NFκB promotes oxidative stress-induced necrosis and ischemia/reperfusion injury by inhibiting Nrf2-ARE pathway

Targeting epigenetic and post-translational modifications of NRF2: key regulatory factors in disease treatment

Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor involved in regulating cellular antioxidant defense and detoxification mechanisms. It mitigates oxidative stress and xenobiotic-induced damage by inducing the expression of cytoprotective enzymes, including HO-1 and NQO1. NRF2 also modulates inflammatory responses by inhibiting pro-inflammatory genes and mediates cell death pathways, including apoptosis and ferroptosis. Targeting NRF2 offers potential therapeutic avenues for treating various diseases. NRF2 is regulated through two principal mechanisms: post-translational modifications (PTMs) and epigenetic alterations. PTMs, including phosphorylation, ubiquitination, and acetylation, play a pivotal role in modulating NRF2's stability, activity, and subcellular localization, thereby precisely controlling its function in the antioxidant response. For instance, ubiquitination can lead to NRF2 degradation and reduced antioxidant activity, while deubiquitination enhances its stability and function. Epigenetic modifications, such as DNA methylation, histone modifications, and interactions with non-coding RNAs (e.g., MALAT1, PVT1, MIR4435-2HG, and TUG1), are essential for regulating NRF2 expression by modulating chromatin architecture and gene accessibility. This paper systematically summarizes the molecular mechanisms by which PTMs and epigenetic alterations regulate NRF2, and elucidates its critical role in cellular defense and disease. By analyzing the impact of PTMs, such as phosphorylation, ubiquitination, and acetylation, as well as DNA methylation, histone modifications, and non-coding RNA interactions on NRF2 stability, activity, and expression, the study reveals the complex cellular protection network mediated by NRF2. Furthermore, the paper explores how these regulatory mechanisms affect NRF2's roles in oxidative stress, inflammation, and cell death, identifying novel therapeutic targets and strategies. This provides new insights into the treatment of NRF2-related diseases, such as cancer, neurodegenerative disorders, and metabolic syndrome. This research deepens our understanding of NRF2's role in cellular homeostasis and lays the foundation for the development of NRF2-targeted therapies.

The Inhibition of Prolyl Endopeptidase (PREP) by KYP-2047 Treatment to Reduce Myocardial Ischemia/Reperfusion Injury

Myocardial ischemia-reperfusion injury (MI/R) is a negative and adverse cardiovascular outcome following myocardial ischemia, cardiac surgery, or circulatory arrest. Prolyl endopeptidase (PREP) appears to be involved in inflammatory responses, so it could be a possible therapeutic target for counteracting ischemia injury. This study aimed to investigate the role of PREP inhibitor, KYP-2047 (4-phenylbutanoyl-l-prolyl-2(S)-cyanopyrolidine), in the modulation of molecular and biochemical processes involved in MI/R. MI/R was induced through coronary artery occlusion (15 min), followed by reperfusion (2 h). KYP-2047 was intraperitoneally administrated at doses of 2.5 mg/kg and 5 mg/kg 24 h before the surgical procedures. The hearts were removed and processed for analysis. KYP-2047 treatment limited ischemic myocardial-induced histological damage and neutrophil accumulation, limiting inflammation, fibrosis, and apoptosis processes. Additionally, KYP-2047 was able to modulate p-38 and p-ERK expression, suggesting an improving role in recovering cardiac function. These findings highlighted the protective effects of KYP-2047 pretreatment in MI/R injury, suggesting PREP as a potential target therapy for the pathogenesis of MI/R. Although the molecular mechanisms underlying the action of KYP-2047 are still to be explored, these results suggested that the regulation of NF-κB, apoptosis, and MAPK pathways by KYP-2047 treatment could preventatively limit the damage caused by MI/R.

The involvement of HDAC3 in the pathogenesis of lung injury and pulmonary fibrosis

Acute lung injury (ALI) and its severe counterpart, acute respiratory distress syndrome (ARDS), are critical respiratory conditions with high mortality rates due primarily to acute and intense pulmonary inflammation. Despite significant research advances, effective pharmacological treatments for ALI and ARDS remain unavailable, highlighting an urgent need for therapeutic innovation. Notably, idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the irreversible progression of fibrosis, which is initiated by repeated damage to the alveolar epithelium and leads to excessive extracellular matrix deposition. This condition is further complicated by dysregulated tissue repair and fibroblast dysfunction, exacerbating tissue remodeling processes and promoting progression to terminal pulmonary fibrosis. Similar to that noted for ALI and ARDS, treatment options for IPF are currently limited, with no specific drug therapy providing a cure. Histone deacetylase 3 (HDAC3), a notable member of the HDAC family with four splice variants (HD3α, -β, -γ, and -δ), plays multiple roles. HDAC3 regulates gene transcription through histone acetylation and adjusts nonhistone proteins posttranslationally, affecting certain mitochondrial and cytoplasmic proteins. Given its unique structure, HDAC3 impacts various physiological processes, such as inflammation, apoptosis, mitochondrial homeostasis, and macrophage polarization. This article explores the intricate role of HDAC3 in ALI/ARDS and IPF and evaluates its therapeutic potential the treatment of these severe pulmonary conditions.

Role of M6a Methylation in Myocardial Ischemia-Reperfusion Injury and Doxorubicin-Induced Cardiotoxicity

Cardiovascular disease remains the leading cause of death worldwide, with acute myocardial infarction and anticancer drug-induced cardiotoxicity being the significant factors. The most effective treatment for acute myocardial infarction is rapid restoration of coronary blood flow by thrombolytic therapy or percutaneous coronary intervention. However, myocardial ischemia-reperfusion injury (MI/RI) after reperfusion therapy is common in acute myocardial infarction, thus affecting the prognosis of patients with acute myocardial infarction. There is no effective treatment for MI/RI. Anthracyclines such as Doxorubicin (DOX) have limited clinical use due to their cardiotoxicity, and the mechanism of DOX-induced cardiac injury is complex and not yet fully understood. N6-methyladenosine (m6A) plays a crucial role in many biological processes. Emerging evidence suggests that m6A methylation plays a critical regulatory role in MI/RI and DOX-induced cardiotoxicity (DIC), suggesting that m6A may serve as a novel biomarker and therapeutic target for MI/RI and DIC. M6A methylation may mediate the pathophysiological processes of MI/RI and DIC by regulating cellular autophagy, apoptosis, oxidative stress, and inflammatory response. In this paper, we first focus on the relationship between m6A methylation and MI/RI, then further elucidate that m6A methylation may mediate the pathophysiological process of MI/RI through the regulation of cellular autophagy, apoptosis, oxidative stress, and inflammatory response. Finally, briefly outline the roles played by m6A in DIC, which will provide a new methodology and direction for the research and treatment of MI/RI and DIC.

