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 gestat...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.展开更多
Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be...Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be re-expanded when reinnervation is allowed.RhoA is a target that regulates the cytoskeleton and promotes neuronal survival and axon regeneration.However,the role of RhoA in dendrite degeneration and regeneration is unknown.In this study,we explored the potential role of RhoA in dendrites.A line of motor neuronal conditional knockout mice was developed by crossbreeding HB9~(Cre+)mice with RhoA~(flox/flox)mice.We established two models for assaying dendrite degeneration and regeneration,in which the brachial plexus was transection or crush injured,respectively.We found that at 28 days after brachial plexus transection,the density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice were slightly decreased compared with that in Cre mice.Dendrites underwent degeneration at 7 and 14 days after brachial plexus transection and recovered at 28–56 days.The density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice recovered compared with results in Cre mice.These findings suggest that RhoA knockout in motor neurons attenuates dendrite degeneration and promotes dendrite regeneration after peripheral nerve injury.展开更多
Mitochondrial dysfunction is proposed to be substantially associated with ageing and ageing-related diseases like Alzheimer's disease(AD). However, it is unclear whether different mouse models with mitochondrialre...Mitochondrial dysfunction is proposed to be substantially associated with ageing and ageing-related diseases like Alzheimer's disease(AD). However, it is unclear whether different mouse models with mitochondrialrelated diseases have similar changes in mitochondrial morphology of the same tissues. Moreover, whether similarities in mitochondrial morphology can be a suitable marker for screening and/or discovering mitochondrial-protective substances remains unknown. Mitochondria morphology in different tissues of a novel mitochondrial outer membrane protein Slc25a46 knockout mouse and a traditional APP_(SWE)/PS1ΔE9 transgenic mouse were examined using transmission electron microscope(TEM). Both young Slc25a46 knockout mice and aged APP_(SWE)/PS1ΔE9 mice models showed similar mitochondrial damage in cerebellum tissues. The results indicated that different mitochondrial-related diseases shared similar alteration and defects in mitochondrial morphology. Furthermore, Lycium ruthenicum Murr. extract, a bioactive food substance with cognition-improving property, could effectively improve muscle strength and increase body weight in the Slc25a46 knockout mice. These findings suggest that mitochondrial morphology defects in mice models, particularly in the mitochondrial compartment, represent a unified and effective marker for screening and validating natural product-derived functional substances with mitochondrial protective properties. It also holds potential application in mitochondrial-impaired senile neurodegenerative diseases, especially in AD.展开更多
Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually di...Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually disrupts acrosome formation and leads to male infertility.Methods An azoospermia sample was filtered,and the laboratory detection and clinical phenotype indicated typical azoospermia in the patient.We sequenced all of the exons in the PICK1 gene and found that there was a novel homozygous variant in the PICK1 gene,c.364delA(p.Lys122SerfsX8),and this protein structure truncating variant seriously affected the biological function.Then we constructed a PICK1 knockout mouse model using clustered regularly interspaced short palindromic repeat cutting technology(CRISPRc).Results The sperm from PICK1 knockout mice showed acrosome and nucleus abnormalities,as well as dysfunctional mitochondrial sheath formation.Both the total sperm and motility sperm counts were decreased in the PICK1 knockout mice compared to wild-type mice.Moreover,the mitochondrial dysfunction was verified in the mice.These defects in the male PICK1 knockout mice may have eventually led to complete infertility.Conclusion The c.364delA novel variant in the PICK1 gene associated with clinical infertility,and pathogenic variants in the PICK1 may cause azoospermia or asthenospermia by impairing mitochondrial function in both mice and humans.展开更多
BACKGROUND: Previous studies have shown that p75 neurotrophin receptor plays an important role in peripheral nerve injury. However, the role of p75 neurotrophin receptor in the regeneration of peripheral nerves remai...BACKGROUND: Previous studies have shown that p75 neurotrophin receptor plays an important role in peripheral nerve injury. However, the role of p75 neurotrophin receptor in the regeneration of peripheral nerves remains poorly understood. OBJECTIVE: To study the effect of p75 neurotrophin receptor on facial nerve regeneration. DESIGN, TIME AND SETTING: A randomized controlled experiment was performed in the Regeneration Laboratory of Flinders University, Australia and the Biomedical Laboratory of Dentistry School, Shandong University from March 2005 to February 2006. MATERIALS: Cholera toxin B subunit, fast blue, and biotin rabbit-anti goat IgG were