Effects of estrogen on estrogen receptor expression in the bursal cells of chick embryos and steroidogenic enzymes gene expression in the bursa: Relevance of estrogen receptor and estrogen synthesis in the bursa of chick embryos

Estrogen has been reported to act on B cell genesis in the bursa of Fabricius of chick embryos. In this study, we attempted to demonstrate the hypothesis that B cell genesis is controlled by estrogen receptor (ER) in the bursal cells and steroidogenic enzymes synthesized in the bursa. We previously reported the presence of estrogen receptor α (ERα) in the bursa during the late stage of embryogenesis and an increase in the expression of ERα messenger RNA (mRNA) between the 13th day and 16th day. The number of ER-positive cells was maximal on the 16th day. In the present study, ER-positive cells in the bursa during the late stage of embryogenesis increased 4 h after β-estradiol treatment on the 14th to 18th day. The concentration of β-estradiol in the embryonic bursa increased. These results suggest that this stage of embryogenesis is critical in B cell development in the bursa in connection with the effect of estrogen treatment. Our findings also showed that the mRNA expression of five steroidogenic enzymes occurred in the bursa of chick embryos. These results suggest that estrogen is synthesized in the embryonic bursa and estrogen acts on the bursal cells in a paracrine fashion.     

Changes in estrogen receptor expression in the chick thymus during late embryonic development

In chickens, although estrogen receptors (ER) are reported to be associated with the immunological processes, detailed information about the differences in ER expression in the tissues related to the development of lymphocytes is not fully known, especially during the developmental stage. To learn more about this immunological relationship, we used semi‐quantitative polymerase chain reaction method to detect the ER expression levels in the thymus tissues of chicks during the developmental stage. Furthermore, ER‐expressing cells were detected by immunohistochemistry. The results of this study show that the expression level of ER increased on embryonic day 16 and decreased on day 20. Furthermore, ER expression was significantly higher in male than in female chickens at day 16. The increased expression on day 16 and decreased level on day 20 were also reproduced in the incidence of immunoreactive cells, although there was a 1‐day delay in the elevated incidence of the cells. This study revealed the changes in ER expression and the incidence of ER‐positive cells in the thymus of chickens during the developmental stage.     

B cell differentiation in the bursa of Fabricius and spleen of embryos and chicks immediately after hatching

Flow cytometric analysis and immunohistochemical observation were used to qualitatively and quantitatively clarify the nature of B cell differentiation in the bursa of Fabricius of chick embryos and to determine the timing of antibody class switching in chicken spleens based on positivity of IgM and IgG on and in the cells. In the bursa, the sIgM‐positive cell population formed from the 12^th to 15^th day of embryogenesis. The proportion of sIgM‐high expressing (sIgM^high) cells was lower among bursacytes than splenocytes of hatched chicks, suggesting that the sIgM^high bursacytes are to be released to peripheral sites. The proportion of sIgM^high cells was higher at 0 days old than at any other examined stage of development. Colonization of the spleen by B cells occurred between the 18^th day of embryogenesis and 0 days old. Antibody class switching was thought to start in the spleen between 1 and 2 weeks of age, because IgG‐positive cells were present in the spleen of 2‐week‐old chicks, but not 0‐day‐old or 1‐week‐old chicks.     

Expression of estrogen receptor 1 and progesterone receptor in primary goat mammary epithelial cells

The exact role and sensitivity of cells to estrogen and progesterone mediated through the steroid receptors during lactation is not known. Expression of estrogen receptor 1 (ESR1) and progesterone receptor (PGR) was quantified in mammary tissue‐derived primary goat mammary epithelial cells (pgMECs) to determine the influence of donor tissue physiology (lactating and juvenile) and cell culture growth conditions (basal and lactogenic) on ESR1 and PGR expression in the derived cells. Relative messenger RNA (mRNA) levels for both receptors were the highest in cell lines derived from mammary tissue of juvenile goats. Maintaining pgMECs in lactogenic conditions resulted in up‐regulation of ESR1 (1.36‐ to 12.35‐fold) and in down‐regulation of PGR (‐2.53‐ to ‐3.62‐fold), compared to basal conditions. Based on Western blotting analysis we suggest that the differences in mRNA expression are translated to the protein level. We suggest that differential expression in lactating conditions is correlated with terminal differentiation of the pgMECs. Double immunostainings showed that estrogen receptor alpha (ER‐α) positive cells do not exclusively belong to the luminal lineage and that ER‐α and PGR can be expressed individually or co‐expressed in the pgMECs. The derived primary cultures/lines in early passages are hormone‐responsive and represent a useful surrogate for mammary tissue in research experiments.     

