Dexmedetomidine attenuates postoperative spatial memory impairment after surgery by reducing cytochrome C.

BACKGROUND: Anesthesia and surgery can induce perioperative neurocognitive disorders (PND). Mitochondrial dysfunction has been proposed to be one of the earliest triggering events in surgery-induced neuronal damage. Dexmedetomidine has been demonstrated to attenuate the impairment of cognition in aged rats induced by surgery in our previous study. METHODS: Male Sprague-Dawley rats underwent hepatic apex resection under anesthesia with propofol to clinically mimic human abdominal surgery. The rats were divided into three groups: Control group, Model group and Dexmedetomidine (Dex) group. Cognitive function was evaluated with the Morris water maze (MWM), Open Field Test (OFT)and Novel object recognition task (NOR). Ultrastructural change in neuronal mitochondria was measured by transmission electron microscopy. Mitochondrial function was measured by mitochondrial membrane potential and activities of mitochondrial complexes. Neuronal morphology was observed with H&E staining and the activation of glial cells was observed by immunohistochemistry in the hippocampus. Protein levels were measured by Western blot (WB) and immunofluorescence at 3 and 7 days after surgery. RESULTS: Surgery-induced cognitive decline lasts three days, but not seven days after surgery in the model group. Transmission electron microscope showed the mitochondrial structure damage in the model group, similar changes were not induced in the Dex group. Dexmedetomidine may reverse the decrease in mitochondrial membrane potential and mitochondrial complex activity. Compared with the Control group, the expression of cytochrome c was significantly increased in model group by Western blot and immunofluorescence on days 3, but not day 7. Rats from the Model group expressed significantly greater levels of Iba-1 and GFAP compared with the Control group and the Dex group. CONCLUSION: Dexmedetomidine appears to reverse surgery-induced behavior, mitigate the higher density of Iba-1 and GFAP, reduce the damage of mitochondrial structure and function by alleviating oxidative stress and protect mitochondrial respiratory chain, thus increasing cytochrome c oxidase (COX) expression and downregulate the expression of cytochrome c protein in the hippocampus of rats.

Investigation of the enhancement for Echinocandin B fermentation with methyl oleate from transcription level.

Echinocandin B (ECB) is the key precursor compound of the antifungal drug Anidulafungin. The effects of the five precursor amino acids on ECB biosynthesis were firstly investigated. It showed that although L-threonine was a main compound of the hexapeptide scaffold of ECB, exogenous addition of L-threonine had no significant effect on the increase of ECB fermentation titer. Meanwhile, the ECB fermentation titer with methyl oleate showed two times higher than that of the other carbon sources. Transcription level analysis of the key genes for ECB biosynthesis indicated that the gene an655543 related to L-threonine biosynthesis showed higher value during the fermentation process, therefore, the exogenous addition of L-threonine had no obvious affection. Furthermore, it indicated that the transcription level of gene ecdA might be the main restriction factor for the ECB biosynthesis. The study provided the research foundation for the modification of the ECB producing strains in the following work.

Attribute-based multi-user collaborative searchable encryption in COVID-19.

With the outbreak of COVID-19, the government has been forced to collect a large amount of detailed information about patients in order to effectively curb the epidemic of the disease, including private data of patients. Searchable encryption is an essential technology for ciphertext retrieval in cloud computing environments, and many searchable encryption schemes are based on attributes to control user's search permissions to protect their data privacy. The existing attribute-based searchable encryption (ABSE) scheme can only implement the situation where the search permission of one person meets the search policy and does not support users to obtain the search permission through collaboration. In this paper, we proposed a new attribute-based collaborative searchable encryption scheme in multi-user setting (ABCSE-MU), which takes the access tree as the access policy and introduces the translation nodes to implement collaborative search. The cooperation can only be reached on the translation node and the flexibility of search permission is achieved on the premise of data security. ABCSE-MU scheme solves the problem that a single user has insufficient search permissions but still needs to search, making the user's access policy more flexible. We use random blinding to ensure the confidentiality and security of the secret key, further prove that our scheme is secure under the Decisional Bilinear Diffie-Hellman (DBDH) assumption. Security analysis further shows that the scheme can ensure the confidentiality of data under chosen-keyword attacks and resist collusion attacks.

