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Deng H, Rao X, Zhang S, Chen L, Zong Y, Zhou R, Meng R, Dong X, Wu G, Li Q. Protein kinase CK2: An emerging regulator of cellular metabolism. Biofactors 2024; 50:624-633. [PMID: 38158592 DOI: 10.1002/biof.2032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/02/2023] [Indexed: 01/03/2024]
Abstract
The protein kinase casein kinase 2 (CK2) exerts its influence on the metabolism of three major cellular substances by phosphorylating essential protein molecules involved in various cellular metabolic pathways. These substances include hormones, especially insulin, rate-limiting enzymes, transcription factors of key genes, and cytokines. This regulatory role of CK2 is closely tied to important cellular processes such as cell proliferation and apoptosis. Additionally, tumor cells undergo metabolic reprogramming characterized by aerobic glycolysis, accelerated lipid β-oxidation, and abnormally active glutamine metabolism. In this context, CK2, which is overexpressed in various tumors, also plays a pivotal role. Hence, this review aims to summarize the regulatory mechanisms of CK2 in diverse metabolic pathways and tumor development, providing novel insights for the diagnosis, treatment, and prognosis of metabolism-related diseases and cancers.
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Affiliation(s)
- Huilin Deng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xinrui Rao
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sijia Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Leichong Chen
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Zong
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Zhou
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Meng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaorong Dong
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qianwen Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Kakadia JH, Khalid MU, Heinemann IU, Han VK. AMPK-mTORC1 pathway mediates hepatic IGFBP-1 phosphorylation in glucose deprivation: a potential molecular mechanism of hypoglycemia-induced impaired fetal growth. J Mol Endocrinol 2024; 72:e230137. [PMID: 38194365 PMCID: PMC10895286 DOI: 10.1530/jme-23-0137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/09/2024] [Indexed: 01/10/2024]
Abstract
Mechanisms underlying limitations in glucose supply that restrict fetal growth are not well established. IGF-1 is an important regulator of fetal growth and IGF-1 bioavailability is markedly inhibited by IGFBP-1 especially when the binding protein is hyperphosphorylated. We hypothesized that the AMPK-mTORC1 pathway increases IGFBP-1 phosphorylation in response to glucose deprivation. Glucose deprivation in HepG2 cells activated AMPK and TSC2, inhibited mTORC1 and increased IGFBP-1 secretion and site-specific phosphorylation. Glucose deprivation also decreased IGF-1 bioavailability and IGF-dependent activation of IGF-1R. AICAR (an AMPK activator) activated TSC2, inhibited mTORC1, and increased IGFBP-1 secretion/phosphorylation. Further, siRNA silencing of either AMPK or TSC2 prevented mTORC1 inhibition and IGFBP-1 secretion and phosphorylation in glucose deprivation. Our data suggest that the increase in IGFBP-1 phosphorylation in response to glucose deprivation is mediated by the activation of AMPK/TSC2 and inhibition of mTORC1, providing a possible mechanistic link between glucose deprivation and restricted fetal growth.
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Affiliation(s)
- Jenica H Kakadia
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
- Children's Health Research Institute, London, Ontario, Canada
| | - Muhammad U Khalid
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Ilka U Heinemann
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Victor K Han
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
- Children's Health Research Institute, London, Ontario, Canada
- Department of Pediatrics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
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3
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He W, Posey EA, Steele CC, Savell JW, Bazer FW, Wu G. Dietary glycine supplementation activates mechanistic target of rapamycin signaling pathway in tissues of pigs with intrauterine growth restriction. J Anim Sci 2024; 102:skae141. [PMID: 38761109 PMCID: PMC11217904 DOI: 10.1093/jas/skae141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 05/16/2024] [Indexed: 05/20/2024] Open
Abstract
The mechanistic target of rapamycin (mTOR) cell signaling pathway serves as the central mechanism for the regulation of tissue protein synthesis and growth. We recently reported that supplementing 1% glycine to corn- and soybean meal-based diets enhanced growth performance between weaning and market weights in pigs with intrauterine growth restriction (IUGR). Results of recent studies have revealed an important role for glycine in activating mTOR and protein synthesis in C2C12 muscle cells. Therefore, the present study tested the hypothesis that dietary glycine supplementation enhanced the mTOR cell signaling pathway in skeletal muscle and other tissues of IUGR pigs. At weaning (21 d of age), IUGR pigs and litter mates with normal birth weights (NBW) were assigned randomly to one of the two groups: supplementation with either 1% glycine or 1.19% l-alanine (isonitrogenous control) to a corn- and soybean meal-based diet. Tissues were obtained from the pigs within 1 wk after the feeding trial ended at 188 d of age to determine the abundances of total and phosphorylated forms of mTOR and its two major downstream proteins: eukaryotic initiation factor 4E-binding protein-1 (4EBP1) and ribosomal protein S6 kinase-1 (p70S6K). Results showed that IUGR decreased (P < 0.05) the abundances of both total and phosphorylated mTOR, 4EBP1, and p70S6K in the gastrocnemius muscle and jejunum. In the longissimus lumborum muscle of IUGR pigs, the abundances of total mTOR did not differ (P > 0.05) but those for phosphorylated mTOR and both total and phosphorylated 4EBP1 and p70S6K were downregulated (P < 0.05), when compared to NBW pigs. These adverse effects of IUGR in the gastrocnemius muscle, longissimus lumborum muscle, and jejunum were prevented (P < 0.05) by dietary glycine supplementation. Interestingly, the abundances of total or phosphorylated mTOR, 4EBP1, and p70S6K in the liver were not affected (P > 0.05) by IUGR or glycine supplementation. Collectively, our findings indicate that IUGR impaired the mTOR cell signaling pathway in the tissues of pigs and that adequate glycine intake was crucial for maintaining active mTOR-dependent protein synthesis for the growth and development of skeletal muscle.
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Affiliation(s)
- Wenliang He
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Erin A Posey
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Chandler C Steele
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Jeffrey W Savell
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Fuller W Bazer
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
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Rosario FJ, Chopra A, Biggar K, Powell TL, Gupta MB, Jansson T. Placental Remote Control of Fetal Metabolism: Trophoblast mTOR Signaling Regulates Liver IGFBP-1 Phosphorylation and IGF-1 Bioavailability. Int J Mol Sci 2023; 24:7273. [PMID: 37108437 PMCID: PMC10138459 DOI: 10.3390/ijms24087273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/02/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
The mechanisms mediating the restricted growth in intrauterine growth restriction (IUGR) remain to be fully established. Mechanistic target of rapamycin (mTOR) signaling functions as a placental nutrient sensor, indirectly influencing fetal growth by regulating placental function. Increased secretion and the phosphorylation of fetal liver IGFBP-1 are known to markedly decrease the bioavailability of IGF-1, a major fetal growth factor. We hypothesized that an inhibition of trophoblast mTOR increases liver IGFBP-1 secretion and phosphorylation. We collected conditioned media (CM) from cultured primary human trophoblast (PHT) cells with a silenced RAPTOR (specific inhibition of mTOR Complex 1), RICTOR (inhibition of mTOR Complex 2), or DEPTOR (activates both mTOR Complexes). Subsequently, HepG2 cells, a well-established model for human fetal hepatocytes, were cultured in CM from PHT cells, and IGFBP-1 secretion and phosphorylation were determined. CM from PHT cells with either mTORC1 or mTORC2 inhibition caused the marked hyperphosphorylation of IGFBP-1 in HepG2 cells as determined by 2D-immunoblotting while Parallel Reaction Monitoring-Mass Spectrometry (PRM-MS) identified increased dually phosphorylated Ser169 + Ser174. Furthermore, using the same samples, PRM-MS identified multiple CK2 peptides coimmunoprecipitated with IGFBP-1 and greater CK2 autophosphorylation, indicating the activation of CK2, a key enzyme mediating IGFBP-1 phosphorylation. Increased IGFBP-1 phosphorylation inhibited IGF-1 function, as determined by the reduced IGF-1R autophosphorylation. Conversely, CM from PHT cells with mTOR activation decreased IGFBP-1 phosphorylation. CM from non-trophoblast cells with mTORC1 or mTORC2 inhibition had no effect on HepG2 IGFBP-1 phosphorylation. Placental mTOR signaling may regulate fetal growth by the remote control of fetal liver IGFBP-1 phosphorylation.
