FIGURE 2:

TWEAK and TWEAK receptors. TWEAK binds Fn14 and transduces proinflammatory signals in kidney cells. In the absence of inflammation TWEAK may also induce cell proliferation, while in the presence of inflammation it promotes cell death. Chimeric mouse studies have established a key role of renal cell Fn14 in kidney injury. Macrophages also express Fn14 and may respond to TWEAK. In addition, they express CD163, which may be released in a soluble form and scavenges TWEAK. The precise role of CD163 in TWEAK dynamics is not fully understood. There is not enough information on the site of Fn14 expression in polarized epithelia.