Objective: To explore the effects of microRNA-126 (miR-126) on the proliferation of human myeloid leukemia mononuclear cells (THP-1)-derived macrophages in high glucose environment and the regulatory role of miR-126 in periodontitis with diabetes. Methods: THP-1 cells were cultured in vitro and 5 μg/L phorbol-12-myristate-13-acetate was applied to induce THP-1 cells differentiating into macrophages for 48 h in low glucose culture medium (5.5 mmol/L). THP-1-derived macrophages were then cultured with low glucose, medium glucose (15 mmol/L) or high glucose (25 mmol/L) media respectively. The proliferation of THP-1-derived macrophages was detected by cell counting kit-8 (CCK-8) method and the expressions of miR-126 and proliferation-associated factors were detected by quantitative real time PCR (qRT-PCR). The miR-126 mimic or inhibitor was transfected into THP-1-derived macrophages for 72 h. The proliferation of cells was detected by CCK-8 method and the expressions of miR-126 or proliferation-associated factors were detected by qRT-PCR. Results: Increasing glucose concentration decreased the proliferation of THP-1-derived macrophages (day 7, A values in low, medium and high glucose groups were 0.369±0.014, 0.214±0.009 and 0.200±0.010, respectively, P<0.01) as well as the survival rate (P<0.05), promoted the expression of miR-126, B-cell lymphoma-2 (Bcl-2)-associated X protein (BAX) and caspase-3 (P<0.05), and suppressed Bcl-2, phosphoinositol-3 kinase regulatory subunit 2 (PIK3R2) expression (P<0.05). After the miR-126 mimic was transfected in cells in low glucose medium for 72 h, compared with negative control (1.005±0.118), the expression of miR-126 significantly increased (2 980.227±170.431, P<0.05), and the proliferation of THP-1 derived macrophages decreased (negative control: 1.816±0.013, mimic group: 1.310±0.048, P<0.01), the level of BAX and caspase-3 significantly increased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly decreased (P<0.05, P<0.01). After the miR-126 inhibitor was transfected in cells cultured in high glucose medium for 72 h, compared with negative control (0.723±0.133), the proliferation of inhibitor group increased (0.984±0.049, P<0.05), the level of BAX and caspase-3 significantly decreased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly increased (P<0.01, P<0.05). Conclusions: High glucose condition can inhibit the proliferation of THP-1-derived macrophages and increase the expression of miR-126. MiR-126 can inhibit the proliferation of THP-1-derived macrophages in high glucose environment through up-regulating the expression of BAX and caspase-3 and down-regulating the expression of PIK3R2 and Bcl-2.
目的： 研究微RNA-126（microRNA-126，miR-126）对高糖环境中人单核细胞（human myeloid leukemia mononuclear cell，THP-1）源性巨噬细胞增殖的影响，探讨miR-126在伴糖尿病牙周炎中的调节作用。 方法： 体外培养THP-1细胞，低糖环境下（糖浓度5.5 mmol/L）以5 μg/L佛波酯作用48 h诱导THP-1分化为巨噬细胞；分别用低糖、中糖（糖浓度15 mmol/L）和高糖（糖浓度25 mmol/L）培养液培养THP-1源性巨噬细胞，细胞计数试剂盒（cell counting kit-8，CCK-8）法检测细胞的增殖情况，通过实时荧光定量PCR（quantitative real time-PCR，qRT-PCR）检测miR-126及增殖相关基因的表达；miR-126模拟物或抑制剂转染细胞72 h后，CCK-8法检测细胞增殖变化，qRT-PCR检测miR-126及增殖相关基因表达的变化。 结果： 糖浓度升高可使THP-1源性巨噬细胞增殖能力显著降低（7 d时低、中、高糖组细胞A值分别为0.369±0.014、0.214±0.009和0.200±0.010，P<0.01），细胞存活率显著下降（P<0.05），并引起细胞中miR-126、B细胞淋巴瘤-2基因（B-cell lymophoma-2，Bcl-2）相关性X蛋白质（Bcl-2-associated X protein，BAX）、天冬氨酸蛋白酶3（caspase-3）表达显著升高（P<0.05），Bcl-2、醇磷脂-3激酶调节亚单位2（phosphoinositol-3 kinase regulatory subunit 2，PIK3R2）表达显著降低（P<0.05）。miR-126模拟物转染低糖培养的细胞72 h后，与阴性对照组（1.005±0.118）相比，低糖-模拟物组miR-126表达（2 980.227±170.431）显著升高（P<0.05），并伴随THP-1源性巨噬细胞的增殖能力下降（阴性对照组：1.816±0.013，模拟物组：1.310±0.048，P<0.01），增殖抑制因子BAX、caspase-3的表达显著升高（P<0.01，P<0.05），增殖促进因子PIK3R2、Bcl-2的表达显著降低（P<0.05，P<0.01）；miR-126抑制剂转染高糖培养的细胞72 h后，与阴性对照组相比（0.723±0.133），高糖-抑制剂组THP-1源性巨噬细胞的增殖能力显著增强（0.984±0.049）（P<0.05），增殖抑制因子BAX、caspase-3表达显著降低（P<0.01，P<0.05），增殖促进因子PIK3R2、Bcl-2表达显著升高（P<0.01，P<0.05）。 结论： 高糖可抑制THP-1源性巨噬细胞的增殖，促进细胞内miR-126表达；miR-126通过上调增殖抑制因子BAX、caspase-3的表达，下调增殖促进因子PIK3R2、Bcl-2的表达，介导高糖对THP-1源性巨噬细胞增殖的抑制作用。.
Keywords: Diabetes mellitus; Macrophages; MicroRNA-126; Periodontitis; Proliferation.