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Conover CA, Oxvig C. The Pregnancy-Associated Plasma Protein-A (PAPP-A) Story. Endocr Rev 2023; 44:1012-1028. [PMID: 37267421 DOI: 10.1210/endrev/bnad017] [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: 02/10/2023] [Revised: 05/01/2023] [Accepted: 05/31/2023] [Indexed: 06/04/2023]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the circulation of pregnant women. In the mid-to-late 1990s, PAPP-A was discovered to be a metzincin metalloproteinase, expressed by many nonplacental cells, that regulates local insulin-like growth factor (IGF) activity through cleavage of high-affinity IGF binding proteins (IGFBPs), in particular IGFBP-4. With PAPP-A as a cell surface-associated enzyme, the reduced affinity of the cleavage fragments results in increased IGF available to bind and activate IGF receptors in the pericellular environment. This proteolytic regulation of IGF activity is important, since the IGFs promote proliferation, differentiation, migration, and survival in various normal and cancer cells. Thus, there has been a steady growth in investigation of PAPP-A structure and function outside of pregnancy. This review provides historical perspective on the discovery of PAPP-A and its structure and cellular function, highlights key studies of the first 50 years in PAPP-A research, and introduces new findings from recent years.
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Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
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2
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Danos N, Patrick M, Barretto J, Bilotta F, Lee M. Effects of pregnancy and lactation on muscle-tendon morphology. J Anat 2023; 243:860-869. [PMID: 37350269 PMCID: PMC10557392 DOI: 10.1111/joa.13916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/08/2023] [Accepted: 06/02/2023] [Indexed: 06/24/2023] Open
Abstract
Pregnancy and lactation hormones have been shown to mediate anatomical changes to the musculoskeletal system that generates animal movement. In this study, we characterize changes in the medial gastrocnemius muscle, its tendon and aponeuroses that are likely to have an effect on whole animal movement and energy expenditure, using the rat model system, Rattus norvegicus. We quantified muscle architecture (mass, cross-sectional area, and pennation angle), muscle fiber type and diameter, and Young's modulus of stiffness for the medial gastrocnemius aponeuroses as well as its contribution to Achilles tendon in three groups of three-month-old female rats: virgin, primiparous pregnant, and primiparous lactating animals. We found that muscle mass drops by 23% during lactation but does not change during pregnancy. We also found that during pregnancy muscle fibers switch from Type I to IIa and during lactation from Type IIb to Type I. The stiffness of connective tissues that has a demonstrated role in locomotion, the aponeurosis and tendon, also changed. Pregnant animals had a significantly less stiff aponeurosis. However, tendon stiffness was most affected during lactation, with a significant drop in stiffness and interindividual variation. We propose that the energetic demands of locomotion may have driven the evolution of these anatomical changes in muscle-tendon units during pregnancy and lactation to ensure more energy can be allocated to fetal development and lactation.
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Affiliation(s)
- Nicole Danos
- Biology DepartmentUniversity of San DiegoSan DiegoCaliforniaUSA
| | | | - Jacob Barretto
- Biology DepartmentUniversity of San DiegoSan DiegoCaliforniaUSA
| | | | - Megan Lee
- Biology DepartmentUniversity of San DiegoSan DiegoCaliforniaUSA
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3
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Martín AI, Moreno-Rupérez Á, Nebot E, Granado M, Jaque D, Nieto-Bona MP, López-Calderón A, Priego T. Time-Dependent Changes in Muscle IGF1-IGFBP5-PAPP System after Sciatic Denervation. Int J Mol Sci 2023; 24:14112. [PMID: 37762414 PMCID: PMC10531309 DOI: 10.3390/ijms241814112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Denervation-induced muscle atrophy is a frequent cause of skeletal muscle diseases. However, the role of the most important muscle growth factor, insulin-like growth factor (IGF-1), in this process is poorly understood. IGF-1 activity is controlled by six IGF-1 binding proteins (IGFBPs). In skeletal muscle, IGFBP-5 seems to have an important role in atrophic processes. Furthermore, pappalysins (PAPP-A) modulate muscle growth by increasing IGF-1 bioavailability through IGFBP cleavage. We aimed to study the time-dependent changes in the IGF1-IGFBP5-PAPP system and its regulators in gastrocnemius muscle after sciatic denervation. Gastrocnemius atrophy and overexpression of IGF-1 was observed from day 3 post-denervation. The proteolytic factors measured were elevated from day 1 post-denervation onwards. Expression of both IGFBP-5 and pappalysins were increased on days 1 and 3. Subsequently, on days 7 to 14 pappalysins returned to control levels while IGFBP-5 remained elevated. The ratio IGFBP-5/PAPP-A was correlated with the main proteolytic markers. All data suggest that the initial increase of pappalysins could facilitate the IGF-1 action on muscle growth, whereas their subsequent decrease could lead to further muscle wasting.
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Affiliation(s)
- Ana Isabel Martín
- Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain; (A.I.M.); (Á.M.-R.); (E.N.); (A.L.-C.)
| | - Álvaro Moreno-Rupérez
- Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain; (A.I.M.); (Á.M.-R.); (E.N.); (A.L.-C.)
| | - Elena Nebot
- Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain; (A.I.M.); (Á.M.-R.); (E.N.); (A.L.-C.)
| | - Miriam Granado
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo 2, 28029 Madrid, Spain;
| | - Daniel Jaque
- Nanomaterials for Bioimaging Group (NanoBIG), Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Avenida Francisco Tomas y Valiente, 28049 Madrid, Spain;
| | - M. Paz Nieto-Bona
- Departamento de Ciencias Básicas de la Salud, Facultad CC Salud, Universidad Rey Juan Carlos, Avenida de Atenas sn, 20922 Madrid, Spain;
| | - Asunción López-Calderón
- Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain; (A.I.M.); (Á.M.-R.); (E.N.); (A.L.-C.)
