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Baxter RC. Endocrine and cellular physiology and pathology of the insulin-like growth factor acid-labile subunit. Nat Rev Endocrinol 2024; 20:414-425. [PMID: 38514815 DOI: 10.1038/s41574-024-00970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/26/2024] [Indexed: 03/23/2024]
Abstract
The acid-labile subunit (ALS) of the insulin-like growth factor (IGF) binding protein (IGFBP) complex, encoded in humans by IGFALS, has a vital role in regulating the endocrine transport and bioavailability of IGF-1 and IGF-2. Accordingly, ALS has a considerable influence on postnatal growth and metabolism. ALS is a leucine-rich glycoprotein that forms high-affinity ternary complexes with IGFBP-3 or IGFBP-5 when they are occupied by either IGF-1 or IGF-2. These complexes constitute a stable reservoir of circulating IGFs, blocking the potentially hypoglycaemic activity of unbound IGFs. ALS is primarily synthesized by hepatocytes and its expression is lower in non-hepatic tissues. ALS synthesis is strongly induced by growth hormone and suppressed by IL-1β, thus potentially serving as a marker of growth hormone secretion and/or activity and of inflammation. IGFALS mutations in humans and Igfals deletion in mice cause modest growth retardation and pubertal delay, accompanied by decreased osteogenesis and enhanced adipogenesis. In hepatocellular carcinoma, IGFALS is described as a tumour suppressor; however, its contribution to other cancers is not well delineated. This Review addresses the endocrine physiology and pathology of ALS, discusses the latest cell and proteomic studies that suggest emerging cellular roles for ALS and outlines its involvement in other disease states.
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Affiliation(s)
- Robert C Baxter
- University of Sydney, Kolling Institute, Royal North Shore Hospital, St Leonards, New South Wales, Australia.
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Franzoni A, Baldan F, Passon N, Mio C, Driul D, Cogo P, Fogolari F, D'Aurizio F, Damante G. Novel IGFALS mutations with predicted pathogenetic effects by the analysis of AlphaFold structure. Endocrine 2023; 79:292-295. [PMID: 36348166 DOI: 10.1007/s12020-022-03244-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 10/25/2022] [Indexed: 11/10/2022]
Abstract
PURPOSE According to the American College of Medical Genetics (ACMG) classification, variants of uncertain significance (VUS) are gene variations whose impact on the disease risk is not yet known. VUS, therefore, represent an unmet need for genetic counselling. Aim of the study is the use the AlphaFold artificial intelligence algorithm to predict the impact of novel mutations of the IGFALS gene, detected in a subject with short stature and initially classified as VUS according to the ACMG classification. METHODS A short-stature girl and her parents have been investigated. IGFALS mutations have been detected through clinical exome and confirmed by Sanger sequencing. The potential presence of co-occurring gene alterations was investigated in the proband by whole exome and CGH array. Structure of the ALS protein (encoded by the IGFALS gene) was evaluated through the AlphaFold artificial intelligence algorithm. RESULTS Two IGFALS variants were found in the proband: c.1349T > C (p.Leu450Pro) and c.1363_1365delCTC (p.Leu455del), both classified as VUS, according to ACMG. Parents' analysis highlighted the in trans position of the two variants. AlphaFold showed that the mutated positions were found the concave side a horseshoe structure of the ALS protein, likely interfering with protein-protein interactions. According to a loss of function (LoF) effect of the two variants, reduced levels of the IGF1 and IGFBP-3 proteins, as well as a growth hormone (GH) excess were detected in the proband's serum. CONCLUSIONS By using the AlphaFold structure we were able to predict two IGFALS gene mutations initially classified as VUS, as potentially pathogenetic. Our proof-of-concept showed a potential application of AlphaFold as tool to a better inform VUS interpretation of genetic tests.
