This study aims to explore the specific mechanism by which puerarin inhibits ferroptosis and improves the myocardial contractile function in myocardial hypertrophy through the nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE)/heme oxygenase-1(HO-1) signaling pathway. The hypertrophic cardiomyocyte model was established using phenylephrine, and H9c2 cells were divided into control group, model group, puerarin group, and puerarin+ML385 group. Cell viability and surface area were detected by cell counting kit-8(CCK-8) and immunofluorescence experiments. The mitochondrial membrane potential and Ca~(2+) concentration were measured. The ferroptosis-related indicators were detected by biochemical and fluorescence staining methods. The expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway was detected by Western blot. A myocardial hypertrophy model was established, and 40 rats were randomly divided into sham group, model group, puerarin group, and puerarin+Nrf2 inhibitor(ML385) group, with 10 rats in each group. Echocardiogram, hemodynamic parameters, and myocardial hypertrophy parameters were measured. Histopathological changes of myocardial tissues were observed by hematoxylin and eosin(HE) staining and Masson staining. Biochemical methods, enzyme-linked immunosorbent assay(ELISA), and fluorescence staining were used to detect inflammatory factors and ferroptosis-related indicators. Immunohistochemistry was used to detect the expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway. Cell experiments showed that puerarin intervention significantly enhanced the viability of hypertrophic cardiomyocytes, reduced their surface area, and restored mitochondrial membrane potential and Ca~(2+) homeostasis. Mechanism studies revealed that puerarin promoted Nrf2 nuclear translocation, upregulated the expression of HO-1, solute carrier family 7 member 11(SLC7A11), and glutathione peroxidase 4(GPX4), and decreased malondialdehyde(MDA), reactive oxygen species(ROS), and iron levels. These protective effects were reversed by ML385. In animal experiments, puerarin improved cardiac function in rats with myocardial hypertrophy, alleviated myocardial hypertrophy and fibrosis, inhibited inflammatory responses and ferroptosis, and promoted nuclear Nrf2 translocation and HO-1 expression. However, combined intervention with ML385 led to deterioration of hemodynamics and a rebound in ferroptosis marker levels. In conclusion, puerarin may inhibit cardiomyocyte ferroptosis through the Nrf2/ARE/HO-1 signaling pathway, thereby improving myocardial contractile function in myocardial hypertrophy.
Animals ; NF-E2-Related Factor 2/genetics* ; Rats ; Ferroptosis/drug effects* ; Signal Transduction/drug effects* ; Isoflavones/pharmacology* ; Male ; Rats, Sprague-Dawley ; Cardiomegaly/genetics* ; Myocytes, Cardiac/metabolism* ; Antioxidant Response Elements/drug effects* ; Myocardial Contraction/drug effects* ; Heme Oxygenase-1/genetics* ; Cell Line

