Mild therapeutic hypothermia upregulates the O-GlcNAcylation level of COX10 to alleviate mitochondrial damage induced by myocardial ischemia-reperfusion injury.

OBJECTIVE: Mild therapeutic hypothermia (MTH) is an important method for perioperative prevention and treatment of myocardial ischemia-reperfusion injury (MIRI). Modifying mitochondrial proteins after protein translation to regulate mitochondrial function is one of the mechanisms for improving myocardial ischemia-reperfusion injury. This study investigated the relationship between shallow hypothermia treatment improving myocardial ischemia-reperfusion injury and the O-GlcNAcylation level of COX10. METHODS: We used in vivo Langendorff model and in vitro hypoxia/reoxygenation (H/R) cell model to investigate the effects of MTH on myocardial ischemia-reperfusion injury. Histological changes, myocardial enzymes, oxidative stress, and mitochondrial structure/function were assessed. Mechanistic studies involved various molecular biology methods such as ELISA, immunoprecipitation (IP), WB, and immunofluorescence. RESULTS: Our research results indicate that MTH upregulates the O-GlcNACylation level of COX10, improves mitochondrial function, and inhibits the expression of ROS to improve myocardial ischemia-reperfusion injury. In vivo, MTH effectively alleviates ischemia-reperfusion induced cardiac dysfunction, myocardial injury, mitochondrial damage, and redox imbalance. In vitro, the OGT inhibitor ALX inhibits the OGT mediated O-GlcNA acylation signaling pathway, downregulates the O-Glc acylation level of COX10, promotes ROS release, and counteracts the protective effect of MTH. On the contrary, the OGA inhibitor ThG showed opposite effects to ALX, further confirming that MTH activated the OGT mediated O-GlcNAcylation signaling pathway to exert cardioprotective effects. CONCLUSIONS: In summary, MTH activates OGT mediated O-glycosylation modified COX10 to regulate mitochondrial function and improve myocardial ischemia-reperfusion injury, which provides important theoretical basis for the clinical application of MTH.

Future Directions in Optimizing Anesthesia to Reduce Perioperative Acute Kidney Injury.

BACKGROUND: Perioperative acute kidney injury (AKI) is common in surgical patients and is associated with high morbidity and mortality. There are currently few options for AKI prevention and treatment. Due to its complex pathophysiology, there is no efficient medication therapy to stop the onset of the injury or repair the damage already done. Certain anesthetics, however, have been demonstrated to affect the risk of perioperative AKI in some studies. The impact of anesthetics on renal function is particularly important as it is closely related to the prognosis of patients. Some anesthetics can induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. Propofol, sevoflurane, and dexmedetomidine are a few examples of anesthetics that have protective association with AKI in the perioperative period. SUMMARY: In this study, we reviewed the clinical characteristics, risk factors, and pathogenesis of AKI. Subsequently, the protective effects of various anesthetic agents against perioperative AKI and the latest research are introduced. KEY MESSAGE: This work demonstrates that a thorough understanding of the reciprocal effects of anesthetic drugs and AKI is crucial for safe perioperative care and prognosis of patients. However, more complete mechanisms and pathophysiological processes still need to be further studied.

Research on fault diagnosis technology of heat meter based on multi classifier fusion of pigeon swarm algorithm.

In order to improve the availability of fault data, the fault data of heat meters had been classified, and balances all kinds of fault data according to interpolation algorithms to meet the needs of fault diagnosis algorithms. Based on the voting mechanism, an integrated model of multi classifier fusion is established, and the weight of each classifier is optimally configured through pigeon swarm algorithm. In the experiment, three kinds of integration models are obtained according to the voting mechanism and pigeon swarm algorithm. The three integrated models are used to diagnose the fault of the heat meter, and the three indicators of precision, recall and F1 Core have achieved satisfactory results.

Stellate Ganglion Block Improves Postoperative Cognitive Dysfunction in aged rats by SIRT1-mediated White Matter Lesion Repair.

