bims-minfam Biomed News
on Inflammation and metabolism in ageing and cancer
Issue of 2024–01–21
thirteen papers selected by
Ayesh Seneviratne, Western University



  1. Nat Aging. 2024 Jan 16.
      A decline in hematopoietic stem cell (HSC) function is believed to underlie hematological shortcomings with age; however, a comprehensive molecular understanding of these changes is currently lacking. Here we provide evidence that a transcriptional signature reported in several previous studies on HSC aging is linked to stress-induced changes in gene expression rather than aging. Our findings have strong implications for the design and interpretation of HSC aging studies.
    DOI:  https://doi.org/10.1038/s43587-023-00558-z
  2. Hong Kong Med J. 2022 Oct;28(5): 344-346
      
    DOI:  https://doi.org/10.12809/hkmj215134
  3. Adv Exp Med Biol. 2023 ;1442 201-210
      Hematopoietic stem cells (HSCs) undergo an age-related functional decline, which leads to a disruption of the blood system and contributes to the development of aging-associated hematopoietic diseases and malignancies. In this section, we provide a summary of the key hallmarks associated with HSC aging. We also examine the causal factors that contribute to HSC aging and emphasize potential approaches to mitigate HSC aging and age-related hematopoietic disorders.
    Keywords:  Aging; HSC; Niche; Therapeutic strategies
    DOI:  https://doi.org/10.1007/978-981-99-7471-9_12
  4. Nat Aging. 2024 Jan 17.
      Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity and differentiation bias toward myeloid lineages. However, the molecular mechanism behind HSC aging remains largely unknown. In this study, we observed that RNA N1-methyladenosine-generating methyltransferase TRMT6-TRMT61A complex is increased in aged murine HSCs due to aging-declined CRL4DCAF1-mediated ubiquitination degradation signaling. Unexpectedly, no difference of tRNA N1-methyladenosine methylome is observed between young and aged hematopoietic stem and progenitor cells, suggesting a noncanonical role of the TRMT6-TRMT61A complex in the HSC aging process. Further investigation revealed that enforced TRMT6-TRMT61A impairs HSCs through 3'-tiRNA-Leu-CAG and subsequent RIPK1-RIPK3-MLKL-mediated necroptosis cascade. Deficiency of necroptosis ameliorates the self-renewal capacity of HSCs and counters the physiologically deleterious effect of enforced TRMT6-TRMT61A on HSCs. Together, our work uncovers a nonclassical role for the TRMT6-TRMT61A complex in HSC aging and highlights a therapeutic target.
    DOI:  https://doi.org/10.1038/s43587-023-00556-1
  5. Int Dent J. 2024 Feb;pii: S0020-6539(23)00944-9. [Epub ahead of print]74(1): 171-172
    FDI World Dental Federation
      
