Fisetin suppresses ferroptosis through Nrf2 and attenuates intervertebral disc degeneration in rats

Ferroptosis: A New Direction in the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is one of the most common musculoskeletal disorders in middle-aged and elderly people, and lower back pain (LBP) is the main clinical symptom [1, 2], which often causes significant pain and great economic burden to patients [3]. The current molecular mechanisms of IVDD include extracellular matrix degradation, cellular pyroptosis, apoptosis, necrotic apoptosis, senescence, and the newly discovered ferroptosis [4, 5], among which ferroptosis, as a new hot spot of research, has a non-negligible role in IVDD. Ferroptosis is an iron-dependent cell death caused by lipid peroxide accumulation [6]. Its main mechanism is cell death caused by lipid peroxidation by oxygen radicals due to iron overload and inhibition of pathways such as SLC7A11-GSH-GPX4. Currently, more and more studies have found a close relationship between IVDD and ferroptosis [7]. In the process of ferroptosis, the most important factors are abnormal iron metabolism, increased ROS, lipid peroxidation, and abnormal proteins such as GSH, GPX4, and system XC-. Our group has previously elucidated the pathogenesis of IVDD in terms of extracellular matrix degradation, myeloid cell senescence and pyroptosis, apoptosis, and inflammatory immunity. Therefore, this time, we will use ferroptosis as an entry point to discover the new mechanism of IVDD and provide guidance for clinical treatment.

Anti-Ferroptotic Effect of Cannabidiol in Human Skin Keratinocytes Characterized by Data-Independent Acquisition-Based Proteomics

Skin cells are susceptible to oxidative stress and various types of cell death, including an iron-dependent form known as ferroptosis. Cannabidiol (CBD) can protect skin cells against oxidative stress, but whether this is attributed to the inhibition of ferroptosis is unknown. Herein, we evaluated the anti-ferroptotic effect of CBD in human keratinocytes using biochemical assays (radical scavenging and iron chelating) and cell-based models (for lipid peroxidation and intracellular iron). CBD's anti-ferroptotic effect was further characterized by proteomic analysis. This study identifies anti-ferroptosis as a mechanism of CBD's skin protective effects.

Fisetin Suppresses Atherosclerosis by Inhibiting Ferroptosis-Related Oxidative Stress in Apolipoprotein E Knockout Mice

INTRODUCTION

Fisetin has been demonstrated to inhibit the occurrence of atherosclerosis; however, the mechanism of fisetin suppressing atherosclerosis remains elusive.

METHODS

The function of fisetin in the inhibition of atherosclerosis was evaluated by hematoxylin and eosin and Oil Red O staining in ApoE-/- mice. Molecular biomarkers of atherosclerosis progression were detected by Western blot and qPCR. Moreover, the inhibition of atherosclerosis on oxidative stress and ferroptosis was evaluated by immunofluorescence staining, qPCR, and Western blot assays.

RESULTS

The obtained results showed that serum lipid was attenuated and consequentially the formation of atherosclerosis was also suppressed by fisetin in ApoE-/- mice. Exploration of the mechanism revealed that molecular biomarkers of atherosclerosis were decreased under fisetin treatment. The level of reactive oxygen species and malondialdehyde declined, while the activity of superoxide dismutases and glutathione peroxidase was increased under the fisetin treatment. Additionally, the suppressor of ferroptosis, glutathione peroxidase 4 proteins, was elevated. The ferritin was decreased in the aortic tissues treated with fisetin.

CONCLUSIONS

In summary, fisetin attenuated the formation of atherosclerosis through the inhibition of oxidative stress and ferroptosis in the aortic tissues of ApoE-/- mice.