| | - Teresa Priego
- Departamento de Fisiología, Facultad de Enfermería, Fisioterapia y Podología, Universidad Complutense de Madrid, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
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4
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Lionikas A, Hernandez Cordero AI, Kilikevicius A, Carroll AM, Bewick GS, Bunger L, Ratkevicius A, Heisler LK, Harboe M, Oxvig C. Stanniocalcin-2 inhibits skeletal muscle growth and is upregulated in functional overload-induced hypertrophy. Physiol Rep 2023; 11:e15793. [PMID: 37568262 PMCID: PMC10510475 DOI: 10.14814/phy2.15793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
AIMS Stanniocalcin-2 (STC2) has recently been implicated in human muscle mass variability by genetic analysis. Biochemically, STC2 inhibits the proteolytic activity of the metalloproteinase PAPP-A, which promotes muscle growth by upregulating the insulin-like growth factor (IGF) axis. The aim was to examine if STC2 affects skeletal muscle mass and to assess how the IGF axis mediates muscle hypertrophy induced by functional overload. METHODS We compared muscle mass and muscle fiber morphology between Stc2-/- (n = 21) and wild-type (n = 15) mice. We then quantified IGF1, IGF2, IGF binding proteins -4 and -5 (IGFBP-4, IGFBP-5), PAPP-A and STC2 in plantaris muscles of wild-type mice subjected to 4-week unilateral overload (n = 14). RESULTS Stc2-/- mice showed up to 10% larger muscle mass compared with wild-type mice. This increase was mediated by greater cross-sectional area of muscle fibers. Overload increased plantaris mass and components of the IGF axis, including quantities of IGF1 (by 2.41-fold, p = 0.0117), IGF2 (1.70-fold, p = 0.0461), IGFBP-4 (1.48-fold, p = 0.0268), PAPP-A (1.30-fold, p = 0.0154) and STC2 (1.28-fold, p = 0.019). CONCLUSION Here we provide evidence that STC2 is an inhibitor of muscle growth upregulated, along with other components of the IGF axis, during overload-induced muscle hypertrophy.
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Affiliation(s)
- Arimantas Lionikas
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Ana I. Hernandez Cordero
- Centre for Heart Lung InnovationUniversity of British Columbia, St. Paul's HospitalVancouverCanada
| | - Audrius Kilikevicius
- Department of Health Promotion and RehabilitationLithuanian Sports UniversityKaunasLithuania
| | - Andrew M. Carroll
- The New Zealand Institute for Plant & Food Research LimitedPalmerston NorthNew Zealand
| | - Guy S. Bewick
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Lutz Bunger
- Animal Genetics Company (AnGeCo)EdinburghScotland
| | - Aivaras Ratkevicius
- Department of Health Promotion and RehabilitationLithuanian Sports UniversityKaunasLithuania
| | - Lora K. Heisler
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Mette Harboe
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Claus Oxvig
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
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5
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Catela C, Chen Y, Weng Y, Wen K, Kratsios P. Control of spinal motor neuron terminal differentiation through sustained Hoxc8 gene activity. eLife 2022; 11:70766. [PMID: 35315772 PMCID: PMC8940177 DOI: 10.7554/elife.70766] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 03/12/2022] [Indexed: 12/30/2022] Open
Abstract
Spinal motor neurons (MNs) constitute cellular substrates for several movement disorders. Although their early development has received much attention, how spinal MNs become and remain terminally differentiated is poorly understood. Here, we determined the transcriptome of mouse MNs located at the brachial domain of the spinal cord at embryonic and postnatal stages. We identified novel transcription factors (TFs) and terminal differentiation genes (e.g. ion channels, neurotransmitter receptors, adhesion molecules) with continuous expression in MNs. Interestingly, genes encoding homeodomain TFs (e.g. HOX, LIM), previously implicated in early MN development, continue to be expressed postnatally, suggesting later functions. To test this idea, we inactivated Hoxc8 at successive stages of mouse MN development and observed motor deficits. Our in vivo findings suggest that Hoxc8 is not only required to establish, but also maintain expression of several MN terminal differentiation markers. Data from in vitro generated MNs indicate Hoxc8 acts directly and is sufficient to induce expression of terminal differentiation genes. Our findings dovetail recent observations in Caenorhabditis elegans MNs, pointing toward an evolutionarily conserved role for Hox in neuronal terminal differentiation.
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Affiliation(s)
- Catarina Catela
- Department of Neurobiology, University of Chicago, Chicago, United States.,University of Chicago Neuroscience Institute, Chicago, United States
| | - Yihan Chen
- Department of Neurobiology, University of Chicago, Chicago, United States.,University of Chicago Neuroscience Institute, Chicago, United States
| | - Yifei Weng
- Department of Neurobiology, University of Chicago, Chicago, United States.,University of Chicago Neuroscience Institute, Chicago, United States
| | - Kailong Wen
- Department of Neurobiology, University of Chicago, Chicago, United States.,University of Chicago Neuroscience Institute, Chicago, United States
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, United States.,University of Chicago Neuroscience Institute, Chicago, United States
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6
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Kashyap S, Zeidler JD, Chini CCS, Chini EN. Implications of the PAPP-A-IGFBP-IGF-1 pathway in the pathogenesis and treatment of polycystic kidney disease. Cell Signal 2020; 73:109698. [PMID: 32569826 DOI: 10.1016/j.cellsig.2020.109698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 12/19/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic diseases implicated in the development of end stage renal disease (ESRD). Although FDA has recently approved a drug against ADPKD, there is still a great need for development of alternative management strategies for ADPKD. Understanding the different mechanisms that lead to cystogenesis and cyst expansion in ADPKD is imperative to develop new therapies against ADPKD. Recently, we demonstrated that caloric restriction can prevent the development of cystic disease in animal models of ADPKD and through these studies identified a new role for pregnancy associated plasma protein-A (PAPP-A), a component of the insulin-like growth factors (IGF) pathway, in the pathogenesis of this disease. The PAPP-A-IGF pathway plays an important role in regulation of cell growth, differentiation, and transformation and dysregulation of this pathway has been implicated in many diseases. Several indirect studies support the involvement of IGF-1 in the pathogenesis of ADPKD. However, it was only recently that we described a direct role for a component of this pathway in pathogenesis of ADPKD, opening a new avenue for the therapeutic approaches for this cystic disease. The present literature review will critically discuss the evidence that supports the role of components of IGF pathway in the pathogenesis of ADPKD and discuss the pharmacological implications of PAPP-A-IGF axis in this disease.