Effect of growth hormone on estrogen receptor binding properties in the chick oviduct in vivo

The equilibrium dissociation constant (K_d) and the maximum binding capacity (B_max) of estrogen receptor in cytosolic and nuclear fractions in oviduct of pullets following various daily injections (1–10 times) of growth hormone (GH: 50 µg/chick) were examined by Scathchard analysis of specific [³H]estradiol‐17β (E₂) binding. The K_d values of receptor in both fractions decreased after three times of GH‐injection. In the B_max values, three times of the injection caused a marked decrease in that value in the cytosolic fraction with a concomitant increase in that in the nuclear fraction, whereas the total B_max (sum of B_max in the cytosolic and nuclear fractions) did not change. A similar relationship between the K_d values in the binding of the two fractions was also observed in 4–10 times of GH‐injection. However, in 4–10 times of GH‐injection the B_max of the both fractions and total B_max was greater than that in vehicle‐injection (control). When the chicks were injected with 6–10 times of GH‐injection, the weight of oviduct was increased. No change in the plasma concentrations of E₂ was found following GH‐ and vehicle‐injections into the chicks. The results suggest that growth hormone stimulates the growth of the chick oviduct by increasing the binding affinity and capacity of estrogen receptor.     

马齿苋多糖对雏鸡免疫功能的影响

采用马齿苋多糖口腔灌注雏鸡,观察对雏难法氏囊免疫功能的影响。试验选取80只1日龄雏鸡随机分为4组,1个空白对照组及3个POP试验组,POP剂量分别为25,50和100mg/kg,每天口腔灌注1次,连续20d。结果显示,POP能显著提升外周血CD4+T淋巴细胞数量及CD4+/CD8+比值(P0.05),显著提高法氏囊指数(P0.05)及法氏囊淋巴细胞增殖指数(P0.05)。试验表明,马齿苋多糖可通过改变法氏囊免疫系统的动态变化,促进免疫器官发育,直接作用于免疫细胞,提高雏鸡的免疫能力。     

Evidence for estrogen receptor expression during medullary bone formation and resorption in estrogen-treated male Japanese quails (Coturnix coturnix japonica)

The temporal expression of estrogen receptor (ER)-α and ER-β mRNA was examined in male Japanese quails. Femurs of quails receiving 17β-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-α was already observed on day 0 and increased slightly during bone formation whereas ER-β was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-α expression simultaneously decreased slightly and ER-β levels remained very low. These results suggest that estrogen activity mediated by ER-α not only affects medullary bone formation but also bone resorption.     

早期鸡胚发育过程中增殖细胞核抗原在法氏囊的表达

法氏囊是鸟类特有的器官,是B淋巴细胞成熟的场所.本研究分析了鸡胚早期发育过程的中法氏囊形态变化及增殖细胞核抗原PCNA表达变化.结果表明鸡胚6.5 d(E6.5)时,法氏囊开始出现在鸡胚泄殖腔的最深处,从最开始E6.5的一些小的囊泡发育成E8的一个大腔,E8～E10,法氏囊继续发育.从E11开始,法氏囊开始出现一些小的皱褶,E11～E18,这些小的皱褶逐渐变得清晰,并贯穿整个法氏囊.在E9时,法氏囊轮廓形成,可以发现在表皮层和基膜层PCNA有着广泛的表达.统计分析表明表皮层的PCNA阳性率在100％左右,在整个发育早期几乎没有变化;而基层的阳性率随着胚胎的发育逐渐下降,在E9、E10、E11、E12、E14和E18表达率分别是97％、93％、71％、55％、56％和20％.     

鸡免疫器官中血管活性肠肽的分布特点

应用免疫组化超敏SP法对鸡不同生长阶段免疫器官中血管活性肠肽(VIP)的表达特点进行了研究,结果显示,胸腺中VIP阳性反应主要分布于被膜及髓质,而皮质内反应较弱;随日龄增加,VIP在被膜和髓质内一直维持较强的表达;实质中VIP强阳性淋巴细胞数量随日龄逐渐增多,至42 d开始减少.脾脏中VIP阳性反应主要出现于被膜及红髓,并在整个生长阶段维持较强的表达,红髓的脾索和脾窦间还有较多的巨噬细胞呈VIP强阳性反应;白髓中仅见动脉周围淋巴鞘中央动脉有VIP的表达,并随日龄的增加逐渐减弱.法氏囊中VIP的表达范围广泛,涉及黏膜、黏膜下层和肌层,尤以黏膜上皮细胞和法氏囊小结髓质的表达为典型;随着日龄增加,黏膜上皮细胞VIP表达逐渐减弱,囊小结髓质一直保持较强的VIP阳性着色,囊小结皮髓质交界处上皮细胞层内VIP强阳性细胞有逐渐增多的趋势.鸡免疫器官中VIP阳性反应物质的广泛分布,提示这3种器官是神经系统以外产生VIP的重要部位,法氏囊中的VIP可参与鸡免疫器官的功能调节,它可作为一种信号分子介导神经内分泌系统和免疫系统之间的相互作用.     