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Affiliation(s)
- Alessandra Franzoni
- SOC Istituto di Genetica Medica, Azienda Sanitaria Universitaria Friuli Centrale Udine, Udine, Italy
| | - Federica Baldan
- SOC Istituto di Genetica Medica, Azienda Sanitaria Universitaria Friuli Centrale Udine, Udine, Italy
| | - Nadia Passon
- SOC Istituto di Genetica Medica, Azienda Sanitaria Universitaria Friuli Centrale Udine, Udine, Italy
| | - Catia Mio
- Dipartimento di Area Medica, Università di Udine, Udine, Italy
| | - Daniela Driul
- SOC Clinica Pediatrica, Azienda Ospedaliero-Universitaria, Udine, Italy
| | - Paola Cogo
- Dipartimento di Area Medica, Università di Udine, Udine, Italy
- SOC Clinica Pediatrica, Azienda Ospedaliero-Universitaria, Udine, Italy
| | - Federico Fogolari
- Dipartimento di Scienze matematiche, Informatiche e Fisiche, Università di Udine, Udine, Italy
| | - Federica D'Aurizio
- SOC Istituto di Patologia Clinica Azienda Sanitaria Universitaria Friuli Centrale Udine, Udine, Italy
| | - Giuseppe Damante
- SOC Istituto di Genetica Medica, Azienda Sanitaria Universitaria Friuli Centrale Udine, Udine, Italy.
- Dipartimento di Area Medica, Università di Udine, Udine, Italy.
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Kim H, Fu Y, Hong HJ, Lee SG, Lee DS, Kim HM. Structural basis for assembly and disassembly of the IGF/IGFBP/ALS ternary complex. Nat Commun 2022; 13:4434. [PMID: 35907924 PMCID: PMC9338993 DOI: 10.1038/s41467-022-32214-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/21/2022] [Indexed: 11/10/2022] Open
Abstract
Insulin-like growth factors (IGFs) have pleiotropic roles in embryonic and postnatal growth and differentiation. Most serum IGFs are bound in a ternary complex with IGF-binding protein 3 (IGFBP3) and acid-labile subunit (ALS), extending the serum half-life of IGFs and regulating their availability. Here, we report cryo-EM structure of the human IGF1/IGFBP3/ALS ternary complex, revealing the detailed architecture of a parachute-like ternary complex and crucial determinants for their sequential and specific assembly. In vitro biochemical studies show that proteolysis at the central linker domain of IGFBP3 induces release of its C-terminal domain rather than IGF1 release from the ternary complex, yielding an intermediate complex that enhances IGF1 bioavailability. Our results provide mechanistic insight into IGF/IGFBP3/ALS ternary complex assembly and its disassembly upon proteolysis for IGF bioavailability, suggesting a structural basis for human diseases associated with IGF1 and IGFALS gene mutations such as complete ALS deficiency (ACLSD) and IGF1 deficiency. Insulin-like growth factor 1 (IGF1) regulates growth and differentiation. Here, authors report the atomic structure of the ternary complex (IGF1/IGF-binding protein3/acid labile subunit) and its assembly/disassembly mechanism for IGF bioavailability.
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Affiliation(s)
- Hyojin Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yaoyao Fu
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Ho Jeong Hong
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Seong-Gyu Lee
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Dong Sun Lee
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea. .,Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea.
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Hwa V, Fujimoto M, Zhu G, Gao W, Foley C, Kumbaji M, Rosenfeld RG. Genetic causes of growth hormone insensitivity beyond GHR. Rev Endocr Metab Disord 2021; 22:43-58. [PMID: 33029712 PMCID: PMC7979432 DOI: 10.1007/s11154-020-09603-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/01/2020] [Indexed: 12/13/2022]
Abstract
Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in severe post-natal growth failure as consequences of insulin-like growth factor I (IGF-I) deficiency. Over the years, recognition of other monogenic defects downstream of GHR has greatly expanded understanding of primary causes of GHI and growth retardation, with either IGF-I deficiency or IGF-I insensitivity as clinical outcomes. Mutations in IGF1 and signaling component STAT5B disrupt IGF-I production, while defects in IGFALS and PAPPA2, disrupt transport and release of circulating IGF-I, respectively, affecting bioavailability of the growth-promoting IGF-I. Defects in IGF1R, cognate cell-surface receptor for IGF-I, disrupt not only IGF-I actions, but actions of the related IGF-II peptides. The importance of IGF-II for normal developmental growth is emphasized with recent identification of defects in the maternally imprinted IGF2 gene. Current application of next-generation genomic sequencing has expedited the pace of identifying new molecular defects in known genes or in new genes, thereby expanding the spectrum of GH and IGF insensitivity. This review discusses insights gained and future directions from patient-based molecular and functional studies.
