Aging drives organ-specific alterations of the inflammatory microenvironment guided by immunomodulatory mediators in mice

Post-death Vesicles of Senescent Bone Marrow Mesenchymal Stromal Polyploids Promote Macrophage Aging and Breast Cancer

Potential systemic factors contributing to aging-associated breast cancer (BC) remain elusive. Here, we reveal that the polyploid giant cells (PGCs) that contain more than two sets of genomes prevailing in aging and cancerous tissues constitute 5-10% of healthy female bone marrow mesenchymal stromal cells (fBMSCs). The PGCs can repair DNA damage and stimulate neighboring cells for clonal expansion. However, dying PGCs in advanced-senescent fBMSCs can form "spikings" which are then separated into membraned mtDNA-containing vesicles (Senescent PGC-Spiking Bodies; SPSBs). SPSB-phagocytosed macrophages accelerate aging with diminished clearance on BC cells and protumor M2 polarization. SPSB-carried mitochondrial OXPHOS components are enriched in BC of elder patients and associated with poor prognosis. SPSB-incorporated breast epithelial cells develop aggressive characteristics and PGCs resembling the polyploid giant cancer cells (PGCCs) in clonogenic BC cells and cancer tissues. These findings highlight an aging BMSC-induced BC risk mediated by SPSB-induced macrophage dysfunction and epithelial cell precancerous transition.

SIGNIFICANCE

Mechanisms underlying aging-associated cancer risk remain unelucidated. This work demonstrates that polyploid giant cells (PGCs) in bone marrow mesenchymal stromal cells (BMSCs) from healthy female bone marrow donors can boost neighboring cell proliferation for clonal expansion. However, the dying-senescent PGCs in the advanced-senescent fBMSCs can form "spikings" which are separated into mitochondrial DNA (mtDNA)-containing spiking bodies (senescent PGC-spiking bodies; SPSBs). The SPSBs promote macrophage aging and breast epithelial cell protumorigenic transition and form polyploid giant cancer cells. These results demonstrate a new form of ghost message from dying-senescent BMSCs, that may serve as a systemic factor contributing to aging-associated immunosuppression and breast cancer risk.

Graphic Abstract

Eternal Youth: A Comprehensive Exploration of Gene, Cellular, and Pharmacological Anti-Aging Strategies

The improvement of human living conditions has led to an increase in average life expectancy, creating a new social and medical problem-aging, which diminishes the overall quality of human life. The aging process of the body begins with the activation of effector signaling pathways of aging in cells, resulting in the loss of their normal functions and deleterious effects on the microenvironment. This, in turn, leads to chronic inflammation and similar transformations in neighboring cells. The cumulative retention of these senescent cells over a prolonged period results in the deterioration of tissues and organs, ultimately leading to a reduced quality of life and an elevated risk of mortality. Among the most promising methods for addressing aging and age-related illnesses are pharmacological, genetic, and cellular therapies. Elevating the activity of aging-suppressing genes, employing specific groups of native and genetically modified cells, and utilizing senolytic medications may offer the potential to delay aging and age-related ailments over the long term. This review explores strategies and advancements in the field of anti-aging therapies currently under investigation, with a particular emphasis on gene therapy involving adeno-associated vectors and cell-based therapeutic approaches.

Lipids and the hallmarks of ageing: From pathology to interventions

Lipids are critical structural and functional architects of cellular homeostasis. Change in systemic lipid profile is a clinical indicator of underlying metabolic pathologies, and emerging evidence is now defining novel roles of lipids in modulating organismal ageing. Characteristic alterations in lipid metabolism correlate with age, and impaired systemic lipid profile can also accelerate the development of ageing phenotype. The present work provides a comprehensive review of the extent of lipids as regulators of the modern hallmarks of ageing viz., cellular senescence, chronic inflammation, gut dysbiosis, telomere attrition, genome instability, proteostasis and autophagy, epigenetic alterations, and stem cells dysfunctions. Current evidence on the modulation of each of these hallmarks has been discussed with emphasis on inherent age-dependent deficiencies in lipid metabolism as well as exogenous lipid changes. There appears to be sufficient evidence to consider impaired lipid metabolism as key driver of the ageing process although much of knowledge is yet fragmented. Considering dietary lipids, the type and quantity of lipids in the diet is a significant, but often overlooked determinant that governs the effects of lipids on ageing. Further research using integrative approaches amidst the known aging hallmarks is highly desirable for understanding the therapeutics of lipids associated with ageing.

