目的利用CRISPR/Cas9技术构建牛磺酸转运体基因(solute carrier family 6 member 6,Slc6a6)敲除大鼠,繁殖并鉴定,为研究牛磺酸缺失对神经系统疾病的影响提供稳定的大鼠模型。方法针对Slc6a6基因第5外显子,设计向导RNA(single-guide RNA,...目的利用CRISPR/Cas9技术构建牛磺酸转运体基因(solute carrier family 6 member 6,Slc6a6)敲除大鼠,繁殖并鉴定,为研究牛磺酸缺失对神经系统疾病的影响提供稳定的大鼠模型。方法针对Slc6a6基因第5外显子,设计向导RNA(single-guide RNA,sgRNA)介导Cas9核酸酶与靶点DNA特异性结合,并切割基因组DNA,被切割后的DNA进行重组修复,从而实现基因的敲除。通过基因型鉴定和测序分析检测新生大鼠基因型。利用Real-time PCR、Western blot技术和免疫组化等方法,分析大鼠脑组织的牛磺酸转运体(taurine transporter,TauT)的mRNA表达和蛋白表达,建立Slc6a6基因敲除大鼠模型。结果 F3代出现21只Slc6a6基因敲除纯合子(TauT^(-/-)),54只杂合子(TauT^(+/-)),27只阴性(TauT^(+/+)),F3代纯合率约为20.59%,基本符合孟德尔遗传定律。Slc6a6基因敲除纯合子大鼠脑组织mRNA水平基本不表达,TauT蛋白表达水平显著低于同窝阴性大鼠。结论本研究利用CRISPR/Cas9系统定向敲除Slc6a6基因,成功构建Slc6a6基因敲除大鼠模型。展开更多
Background Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury （SBI）.Although traditional immunosup...Background Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury （SBI）.Although traditional immunosuppression can reduce autoimmune attack,it will lower the body immunity.Immune tolerance,by contrast,not only does not lower the body immunity,but also could lighten autoimmunity.This study used thymus tolerance to develop an immune system that is tolerant to autologous cerebrospinal fluid （CSF） and autologous brain tissue so that autoimmune injury can be suppressed following the disruption of the blood-brain barrier,thereby reducing brain damage.Methods Eighty experimental rabbits were divided into five groups by random number table method：16 in SBI group （group A）,16 in SBI＋CSF drainage group （group B）,16 in SBI＋CSF drainage＋PBS injection group （group C）,16 in SBI＋CSF drainage＋CSF intrathymic injection group （group D）,and 16 in SBl＋brain homogenate intrathymic injection group （group E）.Rabbits＆#39; CSF was drained in group B; was drained and injected PBS into thymus in group C; was drained and injected CSF into thymus in group D; and was injected brain homogenate in group E.Half of the rabbits in each group were phlebotomized on 1st,3rd,7th,and 14th days to observe the changes in IL-I,TGF-β by ELISA test,and CD4CD25 regulatory T cells ratio by flow cytometry,and in other animals brain tissues were taken on 7th day for exploring FasL expression by RT-PCR.The least significant difference （LSD） test was used to make paired comparisons; P ＜0.05 was considered statistically significant.Results The levels of FasL,TGF-β,and the ratios of CD4CD25 regulatory T cells in groups D and E were apparently higher than those in other three groups （P ＜0.05）.Likewise,the levels of IL-1 in these two groups were lower than the other three groups （P ＜0.05）.Moreover,the ratios of CD4CD25 regulatory T cells and the levels of TGF-β in groups B and C were higher than those in group A,but the level of IL-1 was lower than that in group A （P ＜0.05）.There was no significant difference between groups B and C,and groups D and E.Conclusion Thymic injection of CSF and brain homogenate may be able to reduce inflammation after SBI,so thymus immune tolerance may be a useful therapy to treat SBI.展开更多
文摘Background Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury （SBI）.Although traditional immunosuppression can reduce autoimmune attack,it will lower the body immunity.Immune tolerance,by contrast,not only does not lower the body immunity,but also could lighten autoimmunity.This study used thymus tolerance to develop an immune system that is tolerant to autologous cerebrospinal fluid （CSF） and autologous brain tissue so that autoimmune injury can be suppressed following the disruption of the blood-brain barrier,thereby reducing brain damage.Methods Eighty experimental rabbits were divided into five groups by random number table method：16 in SBI group （group A）,16 in SBI＋CSF drainage group （group B）,16 in SBI＋CSF drainage＋PBS injection group （group C）,16 in SBI＋CSF drainage＋CSF intrathymic injection group （group D）,and 16 in SBl＋brain homogenate intrathymic injection group （group E）.Rabbits＆#39; CSF was drained in group B; was drained and injected PBS into thymus in group C; was drained and injected CSF into thymus in group D; and was injected brain homogenate in group E.Half of the rabbits in each group were phlebotomized on 1st,3rd,7th,and 14th days to observe the changes in IL-I,TGF-β by ELISA test,and CD4CD25 regulatory T cells ratio by flow cytometry,and in other animals brain tissues were taken on 7th day for exploring FasL expression by RT-PCR.The least significant difference （LSD） test was used to make paired comparisons; P ＜0.05 was considered statistically significant.Results The levels of FasL,TGF-β,and the ratios of CD4CD25 regulatory T cells in groups D and E were apparently higher than those in other three groups （P ＜0.05）.Likewise,the levels of IL-1 in these two groups were lower than the other three groups （P ＜0.05）.Moreover,the ratios of CD4CD25 regulatory T cells and the levels of TGF-β in groups B and C were higher than those in group A,but the level of IL-1 was lower than that in group A （P ＜0.05）.There was no significant difference between groups B and C,and groups D and E.Conclusion Thymic injection of CSF and brain homogenate may be able to reduce inflammation after SBI,so thymus immune tolerance may be a useful therapy to treat SBI.
