HOXA10直接调控人子宫内膜间质细胞中p/CAF启动子的活性

目的：筛选与鉴定转录因子同源框蛋白（HOX）A10下游靶基因。方法：用Ad-HOXA10重组腺病毒感染人子宫内膜间质细胞,通过染色体免疫共沉淀（ChIP）方法,筛选HOXA10的下游靶基因;采用萤光素酶报告基因实验结合腺病毒介导的HOXA10过表达和小干扰RNA介导的基因沉默实验,分析HOXA10对下游靶基因的转录调控作用。结果：ChIP-PCR筛选并鉴定p/CAF（p300/CBP相关因子）为HOXA10直接作用的靶基因;过表达HOXA10抑制p/CAF启动子活性达60%;基因沉默内源性HOXA10的表达可以激活p/CAF启动子活性超过2倍以上。结论：p/CAF是HOXA10新的靶基因,HOXA10可能通过调节p/CAF的表达来调控子宫内膜的发育。     

Activation of matrix metalloproteinase-26 by HOXA10 promotes embryo adhesion in vitro

Successful embryonic implantation requires an effective maternal–embryonic molecular dialogue. However, the detailed mechanisms of epithelial-embryo adhesion remain poorly understood. Here, we report that matrix metalloproteinase-26 (MMP-26) is a novel downstream target gene of homeobox a 10 (HOXA10) in human endometrial cells. HOXA10 binds directly to a conserved TTAT unit (−442 to −439) located within the 5′ regulatory region of the MMP-26 gene and regulates the expression and secretion of MMP-26 in a concentration-dependent manner. Moreover, the adenovirus-mediated overexpression of MMP-26 in Ishikawa cells markedly increased BeWo spheroid adhesion. An antibody blocking assay further demonstrated that the promotion of BeWo spheroid adhesion by HOXA10 and MMP-26 was significantly inhibited by pre-treatment with a specific antibody against MMP-26. These results demonstrate that the HOXA10-mediated expression of MMP-26 promotes embryo adhesion during the process of embryonic implantation.     

同源盒基因A10编码蛋白的靶调节基因的筛选与鉴定

目的：筛选和鉴定同源盒基因A10编码蛋白（HOXA10）的靶调节基因。方法：以人子宫内膜细胞系AN3CA为实验对象,采用染色质免疫沉淀方法筛选HOXA10靶基因;采用平端克隆方法构建HOXA10靶基因库;采用DNA序列分析结合生物信息学方法鉴定HOXA10靶基因。结果：共获得含有HOXA10结合片段的克隆197个,选取插入片段大于100bp的质粒67个进行DNA序列分析,其中含有HOXA10结合序列TTAT的基因16个。结论：初步筛选出16个HOXA10候选靶基因,为进一步研究HOXA10的基因调节机理提供了新的思路。     

Direct regulation of beta3-integrin subunit gene expression by HOXA10 in endometrial cells

Estrogen and progesterone regulate HOXA10 expression in the endometrium, where HOXA10 is necessary for implantation. The integrins are also involved in early embryo-endometrial interactions. Here we show that HOXA10 directly regulates beta3-integrin subunit expression in the endometrium, likely mediating the effect of sex steroids on beta3-integrin expression. beta3-Integrin expression was decreased in endometrium shown to have low HOXA10 expression. beta3-Integrin mRNA levels were increased in endometrial adenocarcinoma cells (Ishikawa) transfected with pcDNA3.1/HOXA10, and decreased in cells treated with HOXA10 antisense. Seven consensus HOXA10 binding sites were identified 5' of the beta3-integrin gene. Direct binding of HOXA10 protein to four sites was demonstrated by EMSA. Reporter gene expression increased in BT-20 cells cotransfected with pcDNA3.1/ HOXA10 and pGL3-promoter vector containing region F (encompassing all seven HOXA10 consensus sites). A 41-bp segment (Region A) showed highest affinity binding to HOXA10 protein. Increased reporter expression, equal in magnitude to that obtained with Region F, was obtained with Region A. HOXA10 protein binding within Region A was localized by deoxyribonuclease I footprinting. beta3-Integrin expression was directly up-regulated by HOXA10 through a 41-bp 5'-regulatory element. Sex steroids regulate the expression of endometrial beta3-integrin through a pathway involving HOXA10.     

