1
|
Anderson GM, Hill JW, Kaiser UB, Navarro VM, Ong KK, Perry JRB, Prevot V, Tena-Sempere M, Elias CF. Metabolic control of puberty: 60 years in the footsteps of Kennedy and Mitra's seminal work. Nat Rev Endocrinol 2024; 20:111-123. [PMID: 38049643 PMCID: PMC10843588 DOI: 10.1038/s41574-023-00919-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/19/2023] [Indexed: 12/06/2023]
Abstract
An individual's nutritional status has a powerful effect on sexual maturation. Puberty onset is delayed in response to chronic energy insufficiency and is advanced under energy abundance. The consequences of altered pubertal timing for human health are profound. Late puberty increases the chances of cardiometabolic, musculoskeletal and neurocognitive disorders, whereas early puberty is associated with increased risks of adult obesity, type 2 diabetes mellitus, cardiovascular diseases and various cancers, such as breast, endometrial and prostate cancer. Kennedy and Mitra's trailblazing studies, published in 1963 and using experimental models, were the first to demonstrate that nutrition is a key factor in puberty onset. Building on this work, the field has advanced substantially in the past decade, which is largely due to the impressive development of molecular tools for experimentation and population genetics. In this Review, we discuss the latest advances in basic and translational sciences underlying the nutritional and metabolic control of pubertal development, with a focus on perspectives and future directions.
Collapse
Affiliation(s)
- Greg M Anderson
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, OH, USA
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Victor M Navarro
- Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ken K Ong
- Metabolic Research Laboratory, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - John R B Perry
- Metabolic Research Laboratory, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge, UK
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Vincent Prevot
- University of Lille, Inserm, CHU Lille, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Lille Neuroscience & Cognition, UMR-S 1172, Lille, France
- European Genomic Institute for Diabetes (EGID), Lille, France
| | - Manuel Tena-Sempere
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Cordoba, Spain.
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Cordoba, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Cordoba, Spain.
| | - Carol F Elias
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
- Department of Obstetrics & Gynecology, University of Michigan, Ann Arbor, MI, USA.
- Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
2
|
Yao Z, Lin M, Lin T, Gong X, Qin P, Li H, Kang T, Ye J, Zhu Y, Hong Q, Liu Y, Li Y, Wang J, Fang F. The expression of IGFBP-5 in the reproductive axis and effect on the onset of puberty in female rats. Reprod Biol Endocrinol 2022; 20:100. [PMID: 35821045 PMCID: PMC9277959 DOI: 10.1186/s12958-022-00966-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/18/2022] [Indexed: 11/21/2022] Open
Abstract
Insulin-like growth factor-binding protein-5 (IGFBP-5) has recently been shown to alter the reproductive capacity by regulating insulin-like growth factor (IGF) bioavailability or IGF-independent effects. The present study aimed to investigate the effect and mechanism of IGFBP-5 on the onset of puberty in female rats. Immunofluorescence and real-time quantitative PCR were used to determine the expression and location of IGFBP-5 mRNA and protein distribution in the infant's hypothalamus-pituitary-ovary (HPO) axis prepuberty, peripuberty, puberty and adult female rats. Prepubertal rats with IGFBP-5 intracerebroventricular (ICV) were injected to determine the puberty-related genes expression and the concentrations of reproductive hormones. Primary hypothalamic cells were treated with IGFBP-5 to determine the expression of puberty-related genes and the Akt and mTOR proteins. Results showed that Igfbp-5 mRNA and protein were present on the HPO axis. The addition of IGFBP-5 to primary hypothalamic cells inhibited the expression of Gnrh and Igf-1 mRNAs (P < 0.05) and increased the expression of AKT and mTOR protein (P < 0.01). IGFBP-5 ICV-injection delayed the onset of puberty, reduced Gnrh, Igf-1, and Fshβ mRNAs, and decreased the concentrations of E2, P4, FSH,serum LH levels and the ovaries weight (P < 0.05). More corpus luteum and fewer primary follicles were found after IGFBP-5 injection (P < 0.05).
Collapse
Affiliation(s)
- Zhiqiu Yao
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Maosen Lin
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Tao Lin
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Xinbao Gong
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Pin Qin
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Hailing Li
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Tiezhu Kang
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Jing Ye
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Yanyun Zhu
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Qiwen Hong
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Ya Liu
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Yunsheng Li
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Juhua Wang
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China
| | - Fugui Fang
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China.
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China.
| |
Collapse
|
3
|
Xu Y, Han CY, Park MJ, Gye MC. Increased testicular insulin-like growth factor 1 is associated with gonadal activation by recombinant growth hormone in immature rats. Reprod Biol Endocrinol 2022; 20:72. [PMID: 35459135 PMCID: PMC9034493 DOI: 10.1186/s12958-022-00944-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 04/11/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND In children, recombinant human growth hormone (rhGH) therapy for treatment of short stature has raised concerns of the early onset of puberty. Puberty is initiated by the activation of the hypothalamus-pituitary-gonad axis. Insulin-like growth factor-1 (IGF1) has been known to mediate physiologic effects of GH. To understand the mechanism of precocious sexual maturation following prepubertal GH therapy, the effects of rhGH on the hypothalamus-pituitary-gonad axis were examined in the immature male rats. METHODS Immature male rats were given by daily injection of rhGH (1 or 2 IU/kg) from postnatal day (PND) 21 to PND 23 or 30. The effects of rhGH on kisspeptin-GnRH-LH system in the hypothalamus-pituitary axis, systemic and testicular IGF1, spermatogenesis, steroidogenesis, and circulating testosterone levels were examined. The effects of rhGH on the IGF1 expression and steroidogenesis were examined in progenitor LCs in vitro. RESULTS Testicular steroidogenic pathway and spermatogenesis marker mRNA levels, number and size of 17β-hydroxysteroid dehydrogenase (+) LCs, and blood testosterone levels of rhGH rats were significantly higher than those of controls on PNDs 24 and 31. Hypothalamic Kiss1 and Gnrh1 mRNA of rhGH rats were significantly higher than those of controls on PND 24, indicating early activation of hypothalamic kisspeptin-GnRH neurons by rhGH. Hypothalamic Igf1 mRNA levels of rhGH rats were significantly higher than those of controls on PND 24 but significantly lower than those of controls on PND 31. Testicular Igf1 mRNA levels were significantly higher in rhGH rats than in the controls on PNDs 24 and 31 whereas circulating IGF1 levels were not. In progenitor LCs, rhGH significantly increased Igf1 and steroidogenic pathway mRNA levels and testosterone production. CONCLUSIONS Local increases in testicular IGF1 might be an important mediator of gonadal maturation via activation of LCs steroidogenesis in immature rats given rhGH.
