目的：研究唐氏综合征细胞粘附分子（DSCAM）在大鼠骨髓间质干细胞（MSCs）分化为神经细胞中的作用。方法：在建立黄芩苷诱导大鼠MSCs分化为神经细胞的基础上，采用免疫细胞化学法、Western blot法等检测DSCAM的表达变化；同时采用RNA干扰技术，观察DSCAM-siRNA转染MSCs后诱导分化情况。结果：诱导前大鼠MSCs不表达DSCAM；预诱导液诱导24 h，MSCs开始少量表达DSCAM（1.71±0.67）%；黄芩甙诱导 6 h，部分表达DSCAM（15.79±4.24）%；诱导后3 d，DSCAM表达最高（53.16±5.94）%；诱导后 6 d，DSCAM表达明显下降（28.99±6.72）%。DSCAM-siRNA转染MSCs，DSCAM表达显著下降。而且，诱导前MSCs不表达神经细胞特异性标记蛋白β-III-tubulin；诱导6 h，β-III-tubulin表达为（1.40±0.79）%，诱导3 d达到（41.59±3.17）%，诱导 6 d 为（59.11±4.76）%。但是， DSCAM-siRNA转染MSCs，诱导3 d，6 d，β-III-tubulin蛋白的表达显著下降，分别为（28.57±2.91）%和（43.90±12.31）%。结论：DSCAM可能在MSCs分化为神经细胞中起到重要的作用。［中国当代儿科杂志，2009，11（6）：486-489］

OBJECTIVE: To study the effects of Down syndrome cellular adhesion molecule (DSCAM) on differentiation of rat marrow mesenchymal stem cells (MSCs) into neurons in vitro. METHODS: MSCs from Sprague-Dawley rats were induced into neurons by baicalin. The expression of DSCAM before and after induction was evaluated by immunocytochemical staining and Western blot assay. After knockdown of DSCAM by siRNA transfection, the differentiation rate of neurons derived from MSCs was measured. RESULTS: Before induction, the expression of DSCAM was not detectable in MSCs. After bFGF preinduction for 24 hrs, DSCAM was slightly expressed in MSCs (1.71±0.67%). The DSCAM expression increased 6 hrs after baicalin induction (15.79±4.24%), reached a peak at 3 days (53.16±5.94%) and then decreased gradually. The DSCAM expression 6 days after baicalin induction (28.99±6.72%) was significantly lower than that at 3 days (P<0.01). However, after DSCAM-siRNA transfection, the DSCAM expression in MSCs was significantly reduced. MSCs did not express neuron-specific β-III-tubulin before induction. After baicalin induction for 6 hrs, 3 days and 6 days, the expression of β-III-tubulin was 1.40±0.79%, 41.59±3.17% and 59.11±4.76% respectively. But the β-III-tubulin expression significantly decreased 3 and 6 days after DSCAM-siRNA transfection (28.57±2.91% and 43.90±12.31% respectively). CONCLUSIONS: DSCAM may play an important role in MSCs differentiation into neural cells.［Chin J Contemp Pediatr, 2009, 11 (6):486-489］