雌激素受体α在雌性大鼠脑中的表达

本试验利用免疫组织化学SP法,研究了雌激素受体α在大鼠脑中的表达.结果表明,ER_α免疫反应产物主要定位于神经元细胞核,部分区域出现阳性神经元和阳性突起,在海马CA1、CA2辐射层、齿状回、下托的分子层等出现阳性星形胶质细胞;ER_α在脑中表达广泛,免疫反应产物在端脑的隔外侧核、海马锥体细胞层、大脑皮质等,间脑的缰内侧核、下丘脑室旁核、弓状核、视上核等,中脑的动眼神经核,脑桥的脑桥核外侧部等为高密度;在端脑的尾壳核、杏仁中央核、海马CA4区,间脑的下丘脑室周核、缰外侧核等,中脑的黑质致密带,脑桥的脑桥被盖核等为较高密度;在问脑的视前室周核、丘脑后核、中脑的红核、脑桥的脑桥被盖网状核等为中等密度;在端脑的苍白球,间脑的无名质,无免疫反应产物出现.结果显示,雌激素在调节脑的认知和生殖内分泌过程中,ER_α可能起主要作用;雌激素可通过ER_α调节星形胶质细胞功能.     

Dexamethasone reduces infectious bursal disease mortality in chickens

Very virulent infectious bursal disease virus (vvIBDV) causes high mortality in chickens but measures to reduce the mortality have not been explored. Chickens (8–9 weeks) were treated with 3 agents before and during vvIBDV inoculation. Dexamethasone treatment reduced the mortality of infected chickens (40.7% vs. 3.7%; p < 0.001), but treatment with aspirin or vitamin E plus selenium did not affect the mortality. The bursa of Fabricius appeared to have shrunk in both dead and surviving chickens (p < 0.01). The results indicate that dexamethasone can reduce mortality in vvIBDV-infected chickens and may provide therapeutic clues for saving individual birds infected by the virus.     

ChMDA5通路参与传染性法氏囊病病毒致雏鸡法氏囊损伤的研究

传染性法氏囊病病毒（IBDV）为dsRNA病毒,可造成雏鸡法氏囊损伤进而发生免疫抑制;MDA5是能够特异性识别dsRNA病毒的模式识别受体。为研究鸡MDA5（chMDA5）信号通路在IBDV致雏鸡法氏囊病理损伤中的作用,试验选取50只14日龄SPF雏鸡随机分为IBDV感染组和空白对照组,每组25只,IBDV感染组雏鸡通过点眼、滴鼻感染IBDV JIC7株病毒液,0.6 mL·只^-1,空白对照组雏鸡经相同途径给予相同剂量无菌PBS,感染IBDV后第1、4、7、21及35天采集雏鸡法氏囊。采用qRT-PCR方法检测法氏囊中IBDV载量,chMDA5及chMDA5信号通路衔接蛋白（chIPS-1）、转录因子（chIRF3和chNF-κB）、下游产物细胞因子（chIFN-β、chTNF-α、chIL-1β、chIL-6） mRNA水平变化;间接免疫荧光法检测chMDA5蛋白表达变化,传统病理学方法检查法氏囊病理组织学变化。结果发现,雏鸡感染IBDV后,其法氏囊中chMDA5、chIPS-1、chIRF3、chNF-κB、chIFN-β、chTNF-α、chIL-1β、chIL-6的表达量均显著高于对照组,且法氏囊组织发生形态损伤,上述变化趋势与IBDV载量变化基本一致。结果表明,雏鸡法氏囊chMDA5及其信号转导通路可被IBDV激活,参与到IBDV感染雏鸡法氏囊损伤与抗损伤过程中。     

神经肽Y及其Y1受体阳性细胞在鸭腔上囊中的分布及发育变化(英文)

