梁怡然　衡艳艳　俞小芳　贾平　方艺

(1. 复旦大学附属中山医院肾内科，上海　200032;

2. 长治医学院附属和平医院肾内科，山西长治　046000;

3. 上海市肾脏疾病与血液净化重点实验室，上海　200032;

4. 上海市肾病与透析研究所，上海　200032)



低氧诱导因子短期活化后诱导miR-29c表达上调可延缓5/6肾切除大鼠的肾病进展

梁怡然1Δ衡艳艳2Δ俞小芳1,3,4贾平1,3,4方艺1,3,4

(1. 复旦大学附属中山医院肾内科，上海200032;

2. 长治医学院附属和平医院肾内科，山西长治046000;

3. 上海市肾脏疾病与血液净化重点实验室，上海200032;

4. 上海市肾病与透析研究所，上海200032)

摘要目的： 探讨适度活化低氧诱导因子(hypoxia-inducible factor, HIF)对延缓残肾慢性肾脏病进展的作用及可能机制。方法： 雄性SD大鼠采用二步法5/6肾大部切除术建立残肾模型，随机分为L-mimosine (L-Mim)治疗组(术后5~12周短期给予脯氨酸羟化酶抑制剂，隔日50 mg/kg腹腔给药)和未治疗残肾组，同时设立假手术对照组。术后12周末处死大鼠留取标本。结果： L-Mim治疗组大鼠血肌酐水平[(82.4±6.3)比(130.1±24.1) μmol/L, P<0.05]、24 h尿蛋白水平[(0.7±0.1)比(1.7±0.5) g/d, P<0.05]以及残肾病理改变较未治疗残肾组大鼠有显著改善。miRNA芯片分析结果提示：L-Mim治疗组肾皮质miR-29c丰度高于未治疗残肾组，伴HIF-1α和HIF-2α表达增强。经荧光素酶报告检测系统和体外突变实验明确原肌球蛋白1(TPM1)为miR-29c靶基因之一。HK2细胞转染pre-miR-29c寡核苷酸后可以抑制TGF-β1 (3 ng/mL, 24 h)诱导的原肌球蛋白水平上调(P<0.05或0.01)。结论： 大鼠残肾肾间质纤维化病变明显并伴miR-29c水平下调，适度活化HIF水平可通过上调miR-29c表达延缓残肾功能恶化。

关键词miR-29c；肾小管间质纤维化；低氧诱导因子；原肌球蛋白1

Short-Term Activation of Hypoxia-Inducible Factor Slows Kidney Disease Progression in Rat Model of 5/6 Subtotal Nephrectomy by Up-regulating MiR-29c Expression

LIANGYiran1ΔHENGYanyan2ΔYUXiaofang1,3,4JIAPing1,3,4FANGYi1,3,4

1.DepartmentofNephrology,ZhongshanHospital,FudanUniversity,Shanghai200032,China; 2.DepartmentofNephrology,HepingHospitalAffiliatedtoChangzhiMedicalCollege,Changzhi046000,China; 3.ShanghaiKeyLaboratoryofKidneyandBloodPurification,Shanghai200032,China; 4.ShanghaiInstituteofKidneyandDialysis,Shanghai200032,China

AbstractObjective： To investigate the role and probable mechanism of moderate activation of hypoxia-inducible factor(HIF) in slowing chronic kidney disease progression of remnant kidney.Methods： Rat models of remnant kidney were established by 5/6 subtotal nephrectomy in male Sprague-Dawley rats. And then they were randomly allocated to L-mimosine(L-Mim) treatment group, in which the rats were treated with intraperitoneal injections of L-Mim during 5-12 week after operation, and untreated remnant kidney group. Meanwhile, sham operated rats were set as control group. All rats were sacrificed at the end of week 12, and the specimens were collected. Results： The serum creatinine level in L-Mim treatment group was lower than that in untreated remnant kidney group(82.4±6.3 vs. 130.1±24.1 μmol/L,P<0.05), as well as the 24 h Ualblevel (0.7±0.1 vs. 1.7±0.5 g/d,P<0.05). And the pathological changes in in L-Mim treatment group was slightly improved while compared to untreated remnant kidney group. The result of miRNA microarray analysis showed that miR-29c in renal cortex was up-regulated in L-Mim group compared with untreated remnant group and meanwhile the expressions of HIF-1α and HIF-2α increased. Tropomyosin 1 (TPM1) met the sequence criteria for microRNA-target interaction, which was later confirmed by luciferase reporter system and mutation test in vitro. HK2 cell transfected with pre-miT-29c oligonucleotide could inhibit the tropomyosin up-regulation induced by TGF-β1treatment (3 ng/mL, 24 h),P<0.05 or 0.01.Conclusions： Renal interstitial fibrosis in rat remnant kidney was significant, and it was accompanied by the miR-29c down-regulation. Moderate activation of HIF level may attenuate the deterioration of renal function by up-regulating miR-29c expression.

Key WordsMiR-29c;Renal tubulointerstitial fibrosis;Hypoxia-inducible factor;Tropomyosin-1

肾小管间质纤维化是所有慢性肾脏疾病的共同病理特征，也是各种慢性肾脏疾病进展至终末期肾衰竭的共同途径[1]。肾小管间质的缺血损伤是导致肾小管间质病变进行性发展的重要机制[2-3]，而缺氧又是缺血损伤中的始动环节。因此，作为维持氧自稳平衡的核心调控因子的低氧诱导因子(hypoxia-inducible factor, HIF)在肾脏缺血缺氧损伤中起着重要的调节作用。但HIF本身不能直接感应氧浓度的变化，常氧条件下HIF-α极不稳定，经……