Te-I Weng, Hsiao-Yi Wu, Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan.
World J Gastroenterol. 2013 Nov 7;19(41):7097-105. doi: 10.3748/wjg.v19.i41.7097.
To investigate the pathophysiological role of C/EBP homologous protein (CHOP) in severe acute pancreatitis and associated lung injury.
A severe acute pancreatitis model was induced with 6 injections of cerulein (Cn, 50 μg/kg) at 1-h intervals, then intraperitoneal injection of lipopolysaccharide (LPS, 7.5 mg/kg) in CHOP-deficient (Chop(-/-)) mice and wild-type (WT) mice. Animals were sacrificed under anesthesia, 3 h or 18 h after LPS injection. Serum amylase, lipase, and cytokines [interleukin (IL)-6 and tumor necrosis factor (TNF)-α], pathological changes, acute lung injury, and apoptosis in the pancreas were evaluated. Serum amylase and lipase activities were detected using a medical automatic chemical analyzer. Enzyme-linked immunosorbent assay kits were used to evaluate TNF-α and IL-6 levels in mouse serum and lung tissue homogenates. Apoptotic cells in sections of pancreatic tissues were determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) analysis. The mouse carotid arteries were cannulated and arterial blood samples were collected for PaO2 analysis. The oxygenation index was expressed as PaO2/FiO2.
Administration of Cn and LPS for 9 and 24 h induced severe acute pancreatitis in Chop(-/-) and WT mice. When comparing Chop(-/-) mice and WT mice, we observed that CHOP-deficient mice had greater increases in serum TNF-α (214.40 ± 19.52 pg/mL vs 150.40 ± 16.70 pg/mL; P = 0.037), amylase (4236.40 ± 646.32 U/L vs 2535.30 ± 81.83 U/L; P = 0.041), lipase (1678.20 ± 170.57 U/L vs 1046.21 ± 35.37 U/L; P = 0.008), and IL-6 (2054.44 ± 293.81 pg/mL vs 1316.10 ± 108.74 pg/mL; P = 0.046) than WT mice. The histopathological changes in the pancreases and lungs, decreased PaO2/FiO2 ratio, and increased TNF-α and IL-6 levels in the lungs were greater in Chop(-/-) mice than in WT mice (pancreas: Chop(-/-) vs WT mice, hemorrhage, P = 0.005; edema, P = 0.005; inflammatory cells infiltration, P = 0.005; total scores, P = 0.006; lung: hemorrhage, P = 0.017; edema, P = 0.017; congestion, P = 0.017; neutrophil infiltration, P = 0.005, total scores, P = 0.001; PaO2/FiO2 ratio: 393 ± 17.65 vs 453.8, P = 0.041; TNF-α: P = 0.043; IL-6, P = 0.040). Results from TUNEL analysis indicated increased acinar cell apoptosis in mice following the induction of acute pancreatitis. However, Chop(-/-) mice displayed significantly reduced pancreatic apoptosis compared with the WT mice (201.50 ± 31.43 vs 367.00 ± 47.88, P = 0.016).
These results suggest that CHOP can exert protective effects against acute pancreatitis and limit the spread of inflammatory damage to the lungs.
研究 C/EBP 同源蛋白（CHOP）在重症急性胰腺炎及其相关肺损伤中的病理生理作用。
采用胰胆管内注射 Cerulein（Cn，50μg/kg），每 1 小时 1 次，共 6 次，然后对 CHOP 缺陷（Chop（-/-））小鼠和野生型（WT）小鼠腹腔内注射脂多糖（LPS，7.5mg/kg），建立重症急性胰腺炎模型。在 LPS 注射后 3h 或 18h 麻醉处死动物。评估血清淀粉酶、脂肪酶和细胞因子[白细胞介素（IL）-6 和肿瘤坏死因子（TNF）-α]、胰腺病理变化、急性肺损伤和细胞凋亡。使用医疗自动化学分析仪检测血清淀粉酶和脂肪酶活性。采用酶联免疫吸附试验试剂盒检测小鼠血清和肺组织匀浆中 TNF-α和 IL-6 水平。通过末端脱氧核苷酸转移酶介导的 dUTP-生物素缺口末端标记（TUNEL）分析确定胰腺组织切片中的凋亡细胞。通过颈动脉插管采集动脉血样进行 PaO2 分析。氧合指数表示为 PaO2/FiO2。
Cn 和 LPS 连续给药 9 和 24h 可诱导 Chop（-/-）和 WT 小鼠发生重症急性胰腺炎。与 WT 小鼠相比，CHOP 缺陷型小鼠血清 TNF-α（214.40±19.52pg/mL 比 150.40±16.70pg/mL；P=0.037）、淀粉酶（4236.40±646.32U/L 比 2535.30±81.83U/L；P=0.041）、脂肪酶（1678.20±170.57U/L 比 1046.21±35.37U/L；P=0.008）和 IL-6（2054.44±293.81pg/mL 比 1316.10±108.74pg/mL；P=0.046）水平显著增加。与 WT 小鼠相比，Chop（-/-）小鼠的胰腺和肺部组织病理学变化、PaO2/FiO2 比值降低以及肺部 TNF-α和 IL-6 水平升高更为明显（胰腺：Chop（-/-）比 WT 小鼠，出血，P=0.005；水肿，P=0.005；炎症细胞浸润，P=0.005；总评分，P=0.006；肺：出血，P=0.017；水肿，P=0.017；淤血，P=0.017；中性粒细胞浸润，P=0.005，总评分，P=0.001；PaO2/FiO2 比值：393±17.65 比 453.8，P=0.041；TNF-α，P=0.043；IL-6，P=0.040）。TUNEL 分析结果表明，急性胰腺炎诱导后，小鼠腺泡细胞凋亡增加。然而，与 WT 小鼠相比，Chop（-/-）小鼠的胰腺细胞凋亡明显减少（201.50±31.43 比 367.00±47.88，P=0.016）。
这些结果表明 CHOP 可发挥对急性胰腺炎的保护作用，并限制炎症损伤向肺部的扩散。
