Virus-induced senescence is a driver and therapeutic target in COVID-19

On improving public health after COVID-19 epidemic: A fractal-fractional mathematical solutions with short memory effect and efficient optimal strategies

As per the report of W.H.O. about 7 million people died in India till date due to COVID-19 infection. The transmission of COVID-19 infection can affect the temporal and geographic diversity of environmental pollution, thereby disrupting "planetary health" and livelihood. The consensus is that COVID-19 could have significant long-lasting effects on ecosystem and society. It is possible to reach an agreement to create and maintain an ecologically sound environment and a circular bio-economy to try to solve these issues. For the first time, a fractional mathematical model is formulated where the infection is considered due to unhygienic environment with a synergy between mathematical fractal parameters and biology of the disease transmission. Other mathematical analysis such as the boundedness of solutions, the wellposedness of the proposed model concerning existence results, etc. are investigated. Additionally, evaluation of vaccine-clearance equilibrium point is performed. Sensitivity parameters analysis and model's stability also steps in. To get numerical results, the "Adams-Bashforth-Moulton" method with slight modification in the kernel is used. The fractional parameters: memory effect and fractional diffusion shows a good performance of the proposed model in depicting the disease dynamics. Consequences of follow-up optimal control functions in Susceptives and Vaccinated individuals, where feasible strategies in terms of the control maps are presented.

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

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

Metabolic modeling elucidates phenformin and atpenin A5 as broad-spectrum antiviral drugs against RNA viruses

The SARS-CoV-2 pandemic has reemphasized the urgent need for broad-spectrum antiviral therapies. We developed a computational workflow using scRNA-Seq data to assess cellular metabolism during viral infection. With this workflow we predicted the capacity of cells to sustain SARS-CoV-2 virion production in patients and found a tissue-wide induction of metabolic pathways that support viral replication. Expanding our analysis to influenza A and dengue viruses, we identified metabolic targets and inhibitors for potential broad-spectrum antiviral treatment. These targets were highly enriched for known interaction partners of all analyzed viruses. Indeed, phenformin, an NADH:ubiquinone oxidoreductase inhibitor, suppressed SARS-CoV-2 and dengue virus replication. Atpenin A5, blocking succinate dehydrogenase, inhibited SARS-CoV-2, dengue virus, respiratory syncytial virus, and influenza A virus with high selectivity indices. In vivo, phenformin showed antiviral activity against SARS-CoV-2 in a Syrian hamster model. Our work establishes host metabolism as druggable for broad-spectrum antiviral strategies, providing invaluable tools for pandemic preparedness.

Vesicular Stomatitis Virus Induces NF-κB-Dependent Senescence to Mediate Persistent Inflammation and Injury

Cell senescence, induced by various internal and external stresses, plays a significant role in the development of various diseases such as cancer, neurodegeneration, and infections. Viral infections can also induce cellular senescence, known as virus-induced senescence (VIS), which occurs in close correlation with the severity of the viral infections. However, due to the unclear mechanisms underlying VIS, the effective inhibition of VIS during viral infections is challenging, leading to rapid disease progression. This study utilized the widely used vesicular stomatitis virus (VSV) model virus to simulate RNA virus infections for exploring the mechanisms by which RNA viruses induce cellular senescence. The results indicated that VSV infection, both in vitro and in vivo, could significantly induce the upregulation of senescence-associated markers and the secretion of the senescence-associated secretory phenotype (SASP), promoting the senescence process. Further research found that the activation of the NF-κB pathway played a crucial role in VSV-induced cellular senescence. Targeted inhibition of the NF-κB pathway could reduce the level of organ senescence induced by viral infections, decrease the expression of SASP inflammatory factors, and ameliorate tissue damage in mice. Overall, our findings reveal the mechanisms underlying RNA virus-associated VIS and provide potential targets for inhibiting the occurrence of VIS and preventing disease progression.

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.

Systems analysis unravels a common rural-urban gradient in immunological profile, function, and metabolic dependencies

Urbanization affects environmental exposures and lifestyle, shaping immune system variation and influencing disease susceptibility and vaccine responses. Here, we present systems analysis of immune profiles across the rural-urban gradient, comparing rural and urban Senegalese with urban Dutch individuals. By integrating single-cell phenotyping, metabolic profiling, and functional analysis, we reveal a trajectory of immune remodeling along the gradient. This includes enrichment of proinflammatory CD11c+ B cells associated with altered IgG Fc glycosylation, adaptive NK cells with reduced responsiveness to accessory cytokines, and CD161+CD4+T cells with enhanced cytokine production in rural settings. Metabolic perturbation studies demonstrated distinct dependencies on glycolysis, pentose phosphate pathway, and fatty acid synthesis for cellular cytokine responses across populations. We validate core rural-urban immune signatures in an independent Indonesian cohort, suggesting shared immunological adaptations to urbanization across ancestries and geographical areas. Our findings provide insights into rural-urban immune function in understudied populations.

Acute Macular Neuroretinopathy Mediated by COVID-19 Infection: Insights into its Clinical Features and Pathogenesis

Acute macular neuroretinopathy (AMN) is a rare retinal condition that predominantly affects young females. The incidence of AMN increased significantly during the COVID-19 pandemic, thereby providing a unique opportunity to elucidate the etiology of this disease. In the present study, 24 articles reporting 59 patients were reviewed. The average age of the patients was 33.51 ± 14.02 years, ranging from 16 to 75 years, with females comprising 71.19% of the cases. The average duration of ocular symptoms post-infection was 8.22 ± 10.69 days, ranging from 4 to 150 days. This study investigated the potential pathogenesis of AMN, including the impact of COVID-19 on retinal neurovascular structure and function, immune-mediated inflammatory factor production, blood-retinal barrier disruption, and retinal microvascular damage, as well as potential clinical therapeutic interventions. This research provides a theoretical framework that can inform further investigations of AMN.

HIV-Tat upregulates the expression of senescence biomarkers in CD4+ T-cells

Introduction

Current antiretroviral therapy (ART) for HIV infection reduces plasma viral loads to undetectable levels and has increased the life expectancy of people with HIV (PWH). However, this increased lifespan is accompanied by signs of accelerated aging and a higher prevalence of age-related comorbidities. Tat (Trans-Activator of Transcription) is a key protein for viral replication and pathogenesis. Tat is encoded by 2 exons, with the full-length Tat ranging from 86 to 101 aa (Tat101). Introducing a stop codon in position 73 generates a 1 exon, synthetic 72aa Tat (Tat72). Intracellular, full-length Tat activates the NF-κB pro-inflammatory pathway and increases antiapoptotic signals and ROS generation. These effects may initiate a cellular senescence program, characterized by cell cycle arrest, altered cell metabolism, and increased senescence-associated secretory phenotype (SASP) mediator release However, the precise role of HIV-Tat in inducing a cellular senescence program in CD4+ T-cells is currently unknown.

Methods

Jurkat Tetoff cell lines stably transfected with Tat72, Tat101, or an empty vector were used. Flow cytometry and RT-qPCR were used to address senescence biomarkers, and 105 mediators were assessed in cell supernatants with an antibody-based membrane array. Key results obtained in Jurkat-Tat cells were addressed in primary, resting CD4+ T-cells by transient electroporation of HIV-Tat-FLAG plasmid DNA.

