Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology.

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Targeting therapy-induced senescence as a novel strategy to combat chemotherapy-induced peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a treatment-limiting adverse effect of anticancer therapy that complicates the lifestyle of many cancer survivors. There is currently no gold-standard for the assessment or management of CIPN. Subsequently, understanding the underlying mechanisms that lead to the development of CIPN is essential for finding better pharmacological therapy. Therapy-induced senescence (TIS) is a form of senescence that is triggered in malignant and non-malignant cells in response to the exposure to chemotherapy. Recent evidence has also suggested that TIS develops in the dorsal root ganglia of rodent models of CIPN. Interestingly, several components of the senescent phenotype are commensurate with the currently established primary processes implicated in the pathogenesis of CIPN including mitochondrial dysfunction, oxidative stress, and neuroinflammation. In this article, we review the literature that supports the hypothesis that TIS could serve as a holistic mechanism leading to CIPN, and we propose the potential for investigating senotherapeutics as means to mitigate CIPN in cancer survivors.

Therapeutic Opportunities Presented by Modulation of Cellular Senescence.

Cellular senescence is a permanent state of growth arrest coupled with profound changes in phenotype that can be triggered by multiple extrinsic or intrinsic stimuli. Senescence is a process-level example of the evolution of ageing mechanisms through antagonistic pleiotropy and plays a primary role in tumour suppression, although evidence is mounting for its involvement in other fundamental physiological processes. Evidence from human premature ageing diseases and from transgenic mice in which it is possible to specifically delete senescent cells is consistent with a model in which the accumulation of senescent cells through the life course is responsible for later life chronic disease and impairment. The removal of senescent cells or their reversion to a phenotypically benign state is thus an important emerging goal of translational medicine.Modern bioinformatic approaches based on text mining have compiled co-mentions of cell senescence and age-related diseases allowing an impartial ranking of the impairments most closely associated with this process. Following this schema, the evidence for the involvement of senescence in several highly ranked pathologies is reviewed, alongside potential methods for the ablation of senescent cells or their reversion to their primary phenotype with polyphenolics or inhibitors of p38 MAP kinase. Lastly, the potential for senescence to act as a barrier to the development of bioartificial organs designed to treat some of these conditions is discussed.

Cellular senescence in the pathogenesis of ovarian dysfunction.

The follicular microenvironment is crucial for normal ovarian function, and intra-ovarian factors, in coordination with gonadotropins, contribute to its regulation. Recent research has revealed that the accumulation of senescent cells worsens the adverse environment of various tissues and plays critical roles in chronological aging and various pathological conditions. Cellular senescence involves cell-cycle arrest, a senescence-associated secretory phenotype (SASP), macromolecular damage, and dysmetabolism. In this review, I summarize the latest knowledge regarding the role of cellular senescence in pathological conditions in the ovary, in the context of reproduction. Specifically, cellular senescence is known to impair follicular and oocyte health in cisplatin- and cyclophosphamide-induced primary ovarian insufficiency and to contribute to the pathogenesis of polycystic ovary syndrome (PCOS). In addition, cellular senescence is induced during the decline in ovarian reserve that is associated with chronological aging, endometriosis, psychological stress, and obesity, but it remains unclear whether it plays a causative role in these conditions. Finally, I discuss the potential for use of cellular senescence as a novel therapeutic target. The modification of SASP using a senomorphic and/or the elimination of senescent cells using a senolytic represent promising therapeutic strategies. Further elucidation of the role of cellular senescence in the effects of various insults on ovarian reserve, including chronological aging, as well as in pathogenesis of ovarian pathologies, including PCOS, may facilitate a new era of reproductive medicine.

Addition of Polyphenols to Drugs: The Potential of Controlling "Inflammaging" and Fibrosis in Human Senescent Lung Fibroblasts In Vitro.