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Affiliation(s)
- Fredrick J. Rosario
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Anand Chopra
- Institute of Biochemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Kyle Biggar
- Institute of Biochemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Theresa L. Powell
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Biochemistry, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Madhulika B. Gupta
- Department of Biochemistry, University of Western Ontario, London, ON N6A 3K7, Canada
- Department of Pediatrics, University of Western Ontario, London, ON N6A 3K7, Canada
- Children’s Health Research Institute, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Dya GA, Klychnikov OI, Adasheva DA, Vladychenskaya EA, Katrukha AG, Serebryanaya DV. IGF-Binding Proteins and Their Proteolysis as a Mechanism of Regulated IGF Release in the Nervous Tissue. BIOCHEMISTRY (MOSCOW) 2023; 88:S105-S122. [PMID: 37069117 DOI: 10.1134/s0006297923140079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) play a key role in the maintenance of the nervous tissue viability. IGF-1 and IGF-2 exhibit the neuroprotective effects by stimulating migration and proliferation of nervous cells, activating cellular metabolism, inducing regeneration of damaged cells, and regulating various stages of prenatal and postnatal development of the nervous system. The availability of IGFs for the cells is controlled via their interaction with the IGF-binding proteins (IGFBPs) that inhibit their activity. On the contrary, the cleavage of IGFBPs by specific proteases leads to the IGF release and activation of its cellular effects. The viability of neurons in the nervous tissue is controlled by a complex system of trophic factors secreted by auxiliary glial cells. The main source of IGF for the neurons are astrocytes. IGFs can accumulate as an extracellular free ligand near the neuronal membranes as a result of proteolytic degradation of IGFBPs by proteases secreted by astrocytes. This mechanism promotes interaction of IGFs with their genuine receptors and triggers intracellular signaling cascades. Therefore, the release of IGF by proteolytic cleavage of IGFBPs is an important mechanism of neuronal protection. This review summarizes the published data on the role of IGFs and IGFBPs as the key players in the neuroprotective regulation with a special focus on the specific proteolysis of IGFBPs as a mechanism for the regulation of IGF bioavailability and viability of neurons.
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Affiliation(s)
- German A Dya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Oleg I Klychnikov
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Daria A Adasheva
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Elizaveta A Vladychenskaya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexey G Katrukha
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Daria V Serebryanaya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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6
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Gupta MB, Biggar KK, Li C, Nathanielsz PW, Jansson T. Increased Colocalization and Interaction Between Decidual Protein Kinase A and Insulin-like Growth Factor-Binding Protein-1 in Intrauterine Growth Restriction. J Histochem Cytochem 2022; 70:515-530. [PMID: 35801847 DOI: 10.1369/00221554221112702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased phosphorylation of decidual insulin-like growth factor-binding protein-1 (IGFBP-1) can contribute to intrauterine growth restriction (IUGR) by decreasing the bioavailability of insulin-like growth factor-1 (IGF-1). However, the molecular mechanisms regulating IGFBP-1 phosphorylation at the maternal-fetal interface are poorly understood. Protein kinase A (PKA) is required for normal decidualization. Consensus sequences for PKA are present in IGFBP-1. We hypothesized that the expression/interaction of PKA with decidual IGFBP-1 is increased in IUGR. Parallel reaction monitoring-mass spectrometry (PRM-MS) identified multiple PKA peptides (n=>30) co-immunoprecipitating with IGFBP-1 in decidualized primary human endometrial stromal cells (HESC). PRM-MS also detected active PKApThr197 and greater site-specific IGFBP-1 phosphorylation(pSer119), (pSer98+pSer101) (pSer169+pSer174) in response to hypoxia. Hypoxia promoted colocalization [dual immunofluorescence (IF)] of PKA with IGFBP-1 in decidualized HESC. Colocalization (IF) and interaction (proximity ligation assay) of PKA and IGFBP-1 were increased in decidua collected from placenta of human IUGR pregnancies (n=8) compared with decidua from pregnancies with normal fetal growth. Similar changes were detected in decidual PKA/IGFBP-1 using placenta from baboons subjected to maternal nutrient reduction (MNR) vs controls (n=3 each). In baboons, these effects were evident in MNR at gestational day 120 prior to IUGR onset. Increased PKA-mediated phosphorylation of decidual IGFBP-1 may contribute to decreased IGF-1 bioavailability in the maternal-fetal interface in IUGR.
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Affiliation(s)
- Madhulika B Gupta
- Department of Biochemistry and Department of Pediatrics, University of Western Ontario, London, ON, Canada.,Children's Health Research Institute, London, ON, Canada
| | - Kyle K Biggar
- Institute of Biochemistry, Carleton University, Ottawa, ON, Canada
| | - Cun Li
- University of Wyoming, Laramie, Wyoming
| | | | - Thomas Jansson
- Southwest National Primate Research Center, San Antonio, Texas.,Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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Toschi P, Baratta M. Ruminant Placental Adaptation in Early Maternal Undernutrition: An Overview. Front Vet Sci 2021; 8:755034. [PMID: 34746288 PMCID: PMC8565373 DOI: 10.3389/fvets.2021.755034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
Correct placental development during early gestation is considered the main determinant of fetal growth in late pregnancy. A reduction in maternal nourishment occurring across the early developmental window has been linked to a wide range of pregnancy disorders affecting placental transport capacity and consequently the fetal nutrient supply line, with long-term implications for offspring health and productivity. In livestock, ruminant species specifically experience maternal undernutrition in extensive systems due to seasonal changes in food availability, with significant economic losses for the farmer in some situations. In this review, we aim to discuss the effects of reduced maternal nutrition during early pregnancy on placental development with a specific focus on ruminant placenta physiology. Different types of placental adaptation strategies were examined, also considering the potential effects on the epigenetic landscape, which is known to undergo extensive reprogramming during early mammalian development. We also discussed the involvement of autophagy as a cellular degradation mechanism that may play a key role in the placental response to nutrient deficiency mediated by mammalian target of rapamycin, named the mTOR intracellular pathway.
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Affiliation(s)
- Paola Toschi
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Mario Baratta
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
- Department of Chemistry, Life Sciences and Environmental Sustainability, Viale delle Scienze, University of Parma, Parma, Italy
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Chen AW, Biggar K, Nygard K, Singal S, Zhao T, Li C, Nathanielsz PW, Jansson T, Gupta MB. IGFBP-1 hyperphosphorylation in response to nutrient deprivation is mediated by activation of protein kinase Cα (PKCα). Mol Cell Endocrinol 2021; 536:111400. [PMID: 34314739 PMCID: PMC8634829 DOI: 10.1016/j.mce.2021.111400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 02/06/2023]
Abstract
Fetal growth restriction (FGR) is associated with decreased nutrient availability and reduced insulin-line growth factor (IGF)-I bioavailability via increased IGF binding protein (IGFBP)-1 phosphorylation. While protein kinase C (PKC) is implicated in IGFBP-1 hyperphosphorylation in nutrient deprivation, the mechanisms remain unclear. We hypothesised that the interaction of PKCα with protein kinase CK2β and activation of PKCα under leucine deprivation (L0) mediate fetal hepatic IGFBP-1 hyperphosphorylation. Parallel Reaction Monitoring Mass Spectrometry (PRM-MS) followed by PKCα knockdown demonstrated the PKCα isoform interacts with IGFBP-1 and CK2β under L0. Pharmacological PKCα activation with phorbol 12-myristate 13-acetate (PMA) increased whereas inhibition with bisindolylmaleimide II (Bis II) decreased IGFBP-1 phosphorylation (Ser101/119/169, Ser98 + 101 and Ser169 + 174), respectively. Furthermore, PMA mimicked L0-induced PKCα translocation and IGFBP-1 expression. PKCα expression was increased in baboon fetal liver in FGR, providing biological relevance in vivo. In summary, we report a novel nutrient-sensitive mechanism for PKCα in mediating IGFBP-1 hyperphosphorylation in FGR.
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Affiliation(s)
- Allan W Chen
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Kyle Biggar
- Institute of Biochemistry, Carleton University, Ottawa, ON, Canada
| | - Karen Nygard
- Biotron Integrated Microscopy Facility, University of Western Ontario, London, ON, Canada
| | - Sahil Singal
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Tiffany Zhao
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Cun Li
- University of Wyoming, Laramie, WY, USA; Southwest National Primate Research Center, San Antonio, TX, USA
| | - Peter W Nathanielsz
- University of Wyoming, Laramie, WY, USA; Southwest National Primate Research Center, San Antonio, TX, USA
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, ON, Canada; Department of Pediatrics, University of Western Ontario, London, ON, Canada; Children's Health Research Institute, London, ON, Canada.
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Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells. Biomolecules 2021; 11:biom11091382. [PMID: 34572595 PMCID: PMC8471256 DOI: 10.3390/biom11091382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 01/01/2023] Open
Abstract
Insulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual IGFBP-1 secretion/phosphorylation are poorly understood. Using decidualized primary human endometrial stromal cells (HESCs) from first-trimester placenta, we tested the hypothesis that mTORC1 signaling mechanistically links hypoxia to decidual IGFBP-1 secretion/phosphorylation. Hypoxia inhibited mechanistic target of rapamycin (mTORC1) (p-P70-S6K/Thr389, -47%, p = 0.038; p-4E-BP1/Thr70, -55%, p = 0.012) and increased IGFBP-1 (total, +35%, p = 0.005; phosphorylated, Ser101/+82%, p = 0.018; Ser119/+88%, p = 0.039; Ser 169/+157%, p = 0.019). Targeted parallel reaction monitoring-mass spectrometry (PRM-MS) additionally demonstrated markedly increased dual IGFBP-1 phosphorylation (pSer98+Ser101; pSer169+Ser174) in hypoxia. IGFBP-1 hyperphosphorylation inhibited IGF-1 receptor autophosphorylation/ Tyr1135 (-29%, p = 0.002). Furthermore, silencing of tuberous sclerosis complex 2 (TSC2) activated mTORC1 (p-P70-S6K/Thr389, +68%, p = 0.038; p-4E-BP1/Thr70, +30%, p = 0.002) and reduced total/site-specific IGFBP-1 phosphorylation. Importantly, TSC2 siRNA prevented inhibition of mTORC1 and the increase in secretion/site-specific IGFBP-1 phosphorylation in hypoxia. PRM-MS indicated concomitant changes in protein kinase autophosphorylation (CK2/Tyr182; PKC/Thr497; PKC/Ser657). Overall, mTORC1 signaling mechanistically links hypoxia to IGFBP-1 secretion/phosphorylation in primary HESC, implicating decidual mTORC1 inhibition as a novel mechanism linking uteroplacental hypoxia to fetal growth restriction.