Postoperative cognitive dysfunction (POCD) is a common complication of the central nervous system after surgery, especially in elderly patients. Many factors can influence POCD, one of which is white matter lesion. Nowadays, stellate ganglion block (SGB) is considered as an effective intervention for postoperative cognitive dysfunction and SIRT1 may play a role in that, but the exact mechanism remains unclear. Therefore, the underlying mechanisms that SGB improves postoperative cognitive dysfunction through SIRT1 in aged rats and its association with white matter lesion are yet to be elucidated. The role of SIRT1 in the process that stellate ganglion block improves the cognitive impairment, and its association with white matter lesion was investigated using splenectomy-induced POCD model. To investigate this result further, we performed transection of the cervical sympathetic trunk on the basis of POCD model, and the role of SIRT1 was then verified again by intraperitoneal injection of EX527 (5 mg/kg) five min before surgery. Data show that SGB treatment has neuroprotective effects in POCD rats. SGB treatment can ameliorate cognitive impairment, neuroinflammation and neuronal apoptosis in white matter. Moreover, SGB treatment enhanced the expression of SIRT1 in the hippocampus and white matter, decreased NF-κB activity in the hippocampus and white matter. It also increased the levels of inflammatory factor in serum and white matter, primarily at the level of anti-inflammatory factor. These findings indicated that SIRT1-mediate white matter repair could be a new therapeutic target for neurodegenerative illnesses.

Research Progress on the Role of Pyroptosis in Myocardial Ischemia-Reperfusion Injury.

Myocardial ischemia-reperfusion injury (MIRI) results in the aggravation of myocardial injury caused by rapid recanalization of the ischemic myocardium. In the past few years, there is a growing interest in investigating the complex pathophysiological mechanism of MIRI for the identification of effective targets and drugs to alleviate MIRI. Currently, pyroptosis, a type of inflammatory programmed death, has received greater attention. It is involved in the MIRI development in combination with other mechanisms of MIRI, such as oxidative stress, calcium overload, necroptosis, and apoptosis, thereby forming an intertwined association between different pathways that affect MIRI by regulating common pathway molecules. This review describes the pyroptosis mechanism in MIRI and its relationship with other mechanisms, and also highlights non-coding RNAs and non-cardiomyocytes as regulators of cardiomyocyte pyroptosis by mediating associated pathways or proteins to participate in the initiation and development of MIRI. The research progress on novel small molecule drugs, clinical drugs, traditional Chinese medicine, etc. for regulating pyroptosis can play a crucial role in effective MIRI alleviation. When compared to research on other mature mechanisms, the research studies on pyroptosis in MIRI are inadequate. Although many related protective drugs have been identified, these drugs generally lack clinical applications. It is necessary to further explore and verify these drugs to expand their applications in clinical setting. Early inhibition of MIRI by targeted regulation of pyroptosis is a key concern that needs to be addressed in future studies.

Therapeutic hypothermia alleviates myocardial ischaemia-reperfusion injury by inhibiting inflammation and fibrosis via the mediation of the SIRT3/NLRP3 signalling pathway.

Therapeutic hypothermia (TH) may attenuate myocardial ischaemia-reperfusion injury, thereby improving outcomes in acute myocardial infarction. However, the specific mechanism by which TH alleviates MIRI has not been elucidated so far. In this study, 120 healthy male Sprague-Dawley rats were randomly divided into five groups. Haemodynamic parameters, myocardial infarction area, histological changes and the levels of cardiac enzymes, caspase-1 and inflammatory cytokines were determined. In addition, the extent of myocardial fibrosis, the degree of cardiomyocyte apoptosis and the expression levels of SIRT3, GSDMD-N, fibrosis-related proteins and inflammation-related proteins were estimated.TH reduced myocardial infarct area and cardiac enzyme levels, improved cardiomyopathic damage and haemodynamic indexes, and attenuated myocardial fibrosis, the protein expression levels of collagen I and III, myocardial apoptosis, the levels of inflammatory cytokines and inflammation-related proteins. Notably, the immunofluorescence and protein expression levels of SIRT3 were upregulated in the 34H+DMSO group compared to the I/R group, but this protective effect was abolished by the SIRT3 inhibitor 3-TYP. After administration of Mcc950, the reversal effects of 3-TYP were significantly abolished, and TH could protect against MIRI in a rat isolated heart model by inhibiting inflammation and fibrosis. The SIRT3/NLRP3 signalling pathway is one of the most important signalling pathways in this regard.

Liver fibrosis scores and prognosis in patients with cardiovascular diseases: A systematic review and meta-analysis.