Infectious neutrophil deployment is regulated by resolvin D4

Neutrophils reside in the bone marrow (BM), ready for deployment to sites of injury/infection, initiating inflammation and its resolution. Here, we report that distal infections signal to the BM via resolvins to regulate granulopoiesis and BM neutrophil deployment. Emergency granulopoiesis during peritonitis evoked changes in BM resolvin D1 (RvD1) and BM RvD4. We found that leukotriene B4 stimulates neutrophil deployment. RvD1 and RvD4 each limited neutrophilic infiltration to infections, and differently regulated BM myeloid populations: RvD1 increased reparative monocytes, and RvD4 regulated granulocytes. RvD4 disengaged emergency granulopoiesis, prevented excess BM neutrophil deployment, and acted on granulocyte progenitors. RvD4 also stimulated exudate neutrophil, monocyte, and macrophage phagocytosis, and enhanced bacterial clearance. This mediator accelerated both neutrophil apoptosis and clearance by macrophages, thus expediting the resolution phase of inflammation. RvD4 stimulated phosphorylation of ERK1/2 and STAT3 in human BM-aspirate-derived granulocytes. RvD4 in the 1 to 100 nM range stimulated whole-blood neutrophil phagocytosis of Escherichia coli. RvD4 increased BM macrophage efferocytosis of neutrophils. Together, these results demonstrate the novel functions of resolvins in granulopoiesis and neutrophil deployment, contributing to the resolution of infectious inflammation.

Association of Arachidonic Acid-Derived Lipid Mediators With Disease Severity in Patients With Relapsing and Progressive Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Excessive activation of certain lipid mediator (LM) pathways plays a role in the complex pathogenesis of multiple sclerosis (MS). However, the relationship between bioactive LMs and different aspects of CNS-related pathophysiologic processes remains largely unknown. Therefore, in this study, we assessed the association of bioactive LMs belonging to the ω-3/ω-6 lipid classes with clinical and biochemical (serum neurofilament light [sNfL] and serum glial fibrillary acidic protein [sGFAP]) parameters and MRI-based brain volumes in patients with MS (PwMS) and healthy controls (HCs).

METHODS

A targeted high-performance liquid chromatography-tandem mass spectrometry approach was used on plasma samples of PwMS and HCs of the Project Y cohort, a cross-sectional population-based cohort that contains PwMS all born in 1966 in the Netherlands and age-matched HCs. LMs were compared between PwMS and HCs and were correlated with levels of sNfL, sGFAP, disability (Expanded Disability Status Scale [EDSS]), and brain volumes. Finally, significant correlates were included in a backward multivariate regression model to identify which LMs best related to disability.

RESULTS

The study sample consisted of 170 patients with relapsing remitting MS (RRMS), 115 patients with progressive MS (PMS), and 125 HCs. LM profiles of patients with PMS significantly differed from those of patients with RRMS and HCs, particularly patients with PMS showed elevated levels of several arachidonic acid (AA) derivatives. In particular, 15-hydroxyeicosatetraenoic acid (HETE) (r = 0.24, p < 0.001) correlated (average r = 0.2, p < 0.05) with clinical and biochemical parameters such as EDSS and sNfL. In addition, higher 15-HETE levels were related to lower total brain (r = -0.24, p = 0.04) and deep gray matter volumes (r = -0.27, p = 0.02) in patients with PMS and higher lesion volume (r = 0.15, p = 0.03) in all PwMS.

DISCUSSION

In PwMS of the same birth year, we show that ω-3 and ω-6 LMs are associated with disability, biochemical parameters (sNfL, GFAP), and MRI measures. Furthermore, our findings indicate that, particularly, in patients with PMS, elevated levels of specific products of the AA pathway, such as 15-HETE, associate with neurodegenerative processes. Our findings highlight the potential relevance of ω-6 LMs in the pathogenesis of MS.

Effects of Thyme (Thymus vulgaris L.) Essential Oil on Aging-Induced Brain Inflammation and Blood Telomere Attrition in Chronologically Aged C57BL/6J Mice

Chronological aging is commonly accompanied by chronic low-grade inflammation (or "inflammaging"), a contributor to the development of age-related chronic diseases. Aging increases oxidative stress that accelerates telomere shortening, leading to cell senescence and the generation of senescence-associated secretory phenotype (SASP) that exacerbates inflammation. Dietary antioxidants may help protect telomeres and attenuate inflammation. Thyme essential oil (TEO), reported for its potency against neuroinflammation, was fed to chronologically aged C57BL/6J mice for 24 weeks. The TEO diet showed notable impacts on the hippocampus, indicated by lower expression of the aging-related gene p16^INK4A (p = 0.0783) and significantly lower expression of cyclin D kinase Cdk4 and Cdk6 (p < 0.05) compared to the age-matched control mice. The TEO group also showed significantly lower gene expression of the pro-inflammatory cytokine Il6 (p < 0.05) in the hippocampus and lower Il1b expression in the liver and cerebellum (p < 0.05). In vitro experiments conducted on NIH-3T3 cells expressing SASP revealed the dose-dependent anti-inflammatory activity of TEO. Remarkably, TEO diet-fed mice showed higher survival rates and significantly longer blood telomere lengths than the control mice. Monoterpene antioxidants in TEO, particularly thymol and p-cymene, may primarily contribute to the anti-inflammatory and telomere-protecting activities of TEO.

