ObjectiveTo investigate the association of serum exosomal microRNAs （miRNAs） with hepatic inflammatory injury and histological outcomes in patients with chronic hepatitis B （CHB）. MethodsPeripheral serum samples were collected from six healthy adults and six patients with CHB， and size exclusion chromatography was used to extract exosomes. Small RNA sequencing and transcriptomic analysis were used to identify the serum exosomal miRNAs associated with liver inflammatory injury and fibrosis， and quantitative real-time PCR was used for validation in a mouse model of acute liver injury induced by lipopolysaccharide/D-galactosamine， a rat model of liver fibrosis induced by carbon tetrachloride， and 84 CHB patients undergoing liver biopsy twice before and after treatment. The independent-samples t test was used for comparison of normally distributed continuous data between two groups； an analysis of variance was used for comparison between multiple groups， and the Tukey test was used for further comparison between two groups. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups； the Kruskal-Wallis H test was used for comparison between multiple groups， and the Dunn test was used for further comparison between two groups. The chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups. The univariate and multivariate Logistic regression analyses were used to investigate influencing factors. ResultsAbnormal expression of serum exosomal miR-122-5p was observed in patients with CHB， and it was downregulated in patients with confluent necrosis and advanced fibrosis. In the mouse model of acute liver injury and the rat model of liver fibrosis， compared with the control group， the model group had a significant reduction in the expression level of miR-122-5p in the liver （P=0.048 and 0.014）， and compared with the patients with mild liver injury， the patients with severe confluent necrosis and advanced fibrosis showed a significant reduction in the expression level of miR-122-5p in liver tissue （P<0.05）. Among the 84 CHB patients， the patients with severe hepatic confluent necrosis or advanced liver fibrosis had a significantly lower expression level of serum exosomal miR-122-5p than those with mild liver injury （P<0.001 and P=0.003）. The multivariate Logistic regression analysis showed that the expression level of miR-122-5p was an independent influencing factor for confluent necrosis （odds ratio ［OR］=0.001， 95% confidence interval ［CI］： 0.000‍ ‍—‍ ‍0.037， P=0.005） and liver fibrosis degree （OR=0.568， 95%CI： 0.331‍ ‍—‍ ‍0.856， P=0.019）. In addition， compared with the patients with low expression of miR-122-5p， the patients with high expression of miR-122-5p before treatment had a significantly higher reversal rate of liver fibrosis after 72 weeks of antiviral therapy （64.3% vs 38.1%， P=0.029）. ConclusionSerum exosomal miR-122-5p in CHB patients is closely associated with the progression of hepatic confluent necrosis and fibrosis， and the reduction in the expression level of miR-122-5p may aggravate hepatic confluent necrosis， promote the progression of fibrosis， and affect the histological outcome of CHB patients after antiviral therapy.

L-citrulline is a nonprotein amino acid that plays an important role in human health and has great market demand. Although microbial cell factories have been widely used for biosynthesis, there are still challenges such as genetic instability and low efficiency in the biosynthesis of L-citrulline. In this study, an efficient, plasmid-free, non-inducible L-citrulline-producing strain of Escherichia coli BL21(DE3) was engineered by combined strategies. Firstly, a chassis strain capable of synthesizing L-citrulline was constructed by block of L-citrulline degradation and removal of feedback inhibition, with the L-citrulline titer of 0.43 g/L. Secondly, a push-pull-restrain strategy was employed to enhance the L-citrulline biosynthesis, which realized the L-citrulline titer of 6.0 g/L. Thirdly, the NADPH synthesis and L-citrulline transport were strengthened to promote the synthesis efficiency, which achieved the L-citrulline titer of 11.6 g/L. Finally, fed-batch fermentation was performed with the engineered strain in a 3 L fermenter, in which the L-citrulline titer reached 44.9 g/L. This study lays the foundation for the industrial production of L-citrulline and provides insights for the modification of other amino acid metabolic networks.
