Age-related changes in angiogenesis in human dermis

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 20 weeks of pregnancy to 85 years 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 20-40 weeks of pregnancy to early life period (0-20 years), 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.