scholarly journals Loss-of-function of p53 isoform Δ113p53 accelerates brain aging in zebrafish

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Ting Zhao ◽  
Shengfan Ye ◽  
Zimu Tang ◽  
Liwei Guo ◽  
Zhipeng Ma ◽  
...  
Keyword(s):  
Replicative Senescence ◽  
Brain Aging ◽  
Ventricular Zone ◽  
Human Fibroblasts ◽  
Cell Lineage ◽  
Lineage Tracing ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Antioxidant Genes ◽  
Age Related

AbstractReactive oxygen species (ROS) stress has been demonstrated as potentially critical for induction and maintenance of cellular senescence, and been considered as a contributing factor in aging and in various neurological disorders including Alzheimer’s disease (AD) and amyotrophic lateral sclerosis (ALS). In response to low-level ROS stress, the expression of Δ133p53, a human p53 isoform, is upregulated to promote cell survival and protect cells from senescence by enhancing the expression of antioxidant genes. In normal conditions, the basal expression of Δ133p53 prevents human fibroblasts, T lymphocytes, and astrocytes from replicative senescence. It has been also found that brain tissues from AD and ALS patients showed decreased Δ133p53 expression. However, it is uncharacterized if Δ133p53 plays a role in brain aging. Here, we report that zebrafish Δ113p53, an ortholog of human Δ133p53, mainly expressed in some of the radial glial cells along the telencephalon ventricular zone in a full-length p53-dependent manner. EDU-labeling and cell lineage tracing showed that Δ113p53-positive cells underwent cell proliferation to contribute to the neuron renewal process. Importantly, Δ113p53M/M mutant telencephalon possessed less proliferation cells and more senescent cells compared to wild-type (WT) zebrafish telencephalon since 9-months old, which was associated with decreased antioxidant genes expression and increased level of ROS in the mutant telencephalon. More interestingly, unlike the mutant fish at 5-months old with cognition ability, Δ113p53M/M zebrafish, but not WT zebrafish, lost their learning and memory ability at 19-months old. The results demonstrate that Δ113p53 protects the brain from aging by its antioxidant function. Our finding provides evidence at the organism level to show that depletion of Δ113p53/Δ133p53 may result in long-term ROS stress, and finally lead to age-related diseases, such as AD and ALS in humans.

scholarly journals p53 isoform Δ113p53 promotes zebrafish heart regeneration by maintaining redox homeostasis

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Shengfan Ye ◽  
Ting Zhao ◽  
Wei Zhang ◽  
Zimu Tang ◽  
Ce Gao ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Cell Lineage ◽  
Lineage Tracing ◽  
Full Length ◽  
Heart Regeneration ◽  
Dependent Manner ◽  
Antioxidant Genes ◽  
Wound Site ◽  
Neonatal Mice ◽  
Zebrafish Heart

Abstract Neonatal mice and adult zebrafish can fully regenerate their hearts through proliferation of pre-existing cardiomyocytes. Previous studies have revealed that p53 signalling is activated during cardiac regeneration in neonatal mice and that hydrogen peroxide (H2O2) generated near the wound site acts as a novel signal to promote zebrafish heart regeneration. We recently demonstrated that the expression of the p53 isoform Δ133p53 is highly induced upon stimulation by low-level reactive oxygen species (ROS) and that Δ133p53 coordinates with full-length p53 to promote cell survival by enhancing the expression of antioxidant genes. However, the function of p53 signalling in heart regeneration remains uncharacterised. Here, we found that the expression of Δ113p53 is activated in cardiomyocytes at the resection site in the zebrafish heart in a full-length p53- and ROS signalling-dependent manner. Cell lineage tracing showed that Δ113p53-positive cardiomyocytes undergo cell proliferation and contribute to myocardial regeneration. More importantly, heart regeneration is impaired in Δ113p53M/M mutant zebrafish. Depletion of Δ113p53 significantly decreases the proliferation frequency of cardiomyocytes but has little effect on the activation of gata4-positive cells, their migration to the edge of the wound site, or apoptotic activity. Live imaging of intact hearts showed that induction of H2O2 at the resection site is significantly higher in Δ113p53M/M mutants than in wild-type zebrafish, which may be the result of reduced induction of antioxidant genes in Δ113p53M/M mutants. Our findings demonstrate that induction of Δ113p53 in cardiomyocytes at the resection site functions to promote heart regeneration by increasing the expression of antioxidant genes to maintain redox homeostasis.

