1.Functional analysis of functional membrane microdomains in the biosynthesis of menaquinone-7.
Yajun DONG ; Shixiu CUI ; Yanfeng LIU ; Jianghua LI ; Guocheng DU ; Xueqin LÜ ; Long LIU
Chinese Journal of Biotechnology 2023;39(6):2215-2230
Functional membrane microdomains (FMMs) that are mainly composed of scaffold proteins and polyisoprenoids play important roles in diverse cellular physiological processes in bacteria. The aim of this study was to identify the correlation between MK-7 and FMMs and then regulate the MK-7 biosynthesis through FMMs. Firstly, the relationship between FMMs and MK-7 on the cell membrane was determined by fluorescent labeling. Secondly, we demonstrated that MK-7 is a key polyisoprenoid component of FMMs by analyzing the changes in the content of MK-7 on cell membrane and the changes in the membrane order before and after destroying the integrity of FMMs. Subsequently, the subcellular localization of some key enzymes in MK-7 synthesis was explored by visual analysis, and the intracellular free pathway enzymes Fni, IspA, HepT and YuxO were localized to FMMs through FloA to achieve the compartmentalization of MK-7 synthesis pathway. Finally, a high MK-7 production strain BS3AT was successfully obtained. The production of MK-7 reached 300.3 mg/L in shake flask and 464.2 mg/L in 3 L fermenter.
Bacillus subtilis/metabolism*
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Vitamin K 2/metabolism*
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Bioreactors/microbiology*
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Membrane Microdomains/metabolism*
2.Adaptive phenotypes of Yersinia pestis induced by successive passages in macrophages
Xin CHEN ; Kai SONG ; Yarong WU ; Liting XIAO ; Junyan JIN ; Yipu DU ; Yujun CUI ; Li YU ; Yajun SONG
Chinese Journal of Microbiology and Immunology 2022;42(4):251-257
Objective:To investigate the changes in adaptive phenotypes of Yersinia pestis ( Yp) during successive passages in macrophages. Methods:A Yp strain of 201-MI was induced by 50 successive passages of Yp 201 strain in Raw264.7 cells. Phenotypic characteristics of 201 and 201-MI strains were compared by analyzing their survival rates in macrophages, growth curves, biofilm formation abilities, acid and hydrogen peroxide-stress tolerance, and virulence to mammal cells (Raw264.7 and HeLa cells) and mice. Results:Comparing with 201 strain, 201-MI strain showed various phenotypic changes, including higher survival rate in Raw264.7 cells, faster growth in iron-deficient medium, higher tolerance to acid and hydrogen peroxide, decreased biofilm formation ability, and less damages to Raw264.7 and HeLa cells. More-over, 201-MI strain showed decreased virulence to mice in both subcutaneous and intraperitoneal challenges. Preliminary comparative genomics analysis revealed some indel and nonsense mutations in 201-MI strain, which might account for its phenotype changes.Conclusions:After successive passages in macrophages, Yp showed some phenotypic changes, which might reflect its adaptive evolution under the pressure of macrophages. Detailed multi-omics analysis would be of great help to understand the underlying genetic mechanisms of these changes, and the related Yp-macrophage interaction processes as well.
3.KLF7 in epicardial adipose tissue of coronary heart disease promotes inflammation and adipose differentiation
Yajun Xue ; Wenhua Huang ; Yayan Du ; Yijun Zhou ; Xingxing Dong ; Yutao Wei
Acta Universitatis Medicinalis Anhui 2022;57(2):197-202
Objective :
To explore the epicardial adipose tissue ( EAT) of patients with coronary heart disease , KLF7 stimulates macrophages to secrete inflammatory factors and promotes the differentiation and maturation of adipocytes through the NF⁃κB signaling pathway , and to clarify the mechanism of KLF7 in the occurrence and development of CAD.
