scholarly journals Mitochondrial Dysfunction in Stem Cell Aging

2015 ◽  
Vol 7 (1) ◽  
pp. 15
Author(s):  
Anna Meiliana ◽  
Nurrani Mustika Dewi ◽  
Andi Wijaya
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Mitochondrial Dysfunction ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Tissue Homeostasis ◽  
Cell Aging ◽  
Aging Research ◽  
Age Related

BACKGROUND: Regardless of the precise underlying molecular mechanisms, the fundamental defining manifestation of aging is an overall decline in the functional capacity of various organs to maintain baseline tissue homeostasis and to respond adequately to physiological needs under stress. There is an increasingly urgent need for a more complete understanding of the molecular pathways and biological processes underlying aging and age-related disorders.CONTENT: Mitochondria constitute the most prominent source of adenosine triphosphate (ATP) and are implicated in multiple anabolic and catabolic circuitries. In addition, mitochondria coordinate cell-wide stress responses and control non-apoptotic cell death routines. The involvement of mitochondria in both vital and lethal processes is crucial for both embryonic and postembryonic development, as well as for the maintenance of adult tissue homeostasis. Age-associated telomere damage, diminution of telomere ‘capping’ function and associated p53 activation have emerged as prime instigators of a functional decline of tissue stem cells and of mitochondrial dysfunction that adversely affect renewal and bioenergetic support in diverse tissues. Constructing a model of how telomeres, stem cells and mitochondria interact with key molecules governing genome integrity, ‘stemness’ and metabolism provides a framework for how diverse factors contribute to aging and age-related disorders.SUMMARY: Cellular senescence defined as an irreversible proliferation arrest promotes age-related decline in mammalian tissue homeostasis. The aging of tissue-specific stem cell and progenitor cell compartments is believed to be central to the decline of tissue and organ integrity and function in the elderly. Taken into consideration that the overwhelming majority of intracellular reactive oxygen species (ROS) are of mitochondrial origin, it is reasonable to posit that the elevated ROS production might be caused by alteration in mitochondrial function during senescence. It is likely that mitochondria and stem cells will remain at the forefront of aging research also for the next decade.KEYWORDS: aging, stem cell, mitochondrial biogenesis, mitophagy, senescence, telomeres

scholarly journals Antioxidant Effects of Caffeic Acid Lead to Protection of Drosophila Intestinal Stem Cell Aging

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao Sheng ◽  
Yuedan Zhu ◽  
Juanyu Zhou ◽  
La Yan ◽  
Gang Du ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Caffeic Acid ◽  
Stress Responses ◽  
Adult Stem Cells ◽  
Cell Function ◽  
Cell Aging ◽  
Positive Effects ◽  
Age Related ◽  
Tissue Aging

The dysfunction or exhaustion of adult stem cells during aging is closely linked to tissue aging and age-related diseases. Circumventing this aging-related exhaustion of adult stem cells could significantly alleviate the functional decline of organs. Therefore, identifying small molecular compounds that could prevent the age-related decline of stem cell function is a primary goal in anti-aging research. Caffeic acid (CA), a phenolic compound synthesized in plants, offers substantial health benefits for multiple age-related diseases and aging. However, the effects of CA on adult stem cells remain largely unknown. Using the Drosophila midgut as a model, this study showed that oral administration with CA significantly delayed age-associated Drosophila gut dysplasia caused by the dysregulation of intestinal stem cells (ISCs) upon aging. Moreover, administering CA retarded the decline of intestinal functions in aged Drosophila and prevented hyperproliferation of age-associated ISC by suppressing oxidative stress-associated JNK signaling. On the other hand, CA supplementation significantly ameliorated the gut hyperplasia defect and reduced environmentally induced mortality, revealing the positive effects of CA on tolerance to stress responses. Taken together, our findings report a crucial role of CA in delaying age-related changes in ISCs of Drosophila.

scholarly journals Stem Cell Quiescence versus Senescence: The Key for Healthy Aging