The combination of a polyphenol, quercetin, with dasatinib initiated clinical trials to evaluate the safety and efficacy of senolytics in idiopathic pulmonary fibrosis, a lung disease associated with the presence of senescent cells. Another approach to senotherapeutics consists of controlling inflammation related to cellular senescence or "inflammaging", which participates, among other processes, in establishing pulmonary fibrosis. We evaluate whether polyphenols such as caffeic acid, chlorogenic acid, epicatechin, gallic acid, quercetin, or resveratrol combined with different senotherapeutics such as metformin or rapamycin, and antifibrotic drugs such as nintedanib or pirfenidone, could present beneficial actions in an in vitro model of senescent MRC-5 lung fibroblasts. A senescent-associated secretory phenotype (SASP) was evaluated by the measurement of interleukin (IL)-6, IL-8, and IL-1ß. The senescent-associated ß-galactosidase (SA-ß-gal) activity and cellular proliferation were assessed. Fibrosis was evaluated using a Picrosirius red assay and the gene expression of fibrosis-related genes. Epithelial-mesenchymal transition (EMT) was assayed in the A549 cell line exposed to Transforming Growth Factor (TGF)-ß in vitro. The combination that demonstrated the best results was metformin and caffeic acid, by inhibiting IL-6 and IL-8 in senescent MRC-5 cells. Metformin and caffeic acid also restore cellular proliferation and reduce SA-ß-gal activity during senescence induction. The collagen production by senescent MRC-5 cells was inhibited by epicatechin alone or combined with drugs. Epicatechin and nintedanib were able to control EMT in A549 cells. In conclusion, caffeic acid and epicatechin can potentially increase the effectiveness of senotherapeutic drugs in controlling lung diseases whose pathophysiological component is the presence of senescent cells and fibrosis.

Involvement of Matricellular Proteins in Cellular Senescence: Potential Therapeutic Targets for Age-Related Diseases.

Senescence is a physiological and pathological cellular program triggered by various types of cellular stress. Senescent cells exhibit multiple characteristic changes. Among them, the characteristic flattened and enlarged morphology exhibited in senescent cells is observed regardless of the stimuli causing the senescence. Several studies have provided important insights into pro-adhesive properties of cellular senescence, suggesting that cell adhesion to the extracellular matrix (ECM), which is involved in characteristic morphological changes, may play pivotal roles in cellular senescence. Matricellular proteins, a group of structurally unrelated ECM molecules that are secreted into the extracellular environment, have the unique ability to control cell adhesion to the ECM by binding to cell adhesion receptors, including integrins. Recent reports have certified that matricellular proteins are closely involved in cellular senescence. Through this biological function, matricellular proteins are thought to play important roles in the pathogenesis of age-related diseases, including fibrosis, osteoarthritis, intervertebral disc degeneration, atherosclerosis, and cancer. This review outlines recent studies on the role of matricellular proteins in inducing cellular senescence. We highlight the role of integrin-mediated signaling in inducing cellular senescence and provide new therapeutic options for age-related diseases targeting matricellular proteins and integrins.

Reduction of senescence-associated secretory phenotype and exosome-shuttled miRNAs by Haritaki fruit extract in senescent dermal fibroblasts.

OBJECTIVE: Skin ageing is linked to the accumulation of senescent cells and a "senescence-associated secretory phenotype" (SASP). SASP factors include chemokines, cytokines, and small extracellular vesicles (EVs) containing miRNAs. We characterized SASP profile markers in normal human dermal fibroblasts (HDFs) and evaluated the effect of Haritaki fruit extract on these senescence markers. METHODS: Senescence was induced in HDFs by ionizing radiation (X ray), followed by 14 days of culture. Parallel incubations included fibroblasts treated for 12 days with 10 or 100 µg/mL Haritaki (a standardized extract of Terminalia chebula fruit). Senescence was assessed on Day 14 according to cell morphology, ß-galactosidase activity, RT-qPCR measurement of SASP genes, as well as semi-quantitative (RT-qPCR) expression of miRNAs contained in EVs isolated from the medium. The size and distribution of EVs were measured by Nanoparticle Tracking Analysis. RESULTS: Human dermal fibroblasts exhibited a senescent phenotype 14 days after ionizing-radiation, demonstrated by a flattened and irregular shape, increased ß-galactosidase activity and over-expression of SASP genes. CSF3, CXCL1, IL1ß, IL6 and IL8 genes were increased by 1492%, 1041%, 343%, 478%, 2960% and 293%, respectively. The cell cycle inhibitor, CDKN1A, was increased by 357%, while COL1A1, was decreased by 56% and MMP1 was increased by 293%. NTA analysis of the EVs size distribution indicated a mix of exosomes (45-100 nm) and microvesicles (100-405 nm). miRNA expression in EVs was increased in senescent fibroblasts. miR 29a-3p, miR 30a-3p, miR 34a-5p, miR 24a-3p and miR 186-5p were increased in senescent HDF by 4.17-, 2.43-, 1.17-, 2.01, 12.5-fold, respectively. Incubation of senescent fibroblasts with Haritaki extract strongly decreased SASP mRNA levels and miRNA expression in EVs. CONCLUSION: Haritaki strongly reduced SASP expression and EV-shuttled miRNAs in senescent fibroblasts. These results indicate that Haritaki has strong senomorphic properties and may be a promising ingredient for the development of new anti-ageing dermo-cosmetic products by inhibiting deleterious effects of senescent cells.

