scholarly journals Genetic and Epigenetic Influences on Cutaneous Cellular Senescence

2021 ◽  
Author(s):  
Tapash Jay Sarkar ◽  
Maiko Hermsmeier ◽  
Jessica L. Ross ◽  
G. Scott Herron
Keyword(s):  
Cellular Senescence ◽  
Structural Changes ◽  
Cell Types ◽  
Metabolic Dysfunction ◽  
Protective Function ◽  
Human Organ ◽  
Cellular Processes ◽  
Age Related ◽  
Aged Skin ◽  
Different Cell Types

Skin is the largest human organ system, and its protective function is critical to survival. The epithelial, dermal, and subcutaneous compartments are heterogeneous mixtures of cell types, yet they all display age-related skin dysfunction through the accumulation of an altered phenotypic cellular state called senescence. Cellular senescence is triggered by complex and dynamic genetic and epigenetic processes. A senescence steady state is achieved in different cell types under various and overlapping conditions of chronological age, toxic injury, oxidative stress, replicative exhaustion, DNA damage, metabolic dysfunction, and chromosomal structural changes. These inputs lead to outputs of cell-cycle withdrawal and the appearance of a senescence-associated secretory phenotype, both of which accumulate as tissue pathology observed clinically in aged skin. This review details the influence of genetic and epigenetic factors that converge on normal cutaneous cellular processes to create the senescent state, thereby dictating the response of the skin to the forces of both intrinsic and extrinsic aging. From this work, it is clear that no single biomarker or process leads to senescence, but that it is a convergence of factors resulting in an overt aging phenotype.

scholarly journals The organisation and functions of local Ca2+ signals

2001 ◽  
Vol 114 (12) ◽  
pp. 2213-2222 ◽  
Author(s):  
Martin D. Bootman ◽  
Peter Lipp ◽  
Michael J. Berridge
Keyword(s):  
Cell Proliferation ◽  
Gene Transcription ◽  
Cell Biology ◽  
Building Blocks ◽  
Cell Types ◽  
Diverse Range ◽  
Cellular Processes ◽  
Different Cell Types ◽  
Intracellular Messenger ◽  
Sensory Mechanisms

Calcium (Ca2+) is a ubiquitous intracellular messenger, controlling a diverse range of cellular processes, such as gene transcription, muscle contraction and cell proliferation. The ability of a simple ion such as Ca2+ to play a pivotal role in cell biology results from the facility that cells have to shape Ca2+ signals in space, time and amplitude. To generate and interpret the variety of observed Ca2+ signals, different cell types employ components selected from a Ca2+ signalling ‘toolkit’, which comprises an array of homeostatic and sensory mechanisms. By mixing and matching components from the toolkit, cells can obtain Ca2+ signals that suit their physiology. Recent studies have demonstrated the importance of local Ca2+ signals in defining the specificity of the interaction of Ca2+ with its targets. Furthermore, local Ca2+ signals are the triggers and building blocks for larger global signals that propagate throughout cells.

scholarly journals The aging skin microenvironment dictates stem cell behavior

2020 ◽  
Vol 117 (10) ◽  
pp. 5339-5350 ◽  
Author(s):  
Yejing Ge ◽  
Yuxuan Miao ◽  
Shiri Gur-Cohen ◽  
Nicholas Gomez ◽  
Hanseul Yang ◽  
...  
Keyword(s):  
Dominant Role ◽  
Functional Decline ◽  
Cell Types ◽  
Multiple Organs ◽  
Age Related ◽  
Hair Follicle Stem Cells ◽  
Aged Skin ◽  
Transcriptional Changes ◽  
Follicle Stem Cells