神经肽Y及其Y1受体在神经-免疫-网路中发挥着重要作用。二者在许多脊椎动物胸腺和脾脏中的表达已有研究,但它们在腔上囊中的表达及发育变化特征还未见报道。本试验应用免疫组化技术研究神经肽Y及其Y1受体阳性细胞在鸭腔上囊胚胎及胚后发育中的分布及变化特征。结果显示,在鸭腔上囊中神经肽Y及其Y1受体分别最早表达于26和22d胚龄。神经肽Y阳性细胞分布于黏膜上皮、滤泡、肌层和小动脉平滑肌。Y1受体阳性细胞分布于黏膜上皮、滤泡淋巴细胞。各部位神经肽Y及其Y1受体阳性细胞数量表现出明显增龄变化特征。结果说明鸭腔上囊中存在神经肽Y及其Y1受体,二者可能存在的相互作用主要表现在胚后发育阶段,这与B淋巴细胞的发育与分化以及腔上囊的退化密切相关。     

催情助孕液对小鼠雌、孕激素水平及其受体mRNA表达的影响

分别以0.1、0.2、0.4 mL/d剂量的催情助孕液给21日龄小鼠灌服7d后,检测体质量、脏器指数、血清雌激素和孕激素水平、子宫组织中雌激素和孕激素受体基因mRNA的表达情况,并与腹腔注射雌二醇4d的小鼠进行比较.结果显示与对照组和雌二醇注射组比较,0.2 mL的催情助孕液能显著促进小鼠子宫发育,并增强雌激素水平及其受体基因表达,而对孕激素水平及其受体基因表达无显著影响.结果表明,催情助孕液对动物生殖发育与促进发情具有较好的效果.     

法氏囊在鸡淋巴细胞性白血病发生发展中的作用

用鸡淋巴细胞性白血病病毒ＲＡＶ－１株接种３５只１日龄伊莎鸡雏,于接毒后不同批次扑杀,采取法氏囊做组织学、免疫细胞化学、透射电镜观察。结果：接毒后１个月,法氏囊滤泡髓质淋巴细胞开始转化,接毒后２～５个月更明显,在法氏囊滤泡髓质区形成成淋巴细胞克隆增殖灶。接毒后６个月,法氏囊萎缩。生物素－亲和素（ＢＡ）法染色表明法氏囊一直存有病毒和群特异性抗原,以接毒后３～４个月含量最高。电镜观察,在接毒后１～４个月的实验鸡法氏囊滤泡髓质淋巴细胞、巨噬细胞和网状细胞中观察到淋巴细胞性白血病（ＬＬ）病毒粒子。组织学、免疫细胞化学和电镜观察都表明法氏囊是该病的主要靶器官之一,法氏囊在鸡淋巴细胞性白血病的发生发展中起一定的作用     

Developmental changes in cell proliferation and apoptosis in the normal duck bursa of Fabricius

The aim of this work was to investigate developmental changes in cell proliferation and apoptosis in normal duck bursa of Fabricius using flow cytometry and immunohistochemistry. Studies were carried out on Tianfu ducks on days 24 and 27 of embryogenesis (E24 and E27) along with days 20, 70, and 200 of postnatal development (P20, P70, and P200). Results showed that the percentage of G₀/G₁ bursa cells significantly increased between E24 and P200 while the percentage of cells in the S phase or G₂ + M phase as well as the proliferating index obviously decreased during the same period. Proliferation cell nuclear antigen was detected in lymphocyte and interfollicular epithelium. The proliferative lymphocyte density tended to decrease from E24 to P200. Apoptotic bodies in macrophages, free apoptotic bodies, or nuclei with condensed chromatin in lymphocytes in follicles were identified by transferase-mediated dUTP nick-end labeling. Both flow cytometry and microscopic analysis reveal that the proportion of apoptotic cells and apoptotic lymphocyte density increased from E24 to P20, fell on P70, then rose again on P200. Our foundings demonstrate that cell proliferation decreases and apoptosis increases with age. These changes may account for duck bursa development and involution.     

鸡传染性法氏囊病免疫复合物疫苗的安全性和免疫效力试验

用鸡法氏囊病免疫复合疫苗(IBDV-Icx)和常规IBD活疫苗分别免疫1日龄商品鸡和SPF鸡,进行疫苗的安全性及免疫效力比较.免疫后8d检测,IBDV-Icx免疫组鸡的法氏囊未见明显萎缩,而传统弱毒疫苗免疫组鸡的法氏囊萎缩明显;免疫后28d各组用IBDV标准强毒株进行攻击,IBDV-Icx免疫组鸡的攻毒保护率均为10/10,常规IBD活疫苗对照组分别为8/10及9/10.免疫后3个月,IBDV-Icx免疫组血清抗体可达AGP1∶32,攻击强毒仍为10/10保护,而常规IBD活疫苗免疫后2个月抗体AGP为0,攻毒保护率为1/10,免疫后3个月时攻毒10/10发病.