Rubattu Speranza, Stanzione Rosita, Bianchi Franca, Cotugno Maria, Forte Maurizio, Della Ragione Floriana, Fioriniello Salvatore, D'Esposito Maurizio, Marchitti Simona, Madonna Michele, Baima Simona, Morelli Giorgio, Sciarretta Sebastiano, Sironi Luigi, Gelosa Paolo, Volpe Massimo
Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Ospedale S. Andrea, Rome, Italy.
Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Neuromed, Località Camerelle, Pozzilli, Italy.
Cell Death Dis. 2017 Jun 22;8(6):e2891. doi: 10.1038/cddis.2017.278.
UCP2 maps nearby the lod score peak of STR1-stroke QTL in the SHRSP rat strain. We explored the potential contribution of UCP2 to the high-salt diet (JD)-dependent increased stroke susceptibility of SHRSP. Male SHRSP, SHRSR, two reciprocal SHRSR/SHRSP-STR1/QTL stroke congenic lines received JD for 4 weeks to detect brain UCP2 gene/protein modulation as compared with regular diet (RD). Brains were also analyzed for NF-κB protein expression, oxidative stress level and UCP2-targeted microRNAs expression level. Next, based on knowledge that fenofibrate and Brassica Oleracea (BO) stimulate UCP2 expression through PPARα activation, we monitored stroke occurrence in SHRSP receiving JD plus fenofibrate versus vehicle, JD plus BO juice versus BO juice plus PPARα inhibitor. Brain UCP2 expression was markedly reduced by JD in SHRSP and in the (SHRsr.SHRsp-(D1Rat134-Mt1pa)) congenic line, whereas NF-κB expression and oxidative stress level increased. The opposite phenomenon was observed in the SHRSR and in the (SHRsp.SHRsr-(D1Rat134-Mt1pa)) reciprocal congenic line. Interestingly, the UCP2-targeted rno-microRNA-503 was significantly upregulated in SHRSP and decreased in SHRSR upon JD, with consistent changes in the two reciprocal congenic lines. Both fenofibrate and BO significantly decreased brain microRNA-503 level, upregulated UCP2 expression and protected SHRSP from stroke occurrence. In vitro overexpression of microRNA-503 in endothelial cells suppressed UCP2 expression and led to a significant increase of cell mortality with decreased cell viability. Brain UCP2 downregulation is a determinant of increased stroke predisposition in high-salt-fed SHRSP. In this context, UCP2 can be modulated by both pharmacological and nutraceutical agents. The microRNA-503 significantly contributes to mediate brain UCP2 downregulation in JD-fed SHRSP.
解偶联蛋白2（UCP2）定位于自发性高血压大鼠脑卒中易感品系（SHRSP）中STR1-脑卒中数量性状基因座（QTL）的连锁峰值附近。我们探讨了UCP2对高盐饮食（JD）依赖的SHRSP脑卒中易感性增加的潜在作用。雄性SHRSP、SHRSR以及两个相互的SHRSR/SHRSP-STR1/QTL脑卒中同基因系接受4周的JD饮食，以检测与常规饮食（RD）相比脑UCP2基因/蛋白的调节情况。还对脑进行了核因子κB（NF-κB）蛋白表达、氧化应激水平和UCP2靶向的微小RNA表达水平的分析。接下来，基于非诺贝特和羽衣甘蓝（BO）通过激活过氧化物酶体增殖物激活受体α（PPARα）刺激UCP2表达的知识，我们监测了接受JD加非诺贝特与接受赋形剂、JD加BO汁与BO汁加PPARα抑制剂的SHRSP的脑卒中发生情况。JD使SHRSP以及（SHRsr.SHRsp-（D1Rat134-Mt1pa））同基因系中的脑UCP2表达显著降低，而NF-κB表达和氧化应激水平升高。在SHRSR以及（SHRsp.SHRsr-（D1Rat134-Mt1pa））反向同基因系中观察到相反的现象。有趣的是，UCP2靶向的大鼠微小RNA-503在SHRSP中经JD处理后显著上调，在SHRSR中则下调，在两个相互的同基因系中变化一致。非诺贝特和BO均显著降低脑微小RNA-503水平，上调UCP2表达，并保护SHRSP免于发生脑卒中。体外在内皮细胞中过表达微小RNA-503可抑制UCP2表达，并导致细胞死亡率显著增加，细胞活力下降。脑UCP2下调是高盐喂养的SHRSP中脑卒中易感性增加的一个决定因素。在这种情况下，UCP2可被药物和营养制剂调节。微小RNA-503在JD喂养的SHRSP中对介导脑UCP2下调有显著作用。