OBJECTIF: Le vieillissement cutané est lié à l'accumulation de cellules sénescentes et à un « phénotype sécrétoire associé à la sénescence ¼ (SASP). Le SASP est constitué de chimiokines, cytokines et de petites vésicules extracellulaires (VE) contenant des miARN. Nous avons caractérisé les marqueurs du SASP dans des fibroblastes dermiques humains normaux (HDF) et évalué l'effet d'un extrait de fruit d'Haritaki sur ces marqueurs de la sénescence. MÉTHODES: La sénescence a été induite dans les HDF par des rayonnements ionisants (rayons X), suivis de 14 jours de culture. Parallèlement, des HDF ont été traités pendant 12 jours avec 10 ou 100 µg/mL d'Haritaki (un extrait standardisé de fruit de Terminalia chebula). La sénescence a été évaluée au jour 14 en fonction de la morphologie cellulaire, de l'activité ß-galactosidase, de la mesure des gènes du SASP par RT-PCR, ainsi que de l'expression semi-quantitative (RT-qPCR) des miARN contenus dans les VE isolées du milieu. La taille et la distribution des VE ont été mesurées par Nanoparticle Tracking Analysis (NTA). RÉSULTATS: Les HDF ont présenté un phénotype sénescent 14 jours après le rayonnement ionisant, en effet, ils avaient une forme aplatie et irrégulière, une activité ß-galactosidase accrue et une surexpression des gènes du SASP. Les ARNm de CSF3, CXCL1, IL1ß, IL6 et IL8 ont été augmentés de 1492%, 1041%, 343%, 478%, 2960% et 293%, respectivement. L'inhibiteur du cycle cellulaire, CDKN1A, a été augmenté de 357%, tandis que le COL1A1 a diminué de 56% et la MMP1 a augmenté de 293%. L'analyse NTA de la distribution de taille des VE a montré un mélange d'exosomes (45-100 nm) et de microvésicules (100-405 nm). L'expression des miARN dans les VE a augmenté dans les fibroblastes sénescents. Les miR 29a-3p, miR 30a-3p, miR 34a-5p, miR 24a-3p et miR 186-5p ont été augmentés dans le HDF sénescent de, respectivement, 4,17-, 2,43-, 1,17-, 2,01 et 12,5- fois. L'incubation de fibroblastes sénescents avec l'extrait de Haritaki a fortement diminué les niveaux d'ARNm du SASP et l'expression de miARN dans les VE. CONCLUSION: L'extrait d'Haritaki a fortement réduit l'expression du SASP et de miARN contenus dans les VE des fibroblastes sénescents. Ces résultats indiquent que Haritaki possède de fortes propriétés sénomorphiques et pourrait être un ingrédient prometteur pour le développement de nouveaux produits dermo-cosmétiques anti-âge en inhibant les effets délétères des cellules sénescentes.

Combating Atherosclerosis with Chirality/Phase Dual-Engineered Nanozyme Featuring Microenvironment-Programmed Senolytic and Senomorphic Actions.

