RESUMO
BACKGROUND: Biomimetic peptides are synthetic compounds that are identical to amino acid sequence synthesized by an organism and can interact with growth factor receptors and provide antiaging clinical effects. PURPOSE: The purpose of this study was to investigate the effects of biomimetic peptides on the repair processes in the dermis using a model of cell cultures and in vivo. PATIENTS AND METHODS: Five female volunteers were subjected to the injection of biomimetic peptides 1 month prior to the abdominoplasty procedure. Cell culture, immunocytochemistry, and confocal microscopy methods were used in this study. RESULTS: Biomimetic peptides regulate the synthesis of proteins Ki-67, type I procollagen, AP-1, and SIRT6 in cell cultures of human fibroblasts. They contribute to the activation of regeneration processes and initiation of mechanisms that prevent aging. Intradermal administration of complex of biomimetic peptides produces a more dense arrangement of collagen fibers in the dermis and increased size of the fibers after 2 weeks. The complex of biomimetic peptides was effective in the in vivo experiments, where an increase in the proliferative and synthetic activities of fibroblasts was observed. CONCLUSION: This investigation showed that the studied peptides have biological effects, testifying the stimulation of reparative processes in the skin under their control.
RESUMO
Lymphocyte subsets are major cellular components of the adaptive immune response and in most cases show 24-h (circadian) variations in health. In order to determine overall levels and circadian characteristics of cytotoxic natural killer (NK) and T and B lymphocyte subsets, blood samples were collected every 4 h for 24 h from eleven male controls (C) without neoplastic disease and nine men with untreated non-small cell lung cancer (NSCLC) and analyzed for 3 hormones (melatonin, cortisol, and interleukin 2 [IL2]) and for 11 lymphocyte subpopulations classified by cell surface clusters of differentiation (CD) and antigen receptors. Circadian rhythmicity for each variable was evaluated by ANOVA and 24 h cosine fitting and groups compared. Rhythms in melatonin and cortisol (peaks near 01:30 and 08:00 h) indicated identical synchronization to the light-dark schedule and probable persistent entrainment of rhythms for both groups in metabolism or proliferation of healthy tissues normally tightly coupled to the sleep-wake cycle. Twenty-four hours means were significantly higher in NSCLC for CD16, CD25, cortisol, and IL2 and lower for CD8, CD8bright, and γδTCR. A significant circadian rhythm was found in C with daytime peaks for CD8, CD8dim, CD16, Vδ2TCR, and cortisol and nighttime peaks for CD3, CD4, CD20, and melatonin, and in NSCLC, with daytime peaks for CD16, γδTCR, Vδ2TCR and cortisol, and nighttime peaks for CD4, CD25, and melatonin. Thus, NSCLC was associated with significant increases or decreases in proportions for several lymphocyte subsets that may reflect disease development, but peak times were nevertheless similar between C and NSCLC for each variable, suggesting that timed circadian administration (chronotherapy) of immunotherapy and other cancer treatments may improve efficacy due to persistent circadian entrainment of healthy tissues.