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Medecine Sciences : M/S Dec 2020One of the major challenges of the 21 century is the fight against aging, defined as a set of physiological mechanisms altering the physical and intellectual capacities... (Review)
Review
One of the major challenges of the 21 century is the fight against aging, defined as a set of physiological mechanisms altering the physical and intellectual capacities of human beings. Aging of the skin is only one visible part of this process. It is associated with major healing defects linked in part to the alteration of the biomechanical properties of skin cells, mainly dermal fibroblasts. The immune system, another key component in maintaining skin homeostasis and the efficient healing of wounds, also suffers the effects of time: the consequent skin immunosenescence would limit the anti-infectious and vaccine response, while promoting a pro-tumor environment. The main skin damages due to aging, whether intrinsic or extrinsic, will be detailed before listing the effective anti-aging strategies to combat age-related dermal and epidermal stigmas.
Topics: Aging; Animals; Cellular Senescence; Drugs, Investigational; Epidermis; Humans; Skin; Skin Aging; Therapies, Investigational; Wound Healing
PubMed: 33296633
DOI: 10.1051/medsci/2020232 -
Tissue Engineering. Part B, Reviews Aug 2019Millions of people every year develop scars in response to skin injuries after surgery, trauma, or burns with significant undesired physical and psychological effects.... (Review)
Review
Millions of people every year develop scars in response to skin injuries after surgery, trauma, or burns with significant undesired physical and psychological effects. This review provides an update on engineering strategies for scar-free wound healing and discusses the role of different cell types, growth factors, cytokines, and extracellular components in regenerative wound healing. The use of pro-regenerative matrices combined with engineered cells with less intrinsic potential for fibrogenesis is a promising strategy for achieving scar-free skin tissue regeneration.
Topics: Animals; Cicatrix; Humans; Regeneration; Regenerative Medicine; Skin; Skin Physiological Phenomena; Wound Healing
PubMed: 30938269
DOI: 10.1089/ten.TEB.2018.0350 -
The Yale Journal of Biology and Medicine Mar 2020Psoriasis is a frequent inflammatory skin disease. Fundamental research on the pathogenesis of psoriasis has substantially increased our understanding of skin... (Review)
Review
Psoriasis is a frequent inflammatory skin disease. Fundamental research on the pathogenesis of psoriasis has substantially increased our understanding of skin immunology, which has helped to introduce innovative and highly effective therapies. Psoriasis is a largely T lymphocyte-mediated disease in which activation of innate immune cells and pathogenic T cells result in skin inflammation and hyperproliferation of keratinocytes. B cells have thus far largely been neglected regarding their role for the pathogenesis of psoriasis. However, recent data shed light on their role in inflammatory skin diseases. Interestingly, interleukin (IL)-10-producing regulatory B cells have been assumed to ameliorate psoriasis. In this review, we will discuss the development of disease, pathogenicity, and current developments in therapeutic options. We describe different roles of T cells, B cells, and cytokines for the immunopathology and disease course of psoriasis.
Topics: Biological Products; Humans; Immunity, Innate; Immunosuppressive Agents; Psoriasis; Skin
PubMed: 32226340
DOI: No ID Found -
Medecine Sciences : M/S Dec 2020The skin is a sentinel organ making easily visible the passing of time. Chronological and environmental aging weakens skin structure and functions. The skin barrier, the... (Review)
Review
The skin is a sentinel organ making easily visible the passing of time. Chronological and environmental aging weakens skin structure and functions. The skin barrier, the elastic and mechanical properties of the cutaneous tissue as well as its vascular reactivity are impacted by aging. The barrier dysfunction in aged skin is caused by defects in epidermal keratinocytes renewal and differentiation notably linked to abnormal expression of microRNAs regulating cell death and autophagy. An abnormal balance between synthesis and degradation of matrix proteins modifies the mechanical properties of the dermis in aged skin. Finally, a reduction of the vascular reactivity linked to endothelial dysfunctions is observed in elderly people. These biological processes can be targeted by therapeutic approaches either topical or systemic, especially using anti-oxydants or senolytics. These anti-aging strategies might contribute to restore, at least in part, the functional integrity of aged skin.
