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Baxter RC. Endocrine and cellular physiology and pathology of the insulin-like growth factor acid-labile subunit. Nat Rev Endocrinol 2024; 20:414-425. [PMID: 38514815 DOI: 10.1038/s41574-024-00970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/26/2024] [Indexed: 03/23/2024]
Abstract
The acid-labile subunit (ALS) of the insulin-like growth factor (IGF) binding protein (IGFBP) complex, encoded in humans by IGFALS, has a vital role in regulating the endocrine transport and bioavailability of IGF-1 and IGF-2. Accordingly, ALS has a considerable influence on postnatal growth and metabolism. ALS is a leucine-rich glycoprotein that forms high-affinity ternary complexes with IGFBP-3 or IGFBP-5 when they are occupied by either IGF-1 or IGF-2. These complexes constitute a stable reservoir of circulating IGFs, blocking the potentially hypoglycaemic activity of unbound IGFs. ALS is primarily synthesized by hepatocytes and its expression is lower in non-hepatic tissues. ALS synthesis is strongly induced by growth hormone and suppressed by IL-1β, thus potentially serving as a marker of growth hormone secretion and/or activity and of inflammation. IGFALS mutations in humans and Igfals deletion in mice cause modest growth retardation and pubertal delay, accompanied by decreased osteogenesis and enhanced adipogenesis. In hepatocellular carcinoma, IGFALS is described as a tumour suppressor; however, its contribution to other cancers is not well delineated. This Review addresses the endocrine physiology and pathology of ALS, discusses the latest cell and proteomic studies that suggest emerging cellular roles for ALS and outlines its involvement in other disease states.
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Affiliation(s)
- Robert C Baxter
- University of Sydney, Kolling Institute, Royal North Shore Hospital, St Leonards, New South Wales, Australia.
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2
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Huang Z, Lu X, Huang L, Zhang C, Veldhuis JD, Cowley MA, Chen C. Stimulation of endogenous pulsatile growth hormone secretion by activation of growth hormone secretagogue receptor reduces the fat accumulation and improves the insulin sensitivity in obese mice. FASEB J 2021; 35:e21269. [PMID: 33368660 DOI: 10.1096/fj.202001924rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/23/2020] [Accepted: 11/30/2020] [Indexed: 12/18/2022]
Abstract
Obese individuals often show low growth hormone (GH) secretion, which leads to reduced lipid mobilization and further fat accumulation. Pharmacological approaches to increase GH levels in obese individuals by GH injection or GH-releasing hormone receptor agonist showed promising effects on fat reduction. However, side effects on glucose metabolism and the heavy costs on making large peptides hindered their clinical application. Here, we tested whether stimulation of endogenous GH secretion by a synthetic GH secretagogue receptor (GHSR) agonist, hexarelin, improved the metabolism in a hyperphagic obese mouse model. Male melanocortin 4 receptor knockout mice (MC4RKO) were pair-fed and received continuous hexarelin (10.56 μg/day) or vehicle infusion by an osmotic pump for 3-4 weeks. Hexarelin treatment significantly increased the pulsatile GH secretion without detectable alteration on basal GH secretion in MC4RKO mice. The treated mice showed increased lipolysis and lipid oxidation in the adipose tissue, and reduced de novo lipogenesis in the liver, leading to reduced visceral fat mass, reduced triglyceride content in liver, and unchanged circulating free fatty acid levels. Importantly, hexarelin treatment improved the whole-body insulin sensitivity but did not alter glucose tolerance, insulin levels, or insulin-like growth factor 1 (IGF-1) levels. The metabolic effects of hexarelin were likely through the direct action of GH, as indicated by the increased expression level of genes involved in GH signaling pathways in visceral adipose tissues and liver. In conclusion, hexarelin treatment stimulated the pulsatile GH secretion and reduced the fat accumulation in visceral depots and liver in obese MC4RKO mice with improved insulin sensitivity without altered levels of insulin or IGF-1. It provides evidence for managing obesity by enhancing pulsatile GH secretion through activation of GHSR in the pituitary gland.
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Affiliation(s)
- Zhengxiang Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Xuehan Lu
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Lili Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Chunhong Zhang
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Johannes D Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, MN, USA
| | - Michael A Cowley
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
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3
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Chen S, Chen H, Zhong Y, Ge Y, Li C, Qiao Z, Zhu J. Insulin-like growth factor-binding protein 3 inhibits angiotensin II-induced aortic smooth muscle cell phenotypic switch and matrix metalloproteinase expression. Exp Physiol 2020; 105:1827-1839. [PMID: 32936966 DOI: 10.1113/ep088927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/15/2020] [Indexed: 12/28/2022]
Abstract
NEW FINDINGS What is the central question of this study? Insulin-like growth factor 1 and its major binding protein insulin-like growth factor binding protein 3 (IGFBP3) are involved in collagen deregulation in several cardiovascular diseases: what is the role of IGFBP3 in thoracic aortic dissection and does it regulate aortic smooth muscle cells' phenotypic switch? What is the main finding and its importance? IGFBP3 inhibits aortic smooth muscle cells' phenotypic switch from a contractile to a synthetic phenotype, decreases matrix metalloproteinase 9 activation and suppresses elastin degradation. These findings provide a better understanding of the pathogenesis of thoracic aortic dissection. ABSTRACT Thoracic aortic dissection (TAD) is characterized by aortic media degeneration and is a highly lethal disease. An aortic smooth muscle cell (AoSMC) phenotypic switch is considered a key pathophysiological change in TAD. Insulin-like growth factor binding protein 3 (IGFBP3) was found to be downregulated in aortic tissues of TAD patients. The present work aimed to study the function of IGFBP3 in AoSMCs' phenotypic switch and matrix metalloproteinase (MMP) expression. We established a mouse model of TAD by angiotensin (Ang) II infusion to β-aminopropionitrile-administrated mice, and found decreased IGFBP3 expression accompanied by aortic dilatation and elastin degradation in vivo. Further, mouse (m)AoSMCs were isolated from mouse thoracic aorta and treated with Ang II. Ang II induced downregulation of IGFBP3 in vitro. To further study the function of IGFBP3, primary mAoSMCs were infected with adenovirus expressing IGFBP3 followed by Ang II induction. Enforced upregulation of IGFBP3 decreased MMP9 expression and activation as well as increasing tissue inhibitor of metalloproteinase (TIMP) 1 expression in Ang II-induced mAoSMCs. No difference was observed in MMP2 and TIMP3 expression. IGFBP3 suppressed subsequent Ang II-induced elastin degradation in vitro. IGFBP3 inhibited Ang II-induced mAoSMCs' phenotypic switch as evidenced by increased smooth muscle actin α-2 (ACTA2) and myosin heavy chain 11 (MYH11) expression and decreased secreted phosphoprotein 1 (SPP1) and vimentin expression. Taken together, the present study demonstrates the role of IGFBP3 in preserving AoSMCs' contractile state and reducing MMP9 activation and thus promoting elastic fibre synthesis, which provides a better understanding of the pathogenesis of TAD.