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Affiliation(s)
- Sonu Kashyap
- Signal Transduction and Molecular Nutrition Laboratory, Kogod Aging Center, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Julianna D Zeidler
- Signal Transduction and Molecular Nutrition Laboratory, Kogod Aging Center, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Claudia C S Chini
- Signal Transduction and Molecular Nutrition Laboratory, Kogod Aging Center, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Eduardo Nunes Chini
- Signal Transduction and Molecular Nutrition Laboratory, Kogod Aging Center, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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7
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Kashyap S, Hein KZ, Chini CC, Lika J, Warner GM, Bale LK, Torres VE, Harris PC, Oxvig C, Conover CA, Chini EN. Metalloproteinase PAPP-A regulation of IGF-1 contributes to polycystic kidney disease pathogenesis. JCI Insight 2020; 5:135700. [PMID: 31990681 DOI: 10.1172/jci.insight.135700] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/22/2020] [Indexed: 02/06/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of end-stage renal disease (ESRD). The treatment options for ADPKD are limited. We observed an upregulation in several IGF-1 pathway genes in the kidney of Pkd1RC/RC mice, a model of ADPKD. Pregnancy-associated plasma protein A (PAPP-A), a metalloproteinase that cleaves inhibitory IGF binding proteins (IGFBPs), increasing the local bioactivity of IGF-1, was highly induced in the kidney of ADPKD mice. PAPP-A levels were high in cystic fluid and kidneys of humans with ADPKD. Our studies further showed that PAPP-A transcription in ADPKD was mainly regulated through the cAMP/CREB/CBP/p300 pathway. Pappa deficiency effectively inhibited the development of cysts in the Pkd1RC/RC mice. The role of PAPP-A in cystic disease appears to be regulation of the IGF-1 pathway and cellular proliferation in the kidney. Finally, preclinical studies demonstrated that treatment with a monoclonal antibody that blocks the proteolytic activity of PAPP-A against IGFBP4 ameliorated ADPKD cystic disease in vivo in Pkd1RC/RC mice and ex vivo in embryonic kidneys. These data indicated that the PAPP-A/IGF-1 pathway plays an important role in the growth and expansion of cysts in ADPKD. Our findings introduce a therapeutic strategy for ADPKD that involves the inhibition of PAPP-A.
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Affiliation(s)
- Sonu Kashyap
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
| | - Kyaw Zaw Hein
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
| | - Claudia Cs Chini
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
| | - Jorgo Lika
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
| | - Gina M Warner
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
| | - Laurie K Bale
- Division of Endocrinology and Metabolism, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Vicente E Torres
- Division of Nephrology and Hypertension and Robert M. and Billie Kelley Pirnie Translational PKD Center, Rochester, Minnesota, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension and Robert M. and Billie Kelley Pirnie Translational PKD Center, Rochester, Minnesota, USA
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Cheryl A Conover
- Division of Endocrinology and Metabolism, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Eduardo N Chini
- Department of Anesthesiology and Robert and Arlene Kogod Center on Aging
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8
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Gehrig JL, Venkatesh S, Chang HW, Hibberd MC, Kung VL, Cheng J, Chen RY, Subramanian S, Cowardin CA, Meier MF, O'Donnell D, Talcott M, Spears LD, Semenkovich CF, Henrissat B, Giannone RJ, Hettich RL, Ilkayeva O, Muehlbauer M, Newgard CB, Sawyer C, Head RD, Rodionov DA, Arzamasov AA, Leyn SA, Osterman AL, Hossain MI, Islam M, Choudhury N, Sarker SA, Huq S, Mahmud I, Mostafa I, Mahfuz M, Barratt MJ, Ahmed T, Gordon JI. Effects of microbiota-directed foods in gnotobiotic animals and undernourished children. Science 2019; 365:eaau4732. [PMID: 31296738 PMCID: PMC6683325 DOI: 10.1126/science.aau4732] [Citation(s) in RCA: 234] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/24/2019] [Accepted: 06/07/2019] [Indexed: 12/16/2022]
Abstract
To examine the contributions of impaired gut microbial community development to childhood undernutrition, we combined metabolomic and proteomic analyses of plasma samples with metagenomic analyses of fecal samples to characterize the biological state of Bangladeshi children with severe acute malnutrition (SAM) as they transitioned, after standard treatment, to moderate acute malnutrition (MAM) with persistent microbiota immaturity. Host and microbial effects of microbiota-directed complementary food (MDCF) prototypes targeting weaning-phase bacterial taxa underrepresented in SAM and MAM microbiota were characterized in gnotobiotic mice and gnotobiotic piglets colonized with age- and growth-discriminatory bacteria. A randomized, double-blind controlled feeding study identified a lead MDCF that changes the abundances of targeted bacteria and increases plasma biomarkers and mediators of growth, bone formation, neurodevelopment, and immune function in children with MAM.
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Affiliation(s)
- Jeanette L Gehrig
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Siddarth Venkatesh
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hao-Wei Chang
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Matthew C Hibberd
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Vanderlene L Kung
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jiye Cheng
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Robert Y Chen
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sathish Subramanian
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carrie A Cowardin
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Martin F Meier
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David O'Donnell
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael Talcott
- Division of Comparative Medicine, Washington University, St. Louis, MO 63110, USA
| | - Larry D Spears
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Clay F Semenkovich
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique and Aix-Marseille Université, 13288 Marseille cedex 9, France
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Richard J Giannone
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Christopher Sawyer
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Genome Technology Access Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Richard D Head
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Genome Technology Access Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Dmitry A Rodionov
- A. A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Aleksandr A Arzamasov
- A. A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Semen A Leyn
- A. A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Andrei L Osterman
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Md Iqbal Hossain
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Munirul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Nuzhat Choudhury
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Shafiqul Alam Sarker
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Sayeeda Huq
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Imteaz Mahmud
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Ishita Mostafa
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Mustafa Mahfuz
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Michael J Barratt
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tahmeed Ahmed
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka 1212, Bangladesh
| | - Jeffrey I Gordon
- Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Center for Gut Microbiome and Nutrition Research, Washington University School of Medicine, St. Louis, MO 63110, USA
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9
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Vassilakos G, Barton ER. Insulin-Like Growth Factor I Regulation and Its Actions in Skeletal Muscle. Compr Physiol 2018; 9:413-438. [PMID: 30549022 DOI: 10.1002/cphy.c180010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The insulin-like growth factor (IGF) pathway is essential for promoting growth and survival of virtually all tissues. It bears high homology to its related protein insulin, and as such, there is an interplay between these molecules with regard to their anabolic and metabolic functions. Skeletal muscle produces a significant proportion of IGF-1, and is highly responsive to its actions, including increased muscle mass and improved regenerative capacity. In this overview, the regulation of IGF-1 production, stability, and activity in skeletal muscle will be described. Second, the physiological significance of the forms of IGF-1 produced will be discussed. Last, the interaction of IGF-1 with other pathways will be addressed. © 2019 American Physiological Society. Compr Physiol 9:413-438, 2019.