scholarly journals Transient non-integrative nuclear reprogramming promotes multifaceted reversal of aging in human cells

2019 ◽  
Author(s):  
Tapash Jay Sarkar ◽  
Marco Quarta ◽  
Shravani Mukherjee ◽  
Alex Colville ◽  
Patrick Paine ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Human Fibroblasts ◽  
Human Cells ◽  
Cellular Aging ◽  
Epigenetic Reprogramming ◽  
Epigenetic Clock ◽  
Nuclear Reprogramming ◽  
Loss Of Function ◽  
Age Related

SummaryAging is characterized by a gradual loss of function occurring at the molecular, cellular, tissue and organismal levels1-3. At the chromatin level, aging is associated with the progressive accumulation of epigenetic errors that eventually lead to aberrant gene regulation, stem cell exhaustion, senescence, and deregulated cell/tissue homeostasis3. The technology of nuclear reprogramming to pluripotency, through over-expression of a small number of transcription factors, can revert both the age and the identity of any cell to that of an embryonic cell by driving epigenetic reprogramming2,4,5. Recent evidence has shown that transient transgenic reprogramming can ameliorate age-associated hallmarks and extend lifespan in progeroid mice6. However, it is unknown how this form of ‘epigenetic rejuvenation’ would apply to physiologically aged cells and, importantly, how it might translate to human cells. Here we show that transient reprogramming, mediated by transient expression of mRNAs, promotes a rapid reversal of both cellular aging and of epigenetic clock in human fibroblasts and endothelial cells, reduces the inflammatory profile in human chondrocytes, and restores youthful regenerative response to aged, human muscle stem cells, in each case without abolishing cellular identity. Our method, that we named Epigenetic Reprogramming of Aging (ERA), paves the way to a novel, potentially translatable strategy for ex vivo cell rejuvenation treatment. In addition, ERA holds promise for in vivo tissue rejuvenation therapies to reverse the physiological manifestations of aging and the risk for the development of age-related diseases.

scholarly journals Human Aging DNA Methylation Signatures are Conserved but Accelerated in Cultured Fibroblasts

2019 ◽  
Author(s):  
Gabriel Sturm ◽  
Andres Cardenas ◽  
Marie-Abèle Bind ◽  
Steve Horvath ◽  
Shuang Wang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Replicative Senescence ◽  
Human Fibroblasts ◽  
High Temporal Resolution ◽  
Global Changes ◽  
Mrna Levels ◽  
Cultured Fibroblasts ◽  
Age Related ◽  
Epigenetic Aging

SummaryAging is associated with progressive and site-specific changes in DNA methylation (DNAm). These global changes are captured by DNAm clocks that accurately predict chronological age in humans but relatively little is known about how clocks perform in vitro. Here we culture primary human fibroblasts across the cellular lifespan (∼6 months) and use four different DNAm clocks to show that age-related DNAm signatures are conserved and accelerated in vitro. The Skin & Blood clock shows the best linear correlation with chronological time (r=0.90), including during replicative senescence. Although similar in nature, the rate of epigenetic aging is approximately 62x times faster in cultured cells than in the human body. Consistent with in vivo data, cells aged under hyperglycemic conditions exhibit an approximately three years elevation in baseline DNAm age. Moreover, candidate gene-based analyses further corroborate the conserved but accelerated biological aging process in cultured fibroblasts. Fibroblasts mirror the established DNAm topology of the age-related ELOVL2 gene in human blood and the rapid hypermethylation of its promoter cg16867657, which correlates with a linear decrease in ELOVL2 mRNA levels across the lifespan. Using generalized additive modeling on twelve timepoints across the lifespan, we also show how single CpGs exhibit loci-specific, linear and nonlinear trajectories that reach rates up to −47% (hypomethylation) to +23% (hypermethylation) per month. Together, these high temporal resolution global, gene-specific, and single CpG data highlight the conserved and accelerated nature of epigenetic aging in cultured fibroblasts, which may constitute a system to evaluate age-modifying interventions across the lifespan.Graphical Abstract

scholarly journals Squamous trans-differentiation of pancreatic cancer cells promotes stromal inflammation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Tim DD Somerville ◽  
Giulia Biffi ◽  
Juliane Daßler-Plenker ◽  
Stella K Hur ◽  
Xue-Yan He ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cell Lineage ◽  
Pancreatic Stellate Cells ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Stromal Microenvironment ◽  
Pancreatic Cancer Cells ◽  
Human And Mouse