Methods :
30 patients with coronary heart disease ( CAD group) and 30 patients without coronary heart disease (non⁃CAD group) were collected , and general data and biochemical indicators were collected. qRT⁃PCR was used to detect the expression levels of KLF7 , APN , IL⁃6 , and TNF⁃α mRNA in EAT. Human THP⁃1 cells were cultured in vitro and induced into M1 type macrophages and 3T3 ⁃L1 preadipocytes. The cells were divied into 3 groups : KLF7 up⁃regulated group ( transfected with KLF7 mimic) , KLF7 down⁃regulated group ( transfected with siRNA knockdown KLF7 ) , NC group ( transfected oligopeptide sequence) , transfected two kinds of cells. qRT⁃PCR was used to detect the expression of APN , MCP⁃1 , IL⁃6 and TNF⁃α mRNA in M1 type macrophages , and the protein expression levels of key factors in the NF⁃κB signaling pathway were detected by Westren blot.
The qRT⁃PCR method was used to detect APN , KLF4 , IL⁃6 , MCP⁃1 mRNA and adipocyte differentiation marker peroxisome proliferator⁃activated receptor⁃γ (PPARγ) in 3T3 ⁃L1 preadipocytes 24 h after transfection. CCAAT/enhancer binding protein α (C/EBPα ) , fatty acid binding protein 4 (FABP4) mRNA relative expression levels , and Westren blot was used to detect protein expression levels.
Results :
Compared with the non⁃CAD group , the expression of CAD group decreased , APN decreased , IL⁃6 and TNF⁃α increased significantly , and the difference was statistically significant (P < 0. 01) . KLF7 was highly expressed in human THP⁃1 derived M1 macrophages induced by inflammatory stimuli (LPS) . In M1 macrophages derived from human THP⁃1 , knocking down KLF7 could inhibit the release of inflammatory factors. Transfection with KLF7 ⁃siRNA could significantly inhibit LPS⁃induced phosphorylation of JNK⁃MAPKs , the level of p⁃p65 and the activation of p ⁃IκBa (P < 0. 05) . In 3T3 ⁃L1 preadipocytes , upregulation of KLF7 increased the expression of adipocyte differentiation markers PPARγ , C/EBPa , FABP4 mRNA , and promoted the differentiation of 3T3 ⁃L1 preadipocytes into adipocytes (P < 0. 05) .
Conclusion
The expression of KLF7 in EAT in CAD patients increases. KLF7 activates the activation of macrophages mediated by the JNK⁃NF⁃KB signaling pathway in EAT , promotes inflammation in EAT in CAD patients , and promotes the differentiation and maturation of adipocytes , thereby promoting the development of CAD. It indicates that KLF7 may be a potential therapeutic target for cardiovascular diseases (such as CAD) .
4.A multicenter survey of doctors’ ability to assess severe trauma in China
Peng ZHANG ; Zhe DU ; Zhongdi LIU ; Wei HUANG ; Yajun ZHANG ; Tianbing WANG
Chinese Journal of Emergency Medicine 2021;30(5):533-536
Objective:To investigate the ability of doctors in different regions and levels of hospitals in assessing the severity of severe trauma in China.Methods:A total of 38 trauma centers of China Trauma Rescue & Treatment Association (19 tertiary hospitals and 19 secondary hospitals, including 20 eastern and 18 western hospitals) were selected from November 2018 to May 2020. Two junior, two middle, and two senior emergency surgeons were selected in each center. Injury severity score (ISS) was performed on 10 patients with severe trauma, and the qualified rate was analyzed.Results:The qualified rates of junior, middle, and senior doctors were 56.05%, 56.18%, and 56.71%, respectively ( P>0.05). The qualified rates of tertiary and secondary hospitals were 63.07% and 49.56%, respectively ( P<0.01). The qualified rates of eastern and western hospitals were 67.00% and 44.44%, respectively ( P<0.01). Conclusions:The overall level of injury assessment of severe trauma patients by doctors in China is satisfactory, while there are still differences in hospital levels and regions. In the future, attention should be paid to the training and system construction in primary hospitals. We should actively support the construction and development of hospitals in the western regions and realize the standardization of trauma treatment in China as soon as possible.
