Nitric oxide mediates prolyl hydroxylase 3 expression in mesangial cells and in glomerulonephritis

Renal mesangial cells are regarded as main players in glomerular inflammatory diseases. to investigate a possible crosstalk between inflammatory and hypoxia-driven signaling processes, we stimulated cultured mouse mesangial cells with different inflammatory agents and analyzed the expression of prolyl hydroxylase domain containing proteins (phds), the main regulators of hypoxia-inducible factor (hif) stability. administration of il-1β (1 nm) and tnf-α (1 nm), a combination further referred to as cytokine mix (cm), resulted in a fivefold increase in phd3 but not phd1 and phd2 mrna expression compared to untreated controls. in contrast, a combination of il-1β, tnf-α with lipopolysaccharide (10 μg/ml), and interferon-γ (20 ng/ml) designated as cm+ showed a high (60-fold) induction of phd3 and a moderate (twofold) induction of phd2 mrna expression. interestingly, cm+ but not cm induced the expression of inducible no synthase and endogenously produced no was responsible for the immense induction of phd3 in mesangial cells treated with cm+. we found that cm+ affected phd3 expression mainly via the no/hif axis, whereas phd3 regulation by cm occurred in a nf-κb-dependent manner. in turn, silencing of phd3 expression resulted in a decrease in the mrna expression of icam-1, mip-2, mcp-1, and cxcl-10, which are under control of nf-κb. in a rat model of mesangio-proliferative glomerulonephritis, phd3 mrna and protein expression was markedly induced and this effect was nearly abolished when rats were treated with the inos-specific inhibitor l-nil, thus confirming our findings also in vivo.