Aging manifests with architectural alteration and functional decline of multiple organs throughout an organism. In mammals, aged skin is accompanied by a marked reduction in hair cycling and appearance of bald patches, leading researchers to propose that hair follicle stem cells (HFSCs) are either lost, differentiate, or change to an epidermal fate during aging. Here, we employed single-cell RNA-sequencing to interrogate aging-related changes in the HFSCs. Surprisingly, although numbers declined, aging HFSCs were present, maintained their identity, and showed no overt signs of shifting to an epidermal fate. However, they did exhibit prevalent transcriptional changes particularly in extracellular matrix genes, and this was accompanied by profound structural perturbations in the aging SC niche. Moreover, marked age-related changes occurred in many nonepithelial cell types, including resident immune cells, sensory neurons, and arrector pili muscles. Each of these SC niche components has been shown to influence HF regeneration. When we performed skin injuries that are known to mobilize young HFSCs to exit their niche and regenerate HFs, we discovered that aged skin is defective at doing so. Interestingly, however, in transplantation assays in vivo, aged HFSCs regenerated HFs when supported with young dermis, while young HFSCs failed to regenerate HFs when combined with aged dermis. Together, our findings highlight the importance of SC:niche interactions and favor a model where youthfulness of the niche microenvironment plays a dominant role in dictating the properties of its SCs and tissue health and fitness.

scholarly journals What have we learned from basic science studies on idiopathic pulmonary fibrosis?

2019 ◽  
Vol 28 (153) ◽  
pp. 190029 ◽  
Author(s):  
Toyoshi Yanagihara ◽  
Seidai Sato ◽  
Chandak Upagupta ◽  
Martin Kolb
Keyword(s):  
Extracellular Matrix ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Cellular Senescence ◽  
Basic Science ◽  
Science Studies ◽  
Cell Types ◽  
Age Related ◽  
Tremendous Progress

Idiopathic pulmonary fibrosis is a fatal age-related lung disease characterised by progressive and irreversible scarring of the lung. Although the details are not fully understood, there has been tremendous progress in understanding the pathogenesis of idiopathic pulmonary fibrosis, which has led to the identification of many new potential therapeutic targets. In this review we discuss several of these advances with a focus on genetic susceptibility and cellular senescence primarily affecting epithelial cells, activation of profibrotic pathways, disease-enhancing fibrogenic cell types and the role of the remodelled extracellular matrix.

scholarly journals Skin Aging, Cellular Senescence and Natural Polyphenols

2021 ◽  
Vol 22 (23) ◽  
pp. 12641
Author(s):  
Erika Csekes ◽  
Lucia Račková
Keyword(s):  
Cellular Senescence ◽  
Skin Aging ◽  
The Body ◽  
Skin Changes ◽  
Natural Polyphenols ◽  
Current State ◽  
Age Related ◽  
Aged Skin ◽  
And Function

The skin, being the barrier organ of the body, is constitutively exposed to various stimuli impacting its morphology and function. Senescent cells have been found to accumulate with age and may contribute to age-related skin changes and pathologies. Natural polyphenols exert many health benefits, including ameliorative effects on skin aging. By affecting molecular pathways of senescence, polyphenols are able to prevent or delay the senescence formation and, consequently, avoid or ameliorate aging and age-associated pathologies of the skin. This review aims to provide an overview of the current state of knowledge in skin aging and cellular senescence, and to summarize the recent in vitro studies related to the anti-senescent mechanisms of natural polyphenols carried out on keratinocytes, melanocytes and fibroblasts. Aged skin in the context of the COVID-19 pandemic will be also discussed.

scholarly journals Membrane mechanics govern spatiotemporal heterogeneity of endocytic clathrin coat dynamics

2017 ◽  
Vol 28 (24) ◽  
pp. 3480-3488 ◽  
Author(s):  
N. M. Willy ◽  
J. P. Ferguson ◽  
S. D. Huber ◽  
S. P. Heidotting ◽  
E. Aygün ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Morphological Changes ◽  
Cell Types ◽  
Membrane Tension ◽  
Membrane Mechanics ◽  
Cellular Processes ◽  
Spatiotemporal Heterogeneity ◽  
Multicellular Organisms ◽  
Different Cell Types

