Aucubin alleviates doxorubicin-induced cardiotoxicity through crosstalk between NRF2 and HIPK2 mediating autophagy and apoptosis.

BACKGROUND: Doxorubicin (DOX) is widely used for the treatment of a variety of cancers. However, its clinical application is limited by dose-dependent cardiotoxicity. Recent findings demonstrated that autophagy inhibition and apoptosis of cardiomyocytes induced by oxidative stress dominate the pathophysiology of DOX-induced cardiotoxicity (DIC), however, there are no potential molecules targeting on these. PURPOSE: This study aimed to explore whether aucubin (AU) acting on inimitable crosstalk between NRF2 and HIPK2 mediated the autophagy, oxidative stress, and apoptosis in DIC, and provide a new and alternative strategy for the treatment of DIC. METHODS AND RESULTS: We first demonstrated the protection of AU on cardiac structure and function in DIC mice manifested by increased EF and FS values, decreased serum CK-MB and LDH contents and well-aligned cardiac tissue in HE staining. Furthermore, AU alleviated DOX-induced myocardial oxidative stress, mitochondrial damage, apoptosis, and autophagy flux dysregulation in mice, as measured by decreased ROS, 8-OHdG, and TUNEL-positive cells in myocardial tissue, increased SOD and decreased MDA in serum, aligned mitochondria with reduced vacuoles, and increased autophagosomes. In vitro, AU alleviated DOX-induced oxidative stress, autophagy inhibition, and apoptosis by promoting NRF2 and HIPK2 expression. We also identified crosstalk between NRF2 and HIPK2 in DIC as documented by overexpression of NRF2 or HIPK2 reversed cellular oxidative stress, autophagy blocking, and apoptosis aggravated by HIPK2 or NRF2 siRNA, respectively. Simultaneously, AU promoted the expression and nuclear localization of NRF2 protein, which was reversed by HIPK2 siRNA, and AU raised the expression of HIPK2 protein as well, which was reversed by NRF2 siRNA. Crucially, AU did not affect the antitumor activity of DOX against MCF-7 and HepG2 cells, which made up for the shortcomings of previous anti-DIC drugs. CONCLUSION: These collective results innovatively documented that AU regulated the unique crosstalk between NRF2 and HIPK2 to coordinate oxidative stress, autophagy, and apoptosis against DIC without compromising the anti-tumor effect of DOX in vitro.

Exploring the mechanism of Xingpi Capsule in diarrhea predominant-irritable bowel syndrome treatment based on multiomics technology.

BACKGROUND: Xingpi Capsule (XP), a commercially available over-the-counter herbal medicine in China, plays a prominent role in treating diarrhea-predominant irritable bowel syndrome (IBS-D). Nevertheless, the potential mechanisms remain unclear. PURPOSE: This study aimed to investigate XP efficacy in IBS-D and elucidate the underlying molecular mechanisms. METHODS: A rat IBS-D model was established by senna decoction gavage combined with restraint stress and swimming exhaustion. The changes in rat body weight and stool were recorded daily. Colon pathological changes and the number of colonic goblet cells of rats were observed by hematoxylin-eosin (HE) staining and Alcian blue plus periodic acid-Schiff (AB-PAS) staining, respectively. The expression of Occludin, a tight-junction-associated protein, was examined via immunohistochemistry. Images of colonic microvilli were obtained by TEM. Western blotting (WB) was used to analyze the protein expression of the ASK1/P38 MAPK pathway. The composition of the rat intestinal microbiota was detected by 16S rRNA sequencing. Changes in colonic metabolites were evaluated by liquid chromatography-mass spectrometry (LC-MS). Changes in colon RNA expression were assessed by RNA sequencing (RNA-Seq). The nontoxic range of hypoxanthine (HPX) was screened by Cell Counting Kit-8 (CCK8), the cell model of human colonic epithelial cells (NCM460) induced by lipopolysaccharide (LPS) was established, and the effective concentration of HPX was screened by CCK8. After transfection of pcDNA3.1-MAP3K5, Hoechst 33,342 staining, flow cytometry to detect cell apoptosis, and immunofluorescence to detect the fluorescence changes of ASK1 and ZO-1. WB detection of ASK1/P38 MAPK pathway protein expression changes. RESULTS: XP increased the body weight of IBS-D patients and reduced the loose stool rate, loose stool index, and Bristo score. In addition, XP mitigated colon lesions, increased the number of goblet cells and the expression of Occludin, and prevented severe distortion and effacement of the microvillous structure. Specifically, 16S rRNA gene sequence analysis showed that XP decreased the abundance of Desulfurium and Prevotella 9 at the phylum and genus levels while increasing the abundance of Bacteroides at the genus level. RNA-Seq combined with WB validation showed that XP exerted antidiarrheal effects by inhibiting the ASK1/P38 MAPK signaling pathway. Additionally, XP also increased the relative expression level of the metabolite HPX, as revealed by untargeted metabolomics analysis. Impressively, the correlation analysis between 16S rRNA sequencing and LC-MS suggested that HPX and Prevotella 9 are negatively correlated, which indicated that XP might increase the content of HPX by reducing the abundance of Prevotella 9. Meanwhile, a negative correlation between HPX and ASK1 was indicated through RNA-Seq and LC-MS, which suggested that the inhibition of ASK1 (Map3k5) may be ascribed to the increase in HPX after XP treatment. In vitro experiments have proven that HPX can alleviate LPS-induced NCM460 damage, specifically manifested as enhancing cell viability, reducing cell apoptosis, increasing ZO-1 expression, reducing the fluorescence intensity of MAP3K5 in the model group, and inhibiting the expression of ASK1/P38 MAPK pathway proteins. The protective effect of HPX was reversed after transfection with pcDNA 3.1-MAP3K5, which fully demonstrated that the protective mechanism of HPX was achieved by inhibiting MAP3K5 and its downstream pathways. CONCLUSION: XP displayed multifaceted protection against IBS-D in rats by regulating the intestinal microbiota, increasing the relative expression level of HPX, a metabolite of the microbiota, and inhibiting the ASK1/P38 MAPK signaling pathway.