provided by Sigma, USA; goat-anti choleratoxin B subunit ant/body was provided by List Biologicals, USA. METHODS: In p75 neurotrophin receptor knockout and wild type 129/sv mice, the facial nerves on one side were crushed. At days 2 and 4 following injury, regenerating motor neurons in the facial nuclei were labeled by fast blue, and the regenerating axon was labeled by the anterograde tracer choleratoxin B subunit. MAIN OUTCOME MEASURES: Axonal regenerative velocity and number were detected by immunohistochemical staining of choleratoxin B subunit, growth-associated protein, protein gene product 9.5, and calcitonin-gene-related peptide; survival of motor neurons in the facial nuclei was detected by retrograde fast blue. RESULTS: Axonal growth in the facial nerve of p75 neurotrophin receptor knockout mice was significantly less than in wild type mice. At day 7 after injury, the number of regenerating motor neurons in p75 neurotrophin receptor knockout mice remained significantly less than in wild type mice (P 〈 0.05). The number of positively stained fibers for growth-associated protein-43, protein gene product 9.5, and calcitonin-gene-related peptide in p75 neurotrophin receptor knockout mice was significantly less than in wild type mice (P 〈 0.01). CONCLUSION: p75 neurotrophin receptor promoted axonal regeneration and enhanced the survival rate of motor neurons following facial nerve injury.展开更多
An overt phenotype of aquaporin-1 knockout(AQP1 ko) mice is growth retardation, suggesting possible defects in bone development and metabolism. In the present study, we analyzed the bone mineral density( BMD), bon...An overt phenotype of aquaporin-1 knockout(AQP1 ko) mice is growth retardation, suggesting possible defects in bone development and metabolism. In the present study, we analyzed the bone mineral density( BMD), bone calcium and phosphorus contents, and bone metabolism in an AQP1 ko mouse model. The BMD of femurs in AQP1 ko mice was significantly lower than that of litter-matched wildtype mice as measured by dual energy X-ray absorptiometry. Consistently, the contents of bone total calcium and phosphorus were also significantly lower in AQP1 ko mice. The reduced BMD caused by AQP1 deficiency mainly affect male mice. Bone metabolic activity, as indicated by 99m^Tc-MDP absorption measurements, was remarkably reduced in AQP1 ko mice. These results provide the first evidence that AQP1 play an important role in bone structure and metabolism.展开更多
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 hom...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.展开更多
Background:Liver injury is one of the most common complications during sepsis.Macrophage migration inhibitory factor(MIF)is an important proinflammatory cytokine.This study explored the role of MIF in the lipopolysacc...Background:Liver injury is one of the most common complications during sepsis.Macrophage migration inhibitory factor(MIF)is an important proinflammatory cytokine.This study explored the role of MIF in the lipopolysaccharide(LPS)-induced liver injury through genetically manipulated mouse strains.Methods:The model of LPS-induced liver injury was established in wild-type and Mif-knockout C57/BL6 mice.Serum levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),and total bilirubin(TBil)were detected,and the expressions of MIF,tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were measured.Liver histopathology was conducted to assess liver injury.Moreover,the inhibitions of MIF with(S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester(ISO-1)and 4-iodo-6-phenylpyrimidine(4-IPP)were used to evaluate their therapeutic potential of liver injury.Results:Compared with wild-type mice,the liver function indices and inflammation factors presented no significant difference in the Mif-/-mice.After 72 h of the LPS-induced liver injury,serum levels of ALT,AST,and TBil as well as TNF-αand IL-1βwere significantly increased,but the knockout of Mif attenuated liver injury and inflammatory response.In liver tissue,m RNA levels of TNF-α,IL-1βand NF-κB p65 were remarkably elevated in LPS-induced liver injury,while the knockout of Mif reduced these levels.Moreover,in LPS-induced liver injury,the inhibitions of MIF with ISO-1 and 4-IPP alleviated liver injury and slightly attenuated inflammatory response.Importantly,compared to mice with LPS-induced liver injury,Mif knockout or MIF inhibitions significantly prolonged the survival of the mice.Conclusions:In LPS-induced liver injury,the knockout of Mif or MIF inhibitions alleviated liver injury and slightly attenuated inflammatory response,thereby prolonged the survival of the mice.Targeting MIF may be an important strategy to protect the liver from injury during sepsis.展开更多
Phosphatase of regenerating liver-3 (PRL-3) is a member of the protein tyrosine phosphatase (PTP) superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor me...Phosphatase of regenerating liver-3 (PRL-3) is a member of the protein tyrosine phosphatase (PTP) superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor metastasis, we applied a rapid and efficient method for generating PRL-3 floxed mice and investigated its phenotypes. A BAC retrieval strategy was applied to construct the PRL-3 conditional gene-targeting vector. Exon 4 was selected for deletion to generate a nonfunctional prematurely terminated short peptide as it will cause a frame-shift mutation. Conditional knockout PRL-3 mice were generated by using the Cre-loxP system and were validated by Southern blot and RT-PCR analysis. Further analysis revealed the phenotype characteristics of PRL-3 knockout mice and wildtype mice. In this study, we successfully constructed the PRL-3 conditional knockout mice, which will be helpful to clarify the roles of PRL-3 and the mechanisms in tumor metastasis.展开更多
