High-throughput screening of mouse gene knockouts identifies established and novel skeletal phenotypes

Screening gene function in vivo is a powerful approach to discover novel drug targets. We present high-throughput screening （HTS） data for 3 762 distinct global gene knockout （KO） mouse lines with viable adult homozygous mice generated using either gene-trap or homologous recombination technologies. Bone mass was determined from DEXA scans of male and female mice at 14 weeks of age and by microCT analyses of bones from male mice at 16 weeks of age. Wild-type （WT） cagemates/littermates were examined for each gene KO. Lethality was observed in an additional 850 KO lines. Since primary HTS are susceptible to false positive findings, additional cohorts of mice from KO lines with intriguing HTS bone data were examined. Aging, ovariectomy, histomorphometry and bone strength studies were performed and possible non-skeletal phenotypes were explored. Together, these screens identified multiple genes affecting bone mass： 23 previously reported genes （Calcr, Cebpb, Crtap, Dcstamp, Dkkl, Duoxa2, Enppl, Fgf23, Kissl/Kisslr, Kl （Klotho）, Lrp5, Mstn, Neol, Npr2, Ostml, Postn, Sfrp4, S1c30a5, Sic39a13, Sost, Sumf1, Src, Wnt10b）, five novel genes extensively characterized （Cldn18, Fam20c, Lrrkl, Sgpll, Wnt16）, five novel genes with preliminary characterization （Agpat2, RassfS, Slc10a7, Stc26a7, Slc30a10） and three novel undisclosed genes coding for potential osteoporosis drug targets.

Metabolic regulation of <i>Escherichia coli</i>cultivated under anaerobic and aerobic conditions in response to the specific pathway gene knockouts

Effect of the specific gene knockout on the main metabolism in Escherichia coli was reviewed, and the regulation mechanisms were clarified based on different levels of information such as gene expressions, enzyme activities, intracellular metabolite concentrations, and metabolic fluxes together with fermentation data. The effects of the knockout of such genes as pflA, pta, ppc, pykF, adhE, and ldhA on the metabolic changes were analyzed for the case under anaerobic condition. The effects of the knockout of such genes as pgi, zwf, gnd, ppc pck, pyk, and lpdA on the metabolic changes were also analyzed for the case under aerobic condition. The metabolic regulation analysis was made focusing on the roles of transcription factors.

Knockouts of high-ranking males have limited impact on baboon social networks

Social network structures can crucially impact complex social processes such as collective behaviour or the transmission of information and diseases. However, currently it is poorly understood how social networks change over time. Previous studies on primates suggest that ＇knockouts＇ （due to death or dispersal） of high-ranking individuals might be important drivers for structural changes in animal social networks. Here we test this hypothesis using long-term data on a natural population of ba- boons, examining the effects of 29 natural knockouts of alpha or beta males on adult female social networks. We investigated whether and how knockouts affected （i） changes in grooming and association rates among adult females, and （2） changes in mean degree and global clustering coefficient in these networks. The only significant effect that we found was a decrease in mean degree in grooming networks in the first month after knockouts, but this decrease was rather small, and grooming networks re- bounded to baseline levels by the second month after knockouts. Taken together our results indicate that the removal of high-ranking males has only limited or no lasting effects on social networks of adult female baboons. This finding calls into question the hypothesis that the removal of high-ranking individuals has a destabilizing effect on social network structures in social animals [Current Zoology 61 （1）： 107-113, 2015].

Generation of double knockout cattle via CRISPR-Cas9 ribonucleoprotein(RNP)electroporation

Background Genome editing has been considered as powerful tool in agricultural fields.However,genome editing progress in cattle has not been fast as in other mammal species,for some disadvantages including long gestational periods,single pregnancy,and high raising cost.Furthermore,technically demanding methods such as microinjection and somatic cell nuclear transfer(SCNT)are needed for gene editing in cattle.In this point of view,electroporation in embryos has been risen as an alternative.Results First,editing efficiency of our electroporation methods were tested for embryos.Presence of mutation on embryo was confirmed by T7E1 assay.With first combination,mutation rates for MSTN and PRNP were 57.6%±13.7%and 54.6%±13.5%,respectively.In case of MSTN/BLG,mutation rates were 83.9%±23.6%for MSTN,84.5%±18.0%for BLG.Afterwards,the double-KO embryos were transferred to surrogates and mutation rate was identified in resultant calves by targeted deep sequencing.Thirteen recipients were transferred for MSTN/PRNP,4 calves were delivered,and one calf underwent an induction for double KO.Ten surrogates were given double-KO embryos for MSTN/BLG,and four of the six calves that were born had mutations in both genes.Conclusions These data demonstrated that production of genome edited cattle via electroporation of RNP could be effectively applied.Finally,MSTN and PRNP from beef cattle and MSTN and BLG from dairy cattle have been born and they will be valuable resources for future precision breeding.

Emerging significance of butyrylcholinesterase

Butyrylcholinesterase(BChE;EC 3.1.1.8),an enzyme structurally related to acetylcholinesterase,is widely distributed in the human body.It plays a role in the detoxification of chemicals such as succinylcholine,a muscle relaxant used in anesthetic practice.BChE is well-known due to variant forms of the enzyme with little or no hydrolytic activity which exist in some endogamous communities and result in prolonged apnea following the administration of succinylcholine.Its other functions include the ability to hydrolyze acetylcholine,the cholinergic neurotransmitter in the brain,when its primary hydrolytic enzyme,acetylcholinesterase,is absent.To assess its potential roles,BChE was studied in relation to insulin resistance,type 2 diabetes mellitus,cognition,hepatic disorders,cardiovascular and cerebrovascular diseases,and inflammatory conditions.Individuals who lack the enzyme activity of BChE are otherwise healthy,until they are given drugs hydrolyzed by this enzyme.Therefore,BChE is a candidate for the study of loss-of-function mutations in humans.Studying individuals with variant forms of BChE can provide insights into whether they are protected against metabolic diseases.The potential utility of the enzyme as a biomarker for Alzheimer’s disease and the response to its drug treatment can also be assessed.

Overexpression of proteasome 26S subunit non-ATPase 6 protein and its clinicopathological significance in intrahepatic cholangiocarcinoma

BACKGROUND Currently,intrahepatic cholangiocarcinoma(ICC)poses a continuing,significant health challenge,but the relationship has yet to be established between ICC and the proteasome 26S subunit non-ATPase 6(PSMD6).AIM To investigate the protein expression and clinicopathological significance of PSMD6 in ICC.METHODS The potential impact of the PSMD6 gene on the growth of ICC cell lines was analyzed using clustered regularly interspaced short palindromic repeat knockout screening technology.Forty-two paired specimens of ICC and adjacent noncancerous tissues were collected.PSMD6 protein expression was determined by immunohistochemistry.Receiver operating characteristic curve analysis was performed to validate PSMD6 expression level,and its association with ICC patients’various clinicopathological characteristics was investigated.RESULTS The PSMD6 gene was found to be essential for the growth of ICC cell lines.PSMD6 protein was significantly overexpressed in ICC tissues(P<0.001),but showed no significant association with patient age,gender,pathological grade,or tumor-node-metastasis stage(P>0.05).CONCLUSION PSMD6 can promote the growth of ICC cells,thus playing a pro-oncogenic role.

Assessment of the piroxicam-incited model of synchronized colitis in T-cell receptor alpha chain-deficient mice

