Human Glomerular Microvascular Endothelial Cells

Microbial and Host Inflammatory Factors Induce Permeability and Activate Cytokine Production by Human Glomerular Microvascular Endothelial Cells

The broad impacts of microbial and endogenous inflammatory agonists on the promotion of systemic inflammation and on some vascular endothelial cells have been extensively characterized. Furthermore, endothelial dysfunction is a key feature of sepsis and may contribute to acute kidney injury (AKI). However, the role of glomerular endothelial cells in the pathophysiology of sepsis-associated AKI is not well characterized. To address this gap, we tested the effects of bacterial LPS, and the cytokines, IL-1β and TNF-α, on the barrier function and IL-6/IL-8 production of human glomerular microvascular endothelial cells (HGMVEC).

The effects of IL-1β, TNF-α, and LPS on the barrier function of HGMVEC were assessed using TER as a surrogate for permeability. Compared to treatment with cell culture medium, treatment with each inflammatory agonist induced a concentration-dependent reduction in TER across all tested concentrations over 24 h (Fig. 1A, 1B). These results indicated that all three inflammatory agonists induced HGMVEC permeability.

We quantified IL-6 and IL-8 levels in HGMVEC culture supernatants after 24 h. Compared with the medium, treatment with IL-1β, TNF-α, and LPS significantly increased the production of IL-6 (Fig. 1C) and IL-8 (Fig. 1D) in a concentration-dependent manner. Of the three inflammatory agonists, IL-1β exhibited the highest potency in inducing IL-6 and IL-8 production (EC50 0.0134 ng/mL) by HGMVEC, followed by LPS (EC50 0.179 ng/mL) and TNF-α (EC50 1.31 ng/mL). In conclusion, this study demonstrates that cytokines and microbial LPS, each robustly induce IL-6 and IL-8 and hyperpermeability in HGMVEC.