1
|
Dinges SS, Amini K, Notarangelo LD, Delmonte OM. Primary and secondary defects of the thymus. Immunol Rev 2024; 322:178-211. [PMID: 38228406 PMCID: PMC10950553 DOI: 10.1111/imr.13306] [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] [Indexed: 01/18/2024]
Abstract
The thymus is the primary site of T-cell development, enabling generation, and selection of a diverse repertoire of T cells that recognize non-self, whilst remaining tolerant to self- antigens. Severe congenital disorders of thymic development (athymia) can be fatal if left untreated due to infections, and thymic tissue implantation is the only cure. While newborn screening for severe combined immune deficiency has allowed improved detection at birth of congenital athymia, thymic disorders acquired later in life are still underrecognized and assessing the quality of thymic function in such conditions remains a challenge. The thymus is sensitive to injury elicited from a variety of endogenous and exogenous factors, and its self-renewal capacity decreases with age. Secondary and age-related forms of thymic dysfunction may lead to an increased risk of infections, malignancy, and autoimmunity. Promising results have been obtained in preclinical models and clinical trials upon administration of soluble factors promoting thymic regeneration, but to date no therapy is approved for clinical use. In this review we provide a background on thymus development, function, and age-related involution. We discuss disease mechanisms, diagnostic, and therapeutic approaches for primary and secondary thymic defects.
Collapse
Affiliation(s)
- Sarah S. Dinges
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kayla Amini
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luigi D. Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ottavia M. Delmonte
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Conover CA, Bale LK. Senescence induces proteolytically-active PAPP-A secretion and association with extracellular vesicles in human pre-adipocytes. Exp Gerontol 2023; 172:112070. [PMID: 36549546 PMCID: PMC9868105 DOI: 10.1016/j.exger.2022.112070] [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: 09/26/2022] [Revised: 12/16/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Senescence is a cellular response to various stressors characterized by irreversible cell cycle arrest, resistance to apoptosis and expression of a senescence-associated secretory phenotype (SASP). Interestingly, studies where senescent cells were deleted in mice produced beneficial effects similar to those where the zinc metalloproteinase, PAPP-A, was deleted in mice. In this study, we investigated the effect of senescence on PAPP-A secretion and activity in primary cultures of adult human pre-adipocytes. Cultured pre-adipocytes were isolated from subcutaneous (Sub) and omental (Om) fat. Senescence was induced with low dose etoposide. PAPP-A protein was measured by an ultrasensitive PAPP-A ELISA. PAPP-A proteolytic activity was measured by a specific substrate cleavage assay. Senescence significantly increased PAPP-A levels in both Sub and Om conditioned medium (CM) 8- to 15-fold over non-senescent CM. Proteolytic activity reflected PAPP-A protein with 12- to 18-fold greater activity in senescent CM versus non-senescent CM. Furthermore, PAPP-A was found at high levels on the surface of extracellular vesicles secreted by senescent pre-adipocytes and was proteolytically active. In conclusion, we identified enzymatically active PAPP-A as a component of human pre-adipocyte SASP. This recognition warrants further investigation of PAPP-A as a new biomarker for senescence and a potential therapeutic target to control of the spread of senescence in adipose tissue.
Collapse
Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Metabolism and Nutrition, Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
| | - Laurie K Bale
- Division of Endocrinology, Metabolism and Nutrition, Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
| |
Collapse
|
4
|
Li X, Hager M, McPherson M, Lee M, Hagalwadi R, Skinner ME, Lombard D, Miller RA. Recapitulation of anti-aging phenotypes by global, but not by muscle-specific, deletion of PAPP-A in mice. GeroScience 2022; 45:931-948. [PMID: 36542300 PMCID: PMC9886707 DOI: 10.1007/s11357-022-00692-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022] Open
Abstract
Deletion of pregnancy-associated plasma protein-A (PAPP-A), a protease that cleaves some but not all IGF1 binding proteins, postpones late-life diseases and extends lifespan in mice, but the mechanism of this effect is unknown. Here we show that PAPP-A knockout (PKO) mice display a set of changes, in multiple tissues, that are characteristic of other varieties of slow-aging mice with alterations in GH production or GH responsiveness, including Ames dwarf, Snell dwarf, and GHRKO mice. PKO mice have elevated UCP1 in brown and white adipose tissues (WAT), and a change in fat-associated macrophage subsets that leads to diminished production of inflammatory cytokines. PKO mice also show increased levels of muscle FNDC5 and its cleavage product, the myokine irisin, thought to cause changes in fat cell differentiation. PKO mice have elevated production of hepatic GPLD1 and plasma GPLD1, consistent with their elevation of hippocampal BDNF and DCX, used as indices of neurogenesis. In contrast, disruption of PAPP-A limited to muscle ("muPKO" mice) produces an unexpectedly complex set of changes, in most cases opposite in direction from those seen in PKO mice. These include declines in WAT UCP1, increases in inflammatory macrophages and cytokines in WAT, and a decline in muscle FNDC5 and plasma irisin. muPKO mice do, however, resemble global PKO mice in their elevation of hippocampal BDNF and DCX. The data for the PKO mice support the idea that these changes in fat, macrophages, liver, muscle, plasma, and brain are consistent and biologically significant features of the slow-aging phenotype in mice. The results on the muPKO mice provide a foundation for further investigation of the complex, local, and global circuits by which PAPP-A modulates signals ordinarily controlled by GH and/or IGF1.
Collapse
Affiliation(s)
- Xinna Li
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, 48109, USA.
- , Ann Arbor, USA.
| | - Mary Hager
- College of Literature, Sciences, & the Arts, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Madaline McPherson
- College of Literature, Sciences, & the Arts, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Michael Lee
- College of Literature, Sciences, & the Arts, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Riha Hagalwadi
- College of Literature, Sciences, & the Arts, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mary E Skinner
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, 48109, USA
| | - David Lombard
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, 48109, USA
- Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Richard A Miller
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI, 48109, USA
- University of Michigan Geriatrics Center, Ann Arbor, MI, 48109, USA
| |
Collapse
|
5
|
Judge RA, Sridar J, Tunyasunvunakool K, Jain R, Wang JCK, Ouch C, Xu J, Mafi A, Nile AH, Remarcik C, Smith CL, Ghosh C, Xu C, Stoll V, Jumper J, Singh AH, Eaton D, Hao Q. Structure of the PAPP-A BP5 complex reveals mechanism of substrate recognition. Nat Commun 2022; 13:5500. [PMID: 36127359 PMCID: PMC9489782 DOI: 10.1038/s41467-022-33175-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 09/03/2022] [Indexed: 11/09/2022] Open
Abstract
Insulin-like growth factor (IGF) signaling is highly conserved and tightly regulated by proteases including Pregnancy-Associated Plasma Protein A (PAPP-A). PAPP-A and its paralog PAPP-A2 are metalloproteases that mediate IGF bioavailability through cleavage of IGF binding proteins (IGFBPs). Here, we present single-particle cryo-EM structures of the catalytically inactive mutant PAPP-A (E483A) in complex with a peptide from its substrate IGFBP5 (PAPP-ABP5) and also in its substrate-free form, by leveraging the power of AlphaFold to generate a high quality predicted model as a starting template. We show that PAPP-A is a flexible trans-dimer that binds IGFBP5 via a 25-amino acid anchor peptide which extends into the metalloprotease active site. This unique IGFBP5 anchor peptide that mediates the specific PAPP-A-IGFBP5 interaction is not found in other PAPP-A substrates. Additionally, we illustrate the critical role of the PAPP-A central domain as it mediates both IGFBP5 recognition and trans-dimerization. We further demonstrate that PAPP-A trans-dimer formation and distal inter-domain interactions are both required for efficient proteolysis of IGFBP4, but dispensable for IGFBP5 cleavage. Together the structural and biochemical studies reveal the mechanism of PAPP-A substrate binding and selectivity.
