Influence on Cellular Signal Transduction Pathway in Dairy Cow Mammary Gland Epithelial Cells by Galactopoietic Compound Isolated from Vaccariae segetalis

The galactopoietic mechanism of Vaccaria segetalis is still unknown. Understanding dibutyl phthalate （DBP） separated from Vaccaria segetalis on the expression of lactation signal transduction genes of mammary gland epithelial cells, including prlr, erα, akt1, socs2, pparγ and elf5, will be helpful to reveal the molecular mechanism. Western blot and qRT- PCR were used to study the change of prlr, erα, akt, socs2, pparγ, and elf5 expression at mRNA and protein level. Co- localization expression of prolactin receptor （PRLR） and estrogen receptor α （ERα） was observed by immunofluorescence; the expression changes of miRNAs （21, 125b, 143, and 195） and the secretion of β-casein and lactose were detected by qRT-PCR and RP-HPLC. The results showed that Vaccaria segetalis active compound had similar fuctions as estrogen and/or prolactin （PRL） in dairy cow mammary gland epithelial cells （DCMECs）, increased the expressions of prlr, erα, akt1, and elf5 genes, while repressed pparγ expressions. DBP promoted socs2 mRNA expression, but its protein expressions were repressed. Furthermore, both DBP and PRL could repress the expressions of miRNA-125b, miRNA-143 and miRNA- 195 in DCMECs. DBP could repress the expression of miRNA-21, while the influence of PRL on miRNA-21 was not certain. DBP could promote the lactation ability of DCMECs by regulating the ER and PRLR cellular signal transduction pathway.

Metabolic Regulation of Mammary Gland Epithelial Cells of Dairy Cow by Galactopoietic Compound Isolated from Vaccariae segetalis

In previous experiment, we isolated a compound dibutyl phthalate （DBP） from Vaccaria segetalis which had galactopoietic function on mammary gland epithelial cells of dairy cow （DCMECs）. In this experiment, we ascertained the metabolic regulation function of DBP on DCMECs. Many genes related to lactation including Stat5, AMPK, b-casein, Glut1, SREBP-1, PEPCK, and ACC were detected by real-time PCR. Furthermore, Stat5 and AMPK were detected by Western blot and immunofluorescence co-localization, respectively. The results showed that DBP stimulates the expression of Stat5 and p-Stat5, thus activates Stat5 cell signal transduction pathway and stimulates b-casein synthesis. DBP also raises the activities of Glut1 and AMPK to stimulate glucose uptake and glycometabolism and activates the expression of AMPK downstream target genes PEPCK and ACC and expression of SREBP-1 to stimulate milk fat synthesis. In addition, the activities of HK, G-6-PDH, ICDH, ATPase, and energy charges were stimulated by DBP to increase the energy metabolism level of DCMECs. The results showed DBP stimulates energy metabolism related to galactopoietic function in DCMECs.

The Effects of Insulin and Prolactin on an Epithelial Cell Line from Mammary Gland of Dairy Goat

Mammary epithelial cells with lactational function can be a valuable cellular model for research of the development and regulation of the mammary gland.This paper describes some aspects of function of an epithelial cell line from the mammary gland of the dairy goat.SDS-PAGE,triglyceride and lactose content of cultured cells were used to assess synthetic function of cells and the effects of exposure to insulin and prolactin.Results show that goat mammary epithelial cells can synthesize fat,proteins and lactose when they were cultured in DMEM-F12 medium with added EGF,IGF-1,ITS and FBS.There were no obvious changes after 48h treatment with additional insulin.Prolactin added to the basal medium significantly increased synthesis of proteins and lactose.A mammary gland epithelial cell line from goats which has lactational function has been established.This outcome provides a valuable and convenient model system.

Construction of Antibacterial Peptide CecropinB Eukaryotic Recombinant Vector and Its Expression in Dairy Goat Mammary Gland Epithelial Cells

To investigate the expression of antibacterial peptide CecropinB cDNA in dairy goat mammary gland epithelial cells,the CecropinB gene was cloned and was inserted into a eukaryotic vector pECFP-C1 to construct the recombinant plasmid pECFP-B by genetic engineering technique.Recombinant plasmid pECFP-B was transfected into dairy goat mammary gland epithelial to detect the bactericidal activity of CecropinB.The expression of CecropinB was also detected.The result of RT-PCR demonstrated CecropinB gene was expressed in transfected cells.CecropinB recombinant plasmid DNA was injected into udders and CecropinB was expressed in mammary gland,exhibiting bactericidal activity to Staphylococcus aureus in vivo experiments.

