The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics* ; Glutamic Acid/biosynthesis* ; Fermentation ; Metabolic Engineering ; Bacterial Proteins/metabolism* ; Bioreactors/microbiology* ; Gene Knockout Techniques

Objective:To explore the effect of exosomes released by Mycobacterium tuberculosis ( Mtb) Rv1983-stimulated macrophages on tuberculosis infection and its potential mechanism. Methods:Exosomes (Rv1983-M-Exo) released by macrophages following Mtb Rv1983 stimulation were extracted by hypervelocity centrifugation and then co-cultured with uninfected macrophages. Macrophage activity was detected by prodium iodide (PI) staining. The level of lipid reactive oxygen species (ROS) was detected by lipid peroxidation fluorescence probe. The expression of ferrous ions (Fe 2+ ) and malondialdehyde (MDA) were detected by colorimetry assay. The protein expression of acyl-CoA synthetase long chain family member 4 (ACSL4) in Rv1983-M-Exo was detected by Western blot. Exosomes (Rv1983-M+ siACSL4-Exo) were isolated from Rv1983-stimulated macrophages with interfered ACSL4 expression Rv1983 and co-cultured with uninfected macrophages. The effect of exosomes on the polarization of macrophages was detected by flow cytometry and Western blot. The effects of exosomes on phagocytosis and killing ability of macrophages were analyzed by plate colony assay and BCG-phagocytosis lysosome co-localization assay. Results:Compared with macrophage-derived exosomes (M-Exo), Rv1983-M-Exo promoted ferroptosis in uninfected macrophages, manifested by increased levels of intracellular lipid ROS, MDA and Fe 2+, which were significantly inhibited by ferroptosis inhibitor Fer-1. Rv1983 induced macrophages to release exosomes with high expression of ACSL4. Interfering the expression of ACSL4 in macrophages, the concentration of ACSL4 in the Rv1983-M+ siACSL4-Exo was significantly reduced. When the Rv1983-M+ siACSL4-Exo was co-cultured with uninfected macrophages, the ferroptosis of macrophages was significantly reduced. Rv1983-M-Exo promoted M2 macrophage polarization which showed up-regulation of CD206 and Arg1 expression, and decreased the phagocytosis and killing ability of macrophages, while Rv1983-M+ siACSL4-Exo or Fer-1 in combination with Rv1983-M-Exo reduced the expression of CD206 and Arg1 in macrophages, and promoted the phagocytosis and killing ability. Conclusions:Mtb Rv1983 protein up-regulates the level of ACSL4 in the exosomes secreted by macrophages, thereby inducing ferroptosis in uninfected macrophages, causing M2 polarization of macrophages, weakening phagocytosis and killing ability, and promoting Mtb infection.

【Objective】 To investigate the protective effects of aflexible sleeve penile protection device on reducing postoperative pain and wound edema in patients after circumcision. 【Methods】 A total of 54 patients who underwent circumcision at Yan’an Branch of Peking University Third Hospital during Feb.1 and May 31, 2023 were enrolled.The patients were randomly divided into the experimental group and control group, with 27 patients in either groups.Patients in the experimental group were treated with a flexible sleeve penis protection device after surgery, and patients in the control group were treated with traditional gauze bandage after surgery.Postoperative pain, wound edema and complications were compared between the two groups. 【Results】 In terms of pain, the visual analogue scale of the experimental group was significantly lower at 6 hours [(1.7±0.9) vs.(3.3±1.9), P<0.001] and 2 days [(2.0±1.3) vs.(3.3±1.3), P<0.001] after surgery than that of the control group, but there were no statistically significant differences between the two groups on the 4th and 7th postoperative days (P>0.05).In terms of edema, the edema score of the experimental group was significantly lower than that of the control group on the 2nd postoperative day [(2.0±1.0) vs.(4.0±0.8), P<0.001] , the 4th postoperative day [(1.5±1.2) vs.(2.6±0.9), P<0.001] , and the 7th postoperative day [(0.9±1.3) vs.(2.3±1.5), P<0.001] .There was no statistically significant difference in the incidence of complications between the two groups (P>0.05). 【Conclusion】 The flexible sleeve penile protection device has significant effects of reducing early postoperative pain and reducing edema in patients undergoing circumcision.