Therapeutic Potential of Natural Compounds Acting through Epigenetic Mechanisms in Cardiovascular Diseases: Current Findings and Future Directions

Cardiovascular diseases (CVDs) remain a leading global cause of morbidity and mortality. These diseases have a multifaceted nature being influenced by a multitude of biochemical, genetic, environmental, and behavioral factors. Epigenetic modifications have a crucial role in the onset and progression of CVD. Epigenetics, which regulates gene activity without altering the DNA's primary structure, can modulate cardiovascular homeostasis through DNA methylation, histone modification, and non-coding RNA regulation. The effects of environmental stimuli on CVD are mediated by epigenetic changes, which can be reversible and, hence, are susceptible to pharmacological interventions. This represents an opportunity to prevent diseases by targeting harmful epigenetic modifications. Factors such as high-fat diets or nutrient deficiencies can influence epigenetic enzymes, affecting fetal growth, metabolism, oxidative stress, inflammation, and atherosclerosis. Recent studies have shown that plant-derived bioactive compounds can modulate epigenetic regulators and inflammatory responses, contributing to the cardioprotective effects of diets. Understanding these nutriepigenetic effects and their reversibility is crucial for developing effective interventions to combat CVD. This review delves into the general mechanisms of epigenetics, its regulatory roles in CVD, and the potential of epigenetics as a CVD therapeutic strategy. It also examines the role of epigenetic natural compounds (ENCs) in CVD and their potential as intervention tools for prevention and therapy.

Effects of replacing fishmeal with soybean meal on the immune and antioxidant capacity, and intestinal metabolic functions of red swamp crayfish Procambarus clarkii

Excess utilization of plant protein sources in animal feed has been found to adversely affect the antioxidant properties and immunity of animals. While the role of gut microbes in plant protein-induced inflammation has been identified in various models, the specific mechanisms regulating gut microbes in crustaceans remain unclear. Accordingly, this study was designed to investigate the effects of replacing fishmeal with soybean meal (SM) on the hepatopancreas antioxidant and immune capacities, and gut microbial functions of crayfish, as well as the potential microbial regulatory mechanisms. 750 crayfish (4.00 g) were randomly divided into five groups: SS0, SS25, SS50, SS75, and SS100, and fed diets with different levels of soybean meal substituted for fishmeal for six weeks. High SM supplementation proved detrimental to maintaining hepatopancreas health, as indicated by an increase in hemolymph MDA content, GPT, and GOT activities, the observed rupture of hepatopancreas cell basement membranes, along with the decreased number of hepatopancreatic F cells. Moreover, crayfish subjected to high SM diets experienced obvious inflammation in hepatopancreas, together with up-regulated mRNA expression levels of nfkb, alf, and tlr (p<0.05), whereas the lzm mRNA expression level exhibited the highest value in the SS25 group. Furthermore, hepatopancreas antioxidant properties highly attenuated by the level of dietary SM substitution levels, as evidenced by the observed increase in MDA content (p<0.05), decrease in GSH content (p<0.05), and inhabitation of SOD, CAT, GPx, and GST activities (p<0.05), along with down-regulated hepatopancreas cat, gpx, gst, and mmnsod mRNA expression levels via inhibiting nrf2/keap1 pathway. Functional genes contributing to metabolism identified that high SM diets feeding significantly activated lipopolysaccharide biosynthesis, revealing gut dysfunction acted as the cause of inflammation. The global microbial co-occurrence network further indicated that the microbes contributing more to serum indicators and immunity were in module eigengene 17 (ME17). A structural equation model revealed that the genes related to alf directly drove the serum enzyme activities through microbes in ME17, with OTU399 and OTU533 identified as major biomarkers and classified into Proteobacteria that secrete endotoxins. To conclude, SM could replace 25 % of fishmeal in crayfish diets without negatively affecting immunity, and antioxidant capacity. Excessive SM levels contributed to gut dysfunction and weakened the innate immune system of crayfish.

Histone deacetylase 3-specific inhibitor RGFP966 attenuates oxidative stress and inflammation after traumatic brain injury by activating the Nrf2 pathway

Background

Oxidative stress (OS) and inflammatory reactions play pivotal roles in secondary brain injury after traumatic brain injury (TBI). Histone deacetylase 3 (HDAC3) controls the acetylation of histones and non-histones, which has a significant impact on the central nervous system's reaction to damage. This research determined the implications of RGFP966, a new and specific inhibitor of HDAC3, for the antioxidant (AO) systems mediated by nuclear factor erythroid2-related factor 2 (Nrf2) and the Nod-like receptor protein 3 (NLRP3) inflammasome in TBI. The study also studied the underlying mechanisms of RGFP966's actions. Our objective was to examine the impacts and underlying RGFP966 mechanisms in TBI.

Methods

In vitro, a rat cortical neuron OS model was induced by H2O2, followed by the addition of RGFP966 to the culture medium. Neurons were collected after 24 h for western blot (WB), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and 2'-7'-dichlorodihydrofluorescein diacetate staining. In vivo, RGFP966 (10 mg/kg) was administered post-TBI. Brain tissue water content and modified neurological severity scores were assessed 72 h post-injury. Cortical tissues surrounding the focal injury were subjected to western blot, TUNEL staining, Nissl staining and immunofluorescence/immunohistochemistry staining, and malondialdehyde level, hindered glutathione content and superoxide dismutase activity were measured. Serum was collected for the enzyme-linked immunosorbent assay. Nrf2-specific shRNA lentivirus was injected into the lateral ventricle of rats for 7 days, and cerebral cortex tissue was analyzed by WB and real-time polymerase chain reaction.

Results

During in vitro and in vivo experiments, RGFP966 suppressed HDAC3 expression, promoted Nrf2 nuclear translocation, activated downstream AO enzymes, mitigated excessive reactive oxygen species production and alleviated nerve cell apoptosis. RGFP966 effectively reduced brain edema and histological damage and enhanced neurological and cognitive function in rats with TBI. RGFP966 markedly inhibited NLRP3 inflammasome activation mediated by high-mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4). Nrf2 knockdown in TBI rats attenuated the AO and anti-inflammatory, neuroprotective impacts of RGFP966.

Conclusions

Overall, our findings demonstrate that RGFP966 can mitigate the first brain damage and neurological impairments in TBI. The underlying mechanism involves triggering the Nrf2-mediated AO system and negatively regulating the HMGB1/TLR4-mediated NLRP3 inflammasome pathway.

Potential Targets of Natural Products for Improving Cardiac Ischemic Injury: The Role of Nrf2 Signaling Transduction

Myocardial ischemia is the leading cause of health loss from cardiovascular disease worldwide. Myocardial ischemia and hypoxia during exercise trigger the risk of sudden exercise death which, in severe cases, will further lead to myocardial infarction. The Nrf2 transcription factor is an important antioxidant regulator that is extensively engaged in biological processes such as oxidative stress, inflammatory response, apoptosis, and mitochondrial malfunction. It has a significant role in the prevention and treatment of several cardiovascular illnesses, since it can control not only the expression of several antioxidant genes, but also the target genes of associated pathological processes. Therefore, targeting Nrf2 will have great potential in the treatment of myocardial ischemic injury. Natural products are widely used to treat myocardial ischemic diseases because of their few side effects. A large number of studies have shown that the Nrf2 transcription factor can be used as an important way for natural products to alleviate myocardial ischemia. However, the specific role and related mechanism of Nrf2 in mediating natural products in the treatment of myocardial ischemia is still unclear. Therefore, this review combs the key role and possible mechanism of Nrf2 in myocardial ischemic injury, and emphatically summarizes the significant role of natural products in treating myocardial ischemic symptoms, thus providing a broad foundation for clinical transformation.

