bims-minfam Biomed News
on Inflammation and metabolism in ageing and cancer
Issue of 2024–01–28
thirteen papers selected by
Ayesh Seneviratne, Western University



  1. J Nutr Health Aging. 2024 Jan;pii: S1279-7707(24)00234-3. [Epub ahead of print]28(1): 100162
      
    DOI:  https://doi.org/10.1016/j.jnha.2024.100162
  2. Nat Aging. 2024 Jan 24.
      Sterile inflammation, also known as 'inflammaging', is a hallmark of tissue aging. Cellular senescence contributes to tissue aging, in part, through the secretion of proinflammatory factors collectively known as the senescence-associated secretory phenotype (SASP). The genetic variability of thioredoxin reductase 1 (TXNRD1) is associated with aging and age-associated phenotypes such as late-life survival, activity of daily living and physical performance in old age. TXNRD1's role in regulating tissue aging has been attributed to its enzymatic role in cellular redox regulation. Here, we show that TXNRD1 drives the SASP and inflammaging through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) innate immune response pathway independently of its enzymatic activity. TXNRD1 localizes to cytoplasmic chromatin fragments and interacts with cGAS in a senescence-status-dependent manner, which is necessary for the SASP. TXNRD1 enhances the enzymatic activity of cGAS. TXNRD1 is required for both the tumor-promoting and immune surveillance functions of senescent cells, which are mediated by the SASP in vivo in mouse models. Treatment of aged mice with a TXNRD1 inhibitor that disrupts its interaction with cGAS, but not with an inhibitor of its enzymatic activity alone, downregulated markers of inflammaging in several tissues. In summary, our results show that TXNRD1 promotes the SASP through the innate immune response, with implications for inflammaging. This suggests that the TXNRD1-cGAS interaction is a relevant target for selectively suppressing inflammaging.
    DOI:  https://doi.org/10.1038/s43587-023-00564-1
  3. Aging Biol. 2023 ;pii: 20230011. [Epub ahead of print]1(1):
      In a recent review article published in Cell, López-Otín and colleagues conducted an exhaustive literature review and described 12 hallmarks of aging. The updated model of aging comprehensively captures the key characteristics of the aging phenotype and incorporates new pathways that play a crucial role in age-related processes. Although the updated hallmarks of aging provide a useful framework for describing the phenotype of aging, aging itself is a result of mechanistically complex and interrelated processes that happen during the lifespan of the organism. Here, I propose to shift the focus from a systematic description and categorization of the hallmarks of aging to a model that separates the early, molecular origins of changes from cellular and tissue responses and represents the sequential and causative character of changes in aging. The proposed model aims to prompt discussion among the aging research community, guide future efforts in the field, and provide new ideas for investigation.
    DOI:  https://doi.org/10.59368/agingbio.20230011
  4. Front Cell Dev Biol. 2023 ;11 1356278
      
    Keywords:  ageing; dietary intervention; drug discovery; metabolic disease; metabolic signaling; metabolism; mitochondrial dysfuncion; mitophagy
    DOI:  https://doi.org/10.3389/fcell.2023.1356278
  5. Ageing Res Rev. 2024 Jan 23. pii: S1568-1637(24)00022-9. [Epub ahead of print] 102204
      The pursuit for the fountain of youth has long been a fascination amongst scientists and humanity. Ageing is broadly characterized by a cellular decline with increased susceptibility to age-related diseases, being intimately associated with epigenetic modifications. Recently, reprogramming-induced rejuvenation strategies have begun to greatly alter longevity research not only to tackle age-related defects but also to possibly reverse the cellular ageing process. Hence, in this review, we highlight the major epigenetic changes during ageing and the state-of-art of the current emerging epigenetic reprogramming strategies leveraging on transcription factors. Notably, partial reprogramming enables the resetting of the ageing clock without erasing cellular identity. Promising chemical-based rejuvenation strategies harnessing small molecules, including DNA methyltransferase and histone deacetylase inhibitors are also discussed. Moreover, in parallel to longevity interventions, the foundations of epigenetic clocks for accurate ageing assessment and evaluation of reprogramming approaches are briefly presented. Going further, with such scientific breakthroughs, we are witnessing a rise in the longevity biotech industry aiming to extend the health span and ideally achieve human rejuvenation one day. In this context, we overview the main scenarios proposed for the future of the socio-economic and ethical challenges associated with such an emerging field. Ultimately, this review aims to inspire future research on interventions that promote healthy ageing for all.
    Keywords:  DNA methylation; epigenetic clock; epigenetic reprogramming; histones; longevity; small molecules
    DOI:  https://doi.org/10.1016/j.arr.2024.102204
  6. Front Med (Lausanne). 2023 ;10 1348468
      
