Aging Cell最新文献

{"title":"Hippocampal rejuvenation by a single intracerebral injection of one-carbon metabolites in C57BL6 old wild-type mice.","authors":"Alejandro Antón-Fernández, Rocío Peinado Cauchola, Félix Hernández, Jesús Ávila","doi":"10.1111/acel.14365","DOIUrl":"https://doi.org/10.1111/acel.14365","url":null,"abstract":"<p><p>The Izpisua-Belmonte group identified a cocktail of metabolites that promote partial reprogramming in cultured muscle cells. We tested the effect of brain injection of these metabolites in the dentate gyrus of aged wild-type mice. The dentate gyrus is a brain region essential for memory function and is extremely vulnerable to aging. A single injection of the cocktail containing four compounds (putrescine, glycine, methionine and threonine) partially reversed brain aging phenotypes and epigenetic alterations in age-associated genes. Our analysis revealed three levels: chromatin methylation, RNA sequencing, and protein expression. Functional studies complemented the previous ones, showing cognitive improvement. In summary, we report the reversal of various age-associated epigenetic changes, such as the transcription factor Zic4, and several changes related to cellular rejuvenation in the dentate gyrus (DG). These changes include increased expression of the Sox2 protein. Finally, the increases in the survival of newly generated neurons and the levels of the NMDA receptor subunit GluN2B were accompanied by improvements in both short-term and long-term memory performance. Based on these results, we propose the use of these metabolites to explore new strategies for the development of potential treatments for age-related brain diseases.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14365"},"PeriodicalIF":8.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142386561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Senescent cell transplantation into the skin induces age-related peripheral dysfunction and cognitive decline.","authors":"Ana Catarina Franco, Helene Martini, Stella Victorelli, Anthony B Lagnado, Saranya P Wyles, Jennifer L Rowsey, Nicholas Pirius, Seung-Hwa Woo, Daniela G Costa, Selim Chaib, Stefan G Tullius, Tamar Tchkonia, James L Kirkland, Sundeep Khosla, Diana Jurk, Claudia Cavadas, João F Passos","doi":"10.1111/acel.14340","DOIUrl":"10.1111/acel.14340","url":null,"abstract":"<p><p>Cellular senescence is an established cause of cell and tissue aging. Senescent cells have been shown to increase in multiple organs during aging, including the skin. Here we hypothesized that senescent cells residing in the skin can spread senescence to distant organs, thereby accelerating systemic aging processes. To explore this hypothesis, we initially observed an increase in several markers of senescence in the skin of aging mice. Subsequently, we conducted experiments wherein senescent fibroblasts were transplanted into the dermis of young mice and assessed various age-associated parameters. Our findings reveal that the presence of senescent cells in the dermal layer of young mice leads to increased senescence in both proximal and distal host tissues, alongside increased frailty, and impaired musculoskeletal function. Additionally, there was a significant decline in cognitive function, concomitant with increased expression of senescence-associated markers within the hippocampus brain area. These results support the concept that the accumulation of senescent cells in the skin can exert remote effects on other organs including the brain, potentially explaining links between skin and brain disorders and diseases and, contributing to physical and cognitive decline associated with aging.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14340"},"PeriodicalIF":8.0,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142386563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations of age and sex with characteristics of extracellular vesicles and protein-enriched fractions of blood plasma.","authors":"Yiyao Huang, Junjie Feng, Jiannan Xu, Liang Dong, Wanting Su, Bo Li, Kenneth W Witwer, Lei Zheng","doi":"10.1111/acel.14356","DOIUrl":"10.1111/acel.14356","url":null,"abstract":"<p><p>Extracellular vesicles (EVs) are nanosized particles that are released by various cell types and play vital roles in intercellular communication. They carry biological molecules reflecting the physiological and pathological states of their source cells and tissues, showing potential as biomarkers. However, the impact of demographic factors like age and sex on the properties of blood plasma EVs remains underexplored. This study aims to fill this gap by evaluating how these factors influence the particle count and proteomic profiles of plasma EV preparations and corresponding protein fractions. Plasma samples from 120 healthy volunteers were collected and pooled into six groups: young males (age: 27.6 ± 4.0), young females (27.4 ± 3.8), middle-aged males (48.8 ± 3.8), middle-aged females (48.9 ± 3.9), old males (69.3 ± 3.9), and old females (69.4 ± 4.3). EV- and protein-enriched fractions were separated by size-exclusion chromatography (SEC). Fractions were characterized for particle number concentration and protein composition to identify characteristics