Resolution medicine in cancer, infection, pain and inflammation: are we on track to address the next Pandemic?

Uncontrolled inflammation giving rise to excessive tissue inflammation can lead to chronic inflammation that enhances tissue destruction, amplifying many chronic human pathologies. Normally the acute inflammatory response is protective and should be self-limited returning tissues to functional homeostasis with endogenous programmed resolution via leukocyte vasculature cell-cell interactions and crosstalk that biosynthesize pro-resolving mediators. When failed resolution takes place, as with the use of NSAIDs, tissues undergo chronic inflammation and fibrosis. Herein, we discuss these mechanisms and the role of specialized proresolving mediators, the resolvins, protectins and maresins produced from essential omega-3 fatty acids EPA and DHA, and their contributions via their cognate cell surface receptors, to the resolution response. Harnessing these pathways and their cellular mechanisms can help in providing new therapeutic approaches to many human diseases, infections, organ protection and trauma via resolution medicine to enhance the body's own resilience to challenge.

Role of the cGAS-STING Pathway in Aging-related Endothelial Dysfunction

Endothelial dysfunction develops gradually with age, and is the foundation of many age-related diseases in the elderly. The purpose of this study was to investigate the role of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in aging-related endothelial dysfunction. Endothelial functional parameters and biochemical indices of vascular function were examined in 2-, 6-, 12- and 24-month-old mice. Then, 6-month-old mice were administered RU.521, a specific inhibitor of cGAS, for 6 months, and endothelial functional parameters and biochemical indices of vascular function were re-examined. An in vitro model of cell senescence was established by treating human aortic endothelial cells (HAECs) with D-Galactose (D-GAL). Using inhibitors or siRNA interference, cGAS and STING were suppressed or silenced in senescent HAECs, and changes in the expression of eNOS, the senescence markers, p53, p21 and p16, components of the cGAS-STING pathway and Senescence-Associated β-galactosidase (SA-β-gal) staining were examined. Finally, cGAS, STING and p-IRF3 levels were measured in aorta tissue sections from eight patients. A decline in endothelial function, up-regulation of p53, p21 and p16 expression, and activation of the cGAS-STING pathway were observed in aging mice. Inhibition of cGAS was found to improve endothelial function and reverse the increased expression of aging markers. Our in vitro data demonstrated that D-GAL induced a decrease in eNOS expression and cell senescence, which could be partly reversed by cGAS inhibitor, STING inhibitor, siRNA-cGAS and siRNA-STING treatment. Higher expression levels of cGAS, STING and p-IRF3 were observed in aged human aortic intima tissue compared to young aortic intima tissue. Our study demonstrated that activation of the cGAS-STING pathway played a vital role in aging-related endothelial dysfunction. Thus, the cGAS-STING pathway may be a potential target for the prevention of cardiovascular diseases in the elderly.

The Trace Element Selenium Is Important for Redox Signaling in Phorbol Ester-Differentiated THP-1 Macrophages

Physiological selenium (Se) levels counteract excessive inflammation, with selenoproteins shaping the immunoregulatory cytokine and lipid mediator profile. How exactly differentiation of monocytes into macrophages influences the expression of the selenoproteome in concert with the Se supply remains obscure. THP-1 monocytes were differentiated with phorbol 12-myristate 13-acetate (PMA) into macrophages and (i) the expression of selenoproteins, (ii) differentiation markers, (iii) the activity of NF-κB and NRF2, as well as (iv) lipid mediator profiles were analyzed. Se and differentiation affected the expression of selenoproteins in a heterogeneous manner. GPX4 expression was substantially decreased during differentiation, whereas GPX1 was not affected. Moreover, Se increased the expression of selenoproteins H and F, which was further enhanced by differentiation for selenoprotein F and diminished for selenoprotein H. Notably, LPS-induced expression of NF-κB target genes was facilitated by Se, as was the release of COX- and LOX-derived lipid mediators and substrates required for lipid mediator biosynthesis. This included TXB2, TXB3, 15-HETE, and 12-HEPE, as well as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Our results indicate that Se enables macrophages to accurately adjust redox-dependent signaling and thereby modulate downstream lipid mediator profiles.