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Dya GA, Klychnikov OI, Adasheva DA, Vladychenskaya EA, Katrukha AG, Serebryanaya DV. IGF-Binding Proteins and Their Proteolysis as a Mechanism of Regulated IGF Release in the Nervous Tissue. BIOCHEMISTRY (MOSCOW) 2023; 88:S105-S122. [PMID: 37069117 DOI: 10.1134/s0006297923140079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) play a key role in the maintenance of the nervous tissue viability. IGF-1 and IGF-2 exhibit the neuroprotective effects by stimulating migration and proliferation of nervous cells, activating cellular metabolism, inducing regeneration of damaged cells, and regulating various stages of prenatal and postnatal development of the nervous system. The availability of IGFs for the cells is controlled via their interaction with the IGF-binding proteins (IGFBPs) that inhibit their activity. On the contrary, the cleavage of IGFBPs by specific proteases leads to the IGF release and activation of its cellular effects. The viability of neurons in the nervous tissue is controlled by a complex system of trophic factors secreted by auxiliary glial cells. The main source of IGF for the neurons are astrocytes. IGFs can accumulate as an extracellular free ligand near the neuronal membranes as a result of proteolytic degradation of IGFBPs by proteases secreted by astrocytes. This mechanism promotes interaction of IGFs with their genuine receptors and triggers intracellular signaling cascades. Therefore, the release of IGF by proteolytic cleavage of IGFBPs is an important mechanism of neuronal protection. This review summarizes the published data on the role of IGFs and IGFBPs as the key players in the neuroprotective regulation with a special focus on the specific proteolysis of IGFBPs as a mechanism for the regulation of IGF bioavailability and viability of neurons.
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Affiliation(s)
- German A Dya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Oleg I Klychnikov
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Daria A Adasheva
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Elizaveta A Vladychenskaya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexey G Katrukha
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Daria V Serebryanaya
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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Guevara-Aguirre J, Guevara C, Guevara A, Gavilanes AA. Branding of subjects affected with genetic syndromes of severe short stature in developing countries. BMJ Case Rep 2020; 13:e231737. [PMID: 32041755 PMCID: PMC7021096 DOI: 10.1136/bcr-2019-231737] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2020] [Indexed: 01/10/2023] Open
Abstract
In Ecuador, a developing South American country, subjects affected with genetic syndromes of severe short stature are commonly referred to as dwarfs or midgets. Furthermore, and because in earlier studies some patients had evidenced mental retardation, such abnormality is assumed to exist in all affected subjects. Herein, we present two discrete instances in which this type of branding occurs. The first is that of individuals with Laron syndrome who are still called 'dwarfs' and considered as having a degree of mental retardation despite evidence showing otherwise. A similar problem, that of a girl affected with a genetic syndrome of short stature, which might include mental retardation, is also discussed. Considering that stigmatising is a form of discrimination, it concerns us all. Hence, the use of derogatory terms such as midget, dwarf or cretin, that might unintentionally occur even when delivering the best and most devoted medical care, must be eliminated.
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Affiliation(s)
- Jaime Guevara-Aguirre
- College of Medicine, Universidad San Francisco de Quito, Quito, Pichincha, Ecuador
- Department of Pediatrics, Maastricht University, Maastricht, Limburg, The Netherlands
- Instituto de Endocrinologia y Metabolismo, IEMYR, Quito, Pichincha, Ecuador
| | - Carolina Guevara
- Instituto de Endocrinologia y Metabolismo, IEMYR, Quito, Pichincha, Ecuador
| | - Alexandra Guevara
- Instituto de Endocrinologia y Metabolismo, IEMYR, Quito, Pichincha, Ecuador
| | - Antonio Awd Gavilanes
- Department of Pediatrics, Maastricht University, Maastricht, Limburg, The Netherlands
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Lewitt MS, Boyd GW. The Role of Insulin-Like Growth Factors and Insulin-Like Growth Factor-Binding Proteins in the Nervous System. BIOCHEMISTRY INSIGHTS 2019; 12:1178626419842176. [PMID: 31024217 PMCID: PMC6472167 DOI: 10.1177/1178626419842176] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 01/23/2023]
Abstract
The insulin-like growth factors (IGF-I and IGF-II) and their receptors are widely expressed in nervous tissue from early embryonic life. They also cross the blood brain barriers by active transport, and their regulation as endocrine factors therefore differs from other tissues. In brain, IGFs have paracrine and autocrine actions that are modulated by IGF-binding proteins and interact with other growth factor signalling pathways. The IGF system has roles in nervous system development and maintenance. There is substantial evidence for a specific role for this system in some neurodegenerative diseases, and neuroprotective actions make this system an attractive target for new therapeutic approaches. In developing new therapies, interaction with IGF-binding proteins and other growth factor signalling pathways should be considered. This evidence is reviewed, gaps in knowledge are highlighted, and recommendations are made for future research.
