Advanced oxidation protein products upregulate efflux transporter expression and activity through activation of the Nrf-2-mediated signaling pathway in vitro and in vivo

CYP2E1 mediated advanced oxidation protein products exacerbate acetaminophen induced drug-derived liver injury in vitro and in vivo

Drug-induced liver injury (DILI) is prevalent in the treatment of chronic kidney disease (CKD). Advanced oxidation protein products (AOPPs) are markers of CKD progression and participate in the occurrence and development of liver diseases. However, the mechanisms underlying the regulation of DILI in CKD have not been established. Herein, we demonstrate the involvement of Cytochrome p450 2E1 (CYP2E1) in DILI induced by AOPPs is exacerbated by exposure to acetaminophen (APAP). We used a adenine-induced CKD model, a model of DILI induced by APAP, and the AOPPs model was generated by intraperitoneal injection. The decline in renal function was associated with a significantly increased concentration of Scr, BUN and AOPPs, and renal tissue fibrosis. The ALT, AST, and AOPPs levels and liver tissue necrosis increased significantly in CKD model group compared with the sodium carboxymethyl cellulose (CMCNa) group. In the AOPPs model, compared to the PBS controls, ALT, AST, and AOPP levels, and liver tissue necrosis increased significantly. In HepG2 or L0-2 cell lines, cell survival was significantly reduced in the AOPP + APAP treatment and CYP2E1 protein expression was increased. FPS-ZM1 or NAC attenuated the hepatocyte toxicity induced by AOPP + APAP and suppression of CYP2E1 expression. AOPPs exacerbated APAP-induced DILI through CYP2E1 signaling pathways. Protein uremic toxins, such as AOPPs, can modify drug toxicity in patients with CKD. This study provides new a rationale to reduce the generation of DILIs in clinical treatment in patients with CKD. AOPPs targeting may present a novel approach to reduce the occurrence of DILI.

Astragalus Polysaccharide Enhances Voriconazole Metabolism under Inflammatory Conditions through the Gut Microbiota

Background and Aims

Voriconazole (VRC), a widely used antifungal drug, often causes hepatotoxicity, which presents a significant clinical challenge. Previous studies demonstrated that Astragalus polysaccharide (APS) can regulate VRC metabolism, thereby potentially mitigating its hepatotoxic effects. In this study, we aimed to explore the mechanism by which APS regulates VRC metabolism.

Methods

First, we assessed the association of abnormal VRC metabolism with hepatotoxicity using the Roussel Uclaf Causality Assessment Method scale. Second, we conducted a series of basic experiments to verify the promotive effect of APS on VRC metabolism. Various in vitro and in vivo assays, including cytokine profiling, immunohistochemistry, quantitative polymerase chain reaction, metabolite analysis, and drug concentration measurements, were performed using a lipopolysaccharide-induced rat inflammation model. Finally, experiments such as intestinal biodiversity analysis, intestinal clearance assessments, and Bifidobacterium bifidum replenishment were performed to examine the ability of B. bifidum to regulate the expression of the VRC-metabolizing enzyme CYP2C19 through the gut-liver axis.

Results

The results indicated that APS does not have a direct effect on hepatocytes. However, the assessment of gut microbiota function revealed that APS significantly increases the abundance of B. bifidum, which could lead to an anti-inflammatory response in the liver and indirectly enhance VRC metabolism. The dual-luciferase reporter gene assay revealed that APS can hinder the secretion of pro-inflammatory mediators and reduce the inhibitory effect on CYP2C19 transcription through the nuclear factor-κB signaling pathway.

Conclusions

The study offers valuable insights into the mechanism by which APS alleviates VRC-induced liver damage, highlighting its immunomodulatory influence on hepatic tissues and its indirect regulatory control of VRC-metabolizing enzymes within hepatocytes.