affected by age and biological sex. Plasma EVs and corresponding protein fractions exhibited distinct characteristics, with differential enrichment of markers related to EVs and other blood components, including lipoproteins. Proteomic profiles of both EVs and protein fractions displayed sex- and age-dependent differences. Differentially abundant proteins displayed functions previously identified in the context of aging and sex differences, highlighting their utility as biomarkers. Age and sex significantly affect the characteristics of plasma EVs and proteins, potentially influencing their efficacy and interpretation as biomarkers in clinical applications. This study lays the groundwork for detailed mechanistic research to understand how EVs mediate age- and sex-related effects in health.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14356"},"PeriodicalIF":8.0,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cockayne syndrome B protein is implicated in transcription and associated chromatin dynamics in homeostatic and genotoxic conditions.","authors":"Anastasios Liakos, Katerina Z Ntakou-Zamplara, Nelina Angelova, Dimitris Konstantopoulos, Anna-Chloe Synacheri, Zoi Spyropoulou, Iason A Tsarmaklis, Despoina Korrou-Karava, Georgios Nikolopoulos, Matthieu D Lavigne, Maria Fousteri","doi":"10.1111/acel.14341","DOIUrl":"https://doi.org/10.1111/acel.14341","url":null,"abstract":"<p><p>The integrity of the actively transcribed genome against helix-distorting DNA lesions relies on a multilayered cellular response that enhances Transcription-Coupled Nucleotide Excision Repair (TC-NER). When defective, TC-NER is causatively associated with Cockayne-Syndrome (CS), a rare severe human progeroid disorder. Although the presence of unresolved transcription-blocking lesions is considered a driver of the aging process, the molecular features of the transcription-driven response to genotoxic stress in CS-B cells remain largely unknown. Here, an in-depth view of the transcriptional and associated chromatin dynamics that occur in CS-B cells illuminates the role of CSB therein. By employing high-throughput genome-wide approaches, we observed that absence of a functional CSB protein results in a delay in transcription progression, more positioned +1 nucleosomes, and less dynamic chromatin structure, compared to normal cells. We found that early after exposure to UV, CS-B cells released RNA polymerase II (RNAPII) from promoter-proximal pause sites into elongation. However, the magnitude of this response and the progression of RNAPII were reduced compared to normal counterparts. Notably, we detected increased post-UV retainment of unprocessed nascent RNA transcripts and chromatin-associated elongating RNAPII molecules. Contrary to the prevailing models, we found that transcription initiation is operational in CS-B fibroblasts early after UV and that chromatin accessibility showed a marginal increase. Our study provides robust evidence for the role of CSB in shaping the transcription and chromatin landscape both in homeostasis and in response to genotoxic insults, which is independent of its known role in TC-NER, and which may underlie major aspects of the CS phenotype.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14341"},"PeriodicalIF":8.0,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping epidermal and dermal cellular senescence in human skin aging.","authors":"Grace T Yu, Clarisse Ganier, David B Allison, Tamara Tchkonia, Sundeep Khosla, James L Kirkland, Magnus D Lynch, Saranya P Wyles","doi":"10.1111/acel.14358","DOIUrl":"https://doi.org/10.1111/acel.14358","url":null,"abstract":"<p><p>Single-cell RNA sequencing and spatial transcriptomics enable unprecedented insight into cellular and molecular pathways implicated in human skin aging and regeneration. Senescent cells are individual cells that are irreversibly cell cycle arrested and can accumulate across the human lifespan due to cell-intrinsic and -extrinsic stressors. With an atlas of single-cell RNA-sequencing and spatial transcriptomics, epidermal and dermal senescence and its effects were investigated, with a focus on melanocytes and fibroblasts. Photoaging due to ultraviolet light exposure was associated with higher burdens of senescent cells, a sign of biological aging, compared to chronological aging. A skin-specific cellular senescence gene set, termed SenSkin™, was curated and confirmed to be elevated in the context of photoaging, chronological aging, and non-replicating CDKN1A+ (p21) cells. In the epidermis, senescent melanocytes were associated with elevated melanin synthesis, suggesting haphazard pigmentation, while in the dermis, senescent reticular dermal fibroblasts were associated with decreased collagen and elastic fiber synthesis. Spatial analysis revealed the tendency for senescent cells to cluster, particularly in photoaged skin. This work proposes a strategy for characterizing age-related skin dysfunction through the lens of cellular senescence and suggests a role for senescent epidermal cells (i.e., melanocytes) and senescent dermal cells (i.e., reticular dermal fibroblasts) in age-related skin sequelae.