Senolytic drugs: from discovery to translation

Aging microvasculature: Effects on immune cell trafficking and inflammatory diseases

Leukocyte recruitment to sites of inflammation is vital for orchestrating an effective immune response. Key to this process is the ability of leukocytes to migrate through venular walls, engaging in sequential interactions with endothelial cells, pericytes, and the venular basement membrane. The aging process exerts profound effects on the molecular and functional properties of the vasculature, thereby influencing the profile and dynamics of leukocyte trafficking during inflammation. In this review, by focusing mainly on neutrophils, we summarize key examples of how the aged microvasculature and perivascular stroma cells promote dysregulated leukocyte-venular wall interactions and present the associated molecular mechanisms. Additionally, we discuss the functional implications of such aberrant leukocyte behavior to age-related and chronic inflammatory pathologies.

BQU57 suppresses IL-1β-induced apoptosis and extracellular matrix degradation in nucleus pulposus cells by blocking the NF-κB signaling pathway

BACKGROUND

Intervertebral disc degeneration (IVDD) is a significant contributor to lower back pain (LBP), affecting approximately 80 % of the global population. The RalA inhibitor BQU57 plays a role in various cellular functions; however, its impact on nucleus pulposus cell (NPC) degeneration remains unclear.

METHODS

This study employed a combination of bioinformatics analysis and experimental validation to investigate the role of RalA in IVDD and its inhibitor BQU57 in its therapeutic potential. Gene expression datasets from the GEO database were analyzed to identify genes associated with IVDD, and clinical intervertebral disc samples were collected to validate the upregulation of RalA in degenerated discs. In vivo and in vitro assessments were conducted to evaluate the effects of BQU57 on the extracellular matrix (ECM) metabolism and apoptosis of nucleus pulposus (NP) cells.

RESULTS

Elevated expression of RalA was observed in degenerated intervertebral discs from IVDD patients, and its expression was correlated with disease severity. Further mechanistic studies revealed that the RalA inhibitor BQU57 could balance ECM metabolism and apoptosis, potentially through the activation of the NF-κB signaling pathway.

CONCLUSION

RalA plays a significant role in the pathogenesis of IVDD, and it may serve as a novel therapeutic target for IVDD. BQU57 demonstrates potential as an effective small molecule drug for the prevention and treatment of IVDD.

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.

Pharmacological modulation of cellular senescence: Implications for breast cancer progression and therapeutic strategies

Senescence, defined by the cessation of cell proliferation, plays a critical and multifaceted role in breast cancer progression and treatment. Senescent cells produce senescence-associated secretory phenotypes (SASP) comprising inflammatory cytokines, chemokines, and small molecules, which actively shape the tumor microenvironment, influencing cancer development, progression, and metastasis. This review provides a comprehensive analysis of the types and origins of senescent cells in breast cancer, alongside their markers and detection methods. Special focus is placed on pharmacological strategies targeting senescence, including drugs that induce or inhibit senescence, their molecular mechanisms, and their roles in therapeutic outcomes when combined with chemotherapy and radiotherapy. By exploring these pharmacological interventions and their impact on breast cancer treatment, this review underscores the potential of senescence-targeting therapies to revolutionize breast cancer management.

Bazibushen attenuates fibroblast senescence in silica-induced pulmonary fibrosis via FOXO1/PINK1/Parkin Axis

Silicosis, an age-related disease, is still a heavy burden on global occupational health. Emerging evidence has revealed that targeting senescent cells may be a promising therapeutic strategy for silicosis. This study was designed to investigate the novel function of Bazibushen (BZBS), a known anti-aging drug, in improving silica-induced lung fibrosis. We first confirmed the accumulation of senescent fibroblasts in the fibrotic regions of silicotic lungs. In both young (6-8 weeks) and aged (12 months) silicotic mice, BZBS exhibited anti-fibrosis and anti-senescence effects. Results of in vitro experiments showed the ability of BZBS to block the expression of p21, fibrotic markers, and senescence-associated secretory phenotype factors. Furthermore, BZBS was observed to attenuate mitochondrial dysfunction in senescent fibroblasts through FOXO1/PINK1/Parkin signaling. Collectively, these results indicated BZBS as a potential anti-fibrosis agent, which exerted its role through maintaining mitochondrial homeostasis in senescent fibroblasts.

A novel platform for precise senolysis

The selective eradication of senescent cells using senolytic compounds represents a promising strategy to treat senescence-associated diseases like aging and cancer. However, many senolytics may cause systemic toxicity. Magkouta et al., writing in Nature Aging, introduced mGL392, an advanced senolytic platform utilizing a lipofuscin-binding domain scaffold conjugated with a senolytic drug (e.g., dasatinib). mGL392 effectively eliminates senescent cells in vitro and in vivo, reducing tumor size in melanoma models while minimizing systemic toxicity. Compared to existing senolytics, it offers improved specificity, reducing off-target effects. This innovation presents a safer and more effective approach for treating senescence-related diseases.

Immunosenescence in skeletal muscle: The role-play in cancer cachexia chessboard

With the increase in life expectancy, age-related conditions and diseases have become a widespread and relevant social burden. Among these, immunosenescence and cancer cachexia play a significant often intertwined role. Immunosenescence is the progressive aging decline of both the innate and adaptive immune systems leading to increased infection susceptibility, poor vaccination efficacy, autoimmune disease, and malignancies. Cancer cachexia affects elderly patients with cancer causing severe weight loss, muscle wasting, inflammation, and reduced response to therapies. Whereas the connections between immunosenescence and cancer cachexia have been raising attention, the molecular mechanisms still need to be completely elucidated. This review aims at providing the current knowledge about the interplay between immunosenescence, skeletal muscle, and cancer cachexia, analyzing the molecular pathways known so far to be involved. Finally, we highlight potential therapeutic strategies suited for elderly population aimed to block immunosenescence and to preserve muscle mass in cachexia, also presenting the analysis of the current state-of-the-art of related clinical trials.

Vaccarin ameliorates osteoarthritis by suppressing the c-Jun N-terminal kinase (JNK)-serum amyloid A2 (SAA2) pathway mediating chondrocyte senescence

BACKGROUND

Osteoarthritis is a chronic degenerative joint disease marked by chondrocyte senescence and extracellular matrix degradation. Vaccarin, a flavonoid with anti-inflammatory and antioxidant properties, has not been previously investigated for its therapeutic potential in osteoarthritis.

PURPOSE

To evaluate the therapeutic potential of Vaccarin in osteoarthritis and elucidate its underlying mechanisms.

DESIGN AND METHOD

This study utilized in vitro chondrocyte cultures and RNA sequencing to identify relevant pathways, followed by validation at the genetic, protein, and metabolic levels using multiple approaches. Additionally, the therapeutic effects of Vaccarin were assessed in vivo using a destabilization of the medial meniscus (DMM)-induced osteoarthritis mouse model and human cartilage samples from osteoarthritis patients.

RESULTS

Vaccarin effectively ameliorated osteoarthritis both in vivo and in vitro. Transcriptomic sequencing indicated a significant downregulation of serum amyloid A2 (SAA2) expression following Vaccarin treatment. Multi-omics analysis, validated by human specimens, indicated that SAA2 is minimally secreted in healthy articular cartilage but serves as a crucial osteoarthritis biomarker in Asian populations. Mechanistically, Vaccarin inhibits c-Jun N-terminal kinase (JNK) phosphorylation, thereby reducing SAA2 expression and mitigating chondrocyte inflammation and senescence. Notably, inflammatory conditions upregulate SAA2 expression in chondrocytes via the JNK pathway. Elevated SAA2 levels contribute to mitochondrial dysfunction in chondrocytes, leading to increased reactive oxygen species (ROS) production and exacerbating osteoarthritis progression.

CONCLUSION

This study identifies SAA2 as a potential therapeutic target for osteoarthritis and suggests that Vaccarin presents a promising treatment avenue.

