链佐星、细胞因子及游离脂肪酸诱导β-TC3细胞凋亡

Streptozotocin,cytokines or free fat acid-inducing apoptosis on mouse β-TC3 cell line

目的观察链佐星(链脲菌素,STZ)、细胞因子及游离脂肪酸致β细胞凋亡情况及不同浓度STZ对β细胞破坏的形态改变。方法(1)体外培养小鼠-βTC3细胞株,分别以合适浓度的STZ,棕榈酸及细胞因子(IL-1β,TNF-α,IFN-γ)处理24h。以Annexin V/FITC和PI双染后流式细胞仪分别检测3组处理细胞的凋亡率。(2)用不同浓度的STZ作用该细胞株6h,镜下观察并比较细胞形态变化。结果(1)STZ,棕榈酸及细胞因子处理-βTC3细胞后早期凋亡率较对照组(7.53±2.43)%明显增加,分别为(16.51±4.51)%(P=0.029)、(20.87±5.01)%(P=0.009)和(16.63±6.11)%(P=0.009)。(2)β-TC3细胞在不同浓度STZ作用6h后,随着剂量的增加,细胞形态逐渐发生改变,主要有细胞突起变钝乃至消失,细胞萎缩、变圆,胞浆内颗粒增多,核浓缩等表现。结论STZ、细胞因子及游离脂肪酸均可导致β细胞凋亡明显增加而在不同机制导致的β细胞损伤中起关键作用。STZ诱导的β细胞凋亡速度与其作用浓度呈正相关。

Purpose To observe the pro-apoptosis effects of streptozotocin （STZ）, cytokines and free fat acids on mouse β-TC3 cell line and the morphological alterations of the cells at different concentrations of STZ in vitro. Methods （1） Mouse β-TC3 cells were cultured in vitro and incubated in the culture medium containing STZ, cytokines（IL-1β, TNF-α, IFN-γ） or palmitic acid at a certain concentration for 24 hours. These three groups of treated cells and a group of control cells were double stained with Annexin V/FITC and PI, and measured for apoptosis rate by flow cytometer （FACScan）. （2） After treated with different concentrations of STZ for 6 hours, the morphological changes of β-TC3 cells were observed under an optical microscope. Results （1） After treated with STZ, cytokines or FFA, the early apoptosis rates of β-TC3 cells increased markedly compared to control cells （7.53 ± 2.43）% reaching （16.51 ± 4. 51）% （P〈0.05）, （20.87 ± 5.01 ）% （P〈0.01） and （16.63 ± 6.11 ） （P〈0.01） respectively. （2）β-TC3 cells treated with different concentrations of STZ for 6 hours induced morphological alterations gradually following increasing concentrations. The morphological changes included mainly the cells＇ protuberance blunted or disappeared, cells shrunk and rounded up, cytoplasmic granules accumulated and nucleus condensed. Conclusions STZ, cytokines or FFA could induce the apoptosis of β-TC3 cell lines obviously and play vital roles in the process of β cell destruction under different mechanism. STZ might induce β-cell apoptosis even under low concentrations, and apoptosis may be accelerated under higher concentrations with manifesting shrunk cells other than necrosis.