The roles and mechanisms of senescence-associated secretory phenotype (SASP): can it be controlled by senolysis?

Senolytic intervention improves cognition, metabolism, and adiposity in female APPNL-F/NL-F mice

Senescent cells accumulate throughout the body and brain contributing to unhealthy aging and Alzheimer's disease (AD). The APPNL-F/NL-F amyloidogenic AD mouse model exhibits increased markers of senescent cells and the senescence-associated secretory phenotype (SASP) in visceral white adipose tissue and the hippocampus before plaque accumulation and cognitive decline. We hypothesized that senolytic intervention would alleviate cellular senescence thereby improving spatial memory in APPNL-F/NL-F mice. Thus, 4-month-old male and female APPNL-F/NL-F mice were treated monthly with vehicle, 5 mg/kg dasatinib + 50 mg/kg quercetin, or 100 mg/kg fisetin. Blood glucose levels, energy metabolism, spatial memory, amyloid burden, and senescent cell markers were assayed. Dasatinib + quercetin treatment in female APPNL-F/NL-F mice increased oxygen consumption and energy expenditure resulting in decreased body mass. White adipose tissue mass was decreased along with senescence markers, SASP, blood glucose, and plasma insulin and triglycerides. Hippocampal senescence markers and SASP were reduced along with soluble and insoluble amyloid-β (Aβ)42 and senescence-associated-β-gal activity leading to improved spatial memory. Fisetin had negligible effects on these measures in female APPNL-F/NL-F mice while neither senolytic intervention altered these parameters in the male mice. Considering women have a greater risk of dementia, identifying senotherapeutics appropriate for sex and disease stage is necessary for personalized medicine.

Glutaminase-1 inhibition alleviates senescence of Wharton's jelly-derived mesenchymal stem cells via senolysis

Replicative senescence of mesenchymal stem cells (MSCs) caused by repeated cell culture undermines their potential as a cell therapy because of the reduction in their proliferation and therapeutic potential. Glutaminase-1 (GLS1) is reported to be involved in the survival of senescent cells, and inhibition of GLS1 alleviates age-related dysfunction via senescent cell removal. In the present study, we attempted to elucidate the association between MSC senescence and GLS1. We conducted in vitro and in vivo experiments to analyze the effect of GLS1 inhibition on senolysis and the therapeutic effects of MSCs. Inhibition of GLS1 in Wharton's jelly-derived MSCs (WJ-MSCs) reduced the expression of aging-related markers, such as p16, p21, and senescence-associated secretory phenotype genes, by senolysis. Replicative senescence-alleviated WJ-MSCs, which recovered after short-term treatment with bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide 3 (BPTES), showed increased proliferation and therapeutic effects compared to those observed with senescent WJ-MSCs. Moreover, compared to senescent WJ-MSCs, replicative senescence-alleviated WJ-MSCs inhibited apoptosis in serum-starved C2C12 cells, enhanced muscle formation, and hindered apoptosis and fibrosis in mdx mice. These results imply that GLS1 inhibition can ameliorate the therapeutic effects of senescent WJ-MSCs in patients with muscle diseases such as Duchenne muscular dystrophy. In conclusion, GLS1 is a key factor in modulating the senescence mechanism of MSCs, and regulation of GLS1 may enhance the therapeutic effects of senescent MSCs, thereby increasing the success rate of clinical trials involving MSCs.

Epigenetic regulations of cellular senescence in osteoporosis

Osteoporosis (OP) is a prevalent age-related disease that is characterized by a decrease in bone mineral density (BMD) and systemic bone microarchitectural disorders. With age, senescent cells accumulate and exhibit the senescence-associated secretory phenotype (SASP) in bone tissue, leading to the imbalance of bone homeostasis, osteopenia, changes in trabecular bone structure, and increased bone fragility. Cellular senescence in the bone microenvironment involves osteoblasts, osteoclasts, and bone marrow mesenchymal stem cells (BMSCs), whose effects on bone homeostasis are regulated by epigenetics. Therefore, the epigenetic regulatory mechanisms of cellular senescence have received considerable attention as potential targets for preventing and treating osteoporosis. In this paper, we systematically review the mechanisms of aging-associated epigenetic regulation in osteoporosis, emphasizing the impact of epigenetics on cellular senescence, and summarize three current methods of targeting cellular senescence, which is helpful better to understand the pathogenic mechanisms of cellular senescence in osteoporosis and provides strategies for the development of epigenetic drugs for the treatment of osteoporosis.

Titan mice as a model to test interventions that attenuate frailty and increase longevity

Wild-type murine models for aging research have lifespans of several years, which results in long experimental duration and late output. Here we explore the short-lived non-inbred Titan mouse (DU6) as a mouse model to test longevity interventions. We show that Titan mice exhibit increased frailty and senescence-associated beta-galactosidase activity at an early age. Dietary intervention attenuates the frailty progression of Titan mice. Additionally, cyclic administration of the senolytic drug Navitoclax at an early age increases the lifespan and reduces senescence-associated beta-galactosidase activity. Our data suggests that Titan mice can serve as a cost-effective and timely model for longevity interventions in mammals.

Development of a Folding Paper System To Enable the Analysis of Gene Profile of Short- and Long-Distance Cancer Cell Migration

In cancer metastasis, where mortality rates remain high despite advancements in medical treatments, understanding the molecular pathways and cellular dynamics underlying tumor spread is critical for devising more effective therapeutic strategies. Here, a folding paper system was proposed and developed to mimic native tumor microenvironment. This system, composed of 7 stacked layers of paper enclosed in a holder, allows for the culture of cancer cells under conditions mimicking those found in solid tumors, including limited oxygen and nutrients. Because of the migratory capabilities of cancer cells, the cells in the center layer could migrated to outer layers of the paper stack, enabling the differentiation of cells based on their migratory potential. Subsequent gene expression analysis, conducted through RT-PCR and RNA sequencing, revealed significant correlations between cancer cell migration distance and the expression of genes associated with hypoxia, metabolism, ATP production, and cellular process. Moreover, our study identified cells with aggressive phenotypic traits from the outer layers of the paper stack, highlighting the potential of this system for enabling the study of aggressive cancer cell characteristics. Validation of the folding paper system against clinical carcinoma tissue demonstrated its ability to faithfully mimic the native tumor microenvironment. Overall, our findings underscore the utility of the folding paper system as a valuable tool for investigating and identifying critical molecular pathways involved in cancer metastasis.

The regulatory mechanism of cyclic GMP-AMP synthase on inflammatory senescence of nucleus pulposus cell

BACKGROUND

Cellular senescence features irreversible growth arrest and secretion of multiple proinflammatory cytokines. Cyclic GMP-AMP synthase (cGAS) detects DNA damage and activates the DNA-sensing pathway, resulting in the upregulation of inflammatory genes and induction of cellular senescence. This study aimed to investigate the effect of cGAS in regulating senescence of nucleus pulposus (NP) cells under inflammatory microenvironment.

METHODS

The expression of cGAS was evaluated by immunohistochemical staining in rat intervertebral disc (IVD) degeneration model induced by annulus stabbing. NP cells were harvested from rat lumbar IVD and cultured with 10ng/ml IL-1β for 48 h to induce premature senescence. cGAS was silenced by cGAS specific siRNA in NP cells and cultured with IL-1β. Cellular senescence was evaluated by senescence-associated beta-galactosidase (SA-β-gal) staining and flow cytometry. The expression of senescence-associated secretory phenotype including IL-6, IL-8, and TNF-a was evaluated by ELISA and western blotting.