Vascular senescence and aging: mechanisms, clinical implications, and therapeutic prospects

The aging vasculature is characterized by endothelial dysfunction, arterial stiffness, and increased susceptibility to vascular pathologies. Central to these changes is the process of cellular senescence, where endothelial and vascular smooth muscle cells lose their replicative and functional capacity and adopt a pro-inflammatory secretory phenotype. This review provides an overview of the key mechanisms underlying vascular senescence, including the p53/p21 and p16/Rb pathways, the senescence-associated secretory phenotype (SASP), and oxidative stress, examines its contribution to cardiovascular diseases in older adults, and highlights emerging therapeutic strategies aimed at delaying or reversing these age-related vascular changes. In vascular cells, DNA damage, oxidative stress, and chronic inflammation associated with aging converge to amplify senescence. Clinically, vascular senescence is linked with hypertension, atherosclerosis, and increased overall cardiovascular risk. Several interventions, ranging from senolytics to lifestyle factors, show promise in mitigating these changes; however, long-term studies are needed. Given that vascular senescence is a pivotal driver of cardiovascular pathology in aging, targeting senescent cells or their secretory phenotype may potentially offer new avenues for preventing or attenuating age-related vascular diseases. This review presents an updated and integrative overview of vascular senescence, connecting fundamental cellular mechanisms with their clinical manifestations and highlighting the most promising therapeutic interventions.

Bioorthogonally Activatable Photosensitizer for NIR Fluorescence Imaging-Guided Highly Selective Elimination of Senescent Tumor Cells and Chemotherapy Enhancement

Chemotherapy is a primary modality in cancer treatment, but it may induce cellular senescence, which in turn triggers the release of senescence-associated secretory phenotypes (SASPs) that promote tumor growth and metastasis. To selectively identify senescent cells and mitigate their negative impact on cancer therapy, herein, we have developed a β-galactosidase (β-Gal)-activated and self-immobilizing photosensitizer CyGF-DBCO-T. This photosensitizer can be selectively activated and fluorescently label proteins in situ within senescent cells, enabling near-infrared (NIR) fluorescence imaging-guided photodynamic therapy (PDT) for the precise ablation of these cells. First, we developed an activatable NIR fluorescent probe CyGF-N3 that can specifically in situ label senescent cells. Subsequently, DBCO-T with free radicals underwent a bioorthogonal click reaction with activated CyGF-N3 in senescent cells to generate the photosensitizer CyO-DBCO-T. Under light irradiation, CyO-DBCO-T generated singlet oxygen (1O2) in situ, thereby enabling precise PDT with fluorescence guidance and photoactivation. Both CyGF-N3 and DBCO-T were encapsulated in biotinylated liposomes (CyGF-N3@LIP-B and DBCO-T@LIP-B), which enhanced their water solubility, tumor targeting, and in vivo circulation time. This promoted the accumulation of the probes in senescent tumor cells, thus enabling intense fluorescence imaging of tumor senescence regions in mice and enhancing the efficacy of PDT. This dual-module strategy, guided by fluorescence imaging for PDT, has achieved selective identification and precise ablation of senescent tumor cells in a chemotherapy-induced senescence model, effectively alleviating chemotherapy resistance and suppressing tumor growth.

In vitro senescence and senolytic functional assays

A detailed understanding of aging biology and the development of anti-aging therapeutic strategies remain imperative yet inherently challenging due to the protracted nature of aging. Cellular senescence arises naturally through replicative exhaustion and is accelerated by clinical treatments or environmental stressors. The accumulation of senescent cells-defined by a loss of mitogenic potential, resistance to apoptosis, and acquisition of a pro-inflammatory secretory phenotype-has been implicated as a key driver of chronic disease, tissue degeneration, and organismal aging. Recent studies have highlighted the therapeutic promise of senolytic drugs, which selectively eliminate senescent cells. Compelling results from preclinical animal studies and ongoing clinical trials underscore this potential. However, the clinical translation of senolytics requires further pharmacological validation to refine selectivity, minimize toxicity, and determine optimal dosing. Equally important is the evaluation of senolytics' potential to restore tissue structure and function by reducing the senescent cell burden. In vitro tissue culture models offer a powerful platform to advance these efforts. This review summarizes the current landscape of in vitro systems used for inducing cellular senescence-referred to as "senescence assays"-and for screening senolytic drugs-referred to as "senolytic assays". We conclude by discussing key challenges to improving mechanistic insight, predictive accuracy, and clinical relevance in senolytic drug development, as well as emerging applications of senolytic therapies.

Repair mechanisms of the central nervous system: From axon sprouting to remyelination

The central nervous system (CNS), comprising the brain, spinal cord, and optic nerve, has limited regenerative capacity, posing significant challenges in treating neurological disorders. Recent advances in neuroscience and neurotherapeutics have introduced promising strategies to stimulate CNS repair, particularly in the context of neurodegenerative diseases such as multiple sclerosis. This review explores the complex interplay between inflammation, demyelination, and remyelination possibilities. Glial cells, including oligodendrocyte precursors, oligodendrocytes, astrocytes and microglia play dual roles in injury response, with reactive gliosis promoting repair but also potentially inhibiting recovery through glial scar formation. There is also an emphasis on axonal regeneration, axonal sprouting and stem cell therapies. We highlight the role of neuroplasticity in recovery post-injury and the limited regenerative potential of axons in the CNS due to inhibitory factors such as myelin-associated inhibitors. Moreover, neurotrophic factors support neuronal survival and axonal growth, while stem cell-based approaches offer promise for replacing lost neurons and glial cells. However, challenges such as stem cell survival, integration, and risk of tumor formation remain. Furthermore, we examine the role of neurogenesis in CNS repair and the remodeling of the extracellular matrix, which can facilitate regeneration. Through these diverse mechanisms, ongoing research aims to overcome the intrinsic and extrinsic barriers to CNS repair and advance therapeutic strategies for neurological diseases.

Aging and injury drive neuronal senescence in the dorsal root ganglia

Aging negatively impacts central nervous system function; however, there is limited information about the cellular impact of aging on peripheral nervous system function. Importantly, injury to vulnerable peripheral axons of dorsal root ganglion (DRG) neurons results in somatosensory dysfunction, such as pain, at higher rates in aged individuals. Cellular senescence is common to both aging and injury and contributes to the aged pro-inflammatory environment. We discovered DRG neuron senescence in the context of aging and pain-inducing peripheral nerve injury in young (~3 months) and aged (~24 months) male and female mice. Senescent neurons were dynamic and heterogeneous in their expression of multiple senescence markers, including pro-inflammatory factor IL6. Senescence marker-expressing neurons had nociceptor-like profiles, included high-firing phenotypes and displayed increased excitability after IL6 application. Furthermore, elimination of senescent cells resulted in improvement of nociceptive behaviors in nerve-injured mice. Finally, male and female post-mortem human DRG contained senescent neurons that increased with age (~32 years old versus 65 years old). Overall, we describe a susceptibility of the peripheral nervous system to neuronal senescence-a potential targetable mechanism to treat sensory dysfunction, such as chronic pain, particularly in aged populations.

Genome-Wide Network Analysis of DRG-Sciatic Nerve Network-Inferred Cellular Senescence and Senescence Phenotype in Peripheral Sensory Neurons

Accumulation of senescent neurons in the dorsal root ganglion (DRG) is an important tissue phenotype that causes age-related degeneration of peripheral sensory nerves. Senescent neurons are neurons with arrested cell cycle that have undergone cellular senescence but remain in the tissue and play various biological roles. To understand the accumulation of senescent neurons in the DRG during aging, we aimed to elucidate the mechanism that induces cellular senescence in DRG neurons and the role of senescent DRG neurons. We integrated multiple public transcriptome datasets for DRGs, which include cell bodies in neurons, and the sciatic nerve, which includes axons in neurons, using network medicine-based bioinformatics analysis. We thus inferred the molecular mechanisms involved in cellular senescence of DRG neurons, from molecular responses to senescence, in the DRG-sciatic nerve network. Network medicine-based bioinformatics analysis revealed that age-related Mapk3 decline leads to impaired cholesterol metabolism and biosynthetic function in axons, resulting in compensatory upregulation of Srebf1, a transcription factor involved in lipid and cholesterol metabolism. This in turn leads to CDKN2A-mediated cellular senescence. Furthermore, our analysis revealed that senescent DRG neurons develop a senescence phenotype characterized by activation of antigen-presenting cells via upregulation of Ctss as a hub gene. B cells were inferred as antigen-presenting cells activated by Ctss, and CD8-positive T cells were inferred as cells that receive antigen presentation from B cells.

