Dang Sheng-chun, Zeng Yan-hua, Wang Ping-jiang, Chen Bao-ding, Chen Rong-fang, Kumar Singh Arun, Kumar Pankaj, Feng Shu, Cui Lei, Wang Hao, Zhang Jian-xin
Department of General Surgery, the Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China.
J Zhejiang Univ Sci B. 2014 Jun;15(6):556-65. doi: 10.1631/jzus.B1300244.
It has been shown that macrophages play an important role in the development of severe acute pancreatitis (SAP), and eventually lead to multiple organ failure (MOF). Clodronate-liposome selectively depleted macrophages. This study was to investigate the role of renal macrophage infiltration in acute renal injury in rats with SAP and to evaluate the potential of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) for diagnosis.
Superparamagnetic Fe3O4 nanoparticles were prepared by chemical coprecipitation. SPIO-liposomes and SPIO-clodronate-liposomes were prepared by the thin film method. SAP models were prepared by injection of sodium taurocholate into the subcapsular space of rat pancreas. Sprague-Dawley rats were randomly divided into a control group, SAP plus SPIO-liposome (P) group, and SAP plus SPIO-clodronate-containing liposome (T) group. Kidney injury was evaluated by T2-weighted MRI scan. The levels of serum amylase (SAM), blood urea nitrogen (BUN), and serum creatinine (SCr) were measured by an automated enzymatic method. Serum tumor necrosis factor-α (TNF-α) was measured by enzyme-linked immunosorbent assay (ELISA). Pathological changes in the pancreas and kidney were observed using hematoxylin and eosin (H&E) staining, while cell apoptosis was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. In addition, the macrophage markers (CD68) of the renal tissue were detected with immunohistochemistry.
The pathological changes in the pancreas and kidneys of rats in the T group were milder than those in the P group. The MRI signal intensity of the kidneys in the P and T groups was significantly lower than that in the control group. There were significant changes in the two experimental groups (P<0.01). The levels of SAM, Bun, SCr, and TNF-α in rats in the P group were higher than those in the control group (P<0.01) and in the T group (P<0.01). The apoptosis of the kidney in the T group was higher than that in the P group at 2 and 6 h (P<0.01).
Clodronate-containing liposomes protected against renal injury in SAP rats, and SPIO can be used as a tracer for MRI examination to detect renal injury in SAP rats. SPIO-aided MRI provided an efficient non-invasive way to monitor the migration of macrophages after renal injury in rats with SAP.
研究表明巨噬细胞在重症急性胰腺炎（SAP）的发展过程中起重要作用，并最终导致多器官功能衰竭（MOF）。氯膦酸盐脂质体可选择性清除巨噬细胞。本研究旨在探讨肾巨噬细胞浸润在SAP大鼠急性肾损伤中的作用，并评估超顺磁性氧化铁（SPIO）增强磁共振成像（MRI）用于诊断的潜力。
采用化学共沉淀法制备超顺磁性Fe3O4纳米颗粒。采用薄膜法制备SPIO脂质体和SPIO氯膦酸盐脂质体。通过向大鼠胰腺被膜下注射牛磺胆酸钠制备SAP模型。将Sprague-Dawley大鼠随机分为对照组、SAP加SPIO脂质体（P）组和SAP加含SPIO氯膦酸盐脂质体（T）组。通过T2加权MRI扫描评估肾损伤。采用自动酶法测定血清淀粉酶（SAM）、血尿素氮（BUN）和血清肌酐（SCr）水平。采用酶联免疫吸附测定（ELISA）法测定血清肿瘤坏死因子-α（TNF-α）。用苏木精-伊红（H&E）染色观察胰腺和肾脏的病理变化，用末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）染色检测细胞凋亡。此外，用免疫组织化学法检测肾组织中的巨噬细胞标志物（CD68）。
T组大鼠胰腺和肾脏的病理变化较P组轻。P组和T组大鼠肾脏的MRI信号强度明显低于对照组。两个实验组有显著变化（P<0.01）。P组大鼠的SAM、Bun、SCr和TNF-α水平高于对照组（P<0.01）和T组（P<0.01）。T组肾脏在2 h和6 h时的凋亡率高于P组（P<0.01）。
含氯膦酸盐脂质体可保护SAP大鼠免受肾损伤，SPIO可作为MRI检查的示踪剂用于检测SAP大鼠的肾损伤。SPIO辅助MRI为监测SAP大鼠肾损伤后巨噬细胞的迁移提供了一种有效的非侵入性方法。