Results

In the Jurkat cell model, expression of Tat101 increased the levels of the senescence biomarkers BCL-2, CD87, and p21, and increased the release of sCD30, PDGF-AA, and sCD31, among other factors. Tat101 upregulated CD30 and CD31 co-expression in the Jurkat cell surface, distinguishing these cells from Tat72 and Tetoff Jurkats. The percentage of p21+, p16+, and γ-H2AX+ cells were higher in Tat-expressing CD4+ T-cells, detected as a FLAG+ population compared to their FLAG- (Tat negative) counterparts. Increased levels of sCD31 and sCD26 were also detected in electroporated CD4+ T-cell supernatants.

Discussion

Intracellular, full-length HIV-Tat expression increases several senescence biomarkers in Jurkat and CD4+ T-cells, and SASP/Aging mediators in cell supernatants. Intracellular HIV-Tat may initiate a cellular senescence program, contributing to the premature aging phenotype observed in PWH.

Persistent immune dysregulation and metabolic alterations following SARS-CoV-2 infection

SARS-CoV-2 can cause a variety of post-acute sequelae including Long COVID19 (LC), a complex, multisystem disease characterized by a broad range of symptoms including fatigue, cognitive impairment, and post-exertional malaise. The pathogenesis of LC is incompletely understood. In this study, we performed comprehensive cellular and transcriptional immunometabolic profiling within a cohort that included SARS-CoV-2-naïve controls (NC, N=30) and individuals with prior COVID-19 (~4-months) who fully recovered (RC, N=38) or went on to experience Long COVID symptoms (N=58). Compared to the naïve controls, those with prior COVID-19 demonstrated profound metabolic and immune alterations at the proteomic, cellular, and epigenetic level. Specifically, there was an enrichment in immature monocytes with sustained inflammasome activation and oxidative stress, elevated arachidonic acid levels, decreased tryptophan, and variation in the frequency and phenotype of peripheral T-cells. Those with LC had increased CD8 T-cell senescence and a distinct transcriptional profile within CD4 and CD8 T-cells and monocytes by single cell RNA sequencing. Our findings support a profound and persistent immunometabolic dysfunction that follows SARS-CoV-2 which may form the pathophysiologic substrate for LC. Our findings suggest that trials of therapeutics that help restore immune and metabolic homeostasis may be warranted to prevent, reduce, or resolve LC symptoms.

Nuclear AGO2 supports influenza A virus replication through type-I interferon regulation

The role of Argonaute (AGO) proteins and the RNA interference (RNAi) machinery in mammalian antiviral response has been debated. Therefore, we set out to investigate how mammalian RNAi impacts influenza A virus (IAV) infection. We reveal that IAV infection triggers nuclear accumulation of AGO2, which is directly facilitated by p53 activation. Mechanistically, we show that IAV induces nuclear AGO2 targeting of TRIM71and type-I interferon-pathway genes for silencing. Accordingly, Tp53-/- mice do not accumulate nuclear AGO2 and demonstrate decreased susceptibility to IAV infection. Hence, the RNAi machinery is highjacked by the virus to evade the immune system and support viral replication. Furthermore, the FDA-approved drug, arsenic trioxide, prevents p53 nuclear translocation, increases interferon response and decreases viral replication in vitro and in a mouse model in vivo. Our data indicate that targeting the AGO2:p53-mediated silencing of innate immunity may offer a promising strategy to mitigate viral infections.

Sendotypes predict worsening renal function in chronic kidney disease patients

BACKGROUND

Senescence associated secretory phenotype (SASP) contributes to age-related pathology, however the role of SASP in Chronic Kidney Disease (CKD) is unclear. Here, we employ a variety of omic techniques to show that senescence signatures can separate CKD patients into distinct senescence endotypes (Sendotype).

METHODS

Using specific numbers of senescent proteins, we clustered CKD patients into two distinct sendotypes based on proteomic expression. These clusters were evaluated with three independent criteria assessing inter and intra cluster distances. Differential expression analysis was then performed to investigate differing proteomic expression between sendotypes.

RESULTS

These clusters accurately stratified CKD patients, with patients in each sendotype having different clinical profiles. Higher expression of these proteins correlated with worsened disease symptomologies. Biological signalling pathways such as TNF, Janus kinase-signal transducers and activators of transcription (JAK-STAT) and NFKB were differentially enriched between patient sendotypes, suggesting potential mechanisms driving the endotype of CKD.

CONCLUSION

Our work reveals that, combining clinical features with SASP signatures from CKD patients may help predict whether a patient will have worsening or stable renal trajectory. This has implications for the CKD clinical care pathway and will help clinicians stratify CKD patients accurately.

KEY POINTS

Senescent proteins are upregulated in severe patients compared to mild patients Senescent proteins can stratify patients based on disease severity High expression of senescent proteins correlates with worsening renal trajectories.

Contemporary assessment of short- and functional 90-days outcome in old intensive care patients suffering from COVID-19

PURPOSE

There are limited data about the outcome of old intensive care (ICU) patients suffering from Covid-19 in the post-vaccination era. This study distinguishes the pre- and post-acute illness living conditions of ICU survivors from non-survivors.

METHODS

This prospective international multicenter study included 642 old (≥ 70 years) ICU patients, including data ranging from pre-illness condition to functional 90-days follow-up. The primary endpoint was the difference of living conditions of ICU-survivors before ICU admission and 90-days after ICU discharge. Secondary outcomes were 90-days mortality, and quality of life.

RESULTS

A total of 642 patients were included. Significantly more ICU survivors lived at their own homes without support before ICU admission than non-survivors (p = 0.016), while more non-survivors resided in nursing homes (p = 0.016). ICU mortality was 39 %, 30-days and 90 days mortality were 47 %and 55 %. After 90 days, only 22 % maintained the same living conditions. Surviving patients viewed ICU admission positively after 90 days, while relatives were more uncertain. Quality of life indicated a self-reported average score of 60 (50-75).

CONCLUSION

Living conditions influence the outcome of critically ill old patients suffering from Covid-19. Only a minority returned to their initial habitat after ICU survival. Trial registration numberNCT04321265.

Enhancing immunity during ageing by targeting interactions within the tissue environment

Immunity declines with age. This results in a higher risk of age-related diseases, diminished ability to respond to new infections and reduced response to vaccines. The causes of this immune dysfunction are cellular senescence, which occurs in both lymphoid and non-lymphoid tissue, and chronic, low-grade inflammation known as 'inflammageing'. In this Review article, we highlight how the processes of inflammation and senescence drive each other, leading to loss of immune function. To break this cycle, therapies are needed that target the interactions between the altered tissue environment and the immune system instead of targeting each component alone. We discuss the relative merits and drawbacks of therapies that are directed at eliminating senescent cells (senolytics) and those that inhibit inflammation (senomorphics) in the context of tissue niches. Furthermore, we discuss therapeutic strategies designed to directly boost immune cell function and improve immune surveillance in tissues.

