DIC肾损伤时肾小管上皮细胞AQP1和AQP2蛋白表达的调控机制研究

Disseminated intravascular coagulation （DIC）is often accompanied by sepsis caused acute renal injury, which has mortality rate of 70% with unknown mechanisms and uneffective clinical therapies. Other groups and we have found that in the disease process, AQP expression was significantly abnormal, but the specific regulatory mechanism is unknown. Studies have shown that fact that infection can activate NF-B pathway by TLR4/TLR9 signaling to induce inflammatory cells to produce high levels of nitric oxide (nitric oxide, NO) and ROS, resulting in inhibition of Aquaporin (AQP) expression in renal tubules. We hypothesize that inflammatory mechanisms may cause DIC associated acute polyuria kidney injury, mediated by inflammatory factors and DIC associated factor through activation of specific signaling pathways induced NO, ROS, TNFα, TWEAK, HMGB1 expression, etc., which may affect expression of AQP1 and AQP2 molecules in the renal tubular epithelium and cause renal tubular epithelial cell injury. We aim to study in animal and cell models the role of DIC related factors and inflammation-related factors on AQP1 and AQP2 expression in renal tubular epithelial cells, and illustrate the underluing mechanism. We also hope to identify possible key target molecules involved and discover of new markers for clinical evaluation of tubular function.

脓毒血症导致的DIC常伴有多尿性急性肾损伤,死亡率高达70%。因机制不明，临床缺乏有效的治疗措施。我们的前期研究发现，在该疾病过程中，AQP表达显著异常，但具体调控机制未知。已知感染可以通过TLR4/TLR9活化NF-B通路，诱导炎症细胞产生高量的NO和ROS，抑制肾小管上皮细胞膜上AQP的表达，我们推测炎性所致DIC相关的急性多尿性肾损伤的可能机制是炎性因子和DIC相关因子通过特定信号通路的活化，诱导NO、ROS、TNFα、TWEAK、HMGB1等表达，影响肾小管上皮细胞的AQP1和AQP2分子的表达并导致肾小管上皮细胞损伤。为验证这一设想，本课题将利用动物和细胞模型研究DIC相关因子和炎症相关因素对肾小管上皮细胞AQP1和AQP2表达的影响，揭示炎症所致DIC相关急性多尿性肾损伤的分子病理机制，并期望发现可能的关键靶分子以及发现可用于临床的评估肾小管功能的新指标。

脓毒血症导致的DIC常伴有多尿性急性肾损伤,死亡率高达70%。因机制不明，临床缺乏有效的治疗措施。我们的前期研究发现，在该疾病过程中，AQP表达显著异常，但具体调控机制未知。本课题利用动物和细胞模型研究DIC相关因子和炎症相关因素对肾小管上皮细胞AQP1和AQP2表达的影响，揭示炎症所致DIC相关急性多尿性肾损伤的分子病理机制，并期望发现可能的关键靶分子以及发现可用于临床的评估肾小管功能的新指标。动物实验结果表明AQP-1与IL-1、APC、NGAL均呈正相关；AQP-1在4、6h组的变化趋势明显高于NGAL，由此在LPS诱导大鼠DIC相关的急性非少尿型肾损伤模型中，AQP-1为DIC相关的急性非少尿型肾损伤诊断提供了新的检测指标。实验组各亚组大鼠的血清测定各组血清中AQP-2和对照组相比有明显减低的趋势，AQP-2与TNF-α、AVP、IL-1β呈负相关，提示AQP2可能参与大鼠DIC早期的肾损伤，为非少尿型急性肾损伤早期辅助性诊断提供新的指标。在细胞模型中，AQP-1是8个表达于LPS诱导的HK-2细胞上的AQP当中水平最低的；经LPS处理的细胞存活率降低，细胞易凋亡，同时LPS上调HK-2细胞的促炎因子和趋化因子的表达；AQP-1过表达明显逆转LPS的效果，下调TNF-α、IL-8、IL-1β和单核细胞趋化蛋白-1；LPS激活p38、ERK1/2和JNK通路，但是p38和ERK1/2通路在AQP-1过表达细胞中被阻断；AQP-1过表达可以给予LPS导致的受损HK-2细胞的生存优势，这可能是通过调节p38和ERK1/2通路来控制细胞活力、凋亡和炎症达到的，以上结果提示AQP-1可能是治疗脓毒症引起的急性肾脏损伤的一个有效措施。