Mitochondrial Dysfunction of the Subsynovial Connective Tissue in Patients With Carpal Tunnel Syndrome

In idiopathic carpal tunnel syndrome (CTS), fibrosis and thickening of the subsynovial connective tissue (SSCT) increase pressure within the carpal tunnel, resulting in median nerve entrapment. Mitochondrial dysfunction in tissues reportedly leads to senescent cell accumulation and various diseases through reduced adenosine triphosphate (ATP) and excessive reactive oxygen species (ROS) production; however, no reports have linked this to CTS. Therefore, this study aimed to evaluate mitochondrial function in SSCTs of patients with CTS. This study investigated SSCTs obtained during carpal tunnel release surgery in patients with CTS (CTS group) and those obtained during tendon transfer or tendon rupture surgery in patients without CTS (control group) from April 2021 to March 2023 at our hospital. Outcome measures included superoxide dismutase (SOD) activity, gene expression levels, immunofluorescence staining, ATP production assays, and transmission electron microscopy (TEM). p values were calculated using the Mann-Whitney U test. The CTS and control groups included 10 and 5 patients (mean age, 67.8 ± 9.57 and 65.4 ± 9.75 years), respectively. The CTS group exhibited decreased SOD activity (p = 0.026), increased gene expression of mitochondrial biosynthetic factors, and decreased mitochondrial ATP production (p = 0.027). The CTS group showed increased mitochondrial ROS production (p = 0.038) on immunofluorescence and larger mitochondrial area (p = 0.030) and fewer mitochondrial cristae (p = 0.045) on TEM. Multiple mitochondrial function assays suggested mitochondrial dysfunction of SSCTs in the CTS group. STATEMENT OF CLINICAL SIGNIFICANCE: This research provided important information on the histological changes in the subsynovial connective tissue within the carpal tunnel in carpal tunnel syndrome.

Accelerated Aging in Cancer and Cancer Treatment: Current Status of Biomarkers

BACKGROUND

Aging in humans is a heterogeneous process influenced by both biological and chronological factors. Biological age reflects an individual's physiological reserve and functional status. Increasing evidence suggests that cancer and its therapies accelerate biological aging. Many biomarkers have been evaluated to assess the biological age of patients with cancer. These biomarkers are emerging as potential tools to predict cancer-related toxicity and an individual's functional capacity as well as to individualize treatment.

METHODS

This review summarizes the current literature on aging biomarkers in cancer patients, with a focus on markers of cellular senescence and epigenetic modification. We evaluate the existing evidence supporting their use as predictors of toxicity in patients undergoing chemotherapy and radiation therapy.

RESULTS

Biomarkers such as interleukin-6 (IL-6), leukocyte telomere length (LTL), and DNA methylation age show potential for assessing biological age, frailty, and functional reserve. The expression of p16INK4A has demonstrated promise in predicting therapy-induced toxicity and making treating decisions. However, additional confirmatory studies are necessary to further validate these biomarkers before they can be utilized as decision aids.

CONCLUSION

Aging biomarkers hold promise for individualizing cancer therapy and predicting treatment-related toxicity. However, further studies are essential to validate their reliability and support their integration into clinical practice.

Therapy-induced senescence is a transient drug resistance mechanism in breast cancer

BACKGROUND

Therapy-induced senescence (TIS) is considered a permanent cell cycle arrest following DNA-damaging treatments; however, its irreversibility has recently been challenged. Here, we demonstrate that escape from TIS is universal across breast cancer cells. Moreover, TIS provides a reversible drug resistance mechanism that ensures the survival of the population, and could contribute to relapse.

METHODS

TIS was induced in four different breast cancer cell line with high-dose chemotherapy and cultured until cells escaped TIS. Parental, TIS and repopulating cells were analyzed by bulk and single-cell RNA sequencing and surface proteomics. A genetically engineered mouse model of triple-negative breast cancer was used to prove why current senolytics cannot overcome TIS in tumors.

RESULTS

Screening the toxicity of a diverse panel of FDA-approved anticancer drugs revealed that TIS meditates resistance to half of these compounds, despite their distinct mechanism of action. Bulk and single-cell RNA sequencing, along with surface proteome analysis, showed that while parental and repopulating cells are almost identical, TIS cells are significantly different from both, highlighting their transient nature. Furthermore, investigating dozens of known drug resistance mechanisms offered no explanation for this unique drug resistance pattern. Additionally, TIS cells expressed a gene set associated with immune evasion and a potential KRAS-driven escape mechanism from TIS.

CONCLUSION

Our results reveal that TIS, as a transient drug resistance mechanism, could contribute to overcome the immune response and to relapse by reverting to a proliferative stage.

The interplay of cellular senescence and reprogramming shapes the biological landscape of aging and cancer revealing novel therapeutic avenues

Cellular senescence and cellular reprogramming represent two fundamentally intertwined processes that profoundly influence aging and cancer. This paper explores how the permanent cell-cycle arrest of senescent cells and the identity-resetting capacity of reprogramming jointly shape biological outcomes in later life and tumor development. We synthesize recent findings to show that senescent cells, while halting the proliferation of damaged cells, can paradoxically promote tissue dysfunction and malignancy via their secretory phenotype. Conversely, induced reprogramming of somatic cells-exemplified by Yamanaka factors-resets cellular age and epigenetic marks, offering a potential to rejuvenate aged cells. Key findings highlight shared mechanisms (e.g., DNA damage responses and epigenetic remodeling) and bidirectional crosstalk between these processes: senescence signals can facilitate neighboring cell plasticity, whereas reprogramming attempts can trigger intrinsic senescence programs as a barrier. In aging tissues, transient (partial) reprogramming has been shown to erase senescence markers and restore cell function without inducing tumorigenesis, underlining a novel strategy to combat age-related degeneration. In cancer, we discuss how therapy-induced senescence of tumor cells may induce stem-cell-like traits in some cells and drive relapse, revealing a delicate balance between tumor suppression and tumor promotion. Understanding the interplay between senescence and reprogramming is crucial for developing innovative therapies. By targeting the senescence-reprogramming axis-for instance, via senolytic drugs, SASP inhibitors, or safe reprogramming techniques-there is significant therapeutic potential to ameliorate aging-related diseases and improve cancer treatment. Our findings underscore that carefully modulating cellular senescence and rejuvenation processes could pave the way for novel regenerative and anti-cancer strategies.

Senolytic therapy reduces inflammation in epithelial cells from COPD patients and in smoke-exposure mice

Introduction

Chronic obstructive pulmonary disease (COPD) is a disease of accelerated lung aging, with increased numbers of senescent cells found within the COPD Lung. Senescent cells may drive pathology by causing defective tissue repair and driving chronic inflammation via the release of inflammatory mediators known as the senescence-associated secretory phenotype (SASP). Senolytics are a new class of drugs that selectively remove senescent cells but have not previously been studied in COPD. We examined whether senescent cells are maintained during differentiation of COPD airway epithelial cells at the air-liquid interface and examined the role of the senolytic combination of dasatinib and quercetin on these cells and in a smoke-exposure mouse model.

Methods

Non-smoker and COPD bronchial epithelial cells were differentiated at air-liquid interface (ALI). Senescence markers (p16INKA and p21WAF1) were determined using Western blotting and SASP factors via Olink proteomics and Meso Scale Diagnostics (MSD). Cells and 11 days cigarette smoke (CS)-exposed mice were treated with the senolytic cocktail of dasatinib and quercetin (D + Q).

