Changes in brain ribonuclease (BRB) messenger RNA in granulosa cells (GCs) of dominant vs subordinate ovarian follicles of cattle and the regulation of BRB gene expression in bovine GCs
Changes in brain ribonuclease (BRB) messenger RNA in granulosa cells (GCs) of dominant vs subordinate ovarian follicles of cattle and the regulation of BRB gene expression in bovine GCs
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DOI：
10.1016/j.domaniend.2015.10.008
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发表时间：
2016-04-01
影响因子：
2.1
通讯作者：
Spicer, L. J.
中科院分区：
文献类型：
--
作者：
Dentis, J. L.;Schreiber, N. B.;Spicer, L. J.
脑核糖核酸酶（BRB）是核糖核酸酶A超家族的成员，其在一系列组织中组成性表达，并且是人核糖核酸酶1的功能同系物。本研究旨在研究BRB基因在牛优势卵泡发育过程中颗粒细胞（GC）中的表达，并确定BRB在GC中的激素调节。同步化荷斯坦奶牛（n = 18）的发情周期，并在排卵后第3 ~ 4天或第5 ~ 6天在优势卵泡生长和选择期间切除卵巢。收集卵巢，吸出卵泡液（FFL），收集GC用于RNA分离和定量聚合酶链反应。根据表面直径，将卵泡分类为小（1-5 mm;每个卵巢合并）、中等（5-8 mm;单独收集）或大（8.1-17 mm;单独收集）。用放射免疫法测定FFL中雌二醇（E-2）和孕酮（P-4）水平。小（n = 31）、中（n = 66）和大（n = 33）次级E-2非活性（FFL E-2 < P-4）卵泡GCs中BRB信使RNA（mRNA）的减少是大（n = 16）优势E-2活性（FFL E-2> P-4）卵泡GCs中BRB信使RNA（mRNA）的减少的8.6- 11.8倍（P < 0.05）。在最大的4个卵泡中，GCs BRB mRNA丰度与FFL E-2（r = -0.65）和E-2：P-4比值（r = -0.46）呈负相关（P < 0.01）。在实验2中，（直径8-22 mm）和小（1-5 mm直径）卵泡用胰岛素样生长因子I处理（IGF 1; 0或30 ng/mL）和/或肿瘤坏死因子α（0或30 ng/mL）; IGFI增加（P < 0.05）大卵泡GC中BRB mRNA丰度，而肿瘤坏死因子α降低（P < 0.001）IGF 1诱导的BRB mRNA丰度。在实验3 ~ 6中，E-2、促卵泡激素、成纤维细胞生长因子9、皮质醇、无翅3A、音猬因子对GC中BRB mRNA丰度无影响（P> 0.10），甲状腺素、促黄体生成素增加（P < 0.05），而前列腺素E2（PGE 2）降低（P < 0.05）小卵泡GC中BRB mRNA丰度。重组人RNase 1处理小卵泡GCs后，GCs数量和E-2产量增加（P < 0.05）。总之，BRB是一个生殖和发育调控基因在牛的GC和可能调控E-2的生产在卵泡生长在牛。(C)2016 Elsevier Inc. All rights reserved.
Brain ribonuclease (BRB) is a member of the ribonuclease A superfamily that is constitutively expressed in a range of tissues and is the functional homolog of human ribonuclease 1. This study was designed to characterize BRB gene expression in granulosa cells (GCs) during development of bovine dominant ovarian follicles and to determine the hormonal regulation of BRB in GCs. Estrous cycles of Holstein cows (n = 18) were synchronized, and cows were ovariectomized on either day 3 to 4 or day 5 to 6 after ovulation during dominant follicle growth and selection. Ovaries were collected, follicular fluid (FFL) was aspirated, and GCs were collected for RNA isolation and quantitative polymerase chain reaction. Follicles were categorized as small (1-5 mm; pooled per ovary), medium (5-8 mm; individually collected), or large (8.1-17 mm; individually collected) based on surface diameter. Estradiol (E-2) and progesterone (P-4) levels were measured by radioimmunoassay (RIA) in FFL. Abundance of BRB messenger RNA (mRNA) in GCs was 8.6- to 11.8-fold greater (P < 0.05) in small (n = 31), medium (n = 66), and large (n = 33) subordinate E-2-inactive (FFL E-2 < P-4) follicles than in large (n = 16) dominant E-2-active (FFL E-2 > P-4) follicles. In the largest 4 follicles, GCs BRB mRNA abundance was negatively correlated (P < 0.01) with FFL E-2 (r = -0.65) and E-2:P-4 ratio (r = -0.46). In experiment 2, GCs from large (8-22 mm diameter) and small (1-5 mm diameter) follicles were treated with insulin-like growth factor I (IGF1; 0 or 30 ng/mL) and/or tumor necrosis factor alpha (0 or 30 ng/mL); IGFI increased (P < 0.05) BRB mRNA abundance, and tumor necrosis factor alpha decreased (P < 0.001) the IGF1-induced BRB mRNA abundance in large-follicle GCs. In experiment 3 to 6, E-2, follicle-stimulating hormone, fibroblast growth factor 9, cortisol, wingless 3A, or sonic hedgehog did not affect (P> 0.10) abundance of BRB mRNA in GCs; thyroxine and luteinizing hormone increased (P < 0.05), whereas prostaglandin E2 (PGE2) decreased (P < 0.05) BRB mRNA abundance in small-follicle GCs. Treatment of small-follicle GCs with recombinant human RNase1 increased (P < 0.05) GCs numbers and E-2 production. In conclusion, BRB is a hormonally and developmentally regulated gene in bovine GCs and may regulate E-2 production during follicular growth in cattle. (C) 2016 Elsevier Inc. All rights reserved.