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.

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.

Identification of a new C-23 metabolite in sterol degradation of Mycobacterium neoaurum HGMS2 and analysis of its metabolic pathways / 生物工程学报

Mycobacterium neoaurum has the ability to produce steroidal intermediates known as 22-hydroxy-23, 24-bisnorchol-4-en-3-one (BA) upon the knockout of the genes for either the hydroxyacyl-CoA dehydrogenase (Hsd4A) or acyl-CoA thiolase (FadA5). In a previous study, we discovered a novel metabolite in the fermentation products when the fadA5 gene was deleted. This research aims to elucidate the metabolic pathway of this metabolite through structural identification, homologous sequence analysis of the fadA5 gene, phylogenetic tree analysis of M. neoaurum HGMS2, and gene knockout. Our findings revealed that the metabolite is a C23 metabolic intermediate, named 24-norchol-4-ene-3, 22-dione (designated as 3-OPD). It is formed when a thioesterase (TE) catalyzes the formation of a β-ketonic acid by removing CoA from the side chain of 3, 22-dioxo-25, 26-bisnorchol-4-ene-24-oyl CoA (22-O-BNC-CoA), followed by spontaneously undergoing decarboxylation. These results have the potential to contribute to the development of novel steroid intermediates.

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.

Cathepsin D overexpression in the nervous system rescues lethality and Aβ42 accumulation of cathepsin D systemic knockout in vivo

The lysosome is responsible for protein and organelle degradation and homeostasis and the cathepsins play a key role in maintaining protein quality control. Cathepsin D (CTSD), is one such lysosomal protease, which when deficient in humans lead to neurolipofuscinosis (NCL) and is important in removing toxic protein aggregates. Prior studies demonstrated that CTSD germ-line knockout-CtsdKO (CDKO) resulted in accumulation of protein aggregates, decreased proteasomal activities, and postnatal lethality on Day 26 ± 1. Overexpression of wildtype CTSD, but not cathepsin B, L or mutant CTSD, decreased α-synuclein toxicity in worms and mammalian cells. In this study we generated a mouse line expressing human CTSD with a floxed STOP cassette between the ubiquitous CAG promoter and the cDNA. After crossing with Nestin-cre, the STOP cassette is deleted in NESTIN + cells to allow CTSD overexpression-CTSDtg (CDtg). The CDtg mice exhibited normal behavior and similar sensitivity to sub-chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced neurodegeneration. By breeding CDtg mice with CDKO mice, we found that over-expression of CTSD extended the lifespan of the CDKO mice, partially rescued proteasomal deficits and the accumulation of Aβ42 in the CDKO. This new transgenic mouse provides supports for the key role of CTSD in protecting against proteotoxicity and offers a new model to study the role of CTSD enhancement in vivo.

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.

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.

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.

Mechanism of Renshentang in Treatment of Atherosclerosis Based on Autophagic Effect of TRPV1 on Arterial Smooth Muscle / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Renshentang， recorded in Synopsis of Golden Chamber， in the treatment of atherosclerosis （AS） based on the autophagic effect of transient receptor potential vanilloid subtype 1 （TRPV1） on arterial smooth muscle. MethodFourteen SPF-grade 8-week-old male C57BL/6J mice were assigned to the normal group and 70 8-week-old apolipoprotein E knockout （ApoE-/-） mice were assigned to the experimental group. The AS model was induced by a high-fat diet in the mice in the experimental group for eight weeks. The model mice were then randomly divided into model group， low-， medium-， and high-dose Renshentang groups （2.715， 5.43， and 10.68 g·kg-1·d-1）， and simvastatin group （0.02 g·kg-1·d-1）. Drug treatment lasted eight weeks. Serum was taken and serum total cholesterol （CHO）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， and high-density lipoprotein cholesterol （HDL-C） levels were measured by assay kits to observe the changes in lipid levels in mice. The aorta was stained with hematoxylin-eosin （HE） to observe the overall pathology of the aortic root and oil red O staining was used to detect the lipid deposition in the aortic plaque and calculate the percentage of the aortic root area to the lumen area. The protein expression of TRPV1， adenylate-activated protein kinase （AMPK）， phosphorylated AMPK （p-AMPK）， autophagy effector-1 （Beclin-1）， and microtubule-associated protein 1 light chain 3 （LC3Ⅱ） in mouse aortic tissues was determined by Western blot. ResultCompared with the normal group， the model group showed increased serum CHO， TG， and LDL-C levels， decreased HDL-C， and increased aortic root plaque area （P<0.01）. Compared with the model group， the Renshentang groups showed decreased levels of CHO， TG， and LDL-C in serum （P<0.05， P<0.01）， especially in the low- and medium-dose Renshentang groups （P<0.01）. Compared with the normal group， the simvastatin group and the Renshentang groups showed reduced aortic root plaque area （P<0.05）， especially in the high-dose Renshentang group （P<0.01）. Compared with the normal group， the model group showed decreased relative expression levels of TRPV1， p-AMPK/AMPK， Beclin-1， and LC3Ⅱ/LC3Ⅰ（P<0.05， P<0.01）. Compared with the model group， the medium- and high-dose Renshentang groups showed increased relative expression levels of TRPV1， p-AMPK/AMPK， Beclin-1， and LC3Ⅱ/LC3Ⅰ（P<0.05，P<0.01）. ConclusionThe anti-AS effect of Renshentang recorded in Synopsis of Golden Chamber may be achieved by up-regulating TRPV1 expression to restore the level of autophagy mediated by AMPK.

