Length-independent telomere damage drives post-mitotic cardiomyocyte senescence

Emerging prodrug and nano-drug delivery strategies for the detection and elimination of senescent tumor cells

Tumor cellular senescence, characterized by reversible cell cycle arrest following anti-cancer therapies, presents a complex paradigm in oncology. Given that senescent tumor cells may promote angiogenesis, tumorigenesis, and metastasis, selective killing senescent cells (SCs)-a strategy termed senotherapy-has emerged as a promising approach to improve cancer treatment. However, the clinical implementation of senotherapy faces significant hurdles, including lack of precise methods for SCs identification and the potential for adverse effects associated with highly cytotoxic senolytic agents. In this account, we elucidate recent advancement in developing novel approaches for the detection and selective elimination of SCs, encompassing prodrugs, nanoparticles, and other cutting-edge drug delivery systems such as PROTAC technology and CAR T cell therapy. Furthermore, we explore the paradoxical nature of SCs, which can induce growth arrest in adjacent neoplastic cells and recruit immunomodulatory cells that contribute to tumor suppression. Therefore, we utilize SCs membrane as vehicles to elicit antitumor immunity and potentially augment existing anti-cancer therapies. Finally, the opportunities and challenges are put forward to facilitate the development and clinical transformation of SCs detection, elimination or utilization.

The context-dependent effect of cellular senescence: From embryogenesis and wound healing to aging

Aging is characterized by a steady loss of physiological integrity, leading to impaired function and increased vulnerability to death. Cell senescence is a biological process that progresses with aging and is believed to be a key driver of age-related diseases. Senescence, a hallmark of aging, also demonstrates its beneficial physiological aspects as an anti-cancer, pro-regenerative, homeostatic, and developmental mechanism. A transitory response in which the senescent cells are quickly formed and cleared may promote tissue regeneration and organismal fitness. At the same time, senescence-related secretory phenotypes associated with extended senescence can have devastating effects. The fact that the interaction between senescent cells and their surroundings is very context-dependent may also help to explain this seemingly opposing pleiotropic function. Further, mitochondrial dysfunction is an often-unappreciated hallmark of cellular senescence and figures prominently in multiple feedback loops that induce and maintain the senescent phenotype. This review summarizes the mechanism of cellular senescence and the significance of acute senescence. We concisely introduced the context-dependent role of senescent cells and SASP, aspects of mitochondrial biology altered in the senescent cells, and their impact on the senescent phenotype. Finally, we conclude with recent therapeutic advancements targeting cellular senescence, focusing on acute injuries and age-associated diseases. Collectively, these insights provide a future roadmap for the role of senescence in organismal fitness and life span extension.

Aging at the Crossroads of Organ Interactions: Implications for the Heart

Aging processes underlie common chronic cardiometabolic diseases such as heart failure and diabetes. Cross-organ/tissue interactions can accelerate aging through cellular senescence, tissue wasting, accelerated atherosclerosis, increased vascular stiffness, and reduction in blood flow, leading to organ remodeling and premature failure. This interorgan/tissue crosstalk can accelerate aging-related dysfunction through inflammation, senescence-associated secretome, and metabolic and mitochondrial changes resulting in increased oxidative stress, microvascular dysfunction, cellular reprogramming, and tissue fibrosis. This may also underscore the rising incidence and co-occurrence of multiorgan dysfunction in cardiometabolic aging in the population. Examples include interactions between the heart and the lungs, kidneys, liver, muscles, and brain, among others. However, this phenomenon can also present new translational opportunities for identifying diagnostic biomarkers to define early risks of multiorgan dysfunction, gain mechanistic insights, and help to design precision-directed therapeutic interventions. Indeed, this opens new opportunities for therapeutic development in targeting multiple organs simultaneously to disrupt the crosstalk-driven process of mutual disease acceleration. New therapeutic targets could provide synergistic benefits across multiple organ systems in the same at-risk patient. Ultimately, these approaches may together slow the aging process itself throughout the body. In the future, with patient-centered multisystem coordinated approaches, we can initiate a new paradigm of multiorgan early risk prediction and tailored intervention. With emerging tools including artificial intelligence-assisted risk profiling and novel preventive strategies (eg, RNA-based therapeutics), we may be able to mitigate multiorgan cardiometabolic dysfunction much earlier and, perhaps, even slow the aging process itself.

Anti-senescence therapies: a new concept to address cardiovascular disease

Accumulation of senescent cells is an increasingly recognized factor in the development and progression of cardiovascular (CV) disease (CVD). Senescent cells of different types display a pro-inflammatory and matrix remodelling molecular programme, known as the 'senescence-associated secretory phenotype' (SASP), which has roots in (epi)genetic changes. Multiple therapeutic options (senolytics, anti-SASP senomorphics, and epigenetic reprogramming) that delete or ameliorate cellular senescence have recently emerged. Some drugs routinely used in the clinics also have anti-senescence effects. However, multiple challenges hinder the application of novel anti-senescence therapeutics in the clinical setting. Understanding the biology of cellular senescence, advantages and pitfalls of anti-senescence treatments, and patients who can profit from these interventions is necessary to introduce this novel therapeutic modality into the clinics. We provide a guide through the molecular machinery of senescent cells, systematize anti-senescence treatments, and propose a pathway towards senescence-adapted clinical trial design to aid future efforts.

SGLT2 inhibitors as a novel senotherapeutic approach

Cellular senescence is the permanent cessation of cell proliferation and growth. Senescent cells accumulating in tissues and organs with aging contribute to many chronic diseases, mainly through the secretion of a pro-inflammatory senescence-associated secretory phenotype (SASP). Senotherapeutic (senolytic or senomorphic) strategies targeting senescent cells or/and their SASP are being developed to prolong healthy lifespan and treat age-related pathologies. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of anti-diabetic drugs that promote the renal excretion of glucose, resulting in lower blood glucose levels. Beyond their glucose-lowering effects, SGLT2 inhibitors have demonstrated protective effects against cardiovascular and renal events. Moreover, SGLT2 inhibitors have recently been associated with the inhibition of cell senescence, making them a promising therapeutic approach for targeting senescence and aging. This review examines the latest research on the senotherapeutic potential of SGLT2 inhibitors.

Oleanolic Acid@SPIONs Alleviates Lipid-Oxidative Stress Injury of Zebrafish Blood Vessels via Regulating the Expression of JNK and MAPK Signaling Pathways in Vascular Endothelial Cells

Background and Aims

The incidence of and mortality due to atherosclerosis, a leading cause of cardiovascular disease, is rising annually. Oleanolic acid (OA), an active component of the traditional Chinese medicine Ligustrum lucidum, has been proven to have significant anti-inflammatory and lipid-lowering potential.

Methods

The fli1a::EGFP+ zebrafish fed with oxidized low-density lipoprotein (oxLDL) diet were used as Atherosclerosis model. The zebrafish Atherosclerosis model were fed with oxalic acid driven by superparamagnetic ferrite nanoparticles (OA@SPIONs). Isolation and enrichment of fli1a::EGFP+ zebrafish endothelial cells (zeECs) from each group and RNA-seq to analyze changes in gene transcription. The H&E, MASSION, Oil red O staining were used to identifying pathological phenotypes.

Results

Pathological staining and ultrastructural identification indicated that oxLDL-treated zebrafish exhibited significant lipid plaque deposition and signs of cellular senescence that were significantly alleviated by OA@SPIONs treatment. OA@SPIONs treatment notably improved the ultrastructural integrity of myocardial, liver, and intestinal tissues in oxLDL-treated zebrafish. The RNA-seq results showed that OA@SPIONs treatment significantly altered the expression levels of multiple gene transcripts in zeECs. The KEGG analysis revealed that in the OA@SPION-treated group zeECs, key genes in the JNK and MAPK signaling pathways, such as Cacna1c, Rab1ab (Ras), Map3k1 (MEKK1), Mapk8b (JNK), and JunD, had significantly lower sequencing signals than in the oxLDL+SPION-treated group zeECs. The qPCR results were highly consistent with the RNA-sequencing data.