Collapse
Affiliation(s)
- Yang Xu
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04760, Korea
| | - Chang Yong Han
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04760, Korea
| | - Mi Jung Park
- Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, 01757, Korea.
| | - Myung Chan Gye
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04760, Korea.
| |
Collapse
|
4
|
Dees WL, Hiney JK, Srivastava VK. How alcohol affects insulin-like growth factor-1's influences on the onset of puberty: A critical review. Alcohol Clin Exp Res 2021; 45:2196-2206. [PMID: 34523716 PMCID: PMC8642280 DOI: 10.1111/acer.14711] [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: 06/14/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/30/2022]
Abstract
Alcohol (ALC) is capable of delaying signs associated with pubertal development in laboratory animals, as well as in humans. The normal onset of puberty results from a timely increase in gonadotropin‐releasing hormone (GnRH) secretion, which is associated with a gradual decline in prepubertal inhibitory influences, and the establishment of excitatory inputs that increase GnRH release, which together drive pubertal development. In recent years, insulin‐like growth factor‐1 (IGF‐1) has emerged as a pivotal contributor to prepubertal GnRH secretion and pubertal development, whose critical actions are interfered with by ALC abuse. Here we review the neuroendocrine research demonstrating the important role that IGF‐1 plays in pubertal development, and describe the detrimental effects and mechanisms of action of ALC on the onset and progression of pubertal maturation.
Collapse
Affiliation(s)
- William L Dees
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| | - Jill K Hiney
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| | - Vinod K Srivastava
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
5
|
Huh K, Nah WH, Xu Y, Park MJ, Gye MC. Effects of Recombinant Human Growth Hormone on the Onset of Puberty, Leydig Cell Differentiation, Spermatogenesis and Hypothalamic KISS1 Expression in Immature Male Rats. World J Mens Health 2021; 39:381-388. [PMID: 33474850 PMCID: PMC7994663 DOI: 10.5534/wjmh.200152] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/25/2020] [Accepted: 11/09/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose Recombinant human growth hormone (rhGH) has been used to treat short stature and rhGH-related syndromes. However, there are concerns that rhGH-treatment may cause precocious puberty. We investigated the effects of rhGH-treatment on the puberty onset, sexual maturation, androgen production, and hypothalamic gene expression in prepubertal male rats. Materials and Methods Sprague-Dawley male rats were injected subcutaneously daily with 1 or 2 IU/kg/d rhGH or 0.1 mL saline from postnatal day (PND) 21 to 30. At PND 31 bodyweight, reproductive organs weight, preputial separation, testis histology, circulating testosterone, and expression of testicular steroidogenic pathway genes and hypothalamic Kiss1 were examined. Results By day 4 of injection bodyweights of rhGH groups were significantly higher than those of controls. rhGH 2 IU group showed earlier preputial separation compared to the control group. At PND 31, the weights of testes, epididymides, seminal vesicles, prostates, and preputial glands of the 2 IU-rhGH group were significantly higher than control group. Serum testosterone levels of the 2 IU-rhGH group were significantly higher than control group. Testicular steroidogenic pathway gene Hsd17b3 and Nr5a1 mRNA and cell counts and areas of Leydig cells in rhGH groups were significantly higher than control group, suggesting functional differentiation of Leydig cells. Hypothalamic Kiss1 mRNA levels of the 1 IU-rhGH group were significantly lower than control group, suggesting negative feedback of Kiss1 by elevated testosterone. Conclusions Prepubertal rhGH-treatment in male rats may induce early onset of puberty, sexual maturation, elevation of testosterone, and spermatogenesis, and accompanies downregulation of hypothalamic KISS1.
Collapse
Affiliation(s)
- Kyoung Huh
- Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea
| | - Won Heun Nah
- Department of Life Science and Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul, Korea
| | - Yang Xu
- Department of Life Science and Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul, Korea
| | - Mi Jung Park
- Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
| | - Myung Chan Gye
- Department of Life Science and Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul, Korea.
| |
Collapse
|
6
|
Dees WL, Hiney JK, Srivastava VK. IGF-1 Influences Gonadotropin-Releasing Hormone Regulation of Puberty. Neuroendocrinology 2021; 111:1151-1163. [PMID: 33406521 PMCID: PMC8257778 DOI: 10.1159/000514217] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/08/2020] [Indexed: 11/19/2022]
Abstract
The pubertal process is initiated as a result of complex neuroendocrine interactions within the preoptic and hypothalamic regions of the brain. These interactions ultimately result in a timely increase in the secretion of gonadotropin-releasing hormone (GnRH). Researchers for years have believed that this increase is due to a diminished inhibitory tone which has applied a prepubertal brake on GnRH secretion, as well as to the gradual development of excitatory inputs driving the increased release of the peptide. Over the years, insulin-like growth factor-1 (IGF-1) has emerged as a prime candidate for playing an important role in the onset of puberty. This review will first present initial research demonstrating that IGF-1 increases in circulation as puberty approaches, is able to induce the release of prepubertal GnRH, and can advance the timing of puberty. More recent findings depict an early action of IGF-1 to activate a pathway that releases the inhibitory brake on prepubertal GnRH secretion provided by dynorphin, as well as demonstrating that IGF-1 can also act later in the process to regulate the synthesis and release of kisspeptin, a potent stimulator of GnRH at puberty.