Collapse
Affiliation(s)
| | - Janani Sridar
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | - Rinku Jain
- AbbVie, 1 North Waukegan Road, North Chicago, IL, USA
| | - John C K Wang
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Christna Ouch
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jun Xu
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | - Aaron H Nile
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | | | - Crystal Ghosh
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Chen Xu
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Vincent Stoll
- AbbVie, 1 North Waukegan Road, North Chicago, IL, USA
| | | | - Amoolya H Singh
- Calico Life Sciences LLC, South San Francisco, CA, USA.,GRAIL, Menlo Park, CA, USA
| | - Dan Eaton
- Calico Life Sciences LLC, South San Francisco, CA, USA.
| | - Qi Hao
- Calico Life Sciences LLC, South San Francisco, CA, USA.
| |
Collapse
|
6
|
Therapeutics That Can Potentially Replicate or Augment the Anti-Aging Effects of Physical Exercise. Int J Mol Sci 2022; 23:ijms23179957. [PMID: 36077358 PMCID: PMC9456478 DOI: 10.3390/ijms23179957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 12/30/2022] Open
Abstract
Globally, better health care access and social conditions ensured a significant increase in the life expectancy of the population. There is, however, a clear increase in the incidence of age-related diseases which, besides affecting the social and economic sustainability of countries and regions around the globe, leads to a decrease in the individual’s quality of life. There is an urgent need for interventions that can reverse, or at least prevent and delay, the age-associated pathological deterioration. Within this line, this narrative review aims to assess updated evidence that explores the potential therapeutic targets that can mimic or complement the recognized anti-aging effects of physical exercise. We considered pertinent to review the anti-aging effects of the following drugs and supplements: Rapamycin and Rapamycin analogues (Rapalogs); Metformin; 2-deoxy-D-glucose; Somatostatin analogues; Pegvisomant; Trametinib; Spermidine; Fisetin; Quercetin; Navitoclax; TA-65; Resveratrol; Melatonin; Curcumin; Rhodiola rosea and Caffeine. The current scientific evidence on the anti-aging effect of these drugs and supplements is still scarce and no recommendation of their generalized use can be made at this stage. Further studies are warranted to determine which therapies display a geroprotective effect and are capable of emulating the benefits of physical exercise.
Collapse
|
7
|
Bale LK, West SA, Conover CA. Brain-specific PAPP-A knock-out mice? Exp Gerontol 2021; 154:111548. [PMID: 34509589 DOI: 10.1016/j.exger.2021.111548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/31/2021] [Accepted: 09/04/2021] [Indexed: 10/20/2022]
Abstract
PAPP-A knock-out (KO) mice are a valuable model for investigating the effects of down-regulating localized insulin-like growth factor (IGF) action, which has been shown to extend lifespan and healthspan when the PAPP-A gene is globally deleted. Based on previous mouse models of brain-specific reduction in IGF signaling associated with longevity, we sought to generate brain-specific PAPP-A KO mice and determine effects on metabolism and lifespan. Mice with the PAPP-A gene floxed (fPAPP-A) were crossed with Nestin promoter-driven Cre recombinase transgenic mice. This cross-breeding of mice for Nestin-Cre and mice with other floxed target alleles has been used extensively to investigate brain-specific effects. Our cross-breeding generated four genotypes for study: fPAPP-A/Nestin positive (brain-specific PAPP-A KO); fPAPP-A/Nestin negative (Control for floxed PAPP-A); WT/Nestin positive (Control for Nestin-Cre); WT/Nestin negative (Wild-type Control). The basic genotype screen of neonatal tail snip DNA clearly indicated PAPP-A gene status and the presence (pos) or absence (neg) of Nestin-Cre. We then determined tissue specificity of PAPP-A gene excision. We had expected fPAPP-A/pos mice to be relatively brain-specific for PAPP-A gene deletion and the controls (fPAPP-A/neg, WT/neg and WT/pos mice) to show no effect on PAPP-A expression in brain or other tissues. However, in fPAPP-A/neg mice we found evidence of PAPP-A excision in all tissues examined, i.e., in the presumed absence of Nestin-Cre, indicating germline recombination. We further found that fPAPP-A/pos mice showed near complete excision of the PAPP-A gene in brain, but some also showed germline recombination affecting all tissues tested. To determine if the level of excision indicated by tissue genotyping approximated PAPP-A mRNA expression, we performed RT-qPCR. fPAPP-A/pos mice that showed markedly decreased whole brain PAPP-A mRNA expression (~80%), with little or no effect on expression in the other tissues tested, were designated as "brain-specific" PAPP-A KO. fPAPP-A/pos mice that showed germline recombination had similar decreases in PAPP-A expression in brain but also showed 40-65% decreased PAPP-A mRNA expression in other tissues as well, which was especially striking in kidney, tibia, thymus and spleen. These were designated as "non-specific" PAPP-A KO mice. With unknown and unpredictable specificity until harvest, we chose to assess a surrogate marker of lifespan i.e., thymic involution, in 15- to 18-month-old fPAPP-A/pos and WT/pos mice, the latter an important control for a possible effect of Nestin-Cre per se. Diminished thymic involution as indicated by increased thymic weight (135%, P = 0.035) and decreased histological disruption was seen in "non-specific" PAPP-A KO mice, similar to what was previously reported in 18-month-old global PAPP-A KO mice. There was no significant difference between "brain-specific" PAPP-A KO and control mice. This study highlights the importance of thorough characterization of assumed tissue-specific mouse models and awareness of potential germline recombination for proper data interpretation.
Collapse
Affiliation(s)
- Laurie K Bale
- Division of Endocrinology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - Sally A West
- Division of Endocrinology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America
| | - Cheryl A Conover
- Division of Endocrinology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States of America.
| |
Collapse
|
8
|
Wu H, Li X, Zhou C, Yu Q, Ge S, Pan Z, Zhao Y, Xia S, Zhou X, Liu X, Wang H, Shao Q. Circulating mature dendritic cells homing to the thymus promote thymic epithelial cells involution via the Jagged1/Notch3 axis. Cell Death Discov 2021; 7:225. [PMID: 34462426 PMCID: PMC8404188 DOI: 10.1038/s41420-021-00619-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 11/24/2022] Open
Abstract
Multiple proinflammatory conditions, including chemotherapy, radiotherapy, transplant rejection, and microbial infections, have been identified to induce involution of the thymus. However, the underlying cellular and molecular mechanisms of these inflammatory conditions inducing apoptosis of thymic epithelial cells (TECs), the main components of the thymus, remain largely unknown. In the circulation, mature dendritic cells (mDCs), the predominant initiator of innate and adaptive immune response, can migrate into the thymus. Herein, we demonstrated that mDCs were able to directly inhibit TECs proliferation and induce their apoptosis by activating the Jagged1/Notch3 signaling pathway. Intrathymic injection of either mDCs or recombinant mouse Jagged1-human Fc fusion protein (rmJagged1-hFc) into mice resulted in acute atrophy of the thymus. Furthermore, DAPT, a γ-secretase inhibitor, reversed the effects induced by mDC or rmJagged1-hFc. These findings suggest that acute or aging-related thymus degeneration can be induced either by mass migration of circulating mDCs in a short period of time or by a few but constantly homing mDCs.
Collapse
Affiliation(s)
- Haojie Wu
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Xiaohan Li
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Chen Zhou
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Qihong Yu
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Shiyao Ge
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Zihui Pan
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Yangjing Zhao
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Sheng Xia
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Xiaoming Zhou
- Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Pathology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Xia Liu
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Hui Wang
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China.
| | - Qixiang Shao
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, P. R. China.