Results

Increased senescence markers were maintained in COPD ALI epithelium when differentiated at air-liquid interface, and treatment with D + Q reduced senescence markers, proteases, and Th2 cytokines. Therapeutic oral treatment of D + Q to CS-exposed mice reduced senescence burden while reducing inflammatory cell infiltrates and mouse CXCL1.

Conclusion

COPD subjects show increased airway epithelial senescence, and these cells can be cleared therapeutically using the senolytic cocktail of D + Q, reducing broad-spectrum pulmonary inflammation in vitro and in vivo.

Evaluation of exploratory fluid biomarkers from a phase 1 senolytic trial in mild Alzheimer's disease

Senescent cell accumulation contributes to the progression of age-related disorders including Alzheimer's disease (AD). Clinical trials focused on cellular senescence are in early stages and have yet to establish reliable outcome measures reflecting senescent cell burden or response to senolytics, therapeutics that clear senescent cells. Results from the first open-label trial of senolytics, dasatinib plus quercetin (D ​+ ​Q), in older adults (N ​= ​5) with early AD demonstrated central nervous system penetration of dasatinib and favorable safety and tolerability. Herein, we present exploratory analyses of senescence and AD-associated analytes in blood, cerebrospinal fluid (CSF) and urine from this study in effort to guide biomarker development for future senolytic trials. Immunoassays, mass spectrometry and transcriptomics were performed and changes in analyte levels were assessed from baseline to post-treatment using paired t-tests. Targeted cytokine and chemokine analyses revealed increases in plasma fractalkine and MMP-7 and CSF IL-6 from baseline to post-treatment. Mass spectrometry indicated stable levels of amyloid β and tau proteins in CSF, unchanged urinary metabolites, and modest treatment-associated lipid profile changes. Targeted transcriptomic analysis of peripheral blood mononuclear cells indicated downregulation of inflammatory genes including FOS, FOSB, IL1β, IL8, JUN, JUNB, PTGS2. The levels and treatment responses of the analytes identified here may help inform trial design and outcomes for senolytic studies. Independent validation will be necessary to develop standardized biomarker panels across senolytic trials for AD. ClinicalTrials.gov: NCT04063124.

Epigallocatechin Gallate in Camellia sinensis Ameliorates Skin Aging by Reducing Mitochondrial ROS Production

Background: Reactive oxygen species (ROS) generated by mitochondrial dysfunction damage cellular organelles and contribute to skin aging. Therefore, strategies to reduce mitochondrial ROS production are considered important for alleviating skin aging, but no effective methods have been identified. Methods: In this study, we evaluated substances utilized as cosmetic ingredients and discovered Camellia sinensis (C. sinensis) as a substance that reduces mitochondrial ROS levels. Results:C. sinensis extracts were found to act as senolytics that selectively kill senescent fibroblasts containing dysfunctional mitochondria. In addition, C. sinensis extracts facilitated efficient electron transport in the mitochondrial electron transport chain (ETC) by increasing the efficiency of oxidative phosphorylation (OXPHOS), thereby reducing mitochondrial ROS production, a byproduct of the inefficient ETC. This novel mechanism of C. sinensis extracts led to the restoration of skin aging and the skin barrier. Furthermore, epigallocatechin gallate (EGCG) was identified as an active ingredient that plays a key role in C. sinensis extract-mediated skin aging recovery. Indeed, similar to C. sinensis extracts, EGCG reduced ROS and improved skin aging in an artificial skin model. Conclusions: Our data uncovered a novel mechanism by which C. sinensis extract reverses skin aging by reducing mitochondrial ROS production via selective senescent cell death/increased OXPHOS efficiency. Our results suggest that C. sinensis extract or EGCG may be used as a therapeutic agent to reverse skin aging in clinical and cosmetic applications.

The Role of Aging and Senescence in Bone Marrow Transplantation Outcome

Bone marrow transplantation is considered a cornerstone in the treatment of hematologic malignancies and blood disorders. While it may offer the possibility of a cure through the use of high-dose chemotherapy and radiation, outcomes are significantly impacted by biological and medical factors. Herein, aging is associated with reduced hematopoiesis, immune function, and overall regenerative capacity of tissues. Growth arrest, a crucial property of cellular senescence, inhibits bone marrow function, lowers immune surveillance in aged adults, and reduces the efficiency of bone marrow transplantation. The clinical course for older recipients is further complicated by the presence of prolonged immunosuppression, slower recovery, and higher complication rates, including life-threatening graft-versus-host disease. Accordingly, there is increasing interest in explaining how aging, cellular senescence, and transplant outcomes are interrelated. The current chapter outlines the mechanisms whereby aging and senescence contribute to the immunological dysregulation and poor bone marrow transplantation outcomes observed in elderly cancer patients. The authors' goal is to suggest therapeutic approaches that will enhance the quality of life and survival rates of elderly bone marrow transplant recipients.

Fisetin Clears Senescent Cells Through the Pi3k-Akt-Bcl-2/Bcl-xl Pathway to Alleviate Diabetic Aortic Aging

Vascular aging is a major contributor to age-related cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM) induced early arterial aging and excessive senescent cells (SCs) burden in vessels. Inhibiting cellular senescence or eliminating SCs could effectively improve aging-related CVDs. Fisetin, a flavonoid extracted from cotinus coggygria scop, has shown potential in alleviating aging by clearing SCs. This study investigated the unexplored mechanisms and efficacy of fisetin in alleviating T2DM-related aortic aging. The T2DM mouse model was induced using a high-fat diet and low-dose streptozotocin injection. Chronic fisetin treatment's protective effects against aortic aging were assessed via senescence-associated beta-galactosidase (SA-β-Gal) staining, histopathology, and vasomotor function. RNA-sequencing and western blotting identified relevant signaling pathways and protein expression. Fisetin's effects on SCs and senescence-associated secretory phenotype (SASP) factors were evaluated through cell viability, apoptosis, and co-culture assays. Docking simulations suggested fisetin as a potential Phosphoinositide 3-kinase (Pi3k) inhibitor. In vivo, chronic fisetin treatment reduced aortic SCs burden, alleviating T2DM-related and natural aortic aging. In vitro, fisetin selectively induced apoptosis of senescent endothelial cells via regulating the Pi3k-Protein Kinase B (Akt)-B-cell lymphoma (Bcl)-2/Bcl-xl pathway and suppressed SASP and its detrimental effects. Furthermore, fisetin combined with metformin therapy showed superior anti-aging effects on T2DM-related aortic aging compared to metformin monotherapy. In conclusion, chronic fisetin treatment alleviates T2DM-related aortic aging via clearing the SCs burden and abrogating the SASP factors. Fisetin combined with metformin therapy might be a potential therapeutic strategy for T2DM-related CVDs.

Analysis of the senescence secretome during zebrafish retina regeneration

Introduction

Zebrafish possess the innate ability to regenerate any lost or damaged retinal cell type with Müller glia serving as resident stem cells. Recently, we discovered that this process is aided by a population of damage-induced senescent immune cells. As part of the Senescence Associated Secretory Phenotype (SASP), senescent cells secrete numerous factors that can play a role in the modulation of inflammation and remodeling of the retinal microenvironment during regeneration. However, the identity of specific SASP factors that drive initiation and progression of retina regeneration remains unclear.

Materials and Methods

We mined the SASP Atlas and publicly available RNAseq datasets to identify common, differentially expressed SASP factors after retina injury. These datasets included two distinct acute damage regimens, as well as two chronic, genetic models of retina degeneration. We identified overlapping factors between these models and used genetic knockdown experiments, qRT/PCR and immunohistochemical staining to test a role for one of these factors (npm1a).

Results

We discovered an overlapping set of 31 SASP-related regeneration factors across all data sets and damage paradigms. These factors are upregulated after damage with functions that span the innate immune system, autophagic processing, cell cycle regulation, and cellular stress responses. From among these, we show that depletion of Nucleophosmin 1 (npm1a) inhibits retina regeneration and decreases senescent cell detection after damage.