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Kakadia J, Biggar K, Jain B, Chen AW, Nygard K, Li C, Nathanielsz PW, Jansson T, Gupta MB. Mechanisms linking hypoxia to phosphorylation of insulin-like growth factor binding protein-1 in baboon fetuses with intrauterine growth restriction and in cell culture. FASEB J 2021; 35:e21788. [PMID: 34425031 DOI: 10.1096/fj.202100397r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/21/2022]
Abstract
Hypoxia increases fetal hepatic insulin-like growth factor binding protein-1 (IGFBP-1) phosphorylation mediated by mechanistic target of rapamycin (mTOR) inhibition. Whether maternal nutrient restriction (MNR) causes fetal hypoxia remains unclear. We used fetal liver from a baboon (Papio sp.) model of intrauterine growth restriction due to MNR (70% global diet of Control) and liver hepatocellular carcinoma (HepG2) cells as a model for human fetal hepatocytes and tested the hypothesis that mTOR-mediated IGFBP-1 hyperphosphorylation in response to hypoxia requires hypoxia-inducible factor-1α (HIF-1α) and regulated in development and DNA-damage responses-1 (REDD-1) signaling. Western blotting (n = 6) and immunohistochemistry (n = 3) using fetal liver indicated greater expression of HIF-1α, REDD-1 as well as erythropoietin and its receptor, and vascular endothelial growth factor at GD120 (GD185 term) in MNR versus Control. Moreover, treatment of HepG2 cells with hypoxia (1% pO2 ) (n = 3) induced REDD-1, inhibited mTOR complex-1 (mTORC1) activity and increased IGFBP-1 secretion/phosphorylation (Ser101/Ser119/Ser169). HIF-1α inhibition by echinomycin or small interfering RNA silencing prevented the hypoxia-mediated inhibition of mTORC1 and induction of IGFBP-1 secretion/phosphorylation. dimethyloxaloylglycine (DMOG) induced HIF-1α and also REDD-1 expression, inhibited mTORC1 and increased IGFBP-1 secretion/phosphorylation. Induction of HIF-1α (DMOG) and REDD-1 by Compound 3 inhibited mTORC1, increased IGFBP-1 secretion/ phosphorylation and protein kinase PKCα expression. Together, our data demonstrate that HIF-1α induction, increased REDD-1 expression and mTORC1 inhibition represent the mechanistic link between hypoxia and increased IGFBP-1 secretion/phosphorylation. We propose that maternal undernutrition limits fetal oxygen delivery, as demonstrated by increased fetal liver expression of hypoxia-responsive proteins in baboon MNR. These findings have important implications for our understanding of the pathophysiology of restricted fetal growth.
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Affiliation(s)
- Jenica Kakadia
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Kyle Biggar
- Institute of Biochemistry, Carleton University, Ottawa, ON, Canada
| | - Bhawani Jain
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Allan W Chen
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Karen Nygard
- Biotron Integrated Microscopy Facility, University of Western Ontario, London, ON, Canada
| | - Cun Li
- Department of Animal Science, University of Wyoming, Laramie, WY, USA.,Southwest National Primate Research Center, San Antonio, TX, USA
| | - Peter W Nathanielsz
- Department of Animal Science, University of Wyoming, Laramie, WY, USA.,Southwest National Primate Research Center, San Antonio, TX, USA
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, ON, Canada.,Children's Health Research Institute, London, ON, Canada.,Department of Pediatrics, University of Western Ontario, London, ON, Canada
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11
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Abstract
Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.
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Affiliation(s)
- Daniel J Hoffman
- Department of Nutritional Sciences, Program in International Nutrition, and Center for Childhood Nutrition Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
| | - Theresa L Powell
- Department of Pediatrics and Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Emily S Barrett
- Department of Biostatistics and Epidemiology, School of Public Health and Division of Exposure Science and Epidemiology, Rutgers Environmental and Occupational Health Sciences Institute, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
| | - Daniel B Hardy
- Department of Biostatistics and Epidemiology, School of Public Health and Division of Exposure Science and Epidemiology, Rutgers Environmental and Occupational Health Sciences Institute, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
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12
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Borgo C, D'Amore C, Cesaro L, Sarno S, Pinna LA, Ruzzene M, Salvi M. How can a traffic light properly work if it is always green? The paradox of CK2 signaling. Crit Rev Biochem Mol Biol 2021; 56:321-359. [PMID: 33843388 DOI: 10.1080/10409238.2021.1908951] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
CK2 is a constitutively active protein kinase that assuring a constant level of phosphorylation to its numerous substrates supports many of the most important biological functions. Nevertheless, its activity has to be controlled and adjusted in order to cope with the varying needs of a cell, and several examples of a fine-tune regulation of its activity have been described. More importantly, aberrant regulation of this enzyme may have pathological consequences, e.g. in cancer, chronic inflammation, neurodegeneration, and viral infection. Our review aims at summarizing our current knowledge about CK2 regulation. In the first part, we have considered the most important stimuli shown to affect protein kinase CK2 activity/expression. In the second part, we focus on the molecular mechanisms by which CK2 can be regulated, discussing controversial aspects and future perspectives.
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Affiliation(s)
- Christian Borgo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Claudio D'Amore
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Luca Cesaro
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Stefania Sarno
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lorenzo A Pinna
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Padova, Italy
| | - Maria Ruzzene
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Padova, Italy
| | - Mauro Salvi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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13
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Lin YW, Weng XF, Huang BL, Guo HP, Xu YW, Peng YH. IGFBP-1 in cancer: expression, molecular mechanisms, and potential clinical implications. Am J Transl Res 2021; 13:813-832. [PMID: 33841624 PMCID: PMC8014352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/09/2020] [Indexed: 02/05/2023]
Abstract
Insulin-like growth factor binding protein-1 (IGFBP-1) belongs to the insulin-like growth factor (IGF) system, which plays an indispensable role in normal growth and development, and in the pathophysiology of various tumors. IGFBP-1 has been shown to be associated with the risk of various tumors, and has a vital function in regulating tumor behaviors such as proliferation, migration, invasion and adhesion through different molecular mechanisms. The biological actions of IGFBP-1 in cancer are found to be related to its phosphorylation state, and the IGF-dependent and -independent mechanisms. In this review, we provided an overview of IGFBP-1 in normal physiology, and its aberrantly expression and the underlying molecular mechanisms in a range of common tumors, as well as discussed the potential clinical implications of IGFBP-1 as diagnostic or prognostic biomarkers in cancer.
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Affiliation(s)
- Yi-Wei Lin
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
- Precision Medicine Research Center, Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
| | - Xue-Fen Weng
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
- Precision Medicine Research Center, Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
| | - Bin-Liang Huang
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
- Precision Medicine Research Center, Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
| | - Hai-Peng Guo
- Department of Head and Neck Surgery, The Cancer Hospital of Shantou University Medical CollegeShantou 515041, People’s Republic of China
| | - Yi-Wei Xu
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
- Precision Medicine Research Center, Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
| | - Yu-Hui Peng
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
- Precision Medicine Research Center, Shantou University Medical CollegeShantou, Guangdong, People’s Republic of China
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14
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Kakadia JH, Jain BB, Biggar K, Sutherland A, Nygard K, Li C, Nathanielsz PW, Jansson T, Gupta MB. Hyperphosphorylation of fetal liver IGFBP-1 precedes slowing of fetal growth in nutrient-restricted baboons and may be a mechanism underlying IUGR. Am J Physiol Endocrinol Metab 2020; 319:E614-E628. [PMID: 32744097 PMCID: PMC7642856 DOI: 10.1152/ajpendo.00220.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In cultured fetal liver cells, insulin-like growth factor (IGF) binding protein (IGFBP)-1 hyperphosphorylation in response to hypoxia and amino acid deprivation is mediated by inhibition of mechanistic target of rapamycin (mTOR) and activation of amino acid response (AAR) signaling and casein kinase (CK)2. We hypothesized that fetal liver mTOR inhibition, activation of AAR and CK2, and IGFBP-1 hyperphosphorylation occur before development of intrauterine growth restriction (IUGR). Pregnant baboons were fed a control (C) or a maternal nutrient restriction (MNR; 70% calories of control) diet starting at gestational day (GD) 30 (term GD 185). Umbilical blood and fetal liver tissue were obtained at GD 120 (C, n = 7; MNR, n = 10) and 165 (C, n = 7; MNR, n = 8). Fetal weights were unchanged at GD 120 but decreased at GD 165 in the MNR group (-13%, P = 0.03). IGFBP-1 phosphorylation, as determined by parallel reaction monitoring mass spectrometry (PRM-MS), immunohistochemistry, and/or Western blot, was enhanced in MNR fetal liver and umbilical plasma at GD 120 and 165. IGF-I receptor autophosphorylationTyr1135 (-64%, P = 0.05) was reduced in MNR fetal liver at GD 120. Furthermore, fetal liver CK2 (α/α'/β) expression, CK2β colocalization, proximity with IGFBP-1, and CK2 autophosphorylationTyr182 were greater at GD 120 and 165 in MNR vs. C. Additionally, mTOR complex (mTORC)1 (p-P70S6KThr389, -52%, P = 0.05) and mTORC2 (p-AktSer473, -56%, P < 0.001) activity were decreased and AAR was activated (p-GCN2Thr898, +117%, P = 0.02; p-eIF2αSer51, +294%, P = 0.002; p-ERKThr202, +111%, P = 0.03) in MNR liver at GD 120. Our data suggest that fetal liver IGFBP-1 hyperphosphorylation, mediated by mTOR inhibition and both AAR and CK2 activation, is a key link between restricted nutrient and oxygen availability and the development of IUGR.
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Affiliation(s)
- Jenica H Kakadia
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Bhawani B Jain
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Kyle Biggar
- Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Austen Sutherland
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Biotron Integrated Microscopy Facility, University of Western Ontario, London, Ontario, Canada
| | - Cun Li
- University of Wyoming, Laramie, Wyoming
- Southwest National Primate Research Center, San Antonio, Texas
| | - Peter W Nathanielsz
- University of Wyoming, Laramie, Wyoming
- Southwest National Primate Research Center, San Antonio, Texas
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
- Children's Health Research Institute, London, Ontario, Canada
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15
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Abu Shehab M, Biggar K, Kakadia JH, Dhruv M, Jain B, Nandi P, Nygard K, Jansson T, Gupta MB. Inhibition of decidual IGF-1 signaling in response to hypoxia and leucine deprivation is mediated by mTOR and AAR pathways and increased IGFBP-1 phosphorylation. Mol Cell Endocrinol 2020; 512:110865. [PMID: 32502935 DOI: 10.1016/j.mce.2020.110865] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/10/2020] [Accepted: 05/10/2020] [Indexed: 01/04/2023]
Abstract
Decidual mechanistic target of rapamycin (mTOR) is inhibited, amino acid response (AAR) and protein kinase CK2 are activated, and IGF (insulin-like growth factor) binding protein (IGFBP)-1 is hyperphosphorylated in human intrauterine growth restriction (IUGR). Using decidualized human immortalized endometrial stromal cells (HIESC), we hypothesized that hypoxia and leucine deprivation causing inhibition of decidual IGF-1 signaling is mediated by mTOR, AAR, CK2 and IGFBP-1 phosphorylation. Mass spectrometry demonstrated that hypoxia (1% O2) or rapamycin increased IGFBP-1 phosphorylation singly at Ser101/119/169 (confirmed using immunoblotting) and dually at pSer169 + 174. Hypoxia resulted in mTOR inhibition, AAR and CK2 activation, and decreased IGF-1 bioactivity, with no additional changes with rapamycin + hypoxia. Rapamycin and/or hypoxia promoted colocalization of IGFBP-1 and CK2 (dual-immunofluorescence and proximity ligation assay). Leucine deprivation showed similar outcomes. Changes in IGFBP-1 phosphorylation regulated by mTOR/AAR signaling and CK2 may represent a novel mechanism linking oxygen and nutrient availability to IGF-1 signaling in the decidua.
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Affiliation(s)
- Majida Abu Shehab
- Department of Pediatrics, University of Western Ontario, London, ON, Canada
| | - Kyle Biggar
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada.
| | - Jenica H Kakadia
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Manthan Dhruv
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Bhawani Jain
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | - Pinki Nandi
- Department of Pediatrics, University of Western Ontario, London, ON, Canada
| | - Karen Nygard
- Biotron Integrated Microscopy Facility, University of Western Ontario, London, ON, Canada
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Madhulika B Gupta
- Department of Pediatrics, University of Western Ontario, London, ON, Canada; Department of Biochemistry, University of Western Ontario, London, ON, Canada; Children's Health Research Institute, London, ON, Canada.
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16
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Huber HF, Jenkins SL, Li C, Nathanielsz PW. Strength of nonhuman primate studies of developmental programming: review of sample sizes, challenges, and steps for future work. J Dev Orig Health Dis 2020; 11:297-306. [PMID: 31566171 PMCID: PMC7103515 DOI: 10.1017/s2040174419000539] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nonhuman primate (NHP) studies are crucial to biomedical research. NHPs are the species most similar to humans in lifespan, body size, and hormonal profiles. Planning research requires statistical power evaluation, which is difficult to perform when lacking directly relevant preliminary data. This is especially true for NHP developmental programming studies, which are scarce. We review the sample sizes reported, challenges, areas needing further work, and goals of NHP maternal nutritional programming studies. The literature search included 27 keywords, for example, maternal obesity, intrauterine growth restriction, maternal high-fat diet, and maternal nutrient reduction. Only fetal and postnatal offspring studies involving tissue collection or imaging were included. Twenty-eight studies investigated maternal over-nutrition and 33 under-nutrition; 23 involved macaques and 38 baboons. Analysis by sex was performed in 19; minimum group size ranged from 1 to 8 (mean 4.7 ± 0.52, median 4, mode 3) and maximum group size from 3 to 16 (8.3 ± 0.93, 8, 8). Sexes were pooled in 42 studies; minimum group size ranged from 2 to 16 (mean 5.3 ± 0.35, median 6, mode 6) and maximum group size from 4 to 26 (10.2 ± 0.92, 8, 8). A typical study with sex-based analyses had group size minimum 4 and maximum 8 per sex. Among studies with sexes pooled, minimum group size averaged 6 and maximum 8. All studies reported some significant differences between groups. Therefore, studies with group sizes 3-8 can detect significance between groups. To address deficiencies in the literature, goals include increasing age range, more frequently considering sex as a biological variable, expanding topics, replicating studies, exploring intergenerational effects, and examining interventions.
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Affiliation(s)
- Hillary F. Huber
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
| | - Susan L. Jenkins
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
| | - Cun Li
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Peter W. Nathanielsz
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
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17
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Aguiar-Oliveira MH, Bartke A. Growth Hormone Deficiency: Health and Longevity. Endocr Rev 2019; 40:575-601. [PMID: 30576428 PMCID: PMC6416709 DOI: 10.1210/er.2018-00216] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/07/2018] [Indexed: 12/13/2022]
Abstract
The important role of GH in the control of mammalian longevity was first deduced from extended longevity of mice with genetic GH deficiency (GHD) or GH resistance. Mice with isolated GHD (IGHD) due to GHRH or GHRH receptor mutations, combined deficiency of GH, prolactin, and TSH, or global deletion of GH receptors live longer than do their normal siblings. They also exhibit multiple features of delayed and/or slower aging, accompanied by extension of healthspan. The unexpected, remarkable longevity benefit of severe endocrine defects in these animals presumably represents evolutionarily conserved trade-offs among aging, growth, maturation, fecundity, and the underlying anabolic processes. Importantly, the negative association of GH signaling with longevity extends to other mammalian species, apparently including humans. Data obtained in humans with IGHD type 1B, owing to a mutation of the GHRH receptor gene, in the Itabaianinha County, Brazil, provide a unique opportunity to study the impact of severe reduction in GH signaling on age-related characteristics, health, and functionality. Individuals with IGHD are characterized by proportional short stature, doll facies, high-pitched voices, and central obesity. They have delayed puberty but are fertile and generally healthy. Moreover, these IGHD individuals are partially protected from cancer and some of the common effects of aging and can attain extreme longevity, 103 years of age in one case. We think that low, but detectable, residual GH secretion combined with life-long reduction of circulating IGF-1 and with some tissue levels of IGF-1 and/or IGF-2 preserved may account for the normal longevity and apparent extension of healthspan in these individuals.
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Affiliation(s)
| | - Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, Illinois
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18
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Gupta MB, Jansson T. Novel roles of mechanistic target of rapamycin signaling in regulating fetal growth†. Biol Reprod 2019; 100:872-884. [PMID: 30476008 PMCID: PMC6698747 DOI: 10.1093/biolre/ioy249] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/08/2018] [Accepted: 11/19/2018] [Indexed: 12/18/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) signaling functions as a central regulator of cellular metabolism, growth, and survival in response to hormones, growth factors, nutrients, energy, and stress signals. Mechanistic TOR is therefore critical for the growth of most fetal organs, and global mTOR deletion is embryonic lethal. This review discusses emerging evidence suggesting that mTOR signaling also has a role as a critical hub in the overall homeostatic control of fetal growth, adjusting the fetal growth trajectory according to the ability of the maternal supply line to support fetal growth. In the fetus, liver mTOR governs the secretion and phosphorylation of insulin-like growth factor binding protein 1 (IGFBP-1) thereby controlling the bioavailability of insulin-like growth factors (IGF-I and IGF-II), which function as important growth hormones during fetal life. In the placenta, mTOR responds to a large number of growth-related signals, including amino acids, glucose, oxygen, folate, and growth factors, to regulate trophoblast mitochondrial respiration, nutrient transport, and protein synthesis, thereby influencing fetal growth. In the maternal compartment, mTOR is an integral part of a decidual nutrient sensor which links oxygen and nutrient availability to the phosphorylation of IGFBP-1 with preferential effects on the bioavailability of IGF-I in the maternal-fetal interface and in the maternal circulation. These new roles of mTOR signaling in the regulation fetal growth will help us better understand the molecular underpinnings of abnormal fetal growth, such as intrauterine growth restriction and fetal overgrowth, and may represent novel avenues for diagnostics and intervention in important pregnancy complications.
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Affiliation(s)
- Madhulika B Gupta
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
- Children's Health Research Institute, London, Ontario, Canada
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado | Anschutz Medical Campus, Aurora, Colorado, USA
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19
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Gupta MB, Abu Shehab M, Nygard K, Biggar K, Singal SS, Santoro N, Powell TL, Jansson T. IUGR Is Associated With Marked Hyperphosphorylation of Decidual and Maternal Plasma IGFBP-1. J Clin Endocrinol Metab 2019; 104:408-422. [PMID: 30124960 PMCID: PMC6306389 DOI: 10.1210/jc.2018-00820] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 08/13/2018] [Indexed: 01/03/2023]
Abstract
CONTEXT The mechanisms underpinning intrauterine growth restriction (IUGR), as a result of placental insufficiency, remain poorly understood, no specific treatment is available, and clinically useful biomarkers for early detection are lacking. OBJECTIVE We hypothesized that human IUGR is associated with inhibition of mechanistic target of rapamycin (mTOR) and activation of amino acid response (AAR) signaling, increased protein kinase casein kinase-2 (CK2) activity, and increased insulin-like growth factor-binding protein 1 (IGFBP-1) expression and phosphorylation in decidua and that maternal plasma IGFBP-1 hyperphosphorylation in the first trimester predicts later development of IUGR. DESIGN, SETTING, AND PARTICIPANTS Decidua [n = 16 appropriate-for-gestational age (AGA); n = 16 IUGR] and maternal plasma (n = 13 AGA; n = 13 IUGR) were collected at delivery from two different cohorts. In addition, maternal plasma was obtained in the late first trimester from a third cohort of women (n = 7) who later delivered an AGA or IUGR infant. MAIN OUTCOME MEASURES Total IGFBP-1 expression and phosphorylation (Ser101/Ser119/Ser169), mTOR, AAR, and CK2 activity in decidua and IGFBP-1 concentration and phosphorylation in maternal plasma. RESULTS We show that decidual IGFBP-1 expression and phosphorylation are increased, mTOR is markedly inhibited, and AAR and CK2 are activated in IUGR. Moreover, IGFBP-1 hyperphosphorylation in first-trimester maternal plasma is associated with the development of IUGR. CONCLUSIONS These data are consistent with the possibility that the decidua functions as a nutrient sensor linking limited oxygen and nutrient availability to increased IGFBP-1 phosphorylation, possibly mediated by mTOR and AAR signaling. IGFBP-1 hyperphosphorylation in first-trimester maternal plasma may serve as a predictive IUGR biomarker, allowing early intervention.
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Affiliation(s)
- Madhulika B Gupta
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
- Children's Health Research Institute, London, Ontario, Canada
- Correspondence and Reprint Requests: Madhulika B. Gupta, PhD, Children’s Health Research Institute, VRL Room A5-136 (WC), 800 Commissioners Road E., London, Ontario N6C 2VD, Canada. E-mail:
| | - Majida Abu Shehab
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Biotron Laboratory, University of Western Ontario, London, Ontario, Canada
| | - Kyle Biggar
- Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Sahil S Singal
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Nanette Santoro
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Theresa L Powell
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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20
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Lomas-Soria C, Reyes-Castro LA, Rodríguez-González GL, Ibáñez CA, Bautista CJ, Cox LA, Nathanielsz PW, Zambrano E. Maternal obesity has sex-dependent effects on insulin, glucose and lipid metabolism and the liver transcriptome in young adult rat offspring. J Physiol 2018; 596:4611-4628. [PMID: 29972240 DOI: 10.1113/jp276372] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/15/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Maternal high-fat diet consumption predisposes to metabolic dysfunction in male and female offspring at young adulthood. Maternal obesity programs non-alcoholic fatty liver disease (NAFLD) in a sex-dependent manner. We demonstrate sex-dependent liver transcriptome profiles in rat offspring of obese mothers. In this study, we focused on pathways related to insulin, glucose and lipid signalling. These results improve understanding of the mechanisms by which a maternal high-fat diet affects the offspring. ABSTRACT Maternal obesity (MO) predisposes offspring (F1) to obesity, insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). MO's effects on the F1 liver transcriptome are poorly understood. We used RNA-seq to determine the liver transcriptome of male and female F1 of MO and control-fed mothers. We hypothesized that MO-F1 are predisposed to sex-dependent adult liver dysfunction. Female Wistar rat mothers ate a control (C) or obesogenic (MO) diet from the time they were weaned through breeding at postnatal day (PND) 120, delivery and lactation. After weaning, all male and female F1 ate a control diet. At PND 110, F1 serum, liver and fat were collected to analyse metabolites, histology and liver differentially expressed genes. Male and female MO-F1 showed increased adiposity index, triglycerides, insulin and homeostatic model assessment vs. C-F1 with similar body weight and glucose serum concentrations. MO-F1 males presented greater physiological and histological NAFLD characteristics than MO-F1 females. RNA-seq revealed 1365 genes significantly changed in male MO-F1 liver and only 70 genes in female MO-F1 compared with controls. GO and KEGG analysis identified differentially expressed genes related to metabolic processes. Male MO-F1 liver showed the following altered pathways: insulin signalling (22 genes), phospholipase D signalling (14 genes), NAFLD (13 genes) and glycolysis/gluconeogenesis (7 genes). In contrast, few genes were altered in these pathways in MO-F1 females. In summary, MO programs sex-dependent F1 changes in insulin, glucose and lipid signalling pathways, leading to liver dysfunction and insulin resistance.
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Affiliation(s)
- Consuelo Lomas-Soria
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México.,CONACyT, Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición SZ, México
| | - Luis A Reyes-Castro
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México
| | - Guadalupe L Rodríguez-González
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México
| | - Carlos A Ibáñez
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México
| | - Claudia J Bautista
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México
| | - Laura A Cox
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA.,Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Peter W Nathanielsz
- Department of Animal Science, University of Wyoming, Laramie, WY, USA.,Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Elena Zambrano
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Tlalpan, México, D.F., 14080, México
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21
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Singal SS, Nygard K, Gratton R, Jansson T, Gupta MB. Increased Insulin-like Growth Factor Binding Protein-1 Phosphorylation in Decidualized Stromal Mesenchymal Cells in Human Intrauterine Growth Restriction Placentas. J Histochem Cytochem 2018; 66:617-630. [PMID: 29718759 DOI: 10.1369/0022155418772574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Intrauterine growth restriction (IUGR) is often caused by placental insufficiency, which is believed to be associated with decreased delivery of oxygen and nutrients to the placental barrier. We recently reported that hypoxia and/or leucine deprivation triggered hyperphosphorylation of insulin-like growth factor binding protein-1 (IGFBP-1) in decidualized human immortalized endometrial stromal cells (HIESCs), resulting in decreased insulin-like growth factor-1 (IGF-1) bioactivity. To test the hypothesis that human IUGR is associated with increased decidual IGFBP-1 phosphorylation at discrete sites, we used IUGR and gestational age matched appropriate for gestational age (AGA) placentas ( n=5 each). We performed dual immunofluorescence immunohistochemistry (IHC) using IGFBP-1 and vimentin as decidual and mesenchymal markers, respectively. Employing a unique strategy with imaging software, we extracted signal intensity of IGFBP-1 expressed specifically from truly decidualized cells of the placenta. Relative IGFBP-1 was increased (85%; p=0.0001) and using custom phospho-site-specific antibodies, we found that IGFBP-1 phosphorylation (pSer101; +40%, p=0.0677/pSer119; +60%, p=0.0064/pSer169; +100%, p=0.0021) was markedly enhanced in IUGR. Together, our data links for the first time, increased decidual IGFBP-1 phosphorylation at discrete sites with human IUGR. These novel findings suggest that hyperphosphorylation of IGFBP-1 in decidualized stromal mesenchymal decidua basalis contributes to potentially elevated levels of phosphorylated IGFBP-1 in maternal circulation in IUGR pregnancies.
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Affiliation(s)
- Sahil S Singal
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Biotron, University of Western Ontario, London, Ontario, Canada
| | - Robert Gratton
- Department of Obstetrics & Gynecology, University of Western Ontario, London, Ontario, Canada
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada.,Department of Pediatrics, University of Western Ontario, London, Ontario, Canada.,Children's Health Research Institute, London, Ontario, Canada
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22
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Singal SS, Nygard K, Dhruv MR, Biggar K, Shehab MA, Li SSC, Jansson T, Gupta MB. Co-Localization of Insulin-Like Growth Factor Binding Protein-1, Casein Kinase-2β, and Mechanistic Target of Rapamycin in Human Hepatocellular Carcinoma Cells as Demonstrated by Dual Immunofluorescence and in Situ Proximity Ligation Assay. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:111-124. [PMID: 29037858 PMCID: PMC5745526 DOI: 10.1016/j.ajpath.2017.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/05/2017] [Accepted: 09/07/2017] [Indexed: 12/12/2022]
Abstract
Insulin-like growth factor binding protein (IGFBP)-1 influences fetal growth by modifying insulin-like growth factor-I (IGF-I) bioavailability. IGFBP-1 phosphorylation, which markedly increases its affinity for IGF-I, is regulated by mechanistic target of rapamycin (mTOR) and casein kinase (CSNK)-2. However, the underlying molecular mechanisms remain unknown. We examined the cellular localization and potential interactions of IGFBP-1, CSNK-2β, and mTOR as a prerequisite for protein-protein interaction. Analysis of dual immunofluorescence images indicated a potential perinuclear co-localization between IGFBP-1 and CSNK-2β and a nuclear co-localization between CSNK-2β and mTOR. Proximity ligation assay (PLA) indicated proximity between IGFBP-1 and CSNK-2β as well as mTOR and CSNK-2β but not between mTOR and IGFBP-1. Three-dimensional rendering of the PLA images validated that IGFBP-1 and CSNK-2β interactions were in the perinuclear region and mTOR and CSNK-2β interactions were also predominantly perinuclear rather than nuclear as indicated by mTOR and CSNK-2β co-localization. Compared with control, hypoxia and rapamycin treatment showed markedly amplified PLA signals for IGFBP-1 and CSNK-2β (approximately 18-fold, P = 0.0002). Stable isotope labeling with multiple reaction monitoring-mass spectrometry demonstrated that hypoxia and rapamycin treatment increased IGFBP-1 phosphorylation at Ser98/Ser101/Ser119/Ser174 but most considerably (106-fold) at Ser169. We report interactions between CSNK-2β and IGFBP-1 as well as mTOR and CSNK-2β, providing strong evidence of a mechanistic link between mTOR and IGF-I signaling, two critical regulators of cell growth via CSNK-2.
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Affiliation(s)
- Sahil S Singal
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Biotron Laboratory, University of Western Ontario, London, Ontario, Canada
| | - Manthan R Dhruv
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
| | - Kyle Biggar
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada; Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Majida A Shehab
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
| | - Shawn S-C Li
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, Canada
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada; Department of Pediatrics, University of Western Ontario, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada.
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23
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Stouffer RL, Woodruff TK. Nonhuman Primates: A Vital Model for Basic and Applied Research on Female Reproduction, Prenatal Development, and Women's Health. ILAR J 2017; 58:281-294. [PMID: 28985318 PMCID: PMC5886348 DOI: 10.1093/ilar/ilx027] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 06/30/2017] [Indexed: 12/20/2022] Open
Abstract
The comparative biology of reproduction and development in mammalian species is remarkable. Hence, because of similarities in environmental and neuroendocrine control of the reproductive axis, the cyclic function of the ovary and reproductive tract, establishment and control of the maternal-fetal-placental unit during pregnancy, and reproductive aging from puberty through menopause, nonhuman primates (NHPs) are valuable models for research related to women's reproductive health and its disorders. This chapter provides examples of research over the past 10+ years using Old World monkeys (notably macaque species), baboons, and to a lesser extent New World monkeys (especially marmosets) that contributed to our understanding of the etiology and therapies or prevention of: (1) ovarian disorders, e.g., polycystic ovary syndrome, mitochondrial DNA-based diseases from the oocyte; (2) uterine disorders, for example, endometriosis and uterine transplantation; and (3) pregnancy disorders, for example, preterm labor and delivery, environmental factors. Also, emerging opportunities such as viral (e.g., Zika) induced fetal defects and germline genomic editing to generate valuable primate models of human diseases (e.g., Huntington and muscular dystrophy) are addressed. Although the high costs, specialized resources, and ethical debate challenge the use of primates in biomedical research, their inclusion in fertility and infertility research is vital for continued improvements in women's reproductive health.
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Affiliation(s)
- Richard L Stouffer
- Richard L. Stouffer, Ph.D., is Professor in the Division of Reproductive and Developmental Sciences at the Oregon National Primate Research Center in Beaverton, Oregon and Professor in the Department of Obstetrics and Gynecology at Oregon Health & Sciences University in Portland, Oregon. Teresa K. Woodruff, Ph.D., is Thomas J. Watkins Professor of Obstetrics and Gynecology, Vice Chair of Research (OB/GYN), and Chief of the Division of Reproductive Science in Medicine at the Feinberg School of Medicine, and Professor of Molecular Biosciences at Weinberg College of Arts and Sciences, Northwestern University in Chicago, Illinois.
| | - Teresa K Woodruff
- Richard L. Stouffer, Ph.D., is Professor in the Division of Reproductive and Developmental Sciences at the Oregon National Primate Research Center in Beaverton, Oregon and Professor in the Department of Obstetrics and Gynecology at Oregon Health & Sciences University in Portland, Oregon. Teresa K. Woodruff, Ph.D., is Thomas J. Watkins Professor of Obstetrics and Gynecology, Vice Chair of Research (OB/GYN), and Chief of the Division of Reproductive Science in Medicine at the Feinberg School of Medicine, and Professor of Molecular Biosciences at Weinberg College of Arts and Sciences, Northwestern University in Chicago, Illinois.
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24
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Shehab MA, Biggar K, Singal SS, Nygard K, Shun-Cheng Li S, Jansson T, Gupta MB. Exposure of decidualized HIESC to low oxygen tension and leucine deprivation results in increased IGFBP-1 phosphorylation and reduced IGF-I bioactivity. Mol Cell Endocrinol 2017; 452:1-14. [PMID: 28435049 PMCID: PMC5957756 DOI: 10.1016/j.mce.2017.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/15/2017] [Accepted: 04/06/2017] [Indexed: 12/15/2022]
Abstract
Phosphorylation of decidual IGFBP-1 enhances binding of IGF-I, limiting the bioavailability of this growth factor which may contribute to reduced placental and fetal growth. The mechanisms regulating decidual IGFBP-1 phosphorylation are incompletely understood. Using decidualized human immortalized endometrial stromal cells we tested the hypothesis that low oxygen tension or reduced leucine availability, believed to be common in placental insufficiency, increase the phosphorylation of decidual IGFBP-1. Multiple reaction monitoring-MS (MRM-MS) was used to quantify IGFBP-1 phosphorylation. MRM-MS validated the novel phosphorylation of IGFBP-1 at Ser58, however this site was unaffected by low oxygen tension/leucine deprivation. In contrast, significantly elevated phosphorylation was detected for pSer119, pSer98/pSer101 and pSer169/pSer174 sites. Immunoblotting and dual-immunofluorescence using phosphosite-specific IGFBP-1 antibodies further demonstrated increased IGFBP-1 phosphorylation in HIESC under both treatments which concomitantly reduced IGF-I bioactivity. These data support the hypothesis that down regulation of IGF-I signaling links decidual IGFBP-1 hyperphosphorylation to restricted fetal growth in placental insufficiency.
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Affiliation(s)
- Majida Abu Shehab
- Children's Health Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Kyle Biggar
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Sahil Sagar Singal
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Department of Biotron, University of Western Ontario, London, Ontario, Canada
| | - Shawn Shun-Cheng Li
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Madhulika B Gupta
- Children's Health Research Institute, University of Western Ontario, London, Ontario, Canada; Department of Biochemistry, University of Western Ontario, London, Ontario, Canada; Department of Pediatrics, University of Western Ontario, London, Ontario, Canada.
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25
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Hennig M, Fiedler S, Jux C, Thierfelder L, Drenckhahn JD. Prenatal Mechanistic Target of Rapamycin Complex 1 (m TORC1) Inhibition by Rapamycin Treatment of Pregnant Mice Causes Intrauterine Growth Restriction and Alters Postnatal Cardiac Growth, Morphology, and Function. J Am Heart Assoc 2017; 6:JAHA.117.005506. [PMID: 28778941 PMCID: PMC5586418 DOI: 10.1161/jaha.117.005506] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background Fetal growth impacts cardiovascular health throughout postnatal life in humans. Various animal models of intrauterine growth restriction exhibit reduced heart size at birth, which negatively influences cardiac function in adulthood. The mechanistic target of rapamycin complex 1 (mTORC1) integrates nutrient and growth factor availability with cell growth, thereby regulating organ size. This study aimed at elucidating a possible involvement of mTORC1 in intrauterine growth restriction and prenatal heart growth. Methods and Results We inhibited mTORC1 in fetal mice by rapamycin treatment of pregnant dams in late gestation. Prenatal rapamycin treatment reduces mTORC1 activity in various organs at birth, which is fully restored by postnatal day 3. Rapamycin‐treated neonates exhibit a 16% reduction in body weight compared with vehicle‐treated controls. Heart weight decreases by 35%, resulting in a significantly reduced heart weight/body weight ratio, smaller left ventricular dimensions, and reduced cardiac output in rapamycin‐ versus vehicle‐treated mice at birth. Although proliferation rates in neonatal rapamycin‐treated hearts are unaffected, cardiomyocyte size is reduced, and apoptosis increased compared with vehicle‐treated neonates. Rapamycin‐treated mice exhibit postnatal catch‐up growth, but body weight and left ventricular mass remain reduced in adulthood. Prenatal mTORC1 inhibition causes a reduction in cardiomyocyte number in adult hearts compared with controls, which is partially compensated for by an increased cardiomyocyte volume, resulting in normal cardiac function without maladaptive left ventricular remodeling. Conclusions Prenatal rapamycin treatment of pregnant dams represents a new mouse model of intrauterine growth restriction and identifies an important role of mTORC1 in perinatal cardiac growth.
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Affiliation(s)
- Maria Hennig
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Saskia Fiedler
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Christian Jux
- Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany
| | | | - Jörg-Detlef Drenckhahn
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany .,Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany
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26
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Wan X, Wang S, Xu J, Zhuang L, Xing K, Zhang M, Zhu X, Wang L, Gao P, Xi Q, Sun J, Zhang Y, Li T, Shu G, Jiang Q. Dietary protein-induced hepatic IGF-1 secretion mediated by PPARγ activation. PLoS One 2017; 12:e0173174. [PMID: 28257428 PMCID: PMC5336265 DOI: 10.1371/journal.pone.0173174] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 02/16/2017] [Indexed: 02/07/2023] Open
Abstract
Dietary protein or amino acid (AA) is a crucial nutritional factor to regulate hepatic insulin-like growth factor-1 (IGF-1) expression and secretion. However, the underlying intracellular mechanism by which dietary protein or AA induces IGF-1 expression remains unknown. We compared the IGF-1 gene expression and plasma IGF-1 level of pigs fed with normal crude protein (CP, 20%) and low-protein levels (LP, 14%). RNA sequencing (RNA-seq) was performed to detect transcript expression in the liver in response to dietary protein. The results showed that serum concentrations and mRNA levels of IGF-1 in the liver were higher in the CP group than in the LP group. RNA-seq analysis identified a total of 1319 differentially expressed transcripts (667 upregulated and 652 downregulated), among which the terms “oxidative phosphorylation”, “ribosome”, “gap junction”, “PPAR signaling pathway”, and “focal adhesion” were enriched. In addition, the porcine primary hepatocyte and HepG2 cell models also demonstrated that the mRNA and protein levels of IGF-1 and PPARγ increased with the increasing AA concentration in the culture. The PPARγ activator troglitazone increased IGF-1 gene expression and secretion in a dose dependent manner. Furthermore, inhibition of PPARγ effectively reversed the effects of the high AA concentration on the mRNA expression of IGF-1 and IGFBP-1 in HepG2 cells. Moreover, the protein levels of IGF-1 and PPARγ, as well as the phosphorylation of mTOR, significantly increased in HepG2 cells under high AA concentrations. mTOR phosphorylation can be decreased by the mTOR antagonist, rapamycin. The immunoprecipitation results also showed that high AA concentrations significantly increased the interaction of mTOR and PPARγ. In summary, PPARγ plays an important role in the regulation of IGF-1 secretion and gene expression in response to dietary protein.
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Affiliation(s)
- Xiaojuan Wan
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Songbo Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Jingren Xu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Lu Zhuang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Kongping Xing
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Mengyuan Zhang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Xiaotong Zhu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Lina Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Ping Gao
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Qianyun Xi
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Jiajie Sun
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Yongliang Zhang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Tiejun Li
- Key Laboratory of Subtropical Agro-ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, Hunan, PR China
| | - Gang Shu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Qingyan Jiang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
- * E-mail:
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27
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Donovan EL, Buckels EJ, Hancock S, Smeitink D, Oliver MH, Bloomfield FH, Jaquiery AL. Twin Conception in Sheep Leads to Impaired Insulin Sensitivity and Sexually Dimorphic Adipose Tissue and Skeletal Muscle Phenotypes in Adulthood. Reprod Sci 2016; 24:865-881. [DOI: 10.1177/1933719116670516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Elise L. Donovan
- Liggins Institute, University of Auckland, Auckland, New Zealand
- Gravida: National Centre for Growth and Development, Auckland, New Zealand
| | - Emma J. Buckels
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Serina Hancock
- Liggins Institute, University of Auckland, Auckland, New Zealand
- School of Veterinary and Life Sciences, Murdoch University, Perth, WA, Australia
| | | | - Mark H. Oliver
- Liggins Institute, University of Auckland, Auckland, New Zealand
- Gravida: National Centre for Growth and Development, Auckland, New Zealand
| | - Frank H. Bloomfield
- Liggins Institute, University of Auckland, Auckland, New Zealand
- Gravida: National Centre for Growth and Development, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, University of Auckland, Auckland, New Zealand
| | - Anne L. Jaquiery
- Liggins Institute, University of Auckland, Auckland, New Zealand
- Gravida: National Centre for Growth and Development, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, University of Auckland, Auckland, New Zealand
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28
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Clemmons DR. Role of IGF Binding Proteins in Regulating Metabolism. Trends Endocrinol Metab 2016; 27:375-391. [PMID: 27117513 DOI: 10.1016/j.tem.2016.03.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 03/31/2016] [Accepted: 03/31/2016] [Indexed: 01/10/2023]
Abstract
Insulin-like growth factors (IGFs) circulate in extracellular fluids bound to a family of binding proteins. Although they function in a classical manner to limit the access of the IGFs to their receptors they also have a multiplicity of actions that are independent of this property; they bind to their own receptors or are transported to intracellular and intranuclear sites to influence cellular functions that may directly or indirectly modify IGF actions. The availability of genetically modified animals has helped to determine their functions in a physiological context. These results show that many of their actions are cell type- and context-specific, and have led to a broader understanding of how these proteins function coordinately with IGF-I and -II to regulate growth and metabolism.
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Affiliation(s)
- David R Clemmons
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
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29
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Malkani N, Biggar K, Shehab MA, Li SSC, Jansson T, Gupta MB. Increased IGFBP-1 phosphorylation in response to leucine deprivation is mediated by CK2 and PKC. Mol Cell Endocrinol 2016; 425:48-60. [PMID: 26733150 PMCID: PMC4811673 DOI: 10.1016/j.mce.2015.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/01/2015] [Accepted: 12/07/2015] [Indexed: 01/11/2023]
Abstract
Insulin-like growth factor binding protein-1 (IGFBP-1), secreted by fetal liver, is a key regulator of IGF-I bioavailability and fetal growth. IGFBP-1 phosphorylation decreases IGF-I bioavailability and diminishes its growth-promoting effects. Growth-restricted fetuses have decreased levels of circulating essential amino acids. We recently showed that IGFBP-1 hyperphosphorylation (pSer101/119/169) in response to leucine deprivation is regulated via activation of the amino acid response (AAR) in HepG2 cells. Here we investigated nutrient-sensitive protein kinases CK2/PKC/PKA in mediating IGFBP-1 phosphorylation in leucine deprivation. We demonstrated that leucine deprivation stimulated CK2 activity (enzymatic assay) and induced IGFBP-1 phosphorylation (immunoblotting/MRM-MS). Inhibition (pharmacological/siRNA) of CK2/PKC, but not PKA, prevented IGFBP-1 hyperphosphorylation in leucine deprivation. PKC inhibition also prevented leucine deprivation-stimulated CK2 activity. Functionally, leucine deprivation decreased IGF-I-induced-IGF-1R autophosphorylation when CK2/PKC were not inhibited. Our data strongly support that PKC promotes leucine deprivation-induced IGFBP-1 hyperphosphorylation via CK2 activation, mechanistically linking decreased amino acid availability and reduced fetal growth.
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Affiliation(s)
- Niyati Malkani
- Dept of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Kyle Biggar
- Dept of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Majida Abu Shehab
- Children's Health Research Institute, University of Western Ontario, London, ON, Canada
| | - Shawn Shun-Cheng Li
- Dept of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Thomas Jansson
- Dept of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Madhulika B Gupta
- Dept of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada; Children's Health Research Institute, University of Western Ontario, London, ON, Canada; Dept of Pediatrics, University of Western Ontario, London, Canada.
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30
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Long B, Yin C, Fan Q, Yan G, Wang Z, Li X, Chen C, Yang X, Liu L, Zheng Z, Shi M, Yan X. Global Liver Proteome Analysis Using iTRAQ Reveals AMPK–mTOR–Autophagy Signaling Is Altered by Intrauterine Growth Restriction in Newborn Piglets. J Proteome Res 2016; 15:1262-73. [DOI: 10.1021/acs.jproteome.6b00001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Baisheng Long
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Cong Yin
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Qiwen Fan
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Guokai Yan
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Zhichang Wang
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Xiuzhi Li
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Changqing Chen
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Xingya Yang
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Lu Liu
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Zilong Zheng
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Min Shi
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
| | - Xianghua Yan
- College
of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China
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31
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Damerill I, Biggar KK, Abu Shehab M, Li SSC, Jansson T, Gupta MB. Hypoxia Increases IGFBP-1 Phosphorylation Mediated by mTOR Inhibition. Mol Endocrinol 2015; 30:201-16. [PMID: 26714229 DOI: 10.1210/me.2015-1194] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In fetal growth restriction (FGR), fetal growth is limited by reduced nutrient and oxygen supply. Insulin-like growth factor I (IGF-I) is a key regulator of fetal growth and IGF binding protein -1(IGFBP-1) is the principal regulator of fetal IGF-I bioavailability. Phosphorylation enhances IGFBP-1's affinity for IGF-I. Hypoxia induces IGFBP-1 hyperphosphorylation, markedly decreasing IGF-I bioavailability. We recently reported that fetal liver IGFBP-1 hyperphosphorylation is associated with inhibition of the mechanistic target of rapamycin (mTOR) in a nonhuman primate model of FGR. Here, we test the hypothesis that IGFBP-1 hyperphosphorylation in response to hypoxia is mediated by mTOR inhibition. We inhibited mTOR either by rapamycin or small interfering RNA (siRNA) targeting raptor (mTOR complex [mTORC]1) and/or rictor (mTORC2) in HepG2 cells cultured under hypoxia (1% O2) or basal (20% O2) conditions. Conversely, we activated mTORC1 or mTORC1+mTORC2 by silencing endogenous mTOR inhibitors (tuberous sclerosis complex 2/DEP-domain-containing and mTOR-interacting protein). Immunoblot analysis demonstrated that both hypoxia and inhibition of mTORC1 and/or mTORC2 induced similar degrees of IGFBP-1 phosphorylation at Ser101/119/169 and reduced IGF-I receptor autophosphorylation. Activation of mTORC1+mTORC2 or mTORC1 alone prevented IGFBP-1 hyperphosphorylation in response to hypoxia. Multiple reaction monitoring-mass spectrometry showed that rapamycin and/or hypoxia increased phosphorylation also at Ser98 and at a novel site Ser174. In silico structural analysis indicated that Ser174 was in close proximity to the IGF-binding site. Together, we demonstrate that signaling through the mTORC1 or mTORC2 pathway is sufficient to induce IGFBP-1 hyperphosphorylation in response to hypoxia. This study provides novel understanding of the cellular mechanism that controls fetal IGFBP-1 phosphorylation in hypoxia, and we propose that mTOR inhibition constitutes a mechanistic link between hypoxia, reduced IGF-I bioavailability and FGR.
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Affiliation(s)
- Ian Damerill
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
| | - Kyle K Biggar
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
| | - Majida Abu Shehab
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
| | - Shawn Shun-Cheng Li
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
| | - Thomas Jansson
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
| | - Madhulika B Gupta
- Department of Biochemistry (I.D., K.K.B., S.S.-C.L., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada; Department of Obstetrics and Gynecology (T.J.), University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045; Department of Pediatrics (M.B.G.), University of Western Ontario, London, N6C 2V5 Canada; and Children's Health Research Institute (M.A.S., M.B.G.), University of Western Ontario, London, Ontario, N6C 2V5 Canada
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Malkani N, Jansson T, Gupta MB. IGFBP-1 hyperphosphorylation in response to leucine deprivation is mediated by the AAR pathway. Mol Cell Endocrinol 2015; 412:182-95. [PMID: 25957086 PMCID: PMC5563670 DOI: 10.1016/j.mce.2015.04.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 02/07/2023]
Abstract
Insulin-like growth factor-1 (IGF-I) is the key regulator of fetal growth. IGF-I bioavailability is markedly diminished by IGF binding protein-1 (IGFBP-1) phosphorylation. Leucine deprivation strongly induces IGFBP-1 hyperphosphorylation, and plays an important role in fetal growth restriction (FGR). FGR is characterized by decreased amino acid availability, which activates the amino acid response (AAR) and inhibits the mechanistic target of rapamycin (mTOR) pathway. We investigated the role of AAR and mTOR in mediating IGFBP-1 secretion and phosphorylation in HepG2 cells in leucine deprivation. mTOR inhibition (rapamycin or raptor + rictor siRNA), or activation (DEPTOR siRNA) demonstrated a role of mTOR in leucine deprivation-induced IGFBP-1 secretion but not phosphorylation. When the AAR was blocked (U0126, or ERK/GCN2 siRNA), both IGFBP-1 secretion and hyperphosphorylation (pSer101/pSer119/pSer169) due to leucine deprivation were prevented. CK2 inhibition by TBB also attenuated IGFBP-1 phosphorylation in leucine deprivation. These results suggest that the AAR and mTOR independently regulate IGFBP-1 secretion and phosphorylation in response to decreased amino acid availability.
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Affiliation(s)
- Niyati Malkani
- Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Madhulika B Gupta
- Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada; Department of Pediatrics, University of Western Ontario, London, Canada; Children's Health Research Institute, University of Western Ontario, London, ON, Canada.
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The role and regulation of IGFBP-1 phosphorylation in fetal growth restriction. J Cell Commun Signal 2015; 9:111-23. [PMID: 25682045 DOI: 10.1007/s12079-015-0266-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 01/21/2015] [Indexed: 12/18/2022] Open
Abstract
Fetal growth restriction (FGR) increases the risk of perinatal complications and predisposes the infant to developing metabolic, cardiovascular, and neurological diseases in childhood and adulthood. The pathophysiology underlying FGR remains poorly understood and there is no specific treatment available. Biomarkers for early detection are also lacking. The insulin-like growth factor (IGF) system is an important regulator of fetal growth. IGF-I is the primary regulator of fetal growth, and fetal circulating levels of IGF-I are decreased in FGR. IGF-I activity is influenced by a family of IGF binding proteins (IGFBPs), which bind to IGF-I and decrease its bioavailability. During fetal development the predominant IGF-I binding protein in fetal circulation is IGFBP-1, which is primarily secreted by the fetal liver. IGFBP-1 binds IGF-I and thereby inhibits its bioactivity. Fetal circulating levels of IGF-I are decreased and concentrations of IGFBP-1 are increased in FGR. Phosphorylation of human IGFBP-1 at specific sites markedly increases its binding affinity for IGF-I, further limiting IGF-I bioactivity. Recent experimental evidence suggests that IGFBP-1 phosphorylation is markedly increased in the circulation of FGR fetuses suggesting an important role of IGFBP-1 phosphorylation in the regulation of fetal growth. Understanding of the significance of site-specific IGFBP-1 phosphorylation and how it is regulated to contribute to fetal growth will be an important step in designing strategies for preventing, managing, and/or treating FGR. Furthermore, IGFBP-1 hyperphosphorylation at unique sites may serve as a valuable biomarker for FGR.
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Solomon AL, Siddals KW, Baker PN, Gibson JM, Aplin JD, Westwood M. Placental alkaline phosphatase de-phosphorylates insulin-like growth factor (IGF)-binding protein-1. Placenta 2014; 35:520-2. [PMID: 24856042 DOI: 10.1016/j.placenta.2014.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 01/12/2023]
Abstract
BACKGROUND Insulin-like growth factors (IGF) regulate fetal growth through their effects on placenta. Their actions are influenced by IGF binding protein-1. Phosphorylated IGFBP-1 (pIGFBP-1) has high affinity for IGF-I and usually inhibits IGF-I activity but during pregnancy, it is de-phosphorylated to generate lower affinity isoforms and consequently, increased IGF bioavailability. Here we investigate the role of placenta in this process. RESULTS Our data show that term human placental explants, but not their conditioned medium, can de-phosphorylate IGFBP-1 through the action of placental alkaline phosphatase (PLAP). DISCUSSION PLAP-mediated de-phosphorylation of IGFBP-1 may provide a mechanism for controlling IGF-I bioavailability and action at the maternal/fetal interface.
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Affiliation(s)
- A L Solomon
- Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK
| | - K W Siddals
- Centre for Imaging Sciences, Institute of Population Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - P N Baker
- Gravida, University of Auckland, Auckland, New Zealand
| | - J M Gibson
- Centre for Imaging Sciences, Institute of Population Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - J D Aplin
- Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK
| | - M Westwood
- Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK.
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