- Institute of Medical Genetics and Reproductive Immunity, School of Medical Science and Laboratory Medicine, Jiangsu College of Nursing, Huai'an, 223002, Jiangsu, P. R. China.
| |
Collapse
|
9
|
Hoffman RA, Huang S, Chalasani G, Vallejo AN. Disparate Recruitment and Retention of Plasmacytoid Dendritic Cells to The Small Intestinal Mucosa between Young and Aged Mice. Aging Dis 2021; 12:1183-1196. [PMID: 34341701 PMCID: PMC8279532 DOI: 10.14336/ad.2021.0119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/19/2021] [Indexed: 11/01/2022] Open
Abstract
Plasmacytoid dendritic cells (pDC), a highly specialized class of innate immune cells that serve as rapid sensors of danger signals in circulation or in lymphoid tissue are well studied. However, there remains knowledge gaps about age-dependent changes of pDC function in the intestinal mucosa. Here, we report that under homeostatic conditions, the proportion of pDC expressing C-C chemokine receptor 9 (CCR9) in the intestinal intraepithelial cell (iIEC) population is comparable between young (2-4 months) and aged (18-24 months) mice, but the absolute numbers of iIEC and pDC are significantly lower in aged mice. Employing the classic model of acute endotoxemia induced by lipopolysaccharide (LPS), we found a decrease in the proportion and absolute number of intraepithelial pDC in both young and aged mice despite the LPS-induced increased expression of the chemokine C-C ligand 25 (CCL25), the ligand of CCR9, in the intestinal mucosa of young mice. In adoptive transfer experiments, a significantly lower number of pDC was retained into the intestinal layer of aged host mice after LPS administration. This was associated with recoverable pDC numbers in the intestinal lumen. Furthermore, co-adoptive transfer of young and aged pDC into young hosts also showed significantly lower retention of aged pDC in the epithelial layer compared to the co-transferred young pDC. Collectively, these data show age-associated changes in mucosal CCL25 gene expression and in pDC number. These may underlie the reported inadequate responses to gastrointestinal pathogens during chronologic aging.
Collapse
Affiliation(s)
| | - Sulan Huang
- Department of Health Promotion and Development,
| | | | - Abbe N Vallejo
- Division of Pediatric Rheumatology, Department of Pediatrics, University of Pittsburgh,
- Division of Rheumatology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.
| |
Collapse
|
10
|
Winn BJ, Kersten RC. Teprotumumab: Interpreting the Clinical Trials in the Context of Thyroid Eye Disease Pathogenesis and Current Therapies. Ophthalmology 2021; 128:1627-1651. [PMID: 33930408 DOI: 10.1016/j.ophtha.2021.04.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 11/16/2022] Open
Abstract
Teprotumumab, a monoclonal antibody targeted against the insulin-like growth factor 1 (IGF-1) receptor, was recently approved by the United States Food and Drug Administration for the treatment of thyroid eye disease (TED). Phase 1 studies of teprotumumab for the treatment of malignancies demonstrated an acceptable safety profile but limited effectiveness. Basic research implicating the IGF-1 receptor on the CD-34+ orbital fibrocyte in the pathogenesis of TED renewed interest in the drug. Two multicenter, randomized, double-masked, clinical trials (phase 2 and 3) evaluated the efficacy of 8 infusions of teprotumumab every 3 weeks versus placebo in 170 patients with recent-onset active TED, as defined by a clinical activity score (CAS) of at least 4. Teprotumumab was superior to placebo for the primary efficacy end points in both studies: overall responder rate as defined by a reduction of 2 or more CAS points and a reduction of 2 mm or more in proptosis (69% vs. 20%; P < 0.001; phase 2 study) and proptosis responder rate as defined by a reduction of 2 mm or more in proptosis (83% vs. 10%; P < 0.001; phase 3 study). In both studies, treatment with teprotumumab compared with placebo achieved a significant mean reduction of proptosis (-3.0 mm vs. -0.3 mm, phase 2 study; -3.32 mm vs. -0.53 mm, phase 3 study) and CAS (-4.0 vs. -2.5, phase 2 study; -3.7 vs. -2.0, phase 3 study). Teprotumumab also resulted in a greater proportion of patients with a final CAS of 0 or 1, higher diplopia responder rate, and a larger improvement in the Graves' Ophthalmopathy Quality of Life overall score. More than half of patients (62%, phase 2 trial; 56%, phase 3 trial) who were primary end point responders maintained this response at 51 weeks after the last dose of therapy. The most common adverse events reported with teprotumumab included muscle spasms (25%), nausea (17%), alopecia (13%), diarrhea (13%), fatigue (10%), hearing impairment (10%), and hyperglycemia (8%). Teprotumumab is contraindicated for those with inflammatory bowel disease and who are pregnant. Although the current dosing regimen has proven effective for TED, dose-ranging studies including variable concentrations, infusion frequencies, and durations of teprotumumab therapy in the setting of TED have not been performed.
Collapse
Affiliation(s)
- Bryan J Winn
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California; Ophthalmology Section, Surgical Service, San Francisco Veterans Affairs Medical Center, San Francisco, California.
| | - Robert C Kersten
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California
| |
Collapse
|
11
|
Mohrin M, Liu J, Zavala‐Solorio J, Bhargava S, Maxwell Trumble J, Brito A, Hu D, Brooks D, Koukos G, Alabdulaaly L, Paw JS, Hake K, Kolumam G, Bouxsein ML, Baron R, Kutskova Y, Freund A. Inhibition of longevity regulator PAPP-A modulates tissue homeostasis via restraint of mesenchymal stromal cells. Aging Cell 2021; 20:e13313. [PMID: 33561324 PMCID: PMC7963332 DOI: 10.1111/acel.13313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/08/2020] [Accepted: 12/31/2020] [Indexed: 12/20/2022] Open
Abstract
Pregnancy‐associated plasma protein‐A (PAPP‐A) is a secreted metalloprotease that increases insulin‐like growth factor (IGF) availability by cleaving IGF‐binding proteins. Reduced IGF signaling extends longevity in multiple species, and consistent with this, PAPP‐A deletion extends lifespan and healthspan; however, the mechanism remains unclear. To clarify PAPP‐A’s role, we developed a PAPP‐A neutralizing antibody and treated adult mice with it. Transcriptomic profiling across tissues showed that anti‐PAPP‐A reduced IGF signaling and extracellular matrix (ECM) gene expression system wide. The greatest reduction in IGF signaling occurred in the bone marrow, where we found reduced bone, marrow adiposity, and myelopoiesis. These diverse effects led us to search for unifying mechanisms. We identified mesenchymal stromal cells (MSCs) as the source of PAPP‐A in bone marrow and primary responders to PAPP‐A inhibition. Mice treated with anti‐PAPP‐A had reduced IGF signaling in MSCs and dramatically decreased MSC number. As MSCs are (1) a major source of ECM and the progenitors of ECM‐producing fibroblasts, (2) the originating source of adult bone, (3) regulators of marrow adiposity, and (4) an essential component of the hematopoietic niche, our data suggest that PAPP‐A modulates bone marrow homeostasis by potentiating the number and activity of MSCs. We found that MSC‐like cells are the major source of PAPP‐A in other tissues also, suggesting that reduced MSC‐like cell activity drives the system‐wide reduction in ECM gene expression due to PAPP‐A inhibition. Dysregulated ECM production is associated with aging and drives age‐related diseases, and thus, this may be a mechanism by which PAPP‐A deficiency enhances longevity.