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Affiliation(s)
- Moira S Lewitt
- School of Health & Life Sciences, University of the West of Scotland, Paisley, UK
| | - Gary W Boyd
- School of Health & Life Sciences, University of the West of Scotland, Paisley, UK
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Gubbi S, Quipildor GF, Barzilai N, Huffman DM, Milman S. 40 YEARS of IGF1: IGF1: the Jekyll and Hyde of the aging brain. J Mol Endocrinol 2018; 61:T171-T185. [PMID: 29739805 PMCID: PMC5988994 DOI: 10.1530/jme-18-0093] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 12/30/2022]
Abstract
The insulin-like growth factor 1 (IGF1) signaling pathway has emerged as a major regulator of the aging process, from rodents to humans. However, given the pleiotropic actions of IGF1, its role in the aging brain remains complex and controversial. While IGF1 is clearly essential for normal development of the central nervous system, conflicting evidence has emerged from preclinical and human studies regarding its relationship to cognitive function, as well as cerebrovascular and neurodegenerative disorders. This review delves into the current state of the evidence examining the role of IGF1 in the aging brain, encompassing preclinical and clinical studies. A broad examination of the data indicates that IGF1 may indeed play opposing roles in the aging brain, depending on the underlying pathology and context. Some evidence suggests that in the setting of neurodegenerative diseases that manifest with abnormal protein deposition in the brain, such as Alzheimer's disease, reducing IGF1 signaling may serve a protective role by slowing disease progression and augmenting clearance of pathologic proteins to maintain cellular homeostasis. In contrast, inducing IGF1 deficiency has also been implicated in dysregulated function of cognition and the neurovascular system, suggesting that some IGF1 signaling may be necessary for normal brain function. Furthermore, states of acute neuronal injury, which necessitate growth, repair and survival signals to persevere, typically demonstrate salutary effects of IGF1 in that context. Appreciating the dual, at times opposing 'Dr Jekyll' and 'Mr Hyde' characteristics of IGF1 in the aging brain, will bring us closer to understanding its impact and devising more targeted IGF1-related interventions.
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Affiliation(s)
- Sriram Gubbi
- Institute for Aging ResearchAlbert Einstein College of Medicine, Bronx, New York, USA
- Department of Internal MedicineJacobi Medical Center, Bronx, New York, USA
| | - Gabriela Farias Quipildor
- Institute for Aging ResearchAlbert Einstein College of Medicine, Bronx, New York, USA
- Department of Molecular PharmacologyAlbert Einstein College of Medicine, Bronx, New York, USA
- Division of EndocrinologyDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Nir Barzilai
- Institute for Aging ResearchAlbert Einstein College of Medicine, Bronx, New York, USA
- Division of EndocrinologyDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
- Division of GeriatricsDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
- Department of GeneticsAlbert Einstein College of Medicine, Bronx, New York, USA
| | - Derek M Huffman
- Institute for Aging ResearchAlbert Einstein College of Medicine, Bronx, New York, USA
- Department of Molecular PharmacologyAlbert Einstein College of Medicine, Bronx, New York, USA
- Division of EndocrinologyDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Sofiya Milman
- Institute for Aging ResearchAlbert Einstein College of Medicine, Bronx, New York, USA
- Division of EndocrinologyDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
- Division of GeriatricsDepartment of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
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5
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Hinrichs A, Kessler B, Kurome M, Blutke A, Kemter E, Bernau M, Scholz AM, Rathkolb B, Renner S, Bultmann S, Leonhardt H, de Angelis MH, Nagashima H, Hoeflich A, Blum WF, Bidlingmaier M, Wanke R, Dahlhoff M, Wolf E. Growth hormone receptor-deficient pigs resemble the pathophysiology of human Laron syndrome and reveal altered activation of signaling cascades in the liver. Mol Metab 2018; 11:113-128. [PMID: 29678421 PMCID: PMC6001387 DOI: 10.1016/j.molmet.2018.03.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 03/09/2018] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Laron syndrome (LS) is a rare, autosomal recessive disorder in humans caused by loss-of-function mutations of the growth hormone receptor (GHR) gene. To establish a large animal model for LS, pigs with GHR knockout (KO) mutations were generated and characterized. METHODS CRISPR/Cas9 technology was applied to mutate exon 3 of the GHR gene in porcine zygotes. Two heterozygous founder sows with a 1-bp or 7-bp insertion in GHR exon 3 were obtained, and their heterozygous F1 offspring were intercrossed to produce GHR-KO, heterozygous GHR mutant, and wild-type pigs. Since the latter two groups were not significantly different in any parameter investigated, they were pooled as the GHR expressing control group. The characterization program included body and organ growth, body composition, endocrine and clinical-chemical parameters, as well as signaling studies in liver tissue. RESULTS GHR-KO pigs lacked GHR and had markedly reduced serum insulin-like growth factor 1 (IGF1) levels and reduced IGF-binding protein 3 (IGFBP3) activity but increased IGFBP2 levels. Serum GH concentrations were significantly elevated compared with control pigs. GHR-KO pigs had a normal birth weight. Growth retardation became significant at the age of five weeks. At the age of six months, the body weight of GHR-KO pigs was reduced by 60% compared with controls. Most organ weights of GHR-KO pigs were reduced proportionally to body weight. However, the weights of liver, kidneys, and heart were disproportionately reduced, while the relative brain weight was almost doubled. GHR-KO pigs had a markedly increased percentage of total body fat relative to body weight and displayed transient juvenile hypoglycemia along with decreased serum triglyceride and cholesterol levels. Analysis of insulin receptor related signaling in the liver of adult fasted pigs revealed increased phosphorylation of IRS1 and PI3K. In agreement with the loss of GHR, phosphorylation of STAT5 was significantly reduced. In contrast, phosphorylation of JAK2 was significantly increased, possibly due to the increased serum leptin levels and increased hepatic leptin receptor expression and activation in GHR-KO pigs. In addition, increased mTOR phosphorylation was observed in GHR-KO liver samples, and phosphorylation studies of downstream substrates suggested the activation of mainly mTOR complex 2. CONCLUSION GHR-KO pigs resemble the pathophysiology of LS and are an interesting model for mechanistic studies and treatment trials.
