Here we aim to describe each factor that leads to skin aging and describe their mechanisms. A PubMed database searches (from January 2004 to March 2014) using aging and skin as searched terms. There are substantial evidences showing that aging is associated with damage from free radicals represented by various reactive oxygen species (ROS). Mitochondria are producers and also targets of oxidative stress. The cycle of mitochondrial dysfunction can trigger the aging process. In the cellular senescence and telomeres theory, the diploid cells exhibit a limited proliferation potential. After a finite number of divisions, they enter a state of senescence with a stop replication in cell proliferation. It is suggested that aging is associated mainly with hyper-regulation of apoptosis. Obesity presumably accelerates the process of aging, which is aggravated by smoking. And the influence of the environment, called solar UV irradiation is of considerable importance to skin aging. There are several mechanisms that trigger the natural aging process and contribute to age-related changes, including oxidative stress theory of free radicals, the mitochondrial dysfunction, telomere shortening, UV radiation and other mechanisms that taken together or alone may or not accelerate the change in skin.

. Conception, design, intellectual and scientific content of the study; analysis and interpretation of data; manuscript writing; critical revision. ABSTRACT PURPOSE:To evaluate the expression profile of genes related to Toll Like Receptors (TLR) pathways of human Primary Epidermal keratinocytes of patients with severe burns. METHODS:After obtaining viable fragments of skin with and without burning, culture hKEP was initiated by the enzymatic method using Dispase (Sigma-Aldrich). These cells were treated with Trizol® (Life Technologies) for extraction of total RNA. This was quantified and analyzed for purity for obtaining cDNA for the analysis of gene expression using specific TLR pathways PCR Arrays plates (SA Biosciences). RESULTS:After the analysis of gene expression we found that 21% of these genes were differentially expressed, of which 100% were repressed or hyporegulated. Among these, the following genes (fold decrease): HSPA1A (-58), HRAS (-36), MAP2K3 (-23), TOLLIP (-23), RELA (-18), FOS (-16), and TLR1 (-6.0). CONCLUSIONS:This study contributes to the understanding of the molecular mechanisms related to TLR pathways and underlying wound infection caused by the burn. Furthermore, it may provide new strategies to restore normal expression of these genes and thereby change the healing process and improve clinical outcome.

To discuss the normal mechanism of wound healing (WH), the role of growth factors (GF) in preclinical and clinical studies and its importance in the healing of abnormal wound therapy. For search, we used the PUBMED and LILACS database, and the following descriptors: skin, wound healing, growth factor and clinical trials. We also prioritized the analysis of the Clinical Trials in the previous 10 years. Although there are many studies being conducted in the pre-clinical phase, we see that there are few studies in the clinical phase. 274 studies were identified, and 58 were selected. After tissue injury, repair occurs through coordinated biological actions that are healing. The importance of the study of healing in the skin is not only because of its anatomical location, easy access and exposure, but also because of its vital function. There is accumulating evidence that the process of healing after injury may be mediated by several GF. However, may this class of molecules even act effectively on the clinical response of this pathological condition? Many preclinical studies (in vitro and in vivo) reinforce the importance and efficacy of GF in the regeneration of damaged skin. Furthermore, recent studies have reported the use in adjuvant or not, of GF in clinical treatment to improve WH in humans. Therefore, we conclude that it seems to be effective by the use of GF in adjuvant or not in WH. However, it still seems to be necessary to carry out more clinical trials in phase I and II.

inguinal nodes 3 hours following injection, tortuous collateral lymphatic channels, and dermal backflow consistent with lymphedema. Arrows indicate inguinal nodes, black arrowheads show tortuous lymphatic channels and dermal backflow, and white arrowheads mark the feet where the radiolabelled tracer was injected.