An examination of eicosanoid production in human skin during the sunburn reaction and in relation to melanin production in melanocytic cells PDF Download

Author: Mojgan Masoodi
Publisher:
ISBN:
Category :
Languages : en
Pages : 253

View

Book Description

Author: Karl Gledhill
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Erythema is a hallmark skin response to excessive ultraviolet radiation (UVR) and is associated with cutaneous inflammation. Both are mediated by inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2) and chemoattractants such as 12-hydroxyeicosatetraenoic acid (12-HETE) leading to vasodilation and increased leukocyte infiltration. The erythematous response is more pronounced in individuals with low basal melanin levels or who fail to respond to UVR with a robust up-regulation of melanogenesis. While melanin production is a key function of melanocytes, these cells can also produce NO and PGE2, and are located in close proximity to the dermal vasculature. It has been hypothesized that melanocytes with poor melanogenic capacity may participate in the inflammatory response to UVR. The aim of this project was to investigate the inflammatory response in the skin of individuals with either skin phototype (SPT) 1 or 4 to UVR. Sixteen normal healthy individuals were selected for study (8 SPT-1 & 8 SPT-4). Buttock skin was investigated by immunohistochemistry for leukocyte subtypes, eicosanoid producing enzymes and NO synthases under basal and UVR-stimulated conditions. In addition primary cultures of epidermal melanocytes (EM) were established from 16 individuals (8 SPT-1 & 8 SPT-4) and assessed for the presence of eicosanoid-producing enzymes, melanogenic enzymes and NO synthases, by immunocytochemistry, Polymerase Chain Reaction and Western Blotting and for the production of the main pro-inflammatory eicosanoid PGE2 by ELISA and Mass Spectrometry. Moreover, the fatty acid composition of cultured melanocytes was assessed by Gas Chromatography. Results showed that individuals with SPT-1 had significantly greater neutrophil infiltration into the epidermis than those with SPT-4 at 24 hrs post-UVR. Moreover, CD3+ lymphocyte infiltration into the dermis was significantly greater in individuals with SPT-4 than those with SPT-1 at 24 and 72 hrs post-UVR. NOS-1, NOS-3, 12-LOX and COX-2 expression were significantly increased in SPT-1 skin, while NOS-2 and 15-LOX were significantly increased in SPT-4 skin. As 12-LOX and COX-2 products are chemoattractive (for neutrophils) and pro-inflammatory respectively these data could explain the greater observed neutrophil infiltration in SPT-1. The 15-LOX product (15-HETE) is anti-inflammatory and may suggest that 15-LOX up-regulation in SPT-4 skin may aid resolution of the sunburn response, which in part may be mediated by CD3+ lymphocytes and a class-switch in eicosanoid production from COX to LOX products. Melanocyte primary cultures surprisingly showed that SPT was not correlated with melanin content or melanogenic enzyme expression/activity suggesting that all melanocytes in vitro contained the necessary cellular machinery to produce melanin. This finding may reflect also their equal treatment under these enriched culture conditions, which may or may not be available to these cells in situ. Moreover, all melanocytes expressed the necessary machinery (PLA2, COX-1, cPGES) to produce PGE2. However, only some cultures did so at baseline and in response to UVR, and this was not correlated with SPT. A positive correlation was found however between expression level of dopachrome tautomerase (DCT) and protection against PGE2 production in response to UVR, which may suggest a novel role for DCT unrelated to melanogenesis. In summary this research project has generated data that highlights differences between the skin of individuals with SPT-1 and those with SPT-4, and may provide evidence that the keratinocyte partner contributes significantly to the SPT-associated response. This research may also suggest DCT as a novel therapeutic target to protect EM from participation in the UVR-associated inflammatory response in skin.

Author: Suzanne Pilkington
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Sunburn is prevalent, and while the clinically apparent effects disappear relatively quickly, repeated episodes have longer term consequences including skin cancer. Pro-inflammatory eicosanoid expression and leukocytic infiltration characterise the peak of the sunburn response, however, little is known of these processes during the resolution phase. Therefore, in human skin, we examined the changes in eicosanoid expression and leukocytic infiltration up to 14 days post acute sunburn.Photoprotected buttock skin was exposed to 3x MED of broadband UVR and changes in skin erythema were measured over a 14 day period (n=13; 20-58 years, 5M/8F, phototype I-III). Biopsies and suction blister fluid were sampled from unexposed and UVR-exposed skin across the 14 day time-course and analysed by immunohistochemistry (neutrophil elastase, CD4, CD8, CD68, CD1a, COX-2, EP4) and LC-MS/MS (eicosanoids). Erythema, COX-2 expression, eicosanoid production and infiltration of innate immune cells (neutrophils and macrophage), peaked at D1 post UVR. By D7 erythema showed 60% resolution, while epidermal and dermal expression of the prostaglandin E2 receptor EP4 remained elevated up to D14. Infiltration of adaptive immune cells (CD4+ and CD8+ T cells) peaked later at D4-D7 and remained above baseline at D14 (p

Author: Raja K Sivamani
Publisher: CRC Press
ISBN: 1482214172
Category : Medical
Languages : en
Pages : 460

View

Book Description
Cosmeceuticals and Active Cosmetics discusses the science of nearly two dozen cosmeceuticals used today. This third edition provides ample evidence on specific cosmeceutical substances, their classes of use, skin conditions for which they are used, and points of interest arising from other considerations, such as toxicology and manufacturing. The book discusses both cosmetic and therapeutic uses of cosmeceuticals for various conditions including rosacea, dry skin, alopecia, eczema, seborrheic dermatitis, purpura, and vitiligo. Active ingredients in the following products are discussed: caffeine, curcumin, green tea, Rhodiola rosea, milk thistle, and more. Also covered are topical peptides and proteins, amino acids and derivatives, antioxidants, vitamins E and C, niacinamide, botanical extracts, and biomarine actives. Providing ample scientific references, this book is an excellent guide to understanding the science behind the use of cosmeceuticals to treat a variety of dermatological conditions.

