Department of Pharmacology, School of Basic Medical Science of Wuhan University, Wuhan, 430071, China.
Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
Toxicology. 2018 May 1;400-401:9-19. doi: 10.1016/j.tox.2018.03.004. Epub 2018 Mar 13.
This study aimed to prove that prenatal ethanol exposure (PEE) can induce nephrotic syndrome in male rat offspring and to explore the underlying intrauterine programming mechanisms. Pregnant Wistar rats were intragastrically administered ethanol (4 g/kg d) from gestational day (GD) 9 to GD 20, and the male fetuses were delivered by cesarean section at GD20 and the male adult offspring were euthanized at postnatal week (PW) 24. In vitro, the primary metanephric mesenchyme cells were treated with ethanol at concentrations of 15-60 mM. The results indicated that the kidneys of adult offspring in the PEE group exhibited glomerulosclerosis as well as interstitial fibrosis. The levels of serum creatinine and urine protein were elevated; the serum total cholesterol level was increased and the serum albumin concentration was reduced. In the fetal kidney, developmental retardation was presented in the PEE group via pathological examinations, accompanied by the expressional inhibition of the glial-cell-line-derived neurotrophic factor/c-ret tyrosine kinase receptor (GDNF/c-ret) signaling pathway. Although serum angiotensin II (Ang II) level and the gene expression of renal angiotensin-converting enzyme (ACE) were increased in the PEE group, the expression of renal angiotensin II type 2 receptor (ATR) was significantly inhibited, accompanied by a reduction in the H3K27ac level on the ATR gene promoter. In the non-classical renin-angiotensin system (RAS), the expression of renal angiotensin converting enzyme 2 (ACE2) and Mas receptor (MasR) were inhibited in the PEE group. The above changes of the classical and non-classical RAS all sustained from utero to adulthood. In vitro, ethanol elevated the gene expression of ACE and angiotensin II type 1a receptor (ATR) whereas it reduced the expression of ATR, ACE2, and MasR, accompanied by a reduction in the H3K27ac level on ATR gene promoter. Taken together, these results suggested that PEE can induce fetal kidney developmental retardation and adult nephrotic syndrome, and direct regulation of ethanol to the renal RAS was involved in the mechanism of nephrotic syndrome induced by PEE.
本研究旨在证明产前乙醇暴露（PEE）可诱导雄性大鼠子代发生肾病综合征，并探讨其宫内编程机制。妊娠 Wistar 大鼠从妊娠第 9 天（GD）至第 20 天（GD）经胃内给予乙醇（4g/kg/d），于 GD20 行剖宫产分娩雄性胎儿，雄性幼鼠于生后第 24 周（PW）处死。体外，将原代肾间充质细胞用浓度为 15-60mM 的乙醇处理。结果显示，PEE 组成年子代的肾脏出现肾小球硬化和间质纤维化，血清肌酐和尿蛋白水平升高，血清总胆固醇水平升高，血清白蛋白浓度降低。在胎儿肾脏中，PEE 组通过病理检查发现发育迟缓，同时胶质细胞源性神经营养因子/c-RET 酪氨酸激酶受体（GDNF/c-ret）信号通路的表达受到抑制。尽管 PEE 组血清血管紧张素 II（Ang II）水平和肾血管紧张素转换酶（ACE）基因表达增加，但肾血管紧张素 II 型 2 受体（ATR）的表达显著受到抑制，同时 ATR 基因启动子上的 H3K27ac 水平降低。在非经典肾素-血管紧张素系统（RAS）中，PEE 组肾血管紧张素转换酶 2（ACE2）和 Mas 受体（MasR）的表达受到抑制。经典和非经典 RAS 的上述变化均从宫内持续到成年期。体外实验中，乙醇可增加 ACE 和血管紧张素 II 型 1a 受体（ATR）的基因表达，而降低 ATR、ACE2 和 MasR 的表达，同时 ATR 基因启动子上的 H3K27ac 水平降低。综上所述，这些结果表明 PEE 可导致胎儿肾脏发育迟缓及成年期肾病综合征，乙醇对肾脏 RAS 的直接调节可能参与了 PEE 诱导的肾病综合征的发生机制。