Collapse
Affiliation(s)
- Mary Mohrin
- Calico Life Sciences LLC South San Francisco CA USA
| | - Justin Liu
- Calico Life Sciences LLC South San Francisco CA USA
| | | | | | | | | | - Dorothy Hu
- Harvard School of Dental Medicine Boston MA USA
| | - Daniel Brooks
- Center for Advanced Orthopaedic Studies Beth Israel Deaconess Medical Center Boston MA USA
| | | | | | | | - Kayley Hake
- Calico Life Sciences LLC South San Francisco CA USA
| | | | - Mary L. Bouxsein
- Center for Advanced Orthopaedic Studies Beth Israel Deaconess Medical Center Boston MA USA
- Harvard Medical School Boston MA USA
| | - Roland Baron
- Harvard School of Dental Medicine Boston MA USA
- Harvard Medical School Boston MA USA
| | | | - Adam Freund
- Calico Life Sciences LLC South San Francisco CA USA
| |
Collapse
|
12
|
Jenkins EC, Brown SO, Germain D. The Multi-Faced Role of PAPP-A in Post-Partum Breast Cancer: IGF-Signaling is Only the Beginning. J Mammary Gland Biol Neoplasia 2020; 25:181-189. [PMID: 32901383 DOI: 10.1007/s10911-020-09456-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/24/2020] [Accepted: 09/03/2020] [Indexed: 12/12/2022] Open
Abstract
Insulin-like growth factor (IGF) signaling and control of local bioavailability of free IGF by the IGF binding proteins (IGFBP) are important regulators of both mammary development and breast cancer. A recent genome-wide association study (GWAS) identified small nucleotide polymorphisms that reduce the expression of IGFBP-5 as a risk factor of developing breast cancer. This observation suggests that genetic alterations leading to a decreased level of IGFBP-5 may also contribute to breast cancer. In the current review, we focus on Pregnancy-Associated Plasma Protein A (PAPP-A), a protease involved in the degradation of IGFBP-5. PAPP-A is overexpressed in the majority of breast cancers but its role in cancer has only begun to be explored. More specifically, this review aims at highlighting the role of post-partum involution in the oncogenic function of PAPP-A. Notably, we summarize recent studies indicating that PAPP-A plays a role not only in the degradation of IGFBP-5 but also in the deposition of collagen and activation of the collagen receptor discoidin 2 (DDR2) during post-partum involution. Finally, considering the immunosuppressive microenvironment of post-partum involution, we also discuss the unexpected finding made in Ewing Sarcoma that PAPP-A plays a role in immune evasion. While the immunosuppressive role of PAPP-A in breast cancer remains to be determined, collectively these studies highlight the multifaced role of PAPP-A in cancer that extends well beyond its effect on IGF-signaling.
Collapse
Affiliation(s)
- Edmund Charles Jenkins
- Department of Medicine, Division of Hematology/ Oncology, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY, 10029, USA
| | - Samantha O Brown
- Department of Medicine, Division of Hematology/ Oncology, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY, 10029, USA
| | - Doris Germain
- Department of Medicine, Division of Hematology/ Oncology, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY, 10029, USA.
| |
Collapse
|
13
|
Plausible Links Between Metabolic Networks, Stem Cells, and Longevity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1201:355-388. [PMID: 31898793 DOI: 10.1007/978-3-030-31206-0_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aging is an inevitable consequence of life, and all multicellular organisms undergo a decline in tissue and organ functions as they age. Several well-known risk factors, such as obesity, diabetes, and lack of physical activity that lead to the cardiovascular system, decline and impede the function of vital organs, ultimately limit overall life span. Over recent years, aging research has experienced an unparalleled growth, particularly with the discovery and recognition of genetic pathways and biochemical processes that control to some extent the rate of aging.In this chapter, we focus on several aspects of stem cell biology and aging, beginning with major cellular hallmarks of aging, endocrine regulation of aging and its impact on stem cell compartment, and mechanisms of increased longevity. We then discuss the role of epigenetic modifications associated with aging and provide an overview on a most recent search of antiaging modalities.
Collapse
|
14
|
Hjortebjerg R. IGFBP-4 and PAPP-A in normal physiology and disease. Growth Horm IGF Res 2018; 41:7-22. [PMID: 29864720 DOI: 10.1016/j.ghir.2018.05.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 05/15/2018] [Accepted: 05/29/2018] [Indexed: 02/07/2023]
Abstract
Insulin-like growth factor (IGF) binding protein-4 (IGFBP-4) is a modulator of the IGF system, exerting both inhibitory and stimulatory effects on IGF-induced cellular growth. IGFBP-4 is the principal substrate for the enzyme pregnancy-associated plasma protein-A (PAPP-A). Through IGF-dependent cleavage of IGFBP-4 in the vicinity of the IGF receptor, PAPP-A is able to increase IGF bioavailability and stimulate IGF-mediated growth. Recently, the stanniocalcins (STCs) were identified as novel inhibitors of PAPP-A proteolytic activity, hereby adding additional members to the seemingly endless list of proteins belonging to the IGF family. Our understanding of these proteins has advanced throughout recent years, and there is evidence to suggest that the role of IGFBP-4 and PAPP-A in defining the relationship between total IGF and IGF bioactivity can be linked to a number of pathological conditions. This review provides an overview of the experimental and clinical findings on the IGFBP-4/PAPP-A/STC axis as a regulator of IGF activity and examines the conundrum surrounding extrapolation of circulating concentrations to tissue action of these proteins. The primary focus will be on the biological significance of IGFBP-4 and PAPP-A in normal physiology and in pathophysiology with emphasis on metabolic disorders, cardiovascular diseases, and cancer. Finally, the review assesses current new trajectories of IGFBP-4 and PAPP-A research.
Collapse
Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark; The Danish Diabetes Academy, Odense, Denmark.
| |
Collapse
|
15
|
Bale LK, West SA, Conover CA. Inducible knockdown of pregnancy-associated plasma protein-A gene expression in adult female mice extends life span. Aging Cell 2017; 16:895-897. [PMID: 28600811 PMCID: PMC5506424 DOI: 10.1111/acel.12624] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2017] [Indexed: 01/01/2023] Open
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) knockout (KO) mice, generated through homologous recombination in embryonic stem cells, have a significantly increased lifespan compared to wild-type littermates. However, it is unknown whether this longevity advantage would pertain to PAPP-A gene deletion in adult animals. In the present study, we used tamoxifen (Tam)-inducible Cre recombinase-mediated excision of the floxed PAPP-A (fPAPP-A) gene in mice at 5 months of age. fPAPP-A mice, which were either positive (pos) or negative (neg) for Tam-Cre, received Tam treatment with quarterly boosters. Only female mice could be used with this experimental design. fPAPP-A/neg and fPAPP-A/pos mice had similar weights at the start of the experiment and showed equivalent weight gain. We found that fPAPP-A/pos mice had a significant extension of life span (P = 0.005). The median life span was increased by 21% for fPAPP-A/pos compared to fPAPP-A/neg mice. Analysis of mortality in life span quartiles indicated that the proportion of deaths of fPAPP-A/pos mice were lower than fPAPP-A/neg mice at young adult ages (P = 0.002 for 601-800 days) and higher than fPAPP-A/neg mice at older ages (P = 0.004 for >1000 days). Thus, survival curves and age-specific mortality indicate that female mice with knockdown of PAPP-A gene expression as adults have an extended healthy life span.
Collapse
Affiliation(s)
- Laurie K. Bale
- Endocrine Research UnitMayo Clinic200 First Street SWRochesterMN55905USA
| | - Sally A. West
- Endocrine Research UnitMayo Clinic200 First Street SWRochesterMN55905USA
| | - Cheryl A. Conover
- Endocrine Research UnitMayo Clinic200 First Street SWRochesterMN55905USA
| |
Collapse
|
16
|
Yu M, Wang J, Liu S, Wang X, Yan Q. Novel function of pregnancy-associated plasma protein A: promotes endometrium receptivity by up-regulating N-fucosylation. Sci Rep 2017; 7:5315. [PMID: 28706275 PMCID: PMC5509645 DOI: 10.1038/s41598-017-04735-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 05/19/2017] [Indexed: 12/27/2022] Open
Abstract
Glycosylation of uterine endometrial cells plays important roles to determine their receptive function to blastocysts. Trophoblast-derived pregnancy-associated plasma protein A (PAPPA) is specifically elevated in pregnant women serum, and is known to promote trophoblast cell proliferation and adhesion. However, the relationship between PAPPA and endometrium receptivity, as well as the regulation of N-fucosylation remains unclear. We found that rhPAPPA and PAPPA in the serum samples from pregnant women or conditioned medium of trophoblast cells promoted endometrium receptivity in vitro. Moreover, rhPAPPA increased α1,2-, α1,3- and α1,6-fucosylation levels by up-regulating N-fucosyltransferases FUT1, FUT4 and FUT8 expression, respectively, through IGF-1R/PI3K/Akt signaling pathway in human endometrial cells. Additionally, α1,2-, α1,3- and α1,6-fucosylation of integrin αVβ3, a critical endometrium receptivity biomarker, was up-regulated by PAPPA, thereby enhanced its adhesive functions. Furthermore, PAPPA blockage with antibody inhibited embryo implantation in vivo, mouse embryo adhesion and spreading in vitro, as well as N-fucosylation level of the endometrium in pregnant mice. In summary, this study suggests that PAPPA is essential to maintain a receptive endometrium by up-regulating N-fucosylation, which is a potential useful biomarker to evaluate the receptive functions of the endometrium.
