Ezetimibe ameliorates cisplatin-induced nephrotoxicity: A novel therapeutic approach via modulating AMPK/Nrf2/TXNIP signaling

Cisplatin (Cis) is among the most powerful antineoplastic medications, nevertheless, its serious side effects; particularly nephrotoxicity designates a major concern. Previous studies reported that ezetimibe (Eze), a well-known antihyperlipidemic drug, exerts additional trivial pharmacological effects. In this work, we displayed Eze as an intriguing protective candidate in a cisplatin-induced nephrotoxicity rat model through AMPK activation. Eze (10 mg/kg, p.o.) was administered for two weeks and Cis (10 mg/kg, i.p.) was administered on the 10th day to induce nephrotoxicity in male Wistar rats. Treatment with Eze greatly augmented the phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and the antioxidant regulator; nuclear factor erythroid 2-related factor 2 (Nrf2), thus, mitigating oxidative injury through induction of the antioxidant enzymes, such as heme oxygenase-1 (HO-1) and glutathione reductase (GR). As well, Eze relieved inflammation by reducing protein expression of thioredoxin-interacting protein (TXNIP) and nucleotide-binding domain-like receptor protein 3 (NLRP3), which led to a decrease in the release of caspase-1, in addition to, the inflammatory markers IL-18 and IL-1 β. Besides, Eze ameliorated apoptosis in the renal cells through inhibiting the phosphorylated Apoptosis signal-regulating kinase-1(p-ASK1), caspase-3 and reducing Bax/Bcl2ratio. Correspondingly, histopathological examination corroborated the previous biochemical findings. Collectively, Eze exerts significant renal protection against Cis-induced nephrotoxicity via antioxidant, anti-inflammatory and anti-apoptotic pathways that are probably mediated, at least partly, via activating AMPK/Nrf2/HO-1 pathway and conquering both TXNIP/NLRP3 inflammasome and TXNIP/ASK1 signaling pathways. To confirm the protective effect of Eze via AMPK-activation, an AMPK-inhibitor, dorsomorphin (Dors), when co-administered with Eze abolished its protective effect.

miRNA-141 Induced Pyroptosis in Intervertebral Disk Degeneration by Targeting ROS Generation and Activating TXNIP/NLRP3 Signaling in Nucleus Pulpous Cells

The role and mechanism of pyroptosis in intervertebral disk (IVD) degeneration are unclear. MicroRNAs (miRNAs) regulate the viability and function of nucleus pulposus cells (NPCs) in IVDs and are related to pyroptosis. We performed microarray analyses of normal and degenerated nucleus pulposus (NP) to assess the role of pyroptosis and identify key miRNAs in IVD degeneration. We also evaluated the underlying mechanism of miRNA-mediated pyroptosis in NPCs. In addition, we demonstrated the preventative effects of miRNAs on IVD degeneration in a rat model. The levels of the pyroptosis-related proteins cleaved caspase-1, N-terminal gasdermin D (GSDMD), interleukin (IL)-1β, and IL-18 in the degenerative NP were significantly higher than those in the normal NP. miRNA-141 was significantly upregulated in the degenerated NP. miR-141 mimic suppressed the matrix synthesis function of NPCs. By contrast, reactive oxygen species (ROS) generation, and the expression of TXNIP and NLRP3 were significantly downregulated by an miR-141 inhibitor. Furthermore, the miRNA-141 inhibitor prevented the degeneration of IVDs in vivo. Our findings suggest that miRNA-141 induces pyroptosis and extracellular matrix (ECM) catabolism in NPCs by increasing ROS generation and activating TXNIP/NLRP3 signaling. miRNA-141-regulated pyroptosis may be a novel therapeutic target for IVD degeneration.