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Affiliation(s)
- Suwei Chen
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Hong Chen
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yongliang Zhong
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Yipeng Ge
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Chengnan Li
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhiyu Qiao
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Junming Zhu
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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4
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Varma Shrivastav S, Bhardwaj A, Pathak KA, Shrivastav A. Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3): Unraveling the Role in Mediating IGF-Independent Effects Within the Cell. Front Cell Dev Biol 2020; 8:286. [PMID: 32478064 PMCID: PMC7232603 DOI: 10.3389/fcell.2020.00286] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 04/02/2020] [Indexed: 12/22/2022] Open
Abstract
Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3), one of the six members of the IGFBP family, is a key protein in the IGF pathway. IGFBP-3 can function in an IGF-dependent as well as in an IGF-independent manner. The IGF-dependent roles of IGFBP-3 include its endocrine role in the delivery of IGFs from the site of synthesis to the target cells that possess IGF receptors and the activation of associated downstream signaling. IGF-independent role of IGFBP-3 include its interactions with the proteins of the extracellular matrix and the proteins of the plasma membrane, its translocation through the plasma membrane into the cytoplasm and into the nucleus. The C-terminal domain of IGFBP-3 has the ability to undergo cell penetration therefore, generating a short 8-22-mer C-terminal domain peptides that can be conjugated to drugs or genes for effective intracellular delivery. This has opened doors for biotechnological applications of the molecule in molecular medicine. The aim of this this review is to summarize the complex roles of IGFBP-3 within the cell, including its mechanisms of cellular uptake and its translocation into the nucleus, various molecules with which it is capable of interacting, and its ability to regulate IGF-independent cell growth, survival and apoptosis. This would pave way into understanding the modus operandi of IGFBP-3 in regulating IGF-independent processes and its pleiotropic ability to bind with potential partners thus regulating several cellular functions implicated in metabolic diseases, including cancer.
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Affiliation(s)
- Shailly Varma Shrivastav
- VastCon Inc., Winnipeg, MB, Canada.,Department of Biology, University of Winnipeg, Winnipeg, MB, Canada
| | - Apurva Bhardwaj
- Department of Biology, University of Winnipeg, Winnipeg, MB, Canada
| | - Kumar Alok Pathak
- Research Institute of Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB, Canada.,Department of Surgery, University of Manitoba, Winnipeg, MB, Canada
| | - Anuraag Shrivastav
- Department of Biology, University of Winnipeg, Winnipeg, MB, Canada.,Research Institute of Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB, Canada
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5
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Hetz JA, Menzies BR, Shaw G, Renfree MB. The tammar wallaby: a non-traditional animal model to study growth axis maturation. Reprod Fertil Dev 2019; 31:1276-1288. [PMID: 31030727 DOI: 10.1071/rd18271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 03/26/2019] [Indexed: 11/23/2022] Open
Abstract
Maturation of the growth hormone (GH)/insulin-like growth factor 1 (IGF1) axis is a critical developmental event that becomes functional over the peripartum period in precocial eutherian mammals such as sheep. In mice and marsupials that give birth to altricial young, the GH/IGF1 axis matures well after birth, suggesting that functional maturation is associated with developmental stage, not parturition. Recent foster-forward studies in one marsupial, the tammar wallaby (Macropus eugenii), have corroborated this hypothesis. 'Fostering' tammar young not only markedly accelerates their development and growth rates, but also affects the timing of maturation of the growth axis compared with normal growing young, providing a novel non-traditional animal model for nutritional manipulation. This review discusses how nutrition affects the maturation of the growth axis in marsupials compared with traditional eutherian animal models.
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Affiliation(s)
- Jennifer A Hetz
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia; and Escuela de Agronomía, Pontificia Universidad Católica de Valparaíso, Casilla 4-D, Quillota, Región de Valparaíso, Chile
| | - Brandon R Menzies
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia; and Corresponding author.
| | - Geoffrey Shaw
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
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6
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Lue Y, Swerdloff R, Wan J, Xiao J, French S, Atienza V, Canela V, Bruhn KW, Stone B, Jia Y, Cohen P, Wang C. The Potent Humanin Analogue (HNG) Protects Germ Cells and Leucocytes While Enhancing Chemotherapy-Induced Suppression of Cancer Metastases in Male Mice. Endocrinology 2015; 156:4511-21. [PMID: 26384090 PMCID: PMC4655208 DOI: 10.1210/en.2015-1542] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Humanin is a peptide that is cytoprotective against stresses in many cell types. We investigated whether a potent humanin analogue S14G-humanin (HNG) would protect against chemotherapy-induced damage to normal cells without interfering with the chemotherapy-induced suppression of cancer cells. Young adult male mice were inoculated iv with murine melanoma cells. After 1 week, cancer-bearing mice were randomized to receive either: no treatment, daily ip injection of HNG, a single ip injection of cyclophosphamide (CP), or CP+HNG and killed at the end of 3 weeks. HNG rescued the CP-induced suppression of leucocytes and protected germ cell from CP-induced apoptosis. Lung metastases were suppressed by HNG or CP alone, and further suppressed by CP+HNG treatment. Plasma IGF-1 levels were suppressed by HNG with or without CP treatment. To investigate whether HNG maintains its protective effects on spermatogonial stem cells, sperm output, and peripheral leucocytes after repeated doses of CP, normal adult male mice received: no treatment, daily sc injection of HNG, 6 ip injections of CP at 5-day intervals, and the same regimens of CP+HNG and killed at the end of 4 weeks of treatment. Cauda epididymal sperm counts were elevated by HNG and suppressed by CP. HNG rescued the CP-induced suppression of spermatogonial stem cells, sperm count and peripheral leucocytes. We conclude that HNG 1) protects CP-induced loss of male germ cells and leucocytes, 2) enhances CP-induced suppression of cancer metastases, and 3) acts as a caloric-restriction mimetic by suppressing IGF-1 levels. Our findings suggest that humanin analogues may be promising adjuvants to chemotherapy.
