Objective: To investigate the causal association between amino acids and the primary malignant bone tumor and its underlying mechanism. Methods: Genome-wide association study (GWAS) data of glycine, serine, arginine, glutamine, methionine, and leucine was sourced from the IEU OpenGWAS database and the GWAS Catalog. GWAS data of primary malignant bone tumor were obtained from the FinnGen database. Using each of the six amino acids as the exposure and primary malignant bone tumor as the outcome, two-sample Mendelian randomization (MR) analysis was performed with the inverse-variance weighted method as the primary approach. Multivariable MR analysis was employed to control for collinearity among amino acids. Sensitivity analyses were conducted using Cochran's Q test, MR-Egger regression and the MR Steiger test. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and protein-protein interaction network analysis were explored to explore potential mechanisms and identify key genes. Results: MR analysis results indicated a statistically significant causal association between glycine and primary malignant bone tumor (OR=1.719, 95%CI: 1.083-2.728). No significant causal associations were found for the other five amino acids (all P>0.05). Multivariable MR analysis revealed that, after adjusting for the other five amino acids, confirmed a positive causal association between glycine and primary malignant bone tumor (OR=1.512, 95%CI: 1.125-2.031). Sensitivity analyses revealed no significant heterogeneity, horizontal pleiotropy, or reverse causality (all P>0.05). Genes associated with both glycine metabolism and primary malignant bone tumor were enriched in the JAK-STAT signaling pathway, with serine hydroxymethyltransferase 2 (SHMT2) identified as a key gene. Conclusion Higher glycine levels may increase the risk of primary malignant bone tumor via the SHMT2-JAK-STAT pathway.

Objective: To constructCSF1R+/-mice and to analyze their genotypes, so as to provide animal model basis for disease pathological mechanism and drug target. Methods : A linearized targeting vector was designed according to Cre/Loxp system. A Loxp site was inserted upstream of the 5th exon of theCSF1Rgene, and a neomycin resistance box with Loxp sites on both sides was inserted downstream of the 5th exon. The linearized targeting vector was electroporated into embryonic stem cells. The correctly targeted embryonic stem cells were injected into the blastocysts of C57BL/6J mice to obtain chimeric mice, which were bred with Zp3-Cre mice. The newborn mice were numbered 9-14 days after birth and their tails were cut. The DNA of the mice was extracted, and the genotype of the mice was identified by polymerase chain reaction and agarose gel electrophoresis. The expression of CSF1R in mouse macrophages was detected by flow cytometry. The expression of CSF1R in mouse tissues was detected by Western blot. Results: The results of agarose gel electrophoresis showed that 453 bp bands were amplified in wild type mice, and 453 bp and 650 bp bands were amplified in heterozygous mice. The results of flow cytometry showed that the expression of CSF1R in peritoneal macrophages and bone marrow-derived macrophages of CSF1R heterozygous mice was lower than that of WT group(P<0.05). The results of Western blot showed that the expression of CSF1R in spleen, kidney and brain tissue of CSF1R heterozygous group was lower than that of WT group(P<0.05). Conclusion CSF1R+/-mice are successfully constructed, reproduced and identified, which provides an animal model basis for further revealing the potential mechanism of CSF1R in immune regulation.

Objective:To screen the key genetic,diagnostic and therapeutic targets of chronic obstructive pulmonary disease(COPD)patients by using microarray datasets and Mendelian randomization(MR)method,and to provide the evidence for clinical diagnosis and treatment of COPD.Methods:Four COPD gene expression profile datasets were obtained from the Gene Expression Omnibus(GEO)database.The data were processed and normalized using R software,and differentially expressed genes(DEGs)were screened.MR analysis was performed to explore the causal relationship between COPD and expression quantitative trait loci(eQTL),intersection with DEGs was taken to identify potential key targets.Gene Set Enrichment Analysis(GSEA),Gene Ontology(GO)functional enrichment analysis,and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis were conducted to investigate the functional roles and pathways of the key targets,external datasets were used to validate their expression.Results:A total of 1 571 DEGs were screened,including 820 upregulated genes and 751 downregulated genes.MR analysis identified 286 COPD-related genes,and intersection with DEGs revealed 3 upregulated genes:diacylglycerol kinase gamma(DGKG),neurofilament heavy polypeptide(NEFH),and Fc receptor like B(FCRLB);and 6 downregulated genes:STEAP4 metalloreductase(STEAP4),pleckstrin homology domain containing family F member 2(PLEKHF2),CD3d molecule(CD3D),transgelin 2(TAGLN2),tripartite motif containing 22(TRIM22),and ribosomal protein L9(RPL9).The biological function analysis results indicated that these genes were mainly involved in pathways such as iron ion transport into the cells,oxidoreductase activity,primary immunodeficiency,and Th1 and Th2 cell differentiation.The MR analysis results confirmed the causal relationship between these targets and COPD.The external validation results showed that compared with healthy controls,the expression level of FCRLB in COPD samples was significantly increased(P<0.01),while the expression levels of CD3D and RPL9 were significantly decreased(P<0.05 or P<0.01),which was consistent with the MR analysis results,highlighting the reliability of this study.Conclusion:DGKG,NEFH,FCRLB,STEAP4,PLEKHF2,CD3D,TAGLN2,TRIM22,and RPL9 may serve as important regulatory factors and clinical diagnostic/therapeutic targets in the pathogenesis of COPD,providing clues for early screening,diagnosis,and targeted treatment of COPD.

Objective: To construct microRNA(miR)-22 gene knockout(miR-22-/-) mice using CRISPR/Cas 9 technology, to breed miR-22-/- mice and to identify their genotypes. Methods : In this experiment, CRISPR/Cas 9 technology was used to construct miR-22-/- genetically engineered mice. After gene identification, the F0 generation miR-22-/- mice were mated with wild-type mice in the same litter to obtain F1 generation miR-22-/- mice. The miR-22 knockout efficiency was analyzed at the RNA level by real-time fluorescence quantitative polymerase chain reaction(qPCR). Western blot was used to detect the interaction between miR-22 and target genes. Results : miR-22-/- mice were successfully constructed using CRISPR/Cas 9 technology, gene identification was performed on the bred mice, and three stable genotypes of miR-22+/+,miR-22+/-, and miR-22-/- were identified. The real-time fluorescence quantitative PCR detection results confirmed that miR-22-/- mice showed almost no expression of miR-22 in the heart, liver, lung, kidney, spleen, and thymus tissues compared to wild-type mice in the same litter. Western blot analysis showed that the relative expression level of NLRP3 protein in miR-22-/- mouse tissues was lower than that in wild-type mice. Conclusion A miR-22-/- mouse model is successfully constructed, and stable genetic homozygous miR-22-/- mice is obtained. This indicates that miR-22 has an inhibitory effect on the downstream target gene NLRP3.

Objective: To explore the breeding and genotyping of CCR2 knockout mice, and to verify the applicability of the polymerase chain reaction(PCR) method for genotype detection of CCR2 knockout mice. Methods: The introduced CCR2 pure male mice and wild-type female mice were mated and bred to produce the offspring generation, the obtained F1 generation heterozygous mice were continued to be mated. DNA was extracted by clipping the tail tissues of the mice at the age of 2 weeks, the target gene fragment was amplified by PCR, and the genotypic results were determined by agarose gel electrophoresis. The proportion of purebred progeny carrying the CCR2 knockout gene was increased by genetic crosses, the effect of CCR2 knockout in the progeny mice was verified by using Western blot against major immune cells and key organs, and flow cytometry was used to detect whether the knockout of the CCR2 gene had any effect on the function of the immune system by targeting the major immune cells. Results: CCR2 knockout mice were successfully bred and characterized, and three genotypes of F2 generation mice were obtained: CCR2+/+, CCR2+/-, and CCR2-/-. The offspring genotypes were identified by PCR, and Western blot showed extremely low CCR2 protein expression in CCR2 knockout mice. Flow analysis showed that CCR2 knockdown reduced the expression of CD4+T and Th1 cells in mouse spleen-derived T cells, but did not affect macrophage function. Conclusion Correct breeding and identification are important ways to get the pure CCR2 knockout mice, and PCR method for identifying mouse genotypes is simple, fast and reliable.

Objective:To study effects of different pretreatment methods on the detection of pesticide residues in Angelicae Sinensis Radix,ChrysanthemI Flos,Lych Fructus,Astragali Radix and Lonicerae Japonicae Flos.Methods:The samples were treated with QuEChERS method and high-speed homogenization combined with hydro-phile-lipophile balance(HLB)solid-phase extraction method,and the residual amounts of carbofuran,3-carboxyl-carbofuran,phorate,phorate sulfone,phorate sulfoxide,and methyl isoflurophos were simultaneously determined using UHPLC-MS/MS.With a gradient elutionof 0.1％formic acid solution containing 5 mmol·L-1 ammonium formate and t 0.1％formic acid solution containing 5 mmol·L-1 ammonium formate-acetonitrile(volume ratio of 5:95),Ultra-performance liquid chromatography column Agilent Poroshell 120 SB-C18(2.1 mm × 100 mm,2.7μm)was used at 35 ℃ and the electrospray ion source was scanned in the positive ion mode and detected in the multiple reaction monitoring mode in mass spectrometry.Results:The deviation of the results measured by QuECh-ERS method and HLB solid-phase extraction method was between 9.09％-55.56％.Conclusion:In the selection of the pretreatment method for the detection of pesticide residues in traditional Chinese medicine,it is recommen-ded to take the measurement data of positive samples as the evaluation index and basis,and choose the method with higher measurement value and high extraction efficiency.

Objective To investigate the role and mechanism of suramin(Sur)in acetaminophen(APAP)-induced acute liver injury in mice.Methods 8-10 weeks old C57BL/6J mice were randomly divided into the APAP group and APAP+Sur group(20 mg/kg suramin was injected 1 h before).After 18 hrs of fasting,400 mg/kg APAP was injected intraperitoneally to establish a mouse model of acute liver failure and the survival rate was recorded.An acute liver injury model of mice was established via intraperitoneal injection of 300 mg/kg APAP(other conditions remained unchanged).A control group was also established,with liver tissues and serum collected at 0,2,and 12 hours post-APAP treatment.ELISA and CBA techniques were adopted to detect the release of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in serum and the secretion of inflammatory factors.H&E staining and immunohistochemistry were used to detect liver tissue necrosis and inflammatory cell infiltration.DCFA-DH and ELISA techniques were used to detect the levels of reactive oxygen species(ROS),malondialdehyde(MDA)and glutathione(GSH)in liver tissues.Western blotting was employed to assess the activation of the JNK signaling pathway in liver tissues.Results Suramin treatment improved the survival rate of APAP-induced mice,reduced the release of transaminases and inflammatory factors in serum,and alleviated APAP-induced liver cell necrosis and inflammatory cell infiltration in the liver.Suramin treatment delayed APAP-induced GSH depletion in the liver,reduced MDA and ROS levels,and inhibited JNK pathway activation.Conclusion This study has confirmed the protective effect of suramin against acetaminophen-induced acute liver injury in mice.The mechanism is potentially related to oxidative stress and inflammation.

[Objective] To explore the expression of Nectin-4 in invasive bladder urothelial carcinoma (BUC) tissue and its clinical significance, so as to provide reference for clinical diagnosis and treatment of BUC. [Methods] Nectin-4 expression in 60 cases of invasive BUC and 40 cases of chronic inflammation of bladder mucosa was detected with immunohistochemical staining (IHC) and RNAscope.The results of the two methods were analyzed and compared, and the relationship between the two methods and the clinicopathological characteristics of invasive BUC was discussed.The correlation between the protein expression of Nectin-4 in BUC tissues, human epidermal growth factor receptor 2 (Her-2) and programmed death factor ligand 1 (PD-L1) was analyzed. [Results] The positive protein expression rates of Nectin-4 detected by IHC were 78.33%(47/60) and 17.50% (7/40) in the invasive BUC group and inflammatory group, respectively, while the positive mRNA expression rates of Nectin-4 detected by RNAscope were 83.33% (50/60) and 12.50% (5/40), respectively.The Kappa values of Nectin-4 in the invasive BUC group and inflammatory group were 0.732 and 0.610, respectively, with general consistency.The protein expression of Nectin-4 in invasive BUC was correlated with muscular invasion, histological grade, vascular thrombus, lymph node metastasis and clinical stage (P<0.05). The mRNA expression of Nectin-4 in invasive BUC was correlated with max tumor diameter, muscular invasion, histological grade, vascular thrombus, lymph node metastasis and clinical stage (P<0.05). The high expression of Nectin-4 in invasive BUC was positively correlated with the expression of Her-2 (P=0.002), but not with the expression of PD-L1 (P>0.05). [Conclusion] Nectin-4 is highly expressed in invasive BUC, and is usually associated with the pathological parameters of poor prognosis.Detection of Nectin-4 expression will help to guide clinical diagnosis and treatment.