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Affiliation(s)
- Arne Hinrichs
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany
| | - Barbara Kessler
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany
| | - Mayuko Kurome
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany; Meiji University International Institute for Bio-Resource Research, 1-1-1 Higashimita, Tama, Kawasaki, 214-8571, Japan
| | - Andreas Blutke
- Institute of Veterinary Pathology, Center for Clinical Veterinary Medicine, LMU Munich, Veterinärstr. 13, 80539 Munich, Germany
| | - Elisabeth Kemter
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany
| | - Maren Bernau
- Livestock Center of the Veterinary Faculty, LMU Munich, St.-Hubertus-Str. 12, 85764 Oberschleißheim, Germany
| | - Armin M Scholz
- Livestock Center of the Veterinary Faculty, LMU Munich, St.-Hubertus-Str. 12, 85764 Oberschleißheim, Germany
| | - Birgit Rathkolb
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Simone Renner
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Sebastian Bultmann
- Human Biology and Bioimaging, Faculty of Biology, Biocenter, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Heinrich Leonhardt
- Human Biology and Bioimaging, Faculty of Biology, Biocenter, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Martin Hrabĕ de Angelis
- German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Institute of Experimental Genetics, Helmholtz Zentrum München, and Chair of Experimental Genetics, Technical University of Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Hiroshi Nagashima
- Meiji University International Institute for Bio-Resource Research, 1-1-1 Higashimita, Tama, Kawasaki, 214-8571, Japan
| | - Andreas Hoeflich
- Cell Signaling Unit, Institute of Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Werner F Blum
- University Children`s Hospital, University of Giessen, Feulgenstr.12, 35392 Gießen, Germany
| | - Martin Bidlingmaier
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, 80336 Munich, Germany
| | - Rüdiger Wanke
- Institute of Veterinary Pathology, Center for Clinical Veterinary Medicine, LMU Munich, Veterinärstr. 13, 80539 Munich, Germany
| | - Maik Dahlhoff
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany
| | - Eckhard Wolf
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany; Center for Innovative Medical Models (CiMM), Department of Veterinary Sciences, LMU Munich, Hackerstr. 27, 85764 Oberschleißheim, Germany; Meiji University International Institute for Bio-Resource Research, 1-1-1 Higashimita, Tama, Kawasaki, 214-8571, Japan; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany.
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6
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Perice L, Barzilai N, Verghese J, Weiss EF, Holtzer R, Cohen P, Milman S. Lower circulating insulin-like growth factor-I is associated with better cognition in females with exceptional longevity without compromise to muscle mass and function. Aging (Albany NY) 2017; 8:2414-2424. [PMID: 27744417 PMCID: PMC5115897 DOI: 10.18632/aging.101063] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/28/2016] [Indexed: 12/21/2022]
Abstract
Mutations that reduce somatotropic signaling result in improved lifespan and health-span in model organisms and humans. However, whether reduced circulating insulin-like growth factor-I (IGF-I) level is detrimental to cognitive and muscle function in older adults remains understudied. A cross-sectional analysis was performed in Ashkenazi Jews with exceptional longevity (age ≥95 years). Cognition was assessed using the Mini-Mental State Examination and muscle function with the chair rise test, grip-strength, and gait speed. Muscle mass was estimated using the skeletal muscle index. Serum IGF-I was measured with liquid chromatography mass spectrometry. In gender stratified age-adjusted logistic regression analysis, females with IGF-I levels in the first tertile had lower odds of being cognitively impaired compared to females with IGF-I levels within the upper two tertiles, OR (95% CI) 0.39 (0.19-0.82). The result remained significant after adjustment for multiple parameters. No significant association was identified in males between IGF-I and cognition. No relationship was found between IGF-I tertiles and muscle function and muscle mass in females or males. Lower circulating IGF-I is associated with better cognitive function in females with exceptional longevity, with no detriment to skeletal muscle mass and function.
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Affiliation(s)
- Leland Perice
- Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Nir Barzilai
- Department of Medicine, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Joe Verghese
- Department of Medicine, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Erica F Weiss
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Roee Holtzer
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, NY 10461
| | - Pinchas Cohen
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Sofiya Milman
- Department of Medicine, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Possible effects of an early diagnosis and treatment in patients with growth hormone deficiency: the state of art. Ital J Pediatr 2017; 43:81. [PMID: 28915901 PMCID: PMC5603037 DOI: 10.1186/s13052-017-0402-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/11/2017] [Indexed: 01/16/2023] Open
Abstract
Growth hormone deficiency (GHD) is a relatively uncommon and heterogeneous endocrine disorder presenting in childhood with short stature. However, during the neonatal period, the metabolic effects of GHD may to require prompt replacement therapy to avoid possible life-threatening complications. An increasing amount of data suggests the importance of an early diagnosis and treatment of GHD because of its auxological, metabolic, and neurodevelopmental features with respect to the patients diagnosed and treated later in life. The available results show favourable auxological outcomes for patients with GHD diagnosed and treated with r-hGH early in life compared with those from patients with GHD who do not receive this early diagnosis and treatment. Because delayed referral for GHD diagnosis and treatment is still frequent, these results highlight the need for more attention in the diagnosis and treatment of GHD. Despite these very encouraging data regarding metabolic and neurodevelopmental features, further studies are needed to better characterize these findings. Overall, the importance of early diagnosis and treatment of GHD needs to be addressed.
