profiles and NIR spectra, the details of the aging-induced variation were clearly determined. Namely, aging causes additional crystallization of the PP by developing more helix structures, which involves an increase in lamellar thickness as well as a decrease in the amorphous region. The growth of the rigid crystalline phase restricts the elastic deformation in the amorphous structure, which eventually induces the deterioration of PP by making the polymer hard but brittle. Such observation, in turn, implies that the retarding or accelerating the crystallized structure of PP substantially works to control the progress of the aging.
ABSTRACT
Warfarin, with its narrow therapeutic range, requires the understanding of various influencing factors for personalized medication. Vascular senescence, marked by vascular stiffening and endothelial dysfunction, has an unclear effect on the efficacy and safety of warfarin. Based on previous studies, we hypothesized that vascular senescence increases the risk of bleeding during warfarin therapy. This study aimed to explore these effects using animal models and clinical cohorts. We established rat models of vascular senescence and calcification using d-galactose (D-Gal), vitamin D and nicotine (VDN). After validating the models, we examined changes in the International Normalized Ratio (INR) at fixed warfarin doses (0.20 and 0.35 mg/kg). We found that vascular senescence caused significantly elevated INR values and increasd bleeding risk. In the prospective clinical cohort study(NCT06428110), hospitalized warfarin patients with standard dose adjustments were divided into vascular senescence and control groups based on ultrasound and Computed Tomography (CT) diagnosis. Using propensity score matching (PSM) to exclude the influence of confounding factors, we found that the vascular senescence group had lower steady-state warfarin doses and larger dose adjustments, with a higher probability of INR exceeding the therapeutic range. The vascular senescence group tended to experience more bleeding or thromboembolic/ischemic events during one year of follow-up, while there was no statistical difference. In conclusion, vascular senescence leads to unstable INR values and increases higher bleeding risk during warfarin therapy, highlighting the importance of considering vascular senescence in future precision warfarin therapies. Significance Statement Many factors influence warfarin efficacy, however, the effect of vascular senescence remains unclear. This study aimed to investigate the effects of vascular senescence on the efficacy and safety of warfarin. Through both rat models and clinical cohort studies, our findings indicated that vascular senescence may compromise the stability of warfarin, presenting challenges in maintaining its efficacy and safety.
ABSTRACT
BACKGROUND AND OBJECTIVE: Work discrimination is an important public health problem with consequences for health. This study examined the effect of chronic work discrimination on 4-year changes in HbA1c, as a reflection of glucose control and type 2 diabetes risk in older workers and assessed whether allostatic load (AL) impacted the strength of this association. RESEARCH DESIGN AND METHODS: We used Health and Retirement Study data (2010-2016, n=3,246). Conditional change multinomial logistic regression examined the association between chronic work discrimination, high AL (4 or more out of 8 high-risk biomarkers), and HbA1c, while accounting for relevant covariates. RESULTS: Black participants had the highest rates of baseline (22.7%) and follow-up (28%) HbA1c levels, AL (38%), and chronic work discrimination (39%) (p<0.01). Severe chronic work discrimination was associated with elevated HbA1c (RRR=1.61, 95%CI=1.07,2.43). AL was associated with elevated HbA1c (RRR=1.49, 95%CI=1.04,2.14). Relative to White participants, Hispanic (RRR=1.52, 95%CI=1.07,2.16, RRR=1.81, 95%CI=1.051, 3.12) and Black (RRR=2.42, 95%CI=1.82,3.23, RRR=3.00, 95%CI=1.97,4.56) participants had an increased risk of intermediate and elevated HbA1c respectively. Among those with long job tenure (≥ 5 years) both moderate (RRR=1.81, 95%CI=1.11,2.96) and severe (RRR=1.90, 95%CI=1.15,3.12) chronic work discrimination was associated with elevated HbA1c. DISCUSSION AND IMPLICATIONS: Chronic work discrimination, was associated with HbA1c, however no moderating effects of AL were observed. Findings underscore a need for organizational and public health measures to establish strong anti-discrimination laws in the workplace, to improve the work environment of older workers and diabetes risk.