Dynamics of endocytic clathrin-coated structures can be remarkably divergent across different cell types, cells within the same culture, or even distinct surfaces of the same cell. The origin of this astounding heterogeneity remains to be elucidated. Here we show that cellular processes associated with changes in effective plasma membrane tension induce significant spatiotemporal alterations in endocytic clathrin coat dynamics. Spatiotemporal heterogeneity of clathrin coat dynamics is also observed during morphological changes taking place within developing multicellular organisms. These findings suggest that tension gradients can lead to patterning and differentiation of tissues through mechanoregulation of clathrin-mediated endocytosis.

scholarly journals Functional annotation of lncRNA in high-throughput screening

2021 ◽  
Author(s):  
Chi Wai Yip ◽  
Divya M. Sivaraman ◽  
Anika V. Prabhu ◽  
Jay W. Shin
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Functional Annotation ◽  
Cell Types ◽  
Specific Expression ◽  
Functional Roles ◽  
Cellular Processes ◽  
Cell Type Specific Expression ◽  
Cell Type Specific ◽  
Different Cell Types

Abstract Recent efforts on the characterization of long non-coding RNAs (lncRNAs) revealed their functional roles in modulating diverse cellular processes. These include pluripotency maintenance, lineage commitment, carcinogenesis, and pathogenesis of various diseases. By interacting with DNA, RNA and protein, lncRNAs mediate multifaceted mechanisms to regulate transcription, RNA processing, RNA interference and translation. Of more than 173000 discovered lncRNAs, the majority remain functionally unknown. The cell type-specific expression and localization of the lncRNA also suggest potential distinct functions of lncRNAs across different cell types. This highlights the niche of identifying functional lncRNAs in different biological processes and diseases through high-throughput (HTP) screening. This review summarizes the current work performed and perspectives on HTP screening of functional lncRNAs where different technologies, platforms, cellular responses and the downstream analyses are discussed. We hope to provide a better picture in applying different technologies to facilitate functional annotation of lncRNA efficiently.

scholarly journals A Single Cell Transcriptomic Atlas Characterizes Aging Tissues in the Mouse

2019 ◽  
Author(s):  
◽  
Angela Oliveira Pisco ◽  
Aaron McGeever ◽  
Nicholas Schaum ◽  
Jim Karkanias ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Types ◽  
Cell Type ◽  
Cellular Processes ◽  
Progressive Loss ◽  
Age Related ◽  
Multiple Cell ◽  
Cell Type Specific ◽  
Molecular Information ◽  
Insight Into

AbstractAging is characterized by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death1. Despite rapid advances over recent years, many of the molecular and cellular processes which underlie progressive loss of healthy physiology are poorly understood2. To gain a better insight into these processes we have created a single cell transcriptomic atlas across the life span of Mus musculus which includes data from 23 tissues and organs. We discovered cell-specific changes occurring across multiple cell types and organs, as well as age related changes in the cellular composition of different organs. Using single-cell transcriptomic data we were able to assess cell type specific manifestations of different hallmarks of aging, such as senescence3, genomic instability4 and changes in the organism’s immune system2. This Tabula Muris Senis provides a wealth of new molecular information about how the most significant hallmarks of aging are reflected in a broad range of tissues and cell types.

scholarly journals Mechanisms and Regulation of Cellular Senescence

2021 ◽  
Vol 22 (23) ◽  
pp. 13173
Author(s):  
Lauréline Roger ◽  
Fanny Tomas ◽  
Véronique Gire
Keyword(s):  
Dna Damage ◽  
Cellular Senescence ◽  
Cell Types ◽  
Feedback Loops ◽  
Cellular Structures ◽  
Damage Response ◽  
Different Types ◽  
Secretory Phenotype ◽  
Different Cell Types ◽  
Different Tissues

