Nrf2/Keap1/ARE signaling: Towards specific regulation

Insights of affinity-based probes for target identification in drug discovery

Identifying molecular targets of physiologically active organic compounds remains a major challenge in contemporary biomedical research and drug discovery. In recent years, the development of activity-based protein profiling (ABPP) techniques has proven to be superior to classical molecular target identification methods. ABPP can be classified into activity-based probes (AcBPs) and affinity-based probes (AfBPs). AfBPs bind to target proteins through reversible non-covalent interactions, thus minimizing the impact on the natural biological functions of the protein. The development of AfBPs has great potential for studying drug targets, optimizing drugs, and improving therapeutic efficacy. As a result, there has been a dramatic increase in research and development focused on affinity probes with the use of a wide range of AfBPs such as biotin probes, FITC probes, BRET probes, and radiolabeled probes. This tutorial describes the process of designing and synthesizing different types of AfBPs from biologically active compounds, and then utilizing the probes to identify the target proteins. It also provides insights for subsequent drug discovery and development.

7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN) attenuates inflammation and oxidative stress via MAPK, and Nrf2/HO-1 signaling in Traumatic brain injury

Traumatic brain injury (TBI) is an acquired neurological insult that has become a major cause of mortality.Hence, immediate and appropriate medical attention is essential. The present study investigated the neuroprotective effect of 7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid against a weight drop model of traumatic brain injury (TBI). During the in-vitro analysis, ECN demonstrated neuroprotective potential by remarkably improving the cell viability and also provided significant protection in case of nitric oxide-evoked oxidative stress in HT22 cells. The administration of ECN significantly improved the neurological severity score, and mechanical/periorbital allodynia following TBI, when compared with the TBI-group. The level of brain edema and blood-brain barrier (BBB) disruption were also significantly reduced by ECN treatment. ECN also restored constitutional changes in the protein/lipid profile; simultaneous with histological changes in the brain in contrast to the TBI-group. It significantly ameliorated neuronal loss and also minimized the intracerebral hemorrhages arising from traumatic insult. ECN exhibited potent anti-inflammatory effects, by altering the expression of extracellular-signal-regulated kinase (ERK), p38, and activating protein-1 (AP-1) proteins. It also exhibited antioxidant effects by increasing the production levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Furthermore, ECN also produced an anti-apoptotic effect by downregulation of caspase3 and upregulation of B-cell lymphoma 2 (Bcl-2). It also increased the levels of antioxidants while reducing the levels of oxidative stress and inflammatory markers in comparison to the TBI-group. In short, it was concluded that ECN exhibited protective anti-inflammatory, antioxidant, and anti-apoptotic effects against trauma-induced brain injury.

A review on fumonisin B1-induced mitochondrial dysfunction and its impact on mitophagy and DNA methylation

Fumonisin B1 (FB1) is a food-borne mycotoxin synthesized by Fusarium verticillioides and has been identified as a group 2B carcinogen. Recent research shows that the mitochondria and DNA in cells are targets of FB1. Mitophagy is a form of autophagy that functions to break down impaired mitochondria to preserve the overall functionality of the cell. DNA methylation is an epigenetic process that involves the enzymatic transfer of methyl groups from S-adenosylmethionine (SAM) to the C-5 region of the DNA cytosine ring by DNA methyltransferases (DNMTs). DNA methylation plays a key role in maintaining DNA integrity and FB1 disrupts DNA methylation via FB1-induced folate deficiency. However, there is limited research available on the impact of FB1 on mitophagy as well as FB1-induced oxidative stress and its influence on DNA methylation regulation. In this review, we aim to combine and summarize the current information on FB1-induced mitochondrial dysfunction, its impact on mitophagy as well as its DNA methylation effects.

Swietenine improved the progression of diabetic nephropathy through inhibiting ferroptosis via activating Akt/GSK-3β/Nrf2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Swietenia macrophylla King is a traditional medicinal plant extensively utilized in Asia and its pharmacological properties primarily involve antidiabetic, anti-inflammatory, antioxidant, antibacterial, and antitumor effects. Swietenine (Swi), the major bioactive compound presents in the fruits of S. macrophylla, has demonstrated beneficial therapeutic effects on diabetic nephropathy (DN). However, the underlying mechanism through which Swi influences DN remains unclear.

AIM OF THE STUDY

The current research aims to investigate the effects of Swi on DN and explore its underlying mechanisms associated with ferroptosis, both in vivo and in vitro.

METHODS

A model of streptozotocin/high-fat diet (STZ/HFD)-induced Sprague-Dawley (SD) rats was employed to assess the effect of Swi on improving DN and resisting ferroptosis in vivo. Additionally, mouse podocyte cells (MPC-5 cells) were induced by high glucose (HG) and cultured to explore the potential mechanisms of Swi in treating DN in vitro. To further validate the protective effects of Swi, pathway-specific inhibitors were administered to HG-induced MPC-5 cells to confirm the involvement of the Akt/GSK-3β/Nrf2 signaling pathway in the inhibition of ferroptosis. A combination of proteomics, immunohistochemical staining, western blotting, and cell culture techniques was utilized to explore the pharmacological mechanisms of Swi. Furthermore, network pharmacology and molecular docking analyses were conducted to predict the targets of Swi in relation to DN, which were subsequently validated through Western blotting analysis.

RESULTS

Administration of Swi significantly enhanced renal function and ameliorated pathological alterations in DN rats, as well as improved oxidative stress and inhibited ferroptosis. In vitro studies revealed that Swi dramatically improved the cell viability and mitigated oxidative stress, and inhibited ferroptosis via activating the Akt/GSK-3β/Nrf2 signaling pathway in HG-induced MPC-5 cells.

CONCLUSION

This study demonstrates that Swi improves DN by inhibiting ferroptosis via activating Akt/GSK-3β/Nrf2 signaling pathway for the first time, thereby providing a scientific basis that Swi is expected to be a promising candidate drug for the treatment of DN.

Investigating the Interplay Between the Nrf2/Keap1/HO-1/SIRT-1 Pathway and the p75NTR/PI3K/Akt/MAPK Cascade in Neurological Disorders: Mechanistic Insights and Therapeutic Innovations

Neurological illnesses are debilitating diseases that affect brain function and balance. Due to their complicated aetiologies and progressive nature, neurodegenerative and neuropsychiatric illnesses are difficult to treat. These incurable conditions damage brain functions like mobility, cognition, and emotional regulation, but medication, gene therapy, and physical therapy can manage symptoms. Disruptions in cellular signalling pathways, especially those involving oxidative stress response, memory processing, and neurotransmitter modulation, contribute to these illnesses. This review stresses the interplay between key signalling pathways involved in neurological diseases, such as the Nrf2/Keap1/HO-1/SIRT-1 axis and the p75NTR/PI3K/Akt/MAPK cascade. To protect neurons from oxidative damage and death, the Nrf2 transcription factor promotes antioxidant enzyme production. The Keap1 protein releases Nrf2 during oxidative stress for nuclear translocation and gene activation. The review also discusses how neurotrophin signalling through the p75 neurotrophin receptor (p75NTR) determines cell destiny, whether pro-survival or apoptotic. The article highlights emerging treatment approaches targeting these signalling pathways by mapping these connections. Continued research into these molecular pathways may lead to new neurological disease treatments that restore cellular function and neuronal survival. In addition to enhanced delivery technologies, specific modulators and combination therapies should be developed to fine-tune signalling responses. Understanding these crosstalk dynamics is crucial to strengthening neurological illness treatment options and quality of life.

Novel insights into the central protective role of ACE2 in diabetic cardiomyopathy: from underlying signaling pathways to therapeutic perspectives

Diabetic cardiomyopathy (DCM) is a cardiac complication specific to individuals with diabetes. It is defined as abnormalities of myocardial structure and function in diabetic patients who do not exhibit any obvious coronary artery disease, hypertensive heart disease, valvular heart disease, or inherited cardiomyopathy. A significant cardiovascular protective factor identified recently is angiotensin-converting enzyme 2 (ACE2), which is a rising star in the renin angiotensin system (RAS) and is responsible for the onset and progression of DCM. Nonetheless, there is not a comprehensive review outlining ACE2's effect on DCM. From the perspective of the pathogenesis of DCM, this review summarizes the myocardial protective role of ACE2 in the aspects of alleviating myocardial structure and dysfunction, correcting energy metabolism disorders, and restoring vascular function. Concurrently, we propose the connections between ACE2 and underlying signaling pathways, including ADAM17, Apelin/APJ, and Nrf2. Additionally, we highlight ACE2-related pharmaceutical treatment options and clinical application prospects for preventing and managing DCM. Further and underlying research is extensively required to completely comprehend the principal pathophysiological mechanism of DCM and the distinctive function of ACE2, switching experimental findings into clinical practice and identifying efficient therapeutic approaches.

The protective effects of a single dose myricetin application on CLP-induced rat sepsis model by analyzing some immune mechanisms

INTRODUCTION

In this study, our aim was to investigate the protective effects of myricetin (single dose-100 mg/kg) on CLP-induced rat sepsis model by analyzing some immune mechanisms including inflammation and oxidative stress by different techniques such as Immunohistochemistry, ELISA, tissue biochemistry and Western Blotting.

METHODS

Twenty-eight Wistar albino rats were divided into 4 groups. The pro-inflammatory and anti-inflammatory cytokine levels were measured by ELISA technique. CD68 and Nuclear-Factor-Kappa-B (NF-κB) positivity rates were detected by IHC. Some of oxidative stress parameters were measured by tissue biochemistry, while Toll-like receptor-4 (TLR4) expression others were detected by Western blot technique.

RESULTS

Sepsis caused a significant increase in all pro-inflammatory cytokine and oxidant levels. Also, it led to an increase in the positivity of CD68 and NF-κB markers as well as the expression levels of TNF-alpha, IL-1-beta, TLR4, Keap-1. However, single dose myricetin application normalized pro-inflammatory cytokine levels, increased anti-oxidant and anti-inflammatory cytokine levels, decreased positivity of CD68 and NF-κB and increased NRF2 and HO-1 expressions.

DISCUSSION

As a conclusion, the beneficial effect of myricetin on lung injury also involved inhibition of TLR4/NF-κB pathway, suppression of proinflammatory cytokines and induction of anti-inflammatory cytokine production, regulation of oxidant and anti-oxidant system parameters, and activating the NRF2/Keap1/HO-1 pathway.