Senescence plays a critical role in the development and progression of various diseases. This study introduces an amorphous, high-entropy alloy (HEA)-based nanozyme designed to combat senescence. By adjusting the nanozyme's composition and surface properties, this work analyzes its catalytic performance under both normal and aging conditions, confirming that peroxide and superoxide dismutase (SOD) activity are crucial for its anti-aging therapeutic function. Subsequently, the chiral-dependent therapeutic effect is validated and the senolytic performance of D-handed PtPd2CuFe across several aging models is confirmed. Through multi-Omics analyses, this work explores the mechanism underlying the senolytic action exerted by nanozyme in depth. It is confirm that exposure to senescent conditions leads to the enrichment of copper and iron atoms in their lower oxidation states, disrupting the iron-thiol cluster in mitochondria and lipoic acid transferase, as well as oxidizing unsaturated fatty acids, triggering a cascade of cuproptosis and ferroptosis. Additionally, the concentration-dependent anti-aging effects of nanozyme is validated. Even an ultralow dose, the therapeutic can still act as a senomorphic, reducing the effects of senescence. Given its broad-spectrum action and concentration-adjustable anti-aging potential, this work confirms the remarkable therapeutic capability of D-handed PtPd2CuFe in managing atherosclerosis, a disease involving various types of senescent cells.

Modulating in vitro lung fibroblast activation via senolysis of senescent human alveolar epithelial cells.

Idiopathic pulmonary fibrosis (IPF) is an age-related disease with poor prognosis and limited therapeutic options. Activation of lung fibroblasts and differentiation to myofibroblasts are the principal effectors of disease pathology, but damage and senescence of alveolar epithelial cells, specifically type II (ATII) cells, has recently been identified as a potential trigger event for the progressive disease cycle. Targeting ATII senescence and the senescence-associated secretory phenotype (SASP) is an attractive therapeutic strategy; however, translatable primary human cell models that enable mechanistic studies and drug development are lacking. Here, we describe a novel system of conditioned medium (CM) transfer from bleomycin-induced senescent primary alveolar epithelial cells (AEC) onto normal human lung fibroblasts (NHLF) that demonstrates an enhanced fibrotic transcriptional and secretory phenotype compared to non-senescent AEC CM treatment or direct bleomycin damage of the NHLFs. In this system, the bleomycin-treated AECs exhibit classical hallmarks of cellular senescence, including SASP and a gene expression profile that resembles aberrant epithelial cells of the IPF lung. Fibroblast activation by CM transfer is attenuated by pre-treatment of senescent AECs with the senolytic Navitoclax and AD80, but not with the standard of care agent Nintedanib or senomorphic JAK-targeting drugs (e.g., ABT-317, ruxolitinib). This model provides a relevant human system for profiling novel senescence-targeting therapeutics for IPF drug development.

Repurposing Drugs for Senotherapeutic Effect: Potential Senomorphic Effects of Female Synthetic Hormones.

Repurposing previously approved drugs may fast track the route to the clinic for potential senotherapeutics and improves the inefficiency of the clinical drug development pipeline. We performed a repurposing screen of 240 clinically approved molecules in human primary dermal fibroblasts for their effects on CDKN2A expression. Molecules demonstrating effects on CDKN2A expression underwent secondary screening for senescence-associated beta galactosidase (SAB) activity, based on effect size, direction, and/or molecule identity. Selected molecules then underwent a more detailed assessment of senescence phenotypes including proliferation, apoptosis, DNA damage, senescence-associated secretory phenotype (SASP) expression, and regulators of alternative splicing. A selection of the molecules demonstrating effects on senescence were then used in a new bioinformatic structure-function screen to identify common structural motifs. In total, 90 molecules displayed altered CDKN2A expression at one or other dose, of which 15 also displayed effects on SAB positivity in primary human dermal fibroblasts. Of these, 3 were associated with increased SAB activity, and 11 with reduced activity. The female synthetic sex hormones-diethylstilboestrol, ethynyl estradiol and levonorgestrel-were all associated with a reduction in aspects of the senescence phenotype in male cells, with no effects visible in female cells. Finally, we identified that the 30 compounds that decreased CDKN2A activity the most had a common substructure linked to this function. Our results suggest that several drugs licensed for other indications may warrant exploration as future senotherapies, but that different donors and potentially different sexes may respond differently to senotherapeutic compounds. This underlines the importance of considering donor-related characteristics when designing drug screening platforms.

