5/6肾切除大鼠肾组织时钟基因的表达

Rhythmic Clock Gene Expression in the Kidney in 5/6 Nephrectomy Rats

目的研究5/6肾切除大鼠肾时钟基因per2、bmal1及时钟输出基因dbp的表达节律。方法 SPF级雄性Wistar大鼠,随机分为模型组和假手术组。造模次日置于12h∶12h明暗交替的环境饲养。第12周分别在7AM(ZT0),11AM(ZT4),3PM(ZT8),7PM(ZT12),11PM(ZT16),3AM(ZT20)各时间点两组各处死5只大鼠。Real-timePCR法检测肾bmal1、per2、dbp mRNA表达。结果假手术对照组与模型组per2在ZT8时为谷值点(T),在ZT16～ZT20达到峰值(P),模型组per2的峰值提前4h,两组P/T分别为2.49、2.47;模型组与假手术组肾bmal1mRNA表达的近日节律相似:于ZT4时为峰值点、ZT20为谷值点,但假手术组则自峰值点迅速下降,于ZT12～ZT20在谷值波动。模型组与假手术组dbp mRNA表达趋势相反:假手术组在ZT4及ZT20为谷值点,其余各时间点表达水平均较高,模型组dbp mRNA表达峰值点在ZT16,其余各时间点均在较低水平波动。结论肾组织中时钟基因per2、bmal1及时钟输出基因dbp mRNA的表达呈近日节律,慢性肾衰时该节律发生变化。

Objective To explore diurnal variation of clock gene expression in the kidney in 5/6 subtotal nephrectomy（STNx）rats.Methods Wistar rats were randomly divided into STNx group（group A）and sham STNx group（group B）.Rats were housed in a temperature-controlled room（22±2）℃ and synchronized 12 weeks to the light（L）dark（D）cycle 12∶12 with light on from 7：00 AM（Zeitgeber time ZT 0）.The expression of bmal1,per2 and dbp mRNA in the kidney was examined at 7AM（ZT0）,11AM（ZT4）,3PM（ZT8）,7PM（ZT12）,11PM（ZT16）and 3AM（ZT20）by using real-time PCR.Results The expression of per2 mRNA in group A and group B was in trough（T）at ZT8,that in group A reached the peak（P）at ZT16 and that in group B at ZT20 respectively,and P/T was 2.49 and 2.47 respectively.There was no significant difference in the circadian expression of bmal1 between group A and group B,and bmal1 expression reached the peak at ZT4 and was in trough at ZT20,but it was decreased rapidly and fluctuated in trough from ZT12 to ZT20 in group B.The tendency of dbp mRNA expression in the kidney seemed oppositely in group A and group B：the dbp mRNA expression in group B was in trough at ZT4 and ZT20,and that in group A reached the peak at ZT16 and was in trough in other ZT time points.Conclusion Circadian expression of per2,dbp and bmal1 in the kidney was different in STNx rats.