Collapse
Affiliation(s)
- William L Dees
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA,
| | - Jill K Hiney
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| | - Vinod K Srivastava
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
7
|
Dietary Intake of Selenium in Relation to Pubertal Development in Mexican Children. Nutrients 2019; 11:nu11071595. [PMID: 31337124 PMCID: PMC6682956 DOI: 10.3390/nu11071595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/27/2022] Open
Abstract
Alterations in pubertal timing have been associated with long-term health outcomes. While a few reports have shown that dietary intake of selenium is associated with fertility and testosterone levels in men, no human studies have considered the association between selenium and pubertal development in children. We examined the cross-sectional association of childhood dietary intake of selenium with pubertal development among 274 girls and 245 boys aged 10–18 years in Mexico City. Multiple logistic and ordinal regression models were used to capture the association between energy-adjusted selenium intake (below Recommended Dietary Allowance (RDA) vs. above RDA) and stages of sexual maturity in children, adjusted for covariates. We found that boys with consumption of selenium below the RDA had lower odds of a higher stage for pubic hair growth (odds ratio (OR) = 0.51, 95% confidence interval (95% CI): 0.27–0.97) and genital development (OR = 0.53, 95% CI: 0.28–0.99) as well as a lower probability of having matured testicular volume (OR = 0.37, 95% CI: 0.15–0.88) compared with boys who had adequate daily dietary intake of selenium (above RDA). No associations were found in girls. According to our results, it is possible that inadequate consumption of selenium may be associated with later pubertal development in boys, suggesting a sex-specific pattern. Future work with a larger sample size and measures of selenium biomarkers is needed to confirm our findings and improve understanding of the role of this mineral in children’s sexual development.
Collapse
|
8
|
Aylwin CF, Toro CA, Shirtcliff E, Lomniczi A. Emerging Genetic and Epigenetic Mechanisms Underlying Pubertal Maturation in Adolescence. JOURNAL OF RESEARCH ON ADOLESCENCE : THE OFFICIAL JOURNAL OF THE SOCIETY FOR RESEARCH ON ADOLESCENCE 2019; 29:54-79. [PMID: 30869843 DOI: 10.1111/jora.12385] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The adolescent transition begins with the onset of puberty which, upstream in the brain, is initiated by the gonadotropin-releasing hormone (GnRH) pulse generator that activates the release of peripheral sex hormones. Substantial research in human and animal models has revealed a myriad of cellular networks and heritable genes that control the GnRH pulse generator allowing the individual to begin the process of reproductive competence and sexual maturation. Here, we review the latest knowledge in neuroendocrine pubertal research with emphasis on genetic and epigenetic mechanisms underlying the pubertal transition.
Collapse
|
9
|
Dobolyi A, Lékó AH. The insulin-like growth factor-1 system in the adult mammalian brain and its implications in central maternal adaptation. Front Neuroendocrinol 2019; 52:181-194. [PMID: 30552909 DOI: 10.1016/j.yfrne.2018.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/04/2018] [Accepted: 12/11/2018] [Indexed: 12/15/2022]
Abstract
Our knowledge on the bioavailability and actions of insulin-like growth factor-1 (IGF-1) has markedly expanded in recent years as novel mechanisms were discovered on IGF binding proteins (IGFBPs) and their ability to release IGF-1. The new discoveries allowed a better understanding of the endogenous physiological actions of IGF-1 and also its applicability in therapeutics. The focus of the present review is to summarize novel findings on the neuronal, neuroendocrine and neuroplastic actions of IGF-1 in the adult brain. As most of the new regulatory mechanisms were described in the periphery, their implications on brain IGF system will also be covered. In addition, novel findings on the effects of IGF-1 on lactation and maternal behavior are described. Based on the enormous neuroplastic changes related to the peripartum period, IGF-1 has great but largely unexplored potential in maternal adaptation of the brain, which is highlighted in the present review.
Collapse
Affiliation(s)
- Arpád Dobolyi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences and Eötvös Loránd University, Budapest, Hungary.
| | - András H Lékó
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences and Eötvös Loránd University, Budapest, Hungary; Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary; Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest, Hungary
| |
Collapse
|
10
|
Wolfe A, Divall S, Wu S. The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1). Front Neuroendocrinol 2014; 35:558-72. [PMID: 24929098 PMCID: PMC4175134 DOI: 10.1016/j.yfrne.2014.05.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/01/2014] [Accepted: 05/27/2014] [Indexed: 12/27/2022]
Abstract
The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction.
Collapse
Affiliation(s)
- Andrew Wolfe
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States.
| | - Sara Divall
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States
| | - Sheng Wu
- Johns Hopkins University School of Medicine, Department of Pediatrics, Division of Endocrinology, Baltimore, MD 21287, United States
| |
Collapse
|
11
|
Villamor E, Marin C, Mora-Plazas M, Baylin A. Vitamin D deficiency and age at menarche: a prospective study. Am J Clin Nutr 2011; 94:1020-5. [PMID: 21831989 PMCID: PMC3360555 DOI: 10.3945/ajcn.111.018168] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Early menarche is a risk factor for cardiometabolic disease and cancer. Latitude, which influences sun exposure, is inversely related to age at menarche. This association might be related to vitamin D, but to our knowledge it has not been investigated in prospective epidemiologic studies. OBJECTIVE We studied the association between vitamin D status and the occurrence of menarche in a prospective study in girls from Bogota, Colombia. DESIGN We measured plasma 25-hydroxyvitamin D [25(OH)D] concentrations in a random sample of 242 girls (mean ± SD age: 8.8 ± 1.6 y) and followed them for a median of 30 mo. Girls were asked periodically about the occurrence and date of menarche. Baseline 25(OH)D concentrations were categorized as <50 nmol/L (deficient), ≥50 and <75 nmol/L, or ≥75 nmol/L (sufficient). The incidence of menarche was compared between groups by using time-to-event analyses. RESULTS A total of 57% of girls in the vitamin D-deficient group reached menarche during follow-up compared with 23% of girls in the vitamin D-sufficient group (P-trend = 0.0004). The estimated mean (±SE) ages at menarche in the same groups were 11.8 ± 0.2 y and 12.6 ± 0.2 y, respectively (P = 0.0009). After adjustment for baseline age and BMI-for-age z score in a Cox proportional hazards model, the probability of menarche was twice as high in vitamin D-deficient girls than in girls who were vitamin D-sufficient (HR: 2.05; 95% CI: 1.03, 4.07; P = 0.04). Similar results were obtained in girls aged ≥9 y at baseline (HR: 2.39; 95% CI: 1.14, 5.00; P = 0.02). CONCLUSION Vitamin D deficiency is associated with earlier menarche.