Cellular senescence entails a state of an essentially irreversible proliferative arrest in which cells remain metabolically active and secrete a range of pro-inflammatory and proteolytic factors as part of the senescence-associated secretory phenotype. There are different types of senescent cells, and senescence can be induced in response to many DNA damage signals. Senescent cells accumulate in different tissues and organs where they have distinct physiological and pathological functions. Despite this diversity, all senescent cells must be able to survive in a nondividing state while protecting themselves from positive feedback loops linked to the constant activation of the DNA damage response. This capacity requires changes in core cellular programs. Understanding how different cell types can undergo extensive changes in their transcriptional programs, metabolism, heterochromatin patterns, and cellular structures to induce a common cellular state is crucial to preventing cancer development/progression and to improving health during aging. In this review, we discuss how senescent cells continuously evolve after their initial proliferative arrest and highlight the unifying features that define the senescent state.

scholarly journals Anesthesia, Microcirculation, and Wound Repair in Aging

2014 ◽  
Vol 120 (3) ◽  
pp. 760-772 ◽  
Author(s):  
Itay Bentov ◽  
May J. Reed
Keyword(s):  
Wound Repair ◽  
Anesthetic Management ◽  
Tissue Perfusion ◽  
Cell Types ◽  
Impaired Wound Healing ◽  
Anesthetic Agents ◽  
Microvascular Changes ◽  
Age Related ◽  
Aged Skin

Abstract Age-related changes in skin contribute to impaired wound healing after surgical procedures. Changes in skin with age include decline in thickness and composition, a decrease in the number of most cell types, and diminished microcirculation. The microcirculation provides tissue perfusion, fluid homeostasis, and delivery of oxygen and other nutrients. It also controls temperature and the inflammatory response. Surgical incisions cause further disruption of the microvasculature of aged skin. Perioperative management can be modified to minimize insults to aged tissues. Judicious use of fluids, maintenance of normal body temperature, pain control, and increased tissue oxygen tension are examples of adjustable variables that support the microcirculation. Anesthetic agents influence the microcirculation of a combination of effects on cardiac output, arterial pressure, and local microvascular changes. The authors examined the role of anesthetic management in optimizing the microcirculation and potentially improving postoperative wound repair in older persons.

scholarly journals Chromatin accessibility dynamics of neurogenic niche cells reveal a reversible decline in neural stem cell migration during aging

2021 ◽  
Author(s):  
Robin W Yeo ◽  
Olivia Y Zhou ◽  
Brian Zhong ◽  
Mahfuza Sharmin ◽  
Tyson J Ruetz ◽  
...  
Keyword(s):  
Stem Cell ◽  
Focal Adhesions ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Neurogenic Niche ◽  
Age Related ◽  
Cell Adhesion And Migration ◽  
Different Cell Types ◽  
Migration Pathways

Aging is accompanied by a deterioration in the regenerative and repair potential of stem cell regions in the brain. However, the mechanisms underlying this decline are largely unknown. Here we profile the chromatin landscape of five different cell types freshly isolated from the subventricular zone neurogenic niche of young and old mice. We find that chromatin states exhibit distinct changes with aging in different cell types. Notably, the chromatin of quiescent neural stem cells (NSCs) becomes more repressed with age whereas that of proliferative, activated NSCs becomes more open. Surprisingly, these opposing age-related chromatin changes involve cell adhesion and migration pathways. We experimentally validate that quiescent and activated NSCs exhibit opposite migratory deficits during aging. Quiescent NSCs become more migratory during aging, whereas activated NSCs and progeny become less migratory and less able to mobilize out of the niche in vivo during aging. The cellular mechanism by which aging impairs the migration of activated NSCs and progeny involves increased occurrence of force-producing focal adhesions. Inhibiting the cytoskeletal-regulating kinase ROCK in old activated NSCs and progenitors eliminates cell adhesive forces and boosts migration speed, reverting these cells to a more youthful migratory state. Our work has important implications for restoring the migratory potential of NSCs during aging and brain injury.

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