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Affiliation(s)
- YanHe Lue
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Ronald Swerdloff
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Junxiang Wan
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Jialin Xiao
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Samuel French
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Vince Atienza
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Victor Canela
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Kevin W Bruhn
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Brian Stone
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Yue Jia
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Pinchas Cohen
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
| | - Christina Wang
- Division of Endocrinology (Y.L., R.S., V.A., V.C., B.S., Y.J., C.W.) and Division of Dermatology (K.V.B.), Department of Medicine, Harbor-University of California, Los Angeles Medical Center and Los Angeles Biomedical Research Institute, Torrance, California 90502; University of Southern California Davis School of Gerontology (J.W., J.X., P.C.), University of Southern California, Los Angeles, California 90033; and Department of Pathology (S.F.), Harbor-University of California, Los Angeles Medical Center, Torrance, California 90502
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7
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Nguyen KH, Yao XH, Erickson AG, Mishra S, Nyomba BLG. Glucose intolerance in aging male IGFBP-3 transgenic mice: differential effects of human IGFBP-3 and its mutant IGFBP-3 devoid of IGF binding ability. Endocrinology 2015; 156:462-74. [PMID: 25490144 DOI: 10.1210/en.2014-1271] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We have reported a reduction of insulin secretion and glucose intolerance in young mice overexpressing human IGFBP-3 (phosphoglycerate kinase [PGK]BP3) or its mutant Gly56/Gly80/Gly81-IGFBP-3 (PGKmutBP3) under the PGK promoter. Here, we investigated changes in glucose and lipid homeostasis with age in PGKBP3 and PGKmutBP3 mice compared with wild-type mice. Body weight, glucose tolerance, insulin tolerance, visceral fat, interscapular brown adipose tissue (BAT), serum lipids, and pancreas histology were examined at age 3, 6, and 12 months. Murine IGFBP-3 was similar in all mouse genotypes and decreased with age in parallel with total IGF-1. Visceral fat and BAT masses increased in PGKmutBP3 mice, but not in PGKBP3 mice. Glucose tolerance was impaired in both PGKBP3 and PGKmutBP3 mice. However, PGKBP3 mice had increased expression of uncoupling protein-1 in BAT and reduced adiposity, and continued to have smaller pancreatic β-cell mass and reduced insulin secretion through age 12 months. In contrast, PGKmutBP3 mice developed insulin resistance with age in association with pancreatic β-cell hyperplasia, impaired expression of uncoupling protein-1 in BAT, and increased adiposity. In addition, both PGKBP3 and PGKmutBP3 mice had elevated glycerol in the circulation, but only PGKBP3 mice had elevated free fatty acids and only PGKmutBP3 mice had elevated triglycerides. Estimated free IGF-1 did not increase with age in transgenic mice, as it did in wild-type mice. Thus, overexpression of human IGFBP-3 or its mutant devoid of IGF binding ability leads to glucose intolerance with, however, different effects on insulin secretion, insulin sensitivity, and lipid homeostasis in aging mice.
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Affiliation(s)
- K Hoa Nguyen
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada R3E3P4
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8
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Moody G, Beltran PJ, Mitchell P, Cajulis E, Chung YA, Hwang D, Kendall R, Radinsky R, Cohen P, Calzone FJ. IGF1R blockade with ganitumab results in systemic effects on the GH-IGF axis in mice. J Endocrinol 2014; 221:145-55. [PMID: 24492468 PMCID: PMC4160154 DOI: 10.1530/joe-13-0306] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ganitumab is a fully human MAB to the human type 1 IGF receptor (IGF1R). Binding assays showed that ganitumab recognized murine IGF1R with sub-nanomolar affinity (KD=0.22 nM) and inhibited the interaction of murine IGF1R with IGF1 and IGF2. Ganitumab inhibited IGF1-induced activation of IGF1R in murine lungs and CT26 murine colon carcinoma cells and tumors. Addition of ganitumab to 5-fluorouracil resulted in enhanced inhibition of tumor growth in the CT26 model. Pharmacological intervention with ganitumab in naïve nude mice resulted in a number of physiological changes described previously in animals with targeted deletions of Igf1 and Igf1r, including inhibition of weight gain, reduced glucose tolerance and significant increase in serum levels of GH, IGF1 and IGFBP3. Flow cytometric analysis identified GR1/CD11b-positive cells as the highest IGF1R-expressing cells in murine peripheral blood. Administration of ganitumab led to a dose-dependent, reversible decrease in the number of peripheral neutrophils with no effect on erythrocytes or platelets. These findings indicate that acute IGF availability for its receptor plays a critical role in physiological growth, glucose metabolism and neutrophil physiology and support the presence of a pituitary IGF1R-driven negative feedback loop that tightly regulates serum IGF1 levels through Gh signaling.
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Affiliation(s)
- Gordon Moody
- Oncology Research Therapeutic Area, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, USA David Geffen School of Medicine, Los Angeles, California, USA USC Davis School of Gerontology, Los Angeles, California, USA
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9
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Christie M, Torres RM, Kedl RM, Randolph TW, Carpenter JF. Recombinant murine growth hormone particles are more immunogenic with intravenous than subcutaneous administration. J Pharm Sci 2014; 103:128-39. [PMID: 25133276 PMCID: PMC4137484 DOI: 10.1002/jps.23794] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Evaluation and mitigation of the risk of immunogenicity to protein aggregates and particles in therapeutic protein products remains a primary concern for drug developers and regulatory agencies. To investigate how the presence of protein particles and the route of administration influence the immunogenicity of a model therapeutic protein, we measured the immune response in mice to injections of formulations of recombinant murine growth hormone (rmGH) that contained controlled levels of protein particles. Mice were injected twice over 6 weeks with rmGH formulations via the subcutaneous, intraperitoneal, or intravenous (i.v.) routes. In addition to soluble, monomeric rmGH, the samples prepared contained either nanoparticles of rmGH or both nano- and microparticles of rmGH.The appearance of anti-rmGH IgG1, IgG2a, IgG2b, IgG2c, and IgG3 titers following the second injection of both preparations implies that multiple mechanisms contributed to the immune response. No dependence of the immune response on particle size and distribution was observed. The immune response measured after the second injection was most pronounced when i.v. administration was used. Despite producing high anti-rmGH titers mice appeared to retain the ability to properly regulate and use endogenous growth hormone.
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Affiliation(s)
- Merry Christie
- Department of Pharmaceutical Sciences, University of Colorado Dever, Anschutz Medical Campus, Aurora, Colorado 80045.
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10
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Chin YP, Keni J, Wan J, Mehta H, Anene F, Jia Y, Lue YH, Swerdloff R, Cobb LJ, Wang C, Cohen P. Pharmacokinetics and tissue distribution of humanin and its analogues in male rodents. Endocrinology 2013; 154:3739-44. [PMID: 23836030 PMCID: PMC3776863 DOI: 10.1210/en.2012-2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Humanin (HN) is a novel 24-amino acid mitochondrial-derived peptide that has demonstrated diverse cytoprotective effects, including an emerging role in diabetes. The purpose of this study was to examine the pharmacokinetics of humanin analogues, which show great potential as therapeutic agents (HNG and the non-IGFBP-3 binding, HNGF6A). 11-week-old male IGFBP-3(-/-) and wild type (WT) mice were divided into 3 groups: WT mice treated with HNG, WT mice treated with HNGF6A, and IGFBP-3(-/-) mice treated with HNG. Plasma was obtained from mice following ip injection with HN analogues, and HN levels were measured with ELISA. WT mice treated with HNGF6A and IGFBP-3(-/-) mice treated with HNG displayed a longer half-life of HN compared with WT mice treated with HNG. Following HNG injection, both IGF-1 and IGFBP-3 levels decreased over time. Adult male Sprague Dawley rats were also ip injected with HNG, and HN levels were measured in various tissues (plasma, liver, heart, and brain) by ELISA. The half-life of HN was found to be longer in rats compared with mice. In rats, HN levels were found to be highest in plasma, present in liver, and undetectable in brain or heart. The current study provides evidence of HN and IGFBP-3 association in the circulation and suggests that native HN may modulate the distribution of IGF-1 and IGFBP-3. The results also demonstrate varying kinetic profiles of HN analogues and interspecies variation in rodents. Sustainable levels of circulating HN measured in plasma underline the potential value of HN analogues as a new therapeutic intervention in the treatment of diabetes.
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Affiliation(s)
- Yung-Ping Chin
- Dean, USC Davis School of Gerontology, University of Southern California, Los Angeles, California 90089-0191.