Citrulline/biosynthesis* ; Escherichia coli/genetics* ; Metabolic Engineering/methods* ; Fermentation ; NADP/biosynthesis*

Objective To investigate the association of serum exosomal microRNAs(miRNAs)with hepatic inflammatory injury and histological outcomes in patients with chronic hepatitis B(CHB).Methods Peripheral serum samples were collected from six healthy adults and six patients with CHB,and size exclusion chromatography was used to extract exosomes.Small RNA sequencing and transcriptomic analysis were used to identify the serum exosomal miRNAs associated with liver inflammatory injury and fibrosis,and quantitative real-time PCR was used for validation in a mouse model of acute liver injury induced by lipopolysaccharide/D-galactosamine,a rat model of liver fibrosis induced by carbon tetrachloride,and 84 CHB patients undergoing liver biopsy twice before and after treatment.The independent-samples t test was used for comparison of normally distributed continuous data between two groups;an analysis of variance was used for comparison between multiple groups,and the Tukey test was used for further comparison between two groups.The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups;the Kruskal-Wallis H test was used for comparison between multiple groups,and the Dunn test was used for further comparison between two groups.The chi-square test or the Fisher's exact test was used for comparison of categorical data between groups.The univariate and multivariate Logistic regression analyses were used to investigate influencing factors.Results Abnormal expression of serum exosomal miR-122-5p was observed in patients with CHB,and it was downregulated in patients with confluent necrosis and advanced fibrosis.In the mouse model of acute liver injury and the rat model of liver fibrosis,compared with the control group,the model group had a significant reduction in the expression level of miR-122-5p in the liver(P=0.048 and 0.014),and compared with the patients with mild liver injury,the patients with severe confluent necrosis and advanced fibrosis showed a significant reduction in the expression level of miR-122-5p in liver tissue(P<0.05).Among the 84 CHB patients,the patients with severe hepatic confluent necrosis or advanced liver fibrosis had a significantly lower expression level of serum exosomal miR-122-5p than those with mild liver injury(P<0.001 and P=0.003).The multivariate Logistic regression analysis showed that the expression level of miR-122-5p was an independent influencing factor for confluent necrosis(odds ratio[OR]=0.001,95%confidence interval[CI]:0.000-0.037,P=0.005)and liver fibrosis degree(OR=0.568,95%CI:0.331-0.856,P=0.019).In addition,compared with the patients with low expression of miR-122-5p,the patients with high expression of miR-122-5p before treatment had a significantly higher reversal rate of liver fibrosis after 72 weeks of antiviral therapy(64.3%vs 38.1%,P=0.029).Conclusion Serum exosomal miR-122-5p in CHB patients is closely associated with the progression of hepatic confluent necrosis and fibrosis,and the reduction in the expression level of miR-122-5p may aggravate hepatic confluent necrosis,promote the progression of fibrosis,and affect the histological outcome of CHB patients after antiviral therapy.

BACKGROUND:Dapagliflozin,an inhibitor of sodium-glucose cotransporter 2,can delay the progression of atherosclerosis by regulating glucose metabolism,inhibiting inflammation and improving endothelial cell function. OBJECTIVE:To study the effect of dapagliflozin on cell pyroptosis and endothelial dysfunction induced by oxidized low-density lipoprotein. METHODS:Human umbilical vein endothelial cells were divided into a control group(no intervention),a model group(treated with oxidized low-density lipoprotein for 24 hours),and a dapagliflozin group(treated with oxidized low-density lipoprotein + dapagliflozin for 24 hours).Endothelial cell proliferation activity was measured by cell counting kit-8 assay.The levels of intercellular adhesion molecule 1,vascular cell adhesion molecule 1,and monocyte chemotactic protein-1 in cell supernatant were detected using ELISA.Nitric oxide level in the cells was detected by nitrate reductase assay.The pyroptosis rate and characteristics of endothelial cells were detected by Hoechst 33342/PI fluorescence co-staining and lactate dehydrogenase release assay.The protein expression levels of NLRP3,caspase-1,GSDMD,interleukin-1β,and interleukin-18 were detected by western blot assay. RESULTS AND CONCLUSION:(1)Oxidized low-density lipoprotein could cause pyroptosis and dysfunction of endothelial cells.(2)Compared with the control group,the level of nitric oxide and cell activity were decreased(P<0.05),while lactate dehydrogenase,intercellular adhesion molecule 1,vascular cell adhesion molecule 1,and monocyte chemotactic protein-1 levels were significantly increased in the model group(P<0.05).Compared with the model group,cell activity and nitric oxide levels significantly increased(P<0.05),but lactate dehydrogenase,intercellular adhesion molecule 1,vascular cell adhesion molecule 1,and monocyte chemotactic protein-1 levels were significantly diminished in the dapagliflozin group(P<0.05).(3)Compared with the model group,cell pyroptosis rate and the protein expression of pyroptosis factor NLRP3,caspase-1,GSDMD,interleukin-18 and interleukin-1β significantly reduced in the dapagliflozin group(P<0.05).(4)The results indicate that dapagliflozin inhibits oxidized low-density lipoprotein-induced endothelial pyroptosis and ameliorates endothelial cell dysfunction.

