Icariside II preconditioning evokes robust neuroprotection against ischaemic stroke, by targeting Nrf2 and the OXPHOS/NF-κB/ferroptosis pathway

SETD1B promotes brain cell ferroptosis in ischemic stroke mice via increasing H3K4me3 enrichment on the Tfrc promoter

AIMS

This study investigates the role of SET domain containing 1B (SETD1B), a histone lysine methyltransferase, in promoting ferroptosis induced by ischemic stroke through the upregulation of transferrin receptor 1 (TfR1).

MATERIALS AND METHODS

An ischemic stroke model was established in C57BL/6J mice by subjecting them to 1 h of ischemia followed by 24 h of reperfusion. Brain damage was assessed by neurological impairment and infarct volume. Levels of SETD1B, TfR1, total iron, Fe2+, lipid peroxidation (LPO), ferritin (FPN), and GPX4 were measured. In vitro, HT22 cells were subjected to 14 h of oxygen-glucose deprivation (OGD) followed by 24 h of reoxygenation. SETD1B knockdown was performed to assess its impact on ferroptosis.

KEY FINDINGS

In the ischemic stroke mice, SETD1B expression was elevated, accompanied by increased ferroptosis markers, including higher levels of TfR1, total iron, Fe2+, and LPO, as well as reduced levels of FPN and GPX4. These phenomena were observed in cultured HT22 cells under OGD/R conditions. SETD1B knockdown effectively reversed these effects, decreasing ferroptosis markers and reducing Tfrc expression via preventing H3K4me3 enrichment at the Tfrc promoter.

SIGNIFICANCE

These findings suggest that SETD1B enhances ferroptosis in stroke brain cells by a mechanism involving boosting H3K4me3 enrichment at the Tfrc promoter and subsequent upregulation of the expression of Tfrc. Targeting SETD1B may provide a therapeutic strategy for mitigating ferroptosis in stroke.

Therapeutic time window of sodium of Danshensu on cerebral ischemia and its mechanism of inhibiting oxidative stress and ferroptosis through Nrf2 pathway

BACKGROUND

Sodium of Danshensu (SDSS), extract of salvia miltiorrhiza root, has been shown to have neuroprotective effects on ischemic stroke (IS) in our previous studies. However, its therapeutic time window and mechanism of action remain unclear. Ferroptosis exerts a crucial feature in the development and progression of IS. Nuclear factor-E2-related factor 2 (Nrf2) can positively regulate the transcription of Recombinant Solute Carrier Family 7, member 11 (SLC7A11) and glutathione peroxidase (GPX4) genes that combat lipid peroxidation in ferroptosis.

PURPOSE

The current study aimed to assess therapeutic time window of SDSS and the pharmacological mechanism involved in Nrf2-mediated oxidative stress and ferroptosis.

METHODS

Mice with transient middle cerebral artery occlusion (MCAO) and HT22 cells with oxygen-glucose deprivation/reoxygenation (OGD/R) were induced to simulate IS. Mice were administered SDSS at 1, 3, 6 or 9 h after MCAO to determine the therapeutic time window of SDSS. MicroRNA-seq was conducted to analyze differentially expressed genes in both the MCAO and the SDSS treatment group. The interaction between SDSS and Nrf2 was also investigated using molecular docking, molecular dynamics (MD) simulations, and surface plasmon resonance (SPR) experiments. Furthermore, the neuroprotection of SDSS was investigated in Nrf2-deficient mice to assess the activation mechanism of the Nrf2/GPX4 axis by SDSS. The biomarkers (Fe2 + content, ROS, MDA, GSH, GSH/GSSG), mitochondrial structure, these proteins (Nrf2, SLC7A11, GPX4, FTH1, HO-1, ACSL4 and TFRC) expression were detected by commercial kits, transmission electron microscope (TEM) and Western blotting, respectively.

RESULTS

The therapeutic time window of SDSS should be within 6 hours after MCAO, beyond which SDSS cannot play a therapeutic role. SDSS played a neuroprotective affection in mice and HT22 cells by restraining ROS, MDA and Fe2+ content, elevating GSH level and GSH/GSSG ratio. At the molecular mechanism, SDSS can bind to Nrf2, improve Nrf2 activity and nuclear expression, further enhance SLC7A11, GPX4, FTH1, HO-1 expression and reduce ACSL4 and TFRC expression. However, the neuroprotective effects of SDSS and its effect on ferroptosis-related proteins were partially reversed in Nrf2-deficient mice.

CONCLUSION

The therapeutic time window of SDSS for ischemic stroke is relatively wide. The administration of SDSS can potentially mitigate brain damage through the inhibition of oxidative damage and ferroptosis, which is partly regulated by the Nrf2/GPX4 axis. Therefore, SDSS is a promising candidate for the treatment of ischemic stroke.

Piezo1 disrupts blood-brain barrier via CaMKII/Nrf2 in ischemic stroke

Ischemic stroke (IS) leads to the disruption of blood-brain barrier (BBB) integrity, resulting in brain edema. In this process, endothelial cells, as a crucial component of the BBB, are subjected to external pressure and tensile stress. Piezo1, a mechanically-sensitive ion channel, may be activated by sensing these stresses, further exacerbating the destruction of the BBB. Our findings indicated that after cerebral ischemia/reperfusion (I/R) injury, the expression of Piezo1 in endothelial cells increased. In endothelial-specific Piezo1 knockout (Piezo1ECKO) mice, brain damage, neurological deficits, and BBB disruption caused by I/R injury were significantly alleviated. Moreover, oxidative stress and the inflammatory response in the cerebral cortex induced by I/R were also reduced. In vitro, by activating or knocking out Piezo1 in bEnd.3 cells under oxygen-glucose deprivation/reperfusion (OGD/R), we observed similar effects, further corroborating the in vivo findings. To elucidate the molecular mechanism, we found that the protective effect of Piezo1 deficiency on BBB integrity is mediated by the alleviation of p-CaMKII and the enhancement of Nrf2 nuclear translocation. This, in turn, leads to the upregulation of NQO-1 and HO-1 expression. In summary, our research indicates that Piezo1 exacerbates BBB disruption after cerebral I/R injury by promoting oxidative stress, inflammation, and mitochondrial dysfunction. This process is closely linked to the activation of the Ca2+/CaMKII and Nrf2 pathways, suggesting that Piezo1 may be a potential therapeutic target for IS.

Icariside II inhibits gastric cancer progression by suppressing the Wnt/β-catenin signaling pathway

Gastric cancer is one of the common malignant tumours in clinical practice with poor prognosis and high mortality. Icariside II is a single compound extracted from the traditional Chinese medicine Epimedium brevicornu Maxim, and it is also the main active ingredient of Epimedium brevicornu Maxim that exerts pharmacological effects. Studies have shown that Icariside II has anti-tumour activity, but its mechanism of action on gastric cancer cells is unclear. This study aims to analyze the impact of Icariside II on gastric cancer cells as well as on xenograft tumor models of gastric cancer, and to examine the potential molecular regulatory pathways. GES-1, a normal gastric cell line, and gastric cancer cell lines AGS and MGC803 were cultured to investigate the cytotoxic effects of Icariside II using the methylthiazolyldiphenyl-tetrazolium (MTT). Flow cytometry (FCM) was employed to measure the impact of Icariside II on the apoptosis levels of gastric cancer cells, while western blot analysis was used to examine the expression of apoptosis-related proteins and the Wnt/β-catenin signaling pathway. Subsequently, a xenograft tumor model was established and treated with Icariside II to observe changes in tumor volume and weight in the model mice. Finally, alterations in the expression of the Wnt/β-catenin signaling pathway were assessed through immunofluorescence (IF) and immunohistochemistry (IHC). The results showed that Icariside II had faint significant toxic effect on GES-1 cells, and was able to inhibit the proliferative activity and promote apoptosis of the gastric cancer cells. Moreover, Icariside II was able to inhibit the growth of gastric cancer in nude mice subcutaneous transplantation tumor. In addition, both in vivo and in vitro results indicated that Icariside II inhibited the activation of the Wnt/β-catenin signaling pathway. Icariside II inhibited tumorigenicity of gastric cancer by suppressing the Wnt/β-catenin signaling.

Advances in flavonoid bioactivity in chronic diseases and bioavailability: transporters and enzymes

Flavonoids, abundant in the human diet, have been extensively studied for their therapeutic bioactivities. Recent research has made significantly advances in our understanding of the biological activities of flavonoids, demonstrating their therapeutic effects for various chronic diseases. However, the generally low bioavailability of flavonoids limits their effectiveness. Therefore, it is essential to explore the pharmacokinetics of flavonoids, paying particular attention to the roles of transporters and metabolizing enzymes. This paper reviews recent studies on the bioactivity of flavonoids, highlighting the importance of transporters and metabolic enzymes in their pharmacokinetics.

Targeting FDX1 by trilobatin to inhibit cuproptosis in doxorubicin-induced cardiotoxicity

BACKGROUND AND PURPOSE

Doxorubicin (DOX), an anthracycline chemotherapeutic agent, whose use is limited owing to its dose-dependent cardiotoxicity. Mitochondrial oxidative stress plays a crucial role in the pathogenesis of DOX-induced cardiotoxicity (DIC). Trilobatin (TLB), a naturally occurring food additive, exhibits strong antioxidant properties, but its cardioprotective effects in DIC is unclear. This study investigates the cardioprotective effect of TLB on DIC.

EXPERIMENTAL APPROACH

DOX was used to generate an in vivo and in vitro model of cardiotoxicity. Echocardiography, enzyme-linked immunosorbent assay (ELISA) and haematoxylin and eosin (H&E) staining were used to evaluate the cardiac function in these models. To identify the targets of TLB, RNA-sequence analysis, molecular dynamics simulations, surface plasmon resonance binding assays and protein immunoblotting techniques were used. Transmission electron microscopy, along with dihydroethidium and Mito-SOX staining, was conducted to examine the impact of trilobatin on mitochondrial oxidative stress. SiRNA transfection was performed to confirm the role of ferredoxin 1 (FDX1) in DIC development.