Senolytics and Senomorphics Targeting p38MAPK/NF-κB Pathway Protect Endothelial Cells from Oxidative Stress-Mediated Premature Senescence.

Oxidative stress is a prominent causal factor in the premature senescence of microvascular endothelial cells and the ensuing blood-brain barrier (BBB) dysfunction. Through the exposure of an in vitro model of human BBB, composed of brain microvascular endothelial cells (BMECs), astrocytes, and pericytes to H2O2, this study examined whether a specific targeting of the p38MAPK/NF-κB pathway and/or senescent cells could delay oxidative stress-mediated EC senescence and protect the BBB. Enlarged BMECs, displaying higher ß-galactosidase activity, γH2AX staining, p16 expression, and impaired tubulogenic capacity, were regarded as senescent. The BBB established with senescent BMECs had reduced transendothelial electrical resistance and increased paracellular flux, which are markers of BBB integrity and function, respectively. Premature senescence disrupted plasma-membrane localization of the tight junction protein, zonula occludens-1, and elevated basement membrane-degrading matrix metalloproteinase-2 activity and pro-inflammatory cytokine release. Inhibition of p38MAPK by BIRB796 and NF-κB by QNZ and the elimination of senescent cells by a combination of dasatinib and quercetin attenuated the effects of H2O2 on senescence markers; suppressed release of the pro-inflammatory cytokines interleukin-8, monocyte chemoattractant protein-1, and intercellular adhesion molecule-1; restored tight junctional unity; and improved BBB function. In conclusion, therapeutic approaches that mitigate p38MAPK/NF-κB activity and senescent cell accumulation in the cerebrovasculature may successfully protect BBB from oxidative stress-induced BBB dysfunction.

Cell type-dependent modulation of senescence features using Weo electrolyzed water.

Electrolyzed-reduced water has powerful antioxidant properties with constituents that scavenge reactive oxygen species (ROS), which are known to be produced by several intrinsic and extrinsic processes. When there is an imbalance between ROS production and antioxidant defenses, oxidative stress occurs. Persistent oxidative stress leads to cellular senescence, an important hallmark of aging, and is involved in several age-related conditions and illnesses. This study aims to investigate whether Weo electrolyzed water (WEW) could modulate the phenotype of senescent cells. We compared normal human lung fibroblasts (BJ) and breast cancer cells (T47D) treated with hydrogen peroxide (H2O2) to induce senescence. We assessed the molecular impact of WEW on markers of cellular senescence, senescence-associated secretory phenotype (SASP) factors, and stress response genes. Treatment with WEW modulated markers of cellular senescence, such as the senescence-associated ß-galactosidase (SA-ß-gal) activity, EdU incorporation and p21 expression, similarly in both cell types. However, WEW modulated the expression of SASP factors and stress response genes in a cell type-dependent and opposite fashion, significantly decreasing them in BJ cells, while stimulating their expression in T47D cells. Reduction in the expression of SASP factors and stress-related genes in BJ cells suggests that WEW acts as a protective factor, thereby reducing oxidative stress in normal cells, while making cancer cells more sensitive to the effects of cellular stress, thus increasing their elimination and consequently reducing their deleterious effects. These findings suggest that, due to its differential effects as a senomorphic factor, WEW could have a positive impact on longevity and age-related diseases.

Synergistic roles of CBX4 chromo and SIM domains in regulating senescence of primary human osteoarthritic chondrocytes.