Background:A multitude of mouse models are utilized to emulate and study intestinal inflammation.T-cell receptor alpha chain(TCRα)-deficient mice are used as a model of spontaneous colitis that has similarities with human ulcerative colitis.However,colitis is triggered late in the life of the mouse(age:4-5 months),and inflammation does not develop at the same time in different mice.A previously conducted study reported that the administration of the drug piroxicam triggered predictable and early colitis in TCRα-deficient mice at the age of 6-8 weeks.However,a detailed characterization of ensuing inflammation was not provided.Methods:We conducted an in-depth examination of piroxicam-triggered colitis in TCRα-deficient mice,with emphasis on spatial histopathologic changes and analysis of expression of inflammatory markers.Furthermore,we tested amelioration of colitis with dexamethasone.Results:We confirmed that piroxicam induced a time-prescribed colitis and did so in the proximal colon as well as the cecum of TCRα-deficient mice.Piroxicam adminis-tration was observed to induce epithelial hyperplasia,goblet cell loss,and leukocyte infiltration with occasional ulceration.A Swiss roll technique was used to examine the colon and cecum in its entirety.Importantly,we observed that inflammation was mul-tifocal segmental,with areas of tissue damage in between healthy tissue.In addition,we observed variability in the severity of inflammation among replicate animals and treatments,and that the administration of dexamethasone only partially ameliorated inflammation in the proximal colon.Conclusions:Piroxicam consistently induced multifocal segmental colitis in the proxi-mal colon and cecum,although the degree of inflammation was reduced in the latter.Importantly,spatial variability in inflammation in the large intestine and the inter-replicate variation in the severity of inflammation must be taken into consideration when utilizing this murine model of synchronized colitis.

Skeletal phenotypes and molecular mechanisms in aging mice

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health risks.Research on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial investment.Consequently,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation time.In this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial dysfunction.Overall,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

Tumor necrosis factor α deficiency promotes myogenesis and muscle regeneration

Tumor necrosis factorα(TNFα)exhibits diverse biological functions;however,its regulatory roles in myogenesis are not fully understood.In the present study,we explored the function of TNFαin myoblast proliferation,differentiation,migration,and myotube fusion in primary myoblasts and C2C12 cells.To this end,we constructed TNFαmuscle-conditional knockout(TNFα-CKO)mice and compared them with flox mice to assess the effects of TNFαknockout on skeletal muscles.Results indicated that TNFα-CKO mice displayed phenotypes such as accelerated muscle development,enhanced regenerative capacity,and improved exercise endurance compared to flox mice,with no significant differences observed in major visceral organs or skeletal structure.Using label-free proteomic analysis,we found that TNFα-CKO altered the distribution of several muscle development-related proteins,such as Hira,Casz1,Casp7,Arhgap10,Gas1,Diaph1,Map3k20,Cfl2,and Igf2,in the nucleus and cytoplasm.Gene set enrichment analysis(GSEA)further revealed that TNFαdeficiency resulted in positive enrichment in oxidative phosphorylation and MyoD targets and negative enrichment in JAK-STAT signaling.These findings suggest that TNFα-CKO positively regulates muscle growth and development,possibly via these newly identified targets and pathways.

Knockout of TMEM206 in mice associated with a loss of corneal transparency

AIM:To investigate the role of transmembrane protein 206(TMEM206)in corneal edema in mice by knockout the TMEM206 gene using CRISPR/Cas9 editing technology.METHODS:TMEM206-knockout mice were generated using the CRISPR-Cas9 system.Variations in ophthalmic pathology were observed using slit lamp microscope and optical coherence tomography(OCT),intraocular pressure(IOP)was measured using a TonoLab Rebound Tonometer,and the ultrastructure of the corneal was observed using a transmission electron microscope.RESULTS:Corneal opacity was observed in 4/18 homozygous TMEM206^(-/-)mice whereas a similar change was not observed in heterozygous TMEM206^(+/-)mice and wild-type littermates.OCT examination showed that the mean central cornea thickness was 125±5.4μm in 4 homozygous TMEM206^(-/-)mice developed corneal edema and 115±1.2μm in wild-type mice(t=3.468,P<0.05)at 43wk.The mean IOP was 12.08±0.07 mm Hg in four right eyes with corneal edema and 12.03±0.03 mm Hg in three normal left eyes(P>0.05).Transmission electron microscopy revealed a disruption in the organization of the collagen fibrils in the central part of the cornea in homozygous TMEM206^(-/-)mice.CONCLUSION:TMEM206 is associated with corneal edema which caused organizational disruption of collagen fibrils in corneas of mice.