ABSTRACT
Nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase (N-d) positive neurons have been extensively studied across various animals, and N-d neurodegenerative neurites have been detected in some aged animal models. However, detailed knowledge on N-d positivity and aging-related alterations in the spinal cord and medulla oblongata of pigeons is limited. In this study, we investigated N-d positivity and age-related changes in the pigeon's spinal cord and medulla oblongata and compared them to those in rats and mice. Pigeons, had more N-d neurons in the dorsal horn, around the central canal, and in the column of Terni in the thoracic and lumbar segments, with scattered neurons found in the ventral horn of the spinal segments. N-d neurons were also present in the white matter of the spinal cord. Morphometric analysis revealed that the size of N-d soma in the lumbosacral, cervical, and thoracic regions was substantially altered in aged pigeons compared to young birds. Furthermore, the lumbar to sacral segments underwent significant morphological alterations. The main findings of this study were the presence of age-related N-d positive bodies (ANB) in aged pigeons, predominantly in the external cuneate nucleus (CuE) and occasionally in the gracilis and CuEs. ANBs were also identified in the gracile nuclei and spinal cord in the aged rats and mice, whereas in aged rats, ANBs were detected in the CuE spinal nucleus. Immunohistochemistry showed that the age-related alterations occurred in the cell types and neuropeptides in old animals. The results suggest weak inflammatory response and neuronal dysfunction in the spinal cord in aged pigeons. Our results suggested that the ANB could be a potential aging marker for the central nervous system.
ABSTRACT
BACKGROUND: This study compared the mortality risk of long-lived siblings with the U.S. population average and their spouse controls, and investigated the leading causes of death and the familial effect in death pattern. METHODS: In the Long Life Family Study (LLFS), 1,264 proband siblings (Mean age 90.1, SD 6.4) and 172 spouses (83.8, 7.2) from 511 U.S.-based families were recruited and followed over 12 years. Their survival function was compared with a birth cohort-, baseline age-, sex-, and race-matched pseudo sample from U.S. census data. To examine underlying and contributing causes, we examined in detail 338 deaths with complete death adjudication at the University of Pittsburgh Field Center through the year 2018. A familial effect on survival and death pattern was examined using mixed effect models. RESULTS: The LLFS siblings had better survival than the matched U.S. population average. They also had slightly but not significantly better survival than their spouses' (HR=1.18 [95%CI 0.94-1.49]) after adjusting for age and sex. Age at death ranged from 75-104 years, mean 91.4. The leading causes of death were cardiovascular disease (33.1%), dementia (22.2%), and cancer (10.7%). Mixed effect model shows a significant random effect of family in survival, with adjustment of baseline age and sex. There was no significant familial effect in the underlying cause of death or conditions directly contributing to death among siblings recruited by the University of Pittsburgh Field Center. CONCLUSION: Our findings demonstrate a higher survival in the LLFS siblings than the U.S. census data, with a familial component of survival. We did not find significant correspondence in causes of death between siblings within families.
ABSTRACT
Tackling the issue of healthy aging in society is complex. It requires an interdisciplinary perspective and different forms of innovation. This article provides a commentary on the role of innovation policy in addressing healthy aging, particularly in the UK context. We argue that the wide range of economic activities related to healthy aging is part of a hybrid domain rather than a single sector. This represents a new generation of innovation policy for healthy aging which prioritizes understanding how different actors can be connected to support a spectrum of types of innovation which will contribute to providing better goods, services, and practices for older people. We explore social innovation as it relates to hybrid domains such as healthy aging and discuss the role of place in creating policy which generates both societal and market value. We recommend that policymakers use these concepts to build a better understanding of the economies that are evolving around healthy aging and where opportunities exist to better conceptualize, connect, and support actors, initiatives, and places to optimize economic potential and social outcomes.