BACKGROUND: In patients with nonalcoholic fatty liver disease, liver fibrosis was associated with a higher risk of cardiovascular events. However, the relationship between liver fibrosis scores and clinical outcomes in patients with cardiovascular disease remains unclear. METHODS: Searching from PubMed, EMBASE and Cochrane Library databases yielded cohort studies that reported adjusted effect size between liver fibrosis scores (Fibrosis-4 score [FIB-4] or NAFLD fibrosis score [NFS]) and prognosis in patients with cardiovascular disease. The effect size was computed using a random-effects model. RESULTS: This meta-analysis included twelve cohort studies involving 25,252 patients with cardiovascular disease. Participants with the highest baseline level of FIB-4 or NFS had a significantly increased risk of cardiovascular events (FIB-4, HR: 1.75, 95% CI: 1.53-2.00, I 2  = 0%; NFS, HR: 1.92, 95% CI: 1.50-2.47, I 2  = 47%). This finding was consistent with the analysis of FIB-4 or NFS as a continuous variable (per 1-unit increment FIB-4, HR: 1.15, 95% CI: 1.06-1.24, I 2  = 72%; NFS, HR: 1.15, 95% CI: 1.07-1.24, I 2  = 71%). Furthermore, participants with the highest levels of FIB-4 or NFS had a greater risk of cardiovascular mortality (FIB-4, HR: 2.07, 95% CI: 1.19-3.61, I 2  = 89%; NFS, HR: 3.72, 95% CI: 2.62-5.29, I 2  = 60%) and all-cause mortality (FIB-4, HR: 1.81, 95% CI: 1.24-2.66, I 2  = 90%; NFS, HR: 3.49, 95% CI: 2.82-4.31, I 2  = 25%). This result was also consistent as a continuous variable. CONCLUSION: Higher levels of FIB-4 and NFS are related to an increased risk of cardiovascular events, cardiovascular mortality and all-cause mortality in patients with cardiovascular disease.

Knockout of circRNA single stranded interacting protein 1 (circRBMS1) played a protective role in myocardial ischemia-reperfusion injury though inhibition of miR-2355-3p/Mammalian Sterile20-like kinase 1 (MST1) axis.

Evidence suggests circRBMS1 regulates mRNA to mediate cell apoptosis, inflammation, and oxidative stress in different diseases. MST1 is reported to be the target and activator of apoptosis-related molecules and signaling pathways. Hence, the present study aims to investigate the role of circ-RBMS1/miR-2355-3p/MST1 in the development of I/R injury. In vitro experiments showed increased circ-RBMS1 and decreased miR-2355-3p in H/R-induced HCMs. CircRBMS1 served as a sponge for miR-2355-3p and miR-2355-3p targeted MST1. Furthermore, knockout of circRBMS1 attenuated cell apoptosis, oxidized stress, and inflammation in H/R-induced HCMs. In vivo experiments indicated circRBMS1 knockdown attenuated cardiac function damage, cell apoptosis, oxidative stress injury and inflammatory response through miR-2355-3p/MST1 axis in mice. In summary, these results demonstrated circRBMS1 played a protective role in myocardial I/R injury though inhibition of miR-2355-3p/MST1 axis. It might provide a new therapeutic target for cardiac I/R injury.

Puerarin protects against sepsis-induced myocardial injury through AMPK-mediated ferroptosis signaling.

OBJECTIVE: Research suggests that Puerarin may protect against sepsis-induced myocardial damage. However, the mechanisms responsible for Puerarin's cardioprotective effect remain largely unclear. In this study, our objective is to investigate the role of Puerarin-induced AMPK-mediated ferroptosis signaling in protecting myocardial injury. METHODS: 48 male Sprague-Dawley rats were randomly divided into four groups: control group, LPS group, LPS + Pue group, LPS + Pue + Era (Erastin, ferroptosis activator) group, or LPS + Pue + CC (compound C, AMPK inhibitor) group. During the experiment, cardiac systolic function indexes and myocardial histopathological changes were monitored. The serum levels of myocardial injury marker enzyme, inflammatory response related marker enzyme, and oxidative stress related-marker enzyme were measured with ELISA. Apoptotic cardiomyocytes, the iron content in myocardial tissue, apoptosis-related proteins, AMPK, and ferroptosis-related proteins were determined. RESULTS: Puerarin inhibited the myocardial injury induced by LPS. The cardioprotective effects of Puerarin decreased after adding ferroptosis-activating compound Erastin. The protein expression levels of GPX4 and ferritin were down-regulated, whereas ACSL4, TFR, and heart iron content were up-regulated in LPS + Pue + Era group compared with LPS+Pue group. A significant difference was identified between LPS + Pue + Era group and LPS + Pue group in P-AMPK and T-AMPK levels. Meanwhile, after providing CC, P-AMPK/T-AMPK was significantly reduced, the protein expression levels of GPX4 and ferritin were down-regulated. ACSL4, TFR, and the heart iron content were up-regulated in LPS + Pue + CC group compared to LPS + Pue group. CONCLUSIONS: Puerarin protected against sepsis-induced myocardial injury, and AMPK-mediated ferroptosis signaling played a crucial role in its cardioprotective effect.