Discussion

Our data suggest that differential expression of SASP factors promotes initiation and progression of retina regeneration after both acute and chronic retinal damage. The existence of a common, overlapping set of 31 factors provides a group of novel therapeutic targets for retina regeneration studies.

Inhibiting the Histone Demethylase Kdm4a Restrains Cardiac Fibrosis After Myocardial Infarction by Promoting Autophagy in Premature Senescent Fibroblasts

Premature senescent fibroblasts (PSFs) play an important role in regulating the fibrotic process after myocardial infarction (MI), but their effect on cardiac fibrosis remains unknown. Here, the investigation is aimed to determine whether PSFs contribute to cardiac fibrosis and the underlying mechanisms involved. It is observed that premature senescence of fibroblasts is strongly activated in the injured myocardium at 7 days after MI and identified that Kdm4a is located in PSFs by the analysis of scRNA-seq data and immunostaining staining. Moreover, fibroblast specific gain- and loss-of-function assays showed that Kdm4a promoted the premature senescence of fibroblasts and cardiac interstitial fibrosis, contributing to cardiac remodeling in the advanced stage after MI, without influencing early cardiac rupture. ChIP-seq and ChIP-PCR revealed that Kdm4a deficiency promoted autophagy in PSFs by reducing Trim44 expression through increased levels of the H3K9me3 modification in the Trim44 promoter region. Furthermore, a coculture system revealed that Kdm4a overexpression increased the accumulation of PSFs and the secretion of senescence-associated secretory phenotype (SASP) factors, subsequently inducing cardiac fibrosis, which could be reversed by Trim44 interference. Kdm4a induces the premature senescence of fibroblasts through Trim44-mediated autophagy and then facilitates interstitial fibrosis after MI, ultimately resulting in cardiac remodeling, but not affecting ventricular rupture.

Fisetin: hormesis accounts for many of its chemoprotective effects

The present paper provides the first integrated assessment of the capacity of the flavonol, fisetin, to induce hormetic dose responses. Fisetin was shown to induce hormetic dose responses in cellular and in vivo animal model systems affecting a broad range of endpoints of potential therapeutic and public health significance across the entire lifespan. Fisetin was effective in slowing aging processes, acting as a senolytic agent in multiple organ systems, in an hormetic fashion. In addition, fisetin was broadly neuroprotective, including during fetal development, and preventing the toxicity of methylmercury. Since these findings indicate that fisetin may have the potential to induce multi-system chemoprotective effects, it indicates the need to better clarify the absorption and bioavailability of fisetin and ways to enhance its efficiency.

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.

Mitochondrial Imbalance in Down Syndrome: A Driver of Accelerated Brain Aging?

Down syndrome (DS), caused by trisomy of chromosome 21 (HSA21), is a complex condition associated with neurodevelopmental impairments and accelerated brain aging, often culminating in early-onset Alzheimer's disease (AD). Central to this accelerated aging is mitochondrial imbalance, characterized by disrupted energy metabolism, increased oxidative stress, impaired dynamics, and defective quality control mechanisms like mitophagy. These abnormalities exacerbate neuronal vulnerability, driving cognitive decline and neurodegeneration. This review examines the genetic and biochemical underpinnings of mitochondrial dysfunction in DS, with a focus on the role of HSA21-encoded genes. We also highlight how mitochondrial dysfunction, amplified by oxidative stress and HSA21 gene dosage effects, converges with cellular senescence and neuroinflammation to accelerate Alzheimer-like pathology and brain aging in DS. Finally, we discuss emerging therapeutic strategies targeting mitochondrial pathways, which hold promise for mitigating neurodegenerative phenotypes and improving outcomes in DS.

Mechanisms of hematopoietic clonal dominance in VEXAS syndrome

Clonal dominance characterizes hematopoiesis during aging and increases susceptibility to blood cancers and common nonmalignant disorders. VEXAS syndrome is a recently discovered, adult-onset, autoinflammatory disease burdened by a high mortality rate and caused by dominant hematopoietic clones bearing somatic mutations in the UBA1 gene. However, pathogenic mechanisms driving clonal dominance are unknown. Moreover, the lack of disease models hampers the development of disease-modifying therapies. In the present study, we performed immunophenotype characterization of hematopoiesis and single-cell transcriptomics in a cohort of nine male patients with VEXAS syndrome, revealing pervasive inflammation across all lineages. Hematopoietic stem and progenitor cells (HSPCs) in patients are skewed toward myelopoiesis and acquire senescence-like programs. Humanized models of VEXAS syndrome, generated by inserting the causative mutation in healthy HSPCs through base editing, recapitulated proteostatic defects, cytological alterations and senescence signatures of patients' cells, as well as hematological and inflammatory disease hallmarks. Competitive transplantations of human UBA1-mutant and wild-type HSPCs showed that, although mutant cells are more resilient to the inflammatory milieu, probably through the acquisition of the senescence-like state, wild-type ones are progressively exhausted and overwhelmed by VEXAS clones, overall impairing functional hematopoiesis and leading to bone marrow failure. Our study unveils the mechanism of clonal dominance and provides models for preclinical studies and preliminary insights that could inform therapeutic strategies.

Senescence, NK cells, and cancer: navigating the crossroads of aging and disease

Cellular senescence, a state of stable cell cycle arrest, acts as a double-edged sword in cancer biology. In young organisms, it acts as a barrier against tumorigenesis, but in the aging population, it may facilitate tumor growth and metastasis through the senescence-associated secretory phenotype (SASP). Natural killer (NK) cells play a critical role in the immune system, particularly in the surveillance, targeting, and elimination of malignant and senescent cells. However, age-related immunosenescence is characterized by declining NK cell function resulting in diminished ability to fight infection, eliminate senescent cells and suppress tumor development. This implies that preserving or augmenting NK cell function may be central to defense against age-related degenerative and malignant diseases. This review explores the underlying mechanisms behind these interactions, focusing on how aging influences the battle between the immune system and cancer, the implications of senescent NK cells in disease progression, and the potential of adoptive NK cell therapy as a countermeasure to these age-related immunological challenges.

Depletion of senescent cells improves surgery-induced neuroinflammation in aged mice

Aging has been identified as a leading risk factor for many diseases, including neurodegenerative disorders. While cellular senescence has been linked to age-related neurodegenerative conditions, its involvement in peripheral stress-associated brain disorders is just beginning to be explored. In this study, we investigated the impact of senescent cells on peripheral stress-induced neuroinflammation using orthopedic surgery as a model. Our results demonstrate an increased accumulation of senescent cells and neuroinflammation in the aged mouse hippocampus following surgery. Intermittent treatment of the mice with the senolytic drugs dasatinib and quercetin (D/Q) showed a significant reduction in surgery-induced senescent cell burden. This reduction in senescent cell accumulation was correlated with reduced surgery-induced neuroinflammation, as evidenced by decreased glial cell activity. Consistent with these observations, we also observed reduced levels of proinflammatory senescence-associated secretory phenotype factors in circulation, following fracture surgery, in mice treated with D/Q. Overall, our findings underscore the pivotal role of cellular senescence in surgery-induced neuroinflammation and highlight the therapeutic potential of eliminating senescent cells as a potential strategy to manage peripheral stress-induced neuroinflammatory conditions.