Calcium/calcimimetic via calcium-sensing receptor ameliorates cholera toxin-induced secretory diarrhea in mice

BACKGROUND Enterotoxins produce diarrhea through direct epithelial action and indirectly by activating the enteric nervous system.Calcium-sensing receptor(CaSR)inhibits both actions.The latter has been well documented in vitro but not in vivo.The hypothesis to be tested was that activating CaSR inhibits diarrhea in vivo.AIM To determine whether CaSR agonists ameliorate secretory diarrhea evoked by cholera toxin(CTX)in mice.METHODS CTX was given orally to C57BL/6 mice to induce diarrhea.Calcium and calci-mimetic R568 were used to activate CaSR.To maximize their local intestinal actions,calcium was administered luminally via oral rehydration solution(ORS),whereas R568 was applied serosally using an intraperitoneal route.To verify that their actions resulted from the intestine,effects were also examined on Cre-lox intestine-specific CaSR knockouts.Diarrhea outcome was measured biochemically by monitoring changes in fecal Cl-or clinically by assessing stool consistency and weight loss.RESULTS CTX induced secretory diarrhea,as evidenced by increases in fecal Cl-,stool consistency,and weight loss following CTX exposure,but did not alter CaSR,neither in content nor in function.Accordingly,calcium and R568 were each able to ameliorate diarrhea when applied to diseased intestines.Intestinal CaSR involvement is suggested by gene knockout experiments where the anti-diarrheal actions of R568 were lost in intestinal epithelial CaSR knockouts(villinCre/Casrflox/flox)and neuronal CaSR knockouts(nestinCre/Casrflox/flox).CONCLUSION Treatment of acute secretory diarrheas remains a global challenge.Despite advances in diarrhea research,few have been made in the realm of diarrhea therapeutics.ORS therapy has remained the standard of care,although it does not halt the losses of intestinal fluid and ions caused by pathogens.There is no cost-effective therapeutic for diarrhea.This and other studies suggest that adding calcium to ORS or using calcimimetics to activate intestinal CaSR might represent a novel approach for treating secretory diarrheal diseases.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

一种新的视频运动对象分割技术

本文将用于自然静态图像抠图领域的Knockout技术用于视频运动对象的精确分割,给出了一种新的视频运动对象分割方法。在利用积累差异技术自适应建立背景模型、采用背景差法初步提取当前帧视频对象区域的基础上,用本文提出的方法,自动标记原本采用Knockout技术进行抠图时,需手动进行标记的前景轮廓区域、背景轮廓区域及未知区域。在用本文方法完成对3个区域的自动标记后,再利用Knockout技术对当前帧的视频运动对象进行精确分割。本文还设计了一种新的变系数空域滤波器,该滤波器能有效地对背景差图像进行显著增强。同时,对Otsu自适应阈值化方法进行了改进,改进的方法能更准确地对背景差图像进行阈值化。

Study on the Knockout and the Soluble Prokaryotic Expression of VP5 Protein Transmembrane Region of IBDV

[Objective] The research aimed to construct the prokaryotic expression vector of VP5 protein of IBDV.The transmembrane region sequence of VP5 protein was knocked out.Moreover,the expression,separation and purification of objective protein were carried out.[Method] PCR technology was used to respectively amplify the extracellular and intracellular fragments of VP5 gene of IBDV.Then,the two fragments were simultaneously linked to pET-28b（＋）,and it was the vector-intracellular fragment-extracellular fragment-vector.The recombinant expression plasmid pET-VP5-FC and the improved pET-VP5-SC of VP5 whose transmembrane region gene fragment was knocked out were constructed.Then,the expression plasmid was transformed into BL21（DE3）.After IPTG induction,the recombinant protein was purified by Ni affinity chromatography and the gel filtration chromatography.[Result] The soluble expressed VP5 of IBDV was obtained.[Conclusion] The research laid the foundation for further studying the structure and function of VP5 protein.