BACKGROUND: Cellular senescence is a critical factor contributing to osteoarthritis (OA). Overexpression of chromobox homolog 4 (CBX4) in a mouse system was demonstrated to alleviate post-traumatic osteoarthritis (PTOA) by reducing cellular senescence. Additionally, replicative cellular senescence of WI-38 fibroblasts can be attenuated by CBX4. However, the mechanisms underlying this senomorphic function of CBX4 are not fully understood. In this study, we aimed to investigate the role of CBX4 in cellular senescence in human primary osteoarthritic chondrocytes and to identify the functional domains of CBX4 necessary for its function in modulating senescence. METHODS: Chondrocytes, isolated from 6 individuals undergoing total knee replacement for OA, were transduced with wild-type CBX4, mutant CBX4, and control lentiviral constructs. Senescence-related phenotypic outcomes included the following: multiple flow cytometry-measured markers (p16INK4A, senescence-associated ß-galactosidase [SA-ß-gal] activity and dipeptidyl peptidase-4 [DPP4], and proliferation marker EdU), multiplex ELISA-measured markers in chondrocyte culture media (senescence-associated secretory phenotypes [SASPs], including IL-1ß, IL-6, IL-8, TNF-α, MMP-1, MMP-3, and MMP-9), and PCR array-evaluated senescence-related genes. RESULTS: Compared with control, CBX4 overexpression in OA chondrocytes decreased DPP4 expression and SASP secretion and increased chondrocyte proliferation confirming CBX4 senomorphic effects on primary human chondrocytes. Point mutations of the chromodomain domain (CDM, involved in chromatin modification) alone were sufficient to partially block the senomorphic activity of CBX4 (p16INK4A and DPP4 increased, and EdU decreased) but had minimal effect on SASP secretion. Although having no effect on p16INK4A, DPP4, and EdU, deletion of two small-ubiquitin-like-modifier-interaction motifs (CBX4 ΔSIMs) led to increased SASP secretion (IL-1ß, TNF-α, IL-8). The combination CBX4 CDMΔSIMs altered all these measures adversely and to a greater degree than the single domain mutants. Deletion of the C-terminal (CBX4 ΔC-box) involved with transcriptional silencing of polycomb group proteins increased IL-1ß slightly but significantly but altered none of the other senescence outcome measures. CONCLUSIONS: CBX4 has a senomorphic effect on human osteoarthritic chondrocytes. CDM is critical for CBX4-mediated regulation of senescence. The SIMs are supportive but not indispensable for CBX4 senomorphic function while the C-box is dispensable.

Evaluation of Senescence and Its Prevention in Doxorubicin-Induced Cardiotoxicity Using Dynamic Engineered Heart Tissues.

Background: Doxorubicin is an essential cancer treatment, but its usefulness is hampered by the occurrence of cardiotoxicity. Nevertheless, the pathophysiology underlying doxorubicin-induced cardiotoxicity and the respective molecular mechanisms are poorly understood. Recent studies have suggested involvement of cellular senescence. Objectives: The aims of this study were to establish whether senescence is present in patients with doxorubicin-induced cardiotoxicity and to investigate if this could be used as a potential treatment target. Methods: Biopsies from the left ventricles of patients with severe doxorubicin-induced cardiotoxicity were compared with control samples. Additionally, senescence-associated mechanisms were characterized in 3-dimensional dynamic engineered heart tissues (dyn-EHTs) and human pluripotent stem cell-derived cardiomyocytes. These were exposed to multiple, clinically relevant doses of doxorubicin to recapitulate patient treatment regimens. To prevent senescence, dyn-EHTs were cotreated with the senomorphic drugs 5-aminoimidazole-4-carboxamide ribonucleotide and resveratrol. Results: Senescence-related markers were significantly up-regulated in the left ventricles of patients with doxorubicin-induced cardiotoxicity. Treatment of dyn-EHTs resulted in up-regulation of similar senescence markers as seen in the patients, accompanied by tissue dilatation, decreased force generation, and increased troponin release. Treatment with senomorphic drugs led to decreased expression of senescence-associated markers, but this was not accompanied by improved function. Conclusions: Senescence was observed in the hearts of patients with severe doxorubicin-induced cardiotoxicity, and this phenotype can be modeled in vitro by exposing dyn-EHTs to repeated clinically relevant doses of doxorubicin. The senomorphic drugs 5-aminoimidazole-4-carboxamide ribonucleotide and resveratrol prevent senescence but do not result in functional improvements. These findings suggest that preventing senescence by using a senomorphic during doxorubicin administration might not prevent cardiotoxicity.

Metabolite Profiling of Allium hookeri Leaves Using UHPLC-qTOF-MS/MS and the Senomorphic Activity of Phenolamides.