2021 ◽  
Vol 13 (4) ◽  
pp. 337-49
Author(s):  
Anna Meiliana ◽  
Nurrani Mustika Dewi ◽  
Andi Wijaya
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Healthy Aging ◽  
Molecular Mechanisms ◽  
Adult Stem Cell ◽  
Cell Aging ◽  
Tissue Specific ◽  
Age Related ◽  
Cell Decline ◽  
Tissue Specific Stem Cells

BACKGROUND: Aging tissues lose their homeostatic and regenerative capacities, which has been linked to the degeneration of the stem cells such as the tissue-specific stem cells, the stem cell niches, and systemic cues that regulate stem cell activity.CONTENT: The maintenance of tissue homeostatic and regeneration dependent on its tissue-specific stem cells, that —long-lived cells with the ability to self-renew and differentiate into mature cells. Understanding the molecular mechanisms that governs stem cell survival, self-renewal, quiescence, proliferation, and commitment to specific differentiated cell lineages is critical for identifying the drivers and effectors of age-associated stem cell failure. Such understanding will be critical for the development of therapeutic approaches that can decrease, and possibly reverse and repair the age-related degenerative process in aging tissues.SUMMARY: The exact mechanisms and reasons of aging process were not fully elucidated until now. Stem cells is one of the keys for maintaining tissues heath and understanding how stem cell decline with age will give us opportunities to find strategy in increasing somatic stem cells regenerative capacity and delay the aging process.KEYWORDS: adult stem cell, aging, epigenetic, metabolism, quiescence, senescence

scholarly journals Age-Related Changes in Methylome and Transcriptome of Hematopotietic Stem Cells Underlie Natural Genetic Variations

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2660-2660
Author(s):  
Ying Liang
Keyword(s):  
Dna Methylation ◽  
Stem Cells ◽  
Stem Cell ◽  
Aging Process ◽  
Expression Patterns ◽  
Genetic Variations ◽  
Cell Aging ◽  
Hematopoietic Stem ◽  
Age Related ◽  
Age Related Changes

The aging of hematopoietic stem cells (HSCs) contributes to the aging of blood system and perhaps the whole organism. The aging process is coordinately determined by both genetic and epigenetic factors, and demonstrates inter-individual variations. We used high-throughput sequencing methods to study the age-dependent changes of genome-wide DNA methylation and gene expression patterns in HSCs of C57BL/6 (B6) and DBA/2 mouse strains, which have shown natural variations in HSC aging process. We observed global age-associated decrease of DNA methylation in both strains, but D2 HSCs have a stronger loss of epigenetic control than B6 stem cells during aging. Majority age-related changes of DNA methylation occur from young to mid-aged stages. We identified stable strain-specific differentially methylated regions (DMRs) that overlap with cis-eQTLs. Moreover, transcription factor binding site motifs are more likely to be disrupted in the DMRs, suggesting the potential impact of genetic variations on epigenetic regulation of HSC aging. We further demonstrated that strain-specific DMRs have more profound effects on the aging of B6 HSCs than D2 stem cells. Transposons are differentially regulated by the DMRs in the two strains, in which D2 HSCs are prone to transposon insertion. This study comprehensively investigated the effects of natural genetic and epigenetic variations on HSC aging. Loss of DNA methylation is an epigenetic signature of stem cell aging, and DNA methylation variations correlates with genetic variations, both contributing to inter-individual differences in stem cell and perhaps organismal aging. Disclosures No relevant conflicts of interest to declare.

New insights into skin stem cell aging and cancer

2014 ◽  
Vol 42 (3) ◽  
pp. 663-669 ◽  
Author(s):  
M. Carmen Ortells ◽  
William M. Keyes
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Cell Aging ◽  
Adult Tissue ◽  
Self Renewal ◽  
Tissue Specific ◽  
Regulatory Processes ◽  
Age Related ◽  
Stem Cell Aging ◽  
Growth Properties

Adult tissue homoeostasis requires continual replacement of cells that are lost due to normal turnover, injury and disease. However, aging is associated with an overall decline in tissue function and homoeostasis, suggesting that the normal regulatory processes that govern self-renewal and regeneration may become impaired with age. Tissue-specific SCs (stem cells) lie at the apex of organismal conservation and regeneration, ultimately being responsible for continued tissue maintenance. In many tissues, there are changes in SC numbers, or alteration of their growth properties during aging, often involving imbalances in tumour-suppressor- and oncogene-mediated pathways. Uncovering the molecular mechanisms leading to changes in SC function during aging will provide an essential tool to address tissue-specific age-related pathologies. In the present review, we summarize the age-related alterations found in different tissue SC populations, highlighting recently identified changes in aged HFSCs (hair-follicle SCs) in the skin.