Knockout血清替代品可提高C57BL/6J小鼠胚胎干细胞建系效率

目的:在培养液中添加knockout血清替代品(knockout serum replacement,KSR)代替胎牛血清(FBS)用于建立C57BL/6J小鼠胚胎干细胞(ESC)细胞系,以便消除血清中的不确定因子对ESC增殖的影响。方法:以C57BL/6J小鼠3.5 d的囊胚为材料分离ESC,比较KSR和FBS用于建立小鼠ESC细胞系的效率,并通过体内、外分化验证所分离获得的小鼠ESC的发育潜能。结果:培养液中添加KSR,成功从13个小鼠囊胚中分离获得一个ESC细胞系(MES-1),体外培养传代超过20代仍保持未分化状态,核型为正常XX型,碱性磷酸酶及oct-4基因高表达,悬浮培养可以生成拟胚体,接种到裸鼠皮下可形成畸胎瘤,注射到ICR小鼠3.5 d囊胚中,ESC可以参与胚胎发育并产生嵌合体小鼠。而培养液中添加FBS的对照组未能获得超过3代的ESC细胞系。结论:在培养液中添加KSR代替FBS适合于C57BL/6J小鼠ESC的分离与培养,从而可避免实验前对所用血清的筛选。

BALB/c-HSF_1 Knockout小鼠的主要脏器重量、脏器系数及主要血液生化指标的测定

目的 提供HSF1 Knockout小鼠的脏器重量 ,脏器系数的生物学特性指标。方法 选用成年HSF1Knockout小鼠 5 0只 (雄性 2 1只 ,雌性 2 9只 ) ,分别测定体重和 8个主要脏器重量 ,计算脏器系数 ,测定其主要血液生化指标 ,并对雌雄鼠脏器重量 ,脏器系数进行比较 ,对血液生化指标进行统计。结果 雌雄鼠脾脏系数、肾脏系数差异有显著性 (P <0 0 5 ) ,胃系数、脑系数差异有显著性 (P <0 0 1) ,心脏、肺系数差异不显著 (P >0 0 1)。结论 应注意HSF1 Knockout小鼠实验时的雌雄鼠胃系数、脑系数的显著性差异 ;脾脏系数、肾脏系数的明显差异。

组织特异性KNOCKOUT小鼠──基因打靶技术的新突破

组织特异性ＫＮＯＣＫＯＵＴ小鼠──基因打靶技术的新突破姜宇飞（北京医科大学免疫系北京１０００８３）近十年来，分子生物学研究得到了迅猛的发展。转基因技术及基因Ｋｎｏｃｋｏｕｔ技术为人们在动物体内分析某一特定基因的功能提供了有力的手段。转基因技术是导入一...

不同培养体系对绵羊类胚胎干细胞分离、传代的影响

以小鼠胚胎成纤维细胞(MEF)为饲养层,研究了用Knockout血清替代品(Knockout serum replacement,KSR)代替胚胎干细胞(Embryonic stem cells,ES cell)培养液中的胎牛血清(FBS)和向含KSR的基础培养液中添加40%的小鼠ES细胞条件培养液(ES cell conditioned medium,ESCCM)对绵羊类ES细胞分离、克隆效率的影响。发现使用含FBS的基础培养液最多可以把绵羊类ES细胞传至3代,而使用KSR和添加ESCCM能促进绵羊类ES细胞的分离和克隆,所获得的类ES细胞分别可稳定传至第5和8代。同时对类ES细胞进行核型分析、AKP染色及体外分化能力检测,证实所分离的类ES细胞符合ES细胞的主要特征。由此认为,与FBS相比KSR更加适于绵羊类ES细胞的分离与培养;而小鼠ES细胞在生长过程中可能分泌某些重要的细胞因子,从而达到促进绵羊ES细胞增值的作用。

Photoshop外挂滤镜KnockOut的应用

Photoshop外挂滤镜除了可以制作出很炫的特效,Knock Out外挂滤镜还可以进行精细抠图,介绍了Knock Out的基本操作,通过三个实例分析了Knock Out的应用过程。

浅谈使用KnockOut工具抠出毛发

抠图是图像处理中常做的操作之一，Photoshop中有很多工具都可以实现抠图，但操作步骤过于复杂，不易掌握，本文主要介绍了使用KnockOut工具抠图的方法，对于常见的毛发抠图进行简单化的抠图处理．