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11
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Dean JP, Sprenger CC, Wan J, Haugk K, Ellis WJ, Lin DW, Corman JM, Dalkin BL, Mostaghel E, Nelson PS, Cohen P, Montgomery B, Plymate SR. Response of the insulin-like growth factor (IGF) system to IGF-IR inhibition and androgen deprivation in a neoadjuvant prostate cancer trial: effects of obesity and androgen deprivation. J Clin Endocrinol Metab 2013; 98:E820-8. [PMID: 23533230 PMCID: PMC4430583 DOI: 10.1210/jc.2012-3856] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
CONTEXT Prostate cancer patients at increased risk for relapse after prostatectomy were treated in a neoadjuvant study with androgen deprivation therapy (ADT) in combination with cixutumumab, an inhibitory fully human monoclonal antibody against IGF receptor 1 (IGF-IR). OBJECTIVE A clinical trial with prospective collection of serum and tissue was designed to test the potential clinical efficacy of neoadjuvant IGF-IR blockade combined with ADT in these patients. The effect of body mass index (BMI) on response of IGF-IR/insulin components to IGF-IR blockade was also examined. DESIGN Eligibility for the trial required the presence of high-risk prostate adenocarcinoma. Treatment consisted of bicalutamide, goserelin, and cixutumumab for 13 weeks before prostatectomy. Here we report on an analysis of serum samples from 29 enrolled patients. Changes in IGF and glucose homeostasis pathways were compared to control samples from patients in a concurrent clinical trial of neoadjuvant ADT alone. RESULTS Significant increases were seen in GH (P = .001), IGF-I (P < .0001), IGF-II (P = .003), IGF binding protein (IGFBP)-3 (P < .0001), C-peptide (P = .0038), and insulin (P = .05) compared to patients treated with ADT alone. IGFBP-1 levels were significantly lower in the cixutumumab plus ADT cohort (P = .001). No significant changes in blood glucose were evident. Patients with BMIs in the normal range had significantly higher GH (P < .05) and IGFBP-1 (P < 0.5) levels compared to overweight and obese patients. CONCLUSIONS Patients with IGF-IR blockade in combination with ADT demonstrated significant changes in IGF and glucose homeostasis pathway factors compared to patients receiving ADT alone. In the patients receiving combination therapy, patients with normal BMI had serum levels of glucose homeostasis components similar to individuals in the ADT-alone cohort, whereas patients with overweight and obese BMIs had serum levels that differed from the ADT cohort.
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12
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Parrella E, Maxim T, Maialetti F, Zhang L, Wan J, Wei M, Cohen P, Fontana L, Longo VD. Protein restriction cycles reduce IGF-1 and phosphorylated Tau, and improve behavioral performance in an Alzheimer's disease mouse model. Aging Cell 2013; 12:257-68. [PMID: 23362919 PMCID: PMC3982836 DOI: 10.1111/acel.12049] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2013] [Indexed: 12/21/2022] Open
Abstract
In laboratory animals, calorie restriction (CR) protects against aging, oxidative stress, and neurodegenerative pathologies. Reduced levels of growth hormone and IGF-1, which mediate some of the protective effects of CR, can also extend longevity and/or protect against age-related diseases in rodents and humans. However, severely restricted diets are difficult to maintain and are associated with chronically low weight and other major side effects. Here we show that 4 months of periodic protein restriction cycles (PRCs) with supplementation of nonessential amino acids in mice already displaying significant cognitive impairment and Alzheimer's disease (AD)-like pathology reduced circulating IGF-1 levels by 30-70% and caused an 8-fold increase in IGFBP-1. Whereas PRCs did not affect the levels of β amyloid (Aβ), they decreased tau phosphorylation in the hippocampus and alleviated the age-dependent impairment in cognitive performance. These results indicate that periodic protein restriction cycles without CR can promote changes in circulating growth factors and tau phosphorylation associated with protection against age-related neuropathologies.
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Affiliation(s)
- Edoardo Parrella
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Tom Maxim
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | | | - Lu Zhang
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Junxiang Wan
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Min Wei
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Pinchas Cohen
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Luigi Fontana
- Division of Geriatrics and Nutritional Science, Washington University in St. Louis St. Louis, MO, USA
- Department of Medicine, Salerno University School of Medicine, Salerno, Italy
- Healthy Aging Platform, CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Valter D. Longo
- Longevity Institute, Davis School of Gerontology, and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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13
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de Silva HC, Firth SM, Twigg SM, Baxter RC. Interaction between IGF binding protein-3 and TGFβ in the regulation of adipocyte differentiation. Endocrinology 2012; 153:4799-807. [PMID: 22910030 DOI: 10.1210/en.2011-1444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development of white adipose tissue involves both the hypertrophy of existing adipocytes and the proliferation and differentiation of preadipocytes. Adipogenic differentiation is inhibited by TGFβ signaling through Smad2/3, and IGF binding protein-3 (IGFBP-3) is also known to activate Smad2/3 signaling in some cell types. We previously reported that exogenous or overexpressed IGFBP-3 inhibits adipogenesis in 3T3-L1 cells, but the role of endogenous IGFBP-3 in this process, and its possible interaction with TGFβ, is not known. During 10-d adipogenic differentiation initiated by insulin, dexamethasone, and 3-isobutyl-1-methylxanthine, 3T3-L1 cells expressed increasing levels of IGFBP-3 and TGFβ1, secreting over 1000 pg/ml of both proteins. Exogenous recombinant human IGFBP-3 paralleled TGFβ1 in stimulating Smad2 phosphorylation in 3T3-L1 preadipocytes, but no additive effect was observed for the two agents. In contrast, knockdown of endogenous IGFBP-3 by small interfering RNA (siRNA) significantly impaired Smad2 activation by 0.25 ng/ml TGFβ1. Transient expression of human IGFBP-3 significantly inhibited the induction of adipogenic markers adiponectin and resistin, and the appearance of lipid droplets, but down-regulation of endogenous IGFBP-3 by siRNA had little effect on the expression of either marker during the 10-d differentiation, compared with nonsilencing control siRNA. However, down-regulation of endogenous IGFBP-3 using two different siRNA significantly reversed the inhibitory effect of TGFβ1 on both adiponectin and resistin induction. We conclude that IGFBP-3 activates inhibitory Smad signaling in 3T3-L1 cells and that endogenous IGFBP-3 modulates their adipogenic differentiation by regulating cell sensitivity towards the inhibitory effect of TGFβ.