Collapse
Affiliation(s)
- Eduardo Villamor
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | | | | | | |
Collapse
|
12
|
Divall SA, Williams TR, Carver SE, Koch L, Brüning JC, Kahn CR, Wondisford F, Radovick S, Wolfe A. Divergent roles of growth factors in the GnRH regulation of puberty in mice. J Clin Invest 2010; 120:2900-9. [PMID: 20628204 PMCID: PMC2912185 DOI: 10.1172/jci41069] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 05/26/2010] [Indexed: 11/17/2022] Open
Abstract
Pubertal onset, initiated by pulsatile gonadotropin-releasing hormone (GnRH), only occurs in a favorable, anabolic hormonal milieu. Anabolic factors that may signal nutritional status to the hypothalamus include the growth factors insulin and IGF-1. It is unclear which hypothalamic neuronal subpopulation these factors affect to ultimately regulate GnRH neuron function in puberty and reproduction. We examined the direct role of the GnRH neuron in growth factor regulation of reproduction using the Cre/lox system. Mice with the IR or IGF-1R deleted specifically in GnRH neurons were generated. Male and female mice with the IR deleted in GnRH neurons displayed normal pubertal timing and fertility, but male and female mice with the IGF-1R deleted in GnRH neurons experienced delayed pubertal development with normal fertility. With IGF-1 administration, puberty was advanced in control females, but not in females with the IGF-1R deleted in GnRH neurons, in control males, or in knockout males. These mice exhibited developmental differences in GnRH neuronal morphology but normal number and distribution of neurons. These studies define the role of IGF-1R signaling in the coordination of somatic development with reproductive maturation and provide insight into the mechanisms regulating pubertal timing in anabolic states.
Collapse
Affiliation(s)
- Sara A Divall
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland 21212, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Luckenbach JA, Dickey JT, Swanson P. Regulation of pituitary GnRH receptor and gonadotropin subunits by IGF1 and GnRH in prepubertal male coho salmon. Gen Comp Endocrinol 2010; 167:387-96. [PMID: 19800342 DOI: 10.1016/j.ygcen.2009.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 09/05/2009] [Accepted: 09/25/2009] [Indexed: 02/08/2023]
Abstract
Insulin-like growth factor 1 (IGF1) is a key somatotropic hormone that may convey growth status to the reproductive endocrine system. This study examined effects of IGF1 alone or in combination with gonadotropin-releasing hormone (GnRH) on pituitary transcripts for GnRH receptor (GnRHR) variants, follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), and IGF, as well as secretion of FSH in vitro. Three experiments were conducted with dispersed pituitary cells of prepubertal male coho salmon (Oncorhynchus kisutch) to determine the time course of the response to IGF1, IGF1 concentration response, and GnRH concentration response. IGF1 consistently elevated pituitary transcripts for gnrhr1 and the four gonadotropin subunits (fshb, lhb, cga1, and cga2) by day 10 of culture, while suppressing gh and igf2. Short-term treatment with GnRH (24h) induced minor increases in transcripts for fshb, cga1, and cga2, but suppressed lhb and strongly inhibited gnrhr1 expression. IGF1 significantly increased GnRH-stimulated FSH protein release by the pituitary cells, although not as robustly as previously observed in more reproductively advanced salmon. Our results demonstrate that IGF1 increases steady-state mRNA levels of gnrhr1 and four gonadotropin subunits, and may act alone or with GnRH to increase pituitary FSH release in male coho salmon, over 1year before puberty. These findings suggest that IGF1 may prime pituitary gonadotrope cells of prepubertal salmon to respond to GnRH by stimulating synthesis of GnRHR and FSH during puberty onset.
Collapse
Affiliation(s)
- J Adam Luckenbach
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA.
| | | | | |
Collapse
|
14
|
Abstract
Puberty is the developmental process that culminates in reproductive capability and is the result of a complex series of molecular and physiological events. The release of gonadotropin-releasing hormone from specialized neurons of the hypothalamus begins the hormonal cascade that causes gonadal activation and the physical changes of puberty. Several factors have been proposed to influence the activation of the hypothalamus to trigger puberty, but the involved pathways have not been fully elucidated. The recent observations that the age of pubertal onset may be lowering in American girls calls attention to the lack of knowledge of modulating factors that affect the pubertal process. Genes necessary for puberty have been found by studying persons who do not achieve puberty; such studies have provided insights into the pathways necessary for pubertal development. A multidisciplinary focus is required to elucidate the complex mechanisms involved in the initiation and progression of puberty.
Collapse
Affiliation(s)
- Sara A DiVall
- Division of Endocrinology, Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | | |
Collapse
|
15
|
Yagci A, Zik B. Immunohistochemical Localization of Insulin-Like Growth Factor-I Receptor (IGF-IR) in the Developing and Mature Rat Testes. Anat Histol Embryol 2006; 35:305-9. [PMID: 16968249 DOI: 10.1111/j.1439-0264.2006.00689.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
It has been suggested that insulin-like growth factor-I (IGF-I) plays an important role in the regulation of spermatogenesis in the testes. Its signal is mediated predominantly by the IGF-I receptor (IGF-IR). Signalling through IGF-IR has been shown to have a potent survival function. IGF-IR, a transmembrane tyrosine kinase, is widely expressed across many cell types. In this study, we demonstrated the distribution of IGF-IR in testes of differently aged rats. Anti-IGF-IR is a rabbit polyclonal antibody raised against a peptide mapping at the carboxy terminus of the IGF-IR of human origin. Testicular specimens were fixed in Bouin's solution and embedded in paraffin. The paraffin-embedded sections were processed for standard immunohistochemistry by the labelled streptavidin-biotin technique. At postnatal day 19, IGF-IR immunoreactivity was seen moderately in spermatogonia, and slightly both in leptotene and zygotene primary spermatocytes. At postnatal day 35, immunoreactivity was seen slightly both in the pachytene primary spermatocytes and Leydig cells. Although there was intense immunoreactivity in the Leydig cells and in the elongated spermatids on days 50 and 70, the intensity of reaction was decreased in the elongated spermatids in the 10th month. Our results suggest that IGF-IR may play significant roles in testicular function and germ cell development.
