1.Construction and application of 293T-CymR cell strain
Chinese Journal of Biologicals 2026;39(01):7-16
Objective To construct a 293T-CymR cell strain to express cysteine metabolism regulator(CymR) component by gene editing technology, and to regulate the target gene expression with CuO regulatory sequence promoter.Methods Based on clustered regularly interspaced short palindromic repeats(CRISPR)-Cas9 technology, the intracellular β factor receptor, C-C chemokine receptor(CCR5) gene, one of the safe harbors in HEK293T cell genome, was chosen as the target site for inserting the desired gene. The selection gene Pac(denoted as PuroR) encoding puromycin N-acetyltransferase was linked to the 3'end of the CymR gene via an internal ribosome entry site(IRES), sharing a cytomegalovirus(CMV) promoter. The 293 TCymR monoclonal cell strain capable of expressing CymR was screened by Puro resistance and limiting dilution method. The CymR gene position and protein function in the 293T-CymR monoclonal cell strain were verified by PCR, Western blot and fluorescence analysis.Results The pY93-CymR plasmid expressing both the target and resistance genes, was successfully constructed. Following co-transfection with the pX330-CCR5 plasmid into HEK293T cells, four 293T-CymR monoclonal cell strains were obtained via Puro resistance selection and the limiting dilution method. The PCR and Western blot analysis indicated that CymR gene was successfully inserted into the intended CCR5 site and CymR protein was efficiently produced in three of these clones. Subsequent transfection tests demonstrated that the produced CymR could successfully suppress the gene expression under the CMV promoter containing CuO element.Conclusion CymRgene was successfully inserted into the CCR5 locus of HEK293T cell genome, and 293T-CymR monoclonal cell strains capable of expressing CymR and regulating gene expression were obtained.
2.Research progress on the pathogenesis of myopia
Qihang DIAO ; Ling WANG ; Jiahao WANG ; Mengjun FU
International Eye Science 2025;25(8):1302-1307
In recent years, the prevalence of myopia has shown a significant upward trend characterized by earlier onset and accelerated progression rates. This epidemic not only imposes an increasing socioeconomic burden but also leads to severe vision impairment through high myopia-related complications that profoundly affect daily life. Current research on the pathogenesis of myopia primarily focuses on four mechanistic theories, including scleral remodeling, choroidal hemodynamic abnormalities, dopamine synthesis and metabolism, and inflammatory responses. The advent of high-throughput sequencing technologies has revolutionized our investigative approaches, enabling deeper exploration into myopia development through multi-omics strategies encompassing genomics, proteomics, and metabolomics. These cutting-edge methodologies have provided novel insights for myopia prevention and control, while simultaneously identifying potential therapeutic targets for precision intervention. This review focuses on summarizing the aforementioned research findings.
3.A flavin-containing monooxygenase from Schizosaccharomyces pombe: characterization and application in the synthesis of S-methyl-L-cysteine sulfoxide.
Mengka LIAN ; Zhaolin SONG ; Wenjing GAO ; Gang ZHU ; Mengjun DONG ; Yu LI ; Yihan LIU ; Fenghua WANG ; Fuping LU
Chinese Journal of Biotechnology 2025;41(1):474-485
S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg2+ improved the enzyme activity. The enzyme kinetic analysis showed that the Km and kcat/Km of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics*
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Escherichia coli/metabolism*
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Recombinant Proteins/metabolism*
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Cysteine/biosynthesis*
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Mixed Function Oxygenases/metabolism*
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Schizosaccharomyces pombe Proteins/metabolism*
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Oxygenases/metabolism*
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Kinetics
4.Relationship between oral health status with severity and outcome of pediatric bronchopneumonia
Jianjun ZHANG ; Mengjun ZHAI ; Houcai WANG
Chongqing Medicine 2025;54(9):2128-2131,2137
Objective To explore the relationship between the oral health status with the severity and outcome of pediatric bronchopneumonia.Methods A total of 150 children patients with bronchopneumonia admitted and treated in this hospital from January 2020 to August 2022 were selected as the observation group(n=150).According to the severity of the illness,the children patients were divided into the mild group(n=97)and severe group(n=53).In addition,150 children undergoing physical examination during the same pe-riod were selected as the control group(n=150).The changes in the decay missing filling surface(DMFS),simplified oral hygiene index(OHI-s)and plaque index(PLI)were analyzed.Spearman was used to analyze the relationship between the oral health status and the severity of bronchopneumonia.After one month of treatment,the changes in oral health status were analyzed under different outcome conditions.The receiver op-erating characteristic(ROC)curve was drawn to assess the predictive effect of the oral health status on the outcome of pediatric bronchopneumonia.Results The DMFS,OHI-s scores and PLI scores in the observation group were higher than those in the control group(P<0.05).The DMFS,OHI-s score and PLIscores in the severe group were higher than those in the mild group(P<0.05).Spearman analysis found that DMFS,OHI-s and PLI were positively correlated with the severity(r=0.441,0.253,0.328,P<0.05).The levels of DMFS,OHI-s and PLI in the poor prognosis group were higher than those in the good prognosis group(P<0.05).The area under the curve(AUC)of DMFS,OHI-s and PLI combination in predicting the outcome of bronchopneumonia was 0.851(0.703~0.999),with a sensitivity of 83.78%and a specificity of 92.92%.Con-clusion The oral health status is closely related to the severity of pediatric bronchopneumonia,which can be used to assess the outcome of the children patients.
5.Regulation and mechanism of Gm49394 on islet-β cell apoptosis
Dong LIU ; Qingyuan ZHAO ; Shushu YANG ; Mengjun ZHANG ; Jie LI ; Yuhao LI ; Li WANG ; Yuzhang WU
Journal of Army Medical University 2025;47(18):2211-2222
Objective To explore the potential role and underlying mechanism of the functionally uncharacterized gene Gm49394 on regulating β-cell apoptosis under diabetic conditions.Methods The expression and translational activity of Gm49394 in pancreatic β-cell lines and non-β-cell lines were validated using RNA fluorescence in situ hybridization(RNA-FISH),quantitative real-time PCR(qPCR),Western blotting,and immunofluorescence(IF)assay.The β-cell lines(NIT-1/Min6)with Gm49394 overexpression or knockdown were constructed.The proliferation,apoptosis,mitochondrial function,as well as oxidative stress and endoplasmic reticulum stress markers in these β-cell lines under physiological homeostasis or pathological stress conditions,such as high glucose(30 mmol/L),inflammation(10 ng/mL IFN-γ alone or combined with 10 ng/mL IL-6),and hydrogen peroxide(100 μmol/L H2O2)were detected by flow cytometry and Western blotting.Results RNA-FISH and qPCR indicated that Gm49394 was specifically expressed in pancreatic β-cell lines and up-regulated under high glucose or inflammatory stimulation.IF assay and Western blotting showed that Gm49394 had protein-coding activity.Flow cytometry and Western blotting identified that Gm49394 overexpression did not affect β-cell proliferation,but promoted β-cell apoptosis and increased reactive oxygen species(ROS)and mitochondrial superoxide(MitoSOX)levels in β cells under physiological homeostasis or pathological stress conditions(P<0.05).Under physiological conditions,Gm49394 knockdown failed to induce significant alterations on β-cell apoptosis,ROS,or MitoSOX levels.Under pathological stress conditions,Gm49394 knockdown significantly suppressed β-cell proliferation,apoptosis,as well as oxidative and endoplasmic reticulum stress(P<0.05).Conclusion Gm49394 may promote β-cell apoptosis via oxidative stress and endoplasmic reticulum stress.
