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[目的]探讨麦芽酚铝暴露对大鼠脑皮质神经元微小RNA(miR)29a-和BACE1表达的影响。[方法]取新生24 h内的SD大鼠乳鼠的脑皮质进行原代神经元培养,培养至第3天时加入10μmol/L的阿糖胞苷,应用免疫组化法检测神经元特异性表达蛋白的表达来进行神经元纯度检测,应用不同剂量麦芽酚铝染毒原代神经元,剂量分别为空白对照组(0μmol/L)、低剂量组(20μmol/L)、中剂量组(40μmol/L)、高剂量组(80μmol/L)4组,继续培养24 h收集细胞,荧光实时定量PCR检测miR-29a、BACE1 mRNA表达水平,ELISA法检测BACE1蛋白含量。[结果]免疫组化结果显示:神经元纯度达到95%。荧光实时定量PCR结果显示:对照组、低剂量组、中剂量组、高剂量组BACE1 mRNA的相对表达量分别为1.00±0.00、1.24±0.32、1.64±0.12、1.87±0.06,与对照组相比,中、高剂量组的表达水平升高(P<0.05);而miR-29a的相对表达量分别为1.00±0.00、0.98±0.17、0.47±0.03、0.34±0.08,与对照组相比,中、高剂量组的表达降低(P<0.05);ELISA结果显示:对照组、低剂量组、中剂量组、高剂量组BACE1表达量分别为(406.89±57.47)、(419.52±49.38)、(497.10±4.79)、(508.83±44.59)ng/L,与对照组相比,中、高剂量组的表达水平升高(P<0.05)。[结论]铝可能通过抑制miR-29a的表达,从而负向调控BACE1表达的增多,导致β淀粉样蛋白沉积。
[Objective] To investigate the effect of malto-aluminum exposure on the expression of 29a- and BACE1 in rat cerebral cortical neurons. [Methods] The primary cortical neurons of neonatal SD rats were cultured in neonatal rats within 24 h. At day 3, 10 μmol / L cytarabine was added and the expression of neurons was detected by immunohistochemistry (0μmol / L), low dose group (20μmol / L), middle dose group (40μmol / L), low dose group (20μmol / L) L) and high dose group (80μmol / L) for 24 hours. The expression of miR-29a and BACE1 mRNA was detected by real-time quantitative PCR. The content of BACE1 protein was detected by ELISA. [Result] The results of immunohistochemistry showed that the purity of neurons reached 95%. Fluorescence real-time PCR results showed that the relative expression levels of BACE1 mRNA in the control group, low dose group, medium dose group and high dose group were 1.00 ± 0.00, 1.24 ± 0.32, 1.64 ± 0.12 and 1.87 ± 0.06 respectively, compared with the control group (P <0.05), while the relative expression of miR-29a was 1.00 ± 0.00,0.98 ± 0.17,0.47 ± 0.03,0.34 ± 0.08, respectively, compared with the control group (P <0.05). The results of ELISA showed that the expression of BACE1 in control group, low dose group, medium dose group and high dose group were (406.89 ± 57.47), (419.52 ± 49.38), (497.10 ± 4.79), (508.83 ± 44.59) ng / L, respectively. Compared with the control group, the expression levels in medium and high dose groups increased (P <0.05). [Conclusion] Aluminum may negatively regulate the increase of BACE1 expression by inhibiting the expression of miR-29a, resulting in the deposition of β-amyloid protein.