L-F001, a Multifunctional Fasudil-Lipoic Acid Dimer Prevents RSL3-Induced Ferroptosis via Maintaining Iron Homeostasis and Inhibiting JNK in HT22 Cells

Dihydromyricetin ameliorates neurotoxicity induced by high glucose through restraining ferroptosis by inhibiting JNK-inflammation pathway in HT22 cells

Diabetes mellitus is recognized as an important cause of cognitive dysfunction. Ferroptosis plays a key role in diabetic cognitive dysfunction (DCD). Dihydromyricetin (DHM) has promising neuronal protective effects, but it is unclear the mechanism. Here, the effects of DHM on HG-induced neurotoxicity in HT22 cells and its molecular mechanisms were investigated. Our results demonstrated that the viability of HG (125 mmol/L)-induced HT22 cells was significantly decreased. Furthermore, ferroptosis-related indicators, c-Jun N-terminal kinase (JNK)-inflammatory pathway, TNF-α, IL-1β, and mitochondrial morphology were measured. The results show that mitochondria of HT22 cells also showed wrinkled alterations in response to HG treatment. Meanwhile, the levels of glutathione (GSH) and glutathione peroxidase 4 (GPX4) were decreased, accompanied by an up-regulation of malondialdehyde (MDA), Fe2+, acyl-CoA synthetase long-chain family member 4 (ACSL4), and reactive oxygen species (ROS), indicating ferroptosis occurred in HG-induced HT22 cells. Furthermore, the levels of p-JNK, TNF-α, and IL-6 were up-regulated in HG-induced HT22 cells. DHM or JNK inhibitor SP600125 reversed these changes in HG-induced HT22 cells indicating that HG-induced neurotoxicity in HT22 cells may be associated with ferroptosis induced by the JNK-inflammatory factor pathway. Meanwhile, JNK agonist Anisomycin could attenuate these effects of DHM. Taken together, our data suggest that DHM can ameliorate HG-induced neurotoxicity in HT22 cells by inhibiting ferroptosis via the JNK-inflammatory signaling pathway. Hence, DHM may represent a novel and promising therapeutic intervention for DCD.

Integrating network pharmacology and experimental verification to reveal the ferroptosis-associated mechanism of Changpu-Yizhi-Wan in the treatment of Alzheimer's disease

To explore the pharmacological mechanism of Changpu-Yizhi-Wan (CYW) in the treatment of Alzheimer's disease (AD) from the perspective of ferroptosis based on network pharmacology and experimental verification. The Encyclopedia of Traditional Chinese Medicine 2.0 (ETCM2.0) database was used to collect the active components of CYW, and the putative targets were predicted in ETCM2.0 and SwissTargetPrediction database. The AD related targets were collected from GeneCards, comparative toxicogenomics database (CTD), Online Mendelian Inheritance in Man (OMIM), DisGeNET and Therapeutic Target Database (TTD), the ferroptosis related targets were collected from FerrDb V2 database, and the common targets of CYW, AD and ferroptosis were calculated by Venny2.1 platform. Protein-protein interaction (PPI) analysis was performed by STRING database, and the active compounds-target network and the PPI network were constructed using Cytoscape software. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome pathway enrichment analysis were performed through DAVID database. RSL3 was used to induce HT22 cells to establish a neuronal ferroptosis cell model, and the inhibitory effect of CYW on neuronal ferroptosis was evaluated by cell viability assay, intracellular iron assay and lipid peroxidation staining. The ferroptosis-associated key protein expressions of Nrf2, SLC7A11, GPX4 and FTH1 were detected by Western blot. A total of 100 candidate compounds were identified from CYW, and 1129 putative targets were obtained. 3924 AD-related targets and 564 ferroptosis-related targets were collected, respectively. There were 78 common targets between them and CYW targets, which were potential targets for CYW to regulate ferroptosis in the treatment of AD. PPI network analysis identified 10 key targets, including TP53, IL6, STAT3, HIF1A, NFE2L2, and others. GO, KEGG and Reactome enrichment analysis showed that 78 potential targets were involved in the regulation of ferroptosis and Nrf2-mediated gene transcription. Molecular docking showed that some active components of CYW had good affinity with Nrf2. In RSL3-induced HT22 cells, CYW significantly improved cell viability, reduced intracellular iron levels and inhibited lipid peroxidation, and improved the protein expression of Nrf2, SLC7A11, GPX4 and FTH1. The pharmacological mechanism of CYW in the treatment of AD may be related to the regulation of Nrf2/SLC7A11/GPX4/FTH1 axis to inhibit neuronal ferroptosis.