Interleukin-22 ameliorates alcohol-associated liver fibrosis via Nrf2-ARE signaling: mechanistic insights and clinical correlations

BACKGROUND & AIMS

Alcohol-associated liver fibrosis (ALF) is a key, potentially reversible stage leading to alcohol-associated liver cirrhosis, but effective treatments are lacking. This study explored whether interleukin (IL)-22, a hepatocyte survival factor, plays an anti-fibrotic role in ALF by modulating the Nrf2-ARE antioxidant pathway.

METHODS

IL-22 and Nrf2-ARE inhibitor, ML385, were administered to rat hepatic stellate cells (HSCs) exposed to acetaldehyde. Cell proliferation, cell cycle distribution, and Nrf2-ARE activation were investigated. An ALF mouse model was used to evaluate the effects of IL-22 and ML385 on liver function, fibrosis, and Nrf2-ARE pathway activation. The expression of IL-22 and Nrf2-ARE pathway in ALF/cirrhosis patients was also examined, along with correlations to liver function and liver fibrosis degree.

RESULTS

In vitro, IL-22 upregulated the Nrf2-ARE pathway, and inhibited acetaldehyde-induced HSC proliferation and activation. In ALF mice, IL-22 promoted Nrf2-ARE pathway activation, reduced oxidative stress levels and serum transaminases, and ameliorated fibrosis. The ALF patients showed increased expression of IL-22, IL-22R1, and Nrf2-ARE pathway, positively correlating with the Child-Pugh score and fibrosis severity, suggesting a compensatory response.

CONCLUSIONS

IL-22 alleviates ALF by activating the Nrf2 antioxidant stress pathway, and may offer a promising therapeutic option for ALF/cirrhosis patients.

Toxicarioside H induces ferroptosis in triple-negative breast cancer cells through Nrf2/HO-1 pathway

Recent studies have identified novel cardiac glycosides from natural sources with potential anti-tumor properties. Toxicarioside H (ToxH) is a novel cardiac glycoside isolated by our collaborative research team. However, its ability to induce ferroptosis in triple-negative breast cancer (TNBC) cells has not been investigated. Therefore, this study evaluates whether ToxH has the capability of inducing ferroptosis and elucidates the underlying molecular mechanisms. Treatment with ToxH led to dose- and time-dependent growth inhibition in BT-549 and MDA-MB-468 cells. Flow cytometry analysis and lactate dehydrogenase assay revealed that ToxH induced various forms of cell death in both BT-549 and MDA-MB-468 cells. Examination through transmission electron microscopy, along with flow cytometry analysis of 7-AAD-stained dead cells and ferroptosis markers BODIPY-C11 and Fe2+ ions, identified various forms of cell death induced by ToxH, including apoptosis, autophagy, apoptotic necrosis, and ferroptosis. Co-treatment with the ferroptosis inhibitor Fer-1 significantly reduced ToxH-induced cell death, indicating that ToxH primarily inhibits TNBC cell growth by inducing ferroptosis. Further investigation into the molecular mechanisms revealed upregulation of Nrf2 and HO-1 expression by ToxH. Effective inhibition of ToxH-induced ferroptosis was achieved through shRNA-mediated knockdown of HO-1 expression. Animal experiments demonstrated that ToxH treatment markedly suppressed tumor growth compared to the control group, while co-administration of Fer-1 led to an increase in tumor growth. These findings suggest that ToxH suppresses TNBC cell growth by modulating the Nrf2/HO-1 signaling pathway to induce ferroptosis. ToxH presents itself as a promising cardiac glycoside compound for TNBC treatment, warranting further translational research.

Exploring the Hepatoprotective Effects of Naringin: A Systematic Review and Meta-Analysis of Preclinical Evidence

This study aimed to perform a systematic review and meta-analysis on the hepatoprotective effects of naringin based on the pre-clinical evidence.A detailed literature search was performed using online databases such as Google Scholar, PubMed, Scopus, and EMBASE. Based on the predefined inclusion and exclusion criteria, 20 studies were considered for meta-analysis.The outcomes of the meta-analysis revealed that naringin improved liver function by reducing the elevated levels of ALT, AST, GGT, LDH, ALP, and bilirubin. It improved the enzymatic and non-enzymatic antioxidants, such as SOD, catalase, GSH, GST, GR, and GPx (p < 0.05 for all the parameters), while reducing the LPO/MDA levels (p < 0.05). NAR treatment also alleviated the levels of inflammatory mediators (IL-1β, IL-6, and TNF-α, p < 0.001 for all the parameters; NF-κB, p = 0.29) in various animal models of liver injury. In addition, NAR significantly reduced the caspase-3 and Bax/Bcl-2 ratio (p < 0.05) compared to the control group. Furthermore, naringin treatment has normalised the liver and body weights compared to the disease control group.This systematic review and meta-analysis demonstrate that naringin significantly improved the liver function in various animal models of liver injury, via potent antioxidant and anti-inflammatory mechanisms.

Methyl 3,4-dihydrobenzoate attenuates muscle fiber necroptosis and macrophage pyroptosis by regulating oxidative stress in inflammatory myopathies

Inflammatory cell infiltration and myofiber necrosis are pathological hallmarks of idiopathic inflammatory myopathies (IIM). Methyl 3,4-dihydroxybenzoate (MDHB) is a natural phenolic acid compound, renowned for its anti-inflammatory and antioxidant effects. In this study, we investigated its protective mechanisms targeting muscle fiber necrosis and macrophage pyroptosis by regulating oxidative stress in IIM. In the present study, we found that increased reactive oxygen species (ROS) level and decreased nuclear factor erythroid 2 related factor 2 (Nrf2) protein expression were shown on the muscle fibers of experimental autoimmune myositis (EAM). Receptor-interacting protein 1 (RIPK1) and receptor-interacting protein 3 (RIPK3) protein expression were elevated in EAM. In vitro, MDHB protected C2C12 cells and myotubes against H2O2-induced cell viability damage. MDHB decreased the levels of oxidative stress such as ROS, and mitochondrial superoxide (MitoSOX), and rescued mitochondrial membrane potential and ATP generation. MDHB inhibited necroptosis of the C2C12 cells and myotubes under H2O2 stimulation in a dose-dependent manner. Furthermore, MDHB suppressed lipopolysaccharide and nigericin-induced caspase-1 cleavage and interleukin (IL-1β) secretion, indicating suppression of macrophage pyroptosis in vitro. In vivo, treatment with MDHB suppressed EAM-induced muscle weakness and inflammation. MDHB decreased ROS accumulation, and increased Nrf2 and heme oxygenase-1 (HO-1) expression in EAM mice's muscles, thereby inhibiting necroptosis of inflamed muscle species and macrophage pyroptosis. In conclusion, we demonstrated that MDHB could be a novel therapy for IIM that alleviates inflammation, muscle fiber necroptosis, and macrophage pyroptosis by regulating the Nrf2/HO-1 pathway.

Dietary limonin ameliorates heart failure with preserved ejection fraction by targeting ferroptosis via modulation of the Nrf2/SLC7A11/GPX4 axis: an integrated transcriptomics and metabolomics analysis

Heart failure with preserved ejection fraction (HFpEF) is a complex syndrome characterized by hypertension, metabolic disorders, and impaired diastolic function, with limited therapeutic options. Recent studies have highlighted the role of ferroptosis in the pathogenesis of HFpEF, and the inhibition of ferroptosis occurrence can significantly improve cardiac function. Limonin, a bioactive ingredient derived from citrus fruits, has been confirmed to exert potential anti-inflammatory and antioxidant effects in some cardiovascular diseases. This study aims to investigate the therapeutic effects of limonin on HFpEF and the underlying mechanisms of inhibiting ferroptosis. HFpEF mice were established by a combination of Nω-nitro-L-arginine methyl ester and a high-fat diet for 6 weeks. Subsequently, the HFpEF mice were treated with empagliflozin or limonin via oral gavage for an additional 6 weeks. Limonin curbed body weight gain and improved metabolic disorders and hypertension. Limonin also ameliorated concentric cardiac hypertrophy and diastolic dysfunction. Transcriptomics and metabolomics analyses revealed that limonin regulated ferroptosis-related pathways and lipid peroxidation. In vivo, limonin improved mitochondrial morphology, reduced cardiac Fe2+ levels and ferroptosis markers such as ROS, 4-HNE and MDA, and increased GSH levels, thereby enhancing antioxidant capacity. Mechanistically, limonin regulated the P53/SLC7A11/GPX4 signaling pathway, promoted the nuclear translocation of Nrf2 (its upstream signaling molecule), and subsequently activated its downstream antioxidant elements, ultimately inhibiting ferroptosis. Furthermore, limonin decreased the expressions of ACSL4, COX2, and ALOXs, which reduced the accumulation of lipid peroxides. These results demonstrate that limonin ameliorates HFpEF by targeting ferroptosis via modulation of the Nrf2/SLC7A11/GPX4 axis, providing a novel strategy for HFpEF treatment.

Pharmacotherapeutic role of astringin against chromium induced nephrotoxicity via modulating TLR4/MyD88, HMGB1/RAGE and NF-κB pathway: A biochemical and pharmacokinetic approach

BACKGROUND

Chromium (Cr) is a noxious heavy metal that is reported to induce various organ damages including the kidneys. Astringin (ATN) is a polyphenolic flavonoid that demonstrates immense pharmacological potential.

AIM

This research was planned to assess the potential palliative efficacy of ATN against Cr induced renal toxicity via regulating biochemical and histological parameters.

METHODOLOGY

Thirty-two male albino (Sprague Dawley) rats were divided into four groups: the 1st group (control), 2nd group (Cr 15 mg/kg), 3rd group (Cr 15 mg/kg + ATN 10 mg/kg), and 4th (ATN 10 mg/kg) group. Gene profile was evaluated by using qRT-PCR protocol. The levels of other biochemical parameters were assessed through standard ELISA protocol as well as already reported standard assays. Histology was performed as per the basic principle of histopathology technique. The palliative role of ATN was further confirmed by molecular docking (MD) and molecular dynamic simulation (MDS) approach.