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic

OBJECTIVE: To observe the protective effect of Fisetin on sepsis-associated brain injury and explore its possible mechanism from the perspective of ferroptosis. METHODS: Sprague-Dawley (SD) rats (6-8-week-old male) were randomly divided into three groups: sham operation group (Sham group), colonic ligation and puncture (CLP) induced sepsis model group (CLP group) and Fisetin preprocessing group (CLP+Fisetin group), with 18 rats in each group (12 for observing survival rate and 6 for indicator testing). The CLP+Fisetin group was given Fisetin solution 50 mg×kg^-1×d^-1 by gavage continuously for 5 days before CLP, with dimethyl sulfoxide (DMSO) as the solute, while Sham group and CLP group were given the same dose of DMSO. The model was established at 2 hours after the last gavage. The general condition of each group of rats were observed, and the 10-day mortality were record. The behavioral testing (new object recognition experiment, elevated cross maze experiment) were performed after 7 days of modeling. After 24 hours of modeling, nerve reflex scoring was performed, and then the rats were euthanized and brain tissue was collected. The pathological changes of brain tissue were observed under a microscope by hematoxylin-eosin (HE) staining, the deposition of iron ion in brain tissue was observed by Prussian blue staining. The content of iron in brain tissue was determined by tissue iron kit, and the content of malondialdehyde (MDA) in brain tissue was determined by colorimetry. The expressions of tumor necrosis factor-α (TNF-α), neuron damage marker S100β, nuclear factor E2-related factor 2 (Nrf2), heme oxygenases-1 (HO-1) and glutathione peroxidase 4 (GPX4) were detected by Western blotting. RESULTS: On day 10 post-operation, 12, 3, and 7 animals survived in the Sham group, CLP group, and CLP+Fisetin group, respectively. Compared with the Sham group, rats in the CLP group showed significantly decreased nerve reflex score, new object discrimination index and open arm dwell time. HE staining showed arranged disorderly of neuronal cells, cytoplasm deep staining, nuclear condensation, unclear structures, neuron loss, and significant inflammation in the hippocampus in the hippocampus. Prussian blue staining showed iron ion deposition in the brain tissue. The contents of iron and MDA in brain tissue were elevated, and the expressions of TNF-α and S100β were up-regulated, while the expressions of Nrf2, HO-1, and GPX4 were down-regulated. Compared with the CLP group, the CLP+Fisetin group showed significantly increased neurological reflex score (7.33±1.15 vs. 4.67±1.53), improved new object discrimination index (0.44±0.02 vs. 0.32±0.04), and longer open arm dwell time (minutes: 78.33±9.29 vs. 41.15±9.64). Neuronal cells in the hippocampus were more organized, with less cytoplasmic staining, nuclear condensation, reduced neuronal loss, and fewer inflammatory cells. Iron ion deposition was reduced, and the contents of iron ions and MDA in brain tissue were decreased [iron ion (μg/g): 151.27±14.90 vs. 224.69±17.64, MDA (μmol/g): 470.0±44.3 vs. 709.3±65.4]. The expressions of TNF-α and S100β were significantly decreased (TNF-α/GAPDH: 0.651±0.060 vs. 0.896±0.022, S100β/GAPDH: 0.685±0.032 vs. 0.902±0.014), while the expressions of Nrf2, HO-1, and GPX4 were significantly increased (Nrf2/GAPDH: 0.708±0.108 vs. 0.316±0.112, HO-1/GAPDH: 0.694±0.022 vs. 0.538±0.024, GPX4/GAPDH: 0.620±0.170 vs. 0.317±0.039). All differences were statistically significant (all P < 0.05). CONCLUSION Fisetin pretreatment can inhibit ferroptosis and reduce sepsis-associated brain injury by Nrf2/HO-1/GPX4 pathway.
Animals ; Ferroptosis/drug effects* ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/metabolism* ; Sepsis/complications* ; Male ; Rats ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Neurons/drug effects* ; Signal Transduction ; Brain Injuries/metabolism* ; Flavonols ; Flavonoids/pharmacology* ; Heme Oxygenase-1/metabolism* ; Heme Oxygenase (Decyclizing)

OBJECTIVE: To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms. METHODS: Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting. RESULTS: Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05). CONCLUSION AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals ; Male ; Mice ; Mice, Inbred C57BL ; Liver/pathology* ; Chemical and Drug Induced Liver Injury/drug therapy* ; Diquat/poisoning* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Apoptosis ; Coumarins