    Keywords:  COVID-19; Long COVID; SARS-CoV-2; elderly; frailty
    DOI:  https://doi.org/10.3389/fmed.2023.1348468
  7. Nature. 2024 Jan 26.
      
    Keywords:  Brain; Immunology; Neurodegeneration; Neuroscience; Obesity
    DOI:  https://doi.org/10.1038/d41586-024-00118-4
  8. bioRxiv. 2024 Jan 09. pii: 2023.07.20.549210. [Epub ahead of print]
      Aging and neurodegeneration entail diverse cellular and molecular hallmarks. Here, we studied the effects of aging on the transcriptome, translatome, and multiple layers of the proteome in the brain of a short-lived killifish. We reveal that aging causes widespread reduction of proteins enriched in basic amino acids that is independent of mRNA regulation, and it is not due to impaired proteasome activity. Instead, we identify a cascade of events where aberrant translation pausing leads to reduced ribosome availability resulting in proteome remodeling independently of transcriptional regulation. Our research uncovers a vulnerable point in the aging brain's biology - the biogenesis of basic DNA/RNA binding proteins. This vulnerability may represent a unifying principle that connects various aging hallmarks, encompassing genome integrity and the biosynthesis of macromolecules.
    One-Sentence Summary: Translation pausing reshapes the aging brain proteome, revealing vulnerabilities in the biogenesis of nucleic-acid protein.
    DOI:  https://doi.org/10.1101/2023.07.20.549210
  9. JAMA Netw Open. 2024 Jan 02. 7(1): e2353244
       Importance: Clonal hematopoiesis of indeterminate potential (CHIP), the age-related clonal expansion of hematopoietic stem cells with leukemogenic acquired genetic variants, is associated with incident heart failure (HF).
    Objective: To evaluate the associations of CHIP and key gene-specific CHIP subtypes with incident HF with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF).
    Design, Setting, and Participants: This population-based cohort study included participants from 2 racially diverse prospective cohort studies with uniform HF subtype adjudication: the Jackson Heart Study (JHS) and Women's Health Initiative (WHI). JHS participants were enrolled during 2000 to 2004 and followed up through 2016. WHI participants were enrolled during 1993 to 1998 and followed up through 2022. Participants who underwent whole-genome sequencing, lacked prevalent HF at baseline, and were followed up for HF adjudication were included. Follow-up occurred over a median (IQR) of 12.0 (11.0-12.0) years in the JHS and 15.3 (9.0-22.0) years in the WHI. Statistical analysis was performed from June to December 2023.
    Exposures: Any CHIP and the most common gene-specific CHIP subtypes (DNMT3A and TET2 CHIP).
    Main Outcomes and Measures: First incident hospitalized HF events were adjudicated from hospital records and classified as HFpEF (left ventricular ejection fraction ≥50%) or HFrEF (ejection fraction <50%).
    Results: A total of 8090 participants were included; 2927 from the JHS (median [IQR] age, 56 [46-65] years; 1846 [63.1%] female; 2927 [100.0%] Black or African American) and 5163 from the WHI (median [IQR] age, 67 [62-72] years; 5163 [100.0%] female; 29 [0.6%] American Indian or Alaska Native, 37 [0.7%] Asian or Pacific Islander, 1383 [26.8%] Black or African American, 293 [5.7%] Hispanic or Latinx, 3407 [66.0%] non-Hispanic White, and 14 [0.3%] with other race and ethnicity). The multivariable-adjusted hazard ratio (HR) for composite CHIP and HFpEF was 1.28 (95% CI, 0.93-1.76; P = .13), and for CHIP and HFrEF it was 0.79 (95% CI, 0.49-1.25; P = .31). TET2 CHIP was associated with HFpEF in both cohorts (meta-analyzed HR, 2.35 [95% CI, 1.34 to 4.11]; P = .003) independent of cardiovascular risk factors and coronary artery disease. Analyses stratified by C-reactive protein (CRP) in the WHI found an increased risk of incident HFpEF in individuals with CHIP and CRP greater than or equal to 2 mg/L (HR, 1.94 [95% CI, 1.20-3.15]; P = .007), but not in those with CHIP and CRP less than 2 mg/L or those with CRP greater than or equal to 2 mg/L without CHIP, when compared with participants without CHIP and CRP less than 2 mg/L.
    Conclusions and Relevance: In this cohort study, TET2 CHIP was an independent risk factor associated with incident HFpEF. This finding may have implications for the prevention and management of HFpEF, including development of targeted therapies.
    DOI:  https://doi.org/10.1001/jamanetworkopen.2023.53244
  10. Front Oncol. 2023 ;13 1357842
      