Conclusion

Therefore, our results confirm that SPIONs can effectively deliver OA for stable release in zebrafish and provide strong evidence that OA@SPION-polyethyleneimine exerts protective effects against oxLDL-induced damage in zebrafish by downregulating the expression of the JNK and MAPK signaling pathways.

Is Senolytic Therapy in Cardiovascular Diseases Ready for Translation to Clinics?

Aging is a predominant risk factor for cardiovascular diseases. There is evidence demonstrating that senescent cells not only play a significant role in organism aging but also contribute to the pathogenesis of cardiovascular diseases in younger ages. Encouraged by recent findings that the elimination of senescent cells by pharmacogenetic tools could slow down and even reverse organism aging in animal models, senolytic drugs have been developed, and the translation of results from basic research to clinical settings has been initiated. Because numerous studies in the literature show beneficial therapeutic effects of targeting senescent cells in cardiomyopathies associated with aging and ischemia/reperfusion and in atherosclerotic vascular disease, senolytic drugs are considered the next generation of therapies for cardiovascular disorders. However, recent studies have reported controversial results or detrimental effects caused by senolytic therapeutic approaches, including worsening of cardiac dysfunction, instability of atherosclerotic plaques, and even an increase in mortality in animal models, which challenges the translation of senolytic therapy into the clinical practice. This brief review article will focus on (1) analyzing and discussing the beneficial and detrimental effects of senolytic therapeutic approaches in cardiovascular diseases and cardiovascular aging and (2) future research directions and questions that are essential to understand the controversies and to translate preclinical results of senolytic therapies into clinical practice.

Heart of the matter: Mitochondrial dynamics and genome alterations in cardiac aging

Cardiac pathological aging is a serious health issue, with cardiovascular diseases still being a leading cause of deaths worldwide. Therefore, there is an urgent need to identify culprit factors involved in this process. In the last decades, mitochondria, which are crucial for cardiac function, have emerged as major contributors. Mitochondria are organelles involved in a plethora of metabolic pathways and cell processes ranging from ATP production to calcium homeostasis or regulation of apoptotic pathways. This review provides a general overview of the pathomechanisms involving mitochondria during cardiac aging, with a focus on the role of mitochondrial dynamics and mitochondrial DNA (mtDNA). These mechanisms involve imbalanced mitochondrial fusion and fission, loss of mtDNA integrity leading to tissue mosaic of mitochondrial deficiency, as well as mtDNA release in the cytoplasm, promoting inflammation via the NLRP3, cGAS/STING and TLR9 pathways. Potential links between mtDNA, mitochondrial damage and the accumulation of senescent cells in the heart are also discussed. A better understanding of how these factors impact on heart function and accelerate its pathological aging should lead to the development of new therapies to promote healthy aging and restore age-induced cardiac dysfunction.

Systemic aging fuels heart failure: Molecular mechanisms and therapeutic avenues

Systemic aging influences various physiological processes and contributes to structural and functional decline in cardiac tissue. These alterations include an increased incidence of left ventricular hypertrophy, a decline in left ventricular diastolic function, left atrial dilation, atrial fibrillation, myocardial fibrosis and cardiac amyloidosis, elevating susceptibility to chronic heart failure (HF) in the elderly. Age-related cardiac dysfunction stems from prolonged exposure to genomic, epigenetic, oxidative, autophagic, inflammatory and regenerative stresses, along with the accumulation of senescent cells. Concurrently, age-related structural and functional changes in the vascular system, attributed to endothelial dysfunction, arterial stiffness, impaired angiogenesis, oxidative stress and inflammation, impose additional strain on the heart. Dysregulated mechanosignalling and impaired nitric oxide signalling play critical roles in the age-related vascular dysfunction associated with HF. Metabolic aging drives intricate shifts in glucose and lipid metabolism, leading to insulin resistance, mitochondrial dysfunction and lipid accumulation within cardiomyocytes. These alterations contribute to cardiac hypertrophy, fibrosis and impaired contractility, ultimately propelling HF. Systemic low-grade chronic inflammation, in conjunction with the senescence-associated secretory phenotype, aggravates cardiac dysfunction with age by promoting immune cell infiltration into the myocardium, fostering HF. This is further exacerbated by age-related comorbidities like coronary artery disease (CAD), atherosclerosis, hypertension, obesity, diabetes and chronic kidney disease (CKD). CAD and atherosclerosis induce myocardial ischaemia and adverse remodelling, while hypertension contributes to cardiac hypertrophy and fibrosis. Obesity-associated insulin resistance, inflammation and dyslipidaemia create a profibrotic cardiac environment, whereas diabetes-related metabolic disturbances further impair cardiac function. CKD-related fluid overload, electrolyte imbalances and uraemic toxins exacerbate HF through systemic inflammation and neurohormonal renin-angiotensin-aldosterone system (RAAS) activation. Recognizing aging as a modifiable process has opened avenues to target systemic aging in HF through both lifestyle interventions and therapeutics. Exercise, known for its antioxidant effects, can partly reverse pathological cardiac remodelling in the elderly by countering processes linked to age-related chronic HF, such as mitochondrial dysfunction, inflammation, senescence and declining cardiomyocyte regeneration. Dietary interventions such as plant-based and ketogenic diets, caloric restriction and macronutrient supplementation are instrumental in maintaining energy balance, reducing adiposity and addressing micronutrient and macronutrient imbalances associated with age-related HF. Therapeutic advancements targeting systemic aging in HF are underway. Key approaches include senomorphics and senolytics to limit senescence, antioxidants targeting mitochondrial stress, anti-inflammatory drugs like interleukin (IL)-1β inhibitors, metabolic rejuvenators such as nicotinamide riboside, resveratrol and sirtuin (SIRT) activators and autophagy enhancers like metformin and sodium-glucose cotransporter 2 (SGLT2) inhibitors, all of which offer potential for preserving cardiac function and alleviating the age-related HF burden.

Protection of the genome and the central exome by peripheral non-coding DNA against DNA damage in health, ageing and age-related diseases

DNA in eukaryotic genomes is under constant assault from both exogenous and endogenous sources, leading to DNA damage, which is considered a major molecular driver of ageing. Fortunately, the genome and the central exome are safeguarded against these attacks by abundant peripheral non-coding DNA. Non-coding DNA codes for small non-coding RNAs that inactivate foreign nucleic acids in the cytoplasm and physically blocks these attacks in the nucleus. Damage to non-coding DNA produced during such blockage is removed in the form of extrachromosomal circular DNA (eccDNA) through nucleic pore complexes. Consequently, non-coding DNA serves as a line of defence for the exome against DNA damage. The total amount of non-coding DNA/heterochromatin declines with age, resulting in a decrease in both physical blockage and eccDNA exclusion, and thus an increase in the accumulation of DNA damage in the nucleus during ageing and in age-related diseases. Here, we summarize recent evidence supporting a protective role of non-coding DNA in healthy and pathological states and argue that DNA damage is the proximate cause of ageing and age-related genetic diseases. Strategies aimed at strengthening the protective role of non-coding DNA/heterochromatin could potentially offer better systematic protection for the dynamic genome and the exome against diverse assaults, reduce the burden of DNA damage to the exome, and thus slow ageing, counteract age-related genetic diseases and promote a healthier life for individuals.