A highly aggressive subset of pancreatic ductal adenocarcinomas undergo trans-differentiation into the squamous lineage during disease progression. Here, we investigated whether squamous trans-differentiation of human and mouse pancreatic cancer cells can influence the phenotype of non-neoplastic cells in the tumor microenvironment. Conditioned media experiments revealed that squamous pancreatic cancer cells secrete factors that recruit neutrophils and convert pancreatic stellate cells into cancer-associated fibroblasts (CAFs) that express inflammatory cytokines at high levels. We use gain- and loss-of-function approaches to show that squamous-subtype pancreatic tumor models become enriched with neutrophils and inflammatory CAFs in a p63-dependent manner. These effects occur, at least in part, through p63-mediated activation of enhancers at pro-inflammatory cytokine loci, which includes IL1A and CXCL1 as key targets. Taken together, our findings reveal enhanced tissue inflammation as a consequence of squamous trans-differentiation in pancreatic cancer, thus highlighting an instructive role of tumor cell lineage in reprogramming the stromal microenvironment.

scholarly journals Cannabinoid Receptor 2 Alters Social Memory and Microglial Activity in an Age-Dependent Manner

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5984
Author(s):  
Joanna Agnieszka Komorowska-Müller ◽  
Tanushka Rana ◽  
Bolanle Fatimat Olabiyi ◽  
Andreas Zimmer ◽  
Anne-Caroline Schmöle
Keyword(s):  
Cannabinoid Receptor ◽  
Social Memory ◽  
Brain Aging ◽  
Endocannabinoid System ◽  
Immunohistochemical Analysis ◽  
Cellular Level ◽  
Spatial Learning And Memory ◽  
Dependent Manner ◽  
Cannabinoid Receptor 2 ◽  
Age Related

Physiological brain aging is characterized by gradual, substantial changes in cognitive ability, accompanied by chronic activation of the neural immune system. This form of inflammation, termed inflammaging, in the central nervous system is primarily enacted through microglia, the resident immune cells. The endocannabinoid system, and particularly the cannabinoid receptor 2 (CB2R), is a major regulator of the activity of microglia and is upregulated under inflammatory conditions. Here, we elucidated the role of the CB2R in physiological brain aging. We used CB2R−/− mice of progressive ages in a behavioral test battery to assess social and spatial learning and memory. This was followed by detailed immunohistochemical analysis of microglial activity and morphology, and of the expression of pro-inflammatory cytokines in the hippocampus. CB2R deletion decreased social memory in young mice, but did not affect spatial memory. In fact, old CB2R−/− mice had a slightly improved social memory, whereas in WT mice we detected an age-related cognitive decline. On a cellular level, CB2R deletion increased lipofuscin accumulation in microglia, but not in neurons. CB2R−/− microglia showed an increase of activity markers Iba1 and CD68, and minor upregulation in tnfa and il6 expression and downregulation of ccl2 with age. This was accompanied by a change in morphology as CB2R−/− microglia had smaller somas and lower polarity, with increased branching, cell volume, and tree length. We present that CB2Rs are involved in cognition and age-induced microglial activity, but may also be important for microglial activation itself.

scholarly journals Protein Oxidative Damage at the Crossroads of Cellular Senescence, Aging, and Age-Related Diseases

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Martin A. Baraibar ◽  
Liang Liu ◽  
Emad K. Ahmed ◽  
Bertrand Friguet
Keyword(s):  
Lipid Peroxidation ◽  
Protein Modification ◽  
Replicative Senescence ◽  
Human Fibroblasts ◽  
Potential Effect ◽  
Senescent Phenotype ◽  
Intermediate Metabolism ◽  
Age Related ◽  
Cellular Pathways

Protein damage mediated by oxidation, protein adducts formation with advanced glycated end products and with products of lipid peroxidation, has been implicated during aging and age-related diseases, such as neurodegenerative diseases. Increased protein modification has also been described upon replicative senescence of human fibroblasts, a valid model for studying agingin vitro. However, the mechanisms by which these modified proteins could impact on the development of the senescent phenotype and the pathogenesis of age-related diseases remain elusive. In this study, we performedin silicoapproaches to evidence molecular actors and cellular pathways affected by these damaged proteins. A database of proteins modified by carbonylation, glycation, and lipid peroxidation products during aging and age-related diseases was built and compared to those proteins identified during cellular replicative senescencein vitro. Common cellular pathways evidenced by enzymes involved in intermediate metabolism were found to be targeted by these modifications, although different tissues have been examined. These results underscore the potential effect of protein modification in the impairment of cellular metabolism during aging and age-related diseases.