Collapse
Affiliation(s)
- Ming Yu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, 116044, China
| | - Jiao Wang
- Departmentof Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116023, China
| | - Shuai Liu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, 116044, China
| | - Xiaoqi Wang
- Departmentof Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Qiu Yan
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, 116044, China.
| |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
| | - Claus Oxvig
- Department of Molecular Biology and Genetics; Aarhus Universitet; Aarhus Denmark
| |
Collapse
|
18
|
Modeling the development of the post-natal mouse thymus in the absence of bone marrow progenitors. Sci Rep 2016; 6:36159. [PMID: 27824070 PMCID: PMC5099910 DOI: 10.1038/srep36159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 10/04/2016] [Indexed: 01/01/2023] Open
Abstract
Many mathematical models have been published with the purpose of explaining aspects of T-cell development in the thymus. In this manuscript we adapted a four-compartment model of the thymus and used a range of mathematical approaches with the aim of explaining the dynamics of the four main thymocyte populations in the mouse thymus, from the emergence of the first fetal thymocyte until the death of the animal. At various pre-natal and post-natal stages we investigated experimentally the number and composition of thymocytes populations, their apoptosis and proliferation, along with data from literature, to create and validate the model. In our model the proliferation processes are characterized by decreasing proliferation rates, which allows us to model the natural involution of the thymus. The best results were obtained when different sets of parameters were used for the fetal and post-natal periods, suggesting that birth may induce a discontinuity in the modeled processes. Our model is able to model the development of both pre-natal and post-natal thymocyte populations. Also, our findings showed that the post-natal thymus is able to develop in the absence of the daily input of bone marrow progenitors, providing more evidence to support the autonomous development of the post-natal thymus.
Collapse
|
19
|
Holder A, Mella S, Palmer DB, Aspinall R, Catchpole B. An Age-Associated Decline in Thymic Output Differs in Dog Breeds According to Their Longevity. PLoS One 2016; 11:e0165968. [PMID: 27824893 PMCID: PMC5100965 DOI: 10.1371/journal.pone.0165968] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/20/2016] [Indexed: 01/08/2023] Open
Abstract
The age associated decline in immune function is preceded in mammals by a reduction in thymic output. Furthermore, there is increasing evidence of a link between immune competence and lifespan. One approach to determining thymic output is to quantify signal joint T cell receptor excision circles (sj-TRECs), a method which has been developed and used in several mammalian species. Life expectancy and the rate of aging vary in dogs depending upon their breed. In this study, we quantified sj-TRECs in blood samples from dogs of selected breeds to determine whether there was a relationship between longevity and thymic output. In Labrador retrievers, a breed with a median expected lifespan of 11 years, there was an age-associated decline in sj-TREC values, with the greatest decline occurring before 5 years of age, but with sj-TREC still detectable in some geriatric animals, over 13 years of age. In large short-lived breeds (Burnese mountain dogs, Great Danes and Dogue de Bordeaux), the decline in sj-TREC values began earlier in life, compared with small long-lived breeds (Jack Russell terriers and Yorkshire terriers), and the presence of animals with undetectable sj-TRECs occurred at a younger age in the short-lived breeds. The study findings suggest that age-associated changes in canine sj-TRECs are related to breed differences in longevity, and this research highlights the use of dogs as a potential model of immunosenescence.
Collapse
Affiliation(s)
- Angela Holder
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | - Stephanie Mella
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | - Donald B. Palmer
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Richard Aspinall
- Health and Wellbeing Academy, Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford, Essex, United Kingdom
| | - Brian Catchpole
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| |
Collapse
|
20
|
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]
|
21
|
Abstract
As the primary site of T-cell development, the thymus plays a key role in the generation of a strong yet self-tolerant adaptive immune response, essential in the face of the potential threat from pathogens or neoplasia. As the importance of the role of the thymus has grown, so too has the understanding that it is extremely sensitive to both acute and chronic injury. The thymus undergoes rapid degeneration following a range of toxic insults, and also involutes as part of the aging process, albeit at a faster rate than many other tissues. The thymus is, however, capable of regenerating, restoring its function to a degree. Potential mechanisms for this endogenous thymic regeneration include keratinocyte growth factor (KGF) signaling, and a more recently described pathway in which innate lymphoid cells produce interleukin-22 (IL-22) in response to loss of double positive thymocytes and upregulation of IL-23 by dendritic cells. Endogenous repair is unable to fully restore the thymus, particularly in the aged population, and this paves the way toward the need for exogenous strategies to help regenerate or even replace thymic function. Therapies currently in clinical trials include KGF, use of the cytokines IL-7 and IL-22, and hormonal modulation including growth hormone administration and sex steroid inhibition. Further novel strategies are emerging in the preclinical setting, including the use of precursor T cells and thymus bioengineering. The use of such strategies offers hope that for many patients, the next regeneration of their thymus is a step closer.
Collapse
Affiliation(s)
- Mohammed S Chaudhry
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Enrico Velardi
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jarrod A Dudakov
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Marcel R M van den Brink
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY, USA
| |
Collapse
|
22
|
Metabolic Damage and Premature Thymus Aging Caused by Stromal Catalase Deficiency. Cell Rep 2015; 12:1071-9. [PMID: 26257169 PMCID: PMC4797338 DOI: 10.1016/j.celrep.2015.07.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 11/30/2022] Open
Abstract
T lymphocytes are essential mediators of immunity that are produced by the thymus in proportion to its size. The thymus atrophies rapidly with age, resulting in progressive diminution of new T cell production. This decreased output is compensated by duplication of existing T cells, but it results in gradual dominance by memory T cells and decreased ability to respond to new pathogens or vaccines. Here, we show that accelerated and irreversible thymic atrophy results from stromal deficiency in the reducing enzyme catalase, leading to increased damage by hydrogen peroxide generated by aerobic metabolism. Genetic complementation of catalase in stromal cells diminished atrophy, as did chemical antioxidants, thus providing a mechanistic link between antioxidants, metabolism, and normal immune function. We propose that irreversible thymic atrophy represents a conventional aging process that is accelerated by stromal catalase deficiency in the context of an intensely anabolic (lymphoid) environment.
Collapse
|
23
|
Sharples AP, Hughes DC, Deane CS, Saini A, Selman C, Stewart CE. Longevity and skeletal muscle mass: the role of IGF signalling, the sirtuins, dietary restriction and protein intake. Aging Cell 2015; 14:511-23. [PMID: 25866088 PMCID: PMC4531066 DOI: 10.1111/acel.12342] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2015] [Indexed: 12/11/2022] Open
Abstract
Advancing age is associated with a progressive loss of skeletal muscle (SkM) mass and function. Given the worldwide aging demographics, this is a major contributor to morbidity, escalating socio-economic costs and ultimately mortality. Previously, it has been established that a decrease in regenerative capacity in addition to SkM loss with age coincides with suppression of insulin/insulin-like growth factor signalling pathways. However, genetic or pharmacological modulations of these highly conserved pathways have been observed to significantly enhance life and healthspan in various species, including mammals. This therefore provides a controversial paradigm in which reduced regenerative capacity of skeletal muscle tissue with age potentially promotes longevity of the organism. This paradox will be assessed and considered in the light of the following: (i) the genetic knockout, overexpression and pharmacological models that induce lifespan extension (e.g. IRS-1/s6K KO, mTOR inhibition) versus the important role of these signalling pathways in SkM growth and adaptation; (ii) the role of the sirtuins (SIRTs) in longevity versus their emerging role in SkM regeneration and survival under catabolic stress; (iii) the role of dietary restriction and its impact on longevity versus skeletal muscle mass regulation; (iv) the crosstalk between cellular energy metabolism (AMPK/TSC2/SIRT1) and survival (FOXO) versus growth and repair of SkM (e.g. AMPK vs. mTOR); and (v) the impact of protein feeding in combination with dietary restriction will be discussed as a potential intervention to maintain SkM mass while increasing longevity and enabling healthy aging.