Uncoupling Protein 2 Alleviates Myocardial Ischemia/Reperfusion Injury by Inhibiting Cardiomyocyte Ferroptosis

INTRODUCTION

Following our recent finding that Ucp2 knockout promotes ferroptosis, we aimed to examine whether UCP2 alleviates myocardial ischemia/reperfusion injury (MI/RI) by inhibiting ferroptosis.

METHODS

The left anterior descending coronary arteries of wild-type and Ucp2-/- C57BL/6 mice were ligated for 30 min and reperfused for 2 h to establish an MI/RI model. The effects of UCP2 on ferroptosis and MI/RI were determined by echocardiography, 2,3,5-triphenylttrazolium chloride staining, hematoxylin-eosin staining, Masson's trichrome staining, Sirius red staining, and analysis of myocardial injury markers and ferroptosis indicators. Ferrostatin-1 (Fer-1) and erastin (Era) were used to investigate whether UCP2 alleviated MI/RI by inhibiting ferroptosis and the molecular mechanism.

RESULTS

UCP2 was upregulated in the MI/RI model in WT mice. Deletion of Ucp2 exacerbated ferroptosis, altered the expression levels of multiple ferroptosis-related genes, and significantly exacerbated MI/RI. Knockout of Ucp2 promoted ferroptosis induced by Era and inhibited the antiferroptotic effects of Fer-1. Knockout of Ucp2 activated the p53/TfR1 pathway to exacerbate ferroptosis.

CONCLUSION

Our results showed that UCP2 inhibited ferroptosis in MI/RI, which might be related to regulation of the p53/TfR1 pathway.

Roles of reactive oxygen species in inflammation and cancer

Reactive oxygen species (ROS) constitute a spectrum of oxygenic metabolites crucial in modulating pathological organism functions. Disruptions in ROS equilibrium span various diseases, and current insights suggest a dual role for ROS in tumorigenesis and the immune response within cancer. This review rigorously examines ROS production and its role in normal cells, elucidating the subsequent regulatory network in inflammation and cancer. Comprehensive synthesis details the documented impacts of ROS on diverse immune cells. Exploring the intricate relationship between ROS and cancer immunity, we highlight its influence on existing immunotherapies, including immune checkpoint blockade, chimeric antigen receptors, and cancer vaccines. Additionally, we underscore the promising prospects of utilizing ROS and targeting ROS modulators as novel immunotherapeutic interventions for cancer. This review discusses the complex interplay between ROS, inflammation, and tumorigenesis, emphasizing the multifaceted functions of ROS in both physiological and pathological conditions. It also underscores the potential implications of ROS in cancer immunotherapy and suggests future research directions, including the development of targeted therapies and precision oncology approaches. In summary, this review emphasizes the significance of understanding ROS-mediated mechanisms for advancing cancer therapy and developing personalized treatments.

Sustained activation of NF-κB through constitutively active IKKβ leads to senescence bypass in murine dermal fibroblasts

Although the transcription factor nuclear factor κB (NF-κB) plays a central role in the regulation of senescence-associated secretory phenotype (SASP) acquisition, our understanding of the involvement of NF-κB in the induction of cellular senescence is limited. Here, we show that activation of the canonical NF-κB pathway suppresses senescence in murine dermal fibroblasts. IκB kinase β (IKKβ)-depleted dermal fibroblasts showed ineffective NF-κB activation and underwent senescence more rapidly than control cells when cultured under 20% oxygen conditions, as indicated by senescence-associated β-galactosidase (SA-β-gal) staining and p16INK4a mRNA levels. Conversely, the expression of constitutively active IKKβ (IKKβ-CA) was sufficient to drive senescence bypass. Notably, the expression of a degradation-resistant form of inhibitor of κB (IκB), which inhibits NF-κB nuclear translocation, abolished senescence bypass, suggesting that the inhibitory effect of IKKβ-CA on senescence is largely mediated by NF-κB. We also found that IKKβ-CA expression suppressed the derepression of INK4/Arf genes and counteracted the senescence-associated loss of Ezh2, a catalytic subunit of the Polycomb repressive complex 2 (PRC2). Moreover, pharmacological inhibition of Ezh2 abolished IKKβ-CA-induced senescence bypass. We propose that NF-κB plays a suppressive role in the induction of stress-induced senescence through sustaining Ezh2 expression.

Bu-Shen-Tian-Jing formulas alleviate the mitochondrial damage induced by oxidative stress in ovarian granulosa cells exposed to DEHP through the HDAC3-HSP90AA pathway

CONTEXT

di-(2-Ethylhexyl) phthalate (DEHP) has potential reproductive toxicity. Bu-Shen-Tian-Jing formulations (BSTJFs) are beneficial for female reproductive capacity. However, BSTJF2 has much lower cytotoxicity than BSTJF1.

OBJECTIVE

To investigate the effects of BSTJFs on ovarian granulosa cells exposed to DEHP and determine the potential molecular mechanisms.

METHODS AND MATERIALS

Human granulosa-like tumor cell line (KGN) cells were divided into control, DEHP, BSTJF1 and BSTJF2 groups. The DEHP group were given 1 μM DEHP for 24 h. They were then given BSTJF1 at 200 μg/mL or BSTJF2 at 100 μg/mL for 24 h. The control group was treated with the same concentration of DMSO (0.1%). Oxidative stress and mitochondrial function were measured. The mRNA and protein expression levels of HDAC3 and HSP90AA were determined. Integrative network pharmacology analysis of BSTJF2 was also performed.

RESULTS

DEHP (1 μM) significantly suppressed the proliferation of KGN cells by 17%, significantly increased ROS levels by 28% and MDA levels by 47%, significantly decreased MMP levels by 22% and mtDNA copy by 30%. DEHP significantly increased protein expression of HDAC3 by 21%and HSP90AA by 64%. All these changes were significantly reversed by BSTJFs. Integrative network pharmacology analysis revealed HSP90AA was a key target (degree = 8). Both RGFP966 and BSTJF2 significantly reversed the increased expression of HDAC3 and HSP90AA, attenuated oxidative stress, and mitochondrial damage which were induced by DEHP.

CONCLUSION

BSTJFs might have therapeutic potential on oxidative stress and mitochondrial damage through the HDAC3/HSP90AA pathway which encourages further clinical trials.

The crosstalk between Nrf2 and NF-κB pathways in coronary artery disease: Can it be regulated by SIRT6?