[Objectives]This study was conducted to investigate the similarity and differences between TLR4 knockout mice and C57 BL/6 mice used in liver fibrosis research in terms of growth rate and reproduction ability.[Methods...[Objectives]This study was conducted to investigate the similarity and differences between TLR4 knockout mice and C57 BL/6 mice used in liver fibrosis research in terms of growth rate and reproduction ability.[Methods]Twenty TLR4 knockout mice and C57 BL/6 mice,half male and half female,were selected to compare the growth rates of body weight and body length of mice from the 4th to 12th weeks;and 20 pairs of male and female mice of the same strain were compared for the number of baby mice of the second litter.[Results]The growth rates of body weight and body length of the TLR4 knockout mice were significantly lower than those of C57 BL/6 mice(P<0.05)(except for the 4th and 5th weeks when there was no significant difference in body length);and in terms of reproductive ability,the TLR4 knockout mice were significantly lower than the C57 BL/6 mice(the ratio of the total number of baby mice in the second litter of the two strains,72∶147).[Conclusions]Knockout of the TLR4 gene has a significant impact on the growth and reproduction of mice.展开更多
Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this ...Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.展开更多
Early studies suggested that estrogen receptor alpha (ERa) is involved in estrogen-mediated imprinting effects in prostate development. We recently reported a more complete ERa knockout (KO) mouse model via mating...Early studies suggested that estrogen receptor alpha (ERa) is involved in estrogen-mediated imprinting effects in prostate development. We recently reported a more complete ERa knockout (KO) mouse model via mating β-actin Cre transgenic mice with floxed ERa mice. These ACTB-ERaKO male mice showed defects in prostatic branching morphogenesis, which demonstrates that ERa is necessary to maintain proliferative events in the prostate. However, within which prostate cell type ERa exerts those important functions remains to be elucidated. To address this, we have bred floxed ERa mice with either fibroblast-specific protein (FSP)-Cre or probasin-Cre transgenic mice to generate a mouse model that has deleted ERa gene in either stromal fibroblast (FSP-ERaKO) or epithelial (pes-ERaKO) prostate cells. We found that circulating testosterone and fertility were not altered in FSP.ERaKO and pes-ERaKO male mice. Prostates of FSP-ERaKO mice have less branching morphogenesis compared to that of wild-type littermates. Further analyses indicated that loss of stromal ERa leads to increased stromal apoptosis, reduced expression of insulin-likegrowth factor-1 (IGF-1) and FGFIO, and increased expression of BMP4. Collectively, we have established the first in vivo prostate stromal and epithelial selective ERaKO mouse models and the results from these mice indicated that stromal fibroblast ERa plays important roles in prostatic branching morphogenesis via a paracrine fashion. Selective deletion of the ERa gene in mouse prostate epithelial cells by probasin-Cre does not affect the regular prostate development and homeostasis.展开更多
BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no ef...BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no effective animal model to study its specific mechanism. Therefore, we constructed three lines of Claudin-7 knockout mice using the Cre/LoxP system.AIM To determine the function of the tumor suppressor gene Claudin-7 by generating three lines of Claudin-7 gene knockout mice.METHODS We crossed Claudin-7-floxed mice with CMV-Cre, vil1-Cre, and villin-CreERT2 transgenic mice, and the offspring were self-crossed to obtain conventional Claudin-7 knockout mice, conditional(intestinal specific) Claudin-7 knockout mice, and inducible conditional Claudin-7 knockout mice. Intraperitoneal injection of tamoxifen into the inducible conditional Claudin-7 knockout mice can induce the knockout of Claudin-7. PCR and agarose gel electrophoresis were used to identify mouse genotypes, and Western blot was used to confirm the knockout of Claudin-7. The mental state, body length, and survival time of these mice were observed. The dying mice were sacrificed, and hematoxylin-eosin(HE) staining and immunohistochemical staining were performed to observe changes in intestinal structure and proliferation markers.RESULTS We generated Claudin-7-floxed mice and three lines of Claudin-7 gene knockout mice using the Cre/LoxP system successfully. Conventional and intestinal specific Claudin-7 knockout mice were stunted and died during the perinatal period, and intestinal HE staining in these mice revealed mucosal gland structure disappearance and connective tissue hyperplasia with extensive inflammatory cell infiltration. The inducible conditional Claudin-7 