Senescence-associated lineage-aberrant plasticity evokes T-cell-mediated tumor control

Cellular senescence is a stress-inducible state switch relevant in aging, tumorigenesis and cancer therapy. Beyond a lasting arrest, senescent cells are characterized by profound chromatin remodeling and transcriptional reprogramming. We show here myeloid-skewed aberrant lineage plasticity and its immunological ramifications in therapy-induced senescence (TIS) of primary human and murine B-cell lymphoma. We find myeloid transcription factor (TF) networks, specifically AP-1-, C/EBPβ- and PU.1-governed transcriptional programs, enriched in TIS but not in equally chemotherapy-exposed senescence-incapable cancer cells. Dependent on these master TF, TIS lymphoma cells adopt a lineage-promiscuous state with properties of monocytic-dendritic cell (DC) differentiation. TIS lymphoma cells are preferentially lysed by T-cells in vitro, and mice harboring DC-skewed Eμ-myc lymphoma experience significantly longer tumor-free survival. Consistently, superior long-term outcome is also achieved in diffuse large B-cell lymphoma patients with high expression of a TIS-related DC signature. In essence, these data demonstrate a therapeutically exploitable, prognostically favorable immunogenic role of senescence-dependent aberrant myeloid plasticity in B-cell lymphoma.

Aging shapes infection profiles of influenza A virus and SARS-CoV-2 in human precision-cut lung slices

BACKGROUND

The coronavirus disease 2019 (COVID-19) outbreak revealed the susceptibility of elderly patients to respiratory virus infections, showing cell senescence or subclinical persistent inflammatory profiles and favoring the development of severe pneumonia.

METHODS

In our study, we evaluated the potential influence of lung aging on the efficiency of replication of influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as well as determining the pro-inflammatory and antiviral responses of the distal lung tissue.

RESULTS

Using precision-cut lung slices (PCLS) from donors of different ages, we found that pandemic H1N1 and avian H5N1 IAV replicated in the lung parenchyma with high efficacy. In contrast to these IAV strains, SARS-CoV-2 Early isolate and Delta variant of concern (VOC) replicated less efficiently in PCLS. Interestingly, both viruses showed reduced replication in PCLS from older compared to younger donors, suggesting that aged lung tissue represents a suboptimal environment for viral replication. Regardless of the age-dependent viral loads, PCLS responded to H5N1 IAV infection by an induction of IL-6 and IP10/CXCL10, both at the mRNA and protein levels, and to H1N1 IAV infection by induction of IP10/CXCL10 mRNA. Finally, while SARS-CoV-2 and H1N1 IAV infection were not causing detectable cell death, H5N1 IAV infection led to more cytotoxicity and induced significant early interferon responses.

CONCLUSIONS

In summary, our findings suggest that aged lung tissue might not favor viral dissemination, pointing to a determinant role of dysregulated immune mechanisms in the development of severe disease.

Immunosenescence promotes cancer development: from mechanisms to treatment strategies

The body's innate immune system plays a pivotal role in identifying and eliminating cancer cells. However, as the immune system ages, its functionality can deteriorate, becoming dysfunctional, inefficient, or even inactive-a condition referred to as immunosenescence. This decline significantly increases the risk of malignancies. While the pro-cancer effects of T-cell aging have been widely explored, there remains a notable gap in the literature regarding the impact of aging on innate immune cells, such as macrophages and neutrophils. This review seeks to address this gap, with emphasis on these cell types. Furthermore, although certain cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have demonstrated efficacy across a broad spectrum of cancers, elderly patients are less likely to derive clinical benefit from these treatments. In some cases, they may even experience immune-related adverse events (irAEs). While senolytic strategies have shown promise in exerting anti-cancer effects, their adverse reactions and potential off-target effects present significant challenges. This review aims to elucidate the pro-cancer effects of immunosenescence, its implications for the efficacy and safety of ICIs, and potential anti-aging treatment strategies. In addition, optimizing anti-aging therapies to minimize adverse reactions and enhance therapeutic outcomes remains a critical focus for future research endeavors.

Targeting senescent cells for the treatment of age-associated diseases

Cellular senescence, which entails cellular dysfunction and inflammatory factor release-the senescence-associated secretory phenotype (SASP)-is a key contributor to multiple disorders, diseases and the geriatric syndromes. Targeting senescent cells using senolytics has emerged as a promising therapeutic strategy for these conditions. Among senolytics, the combination of dasatinib and quercetin (D + Q) was the earliest and one of the most successful so far. D + Q delays, prevents, alleviates or treats multiple senescence-associated diseases and disorders with improvements in healthspan across various pre-clinical models. While early senolytic therapies have demonstrated promise, ongoing research is crucial to refine them and address such challenges as off-target effects. Recent advances in senolytics include new drugs and therapies that target senescent cells more effectively. The identification of senescence-associated antigens-cell surface molecules on senescent cells-pointed to another promising means for developing novel therapies and identifying biomarkers of senescent cell abundance.

A comparison of the effect of three different comorbidity indices on overall survival in patients with chronic myeloid leukemia

Aims

It was aimed at measuring the comorbidities of chronic myeloid leukemia (CML) patients at the time of diagnosis with different comorbidity indices and evaluating their effects on disease prognosis.

Methods

The comorbidities of the patients were retrospectively screened and calculated in three different comorbidity indices: the ACE-27 Comorbidity Index, the Age-adjusted Charlson Comorbidity Index, and the Elixhauser Comorbidity Index. C-statistic was used to evaluate the ability of comorbidity indices to discriminate mortality. The relationship between the calculated scores and overall survival (OS) was evaluated with the Kaplan-Meier curve. Mortality risk was analyzed with a multivariate Cox regression model.

Results

A total of 218 CML patients were evaluated, and 211 chronic-phase patients were included in this study. The median age of the patients was 56 years (21-89), and 53% were female. As initial tyrosine kinase inhibitors, 201 (95%) patients were treated with imatinib, 10 (5%) patients with nilotinib. The median follow-up was 94.50 (9-201) months. The median OS was not reached. The most common comorbid conditions were hypertension 23% (n = 48), weight loss 19% (n = 40), diabetes mellitus 13% (n = 27), and cardiovascular disease 9% (n = 19). C-statistic values were 0.76 for ACE-27, 0.41 for ACCI, and 0.32 for ECI scores. In the Cox regression model including comorbidity scores, mortality risk was higher in patients with moderate ACE-27 score (HR: 148.05; 95% CI: 7.89-2751.53; p = 0.012), severe ACE-27 score (HR: 232.36; 95% CI: 14.20-4793.20; p = 0.001), ECOG 3 score (HR: 34.62; 95% CI: 2.67-447.36; p = 0.007), and high ELTS score (HR: 27.52; 95% CI: 1.34-543.68; p = 0.031).

Conclusion

This study showed that the ACE-27 Comorbidity Index is effective in predicting prognosis in CML patients. Therefore, comorbid conditions should be used more frequently as a prognostic marker at the time of diagnosis.

Unveiling the cell-type-specific landscape of cellular senescence through single-cell transcriptomics using SenePy

Senescent cells accumulate in most tissues with organismal aging, exposure to stressors, or disease progression. It is challenging to identify senescent cells because cellular senescence signatures and phenotypes vary widely across distinct cell types and tissues. Here we developed an analytical algorithm that defines cell-type-specific and universal signatures of cellular senescence across a wide range of cell types and tissues. We utilize 72 mouse and 64 human weighted single-cell transcriptomic signatures of cellular senescence to create the SenePy scoring platform. SenePy signatures better recapitulate in vivo cellular senescence than signatures derived from in vitro senescence studies. We use SenePy to map the kinetics of senescent cell accumulation in healthy aging as well as multiple disease contexts, including tumorigenesis, inflammation, and myocardial infarction. SenePy characterizes cell-type-specific in vivo cellular senescence and could lead to the identification of genes that serve as mediators of cellular senescence and disease progression.