Herein, we define the role of ferroptosis in the pathogenesis of diabetic cardiomyopathy (DCM) by examining the expression of key regulators of ferroptosis in mice with DCM and a new ex vivo DCM model. Advanced glycation end-products (AGEs), an important pathogenic factor of DCM, were found to induce ferroptosis in engineered cardiac tissues (ECTs), as reflected through increased levels of Ptgs2 and lipid peroxides and decreased ferritin and SLC7A11 levels. Typical morphological changes of ferroptosis in cardiomyocytes were observed using transmission electron microscopy. Inhibition of ferroptosis with ferrostatin-1 and deferoxamine prevented AGE-induced ECT remodeling and dysfunction. Ferroptosis was also evidenced in the heart of type 2 diabetic mice with DCM. Inhibition of ferroptosis by liproxstatin-1 prevented the development of diastolic dysfunction at 3 months after the onset of diabetes. Nuclear factor erythroid 2-related factor 2 (NRF2) activated by sulforaphane inhibited cardiac cell ferroptosis in both AGE-treated ECTs and hearts of DCM mice by upregulating ferritin and SLC7A11 levels. The protective effect of sulforaphane on ferroptosis was AMP-activated protein kinase (AMPK)-dependent. These findings suggest that ferroptosis plays an essential role in the pathogenesis of DCM; sulforaphane prevents ferroptosis and associated pathogenesis via AMPK-mediated NRF2 activation. This suggests a feasible therapeutic approach with sulforaphane to clinically prevent ferroptosis and DCM.

Fermentative production of amino acids is one of the pillars of the fermentation industry in China. Recently, with the fast development of metabolic engineering and synthetic biology technologies, the metabolic engineering for production of amino acids has been flourishing. Conventional forward metabolic engineering, reversed metabolic engineering based on omics data and in silico simulation, and evolutionary metabolic engineering mimicking the natural evolution, have shown increasingly promising applications. A series of highly efficient and robust amino acids-producing strains have been developed and applied in the industrial production of amino acids. The increasingly fierce market competition has put forward new requirements for strain breeding and selection, such as developing high value-added amino acids, dynamic regulation of cellular metabolism, and adapting to the requirements of new process. This review summarizes the advances and prospects in metabolic engineering for the production of amino acids.