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Affiliation(s)
- Vivian Hwa
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA.
| | - Masanobu Fujimoto
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
- Division of Pediatrics and Perinatology, Faculty of Medicine, Tottori University, 36-1 Nishi-Cho, Yonago, 683-8504, Japan
| | - Gaohui Zhu
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
- Department of Endocrinology, Children's Hospital of Chongqing Medical University, Chongqing, 40014, China
| | - Wen Gao
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Corinne Foley
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Meenasri Kumbaji
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Ron G Rosenfeld
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, 97239, USA.
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Domené S, Domené HM. The role of acid-labile subunit (ALS) in the modulation of GH-IGF-I action. Mol Cell Endocrinol 2020; 518:111006. [PMID: 32861700 DOI: 10.1016/j.mce.2020.111006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 12/17/2022]
Abstract
Acid-labile subunit (ALS) deficiency (ACLSD) constitutes the first monogenic defect involving a member of the Insulin-like Growth Factor (IGF) binding protein system. The lack of ALS completely disrupts the circulating IGF system. Autocrine/paracrine action of local produced IGF-I could explain the mild effect on growth. In the present work we have revised the more relevant clinical and biochemical consequences of complete ACLSD in 61 reported subjects from 31 families. Low birth weight and/or length, reduced head circumference, height between -2 and -3 SD, pubertal delay and insulin resistance are commonly observed. Partial ACLSD could be present in children initially labeled as idiopathic short stature, presenting low IGF-I levels, suggesting that one functional IGFALS allele is insufficient to stabilize ternary complexes. Dysfunction of the GH-IGF axis observed in ACLSD may eventually result in increased risk for type-2 diabetes and tumor progression. Consequently, long term surveillance is recommended in these patients.
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Affiliation(s)
- Sabina Domené
- Centro de Investigaciones Endocrinológicas 'Dr César Bergadá', (CEDIE) CONICET, FEI, División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Horacio M Domené
- Centro de Investigaciones Endocrinológicas 'Dr César Bergadá', (CEDIE) CONICET, FEI, División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina.
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Poyrazoğlu Ş, Hwa V, Baş F, Dauber A, Rosenfeld R, Darendeliler F. A Novel Homozygous Mutation of the Acid-Labile Subunit (IGFALS) Gene in a Male Adolescent. J Clin Res Pediatr Endocrinol 2019; 11:432-438. [PMID: 30717585 PMCID: PMC6878349 DOI: 10.4274/jcrpe.galenos.2019.2018.0301] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Acid-labile subunit (ALS) forms ternary complexes with insulin like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) and is essential for normal circulating IGF-1 levels. The IGFALS gene encodes the ALS and mutations in IGFALS cause ALS deficiency. We describe a patient with ALS deficiency with a novel homozygous frameshift mutation in IGFALS presenting with short stature and delayed puberty but ultimately achieving an adult height (AH) comparable to his target height (TH). A 15.25 year old boy presented with short stature (149.9 cm, -3.04 standard deviation score). The patient had a low circulating IGF-1 concentration, extremely low IGFBP-3 concentration, insulin resistance and osteopenia. The peak growth hormone (GH) response to GH stimulation test was high (31.6 ng/mL). Sequencing of IGFALS revealed a novel, homozygous, frameshift mutation (p.Ser555Thrfs.19). His mother and elder sister were heterozygous carriers. Although he had delayed puberty and short stature at the onset of puberty, he reached his TH and an AH similar to those of his heterozygous mother and sister. The heterozygous carriers had normal or low IGF-1 concentrations and low IGFBP-3 concentrations but not as markedly low as that of the patient. They had normally timed puberty, insulin metabolism and bone mineral density (BMD). The phenotype of ALS deficiency is quite variable. Despite short stature and delayed puberty, patients can achieve normal pubertal growth and AH. ALS deficiency may cause osteopenia and hyperinsulinemia. Heterozygous carriers may have normal prenatal growth, puberty, insulin metabolism and BMD.