Silibinin's role in counteracting neuronal apoptosis and synaptic dysfunction in Alzheimer's disease models

This study investigates silibinin's capacity to mitigate Alzheimer's disease (AD) pathologies with a particular emphasis on its effects on apoptosis and synaptic dysfunction in AD models. Employing APP/PS1 transgenic mice and SH-SY5Y neuroblastoma cell lines, our research assessed the efficacy of silibinin in reducing amyloid-beta (Aβ) deposition, neuroinflammation, and neuronal apoptosis. Our results demonstrate that silibinin significantly decreases Aβ accumulation and neuroinflammation and robustly inhibits apoptosis in neuronal cells. Additionally, silibinin enhances the expression of synaptic proteins, thereby supporting synaptic integrity. Through network pharmacology analysis, we identified potential targets of silibinin in Aβ metabolism and synaptic functions. Mechanistically, our findings suggest that silibinin promotes neuronal survival predominantly via the modulation of the Fyn/GluN2B/CaMKIIα signaling pathway, which protects against Aβ1-42-induced apoptosis. These insights highlight silibinin's potential as a therapeutic agent for AD, particularly its role in reducing neuronal apoptosis and maintaining synaptic function.

Deciphering the role of cytokines in aging: Biomarker potential and effective targeting

Aging is often characterized by chronic inflammation, immune system dysregulation, and cellular senescence with chronically elevated levels of pro-inflammatory cytokines. These small glycoproteins are mainly secreted by immune cells, mediating intercellular communication and immune system modulation through inflammatory signaling. Their pro- and anti-inflammatory effects make them a noteworthy research topic as well as a promising ally in combating inflammation and the aging process. Cytokines exert a synergistic role in aging and disease and may prove useful biomarkers of tissue-specific dysregulation, disease diagnosis and monitoring, presenting potential therapeutic options as anti-inflammatory and senolytic medications. In this review, we address the cellular and molecular mechanisms implicating cytokines in the aging process and related diseases, highlighting their biomarker potential. We focus on the current therapeutic strategies, including specific pharmaceutical agents, supplements, a balanced diet, and healthy habits such as exercise, stress management, and caloric restriction.

Effects of senotherapeutics on gut microbiome dysbiosis and intestinal inflammation in Crohn's disease: A pilot study

Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation in the gastrointestinal tract, and is usually accompanied by dysbiosis in the gut microbiome, a factor that contributes to disease progression. Excessive production of reactive oxygen species (ROS) because of gut microbiome dysbiosis-one of the hallmark features of IBD-promotes chronic inflammation and facilitates the transformation of normal cells into senescent cells. Cellular senescence is associated with the development of various chronic and age-related diseases. We hypothesise that senolytic agents, specifically dasatinib (D) and quercetin (Q), could have a beneficial effect on both the gut microbiome and intestinal cells in IBD. The modulatory effects of a combination of D + Q was assessed in the M-SHIME model with faecal microbiota sourced from Crohn's disease patients. D + Q significantly modulated butyrate and lactate levels in the samples from specific patients. In addition, metabolomic analysis showed that D + Q positively impacted the abundance of anti-inflammatory bacteria while also significantly reducing the several species of pathogenic bacteria. Findings from a Caco-2 cell/THP1 co-culture model of IBD demonstrated that D + Q exerted strong immunomodulatory effects on the gut epithelium, evidenced by reduced NF-kB activity, and lower levels of the pro-inflammatory markers TNF-α, CXCL-10, and MCP-1. Furthermore, D + Q induced the secretion of anti-inflammatory cytokines, including IL-6 and IL-10. However, it should be noted that D + Q also led to the secretion of the pro-inflammatory cytokines IL-8. These findings suggest that D + Q could offer a novel therapeutic approach for advanced IBD management by modulating both the gut microbiome and inflammatory pathways. The results support the potential repurposing of senotherapeutic agents as a strategy for addressing the chronic inflammation central to IBD pathogenesis.

Targeting senescent hepatocytes for treatment of metabolic dysfunction-associated steatotic liver disease and multi-organ dysfunction

Senescent hepatocytes accumulate in metabolic dysfunction-associated steatotic liver disease (MASLD) and are linked to worse clinical outcomes. However, their heterogeneity and lack of specific markers have made them difficult to target therapeutically. Here, we define a senescent hepatocyte gene signature (SHGS) using in vitro and in vivo models and show that it tracks with MASLD progression/regression across mouse models and large human cohorts. Single-nucleus RNA-sequencing and functional studies reveal that SHGS+ hepatocytes originate from p21+ cells, lose key liver functions and release factors that drive disease progression. One such factor, GDF15, increases in circulation alongside SHGS+ burden and disease progression. Through chemical screening, we identify senolytics that selectively eliminate SHGS+ hepatocytes and improve MASLD in male mice. Notably, SHGS enrichment also correlates with dysfunction in other organs. These findings establish SHGS+ hepatocytes as key drivers of MASLD and highlight a potential therapeutic strategy for targeting senescent cells in liver disease and beyond.

PTEN: A Novel Diabetes Nephropathy Protective Gene Related to Cellular Senescence

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The current diagnostic and therapeutic approaches need to be improved. Cellular senescence has been implicated in the pathogenesis of DN, but its precise role remains unclear. This study aimed to identify key pathogenic genes related to cellular senescence in DN and explore their potential as diagnostic biomarkers. Using transcriptomic data from GEO datasets (GSE96804, GSE30122, GSE142025, and GSE104948) and cellular senescence-related genes sourced from the GenAge database, we integrated multiple bioinformatics approaches, including differential expression analysis, weighted gene co-expression network analysis (WGCNA), machine learning and protein-protein interaction (PPI), to identify diagnostic genes. PTEN was identified as a key diagnostic gene. Immune infiltration analysis revealed that PTEN expression is positively correlated with macrophage M2 and dendritic cell resting infiltration and negatively correlated with monocytes and neutrophils. snRNA analysis revealed that PTEN is mainly expressed in mesangial cells. Finally, RT-PCR results revealed that the mRNA expression of PTEN was upregulated in kidneys from db/db mice. Additionally, high-glucose treatment significantly upregulated PTEN expression in cultured human mesangial cells. This study identifies PTEN as a potential diagnostic biomarker for DN which may contribute to early detection and personalized therapeutic strategies.

Targeting senescence in Amyotrophic Lateral Sclerosis: senolytic treatment improves neuromuscular function and preserves cortical excitability in a TDP-43Q331K mouse model

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder marked by progressive motor neuron degeneration in the primary motor cortex (PMC) and spinal cord. Aging is a key factor in ALS onset and progression, with evidence suggesting that biological aging-a process involving cellular decline- far outpaces chronological aging in ALS. This promotes senescent cell accumulation-marked by irreversible cell-cycle arrest, impaired apoptosis, and chronic inflammation-disrupting tissue homeostasis and impairing neuronal support functions. Thus, targeting senescence presents a novel therapeutic strategy for ALS. Here, we investigated the senolytic combination Dasatinib and Quercetin (D&Q) in TDP-43Q331K ALS mice. D&Q improved neuromuscular function and reduced plasma neurofilament light chain, a biomarker of axonal damage. The most pronounced improvement was the improved cortical excitability, accompanied by reductions in senescence and TDP-43 in the PMC. These findings highlight the potential of senolytics to mitigate ALS-related dysfunction, supporting their viability as a therapeutic strategy.

The BCL2 family: from apoptosis mechanisms to new advances in targeted therapy

The B cell lymphoma 2 (BCL2) protein family critically controls apoptosis by regulating the release of cytochrome c from mitochondria. In this cutting-edge review, we summarize the basic biology regulating the BCL2 family including canonical and non-canonical functions, and highlight milestones from basic research to clinical applications in cancer and other pathophysiological conditions. We review laboratory and clinical development of BH3-mimetics as well as more recent approaches including proteolysis targeting chimeras (PROTACs), antibody-drug conjugates (ADCs) and tools targeting the BH4 domain of BCL2. The first BCL2-selective BH3-mimetic, venetoclax, showed remarkable efficacy with manageable toxicities and has transformed the treatment of several hematologic malignancies. Following its success, several chemically similar BCL2 inhibitors such as sonrotoclax and lisaftoclax are currently under clinical evaluation, alone and in combination. Genetic analysis highlights the importance of BCL-XL and MCL1 across different cancer types and the possible utility of BH3-mimetics targeting these proteins. However, the development of BH3-mimetics targeting BCL-XL or MCL1 has been more challenging, with on-target toxicities including thrombocytopenia for BCL-XL and cardiac toxicities for MCL1 inhibitors precluding clinical development. Tumor-specific BCL-XL or MCL1 inhibition may be achieved by novel targeting approaches using PROTACs or selective drug delivery strategies and would be transformational in many subtypes of malignancy. Taken together, we envision that the targeting of BCL2 proteins, while already a success story of translational research, may in the foreseeable future have broader clinical applicability and improve the treatment of multiple diseases.

