Screening of integrins localized on the surface of human epidermal melanocytes

초록

In vivo, melanocytes occupy three-dimensional (3D) space. Nevertheless, most experiments involving melanocytes are performed in a two-dimensional microenvironment, resulting in difficulty obtaining accurate results. Therefore, it is necessary to construct an artificial in vivo-like 3D microenvironment. Here, as a step towards engineering a precisely defined acellular 3D microenvironment supporting the maintenance of human epidermal melanocytes (HEMs), we examined the types of integrin heterodimers that are expressed transcriptionally, translationally, and functionally in HEMs. Real-time PCR and fluorescent immunoassay analyses were used to elucidate the expression of integrin alpha and beta subunit genes at the transcriptional and translational levels, respectively. The functionality of the presumed integrin heterodimers was confirmed using attachment and antibody-inhibition assays. Among the genes encoding 12 integrin subunits (alpha(1), alpha(2), alpha(3), alpha(4), alpha(5), alpha(6), alpha(7), alpha(V), beta(1), beta(3), beta(5), and beta(8)) showing significantly higher transcription levels, proteins translated from the integrin alpha(2), alpha(4), alpha(5), beta(1), beta(3), and beta(5)subunit genes were detected on the surface of HEMs. These HEMs showed significantly increased adhesion to collagen I, fibronectin, laminin, and vitronectin, and functional blockade of the integrin alpha(2)subunits significantly inhibited adhesion to collagen I, fibronectin, and laminin. In addition, there was no significant inhibition of the adhesion to fibronectin or vitronectin in HEMs with functional blockade of the integrin alpha(4), alpha(5), or alpha(V)subunits. These results indicate that the active integrin alpha(2)beta(1)heterodimer and the inactive integrin alpha(4), alpha(5), alpha(V), beta(3), and beta(5)subunits are all localized on the surface of HEMs.

키워드