Acute 7,12-dimethylbenz[a]anthracene exposure causes differential concentration-dependent follicle depletion and gene expression in neonatal rat ovaries.
Acute 7,12-dimethylbenz[a]anthracene exposure causes differential concentration-dependent follicle depletion and gene expression in neonatal rat ovaries.
复制标题
DOI：
10.1016/j.taap.2014.02.011
复制
发表时间：
2014-05-01
影响因子：
3.8
通讯作者：
Keating, Aileen F
中科院分区：
文献类型：
--
作者：
Madden, Jill A;Hoyer, Patricia B;Devine, Patrick J;Keating, Aileen F
长期暴露在包括香烟烟雾在内的有机物燃烧过程中产生的多环芳烃7，12-二甲基苯并[a]蒽(DMBA)中，会耗尽小鼠和大鼠所有类型的卵泡，体外模型也模拟了这种影响。为了探讨在急性DMBA暴露期间卵泡耗尽的机制，观察了两种浓度的DMBA，在卵泡耗竭时有(75 NM)和没有(12.5 nM)两种浓度的DMBA。出生后第4天，F344大鼠的卵巢在培养4天后，单独暴露于溶剂对照组(1%DMSO；CT)或DMBA(12 nM；低浓度或75 nM；高浓度)。在额外培养4或8天后，通过卵泡计数评估DMBA诱导的卵泡耗竭。与对照组相比，DMBA暴露4天后对卵泡数无明显影响，8天后两种浓度的DMBA均导致初级卵泡大量丢失，而低浓度的DMBA也导致次级卵泡耗竭。两种浓度均不影响原始卵泡数或较小的初级卵泡数。分别于暴露后1、2、4天提取RNA，定量RT-PCR检测异种代谢相关基因(CYP2E1、GstMU、Gstpi、Ephx1)、自噬相关基因(ATG7、Becn1)、氧化应激反应相关基因(SOD1、Sod2)和磷脂酰肌醇3-激酶(PI3K)途径相关基因(KITLG、CKit、Akt1)的表达水平。除ATG7和cKit外，DMBA增加了所研究的所有基因的表达(P<；0.05)。DMBA暴露后，BECN1和pAKTThr308蛋白水平升高，而cKit蛋白水平下降。综上所述，这些结果表明DMBA的生物激活增加，增加了对DMBA诱导的卵毒性的机制的了解，并引起了对女性低浓度DMBA暴露的关注。
Chronic exposure to the polycyclic aromatic hydrocarbon 7,12-dimethylbenz[a]anthracene (DMBA), generated during combustion of organic matter including cigarette smoke, depletes all ovarian follicle types in the mouse and rat, and in vitro models mimic this effect. To investigate the mechanisms involved in follicular depletion during acute DMBA exposure, two concentrations of DMBA at which follicle depletion has (75 nM) and has not (12.5 nM) been observed were investigated. Postnatal day four F344 rat ovaries were maintained in culture for four days before a single exposure to vehicle control (1% DMSO; CT) or DMBA (12 nM; low-concentration or 75 nM; high-concentration). After four or eight additional days of culture, DMBA-induced follicle depletion was evaluated via follicle enumeration. Relative to control, DMBA did not affect follicle numbers after 4 days of exposure, but induced large primary follicle loss at both concentrations after 8 days; while, the low-concentration DMBA also caused secondary follicle depletion. Neither concentration affected primordial or small primary follicle number. RNA was isolated and quantitative RT-PCR performed prior to follicle loss to measure mRNA levels of genes involved in xenobiotic metabolism (Cyp2e1, Gstmu, Gstpi, Ephx1), autophagy (Atg7, Becn1), oxidative stress response (Sod1, Sod2) and the phosphatidylinositol 3-kinase (PI3K) pathway (Kitlg, cKit, Akt1) 1, 2 and 4 days after exposure. With the exception of Atg7 and cKit, DMBA increased (P < 0.05) expression of all genes investigated. Also, BECN1 and pAKTThr308 protein levels were increased while cKIT was decreased by DMBA exposure. Taken together, these results suggest an increase in DMBA bioactivation, add to the mechanistic understanding of DMBA-induced ovotoxicity and raise concern regarding female low concentration DMBA exposures.