bims-minfam 2022-10-30 papers

Issue of 2022–10–30
three papers selected by
Ayesh Seneviratne, Western University

Biology (Basel). 2022 Sep 27. pii: 1410. [Epub ahead of print]11(10):

Lysosomes and Their Role in Regulating the Metabolism of Hematopoietic Stem Cells.

Hematopoietic stem cells (HSCs) have the capacity to renew blood cells at all stages of life and are largely quiescent at a steady state. It is essential to understand the processes that govern quiescence in HSCs to enhance bone marrow transplantation. It is hypothesized that in their quiescent state, HSCs primarily use glycolysis for energy production rather than mitochondrial oxidative phosphorylation (OXPHOS). In addition, the HSC switch from quiescence to activation occurs along a continuous developmental path that is driven by metabolism. Specifying the metabolic regulation pathway of HSC quiescence will provide insights into HSC homeostasis for therapeutic application. Therefore, understanding the metabolic demands of HSCs at a steady state is key to developing innovative hematological therapeutics. Lysosomes are the major degradative organelle in eukaryotic cells. Catabolic, anabolic, and lysosomal function abnormalities are connected to an expanding list of diseases. In recent years, lysosomes have emerged as control centers of cellular metabolism, particularly in HSC quiescence, and essential regulators of cell signaling have been found on the lysosomal membrane. In addition to autophagic processes, lysosomal activities have been shown to be crucial in sustaining quiescence by restricting HSCs access to a nutritional reserve essential for their activation into the cell cycle. Lysosomal activity may preserve HSC quiescence by altering glycolysis-mitochondrial biogenesis. The understanding of HSC metabolism has significantly expanded over the decade, revealing previously unknown requirements of HSCs in both their dividing (active) and quiescent states. Therefore, understanding the role of lysosomes in HSCs will allow for the development of innovative treatment methods based on HSCs to fight clonal hematopoiesis and HSC aging.

Keywords: HSCs; glycolysis; lysosomes; metabolism; mitochondria; quiescence

DOI: https://doi.org/10.3390/biology11101410

Immun Ageing. 2022 Oct 26. 19(1): 49

Inflammation and cell-to-cell communication, two related aspects in frailty.

Orietta Pansarasa, Maria Chiara Mimmi, Annalisa Davin, Marta Giannini, Antonio Guaita, Cristina Cereda.

BACKGROUND: Frailty is a complex, multi-dimensional age-related syndrome that increases the susceptibility to adverse health outcomes and poor quality of life. A growing consensus supports the contribution of chronic inflammation and immune system alterations to frailty, however a clear role of such alterations remains to be elucidated. Furthermore, pro- and anti-inflammatory cytokines together with other signaling molecules might spread from activated cells to the adjacent ones through extracellular vesicles (EVs), which have also a role in cellular aging. The aim of the present research was to investigate if EVs play a role in the immune function in frailty. RESULTS: In 219 older adults aged 76-78 years, selected from the InveCe.Ab study (Abbiategrasso, Italy), we investigated inflammation and EVs-mediated intercellular communication. C-reactive protein (CRP) and pro- (IL-1β, IL-2, IL-6, IL-8, IL-12 p70, TNFα and IFNγ) and anti- (IL-4, IL-10, IL-13) inflammatory cytokines were evaluated on plasma of Frail and non-Frail subjects. We reported a significant increase in CRP, interleukin-1β and -6 (IL-1β, IL-6) and tumor necrosis factor alpha (TNFα) plasma levels in frailty. In female Fr subjects, we also reported an increase in interferon-gamma (IFN-γ) and, surprisingly, in IL-13, an anti-inflammatory cytokine, whose increase seems to oppose the inflammaging theory. An inflammatory panel (toll-like receptors 2 and 4 (TLR2 and TLR4), tumor necrosis factor receptors TNFRec5/CD 40 and TNFRec1B/CD120B) and a panel including receptors involved in cellular senescence (insulin-like growth factor 1 receptor (CD221) and interleukin 6 receptor (IL-6R)) were indeed analysed in plasma isolated large EVs (lEVs) from Frail (n = 20) and non-Frail (n = 20) subjects. In lEVs isolated from plasma of Frail subjects we reported an increase in TLR2 and TLR4, TNFRec5/CD 40 and TNFRec1B/CD120B, suggesting a chronic state of inflammation. In addition, CD221 and IL-6R increases in lEVs of Frail individuals.
CONCLUSIONS: To conclude, the pro-inflammatory status, notably the increase in circulating cytokines is pivotal to understand the potential mechanisms underlying the frailty syndrome. Moreover, cytokines release from EVs, mainly the large ones, into the extracellular space suggest their contribution to the formation of a pro-inflammatory and pro-senescent microenvironment that, in turn, can contribute to frailty.

Keywords: Cytokines; Extracellular vesicles; Frailty syndrome; Immune system; Inflammation; Intercellular communication

DOI: https://doi.org/10.1186/s12979-022-00306-8

Cancer Treat Res Commun. 2022 Oct 18. pii: S2468-2942(22)00143-5. [Epub ahead of print]33 100652

The impact of frailty on health outcomes in older adults with lung cancer: A systematic review.

James A Fletcher, Sarah T Fox, Natasha Reid, Ruth E Hubbard, Rahul Ladwa.

BACKGROUND: Frailty is prevalent in older adults with lung cancer, however the impact of frailty in this population is not well understood. The aim of this review was to evaluate the outcomes that are measured in frail older adults with lung cancer, and to determine the associations between frailty and these outcomes.
METHODS: A systematic online search of PubMed, EMBASE, and Cochrane databases was conducted to identify all English-language studies between January 2015 and May 2022 prospectively evaluating frailty and outcomes in older adults (median age > 65 years) with lung cancer. Studies were excluded if frailty was defined by a single domain assessment or not clearly defined. Quality was assessed using the Newcastle-Ottawa Scale.
RESULTS: Of 1891 studies screened, 16 met inclusion criteria. The median number of patients was 96 (range 26-494) and the mean age was 76.6 years. Eight different frailty assessments were used, and frailty definitions varied widely. The most frequently assessed outcomes were overall survival (n = 13,81%), treatment-related toxicity (n = 8,50%), hospitalisation (n = 5,31%), and treatment completion/discontinuation (n = 4,25%). Quality of life (n = 3,19%), function (n = 1,6%), frailty trajectory (n = 1,6%), and emergency visits (n = 1,6%) were infrequently assessed. Frailty had a strong and consistent association with mortality (Hazard Ratio range: 3.5-11.91). It was also associated with treatment-related toxicity and treatment selection. The remaining outcomes were not statistically significant.
CONCLUSION: These data support frailty as an important predictor of mortality in older adults with lung cancer, however further research is warranted to determine the association between frailty and other meaningful endpoints for this vulnerable population.

Keywords: Frail elderly; Frailty; Geriatric oncology; NSCLC; Thoracic malignancies

DOI: https://doi.org/10.1016/j.ctarc.2022.100652