Cutaneous xanthoma consist of foam cells that originate from monocytes or macrophages and accumulate in perivascular areas of the skin. The main component of these cells is oxidized low-density lipoprotein (oxLDL). In this study, we show that mast cells surround the accumulated foam cells, suggesting their involvement in xanthoma formation. Coculture of THP-1 or U937 monocytes with the human mast cell line LUVA upregulated their uptake of oxLDL. Positive staining for intracellular cell adhesion molecule-1 (ICAM-1) at the borders between mast cells and foam cells was seen in pathological specimens of the most common cutaneous xanthoma, xanthelasma palpebrarum, and in cocultures. In the latter, ICAM1 messenger RNA levels were upregulated. The administration of anti-ICAM-1 blocking antibody inhibited the increase in oxLDL uptake by THP-1 or U937 monocytes cocultured with LUVA. Taken together, these results suggest a role for mast cells in the formation of xanthelasma palpebrarum and the involvement of ICAM-1 in this process.

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人类肥大细胞在眼睑黄斑瘤形成中的可能作用

皮肤黄色瘤由源自单核细胞或巨噬细胞的泡沫细胞组成，并积聚在皮肤的血管周围区域。这些细胞的主要成分是氧化低密度脂蛋白（oxLDL）。在这项研究中，我们发现肥大细胞围绕着积累的泡沫细胞，表明它们参与了黄色瘤的形成。THP-1 或 U937 单核细胞与人类肥大细胞系 LUVA 的共培养上调了它们对 oxLDL 的摄取。在最常见的皮肤黄色瘤、眼睑黄斑瘤的病理标本和共培养物中，发现肥大细胞和泡沫细胞之间边界的细胞内细胞粘附分子-1 (ICAM-1) 呈阳性染色。在后者中，ICAM1信使 RNA 水平上调。抗ICAM-1阻断抗体的施用抑制了与LUVA共培养的THP-1或U937单核细胞摄取oxLDL的增加。综上所述，这些结果表明肥大细胞在眼睑黄斑瘤的形成中发挥作用，并且 ICAM-1 参与了这一过程。