1 型糖尿病小鼠模型中胰岛β细胞凋亡的定量测定。

Quantitative determination of apoptosis of pancreatic β-cells in a murine model of type 1 diabetes mellitus.

机构信息

Department of Radiobiology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.

出版信息

J Nucl Med. 2012 Oct;53(10):1585-91. doi: 10.2967/jnumed.111.102459. Epub 2012 Aug 28.

DOI:10.2967/jnumed.111.102459

PMID:22930815

Abstract

UNLABELLED

Type 1 diabetes mellitus is characterized by a significant deficit in pancreatic β-cell mass, presumably caused by β-cell apoptosis. We investigated the incidence of β-cell apoptosis in streptozotocin-treated mice and nonobese diabetic (NOD) mice with (99m)Tc-annexin A5.

METHODS

Vehicle-treated mice, streptozotocin-treated mice, and NOD mice at the ages of 5, 9, 16, and 20 wk (5-8 mice per group) were injected with (99m)Tc-annexin A5 and sacrificed 6 h later for autoradiography, and the regional (99m)Tc-annexin A5 level in the pancreas was evaluated. Pancreatic islets were identified by insulin immunohistochemical staining, and apoptotic cells were determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The (99m)Tc-annexin A5 level in pancreatic islets was expressed as the percentage injected dose per area of pancreatic islets and normalized by animal body weight (%ID × 10(6)/mm(2)/kg). The level of apoptotic cells in pancreatic islets was expressed as the number of TUNEL-positive cells per area of pancreatic islets (cells/mm(2)).

RESULTS

The (99m)Tc-annexin A5 accumulation level was significantly higher (2.5 ± 0.7 vs. 0.7 ± 0.1 %ID × 10(6)/mm(2)/kg, P < 0.05) and the number of TUNEL-positive cells was significantly higher (1,170 ± 535 vs. 5 ± 6 cells/mm(2), P < 0.05) in the pancreatic islets of the streptozotocin-treated mice than in those of the vehicle-treated mice. The (99m)Tc-annexin A5 accumulation level was significantly higher (1.1 ± 0.4 vs. 0.5 ± 0.1 %ID × 10(6)/mm(2)/kg, P < 0.05) and the number of TUNEL-positive cells was significantly higher (152 ± 82 vs. 4 ± 9 cells/mm(2), P < 0.05) in the pancreatic islets of 16-wk-old NOD mice than in those of 5-wk-old NOD mice. In addition, the level of (99m)Tc-annexin A5 correlated with the number of TUNEL-positive cells in the pancreatic islets of the streptozotocin-treated mice (r = 0.821, P < 0.001) and NOD mice (r = 0.721, P < 0.001).

CONCLUSION

There is significant islet cell apoptosis with (99m)Tc-annexin A5 accumulation in the pancreas of both streptozotocin and NOD mice.

摘要

目的

研究链脲佐菌素（streptozotocin，STZ）处理的小鼠和非肥胖型糖尿病（nonobese diabetic，NOD）小鼠胰岛β细胞凋亡的发生情况。

方法

5-20 周龄的 vehicle 处理组、STZ 处理组和 NOD 小鼠（每组 5-8 只）分别给予放射性核素 99mTc-annexin A5 后 6 h 处死，行放射自显影，评价胰腺中 99mTc-annexin A5 的放射性计数。用胰岛素免疫组织化学染色鉴定胰岛，用末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记法（terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling，TUNEL）检测凋亡细胞。以每单位胰岛面积的放射性计数表示胰岛内放射性核素 99mTc-annexin A5 的水平（%ID×106/mm2/kg），并以动物体重标准化。以每单位胰岛面积的 TUNEL 阳性细胞数表示胰岛内凋亡细胞的水平（细胞/mm2）。

结果

与 vehicle 处理组相比，STZ 处理组小鼠胰岛中放射性核素 99mTc-annexin A5 的积聚水平明显升高（2.5±0.7比 0.7±0.1%ID×106/mm2/kg，P<0.05），TUNEL 阳性细胞数明显增加（1170±535比 5±6 细胞/mm2，P<0.05）。与 5 周龄 NOD 小鼠相比，16 周龄 NOD 小鼠胰岛中放射性核素 99mTc-annexin A5 的积聚水平明显升高（1.1±0.4比 0.5±0.1%ID×106/mm2/kg，P<0.05），TUNEL 阳性细胞数明显增加（152±82比 4±9 细胞/mm2，P<0.05）。此外，STZ 处理组和 NOD 小鼠胰岛中放射性核素 99mTc-annexin A5 的积聚水平与 TUNEL 阳性细胞数呈显著正相关（STZ 处理组 r=0.821，P<0.001；NOD 小鼠 r=0.721，P<0.001）。