Objective To construct myeloid-specific Spi1 gene knockout mice and analyze their genotypes,so as to provide animal model basis for the study of pathological mechanism of diseases and drug targets.Methods Ac-cording to the principle of CRISPR/Cas9 technology and Cre/LoxP system,sgRNA and Donor vectors were de-signed and constructed.The transcript of Exon 2(Exon 2)was used as the knockout region,and Loxp elements were placed on both sides of Exon 2.Cas9 protein,sgRNA and Donor vector were mixed and microinjected into the fertilized eggs of C57BL/6J mice,the fertilized eggs were transplanted into the uterus of C57BL/6J pregnant female mice,and F0 generation was obtained after 19～20 days.Positive F0 mice were mated with C57BL/6J mice to ob-tain stable F1 Spi1flox/+mice.Spi1flox/+mice of F1 generation were selfed to obtain Spi1flox/flox mice.Spi1flox/flox mated with Lyz2-Cre+mice to obtain Spi1flox/+/Lyz2-Cre+mice,and then mated with Spi1flox/flox,the Spi1flox/flox/Lyz2-Cre+mice were myeloid-specific Spi1 gene knockout(KO)mice.Spi1flox/flox/Lyz2-cre-mice were used as wild-type(WT)mice.DNA of WT and KO mice was extracted,and the genotypes were identified by agarose gel electro-phoresis after PCR amplification.Western blot was used to detect the expression of spleen focus forming virus provi-ral integration oncogene,Spi-1/purine rich box-1(PU.1)in immune cells of WT and KO mice.Results The results of PCR identification showed that the genotype of mice with only 220 bp amplified by flox primer was Spi1flox/flox homozygote,and the genotype of mice with 700 bp amplified by Lyz2-Cre primer was Lyz2-Cre+.Western blot showed that compared with WT group,the protein PU.1 was not expressed in bone marrow-derived macropha-ges(BMDMs)and peritoneal macrophages(PM)in KO group(P<0.01).There was no significant difference of statistics in the expression level of PU.1 in T cells between KO mice and WT mice.The results of PCR and West-ern blot showed that myeloid-specific Spi1 KO mice were successfully constructed.Conclusion The myeloid-spe-cific Spi1 gene KO mice are successfully constructed and identified,which provides animal model basis for further revealing the potential mechanism of PU.1 inimmune regulation.

Objective To breed and identify the T lymphocyte-conditional Spi1 knockout mice for the further in-vestgation of the specific role of Spi1-encoded protein PU.1.Methods The Lck-Cre mice were mated with Spi1flox/flox mice to obtain Lck-Cre×Spi1flox/flox mice(T lymphocyte-specific Spi1 knockout mice),and the genotype was determined by polymerase chain reaction(PCR)and agarose gel electrophoresis.Magnetic beads were used to sort out the splenic T lymphocytes,and the knockdown efficiency of PU.1 in T cells was detected by Western blot,quantitative real-time PCR(qPCR)and flow cytometry.Results The Lck-Cre×Spi1flox/flox mouse genotype was stably inherited.Compared with Spi1flox/flox mice,the expression level of PU.1 was significantly reduced in splenic T cells of Lck-Cre×Spi1flox/flox mice.Conclusion In this study,the T lymphocyte-specific Spi1 knockout mice was successfully constructed by applying Cre/LoxP system and CRISPR/Cas9 technology,which provided a reliable an-imal model for the subsequent experiments of the specific role of PU.1 in T cell-related diseases.