Effect of intestinal Metrnl gene knockout on intestinal microbiota and ulcerative colitis / 药学实践杂志

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.

Síndrome de Baller-Gerold. A propósito de un caso clínico y revisión de la literatura

El síndrome de Baller-Gerold es secundario a mutaciones en el gen RECQL4 (8q24.3). Este gen pertenece a la familia de las RecQhelicasas y está implicado en otras enfermedades de predisposición al cáncer. El diagnóstico se basa en criterios clínicos y debido al elevado número de diagnósticos diferenciales, encontrar una mutación en el gen puede ayudar a precisar el espectro diagnóstico, el consejo genético y su tratamiento. Se han descrito en la literatura alrededor de 30 casos, aunque se sabe que se ha presentado en menos de 200 000 personas en el mundo, por lo que se considera, una condición clínica rara. Se presenta el caso de una paciente que desde su nacimiento se constataron múltiples malformaciones músculo-esqueléticas: aplasia radial, pulgares aplásicos, malformaciones de la parrilla costal, clinodactilia de todos los dedos de miembros superiores, antebrazos hipoplásicos, clinodactilia del miembro inferior izquierdo. Se le realizó alimentación parenteral por varios días, fue imposible establecer vía oral adecuada por ausencia y/o incoordinación de los reflejos de succión-deglución como expresión de sus malformaciones a nivel de sistema nervioso central. Se presenta el caso por su baja incidencia y prevalencia por lo que es considerada una enfermedad rara.

Baller-Gerold syndrome is secondary to mutations in the RECQL4 gene (8q24.3). This gene belongs to the RecQhelicase family and is implicated in other diseases predisposing to cancer. Diagnosis is based on clinical criteria and due to the high number of differential diagnoses, finding a mutation in the gene can help to specify the diagnostic spectrum, genetic counseling and treatment. Around 30 cases have been described in the literature, although it is known that it has occurred in less than 200,000 people in the world, being considered a rare clinical condition. We present the case of a newborn, who at birth was found to have multiple musculoskeletal malformations: radial aplasia, aplastic thumbs, malformations of the rib cage, clinodactyly of all the fingers of the upper limbs, hypoplastic forearms, clinodactyly of the left lower limb. She was given parenteral feeding for several days, it was impossible to establish an adequate oral route due to the absence and/or incoordination of the sucking-swallowing reflexes as an expression of her malformations at the central nervous system level. The case is presented due to its low incidence and prevalence, which is why it is considered a rare disease.

Effects of liver-specific Nampt knockout on ischemic stroke / 药学实践杂志

Objective Nicotinamide phosphoribosyltransferase (Nampt) is a new therapeutic target for ischemic stroke. The aim of this study was to investigate protective effect of liver-derived Nampt on ischemic stroke. Methods Liver-specific Nampt knockout mice were generated using the Cre/loxP system. NamptloxP/loxP mice were crossed with liver-specific Cre recombinase expression mice (Alb-Cre), and the progeny genotypes were identified by polymerase chain reaction. Body weight of knockout mice and control mice were measured. Nampt in liver and brain was determined by Western blot assay. Middle cerebral artery occlusion (MCAO), a classical ischemic stroke model, was generated in liver-specific Nampt knockout mice and control mice by electrocoagulation. After 24 h of modeling, neurological deficit scores of each group were evaluated and TTC staining was performed to determine the cerebral infarction volume. The level of plasma Nampt in each group was determined by ELISA. Results Liver-specific Nampt knockout mice with the genotype of NamptloxP/loxPAlb-Cre were successfully constructed. The hepatic Nampt expression in knockout mice was significantly decreased by 74.2% compared to control mice, while there was no significant difference in the expression of brain Nampt protein between the knockout group and the control group. Specific knockout of liver Nampt gene expression had no effect on the body weight of mice. Under normal physiological conditions, there was no significant difference in plasma Nampt levels between liver-specific Nampt knockout mice and control mice of the same gender. 24 h after MCAO modeling, there were no significant differences in neurological deficit scores, cerebral infarct volume and plasma Nampt concentration between liver-specific Nampt knockout group and control group. Conclusion Liver-specific Nampt knockout mice are successfully constructed. Liver-derived Nampt has no significant protective effects on ischemic stroke.

Establishment of lens opacity model in Grx2 knockout mice based on CRISPR/cas9 system and the role of Grx2 in the pathogenesis of cataract / 中华实验眼科杂志

Objective:To explore the role of Grx2 in the pathogenesis of cataract by establishing Grx2 knockout (KO) and knockin (KI) mouse models. Methods:Ten black C57BL/6J mice were selected to make Grx2 KO model ( n=5) and Grx2 KI model ( n=5) using CRISPR/Cas9 system.The offspring mice were sequenced by tail clipping and included in the corresponding experimental group according to the genotype.The general condition and lens opacity was recorded.After the mice were sacrificed, the pathological changes of lens were observed by hematoxylin-eosin staining.The contents of reactive oxygen species (ROS) and 8-hydroxy-desoxyguanosine (8-OHdG) were analyzed by enzyme-linked immunosorbent assay (ELISA).The relative expression levels of Grx2, glutathione (GSH), B-cell lymphoma-2 (Bcl-2) , glutathione disulfide (GSSG) and Bcl-2-associated X protein (Bax) in mice lens were assayed.The use and feeding of experimental animals were in accordance with the Regulations on the Management of Experimental Animals issued by the State Science and Technology Commission.The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Chongqing Medical University (No.2020-125). Results:The offspring of Grx2 KO and Grx2 KI homozygous and heterozygous mice were confirmed by tail cutting nested PCR and gene sequencing.Compared with the wild type (WT) mice of same age, the lens opacity of Grx2 KO heterozygous mice occurred earlier, while the lens of Grx2 KI homozygous mice remained transparent all the time.A large number of gaps and vacuoles were found in the lens fibers of 5-month-old Grx2 KO mice.The 8-OHdG content and ROS fluorescence intensity in the lens of 5-month-old Grx2 KO mice were (3.886±0.326)ng/ml and 1 594±132, which were significantly higher than (3.531±0.250)ng/ml and 1 157±123 in WT mice ( t=2.711, P=0.033; t=3.384, P=0.028).The relative expression levels of Grx2, GSH and Bcl-2 in the lens of 5-month-old Grx2 KO mice were 0.23±0.01, 0.70±0.06 and 0.32±0.03, which were significantly lower than 0.52±0.02, 1.04±0.08 and 0.49±0.04 of WT mice ( t=2.815, P=0.020; t=2.457, P=0.033; t=2.279, P=0.041). Conclusions:Grx2 KO and Grx2 KI mouse models are successfully established in this study.The occurrence and development of age-related cataract are accelerated in Grx2 KO mice.

Intervention of Huanglian Jiedutang on Atherosclerosis in ApoE-/- Mice and Its Mechanism / 中国实验方剂学杂志

ObjectiveTo study the intervention of Huanglian Jiedutang on atherosclerosis （AS） in apolipoprotein E knockout （ApoE-/-） mice induced by the high-fat diet. MethodThe ApoE-/- mouse model of AS was induced by the high-fat diet， and Huanglian Jiedutang was used to intervene in the AS in the ApoE-/- mice. The pathological changes of aorta were observed by hematoxylin-eosin （HE） staining. The levels of serum total cholesterol （TC）， triglyceride （TG）， high-density lipoprotein cholesterol （HDL-C）， and low-density lipoprotein cholesterol （LDL-C） were detected by an automatic biochemical analyzer. The protein expression levels of sirtuin-1 （SIRT1） and nuclear factor-kappa B （NF-κB） were determined by Western blot assay， and the mRNA expression levels of adenosine 5'-monophosphate-activated protein kinase （AMPK）， peroxisome proliferators-activated receptors α （PPARα）， tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and NOD-like receptor pyrin domain-containing 3 （NLRP3） were determined by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultAs compared with the normal group， there was a large amount of lipid accumulation in the blood vessels of the model group. In the model group， the levels of serum TG， TC， and LDL-C were increased （P<0.01）， and the level of HDL-C was decreased （P<0.01）. The protein expression level of SIRT1 in the aorta was decreased， while that of NF-κB was increased in the model group （P<0.01）. The mRNA expression levels of IL-6， TNF-α， and IL-1β were higher （P<0.01）， while those of AMPK in the liver were lower in the model group （P<0.01）. Compared with the model group， the Huanglian Jiedutang group reduced the lipid accumulation and inflammatory reaction in the aorta of mice with AS， reduced the levels of TC， TG， and LDL-C （P<0.01）， and increased the level of HDL-C （P<0.01）. Huanglian Jiedutang significantly increased the protein expression level of SIRT1 in the aorta of ApoE-/- mice （P<0.01） and decreased the protein expression levels of NF-κB in the aorta （P<0.05， P<0.01）. Huanglian Jiedutang down-regulated the mRNA expression levels of TNF-α， IL-6， IL-1β， and NLRP3 in the aorta （P<0.05， P<0.01）， and up-regulated the mRNA expression levels of AMPK and PPARα in the liver of ApoE-/- mice （P<0.05， P<0.01）. ConclusionHuanglian Jiedutang has a certain intervention effect on the formation of atherosclerotic aortic plaque in ApoE-/- mice. Its mechanism may be related to the decrease of serum TC， TG， and LDL-C levels， the increase of HDL-C levels， thus playing a role in lowering blood lipid， the increase of SIRT1 protein， the decrease of NF-κB protein， the decrease of inflammatory factors such as TNF-α and IL-6， which protects blood vessels from inflammatory injury， and the improvement of AMPK and PPARα levels to participate in autophagy and apoptosis.

Effects of dexmedetomidine on ADAMTS5 mediated matrix degradation in chondrocytes and expressions of related factors / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of dexmedetomidine (DEX) intervention on the expressions of chondrocytes and related factors in vitro and its possible molecular mechanisms. 【Methods】 C28/I2 normal human chondrocyte lines were cultured in vitro, and dexmedetomidine at the concentration of 1 μmol/L was selected to intervene for 24 h and 48 h, respectively. The morphology and cell density of chondrocytes were observed after DEX culture at different time points. Immunofluorescence technique was used to detect the expression levels of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) in chondrocytes in each group. The expression levels of Adamts5, aggrecan (Acan), versican (Vcan), Furin, proprotein convertase subtilisin/kexin type 6 (Pcsk6), collagen type Ⅰ alpha 1 (Col1a1), collagen type Ⅱ alpha 1 (Col2a1), collagen type X alpha 1 (Col10a1), and SRY2 related high mobility group box gene9 (Sox9) were detected by RT-PCR. Adamts5 gene knockout chondrocytes were constructed by lentivirus transfection technology and treated with DEX; RT-PCR was used to detect the effects of DEX on the expression levels of Acan, Vcan, Furin, Pcsk6 and Sox9 after Adamts5 gene knockout. 【Results】 After 24 and 48 h of intervention with 1 μmol/L DEX, the morphology and size of chondrocytes did not change significantly, but the cell density increased slightly. Immunofluorescence assay showed that the expression of ADAMTS5 increased at first and then decreased after DEX treatment for 24 and 48h, respectively (P=0.032). RT-PCR results showed that with the extension of intervention time, the expression of Adamts5 first increased and then decreased. The expression difference between 48 and 24 h after culture was statistically significant (P=0.032). The change trend of Pcsk6 was the same as that of Adamts5, while the change trend of Acan expression was opposite that of Adamts5. Chondrocytes knocked out Adamts5 gene and intervened with DEX for 24 and 48 h. The results of RT-PCR showed that the expression of Pcsk6 decreased while that of Acan increased and the changes were significant. 【Conclusion】 Dexmedetomidine may activate ADAMTS5 zymogen through Pcsk6, thereby promoting proteoglycan degradation in chondrocytes.

Establishment and identification of a human megakaryocytic cell line with low Ley expression / 中国输血杂志

【Objective】 To establish a stable human megakaryocytic cell line with low expression of Ley antigen to further study the role of Ley on activation of platelets. 【Methods】 The expression level of the Ley antigen in a human megakaryocytic cell line, DAMI, was determined using Western Blot and flow cytometry. The expression level of genes that encode fucosyltransferase (FUTs), which was involved in the biosynthesis of Ley antigen, was also determined to identify the candidate genes to be knocked out. The candidate FUT gene was knocked out via a CRISPR/Cas 9 gene knockout system and cells with low Ley antigen expression were sorted by flow cytometry. The sorted cell line was cultured and characterized. 【Results】 The Ley was expressed intensively on DAMI cell. FUT1 and FUT4 mRNA was expressed relatively higher, both may be key enzymes for the biosynthesis of the Ley antigen. In the DAMI cell line with the knockout of FUT1 gene, the expression of the Ley adntigen was remarkedly reduced, while cell proliferation was not affected compared to the wildtype control cells. 【Conclusions】 Since various FUTs contributes to the biosynthesis of the Ley antigen, the knockout of the primary one of them cannot totally block its biosynthesis, but only reduce its expression. In this study, a stable FUT gene knockout human megakaryocyticcell line is established using CRISPR/Cas 9 technology, which provides basis for the study of the impact of the Ley antigen on platelet functions.

Effects of Bcl3 gene knockout on composition of spleen immune cells and antitumor ability of mice / 中华微生物学和免疫学杂志

Objective:To investigate the effects of Bcl3 gene knockout on the composition of spleen immune cells and antitumor ability of mice.Methods:Bcl3 gene knockout mice (Bcl3 -/-) were established by CRISPR/Cas9 genome editing technology. Blood routine test and flow cytometry were used to detect the immune cell composition in Bcl3 -/- mice. Lung metastasis models were established by injecting mice with B16F10 melanoma cells. The number of tumor nodules in lung and the survival time of mice were used to assess the antitumor ability of wild-type (WT) and Bcl3 -/- mice. Results:Bcl3 -/- mice were successfully bred to a strain with normal growth rate and normal breeding performance. Furthermore, no embryonic death occurred. Compared with WT mice, Bcl3 -/- mice showed splenomegaly and a significant increase in the number of spleen immune cells ( P<0.05). The counts and percentages of platelets and neutrophils in Bcl3 -/- mice were significantly lower than those in WT mice. The proportion of CD19 + B cells showed no significant change, while the proportions of CD3 + T cells and T cell subsets (CD4 + , CD8 + , Treg) increased significantly ( P<0.05). The proportions of NK cells (NK1.1 + ) and neutrophils (Gr1 + ) decreased ( P<0.05), while no significant change in the proportion of DC (CD11b + ) was observed. There were a large number of tumor nodules formed by melanoma cells in the lung of Bcl3 -/- tumor bearing mice, and their survival time was shortened dramatically. Conclusions:Knockout of Bcl3 gene affected the development, differentiation and function of immune cells, thereby reducing the antitumor ability of mice.