Coronary artery disease (CAD) is the leading cause of death worldwide. Oxidative stress and inflammation are major mechanisms responsible for the progression of CAD. Nuclear transcription factor erythroid-2 related factor 2 (Nrf2) is a transcription factor that modulates the cellular redox status. Nrf2 upregulation increases the expression of antioxidant genes, decreases the expression of Nuclear factor-kappa B (NF-kB), and increases free radical metabolism. Activated NF-kB increases the production of inflammatory cytokines causing endothelial dysfunction. The two pathways of Nrf2 and NF-kB can regulate the expression of each other. Foremost, the Nrf2 pathway can decrease the level of active NF-κB by increasing the level of antioxidants and cytoprotective enzymes. Furthermore, the Nrf2 pathway prevents IκB-α degradation, an inhibitor of NF-kB, and thus inhibits NF-κB mediated transcription. Also, NF-kB transcription inhibits Nrf2 activation by reducing the antioxidant response element (ARE) transcription. Sirtuin 6 (SIRT6) is a member of the Sirtuins family that was found to protect against cardiovascular diseases. SIRT6 can suppress the production of Reactive oxygen species (ROS) through deacetylation of NRF2 which results in NRF2 activation. Furthermore, SIRT6 can inhibit the inflammatory process through the downregulation of NF-kB transcription. Therefore, targeting sirtuins could be a therapeutic strategy to treat CAD. This review describes the potential role of SIRT6 in regulating the crosstalk between NRF2 and NF-kB signaling pathways in CAD.

SHARPIN Enhances Ferroptosis in Synovial Sarcoma Cells via NF-κB- and PRMT5-Mediated PGC1α Reduction

Sarcoma is a rare type of cancer for which new therapeutic agents are required. Ferroptosis is a nonapoptotic cell death triggered by iron-mediated lipid peroxidation. We found that TFRC, an iron uptake protein, was expressed at higher levels in sarcoma cell lines than in noncancer and carcinoma cell lines. Glutathione peroxidase 4 (GPX4) protects cells against ferroptosis, and its inhibition using RAS-selective lethal 3 (RSL3) had an antitumor effect that was more pronounced in sarcoma cell lines, particularly synovial sarcoma cells, compared to non-sarcoma cells. Because NF-κB can provoke ferroptosis, we examined the role of SHARPIN, an activator of NF-κB, in sarcoma. We found that SHARPIN expression was significantly associated with reduced survival in cohorts of patients with cancer, including sarcoma. In addition, SHARPIN promoted the sensitivity of sarcoma cells to ferroptosis. Further analyses revealed that the PGC1α/NRF2/SLC7A11 axis and BNIP3L/NIX-mediated mitophagy are regulated through NF-κB and PRMT5 downstream of SHARPIN. Our findings suggest that ferroptosis could have a therapeutic effect in sarcoma, particularly in subpopulations with high TFRC and SHARPIN expression.

Ultrashort wave alleviates oxygenglucose deprivation/reoxygenation injury via upregulation of SPCA1 expression in N2a cells

OBJECTIVES

Application of ultrashort wave (USW) to rats with cerebral ischemia and reperfusion injury could inhibit the decrease of expression of secretory pathway Ca2+-ATPase 1 (SPCA1), an important participant in Golgi stress, reduce the damage of Golgi apparatus and the apoptosis of neuronal cells, thereby alleviating cerebral ischemia-reperfusion injury. This study aims to investigate the effect of USW on oxygen-glucose deprivation/reperfusion (OGD/R) injury and the expression of SPCA1 at the cellular level.

METHODS

N2a cells were randomly divided into a control (Con) group, an OGD/R group, and an USW group. The cells in the Con group were cultured without exposure to OGD. The cells in the OGD/R group were treated with OGD/R. The cells in the USW group were treated with USW after OGD/R. Cell morphology was observed under the inverted phase-contrast optical microscope, cell activity was detected by cell counting kit-8 (CCK-8), apoptosis was detected by flow cytometry, and SPCA1 expression was detected by Western blotting.

RESULTS

Most of the cells in the Con group showed spindle shape with a clear outline and good adhesion. In the OGD/R group, cells were wrinkled, with blurred outline, poor adhesion, and lots of suspended dead cells appeared; compared with the OGD/R group, the cell morphology and adherence were improved, with clearer outlines and fewer dead cells in the USW group. Compared with the Con group, the OGD/R group showed decreased cell activity, increased apoptotic rate, and down-regulating SPCA1 expression with significant differences (all P<0.001); compared with the OGD/R group, the USW group showed increased cell activity, decreased apoptotic rate, and up-regulating SPCA1 expression with significant differences (P<0.01 or P<0.001).

CONCLUSIONS

USW alleviates the injury of cellular OGD/R, and its protective effect may be related to its up-regulation of SPCA1 expression.

Rhodiola wallichiana var.cholaensis protects against myocardial ischemia-reperfusion injury by attenuating oxidative stress-mediated apoptosis via enhancing Nrf2 signaling

The present study aimed to explore the cardioprotective effects of Rhodiola wallichiana var.cholaensis (RW) against hypoxia/reoxygenation (H/R)-induced H9c2 cell injury and ischemia/reperfusion (I/R)-induced myocardial injury. Following treatment with RW, H9c2 cells were subjected to 4 h of hypoxia/3 h of reoxygenation. MTT assay, LDH assay, and flow cytometry were employed to detect cell viability and changes of ROS and mitochondrial membrane potential. Moreover, after RW treatment, rats underwent 30 min of ischemia, followed by 120 min of reperfusion. Masson and TUNEL staining were performed to measure myocardial damage and apoptosis, respectively. The changes in the levels of proteins were detected by ELISA and western blot. The results showed that RW attenuated the H/R-induced increase in LDH release and loss of the mitochondrial membrane potential, as well as the apoptosis in H9c2 cells. Meanwhile, RW significantly reduces the ST-segment elevation and improves cardiomyocytes' injury, inhibit the apoptosis induced by I/R in rats. Furthermore, RW could decrease the levels of MDA and increase the levels of SOD, T-AOC. GSH-Px and GSH both in vivo and in vitro. Besides, RW increased the expressions of Nrf2, HO-1, ARE and NQO1, and decreased the expressions of Keap1, activating the Nrf2 signaling pathway. Taken together, these results suggested that RW exerts cardioprotection on H/R injury in H9c2 cells and I/R injury in rats by attenuating oxidative stress-mediated apoptosis via enhancing Nrf2 signaling.

The role of HDAC3 and its inhibitors in regulation of oxidative stress and chronic diseases

HDAC3 is a specific and crucial member of the HDAC family. It is required for embryonic growth, development, and physiological function. The regulation of oxidative stress is an important factor in intracellular homeostasis and signal transduction. Currently, HDAC3 has been found to regulate several oxidative stress-related processes and molecules dependent on its deacetylase and non-enzymatic activities. In this review, we comprehensively summarize the knowledge of the relationship of HDAC3 with mitochondria function and metabolism, ROS-produced enzymes, antioxidant enzymes, and oxidative stress-associated transcription factors. We also discuss the role of HDAC3 and its inhibitors in some chronic cardiovascular, kidney, and neurodegenerative diseases. Due to the simultaneous existence of enzyme activity and non-enzyme activity, HDAC3 and the development of its selective inhibitors still need further exploration in the future.

