Inhibitory effect of anti-malarial agents on the expression of proinflammatory chemokines via Toll-like receptor 3 signaling in human glomerular endothelial cells

Abstract

Objective Although anti-malarial agents, chloroquine (CQ) and hydroxychloroquine (HCQ) are currently used for the treatment of systemic lupus erythematosus, their efficacy for lupus nephritis (LN) remains unclear. Given that upregulation of glomerular Toll-like receptor 3 (TLR3) signaling plays a pivotal role in the pathogenesis of LN, we examined whether CQ and HCQ affect the expression of the TLR3 signaling-induced representative proinflammatory chemokines, monocyte chemoattractant protein-1 (MCP-1), and C–C motif chemokine ligand 5 (CCL5) in cultured human glomerular endothelial cells (GECs). Methods We examined the effect of polyinosinic-polycytidylic acid (poly IC), an agonist of TLR3, on MCP-1, CCL5 and interferon (IFN)-β expression in GECs. We then analyzed whether pretreatment with CQ, HCQ, or dexamethasone (DEX) inhibits poly IC-induced expression of these chemokines using real-time quantitative reverse transcriptase PCR and ELISA. Phosphorylation of signal transducers and activator of transcription protein 1 (STAT1) was examined using western blotting. Results Poly IC increased MCP-1 and CCL5 expression in a time- and concentration-dependent manner in GECs. Pretreating cells with CQ, but not DEX, attenuated poly IC-induced MCP-1 and CCL5 expression; however, HCQ pretreatment attenuated poly IC-induced CCL5, but not MCP-1. HCQ did not affect the expression of IFN-β and phosphorylation of STAT-1. Conclusion Considering that TLR3 signaling is implicated, at least in part, in LN pathogenesis, our results suggest that anti-malarial agents exert a protective effect against the development of inflammation in GECs, as postulated in LN. Interestingly, CQ is a rather powerful inhibitor compared with HCQ on TLR3 signaling-induced chemokine expression in GECs. In turn, these findings may further support the theory that the use of HCQ is safer than CQ in a clinical setting. However, further detailed studies are needed to confirm our preliminary findings.

Glomerular endothelial expression of type I IFN-stimulated gene, DExD/H-Box helicase 60 via toll-like receptor 3 signaling: possible involvement in the pathogenesis of lupus nephritis

“…Since GECs are directly exposed to circulating viral particles in the glomerulus, endothelial viral and noninfectious stimuli, such as endogenous ligands, can activate regional TLR3 signaling cascade [ 23 ]: the TIR-domain-containing adapter-inducing interferon-β (TRIF)-dependent pathways via transcriptional factors, leading to the subsequent release of type I IFN [ 22 ]. Thus, regional viral and “pseudo” viral immunoreactions, including proinflammatory cytokines/chemokines production via the activation of TLR3 signaling in the intrinsic glomerular cells have been postulated to be involved in the pathogenesis of LN [ 3 , 6 , 7 , 24 ]. Furthermore, sustained activation of type I IFN is believed to participate in LN pathogenesis [ 1 , 2 ].…”

UC-BSCs Exosomes Regulate Th17/Treg Balance in Patients with Systemic Lupus Erythematosus via miR-19b/KLF13

“…[ 11 ]. Research reports in recent years have found that miR-19b is associated with disease progression, is misexpressed in many different human diseases such as atherosclerosis and diabetes, and is involved in the regulation of disease progression [ 13 , 14 , 15 ]. In this study, we first eliminated SLE patients with abnormally low miR-19b expression.…”

“…In SLE, inflammatory cytokines play a major role, and Treg and Th17 cell subgroups can mediate the secretion of inflammatory cytokines [ 13 ]. Recent research found [ 14 , 15 , 16 ], in the stage of active SLE, Treg levels are low and Treg/Th17 levels are decreasing.…”

Effect of sera from lupus patients on the glomerular endothelial fibrinolysis system

“…Glomerular endothelial cells were purchased from ScienCell (Carlsbad, CA, USA). The cells were cultured in gelatin‐coated six‐well cell culture plates using 1 mL/wells of endothelial growth medium‐2 (Lonza, Walkersville, MD, USA) supplemented with 5% fetal bovine serum, 50 μg/mL gentamicin, and 50 μg/mL amphotericin B, as previously described 12 . Confluent cells were used in the experiments.…”

“…The cells were cultured in gelatincoated six-well cell culture plates using 1 mL/wells of endothelial growth medium-2 (Lonza, Walkersville, MD, USA) supplemented with 5% fetal bovine serum, 50 lg/mL gentamicin, and 50 lg/mL amphotericin B, as previously described. 12 Confluent cells were used in the experiments. Patient serum (100 lL) was added to 1 mL of culture medium.…”