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Affiliation(s)
- Şükran Poyrazoğlu
- İstanbul University İstanbul Faculty of Medicine, Unit of Pediatric Endocrinology, İstanbul, Turkey,* Address for Correspondence: İstanbul University İstanbul Faculty of Medicine, Unit of Pediatric Endocrinology, İstanbul, Turkey Phone: +90 212 414 20 00 E-mail:
| | - Vivian Hwa
- Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati Center for Growth Disorders, Cincinnati, Division of Endocrinology, Ohio, USA
| | - Firdevs Baş
- İstanbul University İstanbul Faculty of Medicine, Unit of Pediatric Endocrinology, İstanbul, Turkey
| | - Andrew Dauber
- Children’s National Healthy System, Division of Endocrinology, Washington, USA
| | - Ron Rosenfeld
- Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati Center for Growth Disorders, Cincinnati, Division of Endocrinology, Ohio, USA
| | - Feyza Darendeliler
- İstanbul University İstanbul Faculty of Medicine, Unit of Pediatric Endocrinology, İstanbul, Turkey
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Matsushima N, Takatsuka S, Miyashita H, Kretsinger RH. Leucine Rich Repeat Proteins: Sequences, Mutations, Structures and Diseases. Protein Pept Lett 2019; 26:108-131. [PMID: 30526451 DOI: 10.2174/0929866526666181208170027] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
Abstract
Mutations in the genes encoding Leucine Rich Repeat (LRR) containing proteins are associated with over sixty human diseases; these include high myopia, mitochondrial encephalomyopathy, and Crohn's disease. These mutations occur frequently within the LRR domains and within the regions that shield the hydrophobic core of the LRR domain. The amino acid sequences of fifty-five LRR proteins have been published. They include Nod-Like Receptors (NLRs) such as NLRP1, NLRP3, NLRP14, and Nod-2, Small Leucine Rich Repeat Proteoglycans (SLRPs) such as keratocan, lumican, fibromodulin, PRELP, biglycan, and nyctalopin, and F-box/LRR-repeat proteins such as FBXL2, FBXL4, and FBXL12. For example, 363 missense mutations have been identified. Replacement of arginine, proline, or cysteine by another amino acid, or the reverse, is frequently observed. The diverse effects of the mutations are discussed based on the known structures of LRR proteins. These mutations influence protein folding, aggregation, oligomerization, stability, protein-ligand interactions, disulfide bond formation, and glycosylation. Most of the mutations cause loss of function and a few, gain of function.
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Affiliation(s)
- Norio Matsushima
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan.,Institute of Tandem Repeats, Noboribetsu 059-0464, Japan
| | - Shintaro Takatsuka
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Hiroki Miyashita
- Institute of Tandem Repeats, Noboribetsu 059-0464, Japan.,Hokubu Rinsho Co., Ltd, Sapporo 060-0061, Japan
| | - Robert H Kretsinger
- Department of Biology, University of Virginia, Charlottesville, VA 22904, United States
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Renes JS, van Doorn J, Hokken-Koelega ACS. Current Insights into the Role of the Growth Hormone-Insulin-Like Growth Factor System in Short Children Born Small for Gestational Age. Horm Res Paediatr 2019; 92:15-27. [PMID: 31509834 PMCID: PMC6979433 DOI: 10.1159/000502739] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 08/14/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The reason for the insufficient catch-up growth seen in 10% of children born small for gestational age (SGA) is poorly understood. Disturbances in the growth hormone (GH) - insulin-like growth factor (IGF) axis might underlie this failure to show sufficient catch-up growth. CONCLUSION This review summarizes insights gained in the molecular and (epi) genetic mechanisms of the GH-IGF axis in short children born SGA. The most notable anomalies of the IGF system are the lowered IGF-I levels in both cord blood and the placenta, and the increased expression of IGF-binding proteins (IGFBP)-1 and IGFBP-2, which inhibit IGF-I, in the placenta of SGA neonates. These observations suggest a decreased bioactivity of IGF-I in utero. IGF-I levels remain reduced in SGA children with short stature, as well as IGFBP-3 and acid-labile subunit levels. Proteolysis of IGFBP-3 appears to be increased.