RESULTS

Cr intoxication upregulated the gene expression of high mobility group box1 (HMGB1), tumor necrosis factor- α (TNF-α), nuclear factor- kappa B (NF-κB), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), myeloid differentiation primary response 88 (MYD88), receptor for advanced glycation end products (RAGE), toll-like receptor 4 (TLR4), and interleukin-1β (IL-1β). The levels of reactive oxygen species (ROS) and malondialdehyde were elevated while the activities of glutathione reductase (GSR), glutathione peroxidase (GPx), heme oxygenase-1 (HO-1), superoxide dismutase (SOD) & catalase (CAT) as well as contents of glutathione (GSH) were reduced after Cr intoxication. Moreover, Cr exposure increased the levels of cystatin C, uric acid, neutrophil gelatinase-associated lipocalin (NGAL), creatinine, blood urea nitrogen (BUN), N-acetylglucosamine (NAG), kidney injury molecule-1 (KIM-1) & urea while downregulating the concentrations of creatine clearance. Besides, the levels of B cell lymphoma-2 (Bcl-2) were reduced while the levels of cysteine-aspartic acid protease-9 (Caspase-9), Bcl-2-associated X protein (Bax) and cysteine-aspartic acid protease-3 (Caspase-3) were escalated after Cr intoxication. Renal tissues showed abnormal histology following the exposure to Cr. Nonetheless, ATN treatment effectively restored biochemical as well as histological impairments in renal tissues, thereby demonstrating the nephroprotective potential against Cr intoxication.

CONCLUSION

ATN therapy showed significant renal protection via suppressing oxidative stress, inflammation, apoptosis and histological damages. These findings emphasize the important role of ATN in regulating renal health via modulating TLR4/MyD88, HMGB1/RAGE and NF-κB signaling pathway.

Targeting HMGB2 acts as dual immunomodulator by bolstering CD8+ T cell function and inhibiting tumor growth in hepatocellular carcinoma

T cell exhaustion is a critical obstacle for durable treatment response in hepatocellular carcinoma (HCC). Developing drugs that control tumor growth and simultaneously bolster immune function is of great significance. Although high-mobility group box 2 (HMGB2) has been reported to be crucial to HCC prognosis, its role in the tumor microenvironment remains unclear. Here, we found HMGB2+ CD8+ T cells as being associated with immune exhaustion and resistance to anti-PD-1 treatment through single-cell RNA sequencing. Mechanistically, HMGB2 impaired the oxidative phosphorylation in CD8+ T cells and inactivated the interferon-γ response in tumor cells, reducing the antitumor effector function. Tannic acid, a specific inhibitor of HMGB2, synergized with PD-1 antibody to attenuate tumor growth and reverse T cell exhaustion. Our findings highlight the unique role of HMGB2 as an immune exhaustion associated molecule. Targeting HMGB2 on both CD8+ T cells and tumor cells contributed to promising treatment strategies for HCC.

Arctiin Inhibits Hyperglycemia-Induced Oxidative Stress by Activating the Nrf2/HO-1 Signaling Pathway to Treat Type 2 Diabetic Osteoporosis

Arctiin (ARC), a primary component of burdock (Arctium lappa L.), is widely recognized as a traditional herb and nutritional supplement in Asia. This study set out to explore its potential impact on type 2 diabetic osteoporosis (T2DOP). MC3T3-E1 cells were exposed to a high-glucose environment to simulate diabetic conditions. Treatment with ARC increased the expression of crucial osteogenic transcription factor genes, such as RUNX2, Osterix, and COL1A1. Moreover, ARC mitigated the production of ROS induced by high glucose levels. For in vivo experimentation, db/db mice were used as models for T2DOP. ARC supplementation decreased bone loss and improved bone structural integrity. Collectively, our findings indicate that ARC holds promise as a nutritional intervention for the treatment of T2DOP. By activating the Nrf2/HO-1 signaling pathway, ARC could help counteract oxidative stress and impaired bone differentiation associated with diabetes, thus offering a potential dietary strategy to support bone health. Incorporating ARC-containing foods or supplements into the diet could be a beneficial approach to enhance overall bone quality and potentially reduce the risk of fractures and other bone-related problems in patients with diabetes, highlighting the importance of considering natural compounds for the nutritional management of chronic diseases.

The Nrf2-Keap1/ARE signaling pathway in aquatic animals

The complex and fluctuating conditions of aquatic ecosystems make aquatic organisms vulnerable to oxidative stress. The Nrf2-Keap1/ARE signaling pathway serves as an important intracellular defense mechanism, particularly for aquatic organisms exposed to environmental stressors and toxic substances. Environmental stimuli can disrupt an organism's internal redox balance, leading to cellular oxidative stress responses. To counteract these effects, cells develop intricate defense mechanisms, with the Nrf2-Keap1/ARE signaling pathway is playing a crucial role. In this pathway, the nuclear transcription factor Nrf2 translocates into the nucleus to initiate the transcription of antioxidant genes, thereby reducing reactive oxygen species (ROS)-induced cellular damage and maintaining the organism's oxidative-antioxidative equilibrium. While research on this pathway in mammals is well-established, studies on aquatic organisms are still limited. This review provides a comprehensive analysis of the regulatory functions of the Nrf2-Keap1/ARE pathway on oxidative stress and delves into the molecular structures of Nrf2, Keap1, and ARE, offering insights into the physiological regulation of antioxidant defenses in aquatic organisms.

Nuclear Factor Erythroid 2-Related Factor 2 Activator DDO-1039 Ameliorates Podocyte Injury in Diabetic Kidney Disease via Suppressing Oxidative Stress, Inflammation, and Ferroptosis

Aims: Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease, and podocyte injury is one of the major contributors to DKD. As a crucial transcriptional factor that regulates cellular response to oxidative stress, nuclear factor erythroid 2-related factor 2 (Nrf2) is an attractive therapeutic target for DKD. In this study, we evaluated the therapeutic potential of DDO-1039, a novel small-molecule Nrf2 activator developed with protein-protein interaction strategy, on podocyte injury in DKD. Results: DDO-1039 treatment significantly increased Nrf2 protein level and Nrf2 nuclear translocation, thereby upregulating Nrf2 target genes [heme oxygenase 1, NAD(P)H quinone dehydrogenase 1, glutamate-cysteine ligase modifier, and tyrosine-protein kinase receptor] both in vitro and in vivo. DDO-1039 attenuated glomerular sclerosis and podocyte injury in the high-fat diet/streptozotocin-induced (HFD/STZ) diabetic mice and db/db diabetic mice. It also significantly improved hyperglycemia in both diabetic mice and mitigated proteinuria in HFD/STZ mice. Meanwhile, DDO-1039 attenuated oxidative stress and inflammation as well as apoptosis in vivo and in podocytes stimulated with palmitic acid and high glucose. Interestingly, we identified podocyte protective factor Tyro3 as a novel Nrf2-regulated gene. In addition, podocyte ferroptosis is reduced via activation of glutathione peroxidase 4 by the novel Nrf2 activator. Innovation and conclusion: DDO-1039 activates the Nrf2-based cytoprotective system to mitigate podocyte injury in the context of diabetes, suggesting the potential of DDO-1039 in the treatment of DKD. Antioxid. Redox Signal. 42, 787-806.

Oleanolic Acid Alleviates Neuronal Ferroptosis in Subarachnoid Hemorrhage by Inhibiting KEAP1-Nrf2 and NF-κB Pathways

Oleanolic acid (OA) is a pentacyclic triterpenoid compound, and we previously report that it ameliorates neurological injury in subarachnoid hemorrhage (SAH) model. However, the underlying mechanism is not clear. The aim of this study was to explore the effect and mechanism of OA on SAH. In this study, network pharmacology was applied to screen the targets of OA in SAH treatment. Based on these targets, protein-protein interaction network was constructed, and k-means cluster analysis was used to screen the core targets of OA in SAH treatment. In vitro SAH model was constructed with hemin-induced neuron HT22 and microglia BV2. Then cell counting Kit 8, flow cytometry, western blot, qPCR were performed to evaluate the effects of OA on neurons and microglia. 93 targets were identified as the core targets of OA in SAH treatment. Notably, these targets are closely related to neuroinflammation and oxidative stress responses. OA had good binding activity with KEAP1, NFKB1 and IKBA. OA significantly alleviated the inhibitory effect of hemin on HT22 cell viability. OA significantly inhibited the expression of CD86, promoted the expression of CD206, and promoted the transformation of microglia from M1 type to M2 type. Additionally, OA could inhibit the activation of NF-κB and KEAP1/Nrf2 pathways. In conclusion, OA ameliorates inflammatory response, oxidative stress and ferroptosis in SAH, and suppresses neuronal injury by inhibiting NF-κB and KEAP1/Nrf2 pathways.

Shrimp Virus Regulates ROS Dynamics via the Nrf2 Pathway to Facilitate Viral Replication

Reactive oxygen species (ROS) of hosts are widely involved in intracellular signaling and against pathogens. Viruses manipulate ROS homeostasis of hosts as a strategy to evade ROS-mediated negative effects of their infection, but the mechanisms remain unclear. The economically important aquaculture shrimp, Litopenaeus vannamei, is selected to investigate the molecular mechanism of how white spot syndrome virus (WSSV) regulates ROS dynamics and enhances viral replication. WSSV protein wsv220 binds to the repressor of shrimp nuclear factor erythroid 2-related factor 2 (LvNrf2), called Kelch-like ECH-associated protein 1 (LvKeap1), disrupting LvNrf2/LvKeap1 complex and facilitating LvNrf2 nuclear translocation. This activation of LvNrf2 causes up-regulation of antioxidant genes, including glucose-6-phosphate dehydrogenase (LvG6PDH), which increases nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) production, effectively eliminating excessive ROS. Moreover, WSSV exploits LvNrf2 to establish a positive feedback loop by up-regulating viral immediate early gene wsv051, which further enhances wsv220 expression. Knockdown of LvNrf2 or LvG6PDH reduces WSSV replication and increases host ROS levels. Therefore, WSSV hijacks LvNrf2 pathway to maintain ROS homeostasis and establishes a positive feedback loop to facilitate WSSV replication. These findings reveal a novel molecular mechanism of viral manipulation of host ROS dynamics and suggest potential antiviral strategies targeting LvNrf2 pathway.