Wogonin alleviates liver injury in sepsis through Nrf2-mediated NF-κB signalling suppression.

Sepsis is a life-threatening organ dysfunction syndrome, and liver is a susceptible target organ in sepsis, because the activation of inflammatory pathways contributes to septic liver injury. Oxidative stress has been documented to participate in septic liver injury, because it not only directly induces oxidative genotoxicity, but also exacerbates inflammatory pathways to potentiate damage of liver. Therefore, to ameliorate oxidative stress is promising for protecting liver in sepsis. Wogonin is the compound extracted from the medicinal plant Scutellaria baicalensis Geogi and was found to exert therapeutic effects in multiple inflammatory diseases via alleviation of oxidative stress. However, whether wogonin is able to mitigate septic liver injury remains unknown. Herein, we firstly proved that wogonin treatment could improve survival of mice with lipopolysaccharide (LPS)- or caecal ligation and puncture (CLP)-induced sepsis, together with restoration of reduced body temperature and respiratory rate, and suppression of several pro-inflammatory cytokines in circulation. Then, we found that wogonin effectively alleviated liver injury via potentiation of the anti-oxidative capacity. To be specific, wogonin activated Nrf2 thereby promoting expressions of anti-oxidative enzymes including NQO-1, GST, HO-1, SOD1 and SOD2 in hepatocytes. Moreover, wogonin-induced Nrf2 activation could suppress NF-κB-regulated up-regulation of pro-inflammatory cytokines. Ultimately, we provided in vivo evidence that wogonin activated Nrf2 signalling, potentiated anti-oxidative enzymes and inhibited NF-κB-regulated pro-inflammatory signalling. Taken together, this study demonstrates that wogonin can be the potential therapeutic agent for alleviating liver injury in sepsis by simultaneously ameliorating oxidative stress and inflammatory response through the activation of Nrf2.

High-level production of d-pantothenic acid from glucose by fed-batch cultivation of Escherichia coli.

d-Pantothenic acid (D-PA) is an essential vitamin widely used in food, feed, chemical, and pharmaceutical industries. An Escherichia coli platform was developed for the high-level production of D-PA from glucose through fed-batch cultivation. Initially, the effects of different glucose feeding strategies D-PA synthesis were studied. It was found that D-PA production in glucose control (5 g/L) fed-batch culture reached 24.3 g/L, which was 4.09 times that in the batch culture. Next, the effect of auxotrophic amino acid (isoleucine)-limited feeding on D-PA production was investigated. The results revealed that isoleucine feeding decreased the accumulation of by-product acetic acid and promoted D-PA production significantly. Furthermore, an isoleucine feeding embedded multistage glucose supply strategy was established, and a maximum titer of 39.1 g/L was achieved. To the best of our knowledge, this levels are the highest reported so far in engineered E. coli for the D-PA production. The developed fed-batch feeding strategy may be useful for the industrial D-PA production by E. coli.

Electroacupuncture ameliorates post-traumatic stress disorder in rats via a mechanism involving the BDNF-TrkB signaling pathway.