KEY RESULTS

In DIC mice, TLB improved cardiac function in a dose-dependent manner and inhibited myocardial fibrosis in DIC mice. TLB also attenuated DOX-induced mitochondrial dysfunction and reduced cardiac mitochondrial oxidative stress. TLB was found to directly bind to FDX1 and suppresses cuproptosis after DOX treatment, causing significant inhibition of cuproptosis-related proteins.

CONCLUSIONS AND IMPLICATIONS

This is the first study to show that TLB strongly inhibits DIC by reducing mitochondrial oxidative stress and controlling DOX-mediated cuproptosis by targeting FDX1. Therefore, TLB is as a potential phytochemical cardioprotective candidate for ameliorating DIC.

Traditional Chinese Medicine for Inhibiting Ferroptosis in Ischemic-Related Diseases

Ischemic-related diseases, such as myocardial infarction and stroke, are primarily driven by a deficit in oxygen supply leading to cellular damage and death. Ferroptosis has emerged as an important mechanism contributing to the progression of ischemic injury, characterized by iron-dependent lipid peroxidation. This review aims to provide a comprehensive overview of the significant mechanisms underlying ferroptosis in ischemic conditions and explores the potential effects of traditional Chinese medicines (TCMs) and their extracts. Numerous compounds extracted from TCMs, including flavonoids, polyphenols and terpenes, exhibit potent antiferroptotic effects by activating nuclear factor erythroid 2-related factor 2, upregulating glutathione peroxidase 4, inhibiting lipid peroxidation and so on. These properties render TCMs a promising candidate for developing novel ferroptosis therapeutic strategies. This review underscores the importance of investigating the interactions between ferroptosis and TCMs within the context of ischemic diseases. These findings provide valuable insights for future research to identify targets associated with ferroptosis regulation, thereby expanding the pharmacological perspective of TCMs in treating ischemic diseases and revealing the potential of novel therapeutic strategies. Additionally, this highlights the relevance of integrating traditional and modern medical approaches in addressing complex health issues.

An emerging role of SNAREs in ischemic stroke: From pre-to post-diseases

Ischemic stroke is a debilitating condition characterized by high morbidity, disability, recurrence, and mortality rates on a global scale, posing a significant threat to public health and economic stability. Extensive research has thoroughly explored the molecular mechanisms underlying ischemic stroke, elucidating a strong association between soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor proteins (SNAREs) and the pathogenesis of this condition. SNAREs, a class of highly conserved proteins involved in membrane fusion, play a crucial role in modulating neuronal information transmission and promoting myelin formation in the central nervous system (CNS). Preventing the SNARE complex formation, malfunctions in SNARE-dependent exocytosis, and altered regulation of SNARE-mediated vesicle fusion are linked to excitotoxicity, endoplasmic reticulum (ER) stress, and programmed cell death (PCD) in ischemic stroke. However, its underlying mechanisms remain unclear. This study conducts a comprehensive review of the existing literature on SNARE proteins, encompassing the structure, classification, and expression of the SNARE protein family, as well as the assembly - disassembly cycle of SNARE complexes and their physiological roles in the CNS. We thoroughly examine the mechanisms by which SNAREs contribute to the pathological progression and associated risk factors of ischemic stroke (hypertension, hyperglycemia, dyslipidemia, and atherosclerosis). Furthermore, our findings highlight the promise of SNAREs as a viable target for pharmacological interventions in the treatment of ischemic stroke.

Research progress on the use of traditional Chinese medicine to treat diseases by regulating ferroptosis

Ferroptosis is an emerging form of programmed cell death triggered by iron-dependent lipid peroxidation. It is distinguished from other forms of cell death by its unique morphological changes and characteristic fine-tuned regulatory gene network. Since its pivotal involvement in the pathogenesis and therapeutic interventions of various diseases, such as malignant tumors, cardiovascular and cerebrovascular diseases, and traumatic disorders, has been well-established, ferroptosis has garnered significant attention in contemporary physiological and pathological research. For the advantage of alleviating the clinical symptoms and improving life quality, traditional Chinese medicine (TCM) holds a significant position in the treatment of these ailments. Moreover, increasing studies revealed that TCM compounds and monomers showed evident therapeutic efficacy by regulating ferroptosis via signaling pathways that tightly regulate redox reactions, iron ion homeostasis, lipid peroxidation, and glutathione metabolism. In this paper, we summarized the current knowledge of TCM compounds and monomers in regulating ferroptosis, aiming to provide a comprehensive review of disease management by TCM decoction, Chinese patent medicine, and natural products deriving from TCM through ferroptosis modulation. The formulation composition, chemical structure, and possible targets or mechanisms presented here offer valuable insights into the advancement of TCM exploration.

Rhamnosidase from Parabacteroides distasonis exhibit the catabolism of epimedin C in the human gut microbiota

Epimedin C, an anti-cardiovascular disease natural compound derived from Herba Epimedii, exhibits low oral bioavailability, with its metabolism closely related to the gut microbiota. In this study, we investigated the roles of intestinal bacteria in the catabolism of epimedin C. We discovered that a strain of Parabacteroides distasonis QZH 1201 (P. distasonis) from human fecal samples can convert epimedin C to 2"-O-rhamnosylicariside II and baohuoside I. More importantly, we identified an α-L-rhamnosidase enzyme from P. distasonis (PdRha), which plays a crucial role in this process by efficiently transforming epimedin C into icariside I. PdRha showed optimal activity at pH 6 and a temperature of 50 °C. Under the condition that the final concentration of epimedin C was 0.5 mM, its conversion efficiency reached 78.72 %. Additionally, we investigated the substrate profile of PdRha and discovered that it can hydrolyze rutin, naringin, and icariin, releasing isoquercitrin, prunin, and icariside I. Molecular docking was performed to gain insights into the enzymatic mechanism. This study provides valuable insights into how a common intestinal symbiotic bacterium processes an important natural flavonoid.

α-Synuclein targeted therapy with multiple pathological improvement for Parkinson's disease by macrocyclic amphiphile nanomedicine

The toxic species formed by the pathological aggregation of α-synuclein (α-Syn) is one of the core pathogenic mechanisms in Parkinson's disease, leading to mitochondrial dysfunction, oxidative stress and ultimately degeneration and loss of dopaminergic neurons. Developing effective inhibitors targeting α-Syn fibrillization critically requires the simultaneous achievement of (1) strong and selective binding of α-Syn for efficient disintegration of fibrils, as well as (2) robust transmembrane capability for efficient cellular uptake. Herein, the co-assembly of guanidinium-modified calixarene (GCA) and cyclodextrin (CD), termed GCA-CD, is screened fully accommodating these conditions. GCA-CD binds tightly and selectively towards α-Syn, thereby effectively inhibiting α-Syn aggregation and disintegrating its fibrils, meanwhile the guanidinium of GCA can additionally improve the transmembrane capability of the co-assembly. In vivo investigations demonstrate that the GCA-CD nanomedicine significantly rescues motor deficits and nigrostriatal degeneration of PD-like rats by decreasing the content of α-Syn as well as restoring mitochondrial dysfunction and suppressing oxidative stress. Astonishingly, transcriptome analysis further reveals the role of GCA-CD in dampening cuproptosis through inhibiting FDX1/LIAS signaling pathway, highlighting the multifaceted therapeutic effects of the co-assembly in PD. The findings in this study underscore the comprehensive exposition on the actual function mechanisms of the therapeutic agents, thereby providing valuable insights for informing material design.

Natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in central nervous system diseases: current preclinical evidence and future perspectives

Flavonoids are a class of important polyphenolic compounds, renowned for their antioxidant properties. However, recent studies have uncovered an additional function of these natural flavonoids: their ability to inhibit ferroptosis. Ferroptosis is a key mechanism driving cell death in central nervous system (CNS) diseases, including both acute injuries and chronic neurodegenerative disorders, characterized by iron overload-induced lipid peroxidation and dysfunction of the antioxidant defense system. This review discusses the therapeutic potential of natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in CNS diseases, focusing on their molecular mechanisms, summarizing findings from preclinical animal models, and providing insights for clinical translation. We specifically highlight natural flavonoids such as Baicalin, Baicalein, Chrysin, Vitexin, Galangin, Quercetin, Isoquercetin, Eriodictyol, Proanthocyanidin, (-)-epigallocatechin-3-gallate, Dihydromyricetin, Soybean Isoflavones, Calycosin, Icariside II, and Safflower Yellow, which have shown promising results in animal models of acute CNS injuries, including ischemic stroke, cerebral ischemia-reperfusion injury, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury. Among these, Baicalin and its precursor Baicalein stand out due to extensive research and favorable outcomes in acute injury models. Mechanistically, these flavonoids not only regulate the Nrf2/ARE pathway and activate GPX4/GSH-related antioxidant pathways but also modulate iron metabolism proteins, thereby alleviating iron overload and inhibiting ferroptosis. While flavonoids show promise as ferroptosis inhibitors for CNS diseases, especially in acute injury settings, further studies are needed to evaluate their efficacy, safety, pharmacokinetics, and blood-brain barrier penetration for clinical application.

Trilobatin, a Naturally Occurring GPR158 Ligand, Alleviates Depressive-like Behavior by Promoting Mitophagy

The G-protein-coupled receptor (GPR158), an orphan receptor, is highly expressed in the medial prefrontal cortex (mPFC) and identified as a novel therapeutic target for depression. Trilobatin is a naturally occurring food additive with potent neuroprotective properties. However, its pharmacological effects and molecular mechanisms against depression remain unknown. Therefore, we explored whether trilobatin alleviates depression by targeting GPR158. Our results indicated that trilobatin alleviated chronic unpredictable mild stress (CUMS)-induced depressive-like behavior in mice. Mitophagy contributed to the antidepressant-like effect of trilobatin, as evidenced by the qRT-PCR array. Furthermore, trilobatin up-regulated autophagy-associated protein expression, restored mitochondrial dynamic balance, and inhibited oxidative stress of mPFC in mice after CUMS insult and in corticosterone-induced primary neuron injury. Intriguingly, trilobatin directly bound to GPR158 and decreased its level of protein expression. GPR158 deficiency attenuated depressive-like behavior through promoting mitophagy, while the antidepressant effect of trilobatin was strengthened in GPR158-deficient mice. Our findings highlight that GPR158-mediated mitophagy acts as a crucial pharmacological target for depression and reveal a new-found pharmacological property of trilobatin: serving as a novel naturally occurring ligand of GPR158 to safeguard from depression by oxidative stress by promoting mitophagy.