    Keywords:  aging; epithelial ovarian cancer; inflammation; lymphadenectomy; pyroptosis; serum lipid and lipoprotein levels; vagus nerve
    DOI:  https://doi.org/10.3389/fonc.2023.1357842
  11. Aging Dis. 2023 Nov 29.
      Aging has emerged at the forefront of scientific research due to the growing social and economic costs associated with the growing aging global population. The defining features of aging involve a variety of molecular processes and cellular systems, which are interconnected and collaboratively contribute to the aging process. Herein, we analyze how telomere dysfunction potentially amplifies or accelerates the molecular and biochemical mechanisms underpinning each feature of aging and contributes to the emergence of age-associated illnesses, including cancer and neurodegeneration, via the perspective of telomere biology. Furthermore, the recently identified novel mechanistic actions for telomere maintenance offer a fresh viewpoint and approach to the management of telomeres and associated disorders. Telomeres and the defining features of aging are intimately related, which has implications for therapeutic and preventive approaches to slow aging and reduce the prevalence of age-related disorders.
    DOI:  https://doi.org/10.14336/AD.2023.1128
  12. Front Physiol. 2023 ;14 1279548
      Aging is a natural aspect of mammalian life. Although cellular mortality is inevitable, various diseases can hasten the aging process, resulting in abnormal or premature senescence. As cells age, they experience distinctive morphological and biochemical shifts, compromising their functions. Research has illuminated that cellular senescence coincides with significant alterations in the microRNA (miRNA) expression profile. Notably, a subset of aging-associated miRNAs, originally encoded by nuclear DNA, relocate to mitochondria, manifesting a mitochondria-specific presence. Additionally, mitochondria themselves house miRNAs encoded by mitochondrial DNA (mtDNA). These mitochondria-residing miRNAs, collectively referred to as mitochondrial miRNAs (mitomiRs), have been shown to influence mtDNA transcription and protein synthesis, thereby impacting mitochondrial functionality and cellular behavior. Recent studies suggest that mitomiRs serve as critical sensors for cellular senescence, exerting control over mitochondrial homeostasis and influencing metabolic reprogramming, redox equilibrium, apoptosis, mitophagy, and calcium homeostasis-all processes intimately connected to senescence. This review synthesizes current findings on mitomiRs, their mitochondrial targets, and functions, while also exploring their involvement in cellular aging. Our goal is to shed light on the potential molecular mechanisms by which mitomiRs contribute to the aging process.
    Keywords:  cellular senescence; epigenetics; mitochondria; mitomiRs; noncoding RNA
    DOI:  https://doi.org/10.3389/fphys.2023.1279548