73 research outputs found

    Blocking TGF-β signaling pathway preserves mitochondrial proteostasis and reduces early activation of PDGFRβ+ pericytes in aristolochic acid induced acute kidney injury in wistar male rats

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    The platelet-derived growth factor receptor β (PDGFRβ)+ perivascular cell activation becomes increasingly recognized as a main source of scar-associated kidney myofibroblasts and recently emerged as a new cellular therapeutic target.In this regard, we first confirmed the presence of PDGFRβ+ perivascular cells in a human case of end-stage aristolochic acid nephropathy (AAN) and thereafter we focused on the early fibrosis events of transforming growth factor β (TGFβ) inhibition in a rat model of AAN.Neutralizing anti-TGFβ antibody (1D11) and its control isotype (13C4) were administered (5 mg/kg, i.p.) at Days -1, 0, 2 and 4; AA (15 mg/kg, sc) was injected daily.At Day 5, 1D11 significantly suppressed p-Smad2/3 signaling pathway improving renal function impairment, reduced the score of acute tubular necrosis, peritubular capillaritis, interstitial inflammation and neoangiogenesis. 1D11 markedly decreased interstitial edema, disruption of tubular basement membrane loss of brush border, cytoplasmic edema and organelle ultrastructure alterations (mitochondrial disruption and endoplasmic reticulum edema) in proximal tubular epithelial cells. Moreover, 1D11 significantly inhibited p-PERK activation and attenuated dysregulation of unfolded protein response (UPR) pathways, endoplasmic reticulum and mitochondrial proteostasis in vivo and in vitro.The early inhibition of p-Smad2/3 signaling pathway improved acute renal function impairment, partially prevented epithelial-endothelial axis activation by maintaining PTEC proteostasis and reduced early PDGFRβ+ pericytes-derived myofibroblasts accumulation

    Lipopolysaccharide induces upregulation of neutral endopeptidase 24.11 on human neutrophils: involvement of the CD14 receptor.

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    1. As lipopolysaccharide is a major stimulator of neutrophil responses during Gram-negative bacterial infections, we studied its effect on the membrane expression of neutral endopeptidase 24.11/CD10 on neutrophils in a model of endotoxaemia in vitro. Lipopolysaccharide added to human whole-blood induced a marked and sustained CD10/neutral endopeptidase upregulation that was already detectable at 0.1 ng/ml and was maximal at a lipopolysaccharide concentration of 10 ng/ml. 2. We observed that neither tumour necrosis factor-alpha nor any newly synthesized protein was involved in the upregulation observed after 1 h incubation with 10 ng/ml lipopolysaccharide. 3. We further studied whether the lipopolysaccharide-induced CD10/neutral endopeptidase upregulation was mediated by lipopolysaccharide binding to the neutrophil CD14 receptor. Incubation of whole blood with an anti-CD14 monoclonal antibody before the addition of 0.1 ng/ml or 0.5 ng/ml lipopolysaccharide resulted in complete inhibition of CD10/neutral endopeptidase upregulation. In contrast, at a lipopolysaccharide concentration of 10 ng/ml, the anti-CD14 monoclonal antibody had an incomplete blocking effect. 4. The differential requirement for the CD14 receptor, depending on the lipopolysaccharide dose, was confirmed by the study of a patient suffering from paroxysmal nocturnal haemoglobinuria (in whom a complete defect in neutrophil CD14 expression was previously documented). 5. We finally confirmed these results using purified neutrophils, demonstrating that lipopolysaccharide-induced CD10/neutral endopeptidase upregulation depends on direct interaction with neutrophil CD14.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe
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