Direct regulation of HOXA10 by 1,25-(OH)2D3 in human myelomonocytic cells and human endometrial stromal cells

Vitamin D receptor (VDR) and the functionally active form of its ligand, 1,25-(OH)2D3, have been implicated in female reproduction function and myeloid leukemic cell differentiation. HOXA10 is necessary for embryo implantation and fertility, as well as hematopoeitic development. In this study, we identified a direct role of vitamin D in the regulation of HOXA10 in primary human endometrial stromal cells, the human endometrial stromal cell line (HESC), and in the human myelomonocytic cell line, U937. Treatment of primary endometrial stromal cells, or the cell lines HESC and U937 with 1,25-(OH)2D3 increased HOXA10 mRNA and protein expression. VDR mRNA and protein were detected in primary uterine stromal cells as well as HESC and U937 cells. We cloned the HOXA10 upstream regulatory sequence and two putative vitamin D response elements (VDRE) into luciferase reporter constructs and transfected primary stromal cells and HESC. One putative VDRE (P1: -385 to -434 bp upstream of HOXA10) drove reporter gene expression in response to treatment with 1,25-(OH)2D3. In EMSA, VDR demonstrated binding to the HOXA10 VDRE in the presence of 1,25-(OH)2D3. 1,25-(OH)2D3 up-regulates HOXA10 expression by binding VDR and interacting with a VDRE in the HOXA10 regulatory region. Direct regulation of HOXA10 by vitamin D has implications for fertility and myeloid differentiation.     

Effect of conceptus secretions on HOXA10 and PTGS2 gene expression, and PGE2 release in co-cultured luminal epithelial and stromal cells of the porcine endometrium at the time of early implantation

Homeobox A10 (HOXA10) gene expression was demonstrated in the endometrium of adult porcine uteri, however there is little information concerning the role of this gene in the pig. Objectives of the present study were to examine: 1) the expression of HOXA10 in the endometrium of cyclic and early pregnant gilts; 2) the effect of estradiol (E₂) and progesterone (P₄) on HOXA10 expression in porcine luminal epithelial (LE) and stromal (ST) cells in vitro; 3) the effect of E₂ and conceptus-exposed medium (CEM) on HOXA10 and prostaglandin endoperoxide synthase (PTGS2) gene expression and prostaglandin (PG) E₂ secretion from LE and ST cells in a co-culture model. The abundance of HOXA10 mRNA was increased on day 15 of pregnancy in comparison to day 15 of the estrous cycle. Moreover, increased HOXA10 mRNA level was detected in ST cells after E₂ and P₄ treatment. E₂ stimulated the expression of HOXA10 in LE cells cultured on collagen and pre-treated with steroids, but not in LE on plastic surfaces. Addition of CEM to LE cells cultured in collagen-coated inserts of the co-culture system resulted in elevated HOXA10 and PTGS2 gene expression and PGE₂ secretion in these cells, but not in ST cells cultured in basal compartments. ST cells directly treated with E₂ or CEM showed higher levels of HOXA10 and PTGS2 expression. Blocking of estrogen receptors with ICI-182,780 did not influence the stimulatory effect of CEM. We conclude that HOXA10 expression in the porcine endometrium is closely related to the implantation process and stimulated by conceptus products. Moreover, the co-culture system of LE and ST cells is a promising model for the study of endometrial response to conceptus-derived factors.     