A galactose-tethered tetraphenylethene prodrug mediated apoptosis of senescent cells for osteoporosis treatment

Osteoporosis and bone injury healing in elderly patients are major medical challenges, often exacerbated by the accumulation of senescent cells. Herein, we show that TPE-Gal, which contains a tetraphenylethene unit and a galactose moiety, offers a promising molecular therapy designed to light up and eliminate senescent cells through a hydrolysis reaction catalyzed by β-galactosidase, an enzyme overexpressed in senescent cells. The reaction produces TPE-OH, which, in turn, increases reactive oxygen species levels within the senescent cells, leading to noninflammatory apoptosis of senescent cells. This targeted clearance mechanism helps to alleviate osteoporosis symptoms and promotes bone injury healing. Moreover, apoptotic vesicles, which are generated during the process, are partly phagocytosed by macrophages, mimicking physiological metabolic processes. This study opens new avenues for addressing bone health issues through the designed bioclearance of senescent cells, aligning with the body's natural pathways for maintaining homeostasis.

Global organelle profiling reveals subcellular localization and remodeling at proteome scale

Defining the subcellular distribution of all human proteins and their remodeling across cellular states remains a central goal in cell biology. Here, we present a high-resolution strategy to map subcellular organization using organelle immunocapture coupled to mass spectrometry. We apply this workflow to a cell-wide collection of membranous and membraneless compartments. A graph-based analysis assigns the subcellular localization of over 7,600 proteins, defines spatial networks, and uncovers interconnections between cellular compartments. Our approach can be deployed to comprehensively profile proteome remodeling during cellular perturbation. By characterizing the cellular landscape following HCoV-OC43 viral infection, we discover that many proteins are regulated by changes in their spatial distribution rather than by changes in abundance. Our results establish that proteome-wide analysis of subcellular remodeling provides key insights for elucidating cellular responses, uncovering an essential role for ferroptosis in OC43 infection. Our dataset can be explored at organelles.czbiohub.org.

The transcription factor CitPH4 regulates plant defense-related metabolite biosynthesis in citrus

Wild citrus (Citrus L.) exhibits high disease resistance accompanied by high-acidity fruit, whereas cultivated citrus produces tastier fruit but is more susceptible to disease. This is a common phenomenon, but the underlying molecular mechanisms remain unknown. Citrus PH4 (CitPH4) is a key transcription factor promoting citric acid accumulation in fruits. Accordingly, CitPH4 expression decreased during citrus domestication, along with a reduction in citric acid levels. Here, we demonstrate that a CitPH4-knockout mutant exhibits an acidless phenotype and displays substantially lower resistance to citrus diseases. Metabolome and transcriptome analyses of CitPH4-overexpressing citrus callus, Arabidopsis, and CitPH4-knockout citrus fruits revealed that quercetin, pipecolic acid (Pip), and N-hydroxypipecolic acid (NHP) are pivotal defense-related metabolites. Application of quercetin and Pip inhibited the growth of Xcc and Penicillium italicum, while NHP inhibited the growth of P. italicum and Huanglongbing. Biochemical experiments demonstrated that CitPH4 enhances the expression of quercetin and NHP biosynthesis genes by binding to their promoters. Moreover, Pip and quercetin contents were positively associated with citric acid content in the pulp of fruits from natural citrus populations. Finally, the heterologous expression of CitPH4 in Arabidopsis promoted the expression of stress response genes and enhanced its resistance to the fungal pathogen Botrytis cinerea. The overexpression of CitPH4 in tobacco (Nicotiana tabacum) enhanced disease resistance. This study reveals the mechanism by which CitPH4 regulates disease resistance and fruit acidity, providing a conceptual strategy to control fruit acidity and resistance to devastating diseases.

Reduced functional independence and multimorbidity increases the risk of severe infection among older patients with Omicron: a multicenter retrospective cohort study

BACKGROUND

Multimorbidity and physical function in older adults have been identified as associated with coronavirus disease 2019 (COVID-19) outcomes. This study aimed to investigate whether multimorbidity affects the association of impaired functional independence (FI) with critical COVID-19 among older inpatients during the peak of Omicron infection in China.

METHODS

This is a multicentre, retrospective cohort study in northeastern China. Patients aged ≥ 60 years, who were diagnosed with COVID-19 at the time of admission or during hospitalisation. The Barthel index was used to assess FI. Patients were classified into independent, mildly dependent, moderately dependent, and severely dependent groups. Disease severity was classified as critical, severe, and non-severe and combined into severe or critical and non-severe. Binary logistic regression analysis was used to investigate any correlation between FI and disease severity. Patients were further stratified by presence or absence of multimorbidity.

FINDINGS

In this study, of 1598 patients, 530 (33.17%) developed severe or critical infections during the entire hospital stay. Patients with severe dependency had 7.39 times (95% CI: [4.60, 12.15]) higher risk of serious or critical infections than those without dependency. An interaction was noted between reduced FI and multimorbidity (p for interaction < 0.001). Compared to non-multimorbid patients (OR = 3.71, 95% CI: [1.58, 9.16]), multimorbid patients (OR = 10.04, 95% CI: [5.63, 18.57]) had a more pronounced risk of severe or critical infection.

CONCLUSIONS

Our results provide further scientific evidence on the association between FI, multimorbidity, and disease severity in older COVID-19 patients, contributing to future health decision-making for COVID-19 and other infectious diseases.

Senolytic Treatment Alleviates Corneal Allograft Rejection Through Upregulation of Angiotensin-Converting Enzyme 2 (ACE2)

Purpose

Allograft rejection remains a major cause of failure in high-risk corneal transplants, but the underlying mechanisms are not fully understood. This study aimed to investigate the contribution of transplantation stress-induced cellular senescence to corneal allograft rejection and to elucidate the associated molecular mechanisms.

Methods

Age-matched murine corneal transplantation models were established. Cellular senescence was evaluated using senescence-associated β-galactosidase (SA-β-Gal) staining, western blot, and immunofluorescence staining. The role of cellular senescence in corneal allograft rejection was analyzed using p16 knockout mice and adoptive transfer experiments. Senolytic treatment with ABT-263 was administered intraperitoneally to evaluate its effects on corneal allograft rejection. RNA sequencing and pharmacological approaches were employed to identify the underlying mechanisms.

Results

Surgical injury induced a senescence-like phenotype in both donor corneas and recipient corneal beds, characterized by an increased accumulation of SA-β-Gal-positive cells in the corneal endothelium and stroma and elevated expression of senescence markers p16 and p21. Using genetic and adoptive transfer models, transplantation stress-induced senescence was shown to exacerbate corneal allograft rejection. Importantly, clearance of senescent cells by ABT-263 significantly suppressed ocular alloresponses and immune rejection. Mechanistically, RNA sequencing and loss-of-function experiments demonstrated that the anti-rejection effects of senolytic treatment were closely dependent on angiotensin-converting enzyme 2 (ACE2).