Qishen Granule Protects against Doxorubicin-Induced Cardiotoxicity by Coordinating MDM2-p53-Mediated Mitophagy and Mitochondrial Biogenesis.

Doxorubicin (DOX), the anthracycline chemotherapeutic agent, is widely used for the treatment of various cancers. However, its clinical application is compromised by dose-dependent and fatal cardiotoxicity. This study is aimed at investigating the cardioprotective effects of Qishen granule (QSG) and the specific mechanism by which QSG alleviates DOX-induced cardiotoxicity (DIC) and providing an alternative for the treatment of DIC. We first evaluated the cardioprotective effects of QSG in a DIC mouse model, and the obtained results showed that QSG significantly protected against DOX-induced myocardial structural and functional damage, mitochondrial oxidative damage, and apoptosis. Subsequently, after a comprehensive understanding of the specific roles and recent developments of p53-mediated mitochondrial quality control mechanisms in DIC, we investigated whether QSG acted on MDM2 to regulate the activity of p53 and downstream mitophagy and mitochondrial biogenesis. The in vivo results showed that DOX inhibited mitochondrial biogenesis and blocked mitophagy in the mouse myocardium, while QSG reversed these effects. Mechanistically, we combined nutlin-3, which inhibits the binding of p53 and MDM2, with DOX and QSG and evaluated their influence on mitophagy and mitochondrial biogenesis in H9C2 cardiomyocytes. The obtained results showed that both DOX and nutlin-3 substantially inhibited mitophagy and mitochondrial biogenesis and induced mitochondrial oxidative damage and apoptosis, which could be partially recovered by QSG. Importantly, the immunoprecipitation results showed that QSG promoted the binding of MDM2 to p53, thus decreasing the level of p53 protein and the binding of p53 to Parkin. Collectively, QSG could promote the degradation of p53 by enhancing the binding of MDM2 to the p53 protein, resulting in the reduced binding of p53 to the Parkin protein, thus improving Parkin-mediated mitophagy. Increased degradation of p53 protein by QSG simultaneously enhanced mitochondrial biogenesis mediated by PGC-1α. Ultimately, QSG relieved DOX-induced mitochondrial oxidative damage and apoptosis by coordinating mitophagy and mitochondrial biogenesis.

Facile preparation of novel Pd nanowire networks on a polyaniline hydrogel for sensitive determination of glucose.

In this study, novel Pd nanowire networks (PdNW) grown on three-dimensional polyaniline hydrogel (3D-PANI) were prepared via a facile one-step electrodeposition approach at a constant potential of - 0.2 V and further utilized as an electrochemical sensing material for sensitive determination of glucose in alkaline medium. Compared with the sensor based on Pd nanofilm (PdNF)/3D-PANI prepared by electrodeposition at - 0.9 V, the sensor based on PdNW/3D-PANI presented substantially enhanced electrocatalytic activity towards glucose oxidation, with an excellent sensitivity of 146.6 µA mM-1 cm-2, a linear range from 5.0 to 9800 µM, and a low detection limit of 0.7 µM and was, therefore, demonstrated to be available for the determination of glucose in human serum. These findings are likely attributed to the combination of advantages of both PdNW and 3D-PANI, which outperformed most other Pd-based non-enzymatic glucose sensors reported earlier. Moreover, this non-enzymatic electrochemical sensor based on PdNW/3D-PANI may serve as an alternative tool for the assay of glucose and possibly other biomolecules. Graphical abstract.

