This study aims to investigate the mechanism by which resveratrol(RES) alleviates cerebral vascular endothelial damage in sepsis-associated encephalopathy(SAE) through network pharmacology and animal experiments. By using network pharmacology, the study identified common targets and genes associated with RES and SAE and constructed a protein-protein interaction( PPI) network. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis were performed to pinpoint key signaling pathways, followed by molecular docking validation. In the animal experiments, a cecum ligation and puncture(CLP) method was employed to induce SAE in mice. The mice were randomly assigned to the sham group, CLP group, and medium-dose and high-dose groups of RES. The sham group underwent open surgery without CLP, and the CLP group received an intraperitoneal injection of 0. 9% sodium chloride solution after surgery. The medium-dose and high-dose groups of RES were injected intraperitoneally with 40 mg·kg-1 and 60 mg·kg~(-1) of RES after modeling, respectively, and samples were collected 12 hours later. Neurological function scores were assessed, and the wet-dry weight ratio of brain tissue was detected. Serum superoxide dismutase(SOD), catalase( CAT) activity, and malondialdehyde( MDA) content were measured by oxidative stress kit. Histopathological changes in brain tissue were examined using hematoxylin-eosin(HE) staining. Transmission electron microscopy was employed to evaluate tight cell junctions and mitochondrial ultrastructure changes in cerebral vascular endothelium. Western blot analysis was performed to detect the expression of zonula occludens1( ZO-1), occludin, claudins-5, optic atrophy 1( OPA1), mitofusin 2(Mfn2), dynamin-related protein 1(Drp1), fission 1(Fis1), and hypoxia-inducible factor-1α(HIF-1α). Network pharmacology identified 76 intersecting targets for RES and SAE, with the top five core targets being EGFR, PTGS2, ESR1, HIF-1α, and APP. GO enrichment analysis showed that RES participated in the SAE mechanism through oxidative stress reaction. KEGG enrichment analysis indicated that RES participated in SAE therapy through HIF-1α, Rap1, and other signaling pathways. Molecular docking results showed favorable docking activity between RES and key targets such as HIF-1α. Animal experiment results demonstrated that compared to the sham group, the CLP group exhibited reduced nervous reflexes, decreased water content in brain tissue, as well as serum SOD and CAT activity, and increased MDA content. In addition, the CLP group exhibited disrupted tight junctions in cerebral vascular endothelium and abnormal mitochondrial morphology. The protein expression levels of Drp1, Fis1, and HIF-1α in brain tissue were increased, while those of ZO-1, occludin, claudin-5, Mfn2, and OPA1 were decreased. In contrast, the medium-dose and high-dose groups of RES showed improved neurological function, increased water content in brain tissue and SOD and CAT activity, and decreased MDA content. Cell morphology in brain tissue, tight junctions between endothelial cells, and mitochondrial structure were improved. The protein expressions of Drp1, Fis1, and HIF-1α were decreased, while those of ZO-1, occludin, claudin-5, Mfn2, and OPA1 were increased. This study suggested that RES could ameliorate cerebrovascular endothelial barrier function and maintain mitochondrial homeostasis by inhibiting oxidative stress after SAE damage, potentially through modulation of the HIF-1α signaling pathway.
Animals ; Mice ; Network Pharmacology ; Resveratrol/administration & dosage* ; Male ; Sepsis-Associated Encephalopathy/genetics* ; Signal Transduction/drug effects* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Endothelium, Vascular/metabolism* ; Molecular Docking Simulation ; Protein Interaction Maps/drug effects* ; Humans ; Sepsis/complications* ; Oxidative Stress/drug effects*

Microglial pyroptosis and neuroinflammation have been implicated in the pathogenesis of sepsis-associated encephalopathy (SAE). OGT-mediated O-GlcNAcylation is involved in neurodevelopment and injury. However, its regulatory function in microglial pyroptosis and involvement in SAE remains unclear. In this study, we demonstrated that OGT deficiency augmented microglial pyroptosis and exacerbated secondary neuronal injury. Furthermore, OGT inhibition impaired cognitive function in healthy mice and accelerated the progression in SAE mice. Mechanistically, OGT-mediated O-GlcNAcylation of ATF2 at Ser44 inhibited its phosphorylation and nuclear translocation, thereby amplifying NLRP3 inflammasome activation and promoting inflammatory cytokine production in microglia in response to LPS/Nigericin stimulation. In conclusion, this study uncovers the critical role of OGT-mediated O-GlcNAcylation in modulating microglial activity through the regulation of ATF2 and thus protects against SAE progression.
Animals ; Microglia/metabolism* ; Pyroptosis/physiology* ; Mice ; Sepsis-Associated Encephalopathy/prevention & control* ; Activating Transcription Factor 2/metabolism* ; N-Acetylglucosaminyltransferases/genetics* ; Mice, Inbred C57BL ; Male ; Mice, Knockout