Post-traumatic stress disorder (PTSD) is a mental health condition triggered by a terrifying event, causing flashbacks, nightmares and severe anxiety. It develops in individuals who have experienced a shocking, scary, or dangerous event. Electroacupuncture is reported to be effective for the treatment of PTSD. The present study was carried out to investigate the protective effect of electroacupuncture in a rat model of PTSD, and the mechanism involved. Specific-pathogen-free male Sprague Dawley rats (n = 30) weighing 180 - 220 g (mean weight = 200 ± 20 g) were randomly assigned to three groups of ten rats each: control group, single-prolonged stress (SPS) group, and treatment group. The treatment group rats received electroacupuncture. Changes in PTSD-like behavior were assessed using locomotor activity, elevated plus-maze (EPM) and fear conditioning tests. The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) were determined using real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting, respectively. Co-immunoprecipitation (Co-IP) was used to measure BDNF and TrkB binding interaction, while chromatin immunoprecipitation (ChIP) was used to evaluate the binding between cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and its target genes. Electroacupuncture significantly increased locomotor activity and exploratory behavior, but significantly reduced general fear and anxiety in SPS rats (p < 0.05). It also significantly upregulated the mRNA and protein expressions of BDNF and TrkB, and increased the binding of BDNF to its receptor TrkB (p < 0.05). Electroacupuncture significantly increased the binding of CREB to BDNF promoter region (p < 0.05). Electroacupuncture ameliorates PTSD in rats via a mechanism involving the BDNF-TrkB signaling pathway.

Effect of dissolved oxygen on L-methionine production from glycerol by Escherichia coli W3110BL using metabolic flux analysis method.

L-Methionine is an essential amino acid in humans, which plays an important role in the synthesis of some important amino acids and proteins. In this work, metabolic flux of batch fermentation of L-methionine with recombinant Escherichia coli W3110BL was analyzed using the flux balance analysis method, which estimated the intracellular flux distributions under different dissolved oxygen conditions. The results revealed the producing L-methionine flux of 4.8 mmol/(g cell·h) [based on the glycerol uptake flux of 100 mmol/(g cell·h)] was obtained at 30% dissolved oxygen level which was higher than that of other dissolved oxygen levels. The carbon fluxes for synthesizing L-methionine were mainly obtained from the pathway of phosphoenolpyruvate to oxaloacetic acid [15.6 mmol/(g cell·h)] but not from the TCA cycle. Hence, increasing the flow from phosphoenolpyruvate to oxaloacetic acid by enhancing the enzyme activity of phosphoenolpyruvate carboxylase might be conducive to the production of L-methionine. Additionally, pentose phosphate pathway could provide a large amount of reducing power NADPH for the synthesis of amino acids and the flux could increase from 41 mmol/(g cell·h) to 51 mmol/(g cell·h) when changing the dissolved oxygen levels, thus meeting the requirement of NADPH for L-methionine production and biomass synthesis. Therefore, the following modification of the strains should based on the improvement of the key pathway and the NAD(P)/NAD(P)H metabolism.

Effects of methyl oleate and microparticle-enhanced cultivation on echinocandin B fermentation titer.

Echinocandin B (ECB) is a key precursor of antifungal agent Anidulafungin, which has demonstrated clinical efficacy in patients with invasive candidiasis. In this study, the effects of microparticle-enhanced cultivation and methyl oleate on echinocandin B fermentation titer were investigated. The results showed that the titer was significantly influenced by the morphological type of mycelium, and mycelium pellet was beneficial to improve the titer of this secondary metabolism. First, different carbon sources were chosen for the fermentation, and methyl oleate achieved the highest echinocandin B titer of 2133 ± 50 mg/L, which was two times higher than that of the mannitol. The study further investigated the metabolic process of the fermentation, and the results showed that L-threonine concentration inside the cell could reach 275 mg/L at 168 h with methyl oleate, about 2.5 times higher than that of the mannitol. Therefore, L-threonine may be a key precursor of echinocandin B. In the end, a new method of adding microparticles for improving the mycelial morphology was used, and the addition of talcum powder (20 g/L, diameter of 45 µm) could make the maximum titer of echinocandin B reach 3148 ± 100 mg/L.

Mutagenesis of echinocandin B overproducing Aspergillus nidulans capable of using starch as main carbon source.