The activation of the sirtuin1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway has been shown to mitigate oxidative stress-induced apoptosis and mitochondrial damage by reducing reactive oxygen species (ROS) levels. Clinical trials have demonstrated that Zhongfeng Xingnao Liquid (ZFXN) ameliorates post-stroke cognitive impairment (PSCI). However, the underlying mechanism, particularly whether it involves protecting mitochondria and inhibiting apoptosis through the SIRT1/Nrf2/HO-1 pathway, remains unclear. This study employed an oxygen-glucose deprivation (OGD) cell model using SH-SY5Y cells and induced PSCI in rats through modified bilateral carotid artery ligation (2VO). The effects of ZFXN on learning and memory, neuroprotective activity, mitochondrial function, oxidative stress, and the SIRT1/Nrf2/HO-1 pathway were evaluated both in vivo and in vitro. Results indicated that ZFXN significantly increased the B-cell lymphoma 2 (Bcl2)/Bcl2-associated X (Bax) ratio, reduced terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL)⁺ cells, and markedly improved cognition, synaptic plasticity, and neuronal function in the hippocampus and cortex. Furthermore, ZFXN exhibited potent antioxidant activity, evidenced by decreased ROS and malondialdehyde (MDA) content and increased superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels. ZFXN also demonstrated considerable enhancement of mitochondrial membrane potential (MMP), Tom20 fluorescence intensity, adenosine triphosphate (ATP) and energy charge (EC) levels, and mitochondrial complex I and III activity, thereby inhibiting mitochondrial damage. Additionally, ZFXN significantly increased SIRT1 activity and elevated SIRT1, nuclear Nrf2, and HO-1 levels. Notably, these effects were substantially counteracted when SIRT1 was suppressed by the inhibitor EX-527 in vitro. In conclusion, ZFXN alleviates PSCI by activating the SIRT1/Nrf2/HO-1 pathway and preventing mitochondrial damage.
Sirtuin 1/genetics* ; Animals ; NF-E2-Related Factor 2/genetics* ; Cognitive Dysfunction/genetics* ; Male ; Rats, Sprague-Dawley ; Rats ; Humans ; Signal Transduction/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Heme Oxygenase-1/genetics* ; Stroke/complications* ; Oxidative Stress/drug effects* ; Apoptosis/drug effects* ; Mitochondria/metabolism* ; Reactive Oxygen Species/metabolism* ; Neuroprotective Agents

Inflammation plays a pivotal role in the etiology and progression of various diseases. In traditional Chinese medicine, the whole plants of Thesium chinense Turcz. and its preparations (e.g. Bairui Granules) have been employed to manage inflammatory conditions. While flavonoids were previously considered the primary anti-inflammatory components, other potentially active constituents have been largely overlooked and not thoroughly investigated. This study presents a novel finding that the total alkaloids of T. chinense (BC-Alk) are potent active substances underlying the traditional and clinical applications of T. chinense and Bairui Granules as anti-inflammatory agents. UPLC-MS/MS analysis identified the composition of BC-Alk as quinolizidine alkaloids. The anti-inflammatory efficacy of BC-Alk was evaluated using a lipopolysaccharide (LPS)-induced lung inflammation model in mice. Results demonstrated that BC-Alk significantly mitigated LPS-induced lung inflammation, attenuated the overproduction of IL-1β and the overproduction of inflammatory factors (TNF-α), and ameliorated lung tissue hyperplasia in mice in vivo. Mechanistic studies in vitro revealed that BC-Alk upregulated the expression of Nrf2 and its downstream proteins NQO1 and glutamate-cystine ligase and modifier subunit (GCLM), inhibited NF-κB phosphorylation, and suppressed NLRP3 activation. Collectively, these findings indicate that BC-Alk exerts potent inhibitory effects against lung inflammation by modulating Nrf2, NF-κB, and NLRP3 pathways. This study provides new insights into the anti-inflammatory constituents of T. chinense and Bairui Granules.
Animals ; Lipopolysaccharides/adverse effects* ; Alkaloids/pharmacology* ; NF-kappa B/metabolism* ; NF-E2-Related Factor 2/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Mice ; Signal Transduction/drug effects* ; Anti-Inflammatory Agents/pharmacology* ; Male ; Mice, Inbred C57BL ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Pneumonia/genetics*