Author: Filip Cristiana
Publisher: BoD – Books on Demand
ISBN: 1789231345
Category : Science
Languages : en
Pages : 218

View

Book Description
Oxygen represents only 20% of the Earth's atmosphere, yet it is vital for the survival of aerobic organisms. There is a dark part of the use of oxygen that consists in generating reactive species that are potentially harmful to living organisms. Moreover, reactive oxygen species can combine with nitrogen derivatives and generate many other reactive species. Thus, living organisms are continuously assaulted by reactive species from external or internal sources. However, the real danger comes in the case of high concentrations and prolonged exposure to these species. This book presents an image of the mechanisms of action of reactive species and emphasizes their involvement in diseases. Inflammation and cancer are examined to determine when and how reactive species turn the evolution of a benign process to a malignant one. Some answers may come from recent studies indicating that reactive species are responsible for epigenetic changes.

Author: Néstor P. Sánchez
Publisher: Springer Science & Business Media
ISBN: 1461406889
Category : Medical
Languages : en
Pages : 160

View

Book Description
Atlas of Dermatology in Internal Medicine is the only concise text-atlas to cover the most common and most important cutaneous manifestations of systemic disease in children and adults. It features more than 150 clinical photographs that are accompanied by format-driven, clinically focused text on the diagnosis and management of cutaneous manifestations of connective tissue, pulmonary, renal, GI, endocrine, malignant, infectious, and HIV disease. There is also a separate chapter on skin diseases commonly seen in the ICU. A special feature is its systematic coverage of clinically relevant dermatopathology. The book is a helpful tool for physicians and trainees in internal medicine, family medicine, pediatrics, emergency medicine, and critical care medicine, as well as family, emergency, and critical care nurse practitioners.

Author: Biswanath Dinda
Publisher: Springer
ISBN: 3030055752
Category : Science
Languages : en
Pages : 296

View

Book Description
In this book, the author provides expert analysis on naturally occurring iridoids, their chemistry and their distribution in plants and insects. Particular attention is given to the pharmacology of iridoids and their prospective applications in pharmaceutical and agricultural industries. Iridoids are found in a wide variety of plants and some insects, and they are structurally derived from monoterpenoid natural products. In the first two chapters of this book, the author describes the iridoids classification, occurrence and distribution in plants and insects. The following chapters cover different chromatographic and spectroscopic techniques that can be used to identify and quantify iridoids in herbal formulations, and also the biosynthesis of iridoids, in which the reader will discover a metabolomics and transcriptomics analysis to identify the genes involved in the biosynthesis. The final chapters provide insights on several pharmacological activities of iridoids, their physiological role in insects, pharmacokinetics in mammals, insects and microorganisms, and their applications in medicine and agriculture. This book will engage students and researchers interested in the chemistry of natural products, and it will also appeal to medicinal chemists and practitioners working in the design of new herbal drugs with bioactive pure iridoids.

Author: Fiona M. Cunningham
Publisher:
ISBN:
Category : Medical
Languages : en
Pages : 402

View

Book Description
This volume provides an overview of lipid mediators from synthesis to inhibition. It addresses the immune system and its diseases from a pharmacological viewpoint and combines clinical aspects with basic science.

Author: Koushik Lahiri
Publisher: JP Medical Ltd
ISBN: 9350906589
Category : Medical
Languages : en
Pages : 464

View

Book Description
Comprehensive guide to pigmentary disorders of the skin covering numerous conditions as well as abnormalities of hair and nails.

Author: Aldo Morrone
Publisher: Springer Nature
ISBN: 3030374769
Category : Medical
Languages : en
Pages : 241

View

Book Description
This richly illustrated book is a comprehensive guide to the dermatologic disorders that may be encountered in refugees and other migrants. It will equip readers to diagnose and treat a diverse range of skin diseases and conditions, including, but not limited to, infections caused by bacteria, viruses, fungi, and parasites, dermatologic manifestations of sexually transmitted diseases, dermatoses associated with malnutrition, pigmentary disorders, bullous diseases, connective tissue diseases, and benign and malignant cutaneous neoplasias. Attention is drawn to various neglected tropical skin diseases and to the characteristic signs of torture and genital mutilations. Helpful information is also provided on the significance of skin color and the relevance of ethnic and genetic factors. The clinical chapters are complemented by discussion of the circumstances that give rise to migration, such as poverty, war, and environmental conditions. This enables the reader to gain a more rounded understanding of patients’ circumstances that in turn will positively impact on patient care. This book will be of wide interest to dermatologists, whether experienced or in training, as well as to general physicians and researchers.