Huang Gan Formula Alleviates Systemic Inflammation and Uremia in Adenine-Induced Chronic Kidney Disease Rats May Associate with Modification of Gut Microbiota and Colonic Microenvironment

Purpose

This study aims to investigate the effects of Huang Gan formula (HGF), a Chinese herbal prescription used for chronic kidney disease (CKD), on the regulation of the gut microbiota and colonic microenvironment of CKD.

Methods

CKD rats were induced by 150 mg/kg adenine gavage for 4 weeks, then orally treated with or without 3.6 g/kg or 7.2 g/kg of HGF for 8 weeks. The renal function and structure were analyzed by biochemical detection, hematoxylin and eosin, Masson's trichrome, Sirius red and immunochemical staining. Average fecal weight and number in the colon were recorded to assess colonic motility. Further, the changes in the gut microbiota and colonic microenvironment were evaluated by 16S rRNA sequencing, RT-PCR or immunofluorescence. The levels of inflammatory cytokines, uremic toxins, and NF-κB signaling pathway were detected by RT-PCR, ELISA, chloramine-T method or Western blotting. Redundancy analysis biplot and Spearman's rank correlation coefficient were used for correlation analysis.

Results

HGF significantly improved renal function and pathological injuries of CKD. HGF could improve gut microbial dysbiosis, protect colonic barrier and promote motility of colonic lumens. Further, HGF inhibited systemic inflammation through a reduction of TNF-α, IL-6, IL-1β, TGF-β1, and a suppression of NF-κB signaling pathway. The serum levels of the selected uremic toxins were also reduced by HGF treatment. Spearman correlation analysis suggested that high-dose HGF inhibited the overgrowth of bacteria that were positively correlated with inflammatory factors (eg, TNF-α) and uremic toxins (eg, indoxyl sulfate), whereas it promoted the proliferation of bacteria belonging to beneficial microbial groups and was positively correlated with the level of IL-10.

Conclusion

Our results suggest that HGF can improve adenine-induced CKD via suppressing systemic inflammation and uremia, which may associate with the regulations of the gut microbiota and colonic microenvironment.

Increase in Anticancer Drug-Induced Toxicity by Fisetin in Lung Adenocarcinoma A549 Spheroid Cells Mediated by the Reduction of Claudin-2 Expression

Claudin-2 (CLDN2), a component of tight junction, is involved in the reduction of anticancer drug-induced toxicity in spheroids of A549 cells derived from human lung adenocarcinoma. Fisetin, a dietary flavonoid, inhibits cancer cell growth, but its effect on chemosensitivity in spheroids is unknown. Here, we found that fisetin (20 μM) decreases the protein level of CLDN2 to 22.3%. Therefore, the expression mechanisms were investigated by real-time polymerase chain reaction and Western blotting. Spheroids were formed in round-bottom plates, and anticancer drug-induced toxicity was measured by ATP content. Fisetin decreased the phosphorylated-Akt level, and CLDN2 expression was decreased by a phosphatidylinositol 3-kinase (PI3K) inhibitor, suggesting the inhibition of PI3K/Akt signal is involved in the reduction of CLDN2 expression. Hypoxia level, one of the hallmarks of tumor microenvironment, was reduced by fisetin. Although fisetin did not change hypoxia inducible factor-1α level, it decreased the protein level of nuclear factor erythroid 2-related factor 2, a stress response factor, by 25.4% in the spheroids. The toxicity of doxorubicin (20 μM) was enhanced by fisetin from 62.8% to 40.9%, which was rescued by CLDN2 overexpression (51.7%). These results suggest that fisetin can enhance anticancer drug toxicity in A549 spheroids mediated by the reduction of CLDN2 expression.