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Affiliation(s)
- Judith S Renes
- Department of Paediatrics, Subdivision of Endocrinology, Erasmus University Medical Centre, Sophia Children's Hospital, Rotterdam, The Netherlands,
| | - Jaap van Doorn
- Department of Genetics, Section of Metabolic Diagnostics, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Anita C S Hokken-Koelega
- Department of Paediatrics, Subdivision of Endocrinology, Erasmus University Medical Centre, Sophia Children's Hospital, Rotterdam, The Netherlands
- Dutch Growth Research Foundation, Rotterdam, The Netherlands
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Işık E, Haliloglu B, van Doorn J, Demirbilek H, Scheltinga SA, Losekoot M, Wit JM. Clinical and biochemical characteristics and bone mineral density of homozygous, compound heterozygous and heterozygous carriers of three novel IGFALS mutations. Eur J Endocrinol 2017; 176:657-667. [PMID: 28249955 DOI: 10.1530/eje-16-0999] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 02/13/2017] [Accepted: 03/01/2017] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Acid-labile subunit (ALS) deficiency (ACLSD), caused by homozygous or compound heterozygous IGFALS mutations, is associated with moderate short stature, delayed puberty, low serum IGF-I and ALS and extremely low serum IGFBP-3. Its effect on birth weight, head circumference, bone mineral density (BMD), serum IGF-II and IGFBP-2 is uncertain, as well as the phenotype of heterozygous carriers of IGFALS mutations (partial ACLSD). DESIGN From all available members of five Turkish families, carrying three mutations in exon 2 of IGFALS (c.1462G > A, p.Asp488Asn (families A, B, E); c.251A > G, p.Asn84Ser (families C and E) and c.1477del, p.Arg493fs (family D)), clinical, laboratory and BMD data were collected. METHODS Auxological and biochemical findings were expressed as SDS for age and gender. Ternary complex formation in serum was investigated by size-exclusion chromatography. BMD using DXA bone densitometry was adjusted for height and age (Ha-BMD z-score). RESULTS In ACLSD (n = 24), mean ± s.d. height SDS (-2.7 ± 1.2), head circumference SDS (-2.3 ± 0.5) and body mass index (BMI) (-0.6 ± 1.0 SDS) were lower than those in partial ACLSD (n = 26, P ≤ 0.01) and birth weight SDS (n = 7) tended to be lower (-2.2 ± 1.1 vs -0.6 ± 0.3 in partial ACLSD (P = 0.07)). Serum IGF-I was -3.7 ± 1.4 vs -1.0 ± 1.0, IGF-II: -5.6 ± 0.7 vs -1.3 ± 0.7, ALS: <-4.4 ± 1.2 vs -2.1 ± 0.9 and IGFBP-3: -9.0 ± 1.9 vs -1.6 ± 0.8 SDS respectively (P < 0.001). Ha-BMD z-score was similar and normal in both groups. CONCLUSIONS To the known phenotype of ACLSD (i.e. short stature, reduced serum levels of IGF-I and ALS, extremely low serum IGFBP-3 and disturbed ternary complex formation), we add reduced birth weight, head circumference and serum IGF-II.