    Keywords:  Healthy ageing; Older adults; Oral functions; Oral health professionals
    DOI:  https://doi.org/10.1016/j.identj.2023.10.011
  6. Nat Aging. 2024 Jan 19.
      Machine learning models based on DNA methylation data can predict biological age but often lack causal insights. By harnessing large-scale genetic data through epigenome-wide Mendelian randomization, we identified CpG sites potentially causal for aging-related traits. Neither the existing epigenetic clocks nor age-related differential DNA methylation are enriched in these sites. These CpGs include sites that contribute to aging and protect against it, yet their combined contribution negatively affects age-related traits. We established a new framework to introduce causal information into epigenetic clocks, resulting in DamAge and AdaptAge-clocks that track detrimental and adaptive methylation changes, respectively. DamAge correlates with adverse outcomes, including mortality, while AdaptAge is associated with beneficial adaptations. These causality-enriched clocks exhibit sensitivity to short-term interventions. Our findings provide a detailed landscape of CpG sites with putative causal links to lifespan and healthspan, facilitating the development of aging biomarkers, assessing interventions, and studying reversibility of age-associated changes.
    DOI:  https://doi.org/10.1038/s43587-023-00557-0
  7. Adv Exp Med Biol. 2023 ;1442 17-28
      Hematopoietic stem cells (HSCs) are maintained in the bone marrow microenvironment, also known as the niche, that regulates their proliferation, self-renewal, and differentiation. In this chapter, we will introduce the history of HSC niche research and review the interdependencies between HSCs and their niches. We will further highlight recent advances in our understanding of HSC heterogeneity with regard to HSC subpopulations and their interacting cellular and molecular bone marrow niche constituents.
    Keywords:  Aging; Hematopoietic stem cells; Leukemia; Niche
    DOI:  https://doi.org/10.1007/978-981-99-7471-9_2
  8. Exp Gerontol. 2024 Jan 16. pii: S0531-5565(24)00007-X. [Epub ahead of print] 112365
      Ageing is accompanied by a decline in immune function (immunosenescence), increased inflammation (inflammaging), and more senescent cells which together contribute to age-related disease and infection susceptibility. The innate immune system is the front-line defence against infection and cancer and is also involved in the removal of senescent cells, so preventing innate immunosenescence and inflammaging is vital for health in older age. Extracellular vesicles (EVs) modulate many aspects of innate immune function, including chemotaxis, anti-microbial responses, and immune regulation. Senescent cell derived EVs (SEVs) have different cargo to that of non-senescent cell derived EVs, suggesting alterations in EV cargo across the lifespan may influence innate immune function, possibly contributing to immunosenescence and inflammaging. Here we review current understanding of the potential impact of miRNAs, lipids and proteins, found in higher concentrations in SEVs, on innate immune functions and inflammation to consider whether SEVs are potential influencers of innate immunosenescence and inflammaging. Furthermore, senolytics have demonstrated an ability to return plasma EV content closer to that of non-senescent EVs, therefore the potential use of senotherapeutics (senolytics and senostatics) to ameliorate the effects of SEVs on immunosenescence and inflammaging is also considered as a possible strategy for extending health-span in older adults.
    Keywords:  Ageing; Extracellular vesicles; Immunosenescence; Inflammaging; Senescence
    DOI:  https://doi.org/10.1016/j.exger.2024.112365
  9. JAMA Netw Open. 2024 Jan 02. 7(1): e2351927
       Importance: Clonal hematopoiesis (CH) with acquired pathogenic variants in myeloid leukemia driver genes is common in older adults but of unknown prognostic value.
    Objective: To investigate the prevalence of CH and the utility of the CH risk score (CHRS) in estimating all-cause and disease-specific mortality in older adults with CH.
    Design, Setting, and Participants: This population-based prospective cohort study involved community-dwelling older adults (aged 67-90 years) without hematologic malignant neoplasms (HMs) who were participants in the Atherosclerosis Risk in Communities Visit 5 at 4 US centers: Forsyth County, North Carolina; Jackson, Mississippi; Minneapolis, Minnesota; and Washington County, Maryland. Samples were collected from 2011 to 2013, sequencing was performed in 2022, and data analysis was completed in 2023.
    Exposure: The exposure was a diagnosis of CH. CHRS scores (calculated using 8 demographic, complete blood cell count, and molecular factors) were used to categorize individuals with CH into low-risk (CHRS ≤9.5), intermediate-risk (CHRS >9.5 to <12.5), and high-risk (CHRS ≥12.5) groups.
    Main Outcomes and Measures: The primary outcome was all-cause mortality, and secondary outcomes were HM mortality, cardiovascular disease mortality, and death from other causes.
    Results: Among 3871 participants without a history of HM (mean [SD] age, 75.7 [5.2] years; 2264 [58.5%] female individuals; 895 [23.1%] Black individuals; 2976 White individuals [76.9%]), 938 (24.2%) had CH. According to the CHRS, 562 (59.9%) were low risk, 318 (33.9%) were intermediate risk, and 58 (6.2%) were high risk. During a median (IQR) follow-up of 7.13 (5.63-7.78) years, 570 participants without CH (19.4%) and 254 participants with CH (27.1%) died. Mortality by CHRS risk group was 128 deaths (22.8%) for low risk, 93 (29.2%) for intermediate risk, and 33 (56.9%) for high risk. By use of multivariable competing risk regression, subdistribution hazard ratios (sHRs) for all-cause mortality were 1.08 (95% CI, 0.89-1.31; P = .42) for low-risk CH, 1.12 (95% CI, 0.89-1.41; P = .31) for intermediate-risk CH, and 2.52 (95% CI, 1.72-3.70; P < .001) for high-risk CH compared with no CH. Among individuals in the high-risk CH group, the sHR of death from HM (6 deaths [10.3%]) was 25.58 (95% CI, 7.55-86.71; P < .001) and that of cardiovascular death (12 deaths [20.7%]) was 2.91 (95% CI, 1.55-5.47; P < .001).
    Conclusions and Relevance: In this cohort study, the CHRS was associated with all-cause, HM-related, and cardiovascular disease mortality in older adults with CH and may be useful in shared decision-making to guide clinical management and identify appropriate candidates for clinical trials.
    DOI:  https://doi.org/10.1001/jamanetworkopen.2023.51927
  10. Sci Signal. 2024 Jan 16. 17(819): eadn9627
      The actions of glucagon-like peptide 1 receptor agonists in the CNS reduce systemic inflammation.
    DOI:  https://doi.org/10.1126/scisignal.adn9627