Amino Acids ; China ; Corynebacterium glutamicum/genetics* ; Metabolic Engineering ; Synthetic Biology

BACKGROUND: The 2019 novel coronavirus disease (COVID-19) has had a massive impact on public health, resulting in sudden dietary and behavioral habit changes. Frontline epidemic prevention workers play a pivotal role against COVID-19. They must face high-risk infection conditions, insufficient anti-epidemic material supplies, mental pressure, and so on. COVID-19 seriously affects their dietary and behavioral habits, and poor habits make them more susceptible to COVID-19. However, their baseline dietary and behavioral habits before COVID-19 and their willingness to change these habits after the outbreak of COVID-19 remain unclear for these workers in China. This study aimed to explore the baseline dietary and behavioral habits of frontline workers and their willingness to change these habits after the outbreak of the epidemic; in addition, susceptible subgroups were identified by stratified analyses as targets of protective measures to keep them from being infected with COVID-19. METHODS: A cross-sectional study was conducted through an online questionnaire using a sample of 22,459 valid individuals living in China, including 9402 frontline epidemic prevention workers. RESULTS: Before COVID-19, 23.9% of the frontline epidemic prevention workers reported a high-salt diet, 46.9% of them reported a high frequency of fried foods intake, and 50.9% of them smoked cigarettes. After the outbreak of COVID-19, 34.6% of them expressed a willingness to reduce salt intake, and 43.7% of them wanted to reduce the frequency of pickled vegetables intake. A total of 37.9% of them expressed a willingness to decrease or quit smoking, and 44.5% of them wanted to increase sleep duration. Significant differences in the baseline dietary and behavioral habits and the willingness to change their habits were observed between frontline epidemic prevention workers and other participants. Among the frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19, frontline epidemic prevention experience was a promoting factor for adopting worse dietary and behavioral habits, including those in the high-salt intake subgroup (OR, 2.824; 95% CI, 2.341-3.405) and the 11-20 cigarettes/day subgroup (OR, 2.067; 95% CI, 1.359-3.143). CONCLUSIONS The dietary and behavioral habits of frontline epidemic prevention workers were worse than that those of other participants before COVID-19. They had a greater willingness to adopt healthy dietary and behavioral habits after experiencing the outbreak of COVID-19. However, frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19 continued in engage in these poor habits. Dietary and behavioral intervention policies should be drafted to protect their health, especially frontline epidemic prevention workers with poor habits at baseline.
Adult ; COVID-19/psychology* ; China/epidemiology* ; Cross-Sectional Studies ; Diet/standards* ; Female ; Health Behavior ; Health Knowledge, Attitudes, Practice ; Health Personnel/psychology* ; Humans ; Male ; Risk Reduction Behavior ; SARS-CoV-2 ; Surveys and Questionnaires

Objective: To investigate the feasibility of myeloid and plasmacytoid dendritic cell combined vaccines loaded with heat-treated Lewis lung cancer cell lysates for treatment of lung cancer in mice. Methods: Bone marrow cells were induced by the recombinant mouse fms-like tyrosine kinase receptor 3 ligand (rmFlt3-L) in vitro, myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC) were separated by magnetic beads. The mDC, pDC, and mDC∶pDC=1∶1 were stimulated with heat-treated Lewis lung cancer cell lysates, respectively. The effects of each group on stimulating of lymphocyte proliferation and inducing of T cell to kill tumor cells in vitro were compared. The alternations of the immunophenotypes of CD80, CD86, CD40 and major histocompatibility complex Ⅱ (MHC-Ⅱ) were detected by flow cytometry. The secretion of cytokines including interlukin-12 (IL-12), interlukin-6 (IL-6), and tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). Results: The lymphocyte proliferation in mice stimulated with mDC+ pDC group loaded with heat-treated Lewis lung cancer cell lysates was 10.80±0.66, significantly higher than 8.63±0.65 of mDC group and 7.10±0.46 pDC group under the same culture conditions, respectively (P<0.05). When the ratio of effector cells: target cells (E∶T) was 10∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 31.68%±2.93%, significantly higher than 17.44%±0.97% of mDC group and 10.29%±1.33% of pDC group, respectively (P<0.05). When the ratio of E∶T was 20∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 54.77%±3.28%, significantly higher than 35.25%±1.51% of mDC group