Activation of Sirt6 by icariside Ⅱ alleviates depressive behaviors in mice with poststroke depression by modulating microbiota-gut-brain axis

BACKGROUND

Sirt6-mediated gut microbiota plays a vital role in poststroke depression (PSD). Icariside Ⅱ (ICS Ⅱ) is a naturally-occurring neuroprotectant with Sirt6 induction potency. However, it is unknown whether ICS Ⅱ protects against PSD through modulation of gut microbiota.

OBJECTIVE

This study aimed to reveal the effect and potential mechanisms of ICS Ⅱ on PSD, and the role of the microbiota-gut-brain axis was investigated.

METHODS

Using middle cerebral artery occlusion (MCAO) and chronic unpredictable mild stress (CUMS) to establish post-stroke depression (PSD) mice, we assessed anti-depressant effects of ICS Ⅱ via behavioral tests, immunohistochemistry, and western blot. Transcriptome profiling, molecular docking, and surface plasmon resonance were used to identify key targets. 16S rDNA genomic-derived taxonomic profiling and fecal microbiota transplantation (FMT) were conducted to figure out the mechanistic role of the gut microbiota and short-chain fatty acids (SCFAs).

RESULTS

ICS Ⅱ ameliorated depressive-like behaviors in PSD mice as evidenced by sucrose preference test, forced swimming test and tail suspension test. ICS Ⅱ restored mitochondrial function, reduced oxidative damage and pro-inflammatory cytokines both in brain and intestine through regulation of Sirt6/NF-κB pathway. ICS Ⅱ significantly increased the abundance of gut microbiota (such asAkkermansia and Ligilactobacillus), enhanced SCFAs concentrations, repaired intestinal barrier integrity and upreglated the tight junction protein expression. FMT from ICS II-treated mice replicated these benefits, confirming gut microbiota's role. Mechanistically, ICS Ⅱ directly bound to Sirt6 and enhanced its activity. However, ICS Ⅱ-mediated neuroprotection was neutralized in PSD mice or hydrogen peroxide-induced enteric glial cells when Sirt6 was absent.

CONCLUSION

Our findings expand the pharmacological properties of ICS II by demonstrating its ability to ameliorate PSD through modulation of the microbiota-gut-brain axis. ICS Ⅱ, as a novel Sirt6 activator, could be translated into an alternative microbiota-targeted avenue for coping with PSD.

Targeting intracellular autophagic process for the treatment of post-stroke ischemia/reperfusion injury

Cerebral ischemia/reperfusion (I/R) injury is an important pathophysiological condition of ischemic stroke that involves a variety of physiological and pathological cell death pathways, including autophagy, apoptosis, necroptosis, and phagoptosis, among which autophagy is the most studied. We have reviewed studies published in the past 5 years regarding the association between autophagy and cerebral I/R injury. To the best of our knowledge, this is the first review article summarizing potential candidates targeting autophagic pathways in the treatment of I/R injury post ischemic stroke. The findings of this review may help to better understand the pathogenesis and mechanisms of I/R events and bridge the gap between basic and translational research that may lead to the development of novel therapeutic approaches for I/R injury.

High fructose levels inhibit the proliferation of cardiomyocytes via the Notch1 signaling pathway

Fructose, as a natural and simple sugar, is not significantly harmful to the human body when consumed in moderation and can provide energy for the body. High-fructose diets have been linked to an increased risk of a range of metabolic disorders, including hypertriglyceridemia, hypertension, and diabetes mellitus. These conditions are known to be associated with an elevated risk of developing cardiometabolic diseases. Cardiomyocytes in mammals possess the capacity to proliferate from the moment of their birth. However, this capacity diminishes over time, and cardiac growth is ultimately achieved through cardiomyocyte (CM) hypertrophy. Prior studies have demonstrated that fructose metabolism is enhanced in the heart during pathological hypertrophy [1]. The consumption of foods containing high levels of fructose has been linked to an increase in the size of cardiomyocytes, which can lead to damage to the heart. The impact of high fructose on cardiomyocytes at the point of their initial capacity for proliferation has not been previously documented. In this experiment, our purpose was to explore the impact of high fructose in cardiomyocyte proliferation. To establish an apical resection model in neonatal mice, neonatal ICR mice were randomly divided into a sham-operated group (Sham + PBS), a sham-operated combined high-fructose group (Sham + fructose), an apical resection alone group (AR + PBS) and an apical resection combined with a high-fructose group (AR + fructose). Next, echocardiography was employed to assess the cardiac function of all mice. Masson staining was carried out to analyze cardiac fibrosis. Immunostaining was performed by extracting primary rat cardiomyocytes after the high-fructose intervention to see if proliferation-related markers (Ki67, PH3, Aurora-B) changed, qRT-PCR and immunofluorescence were used to determine changes in the expression profile of Notch1 in the neonatal heart. The results suggest that high fructose could inhibit cardiomyocyte proliferation in vivo and in vitro, The possible mechanism is that high fructose levels inhibit cardiomyocyte proliferation through suppression of Notch1 signaling pathway. In conclusion, high fructose levels inhibit the proliferation of cardiomyocytes via the Notch1 signaling pathway.

Exploring the Kidney-Brain Crosstalk: Biomarkers for Early Detection of Kidney Injury-Related Alzheimer's Disease

Background

The phenomenon of "kidney-brain crosstalk" has stimulated scholarly inquiry into the correlations between kidney injury (KI) and Alzheimer's disease (AD). Nonetheless, the precise interactions and shared mechanisms between KI and AD have yet to be fully investigated. The primary goal of this study was to investigate the link between KI and AD, with a specific focus on identifying diagnostic biomarkers for KI-related AD.

Methods

The first step of the present study was to use Mendelian randomization (MR) analysis to investigate the link between KI and AD, followed by verification of in vivo and in vitro experiments. Subsequently, bioinformatics and machine learning techniques were used to identify biomarkers for KI-associated ferroptosis-related genes (FRGs) in AD, which were validated in following experiments. Moreover, the relationship between hub biomarkers and immune infiltration was assessed using CIBERSORT, and the potential drugs or small molecules associated with the core biomarkers were identified via the DGIdb database.

Results

MR analysis showed that KI may be a risk factor for AD. Experiments showed that the combination of D-galactose and aluminum chloride was found to induce both KI and AD, with ferroptosis emerging as a bridge to facilitate crosstalk between KI and AD. Besides, we identified EGFR and RELA have significant diagnostic value. These biomarkers are associated with NK_cells_resting and B_cells_memory and could be targeted for intervention in KI-related AD by treating gefitinib and plumbagin.

Conclusion

Our study elucidates that ferroptosis may be an important pathway for kidney-brain crosstalk. Notably, gefitinib and plumbagin may be therapeutic candidates for intervening in KI-associated AD by targeting EGFR and RELA.

Discovery of 15-deoxynaphthomycins activating the antioxidant NRF2-ARE pathway from Streptomyces sp. N50 via genome mining, global regulator introduction, and molecular networking

Genome mining is a promising avenue for expanding the repertoire of microbial natural products, which are important for drug development. This approach involves predicting genetically encoded small molecules by examining bacterial genomes via accumulated knowledge of microbial biosynthesis. However, it is also important that the microbes produce the predicted molecule in practice. Here, we introduce an endophytic Streptomyces sp. N50, which was isolated from the medicinal plant Selaginella tamariscina. Upon sequencing its entire genome, 33 biosynthetic gene clusters (BGCs) were identified in a chromosome and a megaplasmid. Subsequent genome mining revealed that the new 15-deoxynaphthomycin could be produced due to the presence of an enoyl reductase domain, which is absent in the known BGC of naphthomycin, a type of ansamycin antibiotics. In addition, the engineered strain with the introduction of the global regulatory gene afsR2 into N50 successfully produced 15-deoxynaphthomycins. Furthermore, molecular network analysis via MS/MS selectively confirmed the presence of additional sulfur-containing 15-deoxynaphthomycin congeners. Eventually, six new 15-deoxynaphthomycins were isolated and elucidated from the engineered strain N50. This family of compounds is known to exhibit various biological activities. Also, the presence of quinone moieties in these compounds, which are known to activate NRF2, they were tested for their ability to activate NRF2. Among the new compounds, three (1, 5, and 6) activated the antioxidant NRF2-ARE signaling pathway. Treatment with these compounds significantly elevated NRF2 levels in HepG2 cells and further induced the expression of NRF2 target genes associated with the antioxidant response. This study suggests that the combination of genome mining, gene engineering and molecular networking is helpful for generating new small molecules as pharmaceutical candidates from microorganisms.