Collapse
Affiliation(s)
- A Yagci
- Department of Histology-Embryology, Faculty of Veterinary Medicine, Afyon Kocatepe University, Afyon, Turkey.
| | | |
Collapse
|
16
|
Davies JS, Thompson NM, Christian HC, Pinilla L, Ebling FJP, Tena-Sempere M, Wells T. Hypothalamic expression of human growth hormone induces post-pubertal hypergonadotrophism in male transgenic growth retarded rats. J Neuroendocrinol 2006; 18:719-31. [PMID: 16965290 DOI: 10.1111/j.1365-2826.2006.01467.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Growth hormone (GH) is known to regulate peripheral components of the hypothalamo-pituitary gonadal (HPG) axis, but it remains unclear whether GH exerts a significant influence on the activity of the hypothalamo-pituitary components of the HPG axis. In this study, we investigated the development of HPG axis function in the male transgenic growth retarded (Tgr) rat, a model of moderate systemic GH deficiency caused by hypothalamic expression of human (h)GH. Impaired postnatal somatotroph expansion and moderate GH deficiency in male Tgr rats were accompanied by a two- to three-fold increase in pituitary gonadotrophin content, but without a significant change in the pituitary gonadotroph population. A three- to nine-fold elevation in basal circulating luteinising hormone concentration was seen in postpubertal Tgr rats, with a smaller increase in follicle-stimulating hormone. Despite this hypergonadotrophism, there was no corresponding increase in steroidogenic (circulating testosterone and seminal vesicle weights) or gametogenic (spermatozoa counts in seminiferous tubules) activity in the postpubertal Tgr testis. Following puberty, the plasma leptin concentration also became progressively elevated in Tgr males. Circulating gonadotrophin and leptin levels were normalised in Tgr rats by peripheral physiological replacement of rat GH, but plasma testosterone concentration was unaffected. These results confirm that hGH exerts a positive influence on the central control of gonadotrophin secretion in the Tgr rat, but the absence of a corresponding elevation in the steroidogenic or gametogenic function of the Tgr testis implies that the peripheral GH/insulin-like growth factor I axis may also exert a permissive influence on testicular function. The relative contribution of somatogenic and lactogenic mechanisms and the potential influence of elevated leptin and decreased sensitivity to androgen feedback to the development of postpubertal hypergonadotrophism in Tgr males remain to be determined.
Collapse
Affiliation(s)
- J S Davies
- School of Biosciences, Cardiff University, Cardiff, UK
| | | | | | | | | | | | | |
Collapse
|
17
|
Zeinoaldini S, Swarts JJM, Van de Heijning BJM. Central application of IGF-1 postpones time of vaginal opening in normally fed, but not in food-restricted rats. HORMONE RESEARCH 2006; 66:169-74. [PMID: 16804316 DOI: 10.1159/000094144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Accepted: 05/19/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Central but also peripheral IGF-1 is suggested to play a role in the initiation of puberty as it directly affects GnRH synthesis and release. A possible intermediate in the effects of IGF-1 on puberty might be the adiposity-signaling hormone leptin, whose plasma levels are decreased in food-restricted (FR) rats. METHODS IGF-1 was chronically centrally infused in 23-day-old prepubertal female rats which were either normally fed or 30% FR, and the effects on time of vaginal opening (VO) and plasma leptin levels were monitored. RESULTS FR treatment postponed time of VO and decreased plasma leptin levels. In normally fed rats centrally infused with IGF-1, time of VO was found to be postponed to the same extent as FR treatment did. The IGF-1 infusion did not affect plasma leptin levels in normally fed animals but increased leptin levels in the FR group compared to controls. Daily food intake was equal between all groups but body weight course was lower in FR rats. IGF-1 treatment did not significantly affect food intake or body weight course. CONCLUSION FR treatment delays the moment of vaginal opening to the same extent as observed in normally fed rats that were centrally infused with IGF-1.
Collapse
Affiliation(s)
- S Zeinoaldini
- Human and Animal Physiology Group, Animal Sciences Group, Wageningen University, Wageningen, The Netherlands
| | | | | |
Collapse
|
18
|
Veldhuis JD, Roemmich JN, Richmond EJ, Bowers CY. Somatotropic and gonadotropic axes linkages in infancy, childhood, and the puberty-adult transition. Endocr Rev 2006; 27:101-40. [PMID: 16434512 DOI: 10.1210/er.2005-0006] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Integrative neuroendocrine control of the gonadotropic and somatotropic axes in childhood, puberty, and young adulthood proceeds via multiple convergent and divergent pathways in the human and experimental animal. Emerging ensemble concepts are required to embody independent, parallel, and interacting mechanisms that subserve physiological adaptations and pathological disruption of reproduction and growth. Significant advances in systems biology will be needed to address these challenges.