Ilex asprella polysaccharides alleviate liver injury via antioxidative, anti-inflammatory, and gut microbiota modulating effect

Ilex asprella, a valued plant traditionally used as food and medicine, is recognized for its effect on liver protection. Polysaccharides, as the key active components in Ilex asprella (IAP), its biological activities are still unexplored. Therefore, this study investigated the preventive effects of IAP on liver injury in vivo. H&E and TUNEL staining revealed IAP could ameliorate the histomorphology changes and liver apoptosis. For antioxidant ability, IAP preconditioning released D-GalN/LPS-induced oxidative stress via Nrf2/HO-1 signaling pathway in liver, as evidenced by increasing superoxide dismutase, total antioxidant capacity, glutathione peroxidase, and inhibiting the activation of Nrf2 and HO-1. Furthermore, IAP reduced the expression of IL-6, IL-1β and TNF-α, showing good anti-inflammatory effects. According to the results from western blot, the phosphorylation of TLR4, p65, IκB, p38, ERK, and JNK were effectively inhibited with IAP pre-treatment, indicating IAP can ameliorate the liver inflammation through TLR4/NF-κB and MAPK signaling pathway. 16S RNA sequencing revealed IAP re-regulated composition of gut microbiota, including inhibiting the harmful bacteria (Parasutterella and Erysipelatoclostridium) enrichment and restoring the probiotics (Lactobacillus, Dubosiella and Bacteroide). In conclusion, this study revealed IAP can improve liver injury by inhibiting liver oxidative stress, releasing inflammation and modulating the gut microbiota.

Selenium promotes neural development through the regulation of GPX4 and SEPP1 in an iPSC-derived neuronal model

Selenium (Se) is incorporated into selenoproteins in the form of selenocysteine, which has biological functions associated with neural development. Unfortunately, the specific roles and mechanisms of selenoproteins at different stages of neuronal development are still unclear. Therefore, in this study, we successfully established a neuronal model derived from induced pluripotent stem cells (iPSC-iNeuron) and used Se nanoparticles (SeNPs@LNT) with high bioavailability to intervene at different stages of neural development in iPSC-iNeuron model. Interestingly, our results showed that SeNPs@LNT could not only accelerate the proliferation of neural progenitor cells (NPCs) by upregulating glutathione peroxidase 4 (GPX4) during the NPC stage, but also can promote neuronal differentiation by increasing selenoprotein P (SEPP1) during the neuronal stage, resulting in efficient and rapid neural development. In addition, further mechanistic studies showed that SeNPs@LNT can regulate selenoproteins by activating the PI3K/Akt/Nrf2 signaling pathway, thereby affecting neuronal development. Notably, Further analysis of ASD patients in National Center for Biotechnology Information single-cell RNA-seq datasets also revealed significantly lower GPX4 expression within NRGN-expressing neurons in ASD patients, and GO enrichment analysis of genes in NRGN-expressing neurons from ASD patients showed that the downregulation of selenoproteins due to aberrant selenoprotein synthesis may be closely associated with decreased ATP synthesis resulting from abnormal mitochondrial and respiratory chain signaling pathways. Taken together, this study provides evidence that SeNPs@LNT exerts a beneficial effect on early neural development through the regulation of selenoproteins.

MSC-derived exosomes alleviate oxidative stress-induced lysosomal membrane permeabilization damage in degenerated nucleus pulposus cells via promoting m6A demethylation of Nrf2

Lysosomal membrane permeabilization (LMP) is a specific feature of lysosomal dysfunction; however, its specific role and underlying mechanisms involved in intervertebral disc degeneration (IVDD) remain elusive. Although the therapeutic potential of mesenchymal stem cell-derived exosomes (MSC-Exo) in ameliorating IVDD has been verified, it remains unclear whether their protective effects are referred to LMP damage. This work revealed that oxidative stress induced-LMP damage directly mediated the pathological process of human IVDD, which aggravated nucleus pulposus cells (NPCs) senescence by disrupting lysosomal autophagy function. Conversely, umbilical cord derived MSC-Exo inhibited LMP damage in degenerated NPCs by activating Nrf2-medaited anti-oxidative stress effects. Specifically, MSC-Exo facilitated H3K27ac modification in the demethylase FTO promoter by promoting histone acetyltransferase activity of p300/CBP, resulting in the enhanced FTO transcription. This process inhibited the elevation of N6-methyladenosine (m6A) modification of Nrf2 in degenerated NPCs, resulting in less recognition of YTHDF2 and enhanced stability of Nrf2 expression. Here, our finding demonstrates oxidative stress induced-LMP damage potentially establishing pathological conditions conducive to the progression of IVDD, and providing epigenetic regulatory targets for MSC-Exo in the treatment of IVDD.

Mechanistic insights into cadmium-induced nephrotoxicity: NRF2-Driven HO-1 activation promotes ferroptosis via iron overload and oxidative stress in vitro

Cadmium (Cd), a pervasive environmental toxicant, poses significant threats to human and animal health through multi-organ toxicity. While ferroptosis has been implicated in Cd-induced pathologies, the molecular mechanisms underlying Cd-mediated nephrotoxicity remain poorly understood. This study elucidates the ferroptosis pathway in CdCl2-exposed PK-15 cells and murine kidney, characterized by iron overload, lipid peroxidation, and mitochondrial dysfunction, which were ameliorated by ferroptosis inhibitor ferrostatin-1. Transcriptomic analysis revealed substantial upregulation of heme oxygenase-1 (HO-1) following CdCl2 exposure. Mechanistically, CdCl2 triggered nuclear translocation of nuclear factor erythroid 2-related factor-2 (NRF2), subsequently activating HO-1 transcription. Over-activated HO-1 catalyzes the decomposition of heme and releases free iron, accompanied with the degradation of ferritin heavy chain 1 (FTH1) induced by CdCl2 exposure, which leads to intracellular iron overload and excessive lipid peroxides production through Fenton reaction, resulting in ferroptosis ultimately. In vivo validation confirmed NRF2/HO-1-mediated ferroptosis in CdCl2-induced murine nephrotoxicity. Both pre-treatment with HO-1 competitive inhibitor Zinc protoporphyrin IX (ZnPP) and knockout of HO-1 gene remarkably alleviated PK-15 cells against ferroptosis induced by CdCl2 treatment. Our findings demonstrate that Cd exposure initiates NRF2-mediated HO-1 overexpression, driving iron-dependent lipid peroxidation and subsequent ferroptosis. This mechanistic insight provides potential therapeutic targets for mitigating Cd-induced renal damage, advancing our understanding of heavy metal toxicity and its cellular consequences.

Nrf2 and its signaling pathways in sepsis and its complications: A comprehensive review of research progress

Sepsis is a life-threatening condition characterized by organ dysfunction resulting from a dysregulated host immune response to infection. It is associated with a high incidence, intricate pathophysiological mechanisms, and rapidly progressive severity, rendering it a leading cause of mortality among patients in intensive care units. The Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) is a transcription factor pivotal for maintaining cellular redox homeostasis by regulating the expression of antioxidant and cytoprotective genes. Emerging evidence suggests that activation of the Nrf2 signaling pathway attenuates sepsis-induced inflammatory responses, oxidative stress, and organ dysfunction, thereby improving clinical outcomes. These findings underscore the potential of Nrf2 as a therapeutic target, offering a promising avenue for the development of novel interventions aimed at mitigating the complications and improving the prognosis of sepsis.

RvD2 mitigates TNFɑ-Induced mitochondrial reactive oxygen species through NRF2 signaling in placental trophoblasts

Introduction

Hypertensive disorders of pregnancy (HDP) are marked by elevated levels of TNFα, which increases reactive oxygen species (ROS) and disrupts metabolism of trophoblasts. Resolvin D2 (RvD2), an omega-3 fatty acid-derived lipid mediator, is known to resolve inflammation, but its role in protecting trophoblasts by promoting antioxidant responses to alleviate ROS remains unclear. Nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2) controls cellular defense mechanisms against oxidative stress and helps with the maintenance of cellular redox homeostasis. Upon translocation to nucleus, NRF2 activates the antioxidant response element (ARE), inducing the expression of genes that can mitigate ROS. Hence, we hypothesized that RvD2 activates NRF2 and prevents TNFα-induced mitochondrial dysfunction in trophoblasts.

Methods

We investigated RvD2's potential protective mechanisms against TNFα-induced oxidative stress in trophoblasts by pretreating JEG cells with 100 nM RvD2, followed by exposure to 50 or 100 ng/mL TNFα.

Results

We also observed that placental TNFα levels were elevated, while NRF2 protein levels were reduced in human HDP placental tissues compared to normotensive placentas. We demonstrate that RvD2 alone enhances NRF2 nuclear translocation, increases glutathione levels and mitochondrial function, and reduces mitochondrial ROS. In contrast, TNFα alone decreases nuclear NRF2 levels, increases mitochondrial ROS and oxygen consumption rates, and impairs migration. Notably, pretreatment of RvD2 before TNFα exposure protects against mitochondrial ROS, increases NRF2 levels, and restores mitochondrial oxygen consumption rates in trophoblasts.

Discussion

These findings demonstrate that RvD2 functions as a positive regulator of endogenous antioxidant properties by enhancing NRF2 levels and mitigating mitochondrial ROS in placental trophoblasts.

Focusing on Keap1, IKKβ, and Bcl2 proteins: predicted targets of stigmasterol in neurodegeneration

Oxidative stress, driven by excess ROS, damages lipids, proteins, and DNA, leading to neuronal apoptosis and inflammation, a key factor in neurodegenerative diseases. This study explored stigmasterol, a bioactive phytosterol, with neuroprotective potential, revealing strong docking interactions, especially with Keap1 (binding energy of -11.62 Kcal/mol). Stigmasterol formed two hydrogen bonds with Ile258 and Val305 in Keap1, suggesting it could disrupt Keap1-Nrf2 interactions, potentially activating antioxidant responses by promoting Nrf2 translocation to the nucleus. In the Bcl2-stigmasterol complex, which exhibited a binding energy of -8.41 Kcal/mol, hydrophobic interactions with residues Ser50, Gln52, and Leu185 stabilized the complex, indicating stigmasterol's role in inhibiting apoptosis by strengthening of Bcl2 mediated inhibition of pro-apoptotic factors like Bax. Furthermore, the IKKβ-stigmasterol complex displayed a hydrogen bond between Asp385 residue and stigmasterol (2.83 Å), with a binding energy of -8.33 Kcal/mol, suggested that stigmasterol may regulate inflammation by stabilizing IKKβ, thereby preventing NF-κB translocation and reducing inflammation. Molecular dynamics simulations confirmed the stability of stigmasterol's interactions, especially with Keap1, which showed low RMSD values and consistent hydrogen bonding. RMSF and Rg analyses indicated that stigmasterol had stabilizing effects on Bcl2 and IKKβ. These results underscore stigmasterol's potential for neuroprotection through antioxidant and anti-inflammatory actions.