RESULTS

cGAS was detected in rat NP cells in cytoplasm and the expression was significantly increased in degenerated IVD. Culturing in 10ng/ml IL-1β for 48 h induced cellular senescence in NP cells with attenuation of G1-S phase transition. In senescent NP cells the expression of cGAS, p53, p16, NF-kB, IL-6, IL-8, TNF-α was significantly increased while aggrecan and collagen type II was reduced than in normal NP cells. In NP cells with silenced cGAS, the expression of p53, p16, NF-kB, IL-6, IL-8, and TNF-α was reduced in inflammatory culturing with IL-1β.

CONCLUSION

cGAS was increased by NP cells in degenerated IVD promoting cellular senescence and senescent inflammatory phenotypes. Targeting cGAS may alleviate IVD degeneration by reducing NP cell senescence.

Immune surveillance of senescence: potential application to age-related diseases

Several lines of evidence suggest that the age-dependent accumulation of senescent cells leads to chronic tissue microinflammation, which in turn contributes to age-related pathologies. In general, senescent cells can be eliminated by the host's innate and adaptive immune surveillance system, including macrophages, NK cells, and T cells. Impaired immune surveillance leads to the accumulation of senescent cells and accelerates the aging process. Recently, senescent cells, like cancer cells, have been shown to express certain types of immune checkpoint proteins as well as non-classical immune-tolerant MHC variants, leading to immune escape from surveillance systems. Thus, immune checkpoint blockade (ICB) may be a promising strategy to enhance immune surveillance of senescence, leading to the amelioration of some age-related diseases and tissue dysfunction.

Senolytic Intervention Improves Cognition, Metabolism, and Adiposity in Female APP NL-F/NL-F Mice

Senescent cells accumulate throughout the body and brain contributing to unhealthy aging and Alzheimer's disease (AD). The APP NL-F/NL-F amyloidogenic AD mouse model exhibits increased markers of senescent cells and the senescence-associated secretory phenotype (SASP) in visceral white adipose tissue before plaque accumulation and cognitive decline. We hypothesized that senolytic intervention would alleviate cellular senescence thereby improving spatial memory in APP NL-F/NL-F mice. Thus, four month old male and female APP NL-F/NL-F mice were treated monthly with vehicle, 5 mg/kg Dasatinib + 50 mg/kg Quercetin, or 100 mg/kg Fisetin. Blood glucose levels, energy metabolism, spatial memory, amyloid burden, and senescent cell markers were assayed. Dasatinib + Quercetin treatment in female APP NL-F/NL-F mice increased oxygen consumption and energy expenditure resulting in decreased body mass. White adipose tissue mass was decreased along with senescence markers, SASP, blood glucose, and plasma insulin and triglycerides. Hippocampal senescence markers and SASP were reduced along with soluble and insoluble amyloid-β (Aβ) 42 and senescence associated-β-gal activity leading to improved spatial memory. Fisetin had negligible effects on these measures in female APP NL-F/NL-F mice while neither senolytic intervention altered these parameters in the male mice. Considering women have a greater risk of dementia, identifying senotherapeutics appropriate for sex and disease stage is necessary for personalized medicine.

Alterations of receptors and insulin-like growth factor binding proteins in senescent cells

The knowledge about cellular senescence expands dynamically, providing more and more conclusive evidence of its triggers, mechanisms, and consequences. Senescence-associated secretory phenotype (SASP), one of the most important functional traits of senescent cells, is responsible for a large extent of their context-dependent activity. Both SASP's components and signaling pathways are well-defined. A literature review shows, however, that a relatively underinvestigated aspect of senescent cell autocrine and paracrine activity is the change in the production of proteins responsible for the reception and transmission of SASP signals, i.e., receptors and binding proteins. For this reason, we present in this article the current state of knowledge regarding senescence-associated changes in cellular receptors and insulin-like growth factor binding proteins. We also discuss the role of these alterations in senescence induction and maintenance, pro-cancerogenic effects of senescent cells, and aging-related structural and functional malfunctions.

Biomarkers of Cellular Senescence and Aging: Current State-of-the-Art, Challenges and Future Perspectives

Population aging has increased the global prevalence of aging-related diseases, including cancer, sarcopenia, neurological disease, arthritis, and heart disease. Understanding aging, a fundamental biological process, has led to breakthroughs in several fields. Cellular senescence, evinced by flattened cell bodies, vacuole formation, and cytoplasmic granules, ubiquitously plays crucial roles in tissue remodeling, embryogenesis, and wound repair as well as in cancer therapy and aging. The lack of universal biomarkers for detecting and quantifying senescent cells, in vitro and in vivo, constitutes a major limitation. The applications and limitations of major senescence biomarkers, including senescence-associated β-galactosidase staining, telomere shortening, cell-cycle arrest, DNA methylation, and senescence-associated secreted phenotypes are discussed. Furthermore, explore senotherapeutic approaches for aging-associated diseases and cancer. In addition to the conventional biomarkers, this review highlighted the in vitro, in vivo, and disease models used for aging studies. Further, technologies from the current decade including multi-omics and computational methods used in the fields of senescence and aging are also discussed in this review. Understanding aging-associated biological processes by using cellular senescence biomarkers can enable therapeutic innovation and interventions to improve the quality of life of older adults.

Cellular Aging and Senescence in Cancer: A Holistic Review of Cellular Fate Determinants

This comprehensive review navigates the complex relationship between cellular aging, senescence, and cancer, unraveling the determinants of cellular fate. Beginning with an overview of cellular aging's significance in cancer, the review explores processes, changes, and molecular pathways influencing senescence. The review explores senescence as a dual mechanism in cancer, acting as a suppressor and contributor, focusing on its impact on therapy response. This review highlights opportunities for cancer therapies that target cellular senescence. The review further examines the senescence-associated secretory phenotype and strategies to modulate cellular aging to influence tumor behavior. Additionally, the review highlights the mechanisms of senescence escape in aging and cancer cells, emphasizing their impact on cancer prognosis and resistance to therapy. The article addresses current advances, unexplored aspects, and future perspectives in understanding cellular aging and senescence in cancer.

The companion dog as a model for inflammaging: a cross-sectional pilot study

Inflammaging, the chronic, progressive proinflammatory state associated with aging, has been associated with multiple negative health outcomes in humans. The pathophysiology of inflammaging is complex; however, it is often characterized by high serum concentrations of inflammatory mediators such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and C-reactive protein (CRP). Few studies have evaluated the effects of age on inflammatory cytokines in companion dogs, and most of these studies included dogs of a single breed. In this cross-sectional study, we measured multiple circulating inflammatory markers and hematological parameters in banked serum samples from 47 healthy companion dogs of various breeds enrolled in the Dog Aging Project. Using univariate linear models, we investigated the association of each of these markers with age, sex, body weight, and body condition score (BCS), a measure of obesity in the dog. Serum IL-6, IL-8, and TNF-α concentrations were all positively associated with age. Lymphocyte count was negatively associated with age. Platelet count had a negative association with body weight. IL-2, albumin, cholesterol, triglyceride, bilirubin, S100A12, and NMH concentrations were not associated with age, weight, BCS, or sex after adjustment for multiple comparisons. Our findings replicate previous findings in humans, including increases in IL-6 and TNF-α with age, giving more evidence to the strength of the companion dog as a model for human aging.

SIRT1 as a potential therapeutic target in pelvic organ prolapse due to protective effects against oxidative stress and cellular senescence in human uterosacral ligament fibroblasts

INTRODUCTION

The pathogenesis of pelvic organ prolapse (POP), an age-related disease, has not been fully elucidated. Therapeutic targets of POP are limited. Silencing information regulator 2 related enzyme 1 (SIRT1), a gene considered capable of regulating oxidative stress and cellular senescence, has been widely demonstrated involved in aging and age-related diseases. The present study aimed to explore the role of SIRT1 in POP in vivo and in vitro.

