scholarly journals The Role of Extracellular Vesicles in Cutaneous Remodeling and Hair Follicle Dynamics

2019 ◽  
Vol 20 (11) ◽  
pp. 2758 ◽  
Author(s):  
Elisa Carrasco ◽  
Gonzalo Soto-Heredero ◽  
María Mittelbrunn

Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, are cell-derived membranous structures that were originally catalogued as a way of releasing cellular waste products. Since the discovery of their function in intercellular communication as carriers of proteins, lipids, and DNA and RNA molecules, numerous therapeutic approaches have focused on the use of EVs, in part because of their minimized risk compared to cell-based therapies. The skin is the organ with the largest surface in the body. Besides the importance of its body barrier function, much attention has been paid to the skin in regenerative medicine because of its cosmetic aspect, which is closely related to disorders affecting pigmentation and the presence or absence of hair follicles. The use of exosomes in therapeutic approaches for cutaneous wound healing has been reported and is briefly reviewed here. However, less attention has been paid to emerging interest in the potential capacity of EVs as modulators of hair follicle dynamics. Hair follicles are skin appendices that mainly comprise an epidermal and a mesenchymal component, with the former including a major reservoir of epithelial stem cells but also melanocytes and other cell types. Hair follicles continuously cycle, undergoing consecutive phases of resting, growing, and regression. Many biomolecules carried by EVs have been involved in the control of the hair follicle cycle and stem cell function. Thus, investigating the role of either naturally produced or therapeutically delivered EVs as signaling vehicles potentially involved in skin homeostasis and hair cycling may be an important step in the attempt to design future strategies towards the efficient treatment of several skin disorders.

2021 ◽  
Author(s):  
Julia Szekeres-Bartho ◽  
Timea Csabai ◽  
Eva Gorgey

AbstractPaternal antigens expressed by the foetus are recognized as foreign. Therefore,—according to the rules of transplantation immunity—the foetus ought to be “rejected”. However, during normal gestation, maternal immune functions are re-adjusted, in order to create a favourable environment for the developing foetus. Some of the mechanisms that contribute to the altered immunological environment, for example, the cytokine balance and NK cell function, with special emphasis on the role of progesterone and the progesterone-induced blocking factor (PIBF) will be reviewed.


Author(s):  
Megan A. Palmer ◽  
Eleanor Smart ◽  
Iain S. Haslam

AbstractCholesterol has long been suspected of influencing hair biology, with dysregulated homeostasis implicated in several disorders of hair growth and cycling. Cholesterol transport proteins play a vital role in the control of cellular cholesterol levels and compartmentalisation. This research aimed to determine the cellular localisation, transport capability and regulatory control of cholesterol transport proteins across the hair cycle. Immunofluorescence microscopy in human hair follicle sections revealed differential expression of ATP-binding cassette (ABC) transporters across the hair cycle. Cholesterol transporter expression (ABCA1, ABCG1, ABCA5 and SCARB1) reduced as hair follicles transitioned from growth to regression. Staining for free cholesterol (filipin) revealed prominent cholesterol striations within the basement membrane of the hair bulb. Liver X receptor agonism demonstrated active regulation of ABCA1 and ABCG1, but not ABCA5 or SCARB1 in human hair follicles and primary keratinocytes. These results demonstrate the capacity of human hair follicles for cholesterol transport and trafficking. Future studies examining the role of cholesterol transport across the hair cycle may shed light on the role of lipid homeostasis in human hair disorders.


2021 ◽  
Vol 8 ◽  
Author(s):  
Emma E. Hamilton-Williams ◽  
Graciela L. Lorca ◽  
Jill M. Norris ◽  
Jessica L. Dunne

In recent years the role of the intestinal microbiota in health and disease has come to the forefront of medical research. Alterations in the intestinal microbiota and several of its features have been linked to numerous diseases, including type 1 diabetes (T1D). To date, studies in animal models of T1D, as well as studies in human subjects, have linked several intestinal microbiota alterations with T1D pathogenesis. Features that are most often linked with T1D pathogenesis include decreased microbial diversity, the relative abundance of specific strains of individual microbes, and altered metabolite production. Alterations in these features as well as others have provided insight into T1D pathogenesis and shed light on the potential mechanism by which the microbiota plays a role in T1D pathogenesis, yet the underlying factors leading to these alterations remains unknown. One potential mechanism for alteration of the microbiota is through diet and nutrition. Previous studies have shown associations of diet with islet autoimmunity, but a direct contributing factor has yet to be identified. Diet, through introduction of antigens and alteration of the composition and function of the microbiota, may elicit the immune system to produce autoreactive responses that result in the destruction of the beta cells. Here, we review the evidence associating diet induced changes in the intestinal microbiota and their contribution to T1D pathogenesis. We further provide a roadmap for determining the effect of diet and other modifiable factors on the entire microbiota ecosystem, including its impact on both immune and beta cell function, as it relates to T1D. A greater understanding of the complex interactions between the intestinal microbiota and several interacting systems in the body (immune, intestinal integrity and function, metabolism, beta cell function, etc.) may provide scientifically rational approaches to prevent development of T1D and other childhood immune and allergic diseases and biomarkers to evaluate the efficacy of interventions.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Andreea Milasan ◽  
Nicolas Tessandier ◽  
Sisareuth Tan ◽  
Alain Brisson ◽  
Eric Boilard ◽  
...  

