Isochlorogenic Acid C Mitigates CCl4-Induced Kidney Ferroptosis, Inflammation, and Fibrogenesis in Mice: Involvement of the SESN2/MAPKs and Hippo Pathways

Renal damage is closely related to oxidative stress, inflammation, ferroptosis, and fibrosis. Renal fibrosis is closely related to oxidative stress, inflammation, and ferroptosis. Isochlorogenic acid C (IaC) has been demonstrated to have a protective effect against kidney injury in both in vivo and in vitro studies. Nonetheless, it remains uncertain whether IaC can mitigate kidney dysfunction induced by carbon tetrachloride (CCl4). In this study, we examined the protective effects of IaC on renal inflammation, ferroptosis, and fibrosis, as well as the underlying regulatory mechanisms. An experimental model of kidney injury was developed using ICR mice (in vivo) and HK-2 cells (in vitro), which were treated with CCl4 or TGFβ1. Gene/protein expressions were detected using RT-qPCR, Western blotting, and immunohistochemistry assays. In addition, to identify the potential mechanisms involved in this process, we conducted RNA interference and signaling pathway inhibition analysis. IaC alleviated CCl4-induced renal dysfunction and fibrosis. It resulted in the down-regulation of fibrosis-associated markers, specifically collagen I and α-SMA. Furthermore, IaC mitigated CCl4-induced renal inflammation by reducing the activities of TNF-α, IL-6, and NF-κB p65. IaC led to an up-regulation in the activities of GSH, SOD, and GPx in the renal tissues of mice. IaC effectively inhibited the elevation of renal ferroptosis-associated markers induced by CCl4, as evidenced by the reduced Fe2+ levels and the increased expression of GSH, GPX4, and SLC7A11. Moreover, IaC significantly enhanced the activation of Sestrin2 (SESN2). IaC resulted in a down-regulation of the expression levels of TGFβ1, YAP, TAZ, p-ERK, p-JNK, and p-p38 in the kidneys. Furthermore, IaC demonstrated an inhibitory effect on inflammation and fibrosis within an in vitro model of TGFβ-induced fibrosis. However, treatment with the inhibitors of MAPKs and YAP significantly enhanced the effects of IaC in TGFβ-stimulated HK-2 cells. Sestrin2 silencing also reversed the effects of IaC in TGFβ-stimulated HK-2 cells. IaC demonstrated effective docking with the active sites of the target proteins SESN2, GPX4, and YAP, thereby corroborating the predicted compatibility of interactions between IaC and these proteins. Our study demonstrates that IaC ameliorates CCl4-induced renal inflammation and fibrosis through modulation of the Hippo pathway and the SESN2/MAPKs pathways. IaC is a promising natural compound that can be used to treat kidney damage.