Dataset Information

CD154 Induces Interleukin-6 Secretion by Kidney Tubular Epithelial Cells under Hypoxic Conditions: Inhibition by Chloroquine.

ABSTRACT: Inflammation is a major contributor to tubular epithelium injury in kidney disorders, and the involvement of blood platelets in driving inflammation is increasingly stressed. CD154, the ligand of CD40, is one of the mediators supporting platelet proinflammatory properties. Although hypoxia is an essential constituent of the inflammatory reaction, if and how platelets and CD154 regulate inflammation in hypoxic conditions remain unclear. Here, we studied the control by CD154 of the proinflammatory cytokine interleukin- (IL-) 6 secretion in short-term oxygen (O2) deprivation conditions, using the HK-2 cell line as a kidney tubular epithelial cell (TEC) model. IL-6 secretion was markedly stimulated by CD154 after 1 to 3 hours of hypoxic stress. Both intracellular IL-6 expression and secretion were stimulated by CD154 and associated with a strong upregulation of IL-6 mRNA and increased transcription. Searching for inhibitors of CD154-mediated IL-6 production by HK-2 cells in hypoxic conditions, we observed that chloroquine, a drug that has been repurposed as an anti-inflammatory agent, alleviated this induction. Therefore, CD154 is a potent early stimulus for IL-6 secretion by TECs in O2 deprivation conditions, a mechanism likely to take part in the deleterious inflammatory consequences of platelet activation in kidney tubular injury. The inhibition of CD154-induced IL-6 production by chloroquine suggests the potential usefulness of this drug as a therapeutic adjunct in conditions associated with acute kidney injury.

SUBMITTER: Dewitte A

PROVIDER: S-EPMC7013356 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

CD154 Induces Interleukin-6 Secretion by Kidney Tubular Epithelial Cells under Hypoxic Conditions: Inhibition by Chloroquine.

Dewitte Antoine A Villeneuve Julien J Lepreux Sébastien S Bouchecareilh Marion M Gauthereau Xavier X Rigothier Claire C Combe Christian C Ouattara Alexandre A Ripoche Jean J

Mediators of inflammation 20200131

Inflammation is a major contributor to tubular epithelium injury in kidney disorders, and the involvement of blood platelets in driving inflammation is increasingly stressed. CD154, the ligand of CD40, is one of the mediators supporting platelet proinflammatory properties. Although hypoxia is an essential constituent of the inflammatory reaction, if and how platelets and CD154 regulate inflammation in hypoxic conditions remain unclear. Here, we studied the control by CD154 of the proinflammatory ...[more]

PMID: 32089648

Similar Datasets

Project description:Hypoxia is the key pathobiological trigger of tubular oxidative stress and cell death that drives the transition of acute kidney injury (AKI) to chronic kidney disease (CKD). The mitochondrial-rich proximal tubular epithelial cells (PTEC) are uniquely sensitive to hypoxia and thus, are pivotal in propagating the sustained tubular loss of AKI-to-CKD transition. Here, we examined the role of PTEC-derived small extracellular vesicles (sEV) in propagating the 'wave of tubular death'. Ex vivo patient-derived PTEC were cultured under normoxia (21 % O2) and hypoxia (1 % O2) on Transwell inserts for isolation and analysis of sEV secreted from apical versus basolateral PTEC surfaces. Increased numbers of sEV were secreted from the apical surface of hypoxic PTEC compared with normoxic PTEC. No differences in basolateral sEV numbers were observed between culture conditions. Biological pathway analysis of hypoxic-apical sEV cargo identified distinct miRNAs linked with cellular injury pathways. In functional assays, hypoxic-apical sEV selectively induced ferroptotic cell death (↓glutathione peroxidase-4, ↑lipid peroxidation) in autologous PTEC compared with normoxic-apical sEV. The addition of ferroptosis inhibitors, ferrostatin-1 and baicalein, attenuated PTEC ferroptosis. RNAse A pretreatment of hypoxic-apical sEV also abrogated PTEC ferroptosis, demonstrating a role for sEV RNA in ferroptotic 'wave of death' signalling. In line with these in vitro findings, in situ immunolabelling of diagnostic kidney biopsies from AKI patients with clinical progression to CKD (AKI-to-CKD transition) showed evidence of ferroptosis propagation (increased numbers of ACSL4+ PTEC), while urine-derived sEV (usEV) from these 'AKI-to-CKD transition' patients triggered PTEC ferroptosis (↑lipid peroxidation) in functional studies. Our data establish PTEC-derived apical sEV and their intravesicular RNA as mediators of tubular lipid peroxidation and ferroptosis in hypoxic kidney injury. This concept of how tubular pathology is propagated from the initiating insult into a 'wave of death' provides novel therapeutic check-points for targeting AKI-to-CKD transition.