Effect of Different Concentrations of Lipopolysaccharide on Expression of NF-κB and LAP in Mammary Epithelial Cells of Dairy Cow

The paper was to study the effects of different concentrations of lipopelysaccharide （LPS） on expression of nuclear factor Kappa B （NF-κB） and lingual antimicrobial peptide （LAP） gene in mammary epithelial ceils of dairy cow. The mammary epithelial ceils of dairy cow were stimulated by different concentrations （50, 100,200,400 and 800 ng/mL） of LPS. The total RNA of cells was extracted after stimulation for 2, 4, 8, 16, 24, 48 and 72 h, respectively, and the mRNA expression levels of NF-κB P65 and LAP were evaluated by real-time quantitative PCR. The results showed that the expression of NF-κB P65 and LAP mRNA treated with 400 ng/mL LPS for 72 h were the highest compared to the control group （ P 〈0.01 ）. The result confirmed that the expression activity of NF-κB was enhanced in inflammatory effects of inammary epithelial cells induced by LPS, which regulated the expression of defense gene LAP, with certain dose and time effects.

Milk production and composition and metabolic alterations in the mammary gland of heat-stressed lactating dairy cows

This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.

Establishment of Immortalized Cow Mammary Epithelial Cells Expressing Both h TERT and SV40 T

Vectors of pcDNA3.1-hTERT and pcDNA 3. 1-SV40 T were established. After linearization, they were cotransfected to mammary epithelial cells of Holstein cow, in order to research on the role of hTERT and SV40 T in immortalized mammary epithelial cells in vitro. Both PT-PCR and immunohistochemical as- says of cells were carried out. Results showed that the expression of hTERT and SV40 T could effectively prolong the culture time in vitro of mammary epithelial cells, and enhance the cell passage number. The obtained cell line could be expressed normally, indicating that the in vitro cultured mammary epithelial cells expressing both hTERT and SV40 T could effectively prolong cell llfe without affecting the characteristics of mammary cells.

奶山羊FTO基因对乳腺上皮细胞脂代谢相关基因表达及甘油三酯合成的影响

试验旨在通过过表达和干扰技术探究脂肪与肥胖相关基因(fat mass and obesity associated,FTO)对奶山羊乳腺上皮细胞脂代谢相关基因的表达及甘油三酯合成的影响。通过克隆得到奶山羊(Capra hircus)乳腺组织FTO基因的CDS区序列,构建FTO过表达载体,并设计合成靶向FTO的siRNA(small interference RNA),利用实时荧光定量PCR(RT-qPCR)技术检测过表达或干扰FTO基因后奶山羊乳腺上皮细胞中脂代谢相关基因及甘油三酯含量的变化。结果表明,奶山羊FTO基因的CDS区全长1518 bp,与绵羊(Ovis aries)(NM_001104931.1)、牛(Bos taurus)(NM_001098142.1)和水牛(Bubalus bubalis)(XM_006043050.4)的序列相似性分别为99%、97%和96%。在乳腺上皮细胞中过表达FTO能够显著上调固醇调节元件结合蛋白1(sterol-regulatory element binding proteins 1,SREBF1)、脂肪酸合成酶(fatty acid synthase,FASN)、二酰甘油酰基转移酶2(diacylglycerol O-acyltransferase 2,DGAT2)的mRNA水平(P<0.05),显著下调甘油三酯水解相关基因如激素敏感脂酶(hormone-sensitive lipase,HSL)的表达水平(P<0.05),同时细胞中甘油三酯含量显著增加。在奶山羊乳腺上皮细胞中干扰FTO得到与之相反的结果。综上,FTO基因在调节奶山羊乳腺上皮细胞脂代谢中发挥重要的作用。

Pregnancies Resulting from Transgenic Embryos with Human Lactoferrin Gene Produced by Somatic Cell Nuclear Transfer

[Objective] The aim of this study is to understand the effects of donor cell type,embryo stage,number and transfer position on the efficiency of goat transgenic clone.[Method] Using somatic cell nuclear transfer technology,the single goat fetal fibroblasts(GFF)and mammary gland epithelial cells(GMGE)harboring human lactoferrin(hLF)gene were transferred to the enucleated oocyte.Reconstructed karyoplast-cytoplast couplets were fused,activated,and cultured in vitro.Embryos at 2-8 cell stage were transferred into oviduct of synchronized recipients,and blastocysts were transferred into uterine horn.[Result] The pregnancy rate was similar between GFF and GMGE(oviduct transfer:26.47% vs.20.00%),and between oviduct transfer and uterine horn transfer(26.47% vs.25.00%)for GFF group;pregnancy rate in the group with the mean number of embryo transferred per recipient of 21.2 was significantly higher than in those the 5.93 group and 9.64 group(40.00% vs.26.67% and 21.43%).[Conclusion] These results indicate that pregnancy rate of goat transgenic clone couldn't be affected by donor cell type,embryo stage and transfer position but be done by the number of embryo transferred per recipient.In addition,the study also suggests the feasibility of making transgenic goat using GMGE as donor cells.