6.Construction of quality control materials for HIV-1 genotypic drug resistance testing based on CRISPR/Cas9 point mutation technique
Mengjun DING ; Xin ZHANG ; Yu WANG ; Jun YAO ; Cong JIN
Chinese Journal of Experimental and Clinical Virology 2024;38(3):231-238
Objective:The human peripheral blood lymphocyte cell line 8E5 is capable of secreting non-infectious HIV-1 viral particles. By targeting the POL region of the HIV-1 proviral gene integrated into the genome of 8E5 cell line and constructing a monoclonal cell line containing a drug resistance mutation site in the POL region using CRISPR/Cas9 point mutation technology, safe and stable HIV-1 genotypic drug resistance test quality control materials can be prepared.Methods:8E5 cells were co-transfected with sgRNA (single guide RNA) and Cas9 coexpression vector and Donor ssODN (donor single-stranded oligonucleotides) carrying the target mutation sites. The positive monoclonal cell lines were obtained through flow microtiter plate sorting, and the editing efficacy of the targeted mutations was validated by Sanger sequencing. Sanger sequencing was performed to verify the editing effect of the targeted mutations on the HIV virus particles secreted into the supernatant of the monoclonal cell lines cultured to the 3rd, 5th and 7th generations.Results:A double sgRNA and Cas9 coexpression vector was successfully constructed and co-transfected with a Donor ssODN carrying the drug-resistant mutation site Q151M to the 8E5 cell line, resulting in the desired outcome. The sequencing result of the target site confirmed the successful mutation at the resistance site and the establishment of a monoclonal homozygous cell line. The Q151M mutation site was detected in non-infectious HIV-1 virus particles secreted by the 8E5 Q151M cell line after transmission. Conclusions:The cell line 8E5 Q151M was successfully constructed using CRISPR/Cas9 point mutation technology to stably carry the Q151M drug resistance mutation site, which provides a new technological platform for the preparation of quality-control materials for testing HIV-1 genotypic drug resistance.
7.Expression and identification of recombinant adenovirus type 5-Norovirus GⅡ.4-VP1 virus-like particles
Chinese Journal of Biologicals 2024;37(2):138-142
Objective To express and identify recombinant adenovirus type 5-Norovirus(NoV)GⅡ.4-VP1 virus-like particles(VLPs)in 293T cells. Methods The recombinant adenovirus plasmids pAd5-eGFP and pAd5-NoV-GⅡ.4-VP1 were transfected into 293T cells respectively,and the recombinant adenovirus rAd5-eGFP and rAd5-NoV-GⅡ.4-VP1 were rescued. The rAd5-eGFP was subcultured in 293T cells to verify the function of the vector. The rAd5-NoV-GⅡ.4-VP1 was subcultured in293T cells,expressed and purified,and then NoV-GⅡ.4-VLP was formed by self-assembly,which was detected by Western blot,ELISA and observed by transmission electron microscope. Results The green fluorescence of the recombinant adenovirus rAd5-eGFP of various generations was observed under microscope,and the brightness increased with the increase of generations. NoV-GⅡ.4-VP1 protein was expressed in the harvested solution of recombinant adenovirus rAd5-NoV-GⅡ.4-VP1 of various generations,with a relative molecular mass of about 58 900. NoV-GⅡ.4-VLP showed specific binding to the rabbit anti-NoV-GⅡ.4-VP1 serum;it had similar conformation to natural NoV virus particles and can effectively identify NoV receptors in volunteer saliva samples;microscopic observation showed that the morphology was complete and spherical,with a diameter of 43. 5 — 58. 3 nm,while there were a few protrusions on the surface of the particles,which might be the P domain exposedon the particle surface during self-assembly of VP1. Conclusion The expressed recombinant adenovirus NoV-GⅡ. 4-VLP has complete VLP structure and good specificity,and is expected to be used in the related research of NoV adenovirus vector vaccine.
8.Clinical characteristics and genetic analysis of a child with Cantú syndrome due to variant of ABCC9 gene
Mengjun XIAO ; Fangjie WANG ; Yingying LI ; Xiaoli YAO ; Weina HOU ; Kun HE
Chinese Journal of Medical Genetics 2024;41(10):1249-1254
Objective:To explore the clinical characteristics and pathogenic variant in a child with Cantú syndrome (CS).Methods:A male who was admitted to the Children′s Hospital Affiliated to Zhengzhou University on February 23, 2022 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected and subjected to whole-exome sequencing (WES). Candidate variant was verified by Sanger sequencing. This study was approved by Medical Ethics Committee of the Children′s Hospital Affiliated to Zhengzhou University (Ethics No. 2023-K-087).Results:The child, a 3-year-and-2-month-old male, was born with hirsutism, with heavy hair all over the body and peculiar facial features. Routine echocardiography 1 month before had discovered atrial septal defect. Sequencing revealed that the child has harbored a heterozygous c. 2438G>C (p.S813T) variant of the ABCC9 gene, which was de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 2438G>C variant was classified as likely pathogenic (PS2+ PM2_Supporting+ PP3). Conclusion:The heterozygous c. 2438G>C variant of the ABCC9 gene probably underlay the pathogenesis of CS in this child.