Project description:BackgroundBlood transfusion, a common basic supporting therapy, can lead to acute hemolytic transfusion reaction (AHTR). AHTR poses a great risk to patients through kidney function damage in a short time. Previous reports found that heme from destroyed red blood cells impaired kidney function, and NLR family pyrin domain containing 3 (NLRP3) inflammasome was augmented in case of kidney injury. However, the detailed mechanism regarding whether NLRP3 inflammasome is involved in kidney function injury in AHTR is not fully understood yet.MethodsHemolysis models were established by vein injection with human blood plasma or mouse heme from destroyed red blood cells. The injured renal tubular epithelial cells (RTECs) were evaluated by tubular damage markers staining in hemolysis models and in primary RTECs in vitro. The activation of NLRP3 inflammasome in RTECs by hemes was investigated by Western blot, ELISA, scanning electron microscopy, immunofluorescent staining, flow cytometry, and hemolysis models. NLRP3 gene knockout mice were employed to confirm these observations in vitro and in vivo. The binding between a novel inhibitor (66PR) and NLRP3 was affirmed by molecule docking and co-immunoprecipitation. The rescue of 66PR on kidney function impairment was explored in murine hemolysis models.ResultsWe found that heme could activate NLRP3 inflammasome in RTECs to induce kidney function injury. NLRP3 gene knockout could prevent the damage of RTECs caused by hemes and recover kidney function in AHTR. Moreover, NLRP3 inflammasome chemical inhibitor, 66PR, could bind to NLRP3 protein and inhibit inflammasome activation in RTECs, which consequently relieved the injury of RTECs caused by hemes, and alleviated kidney function damage in the AHTR model.ConclusionsHemes could activate NLRP3 inflammasome in RTECs, and a novel NLRP3 inflammasome inhibitor named 66PR relieved kidney function damage in AHTR. Our findings provided a new possible strategy to treat kidney function failure in AHTR.

Project description:BACKGROUNDSerum creatinine concentrations (SCrs) are used to determine the presence and severity of acute kidney injury (AKI). SCr is primarily eliminated by glomerular filtration; however, most mechanisms of AKI in critical illness involve kidney proximal tubules, where tubular secretion occurs. Proximal tubular secretory clearance is not currently estimated in the intensive care unit (ICU). Our objective was to estimate the kidney clearance of secretory solutes in critically ill adults.METHODSWe collected matched blood and spot urine samples from 170 ICU patients and from a comparison group of 70 adults with normal kidney function. We measured 7 endogenously produced secretory solutes using liquid chromatography-tandem mass spectrometry. We computed a composite secretion score incorporating all 7 solutes and evaluated associations with 28-day major adverse kidney events (MAKE28), defined as doubling of SCr, dialysis dependence, or death.RESULTSThe urine-to-plasma ratios of 6 of 7 secretory solutes were lower in critically ill patients compared with healthy individuals after adjustment for SCr. The composite secretion score was moderately correlated with SCr and cystatin C (r = -0.51 and r = -0.53, respectively). Each SD higher composite secretion score was associated with a 25% lower risk of MAKE28 (95% CI 9% to 38% lower) independent of severity of illness, SCr, and tubular injury markers. Higher urine-to-plasma ratios of individual secretory solutes isovalerylglycine and tiglylglycine were associated with MAKE28 after accounting for multiple testing.CONCLUSIONAmong critically ill adults, tubular secretory clearance is associated with adverse outcomes, and its measurement could improve assessment of kidney function and dosing of essential ICU medications.FUNDINGGrants from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK/NIH) K23DK116967, the University of Washington Diabetes Research Center P30DK017047, an unrestricted gift to the Kidney Research Institute from the Northwest Kidney Centers, and the Vanderbilt O'Brien Kidney Center (NIDDK 5P30 DK114809-03). The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.

Project description:BackgroundPrior papers have been inconsistent regarding how much creatinine clearance (CrCl) overestimates glomerular filtration rate (GFR). A recent cross-sectional study suggested that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio is larger when GFR is lower among patients with chronic kidney disease (CKD); but there have been no validation of this in other cohorts.MethodsTo fill these gaps in knowledge regarding the relation between CrCl and GFR, we conducted cross-sectional and longitudinal analysis of the Modification of Diet in Renal Disease study (MDRD) and African American Study of Kidney Disease and Hypertension (AASK); and cross-sectional analysis of a clinical dataset from the Mayo Clinic of four different patient populations (CKD patients, kidney transplant recipients, post kidney donation subgroup and potential kidney donors). In the cross-sectional analyses (MDRD, AASK and Mayo Clinic cohort), we examined the relation between the CrCl/iothalamate GFR (iGFR) ratio at different categories of iGFR or different levels of CrCl. In the MDRD and AASK longitudinal analyses, we studied how the CrCl/iGFR ratio changed with those who had improvement in iGFR (CrCl) over time versus those who had worsening of iGFR (CrCl) over time.ResultsObserved CrCl/iGFR ratios were generally on the lower end of the range reported in the literature for CKD (median 1.24 in MDRD, 1.13 in AASK and 1.25 in Mayo Clinic cohort). Among CKD patients in whom CrCl and iGFR were measured using different timed urine collections, CrCl/iGFR ratio were higher with lower iGFR categories but lower with lower CrCl categories. However, among CKD patients in whom CrCl and iGFR were measured using the same timed urine collections (which reduces dis-concordant measurement error), CrCl/iGFR ratio were higher with both lower iGFR categories and lower CrCl categories.ConclusionsThese data refute the recent suggestion that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio increases as GFR decreases in CKD patients. They also highlight the lack of certainty in our knowledge with regard to how much CrCl actually overestimates GFR.

Dataset Information

CD154 Induces Interleukin-6 Secretion by Kidney Tubular Epithelial Cells under Hypoxic Conditions: Inhibition by Chloroquine.

Publications

CD154 Induces Interleukin-6 Secretion by Kidney Tubular Epithelial Cells under Hypoxic Conditions: Inhibition by Chloroquine.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets