1
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Goel D, Kumar S. Advancements in unravelling the fundamental function of the ATAD3 protein in multicellular organisms. Adv Biol Regul 2024; 93:101041. [PMID: 38909398 DOI: 10.1016/j.jbior.2024.101041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/05/2024] [Accepted: 06/18/2024] [Indexed: 06/25/2024]
Abstract
ATPase family AAA domain containing protein 3, commonly known as ATAD3 is a versatile mitochondrial protein that is involved in a large number of pathways. ATAD3 is a transmembrane protein that spans both the inner mitochondrial membrane and outer mitochondrial membrane. It, therefore, functions as a connecting link between the mitochondrial lumen and endoplasmic reticulum facilitating their cross-talk. ATAD3 contains an N-terminal domain which is amphipathic in nature and is inserted into the membranous space of the mitochondria, while the C-terminal domain is present towards the lumen of the mitochondria and contains the ATPase domain. ATAD3 is known to be involved in mitochondrial biogenesis, cholesterol transport, hormone synthesis, apoptosis and several other pathways. It has also been implicated to be involved in cancer and many neurological disorders making it an interesting target for extensive studies. This review aims to provide an updated comprehensive account of the role of ATAD3 in the mitochondria especially in lipid transport, mitochondrial-endoplasmic reticulum interactions, cancer and inhibition of mitophagy.
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Affiliation(s)
- Divya Goel
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Sudhir Kumar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
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2
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Chen L, Li Y, Zambidis A, Papadopoulos V. ATAD3A: A Key Regulator of Mitochondria-Associated Diseases. Int J Mol Sci 2023; 24:12511. [PMID: 37569886 PMCID: PMC10419812 DOI: 10.3390/ijms241512511] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023] Open
Abstract
Mitochondrial membrane protein ATAD3A is a member of the AAA-domain-containing ATPases superfamily. It is important for the maintenance of mitochondrial DNA, structure, and function. In recent years, an increasing number of ATAD3A mutations have been identified in patients with neurological symptoms. Many of these mutations disrupt mitochondrial structure, function, and dynamics and are lethal to patients at a young age. Here, we summarize the current understanding of the relationship between ATAD3A and mitochondria, including the interaction of ATAD3A with mitochondrial DNA and mitochondrial/ER proteins, the regulation of ATAD3A in cholesterol mitochondrial trafficking, and the effect of known ATAD3A mutations on mitochondrial function. In the current review, we revealed that the oligomerization and interaction of ATAD3A with other mitochondrial/ER proteins are vital for its various functions. Despite affecting different domains of the protein, nearly all documented mutations observed in ATAD3A exhibit either loss-of-function or dominant-negative effects, potentially leading to disruption in the dimerization of ATAD3A; autophagy; mitophagy; alteration in mitochondrial number, size, and cristae morphology; and diminished activity of mitochondrial respiratory chain complexes I, IV, and V. These findings imply that ATAD3A plays a critical role in mitochondrial dynamics, which can be readily perturbed by ATAD3A mutation variants.
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Affiliation(s)
| | | | | | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 99089, USA; (L.C.); (Y.L.); (A.Z.)
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3
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Chen L, Li Y, Sottas C, Lazaris A, Petrillo SK, Metrakos P, Li L, Ishida Y, Saito T, Garza S, Papadopoulos V. Loss of mitochondrial ATPase ATAD3A contributes to nonalcoholic fatty liver disease through accumulation of lipids and damaged mitochondria. J Biol Chem 2022; 298:102008. [PMID: 35513069 PMCID: PMC9157002 DOI: 10.1016/j.jbc.2022.102008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/30/2022] [Accepted: 04/12/2022] [Indexed: 11/26/2022] Open
Abstract
Mitochondrial ATPase ATAD3A is essential for cholesterol transport, mitochondrial structure, and cell survival. However, the relationship between ATAD3A and nonalcoholic fatty liver disease (NAFLD) is largely unknown. In this study, we found that ATAD3A was upregulated in the progression of NAFLD in livers from rats with diet-induced nonalcoholic steatohepatitis and in human livers from patients diagnosed with NAFLD. We used CRISPR-Cas9 to delete ATAD3A in Huh7 human hepatocellular carcinoma cells and used RNAi to silence ATAD3A expression in human hepatocytes isolated from humanized liver-chimeric mice to assess the influence of ATAD3A deletion on liver cells with free cholesterol (FC) overload induced by treatment with cholesterol plus 58035, an inhibitor of acetyl-CoA acetyltransferase. Our results showed that ATAD3A KO exacerbated FC accumulation under FC overload in Huh7 cells and also that triglyceride levels were significantly increased in ATAD3A KO Huh7 cells following inhibition of lipolysis mediated by upregulation of lipid droplet-binding protein perilipin-2. Moreover, loss of ATAD3A upregulated autophagosome-associated light chain 3-II protein and p62 in Huh7 cells and fresh human hepatocytes through blockage of autophagosome degradation. Finally, we show the mitophagy mediator, PTEN-induced kinase 1, was downregulated in ATAD3A KO Huh7 cells, suggesting that ATAD3A KO inhibits mitophagy. These results also showed that loss of ATAD3A impaired mitochondrial basal respiration and ATP production in Huh7 cells under FC overload, accompanied by downregulation of mitochondrial ATP synthase. Taken together, we conclude that loss of ATAD3A promotes the progression of NAFLD through the accumulation of FC, triglyceride, and damaged mitochondria in hepatocytes.