Collapse
Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Department of Internal Medicine, Mayo Medical School, Mayo School of Graduate Medical Education, General Clinical Research Center, Mayo Clinic, Rochester, Minnesota 55905, USA.
| | | | | | | |
Collapse
|
19
|
Mendez P, Cardona-Gomez GP, Garcia-Segura LM. Interactions of insulin-like growth factor-I and estrogen in the brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 567:285-303. [PMID: 16370144 DOI: 10.1007/0-387-26274-1_12] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
20
|
Hiney JK, Srivastava V, Dearth RK, Dees WL. Influence of estradiol on insulin-like growth factor-1-induced luteinizing hormone secretion. Brain Res 2004; 1013:91-7. [PMID: 15196971 DOI: 10.1016/j.brainres.2004.03.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2004] [Indexed: 12/01/2022]
Abstract
Several studies suggest an interrelationship between estradiol (E2) and insulin-like growth factor-1 (IGF-1) at the hypothalamic level. The present study was designed to discern if the capability of IGF-1 to release LH and influence the timing of female puberty is influenced by E2. Twenty-eight-day-old female rats were ovariectomized (OVEX), then implanted with a third ventricular (3V) cannula. Two weeks later, these animals received subcutaneous (s.c.) injection of oil, or either one or two injections of E2 in the form of estradiol benzoate (1 microg). Forty-eight hours later, four basal blood samples were drawn then the animals received IGF-1 (200 ng) or saline via the 3V and four more blood samples were taken. Results indicated that E2 replacement lowered basal LH levels and IGF-1 induced a significant LH release in only animals that had E2 levels above 20 pg/ml. These levels of E2 were also associated with increases (p<0.05) in the expression of both IGF-1 receptor (IGF-1R) mRNA and protein. In order to further support the hypothesis that the action of IGF-1 at the time of puberty is influenced by E2, 24-day-old intact female rats received s.c. injection of sesame oil or 0.1 microg of E2. The next day, the E2-treated animals also received twice daily s.c. injections of either IGF-1 (500 ng) or saline until vaginal opening (VO) occurred. The animals that received E2 plus IGF-1 showed VO at 31.1 days, which was 2.5 days earlier (p<0.01) than E2-treated animals and 4 days earlier (p<0.001) than IGF-1-treated and saline control animals. Taken together, these results indicate that the hypothalamic action of IGF-1 to stimulate LH release and advance female pubertal development is dependent upon the influence of E2.
Collapse
Affiliation(s)
- Jill K Hiney
- Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station, TX, 77843-4458, USA
| | | | | | | |
Collapse
|
21
|
Zaczek D, Hammond J, Suen L, Wandji S, Service D, Bartke A, Chandrashekar V, Coschigano K, Kopchick J. Impact of growth hormone resistance on female reproductive function: new insights from growth hormone receptor knockout mice. Biol Reprod 2003; 67:1115-24. [PMID: 12297526 DOI: 10.1095/biolreprod67.4.1115] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
We examined multiple aspects of reproductive function in growth hormone receptor gene knockout (GHR-KO) and normal mice to clarify the role of growth hormone in female reproduction. In adult animals, estrous cycle duration was comparable in all mice housed individually but was significantly longer in group-housed GHR-KO females. Histological evaluation of ovaries of adult females at estrus showed that the numbers of preovulatory follicles and corpora lutea were significantly reduced in GHR-KO mice, as was the plasma estradiol level. The number of atretic preovulatory follicles was reduced in GHR gene-ablated animals. Although reverse transcription polymerase chain reaction analysis revealed reduced ovarian insulin-like growth factor I (IGF-I) mRNA expression in GHR-KO females, the expression of several steroidogenic enzyme mRNAs did not differ between groups. The numbers of active corpora lutea and uterine implantation sites were reduced in GHR-KO females at Day 7 of gestation. When young females were mated to normal males, latency to first mating and age of the female at first mating were significantly delayed in GHR-KO females, but maternal age at first conception was similar between groups. Significantly fewer virgin GHR-KO females exhibited pseudopregnancies when initially placed with vasectomized normal males than did normal female counterparts. Growth hormone resistance and IGF-I insufficiency negatively impacted 1) follicular development/ovulation rate, 2) sexual maturation, 3) production of and responsiveness to pheromonal signals, and 4) the ability of virgin females to respond to coitus by activation of luteal function. Although GHR-KO female mice are fertile, they exhibit quantitative deficits in various parameters of reproductive function.
Collapse
Affiliation(s)
- Denise Zaczek
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale 62901-6512, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Cardona-Gómez GP, Mendez P, DonCarlos LL, Azcoitia I, Garcia-Segura LM. Interactions of estrogen and insulin-like growth factor-I in the brain: molecular mechanisms and functional implications. J Steroid Biochem Mol Biol 2002; 83:211-7. [PMID: 12650718 DOI: 10.1016/s0960-0760(02)00261-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In the brain, as in other tissues, estradiol interacts with growth factors. One of the growth factors that is involved in the neural actions of estradiol is insulin-like growth factor-I (IGF-I). Estradiol and IGF-I cooperate in the central nervous system to regulate neuronal development, neural plasticity, neuroendocrine events and the response of neural tissue to injury. The precise molecular mechanisms involved in these interactions are still not well understood. In the central nervous system there is abundant co-expression of estrogen receptors (ERs) and IGF-I receptors (IGF-IRs) in the same cells. Furthermore, the expression of estrogen receptors and IGF-I receptors in the brain is cross-regulated. In addition, using specific antibodies for the phosphorylated forms of extracellular-signal regulated kinase (ERK) 1 and ERK2 and Akt/protein kinase B (Akt/PKB) it has been shown that estradiol affects IGF-I signaling pathways in the brain. Estradiol treatment results in a dose-dependent increase in the phosphorylation of ERK and Akt/PKB in the brain of adult ovariectomized rats. In addition, estradiol and IGF-I have a synergistic effects on the activation of Akt/PKB in the adult rat brain. These findings suggest that estrogen effects in the brain may be mediated in part by the activation of the signaling pathways of the IGF-I receptor.