and 15.52%±0.73% of pDC group, respectively (P<0.05). When the ratio of E∶T was 40∶1, the killing rate of the mDC+ pDC group loaded with heat-treated tumor cell lysate was 73.01%±0.91%, significantly higher than 51.36%±0.58% of mDC group and 22.65%±1.28% of pDC group, respectively (P<0.05). With the rate of E∶T increased, the killing rate also increased. The mean fluorescence intensities of surface molecules including CD80, CD86, CD40 and MHC-Ⅱ of mDC: pDC=1 group pulsed with heat-treated Lewis lung cancer cell lysates were higher than those of mDC group and pDC group. The IL-6 cytokine concentrations of mDC+ pDC group, mDC group and pDC group loaded with heat-treated Lewis lung cancer cell lysates were (586.67±52.52) pg/ml, (323.33±67.14) pg/ml and (166.67±16.07) pg/ml, respectively. The concentrations of IL-12 in each group were (2 568.75±119.24) pg/ml, (2 156.25±120.55) pg/ml and (672.92±31.46) pg/ml, respectively. The concentrations of TNF-α in each group were (789.33±48.08) pg/ml, (584.89±116.49) pg/ml and (291.56±40.73) pg/ml, respectively. The concentrations of IL-6, IL-12 and TNF-α secreted by mDC+ pDC group were much higher than those of mDC group and pDC group under the same culture conditions (P<0.05). Conclusions The mDCs and pDCs combined vaccines pulsed with heat-treated Lewis lung cancer cell lysates have synergistic effects on inducing of T lymphocyte proliferation and killing tumor cells in vitro. This synergistic anti-tumor effect is related with up-regulation of co-stimulatory molecules and increased secretion of cytokines.

To investigate the feasibility of myeloid and plasmacytoid dendritic cell combined vaccines loaded with heat?treated Lewis lung cancer cell lysates for treatment of lung cancer in mice. Methods Bone marrow cells were induced by the recombinant mouse fms?like tyrosine kinase receptor 3 ligand ( rmFlt3?L) in vitro, myeloid dendritic cells ( mDC) and plasmacytoid dendritic cells (pDC) were separated by magnetic beads. The mDC, pDC, and mDC ∶ pDC＝1 ∶ 1 were stimulated with heat?treated Lewis lung cancer cell lysates, respectively. The effects of each group on stimulating of lymphocyte proliferation and inducing of T cell to kill tumor cells in vitro were compared. The alternations of the immunophenotypes of CD80, CD86, CD40 and major histocompatibility complex Ⅱ( MHC?Ⅱ) were detected by flow cytometry. The secretion of cytokines including interlukin?12 (IL?12), interlukin?6 (IL?6), and tumor necrosis factor α ( TNF?α) were detected by enzyme?linked immunosorbent assay ( ELISA). Results The lymphocyte proliferation in mice stimulated with mDC+pDC group loaded with heat?treated Lewis lung cancer cell lysates was 10.80±0.66, significantly higher than 8.63±0.65 of mDC group and 7.10±0.46 pDC group under the same culture conditions, respectively ( P＜0.05). When the ratio of effector cells:target cells (E ∶ T) was 10 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 31.68%±2.93%, significantly higher than 17.44%±0.97% of mDC group and 10.29%±1.33% of pDC group, respectively (P＜0.05). When the ratio of E ∶ T was 20 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 54.77%± 3.28%, significantly higher than 35.25%± 1.51% of mDC group and 15.52%±0.73% of pDC group, respectively (P＜0.05). When the ratio of E ∶ T was 40 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 73.01%± 0.91%, significantly higher than 51.36%± 0.58% of mDC group and 22.65%± 1.28% of pDC group, respectively (P＜0.05 ). With the rate of E ∶ T increased, the killing rate also increased. The mean fluorescence intensities of surface molecules including CD80, CD86, CD40 and MHC?Ⅱ of mDC:pDC＝1 group pulsed with heat?treated Lewis lung cancer cell lysates were higher than those of mDC group and pDC group. The IL?6 cytokine concentrations of mDC+pDC group, mDC group and pDC group loaded with heat?treated Lewis lung cancer cell lysates were (586.67±52.52) pg／ml, (323.33±67.14) pg／ml and (166.67± 16.07) pg／ml, respectively. The concentrations of IL?12 in each group were ( 2 568.75± 119.24) pg／ml, (2 156.25±120.55) pg／ml and (672.92±31.46) pg／ml, respectively. The concentrations of TNF?α in each group were (789.33±48.08) pg／ml, (584.89±116.49) pg／ml and (291.56±40.73) pg／ml, respectively. The concentrations of IL?6, IL?12 and TNF?α secreted by mDC+pDC group were much higher than those of mDC group and pDC group under the same culture conditions ( P＜0.05). Conclusions The mDCs and pDCs combined vaccines pulsed with heat?treated Lewis lung cancer cell lysates have synergistic effects on inducing of T lymphocyte proliferation and killing tumor cells in vitro. This synergistic anti?tumor effect is related with up?regulation of co?stimulatory molecules and increased secretion of cytokines.

