Er Hakan, Acar Nuray, Kipmen-Korgun Dijle, Celik-Ozenci Ciler, Ustunel Ismail, Asar Mevlut, Korgun Emin Turkay
Department of Histology and Embryology, Medical Faculty, Akdeniz University, 07070 Antalya, Turkey; Department of Biophysics, Medical Faculty, Akdeniz University, 07070 Antalya, Turkey.
Department of Histology and Embryology, Medical Faculty, Akdeniz University, 07070 Antalya, Turkey.
Acta Histochem. 2015 Mar;117(2):137-47. doi: 10.1016/j.acthis.2014.11.010. Epub 2015 Jan 13.
Intrauterine growth restriction (IUGR) is a major clinical problem, which causes perinatal morbidity and mortality. One of the reasons for IUGR is abnormal placentation. In rats, fetal-placental exposure to maternally administered glucocorticoids decreases birth weight and placental weight. Proper placental development depends on the proliferation and differentiation of trophoblasts. Our knowledge about the mitotic regulators that play key roles in synchronizing these events is limited. Also the mechanisms underlying the placental growth inhibitory effects of glucocorticoids have not been elucidated. The aim of this study was to investigate the immunolocalization, mRNA and protein levels of proliferating cell nuclear antigen (PCNA), cyclin D3, p27 and p57 in normal and dexamethasone-induced IUGR Wistar rat placentas by reverse transcriptase polymerase chain reaction (RT-PCR), immunohistochemistry and Western blot. We also compared apoptotic cell numbers at the light microscopic level via terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) and transmission electron microscopy. Glucocorticoid levels were higher in IUGR rats than in control rats after 60 and 120min of injection. We showed reduced gene and protein expressions of PCNA and cyclin D3 and increased expressions of p27 and p57 in IUGR placentas compared to control placentas. Apoptotic cell number was higher in the placentas of the IUGR group. In brief we found that maternal dexamethasone treatment led to a shift from cell proliferation to apoptosis in IUGR placentas. Dexamethasone induced placental and embryonal abnormalities which could be associated with reduced expressions of PCNA and cyclin D3, increased expressions of p27 and p57 and increased rate of apoptosis in IUGR placentas.
宫内生长受限（IUGR）是一个主要的临床问题，可导致围产期发病和死亡。IUGR的原因之一是胎盘形成异常。在大鼠中，胎儿 - 胎盘暴露于母体给予的糖皮质激素会降低出生体重和胎盘重量。正常的胎盘发育取决于滋养层细胞的增殖和分化。我们对在同步这些事件中起关键作用的有丝分裂调节因子的了解有限。此外，糖皮质激素对胎盘生长抑制作用的潜在机制尚未阐明。本研究的目的是通过逆转录聚合酶链反应（RT-PCR）、免疫组织化学和蛋白质印迹法，研究增殖细胞核抗原（PCNA）、细胞周期蛋白D3、p27和p57在正常和地塞米松诱导的IUGR Wistar大鼠胎盘组织中的免疫定位、mRNA和蛋白质水平。我们还通过末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记法（TUNEL）和透射电子显微镜在光学显微镜水平比较了凋亡细胞数量。注射60分钟和120分钟后，IUGR大鼠的糖皮质激素水平高于对照大鼠。与对照胎盘相比，我们发现IUGR胎盘组织中PCNA和细胞周期蛋白D3的基因和蛋白表达降低，而p27和p57的表达增加。IUGR组胎盘的凋亡细胞数量更高。简而言之，我们发现母体地塞米松治疗导致IUGR胎盘组织从细胞增殖向细胞凋亡转变。地塞米松诱导的胎盘和胚胎异常可能与IUGR胎盘组织中PCNA和细胞周期蛋白D3表达降低、p27和p57表达增加以及凋亡率升高有关。
