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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 -
Nutrients Feb 2018The skin is the third most zinc (Zn)-abundant tissue in the body. The skin consists of the epidermis, dermis, and subcutaneous tissue, and each fraction is composed of... (Review)
Review
The skin is the third most zinc (Zn)-abundant tissue in the body. The skin consists of the epidermis, dermis, and subcutaneous tissue, and each fraction is composed of various types of cells. Firstly, we review the physiological functions of Zn and Zn transporters in these cells. Several human disorders accompanied with skin manifestations are caused by mutations or dysregulation in Zn transporters; acrodermatitis enteropathica (Zrt-, Irt-like protein (ZIP)4 in the intestinal epithelium and possibly epidermal basal keratinocytes), the spondylocheiro dysplastic form of Ehlers-Danlos syndrome (ZIP13 in the dermal fibroblasts), transient neonatal Zn deficiency (Zn transporter (ZnT)2 in the secretory vesicles of mammary glands), and epidermodysplasia verruciformis (ZnT1 in the epidermal keratinocytes). Additionally, acquired Zn deficiency is deeply involved in the development of some diseases related to nutritional deficiencies (acquired acrodermatitis enteropathica, necrolytic migratory erythema, pellagra, and biotin deficiency), alopecia, and delayed wound healing. Therefore, it is important to associate the existence of mutations or dysregulation in Zn transporters and Zn deficiency with skin manifestations.
Topics: Carrier Proteins; Cation Transport Proteins; Deficiency Diseases; Fibroblasts; Humans; Keratinocytes; Mutation; Skin; Skin Diseases; Zinc
PubMed: 29439479
DOI: 10.3390/nu10020199 -
Pharmacological Research Apr 2021Exposure to the external environment may lead to instability and dysfunction of the skin, resulting in refractory wound, skin aging, pigmented dermatosis, hair loss,... (Review)
Review
Exposure to the external environment may lead to instability and dysfunction of the skin, resulting in refractory wound, skin aging, pigmented dermatosis, hair loss, some immune-mediated dermatoses, and connective tissue diseases. Nowadays, many skin treatments have not achieved a commendable balance between medical recovery and cosmetic needs. Exosomes are cell-derived nanoscale vesicles carrying various biomolecules, including proteins, nucleic acids, and lipids, with the capability to communicate with adjacent or distant cells. Recent studies have demonstrated that endogenic multiple kinds of exosomes are crucial orchestrators in shaping physiological and pathological development of the skin. Besides, exogenous exosomes, such as stem cell exosomes, can serve as novel treatment options to repair, regenerate, and rejuvenate skin tissue. Herein, we review new insights into the role of endogenic and exogenous exosomes in the skin microenvironment and recent advances in applications of exosomes related to dermatology and cutaneous medical aesthetics. The deep understanding of the mechanisms by which exosomes perform biological functions in skin is of great potential to establish attractive therapeutic methods for the skin.
Topics: Administration, Cutaneous; Animals; Exosomes; Humans; Regeneration; Regenerative Medicine; Skin; Skin Diseases; Skin Physiological Phenomena
PubMed: 33582246
DOI: 10.1016/j.phrs.2021.105490 -
American Family Physician Nov 2017Herpes zoster, or shingles, is caused by reactivation of varicella zoster virus, which causes chickenpox. There are an estimated 1 million cases in the Unites States... (Review)
Review
Herpes zoster, or shingles, is caused by reactivation of varicella zoster virus, which causes chickenpox. There are an estimated 1 million cases in the Unites States annually, with an individual lifetime risk of 30%. Patients with conditions that decrease cell-mediated immunity are 20 to 100 times more likely to develop herpes zoster. Patients may present with malaise, headache, low-grade fever, and abnormal skin sensations for two to three days before the classic maculopapular rash appears. The rash is usually unilateral, confined to a single dermatome, and typically progresses to clear vesicles that become cloudy and crust over in seven to 10 days. Herpes zoster can be treated with acyclovir, valacyclovir, or famciclovir, ideally within 72 hours of the development of the rash. Postherpetic neuralgia is the most common complication, occurring in about one in five patients. It is defined as pain in a dermatomal distribution sustained for at least 90 days after acute herpes zoster. Treatment is focused on symptom control and includes topical lidocaine or capsaicin and oral gabapentin, pregabalin, or tricyclic antidepressants. The varicella zoster virus vaccine decreases the incidence of herpes zoster and is approved for adults 50 years and older. The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommends this vaccine for adults 60 years and older, except for certain immunosuppressed patients.