Topics: Aged; Aged, 80 and over; Aging; Cosmeceuticals; Dermatologic Agents; Epidermis; Humans; Microvessels; Skin; Skin Aging; Skin Physiological Phenomena; Therapies, Investigational
PubMed: 33296632
DOI: 10.1051/medsci/2020223 -
Cells May 2020Exosomes are nano-sized vesicles that serve as mediators for cell-to-cell communication. With their unique nucleic acids, proteins, and lipids cargo compositions that... (Review)
Review
Exosomes are nano-sized vesicles that serve as mediators for cell-to-cell communication. With their unique nucleic acids, proteins, and lipids cargo compositions that reflect the characteristics of producer cells, exosomes can be utilized as cell-free therapeutics. Among exosomes derived from various cellular origins, mesenchymal stem cell-derived exosomes (MSC-exosomes) have gained great attention due to their immunomodulatory and regenerative functions. Indeed, many studies have shown anti-inflammatory, anti-aging and wound healing effects of MSC-exosomes in various in vitro and in vivo models. In addition, recent advances in the field of exosome biology have enabled development of specific guidelines and quality control methods, which will ultimately lead to clinical application of exosomes. This review highlights recent studies that investigate therapeutic potential of MSC-exosomes and relevant mode of actions for skin diseases, as well as quality control measures required for development of exosome-derived therapeutics.
Topics: Exosomes; Humans; Immunologic Factors; Mesenchymal Stem Cells; Regeneration; Skin; Wound Healing
PubMed: 32392899
DOI: 10.3390/cells9051157 -
The Journal of Investigative Dermatology Apr 2021There is increasing evidence that skin aging is significantly enforced by the accumulation of senescent dermal fibroblasts. Various stressors damaging macromolecules... (Review)
Review
There is increasing evidence that skin aging is significantly enforced by the accumulation of senescent dermal fibroblasts. Various stressors damaging macromolecules inside and outside fibroblasts are responsible. In addition, NK cells fail to adequately remove senescent (SEN) fibroblasts from tissues. SEN fibroblasts by the release of the proinflammatory, tissue degrading senescent-associated secretory phenotype factors and vesicles with distinct cargo impact on their endogenous niche and spread senescence and skin aging. In this review, we will further discuss less noticed facets, including the plasticity of distinct dermal fibroblast phenotypes, the underestimated impact of the extracellular matrix itself, and the depletion of fibroblast subsets on skin homeostasis and aging.
Topics: Animals; Cell Communication; Cellular Senescence; Connective Tissue; Extracellular Matrix; Fibroblasts; Humans; Killer Cells, Natural; Mice; Models, Animal; Skin; Skin Aging
PubMed: 33563466
DOI: 10.1016/j.jid.2020.11.010 -
Cells Jun 2019There are many studies on certain skin cell specifications and their contribution to wound healing. In this review, we provide an overview of dermal cell heterogeneity... (Review)
Review
There are many studies on certain skin cell specifications and their contribution to wound healing. In this review, we provide an overview of dermal cell heterogeneity and their participation in skin repair, scar formation, and in the composition of skin substitutes. The papillary, reticular, and hair follicle associated fibroblasts differ not only topographically, but also functionally. Human skin has a number of particular characteristics that are different from murine skin. This should be taken into account in experimental procedures. Dermal cells react differently to skin wounding, remodel the extracellular matrix in their own manner, and convert to myofibroblasts to different extents. Recent studies indicate a special role of papillary fibroblasts in the favorable outcome of wound healing and epithelial-mesenchyme interactions. Neofolliculogenesis can substantially reduce scarring. The role of hair follicle mesenchyme cells in skin repair and possible therapeutic applications is discussed. Participation of dermal cell types in wound healing is described, with the addition of possible mechanisms underlying different outcomes in embryonic and adult tissues in the context of cell population characteristics and extracellular matrix composition and properties. Dermal white adipose tissue involvement in wound healing is also overviewed. Characteristics of myofibroblasts and their activity in scar formation is extensively discussed. Cellular mechanisms of scarring and possible ways for its prevention are highlighted. Data on keloid cells are provided with emphasis on their specific characteristics. We also discuss the contribution of tissue tension to the scar formation as well as the criteria and effectiveness of skin substitutes in skin reconstruction. Special attention is given to the properties of skin substitutes in terms of cell composition and the ability to prevent scarring.