ABSTRACT
Colorectal cancer (CRC) is a major global health concern and represents a significant public health challenge in Hungary, where it exhibits some of the highest morbidity and mortality rates in the European Union. The Mediterranean diet has been suggested to reduce the incidence of CRC, but comprehensive evidence from diverse study designs is needed to substantiate this effect. A systematic literature search was conducted in PubMed, ClinicalTrials.gov, CENTRAL, and the Web of Science to identify randomized controlled trials and human clinical trials from 2008 to 2024 to identify relevant studies. Statistical analysis was performed using the https://metaanalysisonline.com web application using a random effects model to estimate the pooled hazard rates (HRs). Forest plots, funnel plots, and Z-score plots were utilized to visualize results. We identified 15 clinical trials and 9 case-control studies, encompassing a total of 2,217,404 subjects. The pooled analysis indicated that adherence to the Mediterranean diet significantly reduced the prevalence of CRC (HR = 0.84, 95% CI = 0.78-0.91, p < 0.01). This protective effect was consistent across sexes, with HRs of 0.85 (95% CI = 0.75-0.97, p = 0.01) for males and 0.88 (95% CI = 0.79-0.99, p = 0.03) for females. Case-control studies specifically showed a substantial effect (HR = 0.51, 95% CI = 0.38-0.68, p < 0.01). Notable heterogeneity was observed across studies, yet the a priori information size was substantially below the cumulative sample size, ensuring sufficient data for reliable conclusions. The findings from this meta-analysis reinforce the protective role of the Mediterranean diet against CRC. The results of this meta-analysis will inform dietary interventions designed to mitigate CRC risk, which are conducted within the framework of the Semmelweis Study, an ongoing comprehensive cohort study at Semmelweis University, designed to explore the multifaceted causes of unhealthy aging in Hungary. These interventions aim to explore the practical application of Mediterranean dietary patterns in reducing CRC incidence among the Hungarian population.
ABSTRACT
Aging can lead to a series of degenerative changes in skeletal muscle, which would negatively impact physical activity and the quality of life of the elderly. Wolfberry contains numerous bioactive substances. It's vital to further explore the mechanisms underlying its healthy effects on skeletal muscle function during aging progress. This study discusses the benefits and mechanisms of aqueous extract of wolfberry (AEW) to protect skeletal muscle from aging-related persistent DNA damage based on its anti-inflammatory activity. It is found that AEW improves muscle mass, strength, and endurance, modulates the expression of Atrogin-1, MyH, and MuRF-1, and decreases oxidative stress and inflammation levels in aging mice, which is consistent with the in vitro results. Mechanistically, AEW inhibits the pattern recognition receptors (PRRs) pathway induced by inflammatory gene activation, suggesting its potential in response to DNA damage. AEW is also observed to mitigate chromatin decompaction. Network pharmacology is conducted to analyze the potential targets of AEW in promoting DNA repair. In conclusion, the study shows the anti-aging effects of AEW on skeletal muscle by promoting DNA repair and reducing the transcriptional activity of inflammatory factors. AEW intake may become a potential strategy for strengthening skeletal muscle function in the elderly.
ABSTRACT
Reactivation of retroelements in the human genome has been linked to aging. However, whether the epigenetic state of specific retroelements can predict chronological age remains unknown. We provide evidence that locus-specific retroelement DNA methylation can be used to create retroelement-based epigenetic clocks that accurately measure chronological age in the immune system, across human tissues, and pan-mammalian species. We also developed a highly accurate retroelement epigenetic clock compatible with EPICv.2.0 data that was constructed from CpGs that did not overlap with existing first- and second-generation epigenetic clocks, suggesting a unique signal for epigenetic clocks not previously captured. We found retroelement-based epigenetic clocks were reversed during transient epigenetic reprogramming, accelerated in people living with HIV-1, and responsive to antiretroviral therapy. Our findings highlight the utility of retroelement-based biomarkers of aging and support a renewed emphasis on the role of retroelements in geroscience.