Modular Nanotransporters Containing Keap1 Monobodies Are Capable of Reducing the Toxic Effect of Acetaminophen on the Liver of Mice

Previously, we created a modular nanotransporter (MNT) containing a monobody to Keap1, an intracellular protein inhibitor of the Nrf2 transcription factor that controls cellular protection from oxidative stress and is capable of interacting with Keap1 in hepatocytes and protect these cells from the effects of hydrogen peroxide. Oxidative liver damage by acetaminophen was used as a model to study the antitoxic effect of this MNT. Intraperitoneal injection of acetaminophen to mice resulted in an increase in the level of alanine aminotransferase and aspartate aminotransferase in the blood, as well as in liver edema. A significant decrease in the level of these enzymes in the blood, along with a decrease in liver edema, was observed after preliminary intravenous administration of MNT 2 h before the acetaminophen injection. The results obtained can be used as a basis for developing drugs to treat diseases associated with oxidative stress.

Smilax glabra roxb. alleviates cisplatin-induced acute kidney injury in mice by activating the Nrf2/HO-1 Signalling Pathway

BACKGROUND

Owing to its remarkable efficacy, cisplatin (CDDP) is widely used as a chemotherapeutic drug in clinical cancer treatment; however, its severe nephrotoxicity often leads to acute kidney injury (AKI), in turn adversely affecting patient treatment and quality of life. Smilax glabra Roxb. (TFL), a Chinese herbal medicine, has various pharmacological effects, including antitumour, anti-inflammatory, and antioxidant activities, with the antioxidant activity being of useful in the detoxification of heavy metal toxicity.

AIM

This study aimed to investigate, for the first time, the nephroprotective effects of TFL in alleviating CDDP-induced AKI and to elucidate its underlying mechanisms.

METHODS

In vitro and in vivo models of AKI were established using CDDP induction. For the in vivo model, CDDP (20 mg/kg) was intraperitoneally injected on day 7 to induce AKI. TFL treatment was administered daily at doses of 1.95 and 3.9 g/kg starting from the day 1 and continuing for 10 consecutive days. Blood samples were collected on day 10 after 72-h of CDDP injection for analysis. Kidney pathology was observed using haematoxylin and eosin (HE) staining, and mitochondrial ultrastructure was assessed using transmission electron microscopy. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), HO-1, NQO1, caspase-3, and cytochrome C (CYT-C) were determined using western blotting, PCR, and immunofluorescence (IF). Adenosine triphosphate (ATP) levels, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were measured using the corresponding kits. Lastly, reverse validation of the Nrf2/HO-1 pathway was performed using the Nrf2-specific inhibitor, ML385.

RESULTS

After induction with 40 μM CDDP, HK2 cells showed obvious mitochondrial damage, and the protein and mRNA expressions of Nrf2, HO-1, and NQO1 were inhibited, but gradually increased with TFL treatment. Furthermore, CDDP-induced AKI in mice was similar to the observations in the in vitro model using HK2 cells. The protective effects of TFL were reversed with ML385 therapy.

CONCLUSION

In both in vivo and in vitro experiments, TFL activated the Nrf2/HO-1 signalling pathway, promoting the expression of antioxidant enzymes and thereby ameliorating CDDP-induced oxidative stress, mitochondrial dysfunction and renal cell apoptosis.

Esculin, a Coumarin Glucoside Prevents Fluoride-Induced Oxidative Stress and Cardiotoxicity in Zebrafish Larvae

Fluoride (F-) is a major groundwater contaminant spread across the world. In excess concentrations, F- can be detrimental to living beings. F- exposure is linked to cellular redox dyshomeostasis, leading to oxidative stress-mediated pathologies including heart dysfunction. Due to its potent antioxidant properties, various phytochemicals are found to alleviate the symptoms of F- toxicity. Hence, we explore the protective effect of esculin (Esc), a coumarin glucoside on F--induced oxidative stress and cardiotoxicity in zebrafish larvae. The experimental groups consisted of NaF (50 ppm) and Esc (100 μM) groups treated alone and in combination with a control group for 6 h. The groups were maintained till 78 hpf after which the level of oxidants (ROS, LPO, and PCC) and antioxidants (GST, GSH, GPx, SOD, and CAT) were assessed. The results revealed that Esc pretreatment restored the depleted antioxidant markers and reduced the levels of oxidant in the Esc+NaF group, exhibiting its antioxidant potential. In addition, analyses of the heartbeat rate and hemoglobin integrity using o-Dianisidine staining were conducted in the control and experimental groups. Esc treatment prevents F- induced cardiac changes including tachycardia and altered blood flow. Further, the mRNA expression level of antioxidant genes (nrf2, gstp1, hmox1a, prdx1, and nqo1) and cardiac developmental genes (bmp2b, nkx2.5, myh6, and myl7) confirmed that Esc acts as a potent free radical scavenger and antioxidant defense enhancer, protecting zebrafish larvae from NaF-induced oxidative stress and heart dysfunction.

Lysosomal-Mitochondrial Interaction Promotes Tumor Growth in Squamous Cell Carcinoma of the Head and Neck

Communication between intracellular organelles including lysosomes and mitochondria has recently been shown to regulate cellular proliferation and fitness. The way lysosomes and mitochondria communicate with each other [lysosomal-mitochondrial interaction (LMI)] is emerging as a major determinant of tumor proliferation and growth. About 30% of squamous carcinomas [including squamous cell carcinoma of the head and neck (SCCHN)] overexpress transmembrane member 16A (TMEM16A), a calcium-activated chloride channel, which promotes cellular growth and negatively correlates with patient survival. We have recently shown that TMEM16A drives lysosomal biogenesis; however, its impact on mitochondrial function has not been explored. In this study, we show that in the context of high-TMEM16A SCCHN, (i) patients display increased mitochondrial content, specifically complex I; (ii) in vitro and in vivo models uniquely depend on mitochondrial complex I activity for growth and survival; (iii) NRF2 signaling is a critical linchpin that drives mitochondrial function, and (iv) mitochondrial complex I and lysosomal function are codependent for proliferation. Taken together, our data demonstrate that coordinated lysosomal and mitochondrial activity and biogenesis via LMI drive tumor proliferation and facilitate a functional interaction between lysosomal and mitochondrial networks. Therefore, inhibition of LMI instauration may serve as a therapeutic strategy for patients with SCCHN. Implications: Intervention of LMI may serve as a therapeutic approach for patients with high TMEM16A-expressing SCCHN.

Non-coding RNAs and regulation of the PI3K signaling pathway in lung cancer: Recent insights and potential clinical applications

Lung cancer (LC) is one of the most common causes of cancer-related death worldwide. It has been demonstrated that the prognosis of current drug treatments is affected by a variety of factors, including late stage, tumor recurrence, inaccessibility to appropriate treatments, and, most importantly, chemotherapy resistance. Non-coding RNAs (ncRNAs) contribute to tumor development, with some acting as tumor suppressors and others as oncogenes. The phosphoinositide 3-kinase (PI3Ks)/AKT serine/threonine kinase pathway is one of the most important common targets of ncRNAs in cancer, which is widely applied to modulate the cell cycle and a variety of biological processes, including cell growth, mobility survival, metabolic activity, and protein production. Discovering the biology of ncRNA-PI3K/AKT signaling may lead to advances in cancer diagnosis and treatment. As a result, we investigated the expression and role of PI3K/AKT-related ncRNAs in clinical characteristics of lung cancer, as well as their functions as potential biomarkers in lung cancer diagnosis, prognosis, and treatment.

A novel histone deacetylase inhibitor protects the blood-brain barrier by regulating NF-κB and Nrf2 signaling pathways in OGD/R injury

Ischemic stroke, a severe cerebrovascular disease, is particularly prevalent among the elderly. Rsearch has indicated that histone deacetylases (HDACs) are pivotal in the pathogenesis of ischemic stroke. We introduce a novel HDACs inhibitor, HDI-1, as a potential therapeutic strategy for this condition. Our study reveals that HDI-1 expedites the restoration of tight junction proteins, Occludin and Claudin-5, in the oxygen-glucose deprivation/reoxygenation (OGD/R) model using human cerebral microvascular endothelial cells (hCMEC/D3). Moreover, HDI-1 mitigates the impairment of cellular monolayer membrane permeability following injury. This effect may stem from HDI-1's ability to selectively suppress the enzymatic activity of HDAC2. By inhibiting the activation of the NF-κB pathway triggered by OGD/R injury, HDI-1 reduces the secretion of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α, thereby diminishing the inflammatory response in hCMEC/D3 cells. Meanwhile, HDI-1 exhibits antioxidant properties by enhancing the Nrf2/HO-1 signaling pathway. Collectively, our findings propose HDI-1 as a promising candidate for ischemic stroke treatment.

SMND-309 activates Nrf2 signaling to alleviate acetaminophen-induced hepatotoxicity and oxidative stress

BACKGROUND

Acetaminophen (APAP) can be used for pain relief and fever alleviation, the overdose of which, however, may lead to the accumulation of N-acetyl-p-benzoquinone imine (NAPQI), inducing oxidative stress and liver damage. The natural compound SMND-309 has been shown to have hepatoprotective effects and potential antioxidant activity. However, its ability to alleviate acetaminophen-induced acute liver injury (AILI) has not been elucidated.

OBJECTIVE

To explore the protective effect of the natural compound SMND-309 against AILI and the potential mechanism.

METHODS

The AILI model was established using a mouse model and HepG2 cells for pathological evaluation and biochemical assays of mouse liver tissues to assess the level of liver injury. The effects of SMND-309 on cellular ROS levels and mitochondrial membrane potential were detected using DCFH-DA and JC-1 probes. Western blotting was performed to detect the expressions of Nrf2 signaling pathway and key proteins related to APAP metabolism in the combination of immunohistochemistry of liver tissues, with immunofluorescence assay used to detect whether Nrf2 undergoes nuclear translocation. Molecular docking, molecular dynamics simulation (MD) and biofilm layer interference (BLI) experiments were performed to detect the interaction of SMND-309 with Keap1.