METHODS

Expression levels of SIRT1 in uterosacral ligament (USL) tissues from patients with or without POP were measured using immunohistochemical assays. SRT1720, a SIRT1 agonist, was used to upregulate SIRT1, and hydrogen peroxide (H2O2) was used to establish an oxidative stress model in human uterosacral ligament fibroblasts (hUSLFs). The effects of SIRT1 on cell viability, apoptosis, senescence, and reactive oxygen species (ROS) levels were detected, respectively. Western blot assays were used to examine expression levels of apoptosis- and senescence-associated biomarkers. Unpaired Student's t test, Mann-Whitney U test, χ2 test, and one-way ANOVA were performed for determining statistically significant differences.

RESULTS

Compared to the control group, expression levels of SIRT1 were downregulated in USL tissues and hUSLFs from patients with POP, and associated with stage (p < 0.05). hUSLFs of patients with POP had lower growth rates (p < 0.0001) than those of the control group, which were improved by upregulating SIRT1 (p < 0.05). The senescent proportion was higher in the POP group than the control group (43.63 ± 10.62% vs. 4.84 ± 5.32%, p < 0.0001), which could be reduced by upregulating SIRT1 (p < 0.0001). High ROS levels in the POP group were also alleviated by SRT1720. H2O2 exposure increased ROS levels, inhibited proliferation, and triggered apoptosis and senescence in hUSLFs of patients without POP in a concentration-dependent manner. Further, these damages were alleviated by pretreatment with SRT1720.

CONCLUSIONS

SIRT1 is downregulated in patients with POP, and the development of SIRT1 activators or agonists may have applications in the treatment and prevention of POP through antioxidative stress and antisenescence effects.

Microglial response to aging and neuroinflammation in the development of neurodegenerative diseases

ABSTRACT

Cellular senescence and chronic inflammation in response to aging are considered to be indicators of brain aging; they have a great impact on the aging process and are the main risk factors for neurodegeneration. Reviewing the microglial response to aging and neuroinflammation in neurodegenerative diseases will help understand the importance of microglia in neurodegenerative diseases. This review describes the origin and function of microglia and focuses on the role of different states of the microglial response to aging and chronic inflammation on the occurrence and development of neurodegenerative diseases, including Alzheimer's disease, Huntington's chorea, and Parkinson's disease. This review also describes the potential benefits of treating neurodegenerative diseases by modulating changes in microglial states. Therefore, inducing a shift from the neurotoxic to neuroprotective microglial state in neurodegenerative diseases induced by aging and chronic inflammation holds promise for the treatment of neurodegenerative diseases in the future.

Cellular senescence in cancer: molecular mechanisms and therapeutic targets

Aging exhibits several hallmarks in common with cancer, such as cellular senescence, dysbiosis, inflammation, genomic instability, and epigenetic changes. In recent decades, research into the role of cellular senescence on tumor progression has received widespread attention. While how senescence limits the course of cancer is well established, senescence has also been found to promote certain malignant phenotypes. The tumor-promoting effect of senescence is mainly elicited by a senescence-associated secretory phenotype, which facilitates the interaction of senescent tumor cells with their surroundings. Targeting senescent cells therefore offers a promising technique for cancer therapy. Drugs that pharmacologically restore the normal function of senescent cells or eliminate them would assist in reestablishing homeostasis of cell signaling. Here, we describe cell senescence, its occurrence, phenotype, and impact on tumor biology. A "one-two-punch" therapeutic strategy in which cancer cell senescence is first induced, followed by the use of senotherapeutics for eliminating the senescent cells is introduced. The advances in the application of senotherapeutics for targeting senescent cells to assist cancer treatment are outlined, with an emphasis on drug categories, and the strategies for their screening, design, and efficient targeting. This work will foster a thorough comprehension and encourage additional research within this field.

Senescence and fibrosis in salivary gland aging and disease

Salivary gland hypofunction is highly prevalent in aged and diseased individuals leading to significant discomfort and morbidity. One factor that contributes to salivary gland hypofunction is cellular aging, or senescence. Senescent cells can impair gland function by secreting paracrine-acting growth factors and cytokines, known as senescence-associated secretory phenotype (SASP) factors. These SASP factors stimulate inflammation, propagate the senescent phenotype through the bystander effect, and stimulate fibrosis. As senotherapeutics that target senescent cells have shown effectiveness in limiting disease manifestations in other conditions, there is interest in the use of these drugs to treat salivary gland hypofunction. In this review, we highlight the contribution of senescence and fibrosis to salivary gland pathologies. We also discuss therapeutic approaches to eliminate or modulate the senescent SASP phenotype for treating age-related salivary gland diseases and extending health span.

Prevalence and sociodemographic correlates of antinuclear antibody testing by indirect immunofluorescence or solid-phase assays in a Spanish population: the Camargo Cohort

Autoantibodies are the hallmark of autoimmunity, and specifically, antinuclear antibodies (ANA) are one of the most relevant antibodies present in systemic autoimmune diseases (AID). In the present study, we evaluate the relationship between ANA and sociodemographic and biobehavioral factors in a population with a low pre-test probability for systemic AID. ANA were determined in serum samples at baseline visit from 2997 participants from the Camargo Cohort using indirect immunofluorescence assay, and two solid phase assays (SPA), addressable laser bead immunoassay, and fluorescence enzyme immunoassay. Sociodemographic and biobehavioral features of the subjects were obtained at baseline visit using a structured questionnaire. The prevalence of ANA positive results was significantly higher when indirect immunofluorescence assay was used as screening method in comparison with SPAs, being higher in females, older subjects, and those with higher C-reactive protein levels. Considering biobehavioral features, the prevalence was higher in those individuals with a sedentary lifestyle, and in ex- and non-alcohol users. Moreover, considering the relevance of the antibody load using ANA Screen, the prevalence of the antibody load also increased with age, especially in females. In conclusion, the prevalence of ANA varies depending on sociodemographic and biobehavioral features of the subjects, which could be relevant specifically in a population with a low pre-test probability for systemic AIDs.

Anti-aging Factor GRSF1 Attenuates Cerebral Ischemia-Reperfusion Injury in Mice by Inhibiting GPX4-Mediated Ferroptosis

Abnormal accumulation of senescent cells in tissues has been shown to facilitate the onset and progression of various diseases. As an important protein involving in the regulation of cellular senescence process, researches suggested GRSF1 as a potential senolytic target to improve multiple physiological and pathological processes. However, the underlying mechanism of cellular senescence on cerebral ischemia-reperfusion injury (CIRI) has not been revealed. Here, we investigated the effect of GRSF1 on CIRI and delved into its specific mechanisms. In the present study, we established a mouse model of cerebral ischemia-reperfusion (CIR) and observed low expression of anti-aging factor GRSF1, along with greatly increased levels of senescence-related markers p16 and p21 and senescence-associated secretory phenotype TNF-α. Furthermore, we found that the expression of GPX4 was elevated parallel to GRSF1 in CIR mice with overexpression of GRSF1, oxidative stress, and iron metabolism-related proteins were inhibited. Functionally, overexpressing GRSF1 significantly ameliorated infarct volume and neurological function scores and suppressed apoptosis in CIR mice, while administration of GPX4 inhibitors reversed these beneficial phenotypes. Taken together, our results indicate cellular senescence as an important pathological mechanism to exacerbate cerebral injury during CIRI, while GRSF1 could inhibit oxidative stress-mediated ferroptosis through upregulating GPX4 to attenuate reperfusion injury, which makes senolytic treatment, especially GRSF1, a promising therapeutic target for CIRI.