Topics: Animals; Cicatrix; Dermis; Extracellular Matrix; Fibroblasts; Hair Follicle; Humans; Keloid; Myofibroblasts; Regeneration; Skin; Skin Physiological Phenomena; Skin, Artificial; Wound Healing
PubMed: 31216669
DOI: 10.3390/cells8060607 -
Nature Communications Feb 2021Understanding global communications among cells requires accurate representation of cell-cell signaling links and effective systems-level analyses of those links. We...
Understanding global communications among cells requires accurate representation of cell-cell signaling links and effective systems-level analyses of those links. We construct a database of interactions among ligands, receptors and their cofactors that accurately represent known heteromeric molecular complexes. We then develop CellChat, a tool that is able to quantitatively infer and analyze intercellular communication networks from single-cell RNA-sequencing (scRNA-seq) data. CellChat predicts major signaling inputs and outputs for cells and how those cells and signals coordinate for functions using network analysis and pattern recognition approaches. Through manifold learning and quantitative contrasts, CellChat classifies signaling pathways and delineates conserved and context-specific pathways across different datasets. Applying CellChat to mouse and human skin datasets shows its ability to extract complex signaling patterns. Our versatile and easy-to-use toolkit CellChat and a web-based Explorer ( http://www.cellchat.org/ ) will help discover novel intercellular communications and build cell-cell communication atlases in diverse tissues.
Topics: Algorithms; Animals; Cell Communication; Computational Biology; Gene Expression Profiling; Humans; Internet; Mice; Models, Theoretical; Sequence Analysis, RNA; Signal Transduction; Single-Cell Analysis; Skin; Software
PubMed: 33597522
DOI: 10.1038/s41467-021-21246-9 -
Mechanisms of Ageing and Development Sep 2021The skin is comprised of different cell types with different proliferative capacities. Skin aging occurs with chronological age and upon exposure to extrinsic factors... (Review)
Review
The skin is comprised of different cell types with different proliferative capacities. Skin aging occurs with chronological age and upon exposure to extrinsic factors such as photodamage. During aging, senescent cells accumulate in different compartments of the human skin, leading to impaired skin physiology. Diverse skin cell types may respond differently to senescence-inducing stimuli and it is not clear how this results in aging-associated skin phenotypes and pathologies. This review aims to examine and provide an overview of current evidence of cellular senescence in the skin. We will focus on cellular characteristics and behaviour of different skin cell types undergoing senescence in the epidermis and dermis, with a particular focus on the complex interplay between mitochondrial dysfunction, autophagy and DNA damage pathways. We will also examine how the dermis and epidermis cope with the accumulation of DNA damage during aging.
Topics: Aging; Autophagy; Cellular Senescence; DNA Damage; Humans; Mitochondria; Skin; Skin Aging
PubMed: 34166688
DOI: 10.1016/j.mad.2021.111525 -
International Journal of Molecular... Jan 2022Natural substances have traditionally been used in skin care for centuries. There is now an ongoing search for new natural bioactives that not only promote skin health... (Review)
Review
Natural substances have traditionally been used in skin care for centuries. There is now an ongoing search for new natural bioactives that not only promote skin health but also protect the skin against various harmful factors, including ultraviolet radiation and free radicals. Free radicals, by disrupting defence and restoration mechanisms, significantly contribute to skin damage and accelerate ageing. Natural compounds present in plants exhibit antioxidant properties and the ability to scavenge free radicals. The increased interest in plant chemistry is linked to the growing interest in plant materials as natural antioxidants. This review focuses on aromatic and medicinal plants as a source of antioxidant substances, such as polyphenols, tocopherols, carotenoids, ascorbic acid, and macromolecules (including polysaccharides and peptides) as well as components of essential oils, and their role in skin health and the ageing process.
Topics: Aging; Animals; Antioxidants; Ascorbic Acid; Carotenoids; Humans; Oxidative Stress; Phytochemicals; Polyphenols; Skin; Tocopherols
PubMed: 35054770
DOI: 10.3390/ijms23020585