Telomere function and regulation from mouse models to human ageing and disease

Telomeres protect the ends of chromosomes but shorten following cell division in the absence of telomerase activity. When telomeres become critically short or damaged, a DNA damage response is activated. Telomeres then become dysfunctional and trigger cellular senescence or death. Telomere shortening occurs with ageing and may contribute to associated maladies such as infertility, neurodegeneration, cancer, lung dysfunction and haematopoiesis disorders. Telomere dysfunction (sometimes without shortening) is associated with various diseases, known as telomere biology disorders (also known as telomeropathies). Telomere biology disorders include dyskeratosis congenita, Høyeraal-Hreidarsson syndrome, Coats plus syndrome and Revesz syndrome. Although mouse models have been invaluable in advancing telomere research, full recapitulation of human telomere-related diseases in mice has been challenging, owing to key differences between the species. In this Review, we discuss telomere protection, maintenance and damage. We highlight the differences between human and mouse telomere biology that may contribute to discrepancies between human diseases and mouse models. Finally, we discuss recent efforts to generate new 'humanized' mouse models to better model human telomere biology. A better understanding of the limitations of mouse telomere models will pave the road for more human-like models and further our understanding of telomere biology disorders, which will contribute towards the development of new therapies.

Hyperactive mTORC1/4EBP1 signaling dysregulates proteostasis and accelerates cardiac aging

The mechanistic target of rapamycin complex 1 (mTORC1) has a major impact on aging by regulation of proteostasis. It is well established that mTORC1 signaling is hyperactivated with aging and age-related diseases. Previous studies have shown that partial inhibition of mTOR signaling by rapamycin reverses age-related deteriorations in cardiac function and structure in old mice. However, the downstream signaling pathways involved in this protection against cardiac aging have not been established. mTORC1 phosphorylates 4E-binding protein 1 (4EBP1) to promote the initiation of cap-dependent translation. The objective of this project is to examine the role of the mTORC1/4EBP1 axis in age-related cardiac dysfunction. We used a whole-body 4EBP1 KO mouse model, which mimics a hyperactive mTORC1/4EBP1/eIF4E axis, to investigate the effects of hyperactive mTORC1/4EBP1 axis in cardiac aging. Echocardiographic measurements of middle-aged 4EBP1 KO mice show impaired diastolic function and myocardial performance compared to age-matched WT mice and these parameters are at similar levels as old WT mice, suggesting that 4EBP1 KO mice experience accelerated cardiac aging. Old 4EBP1 KO mice show further decline in systolic and diastolic function compared to middle-aged counterparts and have worse systolic and diastolic function than age-matched WT mice. Gene expression levels of heart failure markers are not different between 4EBP1 KO and WT hearts. However, ribosomal biogenesis and protein ubiquitination are significantly increased in 4EBP1 KO hearts when compared to WT controls, suggesting dysregulated proteostasis in 4EBP1 KO hearts. Together, these results show that a hyperactive mTORC1/4EBP1 axis accelerates cardiac aging, potentially by dysregulating proteostasis.

Telomeres in skin aging

Skin aging is influenced by both intrinsic and extrinsic factors. The gradual manifestation of changes in telomere length and telomerase activity, as crucial indicators of aging, elucidates the underlying mechanism of skin aging. This review aims to comprehensively analyze the association between telomeres and aging, along with their impact on skin biological function. Firstly, we summarize the structure and function of telomeres and their role in cell division. Subsequently, we discuss the mechanisms through which telomere regulation contributes to aging processes while analyzing its involvement in skin aging by elaborating on biological markers. Furthermore, this paper presents a summary of recent research progress that reveals the correlation between telomere length and skin aging as well as model building methods; it also proposes telomere length as a potential indicator for predicting skin aging. Finally, anti-aging strategies based on telomere protection are discussed including drug therapy and lifestyle adjustments. This paper provides a systematic overview of the role played by telomeres in the field of skin aging for the first time, offering new perspectives and ideas for future prevention and treatment.

Small extracellular vesicles from young adipose-derived stem cells ameliorate age-related changes in the heart of old mice

BACKGROUND

Aging entails a progressive decline in physiological functions, elevating the risk of age-related diseases like heart failure or aortic stenosis. Stem cell therapies, especially those that use paracrine signaling, can potentially mitigate the adverse effects of aging.

OBJECTIVES

The objective is to explore the potential of small extracellular vesicles (sEVs) derived from young adipose-derived stem cells (ADSC-sEVs) in reversing structural, molecular, and functional changes associated with aging in the heart.

METHODS

Aged C57BL/6J mice were treated intravenously with ADSC-sEVs from young mice or PBS as controls. Young mice were included to identify specific age-associated changes. The impact of sEV treatment on cardiac function was assessed using transthoracic echocardiography and physical endurance tests. Histological and molecular analyses were conducted on heart tissue to evaluate structural changes and markers of senescence, inflammation, and oxidative stress. A comprehensive metabolomic analysis was also performed on heart tissues to identify changes in metabolic profiles associated with aging and treatment status.

RESULTS

The administration of ADSC-sEVs significantly improves several aging-associated cardiac parameters, including oxidative stress, inflammation, and cellular senescence reductions. We also report on the age-related reversal of myocardial structure and function changes, highlighted by decreased fibrosis and improved vascularization. Notably, echocardiographic assessments reveal that sEV treatments ameliorate diastolic dysfunction and left ventricle structural alterations typically associated with aging. Furthermore, the treatment shifts the heart metabolome towards a more youthful profile.

CONCLUSIONS

These results denote the potential of ADSC-sEVs as a novel, noninvasive therapeutic strategy for mitigating cardiac aging-associated functional decline.

Elucidating emerging signaling pathways driving endothelial dysfunction in cardiovascular aging

The risk for developing cardiovascular diseases dramatically increases in older individuals, and aging vasculature plays a crucial role in determining their morbidity and mortality. Aging disrupts endothelial balance between vasodilators and vasoconstrictors, impairing function and promoting pathological vascular remodeling. In this Review, we discuss the impact of key and emerging molecular pathways that transduce aberrant inflammatory signals (i.e., chronic low-grade inflammation-inflammaging), oxidative stress, and mitochondrial dysfunction in aging vascular compartment. We focus on the interplay between these events, which contribute to generating a vicious cycle driving the progressive alterations in vascular structure and function during cardiovascular aging. We also discuss the primary role of senescent endothelial cells and vascular smooth muscle cells, and the potential link between vascular and myeloid cells, in impairing plaque stability and promoting the progression of atherosclerosis. The aim of this summary is to provide potential novel insights into targeting these processes for therapeutic benefit.

H2S Donor SPRC Ameliorates Cardiac Aging by Suppression of JMJD3, a Histone Demethylase

Aims: S-propargyl-cysteine (SPRC) is an endogenous hydrogen sulfide (H2S) donor obtained by modifying the structure of S-allyl cysteine in garlic. This study aims to investigate the effect of SPRC on mitigating cardiac aging and the involvement of jumonji domain-containing protein 3 (JMJD3), a histone demethylase, which represents the primary risk factor in major aging related diseases, in this process, elucidating the preliminary mechanism through which SPRC regulation of JMJD3 occurs. Results: In vitro, SPRC mitigated the elevated levels of reactive oxygen species, senescence-associated β-galactosidase, p53, and p21, reversing the decline in mitochondrial membrane potential, which represented a reduction in cellular senescence. In vivo, SPRC improved Dox-induced cardiac pathological structure and function. Overexpression of JMJD3 accelerated cardiomyocytes and cardiac senescence, whereas its knockdown in vitro reduced the senescence phenotype. The potential binding site of the upstream transcription factor of JMJD3, sheared X box binding protein 1 (XBP1s), was determined using online software. SPRC promoted the expression of cystathionine γ-lyase (CSE), which subsequently inhibited the IRE1α/XBP1s signaling pathway and decreased JMJD3 expression. Innovations: This study is the first to establish JMJD3 as a crucial regulator of cardiac aging. SPRC can alleviate cardiac aging by upregulating CSE and inhibiting endoplasmic reticulum stress pathways, which in turn suppress JMJD3 expression. Conclusions: JMJD3 plays an essential role in cardiac aging regulation, whereas SPRC can suppress the expression of JMJD3 by upregulating CSE, thus delaying cardiac aging, which suggests that SPRC may serve as an aging protective agent, and pharmacological targeting of JMJD3 may also be a promising therapeutic approach in age-related heart diseases. Antioxid. Redox Signal. 42, 301-320.