Understanding the intricacies of cellular senescence in atherosclerosis: Mechanisms and therapeutic implications

Cardiovascular disease is currently the largest cause of mortality and disability globally, surpassing communicable diseases, and atherosclerosis is the main contributor to this epidemic. Aging is intimately linked to atherosclerosis development and progression, however, the mechanism of aging in atherosclerosis is not well known. To emphasize the significant research on the involvement of senescent cells in atherosclerosis, we begin by outlining compelling evidence that indicates various types of senescent cells and SASP factors linked to atherosclerotic phenotypes. We subsequently provide a comprehensive summary of the existing knowledge, shedding light on the intricate mechanisms through which cellular senescence contributes to the pathogenesis of atherosclerosis. Further, we cover that senescence can be identified by both structural changes and several senescence-associated biomarkers. Finally, we discuss that preventing accelerated cellular senescence represents an important therapeutic potential, as permanent changes may occur in advanced atherosclerosis. Together, the review summarizes the relationship between cellular senescence and atherosclerosis, and inspects the molecular knowledge, and potential clinical significance of senescent cells in developing senescent-based therapy, thus providing crucial insights into their biology and potential therapeutic exploration.

The role of cellular senescence-related genes in Asthma: Insights from bioinformatics and animal experiments

BACKGROUND

Asthma is a heterogeneous chronic respiratory disease, affecting about 10% of the global population. Cellular senescence is a multifaceted phenomenon defined as the irreversible halt of the cell cycle, commonly referred to as the senescence-associated secretory phenotype. Recent studies suggest that cellular senescence may play a role in asthma. This study aims to dissect the role and biological mechanisms of CSRGs in asthma, enhancing our understanding of the progression of asthma.

METHODS

The study utilized the GSE147878 dataset, employing methods like WGCNA, Differential analysis, Cibersort, GO, KEGG, unsupervised clustering, and GSVA to explore CSRGs functions and immune cell patterns in asthma. Machine learning identified key diagnostic genes, validated externally with the GSE165934 dataset and through qRT-PCR and WB experiments in animal models.

RESULT

From the GSE147878 dataset, 24 CSRGs were identified, highlighting their role in immune and inflammatory processes in asthma. Differences in CD4 naive T cells and activated dendritic cells between asthma and control groups underscored CSRGs' role in immune regulation. Cluster analysis revealed two distinct asthma patient groups with unique immune microenvironments. Machine learning identified five genes, leading to a TF-miRNA-mRNA network and singling out RHOA and RBM39 as key diagnostic genes, which were experimentally validated. Finally, a nomogram was created based on these genes.

CONCLUSION

This study, utilizing bioinformatics and animal experiments, identified RHOA and RBM39 as key diagnostic genes for asthma, providing new insights into the potential role and biological mechanisms of CSRGs in asthma.

Protective Effect of Curcumin on D-Galactose-Induced Senescence and Oxidative Stress in LLC-PK1 and HK-2 Cells

D-galactose has been widely used as an inducer of cellular senescence and pathophysiological processes related to aging because it induces oxidative stress. On the other hand, the consumption of antioxidants such as curcumin can be an effective strategy to prevent phenotypes related to the enhanced production of reactive oxygen species (ROS), such as aging and senescence. This study aimed to evaluate the potential protective effect of curcumin on senescence and oxidative stress and endoplasmic reticulum stress induced by D-galactose treatment in Lilly Laboratories Culture-Porcine Kidney 1 (LLC-PK1) and human kidney 2 (HK-2) proximal tubule cell lines from pig and human, respectively. For senescence induction, cells were treated with 300 mM D-galactose for 120 h and, to evaluate the protective effect of the antioxidant, cells were treated with 5 µM curcumin for 24 h and subsequently treated with curcumin + D-galactose for 120 h. In LLC-PK1 cells, curcumin treatment decreased by 20% the number of cells positive for senescence-associated (SA)-β-D-galactosidase staining and by 25% the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and increased by 40% lamin B1 expression. In HK-2 cells, curcumin treatment increased by 60% the expression of proliferating cell nuclear antigen (PCNA, 50% Klotho levels, and 175% catalase activity. In both cell lines, this antioxidant decreased the production of ROS (20% decrease for LLC-PK1 and 10 to 20% for HK-2). These data suggest that curcumin treatment has a moderate protective effect on D-galactose-induced senescence in LLC-PK1 and HK-2 cells.

Autophagy and senescence facilitate the development of antiestrogen resistance in ER positive breast cancer

Estrogen receptor positive (ER+) breast cancer is the most common breast cancer diagnosed annually in the US with endocrine-based therapy as standard-of-care for this breast cancer subtype. Endocrine therapy includes treatment with antiestrogens, such as selective estrogen receptor modulators (SERMs), selective estrogen receptor downregulators (SERDs), and aromatase inhibitors (AIs). Despite the appreciable remission achievable with these treatments, a substantial cohort of women will experience primary tumor recurrence, subsequent metastasis, and eventual death due to their disease. In these cases, the breast cancer cells have become resistant to endocrine therapy, with endocrine resistance identified as the major obstacle to the medical oncologist and patient. To combat the development of endocrine resistance, the treatment options for ER+, HER2 negative breast cancer now include CDK4/6 inhibitors used as adjuvants to antiestrogen treatment. In addition to the dysregulated activity of CDK4/6, a plethora of genetic and biochemical mechanisms have been identified that contribute to endocrine resistance. These mechanisms, which have been identified by lab-based studies utilizing appropriate cell and animal models of breast cancer, and by clinical studies in which gene expression profiles identify candidate endocrine resistance genes, are the subject of this review. In addition, we will discuss molecular targeting strategies now utilized in conjunction with endocrine therapy to combat the development of resistance or target resistant breast cancer cells. Of approaches currently being explored to improve endocrine treatment efficacy and patient outcome, two adaptive cell survival mechanisms, autophagy, and "reversible" senescence, are considered molecular targets. Autophagy and/or senescence induction have been identified in response to most antiestrogen treatments currently being used for the treatment of ER+ breast cancer and are often induced in response to CDK4/6 inhibitors. Unfortunately, effective strategies to target these cell survival pathways have not yet been successfully developed. Thus, there is an urgent need for the continued interrogation of autophagy and "reversible" senescence in clinically relevant breast cancer models with the long-term goal of identifying new molecular targets for improved treatment of ER+ breast cancer.

YAP/TAZ as Molecular Targets in Skeletal Muscle Atrophy and Osteoporosis

Skeletal muscles and bones are closely connected anatomically and functionally. Age-related degeneration in these tissues is associated with physical disability in the elderly and significantly impacts their quality of life. Understanding the mechanisms of age-related musculoskeletal tissue degeneration is crucial for identifying molecular targets for therapeutic interventions for skeletal muscle atrophy and osteoporosis. The Hippo pathway is a recently identified signaling pathway that plays critical roles in development, tissue homeostasis, and regeneration. The Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are key downstream effectors of the mammalian Hippo signaling pathway. This review highlights the fundamental roles of YAP and TAZ in the homeostatic maintenance and regeneration of skeletal muscles and bones. YAP/TAZ play a significant role in stem cell function by relaying various environmental signals to stem cells. Skeletal muscle atrophy and osteoporosis are related to stem cell dysfunction or senescence triggered by YAP/TAZ dysregulation resulting from reduced mechanosensing and mitochondrial function in stem cells. In contrast, the maintenance of YAP/TAZ activation can suppress stem cell senescence and tissue dysfunction and may be used as a basis for the development of potential therapeutic strategies. Thus, targeting YAP/TAZ holds significant therapeutic potential for alleviating age-related muscle and bone dysfunction and improving the quality of life in the elderly.

