Abstract: Abstract： Objective To observe the diffusion and aggregation of the microtubule associated protein tau（MAPT）modu⁃ lated by phosphatase and tensin homolog deleted on chromosome ten（PTEN）during the nerve cell differentiation by human bone marrow stem cells（BMSC）in vitro, and to analyse the signification. Methods Adult bone marrow stem cells were iso⁃ lated and induced into nerve-like cells by some cytokines in vitro. The mRNA expression of MAPT was detected by semiquantitative RT-PCR and Western blot assay. The patterns of diffusion and aggregation of the MAPT association of the actin were indicated by Phalloidin-fluoresceineisothioeyanate (FITC) and immunofluorescence (IF) cyto-chemistry, and observed by the laser-confocal microscopy. Results The MAPT mRNA levels were 0.24 ± 0.04 and 0.52 ± 0.04 at 1 week and 2 weeks after the induction， which were significantly higher compared with those of BMSC (0.04 ± 0.02) after the induction (P＜ 0.05). The MAPT protein levels were 0.18 ± 0.03 and 0.44 ± 0.05 at 1 week and 2 weeks after the induction, which were significantly higher compared those of BMSC (0.06 ± 0.04, P＜ 0.05). The distribution patterns of MAPT were changed from the diffusion to the aggregation in cells after treatment by BPV. The nerve-like cells appeared the characteristic of po⁃ larization. Conclusion When the nerve cells derived from bone marrow stem cells obtain the mature differentiation, PTEN may possess the ability of modulating the diffusion and aggregation of MAPT in vitro, also may provide a kind of material ba⁃ sis for the growth of the nerve axon.

Key words: tumor suppressor proteins； tau proteins； cytoskeleton； reverse transcriptase polymerase chain reaction； fluo? roimmunoassay, phosphatase and tensin homolog deleted in chronlosome 10