knockout mice had a normal phenotype at birth, but after the induction with tamoxifen, they exhibited a dying state. Intestinal HE staining showed significant inflammatory cell infiltration, and atypical hyperplasia and adenoma were also observed. Intestinal immunohistochemistry analysis showed abnormal expression and distribution of Ki67, and the normal intestinal proliferation balance was disrupted. The intestinal crypt size in inducible conditional Claudin-7 knockout mice was increased compared with control mice(small intestine: 54.1 ± 2.96 vs 38.4 ± 1.63;large intestine: 44.7 ± 1.93 vs 27.4 ± 0.60; P < 0.001).CONCLUSION The knockout of Claudin-7 in vivo causes extensive inflammation, atypical hyperplasia, and adenoma in intestinal tissue as well as animal death in mice.Claudin-7 may act as a tumor suppressor gene in the development of colorectal cancer.展开更多
An experiment for knockout reaction induced by SHe beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected...An experiment for knockout reaction induced by SHe beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected coincidently. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated, which can be applied to the exclusive spectroscopic study on the structure of exotic nuclei.展开更多
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 acti...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.展开更多
Dear Editor,Genetic inactivation or gene knockout(KO)has been a powerful method of elucidating gene function in mice.The traditional method of generating KO mice via targeting mouse embryonic stem cells through homolo...Dear Editor,Genetic inactivation or gene knockout(KO)has been a powerful method of elucidating gene function in mice.The traditional method of generating KO mice via targeting mouse embryonic stem cells through homologous recombination is labor-intensive and of low efficiency.展开更多
Microtubule-severing proteins(MTSPs),are a family of proteins which use adenosine triphosphate to sever microtubules.MTSPs have been shown to play an important role in multiple microtubule-involved cellular processes....Microtubule-severing proteins(MTSPs),are a family of proteins which use adenosine triphosphate to sever microtubules.MTSPs have been shown to play an important role in multiple microtubule-involved cellular processes.One member of this family,fidgetin(FIGN),is also involved in male fertility;however,no studies have explored its roles in female fertility.In this study,we found mouse fidgetin is rich within oocyte zona pellucida(ZP)and is the only MTSP member to do so.Fidgetin also appears to interact with all three ZP proteins.These findings prompted us to propose that fidgetin might prevent polyspermy.Results from in vitro maturation oocytes analysis showed that fidgetin knockdown did cause polyspermy.We then deleted all three fidgetin isoforms with CRISPR/Cas9 technologies;however,female mice remained healthy and with normal fertility.Of all mouse MTSPs,only the mRNA level of fidgetin-like 1(FIGNL1)significantly increased.Therefore,we assert that fidgetin-like 1 compensates fidgetin's roles in fidgetin knockout female mice.展开更多
Currently,glucose transporter 4(GLUT4)has been considered as the key player for the insulin-stimulated glucose transport in the muscle and adipose tissues.The development of recombinant DNA techniques allows the creat...Currently,glucose transporter 4(GLUT4)has been considered as the key player for the insulin-stimulated glucose transport in the muscle and adipose tissues.The development of recombinant DNA techniques allows the creations of genetically knockout,knockdown and transgenic animals and cells for the study of GLUT4’s physiological functions.Here,we have used key words to search the PubMed and summarized the methods used in Slc2a4 gene knockout,GLUT4 knockdown and overexpression in the whole body and tissue specific manner.The whole body GLUT4-null mice have growth retardation,but normal glucose tolerance and basal glucose turnover rates.Compared with whole body Slc2a4 knockout mice,adipose and muscle double knockout mice have impaired insulin tolerance and glucose intolerance.The results of GLUT4 knockdown in 3T3-L1 adipocytes have shown that its expression is needed for lipogenesis after,but not during,differentiation.Transgenic mice with the whole body GLUT4 overexpression have normal body weight and lowered blood glucose level.The adipose tissue specific overexpression of GLUT4 leads to increases in mouse body weight and adipose tissue weight.The insulin-stimulated GLUT4 translocation in the skeletal muscle contributes to the regulation of glucose homeostasis.Data from both transgenic overexpression and tissue specific Slc2a4 knockout indicate that GLUT4 probably plays a role in the glucose uptake in the fasting state.More studies are warranted to use advanced molecular biology tools to decipher the roles of GLUT4 in the control of glucose homeostasis.展开更多
基金financially supported by the National Research Foundation of Korea(NRF-2021R1A5A1033157 for SRC program:382 Comparative medicine Disease Research Center,NRF-2021R1F1A105195313)the Research Institute of Veterinary Science,the BK21 Four for Future Veterinary Medicine Leading Education and Research Center,and a Seoul National University(SNU)grant(#550e2020005)。
文摘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.
