Examination of Gene Therapy by Bone Marrow Derived Stem Cells to Alport Syndrome

1.GFP小鼠骨髓来源干细胞移植到Col4A4基因敲除小鼠体内的基因治疗研究(1)我们证实了同种异体骨髓移植给照射后的Col4A4基因敲除小鼠，通过Col4A4突变制备的常染色体Alport综合征模型小鼠，导致了常驻肾小球细胞的募集。在本研究中，将绿色荧光蛋白(GFP)小鼠的BM移植到4周龄和8周龄的Col4A4基因敲除小鼠体内，导致12周龄的肾小球细胞重新聚集。(2)免疫组织化学检测，移植后肾小球基底膜(GBM)中未检测到IV型胶原A3(Col4A3)、A4(Col4A4)和A5(COLA5)链。并将转基因小鼠的骨髓来源干细胞移植到Col4A4基因敲除小鼠体内。(1)获得了骨髓细胞中高表达IV型胶原a3、4和a5链的转基因小鼠。(2)通过GFP基因敲除小鼠的骨髓移植，不仅在COL4A4基因敲除小鼠的基底膜中检测到IV型胶原A3、A4和A5链，而且在转基因小鼠的骨髓基质中也检测到了IV型胶原A3、A4和A5链。骨髓来源的干细胞可以作为内皮细胞和系膜细胞进行募集，但不能作为足细胞进行募集。因此认为，只有足细胞才可能在基底膜形成A3-A4-A5(IV)网络，或BMT导致极少数肾小球细胞的募集。

1.Examination of gene therapy by transplantating bone marrow derived stem cells of GFP mouse to Col4a4 knockout mice(1)We demonstrated that allogeic bone marrow transplatation into irradiated COL4a4 knockout mice prepared as autosomal chromosome type Alport syndrome model mice by COL4A4 mutation, leaded, to recruitment of resident glomerular cells. In the present study, transplantation of green fluorescent protein (GFP) mouse's BM into 4-week-old and 8-week-old Col4a4 knockout mice leaded to recruitment of resident glomerular cells at 12 weeks of age.(2)Type IV collagen a3 (COL4A3), a4 (COL4A4) and a5 (COLA5) chains were not detected in the glomerular basement membrane (GBM) after BMT by the immunohistochemistry.2.Generating the transgenic mice overexpressing type IV collagen a3,4, and a5 chains in the bone marrow stem cells and transplantion of the bone marrow derived stem cell of the transgenic mice to Col4a4 knockout mice(1)We generated the transgenic mice overexpressing type IV collagen a3,4, and a5 chains in the bone marrow cells. The survival and growth of the transgenic mice are not different from those of wild-type mice at present.(2)Type IV collagen a3,a4 and a5 chains were not only detected in the GBM of the Col4a4 knockout mouse by the bone marrow transplantation of the GFP mouse but also the transgenic mouse's BMT.3.ConclusionsType IV collagen a3,a4 and a5 chains were not detected in the GBM after BMT. The bone marrow derived stem cells could recruit as endothelial cells and mesangial cells, but couldn't recruit as podocytes. Therefore it is thought that only podcytes may form the a3- a4- a5(IV) network in the GBM, or BMT leads to recruitment of very few glomerular cells.