The plant Allium hookeri, a member of the Allium genus, has a rich history of culinary and medicinal use. Recent studies have unveiled its potent antioxidant and anti-inflammatory properties. While research on A. hookeri has demonstrated its neuroprotective and anti-neuroinflammatory effects, the specific bioactive compounds responsible for these effects remain unidentified in prior research. This study utilized an untargeted metabolomic approach, employing HRESI-qTOF MS/MS-based molecular networking, to comprehensively profile the chemical composition of metabolites in A. hookeri and identify new compounds within the plant. As a result, ten compounds, comprising one novel flavonoid (2) and nine known compounds (1 and 3-10), were isolated and identified through NMR analysis. The inhibitory effects of all isolated compounds on the senescent cell-associated secretory phenotype (SASP), which is pivotal in neuroprotective actions, were evaluated. Biological activity testing revealed N-trans-feruloyltyramine (7) to be the most potent compound, effectively inhibiting SASP markers and contributing to the senomorphic activities of A. hookeri. These findings underscore the potential of phenolamides from A. hookeri as a promising source of bioactive compounds for mitigating senescence-associated diseases.

Could Hyaluronic Acid Be Considered as a Senomorphic Agent in Knee Osteoarthritis? A Systematic Review.

BACKGROUND: Knee osteoarthritis (KOA) is one of the most common causes of disability in elderly patients and tends to be a major burden on social and health care spending. Despite its severe socioeconomic impact, KOA remains, to date, an incurable disease. Due to its proper characteristics, KOA represents a favorable disease model for experimenting with senotherapeutics, a group of treatments that counteract the development of age-related disorders and chronic diseases. In recent years, the use of intra-articular hyaluronic acid (IAHA) in the treatment of diseases related to the wear and tear of the articular cartilage has been gaining popularity. Given its ability in joint lubrification, shock absorption, and cell signaling, our aim is to investigate, through the existing scientific literature, its potential role as a senomorphic agent, emphasizing its crucial function in KOA patients. Indeed, senomorphics are a particular group of senotherapeutics capable of modulating the functions and morphology of senescent cells to those of young cells or delaying the progression of young cells to senescent cells in tissues. METHODS: A search in the scientific literature (PubMed, Cochrane Library, and Google Scholar) was carried out from 2019 to 2023, thus the last 5 years. RESULTS: One hundred thirty-eight articles were found concerning the role of hyaluronic acid injections in KOA patients. In these studies, its therapeutic efficacy, its anti-inflammatory properties, and its low risk of side effects emerged. CONCLUSION: IAHA injections are a valuable treatment option for KOA while they can provide pain relief, improve joint function, and slow the progression of joint degeneration. The inhibitory effect of HA on MMP13 and its action as a senomorphic agent suggests that it may have additional benefits beyond its lubricating and shock-absorbing properties. In order to clarify its mechanisms of action and to optimize its clinical use, further studies are definitely needed.

Senotherapy, cancer, and aging.

INTRODUCTION: We aimed to highlight the effects of senotherapy on the prevention and treatment of cancer in older individuals. The aim of senotherapy is to eliminate senescent cells. These cells express the senescence-associated secretory phenotype (SASP). With production of inflammatory cytokines, growth factors, and different type of proteases, the SASP is responsible for aging-associated disability and diseases. All mammalian cells experience senescence. The main agents of aging include fibroblasts and adipose cells. Senescent tumor cells may undergo genomic reprogramming and re-enter cell cycle with a stem cell phenotype. MATERIALS AND METHODS: We conducted a Medline search for the following key words: senotherapy, senolysis, senomorphic agents. We provide a narrative review of the finding. RESULTS: Different agents may eliminate senescent cells from cell cultures and murine models. These include metformin, rapamycin, desatinib, quercitin, fisetin, ruloxitinib, and BCL2 inhibitors. A randomized controlled study of metformin in 3,000 patients aged 65-79 without glucose intolerance aiming to establish whether senotherapy may prevent or reverse disability and aging associated diseases, including cancer, is ongoing. Senotherapy prolongs the life span and decreases the incidence of cancer in experimental animal models, as well as delays and reverses disability. Senescent tumor cells are found prior to treatment and after chemotherapy and radiation. These elements may be responsible for tumor recurrence and treatment refractoriness. DISCUSSION: Senotherapy may have substantial effects on cancer management including decreased incidence and aggressiveness of cancer, improved tolerance of antineoplastic treatment, and prevention of relapse after primary treatment. Senotherapy may ameliorate several complications of cancer chemotherapy.