基金the Ministry of Science and Technology China Brain Initiative Grant,No.2022ZD0204701the National Natural Science Foundation of China,Nos.82071386&81870982(all to JG)。
文摘Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults.Peripheral axotomy of motor neurons results in the retraction of dendritic arbors,and the dendritic arbor can be re-expanded when reinnervation is allowed.RhoA is a target that regulates the cytoskeleton and promotes neuronal survival and axon regeneration.However,the role of RhoA in dendrite degeneration and regeneration is unknown.In this study,we explored the potential role of RhoA in dendrites.A line of motor neuronal conditional knockout mice was developed by crossbreeding HB9~(Cre+)mice with RhoA~(flox/flox)mice.We established two models for assaying dendrite degeneration and regeneration,in which the brachial plexus was transection or crush injured,respectively.We found that at 28 days after brachial plexus transection,the density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice were slightly decreased compared with that in Cre mice.Dendrites underwent degeneration at 7 and 14 days after brachial plexus transection and recovered at 28–56 days.The density,complexity,and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice recovered compared with results in Cre mice.These findings suggest that RhoA knockout in motor neurons attenuates dendrite degeneration and promotes dendrite regeneration after peripheral nerve injury.
基金supported by National Key R&D Program of China (2018YFD0901101)the Natural Science Foundation of Guangdong Province Research (2019A1515012230)+1 种基金Development Program in Key Areas of Guangdong Province (2019B020210002)the Fundamental Research Funds for the Central Universities (2019KZ01)。
文摘Mitochondrial dysfunction is proposed to be substantially associated with ageing and ageing-related diseases like Alzheimer's disease(AD). However, it is unclear whether different mouse models with mitochondrialrelated diseases have similar changes in mitochondrial morphology of the same tissues. Moreover, whether similarities in mitochondrial morphology can be a suitable marker for screening and/or discovering mitochondrial-protective substances remains unknown. Mitochondria morphology in different tissues of a novel mitochondrial outer membrane protein Slc25a46 knockout mouse and a traditional APP_(SWE)/PS1ΔE9 transgenic mouse were examined using transmission electron microscope(TEM). Both young Slc25a46 knockout mice and aged APP_(SWE)/PS1ΔE9 mice models showed similar mitochondrial damage in cerebellum tissues. The results indicated that different mitochondrial-related diseases shared similar alteration and defects in mitochondrial morphology. Furthermore, Lycium ruthenicum Murr. extract, a bioactive food substance with cognition-improving property, could effectively improve muscle strength and increase body weight in the Slc25a46 knockout mice. These findings suggest that mitochondrial morphology defects in mice models, particularly in the mitochondrial compartment, represent a unified and effective marker for screening and validating natural product-derived functional substances with mitochondrial protective properties. It also holds potential application in mitochondrial-impaired senile neurodegenerative diseases, especially in AD.
基金supported by grants from Zhejiang Provincial Natural Science Foundation of China(No.LQ21H200007)National Natural Science Foundation of China(No.82202605,No.81772664 and No.82172363)+1 种基金Zhejiang Provincial People’s Hospital Excellent Scientific Research Start-up Fundation of China(No.ZRY2019C008)Hangzhou Medical College Fundamental Scientific Research Project of China(No.KYQN202116).
文摘Objective The protein interacting with C kinase 1(PICK1)plays a critical role in vesicle trafficking,and its deficiency in sperm cells results in abnormal vesicle trafficking from Golgi to acrosome,which eventually disrupts acrosome formation and leads to male infertility.Methods An azoospermia sample was filtered,and the laboratory detection and clinical phenotype indicated typical azoospermia in the patient.We sequenced all of the exons in the PICK1 gene and found that there was a novel homozygous variant in the PICK1 gene,c.364delA(p.Lys122SerfsX8),and this protein structure truncating variant seriously affected the biological function.Then we constructed a PICK1 knockout mouse model using clustered regularly interspaced short palindromic repeat cutting technology(CRISPRc).Results The sperm from PICK1 knockout mice showed acrosome and nucleus abnormalities,as well as dysfunctional mitochondrial sheath formation.Both the total sperm and motility sperm counts were decreased in the PICK1 knockout mice compared to wild-type mice.Moreover,the mitochondrial dysfunction was verified in the mice.These defects in the male PICK1 knockout mice may have eventually led to complete infertility.Conclusion The c.364delA novel variant in the PICK1 gene associated with clinical infertility,and pathogenic variants in the PICK1 may cause azoospermia or asthenospermia by impairing mitochondrial function in both mice and humans.