Collapse
|
23
|
Fuentes MA, Opperman LA, Bellinger LL, Carlson DS, Hinton RJ. Regulation of cell proliferation in rat mandibular condylar cartilage in explant culture by insulin-like growth factor-1 and fibroblast growth factor-2. Arch Oral Biol 2002; 47:643-54. [PMID: 12243968 DOI: 10.1016/s0003-9969(02)00052-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) and fibroblast growth factor-2 (FGF-2) regulate the proliferation and differentiation of growth-plate chondrocytes, but surprisingly little is known of the mechanisms underlying growth regulation in secondary cartilages such as the mandibular condylar. The aims here were to investigate whether IGF-1 and FGF-2 receptors are present in mandibular condylar cartilage in vivo from 28-day-old male Sprague-Dawley rats (by immunohistochemistry), how proliferation in that cartilage responds to increasing concentrations of exogenous IGF-1 or FGF-2 in explant culture (by [3H]thymidine incorporation), and whether the expression of these growth factors and their receptors in the cartilage changes during the transition to puberty (quantitative reverse transcriptase-polymerase chain reaction). Immunoreactivity for receptors (R) for IGF-1 and FGF-2 (IGF-1R, FGFR1, and FGFR3) was most pronounced in chondroblasts and hypertrophic chondrocytes, while FGFR2 immunoreactivity was strongest in the articular and prechondroblastic zones. The proliferative response elicited by exogenous IGF-1 was considerably greater than that induced by FGF-2, although the threshold concentration for a significant response was lower for FGF-2. In the transition from prepuberty (31 days) to the beginning of late puberty (42 days), a pronounced trend of increasing IGF-1 and decreasing FGF-2 gene expression was evident. Of the receptors, only FGFR2 and FGFR3 expression increased. These data provide evidence that proliferation in the mandibular condylar cartilage might be regulated in part by IGF-1 and FGF-2, and that expression of these genes changes considerably at puberty. The data also suggest that mechanisms governing proliferation in mandibular condylar cartilage might have as much in common with those regulating cranial sutures as those regulating growth-plate.
Collapse
Affiliation(s)
- Maria Angeles Fuentes
- Department of Pediatric Dentistry, School of Dentistry, University of Connecticut, Farmington, CT 06030, USA
| | | | | | | | | |
Collapse
|
24
|
Froment P, Seurin D, Hembert S, Levine JE, Pisselet C, Monniaux D, Binoux M, Monget P. Reproductive abnormalities in human IGF binding protein-1 transgenic female mice. Endocrinology 2002; 143:1801-8. [PMID: 11956162 DOI: 10.1210/endo.143.5.8815] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanisms responsible for reproductive abnormalities in transgenic female mice overexpressing human IGF binding protein-1 (IGFBP-1) in the liver have been investigated. At 2 months of age, none of these transgenic mice exhibited ovarian cyclicity. Genital tract and ovary tissue weights were reduced in transgenic mice, this weight reduction being disproportionate with the reduction of body weight. Examination of ovarian follicular population revealed a marked decrease in the number of corpora lutea and gonadotropin-dependent follicles, suggesting an alteration of terminal follicular growth and ovulation. Stimulation of ovaries by exogenous gonadotropins revealed that ovaries from transgenic mice ovulated less oocytes than nontransgenic mice. This lower responsiveness of ovaries from transgenic mice to gonadotropins was not associated with a decrease in FSH-, LH- or IGF-I receptor expression. Transgenic and nontransgenic mice have similar circulating LH and FSH concentrations at dioestrus, after castration, 46 h after equine CG administration, or 15 min after GnRH injection. However, LH concentrations were 8-fold higher in pituitaries from transgenic vs. nontransgenic mice. Moreover, the size of LH-immunoreactive cells was reduced and their number was increased, suggesting a subtle alteration of LH secretion. Overall, these data indicate that reduced fertility in transgenic female mice overexpressing human IGFBP-1 are mainly due to an alteration of terminal follicular growth leading to a decrease in natural and induced ovulation rate, likely due to an impairment of IGF-I action on follicular cells. Increased circulating IGFBP-1 concentrations may additionally lead to altered GnRH and LH pulsatility and thereby exacerbate the ovulation defect.
Collapse
Affiliation(s)
- Pascal Froment
- Physiologie de la Reproduction et des Comportements, Unité Mixte de Recherche 6073 Institut National de la Recherche Agronomique-Centre National de la Recherche Scientifique-Université F. Rabelais de Tours, 37380 Nouzilly, France
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
OBJECTIVE To review recent advances in understanding the role of leptin in the physiology and pathophysiology of reproduction, with a focus on relevant clinical situations. DESIGN A MEDLINE computer search was performed to identify relevant articles. RESULT(S) Leptin, an adipocyte hormone important in regulating energy homeostasis, interacts with the reproductive axis at multiple sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory actions at the gonads. More recently, leptin has been shown to play a role in other target reproductive organs, such as the endometrium, placenta, and mammary gland, with corresponding influences on important physiologic processes such as menstruation, pregnancy, and lactation. As a marker of whether nutritional stores are adequate, leptin may act in concert with gonadotropins and the growth hormone axis to initiate the complex process of puberty. Conditions in which nutritional status is suboptimal, such as eating disorders, exercise-induced amenorrhea, and functional hypothalamic amenorrhea, are associated with low serum leptin levels; and conditions with excess energy stores or metabolic disturbances, such as obesity and polycystic ovarian syndrome, often have elevated serum or follicular fluid leptin levels, raising the possibility that relative leptin deficiency or resistance may be at least partly responsible for the reproductive abnormalities that occur with these conditions. CONCLUSION(S) Leptin may act as the critical link between adipose tissue and the reproductive system, indicating whether adequate energy reserves are present for normal reproductive function. Future interventional studies involving leptin administration are expected to further clarify this role of leptin and may provide new therapeutic options for the reproductive dysfunction associated with states of relative leptin deficiency or resistance.