Zinc stabilized Nrf2 by inhibition of HDAC3 in human peripheral blood mononuclear cells

BACKGROUND

The transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) induces several detoxifying proteins, which also include NAD(P)H quinone dehydrogenase 1 (NQO1) and heme oxygenase 1 (HO-1). The expression of these Nrf2-regulated proteins is important for the maintenance of the redox homeostasis in cells. The aim of this study was to investigate the effect of tert-butyl-hydrochinone (tBHQ) stimulation on human PBMC under normal condition and zinc depletion, respectively.

METHOD

Human peripheral blood mononuclear cells (PBMC) were treated with the Nrf2 activator tBHQ in combination with zinc to examine a possible correlation between zinc and redox homeostasis. Therefore, mRNA expression of Nrf2 and its downstream molecules NQO1 and HO-1 were investigated, as well as the protein synthesis of these. In addition, the effect of zinc on histone deacetylase 3 (HDAC3), which is a negative regulator for Nrf2 activity, was analyzed.

RESULTS

Either mRNA, protein expression or both of Nrf2, NQO1 and HO-1 are influenced by zinc. The analysis of HDAC3 shows a negative correlation between its activity and increasing zinc concentrations. By inhibiting HDAC3 zinc stabilizes Nrf2.

CONCLUSION

The results indicate that zinc emphasizes the induction of Nrf2 by its activator tBHQ through increasing gene and protein expression. Additionally, zinc supplementation inhibits HDAC3 activity resulting in reduced Keap1 mRNA expression and thereby stabilizing cytoplasmatic Nrf2. These findings suggests that zinc supplementation has beneficial effects on the redox balance in human cells.

Demonstration of doxorubicin's cardiotoxicity and screening using a 3D bioprinted spheroidal droplet-based system

Doxorubicin (DOX) is a highly effective anthracycline chemotherapy agent effective in treating a broad range of life-threatening malignancies but it causes cardiotoxicity in many subjects. While the mechanism of its cardiotoxic effects remains elusive, DOX-related cardiotoxicity can lead to heart failure in patients. In this study, we investigated the effects of DOX-induced cardiotoxicity on human cardiomyocytes (CMs) using a three-dimensional (3D) bioprinted cardiac spheroidal droplet based-system in comparison with the traditional two-dimensional cell (2D) culture model. The effects of DOX were alleviated with the addition of N-acetylcysteine (NAC) and Tiron. Caspase-3 activity was quantified, and reactive oxygen species (ROS) production was measured using dihydroethidium (DHE) staining. Application of varying concentrations of DOX (0.4 μM-1 μM) to CMs revealed a dose-specific response, with 1 μM concentration imposing maximum cytotoxicity and 0.22 ± 0.11% of viable cells in 3D samples versus 1.02 ± 0.28% viable cells in 2D cultures, after 5 days of culture. Moreover, a flow cytometric analysis study was conducted to study CMs proliferation in the presence of DOX and antioxidants. Our data support the use of a 3D bioprinted cardiac spheroidal droplet as a robust and high-throughput screening model for drug toxicity. In the future, this 3D spheroidal droplet model can be adopted as a human-derived tissue-engineered equivalent to address challenges in other various aspects of biomedical pre-clinical research.

Expression Pattern and Molecular Mechanism of Oxidative Stress-Related Genes in Myocardial Ischemia-Reperfusion Injury

(1) Background: The molecular mechanism of oxidative stress-related genes (OSRGs) in myocardial ischemia-reperfusion injury (MIRI) has not been fully elucidated. (2) Methods: Differential expression analysis, enrichment analysis, and PPI analysis were performed on the MIRI-related datasets GSE160516 and GSE61592 to find key pathways and hub genes. OSRGs were obtained from the Molecular Signatures Database (MSigDB). The expression pattern and time changes of them were studied on the basis of their raw expression data. Corresponding online databases were used to predict miRNAs, transcription factors (TFs), and therapeutic drugs targeting common differentially expressed OSRGs. These identified OSRGs were further verified in the external dataset GSE4105 and H9C2 cell hypoxia-reoxygenation (HR) model. (3) Results: A total of 134 DEGs of MIRI were identified which were enriched in the pathways of "immune response", "inflammatory response", "neutrophil chemotaxis", "phagosome", and "platelet activation". Six hub genes and 12 common differentially expressed OSRGs were identified. A total of 168 miRNAs, 41 TFs, and 21 therapeutic drugs were predicted targeting these OSRGs. Lastly, the expression trends of Aif1, Apoe, Arg1, Col1a1, Gpx7, and Hmox1 were confirmed in the external dataset and HR model. (4) Conclusions: Aif1, Apoe, Arg1, Col1a1, Gpx7, and Hmox1 may be involved in the oxidative stress mechanism of MIRI, and the intervention of these genes may be a potential therapeutic strategy.

Sestrin2 Signaling Pathway Regulates Podocyte Biology and Protects against Diabetic Nephropathy

Sestrin2 regulates cell homeostasis and is an upstream signaling molecule for several signaling pathways. Sestrin2 leads to AMP-activated protein kinase- (AMPK-) and GTPase-activating protein activity toward Rags (GATOR) 1-mediated inhibition of mammalian target of rapamycin complex 1 (mTORC1), thereby enhancing autophagy. Sestrin2 also improves mitochondrial biogenesis via AMPK/Sirt1/peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) signaling pathway. Blockade of ribosomal protein synthesis and augmentation of autophagy by Sestrin2 can prevent misfolded protein accumulation and attenuate endoplasmic reticulum (ER) stress. In addition, Sestrin2 enhances P62-mediated autophagic degradation of Keap1 to release nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 release by Sestrin2 vigorously potentiates antioxidant defense in diabetic nephropathy. Impaired autophagy and mitochondrial biogenesis, severe oxidative stress, and ER stress are all deeply involved in the development and progression of diabetic nephropathy. It has been shown that Sestrin2 expression is lower in the kidney of animals and patients with diabetic nephropathy. Sestrin2 knockdown aggravated diabetic nephropathy in animal models. In contrast, upregulation of Sestrin2 enhanced autophagy, mitophagy, and mitochondrial biogenesis and suppressed oxidative stress, ER stress, and apoptosis in diabetic nephropathy. Consistently, overexpression of Sestrin2 ameliorated podocyte injury, mesangial proliferation, proteinuria, and renal fibrosis in animal models of diabetic nephropathy. By suppressing transforming growth factor beta (TGF-β)/Smad and Yes-associated protein (YAP)/transcription enhancer factor 1 (TEF1) signaling pathways in experimental models, Sestrin2 hindered epithelial-mesenchymal transition and extracellular matrix accumulation in diabetic kidneys. Moreover, modulation of the downstream molecules of Sestrin2, for instance, augmentation of AMPK or Nrf2 signaling and inhibition of mTORC1, has been protective in diabetic nephropathy. Regarding the beneficial effects of Sestrin2 on diabetic nephropathy and its interaction with several signaling molecules, it is worth targeting Sestrin2 in diabetic nephropathy.

