Molecular mechanisms in the process of re-epithelization in wound healing and the action of honey in keratinocytes / Mecanismos moleculares en el proceso de re-epitelización en cicatrización de heridas y la acción de la miel en queratinocitos

SUMMARY: The treatment of chronic wounds has become a public health issue in recent years mainly due to comorbidities associated with an older population and bacterial resistance. Honey has emerged as an alternative treatment for chronic wounds but lack of knowledge of its mechanism of actionin the treated tissue and low quality of evidence in clinical triads has distanced the medical community from honey as a possible treatment. One of the main processes that is altered in chronic wounds is re-epithelialization mediated by keratinocytes, where proliferation and migration processes are altered. Markers of proliferation, migration and activation of keratinocytes, such as adhesion molecules, growth factors, membrane receptors, signal translating proteins, transcription factors, microRNAs, among others are deregulated in this process. In general, honeys from different floral origins have a positive effect on markers of proliferation and migration in keratinocytes. In conclusion there are still few studies that focus on the molecular action of honey in keratinocytes and fail to report details on the honey used not allowing to achieve the same results.

RESUMEN: El tratamiento de heridas crónicas (HC) se ha vuelto un tema de salud pública en los últimos años, principalmente debido a comorbilidades asociadas a una población de mayor edad y a la resistencia bacteriana. La miel ha surgido como un tratamiento alternativo para HC pero la falta de conocimiento de su mecanismo de acción en el tejido tratado y de la baja calidad de la evidencia en triadas clínicas, ha distanciado a la comunidad médica de la miel como posible tratamiento. Uno de los principales procesos que se ve alterado en las HC es la re-epitelización mediada por queratinocitos, donde se ven alterados los procesos de proliferación y migración. Marcadores de proliferación, migración y activación de queratinocitos, como moléculas de adhesión, factores de crecimiento, receptores de membrana, proteínas traductores de señales, factores de transcripción, microARNs, entre otras, se ven desreguladas en éste proceso. De manera general las mieles de diferentes orígenes florales tienen un efecto positivo en marcadores de proliferación y migración en queratinocitos. En conclusión aún existen pocos estudios que se enfoquen en la acción molecular de la miel en queratinocitos y los pocos que existen fallan en la entrega de información en relación a la miel utilizada que pueda hacer reproducibles los resultados.

The potential role of Th17 lymphocytes in patients with psoriasis

Abstract: Background: Psoriasis is a chronic inflammatory disorder, characterized by increased keratinocyte proliferation due to abnormal differentiation of basal keratinocytes. The etiology of the disease is unclear, and according to the survey results, it is hypothesized that a combination of genetic and environmental factors prompts an abnormal immune response in patients with psoriasis. CD4+ Th cells play a multifaceted role in both immune defense and pathogenesis of certain diseases such as psoriasis. Nonetheless, the exact contribution of different subpopulations of Th cells in psoriasis is still not clear. Objective: The aim of present study was to determine the mRNA expression level of RORC as potential inducer of Th17 cell differentiation and expression pattern of Th17-signature cytokines (IL-17A and IL-22). Methods: Twenty patients with psoriasis and twenty-one healthy subjects were included in the study. Peripheral blood mononuclear cells (PBMCs) were separated and expression of three genes were determined by quantitative real-time reverse transcriptase PCR (qRT-PCR). Plasma levels of IL-17 and IL-22 were also evaluated by ELISA. Results: RORC, IL-17A and IL-22 gene expression was significantly higher in patients with psoriasis compared with healthy controls (P<0.05). In addition, a marked increase in plasma IL-17A and IL-22 levels was observed in patient group compared to controls (P<0.001). Study limitations: small number of patients. Conclusion: These data suggest that Th17 response may contribute to the pathogenesis of psoriasis.

Comportamiento clínico de análogo de mucosa bucal injertado en recesiones gingivales inducidas en modelos animales / Clinical behavior of oral mucosa analoguegrafted in gingival recession inducedin animal models

Objetivo: determinar la actividad de un injerto basado en el cocultivo de fibroblastos gingivales y queratinocitos en membrana de colágeno comercial Mem-Lok(R) (BioHorizons), Alabama, Estados Unidos) en el tratamiento de recesiones gingivales. Materiales y métodos. Esta investigación fue descriptiva y de diseño experimental. La muestra se conformó de 10 ratas Sprague Dawley a las que se indujeron recesiones gingivales. A 8 de ellas se les aplicó el injerto y las 2 restantes no recibieron tratamiento. Resultados: el análisis descriptivo de los resultados determinó la posibilidad de obtener un cocultivo celular. Luego de la aplicación del injerto, las características clínicas periodontales indicaron salud, consistencia firme, textura a manera de puntillado, contorno festoneado, biotipo grueso, sondaje periodontal de 1 mm y posición de la encía a nivel del límite amelocementario. Conclusiones: el injerto aplicado logró una cobertura radicular del 100 por ciento en todos los casos. No se observó sangrado ni contracción cicatrizal.

Aim: to determine the effectiveness of a graft based onco-cultivation of gingival fibroblast and keratinocytes in commercial collagen membrane Mem-Lok® (BioHorizons, Alabama,USA) in the treatment of gingival recessions. Materials and methods: This research was descriptiveand experimental in design. The sample was composed of 10 Sprague Dawley rats which were induced gingival recession; two of them were not treated and the graft was applied in eightof them. Results: A descriptive analysis of the results was performed, which showed that it was possible to obtain a cellco-culture. After the application of the graft, clinical periodontal characteristics were observed that indicated health: the consistency was firm, the texture resembled dots, scallopedand knife edge margin, a thick biotype and the depth ofgingival sulcus was 1 mm. Conclusions: The applied graft achieved a 100% radicularcoverage in all cases and no bleeding or scar contractionwas observed.