竹叶黄酮对H_(2)O_(2)诱导奶牛乳腺上皮细胞焦亡的保护作用

旨在以竹叶黄酮(BLF)为添加物,探究BLF对过氧化氢(H_(2)O_(2))诱导奶牛乳腺上皮细胞(BMECs)焦亡的保护作用。本研究以BMECs为研究对象,分为对照组、80μg·mL^(-1) BLF处理组、800μmol·L^(-1) H_(2)O_(2)处理组和80μg·mL^(-1) BLF+800μmol·L^(-1) H_(2)O_(2)处理组。利用RT-qPCR、Western blot、免疫荧光、流式细胞术等技术,检测细胞焦亡相关基因和蛋白表达以及凋亡相关微粒样蛋白(ASC)荧光强度。结果表明,与对照组相比,800μmol·L^(-1) H_(2)O_(2)处理BMECs 8 h显著增加了奶牛乳腺上皮细胞的焦亡(P<0.05),H_(2)O_(2)处理后,NLRP3、ASC、GSDMD、IL-18、IL-1β等焦亡相关基因的相对表达量均显著升高(P<0.05),尤其是NLRP3,说明H_(2)O_(2)显著增加BMECs焦亡。与H_(2)O_(2)处理组相比,BLF可以降低正常细胞焦亡水平,显著降低NLRP3、Nek7、ASC、GSDMD、IL-18、IL-1β基因mRNA上调的趋势,显著缓解了H_(2)O_(2)导致的NLRP3、ASC、Nek7、pro-caspase1、caspase1 p20、GSDMD-N、IL-18和IL-1β胞内焦亡相关蛋白表达的升高(P<0.05),ASC的荧光强度显著降低(P<0.05)。综上所述,H_(2)O_(2)显著上调NLRP3、ASC、Caspase-1、GSDMD、IL-1β、IL-18焦亡基因和蛋白表达水平,诱导奶牛乳腺上皮细胞焦亡。BLF通过降低NLRP3炎症小体通路蛋白和基因表达,降低了炎症因子水平,从而缓解奶牛乳腺上皮细胞焦亡。

基于网络药理学探究金银花-连翘治疗奶牛乳房炎的作用机制及体外验证

为了探究金银花-连翘治疗奶牛乳房炎的作用机制,试验采用中药系统药理学分析(TCMSP)数据库获得金银花-连翘的活性成分及相关作用靶点蛋白,并将作用靶点蛋白进一步转化为靶点基因;利用DisGeNET数据库、GeneCards数据库和NCBI数据库检索奶牛乳房炎相关基因靶点;通过String数据库和Cystoscape v3.7.1软件构建金银花-连翘的有效活性成分靶点与奶牛乳房炎疾病靶点蛋白互作(PPI)网络图;采用David数据库进行金银花-连翘与奶牛乳房炎交集靶点所涉及的GO功能注释与KEGG信号通路富集分析,进而探究金银花-连翘治疗奶牛乳房炎的作用机制;建立奶牛乳腺上皮细胞炎症模型,采用ELISA检测金银花-连翘水提物对相关细胞因子表达的影响。结果表明:金银花-连翘主要活性成分包括β-谷甾醇、山奈酚、木犀草素、槲皮素等;共筛选获得239个药物活性成分主要涉及基因靶点及296个奶牛乳房炎基因靶点,其中交集靶点38个,以肿瘤坏死因子(TNF)、白细胞介素-6(IL-6)、白蛋白(ALB)、白细胞介素-1β(IL-1β)、白细胞介素-8(CXCL8)等为主。GO功能注释到的生物进程主要包括MAP激酶活性的正调控、炎症反应、一氧化氮生物合成过程的正调控等;细胞组分主要包括细胞核、细胞质、细胞表面等;分子功能主要包括细胞因子活性、转录因子活性等。KEGG信号通路主要富集在脂质与动脉粥样硬化、IL-17信号通路等;金银花-连翘水提物在体外可显著降低IL-6、IL-1β和CXCL8水平(P<0.05),发挥抗炎作用。说明金银花-连翘可能通过β-谷甾醇、山奈酚、木犀草素、槲皮素等活性成分调节IL-17信号通路,并作用于IL-6、IL-1β、CXCL8等靶点来治疗奶牛乳房炎。