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Affiliation(s)
- Georgios Vassilakos
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
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10
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Clemmons DR. Role of IGF-binding proteins in regulating IGF responses to changes in metabolism. J Mol Endocrinol 2018; 61:T139-T169. [PMID: 29563157 DOI: 10.1530/jme-18-0016] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 03/21/2018] [Indexed: 12/22/2022]
Abstract
The IGF-binding protein family contains six members that share significant structural homology. Their principal function is to regulate the actions of IGF1 and IGF2. These proteins are present in plasma and extracellular fluids and regulate access of both IGF1 and II to the type I IGF receptor. Additionally, they have functions that are independent of their ability to bind IGFs. Each protein is regulated independently of IGF1 and IGF2, and this provides an important mechanism by which other hormones and physiologic variables can regulate IGF actions indirectly. Several members of the family are sensitive to changes in intermediary metabolism. Specifically the presence of obesity/insulin resistance can significantly alter the expression of these proteins. Similarly changes in nutrition or catabolism can alter their synthesis and degradation. Multiple hormones such as glucocorticoids, androgens, estrogen and insulin regulate IGFBP synthesis and bioavailability. In addition to their ability to regulate IGF access to receptors these proteins can bind to distinct cell surface proteins or proteins in extracellular matrix and several cellular functions are influenced by these interactions. IGFBPs can be transported intracellularly and interact with nuclear proteins to alter cellular physiology. In pathophysiologic states, there is significant dysregulation between the changes in IGFBP synthesis and bioavailability and changes in IGF1 and IGF2. These discordant changes can lead to marked alterations in IGF action. Although binding protein physiology and pathophysiology are complex, experimental results have provided an important avenue for understanding how IGF actions are regulated in a variety of physiologic and pathophysiologic conditions.
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Affiliation(s)
- David R Clemmons
- Department of MedicineUNC School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
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11
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Verbrugge SAJ, Schönfelder M, Becker L, Yaghoob Nezhad F, Hrabě de Angelis M, Wackerhage H. Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review. Front Physiol 2018; 9:553. [PMID: 29910734 PMCID: PMC5992403 DOI: 10.3389/fphys.2018.00553] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/30/2018] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform), Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1. Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a) Igf1-Akt-mTOR pathway, (b) myostatin-Smad signaling, and (c) the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.
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Affiliation(s)
- Sander A. J. Verbrugge
- Exercise Biology Group, Faculty of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Martin Schönfelder
- Exercise Biology Group, Faculty of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Lore Becker
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Fakhreddin Yaghoob Nezhad
- Exercise Biology Group, Faculty of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Freising, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Henning Wackerhage
- Exercise Biology Group, Faculty of Sport and Health Sciences, Technical University of Munich, Munich, Germany
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12
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Conover CA, Oxvig C. PAPP-A: a promising therapeutic target for healthy longevity. Aging Cell 2017; 16:205-209. [PMID: 28035757 PMCID: PMC5334524 DOI: 10.1111/acel.12564] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2016] [Indexed: 12/16/2022] Open
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) is a proteolytic enzyme that was discovered to increase local insulin-like growth factor (IGF) availability for receptor activation through cleavage of inhibitory IGF binding proteins (IGFBPs). Reduced IGF signaling has been associated with increased lifespan and healthspan. Therefore, inhibition of PAPP-A represents a novel approach to indirectly decrease the availability of bioactive IGF. Here, we will review data in support of PAPP-A as a therapeutic target to promote healthy longevity.
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Affiliation(s)
| | - Claus Oxvig
- Department of Molecular Biology and Genetics; Aarhus Universitet; Aarhus Denmark
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13
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PAPP-A and the IGF system. ANNALES D'ENDOCRINOLOGIE 2016; 77:90-6. [DOI: 10.1016/j.ando.2016.04.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 04/11/2016] [Indexed: 01/25/2023]
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14
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Conover CA, Bale LK, Nair KS. Comparative gene expression and phenotype analyses of skeletal muscle from aged wild-type and PAPP-A-deficient mice. Exp Gerontol 2016; 80:36-42. [PMID: 27086066 DOI: 10.1016/j.exger.2016.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 12/17/2022]
Abstract
Mice deficient in pregnancy-associated plasma protein-A (PAPP-A) have extended lifespan associated with decreased incidence and severity of degenerative diseases of age, such as cardiomyopathy and nephropathy. In this study, the effect of PAPP-A deficiency on aging skeletal muscle was investigated. Whole-genome expression profiling was performed on soleus muscles from 18-month-old wild-type (WT) and PAPP-A knock-out (KO) mice of the same sex and from the same litter ('womb-mates') to identify potential mechanisms of skeletal muscle aging and its retardation in PAPP-A deficiency. Top genes regulated in PAPP-A KO compared to WT muscle were associated with increased muscle function, increased metabolism, in particular lipid metabolism, and decreased stress. Fiber cross-sectional area was significantly increased in solei from PAPP-A KO mice. In vitro contractility experiments indicated increased specific force and decreased fatigue in solei from PAPP-A KO mice. Intrinsic mitochondrial oxidative capacity was significantly increased in skeletal muscle of aged PAPP-A KO compared to WT mice. Moreover, 18-month-old PAPP-A KO mice exhibited significantly enhanced endurance running on a treadmill. Thus, PAPP-A deficiency in mice is associated with indices of healthy skeletal muscle function with age.
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Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
| | - Laurie K Bale
- Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
| | - K Sreekumaran Nair
- Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
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15
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Yang TH, Thoreson AR, An KN, Zhao C, Conover CA, Amadio PC. PAPP-A affects tendon structure and mechanical properties. J Struct Biol 2015; 192:59-66. [PMID: 26306763 DOI: 10.1016/j.jsb.2015.08.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 08/20/2015] [Accepted: 08/22/2015] [Indexed: 11/19/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) serves to increase local insulin-like growth factor (IGF) stimulation of proliferation and differentiation in many tissues through proteolysis of inhibitory IGF-binding proteins. The purpose of this study was to investigate the effects of PAPP-A on tendon structure and mechanical properties. A total of 30 tails from 6-month-old mice were tested with 10 tails in each of following groups: PAPP-A knockout (KO), skeletal-specific PAPP-A overexpressing transgenic (Tg) and wild type (WT). Morphologically, the total tail cross-sectional area (CSA), individual tissue CSAs of bone, muscle and tendon, and fascicle diameter were measured. A fascicle pullout test was performed to assess stiffness and strength of interfascicular structures. Fascicles were mechanically characterized through low and high displacement rate uniaxial tension tests providing modulus at each rate, hysteresis area and stress relaxation ratio. The KO mice had a smaller total tail CSA (p<0.05), fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), fast and slow stiffness (p<0.05 for both) and larger hysteresis area (p<0.05) compared to WT and Tg mice. On the other hand, the Tg mice had a larger fascicle diameter (p<0.05), absolute tendon CSA (p<0.05), higher interfascicular strength and stiffness (p<0.05) and lower fascicular modulus at low displacement rates (p<0.05) compared to WT and KO mice. Tg mice also had larger total tail CSA area (p<0.05) and smaller hysteresis area (p<0.05) than KO mice, and larger normalized tendon CSA (p<0.05) than WT mice. Based on these data, we conclude that PAPP-A affects fascicle structure, thereby affecting tendon phenotype.