The total extract of Abelmoschus manihot (L.) medic flowers (TEA) mediated Nrf2-TFAM signalling to regulate mitochondrial antioxidant mechanism

Skin, as the first line of defence of the human body, is exposed to dangers such as overheating substances, ultraviolet rays, and environmental pollutants, and the incidence of skin diseases is increasing annually. Oxidative stress plays a dominant role in most skin diseases. Abelmoschus manihot (L.) medic flower (TEA) is a traditional Chinese medicine widely used to treat injuries to the skin such as water and fire scalds. It has been reported that TEA has excellent antioxidant effects. In this study, we aimed to explore the antioxidant and mitochondrial protection effects of TEA in H2O2-mediated HaCaT cell damage. HaCaT cells were incubated with H2O2 to simulate oxidative stress in the skin. The effect of TEA on HaCaT cells was also evaluated. Cell morphology was observed via inverted microscopy, and cell viability was measured via the MTT reagent. The cells were stained with Hoechst 33,324 solution. Reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA) and ATP detection kits were used to detect the corresponding indicators. The mitochondrial membrane potential was detected by JC-1. RT-PCR was used to detect mRNA and mtDNA expression. The expression of the target protein was detected by Western blotting and immunofluorescence. H2O2 triggered oxidative damage in HaCaT cells, which manifested as apoptosis, increased ROS and MDA contents, and decreased SOD activity. H2O2 activates the KEAP1/Nrf2/NQO1 signalling pathway, which decreases the expression of the intracellular KEAP1 protein and slightly increases the expression of the Nrf2 and NQO1 proteins, further causing mitochondrial oxidative stress, resulting in changes in the mitochondrial membrane potential, a reduction in the mtDNA copy number, and decreased expression of the PGC-1α and TFAM proteins. In addition the expression of mitochondrial respiratory chain genes and proteins decreased. TEA promoted the expression of Nrf2 in HaCaT cells, activated the downstream antioxidant response, and alleviated the oxidative stress and mitochondrial damage caused by H2O2. ML385 is an Nrf2 inhibitor, under which the antioxidant and mitochondrial protective effects of TEA are inhibited. When TFAM was knocked down, the protective effect of TEA on mitochondria was also inhibited. TEA protects HaCaT cells from H2O2-induced oxidative damage and mitochondrial oxidative damage through the KEAP1/Nrf2/NQO1/PGC-1α/TFAM pathway.

Icariside II Alleviates Chondrocyte Inflammatory Injury by Inhibiting the TNIP2/NF-κB Pathway

Icariside II exerts protective effects against various diseases; however, its specific effects on osteoarthritis (OA) remain unclear. Therefore, in this study, we aimed to investigate the effects of icariside II in an in vitro model of OA and analyze its action mechanisms. We established an in vitro OA model by treating a human chondrocyte cell line (CHON-001) with interleukin (IL)-1β, followed by treatment with different concentrations of icariside II. Cell viability was measured using the methyl thiazolyl tetrazolium assay, and the level of lactate dehydrogenase (LDH) released from cells was determined using the appropriate kit. Tumor necrosis factor (TNF)-α, IL-6, and IL-8 levels were determined via enzyme-linked immunosorbent assay. Flow cytometry was used to assess apoptosis. Apoptosisrelated protein expression levels and TNFAIP3-interacting protein 2 (TNIP2)/nuclear factor (NF)-κB signaling pathway were analyzed via reverse transcription-quantitative polymerase chain reaction and western blotting. Furthermore, TNIP2-small interfering RNA (siRNA) was used to determine whether the TNIP2/NF-κB pathway influences the effects of icariside II on OA. Results indicated that Icariside II did not exert any significant toxic effects on CHON-001 cells. It inhibited IL-1β-induced apoptosis and increase in LDH levels and enhanced the inflammatory response. Additionally, icariside II reversed the IL-1β-induced decrease in TNIP2 levels and increase in NF-κB phosphorylation. TNIP2-siRNA revealed that the TNIP2/NF-κB signaling pathway influenced the alleviating effects of icariside II on OA. In conclusion, our results revealed that icariside II attenuated IL-1β-induced inflammatory injury in chondrocytes by increasing TNIP2 expression and inhibiting NF-κB pathway activation, highlighting its therapeutic potential for OA.

Idebenone Protects Photoreceptors Impaired by Oxidative Phosphorylation Disorder in Retinal Detachment

Purpose

Oxidative phosphorylation (OXPHOS) is an aerobic metabolic mechanism, and its dysfunction plays an important role in the pathological changes of ischemic diseases. However, systematic studies on the occurrence of retinal detachment (RD) are lacking.

Methods

Single-cell RNA sequencing (scRNA-seq) of the human retina was performed to detect the metabolic changes of various retinal cells after RD. In this study, animal experiments were conducted to explore the OXPHOS activity after RD. In addition, idebenone, a coenzyme Q10 (CoQ10) analog currently used to treat Leber hereditary optic neuropathy (LHON), was used to improve the OXPHOS disorder in experimental RD model.

Results

ScRNA-seq revealed abnormal energy metabolism and OXPHOS pathways in retinal cells after RD. Adenosine triphosphate (ATP) and reactive oxygen species (ROS) are the main products of OXPHOS, the mouse RD model indicated that the rise in ROS levels may have a greater impact on photoreceptors in the early stage, whereas decreased ATP synthesis was observed in the later stage; these changes threaten the function and morphology of the retina. Idebenone was administered to model mice intragastrically, leading to reduced ROS levels in the early stage post-RD and improved ATP synthesis in the later stage, which was closely related to the maintenance of mitochondrial morphology.

Conclusions

OXPHOS disorder leads to photoreceptor degeneration after RD, which can be alleviated by improving OXPHOS function.

Zhongfeng Xingnao Liquid ameliorates post-stroke cognitive impairment through sirtuin1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway

The activation of the sirtuin1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway has been shown to mitigate oxidative stress-induced apoptosis and mitochondrial damage by reducing reactive oxygen species (ROS) levels. Clinical trials have demonstrated that Zhongfeng Xingnao Liquid (ZFXN) ameliorates post-stroke cognitive impairment (PSCI). However, the underlying mechanism, particularly whether it involves protecting mitochondria and inhibiting apoptosis through the SIRT1/Nrf2/HO-1 pathway, remains unclear. This study employed an oxygen-glucose deprivation (OGD) cell model using SH-SY5Y cells and induced PSCI in rats through modified bilateral carotid artery ligation (2VO). The effects of ZFXN on learning and memory, neuroprotective activity, mitochondrial function, oxidative stress, and the SIRT1/Nrf2/HO-1 pathway were evaluated both in vivo and in vitro. Results indicated that ZFXN significantly increased the B-cell lymphoma 2 (Bcl2)/Bcl2-associated X (Bax) ratio, reduced terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL)+ cells, and markedly improved cognition, synaptic plasticity, and neuronal function in the hippocampus and cortex. Furthermore, ZFXN exhibited potent antioxidant activity, evidenced by decreased ROS and malondialdehyde (MDA) content and increased superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels. ZFXN also demonstrated considerable enhancement of mitochondrial membrane potential (MMP), Tom20 fluorescence intensity, adenosine triphosphate (ATP) and energy charge (EC) levels, and mitochondrial complex I and III activity, thereby inhibiting mitochondrial damage. Additionally, ZFXN significantly increased SIRT1 activity and elevated SIRT1, nuclear Nrf2, and HO-1 levels. Notably, these effects were substantially counteracted when SIRT1 was suppressed by the inhibitor EX-527 in vitro. In conclusion, ZFXN alleviates PSCI by activating the SIRT1/Nrf2/HO-1 pathway and preventing mitochondrial damage.

Pharmacological and Therapeutic Potential of a Natural Flavonoid Icariside II in Human Complication

Emerging challenges to human health necessitate a coordinated effort to find both preventative and therapeutic techniques, with natural products at the forefront of attempts to gain novel medicines and minimize disease transmission and related death. The medicinal potential of chemicals contained in plants has been known for centuries, leading to its use in homes and clinics for the treatment of numerous disorders. Despite global advancements, plant-based medicines continue to be utilized to treat various pathological illnesses or as alternatives to contemporary pharmaceuticals. The safety and low toxicity of natural products have led to their increasing acceptability for the prevention or treatment of many ailments. Flavonoids are biologically active compounds that are classified as polyphenols, which are a type of secondary metabolite found in all plants. Icariside II (ICA-II) is one of the secondary metabolites that belong to the flavonoid category of phytochemicals and is present in Epimedium brevicornum Maxim. In recent years, ICA-II has been discovered to show anti-inflammatory, antioxidant, anticancer, renal protecting, and cardiac protective effects, as well as several other biological characteristics. This review is focused on the exploration of the pharmacological activities of ICA-II. ICA-II is considered a prospective candidate for future clinical investigations due to a number of therapeutic properties.

Targeting PPARα/γ by icariside II to rescue GalN/LPS-induced acute liver injury in mice: Involvement of SIRT6/NF-κB signaling pathway

BACKGROUND

Peroxisome proliferator-activated receptor α and-γ (PPARα/γ) are known to play crucial roles in acute liver injury (ALI). Icariside II (ICS II), a natural flavonoid compound derived from Herba EpimedII, confers neuroprotection with PPARα/γ induction potency.

PURPOSE

This study was aimed to explore whether ICS II has the capacity to protect against ALI, and the role of PPARα/γ in the beneficial effect of ICS II on ALI.

METHODS

Mice challenged by D-galactosamine (GalN)/lipopolysaccharide (LPS) and Kupffer cells (KCs) upon LPS insult were used as ALI models in vivo and in vitro. PPARα/γ-deficient mice were treated with ICS II to validate the potential targets of ICS II on ALI.

RESULTS

We found that ICS II (5, 10, 20 mg/kg) dose-dependently improved the survival rate and liver histology, decreased ALT and AST in GalN/LPS-treated mice. Furthermore, ICS II directly bound to PPARα/γ and increased their activities. The protective properties of ICS II were counteracted when PPARα/γ were knocked out in GalN/LPS-induced mice and LPS-induced KCs, respectively. Mechanistically, ICS II restored mitochondrial function, reduced oxidative stress and inflammation through activating PPARα/γ, which activated Sirt6 and inhibited NF-κB nuclear translocation.

CONCLUSION

Our findings not only highlight PPARα/γ-SIRT6 signaling as a vital therapeutic target to combat ALI, but also reveal ICS II may serve as a novel dual PPARα/γ agonist to safeguard ALI from the oxidation-inflammation vicious circle by mediating SIRT6/NF-κB.