大肠杆菌感染奶牛乳腺上皮细胞和小鼠乳腺组织致其线粒体损伤的机制研究

旨在探究大肠杆菌(Escherichia coli,E.coli)感染奶牛乳腺上皮细胞和小鼠乳腺组织致其线粒体损伤的机制。本试验以奶牛乳腺上皮细胞和小鼠乳腺为研究对象,按试验要求分别随机分成3组:空白对照(Control)组、大肠杆菌(E.coli)组和脂多糖(lipopolysaccharide,LPS)组。Control组奶牛乳腺上皮细胞和小鼠乳腺未被E.coli感染;E.coli组奶牛乳腺上皮细胞和小鼠乳腺被感染复数为5或106 CFU的E.coli感染6或24 h,LPS组奶牛乳腺上皮细胞和小鼠乳腺经1μg·mL^(-1)或20 mg·kg^(-1)体重LPS处理6或24 h,奶牛乳腺上皮细胞每组3个重复,小鼠乳腺每组6只小鼠。结果表明:1)奶牛乳腺上皮细胞胞浆中角18蛋白被染成绿色且均匀分布在细胞浆内,细胞核被DAPI染成蓝色。2)正常培养的奶牛乳腺上皮细胞内线粒体结构完整,细胞连接紧密;经E.coli感染的奶牛乳腺上皮细胞细胞间隙增大,线粒体肿胀,线粒体嵴缺失且部分模糊消失。3)E.coli感染或LPS处理使小鼠乳腺腺泡内出现中性粒细胞,且使奶牛乳腺上皮细胞和小鼠乳腺线粒体能量代谢(D(520 nm)吸光值、ATP的含量、线粒体电子传递链复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ活性降低)、线粒体的融合与分裂(Drp1、Fis1、Mfn1、Mfn 2和OPA 1 mRNA表达减少)和线粒体的生物发生(PGC-1α、NRF1、TFAM和D-Loop的基因表达下降)极显著降低(P<0.05,P<0.01)。上述研究表明,E.coli感染主要通过LPS造成奶牛乳腺上皮细胞和小鼠乳腺线粒体能量代谢紊乱、抑制线粒体分裂与融合以及减少线粒体的生物发生,进而造成线粒体损伤,最终导致乳腺炎的发生。因此,确认E.coli感染是通过诱导线粒体损伤造成奶牛乳腺炎,且线粒体损伤可能是造成乳腺损伤的重要原因之一。

GPR37L1对奶牛乳腺上皮细胞乳成分合成相关基因表达的影响

运用分子生物学技术构建GPR37L1表达和干扰载体,以奶牛乳腺上皮细胞为试验模型,通过瞬时转染技术构建载体转染乳腺上皮细胞,探究GPR37L1对乳成分合成相关基因表达的影响。结果表明,GPR37L1表达和干扰载体构建成功,GPR37L1过表达或干扰可提高或降低乳脂合成相关基因及β-酪蛋白表达,揭示GPR37L1可正向调节乳成分合成。