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Affiliation(s)
- Tai-Hua Yang
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew R Thoreson
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Kai-Nan An
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Chunfeng Zhao
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Cheryl A Conover
- Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
| | - Peter C Amadio
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA.
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16
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The role of PAPP-A in the IGF system: location, location, location. J Cell Commun Signal 2015; 9:177-87. [PMID: 25617049 DOI: 10.1007/s12079-015-0259-9] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 01/12/2015] [Indexed: 12/15/2022] Open
Abstract
Although discovered as a placental protein present abundantly in the circulation of pregnant women, pregnancy-associated plasma protein-A (PAPP-A) is widely expressed in multiple tissues. PAPP-A is a highly specific metalloproteinase binding tightly to glycosaminoglycans present on the surface of cells. By cleaving a subset of insulin-like growth factor binding proteins (IGFBPs), PAPP-A thus functions within tissues as a growth-promoting enzyme, releasing bioactive IGF in close proximity to the IGF receptor. IGFBP-4 is believed to be the principal PAPP-A substrate, and the focus in this review is on PAPP-A enzymatic activity and its role in the PAPP-A-IGFBP-4-IGF axis, which is subject to regulation at several different levels. These include e.g., transcriptional control, competing reactions potentially sequestering IGF from IGFBP-4 and hence antagonizing PAPP-A-mediated IGF activation, and proteolytic inhibition of PAPP-A. The latter may involve the protein stanniocalcin-2 (STC2), recently found to potently inhibit PAPP-A activity by forming a covalent complex with PAPP-A. PAPP-A or complex-bound variants may escape from pathological tissues into the circulation. It is emphasized that the potential use of PAPP-A as a diagnostic or predictive biomarker in nonpregnant individuals requires precise knowledge of analyte identity and assay specificity in addition to an appropriate material for standardization. Finally, PAPP-A may serve as a therapeutic target to indirectly inhibit IGF signaling in tissues where this is driven by increased PAPP-A activity. By taking advantage of the intricate interaction between PAPP-A and IGFBP-4, highly specific and selective inhibition of PAPP-A is possible.
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17
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Jepsen MR, Kløverpris S, Mikkelsen JH, Pedersen JH, Füchtbauer EM, Laursen LS, Oxvig C. Stanniocalcin-2 inhibits mammalian growth by proteolytic inhibition of the insulin-like growth factor axis. J Biol Chem 2014; 290:3430-9. [PMID: 25533459 DOI: 10.1074/jbc.m114.611665] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mammalian stanniocalcin-2 (STC2) is a secreted polypeptide widely expressed in developing and adult tissues. However, although transgenic expression in mice is known to cause severe dwarfism, and targeted deletion of STC2 causes increased postnatal growth, its precise biological role is still unknown. We found that STC2 potently inhibits the proteolytic activity of the growth-promoting metalloproteinase, pregnancy-associated plasma protein-A (PAPP-A). Proteolytic inhibition requires covalent binding of STC2 to PAPP-A and is mediated by a disulfide bond, which involves Cys-120 of STC2. Binding of STC2 prevents PAPP-A cleavage of insulin-like growth factor-binding protein (IGFBP)-4 and hence release within tissues of bioactive IGF, required for normal growth. Concordantly, we show that STC2 efficiently inhibits PAPP-A-mediated IGF receptor signaling in vitro and that transgenic mice expressing a mutated variant of STC2, STC2(C120A), which is unable to inhibit PAPP-A, grow like wild-type mice. Our work identifies STC2 as a novel proteinase inhibitor and a previously unrecognized extracellular component of the IGF system.
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Affiliation(s)
- Malene R Jepsen
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Søren Kløverpris
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Jakob H Mikkelsen
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Josefine H Pedersen
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Ernst-Martin Füchtbauer
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Lisbeth S Laursen
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Claus Oxvig
- From the Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
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18
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Gaidamauskas E, Gyrup C, Boldt HB, Schack VR, Overgaard MT, Laursen LS, Oxvig C. IGF dependent modulation of IGF binding protein (IGFBP) proteolysis by pregnancy-associated plasma protein-A (PAPP-A): multiple PAPP-A-IGFBP interaction sites. Biochim Biophys Acta Gen Subj 2013; 1830:2701-9. [PMID: 23671931 DOI: 10.1016/j.bbagen.2012.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Pregnancy-associated plasma protein-A (PAPP-A) is a local regulator of insulin-like growth factor (IGF) bioavailability in physiological systems, but many structural and functional aspects of the metzincin metalloproteinase remain to be elucidated. PAPP-A cleaves IGF binding protein (IGFBP)-4 and IGFBP-5. Cleavage of IGFBP-4, but not IGFBP-5, depends on the binding of IGF before proteolysis by PAPP-A can occur. The paralogue PAPP-A2 has two substrates among the six IGFBPs: IGFBP-3 and IGFBP-5. METHODS Sets of chimeric proteins between IGFBP-4 and -5, and IGFBP-3 and -5 were constructed to investigate the structural requirements for IGF modulation. At the proteinase level, we investigated the importance of individual acidic amino acids positioned in the proteolytic domain of PAPP-A for proteolytic activity against IGFBP-4 and -5. Interaction between PAPP-A and its substrates was analyzed by surface plasmon resonance. RESULTS AND CONCLUSION We provide data suggesting that the C-terminal domain of the IGFBPs is responsible for IGF-dependent modulation of access to the scissile bond. Loss or reduction of IGFBP proteolysis by PAPP-A was observed upon mutation of residues positioned in the unique 63-residue stretch separating the zinc and Met-turn motifs, and in the short sequence following the Met-turn methionine. A model of the proteolytic domain of PAPP-A suggests the presence of structural calcium ions in the C-terminal subdomain, implicated in IGFBP substrate interactions. GENERAL SIGNIFICANCE Detailed knowledge of interactions between PAPP-A and its substrates is required to understand the modulatory role of PAPP-A on IGF receptor stimulation.