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Affiliation(s)
- Liting Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Yuchang Li
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Chantal Sottas
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Anthoula Lazaris
- Research Institute of the McGill University Health Center, Montreal, Quebec, Canada; Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Stephanie K Petrillo
- Research Institute of the McGill University Health Center, Montreal, Quebec, Canada; Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Peter Metrakos
- Research Institute of the McGill University Health Center, Montreal, Quebec, Canada; Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Lu Li
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Yuji Ishida
- Department of Medicine, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; Research & Development Department, PhoenixBio, Co, Ltd, Higashi-Hiroshima, Hiroshima, Japan
| | - Takeshi Saito
- Department of Medicine, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; University of Southern California Research Center for Liver Diseases, Los Angeles, California, USA
| | - Samuel Garza
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA.
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4
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Wang L, Qi H, Li D, Liu L, Chen D, Gao X. METTL3 is a key regulator of milk synthesis in mammary epithelial cells. Cell Biol Int 2021; 46:359-369. [PMID: 34865263 DOI: 10.1002/cbin.11733] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/31/2021] [Accepted: 11/28/2021] [Indexed: 12/15/2022]
Abstract
The enzyme m6 A methyltransferase-like 3 (METTL3) catalyzes N6 -methyladenosine (m6 A) modification in eukaryotic messenger RNAs (mRNAs). However, the physiological function and molecular mechanism of METTL3 in mammalian cells have not been fully understood. Here we showed that METTL3 was highly expressed in mouse mammary gland of the lactation period. METTL3 was located in the nucleus of bovine mammary epithelial cells (MECs), and methionine (Met) and β-estrodial (E2) upregulated METTL3 protein level. METTL3 knockdown decreased milk protein and fat synthesis, whereas its overexpression had the opposite effects. METTL3 overexpression stimulated mRNA expression and protein phosphorylation of the mechanistic target of rapamycin (mTOR) and mRNA and protein expression of sterol regulatory element binding protein 1 (SREBP1), whereas METTL3 knockdown blocked the stimulatory effects of Met and E2 on these processes. Furthermore, METTL3 overexpression led to increased mRNA m6 A methylation of mTOR and SREBP1, whereas METTL3 knockdown suppressed the stimulatory effects of Met and E2 on these processes. The interaction between METTL3 and glycyl-tRNA synthetase (GlyRS) was confirmed by Co-immunoprecipitation and fluorescence resonance energy transfer approaches, and colocalization observation further showed that Met and E2 treatment increased this interaction. GlyRS knockdown abolished METTL3 protein levels upregulated by Met and E2, and METTL3 knockdown markedly decreased the effects of GlyRS overexpression on mTOR expression and phosphorylation and SREBP1 expression. In summary, we demonstrate that METTL3 is a key positive regulator of Met and E2-stimulated and GlyRS-mediated mTOR and SREBP1 signaling pathways and milk protein and fat synthesis in mammary epithelial cells.