ABSTRACT
Objectives: Despite the growing evidence regarding the influence of social factors on frailty in older adults, the effect of social support remains unclear. This study aims to assess the association between social support and frailty progression (transition and incidence) in a sample of community-dwelling older adults. Methods: Using a cohort study design, 1,059 older adults from the Berlin Initiative Study were followed up for 2.1 years. Multinomial and logistic regression analyses were performed to assess the association of social support using Oslo Social Support Scale-3 with frailty transition and incidence, respectively. Gender differences were explored using stratified analyses. Results: At baseline, frailty prevalence in the study population [mean (SD) age 84.3 (5.6) years; 55.8% women] reached 33.1% with 47.0, 29.4 and 23.6% of the participants reporting moderate, strong and poor social support, respectively. Over the follow-up period, social support was not significantly associated with the frailty transition categories in the adjusted model. Conversely, the adjusted logistic regression analysis showed that participants with poor social support had twice the odds of becoming frail compared to those with strong social support (OR 2.07; 95% CI 1.08-3.95). Gender-stratified analyses showed comparable estimates to the main analysis but were statistically non-significant. Discussion: Our study results underpin the role of social factors in frailty incidence and highlight social support as a potential target for frailty-preventing interventions in older adults. Therefore, it is important to adopt a biopsychosocial model rather than a purely biomedical model to understand and holistically improve the health of community-dwelling older adults.
Subject(s)
Frail Elderly , Frailty , Independent Living , Social Support , Humans , Male , Female , Independent Living/statistics & numerical data , Aged, 80 and over , Aged , Frailty/epidemiology , Frail Elderly/statistics & numerical data , Frail Elderly/psychology , Cohort Studies , Prevalence , Incidence , Disease Progression , Logistic Models , Geriatric Assessment/statistics & numerical dataABSTRACT
Air pollution exposure is closely linked to population age and socioeconomic status. Population aging and imbalance in regional economy are thus anticipated to have important implications on ozone (O3)-related health impacts. Here we provide a driver analysis for O3 mortality burden due to respiratory disease in China over 2013-2050 driven by population aging and regional inequity. Unexpectedly, we find that population aging is estimated to result in dramatic rises in annual O3 mortality burden in China; by 56, 101-137, and 298-485 thousand over the periods 2013-2020, 2020-2030, and 2030-2050, respectively. This reflects the exponential rise in baseline mortality rates with increasing age. The aging-induced mortality burden rise in 2030-2050 is surprisingly large, as it is comparable to the net national mortality burden due to O3 exposure in 2030 (359-399 thousand yr-1). The health impacts of O3 pollution, shown as mortality burden per capita, are inequitably distributed, with more severe effects in less developed provinces than their developed counterparts by 23.1% and 21.5% in 2019 and 2030, respectively. However, the regional inequity in O3 mortality burden is expected to be mitigated in 2050. This temporal variation reflects evolving demographic dividend characterized by a larger proportion of younger individuals in developed regions. These findings are critical for targeted improvement of healthcare services to ensure the sustainability of social development.
ABSTRACT
ABSTRACTMany older adults living with HIV face unique challenges, including comorbidities, loneliness, and isolation. This community-academic partnered study elicited viewpoints from older adults living with HIV about the characteristics of a digital environment ("Virtual Village") to combat against loneliness and isolation. We utilized Choice-Based Conjoint Analyses to determine preferred attributes of a Virtual Village. We also conducted focus groups and interviews with older adults living with HIV and used an iterative, data-driven approach to systematically identify emergent themes. Participants (N = 82) were aged 50-82 years and racially/ethnically diverse. The majority were men (78%), gay (66%), and lived with HIV for ≥15 years (83%). Cost was the factor that most drove participants' preference for joining a Virtual Village. Thematic concerns included lack of technological confidence, internet access, potential for harassment in digital environments, privacy, and preference for in-person interactions. Praises centered on convenience and making connections across geographic distances. Participants emphasized the need for purposive strategies to form a cohesive and supportive community for older adults living with HIV. A moderated environment was recommneded to create a safe, structured, and comfortable digital environment for older adults living with HIV. A Virtual Village should be viewed as a bridge to in-person interactions.