5.The mitochondrial autophagy inhibitor Mdivi-1 improve the injury of epileptic hippocampal neurons by regulating mitochondrial unfolded protein response
Nanchang XIE ; Liyuan DU ; Yajun LIAN
Journal of Apoplexy and Nervous Diseases 2020;37(12):1087-1090
Objective To investigate the changes of mitochondrial unfolded protein response in epileptic hippocampal neurons induced by Mg2+-free solution and the effects of mitochondrial autophagy inhibitors Mdivi-1.Methods Epilepsy model was induced in primary cultured hippocampal neurons of SD rats in vitro by Mg2+-free solution,and further treated with mitochondrial autophagy inhibitor Mdivi-1.Mitochondrial ROS production were detected by MitoSox.The mitochondrial membrane potential was detected by Rhodamine123.The expression of C/EBP homologous protein CHOP,mitochondrial heat shock protein HSP60,mitochondrial protease ClpP,CytC release and caspase-3 activation were detected by Western blotting.Results (1)Compared with the control group,the expression of CHOP,HSP60 and ClpP in the AE group was significantly increased.Compared with the AE group,Mdivi-1 pretreatment enhanced the expression of CHOP,HSP60 and ClpP.(2)Compared with the control group,the production of ROS in the AE group increased,and the mitochondrial menmbrane potential decreased.Compared with the AE group,Mdivi-1 pretreatment significantly decreased the production of mitochondrial ROS and increased the mitochondrial membrane potential.(3)Compared with the control group,the release of CytC and the activation of caspase-3 in the AE group increased.Compared with the AE group,Mdivi-1 pretreatment decreased the release of CytC and caspase-3 activation.Conclusion Mitochondrial unfolded protein response is activated in epileptic hippocampal neurons,while inhibition of mitochondrial autophagy may play a protective role via enhancing mitochondrial unfolded protein response.
6.Ultrashort Echo Time MRI (UTE-MRI) Quantifications of Cortical Bone Varied Significantly at Body Temperature Compared with Room Temperature
Saeed JERBAN ; Nikolaus SZEVERENYI ; Yajun MA ; Tan GUO ; Behnam NAMIRANIAN ; Sarah TO ; Hyungseok JANG ; Eric Y CHANG ; Jiang DU
Investigative Magnetic Resonance Imaging 2019;23(3):202-209
PURPOSE: To investigate the temperature-based differences of cortical bone ultrashort echo time MRI (UTE-MRI) biomarkers between body and room temperatures. Investigations of ex vivo UTE-MRI techniques were performed mostly at room temperature however, it is noted that the MRI properties of cortical bone may differ in vivo due to the higher temperature which exists as a condition in the live body. MATERIALS AND METHODS: Cortical bone specimens from fourteen donors (63 ± 21 years old, 6 females and 8 males) were scanned on a 3T clinical scanner at body and room temperatures to perform T1, T2*, inversion recovery UTE (IR-UTE) T2* measurements, and two-pool magnetization transfer (MT) modeling. RESULTS: Single-component T2*, IR-T2*, short and long component T2*s from bi-component analysis, and T1 showed significantly higher values while the noted macromolecular fraction (MMF) from MT modeling showed significantly lower values at body temperature, as compared with room temperature. However, it is noted that the short component fraction (Frac1) showed higher values at body temperature. CONCLUSION: This study highlights the need for careful consideration of the temperature effects on MRI measurements, before extending a conclusion from ex vivo studies on cortical bone specimens to clinical in vivo studies. It is noted that the increased relaxation times at higher temperature was most likely due to an increased molecular motion. The T1 increase for the studied human bone specimens was noted as being significantly higher than the previously reported values for bovine cortical bone. The prevailing discipline notes that the increased relaxation times of the bound water likely resulted in a lower signal loss during data acquisition, which led to the incidence of a higher Frac1 at body temperature.
