Analysis of recognition sites and application for commercial and homemade antibodies to aquaporin 9 / 解剖学报

Objective To analyze the antigen recognition sites of commercial and homemade antibodies against aquaporin(AQP)9,and to identify the application effect.Methods Western blotting was used to compare the efficacy of three commercial antibodies and self-made antibody in identifying AQP9 genotypes.The antigen recognition sites of four antibodies and their specificities in practical applications were analyzed.Results Western blotting showed that protein bands of three commercial antibodies were detected in both WT and Aqp9-/-mice.The keyhole limpet hemocyanin(KLH)conjugated synthetic peptides corresponding to the three commercial antibodies were derived from rat,human and human,respectively.And The sequences of these three synthetic peptides were different from those of mice.AQP3/7 and AQP9 have similar molecular weight and were expressed in the liver with high homology.An obvious band of self-made antibody was observed at the 27 kD position in WT mice,but no band was observed at the corresponding position in Aqp9-/-mice.Conclusion Commercial antibodies 1 and 3 can be used to assist in the identification of genotypes in Aqp9-/-mice.Homemade antibodies can accurately identify genotypes at the protein level.

Construction of the pore-forming toxin gene exlA knock-out mutant of Pseudomonas aeruginosa and its basic characteristics / 军事医学

Objective To construct a non-trace deletion mutant of exlA in Pseudomonas aeruginosa strain NY8755(NY8755ΔexlA)and investigate the basic characteristics of pore-forming toxin ExlA.Methods The NY8755ΔexlA was constructed using the secondary homologous recombination method.C57BL/6J female mice ages 6 to 8 weeks were infected with NY8755 and NY8755 ΔexlA via aerosolized intratraheal inoculation respectively.Within 7 days of infection,the survival and weight changes of the mice were observed and recorded before the proinflammatory cytokines in the bronchoal-veolar lavage fluid(BALF)of the infected mice in the two groups were detected.Results The sequencing results showed that NY8755 ΔexlA was constructed.After 1×107 CFU NY8755 and NY8755 ΔexlA were infected,all the mice in the wild-type strain group died within 48 hours,while those in the mutant strain group began to die after 48 hours,and 40%of them remained alive 7 days later.The weight of surviving mice in the mutant strain group decreased but recovered gradually.After 12 hours of infection,there were more bloody exudates(redder in color)in the BALF of the wild-type strain group than in the mutant strain group,and the contents of proinflammatory cytokines interleukin-1β(IL-1β)and interleukin-17A (IL-17A)were significantly different. Conclusion Pseudomonas aeruginosa pore-forming toxin ExlA is the key pathogenic virulence factor of the exlA-positive Pseudomonas aeruginosa,which can significantly affect the survival status of mice and cause obvious inflammation in mice. Very little information is available on the action mechanisms of ExlA. In this study, The NY8755ΔexlA and the C57BL/6J mouse models infected with NY8755 and NY8755ΔexlA have been constructed that may be used for the investigation of pathogenesis of exlA-positive Pseudomonas aeruginosa.

Generation of MCM2 gene inducible knockout cervical cancer HeLa cells and its effect on DNA replication / 实用医学杂志

Objective To generate minichromosome maintenance protein 2(MCM2)gene knockout cervi-cal cancer HeLa cell lines using inducible CRISPR/Cas9 technology,and to explore the effect of MCM2 on DNA replication and replication stress.Methods The inducible CRISPR/Cas9 system,TLCV2,was used to construct MCM2 knockout HeLa cell lines.And the cell lines were divided into control group(Control),knockout group 1(KO1),and knockout group 2(KO2).Western blot,Edu incorporation experiment,real-time quantitative PCR(qPCR),immunofluorescence and MTT assay were used to analyze the effects of MCM2 knockout on DNA replica-tion and replication stress induced by hydroxyurea.Results The CRISPR/Cas9 system successfully knocked out the MCM2 gene after induction,and MCM2 knockout affected the stability of MCM2-7 complex.Compared with the control cells,MCM2 knockout cells had a dramatic decrease in the capacity of DNA replication,and the mRNA levels of Cyclin A1,Cyclin E1 and CDK4.Under DNA replication stress,MCM2 knockout cells decreased cell viability,DNA damage repair capacity,and increased genomic instability compared with control cells.Conclusion Knockout of MCM2 gene reduces the DNA replication capacity of HeLa cells under normal conditions and cell viability under replication stress.This study successfully generates MCM2 gene inducible knockout HeLa cell lines,laying the foundation for further research on the role and biological function of MCM2 gene in the occurrence and progression of cervical cancer.

Construction of hepatocyte-specific Sirt3 gene knockout mouse model / 安徽医科大学学报

Objective @#To construct hepatocyte-specific silence information regulator 3 ( Sirt3 ) gene knockout (Sirt3Δhep ) mice by Cre-loxP technique , and to provide an important animal model for further studying the biological function of the hepatocyte Sirt3 gene in diseases . @*Methods @#LoxP-labeled Sirt3flox/flox mice were mated with Alb-Cre homozygous (Alb-Cre + / + ) mice , and the F1 generation Sirt3flox/ - /Alb-Cre + / - mice were then mated with Sirt3flox/flox mice , and the F2 genotype of Sirt3flox/flox/Alb-Cre + / - mice were the Sirt3Δhep mice constructed in this ex- periment. Sirt3flox/flox/Alb-Cre - / - (Sirt3flox/flox ) mice were the control mice . Mouse tail genome DNA was extracted and PCR was used to identify the genotypes of the offspring mice . Immunofluorescence was used to detect Sirt3 ex- pression in mouse hepatocytes . Primary hepatocytes and tissue proteins of Sirt3Δhep mice were extracted , and the ex- pression of Sirt3 in mouse hepatocytes and other tissues was verified by Western blot. HE staining was used to ob- serve mice ′s liver , heart , spleen , and lung tissue structure . @*Results @#Sirt3Δhep mice were successfully identified .Immunofluorescence and Western blot results demonstrated a significant decrease in the expression of Sirt3 in the hepatocytes of these mice compared to the control group ( P < 0. 01) . At the same time , there was no significant difference in the expression of Sirt3 in the heart , spleen , kidney , and lung tissues of Sirt3Δhep mice compared with the control group (P > 0. 05) . The results of HE staining showed that the histological characteristics of the liver , heart , spleen , lungs , kidneys , and other major organs of Sirt3Δhep mice were not significantly different from those of the control group mice . @*Conclusion @#Hepatocyte-specific Sirt3 gene knockout mice are successfully constructed , which provides an animal model to explore further the role and molecular mechanism of the hepatocyte Sirt3 gene in diseases .

Construction and gene identification of myeloid specific Spi1 knockout mice / 安徽医科大学学报

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 @#According to the principle of CRISPR/Cas9 technology and C re/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 microinj ected 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 Spi1 flox/ + mice . Spi1 flox/ + mice of F1 generation were selfed to obtain Spi1 flox/flox mice . Spi1 flox/flox mated with Lyz2-Cre + mice to obtain Spi1 flox/ + /Lyz2-Cre + mice , and then mated with Spi1 flox/flox , the Spi1 flox/flox/Lyz2-Cre + mice were myeloid specific Spi1 gene knockout ( KO) mice . Spi1 flox/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 proviral 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 Spi1 flox/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 .

Breeding and genotyping of T lymphocyte-conditional Spi1 knockout mice / 安徽医科大学学报

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 Spi1 flox/flox mice to obtain Lck-Cre ×Spi1 flox/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 ×Spi1 flox/flox mouse genotype was stably inherited . Compared with Spi1 flox/flox mice , the expression level of PU. 1 was significantly reduced in splenic T cells of Lck-Cre ×Spi1 flox/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 .

Establishment and genotype identification of hepatic stellate cell-specific Grk2 gene knockout mouse model / 中国药理学通报

Aim To establish a stable hepatic stellate cell ( HSC ) -specific G protein-coupled receptor kinase 2 ( GRK2 ) knockout mice and provide the important animal model for further studying the biological function of GRK2 in HSC. Methods The loxP-labeled Grk2 gene mouse (Grk2

Construction of human interleukin-26 lentivirus expression plasmid and gene knockout plasmid and their activity verification in HEK293T cells / 中国生物制品学杂志

@#Objective To construct a lentivirus-based expression plasmid and gene knockout plasmid of human interleukin(IL)-26 so as to lay a foundation of studying the function of IL-26 gene in cell signaling pathway and autophagy.Methods IL-26 gene sequence was amplified from human peripheral blood mononuclear cells by RT-PCR and cloned into pCDH-CMVMCS-EF1-copGFP eukaryotic expression vector to construct overexpression plasmid;Four knockout targets,Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sgRNA2,were designed based on the exon sequence of IL-26,and constructed into lentiCRISPRv2 vector by CRISPR/Cas9 technology to construct gene knockout plasmid. The overexpression plasmid and gene knockout plasmid were transiently transfected into HEK293T cells respectively,and the expression of IL-26 was verified by RT-qPCR and Western blot. In addition,amino acid sequence analysis,structure prediction and subcellular localization observation of IL-26 were performed.Results The results of restriction digestion,sequencing and bioinformatics analysis showed that IL-26 was 516 bp in length,encoding 171 amino acids. The IL-26 mRNA level and protein level of HEK293T cells transfected with IL-26 overexpression plasmid increased by 656. 789 times and 1. 978 times respectively with significant differences as compared with the normal control group(t = 17. 976 and 7. 859,P < 0. 000 1 and < 0. 001,respectively). With the transfection of 4 knockout targets Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sg-RNA2 into HEK293T cells,the expression of IL-26 decreased by 0. 930,0. 980,0. 523 3 and 0. 316 9 times,respectively,among which Exon3sgRNA2 significantly down-regulated the expression of IL-26(t = 7. 440,P < 0. 001). IL-26protein showed signal peptide structure and certain transmembrane function in the first 22 amino acids,which existed in cytoplasm.Conclusion IL-26overexpression and gene knockout plasmids were successfully constructed,which laid a foundation of the follow-up study of the function of IL-26.

Analysis of peripheral immune cell typing in breast cancer lung metastasis model of miR-155 knockout mice / 中国免疫学杂志

Objective:To establish a mouse model of breast cancer lung metastasis with miR-155 knockout(miR155-/-)mice,and to compare the difference of peripheral blood immune cell typing between miR155-/-mice and C57BL/6J wide-type(WT)mice.Methods:Bioinformatics analysis was used to explore the expression level of miR-155 in breast cancer tissues and peripheral serum,and its relationship with prognosis.Mouse model of lung metastasis of breast cancer was established by tail vein injection;peripheral blood was collected for flow cytometry,and the immune cell typing was analyzed;the lung tissues were collected for immunohisto-chemical detection to observe the tumor metastasis.Results:Percentage of T lymphocytes and monocytes in peripheral blood of miR155-/-mice was significantly decreased compared with WT mice(P<0.05),percentage of myeloid inhibitory cells(MDSCs)was increased significantly(P<0.05),in which the proportion of monocyte subsets(M-MDSC)was significantly decreased(P<0.05),while the proportion of granulocyte subsets(G-MDSC)was significantly increased(P<0.05).In lung metastasis model of breast can-cer,percentage of T lymphocytes in peripheral blood of miR155-/-mice was significantly higher compared with WT mice,while per-centage of NK cells was decreased significantly(P<0.05),percentage of neutrophil was significantly decreased(P<0.001),propor-tion of Th cells in T lymphocytes was significantly decreased(P<0.05),proportion of M-MDSCs was significantly decreased(P<0.01),while proportion of G-MDSCs was significantly increased(P<0.01).Conclusion:Deletion of miR-155 gene leads to significant differences in peripheral immune cell typing,making mice more susceptible to lung metastasis of breast cancer.

Construction of HIF-1α gene knockout plasmid and functional verification in naked mole rats based on CRISPR/Cas9 system / 中国实验动物学报

Objective To construct plasmids and knock out HIF-1α gene expression in an naked mole rat skin fibroblasts(NSF)cell line using CRISPR/Cas9 genomic editing technology,to provide an in vitro cell model for studying the mechanism of hypoxia tolerance and the occurrence and development of hypoxia-related diseases in naked mole rats.Methods We designed four pairs of single guide RNA(sgRNA)sequences targeting exons 1～4 of the NSF HIF-1αgene and successfully constructed an expression plasmid.The plasmid with the optimal sgRNA was identified and transfected into 293T cells,and the supernatant was used for detecting the virus titer.Lentivirus particles carrying sgRNAs of HIF-1α were transfected into NSF cells which express Cas9 protein,based on a previous protocol.After transfection,fluorescence signals were observed under a fluorescence microscope,and HIF-1α expression in NSF cells was detected by Western Blot and T7 endonuclease 1(T7E1)analysis.Results Sanger sequencing showed that the designed sgRNA was successfully inserted into pX459 and pKLV2-U6-sgRNA2 vectors,demonstrating successful construction of a recombinant plasmid for transfection.T7E1 digestion successfully removed three bands and the target efficiency of sgRNA was 54％.Western Blot showed that the HIF-1α gene was successfully knocked out and its protein level was significantly reduced in NSF cells from naked mole rats(P=0.0019).There were no obvious morphological changes in HIF-1α-knockout cells under the microscope,and gene knockout had no obvious effect on cell proliferation.Conclusions We successfully constructed an HIF-1α-knockout cell line using CRISPR/Cas9 technology,to provide an experimental basis for further studies of the biological function of HIF-1α,as well as the mechanism of hypoxia tolerance in naked mole rats.The result also provide a theoretical foundation for the prevention and treatment of hypoxia-related diseases.

Berberine Inhibits Atherosclerosis by Regulating Lipophagy Via Targeting Wnt5a/NPC1 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the regulatory effect and molecular mechanism of berberine （BBR） on lipophagy in the prevention and treatment of atherosclerotic （AS） lesions in mice. MethodFifty apolipoprotein E-knockout （ApoE-/-） mice were randomly divided into an AS model group， an atorvastatin group （5 mg·kg-1）， and low-， medium-， and high-dose BBR groups （2.5， 5， 10 mg·kg-1）. Ten C57BL/6J mice were assigned to the control group. After 12 weeks， hematoxylin-eosin （HE） and oil red O staining were performed to assess the histopathological changes of AS plaques in the aorta. Biochemical analysis was used to measure serum lipid levels， and enzyme-linked immunosorbent assay （ELISA） was employed to measure the levels of inflammatory cytokines interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α）， oxidative stress marker reactive oxygen species （ROS）， and serum lipophagy marker Beclin1 and microtubule-associated protein 1 light chain 3 Ⅱ （LC3Ⅱ）. The xanthine oxidase method was used to measure serum superoxide dismutase （SOD） activity. Immunohistochemistry （IHC） was used to detect the distribution of wingless-type MMTV integration site family member 5a （Wnt5a） and Nieman Pick type C1 （NPC1） in the aorta， and Western blot was used to determine the protein expression of Wnt5a and NPC1 in the aorta. ResultCompared with the control group， the AS model group showed significant AS plaque formation， significantly elevated levels of serum total cholesterol （TC）， triglycerides （TG）， low-density lipoprotein cholesterol （LDL-C）， IL-6， TNF-α， and ROS， aortic Wnt5a distribution and protein expression （P<0.01）， and significantly reduced levels of serum high-density lipoprotein cholesterol （HDL-C）， SOD， Beclin1， LC3Ⅱ， and aortic NPC1 distribution and protein expression （P<0.01）. Compared with the AS model group， the atorvastatin group， and high- and medium-dose BBR groups showed a significant reduction in AS plaque area （P<0.05， P<0.01）， significantly decreased levels of serum TC， TG， LDL-C， IL-6， TNF-α， ROS， and aortic Wnt5a distribution and protein expression （P<0.05， P<0.01）， and significantly increased levels of serum HDL-C， SOD， Beclin1， LC3Ⅱ， and aortic NPC1 distribution and protein expression （P<0.05， P<0.01）. There was no statistically significant difference in the above indicators between the atorvastatin group and the medium-dose BBR group. ConclusionBBR can competitively bind to Wnt5a to activate NPC1 expression， upregulate lipophagy levels， reduce blood lipids， and inhibit the release of inflammatory mediators and oxidative stress damage， thereby exerting a preventive and therapeutic effect on AS.

Generation of Mlk3 KO mice by CRISPR/Cas9 and its effect on blood pressure / 生物工程学报

To explore the effect of Mlk3 (mixed lineage kinase 3) deficiency on blood pressure, Mlk3 gene knockout (Mlk3KO) mice were generated. Activities of sgRNAs targeted Mlk3 gene were evaluated by T7 endonuclease I (T7E1) assay. CRISPR/Cas9 mRNA and sgRNA were obtained by in vitro transcription, microinjected into zygote, followed by transferring into a foster mother. Genotyping and DNA sequencing confirmed the deletion of Mlk3 gene. Real- time PCR (RT-PCR), Western blotting or immunofluorescence analysis showed that Mlk3KO mice had an undetectable expression of Mlk3 mRNA or Mlk3 protein. Mlk3KO mice exhibited an elevated systolic blood pressure compared with wild-type mice as measured by tail-cuff system. Immunohistochemistry and Western blotting analysis showed that the phosphorylation of MLC (myosin light chain) was significantly increased in aorta isolated from Mlk3KO mice. Together, Mlk3KO mice was successfully generated by CRISPR/Cas9 system. MLK3 functions in maintaining blood pressure homeostasis by regulating MLC phosphorylation. This study provides an animal model for exploring the mechanism by which Mlk3 protects against the development of hypertension and hypertensive cardiovascular remodeling.

Development and application of a rapid gene manipulating toolbox for Pseudomonas aeruginosa / 生物工程学报

Manipulation of genes, including knock-out or knock-in, replacement of gene elements (such as promoters), fusion with a fluorescent protein gene, and construction of in situ gene reporter, is required in most of the biotechnological laboratories. The widely used gene manipulating methods based on two-step allelic exchange are cumbersome in terms of constructing plasmids, transforming and screening. In addition, the efficiency of using this method for long fragment knockout is low. To simplify the process of gene manipulation, we constructed a minimized integrative vector pln2. When a gene needs to be inactivated, an internal fragment of the target gene (non-frameshift) is cloned into the pln2 plasmid. Once the single-crossover recombination between genome and the constructed plasmid occurs, the endogenous gene is segmented by the plasmid backbone and thus inactivated. We developed a toolbox based on pln2 that can be used for different genomic operation mentioned above. With the help of this toolbox, we successfully knocked out large fragments of 20-270 kb.

Effect of ACE2 deletion on vasoconstriction reactivity of aortic segments in mice with tourniquet shock / 中国病理生理杂志

AIM:To observe the effect of angiotensin-converting enzyme 2(ACE2)deletion on vasoconstric-tion reactivity of aortic segments in ACE2 knockout(KO)mice with tourniquet shock(TS).METHODS:The 8-month-old male mice with C57BL/6 background were divided into wild-type(WT)control group,WT-TS group,KO group and KO-TS group,with 10 mice in each group,of which five were used for determination of vascular reactivity,and the other five for the other assays.The hindlimbs of the mice in WT-TS group and KO-TS group were ligated with tourniquet for 2 h and loosened for 4 h.The mice in WT group and KO group were subjected to the same treatment except for tourniquet liga-tion.The vasoconstriction reactivity of the aorta was measured on tensiometer.The morphological damage of the aorta was evaluated by vascular histopathology.Western blot was used to detect the expression of AT1,MAS,ACE and ACE2 pro-teins in aorta.The serum levels of angiotensin(Ang)Ⅱ and Ang-(1-7)were determined by enzyme-linked immunosorbent assay.RESULTS:Compared with WT group,the mice in WT-TS group had lower vascular reactivity to norepinephrine(NE)and obvious vascular lesions.The expression of ACE protein increased significantly(P＜0.01),while the expres-sion of ACE2 decreased(P＜0.05).The expression of AT1 protein in aorta decreased significantly,the expression of MAS protein increased significantly,and the AT1/MAS ratio decreased(P＜0.01).Serum Ang II level increased,serum Ang-(1-7)level decreased,and Ang Ⅱ/Ang-(1-7)ratio increased(P＜0.05).Compared with WT group,vascular reactivity in KO group increased at low concentration of NE(＜10-7 mol/L),and decreased at high concentration(＞10-7 mol/L)without vascular lesion.The expression levels of aortic AT1,MAS and ACE were all elevated(P＜0.05).The serum level of Ang Ⅱ increased(P＜0.05),but the level of Ang-(1-7)had no obvious change.Compared with KO and WT-TS groups,the aortic reactivity in KO-TS group subtracted apparently(P＜0.05),representing its curve shifting to the right obviously.The morphological damage aggravated slightly,and the expression of AT1 and ACE increased slightly in KO-TS group com-pared with WT-TS group(P＜0.05).However,the expression of MAS increased significantly in vascular tissue(P＜0.01).The serum levels of Ang Ⅱ and Ang-(1-7)further increased and decreased,respectively,and the Ang Ⅱ/Ang-(1-7)ratio increased(P＜0.01).CONCLUSION:Deficiency of ACE2 induces severe aortic hyporeactivity to NE during TS,which may be related to the increased imbalance of renin-angiotensin system in ACE2 gene knockout mice.

Effect of intestinal Metrnl gene knockout on intestinal microbiota and ulcerative colitis / 药学实践与服务

Objective To investigate the effect of intestinal Metrnl on dextran sodium sulfate (DSS)-induced ulcerative colitis mouse model and the regulation mechanism of intestinal microbiota. Methods Different concentrations of DSS (3% DSS and 1% DSS) were used to induce ulcerative colitis on C57 mice to determine the experimental conditions. Intestinal epithelial Metrnl specific knockout mice (Metrnl(-/-)) and its control mice (Metrnl(+/+)) were administrated with 3% DSS for 5 d. Then the survival time, body weight, DAI (disease activity index), colon length and pathological changes in colon tissues were observed. 16S ribosomal RNA gene sequencing was used to detect the composition of intestinal microbiota. Results Compared with 1% DSS, 3% DSS could significantly aggravate ulcerative colitis on C57 mice, such as lower survival rate (P<0.05), more weight loss (P<0.05), higher DAI score (P<0.05), shorter colon length (P<0.05) and higher pathology score (P<0.05). After administrated to 3% DSS for 5 d, comparing with Metrnl(+/+) mice, Metrnl(-/-) mice showed more weight loss (P<0.05), higher DAI score (P<0.05), shorter colon length (P<0.05) and higher pathology score (P<0.05). The 16S ribosomal RNA results showed that the diversity of intestinal microbiota in Metrnl(-/-) mice significantly decreased. Furthermore, Bacteroidetes and Proteobacteria significantly decreased, while Firmicutes increased. Conclusion Metrnl could protect the DSS-induced ulcerative colitis mouse through regulating intestinal microbiota.

Murine models of cerebral cavernous malformations / 国际脑血管病杂志

Cerebral cavernous malformations (CCMs) are the common cerebrovascular malformation. Its incidence was 0.16%-0.5%. CCM can exist in both sporadic and familial forms, with the latter being inherited in an autosomal dominant manner. Its pathogenesis is associated with mutations in the CCM1, CCM2, and CCM3 genes. The somatic mutations of these genes are the basis for the occurrence of brain lesions. In order to explore the pathogenesis of CCM and identify therapeutic targets, various CCM animal models have been developed, providing assistance for the study of the pathological and physiological mechanisms of CCM. However, each CCM model has its own advantages, disadvantages, and applicability. Mice are the most commonly used animals to model CCM. Therefore, this article summarizes the characteristics and research progress of current murine CCM models.

Construction of the Pkd1 gene knockout mouse model with polycystic kidney disease based on CRISPR/Cas9 technology / 中华肾脏病杂志

Objective:To establish a conditional knockout mouse model of polycystic kidney disease 1 ( Pkd1) gene based on CRISPR/Cas9 and Cre-loxP gene editing technology, and to provide an animal model for in-depth research on the role of Pkd1 gene in the development of polycystic kidney disease. Methods:In-Fusion technology was used to construct a targeting vector. Corresponding gRNAs, Cas9 mRNAs, and donor vectors carrying the loxP site were prepared based on the Pkd1 gene, and injected into the fertilized eggs of C57BL/6N mice. The fertilized eggs were transferred to the fallopian tubes of female mice with pseudopregnancy. After the newborn mice were identified by PCR and sequencing analysis, Pkd1 flox/flox F0 generation positive mice were selected. The F0 generation positive mice were bred with wild-type mice, and F1 generation heterozygous mice with Pkd1 flox/+ genotype were selected for offspring. F2 generation homozygous mice with Pkd1 flox/flox genotype were obtained through internal expansion, and then hybridized with Cre positive Ggt1/ Cre mice. F3 generation mice with Pkd1 flox/+Ggt1 Cre genotype were obtained. F4 generation mice with Pkd1 flox/flox Ggt1 Cre genotype were obtained by self crossing or backcrossing with F2 generation Pkd1 flox/flox, namely kidney-specific Pkd1 gene knockout mice ( Ggt1-cKO mice). PCR method was used to identify the genotype of mice, and then the mice were divided into wild-type control (WT) group ( n=6), Pkd1 homozygous control (PKD) group ( n=6), and Ggt1-cKO knockout validation (CKO) group ( n=6) according to the gene identification results. Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the expression of Pkd1 mRNA in the kidneys and other organs of mice in each group. HE staining was used to detect the pathological changes in renal tissues of mice in each group. The automatic biochemical detector was used to detect the blood urea nitrogen and serum creatinine levels of mice, and the kidney coefficient was calculated. Results:The PCR detection results showed that the genotype of offspring mice in CKO group was consistent with Pkd1floxflox Ggt1 Cre. Pkd1 gene was only specifically expressed in the kidney, but not in other tissues. The RT-qPCR results showed that the relative expression of Pkd1 mRNA in the renal medulla of CKO group was significantly lower than that of WT and PKD groups. The kidney volume of the CKO group had increased by about twice compared to the WT group. Under the microscope, it could be observed that there were multiple vacuoles of varying sizes and shapes in the kidneys of the CKO group, and there was a significant increase in the interstitial space of the medullary tissue. The kidney coefficient, blood urea nitrogen, and serum creatinine in the CKO group were significantly higher than those in the WT and PKD groups (all P<0.05). Conclusion:Based on CRISPR/Cas9 and Cre-loxP gene editing technology, Pkd1 gene kidney conditional knockout mice can be successfully constructed, providing an animal model for further studying the action mechanism of Pkd1 gene in polycystic kidney disease.

Exploring the mechanism by which acupuncture and moxibustion reduce colonic mucosal inflammation in rats with ulcerative colitis(UC)based on the P2X7R-NLRP3 inflammasome pathway / 针灸推拿医学（英文版）

Objective:To explore the mechanism of acupuncture and moxibustion for ulcerative colitis(UC)from the perspective of the P2X7 receptor(P2X7R)-nucleotide-binding oligomerization domain(NOD)-like receptor protein 3(NLRP3)inflammasome pathway. Methods:Sprague-Dawley rats were randomly assigned to a normal(N)group,a model(M)group,a herb-partitioned moxibustion(HM)group,and an electroacupuncture(EA)group.For modeling,the rats drank 4%dextran sulfate sodium for 7 d.Rats in the HM group and EA group received 7 consecutive days of HM or EA at bilateral Tianshu(ST25),respectively.The histopathological change in colon tissue was observed by hematoxylin-eosin(HE)staining;immunofluorescence staining was used to detect the protein expression of related molecules in the colon tissue,and enzyme-linked immunosorbent assay was used to detect the concentrations or contents of related molecules in the serum and colon tissue.Wild-type(WT)and P2X7R gene knockout(KO)mice were used to construct UC models,histopathological changes in the colon tissue were observed by HE staining,and the NLRP3 protein expression in the colon tissue was observed by immunohistochemistry. Results:Compared with the N group,the colon histopathological score in the M group was significantly increased,and the protein expression of P2X7R,NLRP3,apoptosis-associated speck-like protein containing CARD(ASC),Caspase-1,interleukin-1β(IL-1β),and interleukin-18(IL-18)in the colon tissue and the protein levels of IL-1β and IL-18 in the serum were significantly increased(P<0.05).Compared with the M group,the histopathological scores of the colon in the HM group and the EA group were significantly decreased,and the protein expression levels of P2X7R,NLRP3,ASC,Caspase-1,IL-1β,and IL-18 in the colon tissue and the protein level of IL-18 in the serum were significantly decreased(P<0.05).After UC modeling,the colonic mucosal epithelial damage and inflammatory cell infiltration in P2X7R KO mice were less than those in WT mice,and the NLRP3 protein expression in the colon was also decreased compared with that in WT mice(P<0.05). Conclusion:HM and EA at Tianshu(ST25)may inhibit the protein activities of P2X7R,NLRP3,ASC,and Caspase-1 in the colon tissue of rats with UC,thereby reducing the downstream molecules IL-1β and IL-18 in the P2X7R-NLRP3 inflammasome pathway to relieve UC inflammation.

Establishment of hKDR+/+ Humanized and Rag1-/- Gene Knockout Double Genetically Modified Mouse Model / 实验动物与比较医学

ObjectiveThrough improving the potential of vascular endothelial growth factor receptor (VEGFR)-humanized mouse model (hKDR+/+) with C57BL/6N background to allow the growth of different mouse tumor cell lines, to establish novel tumor-bearing mouse models which can support in vivo tumorigenesis of different mouse tumor cell lines and be used to evaluate drugs targeting VEGFR.MethodsFirstly, a method to evaluate the in vivo activity of antibody targeting VEGFR based on the hKDR+/+ humanized mouse model was established. Recombinant activating gene 1 (Rag1) knockout mice (Rag1-/-) were established using CRISPR/Cas9 technology. Then these Rag1-/- mice were crossed with hKDR+/+ mice to get a double gene modified homozygous hKDR+/+/Rag1-/- mouse model by screening. Finally, tumor cell lines derived from different mouse strains were tested on the double gene-modified mouse model to compare the differences in tumor growth. ResultsAntibodies designed for VEGFR showed significant anti-tumor activity in hKDR+/+ mice, which significantly reduced tumor volume and weight compared with the PBS group (P<0.01, P<0.05). The number of B cells and T cells in the peripheral blood of Rag1-/- mice and hKDR+/+/Rag1-/- mice decreased (P<0.05, P<0.001). Tumors were observed in hKDR+/+/Rag1-/-, Rag1-/-, wild-type, and hKDR+/+ mice after 7 d of inoculation of MC38 cells derived from C57BL/6 mice. Tumors were only observed in groups of hKDR+/+/Rag1-/- and Rag1-/- mice, but not in the wild-type and hKDR+/+ mice after 10 d of inoculation with CT26 cells derived from BALB/c mice. After 3 weeks of inoculation, the tumor volume of hKDR+/+/Rag1-/- mice was significantly larger than that of Rag1-/- mice (P<0.01). ConclusionRag1 knockout mice were obtained and a novel hKDR+/+/Rag1-/- double genes modified mouse model was further screened. The tumor cell lines from different mouse strain origins were more prone to growth in mice with Rag1 gene deficiency. The results suggest that the reduced immune response of hKDR+/+ humanized mice will improve the capacity of supporting the growth of mouse tumor lines in the model. As a result, more tumor-bearing mouse models may be constructed for the evaluation of drugs targeting VEGFR in this way.

Macrophage MED1 deficiency promotes the development of atherosclerosis in female ApoE and LDLR knockout mice / 西安交通大学学报(医学版)

【Objective】 To study the effect of macrophage mediator 1 (MED1) deficiency on atherosclerosis in female mice. 【Methods】 ApoE knockout (ApoE-/-), LDLR knockout (LDLR-/-), MED1fl/fl, and macrophage MED1 knockout (MED1△Mac) mice were recruited in the study. Two types of mouse model were constructed:ApoE and macrophage MED1 double knockout (MED1△Mac/ApoE-/-) mice and their littermate controls (MED1fl/fl/ApoE-/-). ② LDLR knockout (LDLR-/-) mice receiving bone marrow from MED1△Mac (MED1△Mac→LDLR-/-) or MED1fl/fl (MED1fl/fl→LDLR-/-) mice. Female mice from these two models were fed a Western diet (21% fat and 0.15% cholesterol) for 12 weeks to promote the development of atherosclerosis. Body weight, total cholesterol (TC), and total triglyceride (TG) content in plasma were measured dynamically. After Western diet feeding for 12 weeks, aortic tree and aortic root were collected and hematoxylin-eosin (H&E) and oil red O staining were performed. 【Results】 Plasma TC and TG did not significantly differ between MED1fl/fl/ApoE-/- control group and MED1△Mac/ApoE-/-experimental group. However, the plaque area in aortic tree and aortic root was significantly increased in MED1△Mac/ApoE-/-mice. Moreover, compared with that in MED1fl/fl→LDLR-/- control group, the plaque area of aortic tree and aortic root had an increasing trend in MED1△Mac→LDLR-/- mice group. 【Conclusion】 MED1 deficiency in macrophages promotes the development of atherosclerosis in female ApoE or LDLR knockout mice.