Chk2 Modulates Bmi1-Deficiency-Induced Renal Aging and Fibrosis via Oxidative Stress, DNA Damage, and p53/TGFβ1-Induced Epithelial-Mesenchymal Transition

Renal aging may lead to fibrosis and dysfunction, yet underlying mechanisms remain unclear. We explored whether deficiency of the Polycomb protein Bmi1 causes renal aging via DNA damage response (DDR) activation, inducing renal tubular epithelial cell (RTEC) senescence and epithelial-mesenchymal transition (EMT). Bmi1 knockout mice exhibited oxidative stress, DDR activation, RTEC senescence, senescence-associated secretory phenotype (SASP), and age-related fibrosis in kidneys. Bmi1 deficiency impaired renal structure and function, increasing serum creatinine/urea, reducing creatinine clearance, and decreasing cortical thickness and glomerular number. However, knockout of the serine-threonine kinase Chk2 alleviated these aging phenotypes. Transcriptomics identified transforming growth factor beta 1 (TGFβ1) upregulation in Bmi1-deficient RTECs, but TGFβ1 was downregulated upon Chk2 knockout. The tumor suppressor protein p53 transcriptionally activated TGFβ1, promoting EMT in RTECs. Bmi1 knockout or oxidative stress (induced with H2O2) increased TGFβ1 expression, and EMT in RTECs and was partly reversed by p53 inhibition. Together, Bmi1 deficiency causes oxidative stress and DDR-mediated RTEC senescence/SASP, thus activating p53 and TGFβ1 to induce EMT and age-related fibrosis. However, blocking DDR (via Chk2 knockout) or p53 ameliorates these changes. Our study reveals mechanisms whereby Bmi1 preserves renal structure and function during aging by suppressing DDR and p53/TGFβ1-mediated EMT. These pathways represent potential targets for detecting and attenuating age-related renal decline.

The search for CDK4/6 inhibitor biomarkers has been hampered by inappropriate proliferation assays

CDK4/6 inhibitors are effective at treating advanced HR+ /HER2- breast cancer, however biomarkers that can predict response are urgently needed. We demonstrate here that previous large-scale screens designed to identify which tumour types or genotypes are most sensitive to CDK4/6 inhibitors have misrepresented the responsive cell lines because of a reliance on metabolic proliferation assays. CDK4/6-inhibited cells arrest in G1 but continue to grow in size, thereby producing more mitochondria. We show that this growth obscures the arrest using ATP-based proliferation assays but not if DNA-based assays are used instead. Furthermore, lymphoma lines, previously identified as the most sensitive, simply appear to respond the best using ATP-based assays because they fail to overgrow during the G1 arrest. Similarly, the CDK4/6 inhibitor abemaciclib appears to inhibit proliferation better than palbociclib because it also restricts cellular overgrowth through off-target effects. DepMap analysis of screening data using reliable assay types, demonstrates that palbociclib-sensitive cell types are also sensitive to Cyclin D1, CDK4 and CDK6 knockout/knockdown, whereas the palbociclib-resistant lines are sensitive to Cyclin E1, CDK2 and SKP2 knockout/knockdown. Potential biomarkers of palbociclib-sensitive cells are increased expression of CCND1 and RB1, and reduced expression of CCNE1 and CDKN2A. Probing DepMap with similar data from metabolic assays fails to reveal these associations. Together, this demonstrates why CDK4/6 inhibitors, and any other anti-cancer drugs that arrest the cell cycle but permit continued cell growth, must now be re-screened against a wide-range of cell types using an appropriate proliferation assay. This would help to better inform clinical trials and to identify much needed biomarkers of response.

Regulatory RNAs in immunosenescence

BACKGROUND

Immunosenescence is a multifactorial stress response to different intrinsic and extrinsic insults that cause immune deterioration and is accompanied by genomic or epigenomic perturbations. It is now widely recognized that genes and proteins contributing in the process of immunosenescence are regulated by various noncoding (nc) RNAs, including microRNAs (miRNAs), long ncRNAs, and circular RNAs.

AIMS

This review article aimed to evaluate the regulatore RNAs roles in the process of immunosenescence.

METHODS

We analyzed publications that were focusing on the different roles of regulatory RNAs on the several aspects of immunosenescence.

RESULTS

In the immunosenescence setting, ncRNAs have been found to play regulatory roles at both transcriptional and post-transcriptional levels. These factors cooperate to regulate the initiation of gene expression programs and sustaining the senescence phenotype and proinflammatory responses.

CONCLUSION

Immunosenescence is a complex process with pivotal alterations in immune function occurring with age. The extensive network that drive immunosenescence-related features are are mainly directed by a variety of regulatory RNAs such as miRNAs, lncRNAs, and circRNAs. Latest findings about regulation of senescence by ncRNAs in the innate and adaptive immune cells as well as their role in the immunosenescence pathways, provide a better understanding of regulatory RNAs function in the process of immunosenescence.

Connecting epigenetics and inflammation in vascular senescence: state of the art, biomarkers and senotherapeutics

Vascular diseases pose major health challenges, and understanding their underlying molecular mechanisms is essential to advance therapeutic interventions. Cellular senescence, a hallmark of aging, is a cellular state characterized by cell-cycle arrest, a senescence-associated secretory phenotype macromolecular damage, and metabolic dysregulation. Vascular senescence has been demonstrated to play a key role in different vascular diseases, such as atherosclerosis, peripheral arterial disease, hypertension, stroke, diabetes, chronic venous disease, and venous ulcers. Even though cellular senescence was first described in 1961, significant gaps persist in comprehending the epigenetic mechanisms driving vascular senescence and its subsequent inflammatory response. Through a comprehensive analysis, we aim to elucidate these knowledge gaps by exploring the network of epigenetic alterations that contribute to vascular senescence. In addition, we describe the consequent inflammatory cascades triggered by these epigenetic modifications. Finally, we explore translational applications involving biomarkers of vascular senescence and the emerging field of senotherapy targeting this biological process.

Mechanisms of carboplatin- and paclitaxel-dependent induction of premature senescence and pro-cancerogenic conversion of normal peritoneal mesothelium and fibroblasts

Carboplatin (CPT) and paclitaxel (PCT) are the optimal non-surgical treatment of epithelial ovarian cancer (EOC). Although their growth-restricting influence on EOC cells is well known, their impact on normal peritoneal cells, including mesothelium (PMCs) and fibroblasts (PFBs), is poorly understood. Here, we investigated whether, and if so, by what mechanism, CPT and PCT induce senescence of omental PMCs and PFBs. In addition, we tested whether PMC and PFB exposure to the drugs promotes the development of a pro-cancerogenic phenotype. The results showed that CPT and PCT induce G2/M growth arrest-associated senescence of normal peritoneal cells and that the strongest induction occurs when the drugs act together. PMCs senesce telomere-independently with an elevated p16 level and via activation of AKT and STAT3. In PFBs, telomeres shorten along with an induction of p21 and p53, and their senescence proceeds via the activation of ERK1/2. Oxidative stress in CPT + PCT-treated PMCs and PFBs is extensive and contributes causatively to their premature senescence. Both PMCs and PFBs exposed to CPT + PCT fuel the proliferation, migration, and invasion of established (A2780, OVCAR-3, SKOV-3) and primary EOCs, and this activity is linked with an overproduction of multiple cytokines altering the cancer cell transcriptome and controlled by p38 MAPK, NF-κB, STAT3, Notch1, and JAK1. Collectively, our findings indicate that CPT and PCT lead to iatrogenic senescence of normal peritoneal cells, which paradoxically and opposing therapeutic needs alters their phenotype towards pro-cancerogenic. It cannot be excluded that these adverse outcomes of chemotherapy may contribute to EOC relapse in the case of incomplete tumor eradication and residual disease initiation. © 2023 The Pathological Society of Great Britain and Ireland.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.

