Modulation of Photoaging-Induced Cutaneous Elastin: Evaluation of Gene and Protein Expression of Markers Related to Elastogenesis Under Different Photoexposure Conditions.

INTRODUCTION: Photoaging is the process by which ultraviolet rays gradually induce clinical and histological changes in the skin through the production and organization of biological molecules, such as elastin, which is critical to skin strength and elasticity. After exposure to radiation, elastin may undergo alternative mRNA splicing, resulting in modified proteins that contribute to the formation of aging characteristics, such as solar elastosis. The present work aimed to study two different forms of elastin under these conditions: normal elastin and elastin that had been altered in exon 26A. METHODS: These different forms of elastin were characterized for gene expression by quantitative real-time polymerase chain reaction (qPCR) and for protein expression by immunohistochemistry of ex vivo skins (from photoexposed and non-photoexposed areas) and in vitro reconstituted skin. In addition, up- and downstream molecules in the elastin signaling cascade were evaluated. RESULTS: As a result, a significant increase in the gene expression of elastin 26A was observed in both ex vivo photoexposed skin tissues and the in vitro photoexposed reconstituted skins. Additionally, significant increases in the gene expression levels of matrix metalloproteinase-12 (MMP12) and lysyl oxidase (LOX) were observed in the ex vivo skin model. The evaluation of protein expression levels of some photoaging markers on the reconstituted skin revealed increased tropoelastin and fibrillin-1 expression after photoexposure. CONCLUSION: This work contributes to a better understanding of the biological mechanisms involved in photoaging, making it possible to obtain new strategies for the development of dermocosmetic active ingredients to prevent and treat skin aging.

Radiofrequency therapy in esthetic dermatology: A review of clinical evidences.

BACKGROUND: Chronological skin aging causes the modification of genetic material through enzymes and proteins changes. The process reduces cellular proliferation, along with loss of tissue elasticity, reduced ability to regulate aqueous exchanges, and inefficient tissue replication. Appearance is negatively affected by cumulative changes in coloration, texture, and elasticity over time. The increase in the population's average life expectancy boosts the search for cosmetic therapies that can delay aging, mostly for the noninvasive modalities. Among the various options, radiofrequency therapy is a technique that can help reduce the effects of skin aging. AIM: Therefore, this study aims to review clinical evidence provided by scientific literature on the benefits of using radiofrequency therapy in reducing skin aging effects. METHODS: A review of the literature concerning skin aging, characteristics of radiofrequency therapy, and radiofrequency therapy in the treatment of skin laxity and mechanism of action was conducted using PubMed. RESULTS: The included studies have suggested that the mechanism of radiofrequency action is heating the dermis while preserving the epidermis. This heating causes immediate collagen denaturation, which is followed by the formation of new collagen, naturally providing skin tightening and greater elasticity. CONCLUSION: Even when used as single therapeutic modality, radiofrequency seems to meet the expectations in reducing the effects of skin aging.

Rabbit antithymocyte globulin inhibits monocyte-derived dendritic cells maturation in vitro and polarizes monocyte-derived dendritic cells towards tolerogenic dendritic cells expressing indoleamine 2,3-dioxygenase.

BACKGROUND: Rabbit antithymocyte globulin (rATG) is a polyclonal mixture of immunoglobulin (Ig) G. It is used to prevent graft rejection and also graft versus host disease after transplantation. Its effect on lymphocyte function has been widely studied. Dendritic cells are central actors of the immune system. As antigen presenting cells, they are able to initiate, stimulate, and modulate immune responses. METHODS: In this study, we investigated rATG effects on in vitro differentiation and maturation of monocyte-derived dendritic cells (Mo-DCs). RESULTS: rATG inhibited maturation of immature Mo-DCs and allowed the generation of dendritic cells expressing ILT-3, CD123, CCR6 but not CCR7 and producing Indoleamine 2,3-dioxygenase mRNA as well as interferon-alpha. CONCLUSION: rATG polarizes in vitro Mo-DCs towards tolerogenic dendritic cells.

CD86 molecule is a specific marker for canine monocyte-derived dendritic cells.

In this study, canine monocyte-derived dendritic cells (cMo-DC) were produced in presence of canine GM-CSF (cGM-CSF) and canine IL-4 (cIL-4), and they were characterized by their dendritic morphology, MLR functionality and phenotype. We noticed that cMo-DC were labelled with three anti-human CD86 (FUN-1, BU63 and IT2.2 clones), whereas resting and activated lymphocytes or monocytes were not stained. CD86 expression was induced by cIL-4 and was up-regulated during the differentiation of the cMo-DC, with a maximum at day 7. Furthermore, cMo-DC were very potent even in low numbers as stimulator cells in allogeneic MLR, and BU63 mAb was able to completely block the cMo-DC-induced proliferation in MLR. We also observed that cMo-DC highly expressed MHC Class II and CD32, but we failed to determine their maturation state since the lack of commercially available canine markers. Moreover, cMo-DC contained cytoplasmic periodic microstructures, potentially new ultrastructural markers of canine DC recently described. In conclusion, this work demonstrates that the CD86 costimulatory marker is now usable for a better characterization of in vitro canine DC.

Evaluation of elutriation and magnetic microbead purification of canine monocytes.

An elutriation technique was developed to obtain large quantities of pure canine monocytes. Firstly, peripheral blood mononuclear cells (PBMC) were isolated from whole blood by Ficoll gradient. Then, the PBMC were separated by an elutriation procedure. We demonstrated that these techniques allow the isolation of canine peripheral blood monocytes with a purity of 64% +/- 7.9 when labelled with anti-CD14 antibody. This purity increased to 83% +/- 2.2 after separation by magnetic anti-CD14 microbeads. The cell viability was more than 95% and apoptotic cells were less than 10%. The monocytes purified by these methods were functionally active in a mixed leukocyte reaction (MLR). A lymphocyte fraction was obtained directly only by elutriation with an average of 79.9% +/- 10.7 of CD5+, 7.9% +/- 3.5 of CD21+ and 1.78% +/- 2.53 of CD14+. Our results indicate that this elutriation procedure is a safe method to purify monocytes as well as lymphocytes, useful in MLR.