RESULTS

SMND-309 improved histopathological changes in the liver, decreased alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels, as well as attenuated oxidative stress injury and mitochondrial dysfunction in the HepG2 cell line. Further studies revealed that SMND-309 promoted nuclear translocation of Nrf2 and upregulated the expressions of glutamate-cysteine ligase catalytic subunit (GCLC), heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1). In addition, molecular docking and MD suggested that SMND-309 could bind Keap1 and identified possible binding modes, with BLI experiments confirming that SMND-309 directly interacted with Keap1.

CONCLUSION

SMND-309 exerts hepatoprotective effects against AILI in an Nrf2-ARE signaling pathway-dependent manner.

Flavonoids in Lotus Stamen Extract Inhibit High Glucose-Induced Intracellular Glycation in Fibroblasts by Upregulating the Expression of Glyoxalase 1 and Alleviating Oxidative Stress

Glycation is a process in which reducing sugars bind to proteins, resulting in the formation of advanced glycation end products (AGEs). These AGEs accumulate in the skin, promote excessive collagen crosslinking, and disrupt the extracellular matrix (ECM), impairing normal cellular functions and contributing to skin aging. To evaluate the anti-glycation efficacy of lotus stamen extract (LSE), we employed the BSA-fructose system and a high glucose (HG)-induced fibroblast glycation model. The results demonstrated that LSE effectively inhibited cellular glycation and also exhibited anti-inflammatory, antioxidative, and anti-senescent effects in HG-induced human skin fibroblasts (HSF). Further investigation into the anti-glycation mechanism and component analysis of the lotus stamen ethyl acetate extract (LSEE) led to the identification of 15 flavonoids. The anti-glycation results indicated that these flavonoids are likely the primary active constituents in LSE. Mechanistic studies revealed that GLO1 plays a crucial role in cellular resistance to glycation, and LSEE enhanced GLO1 expression through the Nrf2/Keap1 pro-survival pathway, thereby mitigating intracellular AGE production. In summary, LSEE and its multiple flavonoid components exhibit potent intracellular anti-glycation activity and present significant potential to be developed as a natural and organic product for cosmetic and healthcare applications.

[Dexmedetomidine attenuates heat stress-induced oncosis in human skeletal muscle cells by activating the Nrf2/Ho-1 pathway]

OBJECTIVES

To investigate the protective effects of dexmedetomidine (DEX) against heat stress (HS)-induced oncosis in human skeletal muscle cells (HSKMCs) and its underlying mechanisms.

METHODS

A HSKMC model of HS-induced oncosis were established by 43 ℃ water bath for 4 h, and the effects of treatments with 30 μmol/L DEX, ML385 (a Nrf2 inhibitor) +DEX, si-Nrf2+HS, and si-Nrf2+DEX prior to modeling on cell viability was assessed using CCK-8 assay. Oncosis characteristics were evaluated using transmission electron microscopy and Annexin V-FITC/PI flow cytometry. The oxidative stress markers (GSH, GSH-Px, MDA, SOD and ROS), mitochondrial membrane potential, energy metabolism, and inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the cells were quantified using standard kits, and the expressions of porimin, caspase-3 and Nrf2 pathway proteins were analyzed using Western blotting and qRT-PCR.

RESULTS

HS induced typical oncotic features in HSKMCs including organelle swelling and cytoplasmic vacuolization. DEX pretreatment significantly attenuated these changes, reduced Annexin V+/PI+ cell ratio and cellular porimin expression, and lowered the levels of ROS and MDA while restoring GSH and SOD levels. DEX pretreatment also significantly increased the mitochondrial membrane potential and ATP level, upregulated the expressions of Nrf2, p-Nrf2, HO-1 and NQO1, and suppressed the expressions of TNF-α, IL-6 and IL-1β. The protective effects of DEX were obviously attenuated by interventions with ML385 or si-Nrf2.

CONCLUSIONS

DEX mitigates HS-induced HSKMC oncosis by activating the Nrf2/HO-1 pathway to relieve oxidative stress, mitochondrial dysfunction, and inflammatory responses.

Lycium barbarum L.: a potential botanical drug for preventing and treating retinal cell apoptosis

Retinal cell apoptosis is the primary pathological process in many retinal diseases, including retinitis pigmentosa and age-related macular degeneration, which can cause severe visual impairment and blindness. Lycium barbarum L., a traditional Chinese medicinal botanical drug, has a long history and extensive application in ophthalmic disease prevention and treatment. This study systematically reviewed the key active metabolites in L. barbarum L., including L. barbarum polysaccharides, carotenoids, and flavonoids, that exert retinal protective effects. A comprehensive analysis of the pharmacological effects and underlying molecular mechanisms of L. barbarum L. and its active metabolites in the prevention and treatment of retinal cell apoptosis, including essential aspects such as antioxidant activity, anti-inflammatory properties, autophagy regulation, and mitochondrial function preservation, is essential to establish a comprehensive and solid theoretical basis for further investigation of the medicinal value of L. barbarum L. in ophthalmology and provide a reference for future research directions.

Cisplatin-induced acute kidney injury increased brain 5-hydroxytryptamine levels partly due to the hippuric acid-induced upregulation of CYP2D4 expression and function in the brain of rats

Patients with acute kidney injury (AKI) are often associated with uremic encephalopathy, but its underlying mechanisms remain unclear. This study aimed to investigate how AKI induced neuropsychiatric disorders through cerebral 5-hydroxytryptamine (5-HT) dysregulation in cisplatin-induced AKI rats. Our findings demonstrated that AKI induced anxiety-like behaviors and increased cerebral 5-HT levels, which may be attributed to the upregulated CYP2D4 expression and activity. The intraventricular injection of quinine (CYP2D4 inhibitor) attenuated the elevated cortical 5-HT levels in AKI rats. Intraperitoneal administration of 5-methoxytryptamine (CYP2D4 substrate) also provoked anxiety-like behaviors and cerebral 5-HT accumulation, which were reversed by cotreatment with quinine. Hippuric acid (HA), as a classical uremic toxin, was severely accumulated in both the plasma and brain of AKI rats. In vitro experiments demonstrated that HA-induced reactive oxygen species (ROS) upregulated expression of CYP2D6 (over 70% homology with rat CYP2D4) via suppressing Nrf2/HO-1 pathway in SH-SY5Y cells. These effects were reversed by ROS scavenger N-acetylcysteine, Nrf2 activator sulforaphane, and HO-1 activator cobalt-protoporphyrin IX. Similarly, either Nrf2 inhibitor ML385 or HO-1 inhibitor zinc-protoporphyrin IX exerted up-regulatory effects on CYP2D6 expression. In vivo studies confirmed that HA treatment induced AKI-like behavioral abnormalities in rats, accompanied by increased cerebral 5-HT levels and CYP2D4 expression as well as induced production of ROS, decreased Nrf2 and HO-1 protein levels. Our findings elaborate a novel mechanism between kidney failure and neuropsychiatric complications. Specifically, cisplatin-induced AKI upregulates CYP2D4 expression via HA-mediated ROS release, subsequently promoting generation of cerebral 5-HT by CYP2D4 and revealing material basis of AKI-associated uremic encephalopathy. SIGNIFICANCE STATEMENT: This study revealed that the psychiatric disorders of cisplatin-induced acute kidney injury rats are partly attributed to the increased 5-hydroxytryptamine levels induced by brain CYP2D. The induction of CYP2D4 is mainly due to brain accumulation of hippuric acid via inactivation of Nrf2/HO-1 pathway by reactive oxygen species.

Melatonin augments anti-tumor activity and alleviates nephrotoxicity of gemcitabine in a pancreatic cancer xenograft model targeting P62/Keap1 pathway

Although gemcitabine is a primary chemotherapy for pancreatic cancer, its effectiveness is limited by chemoresistance and nephrotoxicity, posing significant clinical challenges. Therefore, the development of novel therapeutic approaches to prevent pancreatic malignancy remains crucial. This study aimed to investigate the potential of melatonin in enhancing gemcitabine's anticancer efficacy while mitigating its nephrotoxic effects through modulation of the Keap1/p62 pathway. A pancreatic cancer xenograft model was established in rats, which received either gemcitabine (50 mg/kg, I.P.), melatonin (50 mg/kg, I.P.), or their combination three times per week for 2 weeks. Our findings demonstrate that melatonin potentiates gemcitabine's cancer-suppressing effects via modulation of the Kelch-like-ECH associated protein-1 (Keap1)/p62 pathway, resulting in reduced fibrosis, oxidative stress, and inflammatory markers. Additionally, melatonin significantly mitigated gemcitabine-induced nephrotoxicity. These results suggest that melatonin may serve as an adjuvant therapy in pancreatic cancer treatment, enhancing chemotherapy efficacy while reducing its adverse effects.

Importance of systemic redox homeostasis biomarkers and transcription factors in patients undergoing open-heart surgery with cardiopulmonary bypass

PURPOSE

Patients undergoing coronary artery bypass graft surgery and isolated valve disease surgery may experience redox dyshomeostasis associated with cardiopulmonary bypass (CPB).

METHODS

We investigated the impact of CPB on systemic redox homeostasis by analyzing redox biomarkers and antioxidant transcription factors preoperatively and postoperatively using spectrophotometric and immunochemical methods.

RESULTS

Our findings indicate significant variations in protein oxidation biomarkers, antioxidant capacity biomarkers, and transcription coactivator peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) levels after CPB. The ROC analysis indicated that protein carbonyl was valuable in the preoperative (p = 0.009) and postoperative (p = 0.013) periods. We also found that glutathione peroxidase was a valuable redox biomarker during the postoperative period (p = 0.000). An ROC analysis of catalase activity (p = 0.017) before CPB indicated the importance of catalase in eliminating increased hydroperoxide load. The ROC graphs reinforced the value of PGC-1α (p = 0.000) as a biomarker, showing a similar trend to that of catalase before CPB.