Cellular senescence in skin-related research: Targeted signaling pathways and naturally occurring therapeutic agents.

Despite the growing interest by researchers into cellular senescence, a hallmark of cellular aging, its role in human skin remains equivocal. The skin is the largest and most accessible human organ, reacting to the external and internal environment. Hence, it is an organ of choice to investigate cellular senescence and to target root-cause aging processes using senolytic and senomorphic agents, including naturally occurring plant-based derivatives. This review presents different aspects of skin cellular senescence, from physiology to pathology and signaling pathways. Cellular senescence can have both beneficial and detrimental effects on the skin, indicating that both prosenescent and antisenescent therapies may be desirable, based on the context. Knowledge of molecular mechanisms involved in skin cellular senescence may provide meaningful insights for developing effective therapeutics for senescence-related skin disorders, such as wound healing and cosmetic skin aging changes.

Senomorphic effect of diphenyleneiodonium through AMPK/MFF/DRP1 mediated mitochondrial fission.

With an aging population and the numerous health impacts associated with old age, the identification of anti-aging drugs has become an important new research direction. Although mitochondria have been recognized to affect aging, anti-aging drugs specifically targeting the mitochondria are less well characterized. In this study, diphenyleneiodonium (DPI) was identified as a potential senomorphic drug that functions by promoting mitochondrial fission. DPI significantly reduced the number of senescence-associated ß-galactosidase (SA-ß-gal) positive cells and increased the number of proliferating Ki-67 positive cells in BrdU or irradiation stress-induced senescent NIH3T3 cells or IMR90 cells and mouse embryonic fibroblasts (MEFs) replicative senescent cells. Cell cycle arrest genes and senescence-associated secretory phenotype (SASP) factors were downregulated with DPI treatment. In addition, the oxygen consumption rate (OCR) of mitochondrial respiration showed that DPI significantly reduced senescence-associated hyper OCR. Mechanistically, DPI promoted mitochondrial fission by enhancing AMPK/MFF phosphorylation and DRP1 mitochondrial translocation. Inhibition of DRP1 by Mdivi-1 abolished DPI-induced mitochondrial fission and the anti-senescence phenotype. Importantly, Eighty-eight-week-old mice treated with DPI had significantly reduced numbers of SA-ß-gal positive cells and reduced expression of cell cycle arrest genes and SASP factors in their livers and kidneys. Pathological and functional assays showed DPI treatment not only reduced liver fibrosis and immune cell infiltration but also improved aged-related physical impairments in aged mice. Taken together, our study identified a potential anti-aging compound that exerts its effects through modulation of mitochondrial morphology.

Immunotherapeutic approach to reduce senescent cells and alleviate senescence-associated secretory phenotype in mice.

Accumulation of senescent cells (SNCs) with a senescence-associated secretory phenotype (SASP) has been implicated as a major source of chronic sterile inflammation leading to many age-related pathologies. Herein, we provide evidence that a bifunctional immunotherapeutic, HCW9218, with capabilities of neutralizing TGF-ß and stimulating immune cells, can be safely administered systemically to reduce SNCs and alleviate SASP in mice. In the diabetic db/db mouse model, subcutaneous administration of HCW9218 reduced senescent islet ß cells and SASP resulting in improved glucose tolerance, insulin resistance, and aging index. In naturally aged mice, subcutaneous administration of HCW9218 durably reduced the level of SNCs and SASP, leading to lower expression of pro-inflammatory genes in peripheral organs. HCW9218 treatment also reverted the pattern of key regulatory circadian gene expression in aged mice to levels observed in young mice and impacted genes associated with metabolism and fibrosis in the liver. Single-nucleus RNA Sequencing analysis further revealed that HCW9218 treatment differentially changed the transcriptomic landscape of hepatocyte subtypes involving metabolic, signaling, cell-cycle, and senescence-associated pathways in naturally aged mice. Long-term survival studies also showed that HCW9218 treatment improved physical performance without compromising the health span of naturally aged mice. Thus, HCW9218 represents a novel immunotherapeutic approach and a clinically promising new class of senotherapeutic agents targeting cellular senescence-associated diseases.