罗汉果苷V调控高糖状态巨噬细胞M1极化促进骨髓间充质干细胞的成骨分化

Mogroside V promotes osteogenic differentiation of bone marrow mesenchymal stem cells by modulating M1 polarization of macrophages under high glucose condition

背景:糖尿病微环境会造成巨噬细胞过度M1极化,这种高糖炎症状态会抑制骨髓间充质干细胞的成骨分化,从而影响糖尿病骨缺损的愈合。研究表明罗汉果苷Ⅴ具有抗炎、抗氧化、降血糖的作用,但其能否调节高糖炎症状态下巨噬细胞M1极化及骨髓间充质干细胞的成骨分化尚不清楚。目的:探讨罗汉果苷Ⅴ在高糖炎症状态下调节巨噬细胞M1型极化对骨髓间充质干细胞成骨分化的影响。方法:构建糖尿病C57BL/6小鼠模型,从正常和糖尿病小鼠分离骨髓来源巨噬细胞,分别培养于低糖和高糖培养基。使用脂多糖和干扰素γ作为炎症刺激诱导骨髓来源巨噬细胞的M1型极化,同时以160,320,640μmol/L罗汉果苷Ⅴ干预,用流式细胞术检测F4/80^(+)CD86^(+)细胞比例,qRT-PCR检测诱导型一氧化氮合酶、白细胞介素1β、白细胞介素6的mRNA表达水平,ELISA检测骨髓来源巨噬细胞上清液中肿瘤坏死因子α水平。分离C57BL/6小鼠骨髓间充质干细胞,分别使用低糖或高糖成骨诱导液诱导成骨分化,添加M1型巨噬细胞条件培养基作为炎症刺激,以及320μmol/L罗汉果苷Ⅴ干预,成骨诱导14 d后采用qRT-PCR检测碱性磷酸酶、Runt相关因子2、骨钙素、骨桥蛋白的mRNA表达水平,成骨诱导21 d后进行茜素红染色及定量分析。结果与结论:①流式细胞术结果显示320,640μmol/L罗汉果苷Ⅴ组的F4/80^(+)CD86^(+)细胞比例明显低于高糖炎症对照组(P<0.05);②qRT-PCR结果显示160,320,640μmol/L罗汉果苷Ⅴ组的诱导型一氧化氮合酶、白细胞介素6的mRNA相对表达量较高糖炎症对照组显著降低(P<0.05),320,640μmol/L罗汉果苷Ⅴ组白细胞介素1β的mRNA相对表达量较高糖炎症对照组显著降低(P<0.05);③ELISA结果显示160,320,640μmol/L罗汉果苷Ⅴ组的肿瘤坏死因子α分泌水平较高糖炎症对照组显著降低(P<0.05);④320μmol/L罗汉果苷Ⅴ干预后,高糖炎症状态下骨髓间充质干细胞的钙盐沉积增加(P<0.05),且碱性磷酸酶、Runt相关因子2和骨桥蛋白的mRNA相对表达量增加(P<0.05)。结果表明,罗汉果苷Ⅴ可通过抑制高糖炎症状态下骨髓来源巨噬细胞的M1型极化及炎症因子表达,促进骨髓间充质干细胞的成骨分化。

BACKGROUND:The diabetic microenvironment can cause excessive M1 polarization of macrophages,and this hyperglycemic inflammatory state can inhibit osteogenic differentiation of bone marrow mesenchymal stem cells,thus affecting the healing of diabetic bone defects.Studies have indicated that mogroside V possesses anti-inflammatory,antioxidant,and hypoglycemic properties.However,its potential to modulate M1 polarization of macrophages and osteogenic differentiation of bone marrow mesenchymal stem cells under high glucose and inflammatory condition remains unclear.OBJECTIVE:To explore the effect of mogroside V on regulating M1 macrophage polarization and its effect on osteogenic differentiation of bone marrow mesenchymal stem cells under high glucose and inflammatory condition.METHODS:Murine diabetic models were established using C57BL/6 mice.Bone marrow-derived macrophages were isolated from tibia and fibula of normal and diabetic mice,and cultured in low-glucose and high-glucose media.Then M1 polarization of bone marrow-derived macrophages was induced using lipopolysaccharide and interferon-γ.Bone marrow-derived macrophages were treated with 160,320,and 640μmol/L mogroside V.Flow cytometry was employed to determine the proportion of F4/80^(+)CD86^(+)cells.qRT-PCR was utilized to assess mRNA expression levels of inducible nitric oxide synthase,interleukin 1β,and interleukin 6.ELISA was employed to evaluate tumor necrosis factor-αsecretion in bone marrow-derived macrophage supernatants.Bone marrow mesenchymal stem cells were isolated from tibia and fibula of C57BL/6 suckling mice,and induced osteogenic differentiation using low-or highglucose osteogenic induction medium.Bone marrow mesenchymal stem cells were treated with M1 macrophage-conditioned mediums with or without 320μmol/L mogroside V in osteogenic differentiation process.qRT-PCR was employed to assess the mRNA expression of alkaline phosphatase,Runt-related factor 2,osteocalcin,and osteopontin on day 14 after osteogenic induction.Alizarin red staining and quantitative analysis were conducted to evaluate calcium deposition on day 21 after osteogenic induction.RESULTS AND CONCLUSION:(1)Flow cytometry results showed that with the treatment of 320 and 640μmol/L mogroside V,the proportion of F4/80^(+)CD86^(+)bone marrow-derived macrophages was significantly lower than that in the high-glucose control group(P<0.05).(2)qRT-PCR results showed that with the treatment of 160,320,and 640μmol/L mogroside V,the mRNA expression levels of inducible nitric oxide synthase and interleukin 6 were significantly lower than that in the high-glucose control group(P<0.05).With the treatment of 320 and 640μmol/L mogroside V,the mRNA expression level of interleukin 1βwas significantly lower than that in the high-glucose control group(P<0.05).(3)ELISA results exhibited that with the treatment of 160,320,and 640μmol/L mogroside V,the tumor necrosis factor-αsecretion level was significantly lower than that in the high-glucose control group(P<0.05).(4)With the treatment of 320μmol/L mogroside V,calcium salt deposition was increased in bone marrow mesenchymal stem cells under high glucose and inflammatory conditions(P<0.05),and the mRNA relative expression levels of alkaline phosphatase,Runt-related factor 2,and osteopontin were increased(P<0.05).These findings indicate that mogroside V can promote osteogenic differentiation of bone marrow mesenchymal stem cells by inhibiting the M1 polarization of bone marrowderived macrophages under high glucose and inflammatory conditions and reducing the generation of inflammatory factors.