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Affiliation(s)
- Hasanthi C de Silva
- Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, Sydney, New South Wales 2065, Australia
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14
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Mason EJ, Grell JA, Wan J, Cohen P, Conover CA. Insulin-like growth factor (IGF)-I and IGF-II contribute differentially to the phenotype of pregnancy associated plasma protein-A knock-out mice. Growth Horm IGF Res 2011; 21:243-247. [PMID: 21802327 PMCID: PMC3171618 DOI: 10.1016/j.ghir.2011.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 11/28/2022]
Abstract
CONTEXT Insulin-like growth factor (IGF) signaling is essential for achieving optimal body size during fetal development, peak bone mass during puberty, and maximal fecundity in the reproductive period. IGF-II is considered the main fetal IGF, whereas IGF-I is more important postnatally. Pregnancy-associated plasma protein-A (PAPP-A) enhances local IGF signaling through cleavage of inhibitory IGF binding proteins. Conversely, inhibition of PAPP-A results in reduced local IGF action. Thus, PAPP-A knock-out (KO) mice are born as proportional dwarfs due to the dysregulation of IGF-II signaling during early embryogenesis that impacts body size. Relaxation of IgfII imprinting through mutation of a reciprocally imprinted downstream gene, H19, which allowed transcription of IGF-II from the normally silent maternal allele, rescued the dwarf phenotype of PAPP-A KO mice. OBJECTIVE To determine the effect of increased IGF-II expression on postnatal phenotypes of PAPP-A KO mice. DESIGN Young adult wild-type (WT), PAPP-A KO, H19 mutant (ΔH19/WT) and ΔH19/PAPP-A KO mice were characterized for skeletal phenotype (peripheral quantitative computed tomography at the midshaft and distal metaphysis of the femur) and reproductive phenotype (time to first litter, time between litters, pups per litter). RESULTS Serum IGF-II levels were significantly increased in ΔH19/WT and ΔH19/PAPP-A KO mice compared to WT and PAPP-A KO mice; serum IGF-I levels were not affected by H19 mutation. PAPP-A KO mice had reductions in cortical thickness and in cortical and trabecular area, bone mineral content and bone mineral density compared to WT mice. There were no significant differences between PAPP-A KO and ΔH19/PAPP-A KO mice in any of the bone parameters. PAPP-A KO crossed with (×) PAPP-A KO had a longer time until first litter, normal time between subsequent litters, and significantly reduced number of pups per litter compared to WT×WT. ΔH19/PAPP-A KO×ΔH19/PAPP-A KO had an even longer time to first litter, but also longer time between litters. This phenotype was associated with female ΔH19/PAPP-A KO mice. Furthermore, these ΔH19/PAPP-A KO mouse mothers failed to care for their pups. CONCLUSIONS An increase in IGF-II expression did not rescue the skeletal and reproductive deficiencies associated with reduced local IGF-I signaling in PAPP-A KO mice. In addition, the data suggest a potential new role for genomic imprinting at the IgfII/H19 locus affecting maternal behavior.
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Affiliation(s)
- Emily J. Mason
- The Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Jacquelyn A. Grell
- The Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Junxiang Wan
- Division of Endocrinology, Department of Pediatrics, Mattell Children’s Hospital at UCLA, Los Angeles, CA 90095-1742
| | - Pinchas Cohen
- Division of Endocrinology, Department of Pediatrics, Mattell Children’s Hospital at UCLA, Los Angeles, CA 90095-1742
| | - Cheryl A. Conover
- The Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN 55905
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15
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Mehta HH, Gao Q, Galet C, Paharkova V, Wan J, Said J, Sohn JJ, Lawson G, Cohen P, Cobb LJ, Lee KW. IGFBP-3 is a metastasis suppression gene in prostate cancer. Cancer Res 2011; 71:5154-63. [PMID: 21697285 DOI: 10.1158/0008-5472.can-10-4513] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The insulin-like growth factor binding protein IGFBP-3 is a proapoptotic and antiangiogenic protein in prostate cancer (CaP). Epidemiologic studies suggest that low IGFBP-3 is associated with greater risk of aggressive, metastatic prostate cancers, but in vivo functional data are lacking. Here we show that mice that are genetically deficient in IGFBP-3 exhibit weaker growth of primary prostate tumors but higher incidence of metastatic disease. Prostates in IGFBP-3 knockout mice (IGFBP-3KO mice) failed to undergo apoptosis after castration. Spontaneous prostate tumors did not develop in IGFBP-3KO mice, but splenic lymphomas occurred in 23% of female IGFBP-3KO mice by 80 weeks of age. To assess the effects of IGFBP-3 deficiency on prostate cancer development, we crossed IGFBP-3KO mice with a c-Myc-driven model of CaP that develops slow-growing, nonmetastatic tumors. By 24 weeks of age, well-differentiated prostate cancers were observed in all mice regardless of IGFBP-3 status. However, by 80 weeks of age IGFBP-3KO mice tended to exhibit larger prostate tumors than control mice. More strikingly, lung metastases were observed at this time in 55% of the IGFBP-3KO mice but none in the control animals. Cell lines established from IGFBP-3KO:Myc tumors displayed more aggressive phenotypes in proliferation, invasion, and colony formation assays, relative to control Myc tumor cell lines. In addition, Myc:IGFBP-3KO cells exhibited evidence of epithelial-mesenchymal transition. Our findings established a function for IGFBP-3 in suppressing metastasis in prostate cancer, and they also offered the first reported transgenic model of spontaneous metastatic prostate cancer for studies of this advanced stage of disease.
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16
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Williams NG, Interlichia JP, Jackson MF, Hwang D, Cohen P, Rodgers BD. Endocrine actions of myostatin: systemic regulation of the IGF and IGF binding protein axis. Endocrinology 2011; 152:172-80. [PMID: 21147879 PMCID: PMC3219050 DOI: 10.1210/en.2010-0488] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Myostatin's inhibitory actions on striated muscle growth are believed to be directly mediated by locally produced myostatin and possibly by IGF binding proteins (IGFBPs). We therefore measured skeletal muscle, heart, and liver expression, in neonates and adults, and circulating levels of various IGF axis components (IGF-I, IGFBP-1 to IGFBP-3, and acid labile subunit) in wild-type and mstn-/- mice. Compared with wild type, differences in muscle expression were tissue specific, although IGF-I receptor expression was higher in all mstn-/- neonatal tissues and in adult gastrocnemius. Liver expression of several components also differed between genotype as IGF-I receptor, IGFBP-3 and IGFBP-5 expression was higher in mstn-/- neonates and IGF-I and IGFBP-3 in adults. Circulating IGF-I levels were also higher in mstn-/- adults, whereas IGFBP-1 and IGFBP-2 levels were lower. Comparing IGF-I:IGFBP molar ratios suggested that the relative IGF-binding capacity was potentially lower in mstn-/- mice, and thus, total and "free" IGF-I levels may be elevated. This in turn may increase negative feedback control on GH, because mstn-/- liver weights were lower. Bone growth was similar in both genotypes, suggesting that changes in circulating IGF-I may be more important to muscle, whose mass is enhanced in mstn-/- mice, than to bone. Myostatin receptors, but not myostatin itself, are expressed in the liver. Changes in hepatic production of circulating IGF axis components could therefore result from the loss of endocrine myostatin. Thus, myostatin may inhibit striated muscle growth directly at the cellular level and indirectly through systemic effects on the IGF axis.