Dexmedetomidine post-conditioning alleviates myocardial ischemia-reperfusion injury in rats by ferroptosis inhibition via SLC7A11/GPX4 axis activation.

The SLC7A11/GPX4 axis plays an important role in ferroptosis during cardiac ischemia/reperfusion injury (IRI). The present study was designed to evaluate the impact of dexmedetomidine (DEX) post-conditioning on cardiac IRI and to explore whether the effect was achieved by SLC7A11/GPX4 signaling pathway regulation. Rat myocardial IRI was established by occluding the left anterior descending artery for 30 min followed by 2-h reperfusion. The infarct area was detected by diphenyltetrazolium chloride (TTC) staining; the cardiac function was evaluated by echocardiography. The levels of lipid peroxide biomarkers were measured to estimate the injury caused by lipid peroxide. HE staining and Sirius staining were utilized to assess myocardial damage and fibrosis. The mitochondrial morphology was observed by electron micrography. Western blot and quantitative real-time polymerase chain reaction were employed to measure the relative molecular characteristics. Our results showed that DEX administration at the beginning of reperfusion attenuated IRI-induced myocardial injury, alleviated mitochondrial dysfunction, decreased the level of reactive oxygen species (ROS), alleviated mitochondrial dysfunction, inhibited the activation of SLC7A11/GPX4, and modulated the expression of ferroptosis-related proteins, including SLC7A11, glutathione peroxidase 4 (GPX4), ferritin heavy chain (FTH), and cyclooxygenase-2 (COX-2). Conversely, the ferroptosis activator erastin partly suppressed the DEX-mediated cardio protection. Altogether, these results reveal that DEX inhibits ferroptosis by enhancing the expression of SLC7A11 and GPX4, thereby preventing cardiac I/R injury.

LncRNA ROR modulates myocardial ischemia-reperfusion injury mediated by the miR-185-5p/CDK6 axis.

LncRNAs and miRNAs are correlated with the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). Whether lncRNA ROR or miR-185-5p plays a crucial role in MIRI is still unclear. In in-vitro, human cardiac myocytes (HCMs) were treated with hypoxia/reoxygenation (H/R). Wistar rats were used to set up an in-vitro I/R model by means of recanalization after ligation. Evaluation of the myocardial injury marker lactate dehydrogenase (LDH) in HCMs cells was performed. The expression of miR-185-5p and ROR, IL-1ß, and IL-18 were detected by qRT-PCR. ELISA was also performed to evaluate the secretion of IL-1ß and IL-18. Western blotting was carried out to determine CDK6, NLRP3, GSDMD-N, ASC, and cleaved-caspase1 protein expression. The relationship between miR-185-5p and CDK6 or ROR was confirmed by a dual-luciferase reporter assay. Our findings revealed that H/R treated HCMs showed a significantly decreased miR-185-5p expression and increased expression of CDK6 and ROR. ROR knockdown reduced H/R induced pyroptosis and inflammation, while knockdown of miR-185-5p accelerated the effect. Furthermore, miR-185-5p was negatively regulated and absorbed by ROR in HCMs. Overexpression of miR-185-5p reversed the H/R-induced cell pyroptosis and upregulation of LDH, IL-1ß, and IL-18. In HCMs, miR-185-5p was also negatively regulated and related to CDK6 expression. Moreover, overexpression of CDK6 significantly inhibited the effects of miR-185-5p mimics on the inflammatory response and pyroptosis of HCMs. Knockdown of ROR alleviated H/R-induced myocardial injury by elevating miR-185-5p and inhibiting CDK6 expression. Taken together, our results show that the ROR/miR-185-5p/CDK6 axis modulates cell pyroptosis induced by H/R and the inflammatory response of HCMs.