Introduction: Although for a long time considered as simple cellular debris, extracellular vesicles (EVs) are now known to be involved in many pathophysiological processes such as thrombosis, autoimmune diseases and inflammation. Due to their diversity and presence in different tissues, EVs are considered important biomarkers and thus, their precise detection in various biological fluids is important to better understand all their different functional activities. The lymphatic system works in close collaboration with the cardiovascular system to preserve fluid balance throughout the body. Lymphatic vessels are present in almost all vascularized tissues, including the brain and the artery wall, and their role in these organ-related pathologies are under intense investigations. Hypothesis: Since lymphatic vessels are often perceived as "sewers", due to their role in removing interstitial fluid and waste products from peripheral tissues such as the artery wall, we herein want to qualitatively and quantitatively assess the presence of EVs in circulating lymph. Methods and Results: Using several approaches such as a Zetasizer Nano S, electron microscopy and flow cytometry analysis, we have detected and characterized EVs in lymph of healthy animals, and found that these EVs are inclusively derived from red blood cells, platelets and lymphatic endothelial cells. Analysis of lymph from atherosclerotic mice (Ldlr -/- ) confirmed the idea that EVs number and origin varies according to the pathological setting. Conclusion: Herein, we show for the first time that EVs are present in lymph and that their level and origin vary in atherosclerosis. Our work will be setting the stage to a better understanding of the mechanism underlying EV accumulation in peripheral tissues during inflammation, and to better control related diseases.


2021 ◽  
Vol 19 ◽  
Author(s):  
Ayaz M. Belkozhayev ◽  
Minnatallah Al-Yozbaki ◽  
Alex George ◽  
Raigul Ye Niyazova ◽  
Kamalidin O. Sharipov ◽  
...  

There are different modalities of intercellular communication governed by cellular homeostasis. In this review, we will explore one of these forms of communication called extracellular vesicles (EVs). These vesicles are released by all cells in the body and are heterogeneous in nature. The primary function of EVs is to share information through their cargo consisting of proteins, lipids and nucleic acids (mRNA, miRNA, dsDNA etc.) with other cells, which have a direct consequence on their microenvironment. We will focus on the role of EVs of mesenchymal stem cells (MSCs) in the nervous system and how these participate in intercellular communication to maintain physiological function and provide neuroprotection. However, deregulation of this same communication system could play a role in several neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Amyotrophic lateral sclerosis, multiple sclerosis, prion disease and Huntington’s disease. The release of EVs from a cell provides crucial information to what is happening inside the cell and thus could be used in diagnostics and therapy. We will discuss and explore new avenues for the clinical applications of using engineered MSC-EVs and their potential therapeutic benefit in treating neurodegenerative diseases.


Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1255
Author(s):  
Chaorui Guo ◽  
Inga Sileikaite ◽  
Michael J. Davies ◽  
Clare L. Hawkins

Myeloperoxidase (MPO) is involved in the development of many chronic inflammatory diseases, in addition to its key role in innate immune defenses. This is attributed to the excessive production of hypochlorous acid (HOCl) by MPO at inflammatory sites, which causes tissue damage. This has sparked wide interest in the development of therapeutic approaches to prevent HOCl-induced cellular damage including supplementation with thiocyanate (SCN−) as an alternative substrate for MPO. In this study, we used an enzymatic system composed of glucose oxidase (GO), glucose, and MPO in the absence and presence of SCN−, to investigate the effects of generating a continuous flux of oxidants on macrophage cell function. Our studies show the generation of hydrogen peroxide (H2O2) by glucose and GO results in a dose- and time-dependent decrease in metabolic activity and cell viability, and the activation of stress-related signaling pathways. Interestingly, these damaging effects were attenuated by the addition of MPO to form HOCl. Supplementation with SCN−, which favors the formation of hypothiocyanous acid, could reverse this effect. Addition of MPO also resulted in upregulation of the antioxidant gene, NAD(P)H:quinone acceptor oxidoreductase 1. This study provides new insights into the role of MPO in the modulation of macrophage function, which may be relevant to inflammatory pathologies.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2182 ◽  
Author(s):  
Oliver K Fuller ◽  
Martin Whitham ◽  
Suresh Mathivanan ◽  
Mark A Febbraio