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Affiliation(s)
- Emregül Işık
- Department of Pediatric EndocrinologyGaziantep Children's Hospital, Gaziantep, Turkey
| | - Belma Haliloglu
- Department of Pediatric EndocrinologyYeditepe University School of Medicine, İstanbul, Turkey
| | - Jaap van Doorn
- Department of GeneticsUniversity Medical Center Utrecht, The Netherlands
| | - Hüseyin Demirbilek
- Department of Pediatric EndocrinologyHacettepe University Faculty of Medicine, Ankara, Turkey
| | | | | | - Jan M Wit
- Departments of PediatricsLeiden University Medical Center, Leiden, The Netherlands
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Rotwein P. Large-scale analysis of variation in the insulin-like growth factor family in humans reveals rare disease links and common polymorphisms. J Biol Chem 2017; 292:9252-9261. [PMID: 28389567 DOI: 10.1074/jbc.m117.783639] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/06/2017] [Indexed: 01/07/2023] Open
Abstract
The insulin-like growth factors IGF1 and IGF2 are closely related proteins that are essential for normal growth and development in humans and other species and play critical roles in many physiological and pathophysiological processes. IGF actions are mediated by transmembrane receptors and modulated by IGF-binding proteins. The importance of IGF actions in human physiology is strengthened by the rarity of inactivating mutations in their genes and by the devastating impact caused by such mutations on normal development and somatic growth. Large-scale genome sequencing has the potential to provide new insights into human variation and disease susceptibility. Toward this end, the availability of DNA sequence data from 60,706 people through the Exome Aggregation Consortium has prompted the analyses presented here. Results reveal a broad range of potential missense and other alterations in the coding regions of every IGF family gene, but the vast majority of predicted changes were uncommon. The total number of different alleles detected per gene in the population varied over an ∼15-fold range, from 57 for IGF1 to 872 for IGF2R, although when corrected for protein length the rate ranged from 0.22 to 0.59 changes/codon among the 11 genes evaluated. Previously characterized disease-causing mutations in IGF2, IGF1R, IGF2R, or IGFALS all were found in the general population but with allele frequencies of <1:30,000. A few new highly prevalent amino acid polymorphisms were also identified. Collectively, these data provide a wealth of opportunities to understand the intricacies of IGF signaling and action in both physiological and pathological contexts.
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Affiliation(s)
- Peter Rotwein
- From the Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech Health University Health Sciences Center, El Paso, Texas 79905
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Martucci LC, Gutiérrez ML, Karabatas LM, Scaglia PA, Rey RA, Domené HM, Jasper HG, Domené S. Assessment of pathogenicity of natural IGFALS gene variants by in silico bioinformatics tools and in vitro functional studies. Mol Cell Endocrinol 2016; 429:19-28. [PMID: 27018247 DOI: 10.1016/j.mce.2016.03.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/02/2016] [Accepted: 03/23/2016] [Indexed: 11/25/2022]
Abstract
Acid-labile subunit (ALS) is essential for stabilization of IGF-I and IGFBP-3 in ternary complexes within the vascular system. ALS deficient (ALS-D) patients and a subset of children with idiopathic short stature (ISS), presenting IGFALS gene variants, show variable degree of growth retardation associated to IGF-I and IGFBP-3 deficiencies. The aim of this study was to evaluate the potential pathogenicity of eleven IGFALS variants identified in ALS-D and ISS children using in silico and in vitro approaches. We were able to classify seven of these variants as pathogenic since they present impaired synthesis (p.Glu35Lysfs*87, p.Glu35Glyfs*17, p.Asn276Ser, p.Leu409Phe, p.Ser490Trp and p.Cys540Arg), or partial impairment of synthesis and lack of secretion (p.Leu213Phe). We also observed significant reduction of secreted protein for variants p.Ala330Asp, Ala475Val and p.Arg548Trp, while still retaining their ability to form ternary complexes. These findings provide an approach to test the pathogenicity of IGFALS gene variants.