Atopic dermatitis: allergic dermatitis or neuroimmune dermatitis?

Abstract: Advances in knowledge of neurocellulars relations have provided new directions in the understanding and treatment of numerous conditions, including atopic dermatitis. It is known that emotional, physical, chemical or biological stimuli can generate more accentuated responses in atopic patients than in non-atopic individuals; however, the complex network of control covered by these influences, especially by neuropeptides and neurotrophins, and their genetic relations, still keep secrets to be revealed. Itching and airway hyperresponsiveness, the main aspects of atopy, are associated with disruption of the neurosensory network activity. Increased epidermal innervation and production of neurotrophins, neuropeptides, cytokines and proteases, in addition to their relations with the sensory receptors in an epidermis with poor lipid mantle, are the aspects currently covered for understanding atopic dermatitis.

Mechanisms regulating melanogenesis* / Mecanismos reguladores da melanogênese

Skin pigmentation is an important human phenotypic trait whose regulation, in spite of recent advances, has not yet been fully understood. The pigment melanin is produced in melanosomes by melanocytes in a complex process called melanogenesis. The melanocyte interacts with endocrine, immune, inflammatory and central nervous systems, and its activity is also regulated by extrinsic factors such as ultraviolet radiation and drugs. We have carried out a review of the current understanding of intrinsic and extrinsic factors regulating skin pigmentation, the melanogenesis stages and related gene defects. We focused on melanocyte-keratinocyte interaction, activation of melanocortin type 1 receptor (MC1-R) by peptides (melanocyte-stimulating hormone and adrenocorticotropic hormone) resulting from proopiomelanocortin (POMC) cleavage, and mechanisms of ultraviolet-induced skin pigmentation. The identification and comprehension of the melanogenesis mechanism facilitate the understanding of the pathogenesis of pigmentation disorders and the development of potential therapeutic options.

A pigmentação da pele é um importante traço fenotípico do ser humano mas apesar dos recentes avanços a sua regulação não está ainda totalmente esclarecida. O pigmento melanina é produzido nos melanossomas pelos melanócitos, num processo complexo designado por melanogénese. O melanócito interatua com os sistemas endócrino, imunitário, inflamatório e nervoso central e a sua atividade é também regulada por fatores extrínsecos como a radiação ultravioleta e fármacos. Fizemos uma revisão do conhecimento atual sobre os fatores intrínsecos e extrínsecos reguladores da pigmentação cutânea, etapas da melanogénese e defeitos genéticos relacionados. Fizemos enfoque na interação melanócito-keratinócito, na ativação do receptor da melanocortina tipo 1 (MC1-R) pelos péptidos (hormona estimuladora do melanócito e hormona adrenocorticotrófica) resultantes da clivagem da proopiomelanocortina (POMC) e mecanismos da pigmentação induzida pela radiação ultravioleta. A identificação e compreensão dos mecanismos reguladores da pigmentação cutânea facilitam o conhecimento dos mecanismos patogénicos dos distúrbios da pigmentação e o desenvolvimento de potenciais opções terapêuticas.

O Sistema do Hormônio de Crescimento: interações com a pele / Growth Hormone System: skin interactions

O artigo descreve o Sistema do Hormônio de Crescimento (GH), enfatizando suas possíveis ações nas células da epiderme, nas estruturas da derme e na cicatrização de feridas cutâneas. Para tanto, fez-se uma revisão dos conhecimentos sobre o hormônio do crescimento, seu receptor, a proteína carreadora deste hormônio e demais proteínas envolvidas no mecanismo que o GH utiliza para a sua manifestação nos tecidos cutâneos.

This paper describes the growth hormone system, emphasizing its possible effects on epidermal cells, dermal structures and wound healing. A review of the literature was conducted on studies concerning the growth hormone molecule, its receptor and carrier proteins and the other proteins involved in the mechanisms of its manifestation in dermal tissue.

El queratinocito: una celula inmunologica / The keratinocyte: an inmunological cell

El queratinocito es una celula inmunologica que participa activamente en la respuesta inflamatoria e inmunologica. Se efectua una revision de los conocimientos sobre las multiples funciones de esta celula epitelial

Replanteo de las funciones de los queratinocitos / Restate of the keratinocytes functions

Los queratinocitos intervienen activamente en la formación de una barrera mecánica, fisicoquímica e inmunológica. En su evolución centrífuga elaboran queratinas y otras proteínas no estructuradas, las que intervienen en el proceso de queratinización de los epitelios, con y sin estrato córneo. Durante la citodiferenciación adicionan nuevas queratinas, cuyo peso molecular aumenta a medida que las células migran hacia la superficie. La composición química de las queratinas sintetizadas y retenidas por ellos, guarda relación con las variantes histológicas del epitelio bucal. El modelo específico de sus componentes polipeptídicos permite caracterizar cada epitelio. Los queratinocitos también participan en el proceso inmunológico local. Intervienen en la maduración post-tímica e instrucción de algunos linfocitos. Inducen a las células T inmaduras a sintetizar la enzima TdT. Producen sustancias parecidas a las hormonas y excretan interleuquina-1. En gingivitis crónicas, liquen plano y algunas enfermedades cutáneas, expresan antígeno de histocompatibilidad HLA-DR involucrándose, en los procesos inflamatorios, en el reconocimiento y presentación de antígenos a los linfocitos T