法尼酯X受体激动剂GW4064减轻小鼠脓毒症诱导的炎症反应和急性肾损伤

目的 利用脓毒症体内外模型，探讨法尼酯X受体（farnesoid X receptor, FXR）对脓毒症诱导的炎症反应和急性肾损伤的干预作用。方法 在体内构建小鼠脓毒症模型，随机将小鼠分为四组：生理盐水（normal saline, NS）组、脂多糖（lipopolysaccharide, LPS）组、LPS+溶剂对照组和LPS+FXR激动剂（GW4064）组，每组5-8只。LPS组小鼠腹腔注射LPS（10mg/kg），NS组小鼠腹腔注射等量生理盐水，后两组分别在LPS注射前5天始连续腹腔注射GW4064或溶剂对照。LPS注射后24小时留取血和肾脏标本，检测肾功能和炎症因子表达。在体外利用脂多糖处理原代肾小管上皮细胞，分为四组：NS组、LPS组、LPS+DMSO组和LPS+GW4064组，RT-PCR测定上皮细胞促炎因子表达。结果 与NS对照组相比，脂多糖组小鼠肾脏促炎细胞因子白细胞介素6（interleukin6，IL-6）、趋化因子配体2（C-C motif chemokine ligand 2，CCL2）表达显著上调（P<0.01），血肌酐明显升高 (p<0.01)；与LPS组和溶剂对照组小鼠相比，GW4064干预组血肌酐明显下降，肾脏病理损伤减轻，促炎细胞因子IL-6、CCL2表达下调。同时，脂多糖抑制肾脏FXR蛋白和FXR mRNA表达（P<0.05）。在体外，LPS呈剂量依赖性抑制肾小管上皮细胞FXR表达（P<0.05）；与LPS组和DMSO溶剂对照组相比，GW4064干预组可明显抑制肾小管上皮细胞促炎因子IL-6和CCL2表达（P<0.05）。结论 脂多糖可抑制肾脏FXR表达，FXR激活可减少脂多糖诱导的肾小管上皮细胞促炎因子生成，减轻肾脏炎症反应和急性肾损伤。

FXR agonist GW4064 reduces sepsis-induced inflammation and acute kidney injury in mice

Objective To explore the effect of farnesoid X receptor (FXR) on lipopolysaccharide (LPS)-induced inflammation and acute kidney injury (AKI) via sepsis model in vivo and in vitro. Methods Mouse sepsis model was established through LPS administration, and the experimental animals were randomly divided into four groups:normal saline (NS) group, LPS group, LPS+DMSO group, and LPS+GW4064 group. Each group contained 5-8 mice. Mice in LPS group were intraperitoneally injected with LPS at a dose of 10 mg/kg, and mice in NS group were injected with the equal volume of saline. The latter two groups were injected consecutively with GW4064 or vehicle for 5 days before LPS injection. Blood and kidney tissue were collected 24 hours after LPS injection to detect renal function and inflammatory factor expression. Primary tubular epithelial cells (PTECs) were isolated and treated with LPS in vitro and divided into four groups:NS group, LPS group, LPS+DMSO group, LPS+GW4064 group. The expression of proinflammatory factors was determined by RT-PCR. Results Compared with NS group, the expression of renal pro-inflammatory cytokines interleukin6(IL-6) and C-C motif chemokine ligand 2 (CCL2) in LPS group was significantly up-regulated (P<0.01), and the serum creatine level was increased (P<0.01). Compared with LPS group and vehicle group, serum creatine level in GW4064 intervention group was decreased (P<0.05), renal pathological injury was alleviated and the expression of inflammatory factors (IL-6 and CCL2)was down-regulated (P<0.05). At the same time, LPS inhibited FXR expression in protein and mRNA levels in kidney. Also LPS inhibited the expression of FXR in PTECs in vitro (P<0.05). Compared with LPS group and DMSO group, GW4064 intervention group significantly inhibited pro-inflammatory cytokines expression in PTECs (P<0.05). Conclusions LPS inhibits renal FXR expression. Activation of FXR reduces LPS-induced pro-inflammatory cytokines production in PTECs, and alleviates LPS-induce inflammation and AKI.