CONCLUSION

The earlier view of "increased oxidative stress and decreased biofunction" has shifted to exploring the physiological role of redox signaling regulation. We believe that future studies on the effects of CPB on systemic redox regulation processes through redox signaling mechanisms will significantly contribute to the relevant literature.

Sesquiterpene lactones from Cichorium intybus exhibit potent anti-inflammatory and hepatoprotective effects by repression of NF-κB and enhancement of NRF2

ETHNOPHARMACOLOGICAL RELEVANCE

Cichorium intybus is a traditional medicinal herb for hepatitis treatment in China and Europe. Sesquiterpene lactones are the main active ingredients in C. intybus. However, their structure-activity relationship (SAR) and molecular mechanisms of anti-inflammatory and hepatoprotective effects require further elucidation.

AIM OF THE STUDY

To identify new sesquiterpene lactones from C. intybus, and further evaluate their anti-inflammatory effects, SAR, and mechanisms of anti-inflammatory and hepatoprotective properties.

METHODS

Identification of sesquiterpene lactones from C. intybus using chromatographic fractionation, NMR, and mass spectrometry. The repression of inflammation was evaluated in RAW264.7 macrophages incubated with LPS. Western blotting was employed to investigate the anti-inflammatory mechanisms. The hepatoprotective effect was measured in LPS/D-galactosamine (D-GalN)-induced acute hepatitis in mice.

RESULTS

We identified 3 new sesquiterpene lactones and 15 known analogues from C. intybus. SAR analysis showed that the α-methylene-γ-lactone moiety was essential for their anti-inflammatory properties. Furthermore, 8-deoxylactucin was identified as the most potent anti-inflammatory component in LPS-induced RAW264.7 macrophages by reduction of nitric oxide production via inhibiting iNOS expression, and suppression of IL-1β, IL-6, and TNF-α expression. Mechanistically, 8-deoxylactucin not only blocked LPS-induced IKKα/β phosphorylation, IκBα phosphorylation and degradation, and NF-κB nuclear accumulation, but also enhanced NRF2 expression and nuclear translocation, HO-1 and NQO1 expression, and reduced ROS generation in vitro. In vivo, 8-deoxylactucin mitigated LPS/D-GalN-induced acute hepatitis, which manifested as reduction in inflammatory infiltration, live injury, serum levels of AST and ALT, and production of pro-inflammatory cytokines and 4-hydroxynonenal.

CONCLUSION

8-Deoxylactucin, the sesquiterpene lactone isolated from C. intybus, exerted anti-inflammatory and hepatoprotective effects by blocking NF-κB activation and enhancing NRF2 activation.

Nrf2 protects against oxidative damage induced by hemoglobin in the liver of grass carp (Ctenopharyngodon idella)

Hemoglobin (Hb) releases during hemorrhaging and causes oxidative damage, further exacerbates the development of multiple diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates cellular defenses against toxic and oxidative challenges. However, the regulation mechanism of Nrf2 in Hb-induced oxidative stress remains unclear in teleost. To accomplish this goal, a hemolysis model was established by injecting grass carp with phenylalanine (PHZ), and the immunofluorescence analysis (IFA) and hematoxylin and eosin (H&E) staining revealed that PHZ-induced hemolysis caused Hb accumulation and hepatic vacuolization, resulted in tissue damage. Prussian blue, Sirius red, and Masson staining results revealed significant iron deposition and extensive collagen fiber accumulation in the liver. IFA and immunohistochemical analyses demonstrated that PHZ-induced hemolysis markedly increased the production of reactive oxygen species (ROS), malondialdehyde (MDA), and 4-hydroxynonenal (4-HNE). The quantitative real-time PCR (qRT-PCR) analysis data revealed that the PHZ-induced hemolysis also significantly upregulated the expression of antioxidant-related genes through activation of the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/Nrf2 signaling pathway. To further explore the molecule regulation mechanism of PHZ-induced hemolysis, the RNA-seq analysis was performed, and the data revealed that the AMPK/Nrf2 and multiple programmed cell death pathways, including ferroptosis, autophagy, apoptosis, and necroptosis in PHZ injection groups were significant upregulated. In vitro, the hemin supplementation activated the expression of target genes in the AMPK/Nrf2 pathway detected by qRT-PCR. To further verify the regulation function of Nrf2, an Nrf2 activator (4OI) was supplemented, and the flow cytometer analysis results suggested that the Hb-induced cell damage was significantly attenuated. However, the supplementary of ML385 down-regulated the AMPK/Nrf2 pathway and aggravated the hemin induced cell death. In conclusion, these findings highlight the critical regulatory role of the AMPK/Nrf2 signaling pathway in protecting against Hb-induced oxidative damage in the liver of grass carp.

ZC3H15 suppression ameliorates bone cancer pain through inhibiting neuronal oxidative stress and microglial inflammation

BACKGROUND

Patients with advanced-stage malignancies often endure unbearable pain, partly due to the incomplete understanding of its molecular mechanisms. Zinc finger CCCH-type containing 15 (ZC3H15) is a highly conserved eukaryotic protein involved in various cellular processes, including tumor growth and inflammation. However, its impact on cancer-induced pain, especially the underlying mechanisms, remains largely unknown.

METHODS

To evaluate the expression of ZC3H15 in cancer-induced pain, we used microcomputed tomography (MicroCT), immunoblotting, co-immunoprecipitation (Co-IP), behavior tests, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence assays in this investigation. Additionally, we used CCK8, cloning, and migration tests to examine the proliferation and migration of cancer cells. We also used transplantation tumor mouse model to investigate the course of the cancer cell growth. Finally, we looked into the biological processes linked to ZC3H15 using in vivo and in vitro ubiquitination detection, which was later verified.

RESULTS

In this study, we established a bone cancer pain (BCP) murine mouse model that impairs patients' quality of life. Initially, we observed a significant increase in the expression of ZC3H15 in dorsal horn spinal cord tissues of BCP mice, along with severe oxidative stress and inflammation. Subsequently, we found that adeno-associated virus (AAV) expressing ZC3H15 short hairpin RNA (shRNA) (AAV-shZC3H15) to silence ZC3H15 in vivo significantly alleviated the progression of BCP in mice, improving nociceptive behaviors, independent of tumor burden and bone destruction. Subsequently, we made a novel discovery that ZC3H15 knockdown mice with BCP displayed improved neuronal oxidative stress and reactive oxygen species (ROS) generation in spinal cord tissues, which was confirmed in H2O2-treated mouse spinal cord neurons primarily through mediating the kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor, erythroid 2-like transcription factor 2 (NRF2) pathway. Mechanistically, immunoblotting analysis revealed that ZC3H15 could maintain KEAP1 stability and thereby promote NRF2 ubiquitination and degradation under oxidative stress. Furthermore, the suppression of oxidative damage in neurons by ZC3H15 knockdown was significantly abolished upon the deletion of NRF2 expression, identifying the necessity of NRF2 for ZC3H15 in the mediation of BCP progression. Additionally, microglial activation and inflammatory response in spinal cord tissues of BCP mice were also attenuated by AAV-shZC3H15, which was verified in LPS-treated microglial cells in vitro by blocking the inhibitory protein κBα (IκBα)/nuclear factor κB (NF-κB) signaling pathway.

CONCLUSIONS

Our results provide evidence that suppressing ZC3H15 can alleviate BCP by restricting neuronal oxidative stress and microglial activation, contributing to the improvement of nociceptive behaviors. Therefore, we concluded that ZC3H15 may be a potential target for the management of BCP.

Arsenic and Chromium Induced Toxicity on Zebrafish Kidney: Mixture Effects on Oxidative Stress and Involvement of Nrf2-Keap1-ARE, DNA Repair, and Intrinsic Apoptotic Pathways

In polluted water, cooccurrences of two carcinogens, arsenic (As) and chromium (Cr), are extensively reported. Individual effects of these heavy metals have been reported in kidney of fishes, but underlying molecular mechanisms are not well established. There is no report on combined exposure of As and Cr in kidney. Thus, the present study investigated and compared individual and combined effects of As and Cr on zebrafish (Danio rerio) kidney treating at their environmentally relevant concentrations for 15, 30, and 60 days. Increased ROS levels, lipid peroxidation, GSH level, and decreased catalase activity implied oxidative stress in treated zebrafish kidney. Damage in histoarchitecture in treated groups was also noticed. The current study involved gene expression study of Nrf2, an important transcription factor of cellular stress responses along with its negative regulator Keap1 and downstream antioxidant genes nqo1 and ho1. Results indicated activation of Nrf2-Keap1 pathway after combined exposure. Expression pattern of ogg1, apex1, polb, and creb1 revealed the inhibition of base excision repair pathway in treatments. mRNA expression of tumor suppressor genes p53 and brca2 was also altered. Expressional alteration in bax, bcl2, caspase9, and caspase 3 indicated apoptosis (intrinsic pathway) induction, which was maximum in combined group. Inhibition of DNA repair and induction of apoptosis indicated that the activated antioxidant system was not enough to overcome the damage caused by As and Cr. Overall, this study revealed additive effects of As and Cr in zebrafish kidney after chronic exposure focusing cellular antioxidant and DNA damage responses.

Pleiotrophin Prevents H2O2-Induced Senescence of Dental Pulp Stem Cells

BACKGROUND

Dental pulp stem cells (DPSCs) are widely used in research on dental tissue regeneration and systemic disease treatment. However, the oxidative microenvironment often causes cellular senescence, leading to decreased function. Our previous study demonstrated that pleiotrophin (PTN), a secreted extracellular matrix-associated protein, could rescue the proliferative capacity and osteogenic differentiation of replicative senescent DPSCs.

OBJECTIVE

This study aimed to explore the influence and mechanism of PTN on dental pulp stem cells under H2O2-induced oxidative microenvironment.

MATERIALS AND METHODS

DPSCs isolated from human third molars were treated with 100 μm H2O2 for 4 h, mimicking the oxidative microenvironment. To investigate the influence of PTN on DPSC under H2O2-induced oxidative microenvironment, 50 pg/mL PTN was added in the culture medium for 48 h. RT-qPCR, western blotting, SA-β-gal staining, intracellular ROS production and immunofluorescence staining assays were used to analyse the cellular senescence, osteogenic differentiation capacity, oxidative stress conditions and possible mechanism.