Micheliolide ameliorates severe acute pancreatitis in mice through potentiating Nrf2-mediated anti-inflammation and anti-oxidation effects

Severe acute pancreatitis (SAP) is an acute inflammatory injury disease with significant mortality rate and currently without effective strategy being available. Inflammation and oxidative stress play central roles in the etiology of SAP. Micheliolide (MCL), an active monomeric component isolated from Michelia champaca, has been proved its multiple therapeutic properties including anti-inflammatory, antioxidant and anti-cancer. Nevertheless, the therapeutic effect and underlying mechanism of MCL in SAP still remain unclear. Here, we found that caerulein with lipopolysaccharide (LPS)-induced SAP murine models exhibited severe pancreatic injury, including necrosis, edema, and vacuolation of acinar cells in the pancreas, elevated serum levels of amylase and lipase, and reduced number of the exocrine cells. As expected, MCL treatment alleviated these side effects. Mechanistically, MCL triggered nuclear factor erythroid 2-related factor 2 (Nrf2) activation, thereby activating Nrf2-regulated antioxidative pathways and inhibiting nuclear factor kappa B p65 (NF-κB p65)-mediated inflammatory response, resulting in protection against pancreatic injury in SAP mice. In addition, Nrf2 gene deficiency abolished the beneficial effects of MCL on SAP-induced pancreatic inflammation and oxidative stress and blocked the ability of MCL to alleviate the pancreatic injury in SAP mice. Collectively, these findings indicated that the suppression of SAP-induced pancreatic injury by MCL was at least in part due to Nrf2-mediated anti-oxidation effect and inhibition of inflammation.

The ellagitannin metabolite urolithin C attenuated cognitive impairment by inhibiting neuroinflammation via downregulation of MAPK/NF-kB signaling pathways in aging mice

The current study aimed to evaluate the preventive effects of urolithin C (Uro C), a gut microbial metabolite of ellagitannins on D-galactose (D-gal)-induced brain damage during the aging process and to elucidate the underlying mechanisms. In our study, the protective effect of Uro C on D-gal-induced BV2 microglia cell-mediated neuroinflammation damage in primary cortical neurons in vitro was confirmed. The results in an aging model in vivo induced by D-gal demonstrated that Uro C prevented D-gal-induced memory impairment, long-term potentiation (LTP) damage, and synaptic dysfunction through behavioral, electrophysiological, and histological examinations. Additionally, amyloidogenesis was observed in the central nervous system. The findings indicated that Uro C exhibited a preventive effect on the D-gal-induced elevation of β-amyloid (1-42 specific) (Aβ1-42) accumulation, APP levels, ABCE1 levels, and the equilibrium of the cholinergic system in the aging mouse brain. Moreover, Uro C demonstrated downregulation of D-gal-induced glial overactivation through inhibition of the MAPK/NF-kB pathway. This resulted in the regulation of inflammatory mediators and cytokines, including iNOS, IL-6, IL-1β, and TNF-ɑ, in the mouse brain and BV2 microglial cells. Taken together, our results suggested that Uro C treatment could effectively mitigate the D-gal-induced memory impairment and amyloidogenesis, and the underlying mechanism might be tightly related to the improvement of neuroinflammation by suppressing the MAPK/NF-kB pathway, indicating Uro C might be an alternative and promising agent for the treatment of aging and age-associated brain diseases.

Diallyl trisulfide regulates PGK1/Nrf2 expression and reduces inflammation to alleviate neurological damage in mice after traumatic brain injury

BACKGROUND

Diallyl trisulfide (DATS) has a direct antioxidant capacity and emerges as a promising neuroprotective agent. This study was designed to investigate the role of DATS in traumatic brain injury (TBI).

METHODS

TBI mouse models were established using the controlled cortical impact, followed by DATS administration. The effects of DATS on neurological deficit, brain damage, inflammation and phosphoglycerate kinase 1 (PGK1) expression were detected using mNSS test, histological analysis, TUNEL assay, enzyme-linked immunosorbent assay and immunofluorescence. PC12 cells were subjected to H2O2-induced oxidative injury after pre-treatment with DATS, followed by cell counting kit-8 assay, flow cytometry and ROS production detection. Apoptosis-related proteins and the PGK1/nuclear factor erythroid-2 related factor 2 (Nrf2) pathway were examined using Western blot.

RESULTS

DATS ameliorated the cerebral cortex damage, neurological dysfunction and apoptosis, as well as decreased PGK1 expression and expressions of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) in mice after TBI. DATS also enhanced viability, blocked apoptosis and inhibited ROS production in H2O2-induced PC12 cells. DATS downregulated Cleaved-Caspase3, Bax and PGK1 levels, and upregulated Bcl-2 and Nrf2 levels in TBI mouse models and the injured cells.

CONCLUSION

DATS regulates PGK1/Nrf2 expression and inflammation to alleviate neurological damage in mice after TBI.

The interplay between ferroptosis and inflammation: therapeutic implications for cerebral ischemia-reperfusion

Stroke ranks as the second most significant contributor to mortality worldwide and is a major factor in disability. Ischemic strokes account for 71% of all stroke incidences globally. The foremost approach to treating ischemic stroke prioritizes quick reperfusion, involving methods such as intravenous thrombolysis and endovascular thrombectomy. These techniques can reduce disability but necessitate immediate intervention. After cerebral ischemia, inflammation rapidly arises in the vascular system, producing pro-inflammatory signals that activate immune cells, which in turn worsen neuronal injury. Following reperfusion, an overload of intracellular iron triggers the Fenton reaction, resulting in an excess of free radicals that cause lipid peroxidation and damage to cellular membranes, ultimately leading to ferroptosis. The relationship between inflammation and ferroptosis is increasingly recognized as vital in the process of cerebral ischemia-reperfusion (I/R). Inflammatory processes disturb iron balance and encourage lipid peroxidation (LPO) through neuroglial cells, while also reducing the activity of antioxidant systems, contributing to ferroptosis. Furthermore, the lipid peroxidation products generated during ferroptosis, along with damage-associated molecular patterns (DAMPs) released from ruptured cell membranes, can incite inflammation. Given the complex relationship between ferroptosis and inflammation, investigating their interaction in brain I/R is crucial for understanding disease development and creating innovative therapeutic options. Consequently, this article will provide a comprehensive introduction of the mechanisms linking ferroptosis and neuroinflammation, as well as evaluate potential treatment modalities, with the goal of presenting various insights for alleviating brain I/R injury and exploring new therapeutic avenues.

Nuclear factor erythroid 2-related factor-mediated signaling alleviates ferroptosis during cerebral ischemia-reperfusion injury

Cardiac arrest (CA) is a significant challenge for emergency physicians worldwide and leads to increased morbidity and mortality rates. The poor prognosis of CA primarily stems from the complexity and irreversibility of cerebral ischemia-reperfusion injury (CIRI). Ferroptosis, a form of programmed cell death characterized by iron overload and lipid peroxidation, plays a crucial role in the progression and treatment of CIRI. In this review, we highlight the mechanisms of ferroptosis within the context of CIRI, focusing on its role as a key contributor to neuronal damage and dysfunction post-CA. We explore the crucial involvement of the nuclear factor erythroid 2-related factor (Nrf2)-mediated signaling pathway in modulating ferroptosis-associated processes during CIRI. Through comprehensive analysis of the regulatory role of Nrf2 in the cellular responses to oxidative stress, we highlight its potential as a therapeutic target for mitigating ferroptotic cell death and improving the neurological prognosis of patients experiencing CA. Furthermore, we discuss interventions targeting the Kelch-like ECH-associated protein 1/Nrf2/antioxidant response element pathway, including the use of traditional Chinese medicine and Western medicine, which demonstrate potential for attenuating ferroptosis and preserving neuronal function in CIRI. Owing to the limitations in the safety, specificity, and effectiveness of Nrf2-targeted drugs, as well as the technical difficulties and ethical constraints in obtaining the results related to the brain pathological examination of patients, most of the studies focusing on Nrf2-related regulation of ferroptosis in CIRI are still in the basic research stage. Overall, this review aims to provide a comprehensive understanding of the mechanisms underlying ferroptosis in CIRI, offering insights into novel therapeutics aimed at enhancing the clinical outcomes of patients with CA.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Flavonoids Derived from Chinese Medicine: Potential Neuroprotective Agents

Due to their complex pathological mechanisms, neurodegenerative diseases have brought great challenges to drug development and clinical treatment. Studies have shown that many traditional Chinese medicines have neuroprotective pharmacological activities such as anti-inflammatory and anti-oxidation properties and have certain effects on improving the symptoms of neurodegenerative diseases and delaying disease progression. Flavonoids are the main active components of many traditional Chinese medicines for the treatment of neurodegenerative diseases. These compounds have a wide range of biological activities, including anti-inflammatory, anti-oxidative stress, regulation of autophagy balance, inhibition of apoptosis, and promotion of neuronal regeneration. This paper focuses on the neuroprotective effects of six common flavonoids: quercetin, rutin, luteolin, kaempferol, baicalein, and puerarin. It then systematically reviews their characteristics, mechanisms, and key signaling pathways, summarizes the common characteristics and laws of their neuroprotective effects, and discusses the significance of strengthening the research on the neuroprotective effects of these compounds, aiming to provide reference for more research and drug development of these substances as neuroprotective drugs.

Anti-Inflammatory and Antioxidant Effects of Irigenen Alleviate Osteoarthritis Progression through Nrf2/HO-1 Pathway

BACKGROUND/OBJECTIVES

Osteoarthritis (OA) is a prevalent degenerative disease globally, characterized by cartilage degradation and joint dysfunction. Current treatments are insufficient for halting OA progression. Irigenin (IRI), a flavonoid extracted from natural plants with anti-inflammatory and antioxidant properties, has demonstrated potential in mitigating inflammation and oxidative stress in various diseases; however, its effects on OA remain unexplored. This study aims to evaluate the therapeutic effects of IRI on OA through in vivo and in vitro experiments and to elucidate the underlying molecular mechanisms.

METHODS

In vitro, chondrocytes were exposed to hydrogen peroxide (H2O2) to induce an oxidative stress environment and were then treated with IRI. Western blotting, RT-qPCR, immunofluorescence staining assays, flow cytometry, and apoptosis assays were employed to assess the effects of IRI on chondrocyte matrix homeostasis, inflammatory response, and apoptosis. In vivo, an OA rat model was treated with regular IRI injections, and therapeutic effects were evaluated using micro-CT, histological staining, and immunohistochemistry assays.