ABSTRACT
Muscular efficiency during exercise has been used to interrogate aspects of human muscle energetics, including mitochondrial coupling and biomechanical efficiencies. Typically, assessments of muscular efficiency have involved graded exercises. Results of previous studies have been interpreted to indicate a decline in exercise efficiency with aging owing to decreased mitochondrial function. However, discrepancies in variables such as exercise stage duration, cycling cadence, and treadmill walking mechanics may have affected interpretations of results. Furthermore, recent data from our lab examining the ATP to oxygen ratio (P:O) in mitochondrial preparations isolated from NIA mouse skeletal muscle showed no change with aging. Thus, we hypothesized that Delta Efficiency (∆) during steady-rate cycling exercise would not be altered in older healthy subjects compared to young counterparts regardless of biological sex or training status. Young (21-35 years) and older (60-80 years) men (n=21) and women (n=20) underwent continual, progressive leg cycle ergometer tests pedaling at 60 RPM for 3 stages (35, 60, 85 W) lasting 4 minutes. ∆ was calculated as: (∆ Work Accomplished/∆ Energy Expended). Overall, cycling efficiencies were not significantly different in older compared to young subjects. Similarly, trained subjects did not exhibit significantly different exercise efficiency compared to untrained. Moreover, there were no differences between men and women. Hence, our results obtained on healthy young and older subjects are interpreted to mean that previous reports of decreased efficiency in older individuals were attributable to metabolic or biomechanical comorbidities, not aging per se.
ABSTRACT
Mortality of acute lung injury (ALI) increases with age. Alveolar epithelial type 2 cells (AEII) are the progenitor cells of the alveolar epithelium and crucial for repair after injury. We hypothesize that telomere dysfunction-mediated AEII senescence impairs regeneration and promotes the development of ALI. To discriminate between the impact of old age and AEII senescence in ALI, young (3 months) and old (18 months) Sftpc-Ai9 mice and young Sftpc-Ai9-Trf1 mice with inducible Trf1 knockout-mediated senescence in AEII were treated with 1 µg lipopolysaccharide (LPS)/g BW (n=9-11). Control mice received saline (n=7). Mice were sacrificed 4 or 7 days later. Lung mechanics, pulmonary inflammation and proteomes were analyzed and parenchymal injury, AEII proliferation and AEI differentiation rate were quantified using stereology. Old mice showed 55% mortality by day 4, whereas all young mice survived. Pulmonary inflammation was most severe in old mice, followed by Sftpc-Ai9-Trf1 mice. Young Sftpc-Ai9 mice recovered almost completely by day 7, while Sftpc-Ai9-Trf1 mice still showed mild signs of injury. An expansion of AEII was only measured in young Sftpc-Ai9 mice at day 7. Aging and telomere dysfunction-mediated senescence had no impact on AEI differentiation rate in controls, but the reduced number of AEII in Sftpc-Ai9-Trf1 mice also affected de-novo differentiation after injury. In conclusion, telomere dysfunction-mediated AEII senescence promoted parenchymal inflammation in ALI, but did not enhance mortality like old age. While Differentiation rate remained functional with old age and AEII senescence, AEII proliferative capacity was impaired in ALI, affecting the regenerative ability.
ABSTRACT
BACKGROUND: The remarkable regenerative abilities observed in planarians and cnidarians are closely linked to the active proliferation of adult stem cells and the precise differentiation of their progeny, both of which typically deteriorate during aging in low regenerative animals. While regeneration-specific genes conserved in highly regenerative organisms may confer regenerative abilities and long-term maintenance of tissue homeostasis, it remains unclear whether introducing these regenerative genes into low regenerative animals can improve their regeneration and aging processes. RESULTS: Here, we ectopically express highly regenerative species-specific JmjC domain-encoding genes (HRJDs) in Drosophila, a widely used low regenerative model organism. Surprisingly, HRJD expression impedes tissue regeneration in the developing wing disc but extends organismal lifespan when expressed in the intestinal stem cell lineages of the adult midgut under non-regenerative conditions. Notably, HRJDs enhance the proliferative activity of intestinal stem cells while maintaining their differentiation fidelity, ameliorating age-related decline in gut barrier functions. CONCLUSIONS: These findings together suggest that the introduction of highly regenerative species-specific genes can improve stem cell functions and promote a healthy lifespan when expressed in aging animals.