scholarly journals Manifestations and mechanisms of stem cell aging

2011 ◽  
Vol 193 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Ling Liu ◽  
Thomas A. Rando
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Adult Stem Cells ◽  
Cell Aging ◽  
Functional Changes ◽  
Cell Based Therapy ◽  
Age Related ◽  
Stem Cell Aging ◽  
Genetic Interventions ◽  
Cell Functionality

Adult stem cells exist in most mammalian organs and tissues and are indispensable for normal tissue homeostasis and repair. In most tissues, there is an age-related decline in stem cell functionality but not a depletion of stem cells. Such functional changes reflect deleterious effects of age on the genome, epigenome, and proteome, some of which arise cell autonomously and others of which are imposed by an age-related change in the local milieu or systemic environment. Notably, some of the changes, particularly epigenomic and proteomic, are potentially reversible, and both environmental and genetic interventions can result in the rejuvenation of aged stem cells. Such findings have profound implications for the stem cell–based therapy of age-related diseases.

scholarly journals A Computational Model of Stem Cell Molecular Mechanism to Maintain Tissue Homeostasis

2020 ◽  
Author(s):  
Najme Khorasani ◽  
Mehdi Sadeghi ◽  
Abbas Nowzari-Dalini
Keyword(s):  
Decision Making ◽  
Stem Cells ◽  
Stem Cell ◽  
Computational Model ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Tissue Homeostasis ◽  
Short Period ◽  
Dynamic Stochastic ◽  
The Impact

Stem cells, with their capacity to self-renew and to differentiate to more specialized cell types, play a key role to maintain homeostasis in adult tissues. To investigate how, in the dynamic stochastic environment of a tissue, non-genetic diversity and the precise balance between proliferation and differentiation are achieved, it is necessary to understand the molecular mechanisms of the stem cells in decision making process. By focusing on the impact of stochasticity, we proposed a computational model describing the regulatory circuitry as a tri-stable dynamical system to reveal the mechanism which orchestrate this balance. Our model explains how the distribution of noise in genes, linked to the cell regulatory networks, controls cell decision-making to maintain homeostatic state. The noise control over tissue homeostasis is achieved by regulating the probability of differentiation and self-renewal through symmetric and/or asymmetric cell divisions. Our model reveals, when mutations due to the replication of DNA in stem cell division, are inevitable, how mutations contribute to either aging gradually or the development of cancer in a short period of time. Furthermore, our model sheds some light on the impact of more complex regulatory networks on the system robustness against perturbations.

Extracellular Vesicles and Hematopoietic Stem Cell Aging

2021 ◽  
Author(s):  
Laura R. Goldberg
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Extracellular Vesicles ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Natural Aging ◽  
Cell Aging ◽  
Hematopoietic Stem ◽  
Age Related ◽  
Effects Of Aging

Extracellular vesicles (EVs), important mediators of intercellular communication, play a critical role in modulating hematopoiesis within the bone marrow microenvironment. Although few studies have explicitly examined the connections between EVs and hematopoietic stem cell (HSC) aging, there is a growing body of evidence that implicates EVs in numerous age-related biologic processes and diseases. This, coupled with their tremendous capacity to influence hematopoiesis, suggests EVs may be key mediators of HSC aging. This review provides an overview of the effects of aging on HSCs, the role of EVs in aging in general, and then details key work in EV modulation of normal and malignant hematopoiesis, with a particular focus on how these effects may translate into the ability of EVs to drive HSC aging. Finally, it describes an exciting emerging literature that provides direct evidence for EV modulation of HSC phenotypes during natural aging and highlights their potential in HSC rejuvenation. Taken collectively, this body of research has profound implications for the future of HSC aging studies. More clearly defining how EVs modify HSC function in an age-dependent fashion and determining the molecular mechanisms by which they drive these age-related HSC phenotype changes will undoubtedly yield innovative strategies to delay or even reverse age-related hematologic dysfunction.