Construction of a Spink5 conditional knockout mouse model and analysis of its phenotype / 中华皮肤科杂志

Objective:To construct a serine protease inhibitor Kazal type-5 (Spink5) conditional knockout mouse model, and to identify its phenotype.Methods:B cell-specific Spink5 conditional knockout mice of genotype Mb1 cre/+Spink5 floxp/floxp were constructed by using clustered regularly interspaced short palindromic repeats (CRISPR) /CRISPR-associated protein 9 (Cas9) technology, and served as the knockout group. Mice of genotype Mb1 +/+Spink5 floxp/floxp served as the control group. The mice of genotype Mb1 cre/+Spink5 floxp/floxp or Mb1 +/+Spink5 floxp/floxp were sacrificed when they were 4 to 6 weeks old, splenic mononuclear cells were isolated, and B lymphocytes and non-B lymphocytes were sorted by flow cytometry and fluorescence-activated cell sorting. Genotype identification was performed by PCR, and protein expression of lymphoepithelial Kazal-type-related inhibitor (LEKTI) was determined by Western blot analysis. Skin tissues were resected from the mice, and subjected to hematoxylin-eosin staining for measuring the epidermal thickness. Immunofluorescence staining was performed to determine fluorescence intensity of LEKTI protein in the mouse skin tissues. Paired t test or two-independent-sample t test was used for comparisons between groups. Results:Genotype identification results demonstrated that the stable B lymphocyte-specific Spink5 conditional knockout mouse model was successfully constructed. Western blot analysis revealed that the relative protein expression of LEKTI in the B lymphocytes in the knockout group was 0.01 ± 0.02, which was significantly lower than that in the non-B lymphocytes in the knockout group (0.66 ± 0.11, t = 9.99, P < 0.001) , and that in the B lymphocytes in the control group (1.08 ± 0.13, t = 13.78, P < 0.001) . Among 39 mice in the knockout group, 4 presented with dry skin and scattered scaly hypertrophic maculopapules. The epidermal thickness of the lesional skin tissues in the knockout group was 90.42 ± 21.31 μm, significantly higher than that of the non-lesional skin tissues in the knockout group (29.71 ± 3.63 μm, t = 5.05, P = 0.002) and that of normal skin tissues in the control group (12.42 ± 2.21 μm, t = 6.74, P < 0.001) . Immunofluorescence staining showed no significant difference in the fluorescence intensity of LEKTI protein among the lesional skin tissues (46.21 ± 1.21) , non-lesional skin tissues (46.62 ± 2.13) in the knockout group and normal skin tissues in the control group (47.69 ± 1.71, P > 0.05) . Conclusion:The B lymphocyte-specific Spink5 conditional knockout mouse model was successfully constructed, which provides a basis for further exploring mechanisms underlying skin barrier defects and immune dysfunction in Netherton syndrome.

Practical Application Strategies of Cre-LoxP Conditional Gene Knockout / 中国生物化学与分子生物学报

Cre-loxP is an efficient recombination system originated from P1 phage. Its specific recombination patterns based on the locus of X-over P1 make it one of the most commonly used tools for gene editing in recent years. This paper focuses on the practical application of Cre-loxP system. Firstly, the functions and advantages of CRISPR/Cas9 system in Cre sequence insertion and loxP sequence insertion are analyzed. Then, a series of practical application problems of Cre-loxP system are described. For example, in this paper, the selection of Cre recombinase sequence in situ and safe site, the strategy of loxP sequence insertion, the identification of Cre recombinase tag protein, fluorescence identification of "ectopic" expression, primer design of PCR identification and reproductive strategy of mouse were described. At the same time, the optimization of Cre-loxP system in conditional gene knockout is introduced, such as ligand-induced Cre, promoter activated Cre, photo-induced Cre and activity modification of Cre. Through these optimized applications, we can obtain time-controlled conditional gene knockout, regulate the activity of Cre recombinase, and even avoid the toxicity of Cre recombinase itself. Finally, this paper discusses the defects and challenges of Cre-loxP system, and looks into the future development direction of Cre-loxP system. In summary, this paper reviews the practical application of gene knockout based on Cre-loxP system, summarizes the latest research progress and optimization strategies of Cre-loxP system, and prospects the future gene editing based on Cre-loxP system. This paper aims to provide theoretical guidance for solving practical operation problems based on Cre-loxP system, and to provide new research ideas for more accurate, more controllable and more adaptive gene editing in the future.