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Affiliation(s)
- Nolann G Williams
- School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-6351, USA
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17
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Yamada PM, Mehta HH, Hwang D, Roos KP, Hevener AL, Lee KW. Evidence of a role for insulin-like growth factor binding protein (IGFBP)-3 in metabolic regulation. Endocrinology 2010; 151:5741-50. [PMID: 20926583 PMCID: PMC2999488 DOI: 10.1210/en.2010-0672] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
IGF-binding protein (IGFBP)-3 is a metabolic regulator that has been shown to inhibit insulin-stimulated glucose uptake in murine models. This finding contrasts with epidemiological evidence of decreased serum IGFBP-3 in patients with type 2 diabetes. The purpose of this study was to clarify the role of IGFBP-3 in metabolism. Four-week-old male IGFBP-3(-/-) and control mice were subjected to a high-fat diet (HFD) for 12 wk. IGFBP-3(-/-) mice were heavier before the initiation of HFD and at the end of the study period. Resting metabolic rate was significantly decreased in knockout mice; however, respiratory exchange ratio was not significantly different. Fasting blood glucose and insulin levels were significantly elevated in IGFBP-3(-/-) mice. However, IGFBP-3(-/-) mice had relatively normal glucose tolerance because the relative glucose excursion over time was not different between the groups. During hyperinsulinemic clamps, IGFBP-3(-/-) mice had increased basal hepatic glucose production, but after insulin stimulation, no differences in hepatic glucose production were observed. A second cohort of older IGFBP-3(-/-) mice on HFD displayed unexpected evidence of hepatic steatosis. In summary, glucose tolerance and clamp testing indicate that IGFBP-3(-/-) mice preserve insulin sensitivity despite evidence of increased basal glucose turnover and hepatic steatosis. We provide evidence that genetic deletion of IGFBP-3 modulates hepatic carbohydrate and lipid metabolism.
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Affiliation(s)
- P M Yamada
- Pediatric Endocrinology, Mattel Children's Hospital at University of California, Los Angeles, California, USA
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18
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Konijeti R, Henning S, Moro A, Sheikh A, Elashoff D, Shapiro A, Said JW, Heber D, Cohen P, Aronson WJ. Chemoprevention of prostate cancer with lycopene in the TRAMP model. Prostate 2010; 70:1547-54. [PMID: 20687227 PMCID: PMC2930120 DOI: 10.1002/pros.21190] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Dietary lycopene combined with other constituents from whole tomatoes was previously found to have greater chemopreventive effects against prostate cancer as compared to pure lycopene provided in a beadlet formulation. We hypothesized that tomato paste would have greater chemopreventive effects in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice relative to equivalent lycopene doses provided from lycopene beadlets. METHODS Fifty-nine TRAMP mice were randomized to a control diet or to diets providing 28 mg lycopene per kg diet from tomato paste (TP) or from lycopene beadlet (LB), and sacrificed at 20 weeks. Prostate histopathology, prostate weight and serum levels of IGF-I and IGF binding protein-3 were evaluated. RESULTS The incidence of prostate cancer was significantly decreased in the LB group relative to the control group (60% vs. 95%, respectively, P = 0.0197) whereas the difference between the TP and control groups was not statistically significant (80% vs. 95%, P = 0.34). There was no difference in prostate weights between the groups. Total lycopene levels in the serum and prostate tissue were similarly elevated in the LB and TP groups relative to the control group. The ratio of 5-cis-lycopene to trans-lycopene in the serum was significantly greater in the LB group relative to the TP group (P = 0.0001). Oxidative DNA damage was significantly reduced in the livers of mice fed LB and TP diets relative to the control group. CONCLUSIONS This preclinical trial suggests significant chemopreventive activity with a lycopene beadlet-enriched diet. The chemopreventive effects of lycopene from beadlets versus whole tomato products requires further testing in preclinical and clinical models of prostate cancer.
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Affiliation(s)
- Ramdev Konijeti
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Susanne Henning
- Division of Clinical Nutrition, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Aune Moro
- Division of Clinical Nutrition, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Ahmed Sheikh
- Division of Clinical Nutrition, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - David Elashoff
- Department of Biostatistics, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Ari Shapiro
- Division of Clinical Nutrition, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Jonathan W. Said
- Department of Pathology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - David Heber
- Division of Clinical Nutrition, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Pinchas Cohen
- Division of Pediatric Endocrinology, Department of Pediatrics, David Geffen School of Medicine at UCLA
| | - William J. Aronson
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA
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Rehfeldt C, Renne U, Sawitzky M, Binder G, Hoeflich A. Increased fat mass, decreased myofiber size, and a shift to glycolytic muscle metabolism in adolescent male transgenic mice overexpressing IGFBP-2. Am J Physiol Endocrinol Metab 2010; 299:E287-98. [PMID: 20501873 DOI: 10.1152/ajpendo.00492.2009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To elucidate the functional role of insulin-like growth factor (IGF)-binding protein-2 (IGFBP-2) for in vivo skeletal muscle growth and function, skeletal muscle cellularity and metabolism, expression of signal molecules, and body growth and composition were studied in a transgenic mouse model overexpressing IGFBP-2. Postnatal growth rate of transgenic mice was reduced from day 21 of age by 6-8% compared with nontransgenic controls. At 10 wk of age body lean protein and moisture percentages were lower, whereas fat percentage was higher in IGFBP-2 transgenic mice. Muscle weights were reduced (-13% on day 30 of age, -14% on day 72), which resulted from slower growth of myofibers in size but not from decreases in myofiber number. The reduction in muscle mass was associated with lower total DNA, RNA, and protein contents as well as greater DNA/RNA and protein/RNA ratios. The percentage of proliferating (Ki-67-positive) nuclei within myofibers was reduced (3.4 vs. 5.8%) in 30-day-old transgenic mice. These changes were accompanied by slight reductions in specific p44/42 MAPK activity (-18% on day 72) and, surprisingly, by increased levels of phosphorylated Akt (Ser(473)) (+25% on day 30, +66% on day 72). The proportion of white glycolytic fibers (55.9 vs. 53.5%) and the activity of lactate dehydrogenase (+8%) were elevated in 72-day-old transgenic mice. Most of the differences observed between transgenic and nontransgenic mice were more pronounced in males. The results suggest that IGFBP-2 significantly inhibits postnatal skeletal myofiber growth by decreasing myogenic proliferation and protein accretion and enhances glycolytic muscle metabolism.
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Affiliation(s)
- Charlotte Rehfeldt
- Research Divisions-Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee 2, Dummerstorf, Germany.
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20
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Amuzie CJ, Pestka JJ. Suppression of insulin-like growth factor acid-labile subunit expression--a novel mechanism for deoxynivalenol-induced growth retardation. Toxicol Sci 2009; 113:412-21. [PMID: 19805407 DOI: 10.1093/toxsci/kfp225] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Consumption of deoxynivalenol (DON), a trichothecene mycotoxin commonly detected in cereal-based foods, causes impaired growth in many animal species. While growth retardation is used as a basis for regulating DON levels in human food, the underlying mechanisms remain poorly understood. Oral exposure of mice to DON rapidly induces multiorgan expression of proinflammatory cytokines, and this is followed by upregulation of several suppressors of cytokine signaling (SOCS), some of which are capable of impairing growth hormone (GH) signaling. The purpose of this study was to test the hypothesis that impairment of the GH axis precedes DON-induced growth retardation in the mouse. Subchronic dietary exposure of young (4-week old) mice to DON (20 ppm) over a period of 2-8 weeks was found to (1) impair weight gain, (2) result in a steady-state plasma DON concentration (40-60 ng/ml), (3) downregulate hepatic insulin-like growth factor acid-labile subunit (IGFALS) mRNA expression, and (4) reduce circulating insulin-like growth factor 1 (IGF1) and IGFALS levels. Acute oral exposure to DON at 0.5-12.5 mg/kg body weight (bw) markedly suppressed hepatic IGFALS mRNA levels within 2 h in a dose-dependent fashion, whereas 0.1 mg/kg bw was without effect. DON-induced IGFALS mRNA upregulation occurred both with and without exogenous GH treatment. These latter effects co-occurred with robust hepatic suppressors of cytokine signaling 3 upregulation. Taken together, these data suggest that oral DON exposure perturbs GH axis by suppressing two clinically relevant growth-related proteins, IGFALS and IGF1. Both have potential to serve as biomarkers of effect in populations exposed to this common foodborne mycotoxin.