Recent Advancement in Elimination Strategies and Potential Rejuvenation Targets of Senescence

Cellular senescence is a state of exiting the cell cycle, resisting apoptosis, and changing phenotype. Senescent cells (SCs) can be identified by large, distorted morphology and irreversible inability to replicate. In early development, senescence has beneficial roles like tissue patterning and wound healing, where SCs are cleared by the immune system. However, there is a steep rise in SC number as organisms age. The issue with SC accumulation stems from the loss of cellular function, alterations of the microenvironment, and secretions of pro-inflammatory molecules, consisting of cytokines, chemokines, matrix metalloproteinases (MMPs), interleukins, and extracellular matrix (ECM)-associated molecules. This secreted cocktail is referred to as the senescence-associated secretory phenotype (SASP), a hallmark of cellular senescence. The SASP promotes inflammation and displays a bystander effect where paracrine signaling turns proliferating cells into senescent states. To alleviate age-associated diseases, researchers have developed novel methods and techniques to selectively eliminate SCs in aged individuals. Although studies demonstrated that selectively killing SCs improves age-related disorders, there are drawbacks to SC removal. Considering favorable aspects of senescence in the body, this paper reviews recent advancements in elimination strategies and potential rejuvenation targets of senescence to bring researchers in the field up to date.

Ferroptosis in the ageing retina: A malevolent fire of diabetic retinopathy

Ageing retina is prone to ferroptosis due to the iron accumulation and impaired efficiency of intracellular antioxidant defense system. Ferroptosis acts as a cell death modality that is characterized by the iron-dependent accumulation of lipid peroxidation. Ferroptosis is distinctively different from other types of regulated cell death (RCD) at the morphological, biochemical, and genetic levels. Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Its prevalence and severity increase progressively with age. Recent reports have shown that ferroptosis is implicated in the pathophysiology of DR. Under hyperglycemia condition, the endothelial cell and retinal pigment epithelium (RPE) cell will undergo ferroptosis, which contributes to the increased vascular permeability and the disrupted blood retinal barrier (BRB). The underlying etiology of DR can be attributed to the impaired BRB integrity and subsequent damages of the neurovascular units. In the absence of timely intervention, the compromised BRB can ultimately cause profound visual impairments. In particular, the ageing retina is vulnerable to ferroptosis, and hyperglycemia will accelerate the progression of this pathological process. In this article, we discuss the contributory role of ferroptosis in DR pathogenesis, and summarize recent therapeutic trials that targeting the ferroptosis. Further study on the ferroptosis mediated damage would enrich our knowledge of DR pathology, and promote the development of clinical treatment for this degenerative retinopathy.

Age-Related Alterations in Mesenchymal Stem Cell Function: Understanding Mechanisms and Seeking Opportunities to Bypass the Cellular Aging

Undoubtedly, mesenchymal stem cells (MSCs) are the most common cell therapy candidates in clinical research and therapy. They not only exert considerable therapeutic effects to alleviate inflammation and promote regeneration, but also show low-immunogenicity properties, which ensure their safety following allogeneic transplantation. Thanks to the necessity of providing a sufficient number of MSCs to achieve clinically efficient outcomes, prolonged in vitro cultivation is indisputable. However, either following long-term in vitro expansion or aging in elderly individuals, MSCs face cellular senescence. Senescent MSCs undergo an impairment in their function and therapeutic capacities and secrete degenerative factors which negatively affect young MSCs. To this end, designing novel investigations to further elucidate cellular senescence and to pave the way toward finding new strategies to reverse senescence is highly demanded. In this review, we will concisely discuss current progress on the detailed mechanisms of MSC senescence and various inflicted changes following aging in MSC. We will also shed light on the examined strategies underlying monitoring and reversing senescence in MSCs to bypass the comprised therapeutic efficacy of the senescent MSCs.

Inflammatory response in mouse lungs to haze episodes under different backgrounds of particulate matter exposure

Particulate matter (PM) toxicity has mostly been investigated through in vitro exposure or tracheal infusion in animal models. However, given the complexity of ambient conditions, most animal studies do not mimic real-life PM exposure. In this work, we established a novel integrated exposure model to study the dynamic inflammatory response and defense strategies in ambient PM-exposed mice. Three groups of male C57BL/6 mice were kept in three chambers with pre-exposure to filtered air (FA), unfiltered air (UFA), or the air with a low PM concentration (PM2.5 ≤ 75 μg/m3) (LPM), respectively, for 37 days. Then all three groups of mice were exposed to haze challenge for 3 days, followed by exposure in filtered air for 7 days to allow recovery. Our results suggest that following a haze challenge, the defense strategies of mice of filtered air (FA) and low PM (LPM) groups comprised a form of "counterattack", whereas the response of the unfiltered air (UFA) group could be viewed as a "silence". While the latter strategy protected the lung tissues of mice from acute inflammatory damage, it also foreshadowed the development of chronic inflammatory diseases. These findings contribute to explaining previously documented PM-associated pathogenic mechanisms.

Emerging role and therapeutic implications of p53 in intervertebral disc degeneration

Lower back pain (LBP) is a common degenerative musculoskeletal disease that imposes a huge economic burden on both individuals and society. With the aggravation of social aging, the incidence of LBP has increased globally. Intervertebral disc degeneration (IDD) is the primary cause of LBP. Currently, IDD treatment strategies include physiotherapy, medication, and surgery; however, none can address the root cause by ending the degeneration of intervertebral discs (IVDs). However, in recent years, targeted therapy based on specific molecules has brought hope for treating IDD. The tumor suppressor gene p53 produces a transcription factor that regulates cell metabolism and survival. Recently, p53 was shown to play an important role in maintaining IVD microenvironment homeostasis by regulating IVD cell senescence, apoptosis, and metabolism by activating downstream target genes. This study reviews research progress regarding the potential role of p53 in IDD and discusses the challenges of targeting p53 in the treatment of IDD. This review will help to elucidate the pathogenesis of IDD and provide insights for the future development of precision treatments.

Alteration in the chromatin landscape during the DNA damage response: Continuous rotation of the gear driving cellular senescence and aging

The DNA damage response (DDR) is a crucial biological mechanism for maintaining cellular homeostasis in living organisms. This complex process involves a cascade of signaling pathways that orchestrate the sensing and processing of DNA lesions. Perturbations in this process may cause DNA repair failure, genomic instability, and irreversible cell cycle arrest, known as cellular senescence, potentially culminating in tumorigenesis. Persistent DDR exerts continuous and cumulative pressure on global chromatin dynamics, resulting in altered chromatin structure and perturbed epigenetic regulations, which are highly associated with cellular senescence and aging. Sustained DDR activation and heterochromatin changes further promote senescence-associated secretory phenotype (SASP), which is responsible for aging-related diseases and cancer development. In this review, we discuss the diverse mechanisms by which DDR leads to cellular senescence and triggers SASP, together with the evidence for DDR-induced chromatin remodeling and epigenetic regulation in relation to aging.

Attenuated Replication-Competent Herpes Simplex Virus Expressing an ECM-Modifying Transgene Hyaluronan Synthase 2 of Naked Mole Rat in Oncolytic Gene Therapy

Herpes simplex virus (HSV) has proven successful in treating human cancer. Since the approval of talimogene laherparepvec (T-VEC) in 2015, HSV has been thoroughly researched to discover novel mechanisms to combat cancer and treat other diseases. Another HSV-based drug, beremagene geperpavec (B-VEC), received approval in 2023 to treat the rare genetic disease dystrophic epidermolysis bullosa, and was also the first clinically approved HSV vector carrying an extracellular matrix (ECM)-modifying transgene. The ECM is a network of macromolecules surrounding cells, which provides support and regulates cell growth and differentiation, the disruption of which is common in cancer. The naked mole rat (NMR) has a thick ECM and a unique mutation in the hyaluronan synthase 2 (HAS2) gene, which has been linked to the high cancer resistance of the species. To study the effect of this mutation in human cancer, we have developed an attenuated, replication-competent HSV vector expressing the NMR-HAS2 gene. The viral replication, transgene expression and cytotoxic effect of the novel vector was studied in glioma cells. Our results show that an attenuated, replication-competent HSV vector expressing a foreign ECM-modifying transgene, namely HAS2, provides an effective tool to study and combat cancer in humans.

