Age-related changes of blood vessels in the human dermis

Abstract

Blood supply, which determines the general conditions for the functioning of different organs and tissues, including skin, is a factor that is likely to affect skin aging. The available data on age-related characteristics of vascular supply in the skin are insufficient and sometimes controversial. Thus, this work was undertaken to study age-related changes in the number of blood vessels in the human dermis. Blood vessels were visualized via immunohistochemical staining specific to two endothelial markers: von Willebrand factor and CD31 antigen. It was shown that von Willebrand factor and CD31 were present in the endothelial cells of dermal blood vessels at all examined ages, from gestation week 20 to 85 years. The intensity of von Willebrand factor-specific staining was enhanced with age. The intensity of CD31-specific staining did not change with age. The number of dermal blood vessels positively stained either for von Willebrand factor or for CD31 in the dermis gradually decreased with age. The total number of fibroblasts in the dermis, as well as the portion of proliferating PCNA+ fibroblasts, also diminished with age. The decrease in the number of blood vessels was statistically associated with a decrease in the total number of fibroblasts and in the portion of proliferating fibroblasts. Hence, reduced vascular supply is a factor leading to the age-related decrease in the number of dermal fibroblasts, and clinical measures aimed at prevention and treatment of age-related changes of the skin should rely, in particular, on improving its blood supply.