Endocrine Signals Altered by Heat Stress Impact Dairy Cow Mammary Cellular Processes at Different Stages of the Dry Period.
Endocrine Signals Altered by Heat Stress Impact Dairy Cow Mammary Cellular Processes at Different Stages of the Dry Period.
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DOI：
10.3390/ani11020563
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发表时间：
2021-02-21
期刊：
影响因子：
--
通讯作者：
Dahl GE
中科院分区：
文献类型：
--
作者：
Ouellet V;Negrao J;Skibiel AL;Lantigua VA;Fabris TF;Marrero MG;Dado-Senn B;Laporta J;Dahl GE
妊娠后期热应激会增加乳牛的催乳素，降低雌激素浓度。这些激素的改变可能会干扰乳腺在干燥期的重塑，从而可能导致随后的泌乳过程中观察到的生产障碍。本项目旨在更好地了解干热应激后乳腺性能损伤的分子机制。为此，我们研究了不同热环境和体外激素环境下催乳素和雌激素通路及关键细胞过程通路相关基因的表达。本研究结果表明，妊娠后期热应激影响了乳腺中参与干燥期关键细胞过程的基因的表达。此外，我们的研究结果表明，这些变化部分是由雌激素和催乳素信号的改变所调节的。在妊娠后期热应激下发生的激素改变可能扰乱乳腺重塑，导致随后哺乳期间产奶量减少。我们研究了内分泌环境改变对干旱期不同阶段乳腺基因表达的影响。在相对于干燥的第3天和第35天收集体内冷却（CL）或热应激（HT）奶牛的乳腺活检，并将其分为外植体。外植体在三种培养基中培养24 h：基础培养基：不含催乳素或雌激素；CL-mimic：基础+低催乳素+高17β-雌二醇，或HT-mimic：基础+高催乳素+低17β-雌二醇。Real - time qPCR用于定量基因表达。我们发现妊娠后期热应激改变了催乳素和雌激素受体的表达，在第3天下调了与细胞凋亡、自噬和增殖相关的基因，在第35天上调了与这些细胞过程相关的基因。此外，与体内处理相比，我们发现，旨在模拟奶牛暴露在不同环境中的激素反应的体外处理对基因表达的影响较少。进一步的研究将继续揭示妊娠后期热应激引起的生产障碍背后的机制。
Late-gestation heat stress increases blood prolactin and decreases oestrogen concentrations in dry cows. These hormonal alterations may disturb mammary gland remodelling during the dry period, thereby being potentially responsible for the observed production impairments during the subsequent lactation. This project aimed to better understand the molecular mechanisms underlying subsequent impairments in mammary performance after dry period heat stress. For this, we studied the expression of genes encompassing prolactin and oestrogen pathways and key cellular process pathways under different thermal environments and in vitro hormonal milieus. The results of this study revealed that late-gestation heat stress impacted the expression of genes in the mammary gland involved in key cellular processes occurring during the dry period. Furthermore, our results indicated that these modifications are in part modulated by alterations of oestrogen and prolactin signalling. Hormonal alterations occurring under late gestation heat stress may disturb mammary gland remodelling, resulting in a reduced milk yield during the subsequent lactation. We investigated the effects of an altered endocrine environment on mammary gene expression at different stages of the dry period. Mammary gland biopsies from in vivo-cooled (CL) or heat-stressed (HT) cows were collected at d 3 and 35 relative to dry-off and divided into explants. Explants were incubated in vitro for 24 h in one of three media: Basal: no prolactin or estrogen; CL-mimic: Basal + low prolactin + high 17β-estradiol, or HT-mimic: Basal + high prolactin + low 17β-estradiol. Real time qPCR was used to quantify gene expression. We established that late-gestation heat stress changes the expression of prolactin and oestrogen receptors, downregulates genes involved in apoptosis, autophagy and proliferation at d 3 and upregulates genes related to those cellular processes at d 35. Moreover, compared with in vivo treatments, we showed that the expression of fewer genes was impacted by in vitro treatments which aimed to mimic the hormonal response of cows exposed to a different environment. Further research will continue to uncover the mechanisms behind the production impairments caused by late-gestation heat stress.
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影响因子：
3.5
作者：
Connor, E. E.;Meyer, M. J.;Capuco, A. V.
通讯作者：
Capuco, A. V.
影响因子：
3.3
作者：
COLLIER, RJ;DOELGER, SG;WILCOX, CJ
通讯作者：
WILCOX, CJ
影响因子：
3.5
作者：
Chapman, KW;Lawless, HT;Boor, KJ
通讯作者：
Boor, KJ
DOI：
10.1146/annurev-animal-031412-103644
发表时间：
2013-01-01
期刊：
ANNUAL REVIEW OF ANIMAL BIOSCIENCES, VOL 1
影响因子：
--
作者：
Baumgard, Lance H.;Rhoads, Robert P., Jr.
通讯作者：
Rhoads, Robert P., Jr.
影响因子：
3.5
作者：
Macciotta, N. P. P.;Gaspa, G.;Cappio-Borlino, A.
通讯作者：
Cappio-Borlino, A.