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Affiliation(s)
- Ervinas Gaidamauskas
- Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, Denmark
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19
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Tart JK, Johnson RK, Bundy JW, Ferdinand NN, McKnite AM, Wood JR, Miller PS, Rothschild MF, Spangler ML, Garrick DJ, Kachman SD, Ciobanu DC. Genome-wide prediction of age at puberty and reproductive longevity in sows. Anim Genet 2013; 44:387-97. [PMID: 23437861 DOI: 10.1111/age.12028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2013] [Indexed: 11/27/2022]
Abstract
Traditional selection for sow reproductive longevity is ineffective due to low heritability and late expression of the trait. Incorporation of DNA markers into selection programs is potentially a more practical approach for improving sow lifetime productivity. Using a resource population of crossbred gilts, we explored pleiotropic sources of variation that influence age at puberty and reproductive longevity. Of the traits recorded before breeding, only age at puberty significantly affected the probability that females would produce a first parity litter. The genetic variance explained by 1-Mb windows of the sow genome, compared across traits, uncovered regions that influence both age at puberty and lifetime number of parities. Allelic variants of SNPs located on SSC5 (27-28 Mb), SSC8 (36-37 Mb) and SSC12 (1.2-2 Mb) exhibited additive effects and were associated with both early expression of puberty and a greater than average number of lifetime parities. Combined analysis of these SNPs showed that an increase in the number of favorable alleles had positive impact on reproductive longevity, increasing number of parities by up to 1.36. The region located on SSC5 harbors non-synonymous alleles in the arginine vasopressin receptor 1A (AVPR1A) gene, a G-protein-coupled receptor associated with social and reproductive behaviors in voles and humans and a candidate for the observed effects. This region is characterized by high levels of linkage disequilibrium in different lines and could be exploited in marker-assisted selection programs across populations to increase sow reproductive longevity.
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Affiliation(s)
- J K Tart
- Animal Science Department, University of Nebraska, Lincoln, NE, 68583, USA
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20
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Bale LK, Resch ZT, Harstad SL, Overgaard MT, Conover CA. Constitutive expression of pregnancy-associated plasma protein-A in arterial smooth muscle reduces the vascular response to injury in vivo. Am J Physiol Endocrinol Metab 2013; 304:E139-44. [PMID: 23169786 PMCID: PMC3543565 DOI: 10.1152/ajpendo.00376.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) functions to increase local IGF-I bioactivity. In this study, we used transgenic mice that constitutively express human PAPP-A in arterial smooth muscle to test the hypothesis that overexpression of PAPP-A enhances vascular smooth muscle cell (SMC) response to IGF-I in vivo. PAPP-A transgenic (Tg) and wild-type (WT) mice underwent unilateral carotid ligation, a model of injury-induced SMC hyperplasia and neointimal formation. In both WT and PAPP-A Tg mice, endogenous PAPP-A mRNA expression showed peak elevation 5 days after carotid ligation. However, PAPP-A Tg mice had 70-75% less neointima than WT at 5 and 10 days postligation, with a significant reduction in occlusion of the ligated artery. WT and PAPP-A Tg mice had equivalent increases in medial area and vessel remodeling postligation. There was little change in medial area and no evidence of neointima in the contralateral carotid of WT or PAPP-A Tg mice. Both WT and PAPP-A Tg carotids exhibited signs of dedifferentiation of SMC, which precedes the increase in proliferation and migration that results in neointimal formation. However, the number of proliferating cells in the media and neointima of the ligated PAPP-A Tg artery was reduced by 90% on day 5 postsurgery compared with WT. This decrease was associated with a significant decrease in an in vivo marker of IGF-I bioactivity and reduced IGF-I-stimulated receptor phosphorylation ex vivo. These data suggest differential effects of chronic (transgenic) and transient (endogenous) PAPP-A expression on neointimal formation following vascular injury that may be due in part to the differential impact on IGF-I signaling.
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MESH Headings
- Animals
- Arteries/injuries
- Arteries/metabolism
- Arteries/pathology
- Arteries/physiology
- Carotid Artery Injuries/genetics
- Carotid Artery Injuries/metabolism
- Carotid Artery Injuries/pathology
- Carotid Artery Injuries/physiopathology
- Gene Expression/physiology
- Humans
- Insulin-Like Growth Factor I/metabolism
- Mice
- Mice, Transgenic
- Muscle, Smooth, Vascular/injuries
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiology
- Organ Specificity/genetics
- Pregnancy-Associated Plasma Protein-A/genetics
- Pregnancy-Associated Plasma Protein-A/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Transfection
- Tunica Intima/injuries
- Tunica Intima/metabolism
- Tunica Intima/pathology
- Tunica Intima/physiology
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Affiliation(s)
- Laurie K Bale
- Department of Internal Medicine, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN, USA
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21
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Li Y, Zhou C, Zhou X, Song L, Hui R. PAPP-A in cardiac and non-cardiac conditions. Clin Chim Acta 2012; 417:67-72. [PMID: 23262366 DOI: 10.1016/j.cca.2012.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/06/2012] [Accepted: 12/09/2012] [Indexed: 12/30/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A), a newly discovered member of insulin like growth factors (IGFs) axis, has been reported to be a biomarker in both cardiac and non-cardiac conditions. PAPP-A mainly acts as a protease cleaving IGF inhibitors - IGF binding proteins (IGFBPs), thereby setting free IGFs. In cardiac conditions, PAPP-A plays an important role in progressive atherosclerosis. As a biomarker, PAPP-A is not only sensitive, specific and early for diagnosis of acute coronary syndrome, but also an independent risk factor for all-cause mortality or combined cardiovascular events. In non-cardiac conditions, PAPP-A is a new anti-aging target. PAPP-A knock out (KO) mice have a prolonged lifespan than the wild type. In addition, PAPP-A is also a biomarker associated with malignant cancer and end stage renal disease.