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Affiliation(s)
- Lulu Wang
- College of Animal Science, Yangtze University, Jingzhou, China.,College of Life Science, Northeast Agricultural University, Harbin, China
| | - Hao Qi
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Dong Li
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Lijie Liu
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Dongying Chen
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Xuejun Gao
- College of Animal Science, Yangtze University, Jingzhou, China
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5
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Han M, Zhang M. The regulatory mechanism of amino acids on milk protein and fat synthesis in mammary epithelial cells: a mini review. Anim Biotechnol 2021; 34:402-412. [PMID: 34339350 DOI: 10.1080/10495398.2021.1950743] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Mammary epithelial cell (MEC) is the basic unit of the mammary gland that synthesizes milk components including milk protein and milk fat. MECs can sense to extracellular stimuli including nutrients such as amino acids though different sensors and signaling pathways. Here, we review recent advances in the regulatory mechanism of amino acids on milk protein and fat synthesis in MECs. We also highlight how these mechanisms reflect the amino acid requirements of MECs and discuss the current and future prospects for amino acid regulation in milk production.
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Affiliation(s)
- Meihong Han
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Minghui Zhang
- College of Animal Science, Yangtze University, Jingzhou, China
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6
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Song Y, Loor JJ, Li C, Liang Y, Li N, Shu X, Yang Y, Feng X, Du X, Wang Z, Liu G, Li X. Enhanced mitochondrial dysfunction and oxidative stress in the mammary gland of cows with clinical ketosis. J Dairy Sci 2021; 104:6909-6918. [PMID: 33715853 DOI: 10.3168/jds.2020-19964] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/26/2021] [Indexed: 12/13/2022]
Abstract
Ketosis is a common metabolic disorder in high-producing dairy cows during the peripartal period. Negative energy balance leads to increased circulating levels of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB), consequently increasing the risk of ketosis. It is well-known that NEFA and BHB can induce lipotoxicity and oxidative stress in bovine tissues/organs including the liver and adipose tissue. Although the mammary gland is one important site for NEFA and BHB metabolism, whether an overload in their concentrations within mammary cells causes oxidative stress during ketosis remains unclear. Thus, the present study compared oxidative stress status and mitochondrial function in mammary tissues harvested by biopsy from healthy (n = 15) and clinically ketotic (n = 15) dairy cows within 2 to 3 wk postpartum. Compared with healthy cows, ketotic cows had depressed daily milk yield (median: 28.92 vs. 21.56 kg) and dry matter intake (median: 22.36 vs. 19.92 kg/d), accompanied by elevated plasma NEFA (median: 0.32 vs. 1.26 mM), BHB (median: 0.52 vs. 3.69 mM), and lower plasma glucose (median: 4.55 vs. 2.13 mM). As detected by a commercial kit, a greater level of reactive oxygen species in mammary epithelial cells of ketotic cows, and greater oxidant indices including hydrogen peroxide and malondialdehyde coupled with lower antioxidant indices including glutathione peroxidase, catalase, and superoxide dismutase activities as detected by the respective biochemical kits in the homogenate of mammary tissue of ketotic cows indicated increased oxidative stress status. Lower citrate synthase activity and ATP production as detected by the respective commercial kits coupled with lower mRNA and protein abundance of mitochondrial respiratory chain oxidative phosphorylation complexes I-V (CO I-V) in ketotic cows suggested an impairment of mitochondrial function. This was supported by lower mRNA and protein abundance of nucleus-derived mitochondrial function regulators including peroxisome proliferator activated receptor gamma coactivator 1 α, mitofusin 2, nuclear respiratory factor 1, and mitochondrial transcription factor A. Lower mitochondrial membrane potential evaluated via the tetraethylbenzimidazolylcarbocyanine iodide (JC-1) labeling method and swollen mitochondria in mammary epithelial cells of ketotic cows suggested the existence of mitochondrial damage. Overall, the present study revealed extensive mitochondrial dysfunction and oxidative stress in the mammary gland of clinically ketotic cows. As such, data suggest that reduced milk yield in cows with ketosis is partly due to enhanced oxidative stress along with mitochondrial dysregulation in the mammary gland.
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Affiliation(s)
- Yuxiang Song
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Juan J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - Congyi Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Yusheng Liang
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801
| | - Na Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Xin Shu
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Yuchen Yang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Xiancheng Feng
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Xiliang Du
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Zhe Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Guowen Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China
| | - Xinwei Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China.