Sensitive electrochemical sensing platform for selective determination of dopamine based on amorphous cobalt hydroxide/polyaniline nanofibers composites.

In this study, amorphous cobalt hydroxide/polyaniline nanofibers (Co(OH)2/PANINF) composites were successfully prepared. The formation of amorphous Co(OH)2 with irregular surface structure was confirmed by x-ray diffraction, scanning electron microscopy, and selected-area electron diffraction. The non-enzymatic electrochemical sensor for the selective and sensitive determination of dopamine (DA) has been constructed by using Co(OH)2/PANINF composites modified glassy carbon electrode (Co(OH)2/PANINF/GCE), which exhibited excellent electrocatalytic activity toward DA, in a large part owing to the advantages of large surface area of amorphous Co(OH)2 and the synergetic effect between Co(OH)2 and PANINF. The electrochemical kinetics reveal that the DA oxidation involves two electrons and two protons in a quasi-reversible electrode reaction. Differential pulse voltammetry (DPV) studies show remarkable sensing performance for the determination of DA, with a low detection limit of 0.03 µM, and a wide linear range from 0.1 to 200 µM. From a broader perspective, the present study demonstrates that Co(OH)2/PANINF composites would be promising supporting materials for novel sensing platforms.

Arachidonic acid has protective effects on oxygen-glucose deprived astrocytes mediated through enhancement of potassium channel TREK-1 activity.

Polyunsaturated fatty acids (PUFAs) have neuroprotective effects against ischemic brain diseases. The newly discovered potassium channel "TREK-1" is a promising target for therapies against neurodegeneration. Arachidonic acid (AA) is an n-6 PUFA, as well as a potent TREK-1 activator. We previously showed that TREK-1 is expressed at high levels in astrocytes. However, the effect of AA on astrocytes in ischemia remains unknown. Here, we assessed the effects of 3-30µM AA on astrocyte apoptosis, glutamate uptake, and expression of the astrocytic glutamate transporter 1 (GLT-1) and TREK-1 under different conditions. Under normal conditions, 3-30µM AA showed no effect on astrocytic apoptosis or TREK-1 expression, whereas glutamate uptake decreased significantly and its change paralleled the decreased expression of GLT-1. When astrocytes were subjected to 4h of oxygen-glucose deprivation (OGD), 10µM AA markedly alleviated OGD-induced cell death, recovering from 63.50±1.90% to 82.96±4.63% of the control value. AA also rescued the decreased glutamate uptake and increased mRNA, as well as protein levels of GLT-1 and TREK-1. Our results provide new evidence of a protective effect of AA on astrocytes under OGD conditions, suggesting that a low concentration of AA may protect against brain ischemic diseases.

Comparative pharmacokinetics of a tumour-targeting therapy candidate rh-IFNα2a-NGR with rh-IFNα2a administered intravenously in mice and rats.

OBJECTIVES: rh-IFNα2a-NGR is a promising anti-tumor candidate. The aim of present study was to compare pharmacokinetics of rh-IFNα2a-NGR with rh-IFNα2a. METHODS: Pharmacokinetics and elimination were investigated after intravenous administration to mice and rats. Compared tumor and tissue distribution profiles between rh-IFNα2a-NGR and rh-IFNα2a were illustrated in the tumor transplanted mice of SP2/0 myeloma. Double antibody sandwich ELISA method was used to assess the level of both rh-IFNα2a-NGR and rh-IFNα2a in serum, tissue, bile and urine. KEY FINDINGS: After a single intravenous administration, the pharmacokinetic characters of rh-IFNα2a-NGR and rh-IFNα2a were described using a two-compartment model. No significant differences were observed between the two drugs in pharmacokinetic and elimination data. However, the concentration of rh-IFNα2a-NGR in tumor was 5.34 times and 1.52 times as high as that of rh-IFNα2a at 0.5 h (P < 0.01) and 1 h. In addition, immunohistochemical stain displayed rh-IFNα2a-NGR was predominantly located in tumor vascular tissues. CONCLUSIONS: rh-IFNα2a-NGR could be an agent for tumor vascular-targeting therapy and these findings provided references for further clinical study.