scholarly journals Replicative Senescence in Human Fibroblasts Is Delayed by Hydrogen Sulfide in a NAMPT/SIRT1 Dependent Manner

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0164710 ◽  
Author(s):  
Reiko Sanokawa-Akakura ◽  
Shin Akakura ◽  
Siamak Tabibzadeh
Keyword(s):  
Hydrogen Sulfide ◽  
Replicative Senescence ◽  
Human Fibroblasts ◽  
Dependent Manner

scholarly journals Telomere Shortening in Kidneys with Age

2000 ◽  
Vol 11 (3) ◽  
pp. 444-453 ◽  
Author(s):  
ANETTE MELK ◽  
VIDO RAMASSAR ◽  
LISA M. H. HELMS ◽  
RON MOORE ◽  
DAVID RAYNER ◽  
...  
Keyword(s):  
Southern Blotting ◽  
Replicative Senescence ◽  
Regression Line ◽  
Dependent Manner ◽  
Telomere Shortening ◽  
Paired Samples ◽  
Age Related ◽  
Telomere Loss ◽  
Renal Aging

Abstract. The histology and function of the kidney deteriorates with age and age-related diseases, but the mechanisms involved in renal aging are not known. In vitro studies suggest that telomere shortening is important in replicative senescence, and is accelerated by stresses that increase replication. This study explored the relationship between age and telomere length in surgical samples from 24 human kidneys, which were either histologically normal (17) or displayed histologic abnormalities (7). Telomere loss was assessed by two independent methods: Southern blotting of terminal restriction fragments (TRF) and slot blotting using telomere-specific probes. The results of these methods correlated with each other. The mean TRF length determined by Southern blotting in cortex was about 12 kb pairs (kbp) in infancy and was shorter in older kidneys. The slope of the regression line was about 0.029 kbp (0.24%, P = 0.023) per year. Telomere DNA loss in cortex by the slot blot method was 0.25% per year (P = 0.011). By both methods, the telomere loss in medulla was not significant and was less than in cortex. Comparisons of TRF length from 20 paired samples from cortex and medulla showed that TRF was greater in cortex than medulla, with the differences being greater in young kidneys and lessening with age due to telomere loss in cortex. These findings indicate that telomeres shorten in an age-dependent manner in the kidney, either due to developmental factors or aging, particularly in renal cortex.

scholarly journals Squamous trans-differentiation of pancreatic cancer cells promotes stromal inflammation

2019 ◽  
Author(s):  
Tim D.D. Somerville ◽  
Giulia Biffi ◽  
Juliane Daßler-Plenker ◽  
Koji Miyabayashi ◽  
Yali Xu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cell Fate ◽  
Cell Lineage ◽  
Pancreatic Stellate Cells ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Stromal Microenvironment ◽  
Pancreatic Cancer Cells

AbstractA highly aggressive subset of pancreatic ductal adenocarcinomas undergo trans-differentiation into the squamous lineage during disease progression. While the tumorigenic consequences of this aberrant cell fate transition are poorly understood, recent studies have identified a role for the master regulator TP63 in this process. Here, we investigated whether squamous trans-differentiation of pancreatic cancer cells can influence the phenotype of non-neoplastic cells in the tumor microenvironment. Conditioned media experiments revealed that squamous-subtype pancreatic cancer cells secrete factors that convert quiescent pancreatic stellate cells into a specialized subtype of cancer-associated fibroblasts (CAFs) that express inflammatory genes at high levels. We use gain- and loss-of-function approaches in vivo to show that squamous-subtype pancreatic tumor models become enriched with inflammatory CAFs and neutrophils in a TP63-dependent manner. These non cell-autonomous effects occur, at least in part, through TP63-mediated activation of enhancers at pro-inflammatory cytokine loci, which includes IL1A as a key target. Taken together, our findings reveal enhanced tissue inflammation as a consequence of squamous trans-differentiation in pancreatic cancer, thus highlighting an instructive role of tumor cell lineage in reprogramming the stromal microenvironment.

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