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Affiliation(s)
- Lucía C Martucci
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Mariana L Gutiérrez
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Liliana M Karabatas
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Paula A Scaglia
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Rodolfo A Rey
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Horacio M Domené
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Héctor G Jasper
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
| | - Sabina Domené
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá" (CEDIE), CONICET - FEI - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Gallo 1330 - C1425EFD, Buenos Aires, Argentina
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12
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Biological function of hpsh4590 localized in the plasticity zone of Helicobacter pylori. Microb Pathog 2016; 93:63-9. [DOI: 10.1016/j.micpath.2016.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 01/01/2023]
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Poukoulidou T, Kowalczyk J, Metherell L, De Schepper J, Maes M. A novel homozygous mutation of the IGFALS gene in a female adolescent: indirect evidence for a contributing role of the circulating IGF-I pool in the pubertal growth spurt. Horm Res Paediatr 2015; 81:422-7. [PMID: 24819402 DOI: 10.1159/000358329] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/31/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mutations of the IGFALS gene have been reported since 2004 in 24 patients, but only 5 of these are females. CASE REPORT We describe a 14.7-year-old female of a consanguineous Moroccan family with growth retardation and normal-onset but slow progression of puberty without manifest pubertal height gain. RESULTS At age 3.2 years, the patient's height was 85.5 cm (-2.9 SDS) and her weight 9.9 kg (-2.9 SDS) with a head circumference of 44.5 cm (-3.3 SDS). Serum IGF-I and IGFBP-3 concentrations were low with normal basal and stimulated growth hormone (GH) levels. An IGF-I generation test confirmed a lack of response to GH administration. While onset of puberty occurred at a normal age, no significant pubertal growth acceleration was observed despite progression of breast development. Sequencing of the IGFALS gene revealed a novel homozygous frameshift mutation (c.1291delT) with a stop codon (p.W431GfsX10) leading to undetectable serum levels of acid-labile subunit. CONCLUSION We report the phenotype of an adolescent girl with primary IGF-I deficiency due to a novel homozygous mutation of the IGFALS gene, who presented with growth delay, normal pubertal onset with slow progression and no pubertal growth acceleration indirectly suggesting a contributing role of the circulating IGF-I pool in the pubertal growth spurt.
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Affiliation(s)
- Thekla Poukoulidou
- Division of Pediatric Endocrinology, Department of Pediatrics, Cliniques Universitaires Saint-Luc, Catholic University of Louvain, Brussels, Belgium
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Grandone A, Miraglia del Giudice E, Cirillo G, Abbondanza C, Cioffi M, Romano T, Micillo F, Marzuillo P, Perrone L. Clinical features of a new acid-labile subunit (IGFALS) heterozygous mutation: anthropometric and biochemical characterization and response to growth hormone administration. Horm Res Paediatr 2015; 81:67-72. [PMID: 24356109 DOI: 10.1159/000355017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/12/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Homozygous mutations in acid-labile subunit (IGFALS) gene result in short stature, very low circulating levels of acid-labile subunit (ALS), insulin growth factor 1 (IGF1) and insulin growth factor binding protein 3 (IGFBP3) and a poor response to growth hormone (GH). The impact of IGFALS mutations heterozygosity on growth is unknown. PATIENT AND METHODS We describe a 10-year-old girl with severe short stature (height -3.2 SDS), heterozygous for a new IGFALS mutation. RESULTS The girl showed low circulating IGF1, IGFBP3 and ALS levels and normal GH secretion. We found a novel heterozygous frameshift IGFALS mutation (c.1283delA, p.Gln428Argfs*14). Size-exclusion chromatography showed a reduction of the IGF1, IGFBP3 and ALS 150-kDa ternary complex (by about 55%) compared to a control. An IGF-1 generation test, with two different GH dosages, showed a good response in term of increase in IGF1 and in formation of the ternary complex at size-exclusion chromatography. Clinical response after 6 months of therapy with GH was satisfactory (height velocity increased from 3 to 8 cm/year). CONCLUSION We suggest that (1) heterozygous IGFALS mutations can be responsible for a subset of patients with severe short stature (below -2.5 SDS), low IGF1 (below -2 SDS) and normal GH secretion, and (2) the identification by IGFALS molecular screening of this subset of patients could help in the administration of the appropriate therapy.
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Affiliation(s)
- Anna Grandone
- Department of Woman, Child and General and Specialized Surgery, Seconda Università degli Studi di Napoli, Naples, Italy
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