1
|
Yang T, Guo J, Song H, Datsomor O, Chen Y, Jiang M, Zhan K, Zhao G. Hexokinase 1 and 2 mediates glucose utilization to regulate the synthesis of kappa casein via ribosome protein subunit 6 kinase 1 in bovine mammary epithelial cells. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2024; 16:338-349. [PMID: 38362515 PMCID: PMC10867561 DOI: 10.1016/j.aninu.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/09/2023] [Accepted: 01/07/2024] [Indexed: 02/17/2024]
Abstract
Glucose plays a vital part in milk protein synthesis through the mTOR signaling pathway in bovine mammary epithelial cells (BMEC). The objectives of this study were to determine how glucose affects hexokinase (HK) activity in BMEC and investigate the regulatory effect of HK in kappa casein (CSN3) synthesis via the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway in BMEC. For this, HK1 and HK2 were knocked out in BMEC using the CRISPR/Cas9 system. The gene and protein expression, glucose uptake, and cell proliferation were measured. We found that glucose uptake, cell proliferation, CSN3 gene expression levels, and expression of HK1 and HK2 increased with increasing glucose concentrations. Notably, glucose uptake was significantly reduced in HK2 knockout (HK2KO) BMEC treated with 17.5 mM glucose. Moreover, under the same glucose treatment conditions, the proliferative ability and abundance of CSN3 were significantly diminished in both HK1 knockout (HK1KO) and HK2KO BMEC compared with that in wild-type BEMC. We further observed that the phosphorylation levels of ribosome protein subunit 6 kinase 1 (S6K1) were reduced in HK1KO and HK2KO BMEC following treatment with 17.5 mM glucose. As expected, the levels of glucose-6-phosphate and the mRNA expression levels of glycolysis-related genes were decreased in both HK1KO and HK2KO BMEC following glucose treatment. These results indicated that the knockout of HK1 and HK2 inhibited cell proliferation and CSN3 expression in BMEC under glucose treatment, which may be associated with the inactivation of the S6K1 and inhibition of glycolysis.
Collapse
Affiliation(s)
| | | | - Han Song
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Osmond Datsomor
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Yuhang Chen
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Maocheng Jiang
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Kang Zhan
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Guoqi Zhao
- Institute of Animal Culture Collection and Application, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| |
Collapse
|
2
|
Sharmin MM, Hayashi S, Miyaji M, Ishizaki H, Matsuyama H, Haga S, Yonekura S. IGF-1 induces IRE1-XBP1-dependent endoplasmic reticulum biogenesis in bovine mammary epithelial cells. J Dairy Sci 2021; 104:12094-12104. [PMID: 34364639 DOI: 10.3168/jds.2021-20268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 06/18/2021] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) plays a key role in proliferation and galactopoiesis in mammary epithelial cells (MEC), but its definitive functions on endoplasmic reticulum (ER) during protein synthesis remain unknown. The present study aimed to elucidate the effects of IGF-1 on ER biogenesis in MEC in vitro and examined the expression of ER biogenesis-associated genes in the mammary gland during early lactation. We treated mammary alveolar cells-large T antigen cells (immortalized bovine MEC line established via stable transfection with simian virus-40 large T-antigen) with IGF-1 and examined ER biogenesis using the fluorescence intensity of an ER tracker and quantitative real-time PCR. We found IGF-1 significantly increased ER tracker staining and upregulated mRNA levels of ER biogenesis-related genes, such as CHKA (choline kinase α), PCYT1A (choline-phosphate cytidylyltransferase A), and SURF4 (surfeit locus protein 4). We focused on unfolded protein response to explore molecular mechanisms by which IGF-1 induces ER biogenesis. We found IGF-1 significantly increased mRNA levels of the XBP1 splicing form (XBP1s). Based on western blot analysis, IGF-1 induced the expression of (inositol-requiring kinase 1 α) protein, upstream of XBP1s, and phosphorylated-IRE1α. The inhibition of IRE1 endoribonuclease activity with 4-methylumbelliferone 8-carbaldehyde (4μ8C) significantly suppressed the increase in ER tracker fluorescence and ER biogenesis-related gene expression induced by IGF-1. Also, IGF-1-induced XBP1s and ER biogenesis-associated gene expression was inhibited by rapamycin, an inhibitor of mTORC1 (mammalian target of rapamycin complex 1), indicating that IRE1-XBP1 activation by IGF-1 is mediated by mTORC1. Moreover, to clarify the expression of XBP1s and ER biogenesis-associated genes expression under normal physiological conditions, mammary gland tissue from biopsies of dairy cows during late gestation and lactation were analyzed. In vivo data highlighted the significant increases in the mRNA levels of XBP1s and ER biogenesis-related genes in mammary gland tissue immediately after calving through 6 wk of lactation. The mRNA levels of IGF1R (IGF-1 receptor) in mammary glands increased during 6 wk of lactation. Therefore, the present study indicated for the first time that IGF-1 induces ER biogenesis by activating the IRE1-XBP1 axis under the regulation of mTORC1 in bovine MEC line.
Collapse
Affiliation(s)
- Mst Mamuna Sharmin
- Graduate School of Medicine, Science and Technology, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano 399-4598, Japan
| | - Satoko Hayashi
- Graduate School of Medicine, Science and Technology, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano 399-4598, Japan
| | - Makoto Miyaji
- Feed Production and Utilization Group, Division of Dairy Production Research, Hokkaido Agricultural Research Center, NARO, 1 Hitsujigaoka, Toyohira, Sapporo, Hokkaido 062-8555, Japan
| | - Hiroshi Ishizaki
- Grazing Animal Unit, Division of Grassland Farming, Institute of Livestock and Grassland Science, NARO, 768 Senbonmatsu, Nasushiobara, Tochigi 329-2793, Japan
| | - Hiroki Matsuyama
- Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan
| | - Satoshi Haga
- Grazing Animal Unit, Division of Grassland Farming, Institute of Livestock and Grassland Science, NARO, 768 Senbonmatsu, Nasushiobara, Tochigi 329-2793, Japan
| | - Shinichi Yonekura
- Graduate School of Medicine, Science and Technology, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano 399-4598, Japan; Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano 399-4598, Japan.
| |
Collapse
|
3
|
Yang C, Lim W, Bae H, Bazer FW, Song G. C-C motif chemokine ligand 2 induces proliferation and prevents lipopolysaccharide-induced inflammatory responses in bovine mammary epithelial cells. J Dairy Sci 2018; 101:4527-4541. [DOI: 10.3168/jds.2017-13966] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/29/2017] [Indexed: 01/24/2023]
|