Non-Genomic Hallmarks of Aging-The Review

Aging is a natural, gradual, and inevitable process associated with a series of changes at the molecular, cellular, and tissue levels that can lead to an increased risk of many diseases, including cancer. The most significant changes at the genomic level (DNA damage, telomere shortening, epigenetic changes) and non-genomic changes are referred to as hallmarks of aging. The hallmarks of aging and cancer are intertwined. Many studies have focused on genomic hallmarks, but non-genomic hallmarks are also important and may additionally cause genomic damage and increase the expression of genomic hallmarks. Understanding the non-genomic hallmarks of aging and cancer, and how they are intertwined, may lead to the development of approaches that could influence these hallmarks and thus function not only to slow aging but also to prevent cancer. In this review, we focus on non-genomic changes. We discuss cell senescence, disruption of proteostasis, deregualation of nutrient sensing, dysregulation of immune system function, intercellular communication, mitochondrial dysfunction, stem cell exhaustion and dysbiosis.

Deconvolution of immune cell composition and biological age of hepatocellular carcinoma using DNA methylation

Hepatocellular carcinoma (HCC) has been an approved indication for the administration of immunotherapy since 2017, but biomarkers that predict therapeutic response have remained limited. Understanding and characterizing the tumor immune microenvironment enables better classification of these tumors and may reveal biomarkers that predict immunotherapeutic efficacy. In this paper, we applied a cell-type deconvolution algorithm using DNA methylation array data to investigate the composition of the tumor microenvironment in HCC. Using publicly available and in-house datasets with a total cohort size of 57 patients, each with tumor and matched normal tissue samples, we identified key differences in immune cell composition. We found that NK cell abundance was significantly decreased in HCC tumors compared to adjacent normal tissue. We also applied DNA methylation "clocks" which estimate phenotypic aging and compared these findings to expression-based determinations of cellular senescence. Senescence and epigenetic aging were significantly increased in HCC tumors, and the degree of age acceleration and senescence was strongly associated with decreased NK cell abundance. In summary, we found that NK cell infiltration in the tumor microenvironment is significantly diminished, and that this loss of NK abundance is strongly associated with increased senescence and age-related phenotype. These findings point to key interactions between NK cells and the senescent tumor microenvironment and offer insights into the pathogenesis of HCC as well as potential biomarkers of therapeutic efficacy.

Coagulation Dysfunctions in Non-Alcoholic Fatty Liver Disease-Oxidative Stress and Inflammation Relevance

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Its incidence is progressively rising and it is possibly becoming a worldwide epidemic. NAFLD encompasses a spectrum of diseases accounting for the chronic accumulation of fat within the hepatocytes due to various causes, excluding excessive alcohol consumption. In this study, we aimed to focus on finding evidence regarding the implications of oxidative stress and inflammatory processes that form the multifaceted pathophysiological tableau in relation to thrombotic events that co-occur in NAFLD and associated chronic liver diseases. Recent evidence on the pathophysiology of NAFLD suggests that a complex pattern of multidirectional components, such as prooxidative, proinflammatory, and prothrombotic components, better explains the multiple factors that promote the mechanisms underlying the fatty acid excess and subsequent processes. As there is extensive evidence on the multi-component nature of NAFLD pathophysiology, further studies could address the complex interactions that underlie the development and progression of the disease. Therefore, this study aimed to describe possible pathophysiological mechanisms connecting the molecular impairments with the various clinical manifestations, focusing especially on the interactions among oxidative stress, inflammation, and coagulation dysfunctions. Thus, we described the possible bidirectional modulation among coagulation homeostasis, oxidative stress, and inflammation that occurs in the various stages of NAFLD.

Combining old and new concepts in targeting telomerase for cancer therapy: transient, immediate, complete and combinatory attack (TICCA)

Telomerase can overcome replicative senescence by elongation of telomeres but is also a specific element in most cancer cells. It is expressed more vastly than any other tumor marker. Telomerase as a tumor target inducing replicative immortality can be overcome by only one other mechanism: alternative lengthening of telomeres (ALT). This limits the probability to develop resistance to treatments. Moreover, telomerase inhibition offers some degree of specificity with a low risk of toxicity in normal cells. Nevertheless, only one telomerase antagonist reached late preclinical studies. The underlying causes, the pitfalls of telomerase-based therapies, and future chances based on recent technical advancements are summarized in this review. Based on new findings and approaches, we propose a concept how long-term survival in telomerase-based cancer therapies can be significantly improved: the TICCA (Transient Immediate Complete and Combinatory Attack) strategy.

RNA-binding proteins in cellular senescence

Cellular senescence is a state of irreversible cell cycle arrest that is triggered and controlled by various external and/or internal factors. Among them, the regulation of senescence-associated genes is an important molecular event that plays a role in senescence. The regulation of gene expression can be achieved by various types of modulating mechanisms, and RNA-binding proteins (RBPs) are commonly known as critical regulators targeting a global range of transcripts. RBPs bind to RNA-binding motifs of the target transcripts and are involved in post-transcriptional processes such as RNA transport, stabilization, splicing, and decay. These RBPs may also play critical roles in cellular senescence by regulating the expression of senescence-associated genes. The biological functions of RBPs in controlling cellular senescence are being actively studied. Herein, we summarized the RBPs that influence cellular senescence, particularly by regulating processes such as the senescence-associated secretory phenotype, cell cycle, and mitochondrial function.

Cell Survival, Death, and Proliferation in Senescent and Cancer Cells: the Role of (Poly)phenols

Cellular senescence has long been considered a permanent state of cell cycle arrest occurring in proliferating cells subject to different stressors, used as a cellular defense mechanism from acquiring potentially harmful genetic faults. However, recent studies highlight that senescent cells might also alter the local tissue environment and concur to chronic inflammation and cancer risk by secreting inflammatory and matrix remodeling factors, acquiring a senescence-associated secretory phenotype (SASP). Indeed, during aging and age-related diseases, senescent cells amass in mammalian tissues, likely contributing to the inevitable loss of tissue function as we age. Cellular senescence has thus become one potential target to tackle age-associated diseases as well as cancer development. One important aspect characterizing senescent cells is their telomere length. Telomeres shorten as a consequence of multiple cellular replications, gradually leading to permanent cell cycle arrest, known as replicative senescence. Interestingly, in the large majority of cancer cells, a senescence escape strategy is used and telomere length is maintained by telomerase, thus favoring cancer initiation and tumor survival. There is growing evidence showing how (poly)phenols can impact telomere maintenance through different molecular mechanisms depending on dose and cell phenotypes. Although normally, (poly)phenols maintain telomere length and support telomerase activity, in cancer cells this activity is negatively modulated, thus accelerating telomere attrition and promoting cancer cell death. Some (poly)phenols have also been shown to exert senolytic activity, thus suggesting both antiaging (directly eliminating senescent cells) and anticancer (indirectly, via SASP inhibition) potentials. In this review, we analyze selective (poly)phenol mechanisms in senescent and cancer cells to discriminate between in vitro and in vivo evidence and human applications considering (poly)phenol bioavailability, the influence of the gut microbiota, and their dose-response effects.