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7
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Lang L, Loveless R, Teng Y. Emerging Links between Control of Mitochondrial Protein ATAD3A and Cancer. Int J Mol Sci 2020; 21:E7917. [PMID: 33113782 PMCID: PMC7663417 DOI: 10.3390/ijms21217917] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/17/2022] Open
Abstract
Spanning from the mitochondria's outer surface to the inner membrane, the nuclear-encoded protein ATAD3A maintains vital roles in regulating mitochondrial dynamics, homeostasis, metabolism, and interactions with the endoplasmic reticulum. Recently, elevated levels of ATAD3A have been reported in several types of cancer and to be tightly correlated with cancer development and progression, including increased cancer cell potential of proliferation, metastasis, and resistance to chemotherapy and radiotherapy. In the current review, we reveal ATAD3A as the link between mitochondrial functions and cancer biology and the accumulating evidence presenting ATAD3A as an attractive target for the development of novel cancer therapy to inhibit aberrant cancer metabolism and progression.
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Affiliation(s)
- Liwei Lang
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (L.L.); (R.L.)
| | - Reid Loveless
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (L.L.); (R.L.)
| | - Yong Teng
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA; (L.L.); (R.L.)
- Georgia Cancer Center, Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Department of Medical Laboratory, Imaging and Radiologic Sciences, College of Allied Health, Augusta University, Augusta, GA 30912, USA
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8
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Tong J, Sun M, Zhang H, Yang D, Zhang Y, Xiong B, Jiang L. Proteomic analysis of bovine mammary epithelial cells after in vitro incubation with S. agalactiae: potential biomarkers. Vet Res 2020; 51:98. [PMID: 32746898 PMCID: PMC7398202 DOI: 10.1186/s13567-020-00808-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 05/19/2020] [Indexed: 12/21/2022] Open
Abstract
Streptococcus agalactiae is one of the causative agents of subclinical mastitis, a common disease of dairy cows that causes great economic losses in the industry worldwide. It is thought that pathology is mainly due to inflammatory damage of bovine mammary epithelial cells (bMECs); however, the mechanism by which S. agalactiae damages the bMECs is not clear. The aim of this study was to evaluate the inflammatory effects of S. agalactiae on bMECs and the resulting changes in protein profiles. The bMECs were incubated with S. agalactiae for different times and assayed for cell viability by MTT assay, apoptosis by annexin V and propidium iodide dual staining, and morphological and ultrastructural changes by scanning and transmission electron microscopy. Quantitative real-time PCR was used to determine the effect of S. agalactiae on expression of mRNA of inflammatory factors in bMECs and protein levels were quantitated by liquid chromatography/mass spectrometry. Exposure to S. agalactiae significantly decreased the cell viability and triggered apoptosis, as well as up-regulating TNF-α, IL-1β and IL-6 mRNA, and inhibiting IL-8 expression. S. agalactiae also induced morphological and ultrastructural changes. Furthermore, we identified 325 up-regulated and 704 down-regulated proteins in the treated vs control group. All significant differentially expressed proteins (DSEPs) were classified into three major areas by function: biological processes, cellular components and molecular functions. These differentially expressed proteins included enzymes and proteins associated with various metabolic processes and cellular immunity. Pathway enrichment analysis showed that eight down-regulated signaling pathways were significantly enriched. Exposure to even subclinical levels of S. agalactiae can lead to inflammation and bMEC damage. Our data suggest some possible molecular mechanisms for the harmful effects of subclinical mastitis in dairy cows.
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Affiliation(s)
- Jinjin Tong
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China
| | - Mingwei Sun
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China
| | - Hua Zhang
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China
| | - Delian Yang
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China
| | - Yonghong Zhang
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China
| | - Benhai Xiong
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
| | - Linshu Jiang
- Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, People's Republic of China.
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9
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Zhen Z, Zhang M, Yuan X, Li M. Transcription factor E2F4 is a positive regulator of milk biosynthesis and proliferation of bovine mammary epithelial cells. Cell Biol Int 2020; 44:229-241. [PMID: 31475773 DOI: 10.1002/cbin.11225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 08/22/2019] [Indexed: 01/24/2023]
Abstract
The transcription factor E2F4 is a key determinant of cell differentiation and cell-cycle progression, but its function and regulatory mechanism are not completely understood. Here, we report that E2F4 acts as a positive regulator of the biosynthesis of milk components and proliferation of bovine mammary epithelial cells (BMECs). Overexpression of E2F4 in BMECs resulted in the upregulation of β-casein, triglyceride, and lactose levels and increased cell proliferation, whereas E2F4 knockdown by small interfering RNA had the opposite effects. We further detected that overexpression of E2F4 significantly increased the messenger RNA expression of mTOR, SREBP-1c, and Cyclin D1, and increased protein levels of SREBP-1c, and Cyclin D1, and the ratio of p-mTOR/mTOR, whereas E2F4 knockdown had the opposite effects. E2F4 was almost entirely located in the nucleus, and we further identified, via ChIP-qPCR analysis, that mTOR, SREBP-1c, and Cyclin D1 were E2F4 target genes, and exogenous administration of methionine, leucine, β-estradiol, and prolactin markedly increased the protein levels of E2F4 and its binding to the promoters of these three genes. In summary, our data reveal that E2F4 responds to extracellular stimuli and regulates the expression of mTOR, SREBP-1c, and Cyclin D1 for milk biosynthesis and proliferation of BMECs.
