Immunohistochemical clues at aging of the skin microvascular unit.
BACKGROUND
Skin aging is a multifaceted process influenced by various factors affecting at variable degree at different body sites. This study focused on the aging process affecting dermal dendrocytes and the microvasculature. We also explored the effect of substance P released by capsaicin because this neuropeptide is known to affect the microvasculature environment.


METHODS
The first part of the present study was undertaken in two groups of 35 men who were younger than 30 years and older than 65 years, respectively. A skin biopsy was taken from the intact skin of a thigh during orthopedic surgical intervention after road accident. The second part of the study was performed on 30 men aged 65-68 years. They applied once daily a 0.05% capsaicin gel and the vehicle in a randomized design on the volar forearms. A skin biopsy was taken at inclusion and after a 5-month treatment phase. Immunohistochemistry was performed using a panel of antibodies. Dermal cells were distinguished according to the presence of factor XIIIa, CD34 or thrombomodulin. Blood and lymphatic vessels were studied by Ulex europaeus agglutinin-1, human podoplanin, human vascular endothelial growth factor-C (H-VEGF-C) and alpha-actin immunoreactivities.


RESULTS
In the study phase 1, a significant decrease in thrombomodulin-positive cells and vascularity were evidenced in the aged group. In the study phase 2, capsaicin appeared to boost the factor XIIIa-positive dendrocytes, the thrombomodulin-positive cells and the blood vessel network as well.


CONCLUSIONS
Specific subsets of the dermal dendrocyte populations and the blood microvasculature appear affected by aging. Capsaicin may limit these aging effects.
Quatresooz
Pascale
P
Department of Dermatopathology, University Hospital Sart Tilman, Liège, Belgium. pascale.quatresooz@chu.ulg.ac.be
Piérard
Gérald E
GE
D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D018952:Antigens, CD34 / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology; D003713:Dendritic Cells / Q000378:metabolism / Q000473:pathology; D026122:Factor XIIIa / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D055806:Microvessels / Q000187:drug effects / Q000473:pathology; D018689:Sensory System Agents / Q000494:pharmacology; D012867:Skin / Q000098:blood supply* / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D013373:Substance P / Q000378:metabolism*; D018180:Thrombomodulin / Q000378:metabolism
D018952:Antigens, CD34; D018689:Sensory System Agents; D018180:Thrombomodulin; D013373:Substance P; D026122:Factor XIIIa; D002211:Capsaicin