Inhibition of TRPV4 attenuates ferroptosis against LPS-induced ALI via Ca2+ pathway.

Acute lung injury (ALI) is an inflammation of the lungs with high incidence rate and mortality. Ferroptosis is a new cell death, which has influence in body organs. Transient receptor potential vanillin-4 (TRPV4) channel is a key mediator of Ca2+, its activation induces ferroptosis. The purpose of the study is to investigate the function of TRPV4 on ferroptosis in ALI mice induced by lipopolysaccharide (LPS). In vitro, the regulation of TRPV4 on Ca2+ and ferroptosis was detected by CCK-8, fluorescent probe, and western blot in BEAS-2B cells. In vivo, the role of TRPV4 antagonists on ALI mice was analyzed by determination of pulmonary inflammation, pulmonary edema, and ferroptosis. In vitro, ferroptosis was induced in ALI. TRPV4 expression and intracellular Ca2+ concentration were up-regulated in ALI, and TRPV4 antagonist suppressed LPS-induced ferroptosis in BEAS-2B cells, including decreased MDA and ROS levels, increased GPX4 protein level and cell viability. In vivo, ALI mice showed activated ferroptosis compared with the control group, and administration of TRPV4 inhibition had protective effects on ALI mice, including improving lung pathological characteristics, and reducing the degree of pulmonary edema, inflammation, and ferroptosis. The results manifested that ferroptosis mediated lung injury in LPS-induced ALI, and TRPV4 antagonists might moderate LPS-induced damage by suppressing ferroptosis.

Effects of dexmedetomidine on the expression profile of tsRNAs in LPS-induced acute lung injury.

BACKGROUND: Acute lung injury (ALI) is characterized by impaired alveolar function and excessive inflammation, which is commonly seen in clinical anesthesia and intensive care units. tRNA-derived small RNA (tsRNA) is a non-coding RNA that can be used as a potential disease diagnostic biomarker. The connection between ALI and tsRNA remains unknown. We aimed to explore the possible regulatory functions and mechanisms of tsRNAs in ALI treated with DEX. METHODS: Firstly, we established the ALI model by LPS injection and explored the effect of dexmedetomidine (DEX) treatment on lung damage. Then, the lung tissues were obtained from the LPS and LPS + DEX group for small RNA sequencing. RESULTS: We proved that DEX could ameliorate pulmonary injury, and decreased inflammation, pulmonary edema, and ferroptosis (MDA down-regulation and GPX4 up-regulation) in ALI. Furthermore, in the tsRNA expression profile, the top 10 down-regulated tsRNAs were tsRNA-1018, tsRNA-3045b, tsRNA-5021a, tsRNA-1020, tsRNA-5002b, tsRNA-3045b, tsRNA-1026, tsRNA-5004a, tsRNA-5005b and tsRNA-1009, and the top 10 up-regulated tsRNAs were tsRNA-3025b, tsRNA-3025a, tsRNA-5016b, tsRNA-3042b, tsRNA-3029b, tsRNA-3028b, tsRNA-5006a, tsRNA-3027b, tsRNA-3027a, and tsRNA-5009b. The enrichment analysis of GO terms and KEGG pathways pointed that target genes of DE-tsRNAs were mainly enriched in regulation of transcription-associated GO terms, NF-kappa B signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. The RT-qPCR results of tsRNA-1020 and tsRNA-1018 were in accordance with small RNA sequencing data. CONCLUSION: DEX affected the abnormal expression of tsRNAs in ALI. These aberrantly expressed tsRNAs and enriched physiological processes provide a scientific basis for the diagnosis and treatment of ALI.

Mechanisms and Efficacy of Intravenous Lipid Emulsion Treatment for Systemic Toxicity From Local Anesthetics.

