β淀粉样蛋白诱导大鼠小胶质细胞脂多糖受体CD14和肿瘤坏死因子-α mRNA的表达

LPS receptor(CD14) and TNF-α mRNA expression in Microglia induced by β-amyloiy

目的:研究不同浓度的β淀粉样蛋白(Aβ1-42)诱导大鼠小胶质细胞脂多糖受体CD14和肿瘤坏死因子-αmRNA表达的变化。方法:小胶质细胞株复苏培养后分为2组:Aβ1-42组和抗CD14加Aβ1-42组。抗CD14加Aβ1-42组使用抗CD14抗体拮抗CD14的表达,再分别用不同浓度的Aβ1-42(0、62.5nmol/L、125nmol/L、250nmol/L)进行干预,2组均在Aβ1-42干预2h后用RT-PCR法检测CD14及TNF-αmRNA表达的量。结果:不同浓度的Aβ1-42干预小胶质细胞2h后,62.5nmol/L与0nmol/LAβ1-42组CD14mRNA的表达相比较,差异无统计学意义。当Aβ1-42浓度为125nmol/L和250nmol/L时,CD14mRNA的表达逐渐增加(P<0.05)。使用CD14抗体后,抗CD14加Aβ1-42组中CD14mRNA的表达与Aβ1-42组比降低(P<0.05)。Aβ1-42组TNF-αmRNA的表达随Aβ1-42的浓度增加而增加(P<0.05),与Aβ1-42组相比,抗CD14加Aβ1-42组中TNF-αmRNA的表达在Aβ1-42浓度为125nmol/L开始明显受到抑制(P<0.05)。结论:Aβ1-42诱导的小胶质细胞可通过脂多糖受体CD14使TNF-αmRNA的表达增加,且与Aβ1-42的作用浓度呈正相关。

Aim： To observe the changes of LPS receptor （CD14） mRNA expression in microglia induced by β-amyloiy of different doses. Methods ： Microglia were divided into two groups after the recovery of cuhure：Aβ group and Anti- CD14 ＋ Aβ group. Anti-CD14 ＋ Aβ groups were inhibited by Anti-CD14 first, then both of the two groups were treated with Aβ1-42 of different doses（0,62.5 nmol/L, 125 nmol/L,250 nmol/L） respectively. After 2 h, CD14 and TNF-α mRNA were detected by RT-PCR. Results： Affter microglia were intervened by different doses of Aβ1-42 for 2 h, the levels of CD14 mR- NA weren＇t statistically significant at 62.5 nmol/L and 0 nmol/L Aβ1-42 of Aβ1-42 group. When the doses of Aβ1-42 were at 125 nmol/L and 250 nmol/L, the levels of CD14 mRNA were gradually increased （ P 〈 0.05 ）. Compared with Aβ1-42 group, the levels of CD14 mRNA were greatly decreased in ANti-CD14 ＋ Aβ1-42 group （P 〈 0.05 ）. The levels of TNF-α mRNA were increased relating to the doses of Aβ1-42 in Aβ1-42 groups （P 〈 0.05）. Compared with Aβ1-42 group, the levels of TNF-α mRNA were significantly inhibited at 125 nmol/L of Aβ1-42 （P 〈 0.05 ）. Conclusion： LPS receptor （CD14） is expressed in active microglia induced by Aβ1-42, and TNF-α is expressed by CD14. CD14 and TNF-α are expressed in active microglia induced by Aβ1-42 , which may be associated with Aβ1-42 of doses.