Conclusions

These findings highlight transplantation stress-induced senescence as a pivotal pathogenic factor in corneal allograft rejection. Senolytic therapy emerges as a potential novel strategy to mitigate transplant rejection and improve corneal allograft survival.

Therapeutic potential of nicotinamide and ABT263 in alcohol-associated liver disease through targeting cellular senescence

Alcohol-associated liver disease (ALD) is a major cause of liver-related morbidity and mortality, yet clinically effective therapies for ALD remain lacking. Here, we demonstrate that alcohol intake and its metabolite, acetaldehyde (ACH), induce senescence in the liver and liver cells, respectively. To assess the therapeutic potential of targeting liver senescence in ALD, we treated ALD-affected mice with the senolytic compound ABT263 and the senomorphic NAD+ precursor, nicotinamide (NAM). The results show that ABT263 effectively clears senescent hepatocytes and stellate cells, and reduces liver triglyceride (TG), but increases plasma alanine aminotransferase and TG levels. Conversely, NAM efficiently suppresses senescence and the senescence-associated secretory phenotype (SASP), protecting the liver from alcohol-induced injury in ALD mice. RNA-sequencing analysis revealed that ABT263 treatment downregulated genes involved in adipogenesis while activating the complement pathway. In contrast, NAM upregulated metabolism-related genes, such as Sirt1, and downregulated DNA damage marker genes, including Rec8 and E2f1, in the liver. These findings suggest that cellular senescence plays a critical role in alcohol-induced liver injury. Compared with senescent cell clearance by ABT263, suppressing senescence and SASP by NAM may provide a safer and more effective therapeutic approach for ALD.

[Mechanism and significance of cell senescence induced by viral infection]

Virus-induced senescence (VIS) is a significant biological phenomenon, which is associated with declining immune function, accelerating aging process and causing aging-related diseases. A variety of common viruses, including RNA viruses (such as SARS-CoV-2), DNA viruses (such as herpesviruses and hepatitis B virus), and prions can cause VIS in host cells. The primary mechanisms include abnormal activation of the cGAS-STING signaling pathway, DNA damage response, and potential correlations with the integrated stress response due to intracellular phase separation. Viral infection and cellular senescence influence each other: cellular senescence serves as a defense to restrict viral replication and transmission, while some viruses exploit cellular senescence to enhance their infectivity and replication. Understanding the mechanisms of VIS is conducive to the development of therapeutic strategies for viral infections and promotion of healthy aging. However, there is lack of research on therapeutic targets and drug development in this field so far. Although senolytics may be effective for anti-senescent cells therapy, their efficacy for VIS needs evidence from further clinical trials. This article reviews the research progress on the connection between viral infection and cellular senescence, to provide insights for the prevention and treatment of aging related diseases.

[Advances in inflammaging in liver disease]

Inflammaging is a process of cellular dysfunction associated with chronic inflammation, which plays a significant role in the onset and progression of liver diseases. Research on its mechanisms has become a hotspot. In viral hepatitis, inflammaging primarily involve oxidative stress, cell apoptosis and necrosis, as well as gut microbiota dysbiosis. In non-alcoholic fatty liver disease, inflammaging is more complex, involving insulin resistance, fat deposition, lipid metabolism disorders, gut microbiota dysbiosis, and abnormalities in NAD+ metabolism. In liver tumors, inflammaging is characterized by weakening of tumor suppressive mechanisms, remodeling of the liver microenvironment, metabolic reprogramming, and enhanced immune evasion. Therapeutic strategies targeting inflammaging have been developing recently, and antioxidant therapy, metabolic disorder improvement, and immunotherapy are emerging as important interventions for liver diseases. This review focuses on the mechanisms of inflammaging in liver diseases, aiming to provide novel insights for the prevention and treatment of liver diseases.

Resolution of oncogene-induced senescence markers in HPV-infected cervical cancer tissue

BACKGROUND

Oncogene-Induced Senescence (OIS) is a form of senescence that occurs as a consequence of oncogenic overstimulation and possibly infection by oncogenic viruses. Whether senescence plays a role in the pathogenesis of cervical cancer (CC) is not well understood. Moreover, whether cervical epithelial cells that are part of the premalignant cervical intraepithelial neoplasia (CIN), exhibit markers of OIS in Human Papillomavirus (HPV)-infected tissue, has not been investigated.

METHODS

We utilized a set of patient-derived premalignant and malignant tissue samples to investigate the protein (Ki67 and Lamin B1) and gene (TP53, IL1A, CCL2, and MMP9) expression of several OIS-associated biomarkers using immunohistochemistry (IHC) and qRT-PCR, respectively. Furthermore, we characterized the HPV status of all tissue samples.

RESULTS

Most of the CC samples (34/37) were positive for HPV, mainly HPV-16 which was observed in 62.2% of the CC samples. Among CINs, HPV infection was found in 60.2% of the 32 samples with HPV-16 as the dominant genotype in 58.5% of the CINs. IHC analysis revealed a significant increase in the expression levels of both Ki67 and Lamin B1 proteins in CC tissue compared to CIN. On average, 93% of tumor cells were positive for Ki67 in comparison to only 25% of premalignant cells in CIN samples. Similarly, Lamin B1 expression was observed in 89% of tumor cells in malignant tissue on average, compared to 60% in CIN samples. Importantly, Lamin B1 expression was elevated in nonmalignant cervical tissue suggesting that its downregulation is more predominant in the premalignant state. Furthermore, RT-PCR revealed a significant decrease in the expression of TP53, IL1a, CCL2, and MMP9 markers in CC samples compared to CINs. Specifically, 84% of CC samples showed reduced TP53 expression, 90% showed reduced IL1a expression, 74% showed reduced CCL2 expression, and 76% showed reduced MMP9 expression when compared with their premalignant baseline. Infection of HPV was confirmed in 61% of the tumor tissues while only 25% of the CINs were positive for HPV.

CONCLUSION

This work shall provide an opportunity to further examine the role of OIS in the process of HPV-driven CC development.

COVID-19 beyond the lungs: Unraveling its vascular impact and cardiovascular complications-mechanisms and therapeutic implications

COVID-19, caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), is primarily a respiratory illness but significantly affects the cardiovascular system as well. After entering the body through the respiratory tract, the virus directly and indirectly disrupts the vascular system. Vascular endothelial cells (ECs), which express ACE2 and TMPRSS2, are targets for viral invasion. However, the predominant cause of widespread vascular damage is the "cytokine storm" induced by the immune response. This leads to EC activation, inflammation, neutrophil activation, and neutrophil-platelet aggregation, causing endothelial injury. Additionally, increased expression of plasminogen activator inhibitor-1 disrupts the balance between prothrombotic and fibrinolytic processes, while activation of the renin-angiotensin-aldosterone system adds oxidative stress to the vascular endothelium. In the heart, SARS-CoV-2 invades ECs, leading to apoptosis and pyroptosis, exacerbated by inflammation and elevated catecholamines. These factors contribute to arrhythmias, strokes, and myocardial infarction in severe cases of COVID-19. This narrative review aims to explore the mechanisms by which SARS-CoV-2 affects the cardiovascular system and to highlight the resulting complications. It also identifies research gaps and discusses potential therapeutic strategies to mitigate the cardiovascular impacts of COVID-19.

