FIGURE 2.

Activation of complement system-induced formation of MAC (C5b-9). Complement could be activated by three pathways including classical, lectin, and alternative signaling pathways, which came together toward production of C5 convertase and formation of C5b that bound to C6, C7, C8, and multiple C9 to generate the MAC. This process could be mostly inhibited by circulating inhibitors, podocyte-positive regulatory proteins, and natural products such as Astragaloside IV. However, this inhibitory effect might be devastated at high levels of complement. MAC could insert into the podocyte membrane, even in sublytic quantity, evoked cell injury under a lack of inflammation condition.