Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells
This study aimed to examine the effects of increasing levels of three 18-carbon fatty acids (stearate, oleate and linoleate) on mammary lipogenesis, and to evaluate their effects on the milk lipogenic pathway in porcine mammary epithelial cells (pMECs). We found that increasing the three of 18-carbo...
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MDPI AG
2021-01-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/3/1294 |
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| author | Yantao Lv Fang Chen Shihai Zhang Jun Chen Yinzhi Zhang Min Tian Wutai Guan |
| author_facet | Yantao Lv Fang Chen Shihai Zhang Jun Chen Yinzhi Zhang Min Tian Wutai Guan |
| author_sort | Yantao Lv |
| collection | DOAJ |
| description | This study aimed to examine the effects of increasing levels of three 18-carbon fatty acids (stearate, oleate and linoleate) on mammary lipogenesis, and to evaluate their effects on the milk lipogenic pathway in porcine mammary epithelial cells (pMECs). We found that increasing the three of 18-carbon fatty acids enhanced the cellular lipid synthesis in a dose-dependent manner, as reflected by the increased (triacylglycerol) TAG content and cytosolic lipid droplets in pMECs. The increased lipid synthesis by the three 18-carbon fatty acids was probably caused by the up-regulated expression of major genes associated with milk fat biosynthesis, including <i>CD36</i> (long chain fatty acid uptake); <i>GPAM</i>, <i>AGPAT6</i>, <i>DGAT1</i> (TAG synthesis); <i>PLIN2</i> (lipid droplet formation); and <i>PPARγ</i> (regulation of transcription). Western blot analysis of CD36, DGAT1 and PPARγ proteins confirmed this increase with the increasing incubation of 18-carbon fatty acids. Interestingly, the mRNA expressions of <i>ACSL3</i> and <i>FABP3</i> (fatty acids intracellular activation and transport) were differentially affected by the three 18-carbon fatty acids. The cellular mRNA expressions of <i>ACSL3</i> and <i>FABP3</i> were increased by stearate, but were decreased by oleate or linoleate. However, the genes involved in fatty acid de novo synthesis (<i>ACACA</i> and <i>FASN</i>) and the regulation of transcription (<i>SREBP1</i>) were decreased by incubation with increasing concentrations of 18-carbon fatty acids. In conclusion, our findings provided evidence that 18-carbon fatty acids (stearate, oleate and linoleate) significantly increased cytosolic TAG accumulation in a dose-dependent manner, probably by promoting lipogenic genes and proteins that regulate the channeling of fatty acids towards milk TAG synthesis in pMECs. |
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| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-09T03:25:21Z |
| publishDate | 2021-01-01 |
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| series | International Journal of Molecular Sciences |
| spelling | doaj.art-5471ae8d1eba4458acd07d4bc84350ac2023-12-03T15:02:38ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-01-01223129410.3390/ijms22031294Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial CellsYantao Lv0Fang Chen1Shihai Zhang2Jun Chen3Yinzhi Zhang4Min Tian5Wutai Guan6College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaCollege of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, ChinaThis study aimed to examine the effects of increasing levels of three 18-carbon fatty acids (stearate, oleate and linoleate) on mammary lipogenesis, and to evaluate their effects on the milk lipogenic pathway in porcine mammary epithelial cells (pMECs). We found that increasing the three of 18-carbon fatty acids enhanced the cellular lipid synthesis in a dose-dependent manner, as reflected by the increased (triacylglycerol) TAG content and cytosolic lipid droplets in pMECs. The increased lipid synthesis by the three 18-carbon fatty acids was probably caused by the up-regulated expression of major genes associated with milk fat biosynthesis, including <i>CD36</i> (long chain fatty acid uptake); <i>GPAM</i>, <i>AGPAT6</i>, <i>DGAT1</i> (TAG synthesis); <i>PLIN2</i> (lipid droplet formation); and <i>PPARγ</i> (regulation of transcription). Western blot analysis of CD36, DGAT1 and PPARγ proteins confirmed this increase with the increasing incubation of 18-carbon fatty acids. Interestingly, the mRNA expressions of <i>ACSL3</i> and <i>FABP3</i> (fatty acids intracellular activation and transport) were differentially affected by the three 18-carbon fatty acids. The cellular mRNA expressions of <i>ACSL3</i> and <i>FABP3</i> were increased by stearate, but were decreased by oleate or linoleate. However, the genes involved in fatty acid de novo synthesis (<i>ACACA</i> and <i>FASN</i>) and the regulation of transcription (<i>SREBP1</i>) were decreased by incubation with increasing concentrations of 18-carbon fatty acids. In conclusion, our findings provided evidence that 18-carbon fatty acids (stearate, oleate and linoleate) significantly increased cytosolic TAG accumulation in a dose-dependent manner, probably by promoting lipogenic genes and proteins that regulate the channeling of fatty acids towards milk TAG synthesis in pMECs.https://www.mdpi.com/1422-0067/22/3/129418-carbon fatty acidsporcine mammary epithelial cellsmilk fat biosynthesislipogenic genes |
| spellingShingle | Yantao Lv Fang Chen Shihai Zhang Jun Chen Yinzhi Zhang Min Tian Wutai Guan Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells International Journal of Molecular Sciences 18-carbon fatty acids porcine mammary epithelial cells milk fat biosynthesis lipogenic genes |
| title | Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells |
| title_full | Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells |
| title_fullStr | Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells |
| title_full_unstemmed | Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells |
| title_short | Metabolic Transition of Milk Triacylglycerol Synthesis in Response to Varying Levels of Three 18-Carbon Fatty Acids in Porcine Mammary Epithelial Cells |
| title_sort | metabolic transition of milk triacylglycerol synthesis in response to varying levels of three 18 carbon fatty acids in porcine mammary epithelial cells |
| topic | 18-carbon fatty acids porcine mammary epithelial cells milk fat biosynthesis lipogenic genes |
| url | https://www.mdpi.com/1422-0067/22/3/1294 |
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