采食高淀粉高油日粮奶牛的泌乳性能、乳成分变化及乳腺差异表达基因筛选

【目的】研究高淀粉高油日粮对奶牛泌乳性能和乳腺组织转录组的影响,探索乳脂下降综合征(Milk fat depression,MFD)的分子机制。【方法】选用8头荷斯坦泌乳奶牛,随机分为对照组和处理组(4头/组),采用2×2反转试验设计,分为2期,每期23 d,期间2组对调。每期的前16 d,对照组奶牛饲喂低淀粉低油的基础饲粮,对照组日粮的泌乳净能为6.78 MJ/kg;处理组奶牛在基础饲粮基础上添加266 g/kg(DM基础)细粉碎玉米和46 g/kg(DM基础)大豆油;后7 d 2组奶牛均喂基础饲粮,处理组日粮的泌乳净能为7.66 MJ/kg。分别于每期的第1、4、7、10、13、16、19和22天测定产奶量和乳成分,第16天采集乳腺组织用于检测转录本的变化。【结果】与对照组相比,处理组第13、16天奶牛的干物质采食量和产奶量显著降低(P<0.05);饲喂高淀粉高油饲粮7 d后乳脂率开始降低,其中,第10、13、16和19天的乳脂率和乳脂产量显著降低(P<0.05);第13、16和19天的乳蛋白、乳糖和非脂固形物含量显著提高(P<0.05)。在奶牛乳腺对照组和处理组中共检测到235个显著差异表达的基因,其中,64个上调、171个下调。GO分析表明,差异表达基因主要与炎症反应、α−氨基酸代谢、有机氮化合物代谢、细胞发育、脂质生物合成和脂肪细胞分化等相关;KEGG分析表明,差异表达基因主要与轴突导向、NF-κB信号通路、钙信号通路等相关。结合差异表达基因与泌乳性能的相关性分析,本研究筛选出了部分与脂质调控相关的基因作为研究奶牛MFD状态下脂质代谢的候选基因,包括在乳腺中下调表达的FGFR4、VDR、HTR2B、CCL21和TYRP1。【结论】高淀粉高油饲粮饲喂奶牛降低了干物质采食量、产奶量和乳脂率,提高了乳蛋白、乳糖和非脂固形物含量,下调了奶牛乳腺中脂肪酸合成相关基因的表达。本研究为科学配制日粮和研究MFD的分子机制研究提供了数据参考。

结缔组织生长因子体外调控奶牛乳腺上皮细胞生长和泌乳分化

旨在探究结缔组织生长因子在体外培养体系中对奶牛乳腺上皮细胞生长和泌乳分化的调控作用。本研究主要通过人为添加结缔组织生长因子(connective tissue growth factor,CTGF)重组蛋白和过表达CTGF基因分析其对细胞增殖、凋亡、乳脂和乳蛋白合成分泌及信号通路的影响。使用EdU试剂盒和流式细胞仪分别检测细胞增殖凋亡情况;应用尼罗红染料和甘油三酯试剂盒检测细胞内脂滴数量和细胞外培养液乳脂含量;实时荧光定量PCR和蛋白免疫印迹检测细胞增殖凋亡,β酪蛋白,乳脂和乳蛋白合成关键信号分子以及细胞外基质细胞表面受体β1整联蛋白的表达;免疫共沉淀分析CTGF和β1整联蛋白之间的蛋白质相互作用。结果表明:体外培养时,无论CTGF重组蛋白还是CTGF过表达均能通过增强增殖、抑制凋亡促进贴壁细胞生长;实时荧光定量PCR和蛋白免疫印迹结果表明,CTGF在转录和翻译水平增强促增殖的CyclinD1、MAPK和Bcl2表达,抑制促凋亡的Caspase3和Bax表达;CTGF一方面上调乳脂合成关键基因FASN、SREBP1、PPARγ表达水平,促进细胞内脂滴合成和胞外甘油三酯分泌;另一方面上调乳蛋白合成关键基因PRLR、STAT5和p-STAT5表达水平,进而显著促进β酪蛋白合成;CTGF上调β1整联蛋白表达水平,Co-IP也证实了CTGF和β1整联蛋白之间存在蛋白质相互作用。综上所述,CTGF促进体外培养的奶牛乳腺上皮细胞生长及泌乳能力;CTGF与β1整联蛋白共存于黏附复合物,可以通过影响β1整联蛋白信号途径实现其部分生物学作用。

催乳素对奶牛RANKL基因启动子活性的研究

文章以奶牛乳腺上皮细胞为实验模型,探讨催乳素对RANKL基因启动子活性的调节。采用Western Blot方法检测催乳素对RANKL蛋白表达的影响,构建RANKL启动子荧光素酶载体,采用双荧光素酶报告基因检测系统检测催乳素对RANKL基因启动子活性影响,采用定点合成突变的方法,构建突变型RANKL启动子荧光素酶载体,运用双荧光素酶报告基因检测系统检测催乳素对突变型RANKL启动子活性影响。结果表明,催乳素能够显著提高乳腺上皮细胞RANKL启动子活性及RANKL蛋白表达,催乳素响应元件在奶牛RANKL基因启动子-826~-814 bp区域。

miR-223对脂多糖诱导的奶牛乳腺上皮细胞炎症反应的影响

以中国荷斯坦奶牛乳腺上皮细胞(dairy cow mammary epithelial cell,DCMECs)为研究模型,探讨mi R-223对脂多糖(lipopolysaccharide,LPS)诱导的DCMECs炎症反应与乳脂合成的影响。应用Western blot检测肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)与脂肪酸合成酶(fatty acid synthase,FASN)的表达情况,通过脂质体转染技术将mi R-223转染至DCMECs,qRT-PCR检测mi R-223的相对表达量,采用原位荧光技术分别检测DCMECs的凋亡与乳脂合成能力。结果表明LPS诱导DCMECs炎症反应的最佳浓度为1μg/m L;添加LPS可促进DCMECs mi R-223的表达;DCMECs转染mi R-223后,mi R-223的表达显著上调;mi R-223可下调LPS诱导的DCMECs炎症蛋白因子TNF-α,上调乳脂合成相关蛋白FASN,抑制LPS诱导的细胞凋亡,促进LPS诱导的乳脂合成。

过表达miRNA-424-5p靶向AKT3对奶牛子宫内膜上皮细胞凋亡的影响

[目的]本试验通过过表达miRNA-424-5p,明确miRNA-424-5p与其靶基因丝氨酸/苏氨酸激酶3(AKT serine/threonine kinase 3,AKT3)对奶牛子宫内膜上皮细胞凋亡影响的机制,为阐明miRNA-424-5p在奶牛胎盘分离过程中的作用机制提供试验基础和理论依据。[方法]试验分为3组:空白对照组(Control)、阴性对照组(miRNA-424-5p mimics NC)和过表达组(miRNA-424-5p mimics)。采用茎环法实时荧光定量PCR检测转染miRNA-424-5p mimics后奶牛子宫内膜上皮细胞miRNA-424-5p的表达变化;采用Western blotting及实时荧光定量PCR检测过表达后AKT3和凋亡相关因子的表达变化,采用Annexin V-FITC/PI法检测奶牛子宫内膜上皮细胞凋亡情况。[结果]与空白对照及阴性对照组相比,转染miRNA-424-5p mimics后子宫内膜上皮细胞miRNA-424-5p mRNA的表达量极显著升高(P<0.01),B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)相关X蛋白(Bax)、半胱氨酸天冬氨酸蛋白酶3(cysteinyl aspartate specific proteinase 3,Caspase3)和Caspase9的mRNA表达量极显著升高(P<0.01),AKT3和Bcl-2的mRNA表达量极显著降低(P<0.01);Bax和Caspase3蛋白表达量极显著升高(P<0.01),Caspase9蛋白表达量显著升高(P<0.05),AKT3和Bcl-2蛋白表达量极显著降低(P<0.01);细胞凋亡率极显著升高(P<0.01)。[结论]过表达miRNA-424-5p可通过靶向调控AKT3使奶牛子宫内膜上皮细胞凋亡因子Bax、Caspase3和Caspase9的表达量增加,使Bcl-2的表达量降低,进而促进细胞凋亡。

RANKL对LPS诱导奶牛乳腺上皮细胞炎症反应的作用研究

文章研究利用LPS诱导建立奶牛乳腺上皮细胞炎症模型,过表达RANKL后,采用MTT法检测奶牛乳腺上皮细胞炎症模型中奶牛乳腺上皮细胞活力,采用荧光定量PCR技术检测奶牛乳腺上皮细胞炎症模型中炎症因子IL1β、IL6、i NOS、TNF-α的m RNA表达,探讨RANKL对LPS诱导的奶牛乳腺上皮细胞炎症反应的作用。结果表明,以10μg/mL LPS处理奶牛乳腺上皮细胞24 h建立奶牛乳腺上皮细胞炎症模型,RANKL可显著提高奶牛乳腺上皮细胞炎症模型中奶牛乳腺上皮细胞活力,降低奶牛乳腺上皮细胞炎症模型中IL1β、IL6、i NOS的mRNA表达,同时显著降低奶牛乳腺上皮细胞炎症模型中TNF-α的mRNA及蛋白表达。

热应激对奶牛免疫功能、消化道稳态和乳腺健康的影响及机制

奶牛单位体重散热面积小,且汗腺不发达,在产奶过程中易产生大量热量,这会导致它们易遭受热应激,进而给奶牛带来多方面的不良影响,是制约奶业健康发展的重要因素之一。正常的免疫功能、消化道稳态和乳腺健康是奶牛发挥生产潜能的基本保障。热应激会严重抑制奶牛免疫功能,破坏消化道稳态,损害乳腺健康。本文系统综述了热应激对奶牛免疫功能、消化系统微生态和乳腺功能与健康的影响以及机制研究进展,旨在为缓解热应激对奶牛健康的损害,制定健康饲养管理方案提供理论参考。