Echinocandin B, a kind of antimycotic with cyclic lipo-hexapeptides, was produced by fermentation with Aspergillus nidulans using fructose as main carbon source. The objective of this study was to screen a high-yield mutant capable of using cheap starch as main carbon source by atmospheric and room temperature plasma (ARTP) treatment in order to decrease the production cost of echinocandin B. A stable mutant A. nidulans ZJB19033, which can use starch as optimal carbon source instead of expensive fructose, was selected from two thousands isolates after several cycles of ARTP mutagenesis. To further increase the production of echinocandin B, the optimization of fermentation medium was performed by response surface methodology (RSM), employing Plackett-Burman design (PBD) followed by Box-Behnken design (BBD). The optimized fermentation medium provided the optimal yield of echinocandin B, 2425.9 ± 43.8 mg/L, 1.3-fold compared to unoptimized medium. The results indicated that the mutant could achieve high echinocandin B production using cheap starch as main carbon source, and the cost of carbon sources in fermentation medium reduced dramatically by about 45%.

Use of propofol for prevention of post-delivery nausea during cesarean section: a double-blind, randomized, placebo-controlled trial.

PURPOSE: Nausea and vomiting are common, undesirable symptoms during cesarean section. We conducted this study to assess the antiemetic properties of propofol for the prevention and immediate treatment of post-delivery nausea and vomiting during cesarean section under combined spinal-epidural anesthesia. METHODS: Eighty women undergoing elective cesarean delivery under combined spinal-epidural anesthesia were randomized to receive either propofol at a plasma concentration of 1000 ng/mL or normal saline immediately after clamping of the umbilical cord. The incidence of post-delivery nausea and vomiting, patients requiring rescue antiemetic, bispectral index, sedation score, and the incidence of hypotension were assessed intraoperatively. Satisfaction and neonatal behavioral neurological assessments were evaluated postoperatively. RESULTS: The incidence of nausea was significantly lower in the propofol group compared to the placebo group (25% versus 60%, P < 0.001). The incidence of retching and vomiting showed no significant difference between the two groups. Propofol 20 mg as a rescue antiemetic was significantly effective in both the groups. Satisfaction level of patients and obstetricians in the propofol group was higher than in the placebo group. There was no statistical difference in the incidence of hypotension between the two groups both pre- and post-delivery. There was no difference in postoperative neonatal behavioral neurological assessment between groups. CONCLUSION: Propofol at a plasma concentration of 1000 ng/mL significantly reduced the incidence of post-delivery nausea compared to placebo, but had no effect on reducing retching or vomiting episodes during cesarean section.

Correlation between antiplatelet therapy in secondary prevention of acute cerebral infarction and cerebral microbleeds: A susceptibility-weighted imaging (SWI) study.

OBJECTIVE: To investigate the clinical significance of antiplatelet aggregation therapy for patients diagnosed with acute cerebral infarction (ACI) complicated with the cerebral microbleeds (CMBs). METHODS: Thirty patients with ACI and 36 patients with intracerebral hemorrhage (ICH) were included in this research. Two groups, studied by susceptibility-weighted imaging (SWI), were compared in terms of the number, location, and severity of CMBs. Then, 30 cases of ACI patients were divided into CMBs sub-group and non-CMBs sub-group. Univariate analysis between these two sub-groups was performed to determine the risk factors regarding the incidence of CMBs. For ACI patients, the number of CMBs before and after applying anti-platelet treatment were compared to examine the impacts of anti-platelet treatment on hemorrhagic transformation. RESULTS: CMBs were found to be more prevalent and severe in ICH patients than in ACI patients. CMBs in patients with ICH were more severe than in patients with ischemic stroke (IS), which indicates that CMBs closely relate to ICH. Hypertension and leukoaraiosis were found to have significant effects on the incidence of CMBs. After anti-platelet treatment, patients with CMBs (≥5) increased the number of CMB, whereas there was no obvious effect on patients with the CMBs less than 5 or no CMBs. CONCLUSIONS: The number of CMBs increased significantly among ACI patients with 5 or more CMBs before the anti-platelet treatment. CMBs are more frequently found in patients with hemorrhagic stroke than in patients with ischemic stroke, and more severe than the latter, which suggests that the clinical impact of higher association between the increase of the number of the CMBs and the hemorrhagic stroke.