Integrated network pharmacology and transcriptomics to explore the mechanism of compound Dihuang granule (CDG) protects dopaminergic neurons by regulating the Nrf2/HMOX1 pathway in the 6-OHDA/MPP+-induced model of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a degenerative neurological disease that worsens over time. Ferroptosis has been proven to contribute to PD pathogenesis. CDG exhibits neuroprotective effects. However, CDG's potential mechanism in PD therapy remains uncertain.

PURPOSE

The purpose of this investigation is to ascertain the specific molecular mechanisms of CDG against neuronal ferroptosis and present an alternative option for PD management.

METHODS

Network pharmacology along with LC-MS were used to identify possible targets and candidate pathways. Then RNA-sequencing combined in the in vitro and in vivo experiments were utilized to validate these findings.

RESULTS

According to network pharmacology prediction, NFE2L2, HMOX1 and PTGS2 may be the key genes for ferroptosis in PD. In the in vivo experiments, CDG ultimately improved the neurobehavior of PD rats by alleviating the damage of dopamine neurons, decreasing the levels of MDA, ROS and Fe2+, increasing the GSH level, inhibiting ferroptosis by decreasing ACSL4, TF, and PTGS2 expression levels, and increasing the GPX4, FTH, Nrf2, and HMOX1 levels. RNA-seq analysis showed the differential genes in Model and CDG group were all enriched in Nrf2 and HMOX1, and the enrichment analysis of these differential genes showed they were closely related to the ferroptosis. Subsequently, in vitro experiments, the CDG, OE-Nrf2 and OE-HMOX1 group showed more active cell vitality, with decreasing levels of MDA, ROS, Fe2+, ACSL4, TF and PTGS2, and increasing level GSH, GPX4, FTH, Nrf2 and HMOX1.

CONCLUSION

CDG has a neuroprotective involvement in alleviating ferroptosis by regulating the Nrf2/HMOX1 pathway. Moreover, this research offers pharmacological evidence supporting the applications of CDG for treating PD.

Zinc as a Mediator Through the ROCK1 Pathway of Cognitive Impairment in Aluminum-Exposed Workers: A Clinical and Animal Study

Aluminum (Al) exposure was implicated in neurodegenerative diseases and cognitive impairment, yet the involvement of zinc (Zn) and its mechanism in Al-induced mild cognitive impairment (MCI) remains poorly understood. The objective is to explore the role of Zn in Al-induced cognitive impairment and its potential mechanisms. Montreal cognitive assessment (MoCA) test scores and serum Al, Zn from Al industry workers were collected. A mediation analysis was performed to evaluate the role of serum Zn among serum Al and MoCA test scores. Subsequently, an Al-exposure study was conducted on a rat model categorized into control, low-, medium-, and high-dose groups. After a Morris Water Maze test and detection of Al, Zn content in the hippocampus, integrated transcriptomic and proteomic analyses between the control group and the high-dose group were performed to identify the differentially expressed genes (DEPs), proteins (DEPs), and pathways. To corroborate these findings, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) were selected to identify the gene and protein results. Zn overall mediates the relationship between serum Al and cognitive function (mediation effect 17.82%, effect value =  - 0.0351). In the Al-exposed rat model, 734 DEGs, 18 miRNAs, 35 lncRNAs, 64 circRNAs, and 113 DEPs were identified between the high-dose group and the control group. Among them, ROCK1, DMD, and other four DEPs were identified as related to zinc finger proteins (ZNF). Co-enrichment analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) linked these changes to the RHOA/ROCK1 signaling axis. ZNF-related proteins Rock1, DMD, and DHX57 in the high-dose group were downregulated (p = 0.006, 0.003, 0.04), and the expression of Myl9, Rhoa, miR431, and miR182 was also downregulated (p = 0.003, 0.032, 0.032, and 0.046). These findings also show correlations between Al, Zn levels in the hippocampus, water maze performance, and expressions of Myl9, Rhoa, miR431, miR182, DMD, ROCK1, and DHX57, with both negative and positive associations. Based on the results, we determined that Zn was involved in Al-induced MCI in Al workers and Al-exposed rat models. Al exposure and interaction with Zn could trigger the downregulation of ZNF of ROCK1, DMD, and DHX57. miR431, miR182 regulate RHOA/ROCK1 was one of the Zn-involved pathways in Al-induced cognitive impairment.