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Affiliation(s)
- Chidozie J Amuzie
- Comparative Medicine and Integrative Biology Program, Michigan State University, East Lansing, Michigan 48824, USA
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21
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Schubert R, Schmitz N, Pietzner J, Tandi C, Theisen A, Dresel R, Christmann M, Zielen S. Growth hormone supplementation increased latency to tumourigenesis in Atm-deficient mice. Growth Factors 2009; 27:265-73. [PMID: 19626507 DOI: 10.1080/08977190903112663] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Growth hormone (GH) is important for cell growth and differentiation, has multiple effects on lymphoid tissue and may promote blast cell proliferation and cancer development. We studied the effect of GH on longevity and tumour formation in Atm-deficient mice, an established model of the human cancer prone syndrome ataxia telangiectasia (AT). AT is a devastating recessive disorder that is characterized by progressive cerebellar ataxia, immunodeficiency, chromosomal instability and cancer susceptibility. Since AT patients also show endocrinological abnormalities the question has been raised as to whether GH therapy could be beneficial and/or increase the cancer risk in AT. We found that treatment with GH significantly increased longevity of Atm-deficient mice. In addition, GH ameliorated locomotoric behaviour and improved T-cell immunity. Thus, our data demonstrated that GH treatment is not necessarily accompanied by increased cancer development in diseases with chromosomal instability and cancer susceptibility and might be beneficial for AT patients.
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Affiliation(s)
- Ralf Schubert
- Pediatric Children's Hospital, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany.
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22
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Ueki I, Giesy SL, Harvatine KJ, Kim JW, Boisclair YR. The acid-labile subunit is required for full effects of exogenous growth hormone on growth and carbohydrate metabolism. Endocrinology 2009; 150:3145-52. [PMID: 19299456 PMCID: PMC2703525 DOI: 10.1210/en.2008-1740] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Normal postnatal growth is dependent in part on overlapping actions of GH and IGF-I. These actions reflect GH stimulation of IGF-I production in liver and extrahepatic tissues, representing respectively the endocrine and autocrine/paracrine arms of the IGF system. Recent experiments in genetically modified mice show that each source of IGF-I can compensate for absence of the other but do not resolve their relative role in postnatal growth. In an effort to address this issue, we studied the GH responsiveness of mice harboring a null mutation of the acid-labile subunit (ALS). Null ALS mice have a substantial reduction in endocrine IGF-I but, unlike other models of plasma IGF-I deficiency, have no obvious additional endocrine defects. Wild type and null ALS mice of both sexes received daily sc injections of saline or recombinant bovine GH between d 35 and 63 of postnatal age. The GH-stimulated body weight gain of null ALS mice was reduced by more than 30% relative to wild type mice, irrespective of sex. Reductions in GH responsiveness were also seen for kidney and linear growth. Absence of ALS eliminated the ability of GH to increase plasma IGF-I despite intact GH-dependent stimulation of IGF-I expression in liver, adipose tissue, and skeletal muscle. GH treatment was also less efficient in antagonizing insulin action in null ALS mice. Overall, these results suggest that the GH effects mediated by endocrine IGF-I depends on ALS, and accordingly null ALS mice are less responsive to exogenous GH therapy.
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Affiliation(s)
- Iori Ueki
- Department of Animal Science, Cornell University, Ithaca, New York 14853, USA
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Fan Y, Menon RK, Cohen P, Hwang D, Clemens T, DiGirolamo DJ, Kopchick JJ, Le Roith D, Trucco M, Sperling MA. Liver-specific deletion of the growth hormone receptor reveals essential role of growth hormone signaling in hepatic lipid metabolism. J Biol Chem 2009; 284:19937-44. [PMID: 19460757 DOI: 10.1074/jbc.m109.014308] [Citation(s) in RCA: 196] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Growth hormone (GH) plays a pivotal role in growth and metabolism, with growth promotion mostly attributed to generation of insulin-like growth factor I (IGF-I) in liver or at local sites of GH action, whereas the metabolic effects of GH are considered to be intrinsic to GH itself. To distinguish the effects of GH from those of IGF-I, we developed a Cre-lox-mediated model of tissue-specific deletion of the growth hormone receptor (GHR). Near total deletion of the GHR in liver (GHRLD) had no effect on total body or bone linear growth despite a >90% suppression of circulating IGF-I; however, total bone density was significantly reduced. Circulating GH was increased 4-fold, and GHRLD displayed insulin resistance, glucose intolerance, and increased circulating free fatty acids. Livers displayed marked steatosis, the result of increased triglyceride synthesis and decreased efflux; reconstitution of hepatic GHR signaling via adenoviral expression of GHR restored triglyceride output to normal, whereas IGF-I infusion did not correct steatosis despite restoration of circulating GH to normal. Thus, with near total absence of circulating IGF-I, GH action at the growth plate, directly and via locally generated IGF-I, can regulate bone growth, but at the expense of diabetogenic, lipolytic, and hepatosteatotic consequences. Our results indicate that IGF-I is essential for bone mineral density, whereas hepatic GH signaling is essential to regulate intrahepatic lipid metabolism. We propose that circulating IGF-I serves to amplify the growth-promoting effects of GH, while simultaneously dampening the catabolic effects of GH.
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Affiliation(s)
- Yong Fan
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA
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Anzo M, Cobb LJ, Hwang DL, Mehta H, Said JW, Yakar S, LeRoith D, Cohen P. Targeted deletion of hepatic Igf1 in TRAMP mice leads to dramatic alterations in the circulating insulin-like growth factor axis but does not reduce tumor progression. Cancer Res 2008; 68:3342-9. [PMID: 18451161 DOI: 10.1158/0008-5472.can-07-3165] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The role of systemic and local insulin-like growth factor I (IGF-I) in the development of prostate cancer is still controversial. Transgenic adenocarcinoma mouse prostate (TRAMP) mice express the SV40 T-antigen under the control of the probasin promoter, and spontaneously develop prostate cancer. We crossed TRAMP mice with liver IGF-deficient (LID) mice to produce LID-TRAMP mice, a mouse model of prostate cancer with low serum IGF-I, to allow us to study the effect of circulatory IGF-I levels on the development of prostate cancer. LID mice have a targeted deletion of the hepatic Igf1 gene but retain normal expression of Igf1 in extrahepatic tissues. Serum IGF-I and IGFBP-3 levels in LID and LID-TRAMP mice were measured using novel assays, which showed that they are approximately 10% and 60% of control L/L- mice, respectively. Serum growth hormone (GH) levels of LID-TRAMP mice were 3.5-fold elevated relative to L/L-TRAMP mice (P < 0.001), but IGFBP-2 levels were not different. Surprisingly, rates of survival, metastasis, and the ratio of genitourinary tissue weight to body weight were not significantly different between LID-TRAMP and L/L-TRAMP mice. There was also no difference in the pathologic stage of the prostate cancer between the two groups at 9 to 19 weeks of age. LID-TRAMP tumors displayed increased levels of GH receptors and increased Akt phosphorylation. These results are in striking contrast with the published model of the GH-deficient lit/lit-TRAMP, which has smaller tumors and improved survival, and indicate that the reduction in systemic IGF-I is not sufficient to inhibit prostate cancer tumor progression in the TRAMP model, which may require a reduction of GH levels as well.
