Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387, Krakow, Poland.
Pigment Cell Melanoma Res. 2012 Nov;25(6):804-14. doi: 10.1111/pcmr.12008. Epub 2012 Oct 1.
Melanosomes were recently shown to protect ARPE-19 cells, a human retinal pigment epithelium (RPE) cell line, against oxidative stress induced by hydrogen peroxide. One postulated mechanism of antioxidant action of melanin is its ability to bind metal ions. The aim here was to determine whether melanosomes are competent to bind iron within living cells, exhibiting a property previously shown only in model systems. The outcomes indicate retention of prebound iron and accumulation of iron by granules after iron delivery to cells via the culture medium, as determined by both colorimetric and electron spin resonance analyses for bound-to-melanosome iron. Manipulation of iron content did not affect the pigment's ability to protect cells against H(2) O(2) , but the function of pigment granules within RPE cells should be extended beyond a role in light irradiation to include participation in iron homeostasis.
黑素小体最近被证明可以保护 ARPE-19 细胞（一种人视网膜色素上皮细胞系）免受过氧化氢诱导的氧化应激。黑色素的一种抗氧化作用的假设机制是其结合金属离子的能力。这里的目的是确定黑素小体是否有能力在活细胞内结合铁，表现出以前仅在模型系统中显示的特性。结果表明，通过细胞培养基向细胞内输送铁后，颗粒内的铁结合和铁的积累得以保留，这通过比色法和电子自旋共振分析结合到黑素小体铁的方法得以确定。铁含量的操作并不影响色素保护细胞免受 H 2 O 2 的能力，但 RPE 细胞内色素颗粒的功能应该扩展到光照射以外的作用，包括参与铁稳态。