基金the Natural Science Foundation of Shandong Province,No. Y2008C54
文摘BACKGROUND: Previous studies have shown that p75 neurotrophin receptor plays an important role in peripheral nerve injury. However, the role of p75 neurotrophin receptor in the regeneration of peripheral nerves remains poorly understood. OBJECTIVE: To study the effect of p75 neurotrophin receptor on facial nerve regeneration. DESIGN, TIME AND SETTING: A randomized controlled experiment was performed in the Regeneration Laboratory of Flinders University, Australia and the Biomedical Laboratory of Dentistry School, Shandong University from March 2005 to February 2006. MATERIALS: Cholera toxin B subunit, fast blue, and biotin rabbit-anti goat IgG were provided by Sigma, USA; goat-anti choleratoxin B subunit ant/body was provided by List Biologicals, USA. METHODS: In p75 neurotrophin receptor knockout and wild type 129/sv mice, the facial nerves on one side were crushed. At days 2 and 4 following injury, regenerating motor neurons in the facial nuclei were labeled by fast blue, and the regenerating axon was labeled by the anterograde tracer choleratoxin B subunit. MAIN OUTCOME MEASURES: Axonal regenerative velocity and number were detected by immunohistochemical staining of choleratoxin B subunit, growth-associated protein, protein gene product 9.5, and calcitonin-gene-related peptide; survival of motor neurons in the facial nuclei was detected by retrograde fast blue. RESULTS: Axonal growth in the facial nerve of p75 neurotrophin receptor knockout mice was significantly less than in wild type mice. At day 7 after injury, the number of regenerating motor neurons in p75 neurotrophin receptor knockout mice remained significantly less than in wild type mice (P 〈 0.05). The number of positively stained fibers for growth-associated protein-43, protein gene product 9.5, and calcitonin-gene-related peptide in p75 neurotrophin receptor knockout mice was significantly less than in wild type mice (P 〈 0.01). CONCLUSION: p75 neurotrophin receptor promoted axonal regeneration and enhanced the survival rate of motor neurons following facial nerve injury.
基金Supported by the National Natural Science Foundation of China(Nos30470405 and 30670477)National Natural ScienceFund for Distinguished Young Scholars(No30325011)+1 种基金Distinguished Young Scholars Fund of Jilin Province(No20030112)Excellent Young Tea
文摘An overt phenotype of aquaporin-1 knockout(AQP1 ko) mice is growth retardation, suggesting possible defects in bone development and metabolism. In the present study, we analyzed the bone mineral density( BMD), bone calcium and phosphorus contents, and bone metabolism in an AQP1 ko mouse model. The BMD of femurs in AQP1 ko mice was significantly lower than that of litter-matched wildtype mice as measured by dual energy X-ray absorptiometry. Consistently, the contents of bone total calcium and phosphorus were also significantly lower in AQP1 ko mice. The reduced BMD caused by AQP1 deficiency mainly affect male mice. Bone metabolic activity, as indicated by 99m^Tc-MDP absorption measurements, was remarkably reduced in AQP1 ko mice. These results provide the first evidence that AQP1 play an important role in bone structure and metabolism.
文摘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.
基金supported by grants from the National Natural Science Foundation of China(81971881)Medical Science and Technology Project of Henan Provincial Health Commission(SB201901045)。
文摘Background:Liver injury is one of the most common complications during sepsis.Macrophage migration inhibitory factor(MIF)is an important proinflammatory cytokine.This study explored the role of MIF in the lipopolysaccharide(LPS)-induced liver injury through genetically manipulated mouse strains.Methods:The model of LPS-induced liver injury was established in wild-type and Mif-knockout C57/BL6 mice.Serum levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),and total bilirubin(TBil)were detected,and the expressions of MIF,tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were measured.Liver histopathology was conducted to assess liver injury.Moreover,the inhibitions of MIF with(S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester(ISO-1)and 4-iodo-6-phenylpyrimidine(4-IPP)were used to evaluate their therapeutic potential of liver injury.Results:Compared with wild-type mice,the liver function indices and inflammation factors presented no significant difference in the Mif-/-mice.After 72 h of the LPS-induced liver injury,serum levels of ALT,AST,and TBil as well as TNF-αand IL-1βwere significantly increased,but the knockout of Mif attenuated liver injury and inflammatory response.In liver tissue,m RNA levels of TNF-α,IL-1βand NF-κB p65 were remarkably elevated in LPS-induced liver injury,while the knockout of Mif reduced these levels.Moreover,in LPS-induced liver injury,the inhibitions of MIF with ISO-1 and 4-IPP alleviated liver injury and slightly attenuated inflammatory response.Importantly,compared to mice with LPS-induced liver injury,Mif knockout or MIF inhibitions significantly prolonged the survival of the mice.Conclusions:In LPS-induced liver injury,the knockout of Mif or MIF inhibitions alleviated liver injury and slightly attenuated inflammatory response,thereby prolonged the survival of the mice.Targeting MIF may be an important strategy to protect the liver from injury during sepsis.