Collapse
Affiliation(s)
- Adam P. Sharples
- Stem Cells, Ageing & Molecular Physiology Unit; Research Institute for Sport and Exercise Sciences (RISES); Exercise Metabolism and Adaptation Research Group (EMARG); Liverpool John Moores University; Tom Reilly Building Liverpool L3 3AF UK
| | - David C. Hughes
- Stem Cells, Ageing & Molecular Physiology Unit; Research Institute for Sport and Exercise Sciences (RISES); Exercise Metabolism and Adaptation Research Group (EMARG); Liverpool John Moores University; Tom Reilly Building Liverpool L3 3AF UK
- Department of Neurobiology, Physiology and Behavior; University of California; Davis California CA 95616 USA
| | - Colleen S. Deane
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research; School of Medicine; University of Nottingham; Royal Derby Hospital; Derby DE22 3DT UK
- School of Health and Social Care; Bournemouth University; Bournemouth BH12 5BB UK
| | - Amarjit Saini
- Department of Physiology and Pharmacology; Karolinska Institutet; Stockholm 171 77 Sweden
| | - Colin Selman
- Glasgow Ageing Research Network (GARNER); Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medicine, Veterinary and Life Sciences; University of Glasgow; Glasgow G12 8QQ UK
| | - Claire E. Stewart
- Stem Cells, Ageing & Molecular Physiology Unit; Research Institute for Sport and Exercise Sciences (RISES); Exercise Metabolism and Adaptation Research Group (EMARG); Liverpool John Moores University; Tom Reilly Building Liverpool L3 3AF UK
| |
Collapse
|
24
|
Zhou S, Cui M, Yin Z, Li R, Zhu J, Zhou H. Correlation of single nucleotide polymorphisms in the pregnancy-associated plasma protein-A gene with carotid plaques. BMC Cardiovasc Disord 2015; 15:60. [PMID: 26122709 PMCID: PMC4485363 DOI: 10.1186/s12872-015-0041-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 05/22/2015] [Indexed: 01/28/2023] Open
Abstract
Background Pregnancy-associated plasma protein A (PAPP-A) is abundantly expressed in carotid plaques. This study investigated the association between single nucleotide polymorphisms (SNPs) of PAPP-A and the presence of carotid plaques. Methods A total of 408 patients with carotid plaques and 493 controls were included in the study. All subjects were Southern Chinese Han. Carotid plaques were analyzed by computer tomography angiography. PAPP-A SNPs were identified by ligase detection reaction-polymerase chain reaction analysis. The PAPP-A genotypes rs3747823, rs7020782, and rs13290387 were analyzed. Results The rs7020782 C allele genotype correlated with an increased risk of developing carotid plaques under the dominant, recessive, and additive models (adjusted odds ratios: 2.60, 2.36, and 3.48, respectively; P ≤ 0.001). Only C allele-carrying genotypes correlated with a significantly increased risk of carotid plaque based on studies stratified by age and sex under the dominant model. rs7020782 remained significantly associated with the risk of carotid plaque calcification after adjusting for age and potential confounders (adjusted odds ratio, 1.89; 95 % confidence interval, 1.17–3.08; P = 0.010). Conclusions This study found, for the first time, that the A˃C variation of rs7020782 might be an independent risk factor for carotid plaque development and calcification. The determination of such genotypes could provide a new tool for identifying individuals at high risk for carotid atherosclerosis. Electronic supplementary material The online version of this article (doi:10.1186/s12872-015-0041-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Shiming Zhou
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| | - Min Cui
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| | - Zegang Yin
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| | - Rui Li
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| | - Jie Zhu
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| | - Huadong Zhou
- Department of Neurology, Daping Hospital, Third Military Medical University, No. 10 Changjiang Branch Road, Daping, Chongqing, 400042, China.
| |
Collapse
|
25
|
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.
Collapse
|
26
|
Tissue-specific changes in pregnancy associated plasma protein-A expression with age in mice. Exp Gerontol 2014; 57:13-7. [PMID: 24815423 DOI: 10.1016/j.exger.2014.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/17/2014] [Accepted: 04/21/2014] [Indexed: 11/20/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) is a novel zinc metalloproteinase that functions in many systems outside of pregnancy. Data in both humans and mice suggest a role for PAPP-A in aging and age-related diseases. However, our knowledge of tissue-specific PAPP-A expression and possible changes in this expression with age is limited. Thus, the aim of this study was to determine PAPP-A mRNA expression in multiple tissues with age in both male and female mice using real-time PCR. These included the heart, liver, kidney, bone, fat, skeletal muscle, gonads, brain, thymus and spleen. In young mice, PAPP-A mRNA was expressed at relatively high levels in all tissues examined except for liver. The only difference in expression between males and females was seen in the kidney, subcutaneous fat and gonads. The highest PAPP-A mRNA expression levels were found in visceral fat and these were 10-fold higher than in subcutaneous fat. PAPP-A expression significantly increased with age in kidney, brain and gonads. PAPP-A expression significantly deceased with age in bone and skeletal muscle. In the thymus, PAPP-A mRNA showed a biphasic response with age. There were no age-related changes in PAPP-A expression seen in any of the other tissues examined. Expression of IGFBP-5 mRNA, a marker of insulin-like growth factor-I (IGF-I) bioactivity known to be regulated by PAPP-A, paralleled the changes in PAPP-A expression with age in kidney, bone, skeletal muscle and thymus. Thus, tissue-specific PAPP-A expression in mice is differentially affected during aging, and may regulate local IGF-I bioactivity in certain tissues.
Collapse
|
27
|
Bale LK, Chakraborty S, Conover CA. Inducible reduction in pregnancy-associated plasma protein-A gene expression inhibits established atherosclerotic plaque progression in mice. Endocrinology 2014; 155:1184-7. [PMID: 24506074 PMCID: PMC3959602 DOI: 10.1210/en.2013-2110] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) is a novel zinc metalloproteinase implicated in cardiovascular disease. The aim of this study was to determine whether a reduction in PAPP-A expression in the adult affects the progression of established atherosclerotic plaque. Apolipoprotein E-null mice were fed a high-fat diet for 5 weeks to initiate early-stage plaque development before tamoxifen-inducible, Cre recombinase-mediated excision of the floxed PAPP-A gene. High-fat feeding was continued, and after 10 weeks the aorta and brachiocephalic artery were harvested for atherosclerotic plaque analyses of overall burden and morphology, respectively. An inducible decrease in PAPP-A gene expression significantly inhibited atherosclerotic plaque progression as assessed by a 70% reduction in plaque burden in the aorta (P = .012) without an effect on the elevated circulating levels of cholesterol and triglycerides in this model. Furthermore, this reduction in PAPP-A prevented the development of advanced plaque with necrotic cores and buried fibrous caps in the brachiocephalic artery. These data indicate PAPP-A as a potential target to limit progression of established atherosclerotic plaque.