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14358"},"PeriodicalIF":8.0,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between prescription drugs and all-cause mortality risk in the UK population.","authors":"Jonas Morin, Yves Rolland, Heike A Bischoff-Ferrari, Alejandro Ocampo, Kevin Perez","doi":"10.1111/acel.14334","DOIUrl":"https://doi.org/10.1111/acel.14334","url":null,"abstract":"<p><p>Although most drugs currently approved are meant to treat specific diseases or symptoms, it has been hypothesized that some might bear a beneficial effect on lifespan in healthy older individuals, outside of their specific disease indication. Such drugs include, among others, metformin, SGLT2 inhibitors and rapamycin. Since 2006, the UK biobank has recorded prescription medication and mortality data for over 500'000 participants, aged between 40 and 70 years old. In this work, we examined the impact of the top 406 prescribed medications on overall mortality rates within the general population of the UK. As expected, most drugs were linked to a shorter lifespan, likely due to the life-limiting nature of the diseases they are prescribed to treat. Importantly, a few drugs were associated with increased lifespans, including notably Sildenafil, Atorvastatin, Naproxen and Estradiol. These retrospective results warrant further investigation in randomized controlled trials.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14334"},"PeriodicalIF":8.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dysregulated nicotinamide adenine dinucleotide metabolome in patients hospitalized with COVID-19.","authors":"Rodrigo J Valderrábano, Benjamin Wipper, Karol Mateusz Pencina, Marie Migaud, Yili Valentine Shang, Nancy K Latham, Monty Montano, James M Cunningham, Lauren Wilson, Liming Peng, Yusnie Memish-Beleva, Avantika Bhargava, Pamela M Swain, Phoebe Lehman, Siva Lavu, David J Livingston, Shalender Bhasin","doi":"10.1111/acel.14326","DOIUrl":"https://doi.org/10.1111/acel.14326","url":null,"abstract":"<p><p>Nicotinamide adenine dinucleotide (NAD⁺) depletion has been postulated as a contributor to the severity of COVID-19; however, no study has prospectively characterized NAD⁺ and its metabolites in relation to disease severity in patients with COVID-19. We measured NAD⁺ and its metabolites in 56 hospitalized patients with COVID-19 and in two control groups without COVID-19: (1) 31 age- and sex-matched adults with comorbidities, and (2) 30 adults without comorbidities. Blood NAD⁺ concentrations in COVID-19 group were only slightly lower than in the control groups (p < 0.05); however, plasma 1-methylnicotinamide concentrations were significantly higher in patients with COVID-19 (439.7 ng/mL, 95% CI: 234.0, 645.4 ng/mL) than in age- and sex-matched controls (44.5 ng/mL, 95% CI: 15.6, 73.4) and in healthy controls (18.1 ng/mL, 95% CI 15.4, 20.8; p < 0.001 for each comparison). Plasma nicotinamide concentrations were also higher in COVID-19 group and in controls with comorbidities than in healthy control group. Plasma concentrations of 2-methyl-2-pyridone-5-carboxamide (2-PY), but not NAD⁺, were significantly associated with increased risk of death (HR = 3.65; 95% CI 1.09, 12.2; p = 0.036) and escalation in level of care (HR = 2.90, 95% CI 1.01, 8.38, p = 0.049). RNAseq and RTqPCR analyses of PBMC mRNA found upregulation of multiple genes involved in NAD⁺ synthesis as well as degradation, and dysregulation of NAD⁺-dependent processes including immune response, DNA repair, metabolism, apoptosis/autophagy, redox reactions, and mitochondrial function. Blood NAD⁺ concentrations are modestly reduced in COVID-19; however, NAD⁺ turnover is substantially increased with upregulation of genes involved in both NAD⁺ biosynthesis and degradation, supporting the rationale for NAD+ augmentation to attenuate disease severity.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14326"},"PeriodicalIF":8.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sirtuin 3 reinforces acylcarnitine metabolism and maintains thermogenesis in brown adipose tissue of aging mice.","authors":"Kuiliang Zhang, Yucheng Wang, Yujie Sun, Lamei Xue, Yu Wang, Chenzhipeng Nie, Mingcong Fan, Haifeng Qian, Hao Ying, Li Wang, Yan Li","doi":"10.1111/acel.14332","DOIUrl":"https://doi.org/10.1111/acel.14332","url":null,"abstract":"<p><p>Acylcarnitine (ACar) is a novel fuel source for activating thermogenesis in brown adipose tissue (BAT). However, whether ACar metabolism underlies BAT thermogenesis decline with aging remain unclear. Here, the L-carnitine-treated young and aging mice were used to investigate the effects of activation of ACar metabolism on BAT thermogenesis during aging. We showed that long term L-carnitine feeding, which results in an elevation in circulating ACar levels, failed to improve cold sensitivity of aging mice, which still displayed impaired thermogenesis and ACar metabolism in interscapular BAT (iBAT). The RNA-sequencing was used to identify the key regulator for the response of aging mice to LCar induced activation of ACar metabolism in BAT, and we identified Sirt3 as a key regulator for the response of aging mice to L-carnitine induced activation of ACar metabolism in iBAT. Then the adipose-specific Sirt3 knockout (Sirt3 AKO) mice were used to investigate the role of Sirt3 in ACar metabolism and thermogenesis of BAT and explore the underlying mechanism, and the results showed that Sirt3 AKO mice displayed defective ACar metabolism and thermogenesis in iBAT. Mechanically, Sirt3 regulated ACar metabolism via HIF1α-PPARα signaling pathway to promote iBAT thermogenesis, and knockdown or inhibition of HIF1α ameliorated impaired ACar metabolism and thermogenesis of iBAT in the absence of Sirt3. Collectively, we propose that Sirt3 regulated ACar metabolism is critical in maintaining thermogenesis in BAT of aging mice, which can promote the development of anti-aging intervention strategy.