Geroscience, the new interdisciplinary field that aims to understand the relationship between aging and chronic age-related diseases (ARDs) and geriatric syndromes (GSs), is based on epidemiological evidence and experimental data that aging is the major risk factor for such pathologies and assumes that aging and ARDs/GSs share a common set of basic biological mechanisms. A consequence is that the primary target of medicine is to combat aging instead of any single ARD/GSs one by one, as favored by the fragmentation into hundreds of specialties and sub-specialties. If the same molecular and cellular mechanisms underpin both aging and ARDs/GSs, a major question emerges: which is the difference, if any, between aging and ARDs/GSs? The hypothesis that ARDs and GSs such as frailty can be conceptualized as accelerated aging will be discussed by analyzing in particular frailty, sarcopenia, chronic obstructive pulmonary disease, cancer, neurodegenerative diseases such as Alzheimer and Parkinson as well as Down syndrome as an example of progeroid syndrome. According to this integrated view, aging and ARDs/GSs become part of a continuum where precise boundaries do not exist and the two extremes are represented by centenarians, who largely avoided or postponed most ARDs/GSs and are characterized by decelerated aging, and patients who suffered one or more severe ARDs in their 60s, 70s, and 80s and show signs of accelerated aging, respectively. In between these two extremes, there is a continuum of intermediate trajectories representing a sort of gray area. Thus, clinically different, classical ARDs/GSs are, indeed, the result of peculiar combinations of alterations regarding the same, limited set of basic mechanisms shared with the aging process. Whether an individual will follow a trajectory of accelerated or decelerated aging will depend on his/her genetic background interacting lifelong with environmental and lifestyle factors. If ARDs and GSs are manifestations of accelerated aging, it is urgent to identify markers capable of distinguishing between biological and chronological age to identify subjects at higher risk of developing ARDs and GSs. To this aim, we propose the use of DNA methylation, N-glycans profiling, and gut microbiota composition to complement the available disease-specific markers.
Cell‐free DNA (cfDNA) is present in the circulating plasma and other body fluids and is known to originate mainly from apoptotic cells. Here, we provide the first in vivo evidence of global and local chromatin changes in human aging by analyzing cfDNA from the blood of individuals of different age groups. Our results show that nucleosome signals inferred from cfDNA are consistent with the redistribution of heterochromatin observed in cellular senescence and aging in other model systems. In addition, we detected a relative cfDNA loss at several genomic locations, such as transcription start and termination sites, 5′UTR of L1HS retrotransposons and dimeric AluY elements with age. Our results also revealed age and deteriorating health status correlate with increased enrichment of signals from cells in different tissues. In conclusion, our results show that the sequencing of circulating cfDNA from human blood plasma can be used as a noninvasive methodology to study age‐associated changes to the epigenome in vivo.
Human aging is a lifelong process characterized by a continuous trade-off between pro-and anti-inflammatory responses, where the best-adapted and/or remodeled genetic/epigenetic profile may develop a longevity phenotype. Centenarians and their offspring represent such a phenotype and their comparison to patients with age-related diseases (ARDs) is expected to maximize the chance to unravel the genetic makeup that better associates with healthy aging trajectories. Seemingly, such comparison is expected to allow the discovery of new biomarkers of longevity together with risk factor for the most common ARDs. MicroRNAs (miRNAs) and their shuttles (extracellular vesicles in particular) are currently conceived as those endowed with the strongest ability to provide information about the trajectories of healthy and unhealthy aging. We review the available data on miRNAs in aging and underpin the evidence suggesting that circulating miRNAs (and cognate shuttles), especially those involved in the regulation of inflammation (inflamma-miRs) may constitute biomarkers capable of reliably depicting healthy and unhealthy aging trajectories.
Background: Post-operative delirium (POD) is a common complication in elderly patients undergoing surgery, but the underpinning causes are not clear. We hypothesized that inflammaging, the subclinical low and chronic grade inflammation characteristic of old people, can contribute to POD onset. Accordingly, we investigated the association of pre-operative and circulating cytokines in elderly patients (>65 years), admitted for elective and emergency surgery.Methods: This is a secondary analysis of a sub-cohort of patients belonging to a previous large case–control study, where 351 patients were clinically and cognitively thoroughly characterized, together with the assessment of POD (47 patients) by confusion assessment method and delirium rating scale. Seventy-four pre-operative plasma samples were selected from a larger bio-bank and they included 37 subjects with POD and 37 without POD. Inflammaging related cytokines, i.e., IL-1β, IL-2, IL-6, IL-8, IL-10, and TNF-α, were assayed by ELISA in pre-operative blood samples; univariate and multivariable analyses have been applied to identify cytokines independently associated to POD. Associations of cytokine levels with functional status, cognitive decline, intra-hospital mortality, and comorbidity were also analyzed independently of POD onset.Results: High IL-6 and low-IL-2 levels were significantly associated with POD. After adjustment for potential confounders in multivariate analysis, high level of pre-operative IL-6 was confirmed to be significantly associated with risk of POD onset. High level of IL-6 was also associated with several baseline features (including poor functional status, cognitive impairment, emergency admission, and higher comorbidity burden) and intra-hospital mortality.Conclusion: Pre-operative, high-plasma level of IL-6 (≥9 pg/mL) was significantly associated with POD onset. We propose IL-6 as an additional risk factor of POD onset together with the previously identified factors. Discovery of all risk factors contributing to POD onset will permit to improve hospitalized patient management and the decrease of healthcare cost.
The immune system is comprised of several CD4 þ T regulatory (Treg) cell types, of which two, the Foxp3 þ Treg and T regulatory type 1 (Tr1) cells, have frequently been associated with transplant tolerance. However, whether and how these two Treg-cell types synergize to promote allograft tolerance remains unknown. We previously developed a mouse model of allogeneic transplantation in which a specific immunomodulatory treatment leads to transplant tolerance through both Foxp3 þ Treg and Tr1 cells. Here, we show that Foxp3 þ Treg cells exert their regulatory function within the allograft and initiate engraftment locally and in a non-antigen (Ag) specific manner. Whereas CD4 þ CD25 À T cells, which contain Tr1 cells, act from the spleen and are key to the maintenance of long-term tolerance. Importantly, the role of Foxp3 þ Treg and Tr1 cells is not redundant once they are simultaneously expanded/induced in the same host. Moreover, our data show that long-term tolerance induced by Foxp3 þ Treg-cell transfer is sustained by splenic Tr1 cells and functionally moves from the allograft to the spleen.Key words: Graft, spleen, T regulatory cells, transplant tolerance Abbreviations: 2TT mice, mice comprising two Tregcell types; ENGR-2TT mice, engrafted mice analyzed 30 days after transplant; TOL-2TT mice, tolerant mice analyzed 150 days after transplant and after donor cell boost; Fir/Tiger mice, double reporter mice Foxp3-RFP and Il10-eGFP.
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