RESUMO
Present research is aimed to examine the number of dermal blood vessels, vascular endothelial growth factor (VEGF), delta-like ligand 4(Dll4) and Jagged-1 (Jag-1) in dermal blood vessels of human from 20weeks of pregnancy to 85years old. Numbers and proliferative activity of dermal fibroblast-like cells were also examined. Blood vessels were viewed with immunohistochemical staining for von Willebrand factor or CD31. VEGF, Dll4, Jag-1, and proliferating cell nuclear antigen (PCNA) were detected immunohistochemically. Results showed that the numbers of fibroblast-like cells, PCNA positive fibroblast-like cells, von Willebrand factor positive or CD31 positive blood vessels in dermis are dramatically decreased with age. The intensity of immunohistochemical staining for VEGF or Jag-1 in blood vessels of dermis is increased from antenatal to deep old period. The degree of immunohistochemical staining of dermal blood vessels for Dll4 has gone up from 20-40weeks of pregnancy to early life period (0-20years), and further decreased below antenatal values. Age-related decrease in the number of dermal blood vessels is suggested to be due to an impairment of VEGF signaling and to be mediated by Dll4 and Jag-1. It may be supposed that diminishing in blood supply of dermis occurring with age is a cause of a decrease in the number and proliferative pool of dermal fibroblasts.
Assuntos
Envelhecimento/fisiologia , Derme/irrigação sanguínea , Neovascularização Fisiológica/fisiologia , Envelhecimento da Pele/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Contagem de Células , Criança , Pré-Escolar , Derme/citologia , Derme/embriologia , Derme/metabolismo , Feminino , Feto/irrigação sanguínea , Feto/metabolismo , Fibroblastos/citologia , Humanos , Lactente , Recém-Nascido , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Jagged-1 , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Serrate-Jagged , Caracteres Sexuais , Envelhecimento da Pele/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator de von Willebrand/metabolismoRESUMO
Skin aging is an extremely important medical and social problem in the modern world. Therefore, a goal of the present work was to estimate changes in the numbers of fibroblast-like cells, proliferating cells nuclear antigen-positive cells, CD45-positive cells, mast cells, and eosinophils in human dermis at different ages. Skin specimens from human fetuses that died antenatally from 20 to 40 weeks of pregnancy and humans who died from different causes from 1 day to 85 years of life were used for the study. Results showed a decrease in a total number and the number of proliferating cells nuclear antigen-positive fibroblast-like cells in dermis with progression of age. The numbers of CD45-positive cells and mast cells are gradually increased with aging. Eosinophils are almost absent in dermis independently on age. Mast cells are probably a main factor that potentially can be involved in tissue damage and aging changes in skin. Mast cells should be regarded as an important target for anti-aging therapy.