Biomarkers
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Body Temperature
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Female
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Humans
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Incidence
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Magnetic Resonance Imaging
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Relaxation
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Tissue Donors
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Water
7.Investigation the correlation between atherosclerotic plaque stability and junctional adhesion molecule A in ApoE-/-mice
Jingxi DU ; Yajun ZHANG ; Yunyou DUAN ; Lijun YUAN ; Tao HUANG ; Tian ZHOU
Chinese Journal of Ultrasonography 2016;25(4):345-350
Objective To explore the relationship between atherosclerotic plaque stability and junctional adhesion molecule A (JAM-A) in atherosclerotic mice.Methods Twenty-six apolipoprotein E gene knockout(ApoE-/-) mice were divided into three groups.Group A (six mice) was control group,group B (ten mice) was disposed by ligation and high-fat diet and group C was disposed by high-fat diet with ten mice.The formation process of plaques were observed with high resolution ultrasound(22 MHz),and plaque markers were detected to evaluate palque stability for secondary grouping (group D was vulnerable plaque group and group E was stable plaque group).The plaque stability were evaluated by plaque vulnerability index and the expression of JAM-A were analyzed using immunohistochemical staining.The relationship between atherosclerotic plaque stability and JAM-A in atherosclerotic mice were estimated with statistical methods at last.Results There was no plaque in carotid artery of group A.On the contrary,obvious plaques were observed in carotid artery of group B and C.The total serum lipids level in group A was normal.But high-fat diet could obviously decrease the serum HDL-cholesterol level of group B and group C when compared with the controls(P <0.05).High-fat diet could increase the ratio of non-HDL-cholesterol (TC,TG,LDL).As shown with pathological staining,the content of extracellular lipids and foam cells in the plaque were significantly increased vs.control (P < 0.05).On the contrary,the content of smooth muscle cells and collagen fibers were significantly increased vs.control(P <0.05).The plaque vulnerability index of group D was higher than that in group E(P <0.01).The expression of JAMA was increased in group D and E,and in group D was higher(P <0.01).While,few JAM-A expression in group A.There was significant correlation between plaque vulnerability index and JAM-A (P<0.01).Conclusions High resolution uhrasound(22 MHz) can observe the formation of carotid plaque in ApoE-/-mice.There was a positive correlation between JAM-A expression and the vulnerability of plaque in carotid artery.JAM-A might be used for evaluation of plaque stability as a new indicator.
8.Inhibition of replication and transcription of WSN influenza A virus by IFIT family genes.
Lidan HOU ; Jing LI ; Hongren QU ; Limin YANG ; Yajun CHEN ; Qianqian DU ; Wenjun LIU
Chinese Journal of Biotechnology 2015;31(1):123-134
IFIT family genes are a kind of interferon stimulated genes (ISGs), and play important roles in antiviral sector and immunity regulation. To study the regulatory effect of IFIT family genes during influenza A virus (IAV) infection, we used RNA-sequencing analysis (RNA-Seq) technique and found that when 293T cells were infected by A/WSN/33 (WSN), the concentration of IFIT family genes were increased. Further study reveals that overexpression of IFIT2 or IFIT3 could inhibit IAV replication and transcription, and cause the dose-dependent inhibition of polymerase activity of vRNP. In addition, IFIT2 and IFIT3 encoding protein could colocalize with NS1 in 293T cells infected by WSN, indicating that they might interact with each other. The results suggest that IFIT family genes can inhibit the replication and transcription of IAV, which contributes to our understanding of the regulatory effect of host factors during influenza virus infection.
HEK293 Cells
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Humans
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Influenza A virus
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physiology
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Influenza, Human
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genetics
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Intracellular Signaling Peptides and Proteins
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genetics
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Proteins
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genetics
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Virus Replication
9.Clinical significance of the detection of visfatin in the peripheral blood of patients with coronary atherosclerotic heart disease