RESULTS

IRI treatment restored matrix homeostasis in chondrocytes and effectively suppressed H2O2-induced inflammation and apoptosis. Subsequent studies further revealed that IRI exerts its therapeutic effects by activating the Nrf2/HO-1 pathway. Inhibition of Nrf2 expression in chondrocytes partially blocked the anti-inflammatory and antioxidant effects of IRI. In the OA rat model, regular IRI injections effectively ameliorated cartilage degeneration.

CONCLUSIONS

This study identifies IRI as a promising strategy for OA treatment by modulating inflammation and apoptosis through the Nrf2/HO-1 pathway.

Lithocarpus polystachyus Rehd. ameliorates cerebral ischemia/reperfusion injury through inhibiting PI3K/AKT/NF-κB pathway and regulating NLRP3-mediated pyroptosis

Introduction

Ischemic stroke (IS) is a serious threat to human life and health, and cerebral ischemia/reperfusion injury (CIRI) exacerbates IS by enhancing neuroinflammation and oxidative stress. Sweet tea (ST) comprises several bioactive components, such as phlorizin, trilobatin, and phloretin, with diverse pharmacological activities. However, it remains uncertain whether ST can confer protection against CIRI. In this study, we aimed to investigate the impact and potential underlying mechanism of ST in the context of CIRI.

Methods

CIRI model were established in male sprague dawley (SD) rats. The neurobehavioral assessment, the volume of cerebral infarction and the morphology of neurons were measured to complete the preliminary pharmacodynamic study. The therapeutic targets and pathways of ST on IS were obtained by protein-protein interaction, molecular docking and Metascape database. The predicted results were further verified in vivo.

Results

Our results revealed that ST treatment significantly ameliorated brain damage in rats subjected to CIRI by mitigating mitochondrial oxidative stress and neuroinflammation. Additionally, we identified the PI3K/AKT/NF-κB pathway and the NLRP3-mediated pyroptosis axis as crucial processes, with molecular docking suggested direct interactions between the main compounds of ST and NLRP3.

Conclusion

ST safeguards against CIRI-induced neuronal loss, neuroinflammation and oxidative stress through the inhibition of the PI3K/AKT/NF-κB pathway and the regulation of NLRP3-mediated pyroptosis.

Ferroptosis in Ischemic Stroke and Related Traditional Chinese Medicines

Stroke is a severe neurological disorder resulting from the rupture or blockage of blood vessels, leading to significant mortality and disability worldwide. Among the different types of stroke, ischemic stroke (IS) is the most prevalent, accounting for 70-80% of cases. Cell death following IS occurs through various mechanisms, including apoptosis, necrosis, and ferroptosis. Ferroptosis, a recently identified form of regulated cell death characterized by iron overload and lipid peroxidation, was first described by Dixon in 2012. Currently, the only approved pharmacological treatment for IS is recombinant tissue plasminogen activator (rt-PA), which is limited by a narrow therapeutic window and often results in suboptimal outcomes. Recent research has identified several traditional Chinese medicines (TCMs) that can inhibit ferroptosis, thereby mitigating the damage caused by IS. This review provides an overview of stroke, the role of ferroptosis in IS, and the potential of certain TCMs to inhibit ferroptosis and contribute to stroke treatment.

NDRG2 regulates glucose metabolism and ferroptosis of OGD/R-treated astrocytes by the Wnt/β-catenin signaling

Ischemic stroke is one main type of cerebrovascular disorders with leading cause of death and disability worldwide. Astrocytes are the only nerve cell type storing glycogen in the brain, which regulate the glucose metabolism and handle the energy supply and survive of neurons. Astrocyte ferroptosis contributes to neuron injury in brain disorders. N-myc downstream-regulated gene 2 (NDRG2) has been implicated in the progression of brain diseases, including ischemic stroke. However, whether NDRG2 could affect the glucose metabolism and ferroptosis of astrocytes during ischemic stroke remains largely unknown. Mouse astrocytes were treated with oxygen-glucose deprivation/reoxygenation (OGD/R) to establish the in vitro model. Glial fibrillary acidic protein, NDRG2, Wnt3a and β-catenin expression levels were detected by immunofluorescence staining and western blot analyses. Glucose metabolism was investigated by glucose uptake, lactate production, nicotinamide adenine dinucleotide phosphate hydrogen/nicotinamide adenine dinucleotide phosphate (NADPH/NADP+), ATP and glycolysis enzymes (HK2, PKM2 and lactate dehydrogenase A [LDHA]) levels. Ferroptosis was assessed via reactive oxygen species (ROS), glutathione (GSH), iron and ferroptosis-related markers (GPX4 and PTGS2) contents. Glycolysis enzymes and ferroptosis-related markers levels were measured via western blot. NDRG2 expression was elevated in OGD/R-induced astrocytes. NDRG2 overexpression aggravated OGD/R-induced loss of glucose metabolism through reducing glucose uptake, lactate production, NADPH/NADP+ and ATP levels. NDRG2 upregulation exacerbated OGD/R-caused reduction of glycolysis enzymes (HK2, PKM2 and LDHA) levels. NDRG2 promoted OGD/R-induced ferroptosis of astrocytes by increasing ROS, iron and PTGS2 levels and decreasing GSH and GPX4 levels. NDRG2 overexpression enhanced OGD/R-induced decrease of Wnt/β-catenin signaling activation by reducing Wnt3a and β-catenin expression. NDRG2 silencing played an opposite effect. Inhibition of Wnt/β-catenin signaling activation by IWR-1 attenuated the influences of NDRG2 knockdown on glucose metabolism, glycolysis enzymes levels and ferroptosis. These findings demonstrated that NDRG2 contributes to OGD/R-induced inhibition of glucose metabolism and promotion of ferroptosis in astrocytes through inhibiting Wnt/β-catenin signaling activation, which might be associated with ischemic stroke progression.

Exploring the protective effect and mechanism of icariside II on the bladder in a rat model of radiation cystitis based on transcriptome sequencing

PURPOSE

Radiation cystitis (RC) is a complex and common complication after radiotherapy for pelvic cancer. Icariside II (ICAII) is a flavonoid compound extracted from Epimedium, a traditional Chinese medicine, with various pharmacological activities. The aim of the present study was to investigate the cysto-protective effects of ICAII in RC rats and its possible mechanisms.

MATERIALS AND METHODS

A rat model of induced radiation cystitis using pelvic X-ray irradiation was used, and bladder function was assessed by bladder volume and bladder leakage point pressure (LPP) after ICAII treatment. HE and Masson stains were used to assess the histopathological changes in the bladder. IL-6, TNF-α, IL-10, IL-4 and IL-1β were measured by ELISA to assess the level of inflammation. The gene-level changes in ICAII-treated RC were observed by transcriptome sequencing, and then the potential targets of action and biological mechanisms were explored by PPI, GO and KEGG enrichment analysis of the differentially expressed genes. Finally, the predicted targets of action were experimentally validated using immunohistochemistry, RT-qPCR, molecular docking and CETSA.

RESULTS

ICAII significantly increased bladder volume and the LPP, ameliorated pathological damage to bladder tissues, decreased the levels of IL-6, TNF-α, and IL-1β, and increased the levels of IL-10 and IL-4 in radiation-injured rats. A total of 90 differentially expressed genes were obtained by transcriptome sequencing, and PPI analysis identified H3F3C, ISG15, SPP1, and LCN2 as possible potential targets of action. GO and KEGG analyses revealed that these differentially expressed genes were mainly enriched in the pathways metabolism of xenobiotics by cytochrome P450, arachidonic acid metabolism, Staphylococcus aureus infection and chemical carcinogenesis - reactive oxygen species. Experimental validation showed that ICAII could significantly increase the expression of H3F3C and ISG15 and inhibit the expression of SPP1 and LCN2. ICAII binds well to H3F3C, ISG15, SPP1 and LCN2, with the best binding ability to H3F3C. Furthermore, ICAII inhibited the protein degradation of H3F3C in bladder epithelial cells.

CONCLUSIONS

ICAII may alleviate the bladder inflammatory response and inhibit the fibrosis process of bladder tissues through the regulation of H3F3C, ISG15, SPP1, and LCN2 targets and has a protective effect on the bladder of radioinjured rats. In particular, H3F3C may be one of the most promising therapeutic targets.

Chinese medicine PaBing-II protects human iPSC-derived dopaminergic neurons from oxidative stress

Background

PaBing-II Formula (PB-II) is a traditional Chinese medicine for treating Parkinson's disease (PD). However, owing to the complexity of PB-II and the difficulty in obtaining human dopaminergic neurons (DAn), the mechanism of action of PB-II in PD treatment remains unclear. The aim of this study was to investigate the mechanisms underlying the therapeutic benefits of PB-II in patients with PD.

Methods

hiPSCs derived DAn were treated with H2O2 to construct the DAn oxidative damage model. SwissTargetPrediction was employed to predict the potential targets of the main compounds in serum after PB-II treatment. Metascape was used to analyze the pathways. Sprague-Dawley rats were used to construct the 6-hydroxydopamine (6-OHDA)-induced PD model, and the duration of administration was four weeks. RNA sequencing was used for Transcriptome analysis to find the signal pathways related to neuronal damage. The associated inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA). We identified PB-II as an Nrf2 activator using antioxidant-responsive element luciferase assay in MDA-MB-231 cells.

Results

In vitro experiments showed that the treatment of PB-II-treated serum increased the percentage of TH+ cells, decreased inflammation and the apoptosis, reduced cellular reactive oxygen species, and upregulated the expression of Nrf2 and its downstream genes. Pathway analysis of the RNA-seq data of samples before and after the treatment with PB-II-treated serum identified neuron-associated pathways. In vivo experiments demonstrated that PB-II treatment of PD rat model could activate the Nrf2 signaling pathway, protect the midbrain DAn, and improve the symptoms in PD rats.

Conclusion

PB-II significantly protects DAn from inflammation and oxidative stress via Nrf2 pathway activation. These findings elucidate the roles of PB-II in PD treatment and demonstrate the application of hiPSC-derived DAn in research of Chinese medicine.