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Affiliation(s)
- Makoto Anzo
- David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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SnoRNA Snord116 (Pwcr1/MBII-85) deletion causes growth deficiency and hyperphagia in mice. PLoS One 2008; 3:e1709. [PMID: 18320030 PMCID: PMC2248623 DOI: 10.1371/journal.pone.0001709] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Accepted: 01/21/2008] [Indexed: 11/30/2022] Open
Abstract
Prader-Willi syndrome (PWS) is the leading genetic cause of obesity. After initial severe hypotonia, PWS children become hyperphagic and morbidly obese, if intake is not restricted. Short stature with abnormal growth hormone secretion, hypogonadism, cognitive impairment, anxiety and behavior problems are other features. PWS is caused by lack of expression of imprinted genes in a ∼4 mb region of chromosome band 15q11.2. Our previous translocation studies predicted a major role for the C/D box small nucleolar RNA cluster SNORD116 (PWCR1/HBII-85) in PWS. To test this hypothesis, we created a ∼150 kb deletion of the >40 copies of Snord116 (Pwcr1/MBII-85) in C57BL/6 mice. Snord116del mice with paternally derived deletion lack expression of this snoRNA. They have early-onset postnatal growth deficiency, but normal fertility and lifespan. While pituitary structure and somatotrophs are normal, liver Igf1 mRNA is decreased. In cognitive and behavior tests, Snord116del mice are deficient in motor learning and have increased anxiety. Around three months of age, they develop hyperphagia, but stay lean on regular and high-fat diet. On reduced caloric intake, Snord116del mice maintain their weight better than wild-type littermates, excluding increased energy requirement as a cause of hyperphagia. Normal compensatory feeding after fasting, and ability to maintain body temperature in the cold indicate normal energy homeostasis regulation. Metabolic chamber studies reveal that Snord116del mice maintain energy homeostasis by altered fuel usage. Prolonged mealtime and increased circulating ghrelin indicate a defect in meal termination mechanism. Snord116del mice, the first snoRNA deletion animal model, reveal a novel role for a non-coding RNA in growth and feeding regulation.
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Ding F, Li HH, Zhang S, Solomon NM, Camper SA, Cohen P, Francke U. SnoRNA Snord116 (Pwcr1/MBII-85) deletion causes growth deficiency and hyperphagia in mice. PLoS One 2008. [PMID: 18320030 DOI: 10.1371/journal.pone.001709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
Prader-Willi syndrome (PWS) is the leading genetic cause of obesity. After initial severe hypotonia, PWS children become hyperphagic and morbidly obese, if intake is not restricted. Short stature with abnormal growth hormone secretion, hypogonadism, cognitive impairment, anxiety and behavior problems are other features. PWS is caused by lack of expression of imprinted genes in a approximately 4 mb region of chromosome band 15q11.2. Our previous translocation studies predicted a major role for the C/D box small nucleolar RNA cluster SNORD116 (PWCR1/HBII-85) in PWS. To test this hypothesis, we created a approximately 150 kb deletion of the > 40 copies of Snord116 (Pwcr1/MBII-85) in C57BL/6 mice. Snord116del mice with paternally derived deletion lack expression of this snoRNA. They have early-onset postnatal growth deficiency, but normal fertility and lifespan. While pituitary structure and somatotrophs are normal, liver Igf1 mRNA is decreased. In cognitive and behavior tests, Snord116del mice are deficient in motor learning and have increased anxiety. Around three months of age, they develop hyperphagia, but stay lean on regular and high-fat diet. On reduced caloric intake, Snord116del mice maintain their weight better than wild-type littermates, excluding increased energy requirement as a cause of hyperphagia. Normal compensatory feeding after fasting, and ability to maintain body temperature in the cold indicate normal energy homeostasis regulation. Metabolic chamber studies reveal that Snord116del mice maintain energy homeostasis by altered fuel usage. Prolonged mealtime and increased circulating ghrelin indicate a defect in meal termination mechanism. Snord116del mice, the first snoRNA deletion animal model, reveal a novel role for a non-coding RNA in growth and feeding regulation.
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Affiliation(s)
- Feng Ding
- Department of Genetics, Stanford University, Stanford, California, USA
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Raina K, Blouin MJ, Singh RP, Majeed N, Deep G, Varghese L, Glodé LM, Greenberg NM, Hwang D, Cohen P, Pollak MN, Agarwal R. Dietary feeding of silibinin inhibits prostate tumor growth and progression in transgenic adenocarcinoma of the mouse prostate model. Cancer Res 2007; 67:11083-91. [PMID: 18006855 DOI: 10.1158/0008-5472.can-07-2222] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Herein, for the first time, we evaluated the chemopreventive efficacy of dietary silibinin against prostate cancer (PCa) growth and progression in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice from two different genetic backgrounds [C57BL/6 (TRAMP) x FVB; C57BL/6 (TRAMP) x C57BL/6]. At 4 weeks of age, mice were fed control or 0.1% to 1% silibinin-supplemented diets until 23 to 24 weeks of age. Silibinin-fed groups had a lower tumor grade and higher incidence of prostatic intraepithelial neoplasia (PIN) at the expense of a strong decrease in adenocarcinoma incidence. Prostate tissue showed a 47% (P < 0.001) decrease in proliferating cell nuclear antigen (PCNA)-positive cells and an approximately 7-fold (P < 0.001) increase in apoptotic cells at the highest silibinin dose. As potential mechanisms of silibinin efficacy, an approximately 50% (P < 0.05) decrease in insulin-like growth factor (IGF) receptor type I beta and an approximately 13-fold (P < 0.001) increase in IGF-binding protein 3 (IGFBP-3) protein levels were also observed. These changes were specific to tumors as they were not reflected in circulating IGF-IGFBP-3 system. Additionally, silibinin decreased protein expression of cyclin-dependent kinases (Cdk) by more than 90% (P < 0.001) with a concomitant increase in Cdk inhibitors, Cip1/p21 and Kip1/p27 (P < 0.05, for both). A dose-dependent decrease was also observed in cyclin B1, cyclin E, and cyclin A protein levels by silibinin. Together, these findings suggest that oral silibinin blocks PCa growth and progression at PIN stage in TRAMP mice via modulation of tumor IGF-IGFBP-3 axis and cell cycle regulation, and therefore it has practical and translational potential in suppressing growth and neoplastic conversion of PIN to PCa in humans.
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Affiliation(s)
- Komal Raina
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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