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Affiliation(s)
- Yuehua Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
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22
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Deb C, Li B, Baylink DJ, Xing W, Zhang W, Chen M, Wergedal JE, Mohan S, Qin X. Transgenic overexpression of pregnancy-associated plasma protein-A in skeletal muscle of mice increases myofiber size and central nucleation in sedentary muscle and promotes muscle regeneration in the injured muscle. Growth Horm IGF Res 2012; 22:173-179. [PMID: 22709655 DOI: 10.1016/j.ghir.2012.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 05/25/2012] [Accepted: 05/27/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE While there is compelling evidence for an anabolic role of PAPP-A, an IGFBP protease, in muscle development, its effect on dynamic regulation of muscle regeneration has not been investigated. In this study, we evaluated the effect of transgenic PAPP-A overexpression in skeletal muscle of mice on myofiber formation in intact and crush-injured tibialus anterior muscle. DESIGN Skeletal muscle in transgenic mice overexpressing human PAPP-A in skeletal muscle was subjected to crush-injury. Myofiber formation and myogenic gene expression were then evaluated in injured or intact muscle of PAPP-A transgenic mice and wild-type mice. RESULTS In the intact muscle, aging PAPP-A transgenic (Tg.) mice (age of 12 months) showed more than a 2-fold increase in both myofiber size and number of nuclei per myofiber compared with their wild-type (Wt.) littermates. Myofibers with centered nuclei, a hallmark of muscle regeneration, were increased from <1% in Wt. mice to 65% in Tg. muscle. In the injured muscle, reduced inflammatory cell infiltration and increased new myofiber size and the area occupied by new myofibers were observed in PAPP-A transgenic mice compared to wild-type littermates. MyoD and creatine kinase in the injured muscle was also significantly increased in the Tg. mice. Although TNF-α induced PAPP-A expression in skeletal myoblast culture and its expression increased upon injury, abrogation of TNF-α signaling in TNF-α receptor knockout mice had no impact on the extent of injury induction of PAPP-A. We also found that TGF-β expression was significantly increased following muscle injury in vivo and treatment with recombinant TGF-β in vitro significantly enhanced PAPP-A expression in skeletal myoblasts. CONCLUSION Our findings demonstrate that exogenous PAPP-A can promote recovery of muscle injury in aging mice albeit the expression of endogenous PAPP-A had already been increased dramatically upon muscle injury.
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Affiliation(s)
- Chandra Deb
- Division of Regenerative Medicine, Department of Medicine, Loma Linda University, CA 92354, USA
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Frystyk J. Quantification of the GH/IGF-axis components: lessons from human studies. Domest Anim Endocrinol 2012; 43:186-97. [PMID: 22153974 DOI: 10.1016/j.domaniend.2011.11.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 11/08/2011] [Accepted: 11/09/2011] [Indexed: 11/30/2022]
Abstract
Originally, the circulating bioactivity of IGF-I was estimated by bioassays measuring the ability of serum to stimulate uptake of labeled sulfate or thymidine in cultures of costal cartilage or by the ability of serum to stimulate the uptake of glucose in fat tissue cultures. However, because of their laborious and unspecific nature, the original bioassays were quickly abandoned with the development of the first RIA for IGF-I in 1977. Consequently, for the past three decades the endogenous IGF-I bioactivity has been almost exclusively estimated by the use of immunoassays. Beyond any doubt, the immunoassays have provided an extensive insight into IGF-I physiology and pathophysiology. However, immunoassays ignore the presence of the IGFBPs, which are important regulators of IGF-I action in vivo. In addition, immunoassays do not consider the presence of IGF-II, which also interacts with the IGF-I receptor (IGF-IR). This aroused our interest to reintroduce the bioassay; therefore, we established a cell-based kinase receptor activation (KIRA) assay based on cells transfected with the human IGF-IR. The output signal of the KIRA assay is IGF-IR phosphorylation, and, as such, it is highly specific. Further, because detection of phosphorylated IGF-IRs is based on modern immunoassay techniques, the overall performance of the assay is close to that of a traditional IGF-I immunoassay. The first part of this review comprises a short description of the bioassay, and a more in-depth presentation of the data that have been obtained so far. It will be demonstrated that the bioassay is indeed able to yield novel information on the IGF system, most likely because it is able to integrate the different components of the IGF system into one signal: IGF-IR activation. As IGF-I, circulating GH is bound to larger proteins, the far most important GH-binding protein (GHBP) is identical to the extracellular domain of the GH receptor (GHR). Because of its origin, GHBP binds GH with the same affinity as GHR and, consequently, GHBP may affect GH bioactivity as well as pharmacokinetics. To improve our knowledge on the complex interaction between GH and GHBP in vivo, we found it of interest to develop a method for determination of free GH. To this end, we developed an ultrafiltration assay that enabled isolation of free GH in undiluted serum during approached in vivo-like conditions. The last part of this review presents our current data on free GH and its interaction with GHBP.
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Affiliation(s)
- J Frystyk
- Medical Research Laboratories, Institute of Clinical Medicine, Faculty of Health Sciences, Aarhus University and Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Nørrebrogade 44, DK-8000 Aarhus C, Denmark.
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Conover CA. Key questions and answers about pregnancy-associated plasma protein-A. Trends Endocrinol Metab 2012; 23:242-9. [PMID: 22463950 PMCID: PMC3348390 DOI: 10.1016/j.tem.2012.02.008] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 02/20/2012] [Accepted: 02/26/2012] [Indexed: 11/26/2022]
Abstract
Twenty-five years after it was identified as a circulating protein of unknown function derived from the placenta, pregnancy-associated plasma protein-A (PAPP-A) was discovered to be a novel zinc metalloproteinase expressed by a variety of cell types. Great progress has been made in understanding the biology of PAPP-A and its regulation during recent years, especially in regard to physiological and pathophysiological inflammatory injury responses. However, much remains to be learned about this complex protein and its potential clinical implications outside pregnancy. In this article we address some of the outstanding questions about PAPP-A, in particular about its newly emerging role in the insulin-like growth factor (IGF) system.
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Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology and Metabolism, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905, USA.
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Woelfle J, Roth CL, Wunsch R, Reinehr T. Pregnancy-associated plasma protein A in obese children: relationship to markers and risk factors of atherosclerosis and members of the IGF system. Eur J Endocrinol 2011; 165:613-22. [PMID: 21753069 DOI: 10.1530/eje-11-0423] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Pregnancy-associated plasma protein A (PAPPA) is a large placenta-derived glycoprotein, which serves as a protease of several IGF-binding proteins (IGFBPs). In non-pregnant adults, measurable PAPPA levels were detected and have been implicated in the pathophysiology of atherosclerotic plaques. However, data in children is lacking. OBJECTIVE To study the relationship between PAPPA, markers of atherosclerosis, and members of the IGF system in pediatric obesity. PATIENTS AND DESIGN Eighty-two obese and 52 nonobese children and 1-year longitudinal follow-up study for obese cohort. INTERVENTION Outpatient 1-year intervention program based on exercise, behavior, and nutrition therapy. MAIN OUTCOME MEASURES Changes in PAPPA levels, carotid intima media thickness (IMT), weight, blood pressure, lipids, metabolic markers, and members of IGF system. RESULTS Baseline PAPPA (PAPPA(BL)) serum levels did not differ between obese and lean subjects. PAPPA(BL) correlated significantly with IGF1, IGFBP1, and serum cholesterol. During the 1-year-program mean IMT decreased from 0.66 ± 0.01 to 0.63 ± 0.01 mm (P<0.05) and PAPPA from 1.83 ± 0.12 to 1.58 ± 0.11 μU/l (P<0.00). In linear regression analysis with IMT after intervention as dependent variable, PAPPA contributed significantly to the observed variance. The longitudinal change of PAPPA correlated significantly with the change of serum triglycerides. CONCLUSION In this cohort of obese children, PAPPA serum levels correlated significantly with other cardiovascular risk factors. The lack of a direct correlation between PAPPA and IMT suggests that the described association of atherosclerotic plaques and increased PAPPA levels might reflect an indirect mechanism of PAPPA with cardiovascular risk factors such as serum lipids rather than a direct effect on the vasculature.