Topics: Antiviral Agents; Female; Herpes Zoster; Herpes Zoster Vaccine; Humans; Male; Neuralgia, Postherpetic; Skin
PubMed: 29431387
DOI: No ID Found -
Theranostics 2022Small extracellular vesicles (sEVs) have been proposed as a possible solution to the current lack of therapeutic interventions for endogenous skin regeneration. We... (Meta-Analysis)
Meta-Analysis Review
Small extracellular vesicles (sEVs) have been proposed as a possible solution to the current lack of therapeutic interventions for endogenous skin regeneration. We conducted a systematic review of the available evidence to assess sEV therapeutic efficacy and safety in wound healing and skin regeneration in animal models. 68 studies were identified in Web of Science, Scopus, and PubMed that satisfied a set of prespecified inclusion criteria. We critically analyzed the quality of studies that satisfied our inclusion criteria, with an emphasis on methodology, reporting, and adherence to relevant guidelines (including MISEV2018 and ISCT criteria). Overall, our systematic review and meta-analysis indicated that sEV interventions promoted skin regeneration in diabetic and non-diabetic animal models and influenced various facets of the healing process regardless of cell source, production protocol and disease model. The EV source, isolation methods, dosing regimen, and wound size varied among the studies. Modification of sEVs was achieved mainly by manipulating source cells via preconditioning, nanoparticle loading, genetic manipulation, and biomaterial incorporation to enhance sEV therapeutic potential. Evaluation of potential adverse effects received only minimal attention, although none of the studies reported harmful events. Risk of bias as assessed by the SYRCLE's ROB tool was uncertain for most studies due to insufficient reporting, and adherence to guidelines was limited. In summary, sEV therapy has enormous potential for wound healing and skin regeneration. However, reproducibility and comprehensive evaluation of evidence are challenged by a general lack of transparency in reporting and adherence to guidelines. Methodological rigor, standardization, and risk analysis at all stages of research are needed to promote translation to clinical practice.
Topics: Animals; Biocompatible Materials; Extracellular Vesicles; Reproducibility of Results; Skin; Wound Healing
PubMed: 36185607
DOI: 10.7150/thno.73436 -
Cells Jun 2023The skin is the organ that serves as the outermost layer of protection against injury, pathogens, and homeostasis with external factors; in turn, it can be damaged by... (Review)
Review
The skin is the organ that serves as the outermost layer of protection against injury, pathogens, and homeostasis with external factors; in turn, it can be damaged by factors such as burns, trauma, exposure to ultraviolet light (UV), infrared radiation (IR), activating signaling pathways such as Toll-like receptors (TLR) and Nuclear factor erythroid 2-related factor 2 (NRF2), among others, causing a need to subsequently repair and regenerate the skin. However, pathologies such as diabetes lengthen the inflammatory stage, complicating the healing process and, in some cases, completely inhibiting it, generating susceptibility to infections. Exosomes are nano-sized extracellular vesicles that can be isolated and purified from different sources such as blood, urine, breast milk, saliva, urine, umbilical cord bile cells, and mesenchymal stem cells. They have bioactive compounds that, thanks to their paracrine activity, have proven to be effective as anti-inflammatory agents, inducers of macrophage polarization and accelerators of skin repair and regeneration, reducing the possible complications relating to poor wound repair, and prolonged inflammation. This review provides information on the use of exosomes as a promising therapy against damage from UV light, infrared radiation, burns, and skin disorders.
Topics: Female; Humans; Wound Healing; Exosomes; Skin; Skin Diseases; Burns
PubMed: 37371095
DOI: 10.3390/cells12121625 -
International Journal of Molecular... Nov 2020As the most dominant cell type in the skin, keratinocytes play critical roles in wound repair not only as structural cells but also exerting important immune functions.... (Review)
Review
As the most dominant cell type in the skin, keratinocytes play critical roles in wound repair not only as structural cells but also exerting important immune functions. This review focuses on the communications between keratinocytes and immune cells in wound healing, which are mediated by various cytokines, chemokines, and extracellular vesicles. Keratinocytes can also directly interact with T cells via antigen presentation. Moreover, keratinocytes produce antimicrobial peptides that can directly kill the invading pathogens and contribute to wound repair in many aspects. We also reviewed the epigenetic mechanisms known to regulate keratinocyte immune functions, including histone modifications, non-protein-coding RNAs (e.g., microRNAs, and long noncoding RNAs), and chromatin dynamics. Lastly, we summarized the current evidence on the dysregulated immune functions of keratinocytes in chronic nonhealing wounds. Based on their crucial immune functions in skin wound healing, we propose that keratinocytes significantly contribute to the pathogenesis of chronic wound inflammation. We hope this review will trigger an interest in investigating the immune roles of keratinocytes in chronic wound pathology, which may open up new avenues for developing innovative wound treatments.