Fisetin as a Blueprint for Senotherapeutic Agents - Elucidating Geroprotective and Senolytic Properties with Molecular Modeling

Targeting senescent cells and the factors that accelerate this pathological state has recently emerged as a novel field in medicinal chemistry. As attention shifts to synthetic substances, studies on natural agents are often overlooked. In this paper, we present a detailed computational modeling study that encompasses quantum mechanics and molecular dynamics to elucidate the senotherapeutic activity of fisetin, a natural flavonoid. The mitochondrial environment, serving as a proxy for senescence, received special attention. Throughout the study, fisetin's outstanding geroprotective properties-exhibiting significant potential against ⋅OOH, O2⋅-, and ⋅OH radicals, surpassing those of Trolox or ascorbate-were identified. Furthermore, fisetin demonstrated a high capacity to restore oxidatively damaged biomolecules to their pristine forms, thereby renewing the functionality of proteins and amino acids. The senolytic properties were examined in terms of Bcl-2 and Bcl-xL inhibition. The results indicated that fisetin not only binds effectively to these proteins but also, with appropriate modifications, may exhibit specific selectivity toward either target. This study highlights fisetin's remarkable activity in these areas and provides a molecular description of the underlying processes, paving the way for future research.

Systemic aging and aging-related diseases

Aging is a biological process along with systemic and multiple organ dysfunction. It is more and more recognized that aging is a systemic disease instead of a single-organ functional disorder. Systemic aging plays a profound role in multiple diseases including neurodegenerative diseases, cardiovascular diseases, and malignant diseases. Aged organs communicate with other organs and accelerate aging. Skeletal muscle, heart, bone marrow, skin, and liver communicate with each other through organ-organ crosstalk. The crosstalk can be mediated by metabolites including lipids, glucose, short-chain fatty acids (SCFA), inflammatory cytokines, and exosomes. Metabolic disorders including hyperglycemia, hyperinsulinemia, and hypercholesterolemia caused by chronic diseases accelerate hallmarks of aging. Systemic aging leads to the destruction of systemic hemostasis, causes the release of inflammatory cytokines, senescence-associated secretory phenotype (SASP), and the imbalance of microbiota composition. Released inflammatory factors further aggregate senescence, which promotes the aging of multiple solid organs. Targeting senescence or delaying aging is emerging as a critical health strategy for solving age-related diseases, especially in the old population. In the current review, we will delineate the mechanisms of organ crosstalk in systemic aging and age-related diseases to provide therapeutic targets for delaying aging.

Stone L, Haglund L. Senolytic treatment for low back pain

Senescent cells (SnCs) accumulate because of aging and external cellular stress throughout the body. They adopt a senescence-associated secretory phenotype (SASP) and release inflammatory and degenerative factors that actively contribute to age-related diseases, such as low back pain (LBP). The senolytics, o-vanillin and RG-7112, remove SnCs in human intervertebral discs (IVDs) and reduce SASP release, but it is unknown whether they can treat LBP. sparc-/- mice, with LBP, were treated orally with o-vanillin and RG-7112 as single or combination treatments. Treatment reduced LBP and SASP factor release and removed SnCs from the IVD and spinal cord. Treatment also lowered degeneration scores in the IVDs, improved vertebral bone quality, and reduced the expression of pain markers in the spinal cord. Together, our data suggest RG-7112 and o-vanillin as potential disease-modifying drugs for LBP and other painful disorders linked to cell senescence.

Combating chronic kidney disease-associated cachexia: A literature review of recent therapeutic approaches

In 2008, the Society on Sarcopenia, Cachexia, and Wasting Disorders introduced a generic definition for all types of cachexia: "a complex metabolic syndrome associated with the underlying illness characterized by a loss of muscle, with or without fat loss". It is well-known that the presence of inflammatory burden in end-stage renal disease (ESRD) patients may lead to the evolution of cachexia. Since the etiology of cachexia in chronic kidney disease (CKD) is multifactorial, thus the successful treatment must involve several concomitant measures (nutritional interventions, appetite stimulants, and anti-inflammatory pharmacologic agents) to provide integrated effective therapeutic modalities to combat causative factors and alleviate the outcomes of patients. Given the high mortality rate associated with cachexia, developing new therapeutic modalities are prerequisite for ameliorating patients with CKD worldwide. The present review aims to discuss some therapeutic strategies and provide an update on advances in nutritional approaches to counteract cachexia.

Protocol for a pilot clinical trial of the senolytic drug combination Dasatinib Plus Quercetin to mitigate age-related health and cognitive decline in mental disorders

Background

Major depressive disorder (MDD) and schizophrenia are linked to accelerated aging leading to reduced lifespan, health span and cognitive decline. Cellular senescence, in which cells lose proliferative capacity and develop a senescence-associated secretory phenotype (SASP), plays a role in this process. Emerging research suggests that the senolytic regimen of dasatinib+quercetin (D+Q) reduces senescent cells, potentially mitigating age-related health and cognitive decline. This pilot study aims to assess the feasibility and safety of D+Q in older adults with schizophrenia, schizoaffective disorder, and treatment-resistant depression (TRD).

Methods

This single-center study will recruit 30 participants total aged 50 years or older with schizophrenia/schizoaffective disorder or 60 years or older with TRD; the difference in age limits is because individuals with schizophrenia are biologically about 10 years older than general population owing to metabolic burden. Each participant will receive two consecutive days of 100 mg oral dasatinib plus 1250 mg oral quercetin at baseline and weeks one through three, (i.e., two days on, five days off ) along with lifestyle risk management education.Questionnaires and assessments will measure health and cognitive function as well as psychiatric function at baseline, week 10, and one year. Magnetic Resonance Imaging (MRI) will measure structural and functional brain health at baseline and 10 weeks. Blood sampling for SASP testing will occur at seven time points: baseline, weeks one through four, week 10, and one year.

Conclusion

This pilot aims to evaluate the safety and feasibility of the senolytic regimen and D+Q's potential to counteract accelerated aging in adults with schizophrenia/schizoaffective disorder and TRD.

Trial registration

Dasatinib Plus Quercetin for Accelerated Aging in Mental Disorders is registered on ClinicalTrials.gov: NCT05838560; posted May 1, 2023.

Autophagy regulates cellular senescence by mediating the degradation of CDKN1A/p21 and CDKN2A/p16 through SQSTM1/p62-mediated selective autophagy in myxomatous mitral valve degeneration