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Affiliation(s)
- Zhen Zhen
- The Key Laboratory of Dairy Science of Education Ministry, Food College, Northeast Agricultural University, Changjiang Road 600, Xiangfang District, Harbin, 150030, China
| | - Minghui Zhang
- The Key Laboratory of Dairy Science of Education Ministry, Food College, Northeast Agricultural University, Changjiang Road 600, Xiangfang District, Harbin, 150030, China
| | - Xiaohan Yuan
- The Key Laboratory of Dairy Science of Education Ministry, Food College, Northeast Agricultural University, Changjiang Road 600, Xiangfang District, Harbin, 150030, China
| | - Meng Li
- The Key Laboratory of Dairy Science of Education Ministry, Food College, Northeast Agricultural University, Changjiang Road 600, Xiangfang District, Harbin, 150030, China
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10
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Wang Y, Guo W, Xu H, Tang K, Zan L, Yang W. Melatonin suppresses milk fat synthesis by inhibiting the mTOR signaling pathway via the MT1 receptor in bovine mammary epithelial cells. J Pineal Res 2019; 67:e12593. [PMID: 31278759 DOI: 10.1111/jpi.12593] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/30/2019] [Accepted: 07/01/2019] [Indexed: 01/13/2023]
Abstract
Milk fat content is an important criterion for assessing milk quality and is one of the main target traits of dairy cattle breeding. Recent studies have shown the importance of melatonin in regulating lipid metabolism, but the potential effects of melatonin on milk fat synthesis in bovine mammary epithelial cells (BMECs) remain unclear. Here, we showed that melatonin supplementation at 10 μmol/L significantly downregulated the mRNA expression of lipid metabolism-related genes and resulted in lower lipid droplet formation and triglyceride accumulation. Moreover, melatonin significantly upregulated melatonin receptor subtype melatonin receptor 1a (MT1) gene expression, and the negative effects of melatonin on milk fat synthesis were reversed by treatment with the nonselective MT1/melatonin receptor subtype melatonin receptor 1b (MT2) antagonist. However, a selective MT2 antagonist did not modify the negative effects of melatonin on milk fat synthesis. In addition, KEGG analysis revealed that melatonin inhibition of milk fat synthesis may occur via the mTOR signaling pathway. Further analysis revealed that melatonin significantly suppressed the activation of the mTOR pathway by restricting the phosphorylation of mTOR, 4E-BP1, and p70S6K, and the inhibition of melatonin on milk fat synthesis was reversed by mTOR activator MHY1485 in BMECs. Furthermore, in vivo experiments in Holstein dairy cows showed that exogenous melatonin significantly decreased milk fat concentration. Our data from in vitro and in vivo studies revealed that melatonin suppresses milk fat synthesis by inhibiting the mTOR signaling pathway via the MT1 receptor in BMECs. These findings lay a foundation to identify a new potential means for melatonin to modulate the fat content of raw milk in Holstein dairy cows.
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Affiliation(s)
- Yujuan Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
- The Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Wenli Guo
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Haichao Xu
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Keqiong Tang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Linsen Zan
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
- The Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Wucai Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
- The Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
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11
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Luo C, Qi H, Huang X, Li M, Zhang L, Lin Y, Gao X. GlyRS is a new mediator of amino acid‐induced milk synthesis in bovine mammary epithelial cells. J Cell Physiol 2018; 234:2973-2983. [DOI: 10.1002/jcp.27115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/02/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Chaochao Luo
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Hao Qi
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Xin Huang
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Meng Li
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Li Zhang
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Ye Lin
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
| | - Xuejun Gao
- The Key Laboratory of Dairy Science of Education MinistryNortheast Agricultural UniversityHarbin China
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