Mechanism of RSL3-induced ferroptotic cell death in HT22 cells: crucial role of protein disulfide isomerase

Protein disulfide isomerase (PDI) was recently shown to be an upstream mediator of erastin-induced, glutathione depletion-associated ferroptosis through its catalysis of nitric oxide synthase (NOS) dimerization and nitric oxide (NO) accumulation. A recent study reported that RSL3, a known ferroptosis inducer and glutathione peroxidase 4 (GPX4) inhibitor, can inhibit thioredoxin reductase 1 (TrxR1). The present study seeks to test the hypothesis that RSL3 may, through its inhibition of TrxR1, facilitate PDI activation ( i. e., in a catalytically active, oxidized state), thereby enhancing RSL3-induced ferroptosis through NOS dimerization and NO accumulation. Using HT22 mouse neuronal cells as an in vitro model, we show that treatment of these cells with RSL3 strongly increases NOS protein levels and that PDI-mediated NOS dimerization is activated by RSL3, resulting in NO accumulation. Mechanistically, we find that PDI is activated in cells treated with RSL3 because of its inhibition of TrxR1, and the activated PDI then catalyzes NOS dimerization, which is followed by the accumulation of cellular NO, ROS and lipid-ROS and ultimately ferroptotic cell death. Genetic or pharmacological inhibition of PDI or TrxR1 partially abrogates RSL3-induced NOS activation and the subsequent accumulation of cellular NO, ROS/lipid-ROS, and ultimately ferroptosis in HT22 cells. The results of this study clearly show that PDI activation resulted from RSL3 inhibition of TrxR1 activity contributes crucially to RSL3-induced ferroptosis in a cell culture model through the PDI→NOS→NO→ROS/lipid-ROS pathway, in addition to its known inhibition of GPX4 activity.

NOX4-mediated astrocyte ferroptosis in Alzheimer's disease

This study investigates NADPH oxidase 4 (NOX4) involvement in iron-mediated astrocyte cell death in Alzheimer's Disease (AD) using single-cell sequencing data and transcriptomes. We analyzed AD single-cell RNA sequencing data, identified astrocyte marker genes, and explored biological processes in astrocytes. We integrated AD-related chip data with ferroptosis-related genes, highlighting NOX4. We validated NOX4's role in ferroptosis and AD in vitro and in vivo. Astrocyte marker genes were enriched in AD, emphasizing their role. NOX4 emerged as a crucial player in astrocytic ferroptosis in AD. Silencing NOX4 mitigated ferroptosis, improved cognition, reduced Aβ and p-Tau levels, and alleviated mitochondrial abnormalities. NOX4 promotes astrocytic ferroptosis, underscoring its significance in AD progression.

SIRT1 activated by AROS sensitizes glioma cells to ferroptosis via induction of NAD+ depletion-dependent activation of ATF3