基金supported by Grants from MOST of China (No. 2005CB522501, No.2006BAI23B00, and No.2006CB943503) to Xiang Gao
文摘Phosphatase of regenerating liver-3 (PRL-3) is a member of the protein tyrosine phosphatase (PTP) superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor metastasis, we applied a rapid and efficient method for generating PRL-3 floxed mice and investigated its phenotypes. A BAC retrieval strategy was applied to construct the PRL-3 conditional gene-targeting vector. Exon 4 was selected for deletion to generate a nonfunctional prematurely terminated short peptide as it will cause a frame-shift mutation. Conditional knockout PRL-3 mice were generated by using the Cre-loxP system and were validated by Southern blot and RT-PCR analysis. Further analysis revealed the phenotype characteristics of PRL-3 knockout mice and wildtype mice. In this study, we successfully constructed the PRL-3 conditional knockout mice, which will be helpful to clarify the roles of PRL-3 and the mechanisms in tumor metastasis.
基金National Natural Science Foundation of China(81960761,81960751,81902764)。
文摘[Objectives]This study was conducted to investigate the similarity and differences between TLR4 knockout mice and C57 BL/6 mice used in liver fibrosis research in terms of growth rate and reproduction ability.[Methods]Twenty TLR4 knockout mice and C57 BL/6 mice,half male and half female,were selected to compare the growth rates of body weight and body length of mice from the 4th to 12th weeks;and 20 pairs of male and female mice of the same strain were compared for the number of baby mice of the second litter.[Results]The growth rates of body weight and body length of the TLR4 knockout mice were significantly lower than those of C57 BL/6 mice(P<0.05)(except for the 4th and 5th weeks when there was no significant difference in body length);and in terms of reproductive ability,the TLR4 knockout mice were significantly lower than the C57 BL/6 mice(the ratio of the total number of baby mice in the second litter of the two strains,72∶147).[Conclusions]Knockout of the TLR4 gene has a significant impact on the growth and reproduction of mice.
文摘Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.
文摘Early studies suggested that estrogen receptor alpha (ERa) is involved in estrogen-mediated imprinting effects in prostate development. We recently reported a more complete ERa knockout (KO) mouse model via mating β-actin Cre transgenic mice with floxed ERa mice. These ACTB-ERaKO male mice showed defects in prostatic branching morphogenesis, which demonstrates that ERa is necessary to maintain proliferative events in the prostate. However, within which prostate cell type ERa exerts those important functions remains to be elucidated. To address this, we have bred floxed ERa mice with either fibroblast-specific protein (FSP)-Cre or probasin-Cre transgenic mice to generate a mouse model that has deleted ERa gene in either stromal fibroblast (FSP-ERaKO) or epithelial (pes-ERaKO) prostate cells. We found that circulating testosterone and fertility were not altered in FSP.ERaKO and pes-ERaKO male mice. Prostates of FSP-ERaKO mice have less branching morphogenesis compared to that of wild-type littermates. Further analyses indicated that loss of stromal ERa leads to increased stromal apoptosis, reduced expression of insulin-likegrowth factor-1 (IGF-1) and FGFIO, and increased expression of BMP4. Collectively, we have established the first in vivo prostate stromal and epithelial selective ERaKO mouse models and the results from these mice indicated that stromal fibroblast ERa plays important roles in prostatic branching morphogenesis via a paracrine fashion. Selective deletion of the ERa gene in mouse prostate epithelial cells by probasin-Cre does not affect the regular prostate development and homeostasis.