Mitochondrial Mutation Leads to Cardiomyocyte Hypertrophy by Disruption of Mitochondria-Associated ER Membrane

m.3243A>G is the most common pathogenic mtDNA mutation. High energy-demanding organs, such as heart, are usually involved in mitochondria diseases. However, whether and how m.3243A>G affects cardiomyocytes remain unknown. We have established patient-specific iPSCs carrying m.3243A>G and induced cardiac differentiation. Cardiomyocytes with high m.3243A>G burden exhibited hypertrophic phenotype. This point mutation is localised in MT-TL1 encoding tRNALeu (UUR). m.3243A>G altered tRNALeu (UUR) conformation and decreased its stability. mtDNA is essential for mitochondrial function. Mitochondria dysfunction occurred and tended to become round. Its interaction with ER, mitochondria-associated ER membrane (MAM), was disrupted with decreased contact number and length. MAM is a central hub for calcium trafficking. Disrupted MAM disturbed calcium homeostasis, which may be the direct and leading cause of cardiomyocyte hypertrophy, as MAM enforcement reversed this pathological state. Considering the threshold effect of mitochondrial disease, mito-TALENs were introduced to eliminate mutant mitochondria and release mutation load. Mutation reduction partially reversed the cellular behaviour and made it approach to that of control one. These findings reveal the pathogenesis underlying m.3243A>G from perspective of organelle interaction, rather than organelle. Beyond mitochondria quality control, its proper interaction with other organelles, such as ER, matters for mitochondria disease. This study may provide inspiration for mitochondria disease intervention.

Roadmap for alleviating the manifestations of ageing in the cardiovascular system

Ageing of the cardiovascular system is associated with frailty and various life-threatening diseases. As global populations grow older, age-related conditions increasingly determine healthspan and lifespan. The circulatory system not only supplies nutrients and oxygen to all tissues of the human body and removes by-products but also builds the largest interorgan communication network, thereby serving as a gatekeeper for healthy ageing. Therefore, elucidating organ-specific and cell-specific ageing mechanisms that compromise circulatory system functions could have the potential to prevent or ameliorate age-related cardiovascular diseases. In support of this concept, emerging evidence suggests that targeting the circulatory system might restore organ function. In this Roadmap, we delve into the organ-specific and cell-specific mechanisms that underlie ageing-related changes in the cardiovascular system. We raise unanswered questions regarding the optimal design of clinical trials, in which markers of biological ageing in humans could be assessed. We provide guidance for the development of gerotherapeutics, which will rely on the technological progress of the diagnostic toolbox to measure residual risk in elderly individuals. A major challenge in the quest to discover interventions that delay age-related conditions in humans is to identify molecular switches that can delay the onset of ageing changes. To overcome this roadblock, future clinical trials need to provide evidence that gerotherapeutics directly affect one or several hallmarks of ageing in such a manner as to delay, prevent, alleviate or treat age-associated dysfunction and diseases.

The senotherapeutic potential of phytochemicals for age-related intestinal disease

During the last few decades, life expectancy has increased worldwide along with the prevalence of several age-related diseases. Among aging pathways, cellular senescence and chronic inflammation (or "inflammaging") appear to be connected to gut homeostasis and dysbiosis of the microbiome. Cellular senescence is a state of essentially irreversible cell cycle arrest that occurs in response to stress. Although senescent cells (SC) remain metabolically active, they do not proliferate and can secrete inflammatory and other factors comprising the senescence-associated secretory phenotype (SASP). Accumulation of SCs has been linked to onset of several age-related diseases, in the brain, bones, the gastrointestinal tract, and other organs and tissues. The gut microbiome undergoes substantial changes with aging and is tightly interconnected with either successful (healthy) aging or disease. Senotherapeutic drugs are compounds that can clear senescent cells or modulate the release of SASP factors and hence attenuate the impact of the senescence-associated pro-inflammatory state. Phytochemicals, phenolic compounds and terpenes, which have antioxidant and anti-inflammatory activities, could also be senotherapeutic given their ability to act upon senescence-linked cellular pathways. The aim of this review is to dissect links among the gut microbiome, cellular senescence, inflammaging, and disease, as well as to explore phytochemicals as potential senotherapeutics, focusing on their interactions with gut microbiota. Coordinated targeting of these inter-related processes might unveil new strategies for promoting healthy aging.

Senescent myoblasts exhibit an altered exometabolome that is linked to senescence-associated secretory phenotype signaling

Cellular senescence has been implicated in the aging-related dysfunction of satellite cells, the resident muscle stem cell population primarily responsible for the repair of muscle fibers. Despite being in a state of permanent cell cycle arrest, these cells remain metabolically active and release an abundance of factors that can have detrimental effects on the cellular microenvironment. This phenomenon is known as the senescence-associated secretory phenotype (SASP), and its metabolic profile is poorly characterized in senescent muscle. In the present investigation, we examined the intracellular and extracellular metabolome of C2C12 myoblasts using a bleomycin (BLEO)-mediated model of DNA damage-induced senescence. We also evaluated the relationship between the senescent metabolic phenotype and SASP signaling through molecular and network-based analyses. Senescent myoblasts exhibited a significantly altered extracellular metabolome (i.e., exometabolome), including increased secretion of several aging-associated metabolites. Four of these metabolites-trimethylamine-N-oxide (TMAO), xanthine, choline, and oleic acid-were selected for individual dose-response experiments to determine whether they could drive the senescence phenotype. Although most of the tested metabolites did not independently alter senescence markers, oleic acid treatment of healthy myoblasts significantly upregulated the SASP genes Ccl2, Cxcl12, and Il33 (p < 0.05). A gene-metabolite interaction network further revealed that oleic acid was one of the most interconnected metabolites to key senescence-associated genes. Notably, oleic acid interacted with several prominent SASP genes, suggesting a potential epigenetic effect between this monounsaturated fatty acid and SASP regulation. In summary, the exometabolome, particularly oleic acid, is implicated in SASP signaling within senescent myoblasts.NEW & NOTEWORTHY Cellular senescence and its accompanying secretory phenotype [i.e., the senescence-associated secretory phenotype (SASP)] have been linked to the aging-associated dysfunction of skeletal muscle, yet little is known about this phenomenon in satellite cells. We report that senescent myoblasts experience a significantly altered extracellular metabolome primarily characterized by the substantial release of nonesterified fatty acids. Targeted evaluation of several extracellular senescence-associated metabolites reveals a potential epigenetic role for long-chain fatty acids, particularly oleic acid, in regulating SASP-related gene expression.

Recent advances in biomarkers for senescence: Bridging basic research to clinic

In this review, we review the current status of biomarkers for aging and possible perspectives on anti-aging or rejuvenation from the standpoint of biomarkers. Aging is observed in all cells and organs, and we focused on research into senescence in the skin, musculoskeletal system, immune system, and cardiovascular system. Commonly used biomarkers include SA-βgal, cell-cycle markers, senescence-associated secretory phenotype (SASP) factors, damage-associated molecular patterns (DAMPs), and DNA-damage-related markers. In addition, each organ or cell has its specific markers. Generally speaking, a combination of biomarkers is required to define age-related changes. When considering the translation of basic research, biomarkers that are highly sensitive, highly specific, with validation and reliability as well as being non-invasive are optimal; however, currently reported markers do not fulfill the prerequisite for biomarkers. In addition, rodent models of aging do not necessarily represent human aging, and markers in rodent or cell models are not applicable in clinical settings. The prerequisite of clinically applicable biomarkers is that they provide useful information for clinical decision-making, such as predicting disease risk, diagnosing disease, monitoring disease progression, or guiding treatment decisions. Therefore, the development of non-invasive robust, reliable, and useful biomarkers in humans is necessary to develop anti-aging therapy for humans. Geriatr Gerontol Int 2025; 25: 139-147.

