Figure 4.

Glycation increases the sensitivity of hRBC to MAC-mediated lysis and of HUVEC to MAC-induced release of growth factors. (A) hRBC were incubated without or with 50 mM ribose for 48 h at room temperature followed by reduction with NaBH₃CN (open column, cells not exposed to NaBH₃CN; filled columns, cells exposed to NaBH₃CN). Cell volume was adjusted in glycated and nonglycated control cells, and aliquots of cells were separated for rescue with immunoaffinity-purified human CD59 (4 μg) or incubation with neutralizing anti-CD59 Ab (YTH53.1), before exposure to purified human C5b6, C7, C8, and C9 to form the MAC. The last column to the right represents cells that were first exposed to the anti-CD59 Ab and then rescued with affinity-purified human CD59. (Inset) Similar osmotic fragility of control (□) and glycated (■) cells after volume adjustment. (B) HUVEC were incubated with or without 50 mM ribose (24 h, 37°C), followed by reduction with NaBH₃CN. Cells were then exposed to purified human C5b6, C7, C8, and C9 to form the MAC, and the mitogenic activity in the conditioned medium was measured as in ref. 13. Results are expressed as the ratio of mitogenic activity released into the conditioned media in the presence or absence of MAC.