3-Hydroxypropionic acid production by recombinant Escherichia coli ZJU-3HP01 using glycerol-glucose dual-substrate fermentative strategy.

3-Hydroxypropionic acid (3-HP) is an important platform synthesis block for sets of chemicals, but the relatively low production of 3-HP from biological sources presented major barriers for its industrial applications. In this study, a dual-substrate fermentative strategy by glycerol and glucose was proposed, and the aim was to evaluate the effect of different substrate addition strategies on the fermentation process. The results indicated that the optimal cosubstrate was glucose (20 g/L), and the enzymatic activity of aldehyde dehydrogenase (AldH) could be improved 3.5-fold as compared with no glucose addition. Continuous fed-batch fermentation at a constant speed displayed better 3-HP production of 17.20 g/L and highest specific 3-HP productivity of 1.79 mmol/(g cell·H) than the other fed-batch mode. The addition of glucose could greatly reduce the imbalance of the activity between glycerol dehydratase and AldH and provide a feasible method for improving 3-HP production. These results would be helpful in developing the 3-HP fermentation process.

[Micro-Raman Spectral Characteristics and Implication of FeS2 from Metamorphic Belt between Coal and Intrusion in Wolonghu Coal Mine of Anhui Province, China].

Some FeS2 samples among metamorphic belt between coal and intrusion from Wolonghu mine in the north of Anhui Province were retrieved to characterize the signature of Raman Spectral. The results show that, all Raman data of different samples can be divided into 3 types as Ⅰ, Ⅱ and Ⅲ according to distinct differences of in Raman mode (M), Raman shift (Δν) and scattering intensity (Ⅰ). There are five strong scattering modes including high value Eg (1.16~1.59×103), high value Ag (2.33~2.53×103) and low value Tg (0.20~0.27×103) in typeⅠand only former three modes in type Ⅱ although the value of Eg, Ag and Tg are similar between them. While there are only two modes of high value Eg about 327.6~328.8 cm-1 and low value Ag 389.0~390.1 cm-1. Our analyses indicate that type Ⅰ samples must be mixed crystal of pyrite and natural coke for the former three peaks are same to deformation and stretching vibration of Fe-[S2]2- and stretching vibration of S­S in pyrite, while the latter two are similar to the vibration of Tiny graphite crystals and stretching vibration of C­C among graphite crystal from Raman data. And typeⅡsample may be pyrite for typical pyrite Scattering peak and Type Ⅲ sample possibility are low-temperature crystalloblastic of pyrite for Marcasite spectrum features in Raman. Further analysis also showed that the formation pressure of typeⅠ and Ⅱ are the same while type Ⅲ samples formed in low pressure for Raman scattered intensity of typeⅠand Ⅱ are similar, and type Ⅲ samples is obviously lower than the former two. And the formation temperature of typeⅠ, typeⅡ and type Ⅲ significantly decreased in turn for Ag peak of them are turn to high frequency about 4.4~6.7, 4.5~8.4cm-1 respectively compared with the former. Thus，The authors' studies suggest that pyrite samples from Metamorphic coal and metamorphic zone in Wolonghu coal mine are products in high temperature, but samples from Magmatic rocks are Marcasite formed at low temperature.

Mutagenesis breeding of high echinocandin B producing strain and further titer improvement with culture medium optimization.

A combination of microbial strain improvement and statistical optimization is investigated to maximize echinocandin B (ECB) production from Aspergillus nidulans ZJB-0817. A classical sequential mutagenesis was studied first by using physical (ultraviolet irradiation at 254 nm) and chemical mutagens (lithium chloride and sodium nitrite). Mutant strain ULN-59 exhibited 2.1-fold increase in ECB production to 1583.1 ± 40.9 mg/L when compared with the parent strain (750.8 ± 32.0 mg/L). This is the first report where mutagenesis is applied in Aspergillus to improve ECB production. Further, fractional factorial design and central composite design were adopted to optimize the culture medium for increasing ECB production by the mutant ULN-59. Results indicated that four culture media including peptone, K2HPO4, mannitol and L-ornithine had significant effects on ECB production. The optimized medium provided another 1.4-fold increase in final ECB concentration to 2285.6 ± 35.6 mg/L compared to the original medium. The results of this study indicated the combined application of a classical mutation and medium optimization can improve effectively ECB production from A. nidulans and could be a promising tool to improve other secondary metabolites production by fungal strains.