Ferroptosis is a type of programmed cell death resulting from iron overload-dependent lipid peroxidation, and could be promoted by activating transcription factor 3 (ATF3). SIRT1 is an enzyme accounting for removing acetylated lysine residues from target proteins by consuming NAD+, but its role remains elusive in ferroptosis and activating ATF3. In this study, we found SIRT1 was activated during the process of RSL3-induced glioma cell ferroptosis. Moreover, the glioma cell death was aggravated by SIRT1 activator SRT2183, but suppressed by SIRT inhibitor EX527 or when SIRT1 was silenced with siRNA. These indicated SIRT1 sensitized glioma cells to ferroptosis. Furthermore, we found SIRT1 promoted RSL3-induced expressional upregulation and nuclear translocation of ATF3. Silence of ATF3 with siRNA attenuated RSL3-induced increases of ferrous iron and lipid peroxidation, downregulation of SLC7A11 and GPX4 and depletion of cysteine and GSH. Thus, SIRT1 promoted glioma cell ferroptosis by inducting ATF3 activation. Mechanistically, ATF3 activation was reinforced when RSL3-induced decline of NAD+ was aggravated by FK866 that could inhibit NAD + synthesis via salvage pathway, but suppressed when intracellular NAD+ was maintained at higher level by supplement of exogenous NAD+. Notably, the NAD + decline caused by RSL3 was enhanced when SIRT1 was further activated by SRT2183, but attenuated when SIRT1 activation was inhibited by EX527. These indicated SIRT1 promoted ATF3 activation via consumption of NAD+. Finally, we found RSL3 activated SIRT1 by inducing reactive oxygen species-dependent upregulation of AROS. Together, our study revealed SIRT1 activated by AROS sensitizes glioma cells to ferroptosis via activation of ATF3-dependent inhibition of SLC7A11 and GPX4.

L-F001, a multifunctional fasudil-lipoic acid dimer, antagonizes hypoxic-ischemic brain damage by inhibiting the TLR4/MyD88 signaling pathway

INTRODUCTION

Neonatal hypoxic-ischemic brain damage (HIBD) is a serious inflammatory injury. At present, the standard treatment for this disease is hypothermia therapy, and the effect of drug intervention is still limited. L-F001 is a compound of fasudil and lipoic acid. Previous in vitro experiments have confirmed that L-F001 has anti-inflammatory neuroprotective functions. However, its therapeutic effect on neonates with HIBD remains unknown. This study was aimed at exploring the therapeutic effect of L-F001 on HIBD rats.

METHODS

The newborn rats were divided into three groups: Sham operation group, HIBD group, and HIBD + L-F001 group. HE staining, Nissil staining, the immunofluorescence of iNOS and COX-2, ELISA (IL-1β, IL-6, TNF-α, and IL-10), and western blotting analyses were performed to determine the therapeutic effect of L-F001. Finally, we evaluated the growth and development of each group by measuring body weight.

RESULTS

The hippocampal structure of HIBD rats was disordered, and the Nissil body was small and shallow. The expressions of iNOS and COX-2 in HIBD rats were increased, whereas the expressions of IL-1β, IL-6, and TNF-α in plasma were upregulated, and the expression of IL-10 was decreased. L-F001 could improve the tissue structure and reduce the expression of iNOS and COX-2 in HIBD rats. Meanwhile, L-F001 could also reduce the expression of pro-inflammatory cytokines and restore the content of anti-inflammatory cytokines in plasma. We further found that the TLR4 pathway was activated after hypoxic-ischemia in neonatal rats. L-F001 could inhibit the activation of TLR4 pathway. Finally, we found that after L-F001 treatment, the body weight of HIBD rats increased significantly compared with the untreated group.

CONCLUSIONS

L-F001 antagonizes the inflammatory response after hypoxic-ischemia by inhibiting the activation of the TLR4 signaling pathway, thus playing a neuroprotective role. L-F001 may be a potential therapeutic agent for neonatal HIBD.

The Regulatory Role of Ferroptosis in Bone Homeostasis

Ferroptosis is an iron-dependent form of programmed cell death and an important type of biological catabolism. Through the action of divalent iron or ester oxygenase, ferroptosis can induce lipid peroxidation and cell death, regulating a variety of physiological processes. The role of ferroptosis in the modulation of bone homeostasis is a significant topic of interest. Herein, we review and discuss recent studies exploring the mechanisms and functions of ferroptosis in different bone-related cells, including mesenchymal stem cells, osteoblasts, osteoclasts, and osteocytes. The association between ferroptosis and disorders of bone homeostasis is also explored in this review. Overall, we aim to provide a detailed overview of ferroptosis, summarizing recent understanding on its role in regulation of bone physiology and bone disease pathogenesis.