Physical activity has systemic effects on the body, affecting almost every organ. It is important not only for general health and wellbeing, but also in the prevention of diseases. The mechanisms behind the therapeutic effects of physical activity are not completely understood; however, studies indicate these benefits are not confined to simply managing energy balance and body weight. They also include systemic factors which are released into the circulation during exercise and which appear to underlie the myriad of benefits exercise can elicit. It was shown that along with a number of classical cytokines, active tissues also engage in inter-tissue communication via extracellular vesicles (EVs), specifically exosomes and other small EVs, which are able to deliver biomolecules to cells and alter their metabolism. Thus, EVs may play a role in the acute and systemic adaptations that take place during and after physical activity, and may be therapeutically useful in the treatment of a range of diseases, including metabolic disorders such as type 2 diabetes and obesity; and the focus of this review, neurological disorders such as Alzheimer’s disease.


2018 ◽  
Vol 11 (01) ◽  
pp. 1850015
Author(s):  
A. Fasano ◽  
G. Guarnieri ◽  
A. Farina

We consider the process of hemodialysis performed by means of a hollow fiber dialyzer with a special focus on the dynamics of the light solutes (including metabolic waste products) through the porous fibers membrane. The model we illustrate here completes the one formulated in a previous paper in which solutes concentrations in the dialyzate were neglected. Exploiting the large difference between the characteristic time of the processes in the machine and the relaxation time to equilibrium in the body, we confine our study to the case of constant input data in order to emphasize the role of the solute transport mechanisms. Numerical solutions show that diffusion is dominant at the early stage of filtration.


Multiple nutritional, environmental and lifestyle factors can directly affect hair follicles, to weaken and make them sensitive to the action of androgens. Hair loss can be corrected and hair growth can be improved by addressing these non-androgenic factors. Patients having hair fall, thinning, loss of volume and poor growth can be precursors to androgenetic alopecia. Recent research has shown that androgens inhibit hair growth through release of Transforming Growth Factor (TGF) ß1. Further study of this mechanism reveals that generation of Reactive Oxygen Species (ROS) induced by androgens leads to release of TGF ß1 and use of ROS scavengers can block the release of TGF ß1, explaining beneficial role of antioxidants in hair growth. The binding of ROS to intracellular proteins also causes hair loss by altering the protein structure, changing their immune recognition and converting them to new antigens targeted by inflammatory and immune systems. Calorie restriction and individual micronutrient deficiencies lead to a new process of intracellular destruction or autophagy before cell apoptosis, which could explain cessation of hair growth. Telogen is not a resting phase but now defined as active conservation of follicles under unfavourable conditions. Thus any stress, trauma, metabolic change or insult causes telogen. Micronutrients zinc, copper, selenium maintains immunity, control inflammation and preserve antioxidant activity of the cells. Vitamins A, C, D have a role in phagocytosis and antibodies maintaining resistance. Vitamin D3 modulates the hair-inductive capacity of dermal papilla cells. Vitamin and micronutrient deficiencies are prevalent among all the population of the world. Nutritive value of the foods has reduced over the years by 30%. Endocrine Disrupting chemicals are creating further damage to the hormonal balance of the body. All these can be countered by use of antioxidants and a well-planned nutritional program which will ensure strengthening and regrowth of hair follicles, without the use of Finasteride.


2021 ◽  
Vol 59 (5) ◽  
pp. 631-637
Author(s):  
M. V. Kireeva ◽  
E. M. Agafonova ◽  
A. E. Dimitreva ◽  
K. V. Sakharova ◽  
S. O. Krasnenko ◽  
...  

Alopecia areata (АA) is an autoimmune multifactorial disease characterized by increased hair loss as a result of morphological and functional changes in hair follicles. АA is divided into four main forms, among which the most severe is the universal form (UA), in which complete hair loss is possible throughout the body. Alopecia in the practice of a rheumatologist can occur with some systemic diseases of the connective tissue, with the use of high doses of chemotherapy drugs and, more recently, with the use of inhibitors of tumor necrosis factors alpha (TNF-α). The article presents 3 clinical cases of the development of UA during therapy with TNF-α. Possible mechanisms are discussed, as well as the role of pro-inflammatory cytokines in the development of this condition.


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