Objective:To explore the effect of exosomes released by Mycobacterium tuberculosis ( Mtb) Rv1983-stimulated macrophages on tuberculosis infection and its potential mechanism. Methods:Exosomes (Rv1983-M-Exo) released by macrophages following Mtb Rv1983 stimulation were extracted by hypervelocity centrifugation and then co-cultured with uninfected macrophages. Macrophage activity was detected by prodium iodide (PI) staining. The level of lipid reactive oxygen species (ROS) was detected by lipid peroxidation fluorescence probe. The expression of ferrous ions (Fe 2+ ) and malondialdehyde (MDA) were detected by colorimetry assay. The protein expression of acyl-CoA synthetase long chain family member 4 (ACSL4) in Rv1983-M-Exo was detected by Western blot. Exosomes (Rv1983-M+ siACSL4-Exo) were isolated from Rv1983-stimulated macrophages with interfered ACSL4 expression Rv1983 and co-cultured with uninfected macrophages. The effect of exosomes on the polarization of macrophages was detected by flow cytometry and Western blot. The effects of exosomes on phagocytosis and killing ability of macrophages were analyzed by plate colony assay and BCG-phagocytosis lysosome co-localization assay. Results:Compared with macrophage-derived exosomes (M-Exo), Rv1983-M-Exo promoted ferroptosis in uninfected macrophages, manifested by increased levels of intracellular lipid ROS, MDA and Fe 2+, which were significantly inhibited by ferroptosis inhibitor Fer-1. Rv1983 induced macrophages to release exosomes with high expression of ACSL4. Interfering the expression of ACSL4 in macrophages, the concentration of ACSL4 in the Rv1983-M+ siACSL4-Exo was significantly reduced. When the Rv1983-M+ siACSL4-Exo was co-cultured with uninfected macrophages, the ferroptosis of macrophages was significantly reduced. Rv1983-M-Exo promoted M2 macrophage polarization which showed up-regulation of CD206 and Arg1 expression, and decreased the phagocytosis and killing ability of macrophages, while Rv1983-M+ siACSL4-Exo or Fer-1 in combination with Rv1983-M-Exo reduced the expression of CD206 and Arg1 in macrophages, and promoted the phagocytosis and killing ability. Conclusions:Mtb Rv1983 protein up-regulates the level of ACSL4 in the exosomes secreted by macrophages, thereby inducing ferroptosis in uninfected macrophages, causing M2 polarization of macrophages, weakening phagocytosis and killing ability, and promoting Mtb infection.

Aim To investigate the mechanism and search for potential biomarkers of ovalbumin ( OVA ) -induced asthma in mice base on lipidomics. Methods A BALB/c mouse model of asthma was prepared by OVA. TNF-α, IL-4, IL-10, IFN-γ levels in BALF and IgE level in serum were measured by ELISA. The inflammatory changes in mouse lung tissue were observed using HE staining. Lipid mediators ( LMs) in lung tissue and serum were quantified with UPLC-MS/ MS strategy. Results IgE level in serum and TNF-α, IFN-γ levels in BALF were higher (P <0.05) of asthmatic mice.Typical inflammatory manifestations were seen in lung tissue of asthmatic mice. A total of 57 lipid mediators were quantified with UPLC-MRM. LMs metabolic profiles differed significantly in serum and lung tissue between asthmatic and normal mice, 17 significantly different LMs were found in lung tissue and 6 LMs were found in serum, and the differential metabolites were produced through the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 oxidase (P450) metabolic pathways. Conclusions OVA-induced allergic asthma can cause disorder of lip-id mediators, LMs and cytokines are involved in the occurrence and development of asthma. The differential LMs have potential research value as biomarkers for the development of allergic asthma.

Prostate cancer is the most common male malignant tumor in the world, and its death toll is second only to lung cancer. Androgen deprivation therapy (ADT) is a major treatment for prostate cancer besides radical surgery. ADT treatment will lead to the inevitable progression of prostate cancer patients to castration-resistant prostate cancer (CRPC). The current research results have confirmed that the transformation from androgen deprivation prostate cancer (ADPC) to CRP is related to the reactivation of the androgen receptor signal pathway. In this review, the research progress on the mechanism of the androgen receptor signaling pathway in CRPC was reviewed in order to provide a scientific basis and new ideas for the diagnosis and treatment of CRP.