Trilobatin suppresses aging-induced cognitive impairment by targeting SIRT2: Involvement of remodeling gut microbiota to mediate the brain-gut axis

BACKGROUND

Aging is associated with learning and memory disorder, affecting multiple brain areas, especially the hippocampus. Previous studies have demonstrated trilobatin (TLB), as a natural food additive, can extend the life of Caenorhabditis elegans and exhibit neuroprotection in Alzheimer's disease mice. However, the possible significance of TLB in anti-aging remains elusive.

PURPOSE

This study aimed to delve into the physiological mechanism by which TLB ameliorated aging-induced cognitive impairment in senescence-accelerated mouse prone 8 (SAMP8) mice.

METHODS

6-month-old SAMP8 mice were administrated with TLB (5, 10, 20 mg/kg/day, i.g.) for 3 months. The therapeutic effect of TLB on aging-induced cognitive impairment was assessed in mice using behavioral tests and aging score. The gut microbiota composition in fecal samples was analyzed by metagenomic analysis. The protective effects of TLB on blood-brain barrier (BBB) and intestinal barrier were detected by transmission electron microscope, H&E staining and western blot (WB) assay. The inhibitive effects of TLB on inflammation in brain and intestine were assessed using immunofluorescence, WB and ELISA assay. Molecular docking and surface plasma resonance (SPR) assay were utilized to investigate interaction between TLB and sirtuin 2 (SIRT2).

RESULTS

Herein, the findings exhibited TLB mitigated aging-induced cognitive impairment, neuron injury and neuroinflammation in hippocampus of aged SAMP8 mice. Moreover, TLB treatment repaired imbalance of gut microbiota in aged SAMP8 mice. Furthermore, TLB alleviated the damage to BBB and intestinal barrier, concomitant with reducing the expression of SIRT2, phosphorylated levels of c-Jun NH2 terminal kinases (JNK) and c-Jun, and expression of MMP9 protein in aged SAMP8 mice. Molecular docking and SPR unveiled TLB combined with SIRT2 and down-regulated SIRT2 protein expression. Mechanistically, the potential mechanism of SIRT2 in TLB that exerted anti-aging effect was validated in vitro. As expected, SIRT2 deficiency attenuated phosphorylated level of JNK in HT22 cells treated with d-galactose.

CONCLUSION

These findings reveal, for the first time, SIRT2-mediated brain-gut barriers contribute to aging and aging-related diseases, and TLB can rescue aging-induced cognitive impairment by targeting SIRT2 and restoring gut microbiota disturbance to mediate the brain-gut axis. Overall, this work extends the potential application of TLB as a natural food additive in aging-related diseases.

Mechanism of ferroptosis regulating ischemic stroke and pharmacologically inhibiting ferroptosis in treatment of ischemic stroke

Ferroptosis is a newly discovered form of programmed cell death that is non-caspase-dependent and is characterized by the production of lethal levels of iron-dependent lipid reactive oxygen species (ROS). In recent years, ferroptosis has attracted great interest in the field of cerebral infarction because it differs morphologically, physiologically, and genetically from other forms of cell death such as necrosis, apoptosis, autophagy, and pyroptosis. In addition, ROS is considered to be an important prognostic factor for ischemic stroke, making it a promising target for stroke treatment. This paper summarizes the induction and defense mechanisms associated with ferroptosis, and explores potential treatment strategies for ischemic stroke in order to lay the groundwork for the development of new neuroprotective drugs.

Astrocytic stress response is induced by exposure to astrocyte-binding antibodies expressed by plasmablasts from pediatric patients with acute transverse myelitis

BACKGROUND

Pediatric acute transverse myelitis (ATM) accounts for 20-30% of children presenting with a first acquired demyelinating syndrome (ADS) and may be the first clinical presentation of a relapsing ADS such as multiple sclerosis (MS). B cells have been strongly implicated in the pathogenesis of adult MS. However, little is known about B cells in pediatric MS, and even less so in pediatric ATM. Our lab previously showed that plasmablasts (PB), the earliest B cell subtype producing antibody, are expanded in adult ATM, and that these PBs produce self-reactive antibodies that target neurons. The goal of this study was to examine PB frequency and phenotype, immunoglobulin selection, and B cell receptor reactivity in pediatric patients presenting with ATM to gain insight to B cell involvement in disease.

METHODS

We compared the PB frequency and phenotype of 5 pediatric ATM patients and 10 pediatric healthy controls (HC) and compared them to previously reported adult ATM patients using cytometric data. We purified bulk IgG from the plasma samples and cloned 20 recombinant human antibodies (rhAbs) from individual PBs isolated from the blood. Plasma-derived IgG and rhAb autoreactivity was measured by mean fluorescence intensity (MFI) in neurons and astrocytes of murine brain or spinal cord and primary human astrocytes. We determined the potential impact of these rhAbs on astrocyte health by measuring stress and apoptotic response.

RESULTS

We found that pediatric ATM patients had a reduced frequency of peripheral blood PB. Serum IgG autoreactivity to neurons in EAE spinal cord was similar in the pediatric ATM patients and HC. However, serum IgG autoreactivity to astrocytes in EAE spinal cord was reduced in pediatric ATM patients compared to pediatric HC. Astrocyte-binding strength of rhAbs cloned from PBs was dependent on somatic hypermutation accumulation in the pediatric ATM cohort, but not HC. A similar observation in predilection for astrocyte binding over neuron binding of individual antibodies cloned from PBs was made in EAE brain tissue. Finally, exposure of human primary astrocytes to these astrocyte-binding antibodies increased astrocytic stress but did not lead to apoptosis.

CONCLUSIONS

Discordance in humoral immune responses to astrocytes may distinguish pediatric ATM from HC.

Panax notoginseng Saponins Activate Nuclear Factor Erythroid 2-Related Factor 2 to Inhibit Ferroptosis and Attenuate Inflammatory Injury in Cerebral Ischemia-Reperfusion

Panax notoginseng saponins (PNS), the primary medicinal ingredient of Panax notoginseng, mitigates cerebral ischemia-reperfusion injury (CIRI) by inhibiting inflammation, regulating oxidative stress, promoting angiogenesis, and improving microcirculation. Moreover, PNS activates nuclear factor erythroid 2-related factor 2 (Nrf2), which is known to inhibit ferroptosis and reduce inflammation in the rat brain. However, the molecular regulatory roles of PNS in CIRI-induced ferroptosis remain unclear. In this study, we aimed to investigate the effects of PNS on ferroptosis and inflammation in CIRI. We induced ferroptosis in SH-SY5Y cells via erastin stimulation and oxygen glucose deprivation/re-oxygenation (OGD/R) in vitro. Furthermore, we determined the effect of PNS treatment in a rat model of middle cerebral artery occlusion/reperfusion and assessed the underlying mechanism. We also analyzed the changes in the expression of ferroptosis-related proteins and inflammatory factors in the established rat model. OGD/R led to an increase in the levels of ferroptosis markers in SH-SY5Y cells, which were reduced by PNS treatment. In the rat model, combined treatment with an Nrf2 agonist, Nrf2 inhibitor, and PNS-Nrf2 inhibitor confirmed that PNS promotes Nrf2 nuclear localization and reduces ferroptosis and inflammatory responses, thereby mitigating brain injury. Mechanistically, PNS treatment facilitated Nrf2 activation, thereby regulating the expression of iron overload and lipid peroxidation-related proteins and the activities of anti-oxidant enzymes. This cascade inhibited ferroptosis and mitigated CIRI. Altogether, these results suggest that the ferroptosis-mediated activation of Nrf2 by PNS reduces inflammation and is a promising therapeutic approach for CIRI.

Baohuoside I suppresses the NLRP3 inflammasome activation via targeting GPER to fight against Parkinson's disease

BACKGROUND

Accumulating evidence indicates the crucial role of microglia-mediated inflammation and the NLR family pyrin domain containing 3 (NLRP3) inflammasome-mediated pyroptosis in the pathogenesis of Parkinson's disease (PD). Baohuoside I, a natural flavonoid extracted from Herba Epimedii, has been shown to possess anti-inflammatory effects, but its potential neuroprotective effects and mechanism against PD have not been documented.

STUDY DESIGN AND METHODS

The anti-inflammatory effects of Baohuoside I were evaluated by LPS-induced BV2 cells or primary microglia isolated from wide type or G protein-coupled estrogen receptor (GPER) gene knockout mice. The underlying mechanism related to GPER-mediated NLRP3 inflammasome inhibition was further explored using LPS-induced GPER+/+ or GPER-/- mouse models of PD. The neuroprotective effects of Baohuoside I were detected through western blot analysis, real-time PCR, molecular docking, mouse behavioral tests, immunofluorescence, and immunohistochemistry.

RESULTS

Baohuoside I significantly alleviated LPS-induced neuroinflammation by inhibiting the activation of NF-κB signal and the increase of pyroptosis levels as evidenced by the downregulated expression of pyroptosis-related proteins (NLRP3, ASC, pro-Caspase-1, IL-1β) in microglia cells. Intragastric administration of Baohuoside I protected against LPS-induced motor dysfunction and loss of dopaminergic neurons, reduced pro-inflammatory cytokines expressions, and inhibited microglial (Iba-1) and astrocyte (GFAP) activation in the nigrostriatal pathway in LPS-induced mouse model of PD. Pretreatment with GPER antagonist G15 in microglia cells or GPER gene deletion in mice significantly blocked the inhibitory effects of Baohuoside I on LPS-induced neuroinflammation and activation of the NLRP3/ASC/Caspase-1 pathway. Molecular docking further indicated that Baohuoside I might bind to GPER directly with a binding energy of -10.4 kcal/mol.

CONCLUSION

Baohuoside I provides neuroprotective effects against PD by inhibiting the activation of the NF-κB signal and NLRP3/ASC/Caspase-1 pathway. The molecular target for its anti-inflammatory effects is proved to be GPER in the PD mouse model. Baohuoside I may be a valuable anti-neuroinflammatory agent and a drug with well-defined target for the treatment of PD.