基金the National Natural Science Foundation of China,No.81372585 and No.81772557Beijing Health System High Level Training Plan of Health Technical Personnel,No.2014-3-048
文摘BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no effective animal model to study its specific mechanism. Therefore, we constructed three lines of Claudin-7 knockout mice using the Cre/LoxP system.AIM To determine the function of the tumor suppressor gene Claudin-7 by generating three lines of Claudin-7 gene knockout mice.METHODS We crossed Claudin-7-floxed mice with CMV-Cre, vil1-Cre, and villin-CreERT2 transgenic mice, and the offspring were self-crossed to obtain conventional Claudin-7 knockout mice, conditional(intestinal specific) Claudin-7 knockout mice, and inducible conditional Claudin-7 knockout mice. Intraperitoneal injection of tamoxifen into the inducible conditional Claudin-7 knockout mice can induce the knockout of Claudin-7. PCR and agarose gel electrophoresis were used to identify mouse genotypes, and Western blot was used to confirm the knockout of Claudin-7. The mental state, body length, and survival time of these mice were observed. The dying mice were sacrificed, and hematoxylin-eosin(HE) staining and immunohistochemical staining were performed to observe changes in intestinal structure and proliferation markers.RESULTS We generated Claudin-7-floxed mice and three lines of Claudin-7 gene knockout mice using the Cre/LoxP system successfully. Conventional and intestinal specific Claudin-7 knockout mice were stunted and died during the perinatal period, and intestinal HE staining in these mice revealed mucosal gland structure disappearance and connective tissue hyperplasia with extensive inflammatory cell infiltration. The inducible conditional Claudin-7 knockout mice had a normal phenotype at birth, but after the induction with tamoxifen, they exhibited a dying state. Intestinal HE staining showed significant inflammatory cell infiltration, and atypical hyperplasia and adenoma were also observed. Intestinal immunohistochemistry analysis showed abnormal expression and distribution of Ki67, and the normal intestinal proliferation balance was disrupted. The intestinal crypt size in inducible conditional Claudin-7 knockout mice was increased compared with control mice(small intestine: 54.1 ± 2.96 vs 38.4 ± 1.63;large intestine: 44.7 ± 1.93 vs 27.4 ± 0.60; P < 0.001).CONCLUSION The knockout of Claudin-7 in vivo causes extensive inflammation, atypical hyperplasia, and adenoma in intestinal tissue as well as animal death in mice.Claudin-7 may act as a tumor suppressor gene in the development of colorectal cancer.
基金supported by the National Basic Research Program of China (No. 2007CB815002)National Natural Science Foundation of China(Nos. 11035001, 10775003, 10827505, 10821140159)
文摘An experiment for knockout reaction induced by SHe beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected coincidently. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated, which can be applied to the exclusive spectroscopic study on the structure of exotic nuclei.
文摘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.
文摘Dear Editor,Genetic inactivation or gene knockout(KO)has been a powerful method of elucidating gene function in mice.The traditional method of generating KO mice via targeting mouse embryonic stem cells through homologous recombination is labor-intensive and of low efficiency.
基金supported by the National Natural Science Foundation of China(Grant No.31671561)to Dong Zhang.
文摘Microtubule-severing proteins(MTSPs),are a family of proteins which use adenosine triphosphate to sever microtubules.MTSPs have been shown to play an important role in multiple microtubule-involved cellular processes.One member of this family,fidgetin(FIGN),is also involved in male fertility;however,no studies have explored its roles in female fertility.In this study,we found mouse fidgetin is rich within oocyte zona pellucida(ZP)and is the only MTSP member to do so.Fidgetin also appears to interact with all three ZP proteins.These findings prompted us to propose that fidgetin might prevent polyspermy.Results from in vitro maturation oocytes analysis showed that fidgetin knockdown did cause polyspermy.We then deleted all three fidgetin isoforms with CRISPR/Cas9 technologies;however,female mice remained healthy and with normal fertility.Of all mouse MTSPs,only the mRNA level of fidgetin-like 1(FIGNL1)significantly increased.Therefore,we assert that fidgetin-like 1 compensates fidgetin's roles in fidgetin knockout female mice.
文摘Currently,glucose transporter 4(GLUT4)has been considered as the key player for the insulin-stimulated glucose transport in the muscle and adipose tissues.The development of recombinant DNA techniques allows the creations of genetically knockout,knockdown and transgenic animals and cells for the study of GLUT4’s physiological functions.Here,we have used key words to search the PubMed and summarized the methods used in Slc2a4 gene knockout,GLUT4 knockdown and overexpression in the whole body and tissue specific manner.The whole body GLUT4-null mice have growth retardation,but normal glucose tolerance and basal glucose turnover rates.Compared with whole body Slc2a4 knockout mice,adipose and muscle double knockout mice have impaired insulin tolerance and glucose intolerance.The results of GLUT4 knockdown in 3T3-L1 adipocytes have shown that its expression is needed for lipogenesis after,but not during,differentiation.Transgenic mice with the whole body GLUT4 overexpression have normal body weight and lowered blood glucose level.The adipose tissue specific overexpression of GLUT4 leads to increases in mouse body weight and adipose tissue weight.The insulin-stimulated GLUT4 translocation in the skeletal muscle contributes to the regulation of glucose homeostasis.Data from both transgenic overexpression and tissue specific Slc2a4 knockout indicate that GLUT4 probably plays a role in the glucose uptake in the fasting state.More studies are warranted to use advanced molecular biology tools to decipher the roles of GLUT4 in the control of glucose homeostasis.