To investigate the feasibility of myeloid and plasmacytoid dendritic cell combined vaccines loaded with heat?treated Lewis lung cancer cell lysates for treatment of lung cancer in mice. Methods Bone marrow cells were induced by the recombinant mouse fms?like tyrosine kinase receptor 3 ligand ( rmFlt3?L) in vitro, myeloid dendritic cells ( mDC) and plasmacytoid dendritic cells (pDC) were separated by magnetic beads. The mDC, pDC, and mDC ∶ pDC＝1 ∶ 1 were stimulated with heat?treated Lewis lung cancer cell lysates, respectively. The effects of each group on stimulating of lymphocyte proliferation and inducing of T cell to kill tumor cells in vitro were compared. The alternations of the immunophenotypes of CD80, CD86, CD40 and major histocompatibility complex Ⅱ( MHC?Ⅱ) were detected by flow cytometry. The secretion of cytokines including interlukin?12 (IL?12), interlukin?6 (IL?6), and tumor necrosis factor α ( TNF?α) were detected by enzyme?linked immunosorbent assay ( ELISA). Results The lymphocyte proliferation in mice stimulated with mDC+pDC group loaded with heat?treated Lewis lung cancer cell lysates was 10.80±0.66, significantly higher than 8.63±0.65 of mDC group and 7.10±0.46 pDC group under the same culture conditions, respectively ( P＜0.05). When the ratio of effector cells:target cells (E ∶ T) was 10 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 31.68%±2.93%, significantly higher than 17.44%±0.97% of mDC group and 10.29%±1.33% of pDC group, respectively (P＜0.05). When the ratio of E ∶ T was 20 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 54.77%± 3.28%, significantly higher than 35.25%± 1.51% of mDC group and 15.52%±0.73% of pDC group, respectively (P＜0.05). When the ratio of E ∶ T was 40 ∶ 1, the killing rate of the mDC+pDC group loaded with heat?treated tumor cell lysate was 73.01%± 0.91%, significantly higher than 51.36%± 0.58% of mDC group and 22.65%± 1.28% of pDC group, respectively (P＜0.05 ). With the rate of E ∶ T increased, the killing rate also increased. The mean fluorescence intensities of surface molecules including CD80, CD86, CD40 and MHC?Ⅱ of mDC:pDC＝1 group pulsed with heat?treated Lewis lung cancer cell lysates were higher than those of mDC group and pDC group. The IL?6 cytokine concentrations of mDC+pDC group, mDC group and pDC group loaded with heat?treated Lewis lung cancer cell lysates were (586.67±52.52) pg／ml, (323.33±67.14) pg／ml and (166.67± 16.07) pg／ml, respectively. The concentrations of IL?12 in each group were ( 2 568.75± 119.24) pg／ml, (2 156.25±120.55) pg／ml and (672.92±31.46) pg／ml, respectively. The concentrations of TNF?α in each group were (789.33±48.08) pg／ml, (584.89±116.49) pg／ml and (291.56±40.73) pg／ml, respectively. The concentrations of IL?6, IL?12 and TNF?α secreted by mDC+pDC group were much higher than those of mDC group and pDC group under the same culture conditions ( P＜0.05). Conclusions The mDCs and pDCs combined vaccines pulsed with heat?treated Lewis lung cancer cell lysates have synergistic effects on inducing of T lymphocyte proliferation and killing tumor cells in vitro. This synergistic anti?tumor effect is related with up?regulation of co?stimulatory molecules and increased secretion of cytokines.