OGG1 and MUTYH repair activities promote telomeric 8-oxoguanine induced senescence in human fibroblasts

Telomeres are hypersensitive to the formation of the common oxidative lesion 8-oxoguanine (8oxoG), which impacts telomere stability and function. OGG1 and MUTYH glycosylases initiate base excision repair (BER) to remove 8oxoG or prevent mutation. Here, we show OGG1 loss or inhibition, or MUTYH loss, partially rescues telomeric 8oxoG-induced premature senescence and associated proinflammatory responses, while loss of both glycosylases causes a near complete rescue in human fibroblasts. Glycosylase deficiency also suppresses 8oxoG-induced telomere fragility and dysfunction, indicating that downstream single-stranded break (SSB) repair intermediates impair telomere replication. Preventing BER initiation suppresses PARylation and confers resistance to the synergistic effects of PARP inhibitors on 8oxoG-induced senescence. However, OGG1 activity is essential for preserving cell growth after chronic telomeric 8oxoG formation, whereas MUTYH promotes senescence to prevent chromosomal instability from unrepaired damage. Our studies reveal that inefficient completion of 8oxoG BER at telomeres triggers cellular senescence via SSB intermediates which disrupt telomere function.

Geroscience in heart failure: the search for therapeutic targets in the shared pathobiology of human aging and heart failure

Age is a major risk factor for heart failure, but one that has been historically viewed as non-modifiable. Emerging evidence suggests that the biology of aging is malleable, and can potentially be intervened upon to treat age-associated chronic diseases, such as heart failure. While aging biology represents a new frontier for therapeutic target discovery in heart failure, the challenges of translating Geroscience research to the clinic are multifold. In this review, we propose a strategy that prioritizes initial target discovery in human biology. We review the rationale for starting with human omics, which has generated important insights into the shared (patho)biology of human aging and heart failure. We then discuss how this knowledge can be leveraged to identify the mechanisms of aging biology most relevant to heart failure. Lastly, we provide examples of how this human-first Geroscience approach, when paired with rigorous functional assessments in preclinical models, is leading to early-stage clinical development of gerotherapeutic approaches for heart failure.

Novel Therapeutic Strategies Targeting Fibroblasts to Improve Heart Disease

Cardiac fibrosis represents the terminal pathological manifestation of various heart diseases, with the formation of fibroblasts playing a pivotal role in this process. Consequently, targeting the formation and function of fibroblasts holds significant potential for improving outcomes in heart disease. Recent research reveals the considerable potential of fibroblasts in ameliorating cardiac conditions, demonstrating different functional characteristics at various time points and spatial locations. Therefore, precise modulation of fibroblast activity may offer an effective approach for treating cardiac fibrosis and achieving targeted therapeutic outcomes. In this review, we focus on the fate and inhibition of fibroblasts, analyze their dynamic changes in cardiac diseases, and propose a framework for identifying markers of fibroblast activation mechanisms and selecting optimal time windows for therapeutic intervention. By synthesizing research findings in these areas, we aim to provide new strategies and directions for the precise treatment of fibroblasts in cardiac diseases.

Neuregulin-1 reduces Doxorubicin-induced cardiotoxicity by upregulating YAP to inhibit senescence

The cardiotoxicity of Doxorubicin (Dox) limits its clinical application, creating an urgent need to investigate its underlying mechanism and develop effective therapies. Senescence plays an important role in Dox-induced cardiotoxicity (DIC). Recently, Neuregulin-1 (NRG1) was found to regulate Yes-associated protein (YAP), which was reported to inhibit senescence, suggesting that NRG1 might be used to treat DIC by inhibiting senescence through YAP regulation. We examined the changes and regulatory roles of YAP and senescence in Dox cardiotoxicity and whether NRG1 could reduce DIC in chronic DIC mice and Dox-treated H9c2 cells. Our study revealed that sustained small doses of Dox impaired cardiac function and H9c2 cell viability, induced myocardial senescence, and inhibited YAP expression. Conversely, high levels of YAP inhibited Dox-induced senescence in H9c2 cells, indicating that Dox promotes myocardial senescence by inhibiting YAP. In addition, we found that exogenous NRG1 inhibited the phosphorylation of LATS1 and MST1, thereby inhibiting YAP phosphorylation and promote the nuclear translocation of YAP, inhibiting senescence and attenuating Dox-induced cardiotoxicity. YAP knockdown or inhibition of YAP binding to TEA domain transcription factor protein （TEAD）blocks the protective effects of NRG1. In conclusion, our study suggests that Dox-induced myocardial senescence through YAP inhibition is one of the pathological mechanisms of its cardiotoxicity. Additionally, NRG1 reduces DIC by upregulating YAP to inhibit senescence.

The role of CYP-sEH derived lipid mediators in regulating mitochondrial biology and cellular senescence: implications for the aging heart

Cellular senescence is a condition characterized by stable, irreversible cell cycle arrest linked to the aging process. The accumulation of senescent cells in the cardiac muscle can contribute to various cardiovascular diseases (CVD). Telomere shortening, epigenetic modifications, DNA damage, mitochondrial dysfunction, and oxidative stress are known contributors to the onset of cellular senescence in the heart. The link between mitochondrial processes and cellular senescence contributed to the age-related decline in cardiac function. These include changes in mitochondrial functions and behaviours that arise from various factors, including impaired dynamics, dysregulated biogenesis, mitophagy, mitochondrial DNA (mtDNA), reduced respiratory capacity, and mitochondrial structural changes. Thus, regulation of mitochondrial biology has a role in cellular senescence and cardiac function in aging hearts. Targeting senescent cells may provide a novel therapeutic approach for treating and preventing CVD associated with aging. CYP epoxygenases metabolize N-3 and N-6 polyunsaturated fatty acids (PUFA) into epoxylipids that are readily hydrolyzed to diol products by soluble epoxide hydrolase (sEH). Increasing epoxylipids levels or inhibition of sEH has demonstrated protective effects in the aging heart. Evidence suggests they may play a role in cellular senescence by regulating mitochondria, thus reducing adverse effects of aging in the heart. In this review, we discuss how mitochondria induce cellular senescence and how epoxylipids affect the senescence process in the aged heart.

Roles of chromatin and genome instability in cellular senescence and their relevance to ageing and related diseases

Ageing is a complex biological process in which a gradual decline in physiological fitness increases susceptibility to diseases such as neurodegenerative disorders and cancer. Cellular senescence, a state of irreversible cell-growth arrest accompanied by functional deterioration, has emerged as a pivotal driver of ageing. In this Review, we discuss how heterochromatin loss, telomere attrition and DNA damage contribute to cellular senescence, ageing and age-related diseases by eliciting genome instability, innate immunity and inflammation. We also discuss how emerging therapeutic strategies could restore heterochromatin stability, maintain telomere integrity and boost the DNA repair capacity, and thus counteract cellular senescence and ageing-associated pathologies. Finally, we outline current research challenges and future directions aimed at better comprehending and delaying ageing.

SenNet recommendations for detecting senescent cells in different tissues

Once considered a tissue culture-specific phenomenon, cellular senescence has now been linked to various biological processes with both beneficial and detrimental roles in humans, rodents and other species. Much of our understanding of senescent cell biology still originates from tissue culture studies, where each cell in the culture is driven to an irreversible cell cycle arrest. By contrast, in tissues, these cells are relatively rare and difficult to characterize, and it is now established that fully differentiated, postmitotic cells can also acquire a senescence phenotype. The SenNet Biomarkers Working Group was formed to provide recommendations for the use of cellular senescence markers to identify and characterize senescent cells in tissues. Here, we provide recommendations for detecting senescent cells in different tissues based on a comprehensive analysis of existing literature reporting senescence markers in 14 tissues in mice and humans. We discuss some of the recent advances in detecting and characterizing cellular senescence, including molecular senescence signatures and morphological features, and the use of circulating markers. We aim for this work to be a valuable resource for both seasoned investigators in senescence-related studies and newcomers to the field.