Collapse
Affiliation(s)
- Laurie K Bale
- Division of Endocrinology, Diabetes, Metabolism and Nutrition, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905
| | | | | |
Collapse
|
28
|
Conover CA, Bale LK, Powell DR. Inducible knock out of pregnancy-associated plasma protein-a gene expression in the adult mouse: effect on vascular injury response. Endocrinology 2013; 154:2734-8. [PMID: 23748359 PMCID: PMC3713220 DOI: 10.1210/en.2013-1320] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pregnancy-associated plasma protein-A (PAPP-A) enhances local IGF signaling through its ability to proteolyze inhibitory IGF binding proteins. In vivo, PAPP-A (like IGF) appears to exhibit antagonistic pleiotropy; ie, it has beneficial effects early in life but detrimental effects later in life. Accordingly, PAPP-A knockout (KO) mice are born as proportional dwarfs and have diminished reproductive vigor and reduced peak bone mass acquisition at puberty. On the other hand, PAPP-A KO mice live approximately 30% longer than their wild-type littermates, with decreased incidence and severity of age-related diseases and resistance to adverse responses of vascular injury. To be able to distinguish the impact of PAPP-A deficiency in the adult from that in early life, we developed a mouse model suitable for inducible Cre recombinase-mediated excision of the PAPP-A gene. In this study, we characterize the conditional PAPP-A KO mouse model for efficacy of tamoxifen-induced floxed PAPP-A excision in various tissues of adult mice and demonstrate a significant (P = .0001) reduction of neointimal formation in these mice after unilateral carotid artery ligation.
Collapse
Affiliation(s)
- Cheryl A Conover
- The Endocrine Research Unit, Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA.
| | | | | |
Collapse
|
29
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
30
|
Impact of immune-metabolic interactions on age-related thymic demise and T cell senescence. Semin Immunol 2012; 24:321-30. [DOI: 10.1016/j.smim.2012.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 03/29/2012] [Accepted: 04/09/2012] [Indexed: 01/13/2023]
|
31
|
Conover CA. Role of PAPP-A in aging and age-related disease. Exp Gerontol 2012; 48:612-3. [PMID: 22790018 DOI: 10.1016/j.exger.2012.06.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 06/18/2012] [Accepted: 06/20/2012] [Indexed: 11/28/2022]
Abstract
As suggested by its name, pregnancy-associated plasma protein-A (PAPP-A) plays an important role in pregnancy and fetal development (Brizot et al., 1996; Lin et al., 1974; Smith et al., 2002). On the opposite end of life's spectrum, recent studies using genetically-engineered mice indicate a newly recognized role for PAPP-A in aging and in the development of age-related disease. These latter studies will be reviewed in this article.
Collapse
Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Metabolism and Nutrition, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
32
|
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.
Collapse
Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology and Metabolism, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
33
|
Li Q, Kobayashi M, Inagaki H, Hirata Y, Hirata K, Shimizu T, Wang RS, Suda M, Kawamoto T, Nakajima T, Kawada T. Effects of subchronic inhalation exposure to ethyl tertiary butyl ether on splenocytes in mice. Int J Immunopathol Pharmacol 2012; 24:837-47. [PMID: 22230391 DOI: 10.1177/039463201102400403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ethyl tertiary-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. The current use of ETBE in gasoline or petrol is modest but increasing. To investigate the effects of ETBE on splenocytes, mice were exposed to 0 (control), 500 ppm, 1750 ppm, or 5000 ppm of ETBE by inhalation for 6 h/day for 5 days/wk over a 6- or 13-week period. Splenocytes were harvested from the control and exposed mice, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (PerCP-Cy5.5-CD45R/B220), (2) T cells (PerCP-Cy5-CD3e), (3) T cell subsets (FITC-CD4 and PE-CD8a), (4) natural killer (NK) cells (PE-NK1.1), and (5) macrophages (FITC-CD11b). Body weight and the weight of the spleen were also examined. ETBE-exposure did not affect the weight of the spleen or body weight, while it transiently increased the number of RBC and the Hb concentration. The numbers of splenic CD3+, CD4+, and CD8+ T cells, the percentage of CD4+ T cells and the CD4+/CD8+ T cell ratio in the ETBE-exposed groups were significantly decreased in a dose-dependent manner. However, ETBE exposure did not affect the numbers of splenic NK cells, B cells, or macrophages or the total number of splenocytes. The above findings indicate that ETBE selectively affects the number of splenic T cells in mice.
Collapse
Affiliation(s)
- Q Li
- Department of Hygiene and Public Health, Nippon Medical School, Tokyo.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Griffin P, Michel JJ, Huysman K, Logar AJ, Vallejo AN. Integration of immunity with physical and cognitive function in definitions of successful aging. Aging Dis 2012; 3:34-50. [PMID: 22500270 PMCID: PMC3320803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 02/27/2012] [Accepted: 02/27/2012] [Indexed: 05/31/2023] Open
Abstract
Studies comparing chronologically "young" versus "old" humans document age-related decline of classical immunological functions. However, older adults aged ≥65 years have very heterogeneous health phenotypes. A significant number of them are functionally independent and are surviving well into their 8(th)-11(th) decade life, observations indicating that aging or old age is not synonymous with immune incompetence. While there are dramatic age-related changes in the immune system, not all of these changes may be considered detrimental. Here, we review evidences for novel immunologic processes that become elaborated with advancing age that complement preserved classical immune functions and promote immune homeostasis later in life. We propose that elaboration such of late life immunologic properties is indicative of beneficial immune remodeling that is an integral component of successful aging, an emerging physiologic construct associated with similar age-related physiologic adaptations underlying maintenance of physical and cognitive function. We suggest that a systems approach integrating immune, physical, and cognitive functions, rather than a strict immunodeficiency-minded approach, will be key towards innovations in clinical interventions to better promote protective immunity and functional independence among the elderly.
Collapse
Affiliation(s)
- Patricia Griffin
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Joshua J. Michel
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Kristy Huysman
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Alison J. Logar
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Abbe N. Vallejo
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
- Department of Immunology, the Pittsburgh Cancer Institute, and the McGowan Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| |
Collapse
|
35
|
Cortina ME, Litwin S, Roux ME, Miranda S. Impact of mouse pregnancy on thymic T lymphocyte subsets. Reprod Fertil Dev 2012; 24:1123-33. [DOI: 10.1071/rd11252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 02/28/2012] [Indexed: 11/23/2022] Open
Abstract
It has been reported that fetal lymphoid progenitor cells are acquired during gestation and are able to develop in the maternal mouse thymus into functional T cells. Moreover, previous pregnancies increase the number of fetal cells in the mother. In the present study, we investigated whether mouse pregnancy induces changes in T lymphocyte subsets in the maternal thymus. We determined the T lymphocyte subsets in two allogeneic cross-breedings, namely CBA/J × BALB/c (normal) and CBA/J × DBA/2 (abortion prone), and investigated the effects of the age and parity of the female, as well as pregnancy outcome, on thymocyte populations. In addition, hormonal effects were evaluated in a syngeneic combination (CBA/J × CBA/J). We found that during pregnancy both hormonal and allogeneic stimuli induced a reduction in the CD4+CD8+ subset with an increase in the CD4+CD8– population. Only young females of the normal combination exhibited an increase in the CD4–CD8+ population. All young mice showed an increase in CD4+CD25+FoxP3+ T cells. Interestingly, the γδT thymus pool was increased in all females of the normal allogeneic pregnancy only, suggesting the participation of this pool in the observed beneficial effect of multiparity in this cross-breeding. Our results demonstrate that allogeneic pregnancies induce important variations in maternal thymocyte subpopulations depending on the age of the female and the male component of the cross-breeding.
