High concentration glucose induces inflammation in podocytes via TLR4.

Primary podocyte cultures were defined by positive staining for the podocyte markers podocin and nephrin (A). Primary cultures of podocytes harvested from WT and TLR4−/−mice, were cultured in media containing physiological concentration glucose (5.5 mM glucose+24.5 mM mannitol) as an osmotic control or high-concentration glucose (5.5 mM glucose+24.5 mM glucose) for 12 hours. High glucose induced upregulation of TLR4 (B), its ligands (C) and downstream molecules (D) in WT podocytes compared to osmotic controls. Upregulation of downstream molecules induced by high glucose was not seen in TLR4−/− podocytes(D). NF-κB DNA binding activity was increased by 2 fold in WT podocytes by high glucose stimulation, but not in TLR4−/− podocytes (E & F). Data are presented as means ± SEM; * p<0.05; ** p<0.01; *** p<0.001.