Senescence as a therapeutic target in cancer and age-related diseases

Cellular senescence is a stress response that restrains the growth of aged, damaged or abnormal cells. Thus, senescence has a crucial role in development, tissue maintenance and cancer prevention. However, lingering senescent cells fuel chronic inflammation through the acquisition of a senescence-associated secretory phenotype (SASP), which contributes to cancer and age-related tissue dysfunction. Recent progress in understanding senescence has spurred interest in the development of approaches to target senescent cells, known as senotherapies. In this Review, we evaluate the status of various types of senotherapies, including senolytics that eliminate senescent cells, senomorphics that suppress the SASP, interventions that mitigate senescence and strategies that harness the immune system to clear senescent cells. We also summarize how these approaches can be combined with cancer therapies, and we discuss the challenges and opportunities in moving senotherapies into clinical practice. Such therapies have the potential to address root causes of age-related diseases and thus open new avenues for preventive therapies and treating multimorbidities.

The DNA Damage Response as an Auxiliary Indicator of Senescence in Cancer: A User-Friendly Toolkit of Markers and Detection Methods

Senescence is a cellular stress response causing a stable exit from the cell cycle. Limitation of cell proliferation is accompanied by a variety of characteristic changes, including cellular and nuclear morphological alterations, chromatin rearrangements, metabolic reprogramming, nuclear envelope rupture, and an immunomodulatory secretome, termed senescence-associated secreted phenotype (SASP). Senescence is a robust mechanism of tissue homeostasis, with crucial roles in eliminating dysfunctional and/or premalignant cells, and tissue repair. Activation of oncogenes triggers senescence, which in turn arrests DNA-damaged cells. This type of response, known as oncogene-induced senescence (OIS) is a powerful barrier to oncogenesis. However, in specific contexts, senescent cells support tumor progression, mainly via their secretome-mediated activities. The dynamic, context-dependent and ambivalent nature of senescence challenges the identification, characterization, and specific targeting of senescent cells for disease management. Importantly, senescence is highly intertwined with DNA damage response and repair (DDR/R) machinery that safeguards genome integrity. DNA damage events are frequently prevalent, while DDR/R signaling pathways are active during cellular senescence. In this regard, it can serve as an auxiliary indicator for senescent cells. In this chapter, we emphasize DDR/R as a shared hallmark of cancer and senescence. We provide a wieldy toolkit of experimental methods for monitoring DDR-related senescence markers, and we demonstrate the potential of using natural language processing to extract additional DDR/R biomarkers tailored to specific cancer types. Our methodologies can facilitate a comprehensive study of senescence in aging and cancer.

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

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

Lipid remodeling in context of cellular senescence

Cellular senescence is a response that irreversibly arrests stressed cells thus providing a potent tumor suppressor mechanism. In parallel, senescent cells exhibit an immunogenic secretome called SASP (senescence-associated secretory phenotype) that impairs tissue homeostasis and is involved in numerous age-related diseases. Senescence establishment is achieved through the unfolding of a profound transcriptional reprogramming together with morphological changes. These alterations are accompanied by important metabolic adaptations characterized by biosynthetic pathways reshuffling and lipid remodeling. In this mini-review we highlight the intricate links between lipid metabolism and the senescence program and we discuss the potential interventions on lipid pathways that can alleviate the senescence burden.

Post-acute sequelae of SARS-CoV-2 infection (Long COVID) in older adults

Long COVID, also known as PASC (post-acute sequelae of SARS-CoV-2), is a complex infection-associated chronic condition affecting tens of millions of people worldwide. Many aspects of this condition are incompletely understood. Among them is how this condition may manifest itself in older adults and how it might impact the older population. Here, we briefly review the current understanding of PASC in the adult population and examine what is known on its features with aging. Finally, we outline the major gaps and areas for research most germane to older adults.

Rapid progression of CD8 and CD4 T cells to cellular exhaustion and senescence during SARS-CoV2 infection

Risk factors for the development of severe COVID-19 include several comorbidities, but age was the most striking one since elderly people were disproportionately affected by SARS-CoV-2 infection. Among the reasons for this markedly unfavorable response in the elderly, immunosenescence and inflammaging appear as major drivers of this outcome. A finding that was also notable was that hospitalized patients with severe COVID-19 have an accumulation of senescent T cells, suggesting that immunosenescence may be aggravated by SARS-CoV-2 infection. The present work was designed to examine whether these immunosenescence changes are characteristic of COVID-19 and whether it is dependent on disease severity using cross-sectional and longitudinal studies. Our cross-sectional data show that COVID-19, but not other respiratory infections, rapidly increased cellular senescence and exhaustion in CD4 and CD8 T cells during early infection. In addition, longitudinal analyses with patients from Brazil and Portugal provided evidence of increased frequencies of senescent and exhausted T cells over a 7-d period in patients with mild/moderate and severe COVID-19. Altogether, the study suggests that accelerated immunosenescence in CD4 and especially CD8 T-cell compartments may represent a common and unique outcome of SARS-CoV2 infection.

Maternal infection of SARS-CoV-2 during the first and second trimesters leads to newborn telomere shortening

BACKGROUND

Initial telomere length (TL) in newborns is the major determinant for TL in later life while TL in newborn/early-life predicts long-term health and lifespan. It is important to identify key factors that affect telomere homeostasis throughout embryonic development for precision interventions to maintain optimal TL in fetus/prenatal infants. SARS-CoV-2 has caused a widespread global pandemic of COVID-19, but it remains unclear whether maternal SARS-CoV-2 infection impairs prenatal telomere homeostasis.

METHODS

We recruited 413 normally delivered newborns whose mothers were either non-infected or infected with SARS-CoV-2 during different trimesters of pregnancy (otherwise healthy). Telomere length (TL) in cord blood (CB) was assessed using qPCR. CB and maternal blood were analyzed for cytokine levels. Placental senescence was determined using senescence-associated β-galactosidase staining.

RESULTS

Control (non-infected maternal) newborn TL was significantly longer than that from maternal infection (1.568 ± 0.340 vs 1.390 ± 0.350, P = 0.005). Such shorter TL was observed only if maternal infection of SARS-CoV-2 occurred in the first and second trimesters of pregnancy (1.261 ± 0.340 and 1.346 ± 0.353, P < 0.0001 and 0.001, respectively). There were no differences in TL between controls and infection at the third trimester (1.568 ± 0.340 vs 1.565 ± 0.329, P > 0.05). Across the first trimester, there was a positive correlation between newborn TL and gestational weeks with maternal infection, suggesting that the earlier maternal infection occurs, the worse effect is taken on fetal telomere homeostasis. Placental senescence coupled with the downregulated expression of telomerase reverse transcriptase was significantly more frequent from the maternal infection at the first trimester. There were no differences in IL-6, C reactive protein and other cytokine levels in CB and maternal serum or placentas.

CONCLUSIONS

Maternal SARS-CoV-2 infection at the first and second trimesters leads to significantly shorter TL and earlier infection causes much more severe TL damage. The infection-mediated cell senescence and other histopathological abnormalities result in defective placental function through which fetal telomere homeostasis is impaired. Thus, vaccination against COVID-19 should be done in advance for women who plan pregnancy.