[Effect of microparticle on fermentation process of filamentous microorganisms--a review].

Filamentous microorganisms are important biocatalysts for the fermentation industry. They usually present three types of mycelial morphology in submerged cultivation: dispersed mycelium, clumps and pellet, which have an important relationship with the product quality and yield. This paper summarizes the effect of mycelial morphology on the fermentation results as well as the effect of adding microparticles on mycelial morphology, mycelial structure and fermentation yield during the fermentation process of filamentous microorganisms.

[Optimization of the fermentative production of L-methionine by engineered Escherichia coli].

As the only essential amino acid containing elemental sulphur, L-methionine has important physiological and biochemical functions in living organisms. However, the fermentative production of L-methionine has not met the requirements of industrial production because of its low production level. In this paper, the fermentation process of an efficient L-methionine producing strain E. coli W3110ΔIJAHFEBC trc-fliY trc-malY/PAM glyA-22 metF constructed previously was systematically optimized. Based on the optimal initial glucose concentration, the effects of different fed-batch fermentation processes, including DO-Stat, pH-Stat, controlling residual sugar control at different level and feeding glucose with constant rate, on L-methionine fermentation were studied. It was found that the control of glucose concentration greatly affected the fermentation process. Subsequently, an optimal fed-batch fermentation process was developed, where the L-methionine titer was increased to 31.71 g/L, the highest yield reported to date, while the fermentation time was shortened to 68 h. Meanwhile, a fermentation kinetics model under the optimal fed-batch fermentation conditions was established, which fitted well with the biosynthesis process of L-methionine. This study may facilitate further development of the fermentative production of L-methionine.

STING Membrane Prevents Post-Surgery Tissue Adhesion and Tumor Recurrence of Colorectal Cancer.

Surgery is the standard treatment regimen for resectable colorectal cancer (CRC). However, it is very hard to completely remove all cancer cells in clinical practice, leading to the high recurrence rates of the disease. Moreover, the post-surgery tissue adhesion greatly prevents the possibility of reoperation, significantly limiting the long-term surviving of CRC patients. To overcome CRC recurrence and avoid the post-surgery tissue adhesion, this work develops a novel stimulator of interferon genes "STING" membrane based on the coaxial electrospinning technology and hyaluronic acid modification. A reactive oxygen species responsive prodrug of gambogic acid (GB) and a potent STING agonist (CDN) are coloaded in the core-shell structure of the membrane, which endows the loaded drug with sustained and sequential release patterns. The localized delivery of GB and CDN can selectively induce efficient immunogenic cell death of cancer cells and then evoke the systemic anticancer immunity by activating the Cyclic GMP-AMP (cGAMP) synthase/STING pathway. As-designed "STING" membrane not only safely prevents tumor recurrence through the synergistic chemoimmunotherapy but also efficiently avoids the post-surgery tissue adhesion, facilitating the clinical intervention of CRC.

[Efficient synthesis of L-methionine by engineering the one carbon module of Escherichia coli].

