Nanostructural change of human melanocytes stimulated with α-melanocyte stimulating hormone observed by atomic force microscopy.

Abstract

It is well known that α-melanocyte stimulating hormone (α-MSH) induces melanization, but structural changes of melanocytes after α-MSH exposure are not well known. This study investigated the serial morphologic changes of human cultured melanocytes after stimulation with α-MSH using atomic force microscopy (AFM). Cultured human melanocytes were treated with α-MSH for 7 days. Contact mode AFM images were obtained using a NANOstation II and fixed melanocytes were scanned in PBS solution at a resolution of 512 × 512 pixels, at a scan speed of 0.4 line/s. The surface roughness and pore-like structures of the melanocytes were measured from topographic images using the Scanning Probe Imaging Processor. The surface roughness of cell body did not change significantly over time. All three roughness parameters (Sa, Sq, Sz) inside the pore-like structures on the dendrites increased significantly. The number of pore-like structures increased and the length and the breadth of pore-like structures also increased gradually. Pore-like structures changed statistically significantly in response to α-MSH stimulation. Further study will be needed to clarify whether the nature of pore-like structures is related to movement of melanosomes.