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Affiliation(s)
- Joachim Woelfle
- Pediatric Endocrinology Division, Children's Hospital, University of Bonn, Adenauerallee 119, 53113 Bonn, Germany.
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Kamrava M, Gius D, Casagrande G, Kohn E. Will targeting insulin growth factor help us or hurt us?: An oncologist's perspective. Ageing Res Rev 2011; 10:62-70. [PMID: 19896561 PMCID: PMC2888889 DOI: 10.1016/j.arr.2009.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 10/22/2009] [Accepted: 10/28/2009] [Indexed: 12/17/2022]
Abstract
The insulin/insulin growth factor (IGF) pathway is a critical mediator of longevity and aging. Efforts to extend longevity by altering the insulin/IGF pathway may have varying effects on other physiological processes. Reduced insulin/IGF levels may decrease the incidence of certain cancers as well as the risk of developing metastatic disease. However, it may also increase the risk of developing cardiovascular disease as well as cardiovascular related mortality. Pursuing the right insulin/IGF pathway targets will require striking a balance between inhibiting cancer cell development and progression and avoiding damage to tissues under normal insulin/IGF-mediated control. This review will discuss the roles of the insulin/IGF pathway in aging and longevity and the development of cancer cell metastasis and considerations in taking insulin/IGF directed targets to the oncology clinic.
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Affiliation(s)
- Mitchell Kamrava
- Molecular Radiation Oncology Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute
| | - David Gius
- Molecular Radiation Oncology Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute
| | - Giovanna Casagrande
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute
| | - Elise Kohn
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute
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Abstract
Insulin-like growth factor-1 (IGF-1) plays a central role in cellular growth, differentiation, survival, and cell cycle progression. It is expressed early during development and its effects are mediated through binding to a tyrosine kinase receptor, the insulin-like growth factor-1 receptor (IGF-1R). In the circulation, the IGFs bind to IGF-binding proteins (IGFBPs), which determine their bioavailability and regulate the interaction between the IGFs and IGF-1R. Studies in animal models and in humans have established critical roles for IGFs in skeletal growth and development. In this review we present new and old findings from mouse models of the IGF system and discuss their clinical relevance to normal and pathological skeletal physiology.
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Affiliation(s)
- Shoshana Yakar
- Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA.
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Phang D, Rehage M, Bonafede B, Hou D, Xing W, Mohan S, Wergedal JE, Qin X. Inactivation of insulin-like-growth factors diminished the anabolic effects of pregnancy-associated plasma protein-A (PAPP-A) on bone in mice. Growth Horm IGF Res 2010; 20:192-200. [PMID: 20144555 DOI: 10.1016/j.ghir.2010.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 01/06/2010] [Accepted: 01/12/2010] [Indexed: 11/16/2022]
Abstract
In vivo studies have provided ubiquitous evidence that pregnancy-associated plasma protein-A (PAPP-A) functions as a potent anabolic factor. While some evidence supports the prediction that increasing IGF bioavailability contributes to the anabolic effects of PAPP-A, definitive evidence has been lacking. This important issue has been addressed in this study using a unique mouse model in which PAPP-A was overexpressed in bone either alone or together with a protease-resistant IGFBP-4 analog (PRBP-4) which serves as an IGF inhibitor. PAPP-A transgenic mice exhibited a 25% increase in skull bone mineral density (BMD) whereas PRBP-4 transgenic mice showed a 20-25% decrease in this parameter at an age of 3months. Femur/tibia size-related parameters were significantly increased in PAPP-A transgenic mice but decreased in PRBP-4 transgenic mice. This data clearly demonstrates that PAPP-A transgenic mice exhibit opposite phenotypes in both flat bone and long bone compared to PRBP-4 transgenic mice which have reduced IGF bioavailability in bone. Importantly, PRBP-4 and PRBP-4/PAPP-A double transgenic mice shared essentially identical phenotypes in both flat and long bones. Calvarial thickness, skull BMD and long bone parameters were reduced to similar degrees in PRBP-4 and PRBP-4/PAPP-A transgenic mice relative to wild-type littermates. Our findings provide compelling evidence that PAPP-A increases bone formation primarily by increasing IGF bioavailability and that other alternative pathways may play a negligible role in mediating the anabolic effect of PAPPA in bone. This clear definition of PAPP-A's mechanism of action is critical for future translational studies on the therapeutic application of PAPP-A.
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Affiliation(s)
- David Phang
- Musculoskeletal Disease Center, Loma Linda University, Loma Linda, CA 92354, United States
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Bartke A. Impact of reduced insulin-like growth factor-1/insulin signaling on aging in mammals: novel findings. Aging Cell 2008; 7:285-90. [PMID: 18346217 DOI: 10.1111/j.1474-9726.2008.00387.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Growth hormone deficiency or resistance resulting from spontaneous or experimentally produced mutations in laboratory mice delay aging and increase lifespan. Alterations in insulin-like growth factor-1 (IGF-1) and insulin signaling emerged as likely mechanisms linking growth hormone and aging, and increased longevity was reported in mice with selective deletion of IGF-1 receptor in all tissues or insulin receptor in fat. Recent studies in mice with reduced IGF-1 levels or deletion of pregnancy-associated plasma protein-A, a protease that cleaves one of the IGF-1 binding proteins, strongly support the role of IGF-1 in the control of longevity. Reports of increased lifespan in mice with deletion of insulin receptor substrate (IRS) 1, reduced expression of IRS2, or selective deletion of IRS2 in the brain specifically implicate the IRS-PI3K-Akt-Foxo signaling pathway (which is shared by IGF-1 and insulin) in the control of aging. These important novel findings also strengthen the evidence for evolutionary conservation of mechanisms regulating lifespan in worms, insects and mammals.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, School of Medicine, Southern Illinois University, Springfield, IL 62794-9628, USA.
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