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8
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Brain Structure and Function Associated with Younger Adults in Growth Hormone Receptor-Deficient Humans. J Neurosci 2017; 37:1696-1707. [PMID: 28073935 DOI: 10.1523/jneurosci.1929-16.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 12/15/2016] [Accepted: 12/19/2016] [Indexed: 12/30/2022] Open
Abstract
Growth hormone receptor deficiency (GHRD) results in short stature, enhanced insulin sensitivity, and low circulating levels of insulin and insulin-like growth factor 1 (IGF-1). Previous studies in mice and humans suggested that GHRD has protective effects against age-related diseases, including cancer and diabetes. Whereas GHRD mice show improved age-dependent cognitive performance, the effect of GHRD on human cognition remains unknown. Using MRI, we compared brain structure, function, and connectivity between 13 people with GHRD and 12 unaffected relatives. We assessed differences in white matter microstructural integrity, hippocampal volume, subregional volumes, and cortical thickness and surface area of selected regions. We also evaluated brain activity at rest and during a hippocampal-dependent pattern separation task. The GHRD group had larger surface areas in several frontal and cingulate regions and showed trends toward larger dentate gyrus and CA1 regions of the hippocampus. They had lower mean diffusivity in the genu of the corpus callosum and the anterior thalamic tracts. The GHRD group showed enhanced cognitive performance and greater task-related activation in frontal, parietal, and hippocampal regions compared with controls. Furthermore, they had greater functional synchronicity of activity between the precuneus and the rest of the default mode network at rest. The results suggest that, compared with controls, GHRD subjects have brain structure and function that are more consistent with those observed in younger adults reported in previous studies. Further investigation may lead to improved understanding of underlying mechanisms and could contribute to the identification of treatments for age-related cognitive deficits.SIGNIFICANCE STATEMENT People and mice with growth hormone receptor deficiency (GHRD or Laron syndrome) are protected against age-related diseases including cancer and diabetes. However, in humans, it is unknown whether cognitive function and brain structure are affected by GHRD. Using MRI, we examined cognition in an Ecuadorian population with GHRD and their unaffected relatives. The GHRD group showed better memory performance than their relatives. The differences in brain structure and function that we saw between the two groups were not consistent with variations typically associated with brain deficits. This study contributes to our understanding of the connection between growth genes and brain aging in humans and provides data indicating that GHR inhibition has the potential to protect against age-dependent cognitive decline.
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9
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Milman S, Huffman DM, Barzilai N. The Somatotropic Axis in Human Aging: Framework for the Current State of Knowledge and Future Research. Cell Metab 2016; 23:980-989. [PMID: 27304500 PMCID: PMC4919980 DOI: 10.1016/j.cmet.2016.05.014] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 05/24/2016] [Accepted: 05/26/2016] [Indexed: 12/19/2022]
Abstract
Mutations resulting in reduced signaling of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis are associated with increased life- and healthspan across model organisms. Similar findings have been noted in human cohorts with functional mutations in the somatotropic axis, suggesting that this pathway may also be relevant to human aging and protection from age-related diseases. While epidemiological data indicate that low circulating IGF-1 level may protect aging populations from cancer, results remain inconclusive regarding most other diseases. We propose that studies in humans and animals need to consider differences in sex, pathway function, organs, and time-specific effects of GH/IGF-1 signaling in order to better define the role of the somatotropic axis in aging. Agents that modulate signaling of the GH/IGF-1 pathway are available for human use, but before they can be implemented in clinical studies that target aging and age-related diseases, researchers need to address the challenges discussed in this Review.
