Oxypurinol protects renal ischemia/reperfusion injury via heme oxygenase-1 induction

Insights into flavor quality and metabolites profiles of fresh cheese with different probiotics by SPME-GC-MS and untargeted metabolomics

In this study, fresh cheeses produced with four novel probiotics (Lactobacillus casei PB-LC39, Lactobacillus rhamnosus PB-LR76, Lactobacillus helveticus HH-LH17, and Lactobacillus plantarum HH-LP56) were named as LC, LR, LH, and LP, respectively. SPME-GC-MS and untargeted metabolomics were used to compare and analyze the flavor quality, metabolites and metabolic pathways of LC, LR, LH and LP, and the potential function of differential metabolites was emphasized. The results demonstrated that the incorporation of probiotics resulted in a significant increase in the number of volatile flavor compounds and varying flavor profiles within the cheese. Especially LC, exhibited aromas reminiscent of wine, fruit and rose, and displayed the most favorable flavor qualities among all probiotic cheeses. The results of differential metabolite screening and metabolic pathway demonstrated that probiotic cheese could result in the production of 146-192 differential metabolites, mainly carbohydrates, proteins and acids. Arginine biosynthesis was a key differential metabolite pathway made by probiotics. The LC, LR, LH, and LP groups contained 22, 27, 23, and 24 functional metabolites, including L-carnitine, naringenin, and turanose et al., which might confer anti-inflammatory and improve lipid metabolism functions. These findings provide a theoretical basis for the further functional evaluation and development of probiotic cheese.

An enzyme-mimicking reactive oxygen species scavenger targeting oxidative stress-inflammation cycle ameliorates IR-AKI by inhibiting pyruvate dehydrogenase kinase 4

Rationale: Ischemia-reperfusion-induced acute kidney injury (IR-AKI), characterized by the abrupt decline in renal function, is distinguished by the intricate interplay between oxidative stress and inflammation. In this study, a reactive oxygen species (ROS) scavenger-CF@PDA was developed to effectively target antioxidant and anti-inflammatory pathways to disrupt the oxidative stress-inflammation cycle in IR-AKI. Methods: UV-vis absorption spectra, FTIR spectra, and TEM were employed to determine the successful construction of CF@P. ABTS, TMB, and NBT analyses were performed to detect the antioxidant ability and enzyme-mimicking ability of CF@P. In vitro and in vitro, the antioxidant/anti-inflammatory effect of CF@P was detected by MTT, qPCR, fluorescence, and flow cytometry. Multi-omics revealed the mechanism of CF@P in IR-AKI therapy, and molecular docking was further used to determine the mechanism. MRI and photoacoustic imaging were employed to explore the dual-mode imaging capacity of CF@P in IR-AKI management. Results: CF@P could disrupt the oxidative stress-inflammatory cascade by scavenging ROS, reducing pro-inflammatory cytokines, and modulation of macrophage polarization. Subsequent multi-omics indicated that the renal protective effects may be attributed to the inhibition of pyruvate dehydrogenase kinase 4 (PDK4). Metabolomics demonstrated that CF@P could improve the production of antioxidant compounds and reduce nephrotoxicity. Additionally, CF@P exhibited promising capabilities in T1-MRI and photoacoustic imaging for AKI management. Conclusions: Collectively, CF@P, possessing antioxidant/anti-inflammatory properties by inhibiting PDK4, as well as imaging capabilities and superior biocompatibility, holds promise as a therapeutic strategy for IR-AKI.

Neutrophils and NADPH Oxidases Are Major Contributors to Mild but Not Severe Ischemic Acute Kidney Injury in Mice

Upregulation of free radical-generating NADPH oxidases (NOX), xanthine oxidoreductase (XOR), and neutrophil infiltration-induced, NOX2-mediated respiratory burst contribute to renal ischemia-reperfusion injury (IRI), but their roles may depend on the severity of IRI. We investigated the role of NOX, XOR, and neutrophils in developing IRI of various severities. C57BL/6 and Mcl-1ΔMyelo neutrophil-deficient mice were used. Oxidases were silenced by RNA interference (RNAi) or pharmacologically inhibited. Kidney function, morphology, immunohistochemistry and mRNA expression were assessed. After reperfusion, the expression of NOX enzymes and XOR increased until 6 h and from 15 h, respectively, while neutrophil infiltration was prominent from 3 h. NOX4 and XOR silencing or pharmacological XOR inhibition did not protect the kidney from IRI. Attenuation of NOX enzyme-induced oxidative stress by apocynin and neutrophil deficiency improved kidney function and ameliorated morphological damage after mild but not moderate/severe IRI. The IR-induced postischemic renal functional impairment (BUN, Lcn-2), tubular necrosis score, inflammation (TNF-α, F4/80), and decreases in the antioxidant enzyme (GPx3) mRNA expression were attenuated by both apocynin and neutrophil deficiency. Inhibition of NOX enzyme-induced oxidative stress or the lack of infiltration by NOX2-expressing neutrophils can attenuate reperfusion injury after mild but not moderate/severe renal IR.