Acute Kidney Injury Induced Lupus Exacerbation Through the Enhanced Neutrophil Extracellular Traps (and Apoptosis) in Fcgr2b Deficient Lupus Mice With Renal Ischemia Reperfusion Injury

Abstract

Renal ischemia is the most common cause of acute kidney injury (AKI) that might be exacerbate lupus activity through neutrophil extracellular traps (NETs) and apoptosis. Here, the renal ischemia reperfusion injury (I/R) was performed in Fc gamma receptor 2b deficient (Fcgr2b-/-) lupus mice and the in vitro experiments. At 24 h post-renal I/R injury, NETs in peripheral blood neutrophils and in kidneys were detected using myeloperoxidase (MPO), neutrophil elastase (NE) and citrullinated histone H3 (CitH3), as well as kidney apoptosis (activating caspase-3), which were prominent in Fcgr2b-/- mice more compared to wild-type (WT). After 120 h renal-I/R injury, renal NETs (using MPO and NE) were non-detectable, whereas glomerular immunoglobulin (Ig) deposition and serum anti-dsDNA were increased in Fcgr2b-/- mice. These results imply that renal NETs at 24 h post-renal I/R exacerbated the lupus nephritis at 120 h post-renal I/R injury in Fcgr2b-/- lupus mice. Furthermore, a Syk inhibitor attenuated NETs, that activated by phorbol myristate acetate (PMA; a NETs activator) or lipopolysaccharide (LPS; a potent inflammatory stimulator), more prominently in Fcgr2b-/- neutrophils than the WT cells as determined by dsDNA, PAD4 and MPO. In addition, the inhibitors against Syk and PAD4 attenuated lupus characteristics (serum creatinine, proteinuria, and anti-dsDNA) in Fcgr2b-/- mice at 120 h post-renal I/R injury. In conclusion, renal I/R in Fcgr2b-/- mice induced lupus exacerbation at 120 h post-I/R injury partly because Syk-enhanced renal NETs led to apoptosis-induced anti-dsDNA, which was attenuated by a Syk inhibitor.

A Comparison Between 1 Day versus 7 Days of Sepsis in Mice with the Experiments on LPS-Activated Macrophages Support the Use of Intravenous Immunoglobulin for Sepsis Attenuation

“…On the other hand, the intracellular reactive oxygen species (ROS) was determined by DHE (dihydroethidium) assay (ab236206; Abcam, Cambridge, MA, USA), according to the manufacturer’s instructions as previously described. 24 …”

Neutrophil Extracellular Traps in Severe SARS-CoV-2 Infection: A Possible Impact of LPS and (1→3)-β-D-glucan in Blood from Gut Translocation

“…For serum dsDNA, Quant-iT™ PicoGreen reagent (Thermo Fisher Scientific, Paisley, UK) was used according to the manufacturer’s directions. Briefly, an aqueous working solution was added to the samples for 5 min at room temperature and measured dsDNA at 480/520 nm on a fluorescent microplate reader (Bio-Tek, Santa Clara, CA, USA) [ 8 , 9 , 24 ]. Proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8) and neutrophil elastase were measured by enzyme-linked immunosorbent assay (ELISA) from Invitrogen (Waltham, MA, USA) and Abcam270204 (Cambridge, UK), respectively.…”

“…After 2 h of incubation, the coverslips were fixed with 4% formaldehyde, blocked with Tris-buffered saline (TBS) in 2% bovine serum albumin (BSA) (Sigma-Aldrich), and permeabilized by TBS with 0.05% Tween 20 (Sigma-Aldrich). Then, NETs formation was detected by nuclear morphology staining using a blue-fluorescent DNA-staining color 4′,6-diamidino2-phenylindole (DAPI) [ 8 , 9 , 24 ]. For detection of free dsDNA in the supernatant, the supernatant from 2-hour-stimulated neutrophils (5 × 10 5 cells/well) was mixed with QuantiTTM PicoGreen reagent (Thermo Fisher Scientific).…”

“…Indeed, COVID-19-induced neutrophilia might be associated with profound systemic inflammatory cytokines during COVID-19 infection through several proinflammatory activities, including neutrophil extracellular traps (NETs) [ 7 ]. As such, NETosis (neutrophils death after NETs) is inducible by several mechanisms, including damage-associated molecular patterns (DAMPs) or pathogen-associated molecular patterns (PAMPs), through the peptidyl-arginine deiminase 4 ( PAD4 ) enzyme, that can be activated by the NADPH oxidase 2 (NOX2)-dependent or NOX2-independent pathway [ 8 , 9 ]. During severe infection, both DAMPs and PAMPs activate NETs formation that partly enhances cytokine storm and systemic inflammation, leading to the prominent multi-organ dysfunctions, referred to as “sepsis” [ 10 ].…”

Lactobacillus rhamnosus attenuates Thai chili extracts induced gut inflammation and dysbiosis despite capsaicin bactericidal effect against the probiotics, a possible toxicity of high dose capsaicin

“…To quantitatively determine the intestinal tight junction injury, gene expression of occludin and ZO-1 were determined with quantitative reverse transcription polymerase chain reaction (qRT-PCR) following a published protocol [ 39 ]. Briefly, total RNA was prepared from the colon tissue samples with an RNA-easy mini kit (Qiagen, Hilden, Germany) and was quantified by Nanodrop 1000 Spectrophotometer (Thermo Scientific).…”