Collapse
Affiliation(s)
- Stergios Moschos
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
| | | | | |
Collapse
|
26
|
Cardona-Gómez GP, Mendez P, DonCarlos LL, Azcoitia I, Garcia-Segura LM. Interactions of estrogens and insulin-like growth factor-I in the brain: implications for neuroprotection. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 37:320-34. [PMID: 11744097 DOI: 10.1016/s0165-0173(01)00137-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Data from epidemiological studies suggest that the decline in estrogen following menopause could increase the risk of neurodegenerative diseases. Furthermore, experimental studies on different animal models have shown that estrogen is neuroprotective. The mechanisms involved in the neuroprotective effects of estrogen are still unclear. Anti-oxidant effects, activation of different membrane-associated intracellular signaling pathways, and activation of classical nuclear estrogen receptors (ERs) could contribute to neuroprotection. Interactions with neurotrophins and other growth factors may also be important for the neuroprotective effects of estradiol. In this review we focus on the interaction between insulin-like growth factor-I (IGF-I) and estrogen signaling in the brain and on the implications of this interaction for neuroprotection. During the development of the nervous system, IGF-I promotes the differentiation and survival of specific neuronal populations. In the adult brain, IGF-I is a neuromodulator, regulates synaptic plasticity, is involved in the response of neural tissue to injury and protects neurons against different neurodegenerative stimuli. As an endocrine signal, IGF-I represents a link between the growth and reproductive axes and the interaction between estradiol and IGF-I is of particular physiological relevance for the regulation of growth, sexual maturation and adult neuroendocrine function. There are several potential points of convergence between estradiol and IGF-I receptor (IGF-IR) signaling in the brain. Estrogen activates the mitogen-activated protein kinase (MAPK) pathway and has a synergistic effect with IGF-I on the activation of Akt, a kinase downstream of phosphoinositol-3 kinase. In addition, IGF-IR is necessary for the estradiol induced expression of the anti-apoptotic molecule Bcl-2 in hypothalamic neurons. The interaction of ERs and IGF-IR in the brain may depend on interactions between neural cells expressing ERs with neural cells expressing IGF-IR, or on direct interactions of the signaling pathways of alpha and beta ERs and IGF-IR in the same cell, since most neurons expressing IGF-IR also express at least one of the ER subtypes. In addition, studies on adult ovariectomized rats given intracerebroventricular (i.c.v.) infusions with antagonists for ERs or IGF-IR or with IGF-I have shown that there is a cross-regulation of the expression of ERs and IGF-IR in the brain. The interaction of estradiol and IGF-I and their receptors may be involved in different neural events. In the developing brain, ERs and IGF-IR are interdependent in the promotion of neuronal differentiation. In the adult, ERs and IGF-IR interact in the induction of synaptic plasticity. Furthermore, both in vitro and in vivo studies have shown that there is an interaction between ERs and IGF-IR in the promotion of neuronal survival and in the response of neural tissue to injury, suggesting that a parallel activation or co-activation of ERs and IGF-IR mediates neuroprotection.
Collapse
Affiliation(s)
- G P Cardona-Gómez
- Instituto Cajal, C.S.I.C., Avenida Doctor Arce 37, E-28002, Madrid, Spain
| | | | | | | | | |
Collapse
|
27
|
Chauhan NB, Siegel GJ, Lichtor T. Distribution of intraventricularly administered antiamyloid-beta peptide (Abeta) antibody in the mouse brain. J Neurosci Res 2001; 66:231-5. [PMID: 11592118 DOI: 10.1002/jnr.1215] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There is considerable interest in utilizing the intracerebroventricular (icv) route of administration of antibodies in the brain for various studies and for the therapy of malignancies, but very little is known about the anatomic extent of distribution of the antibody in brain after injection into the third ventricle. To explore the potential for icv administration of antiamyloid-beta peptide (Abeta) in reducing Abeta toxicity in brain in Alzheimer's disease, we first mapped the time course and path of transit of horseradish peroxidase (HRP)-labeled antibody. The results show that, after a single injection into the mouse third venticle, the HRP-labeled antibody is localized within the microvasculature, first that of the corticohippocampal region close to the site of injection at 3 hr. By 24 hr, the antibody is distributed throughout the hippocampus and frontoparietal cortex close to the injection site, as well as in the deep and outer cerebral cortex and cerebellar cortex remote from the injection site. The injected antibody is almost entirely removed by 4 days. Therefore, the antibody had diffused throughout all the brain by 24 hr, showing the feasibility of small quantities of anti-Abeta antibody infused into the third ventricle to reach extracellular epitopes throughout the brain parenchyma rapidly.
Collapse
Affiliation(s)
- N B Chauhan
- Department of Neuroscience, Finch University of Health Sciences, The Chicago Medical School, North Chicago, Illinois, USA
| | | | | |
Collapse
|
28
|
Stoker TE, Parks LG, Gray LE, Cooper RL. Endocrine-disrupting chemicals: prepubertal exposures and effects on sexual maturation and thyroid function in the male rat. A focus on the EDSTAC recommendations. Endocrine Disrupter Screening and Testing Advisory Committee. Crit Rev Toxicol 2000; 30:197-252. [PMID: 10759431 DOI: 10.1080/10408440091159194] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Puberty in mammalian species is a period of rapid interactive endocrine and morphological changes. Therefore, it is not surprising that exposure to a variety of pharmaceutical and environmental compounds has been shown to dramatically alter pubertal development. This concern was recognized by the Endocrine Disrupter Screening and Testing Advisory Committee (EDSTAC) that acknowledged the need for the development and standardization of a protocol for the assessment of the impact of endocrine-disrupting compounds (EDC) in the pubertal male and recommended inclusion of an assay of this type as an alternative test in the EDSTAC tier one screen (EPA, 98). The pubertal male protocol was designed to detect alterations of pubertal development, thyroid function, and hypothalamic-pituitary-gonadal (HPG) system peripubertal maturation. In this protocol, intact 23-day-old weanling male rats are exposed to the test substance for 30 days during which pubertal indices are measured. After necropsy, reproductive and thyroid tissues are weighed and evaluated histologically and serum taken for hormone analysis. The purpose of this review was to examine the available literature on pubertal development in the male rat and evaluate the efficacy of the proposed protocol for identifying endocrine-disrupting chemicals. The existing data indicate that this assessment of puberty in the male rat is a simple and effective method to detect the EDC activity of pesticides and toxic substances.
Collapse
Affiliation(s)
- T E Stoker
- Gamete and Early Embryo Biology Branch, Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | | | | | | |
Collapse
|