Esculetin, a natural dihydroxy coumarin derived from the Chinese herbal medicine Cortex Fraxini, has demonstrated significant pharmacological activities, including anticancer properties. Ferroptosis, an iron-dependent form of regulated cell death, has garnered considerable attention due to its lethal effect on tumor cells. However, the exact role of ferroptosis in esculetin-mediated anti-hepatocellular carcinoma (HCC) effects remains poorly understood. This study investigated the impact of esculetin on HCC cells both in vitro and in vivo. The findings indicate that esculetin effectively inhibited the growth of HCC cells. Importantly, esculetin promoted the accumulation of intracellular Fe²⁺, leading to an increase in ROS production through the Fenton reaction. This event subsequently induced lipid peroxidation (LPO) and triggered ferroptosis within the HCC cells. The occurrence of ferroptosis was confirmed by the elevation of malondialdehyde (MDA) levels, the depletion of glutathione peroxidase (GSH-Px) activity, and the disruption of mitochondrial morphology. Notably, the inhibitor of ferroptosis, ferrostatin-1 (Fer-1), attenuated the anti-tumor effect of esculetin in HCC cells. Furthermore, the findings revealed that esculetin inhibited the Nrf2-xCT/GPx4 axis signaling in HCC cells. Overexpression of Nrf2 upregulated the expression of downstream SLC7A11 and GPX4, consequently alleviating esculetin-induced ferroptosis. In conclusion, this study suggests that esculetin exerts an anti-HCC effect by inhibiting the activity of the Nrf2-xCT/GPx4 axis, thereby triggering ferroptosis in HCC cells. These findings may contribute to the potential clinical use of esculetin as a candidate for HCC treatment.
Umbelliferones/administration & dosage* ; Ferroptosis/drug effects* ; Carcinoma, Hepatocellular/physiopathology* ; NF-E2-Related Factor 2/genetics* ; Humans ; Liver Neoplasms/physiopathology* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Animals ; Cell Line, Tumor ; Mice ; Amino Acid Transport System y+/genetics* ; Mice, Inbred BALB C ; Male ; Signal Transduction/drug effects* ; Lipid Peroxidation/drug effects* ; Reactive Oxygen Species/metabolism* ; Mice, Nude

OBJECTIVE: To explore the protective effects and underlying mechanisms of H ₂S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells. METHODS: Cell viability was evaluated using CCK-8 assay. Apoptosis was measured using flow cytometry. Reagent kits were used to detect carbonyl stress markers malondialdehyde, 4-hydroxynonenal, thiobarbituric acid reactive substances, and protein carbonylation. Aldehyde-protein adduct formation and alcohol dehydrogenase, aldehyde dehydrogenase 2, aldo-keto reductase, nuclear factor E2-related factor 2 (Nrf2), and cystathionine β-synthase (CBS) expression were determined using western blotting or real-time PCR. Sulforaphane (SFP) was used to activate Nrf2. RNA interference was used to inhibit CBS expression. RESULTS: GYY4137 (an H ₂S donor) pretreatment significantly reversed the uranium-induced increase in carbonyl stress markers and aldehyde-protein adducts. GYY4137 effectively restored the uranium-decreased Nrf2 expression, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2, accompanied by a reversal of the uranium-decreased expression of CBS and aldehyde-metabolizing enzymes. The application of CBS siRNA efficiently abrogated the SFP-enhanced effects on the expression of CBS, Nrf2 activation, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2 and concomitantly reversed the SFP-enhanced effects of the uranium-induced mRNA expression of aldehyde-metabolizing enzymes. Simultaneously, CBS siRNA reversed the SFP-mediated alleviation of the uranium-induced increase in reactive aldehyde levels, apoptosis rates, and uranium-induced cell viability. CONCLUSION H ₂S induces Nrf2 activation and nuclear translocation, which modulates the expression of aldehyde-metabolizing enzymes and the CBS/H ₂S axis. Simultaneously, the Nrf2-controlled CBS/H ₂S axis may at least partially promote Nrf2 activation and nuclear translocation. These events form a cycle-regulating mode through which H ₂S attenuates the carbonyl stress-mediated NRK-52E cytotoxicity triggered by uranium.
NF-E2-Related Factor 2/genetics* ; Animals ; Hydrogen Sulfide/pharmacology* ; Rats ; Signal Transduction/drug effects* ; Lipid Peroxidation/drug effects* ; Cell Line ; Uranium/toxicity* ; Antioxidant Response Elements ; Kidney/metabolism* ; Oxidative Stress/drug effects* ; Cell Survival/drug effects* ; Apoptosis/drug effects*

OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment of "biaoben acupoint combination" on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury (MIRI) and explore its mechanism. METHODS: Fifty male SD rats were randomly divided into a sham-operation group, a model group, an EA pretreatment group, an EA pretreatment + Compound C group and an EA pretreatment+ML385 group, 10 rats in each group. In the EA pretreatment, the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, EA was delivered at bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, with continuous wave and 2 Hz of frequency, 1 mA of current, once daily for consecutive 7 days. On day 8, in the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, 30 min before model preparation, the intraperitoneal injection with Compound C (0.3 mg/kg) and ML385 (30 mg/kg) was administered respectively. Except in the sham-operation group, the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups. In the sham-operation group, the thread was not ligated. After modeling, the content of reactive oxygen species (ROS) in the ischemic area was measured by flow cytometry, superoxide dismutase (SOD) was detected using xanthine oxidase method, and malondialdelyde (MDA) was detected using thiobarbituric acid (TBA) chromatometry. The morphology of myocardial tissue in the ischemic area was observed with HE staining, and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy. Using immunofluorescence analysis, the positive expression of mitochondrial fission factor (MFF), mitochondrial fission 1 protein antibody (Fis1) and dynamin-related protein 1 (Drp1) was detected; and with immunohistochemical method used, the protein expression of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor E2-associated factor2 (Nrf2) and Drp1 in the ischemic area was detected. RESULTS: Compared with the sham-operation group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 increased in the model group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 decreased (P<0.01), and the protein expression of Drp1 elevated (P<0.01). Compared with the model group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01), and the protein expression of Drp1 declined (P<0.01); and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the positive expression of MFF, Fis1 and Drp1, and the protein expression of Drp1 were all reduced (P<0.01). When compared with the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01, P<0.05), and the protein expression of Drp1 decreased (P<0.05). In comparison with the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the cardiac muscle fiber rupture, cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group. The morphological changes were similar among the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group. CONCLUSION Electroacupuncture pretreatment of "biaoben acupoint combination" attenuates myocardial injury in MIRI rats, probably through promoting the phosphorylation of AMPK and Nrf2, inhibiting the excessive mitochondrial fission induced by Drp1, and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Myocardial Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology* ; Rats ; Acupuncture Points ; Mitochondrial Dynamics ; Humans ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/genetics* ; Superoxide Dismutase/metabolism*

BACKGROUND: Immunosuppression is closely related to the pathogenesis of sepsis, but the underlying mechanisms have not yet been fully elucidated. In this study, we aimed to examine the role of the Sterile Alpha Motif, Src Homology 3 domain and nuclear localization signal 1 (SAMSN1) in sepsis and elucidate its potential molecular mechanism in sepsis induced immunosuppression. METHODS: RNA sequencing databases were used to validate SAMSN1 expression in sepsis. The impact of SAMSN1 on sepsis was verified using gene knockout mice. Flow cytometry was employed to delineate how SAMSN1 affects immunity in sepsis, focusing on immune cell types and T cell functions. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated gene editing in RAW264.7 macrophages enabled interrogation of SAMSN1 's regulatory effects on essential macrophage functions, including cell proliferation and phagocytic capacity. The mechanism of SAMSN1 in the interaction between macrophages and T cells was investigated using the RAW264.7 cell line and primary cell lines. RESULTS: SAMSN1 expression was significantly increased in patients with sepsis and was positively correlated with sepsis mortality. Genetic deletion of Samsn1 in murine sepsis model improved T cell survival, elevated T cell cytolytic activity, and activated T cell signaling transduction. Concurrently, Samsn1 knockout augmented macrophage proliferation capacity and phagocytic efficiency. In macrophage, SAMSN1 binds to Kelch-like epichlorohydrin-associated protein 1 (KEAP1), causing nuclear factor erythroid 2-related factor 2 (NRF2) to dissociate from the KEAP1-NRF2 complex and translocate into the nucleus. This promotes the transcription of the coinhibitory molecules CD48/CD86/carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1), which bind to their corresponding receptors natural killer cell receptor 2B4/CD152/T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) on the surface of T cells, inducing T-cell exhaustion. CONCLUSIONS SAMSN1 deletion augmented adaptive T cell immunity and macrophage phagocytic-proliferative dual function. Furthermore, it mediates the KEAP1-NRF2 axis, which affects the expression of coinhibitory molecules on macrophages, leading to T-cell exhaustion. This novel immunosuppression mechanism potentially provides a candidate molecular target for sepsis immunotherapy.
Animals ; NF-E2-Related Factor 2/metabolism* ; Mice ; Macrophages/immunology* ; Sepsis/metabolism* ; Kelch-Like ECH-Associated Protein 1/genetics* ; T-Lymphocytes/immunology* ; Humans ; Signal Transduction/physiology* ; RAW 264.7 Cells ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Flow Cytometry ; T-Cell Exhaustion