L-methionine, also known as L-aminomethane, is one of the eight essential amino acids required by the human body and has important applications in the fields of feed, medicine, and food. In this study, an L-methionine high-yielding strain was constructed using a modular metabolic engineering strategy based on the M2 strain (Escherichia coli W3110 ΔIJAHFEBC/PAM) previously constructed in our laboratory. Firstly, the production of one-carbon module methyl donors was enhanced by overexpression of methylenetetrahydrofolate reductase (methylenetetrahydrofolate reductase, MetF) and screening of hydroxymethyltransferase (GlyA) from different sources, optimizing the one-carbon module. Subsequently, cysteamine lyase (hydroxymethyltransferase, MalY) and cysteine internal transporter gene (fliY) were overexpressed to improve the supply of L-homocysteine and L-cysteine, two precursors of the one-carbon module. The production of L-methionine in shake flask fermentation was increased from 2.8 g/L to 4.05 g/L, and up to 18.26 g/L in a 5 L fermenter. The results indicate that the one carbon module has a significant impact on the biosynthesis of L-methionine, and efficient biosynthesis of L-methionine can be achieved through optimizing the one carbon module. This study may facilitate further improvement of microbial fermentation production of L-methionine.

Electroacupuncture ameliorates surgery-induced spatial memory deficits by promoting mitophagy in rats.

Background: This study sought to explore the mechanism underlying the therapeutic effects of electroacupuncture (EA) on spatial memory deficits caused by surgery. Methods: Hepatic apex resection was performed under propofol-based total intravenous anesthesia. Male Sprague-Dawley rats were subjected to EA treatment or EA + mitochondrial division inhibitor-1 (mdivi-1) treatment once a day for three consecutive days after surgery. The Morris water maze test was used to evaluate the spatial memory of the rats after surgery. Tissue from the hippocampus of each rat was frozen and used for transcriptomic and proteomic analyses to identify potential targets for EA treatment. Western blotting was used to confirm the protein expression levels. The levels of reactive oxygen species (ROS) and adenosine triphosphate (ATP) were detected using commercial kits. The rat mitochondria were then isolated, and the activity of mitochondrial complex V was assessed. Results: EA attenuated surgery-induced spatial memory deficits on postoperative day 3, while these effects were reversed by treatment with the mdivi-1 (P<0.05). Ribonucleic acid (RNA)-sequencing revealed that EA upregulated multiple metabolic pathways and the phosphatidylinositol 3­kinas/protein kinase B signaling pathway. The proteomic and western blotting results suggested that the EA treatment substantially downregulated coiled-coil-helix-coiled-coil-helix domain containing 3 (ChChd3) expression in the hippocampus. The EA treatment significantly increased the autophagy-related protein levels, including phosphatase and tensin homolog-induced kinase 1, Parkin, MAP1LC3 (LC3), and Beclin1, and inhibited the production of ROS and inflammatory cytokine interleukin-1ß in the hippocampus (P<0.05). Conclusions: These results suggest that EA ameliorates postoperative spatial memory deficits and protects hippocampus from oxidative stress and inflammation through enhanced autophagy in an animal model of perioperative neurocognitive disorders (PNDs).

High-Level Production of l-Methionine by Dynamic Deregulation of Metabolism with Engineered Nonauxotroph Escherichia coli.

l-Methionine is the only sulfur-containing amino acid among the essential amino acids, and it is mainly produced by the chemical method in industry so far. The fermentation production of l-methionine by genetically engineered strains is an attractive alternative. Due to the complex metabolic mechanism and multilevel regulation of the synthesis pathway in the organism, the fermentation production of l-methionine by genetically engineered strains was still not satisfied. In this study, the biosynthesis pathway of l-methionine was regulated based on the previous studies. As the competitive pathway and an essential amino acid for cell growth, the biosynthesis pathway of l-lysine was first repaired by complementation of the lysA gene in situ on the genome and then replaced the in situ promoter with the dynamically regulated promoter PfliA to construct a nonauxotroph strain. In addition, the central metabolic pathway and l-cysteine catabolism pathway were further modified to promote the cell growth and enhance the l-methionine production. Finally, the l-methionine fermentation yield in a 5 L bioreactor reached 17.74 g/L without adding exogenous amino acids. These strategies can effectively balance the contradiction between cell growth and l-methionine production and alleviate the complexity of fermentation operation and the cost with auxotroph strains, which provide a reference for the industrial production of l-methionine by microbial fermentation.