A Mitochondrial Basis for Heart Failure Progression

In health, the human heart is able to match ATP supply and demand perfectly. It requires 6 kg of ATP per day to satisfy demands of external work (mechanical force generation) and internal work (ion movements and basal metabolism). The heart is able to link supply with demand via direct responses to ADP and AMP concentrations but calcium concentrations within myocytes play a key role, signalling both inotropy, chronotropy and matched increases in ATP production. Calcium/calmodulin-dependent protein kinase (CaMKII) is a key adapter to increased workload, facilitating a greater and more rapid calcium concentration change. In the failing heart, this is dysfunctional and ATP supply is impaired. This review aims to examine the mechanisms and pathologies that link increased energy demand to this disrupted situation. We examine the roles of calcium loading, oxidative stress, mitochondrial structural abnormalities and damage-associated molecular patterns.

Senescence and tissue fibrosis: opportunities for therapeutic targeting

Cellular senescence is a key hallmark of aging. It has now emerged as a key mediator in normal tissue turnover and is associated with a variety of age-related diseases, including organ-specific fibrosis and systemic sclerosis (SSc). This review discusses the recent evidence of the role of senescence in tissue fibrosis, with an emphasis on SSc, a systemic autoimmune rheumatic disease. We discuss the physiological role of these cells, their role in fibrosis, and that targeting these cells specifically could be a new therapeutic avenue in fibrotic disease. We argue that targeting senescent cells, with senolytics or senomorphs, is a viable therapeutic target in fibrotic diseases which remain largely intractable.

Emerging insights in senescence: pathways from preclinical models to therapeutic innovations

Senescence is a crucial hallmark of ageing and a significant contributor to the pathology of age-related disorders. As committee members of the young International Cell Senescence Association (yICSA), we aim to synthesise recent advancements in the identification, characterisation, and therapeutic targeting of senescence for clinical translation. We explore novel molecular techniques that have enhanced our understanding of senescent cell heterogeneity and their roles in tissue regeneration and pathology. Additionally, we delve into in vivo models of senescence, both non-mammalian and mammalian, to highlight tools available for advancing the contextual understanding of in vivo senescence. Furthermore, we discuss innovative diagnostic tools and senotherapeutic approaches, emphasising their potential for clinical application. Future directions of senescence research are explored, underscoring the need for precise, context-specific senescence classification and the integration of advanced technologies such as machine learning, long-read sequencing, and multifunctional senoprobes and senolytics. The dual role of senescence in promoting tissue homoeostasis and contributing to chronic diseases highlights the complexity of targeting these cells for improved clinical outcomes.

The role of cardiomyocyte senescence in cardiovascular diseases: A molecular biology update

Cardiovascular diseases (CVD) are the leading cause of death worldwide, and advanced age is a main contributor to the prevalence of CVD. Cellular senescence is an irreversible state of cell cycle arrest that occurs in old age or after cells encounter various stresses. Senescent cells not only result in the reduction of cellular function, but also produce senescence-associated secretory phenotype (SASP) to affect surrounding cells and tissue microenvironment. There is increasing evidence that the gradual accumulation of senescent cardiomyocytes is causally involved in the decline of cardiovascular system function. To highlight the role of senescent cardiomyocytes in the pathophysiology of age-related CVD, we first introduced that senescent cardiomyoyctes can be identified by structural changes and several senescence-associated biomarkers. We subsequently provided a comprehensive summary of existing knowledge, outlining the compelling evidence on the relationship between senescent cardiomyocytes and age-related CVD phenotypes. In addition, we discussed that the significant therapeutic potential represented by the prevention of accelerated senescent cardiomyocytes, and the current status of some existing geroprotectors in the prevention and treatment of age-related CVD. Together, the review summarized the role of cardiomyocyte senescence in CVD, and explored the molecular knowledge of senescent cardiomyocytes and their potential clinical significance in developing senescent-based therapies, thereby providing important insights into their biology and potential therapeutic exploration.

Age-related testosterone decline: mechanisms and intervention strategies

Contemporary societies exhibit delayed reproductive age and increased life expectancy. While the male reproductive system demonstrates relatively delayed aging compared to that of females, increasing age substantially impacts its function. A characteristic manifestation is age-induced testosterone decline. Testosterone, a crucial male sex hormone, plays pivotal roles in spermatogenesis and sexual function, and contributes significantly to metabolism, psychology, and cardiovascular health. Aging exerts profound effects on the hypothalamic-pituitary-gonadal axis and Leydig cells, precipitating testosterone reduction, which adversely affects male health. Exogenous testosterone supplementation can partially ameliorate age-related testosterone deficiency; however, its long-term safety remains contentious. Preserving endogenous testosterone production capacity during the aging process warrants further investigation as a potential intervention strategy.

Association Analysis of Telomere Length and Vision in a Large Community-Based Survey

PURPOSE

To investigate whether there is a direct, age-independent association between telomere length and visual acuity decline in a large community-based cohort study.

METHODS

Participants older than 40 with linked leukocyte telomere length (LTL) were enrolled in NHANES. LTL was assayed using qPCR from the participants' blood samples. Best corrected visual acuity (BCVA) of the better-seeing eye was analyzed, with visual impairment (VI) defined as the BCVA of 20/40 or worse. LTL was grouped into quartiles, and its association with BCVA and VI was evaluated after adjusting for covariates.

RESULTS

Among the 4,480 enrolled participants, the weighted means of age, BCVA, and telomere length were 56.1 ± 11.9 years, 0.05 ± 0.08 logMAR, and 5,662 ± 36 base pairs, respectively. The proportion of VI was 2.6%. After adjusting for covariates including sex, ethnicity, education, family poverty income ratio, general health status, hypertension, diabetes, smoking, and body mass index, BCVA was significantly worse in participants with shorter LTL, with a significant trend (p = 0.002). However, after further adjusting for age, the association between LTL and BCVA was no longer significant, without a trend (p = 0.640). No significant association or trend between LTL and VI was found in the stepwise logistic model.

CONCLUSIONS

No age-independent association between LTL and BCVA was found. Our study indicates LTL may not serve as a biomarker for age-related visual acuity decline.

The potential of flavonoids to mitigate cellular senescence in cardiovascular disease

Aging is one of the most significant factors affecting cardiovascular health, with cellular senescence being a central hallmark. Senescent cells (SCs) secrete a specific set of signaling molecules known as the senescence-associated secretory phenotype (SASP). The SASP has a remarkable impact on age-associated diseases, particularly cardiovascular diseases (CVD). Targeting SCs through anti-aging therapies represents a novel strategy to effectively retard senescence and attenuate disease progression. Accumulating evidence demonstrates that the flavonoids, widely presented in fruits and vegetables worldwide, can delay or treat CVD via selectively eliminating SCs (senolytics) and modulating SASPs (senomorphics). Nevertheless, only sporadic research has illustrated the application of flavonoids in targeting SCs for CVD, which requires further exploration. This review recapitulates the hallmarks and key molecular mechanisms involved in cellular senescence, then summarizes senescence of different types of cardiac cells and describes the mechanisms by which cellular senescence affects CVD development. The discussion culminates with the potential use of flavonoids via exerting their biological effects on cellular senescence to reduce CVD incidence. This summary will provide valuable insights for cardiovascular drug design, development and clinical applications leveraging flavonoids.