p57与同源框基因HOXA10在子宫内膜基质细胞体外蜕膜化过程中的表达

本文旨在从mRNA和蛋白水平研究子宫内膜基质细胞(endometrial stromalcell,ESC)体外蜕膜化过程中p57和同源框基因HOXA10(homeobox A10 gene)的表达变化以及HOXA10的亚细胞定位,从而推测其在蜕膜化过程中的作用。本实验联合使用0.5mmol/L8-溴-cAMP和1×10?6mol/LMPA(medroxyprogesterone acetate)作用1、2、4d(D1、D2、D4)诱导ESC发生蜕膜化,相应时间点提取mRNA和蛋白质行半定量RT-PCR和免疫印迹,同时以2%低血清培养ESC1、4d作为对照(C1、C4)。用间接免疫荧光和基因转染的方法,观察蜕膜化过程中HOXA10的亚细胞定位。结果显示:(1)蜕膜化过程中HOXA10的表达进行性下降,D2开始与对照组(C4)比较具有显著性差异(P<0.05)。(2)相反,蜕膜化过程中p57的表达进行性上升,D2开始与对照组C4比较也有显著性差异(P<0.05)。(3)低血清培养ESC1、4d后,p57和HOXA10的表达没有显著性差异(P>0.05)。(4)蜕膜化过程中HOXA10始终定位于胞核,不发生胞浆胞核穿梭。以上观察结果表明:(1)p57的高表达是ESC脱离细胞周期走向分化的因素之一。(2)HOXA10的低表达可能是p57上调的原因之一。(3)孕激素受体(progesterone receptor,PR)途径参与了促进ESC脱离细胞周期而走向分化的过程。     

HOXA10 and HOXA13 sequence variations in human female genital malformations including congenital absence of the uterus and vagina

Congenital genital malformations occurring in the female population are estimated to be 5 per 1000 and associate with infertility, abortion, stillbirth, preterm delivery and other organ abnormalities. Complete aplasia of the uterus, cervix and upper vagina (Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome) has an incidence of 1 per 4000 female live births. The molecular etiology of congenital genital malformations including MRKH is unknown up to date. The homeobox (HOX) genes HOXA10 and HOXA13 are involved in the development of human genitalia. In this investigation, HOXA10 and HOXA13 genes of 20 patients with the MRKH syndrome, 7 non-MRKH patients with genital malformations and 53 control women were sequenced to assess for DNA variations. A total of 14 DNA sequence variations (10 novel and 4 known) within exonic and untranslated regions were detected in HOXA10 and HOXA13 among our cohorts. Four HOXA10 and two HOXA13 DNA sequence variations were found solely in patients with genital malformations. In addition to mutations resulting in synonymous amino acid substitutions, in the HOXA10 gene a missense mutation was identified and predicted by computer analysis as probably damaging to protein function in two non-MRKH patients, one with a bicornate and the other patient with a septated uterus. A novel exonic HOXA10 cytosine deletion was also identified in a non-MRKH patient with a septate uterus and renal malformations resulting in a premature stop codon and loss of the homeodomain helix 3/4. This cytosine deletion and the missense mutation in HOXA10 were analysed by real time PCR and sequencing, respectively, in two additional larger cohorts of 103 patients with MRKH and 109 non-MRKH patients with genital malformations. No other patients were found with the cytosine deletion however one additional patient was identified regarding the missense mutation. Rare DNA sequence variations in the HOXA10 gene could contribute to the misdevelopment of female internal genitalia.     

Benzo(a)pyrene inhibits endometrial cell apoptosis in early pregnant mice via the WNT5A pathway

Benzo(a)pyrene (BaP) is an endocrine-disrupting pollutant present in various aspects of daily life, and studies have demonstrated that BaP exerts reproductive toxicity. We previously showed that BaP damages endometrial morphology and decreases the number of implantation sites in early pregnant mice, but the mechanisms underlying these effects remain unclear. The endometrial function is crucial for implantation, which is associated with endometrial cell apoptosis. In this study, we focused on the effect of BaP on endometrial cell apoptosis and the role of WNT signaling during this process. Pregnant mice were gavaged with corn oil (control group) or 0.2 mg·kg⁻¹·day ⁻¹ BaP (treatment group) from Days 1 to 6 of pregnancy. BaP impaired endometrial function by decreasing the expression of HOXA10 and BMP2, two markers of receptivity and decidualization. WNT5A and β-catenin were activated in the BaP group. BaP affected the expression of apoptosis-related proteins and inhibited the apoptosis of endometrial stromal cells. In vitro, human endometrial stromal cells (HESCs) were treated with different concentrations of BaP (dimethyl sulfoxide (DMSO); 5, 10 µM). WNT5A and β-catenin were also upregulated in the BaP treatment group. HESC apoptosis was restrained by BaP. Inhibiting WNT5A by SFRP5 partially restored the effect of BaP on apoptosis. In summary, these results suggested that BaP exposure during early pregnancy activates WNT5A/β-catenin signaling pathway, which inhibits the endometrial cell apoptosis and potentially destroys endometrial function.