9.Improved effect and underlying mechanism of methylene blue on cognitive function in brain-inflammatory-aging rats
Jiantao WANG ; Xudong ZHAO ; Li DENG ; Mengjun GE ; Beibei GAO ; Lei LI
Chinese Journal of Geriatric Heart Brain and Vessel Diseases 2024;26(3):336-340
Objective To determine the improved effect of methylene blue(MB)on cognitive func-tion in brain-inflammatory-aging rats and investigate the underlying mechanism.Methods A total of 38 healthy 12-month-old SD rats were randomly divided into healthy control group,lipopo-lysaccharide(LPS)group,MB vehicle group and MB group,with 8 rats in the control and 10 rats in the other three groups.LPS was injected into the fourth ventricle with aid of a subcutaneous sustained release pump to establish a rat model of brain chronic inflammatory aging.MB of 0.5 mg/(kg·d)was added into the pump in the rats from the MB group.T-maze test and new object recognition test were employed to evaluate the learning and memory abilities of the rats.The acti-vation of microglia and astrocytes in the hippocampal CA1 region of the rats was detected by im-munofluorescence assay.The release of inflammatory factors IL-1β and IL-6 was measured by ELISA,and neuronal death in the CA1 region was assessed by neuronal nuclei(NeuN)fluores-cence staining.Results There was no significant difference in the exploration time for new and old objects between the LPS group and the MB solvent group(P>0.05).The MB group spent significantly longer time in exploring the new objects than the old object(22.50±4.32 s vs 11.60± 3.01 s,P=0.000).The alternating selection rate of new arm and expression level of NeuN antigen were significantly decreased,and the expression levels of ionized calcium binding adaptor mole-cule-1(Iba-1)and glial fibrillary acidic protein(GFAP)and the contents of IL-1β and IL-6 were obviously increased(P<0.05)in the LPS group and the MB vehicle group than the healthy con-trol group.Compared with the MB vehicle group,the MB group had notably increased alternating selection rate of new arms and higher NeuN expression level,and decreased Iba-1 and GFAP ex-pression and IL-1β and IL-6 contents(P<0.05).Conclusion Subcutaneous administration of MB could significantly inhibit the damages of spatial learning and memory abilities in the LPS-induced brain chronic inflammatory aging rats.The mechanism may be closely associated with MB inhibi-ting inflammatory glial cells and protecting hippocampal pyramidal neurons.
10.Characterization of CD8+T cell subsets in male and female non-obese diabetic mice
Shushu YANG ; Dong LIU ; Jie LI ; Mengjun ZHANG ; Li WANG
Journal of Army Medical University 2024;46(8):837-848
Objective To compare and analyze the differences in CD8+naive,effector,memory,exhausted and regulatory T cells in order to investigate the impact of gender on the differentiation fate of CD8+T cells in the context of type 1 diabetes (T1D)based on female and male non-obese diabetic (NOD)mice and healthy Institute for Cancer Research (ICR)mice.Methods The frequencies and phenotypes of CD8+T cell differentiation subsets including naive T cells (TN),central memory T cells (TCM),effector T cells(TEFF),effector precursor T cells (TEP),exhausted T cells (TEX),precursor exhausted T cells (TPEX)and regulatory T cells (Tregs)in the spleen,pancreatic draining lymph nodes (pLN)and pancreas infiltrating lymphocytes (PIL)of male and female NOD mice were detected by flow cytometry.Results The frequencies of IFN-γ+,CD107a+and CCL5+CD8+TEFF in pLN and PIL of female NOD mice were significantly higher than those of male NOD mice.However,the frequencies of CD8+TN,CD8+TCM,CD8+TEX,CD8+TPEX and CD122+CD8+Tregs subsets in the spleen were significantly decreased.While there were no significant differences in the above CD8+T cell subsets except CD8+Tregs between female and male ICR mice. Conclusion Androgen may inhibit the differentiation of memory T cells into effector T cells and promote the exhaustion of effector T cells,leading to the difference in morbidity between the male and female mice.


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