SUMOylation of TP53INP1 is involved in miR-30a-5p-regulated heart senescence

Heart senescence is critical for cardiac function. This study aimed to characterize the role and mechanism of action of miR-30a-5p in cardiac senescence. miR-30a-5p was downregulated in aged mouse hearts and neonatal rat cardiomyocytes (NRCMs). In vivo, using a combination of echocardiography and different molecular biological approaches, we investigated the role of miR-30a-5p knockout or overexpression in natural- or D-galactose-induced heart aging in mice. In vitro, using RNA sequencing and a series of molecular biology methods, the mechanism by which miR-30a-5p regulates cardiac senescence was explored in cardiomyocytes. miR-30a-5p knockout mice showed aggravated natural- or D-galactose-induced heart aging compared to wild-type littermate mice, with significantly decreased heart function, an increased number of γH2AX-positive cells, reduced telomere length, and upregulated p21 and p53 expression. Cardiac-specific knockdown of miR-30a-5p using adeno-associated virus 9 in D-galactose-induced senescent wild-type mice resulted in effects similar to those observed in knockout mice. Notably, the overexpression of miR-30a-5p in wild-type murine hearts alleviated D-galactose-induced heart senescence by improving heart function, increasing telomere length, decreasing the number of γH2AX-positive cells, and downregulating p53 and p21 expression. This was confirmed in D-galactose-treated or naturally aged NRCMs. Mechanistically, TP53INP1 was identified as a target of miR-30a-5p by mediating the SUMOylation of TP53INP1 and its translocation from the cytoplasm to the nucleus to interact with p53. Furthermore, this study demonstrated that cardiac-specific TP53INP1 deficiency ameliorates miR-30a-5p knockout-aggravated cardiac dysfunction and heart senescence. This study identified miR-30a-5p as a crucial modulator of heart senescence and revealed that the miR-30a-5p-TP53INP1-p53 axis is essential for heart and cardiomyocyte aging.

Senescent endothelial cells: a potential target for diabetic retinopathy

Diabetic retinopathy (DR) is a diabetic complication that results in visual impairment and relevant retinal diseases. Current therapeutic strategies on DR primarily focus on antiangiogenic therapies, which particularly target vascular endothelial growth factor and its related signaling transduction. However, these therapies still have limitations due to the intricate pathogenesis of DR. Emerging studies have shown that premature senescence of endothelial cells (ECs) in a hyperglycemic environment is involved in the disease process of DR and plays multiple roles at different stages. Moreover, these surprising discoveries have driven the development of senotherapeutics and strategies targeting senescent endothelial cells (SECs), which present challenging but promising prospects in DR treatment. In this review, we focus on the inducers and mechanisms of EC senescence in the pathogenesis of DR and summarize the current research advances in the development of senotherapeutics and strategies that target SECs for DR treatment. Herein, we highlight the role played by key factors at different stages of EC senescence, which will be critical for facilitating the development of future innovative treatment strategies that target the different stages of senescence in DR.

Targeting senescent cells in atherosclerosis: Pathways to novel therapies

Targeting senescent cells has recently emerged as a promising strategy for treating age-related diseases, such as atherosclerosis, which significantly contributes to global cardiovascular morbidity and mortality. This review elucidates the role of senescent cells in the development of atherosclerosis, including persistently damaging DNA, inducing oxidative stress and secreting pro-inflammatory factors known as the senescence-associated secretory phenotype. Therapeutic approaches targeting senescent cells to mitigate atherosclerosis are summarized in this review, which include the development of senotherapeutics and immunotherapies. These therapies are designed to either remove these cells or suppress their deleterious effects. These emerging therapies hold potential to decelerate or even alleviate the progression of AS, paving the way for new avenues in cardiovascular research and treatment.

Monoamine oxidases: A missing link between mitochondria and inflammation in chronic diseases ?

The role of mitochondria spans from the regulation of the oxidative phosphorylation, cell metabolism and survival/death pathways to a more recently identified function in chronic inflammation. In stress situations, mitochondria release some pro-inflammatory mediators such as ATP, cardiolipin, reactive oxygen species (ROS) or mitochondrial DNA, that are believed to participate in chronic diseases and aging. These mitochondrial Damage-Associated Molecular Patterns (mito-DAMPs) can modulate specific receptors among which TLR9, NLRP3 and cGAS-STING, triggering immune cells activation and sterile inflammation. In order to counter the development of chronic diseases, a better understanding of the underlying mechanisms of low grade inflammation induced by mito-DAMPs is needed. In this context, monoamine oxidases (MAO), the mitochondrial enzymes that degrade catecholamines and serotonin, have recently emerged as potent regulators of chronic inflammation in obesity-related disorders, cardiac diseases, cancer, rheumatoid arthritis and pulmonary diseases. The role of these enzymes in inflammation embraces their action in both immune and non-immune cells, where they regulate monoamines levels and generate toxic ROS and aldehydes, as by-products of enzymatic reaction. Here, we discuss the more recent advances on the role and mechanisms of action of MAOs in chronic inflammatory diseases.

T-2 Toxin Induces Immunosenescence in RAW264.7 Macrophages by Activating the HIF-1α/cGAS-STING Pathway

T-2 toxin induces cell immunotoxicity by triggering an intracellular hypoxic microenvironment and activates hypoxia-inducible factor-1α (HIF-1α), which exerts cellular protective effects. Mycotoxins can also induce senescence. The aging of immune function, termed "immunosenescence," is an important factor in the decline of biological immunity and accelerates senescence. However, the mechanism underlying T-2 toxin-induced immunosenescence remains unclear. This study aimed to elucidate the roles of HIF-1α and cGAS-STING signaling in this process and uncover the mechanisms through which T-2 toxin impacts cytoskeletal integrity and cellular senescence using a RAW264.7 macrophage model. The cells were treated with T-2 toxin (14 nM) for 1-24 h. We revealed that T-2 toxin-induced immunosenescence in RAW264.7 cells by activating the HIF-1α/cGAS-STING axis. The cGAS-STING pathway promotes cell senescence and apoptosis; however, we revealed that HIF-1α negatively regulated this pathway, thereby inhibiting cellular senescence and apoptosis. However, PARP 1 cleavage by caspase 3/9 inhibited DNA repair and accelerated the transition from senescence to apoptosis. At the late stages of T-2 toxin exposure (12 h), HIF-1α accelerated cellular senescence by disrupting the dynamic balance of cytoskeletal α-tubulin and F-actin and destabilizing the cytoskeletal structure. Our research demonstrates that T-2 toxin induces immunosenescence in RAW264.7 cells by activating the cGAS-STING pathway, with HIF-1α signaling serving as a negative regulator. This study provides a deeper understanding of T-2 toxin-induced immunosenescence.

Cell senescence in cardiometabolic diseases

Cellular senescence has been implicated in many age-related pathologies including atherosclerosis, heart failure, age-related cardiac remodeling, diabetic cardiomyopathy and the metabolic syndrome. Here, we will review the characteristics of senescent cells and their endogenous regulators, and summarize the metabolic stressors that induce cell senescence. We will discuss the evidence of cell senescence in the onset and progression of several cardiometabolic diseases and the therapeutic potential of anti-senescence therapies.

Suppression of autophagy induces senescence in the heart

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout (Atg7cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro, suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where reactivation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Are immunosenescent T cells really senescent?

Loss of proper T-cell functioning is a feature of aging that increases the risk of developing chronic diseases. In aged individuals, highly differentiated T cells arise with a reduced expression of CD28 and CD27 and an increased expression of KLRG-1 or CD57. These cells are often referred to as immunosenescent T cells but may still be highly active and contribute to autoimmunity. Another population of T cells known as exhausted T cells arises after chronic antigen stimulation and loses its effector functions, leading to a failure to combat malignancies and viral infections. A process called cellular senescence also increases during aging, and targeting this process has proven to be fruitful against a range of age-related pathologies in animal models. Cellular senescence occurs in cells that are irreparably damaged, limiting their proliferation and typically leading to chronic secretion of pro-inflammatory factors. To develop therapies against pathologies caused by defective T-cell function, it is important to understand the differences and similarities between immunosenescence and cellular senescence. Here, we review the hallmarks of cellular senescence versus senescent and exhausted T cells and provide considerations for the development of specific therapies against age-related diseases.

