Tsuji Ai, Ikeda Yuka, Murakami Mutsumi, Kitagishi Yasuko, Matsuda Satoru
Department of Food Science and Nutrition Faculty of Human Life and Environment Nara Woman's University Nara Japan.
Reprod Med Biol. 2021 Jun 16;20(4):477-484. doi: 10.1002/rmb2.12396. eCollection 2021 Oct.
Psychological stress could negatively influence female reproductive ability. d-Leucine (d-Leu) is a d-type amino acid found in foods and mammalian tissues. We have examined the protective effects of d-Leu on oocyte abnormality induced by psychological stress.
Female mice (6-week-old) were divided into three groups: control, restraint stress (RS), and RS/d-Leu. The RS and RS/d-Leu mice were holed for 3 hours daily during 14 days. RS/d-Leu mice were fed 0.3% d-Leu diet. The oocyte maturation failure was analyzed by shapes of spindles and chromosomes. In addition, levels of heme-oxygenase-1 (HO-1) and superoxide dismutase (SOD) expression in the ovaries were also examined. Whether d-Leu reduces the generation of reactive oxygen species (ROS) in cultured cells, K562 cells were treated with d-Leu, and then ROS in K562 were analyzed.
Oocyte maturation failure was increased in RS mice. d-Leu reduced abnormal oocytes to control level. The expression levels of HO-1 and SOD2 increased in RS/d-Leu mice compared to those of RS mice. ROS levels were decreased in K562 cells with d-Leu in a dose-dependent manner.
We concluded that d-Leu protects oocytes from psychological stress through the induction of HO-1 and SOD2 expression then by reducing oxidative stress.
心理压力可能对雌性生殖能力产生负面影响。d-亮氨酸（d-Leu）是一种存在于食物和哺乳动物组织中的d型氨基酸。我们研究了d-Leu对心理压力诱导的卵母细胞异常的保护作用。
将6周龄雌性小鼠分为三组：对照组、束缚应激组（RS）和RS/d-Leu组。RS组和RS/d-Leu组小鼠在14天内每天束缚3小时。RS/d-Leu组小鼠喂食含0.3% d-Leu的饮食。通过纺锤体和染色体形态分析卵母细胞成熟失败情况。此外，还检测了卵巢中血红素加氧酶-1（HO-1）和超氧化物歧化酶（SOD）的表达水平。为了确定d-Leu是否能减少培养细胞中活性氧（ROS）的产生，用d-Leu处理K562细胞，然后分析K562细胞中的ROS。
RS组小鼠卵母细胞成熟失败增加。d-Leu将异常卵母细胞数量降低至对照水平。与RS组小鼠相比，RS/d-Leu组小鼠中HO-1和SOD2的表达水平升高。d-Leu可使K562细胞中的ROS水平呈剂量依赖性降低。
我们得出结论，d-Leu通过诱导HO-1和SOD2表达，进而降低氧化应激，保护卵母细胞免受心理压力的影响。