Cdc42 improve SARS-CoV-2 spike protein-induced cellular senescence through activating of Wnt/β-Catenin signaling pathway

Introduction

SARS-CoV-2 infection drove senescent cells and the senescence-associated phenotypes were reported playing roles in disease progression, which contributes to severe COVID-19 and related sequelae. Cdc42 is involved in the regulation of cellular senescence. This study, aimed to investigate the mechanism of the SARS-CoV-2 spike protein regulating cellular senescence through Cdc42.

Methods

K18-hACE2 mice were infected with SARS-CoV-2 Omicron BA.4 or stimulated with spike protein through the airway, the senescent cells and Cdc42 expression in lung tissue were detected. Overexpression of spike protein or exogenous incubation of spike protein was used to simulate the induction of cellular senescence by spike protein. Mechanistic insights into the role of Cdc42 were mainly explored using Western Blot and qRT-PCR.

Results

Spike protein, SARS-CoV-2 infection related, accelerates cell aging by upregulating Cdc42 expression, which furtherly activated the Wnt/β-catenin signaling pathway. Conversely, treatment with ML141 in animal models, a Cdc42 inhibitor, reduced cellular senescence and ameliorated lung injury and inflammation. These results suggest that the upregulation of Cdc42 by the SARS-CoV-2 spike protein induces cellular senescence and enhances β-catenin nuclear translocation.

Discussion

This study provides insights into the mechanisms underlying cellular senescence induced by the SARS-CoV-2 spike protein, offering potential strategies to mitigate the inflammatory response and complications associated with COVID-19 in both the acute and long-term phases.

Targeting senescent cells in aging and COVID-19: from cellular mechanisms to therapeutic opportunities

The COVID-19 pandemic has caused a global health crisis and significant social economic burden. While most individuals experience mild or non-specific symptoms, elderly individuals are at a higher risk of developing severe symptoms and life-threatening complications. Exploring the key factors associated with clinical severity highlights that key characteristics of aging, such as cellular senescence, immune dysregulation, metabolic alterations, and impaired regenerative potential, contribute to disruption of tissue homeostasis of the lung and worse clinical outcome. Senolytic and senomorphic drugs, which are anti-aging treatments designed to eliminate senescent cells or decrease the associated phenotypes, have shown promise in alleviating age-related dysfunctions and offer a novel approach to treating diseases that share certain aspects of underlying mechanisms with aging, including COVID-19. This review summarizes the current understanding of aging in COVID-19 progression, and highlights recent findings on anti-aging drugs that could be repurposed for COVID-19 treatment to complement existing therapies.

Influenza, SARS-CoV-2, and Their Impact on Chronic Lung Diseases and Fibrosis: Exploring Therapeutic Options

Respiratory tract infections represent a significant global public health concern, disproportionately affecting vulnerable populations such as children, the elderly, and immunocompromised individuals. RNA viruses, particularly influenza viruses and coronaviruses, significantly contribute to respiratory illnesses, especially in immunosuppressed and elderly individuals. Influenza A viruses (IAVs) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to pose global health threats due to their capacity to cause annual epidemics, with profound implications for public health. In addition, the increase in global life expectancy is influencing the dynamics and outcomes of respiratory viral infections. Understanding the molecular mechanisms by which IAVs and SARS-CoV-2 contribute to lung disease progression is therefore crucial. The aim of this review is to comprehensively explore the impact of IAVs and SARS-CoV-2 on chronic lung diseases, with a specific focus on pulmonary fibrosis in the elderly. It also outlines potential preventive and therapeutic strategies and suggests directions for future research.

Blockade of endothelin receptors mitigates SARS-CoV-2-induced osteoarthritis

Joint pain and osteoarthritis can occur as coronavirus disease 2019 (COVID-19) sequelae after infection. However, little is known about the damage to articular cartilage. Here we illustrate knee joint damage after wild-type, Delta and Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in vivo. Rapid joint injury with cystic lesions at the osteochondral junction was observed in two patients with post-COVID osteoarthritis and recapitulated in a golden Syrian hamster model. SARS-CoV-2-activated endothelin-1 signalling increased vascular permeability and caused viral spike proteins leakage into the subchondral bone. Osteoclast activation, chondrocyte dropout and cyst formation were confirmed histologically. The US Food and Drug Administration-approved endothelin receptor antagonist, macitentan, mitigated cystic lesions and preserved chondrocyte number in the acute phase of viral infection in hamsters. Delayed macitentan treatment at post-acute infection phase alleviated chondrocyte senescence and restored subchondral bone loss. It is worth noting that it could also attenuate viral spike-induced joint pain. Our work suggests endothelin receptor blockade as a novel therapeutic strategy for post-COVID arthritis.

SARS-CoV-2 N protein-induced Dicer, XPO5, SRSF3, and hnRNPA3 downregulation causes pneumonia

Though RNAi and RNA-splicing machineries are involved in regulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication, their precise roles in coronavirus disease 2019 (COVID-19) pathogenesis remain unclear. Herein, we show that decreased RNAi component (Dicer and XPO5) and splicing factor (SRSF3 and hnRNPA3) expression correlate with increased COVID-19 severity. SARS-CoV-2 N protein induces the autophagic degradation of Dicer, XPO5, SRSF3, and hnRNPA3, inhibiting miRNA biogenesis and RNA splicing and triggering DNA damage, proteotoxic stress, and pneumonia. Dicer, XPO5, SRSF3, and hnRNPA3 knockdown increases, while their overexpression decreases, N protein-induced pneumonia's severity. Older mice show lower expression of Dicer, XPO5, SRSF3, and hnRNPA3 in their lung tissues and exhibit more severe N protein-induced pneumonia than younger mice. PJ34, a poly(ADP-ribose) polymerase inhibitor, or anastrozole, an aromatase inhibitor, ameliorates N protein- or SARS-CoV-2-induced pneumonia by restoring Dicer, XPO5, SRSF3, and hnRNPA3 expression. These findings will aid in developing improved treatments for SARS-CoV-2-associated pneumonia.

Guidelines for minimal information on cellular senescence experimentation in vivo

Cellular senescence is a cell fate triggered in response to stress and is characterized by stable cell-cycle arrest and a hypersecretory state. It has diverse biological roles, ranging from tissue repair to chronic disease. The development of new tools to study senescence in vivo has paved the way for uncovering its physiological and pathological roles and testing senescent cells as a therapeutic target. However, the lack of specific and broadly applicable markers makes it difficult to identify and characterize senescent cells in tissues and living organisms. To address this, we provide practical guidelines called "minimum information for cellular senescence experimentation in vivo" (MICSE). It presents an overview of senescence markers in rodent tissues, transgenic models, non-mammalian systems, human tissues, and tumors and their use in the identification and specification of senescent cells. These guidelines provide a uniform, state-of-the-art, and accessible toolset to improve our understanding of cellular senescence in vivo.