Losmapimod ameliorates doxorubicin-induced cardiotoxicity through attenuating senescence and inflammatory pathways

Irreversible cardiotoxicity limits the clinical application of doxorubicin (DOX). DOX-induced cardiotoxicity has been associated with induction of senescence and activation of the p38 MAPK pathway. Losmapimod (LOSM), an orally active p38 MAPK inhibitor, is an anti-inflammatory agent with cardioprotective effects. Nevertheless, the effect of LOSM against DOX-induced cardiotoxicity has not been reported. In this study, we determined the effects of LOSM on DOX-induced chronic cardiotoxicity in C57BL/6 N mice. Five-week-old C57BL/6 N mice were fed diet containing LOSM (estimated daily intake 12 mg/kg/day) or a control diet for four days. Thereafter, mice were randomized to receive six weekly intraperitoneal injections of either DOX (4 mg/kg) or saline. Three days after the last injection, cardiac function was assessed by trans-thoracic echocardiography. Activation of p38, JNK, and ERK1/2 MAPKs were assessed by immunoblotting in the heart and liver. Gene expressions of senescence, inflammatory, oxidative stress, and mitochondrial function markers were quantified using real-time PCR and serum inflammatory markers were assessed by Luminex. Our results demonstrated that LOSM attenuated p38 MAPK activation, ameliorated DOX-induced cardiac dysfunction, and abrogated DOX-induced expression of the senescence marker p21Cip1. Additionally, LOSM demonstrated anti-inflammatory effects, with reduced cardiac Il-1α and Il-6 gene expression in DOX-treated mice. Systemic inflammation, assessed by serum cytokine levels, showed decreased IL-6 and CXCL1 in both DOX-treated mice and mice on LOSM diet. LOSM significantly increased mitofusin2 gene expression, which may enhance mitochondrial fusion. These findings underscore the potential therapeutic efficacy of p38 MAPK inhibition, exemplified by LOSM, in ameliorating DOX-induced cardiotoxicity, senescence, and inflammation.

Senescence Biomarkers CKAP4 and PTX3 Stratify Severe Kidney Disease Patients

INTRODUCTION

Cellular senescence is the irreversible growth arrest subsequent to oncogenic mutations, DNA damage, or metabolic insult. Senescence is associated with ageing and chronic age associated diseases such as cardiovascular disease and diabetes. The involvement of cellular senescence in acute kidney injury (AKI) and chronic kidney disease (CKD) is not fully understood. However, recent studies suggest that such patients have a higher-than-normal level of cellular senescence and accelerated ageing.

METHODS

This study aimed to discover key biomarkers of senescence in AKI and CKD patients compared to other chronic ageing diseases in controls using OLINK proteomics.

RESULTS

We show that senescence proteins CKAP4 (p-value < 0.0001) and PTX3 (p-value < 0.0001) are upregulated in AKI and CKD patients compared with controls with chronic diseases, suggesting the proteins may play a role in overall kidney disease development.

CONCLUSIONS

CKAP4 was found to be differentially expressed in both AKI and CKD when compared to UHCs; hence, this biomarker could be a prognostic senescence biomarker of both AKI and CKD.

Prognostic Significance and Biologic Associations of Senescence-Associated Secretory Phenotype Biomarkers in Heart Failure

BACKGROUND

The role of cellular senescence in human heart failure (HF) remains unclear. The senescence-associated secretory phenotype (SASP) is composed of proteins released by senescent cells. We assessed the prognostic significance and biologic pathways associated with the SASP in human HF using a plasma proteomics approach.

METHODS AND RESULTS

We measured 25 known SASP proteins among 2248 PHFS (Penn HF Study) participants using the SOMAScan V4 assay. We extracted the common variance in these proteins to generate SASP factor scores and assessed the relationship between these SASP factor scores and (1) all-cause death and (2) the composite of death or HF hospital admission. We also assessed the relationship of each SASP factor to 4746 other proteins, correcting for multiple comparisons, followed by pathway analyses. Two SASP factors were identified. Both factors were associated with older age, lower estimated glomerular filtration rate, and more advanced New York Heart Association class, among other clinical variables. Both SASP factors exhibited a significant positive association with the risk of death independent of the Meta-Analysis of Global-Group in Chronic HF score and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. The 2 identified SASP factors were associated with 1201 and 1554 proteins, respectively, belonging to various pathways including the coagulation system, complement system, acute phase response signaling, and retinoid X receptor-related pathways that regulate cell metabolism.

CONCLUSIONS

Increased SASP components are independently associated with adverse outcomes in HF. Biologic pathways associated with SASP are predominantly related to coagulation, inflammation, and cell metabolism.

Identification of Prominin-2 as a new player of cardiomyocyte senescence in the aging heart

The aging heart is characterized by a number of structural changes leading to ventricular stiffness, impaired resistance to stress and increased risk of developing heart failure (HF). Genetic or pharmacological removal of senescent cells has recently demonstrated the possibility to relieve some cardiac aging features such as hypertrophy and fibrosis. However, the contribution of the different cell types in cardiac aging remains fragmentary due to a lack of cell-specific markers. Cardiomyocytes undergo post-mitotic senescence in response to telomere damage, characterized by persistent DNA damage response and expression of the classical senescence markers p21 and p16, which are shared by many other cell types. In the present study, we used transcriptomic approaches to discover new markers specific for cardiomyocyte senescence. We identified Prominin2 (Prom2), encoding a transmembrane glycoprotein, as the most upregulated gene in cardiomyocytes of aged mice compared to young mice. We showed that Prom2 was upregulated by a p53-dependent pathway in stress-induced premature senescence. Prom2 expression correlated with cardiomyocyte hypertrophy in the hearts of aged mice and was increased in atrial samples of patients with HF with preserved ejection fraction. Consistently, Prom2 overexpression was sufficient to drive senescence, hypertrophy and resistance to cytotoxic stress while Prom2 shRNA silencing inhibited these features in doxorubicin-treated cardiac cells. In conclusion, we identified Prom2 as a new player of cardiac aging, linking cardiomyocyte hypertrophy to senescence. These results could provide a better understanding and targeting of cell-type specific senescence in age-associated cardiac diseases.

The impact of aging on cardiac repair and regeneration

In contrast to neonates and lower organisms, the adult mammalian heart lacks any capacity to regenerate following injury. The vast majority of our understanding of cardiac regeneration is based on research in young animals. Research in aged individuals is rare. This is unfortunate as aging induces many changes in the heart. The first part of this review covers the main technologies being pursued in the cardiac regeneration field and how they are impacted by the aging processes. The second part of the review covers the significant amount of aging-related research that could be used to aid cardiac regeneration. Finally, a perspective is provided to suggest how cardiac regenerative technologies can be improved by addressing aging-related effects.

Role of the telomeric factor TRF2 in post-hypoxic brain damages

The neuronal excitotoxicity that follows reoxygenation after a hypoxic period may contribute to epilepsy, Alzheimer's disease, Parkinson's disease and various disorders that are related to inadequate supplement of oxygen in neurons. Therefore, counteracting the deleterious effects of post-hypoxic stress is an interesting strategy to treat a large spectrum of neurodegenerative diseases. Here, we show that the expression of the key telomere protecting protein Trf2 decreases in the brain of mice submitted to a post-hypoxic stress. Moreover, downregulating the expression of Terf2 in hippocampal neural cells of unchallenged mice triggers an excitotoxicity-like phenotype including glutamate overexpression and behavioral alterations while overexpressing Terf2 in hippocampal neural cells of mice subjected to a post-hypoxic treatment prevents brain damages. Moreover, Terf2 overexpression in culture neurons counteracts the oxidative stress triggered by glutamate. Finally, we provide evidence that the effect of Terf2 downregulation on excitotoxicity involves Sirt3 repression leading to mitochondrial dysfunction. We propose that increasing the level of Terf2 expression is a potential strategy to reduce post-hypoxic stress damages.