目的 探索通过药物调控过氧化物酶体增殖物激活受体γ/视黄醛X受体α（PPAR-γ/RXR-α）对改善丰宫并殖吸虫感染所致大鼠肺损伤的作用。方法 从云南省疫源地采集溪蟹，分离丰宫并殖吸虫后尾蚴，于SD大鼠腹壁皮下注射后尾蚴（8条/鼠），感染大鼠分为高脂饮食组、罗格列酮组、蓓萨罗丁组，每组10只，分别予以高脂饮食（高脂饲料）、罗格列酮[3 mg/（kg•d）]、蓓萨罗丁[10 mg/（kg•d）]灌胃，连续给药7 d，以感染大鼠和健康大鼠分别为感染对照组和健康对照组。首次给药后28 d处死大鼠，取肺组织和心尖血液，制备肺组织切片，HE染色观察肺组织的损伤情况，并进行肺泡炎半定量评分；ELISA检测血清白细胞介素-1β（IL-1β）和肿瘤坏死因子α（TNF-α）水平；提取肺组织总蛋白，蛋白质免疫印迹（Western blotting）检测肺PPAR-γ/RXR-α信号通路[PPAR-γ、RXR-α、脂肪酸转运蛋白3（FATP3）、载脂蛋白A1（ApoA1）]、核因子κB（NF-κB）信号通路[p65、激活子蛋白1（AP1）]和janus激酶（JAK）/信号传导及转录激活（STAT）信号通路（JAK2、STAT3）关键靶分子蛋白的相对表达量。多组间比较采用单因素ANOVA分析。结果 除蓓萨罗丁组2只大鼠感染失败外，其余大鼠均被感染成功，肺脏可见寄生虫囊包或在胸腔中可查见寄生虫。HE染色显示，感染对照组大鼠肺泡间隔中可见大量炎性细胞浸润，肺泡壁增厚，出现肺泡腔塌陷或闭合；高脂饮食组可见明显炎症损伤，与感染对照组相比较轻，肺泡腔充气略改善；罗格列酮组和蓓萨罗丁组肺泡间隔的炎性细胞较感染对照组明显减少，肺泡壁增厚程度明显减轻，肺泡腔充气明显改善。健康对照组、感染对照组、高脂饮食组、罗格列酮组、蓓萨罗丁组大鼠的肺泡炎半定量评分分别为（0.300 ± 0.053）、（2.200 ± 0.189）、（1.900 ± 0.320）、（1.300 ± 0.301）和（1.500 ± 0.112）分（F = 12.033，P < 0.05）。ELISA检测结果显示，健康对照组、感染对照组、高脂饮食组、罗格列酮组、蓓萨罗丁组大鼠血清IL-1β水平分别为（103.23 ± 3.37）、（111.59 ± 20.49）、（110.13 ± 12.95）、（89.91 ± 14.84）和（96.34 ± 19.03）pg/ml，TNF-α水平分别为（144.81 ± 1.35）、（180.21 ± 23.38）、（171.76 ± 27.83）、（155.37 ± 13.67）和（143.24 ± 23.66）pg/ml，5组之间差异均有统计学意义（F = 17.236、13.558，均P < 0.05）；其中，感染对照组IL-1β和TNF-α水平均高于健康对照组，罗格列酮组和蓓萨罗丁组低于感染对照组（均P < 0.05）。Western blotting检测结果显示，健康对照组、感染对照组、高脂饮食组、罗格列酮组、蓓萨罗丁组大鼠肺组织中，PPAR-γ的相对表达水平分别为0.51 ± 0.09、0.67 ± 0.06、0.75 ± 0.08、0.34 ± 0.02和0.56 ± 0.04，RXR-α分别为0.89 ± 0.05、0.15 ± 0.03、0.81 ± 0.09、0.22 ± 0.02和0.61 ± 0.10，FATP3分别为0.59 ± 0.06、0.64 ± 0.060、0.68 ± 0.09、0.59 ± 0.09和0.55 ± 0.03，ApoA1分别为0.58 ± 0.04、0.83 ± 0.11、0.92 ± 0.19、0.71 ± 0.04和0.63 ± 0.08，5组之间差异均有统计学意义（F = 25.70、67.12、8.94、11.58，均P < 0.05）；p65的相对表达水平分别为0.25 ± 0.19、1.01 ± 0.21、0.27 ± 0.15、0.32 ± 0.01和0.22 ± 0.11，AP1分别为0.11 ± 0.09、1.12 ± 0.36、0.08 ± 0.02、0.03 ± 0.00和0.02 ± 0.01，JAK2分别为0.76 ± 0.18、1.11 ± 0.24、0.34 ± 0.06、0.42 ± 0.01和0.35 ± 0.04，STAT3分别为0.80 ± 0.33、1.11 ± 0.27、0.68 ± 0.22、0.77 ± 0.06和0.68 ± 0.19，5组之间差异均有统计学意义（F = 43.77、85.19、37.22、17.63，均P < 0.05）。其中，感染对照组PPAR-γ、FATP3、ApoA1、p65、AP1、JAK2和STAT3的相对表达水平高于健康对照组，罗格列酮组和蓓萨罗丁组低于感染对照组；感染对照组RXR-α的相对表达水平低于健康对照组，高脂饮食组、罗格列酮组和蓓萨罗丁高于感染对照组（均P < 0.05）。结论 建立了丰宫并殖吸虫感染大鼠肺损伤模型，药物调控PPAR-γ/RXR-α信号通路可通过抑制NF-κB和JAK/STAT信号通路发挥抗炎作用，减轻肺损伤的严重程度。

Objective To explore the effect of drug-regulation on peroxisome proliferator-activated receptor-γ/retinoid X receptor-α (PPAR-γ/RXR-α) signalling pathway to improve lung injury caused by Paragonimus proliferus infection in rats. Methods The P. proliferus were isolated from crabs collected in Yunnan Province, and SD rats were infected with 8 metacercariae per rat via subcutaneous injection at abdominal wall. The infected rats were divided into the high-fat-diet group, rosiglitazone group and bexarotene group, with 10 rats in each group, and were given with high-fat-feeding (high-fat diet), rosiglitazone [3 mg/(kg·d)], bexarotene [10 mg/(kg·d)] by gavage for 7 days. The infected and healthy rats were used as the infection control group and healthy control group. On 28 d post-mediated, the rats were sacrificed to collect lung tissue and heart apical blood. The lung tissue sections were prepared and stained with hematoxylin-eosin to assess the tissue damage and score the alveolitis semi-quantitatively. Serum interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) levels were detected by ELISA. The lung tissue total protein was extracted for examining relative expression levels of PPAR-γ/RXR-α signalling pathway-related key target proteins indluding PPAR-γ, RXR-α, fatty acid transporter 3 (FATP3), apolipoprotein A1 (ApoA1), nuclear factor kappa-B (NF-κB) signalling pathway proteins [p65, activator protein (AP1）], janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling pathway proteins （JAK2, STAT3） by Western blotting. The inter-group data were compared using single-factor ANOVA analysis. Results All rats were successfully infected except 2 rats in the bexarotin group. Parasitic cysts were found in the lungs or the chest cavity. HE staining showed that in the infection control group, a large number of inflammatory cells infiltrated the alveolar septum, the alveolar wall thickened, and the alveolar cavity collapsed or closed. In the high-fat diet group, obvious inflammation injury was shown. Compared with the infection control group, the alveolar cavity inflation was slightly improved. The inflammatory cells of alveolar septum in the rosiglitazone group and bexarotene group were significantly reduced. Compared to the infection control group, the degree of alveolar wall thickening was significantly reduced, and the alveolar cavity inflation was significantly improved. The semi-quantitative alveolitis scores were 0.300 ± 0.053, 2.200 ± 0.189, 1.900 ± 0.320, 1.300 ± 0.301 and 1.500 ± 0.112 (F = 12.033, P < 0.05) in the healthy control group, the infection control group, the high-fat diet group, the rosiglitazone group and the bexarotene group, respectively. ELISA tests show that serum IL-1β levels in the healthy control group, infected control group, high-fat diet group, rosiglitazone group and bexarotene group were (103.23 ± 3.37), (111.59 ± 20.49), (110.13 ± 12.95), (89.91 ± 14.84) and (96.34 ± 19.03) pg/ml, respectively. TNF-α levels were (144.81 ± 1.35), (180.21 ± 23.38), (171.76 ± 27.83), (155.37 ± 13.67) and (143.24 ± 23.66) pg/ml, respectively. There was a significant difference among the five groups (F = 17.236, 13.558; P < 0.05). Western blotting showed that in the lung tissue of rats in the healthy control group, the infection control group, high-fatdiet group, rosiglitazone group, and bexarotene group, PPAR-γ relative expression level were 0.51 ± 0.09, 0.67 ± 0.06, 0.75 ± 0.08, 0.34 ± 0.02 and 0.56 ± 0.04, respectively; RXR-α were 0.89 ± 0.05, 0.15 ± 0.03, 0.81 ± 0.09, 0.22 ± 0.02 and 0.61 ± 0.10, respectively; FATP3 were 0.59 ± 0.06, 0.64 ± 0.06, 0.68 ± 0.09, 0.59 ± 0.09 and 0.55 ± 0.03, respectively; ApoA1 were 0.58 ± 0.04, 0.83 ± 0.11, 0.92 ± 0.19, 0.71 ± 0.04 and 0.63 ± 0.08, respectively, and the differences among the five groups were statistically significant (F = 25.70, 67.12, 8.94, 11.58; All P < 0.05). P65 the relative expression level were 0.25 ± 0.19, 1.01 ± 0.21, 0.27 ± 0.15, 0.32 ± 0.01 and 0.22 ± 0.11, respectively; AP1 were 0.11 ±0.09, 1.12 ± 0.36, 0.08 ± 0.02, 0.03 ± 0.01 and 0.02 ± 0.01, respectively; JAK2 were 0.76 ± 0.18, 1.11 ± 0.24, 0.34 ± 0.06, 0.42 ± 0.01 and 0.35 ± 0.04, respectively; STAT3 were 0.80 ± 0.33, 1.11 ± 0.27, 0.68 ± 0.22, 0.77 ± 0.06 and 0.68 ± 0.19, respectively, the difference between the 5 groups were statistically significant (F = 43.77, 85.19, 37.22, 17.63; All P < 0.05). Among them, the relative expression levels of PPAR-γ, FATP3, ApoA1, p65, AP1, JAK2 and STAT3 in the infection control group were higher than those in the healthy control group, while those in rosiglitazone group and bexarotene group were lower than those in the infection control group (all P < 0.05). Conclusion A lung injury model of rat infected with P. proliferus was established. The rat model demonstrated that PPAR-γ/RXR-α signalling pathway plays an important role in the mechanism of lung injury caused by P. proliferus infection, and regulation of this signalling pathway by drugs may exert anti-inflammatory effects by inhibiting the NF-κB and JAK/STAT signalling pathways, thereby, reducing the extent of lung injury severity.