scholarly journals Intestinal Stem Cell Aging: Origins and Interventions

2020 ◽  
Vol 82 (1) ◽  
pp. 203-226 ◽  
Author(s):  
Heinrich Jasper
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Intestinal Stem Cells ◽  
Intestinal Stem Cell ◽  
Cell Aging ◽  
Control Mechanisms ◽  
Regenerative Processes ◽  
Age Related ◽  
Stem Cell Aging ◽  
Multicellular Organisms

Regenerative processes that maintain the function of the gastrointestinal (GI) epithelium are critical for health and survival of multicellular organisms. In insects and vertebrates, intestinal stem cells (ISCs) regenerate the GI epithelium. ISC function is regulated by intrinsic, local, and systemic stimuli to adjust regeneration to tissue demands. These control mechanisms decline with age, resulting in significant perturbation of intestinal homeostasis. Processes that lead to this decline have been explored intensively in Drosophila melanogaster in recent years and are now starting to be characterized in mammalian models. This review presents a model for age-related regenerative decline in the fly intestine and discusses recent findings that start to establish molecular mechanisms of age-related decline of mammalian ISC function.

scholarly journals Loss of epigenetic polarity is a hallmark of hematopoietic stem cell aging

2020 ◽  
Vol 29 (R2) ◽  
pp. R248-R254
Author(s):  
Eva Mejia-Ramirez ◽  
Hartmut Geiger ◽  
M Carolina Florian
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Function ◽  
Tissue Homeostasis ◽  
Cell Aging ◽  
Special Focus ◽  
Hematopoietic Stem ◽  
Stem Cell Aging ◽  
Stem Cell Divisions ◽  
Functional Deterioration

Abstract Changes of polarity in somatic stem cells upon aging or disease lead to a functional deterioration of stem cells and consequently loss of tissue homeostasis, likely due to changes in the mode (symmetry versus asymmetry) of stem cell divisions. Changes in polarity of epigenetic markers (or ‘epi-polarity’) in stem cells, which are linked to alterations in chromatin architecture, might explain how a decline in the frequency of epipolar stem cells can have a long-lasting impact on the function of especially aging stem cells. The drift in epipolarity might represent a novel therapeutic target to improve stem cell function upon aging or disease. Here we review basic biological principles of epigenetic polarity, with a special focus on epipolarity and aging of hematopoietic stem cells.

scholarly journals Age-related changes in Polycomb gene regulation disrupt lineage fidelity in intestinal stem cells

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Helen M Tauc ◽  
Imilce A Rodriguez-Fernandez ◽  
Jason A Hackney ◽  
Michal Pawlak ◽  
Tal Ronnen Oron ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Tissue Homeostasis ◽  
Intestinal Stem Cells ◽  
Chromatin Regulation ◽  
Somatic Stem Cells ◽  
Cell Specification ◽  
Age Related ◽  
The Impact ◽  
Age Related Changes

Tissue homeostasis requires long-term lineage fidelity of somatic stem cells. Whether and how age-related changes in somatic stem cells impact the faithful execution of lineage decisions remains largely unknown. Here, we address this question using genome-wide chromatin accessibility and transcriptome analysis as well as single cell RNA-seq to explore stem cell-intrinsic changes in the aging Drosophila intestine. These studies indicate that in stem cells of old flies, promoters of Polycomb (Pc) target genes become differentially accessible, resulting in the increased expression of enteroendocrine (EE) cell specification genes. Consistently, we find age-related changes in the composition of the EE progenitor cell population in aging intestines, as well as a significant increase in the proportion of EE-specified intestinal stem cells (ISCs) and progenitors in aging flies. We further confirm that Pc-mediated chromatin regulation is a critical determinant of EE cell specification in the Drosophila intestine. Pc is required to maintain expression of stem cell genes while ensuring repression of differentiation and specification genes. Our results identify Pc group proteins as central regulators of lineage identity in the intestinal epithelium and highlight the impact of age-related decline in chromatin regulation on tissue homeostasis.

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