Fig. 4
From: Disulfide high mobility group box-1 causes bladder pain through bladder Toll-like receptor 4
Role of HMGB1 in PAR4 induced bladder pain. Activation of PAR4 receptors on urothelial cells elicits release of urothelial macrophage migration inhibitory factor (MIF). MIF binds to urothelial MIF receptors (CD74/CXCR4) to mediate release of urothelial HMGB1. Disulfide HMGB1 (ds HMGB1) may bind to TLR4 receptors in urothelium and/or nerve terminal innervating the bladder to mediate bladder pain