Objective: To analyze the influence of the confidence to pre-exposure prophylaxis (PrEP) on the willingness to use PrEP in men who have sex with men (MSM) by using the path analysis model based on structural equation model approach. Methods: A total of 550 MSM were recruited in Urumqi by snowball method and a questionnaire survey was conducted among them. According to the professional knowledge and analysis results of the confidence and willingness to use PrEP, structural equation model (SEM) analysis method was used to construct a path analysis model. Results: A total of 513 MSM participated in the survey. The modified path equation model was well fitted, with the modified fitting index as: GFI=0.993, RMSEA<0.001, and AGFI=0.984. The confidence to PrEP had direct influence on the willingness; the degree of influence from sex partners, the attitude of sex partner to PrEP and the positive emotions not only had direct effects on willingness of PrEP use, but also had indirect effects on willingness of PrEP use by affecting the confidence to it; the role in sexual behavior, AIDS severity, HIV prevention behavior had direct effects on willingness of PrEP use. The proportion of HIV infection in the population had no direct effects on willingness of PrEP use, but had indirect effects on willingness of PrEP use by affecting the confidence to it. Conclusions The confidence to PrEP had influence on willingness of PrEP use in MSM, therefore targeted activities can be conducted to improve the confidence and willingness of MSM in taking the PrEP and reducing the risk of HIV infection in MSM. Compared with the traditional multiple regression analysis, the path analysis using the structural equation model could better reveal the mediating effect between the independent variables and dependent variables.

Objective: To investigate the mutation of P4HA2 gene in Tujia high myopia patients. Methods: Clinical data and genomic DNA were collected from 288 Tujia patients with high myopia, whose spherical error ≥-6.00 diopters and axial length≥26 mm.All coding exons regions of P4HA2 were screened in patients to detect causative mutation by Sanger sequencing.The detected mutation was further screened in 192 normal control chromosomes in the same district.The pathogenicity of genetic mutations was predicted through bioinformatics analysis.This study followed the Declaration of Helsinki.All patients or their guardians signed informed consent. Results: Four variations of P4HA2 gene were found in 288 patients, including one missense mutations(c.145C>A), two in-containing mutations (c.1306-62C>T, c.82+ 22C>T) and one insertion mutation (c.179+ 16_179+ 17 ins T). Missense mutation c. 145C>A was predicted as suspicious pathogenic gene by Polyphen2.According to the standard of ACMG in the United States, the variation was uncertain in pathogenicity. Conclusions Missense mutation c. 145C>A in P4HA2 gene is a suspicious pathogenic gene mutation in Tujia patients with high myopia.

OBJECTIVE: To investigate the effect of calenduloside E on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and explore the underlying molecular mechanism. METHODS: CCK-8 assay was used to examine the effect of different concentrations of calenduloside E (0-30 μg/mL) on the viability of RAW264.7 cells. The release of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in RAW264.7 cells in response to pretreatment with 6, 8, and 10 μg/mL calenduloside E for 2 h followed by stimulation with 100 ng/mL LPS was detected using enzyme-linked immunosorbent assay (ELISA). The expression levels of iNOS and COX-2 and the activation of JAK-stats, MAPKs and NF-кB signaling pathways in the treated cells were determined using Western blotting. A reactive oxygen species (ROS) detection kit was used to detect ROS production in the cells, and the nuclear translocation of the transcription factor stat3 was observed by laser confocal microscopy. RESULTS: Calenduloside E below 20 μg/mL did not significantly affect the viability of RAW264.7 cells. Calenduloside E dose-dependently decreased the expression levels of iNOS and COX-2 induced by LPS, inhibited LPS-induced release of TNF-α and IL-1β, and suppressed LPS-induced JAK1-stat3 signaling pathway activation and stat3 nuclear translocation. Calenduloside E also significantly reduced ROS production induced by LPS in RAW264.7 cells. CONCLUSIONS Calenduloside E inhibits LPS-induced inflammatory response by blocking ROS-mediated activation of JAK1-stat3 signaling pathway in RAW264.7 cells.
Animals ; Lipopolysaccharides ; Mice ; NF-kappa B ; Oleanolic Acid ; analogs & derivatives ; RAW 264.7 Cells ; Reactive Oxygen Species ; Saponins ; Signal Transduction