Trilobatin attenuates cerebral ischaemia/reperfusion-induced blood-brain barrier dysfunction by targeting matrix metalloproteinase 9: The legend of a food additive

BACKGROUND AND PURPOSE

Blood-brain barrier (BBB) breakdown is one of the crucial pathological changes of cerebral ischaemia-reperfusion (I/R) injury. Trilobatin (TLB), a naturally occurring food additive, exerts neuroprotective effects against cerebral I/R injury as demonstrated in our previous study. This study was designed to investigate the effect of TLB on BBB disruption after cerebral I/R injury.

EXPERIMENTAL APPROACH

Rats with focal cerebral ischaemia caused by transient middle cerebral artery occlusion were studied along with brain microvascular endothelial cells and human astrocytes to mimic BBB injury caused by oxygen and glucose deprivation/reoxygenation (OGD/R).

KEY RESULTS

The results showed that TLB effectively maintained BBB integrity and inhibited neuronal loss following cerebral I/R challenge. Furthermore, TLB increased tight junction proteins including ZO-1, Occludin and Claudin 5, and decreased the levels of apolipoprotein E (APOE) 4, cyclophilin A (CypA) and phosphorylated nuclear factor kappa B (NF-κB), thereby reducing proinflammatory cytokines. TLB also decreased the Bax/Bcl-2 ratio and cleaved-caspase 3 levels along with a reduced number of apoptotic neurons. Molecular docking and transcriptomics predicted MMP9 as a prominent gene evoked by TLB treatment. The protective effects of TLB on cerebral I/R-induced BBB breakdown was largely abolished by overexpression of MMP9, and the beneficial effects of TLB on OGD/R-induced loss of BBB integrity in human brain microvascular endothelial cells and astrocyte co-cultures was markedly reinforced by knockdown of MMP9.

CONCLUSIONS AND IMPLICATIONS

Our findings reveal a novel property of TLB: preventing BBB disruption following cerebral I/R via targeting MMP9 and inhibiting APOE4/CypA/NF-κB axis.

Ferroptosis and endoplasmic reticulum stress in ischemic stroke

Ferroptosis is a form of non-apoptotic programmed cell death, and its mechanisms mainly involve the accumulation of lipid peroxides, imbalance in the amino acid antioxidant system, and disordered iron metabolism. The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum, and the progression of inflammatory diseases can trigger endoplasmic reticulum stress. Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival. Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke. However, there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke. This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke, aiming to provide a reference for developing treatments for ischemic stroke.

Moderate mechanical stress suppresses chondrocyte ferroptosis in osteoarthritis by regulating NF-κB p65/GPX4 signaling pathway

Ferroptosis is a recently identified form of programmed cell death that plays an important role in the pathophysiological process of osteoarthritis (OA). Herein, we investigated the protective effect of moderate mechanical stress on chondrocyte ferroptosis and further revealed the internal molecular mechanism. Intra-articular injection of sodium iodoacetate (MIA) was conducted to induce the rat model of OA in vivo, meanwhile, interleukin-1 beta (IL-1β) was treated to chondrocytes to induce the OA cell model in vitro. The OA phenotype was analyzed by histology and microcomputed tomography, the ferroptosis was analyzed by transmission electron microscope and immunofluorescence. The expression of ferroptosis and cartilage metabolism-related factors was analyzed by immunohistochemical and Western blot. Animal experiments revealed that moderate-intensity treadmill exercise could effectively reduce chondrocyte ferroptosis and cartilage matrix degradation in MIA-induced OA rats. Cell experiments showed that 4-h cyclic tensile strain intervention could activate Nrf2 and inhibit the NF-κB signaling pathway, increase the expression of Col2a1, GPX4, and SLC7A11, decrease the expression of MMP13 and P53, thereby restraining IL-1β-induced chondrocyte ferroptosis and degeneration. Inhibition of NF-κB signaling pathway relieved the chondrocyte ferroptosis and degeneration. Meanwhile, overexpression of NF-κB by recombinant lentivirus reversed the positive effect of CTS on chondrocytes. Moderate mechanical stress could activate the Nrf2 antioxidant system, inhibit the NF-κB p65 signaling pathway, and inhibit chondrocyte ferroptosis and cartilage matrix degradation by regulating P53, SLC7A11, and GPX4.

Natural product-derived ferroptosis mediators

It has been 11 years since ferroptosis, a new mode of programmed cell death, was first proposed. Natural products are an important source of drug discovery. In the past five years, natural product-derived ferroptosis regulators have been discovered in an endless stream. Herein, 178 natural products discovered so far to trigger or resist ferroptosis are classified into 6 structural classes based on skeleton type, and the mechanisms of action that have been reported are elaborated upon. If pharmacodynamic data are sufficient, the structure and bioactivity relationship is also presented. This review will provide medicinal chemists with some effective ferroptosis regulators, which will promote the research of natural product-based treatment of ferroptosis-related diseases in the future.

Progress of Ferroptosis in Ischemic Stroke and Therapeutic Targets

Ferroptosis is an iron-dependent form of programmed cell death (PCD) and ischemic stroke (IS) has been confirmed to be closely related to ferroptosis. The mechanisms of ferroptosis were summarized into three interrelated aspects: iron metabolism, lipid peroxide metabolism, as well as glutathione and amino acid metabolism. What's more, the causal relationship between ferroptosis and IS has been elucidated by several processes. The disruption of the blood-brain barrier, the release of excitatory amino acids, and the inflammatory response after ischemic stroke all lead to the disorder of iron metabolism and the antioxidant system. Based on these statements, we reviewed the reported effects of compounds and drugs treating IS by modulating key molecules in ferroptosis. Through detailed analysis of the roles of these key molecules, we have also more clearly demonstrated the essential effect of ferroptosis in the occurrence of IS so as to provide new targets and ideas for the therapeutic targets of IS.

Icariside II prevents kidney fibrosis development in chronic kidney disease by promoting fatty acid oxidation

Renal interstitial fibrosis (RIF) is the main pathological basis for the progression of chronic kidney disease (CKD), however, effective interventions are limited. Here, we investigated the effect of Icariside II (ICA-II) on RIF and explored the underlying mechanisms. Rats receiving 5/6 ablation and infarction (A/I) surgery were gavaged with ICA-II (5 or 10 mg/kg) for 8 weeks. In vitro, TGF-β1-stimulated NRK-52E cells were treated with ICA-II and (or) oleic acid, etomoxir, ranolazine, fenofibrate, and GW6471. The effects of ICA-II on RIF, fatty acid oxidation, lipid deposition, and mitochondrial function were determined by immunoblotting, Oil red O staining, colorimetric, and fluorometric assays. Using adeno-associated virus injection and co-culture methods, we further determined mechanisms of ICA-II anti-RIF. ICA-II ameliorated the fibrotic responses in vivo and in vitro. RNA-seq analysis indicated that ICA-II regulated fatty acid degradation and PPAR pathway in 5/6 (A/I) kidneys. ICA-II attenuated lipid accumulation and up-regulated expression of PPARα, CPT-1α, Acaa2, and Acadsb proteins in vivo and in vitro. Compared to ICA-II treatment, ICA-II combined with Etomoxir exacerbated mitochondrial dysfunction and fibrotic responses in TGF-β-treated NRK-52E cells. Importantly, we determined that ICA-II improved lipid metabolism, fatty acid oxidation, mitochondrial function, and RIF by restoring PPARα. Co-culture revealed that ICA-II decreased the expression of Fibronectin, Collagen-I, α-SMA, and PCNA proteins in NRK-49F cells by restoring PPARα of renal tubular cells. ICA-II may serve as a promising therapeutic agent for RIF in 5/6 (A/I) rats, which may be important for the prevention and treatment of CKD.

The role of ferroptosis and its mechanism in ischemic stroke

Ischemic stroke is an acute cerebrovascular disease with a high morbidity, mortality, and disability rate. Persistent ischemia of brain tissue can cause irreversible damage to neurons, leading to neurological dysfunction and seriously affecting patients' quality of life. However, current clinical therapies are limited and have not achieved satisfactory outcome, due to the incomplete understanding of the mechanism of neuronal damage during ischemic stroke. Recent studies have found that ferroptosis is implicated in the pathophysiology of ischemic stroke. Ferroptosis is an iron-dependent regulated cell death driven by lipid peroxidation. Under normal physiological conditions, GSH/GPX4, FSP1/CoQ10, GCH/BH4 and other anti-ferroptosis pathways can function effectively to suppress the occurrence of ferroptosis. After ischemic stroke, two typical ferroptosis characteristics, lipid peroxidation and iron accumulation, are observed, accompanied by changes in the expression of ferroptosis related genes such as GPX4, ACSL4, and SLC7A11, suggesting that ferroptosis plays a key role in ischemic stroke, which provides a new idea for the clinical treatment of ischemic stroke. This article reviewed the pathological mechanisms of ferroptosis in the occurrence and development of ischemic stroke, as well as the related progress of ferroptosis targeted therapy.

Neuroprotection during Thrombectomy for Acute Ischemic Stroke: A Review of Future Therapies

Stroke is a major cause of death and disability worldwide. Endovascular thrombectomy has been impactful in decreasing mortality. However, many clinical results continue to show suboptimal functional outcomes despite high recanalization rates. This gap in recanalization and symptomatic improvement suggests a need for adjunctive therapies in post-thrombectomy care. With greater insight into ischemia-reperfusion injury, recent preclinical testing of neuroprotective agents has shifted towards preventing oxidative stress through upregulation of antioxidants and downstream effectors, with positive results. Advances in multiple neuroprotective therapies, including uric acid, activated protein C, nerinetide, otaplimastat, imatinib, verapamil, butylphthalide, edaravone, nelonemdaz, ApTOLL, regional hypothermia, remote ischemic conditioning, normobaric oxygen, and especially nuclear factor erythroid 2-related factor 2, have promising evidence for improving stroke care. Sedation and blood pressure management in endovascular thrombectomy also play crucial roles in improved stroke outcomes. A hand-in-hand approach with both endovascular therapy and neuroprotection may be the key to targeting disability due to stroke.