Advanced oxidation protein products upregulate ABCB1 expression and activity via HDAC2-Foxo3α-mediated signaling in vitro and in vivo

The unpredictable pharmacokinetics of non-renal cleared drugs in chronic kidney disease (CKD) patients is associated with the activity of drug transporters. However, the mechanisms underlying regulation of drug transporters are yet to be established. In this study, we demonstrated the involvement of a HDAC2-Foxo3α pathway in advanced oxidation protein products (AOPPs)-induced ATP-binding cassette subfamily B member 1 (ABCB1) expression and activity. The correlation of AOPPs accumulation with concentration of cyclosporine in plasma was evaluated in 194 patients with transplantation. Molecular changes in acetylation of various histones and related regulatory molecules were examined in HepG2 cell cultures treated with AOPPs. Accumulation of AOPPs in serum in relation to molecular changes in HDAC2-Foxo3α in vivo were evaluated in 5/6 nephrectomy (5/6 nx) and oral adenine (Adenine) CKD rat models. Interestingly, the cyclosporine level was negatively correlated with AOPPs in plasma. In addition, AOPPs markedly suppressed the expression of histone deacetylase 2 (HDAC2), inducing ABCB1 expression and activity in vitro and in vivo. Importantly, AOPPs modulated phosphorylation of Foxo3α and the upstream Akt protein. Our findings indicate that AOPPs regulate the expression and activity of ABCB1 via reducing HDAC2 expression and activating Foxo3α-dependent signaling. The collective results support the utility of AOPPs as a potential target for drug and/or dosage adjustment in CKD patients. Targeting of AOPPs presents a novel approach to regulate non-renal clearance.

Emerging mechanisms and applications of ferroptosis in the treatment of resistant cancers

The development of chemotherapy drugs has promoted anticancer treatment, but the effect on tumours is not clear because of treatment resistance; thus, it is necessary to further understand the mechanism of cell death to explore new therapeutic targets. As a new type of programmed cell death, ferroptosis is increasingly being targeted in the treatment of many cancers with clinical drugs and experimental compounds. Ferroptosis is stimulated in tumours with inherently high levels of ferrous ions by a reaction with abundant polyunsaturated fatty acids and the inhibition of antioxidant enzymes, which can overcome treatment resistance in cancers mainly through GPX4. In this review, we focus on the intrinsic cellular regulators against ferroptosis in cancer resistance, such as GPX4, NRF2 and the thioredoxin system. We summarize the application of novel compounds and drugs to circumvent treatment resistance. We also introduce the application of nanoparticles for the treatment of resistant cancers. In conclusion, targeting ferroptosis represents a considerable strategy for resistant cancer treatment.

AGE receptor 1 silencing enhances advanced oxidative protein product-induced epithelial-to-mesenchymal transition of human kidney proximal tubular epithelial cells via RAGE activation

Advanced oxidative protein products (AOPPs) are novel uremic toxins whose concentrations continuously increases in patients with chronic kidney disease (CKD). Epithelial-to-mesenchymal transition (EMT) of tubular cells is the main mechanism underlying CKD pathogenesis. Studies have shown that AOPPs can induce EMT and promote renal fibrosis. However, the mechanism through which AOPPs induce tubular cell-EMT is poorly understood. In this study, we aimed to clarify the mechanisms underlying AOPP-induced EMT in human kidney proximal tubular (HKC-8) epithelial cells. Small molecule inhibitor, CRISPR-Cas9 knockout technology, siRNA knockdown technology, western blot, and reverse transcription-quantitative polymerase chain reaction were applied to investigate the mechanisms underlying AOPP-induced EMT in HKC-8 cells. AOPP treatment was found to significantly induce EMT, as evidenced by increased α-smooth muscle actin (α-SMA) and decreased E-cadherin levels, and upregulated Wnt1, β-catenin, Tcf4, and Gsk-3β expression. Conversely, blockade of Wnt/β-catenin signaling using small molecule inhibitor ICG-001 hindered AOPP-induced EMT. Moreover, knockout of receptor of advanced glycation end-products (RAGE) reversed these aforementioned effects, whereas AGE receptor 1 (AGER1)-specific siRNA transfection enhanced them. Taken together, these data suggested that AOPPs could induce HKC-8 cell EMT by activating the RAGE/Wnt/β-catenin signaling pathway and AGER1 could restore EMT by antagonizing the role of RAGE. These results may provide a new theoretical basis for EMT and help identify new therapeutic targets for suppressing CKD progression.