Horn S, Gopas J, Bashan N
Department of Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Biochem Pharmacol. 1990 Feb 15;39(4):775-80. doi: 10.1016/0006-2952(90)90158-h.
Phenylhydrazine (Phz) is a powerful hemolytic agent which has several effects on both normal and G6PD deficient red blood cells (RBCs). We have studied the mechanism of removal of Phz-damaged human RBCs by murine macrophages. Phagocytosis of Phz-treated RBCs was found to be 50 RBCs/100 mac as compared to 2 RBCs/100 mac of the controls. EGTA and sodium azide inhibited the phagocytosis, indicating a requirement for both calcium ions and energy. Incubation of macrophages with sugars such as D-galactose or D-mannose reduced phagocytosis of Phz-treated RBCs by up to 60%, indicating the involvement of a macrophage lectin-like receptor in the recognition of Phz-treated RBCs. The presence of serum in the phagocytosis assay did not affect either phagocytosis of Phz-treated RBCs or inhibition by sugars. beta-Galactosidase, but not neuraminidase, treatment of RBCs caused a significant inhibition in phagocytosis of Phz-treated RBCs. These results suggest that galactosyl residues are exposed on RBC membrane during oxidation, probably not as a result of desialization. We conclude that Phz-treated RBCs are detected as damaged cells mainly due to sugar changes on their membrane, which are directly recognized by lectin-like receptors on the macrophages.
苯肼（Phz）是一种强效溶血剂，对正常和葡萄糖-6-磷酸脱氢酶（G6PD）缺乏的红细胞（RBC）均有多种作用。我们研究了小鼠巨噬细胞清除经苯肼处理的人红细胞的机制。发现经苯肼处理的红细胞的吞噬作用为每100个巨噬细胞吞噬50个红细胞，而对照组为每100个巨噬细胞吞噬2个红细胞。乙二醇双乙醚二胺四乙酸（EGTA）和叠氮化钠抑制了吞噬作用，表明需要钙离子和能量。用D-半乳糖或D-甘露糖等糖类孵育巨噬细胞可使经苯肼处理的红细胞的吞噬作用降低多达60%，表明巨噬细胞凝集素样受体参与了对经苯肼处理的红细胞的识别。吞噬试验中血清的存在对经苯肼处理的红细胞的吞噬作用或糖类的抑制作用均无影响。用β-半乳糖苷酶而非神经氨酸酶处理红细胞会导致经苯肼处理的红细胞的吞噬作用显著受到抑制。这些结果表明，半乳糖基残基在氧化过程中暴露于红细胞膜上，可能不是去唾液酸化的结果。我们得出结论，经苯肼处理的红细胞被检测为受损细胞主要是由于其膜上的糖类变化，这些变化被巨噬细胞上的凝集素样受体直接识别。