Local anesthetics are widely used clinically for perioperative analgesia to achieve comfort in medical treatment. However, when the concentration of local anesthetics in the blood exceeds the tolerance of the body, local anesthetic systemic toxicity (LAST) will occur. With the development and popularization of positioning technology under direct ultrasound, the risks and cases of LAST associated with direct entry of the anesthetic into the blood vessel have been reduced. Clinical occurrence of LAST usually presents as a series of severe toxic reactions such as myocardial depression, which is life-threatening. In addition to basic life support (airway management, advanced cardiac life support, etc.), intravenous lipid emulsion (ILE) has been introduced as a treatment option in recent years and has gradually become the first-line treatment for LAST. This review introduces the mechanisms of LAST and identifies the clinical symptoms displayed by the central nervous system and cardiovascular system. The paper features the multimodal mechanism of LAST reversal by ILE, describes research progress in the field, and identifies other anesthetics involved in the resuscitation process of LAST. Finally, the review presents key issues in lipid therapy. Although ILE has achieved notable success in the treatment of LAST, adverse reactions and contraindications also exist; therefore, ILE requires a high degree of attention during use. More in-depth research on the treatment mechanism of ILE, the resuscitation dosage and method of ILE, and the combined use with other resuscitation measures is needed to improve the efficacy and safety of clinical resuscitation after LAST in the future.

Rapamycin inhibits LOC102553434-mediated pyroptosis to improve lung injury induced by limb ischemia-reperfusion.

Limb ischemia reperfusion (I/R) triggers local or systemic injury, and whether the process is mediated by pyroptosis remains unclear, we aimed to explore whether pyroptosis was involved in the process of rapamycin alleviating lung injury induced by I/R and investigate the molecular mechanisms. The histopathology of lung injury induced by I/R was confirmed by hematoxylin-eosin (HE) staining, and malondialdehyde (MDA), superoxide dismutase (SOD), and the expression of pyroptosis related molecules were detected. RNA sequencing was used to mine key long non-coding RNAs (lncRNAs). The model of lipopolysaccharide (LPS)-induced L2 cell damage was also used to explore the effect and mechanism of rapamycin on lncRNA. Rapamycin treatment alleviated I/R-induced lung histopathologically injury and increased the concentration of MDA while decreased activity of SOD and expression of NLRP3, Caspase-1, interleukin-1ß (IL-1ß), and IL-18 in rat. A total of 63 differentially expressed lncRNAs (DElncRNAs) were identified from IR + Rap group compared with IR group, and these DElncRNAs were mainly involved in cell adhesion molecules (CAMs) and endocytosis pathway. The lncRNA LOC102553434 and its target gene MMP9 were most significantly up-regulated in I/R-injured rat. In vitro experiments showed that LPS induction caused a significant increase in LOC102553434, MMP9, IL-1ß, and IL-18 in L2 cells, but rapamycin treatment significantly reversed the effects. After interfering with the expression of LOC102553434 in the LPS-injured cells pretreated with rapamycin, cell proliferation significantly increased, and the expression of MMP, NLRP3 and caspase-1 were significantly decreased. Rapamycin protects the lung from limb I/R injury by regulating LOC102553434 expression and inhibiting pyroptosis pathway. LOC102553434 plays a role in promoting pyroptosis and thus provides a target for clinical treatment of I/R-induced lung injury. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02708-9.

Dexmedetomidine Mitigated NLRP3-Mediated Neuroinflammation via the Ubiquitin-Autophagy Pathway to Improve Perioperative Neurocognitive Disorder in Mice.

