ABSTRACT
<p><b>OBJECTIVE</b>Factor VIII( FVIII) gene knockout mouse model was established for further study on the treatment of hemophilia A.</p><p><b>METHODS</b>Exons 16-19 of the mouse FVIII gene were knocked out by ET clone, ES homologous recombination and tetraploid embryo compensation technology. PCR, reverse transcriptase-PCR(RT-PCR) and immunohistochemistry were used to detect the transcription and translation pattern of FVIII. The phenotype of the knockout mice was analyzed by examining the activated partial thromboplastin time (APTT) and FVIII activity (FVIII:C).</p><p><b>RESULTS</b>PCR, RT-PCR and immunohistochemistry confirmed that FVIII was deficient in the FVIII gene knockout mouse. The APTT results showed that FVIII-deficient mouse plasma had a prolonged clotting time compared to normal mouse plasma. The FVIII:C in heterozygous, hemizygous and homozygous mice was 80%, 8% and 10% of that in normal mice, respectively.</p><p><b>CONCLUSION</b>The phenotype of the FVIII gene knockout mouse appears grossly similar to that of human with hemophilia A. Establishment of this model may promote the development of new technologies of treatment to hemophilia A.</p>
Subject(s)
Animals , Female , Humans , Male , Mice , Disease Models, Animal , Embryo, Mammalian , Factor VIII , Genetics , Metabolism , Hemophilia A , Genetics , Metabolism , Mice, Inbred ICR , Mice, Knockout , Partial Thromboplastin TimeABSTRACT
Objective To observe the effect of raloxifene, a selective estrogen receptor modulator, on osteoporosis in the osteoprotegerin (OPG) gene knock-out female and male mice. Methods Two groups of OPG gene deficient (OPG-/-) female and male mice, 20 mice in each group, were assigned to raloxifene-treated (3 mg The effect of raloxifene was evaluated by comparing the values of bone mineral density (BMD) , bone strength,histomorphometric measurement and osteoclast number between the raloxifene treated group and placebo group.Results As compared with placebo group osteoporotic manifestations were improved in OPG-/- female mice treated with raloxifene orally. BMD was increased both in lumbar vertebrae (P<0.05) and femurs (P<0.01).Bone strength was measured in femurs by three-point bending test and vertebrae by stress test. Results showed that ultimate load, ultimate stress and Young's modulus were increased both at lumbar and femur bone, suggesting decreased risk of fracture. Tartrate-resistant acid phosphatase, a marker enzyme of osteoclasts, was detected, and the number of osteoclasts declined significantly after the treatment of raloxifene. At the same time, results of histomorphometric measurements indicated that bone trabecular volume was increased and bone formation rate decreased from(8.05±4.02)mm3·mm-2·year-1 to (5.48±1.89)mm3·mm-2· year-1(P＜0.05).These findings were found in the group of OPG-/- female mice treated with reloxifene but not in male mice. Conclusions Raloxifene is effective in treating osteoporosis in female OPG-/- mice, indicating that its action is at least in part independent of OPG gene. But it is ineffective in male OPG-/- mice.
ABSTRACT
Adiponectin is an adipocyte-derived secretory protein. It was found to be associated with insulin resistance, inflammation and arteriosclerosis. To further study the biological function and expression of adiponection in vivo, adipoenctin gene knock-out and LacZ gene knock-in mouse model was constructed. Gene targeting strategy was designed to replace part of exon 2 and exon 3 of adiponectin gene with full length LacZ gene in frame with remaining upstream ATG and signal peptide sequence of exon 2. The targeting vector (Adipo-LacZ-XpPNT) was constructed and verified by restriction enzyme digestion and sequencing. CJ7 ES cells were transfected with targeting vector linearized by NotⅠ digestion, selected in the medium containing both G418 and ganciclovoir. Resistant clones were screened by PCR and further confirmed by Southern blot for correct homologous recombinants. Chimera mice were obtained by routing microinjection of homologous recombined ES cells into blastocysts. After mating, mice heterozygous and further homozygous for adiponectin knockout and LacZ gene knock-in were established. Expression of both endogenous adiponectin and exogenous LacZ gene in mouse tissues and sera were detected by RT-PCR, Northern-blot, Western blot and ELISA. The results show that adiponectin was disrupted at both mRNA and protein levels. LacZ gene is expressed exclusively in adipose tissue of mutant mice. Its expression profile is identical to endogenous adiponection. Unexpectedly, LacZ activity could not be detected in both adipose tissue and serum although LacZ protein can be detected in adipose tissue but not in serum of mutant mice. In conclusion, mice homozygous for adiponectin knockout and LacZ gene knock-in have been successfully constructed. Mutant mice display LacZ expression profile identical to endogenous adiponectin albeit neither LacZ activity nor protein can be detected in serum of mutant mice.
ABSTRACT
<p><b>OBJECTIVE</b>To test whether splicing overlapping extension(SOE) method can be a tool for obtaining rare fusion gene's transcripts and to study the tumorigenic capacity of a novel fusion gene AML1-MTG16.</p><p><b>METHODS</b>SOE method was used to obtain AML1- MTG16 fusion gene's transcripts. MTG16, AML1-MTG16 and AML1-MTG16 without III,VI conserved domains of MTG16 segment were inserted into pEGFP- C1,pDsRed-N1 vector respectively,then transfected NIH3T3 cell line by lipofection. Forty-eight hours later, the transfected cells were examined by laser-scanning confocal microscopy. Stable transfected cells were obtained by G418 500ug/ul selection for one month. Growth curve, soft agar colonies formation tumorigenesis in nude mice were done to compare the difference between stable transfected cells.</p><p><b>RESULTS</b>Recombined AML1-MTG16 by SOE contained its CDS. NIH3T3 expressing AML1-MTG16 had a faster proliferation in medium, colony growth in soft agar. AML1-MTG16 expression cells also induced tumors formation following injection into nude mouse. MTG16,AML1-MTG16 and AML1-MTG16 without III,VI conserved domains of MTG16 were colocalized in the nucleus of cotransfected NIH3T3 cells under the examination of laser-scanning confocal microscope.</p><p><b>CONCLUSION</b>SOE is an effective method to get rare fusion gene's transcripts. AML1-MTG16 plays an important role in leukemogenesis. MTG16 may also have a carcinogenic property within the AML1-MTG16 fusion gene. Carcinogenic property of AML1-MTG16 is restricted to its localization in the nuclear matrix. N terminal of MTG16 may play an important part in the carcinogenic activity of AML1-MTG16.</p>