糖基化终产物对成骨细胞Ⅰ型胶原积聚的影响

The effect of advanced glycation end products on the accumulation of type Ⅰ collagen

目的探讨糖基化终产物(AGEs)对成骨细胞与破骨前体细胞共培养体系中Ⅰ型胶原合成与降解的影响。方法在成骨细胞与破骨前体细胞共培养体系中分别加入不同浓度的糖基化终产物(50、100、200、400mg/L)干预24h,以无血清培养基和相应浓度的牛血清白蛋白为对照。用免疫印迹的方法检测Ⅰ型胶原蛋白水平的表达,酶联免疫吸附法检测上清中Ⅰ型胶原的含量,用明胶酶谱法检测上清中MMP-2、MMP-9的活性。结果 AGEs干预组的Ⅰ型胶原蛋白水平和上清中含量与对照组比较有显著差异,Ⅰ型胶原蛋白水平随浓度增加而增加(P<0.05),上清中Ⅰ型胶原含量随AGEs浓度增加而减少(P<0.05)。糖基化终产物干预后,上清中MMP-2、MMP-9的活性随着AGEs浓度的增加而增加(P<0.05)。结论 AGEs可能通过打破Ⅰ型胶原合成与降解之间的平衡,使其降解多于合成,Ⅰ型胶原总量减少,从而参与骨质疏松的发病,使骨骼脆性增加。

Objective To explore the effect of advanced glycation end products （AGEs） on the synthesis and degradation of type I collagen in a cocultured system of osteoblast and osteoclast precursors. Methods The AGEs of 50, 100, 200, and 400 mg/L different concentrations were respectively added into the cocultured system of osteoblast and osteoclast precursors for 24 hours. The serum free medium and bovine serum albumin （BSA） were considered as negative control. The expression of type I collagen protein was measured using Western blotting method. The concentration of type Ⅰ collagen in the supernatant was measured using enzyme linked immunosorbent assay （ELISA）. The activity of MMP-9 and MMP-2 were measured using gelatin enzymogram. Results The expression of type Ⅰ collagen protein and concentration of type Ⅰ collagen in the supernatant in AGEs group were significantly different with those of DMEM and BSA groups. The level of type Ⅰ collagen protein expression increased with the increase of AGEs concentration. However, type I collagen in the supernatant decreased with the increase of AGEs concentration （ P 〈 0.05 ）. The activities of MMP-9 and MMP-2 increased with the increase of AGEs concentration （ P 〈 0. 05 ）. Conclusion AGEBSA may break the balance between the synthesis and the degradation of type Ⅰ collagen, resulting in degradation excess synthesis. The content of type Ⅰ collagen decreases, leading to the occurrence of osteoporosis and the increase of bone fragility.