Oridonin Protects against Myocardial Ischemia-Reperfusion Injury by Inhibiting GSDMD-Mediated Pyroptosis

Pyroptosis serves a crucial function in various types of ischemia and reperfusion injuries. Oridonin, a tetracycline diterpene derived from Rabdosia rubescens, can significantly inhibit the aggregation of NLRP3-mediated inflammasome. This experiment is aimed at investigating the effect of oridonin on pyroptosis in mice cardiomyocytes. Based on the models of myocardial ischemia/reperfusion (I/R) and hypoxia/reoxygenation (H/R), Evans Blue/TTC double staining, TUNEL staining, and Western blotting were applied to determine the effects of oridonin on myocardial damage, cellular activity and signaling pathways involved in pyroptosis. During I/R and H/R treatments, the extent of gasdermin D-N domains was upregulated in cardiomyocytes. Apart from that, oridonin improved cell survival in vitro and decreased the myocardial infarct size in vivo by also downregulating the activation of pyroptosis. Finally, the expression levels of ASC, NLRP3 and p-p65 were markedly upregulated in cardiomyocytes after H/R treatment, whereas oridonin suppressed the expression of these proteins. The present experiment revealed that myocardial I/R injury and pyroptosis can be alleviated and inhibited by oridonin pretreatment via NF-κB/NLRP3 signaling pathway, both in vivo and in vitro. Therefore, oridonin may serve as a potentially novel agent for the clinical treatment of myocardial ischemia-reperfusion injuries.

Melatonin suppresses ferroptosis via activation of the Nrf2/HO-1 signaling pathway in the mouse model of sepsis-induced acute kidney injury

BACKGROUND

Ferroptosis is a regulated form of cell death. At present, the role of ferroptosis in sepsis-induced acute kidney injury (SAKI) has not been studied. Melatonin (MEL) has been reported to be an effective ferroptosis inhibitor, but it is unclear whether Melatonin can regulate ferroptosis in SAKI and whether its downstream mechanism correlates with the Nrf2/HO-1 pathway.

METHODS

The cecal ligation and puncture (CLP) method and LPS injection were used to induce SAKI in mouse model. Ferroptosis markers, including malondialdehyde (MDA) and glutathione peroxidase 4 (GPX4), were assessed. The ferroptosis inhibitor ferrostatin-1 (Fer-1) was used to explore the role of ferroptosis in SAKI. The GPX4 inhibitor RSL3, the HO-1 inhibitor zinc protoporphyrin(ZnPP), and the Nrf2 inhibitor ML385 were used to explore the specific mechanism of MEL in alleviation of SAKI.

RESULTS

The ferroptosis level was increased in the renal tissue of CLP- and LPS-induced septic mice. Both Fer-1 and MEL administration could suppress ferroptosis and attenuate kidney injury upon sepsis challenge. RSL3 partially blocked MEL's beneficial renal-protective effects. MEL up-regulated Nrf2 and HO-1 in CLP mice, and both ZnPP and ML385 blocked the MEL-mediated effects of ferroptosis inhibition and renal protection.

CONCLUSIONS

Ferroptosis aggravates SAKI. Melatonin treatment suppresses ferroptosis and alleviates kidney injury in the context of experimental sepsis by upregulating Nrf2/HO-1 pathway.

Normal and Pathological NRF2 Signalling in the Central Nervous System

The nuclear factor erythroid 2-related factor 2 (NRF2) was originally described as a master regulator of antioxidant cellular response, but in the time since, numerous important biological functions linked to cell survival, cellular detoxification, metabolism, autophagy, proteostasis, inflammation, immunity, and differentiation have been attributed to this pleiotropic transcription factor that regulates hundreds of genes. After 40 years of in-depth research and key discoveries, NRF2 is now at the center of a vast regulatory network, revealing NRF2 signalling as increasingly complex. It is widely recognized that reactive oxygen species (ROS) play a key role in human physiological and pathological processes such as ageing, obesity, diabetes, cancer, and neurodegenerative diseases. The high oxygen consumption associated with high levels of free iron and oxidizable unsaturated lipids make the brain particularly vulnerable to oxidative stress. A good stability of NRF2 activity is thus crucial to maintain the redox balance and therefore brain homeostasis. In this review, we have gathered recent data about the contribution of the NRF2 pathway in the healthy brain as well as during metabolic diseases, cancer, ageing, and ageing-related neurodegenerative diseases. We also discuss promising therapeutic strategies and the need for better understanding of cell-type-specific functions of NRF2 in these different fields.

Inflammatory response to the ischaemia-reperfusion insult in the liver after major tissue trauma

BACKGROUND

Polytrauma is often accompanied by ischaemia-reperfusion injury to tissues and organs, and the resulting series of immune inflammatory reactions are a major cause of death in patients. The liver is one of the largest organs in the body, a characteristic that makes it the most vulnerable organ after multiple injuries. In addition, the liver is an important digestive organ that secretes a variety of inflammatory mediators involved in local as well as systemic immune inflammatory responses. Therefore, this review considers the main features of post-traumatic liver injury, focusing on the immuno-pathophysiological changes, the interactions between liver organs, and the principles of treatment deduced.

METHODS

We focus on the local as well as systemic immune response involving the liver after multiple injuries, with emphasis on the pathophysiological mechanisms.

RESULTS

An overview of the mechanisms underlying the pathophysiology of local as well as systemic immune responses involving the liver after multiple injuries, the latest research findings, and the current mainstream therapeutic approaches.

CONCLUSION

Cross-reactivity between various organs and cascade amplification effects are among the main causes of systemic immune inflammatory responses after multiple injuries. For the time being, the pathophysiological mechanisms underlying this interaction remain unclear. Future work will continue to focus on identifying potential signalling pathways as well as target genes and intervening at the right time points to prevent more severe immune inflammatory responses and promote better and faster recovery of the patient.

Epigenetic Therapeutics Targeting NRF2/KEAP1 Signaling in Cancer Oxidative Stress

The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) and its negative regulator kelch-like ECH-associated protein 1 (KEAP1) regulate various genes involved in redox homeostasis, which protects cells from stress conditions such as reactive oxygen species and therefore exerts beneficial effects on suppression of carcinogenesis. In addition to their pivotal role in cellular physiology, accumulating innovative studies indicated that NRF2/KEAP1-governed pathways may conversely be oncogenic and cause therapy resistance, which was profoundly modulated by epigenetic mechanism. Therefore, targeting epigenetic regulation in NRF2/KEAP1 signaling is a potential strategy for cancer treatment. In this paper, the current knowledge on the role of NRF2/KEAP1 signaling in cancer oxidative stress is presented, with a focus on how epigenetic modifications might influence cancer initiation and progression. Furthermore, the prospect that epigenetic changes may be used as therapeutic targets for tumor treatment is also investigated.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

Reciprocal regulation of NRF2 by autophagy and ubiquitin-proteasome modulates vascular endothelial injury induced by copper oxide nanoparticles

NRF2 is the key antioxidant molecule to maintain redox homeostasis, however the intrinsic mechanisms of NRF2 activation in the context of nanoparticles (NPs) exposure remain unclear. In this study, we revealed that copper oxide NPs (CuONPs) exposure activated NRF2 pathway in vascular endothelial cells. NRF2 knockout remarkably aggravated oxidative stress, which were remarkably mitigated by ROS scavenger. We also demonstrated that KEAP1 (the negative regulator of NRF2) was not primarily involved in NRF2 activation in that KEAP1 knockdown did not significantly affect CuONPs-induced NRF2 activation. Notably, we demonstrated that autophagy promoted NRF2 activation as evidenced by that ATG5 knockout or autophagy inhibitors significantly blocked NRF2 pathway. Mechanically, CuONPs disturbed ubiquitin–proteasome pathway and consequently inhibited the proteasome-dependent degradation of NRF2. However, autophagy deficiency reciprocally promoted proteasome activity, leading to the acceleration of degradation of NRF2 via ubiquitin–proteasome pathway. In addition, the notion that the reciprocal regulation of NRF2 by autophagy and ubiquitin–proteasome was further proven in a CuONPs pulmonary exposure mice model. Together, this study uncovers a novel regulatory mechanism of NRF2 activation by protein degradation machineries in response to CuONPs exposure, which opens a novel intriguing scenario to uncover therapeutic strategies against NPs-induced vascular injury and disease.