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14332"},"PeriodicalIF":8.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142337679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A longevity-specific bank of induced pluripotent stem cells from centenarians and their offspring.","authors":"Todd W Dowrey, Samuel F Cranston, Nicholas Skvir, Yvonne Lok, Brian Gould, Bradley Petrowitz, Daniel Villar, Jidong Shan, Marianne James, Mark Dodge, Anna C Belkina, Richard M Giadone, Sofiya Milman, Paola Sebastiani, Thomas T Perls, Stacy L Andersen, George J Murphy","doi":"10.1111/acel.14351","DOIUrl":"10.1111/acel.14351","url":null,"abstract":"<p><p>Centenarians provide a unique lens through which to study longevity, healthy aging, and resiliency. Moreover, models of human aging and resilience to disease that allow for the testing of potential interventions are virtually non-existent. We obtained and characterized over 96 centenarian and offspring peripheral blood samples including those connected to functional independence data highlighting resistance to disability and cognitive impairment. Targeted methylation arrays were used in molecular aging clocks to compare and contrast differences between biological and chronological age in these specialized subjects. Isolated peripheral blood mononuclear cells (PBMCs) from 20 of these subjects were then successfully reprogrammed into high-quality induced pluripotent stem cell (iPSC) lines which were functionally characterized for pluripotency, genomic stability, and the ability to undergo directed differentiation. The result of this work is a one-of-a-kind resource for studies of human longevity and resilience that can fuel the discovery and validation of novel therapeutics for aging-related disease.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14351"},"PeriodicalIF":8.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142337676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic analysis across aged tissues reveals distinct signatures and the crucial involvement of midgut barrier function in the regulation of aging.","authors":"Congying Zhang, Jinlong Wang, Tianzhao Yao, Jiaxin Hu, Feifei Sun, Chunlu Feng, Zhendong Sun, Yuzhuo Shao, Zhu Wang, Jiarui Wu, Yunpeng Huang","doi":"10.1111/acel.14344","DOIUrl":"https://doi.org/10.1111/acel.14344","url":null,"abstract":"<p><p>The process of aging is a natural phenomenon characterized by gradual deterioration in biological functions and systemic homeostasis, which can be modulated by both genetic and environmental factors. Numerous investigations conducted on model organisms, including nematodes, flies, and mice, have elucidated several pivotal aging pathways, such as insulin signaling and AMPK signaling. However, it remains uncertain whether the regulation of the aging process is uniform or diverse across different tissues and whether manipulating the same aging factor can result in consistent outcomes in various tissues. In this study, we utilize the Drosophila organism to investigate tissue-specific proteome signatures during the aging process. Although distinct proteins undergo changes in aged tissues, certain common altered functional networks are constituently identified across different tissues, including the decline of the mitochondrial ribosomal network, autophagic network, and anti-ROS defense networks. Furthermore, downregulation of insulin receptor (InR) in the midguts, muscle, and central nervous system (CNS) of flies leads to a significant extension in fly lifespans. Notably, despite manipulating the same aging gene InR, diverse alterations in proteins are observed across different tissues. Importantly, knockdown of InR in the midguts leads to a distinct proteome compared with other tissues, resulting in enhanced actin nucleation and glutathione metabolism, while attenuating age-related elevation of serine proteases. Consequently, knockdown of InR results in rejuvenation of the integrity of the midgut barrier and augmentation of anti-ROS defense capabilities. Our findings suggest that the barrier function of the midgut plays a pivotal role in defending against aging, underscoring the paramount importance of maintaining optimal gut physiology to effectively delay the aging process. Moreover, when considering age-related changes across various tissues, it is more reasonable to identify functional networks rather than focusing solely on individual proteins.</p>","PeriodicalId":119,"journal":{"name":"Aging Cell","volume":" ","pages":"e14344"},"PeriodicalIF":8.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142337678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}