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Affiliation(s)
- Sofiya Milman
- Department of Medicine, Division of Endocrinology, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Medicine, Division of Geriatrics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Derek M Huffman
- Department of Medicine, Division of Endocrinology, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Nir Barzilai
- Department of Medicine, Division of Endocrinology, Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Medicine, Division of Geriatrics, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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10
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van Dijk G, van Heijningen S, Reijne AC, Nyakas C, van der Zee EA, Eisel ULM. Integrative neurobiology of metabolic diseases, neuroinflammation, and neurodegeneration. Front Neurosci 2015; 9:173. [PMID: 26041981 PMCID: PMC4434977 DOI: 10.3389/fnins.2015.00173] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 04/28/2015] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a complex, multifactorial disease with a number of leading mechanisms, including neuroinflammation, processing of amyloid precursor protein (APP) to amyloid β peptide, tau protein hyperphosphorylation, relocalization, and deposition. These mechanisms are propagated by obesity, the metabolic syndrome and type-2 diabetes mellitus. Stress, sedentariness, dietary overconsumption of saturated fat and refined sugars, and circadian derangements/disturbed sleep contribute to obesity and related metabolic diseases, but also accelerate age-related damage and senescence that all feed the risk of developing AD too. The complex and interacting mechanisms are not yet completely understood and will require further analysis. Instead of investigating AD as a mono- or oligocausal disease we should address the disease by understanding the multiple underlying mechanisms and how these interact. Future research therefore might concentrate on integrating these by “systems biology” approaches, but also to regard them from an evolutionary medicine point of view. The current review addresses several of these interacting mechanisms in animal models and compares them with clinical data giving an overview about our current knowledge and puts them into an integrated framework.
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Affiliation(s)
- Gertjan van Dijk
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Steffen van Heijningen
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Aaffien C Reijne
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands ; Systems Biology Centre for Energy Metabolism and Ageing, University Medical Center, University of Groningen Groningen, Netherlands
| | - Csaba Nyakas
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Eddy A van der Zee
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Ulrich L M Eisel
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands ; University Centre of Psychiatry, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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Brown K, Rodgers J, Johnstone H, Adams W, Clarke M, Gibson M, Cheetham T. Abnormal cognitive function in treated congenital hypopituitarism. Arch Dis Child 2004; 89:827-30. [PMID: 15321857 PMCID: PMC1763198 DOI: 10.1136/adc.2003.029116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To assess cognitive function in school age children with congenital pituitary hormone deficiency (PHD). METHODS Ten children with PHD (aged 6.0-15.6 years, mean 11.5 years) and sibling controls (aged 8.7-14.9 years, mean 12.1 years) were assessed using the Wechsler Intelligence Scale for Children (WISC-III UK). RESULTS The patients' full scale IQ scores were all below average (mean 75, 95% CI 70-80), but were not significantly different to those of sibling controls (mean 82, 95% CI 75-89). There was no difference in verbal IQ between patients and siblings, but performance IQ was significantly reduced (mean 75, 95% CI 68-82 in patients; mean 88, 95% CI 80-96 in sibling controls). The reduced performance IQ reflected a poorer performance in tasks assessing perceptual organisational skills. CONCLUSIONS Data suggest that children with PHD have an IQ that is below average when compared to the population norm and a reduced performance IQ when compared to sibling controls. This may reflect abnormal brain development or could be linked to the impact of hypoglycaemia or low thyroxine concentrations in early life. This information is of value when counselling parents and planning a child's care and education, although further, more extensive studies of patients and siblings are required.
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Affiliation(s)
- K Brown
- Department of Paediatrics, Royal Victoria Infirmary, Newcastle upon Tyne, UK
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