Background: Surgery and anesthesia-induced perioperative neurocognitive disorder (PND) are closely related to NOD-like receptors (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome microglia inflammatory response. Inhibiting the occurrence of neuroinflammation is an important treatment method to improve postoperative delirium. Fewer NLRP3-targeting molecules are currently available in the clinic to reduce the incidence of postoperative delirium. Dexmedetomidine (DEX), an α2 adrenergic receptor agonist has been shown to have antioxidant and anti-inflammatory activities. The present study showed that DEX reduced the production of cleaved caspase1 (CASP1) and destroyed the NLRP3-PYD And CARD Domain Containing (PYCARD)-CASP1 complex assembly, thereby reducing the secretion of IL-1ß interleukin beta (IL-1ß). DEX promoted the autophagy process of microglia and reduced NLRP3 expression. More interestingly, it promoted the ubiquitination and degradation of NLRP3. Thus, this study demonstrated that DEX reduced NLRP3-mediated inflammation through the activation of the ubiquitin-autophagy pathway. This study provided a new mechanism for treating PND using DEX. Methods: C57BL/6 mice were pre-administered DEX 3 days in advance, and an abdominal exploration model was used to establish a perioperative neurocognitive disorder model. The anti-inflammatory effect of DEX was explored in vivo by detecting NLRP3-CASP1/IL-1ß protein expression and behavioral testing. Primary microglia were stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in vitro, the expression of CASP1 and IL-1ß was detected in the supernatant of cells, and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) and sequestosome 1 (SQSTM1) was examined in the cytoplasm. Meanwhile, Co-immunoprecipitation (Co-IP) was used to detect NLRP3 protein ubiquitination so as to clarify the new mechanism underlying the anti-inflammatory effect of DEX. Results: Pre-administration of DEX reduced the protein expression of NLRP3, CASP1, and IL-1ß in the hippocampus of mice induced by surgery and also improved the impairment of learning and memory ability. At the same time, DEX also effectively relieved the decrease in spine density of the hippocampal brain induced by surgery. DEX decreased the cleaved CASP1 expression, blocked the assembly of NLRP3-PYCARD-CASP1 complex, and also reduced the secretion of mature IL-1ß in vitro. Mechanically, it accelerated the degradation of NLRP3 inflammasome via the autophagy-ubiquitin pathway and reduced the green fluorescent protein/red fluorescent protein MAP1LC3B ratio, which was comparable to the effect when using the autophagy activator rapamycin (Rapa). Furthermore, it increased the ubiquitination of NLRP3 after LPS plus ATP stimulated microglia. Conclusion: DEX attenuated the hippocampal brain inflammation by promoting NLRP3 inflammasome degradation via the autophagy-ubiquitin pathway, thus improving cognitive impairment in mice.

Cigarette smoke extract promotes DNA methyltransferase 3a expression in dendritic cells, inducing Th-17/Treg imbalance via the c-Jun/allograft inflammatory factor 1 axis.

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disorder. Although numerous studies on COPD have been conducted, therapeutic strategies for COPD are limited, and its pathological mechanism is still unclear. The present study aimed to explore the role of DNA methyltransferase 3a (DNMT3a) in dendritic cells (DCs) and the possible role of the Th-17/Treg cell balance in COPD. Immature DCs (iDCs) were induced and cocultured with CD4+ T cells. An in vitro COPD model was established by treatment with cigarette smoke extract (CSE). DNMT3a or allograft inflammatory factor 1 (AIF1) and c-Jun N-terminal kinase (JNK) were inhibited and overexpressed, respectively, by transfection with sh-DNMT3a or sh-AIF1 and JNK overexpression plasmids. The 3- (4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to measure cell viability. The Th17/Treg cell ratio was determined by flow cytometry. The expression levels of DNMT3a, c-Jun and AIF1 were measured using RT-qPCR or western blotting. Chromatin immunoprecipitation (CHIP) was used to confirm the interaction between c-Jun and the AIF1 promoter region. CSE stimulation promoted the expression of DNMT3a, and AIF1, and the ratio of p-c-Jun/c-Jun in iDCs. Besides, the iDC-mediated differentiation of Th17 cells was in a dose-dependent manner. However, knockdown of DNMT3a or AIF1 reversed the above effects caused by CSE. Inhibition of c-Jun signaling by treatment with the JNK inhibitor SP600125 also suppressed the iDC-mediated differentiation of Th17 cells, which was promoted by CSE. CHIP analysis showed that c-Jun could bind to the promoter region of AIF1. DNMT3a could regulate the iDC-mediated Th17/Treg balance by regulating the c-Jun/AIF1 axis.

Sevoflurane postconditioning reduces myocardial ischemia reperfusion injury-induced necroptosis by up-regulation of OGT-mediated O-GlcNAcylated RIPK3.