Sepsis-associated encephalopathy (SAE) is one of the complications of sepsis, causes cognitive dysfunction ranging from mild attention deficits to progression into coma, which severely impairs patients' ability to live and mental health, and increases the long-term disability and mortality rates. Although the clinical attention to SAE has been increasing in recent years, effective interventions to improve cognitive dysfunction in sepsis survivors are still in the preclinical stage. The pathogenesis of SAE is numerous and complex, and mitochondrial dysfunction, as one of the key pathogenic mechanisms, plays a role in the cognitive development process through oxidative stress imbalance, energy metabolism disorders, and activation of apoptosis signaling pathway. The present review systematically integrates the recent studies on mitochondrial dysfunction in the development of cognitive disorders. This review systematically integrates the cutting-edge research results in recent years, discusses the mitochondrial structural disruption, mitochondrial kinetic abnormalities, respiratory chain dysfunction, and comprehensively comprehends the research progress of mitochondria-targeted antioxidant, mitochondrial autophagy activator, mitochondrial biosynthesis modifier and other novel intervention strategies in improving cognitive function of SAE patients, with the aim of providing theoretical basis for the breakthrough of the current status of clinical treatment of SAE and the targeting of mitochondria for treatment. The aim is to provide theoretical basis for breaking through the status of SAE clinical treatment and targeting mitochondrial therapy.
Humans ; Sepsis-Associated Encephalopathy/metabolism* ; Mitochondria/metabolism* ; Sepsis/complications* ; Oxidative Stress ; Cognitive Dysfunction ; Autophagy

OBJECTIVE: To evaluate the effects of ferroptosis in hippocampal neurons on cognitive dysfunction in rats with sepsis-associated encephalopathy (SAE) and its potential molecular mechanisms. METHODS: (1) Screening experiment of SAE modeling conditions: 42 healthy male Sprague-Dawley (SD) rats were divided into normal saline (NS) control group (n = 6) and lipopolysaccharide (LPS) 5, 15, 30 mg/kg groups (each n = 12) according to the random number table method. The SAE modeling conditions were determined by survival and the changes in mean arterial pressure (MAP) and heart rate (HR) within 72 hours, the percentage of stiffness status, the levels of serum inflammatory factors including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), neuron specific enolase (NSE, a marker of neuronal injury), serum iron and lactic acid (Lac) contents, and the morphological changes in CA1 of hippocampus after 72 hours. (2) Deferoxamine (Def) intervention experiment: according to the results of screening experiments, 28 healthy male SD rats were divided into NS control group (n = 8), SAE group (n = 10) and Def+SAE group (n = 10) according to the random number table method. In the Def+SAE group, 100 mg/kg Def was injected intraperitoneally 12 hours before the modeling, once every 12 hours, with a total of 7 times; the rats in the NS control group and SAE group were injected with the same amount of NS. Then the cognitive function of rats was evaluated by fear conditioning test for the percentage of stiffness status; serum IL-6, TNF-α and NSE levels were determined by enzyme-linked immunosorbent assay (ELISA); the levels of serum Lac, serum iron and hippocampal malondialdehyde (MDA) and iron contents were determined by chemical colorimetric; the protein expressions of nuclear factor E2 related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and NAPDH oxidase 1 (NOX1) in hippocampus were determined by Western Blot; morphological changes in hippocampal CA1 were observed after hematoxylin and eosin (HE) staining. RESULTS: (1) Compared with the NS control group, intraperitoneal injection of 15 mg/kg LPS could significantly reduce the MAP and HR as time prolonged, and the reduction was most significant at 72 hours. The 72-hour survival rate was significantly reduced and cognitive function was impaired. The levels of serum IL-6, TNF-α, Lac and NSE were increased while the serum iron content was decreased significantly. The morphology of vertebral cells in hippocampal CA1 was irregular and some of the cells were obviously vacuolated. In the LPS 5 mg/kg group, there were no significant changes in vital signs, inflammation, organ function or cognitive dysfunction, while the symptoms of septic shock were apparent in the LPS 30 mg/kg group. Therefore, SAE model was reproduced by intraperitoneal injection of 15 mg/kg LPS for 72 hours. (2) Compared with the NS control group, the percentage of stiffness in the SAE group was significantly reduced. The levels of serum IL-6, NSE and hippocampal MDA, iron were significantly increased. The serum iron contents and hippocampal Nrf2 and GPX4 protein expressions were significantly reduced, while the hippocampal NOX1 protein expression was significantly increased. The morphology of vertebral cells in hippocampal CA1 was irregular and the cytoplasm was deeply stained. The results indicated that the level of oxidative stress in the hippocampus of SAE rats was increased, the neuron degenerations were obvious, and the cognitive function of rats were impaired. Compared with the SAE group, the percentage of stiffness in the Def+SAE group was significantly increased [(63.4±6.4)% vs. (47.6±6.0)%, P < 0.05]. The levels of serum IL-6, NSE, iron and hippocampal MDA, iron were significantly reduced [serum IL-6 (ng/L): 73.14±8.31 vs. 99.86±12.37, serum NSE (μg/L): 3.67±0.51 vs. 5.92±0.79, serum iron (mg/L): 68.43±8.12 vs. 134.60±15.63, hippocampal MDA (mol/g): 4.62±0.90 vs. 6.62±0.84, hippocampal iron (μg/g): 155.32±17.86 vs. 221.54±27.54, all P < 0.05]. The hippocampal protein expressions of Nrf2 and GPX4 were significantly increased [Nrf2/β-actin: 0.41±0.07 vs. 0.18±0.03, GPX4/β-actin: 0.74±0.09 vs. 0.40±0.06, all P < 0.05] while the hippocampal NOX1 protein expression was significantly reduced (NOX1/β-actin: 0.62±0.08 vs. 1.11±0.16, P < 0.05). The vertebral cells was significantly improved as compared with the SAE group. These findings showed that the oxidative stress level in hippocampus of the Def+SAE group was reduced, neuron degeneration was significantly alleviated, and the cognitive function of the rats was significantly improved. CONCLUSIONS The cognitive function of rats with SAE was significantly impaired, the hippocampal neurons were obviously damaged and ferroptosis was increased. Def pretreatment could significantly reduce iron deposition and ferroptosis in hippocampal neurons of SAE rats and improve cognitive dysfunction, which may be related to activation of Nrf2/GPX4 signaling pathway.
Animals ; Cognitive Dysfunction ; Ferroptosis ; Hippocampus ; Male ; NF-E2-Related Factor 2/metabolism* ; Neurons ; Rats ; Rats, Sprague-Dawley ; Sepsis ; Sepsis-Associated Encephalopathy ; Signal Transduction ; Tumor Necrosis Factor-alpha