Topics: Animals; Chemokines; Chronic Disease; Cytokines; Humans; Inflammation; Keratinocytes; MicroRNAs; Skin; Wound Healing
PubMed: 33233704
DOI: 10.3390/ijms21228790 -
Military Medical Research Aug 2023Skin wounds are characterized by injury to the skin due to trauma, tearing, cuts, or contusions. As such injuries are common to all human groups, they may at times... (Review)
Review
Skin wounds are characterized by injury to the skin due to trauma, tearing, cuts, or contusions. As such injuries are common to all human groups, they may at times represent a serious socioeconomic burden. Currently, increasing numbers of studies have focused on the role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in skin wound repair. As a cell-free therapy, MSC-derived EVs have shown significant application potential in the field of wound repair as a more stable and safer option than conventional cell therapy. Treatment based on MSC-derived EVs can significantly promote the repair of damaged substructures, including the regeneration of vessels, nerves, and hair follicles. In addition, MSC-derived EVs can inhibit scar formation by affecting angiogenesis-related and antifibrotic pathways in promoting macrophage polarization, wound angiogenesis, cell proliferation, and cell migration, and by inhibiting excessive extracellular matrix production. Additionally, these structures can serve as a scaffold for components used in wound repair, and they can be developed into bioengineered EVs to support trauma repair. Through the formulation of standardized culture, isolation, purification, and drug delivery strategies, exploration of the detailed mechanism of EVs will allow them to be used as clinical treatments for wound repair. In conclusion, MSC-derived EVs-based therapies have important application prospects in wound repair. Here we provide a comprehensive overview of their current status, application potential, and associated drawbacks.
Topics: Humans; Skin; Soft Tissue Injuries; Extracellular Vesicles; Mesenchymal Stem Cells; Wound Healing
PubMed: 37587531
DOI: 10.1186/s40779-023-00472-w -
Diagnostic Criteria of Ulcerative Pyoderma Gangrenosum: A Delphi Consensus of International Experts.JAMA Dermatology Apr 2018Pyoderma gangrenosum is a rare inflammatory skin condition that is difficult to diagnose. Currently, it is a "diagnosis of exclusion," a definition not compatible with...
IMPORTANCE
Pyoderma gangrenosum is a rare inflammatory skin condition that is difficult to diagnose. Currently, it is a "diagnosis of exclusion," a definition not compatible with clinical decision making or inclusion for clinical trials.
OBJECTIVE
To propose and validate diagnostic criteria for ulcerative pyoderma gangrenosum.
EVIDENCE REVIEW
Diagnostic criteria were created following a Delphi consensus exercise using the RAND/UCLA Appropriateness Method. The criteria were validated against peer-reviewed established cases of pyoderma gangrenosum and mimickers using k-fold cross-validation with methods of multiple imputation.
FINDINGS
Delphi exercise yielded 1 major criterion-biopsy of ulcer edge demonstrating neutrophilic infiltrate-and 8 minor criteria: (1) exclusion of infection; (2) pathergy; (3) history of inflammatory bowel disease or inflammatory arthritis; (4) history of papule, pustule, or vesicle ulcerating within 4 days of appearing; (5) peripheral erythema, undermining border, and tenderness at ulceration site; (6) multiple ulcerations, at least 1 on an anterior lower leg; (7) cribriform or "wrinkled paper" scar(s) at healed ulcer sites; and (8) decreased ulcer size within 1 month of initiating immunosuppressive medication(s). Receiver operating characteristic analysis revealed that 4 of 8 minor criteria maximized discrimination, yielding sensitivity and specificity of 86% and 90%, respectively.
CONCLUSIONS AND RELEVANCE
This Delphi exercise produced 1 major criterion and 8 minor criteria for the diagnosis of ulcerative pyoderma gangrenosum. The criteria may serve as a guideline for clinicians, allowing for fewer misdiagnoses and improved patient selection for clinical trials.
Topics: Area Under Curve; Biopsy; Consensus; Delphi Technique; Humans; Neutrophils; Pyoderma Gangrenosum; ROC Curve; Skin; Skin Ulcer
PubMed: 29450466
DOI: 10.1001/jamadermatol.2017.5980