COVID-19-Associated Sepsis: Potential Role of Phytochemicals as Functional Foods and Nutraceuticals

The acute manifestations of coronavirus disease 2019 (COVID-19) exhibit the hallmarks of sepsis-associated complications that reflect multiple organ failure. The inflammatory cytokine storm accompanied by an imbalance in the pro-inflammatory and anti-inflammatory host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to severe and critical septic shock. The sepsis signature in severely afflicted COVID-19 patients includes cellular reprogramming and organ dysfunction that leads to high mortality rates, emphasizing the importance of improved clinical care and advanced therapeutic interventions for sepsis associated with COVID-19. Phytochemicals of functional foods and nutraceutical importance have an incredible impact on the healthcare system, which includes the prevention and/or treatment of chronic diseases. Hence, in the present review, we aim to explore the pathogenesis of sepsis associated with COVID-19 that disrupts the physiological homeostasis of the body, resulting in severe organ damage. Furthermore, we have summarized the diverse pharmacological properties of some potent phytochemicals, which can be used as functional foods as well as nutraceuticals against sepsis-associated complications of SARS-CoV-2 infection. The phytochemicals explored in this article include quercetin, curcumin, luteolin, apigenin, resveratrol, and naringenin, which are the major phytoconstituents of our daily food intake. We have compiled the findings from various studies, including clinical trials in humans, to explore more into the therapeutic potential of each phytochemical against sepsis and COVID-19, which highlights their possible importance in sepsis-associated COVID-19 pathogenesis. We conclude that our review will open a new research avenue for exploring phytochemical-derived therapeutic agents for preventing or treating the life-threatening complications of sepsis associated with COVID-19.

Long COVID as a disease of accelerated biological aging: An opportunity to translate geroscience interventions

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy and a paucity of clinical trials addressing its biological root causes. Notably, many of the symptoms of long COVID are typically seen with advancing age. Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a translational framework for studying long COVID as a state of effectively accelerated biological aging, identifying research gaps and offering recommendations for future preclinical and clinical studies.

Epigenetics and environmental health

Epigenetic modifications including DNA methylation, histone modifications, chromatin remodeling, and RNA modifications complicate gene regulation and heredity and profoundly impact various physiological and pathological processes. In recent years, accumulating evidence indicates that epigenetics is vulnerable to environmental changes and regulates the growth, development, and diseases of individuals by affecting chromatin activity and regulating gene expression. Environmental exposure or induced epigenetic changes can regulate the state of development and lead to developmental disorders, aging, cardiovascular disease, Alzheimer's disease, cancers, and so on. However, epigenetic modifications are reversible. The use of specific epigenetic inhibitors targeting epigenetic changes in response to environmental exposure is useful in disease therapy. Here, we provide an overview of the role of epigenetics in various diseases. Furthermore, we summarize the mechanism of epigenetic alterations induced by different environmental exposures, the influence of different environmental exposures, and the crosstalk between environmental variation epigenetics, and genes that are implicated in the body's health. However, the interaction of multiple factors and epigenetics in regulating the initiation and progression of various diseases complicates clinical treatments. We discuss some commonly used epigenetic drugs targeting epigenetic modifications and methods to prevent or relieve various diseases regulated by environmental exposure and epigenetics through diet.

The ocular immunological alterations in the process of high-risk corneal transplantation rejection

PURPOSE

This study aims to reveal the immunopathogenesis of the high-risk corneal transplantation using a comparative proteomic approach.

METHODS

The immunological properties of ocular tissues (including corneal grafts, aqueous humour, and iris-ciliary body) were analysed using a high-risk rabbit corneal transplantation model employing a comparative proteomic approach.

RESULTS

The corneal grafts revealed a dramatic increase in the immune response both at the early (postoperative day 7) and rejection stages, along with the appearance of transplantation stress-induced cellular senescence in the early stage. The aqueous humour (AH) displayed persistent pathological alterations, indicated by the significant enrichment of complement and coagulation cascades pathway in the early stage and interleukin (IL)-17 signalling pathway in the rejection stage. More surprisingly, the pronounced elevation of immune response was also observed in the iris-ciliary body (I-CB) tissues at the early and rejection stages. The enriched immune-related pathways were associated with antigen processing and presentation, complement and coagulation cascades, and IL-17 signalling pathway. Furthermore, proteomic analysis revealed that the implantation of Cyclosporine A drug delivery system (CsA-DDS) into the anterior chamber obviously mitigated corneal transplantation rejection by inhibiting immunoreaction both in the corneal grafts and I-CB tissues.

CONCLUSION

The results highlighted the involvement of intraocular immunity both in the grafts and I-CB tissues during corneal transplantation rejection, further suggesting the anterior chamber as an optimal drug-delivery site for its treatment.

SARS-CoV-2 spike-induced syncytia are senescent and contribute to exacerbated heart failure

SARS-CoV-2 spike protein (SARS-2-S) induced cell-cell fusion in uninfected cells may occur in long COVID-19 syndrome, as circulating SARS-2-S or extracellular vesicles containing SARS-2-S (S-EVs) were found to be prevalent in post-acute sequelae of COVID-19 (PASC) for up to 12 months after diagnosis. Although isolated recombinant SARS-2-S protein has been shown to increase the SASP in senescent ACE2-expressing cells, the direct linkage of SARS-2-S syncytia with senescence in the absence of virus infection and the degree to which SARS-2-S syncytia affect pathology in the setting of cardiac dysfunction are unknown. Here, we found that the senescent outcome of SARS-2-S induced syncytia exacerbated heart failure progression. We first demonstrated that syncytium formation in cells expressing SARS-2-S delivered by DNA plasmid or LNP-mRNA exhibits a senescence-like phenotype. Extracellular vesicles containing SARS-2-S (S-EVs) also confer a potent ability to form senescent syncytia without de novo synthesis of SARS-2-S. However, it is important to note that currently approved COVID-19 mRNA vaccines do not induce syncytium formation or cellular senescence. Mechanistically, SARS-2-S syncytia provoke the formation of functional MAVS aggregates, which regulate the senescence fate of SARS-2-S syncytia by TNFα. We further demonstrate that senescent SARS-2-S syncytia exhibit shrinked morphology, leading to the activation of WNK1 and impaired cardiac metabolism. In pre-existing heart failure mice, the WNK1 inhibitor WNK463, anti-syncytial drug niclosamide, and senolytic dasatinib protect the heart from exacerbated heart failure triggered by SARS-2-S. Our findings thus suggest a potential mechanism for COVID-19-mediated cardiac pathology and recommend the application of WNK1 inhibitor for therapy especially in individuals with post-acute sequelae of COVID-19.

Therapy-Induced Cellular Senescence: Potentiating Tumor Elimination or Driving Cancer Resistance and Recurrence?

Cellular senescence has been increasingly recognized as a hallmark of cancer, reflecting its association with aging and inflammation, its role as a response to deregulated proliferation and oncogenic stress, and its induction by cancer therapies. While therapy-induced senescence (TIS) has been linked to resistance, recurrence, metastasis, and normal tissue toxicity, TIS also has the potential to enhance therapy response and stimulate anti-tumor immunity. In this review, we examine the Jekyll and Hyde nature of senescent cells (SnCs), focusing on how their persistence while expressing the senescence-associated secretory phenotype (SASP) modulates the tumor microenvironment through autocrine and paracrine mechanisms. Through the SASP, SnCs can mediate both resistance and response to cancer therapies. To fulfill the unmet potential of cancer immunotherapy, we consider how SnCs may influence tumor inflammation and serve as an antigen source to potentiate anti-tumor immune response. This new perspective suggests treatment approaches based on TIS to enhance immune checkpoint blockade. Finally, we describe strategies for mitigating the detrimental effects of senescence, such as modulating the SASP or targeting SnC persistence, which may enhance the overall benefits of cancer treatment.