OBJECTIVETo observe the efficacy of Xingnaojing Injection (XI) in treatment of sepsis-associated encephalopathy (SAE).

METHODSTotally 65 SAE patients were retrospectively analyzed at EICU from September 2010 to September 2013. They were assigned to the control group (32 cases) and the treatment group (33 cases) according to whether they received XI. Patients in the control group received anti-infection and symptomatic support, while those in the treatment group were intravenously injected with XI at 20 mL per day for additional 7-10 days. The fever clearance time, Glasgow coma scale (GCS), C-reactive protein (CRP), neuron-specific enolase (NSE), and improvement of electroen-cephalogram (EEG) were observed in the two groups.

RESULTSCompared with the control group, the fever clearance time was shortened, CRP levels decreased, GCS score and efficacy of EEG was alleviated in the treatment group after treatment with statistical difference (P < 0.05). No adverse reaction occurred during medication.

CONCLUSIONX1 was safe and effective in treatment of SAE.

C-Reactive Protein ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Humans ; Injections ; Phosphopyruvate Hydratase ; metabolism ; Sepsis-Associated Encephalopathy ; drug therapy ; Treatment Outcome

BACKGROUNDBrain dysfunction is a frequent complication of sepsis, usually defined as sepsis-associated encephalopathy (SAE). Although the Notch signaling pathway has been proven to be involved in both ischemia and neuronal proliferation, its role in SAE is still unknown. Here, the effect of the Notch signaling pathway involved γ-secretase inhibitor DAPT on SAE in septic rats was investigated in a cecal ligation and puncture (CLP) model.

METHODSFifty-nine Sprague-Dawley rats were randomly divided into four groups, with the septic group receiving the CLP operation. Twenty-four hours after CLP or sham treatment, rats were sacrificed and their hippocampus was harvested for Western blot analysis. TNF-α expression was determined using an enzyme-linked immunosorbent assay (ELISA) kit. Neuronal apoptosis was assessed by TUNEL staining, and neuronal cell death was detected by H&E staining. Finally, a novel object recognition experiment was used to evaluate memory impairment.

RESULTSOur data showed that sepsis can increase the expression of hippocampal Notch receptor intracellular domain (NICD) and poly (adenosine diphosphate [ADP]-ribose) polymerase-1 (PARP-1), as well as the inflammatory response, neuronal apoptosis, neuronal death, and memory dysfunction in rats. The γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butyl ester (DAPT) can significantly decrease the level of NICD and PARP-1, reduce hippocampal neuronal apoptosis and death, attenuate TNF-α release and rescue cognitive impairment caused by CLP.

CONCLUSIONThe neuroprotective effect of DAPT on neuronal death and memory impairment in septic rats, which could be a new therapeutic approach for treating SAE in the future.

Amyloid Precursor Protein Secretases ; antagonists & inhibitors ; Animals ; Apoptosis ; drug effects ; Dipeptides ; therapeutic use ; Hippocampus ; drug effects ; metabolism ; Male ; Neurons ; cytology ; drug effects ; Neuroprotective Agents ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerases ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Notch ; metabolism ; Sepsis ; complications ; Sepsis-Associated Encephalopathy ; drug therapy ; enzymology ; Signal Transduction ; drug effects