CuONPs exposure activates NRF2 signaling in vascular endothelial cells and mouse thoracic aorta.

KEAP1 is dispensable for NRF2 activation in CuONPs-treated vascular endothelial cells.

CuONPs-induced autophagy facilitates NRF2 activation in vascular endothelial cells and mouse thoracic aorta.

Autophagy and ubiquitin–proteasome reciprocally regulate NRF2 activation in CuONPs-treated vascular endothelial cells and mouse thoracic aorta.

Interaction between COX-2 and ER stress is involved in the apoptosis-induced myocardial ischemia/reperfusion injury

PURPOSE

Apoptosis induced by excessive endoplasmic reticulum (ER) stress is accompanied by the occurrence and progression of myocardial ischemia/reperfusion (I/R) injury. COX-2 is also known to affect the development of I/R damage in myocardium. However, the interaction between COX-2 and ER stress in aggravating myocardial I/R lesion is not well characterized. Therefore, the purpose of our research was to explore the interaction between COX-2 and ER stress on myocardial apoptosis.

METHODS

The left anterior descending (LAD) coronary artery was ligatured with a 6-0# suture for 0.5 hours and subsequently subjected to reperfusion for 3 hours to simulate myocardial I/R in mice. Oxygen glucose deprivation/reoxygenation (OGD/R) was performed on H9c2 cells to construct an in vitro model of this experiment. NS398 (COX-2 specific inhibitor) and Salubrinal (Sal, ER stress inhibitor) were administered to assess the function of COX-2 and ER stress in myocardial I/R impairment. CCK-8 assay was used to evaluate the viability of H9c2 cells under different treatment conditions. TUNEL and Hoechst staining were used to detect the occurrence of apoptosis. Infarct area/area at risk and Hematoxylin-eosin stained sections were assessed after I/R. Protein expressions of glucose-regulated protein 78 (GRP78), COX-2, phosphorylation of eukaryotic translation initiation factor 2 alpha (p-eIF2α), CCAAT/enhancer-binding protein homologous protein (CHOP), and Cleaved caspase 3 in the myocardium were examined using Western blotting. Changes in Cleaved caspase 3 expression in myocardial slices were measured by immunohistochemistry.

RESULTS

Sal or NS398 partly reduced I/R-induced damage as testified by the apparent decrease in infarct size after I/R and reduced cell viability following OGD/R. Sal distinctly increased p-eIF2α, but caused decreased expression of COX-2, Cleaved caspase 3, and ER stress-associated proteins after I/R, suggesting that Sal effectively inhibited ER stress, apoptosis, and COX-2. Pretreatment with NS398 blocked I/R or OGD/R-induced upregulation of COX-2, Cleaved caspase 3, and ER stress-related marker proteins.

CONCLUSIONS

Interaction of COX-2 and ER stress regulates apoptosis and contributes to Myocardial lesion induced by I/R.

PART1 destabilized by NOVA2 regulates blood-brain barrier permeability in endothelial cells via STAU1-mediated mRNA degradation

Blood-brain barrier dysfunction is recognized as a precursor of Alzheimer's disease development. Endothelial cells as structural basis of blood-brain barrier were observed tight junction failure in amyloid-β(1-42)-stimulated environment. In this study, we found NOVA2, PPP2R3A were down-regulated while PART1, p-NFκB-p65 were up-regulated in amyloid-β(1-42)-incubated endothelial cells. Knockdown of either NOVA2 or PPP2R3A and overexpression of PART1 all increased blood-brain barrier permeability. Lower blood-brain barrier permeability was observed in overexpression of NOVA2 and PPP2R3A and knockdown of PART1 and NFκB-p65. Same tendencies were found in the tight junction-related proteins expressions. Furthermore, overexpression and knockdown of NOVA2 and PART1 had no effect on cell viability. Mechanistically, NOVA2 overexpression was confirmed to reduce half-life of PART1. PART1 could destabilize PPP2R3A messenger RNA (mRNA) by interacting with STAU1. In addition, p-NFκB-p65 functioning as transcription factor reduced the expression of tight junction-related proteins, which was prompted by low protein level of PPP2R3A. Our study highlights the crucial role of NOVA2/PART1/PPP2R3A/p-NFκB-p65 pathway in amyloid-β(1-42)-incubated endothelial cells to modulating blood-brain barrier permeability through STAU1-mediated messenger RNA degradation, implying a potential mechanism of lncRNA and protein interaction in pathogenesis of Alzheimer's disease.

Role and Potential Mechanism of Heme Oxygenase-1 in Intestinal Ischemia-Reperfusion Injury

Intestinal ischemia-reperfusion (IR) injury is a complex, multifactorial, and pathophysiological condition with high morbidity and mortality, leading to serious difficulties in treatment, especially in humans. Heme oxygenase (HO) is the rate-limiting enzyme involved in heme catabolism. HO-1 (an inducible form) confers cytoprotection by inhibiting inflammation and oxidation. Furthermore, nuclear factor-erythroid 2-related factor 2 (Nrf2) positively regulates HO-1 transcription, whereas BTB and CNC homolog 1 (Bach1) competes with Nrf2 and represses its transcription. We investigated the role and potential mechanism of action of HO-1 in intestinal IR injury. Intestinal ischemia was induced for 45 min followed by 4 h of reperfusion in wild-type, Bach1-deficient, and Nrf2-deficient mice, and a carbon monoxide (CO)-releasing molecule (CORM)-3 was administered. An increase in inflammatory marker levels, nuclear factor-κB (NF-κB) activation, and morphological impairments were observed in the IR-induced intestines of wild-type mice. These inflammatory changes were significantly attenuated in Bach1-deficient mice or those treated with CORM-3, and significantly exacerbated in Nrf2-deficient mice. Treatment with an HO-1 inhibitor reversed this attenuation in IR-induced Bach1-deficient mice. Bach1 deficiency and treatment with CORM-3 resulted in the downregulation of NF-κB activation and suppression of adhesion molecules. Together, Bach1, Nrf2, and CO are valuable therapeutic targets for intestinal IR injury.