Chinese Journal of Postgraduates of Medicine 2012;35(19):17-20
Objective To detect the level of visfatin in the peripheral blood ofpafients with coronary atherosclerotic heart disease (coronary heart disease),and investigate the conelation between the level of visfatin and the lesion degree of coronary heart disease.Methods Two hundred and twenty patients who were diagnosed as coronary heart disease by coronary artery angiography from January to June 2011 (coronary heart disease group) were enrolled in this study,including 74 cases with stable angina pectoris(stable angina pectoris group),60 cases with unstable angina pectoris (unstable angina pectoris group),and 86 cases with acute myocardial infarction (myocardial infarction group).And 20 healthy persons with normal coronary artery angiography were selected as control group.The biochemical parameters of triglyceride (TG),total cholesterol (TC),high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were detected by biochemistry autoanalyzer.The level of serum visfatin was detected by ELISA analysis.The serum biochemical parameters and serum visfatin among all the groups were compared and the correlation between them was analyzed.ResuIts The level of serum visfatin of coronary heart disease group [(34.07 ±5.51) μg/L] was significantly higher than that of control group [(13.22 ±3.17) μg/L](P<0.05).TC and LDL-C of different coronary heart disease groups had no significant differences compared with that of control group (P > 0.05).TG,H DL-C and serum visfatin of stable angina pectoris group,unstable angina pectoris group and myocardial infarction group [(1.44 ±0.27) mmol/L,(1.16 ±0.12) mmol/L,(21.36 ± 3.35) μg/L; ( 1.84 ±0.32) mmol/L,(1.01 ± 0.08) mmol/L,(27.78 ±4.47) μg/L; (2.31 ±0.34)mmol/L,(0.93 ± 0.06) mmol/L,(33.14 ± 5.66) μ g/L] had statistical significance compared with those of control group [(0.93 ±0.25) mmol/L,(1.48 ± 0.24) mmol/L,(13.22 ±3.17) μg/L](P<0.05 or <0.01).TG,C,ensini score and serum visfatin of unstable angina pectoris group were significantly higher than those of stable angina pectoris group and HDL-C was obviously lower than that of stable angina pectoris group (P <0.05).Gensini score and serum visfatin of myocardial infarction group were significantly higher than those of unstable angina pectoris group and HDL-C was obviously lower than that of unstable angina pectoris group (P < 0.05).Spearman correlation analysis showed that the level of serum visfatin of coronary heart disease group was positively correlated with TG and Gensini score (P <0.05 or <0.01 ) and negatively correlatedwith HDL-C (P < 0.01 ),and had no correlation with TC and LDL-C (P > 0.05).Conclusions The highlevel expression of visfatin in the peripheral blood may be a risk factor of coronary heart disease.The changes of serum visfatin can reflect the lesion severity degree of coronary artery.
10.Effects of Louxie mixture on vascular reactivity in atherosclerosis rats
Jinrong CUI ; Zhaohong WANG ; Yajun XUE ; Zhenye WANG ; Shoulong DU
International Journal of Traditional Chinese Medicine 2011;33(6):498-501
Objective To investigate the effect of Chinese medicine Louxie mixture on vascular reactivity in atherosclerosis rats. Methods Forty male rats were randomly divided into four groups: the control group (A group, n=10) was fed with normal diet; the model group (B group, n=10), atorvastatin treated group (C group, n=10 and Louxie mixture group (D group, n=10) were fed with high fat/cholesterol diet. Atorvastatin 10 mg/kg·d-1 was administered to C group and Louxie mixture to D group for 10 weeks by gavages. Serum endothelin-1 (ET-1), nitric oxide (NO) and nitric oxide syntheses (NOS) were observed in different groups before and after the treatment. Vascular reactivity of aortic rings was measured by both the sodium nitroprusside(SNP)-induced endothelium-independent relaxation (NEDR) and the acetylcholine (Ach)-induced endothelium-dependent relaxation (EDR) in different groups. Results After treatment, the (19.03±1.72)μmol/l; NOS (24.78±0.25)U/ml vs (15.36±0.24U/ml), P<0.01], while the level of ET-1in B levels of NO and NOS in B group were significantly lower than those in A group [NO(35.73±3.72)μmol/l vs group was higher than that in A group [(34.58±4.00) pg/ml vs (117.58±5.34)pg/ml,P<0.01]. The levels of NO and NOS were significantly increased and the level of ET-1 was decreased in C and D groups after the treatment [NO(C: 31.30±1.96 umol/l;D: 32.85±3.70 umol/l); NOS (C: 21.96±1.07 U/ml ; D: 19.78± 1.20U/ml ); ET (C:58.26±5.14 pg/ml; D:59.30±5.73 pg/ml), P<0.01]. The activities of NEDR were similar in four groups[SNP Emax (A: 97.33±1.31; B: 98.24±1.04;C: 97.52±1.09; D: 97.91±1.59)%, P>0.05], but the level of EDR in the B group (P<0.01) was the lowest among four groups [Ach Emax (A: 72.65±3.31; B: 32.68±2.39;C: 61.63±2.07; D: 57.58±2.43)%, P<0.01]. Conclusion Chinese medicine Louxie mixture can protect vascular function in atherosclerosis rats.


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