Myxomatous mitral valve degeneration (MMVD) is one of the most important age-dependent degenerative heart valve disorders in both humans and dogs. It is characterized by the aberrant remodeling of extracellular matrix (ECM), regulated by senescent myofibroblasts (aVICs) transitioning from quiescent valve interstitial cells (qVICs), primarily under TGFB1/TGF-β1 control. In the present study, we found senescent aVICs exhibited impaired macroautophagy/autophagy as evidenced by compromised autophagy flux and immature autophagosomes. MTOR-dependent autophagy induced by rapamycin and torin-1 attenuated cell senescence and decreased the expression of cyclin-dependent kinase inhibitors (CDKIs) CDKN2A/p16INK4A and CDKN1A/p21CIP1. Furthermore, induction of autophagy in aVICs by ATG (autophagy related) gene overexpression restored autophagy flux, with a concomitant reduction in CDKN1A and CDKN2A expression and senescence-associated secretory phenotype (SASP). Conversely, autophagy deficiency induced CDKN1A and CDKN2A accumulation and SASP, whereas ATG re-expression alleviated senescent phenotypic transformation. Notably, CDKN1A and CDKN2A localized to autophagosomes and lysosomes following MTOR antagonism or MG132 treatment. SQSTM1/p62 was identified as the autophagy receptor to selectively sequester CDKN1A and CDKN2A cargoes for autophagic degradation. Our findings are the first demonstration that CDKN1A and CDKN2A are degraded through SQSTM1-mediated selective autophagy, independent of the ubiquitin-proteasome pathway. These data will inform development of therapeutic strategies for the treatment of canine and human MMVD, and for the treatment of Alzheimer disease, Parkinson disease and other age-related degenerative disorders.Abbreviations: ACTA2/α-SMA: actin alpha 2, smooth muscle; AKT: AKT serine/threonine kinase; aVICs: activated valve interstitial cells; ATG: autophagy related; baf-A1: bafilomycin A1; BrdU, bromodeoxyuridine; BSA: bovine serum albumin; CDKIs, cyclin-dependent kinase inhibitors; CDKN1A/p21: cyclin dependent kinase inhibitor 1A; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; co-IP: co-immunoprecipitation; DMSO: dimethylsulfoxide; ECM, extracellular matrix; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; eGFP: green fluorescent protein; ELISA: enzyme-linked immunosorbent assay; HEK-293T, human embryonic kidney 293T; HRP: horseradish peroxidase; KO: knockout; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; LIR: MAP1LC3/LC3-interacting region; MFS: Marfan syndrome; MKI67/Ki-67: marker of proliferation Ki-67; MMVD: myxomatous mitral valve degeneration; MTOR: mechanistic target of rapamycin kinase; MTORC: MTOR complex; OE: overexpression; PBST, phosphate-buffered saline with 0.1% Tween-20; PCNA: proliferating cell nuclear antigen; PIK3CA/PI3K: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; PLA: proximity ligation assays; PSMA1: proteasome 20S subunit alpha 1; PSMB5: proteasome 20S subunit beta 5; qVICs: quiescent valve interstitial cells; qRT-PCR: quantitative real-time PCR; SA-GLB1/β-gal: SA-senescence-associated GLB1/β-galactosidase; ROS: reactive oxygen species; SASP: senescence-associated secretory phenotype; RPS6KB1/p70 S6K: ribosomal protein S6 kinase B1; SMAD: SMAD family member; SQSTM1/p62: sequestosome 1; STEM: scanning transmission electron microscopy; TGFB: transforming growth factor beta; TGFBR: transforming growth factor beta receptor; TP53/p53: tumor protein p53; UPS: ubiquitin-proteasome system; WT, wild-type.

The Aging Immune System: A Critical Attack on Ischemic Stroke

Ischemic stroke caused by cerebrovascular embolism is an age-related disease with high rates of disability and mortality. Although the mechanisms of immune and inflammatory development after stroke have been of great interest, most studies have neglected the critical and unavoidable factor of age. As the global aging trend intensifies, the number of stroke patients is constantly increasing, emphasizing the urgency of finding effective measures to address the needs of elderly stroke patients. The concept of "immunosenescence" appears to explain the worse stroke outcomes in older individuals. Immune remodeling due to aging involves dynamic changes at all levels of the immune system, and the overall consequences of central (brain-resident) and peripheral (non-brain-resident) immune cells in stroke vary according to the age of the individual. Lastly, the review outlines recent strategies aimed at immunosenescence to improve stroke prognosis.

New Horizons in Myotonic Dystrophy Type 1: Cellular Senescence as a Therapeutic Target

Myotonic dystrophy type 1 (DM1) is considered a progeroid disease (i.e., causing premature aging). This hypervariable disease affects multiple systems, such as the musculoskeletal, central nervous, gastrointestinal, and others. Despite advances in understanding the underlying pathogenic mechanism of DM1, numerous gaps persist in our understanding, hindering elucidation of the heterogeneity and severity of its symptoms. Accumulating evidence indicates that the toxic intracellular RNA accumulation associated with DM1 triggers cellular senescence. These cells are in a state of irreversible cell cycle arrest and secrete a cocktail of cytokines, referred to as a senescence-associated secretory phenotype (SASP), that can have harmful effects on neighboring cells and more broadly. We hypothesize that cellular senescence contributes to the pathophysiology of DM1, and clearance of senescent cells is a promising therapeutic approach for DM1. We will discuss the therapeutic potential of different senotherapeutic drugs, especially senolytics that eliminate senescent cells, and senomorphics that reduce SASP expression.

Aging, cellular senescence and Parkinson's disease

Parkinson's disease (PD) is the most common neurodegenerative movement disorder, affecting 1-2% of people over age 65. The risk of developing PD dramatically increases with advanced age, indicating that aging is likely a driving factor in PD neuropathogenesis. Several age-associated biological changes are also hallmarks of PD neuropathology, including mitochondrial dysfunction, oxidative stress, and neuroinflammation. Accumulation of senescent cells is an important feature of aging that contributes to age-related diseases. How age-related cellular senescence affects brain health and whether this phenomenon contributes to neuropathogenesis in PD is not yet fully understood. In this review, we highlight hallmarks of aging, including mitochondrial dysfunction, loss of proteostasis, genomic instability and telomere attrition in relation to well established PD neuropathological pathways. We then discuss the hallmarks of cellular senescence in the context of neuroscience and review studies that directly examine cellular senescence in PD. Studying senescence in PD presents challenges and holds promise for advancing our understanding of disease mechanisms, which could contribute to the development of effective disease-modifying therapeutics. Targeting senescent cells or modulating the senescence-associated secretory phenotype (SASP) in PD requires a comprehensive understanding of the complex relationship between PD pathogenesis and cellular senescence.

Senescence as a molecular target in skin aging and disease

Skin aging represents a multifactorial process influenced by both intrinsic and extrinsic factors, collectively known as the skin exposome. Cellular senescence, characterized by stable cell cycle arrest and secretion of pro-inflammatory molecules, has been implicated as a key driver of physiological and pathological skin aging. Increasing evidence points towards the role of senescence in a variety of dermatological diseases, where the accumulation of senescent cells in the epidermis and dermis exacerbates disease progression. Emerging therapeutic strategies such as senolytics and senomorphics offer promising avenues to target senescent cells and mitigate their deleterious effects, providing potential treatments for both skin aging and senescence-associated skin diseases. This review explores the molecular mechanisms of cellular senescence and its role in promoting age-related skin changes and pathologies, while compiling the observed effects of senotherapeutics in the skin and discussing the translational relevance.

Long-Term Liver Machine Perfusion Preservation: A Review of Recent Advances, Benefits and Logistics

BACKGROUND

The global shortage of suitable donor livers for transplantation has prompted efforts to expand the donor pool by using extended criteria donors. Machine preservation technology has shown promise in optimizing graft preservation and improving logistics. Additionally, it holds potential for organ repair, regeneration, therapeutic applications during extended preservation periods, and enhancing organ allocation.

METHODS

We conducted a comprehensive literature review using PubMed, Embase, and Web of Science databases. All studies published between January 1, 2022, and February 7, 2024, that described machine perfusion preservation of livers for more than 24 h were eligible for inclusion. The findings were synthesized in a narrative review format to highlight key benefits and advancements.

RESULTS

We identified eleven studies from multiple research groups, employing various techniques, devices, and preservation durations. Perfusion durations ranged from 1 to 13 days, with notable variations in protocols for long-term preservation beyond 24 h. Viability was assessed during perfusion only. No livers were transplanted. Among the reviewed studies, the introduction of a dialysis system emerged as the most effective strategy for managing waste accumulation during long-term liver perfusion. Differences were also observed in hemodynamics, oxygenation, organ chambers, supplemental regimens, and glycemic control.

CONCLUSION

Over the past two years, substantial progress has been made in refining protocols for long-term liver machine perfusion, with significant advancements in waste management, enabling successful multi-day perfusions. While these developments are promising, further research is necessary to standardize and optimize long-term perfusion protocols, establishing a reliable platform for both organ preservation and therapeutic applications.