TAB2 deficiency induces dilated cardiomyopathy by promoting RIPK1-dependent apoptosis and necroptosis

Mutations in TGF-β-activated kinase 1 binding protein 2 (TAB2) have been implicated in the pathogenesis of dilated cardiomyopathy and/or congenital heart disease in humans, but the underlying mechanisms are currently unknown. Here, we identified an indispensable role for TAB2 in regulating myocardial homeostasis and remodeling by suppressing receptor-interacting protein kinase 1 (RIPK1) activation and RIPK1-dependent apoptosis and necroptosis. Cardiomyocyte-specific deletion of Tab2 in mice triggered dilated cardiomyopathy with massive apoptotic and necroptotic cell death. Moreover, Tab2-deficient mice were also predisposed to myocardial injury and adverse remodeling after pathological stress. In cardiomyocytes, deletion of TAB2 but not its close homolog TAB3 promoted TNF-α-induced apoptosis and necroptosis, which was rescued by forced activation of TAK1 or inhibition of RIPK1 kinase activity. Mechanistically, TAB2 critically mediates RIPK1 phosphorylation at Ser321 via a TAK1-dependent mechanism, which prevents RIPK1 kinase activation and the formation of RIPK1-FADD-caspase-8 apoptotic complex or RIPK1-RIPK3 necroptotic complex. Strikingly, genetic inactivation of RIPK1 with Ripk1-K45A knockin effectively rescued cardiac remodeling and dysfunction in Tab2-deficient mice. Together, these data demonstrated that TAB2 is a key regulator of myocardial homeostasis and remodeling by suppressing RIPK1-dependent apoptosis and necroptosis. Our results also suggest that targeting RIPK1-mediated cell death signaling may represent a promising therapeutic strategy for TAB2 deficiency-induced dilated cardiomyopathy.

Activation of Nrf2 by Lithospermic Acid Ameliorates Myocardial Ischemia and Reperfusion Injury by Promoting Phosphorylation of AMP-Activated Protein Kinase α (AMPKα)

Background: As a plant-derived polycyclic phenolic carboxylic acid isolated from Salvia miltiorrhiza, lithospermic acid (LA) has been identified as the pharmacological management for neuroprotection and hepatoprotection. However, the role and mechanism of lithospermic acid in the pathological process of myocardial ischemia-reperfusion injury are not fully revealed. Methods: C57BL/6 mice were subjected to myocardial ischemia and reperfusion (MI/R) surgery and pretreated by LA (50 mg/kg, oral gavage) for six consecutive days before operation. The in vitro model of hypoxia reoxygenation (HR) was induced by hypoxia for 24 h and reoxygenation for 6 h in H9C2 cells, which were subsequently administrated with lithospermic acid (100 μM). Nrf2 siRNA and dorsomorphin (DM), an inhibitor of AMPKα, were used to explore the function of AMPKα/Nrf2 in LA-mediated effects. Results: LA pretreatment attenuates infarct area and decreases levels of TnT and CK-MB in plasm following MI/R surgery in mice. Echocardiography and hemodynamics indicate that LA suppresses MI/R-induced cardiac dysfunction. Moreover, LA ameliorates oxidative stress and cardiomyocytes apoptosis following MI/R operation or HR in vivo and in vitro. In terms of mechanism, LA selectively activates eNOS, simultaneously increases nuclear translocation and phosphorylation of Nrf2 and promotes Nrf2/HO-1 pathway in vivo and in vitro, while cardioprotection of LA is abolished by pharmacological inhibitor of AMPK or Nrf2 siRNA in H9C2 cells. Conclusion: LA protects against MI/R-induced cardiac injury by promoting eNOS and Nrf2/HO-1 signaling via phosphorylation of AMPKα.

Sirtuin 1 activated by SRT1460 protects against myocardial ischemia/reperfusion injury

BACKGROUND

Ischemia reperfusion usually results in certain degree of damage to the myocardium, which is called myocardial ischemia/reperfusion (I/R) injury.

OBJECTIVE

Previous studies have found that Sirt1 plays a critical role in I/R injury by protecting cardiac function. SRT1460 is the activator for Sirt1 that participates in the regulation of various diseases. However, whether SRT1460 has any effects on myocardial I/R injury needs further study.

METHODS

The I/R rat model and H/R H9C2 model were established to simulate myocardial I/R injury. The infarct area of the rat heart was examined through TTC staining. The EF and FS of rats were detected through echocardiography. The levels of CK-MB, LDH, MDA, SOD and CK in cardiac tissues, serum or H9C2 cells were measured using commercial kits. Cell viability was assessed through MTT assay. Apoptosis was determined through flow cytometry analysis. Sirt1 expression was measured through western blot.

RESULTS

Our work found that SRT1460 reduced the infarct area of the heart induced by myocardial I/R injury. In addition, SRT1460 was confirmed to ameliorate cardiac dysfunction induced by myocardial I/R injury. Further exploration discovered that SRT1460 weakened oxidative stress induced by myocardial I/R injury. Findings from in vitro assays demonstrated that SRT1460 relieved injury of H/R-treated H9C2 cells. Finally, rescue assays proved that Sirt1 knockdown reversed the protective effects of SRT1460 on the injury of H/R-treated H9C2 cells.

CONCLUSION

Sirt1 activated by SRT1460 protected against myocardial I/R injury. This discovery may offer new sights on the treatment of myocardial I/R injury.

Role of Oxidative Stress in Reperfusion following Myocardial Ischemia and Its Treatments

Myocardial ischemia is a disease with high morbidity and mortality, for which reperfusion is currently the standard intervention. However, the reperfusion may lead to further myocardial damage, known as myocardial ischemia/reperfusion injury (MI/RI). Oxidative stress is one of the most important pathological mechanisms in reperfusion injury, which causes apoptosis, autophagy, inflammation, and some other damage in cardiomyocytes through multiple pathways, thus causing irreversible cardiomyocyte damage and cardiac dysfunction. This article reviews the pathological mechanisms of oxidative stress involved in reperfusion injury and the interventions for different pathways and targets, so as to form systematic treatments for oxidative stress-induced myocardial reperfusion injury and make up for the lack of monotherapy.

Activation of cannabinoid 2 receptors by JWH-133 protects against ovarian ischemia-reperfusion injury in rats

We investigated the efficacy of activated cannabinoid 2 receptors for alleviating ovarian ischemia-reperfusion injury in rats. Female Wistar albino rats were divided randomly into six groups: ischemia-reperfusion (IRG); ischemia-reperfusion + 0.2 mg/kg JWH-133 (JIRG1), ischemia-reperfusion + 1 mg/kg JWH-133 (JIRG2); ischemia-reperfusion + 5 mg/kg JWH-133 (JIRG3); solvent control, and sham control. Ovarian ischemia was established for 3 h followed by reperfusion for 3 h. Ovarian tissue was investigated using histology, immunohistochemistry and biochemistry. Administration of JWH-133 synthetic cannabinoid reduced nuclear factor kappa-B immunoreactivity as well as TUNEL positivity scores and malondialdehyde levels. These reductions were significant in all cases except for the malondialdehyde levels in the 1 mg/kg JWH-133 group. Activation of cannabinoid 2 receptors by JWH-133 reduced ovarian ischemia-reperfusion injury due to its antioxidant and anti-inflammatory effects.