RESULTS

H2O2 treatment increased the ratio of SA-β-gal-positive DPSCs and upregulated the senescence-related gene expression, including P53, P21 and P16. PTN pretreatment downregulated the ratio of SA-β-gal-positive DPSCs and the expression of these genes. Besides, PTN pretreatment partially reversed the H2O2-induced decreased osteogenic differentiation potential of DPSCs, total antioxidant capacity and Nrf2 and HO-1 mRNA expression in DPSCs. Western blotting and immunofluorescent staining results indicated that PTN pretreatment enhanced the Nrf2 nuclear translocation under oxidative stress conditions and observable higher fluorescence signals in the nucleus denoted PTN and Nrf2 colocalisation. Western blotting results showed that PTN reversed the decreased expression of p-AKT in the H2O2-induced oxidative environment. However, the PI3K inhibitor LY294002 blocked the upregulated levels of total Nrf2. Immunofluorescence staining displayed that LY294002 also inhibited the nuclear translocation of Nrf2 which was enhanced under PTN pretreatment.

CONCLUSIONS

This study demonstrated that PTN could prevent senescent damage induced by H2O2 on DPSCs, mainly by combining with Nrf2 and enhancing its nuclear translocation.

Tanshinone IIA mitigates postoperative cognitive dysfunction in aged rats by inhibiting hippocampal inflammation and ferroptosis: Role of Nrf2/SLC7A11/GPX4 axis activation

OBJECTIVE

Postoperative cognitive dysfunction (POCD) is a common and debilitating complication in elderly patients following surgery, leading to increased morbidity and reduced quality of life. This study aims to investigate the neuroprotective effects of Tanshinone IIA, a lipophilic compound derived from Salvia miltiorrhiza, in an aged rat model of POCD, and explore its underlying molecular mechanisms.

METHODS

POCD model was established by a modified abdominal exploratory laparotomy. Rats were then intraperitoneally administered with Tanshinone IIA (10 mg/kg, 20 mg/kg, or 40 mg/kg) for 30 days. Cognitive functions were assessed using the morris water maze, novel object recognition test, and Y-maze test. Synaptic structures in the hippocampal CA1 region were examined by electron microscopy. Inflammatory and ferroptosis pathways were evaluated by measuring inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-4), nitric oxide synthase (iNOS) activity, lipid peroxidation products (malondialdehyde [MDA]; 4-hydroxy-2-nonenal [4-HNE]), Fe2 + levels, and antioxidant enzymes (superoxide dismutase [SOD], glutathione [GSH]) using ELISA and commercial kits. mRNA and proteins levels were quantified by real-time quantitative polymerase chain reaction and western blot analysis.

RESULTS

Tanshinone IIA significantly ameliorated cognitive deficits in aged POCD rats according to behavioral tests. It also restored synaptic ultrastructure in the hippocampal CA1 region and upregulated the expressions of synaptic proteins, including synapsin-1 and PSD-95. In addition, Tanshinone IIA effectively suppressed the hippocampal inflammatory pathway, as evidenced by the decreased levels of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), an increased level of the anti-inflammatory cytokine IL-4, and the upregulation of the iNOS/NO pathway in the hippocampus. Furthermore, Tanshinone IIA mitigated ferroptosis by reducing MDA and 4-HNE contents, lowering Fe2+ level, and enhancing SOD activity and GSH level. Notably, Tanshinone IIA activated the Nrf2/SLC7A11/GPX4 axis in the hippocampus of aged POCD rats.

CONCLUSION

These findings suggest that Tanshinone IIA exerts neuroprotective effects in an aged rat model of POCD by attenuating hippocampal inflammation and ferroptosis, primarily through the activation of the Nrf2/SLC7A11/GPX4 axis.

Novel therapeutic strategy: Nrf2 activation in targeting senescence-related changes in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, largely driven by the accumulation of senescent bronchial epithelial cells, which contribute to inflammation and tissue remodeling. This study investigates the therapeutic potential of nuclear factor erythroid 2-related factor 2 (Nrf2) activation in targeting senescence-related changes to alleviate COPD progression.

Methods

Single-cell transcriptome analysis, in vitro COPD cell models, and a COPD mouse model were utilized to examine the effects of Nrf2 activation. Specifically, the study focused on the impact of Nrf2 on senescent ciliated epithelial cells and the associated secretory phenotype. Respiratory function tests and lung pathology assessments were conducted to evaluate the intervention's efficacy in the mouse model.

Results

The study identified a significant presence of senescent ciliated epithelial cells in COPD patients, contributing to disease progression. Nrf2 activation in vitro reduced senescence markers, enhanced cell proliferation, and decreased inflammatory cytokines. In vivo, Nrf2 activation significantly improved lung function and reduced pathological damage in the COPD mouse model.

Conclusions

The findings underscore the potential of Nrf2 activation as a therapeutic strategy to mitigate COPD progression by modulating the senescence-associated secretory phenotype (SASP). This study suggests that Nrf2 activators could offer a promising approach to improving clinical outcomes for COPD patients.

Oxidative Stress Induced by Nuclear Factor Erythroid 2-Related Factor 2 (NRF2) Dysfunction Aggravates Chronic Inflammation Through the NAD+/SIRT3 Axis and Promotes Renal Injury in Diabetes

Diabetic nephropathy (DN), one of the most common and severe microvascular complications of diabetes, significantly increases the risk of renal failure and cardiovascular events. A high-glucose environment can lead to mitochondrial dysfunction in macrophages, which, through remodeling of energy metabolism, mediates the polarization of a pro-inflammatory phenotype and contributes to the formation of a chronic inflammatory microenvironment. Recent studies have found that high-glucose stimulation induces dysregulation of the nuclear factor erythroid 2-related factor 2 (NRF2) redox pathway in macrophages, leading to the generation of oxidative stress (OS) that further drives chronic inflammation. Therefore, it is crucial to fully understand how OS affects macrophage phenotypes and functions following NRF2 inhibition. This review analyzes the role of OS induced by NRF2 dysfunction in the chronic inflammation of DN and explores the relationship between OS and macrophage mitochondrial energy metabolism through the NAD⁺/NADH-SIRT3 axis, providing new therapeutic targets for targeting OS to improve the inflammatory microenvironment and vascular damage in DN.

Scopoletin alleviates acetaminophen-induced hepatotoxicity through modulation of NLRP3 inflammasome activation and Nrf2/HMGB1/TLR4/NF-κB signaling pathway

Scopoleitin (SP), a bioactive compound from many edible plants and fruits, exerts a wide range of biological activities, however the role and mechanism of SP in acetaminophen (APAP)-induced hepatotoxicity remains unclear. In this study, we verified the protective effect of SP on APAP-induced liver injury (AILI) hepatotoxicity and explore the underlying molecular mechanisms. Here, we showed that SP alleviated AILI by reducing serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels, hepatic histopathological damage, inflammation, and liver cell apoptosis. In addition, SP attenuated the accumulation of malondialdehyde (MDA) and exhaustion of glutathione (GSH) levels and increased the superoxide dismutase (SOD) levels induced by APAP. Consistently, SP significantly reduced the gene transcription of cytochrome P450 (CYP)2E1, CYP1A2, and CYP3A11 in the livers of mice induced by APAP. Moreover, SP pretreatment effectively promoted the expression of Nrf2, Keap1, and its signal downstream HO-1, NQO1, GCLc, and GCLm, suggesting the activation of the Nrf2 signaling pathway. SP inhibited APAP-induced hepatocyte apoptosis by regulating the protein levels of apoptosis-related proteins (cytochrome C, Bax, Caspase-3, Bcl2, and PARP). SP suppressed APAP-induced expression of NLRP3 and reduced the levels of proinflammatory factors, including tumor necrosis factor-alpha (TNF-α), F4/80, Caspase-1, and interleukin (IL)-1 beta (IL-1β). Moreover, SP downregulated APAP-induced high-mobility group box 1 (HMGB1) and toll-like receptor 4 (TLR4) expression, inhibited nuclear factor kappa-B (NF-κB) and MAPK activation. Taken together, our study reveals the protective roles of SP against AILI through the downregulation of NLRP3 expression, and the inhibition of the Nrf2/HMGB1/TLR4/NF-κB signaling pathways.

Multi-Omics Reveal the Effects and Regulatory Mechanism of Dietary Magnolol Supplementation on Production Performance of Post-Peak Laying Hens

This study aimed to investigate the therapeutic effects of magnolol on production performance in postpeak laying hens. We divided the hens into three groups (ND, MAG300, MAG500) and conducted a 10-week feeding trial. The results indicated that daily supplementation with magnolol improved the laying rate, reduced the feed-to-egg ratio, controlled liver fat accumulation, and alleviated ovarian oxidative stress and apoptosis. Additionally, 16S rDNA analysis revealed that magnolol increased microbial diversity in the cecum, augmented the abundance of beneficial bacteria, and diminished the abundance of harmful bacteria. Untargeted metabolomics of blood demonstrated that magnolol reduced the concentration of glycerophospholipid-related metabolites while increasing the levels of propionate and amino acid metabolites. Furthermore, liver transcriptome analysis indicated that magnolol inhibited fatty acid synthesis, transport, and elongation, while promoting fatty acid oxidation. These results collectively demonstrate that magnolol can positively regulate the gut-liver-ovary axis to enhance the production performance in laying hens.

Oxidative Stress on the Ground and in the Microgravity Environment: Pathophysiological Effects and Treatment

With the continued exploration of the universe, there is an increasingly urgent need to address the health challenges arising from spaceflight. In space, astronauts are exposed to radiation, confinement and isolation, circadian rhythm dysregulation, and microgravity conditions that are different from those on Earth. These risk factors jeopardize astronauts' health, thus affecting the quality of space missions. Among these factors, gravitational changes influence the balance between oxidation and antioxidants, stimulating the production of reactive oxygen species (ROS), finally leading to oxidative stress (OS). OS leads to oxidative damage of biomolecules such as lipids, proteins, and DNA, which causes the development of various diseases. The occurrence of OS is increased in microgravity and affects multiple systems, including the musculoskeletal, cardiovascular, nervous, and immune systems. In this review, we discuss the mechanisms of OS, the physiological effects on different systems caused by OS in microgravity environment, and potential treatments for OS. Finally, treatment strategies for oxidative stress in microgravity are summarized, providing some promising approaches for protecting the health of astronauts in future space exploration.