Urban aerosol particulate matter promotes mitochondrial oxidative stress-induced cellular senescence in human retinal pigment epithelial ARPE-19 cells

Environmental exposure to urban particulate matter (UPM) is a serious health concern worldwide. Although several studies have linked UPM to ocular diseases, no study has reported effects of UPM exposure on senescence in retinal cells. Therefore, this study aimed to investigate the effects of UPM on senescence and regulatory signaling in human retinal pigment epithelial ARPE-19 cells. Our study demonstrated that UPM significantly promoted senescence, with increased senescence-associated β-galactosidase activity. Moreover, both mRNA and protein levels of senescence markers (p16 and p21) and the senescence-associated secretory phenotype, including IL-1β, matrix metalloproteinase-1, and -3 were upregulated. Notably, UPM increased mitochondrial reactive oxygen species-dependent nuclear factor-kappa B (NF-κB) activation during senescence. In contrast, use of NF-κB inhibitor Bay 11-7082 reduced the level of senescence markers. Taken together, our results provide the first in vitro preliminary evidence that UPM induces senescence by promoting mitochondrial oxidative stress-mediated NF-κB activation in ARPE-19 cells.

Lipid and glucose metabolism in senescence

Senescence is an inevitable biological process. Disturbances in glucose and lipid metabolism are essential features of cellular senescence. Given the important roles of these types of metabolism, we review the evidence for how key metabolic enzymes influence senescence and how senescence-related secretory phenotypes, autophagy, apoptosis, insulin signaling pathways, and environmental factors modulate glucose and lipid homeostasis. We also discuss the metabolic alterations in abnormal senescence diseases and anti-cancer therapies that target senescence through metabolic interventions. Our work offers insights for developing pharmacological strategies to combat senescence and cancer.

Cellular senescence in asthma: from pathogenesis to therapeutic challenges

Asthma is a heterogeneous chronic respiratory disease that impacts nearly 10% of the population worldwide. While cellular senescence is a normal physiological process, the accumulation of senescent cells is considered a trigger that transforms physiology into the pathophysiology of a tissue/organ. Recent advances have suggested the significance of cellular senescence in asthma. With this review, we focus on the literature regarding the physiology and pathophysiology of cellular senescence and cellular stress responses that link the triggers of asthma to cellular senescence, including telomere shortening, DNA damage, oncogene activation, oxidative-related senescence, and senescence-associated secretory phenotype (SASP). The association of cellular senescence to asthma phenotypes, airway inflammation and remodeling, was also reviewed. Importantly, several approaches targeting cellular senescence, such as senolytics and senomorphics, have emerged as promising strategies for asthma treatment. Therefore, cellular senescence might represent a mechanism in asthma, and the senescence-related molecules and pathways could be targeted for therapeutic benefit.

Tumor Microenvironment as a Therapeutic Target in Melanoma Treatment

The role of the tumor microenvironment in tumor growth and therapy has recently attracted more attention in research and drug development. The ability of the microenvironment to trigger tumor maintenance, progression, and resistance is the main cause for treatment failure and tumor relapse. Accumulated evidence indicates that the maintenance and progression of tumor cells is determined by components of the microenvironment, which include stromal cells (endothelial cells, fibroblasts, mesenchymal stem cells, and immune cells), extracellular matrix (ECM), and soluble molecules (chemokines, cytokines, growth factors, and extracellular vesicles). As a solid tumor, melanoma is not only a tumor mass of monolithic tumor cells, but it also contains supporting stroma, ECM, and soluble molecules. Melanoma cells are continuously in interaction with the components of the microenvironment. In the present review, we focus on the role of the tumor microenvironment components in the modulation of tumor progression and treatment resistance as well as the impact of the tumor microenvironment as a therapeutic target in melanoma.

"How sad it is! I shall grow old, and horrible, and dreadful" - The ups and downs of cell senescence

This issue of the Biomedical Journal contains a special section about cell senescence. The reader gets an insight into the crosstalk between immune system and senescent cells, into an approach to fight aging by tweaking macronutrient intake, and also learns about the connection that does (not) exist between body mass and cancer risk. Further articles in the current issue give details about the effect of Damask rose on PCOS, illustrate the issues gender bias may exert in research studies, go into a joint drug approach in ischemia-reperfusion injury, and a promising tool to diagnose Parkinsonian disorders. Two articles dive into challenges related to obstructive sleep apnea, another article explores the benefits a composite mixture may have for improving bone cement material, with lastly a research team presenting a modified procedure to managing involutional lower eyelid entropion in individuals of Asian descent. Finally, BMJ issue 46-3 is complemented with a correspondence about mpox spreading from endemic areas to other parts of the world.

Palbociclib-Induced Cellular Senescence Is Modulated by the mTOR Complex 1 and Autophagy

Despite not dividing, senescent cells acquire the ability to synthesize and secrete a plethora of bioactive molecules, a feature known as the senescence-associated secretory phenotype (SASP). In addition, senescent cells often upregulate autophagy, a catalytic process that improves cell viability in stress-challenged cells. Notably, this "senescence-related autophagy" can provide free amino acids for the activation of mTORC1 and the synthesis of SASP components. However, little is known about the functional status of mTORC1 in models of senescence induced by CDK4/6 inhibitors (e.g., Palbociclib), or the effects that the inhibition of mTORC1 or the combined inhibition of mTORC1 and autophagy have on senescence and the SASP. Herein, we examined the effects of mTORC1 inhibition, with or without concomitant autophagy inhibition, on Palbociclib-driven senescent AGS and MCF-7 cells. We also assessed the pro-tumorigenic effects of conditioned media from Palbociclib-driven senescent cells with the inhibition of mTORC1, or with the combined inhibition of mTORC1 and autophagy. We found that Palbociclib-driven senescent cells display a partially reduced activity of mTORC1 accompanied by increased levels of autophagy. Interestingly, further mTORC1 inhibition exacerbated the senescent phenotype, a phenomenon that was reversed upon autophagy inhibition. Finally, the SASP varied upon inhibiting mTORC1, or upon the combined inhibition of mTORC1 and autophagy, generating diverse responses in cell proliferation, invasion, and migration of non-senescent tumorigenic cells. Overall, variations in the SASP of Palbociclib-driven senescent cells with the concomitant inhibition of mTORC1 seem to depend on autophagy.

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Molecular Mechanisms of Western Diet-Induced Obesity and Obesity-Related Carcinogenesis-A Narrative Review

The present study aims to provide a narrative review of the molecular mechanisms of Western diet-induced obesity and obesity-related carcinogenesis. A literature search of the Cochrane Library, Embase and Pubmed databases, Google Scholar and the grey literature was conducted. Most of the molecular mechanisms that induce obesity are also involved in the twelve Hallmarks of Cancer, with the fundamental process being the consumption of a highly processed, energy-dense diet and the deposition of fat in white adipose tissue and the liver. The generation of crown-like structures, with macrophages surrounding senescent or necrotic adipocytes or hepatocytes, leads to a perpetual state of chronic inflammation, oxidative stress, hyperinsulinaemia, aromatase activity, activation of oncogenic pathways and loss of normal homeostasis. Metabolic reprogramming, epithelial mesenchymal transition, HIF-1α signalling, angiogenesis and loss of normal host immune-surveillance are particularly important. Obesity-associated carcinogenesis is closely related to metabolic syndrome, hypoxia, visceral adipose tissue dysfunction, oestrogen synthesis and detrimental cytokine, adipokine and exosomal miRNA release. This is particularly important in the pathogenesis of oestrogen-sensitive cancers, including breast, endometrial, ovarian and thyroid cancer, but also 'non-hormonal' obesity-associated cancers such as cardio-oesophageal, colorectal, renal, pancreatic, gallbladder and hepatocellular adenocarcinoma. Effective weight loss interventions may improve the future incidence of overall and obesity-associated cancer.