Inhalation anesthetics have been demonstrated to have protective effects against myocardial ischemia reperfusion injury (MIRI). O-linked GlcNAcylation (O-GlcNAc) modifications have been shown to protect against MIRI. This study aimed to investigate whether O-GlcNAcylation and necroptosis signaling were important for sevoflurane postconditioning (SPC) induced cardioprotective effects. Apart from rats in the SHAM and sevoflurane (SEVO) group, rats underwent 30 min ischemia followed by 2 h reperfusion. Cardiac hemodynamics and function were determined. In addition, myocardial infarction size, cardiac function parameters, myocardial lactic dehydrogenase (LDH) content, myocardium histopathological changes, necrotic myocardium, O-GlcNAcylation, and protein expression levels of necroptosis biomarkers were measured, together with co-immunoprecipitation experiments using proteins associated with the necroptosis pathway and O-GlcNAcylation. SPC reduced myocardial infarction size, ameliorated cardiac function, restored hemodynamic performance, improved histopathological changes, and reduced receptor-interacting protein kinase 1 (RIPK1)/receptor-interacting protein kinase 3 (RIPK3)/mixed lineage kinase domain-like (MLKL) mediated necroptosis. In addition, SPC up-regulated O-GlcNAc transferase (OGT) mediated O-GlcNAcylation, increased O-GlcNAcylated RIPK3, and inhibited the association of RIPK3 and MLKL. However, OSMI-1, an OGT inhibitor, abolished SPC mediated cardioprotective effects and inhibited OGT mediated up-regulation of O-GlcNAcylation and down-regulation of RIPK3 and MLKL proteins induced by SPC. Our study demonstrated that SPC restrained MIRI induced necroptosis via regulating OGT mediated O-GlcNAcylation of RIPK3 and lessening the formulation of RIPK3/MLKL complex.

[Effect of new simple breathing apparatus on oxygen therapy in patients with severe and critical coronavirus disease 2019].

OBJECTIVE: To make a new simple respirator and observe the oxygen therapy effect of the respirator on patients with severe and critical coronavirus disease 2019 (COVID-19). METHODS: Based on the infectivity and hospital requirements of COVID-19, a new simple respirator was designed by the medical staff of the Department of Anesthesiology of the Second Affiliated Hospital of Nanchang University, which was applied on the 22 patients with severe and critical COVID-19 who needed oxygen therapy admitted to the Cancer Center of Tongji Medical College of Huazhong University of Science and Technology from February 15th to March 15th in 2020. The new simple respirator contained two National Utility Model Patents (a respirator: ZL 2015 2 0410623.6, a fluid switch and oxygen suction device: ZL 2017 2 0873509.6), which was mainly composed of anesthesia mask and filter, L-shaped connecting tube, soft breathing bladder, connecting tube and elastic fixing belt. When in use, the anesthesia mask was fixed to the patient's mouth and nose with elastic straps, the connecting tube was inserted into the oxygen meter interface, the oxygen flow was adjusted to 6-10 L/min, and the L-shaped connecting tube was opened immediately after the soft breathing bag was full. The carbon dioxide and excess oxygen in the body was discharged from exhaust port. The oxygen flow was lowered to 2-3 L/min, the patient's respiratory rate (RR) was observed through the soft breathing bag fluctuations, and the oxygen flow was adjusted at any time. The changes of pulse oxygen saturation (SpO2), RR and heart rate (HR) before and after application of new simple respirator were observed, and the blood gas test results of part of the patients were collected. RESULTS: Twenty-two patients with severe and critical COVID-19 had significantly higher SpO2 at 10 minutes after application of the new simple ventilator than before application (0.994±0.007 vs. 0.952±0.017, P < 0.01), and RR was significantly lower than that before application (times/min: 27.59±3.63 vs. 29.64±3.81, P < 0.01); after 1 day of application, each index was further improved. All 13 patients who received blood gas analysis indicated no carbon dioxide accumulation. CONCLUSIONS: The new simple respirator can significantly improve the oxygen therapy effect of patients with severe and critical COVID-19. At the same time, 2019 novel coronavirus (2019-nCoV) can be filtered through the filter to reduce the formation of aerosol and protect the medical staff and patients.

Location detection of key areas in medical images based on Haar-like fusion contour feature learning.

BACKGROUND: Key area location is an important content of medical image processing and an important detail of auxiliary medical diagnosis. OBJECTIVE: In this paper, a prior knowledge fusion method based on Haar-like feature and contour feature is proposed to locate and detect key areas in medical images. METHOD: For the image to be processed, six Haar-like features and five contour features are extracted respectively. The improvement of Haar-like feature extraction template better adapts to the complexity of regional structure of medical images. The design of the contour feature extraction process fully reflects the consideration of feature invariance. The two features, together with prior knowledge, are fed into their respective decision makers and final fusers as the basis for determining and locating key regions. RESULTS: The experimental results show that the proposed method has excellent performance in locating key regions of medical images on MRI. When the capacity of the database increases from 10 to 200, the accuracy of locating the key areas of the image to be processed still reaches more than 90%. CONCLUSION: The proposed method realizes the accurate location of the key areas of medical images, which is of great significance for the auxiliary medical diagnosis.