Collapse
|
36
|
Chen HC, Lee YS, Sieber M, Lu HT, Wei PC, Wang CN, Peng HH, Chao AS, Cheng PJ, Chang SD, Chen SJ, Wang TH. MicroRNA and messenger RNA analyses of mesenchymal stem cells derived from teeth and the Wharton jelly of umbilical cord. Stem Cells Dev 2011; 21:911-22. [PMID: 21732813 DOI: 10.1089/scd.2011.0186] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Microarray analyses of transcriptomes have been used to characterize mesenchymal stem cells (MSCs) of various origins. MicroRNAs (miRNAs) are short, nonprotein-coding RNAs involved in post-transcriptional gene inhibition in a variety of tissues, including cancer cells and MSCs. This study has integrated the use of miRNA and mRNA expression profiles to analyze human MSCs derived from Wharton's jelly (WJ) of the umbilical cord, milk teeth (MT), and adult wisdom teeth (AT). Because both miRNA and mRNA expression in MT and AT MSCs were so similar, they were combined together as tooth MSCs for comparison with WJ MSCs. Twenty-five genes that were up-regulated in tooth MSCs and 41 genes that were up-regulated in WJ MSCs were identified by cross-correlating miRNA and mRNA profiles. Functional network analysis show that tooth MSCs signature genes, represented by SATB2 and TNFRSF11B, are involved in ossification, bone development, and actin cytoskeleton organization. In addition, 2 upregulated genes of tooth MSCs-NEDD4 and EMP1-have been shown to be involved in neuroectodermal differentiation. The signature genes of WJ MSCs, represented by KAL1 and PAPPA, are involved in tissue development, regulation of cell differentiation, and bone morphogenetic protein signaling pathways. In conclusion, the combined interrogation of miRNA and mRNA expression profiles in this study proved useful in extracting reliable results from a genome-wide comparison of multiple types of MSCs. Subsequent functional network analysis provided further functional insights about these MSCs.
Collapse
Affiliation(s)
- Hua-Chien Chen
- Department of Biomedical Sciences, Chang Gung University, Tao-Yuan, Taiwan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Selman C, Withers DJ. Mammalian models of extended healthy lifespan. Philos Trans R Soc Lond B Biol Sci 2011; 366:99-107. [PMID: 21115536 PMCID: PMC3001304 DOI: 10.1098/rstb.2010.0243] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Over the last two centuries, there has been a significant increase in average lifespan expectancy in the developed world. One unambiguous clinical implication of getting older is the risk of experiencing age-related diseases including various cancers, dementia, type-2 diabetes, cataracts and osteoporosis. Historically, the ageing process and its consequences were thought to be intractable. However, over the last two decades or so, a wealth of empirical data has been generated which demonstrates that longevity in model organisms can be extended through the manipulation of individual genes. In particular, many pathological conditions associated with the ageing process in model organisms, and importantly conserved from nematodes to humans, are attenuated in long-lived genetic mutants. For example, several long-lived genetic mouse models show attenuation in age-related cognitive decline, adiposity, cancer and glucose intolerance. Therefore, these long-lived mice enjoy a longer period without suffering the various sequelae of ageing. The greatest challenge in the biology of ageing is to now identify the mechanisms underlying increased healthy lifespan in these model organisms. Given that the elderly are making up an increasingly greater proportion of society, this focused approach in model organisms should help identify tractable interventions that can ultimately be translated to humans.
Collapse
Affiliation(s)
- Colin Selman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | | |
Collapse
|
38
|
Allard JB, Duan C. Comparative endocrinology of aging and longevity regulation. Front Endocrinol (Lausanne) 2011; 2:75. [PMID: 22654825 PMCID: PMC3356063 DOI: 10.3389/fendo.2011.00075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 10/28/2011] [Indexed: 01/06/2023] Open
Abstract
Hormones regulate growth, development, metabolism, and other complex processes in multicellular animals. For many years it has been suggested that hormones may also influence the rate of the aging process. Aging is a multifactorial process that causes biological systems to break down and cease to function in adult organisms as time passes, eventually leading to death. The exact underlying causes of the aging process remain a topic for debate, and clues that may shed light on these causes are eagerly sought after. In the last two decades, gene mutations that result in delayed aging and extended longevity have been discovered, and many of the affected genes have been components of endocrine signaling pathways. In this review we summarize the current knowledge on the roles of endocrine signaling in the regulation of aging and longevity in various animals. We begin by discussing the notion that conserved systems, including endocrine signaling pathways, "regulate" the aging process. Findings from the major model organisms: worms, flies, and rodents, are then outlined. Unique lessons from studies of non-traditional models: bees, salmon, and naked mole rats, are also discussed. Finally, we summarize the endocrinology of aging in humans, including changes in hormone levels with age, and the involvement of hormones in aging-related diseases. The most well studied and widely conserved endocrine pathway that affects aging is the insulin/insulin-like growth factor system. Mutations in genes of this pathway increase the lifespan of worms, flies, and mice. Population genetic evidence also suggests this pathway's involvement in human aging. Other hormones including steroids have been linked to aging only in a subset of the models studied. Because of the value of comparative studies, it is suggested that the aging field could benefit from adoption of additional model organisms.
Collapse
Affiliation(s)
- John B. Allard
- Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, USA
| | - Cunming Duan
- Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, USA
- *Correspondence: Cunming Duan, Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Natural Science Building, Ann Arbor, MI 48109, USA. e-mail:
| |
Collapse
|
39
|
Abstract
This article focuses on the role of PAPP-A in mammalian aging. It introduces PAPP-A and a little of its history, briefly discusses the function of PAPP-A in the insulin-like growth factor (IGF) system and the regulators of PAPP-A expression, and then reviews data concerning PAPP-A in aging and age-related diseases especially in regard to the PAPP-A knockout (KO) mouse. The PAPP-A KO mouse is a valuable new model to test hypotheses concerning the control of the tissue availability of IGF, independent from systemic levels, on healthspan as well as lifespan.
Collapse
Affiliation(s)
- Cheryl A Conover
- Division of Endocrinology, Metabolism, and Nutrition, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
40
|
Thymic fatness and approaches to enhance thymopoietic fitness in aging. Curr Opin Immunol 2010; 22:521-8. [PMID: 20650623 DOI: 10.1016/j.coi.2010.06.010] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 06/18/2010] [Accepted: 06/29/2010] [Indexed: 12/19/2022]
Abstract
With advancing age, the thymus undergoes striking fibrotic and fatty changes that culminate in its transformation into adipose tissue. As the thymus involutes, reduction in thymocytes and thymic epithelial cells precede the emergence of mature lipid-laden adipocytes. Dogma dictates that adipocytes are 'passive' cells that occupy non-epithelial thymic space or 'infiltrate' the non-cellular thymic niches. The provenance and purpose of ectopic thymic adipocytes during aging in an organ that is required for establishment and maintenance of T cell repertoire remains an unsolved puzzle. Nonetheless, tantalizing clues about elaborate reciprocal relationship between thymic fatness and thymopoietic fitness are emerging. Blocking or bypassing the route toward thymic adiposity may complement the approaches to rejuvenate thymopoiesis and immunity in elderly.
Collapse
|
41
|
Chen YF, Wu CY, Kao CH, Tsai TF. Longevity and lifespan control in mammals: lessons from the mouse. Ageing Res Rev 2010; 9 Suppl 1:S28-35. [PMID: 20667513 DOI: 10.1016/j.arr.2010.07.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 07/14/2010] [Indexed: 01/18/2023]
Abstract
Aging, which affects all organ systems, is one of the most complex phenotypes. Recent discoveries in long-lived mutant mice have revealed molecular mechanisms of longevity in mammals which may contribute to our understanding of why humans age. These mutations include naturally occurring spontaneous mutations, and those of mice genetically modified by modern genomic technologies. It is generally believed that the most fundamental mechanisms of aging are evolutionarily conserved across species. The following types of longevity mechanisms have been intensively studied: suppression of the somatotropic (growth hormone/insulin-like growth factor 1) axis, decreased metabolism and increased resistance of oxidative stress, reduced insulin secretion and increased insulin sensitivity, and delayed reproductive maturation and reduced fertility. In addition, many of the mutations have a sex-dependent effect on lifespan, and when present in different genetic backgrounds, the effects of the same gene mutation can vary considerably. The present review discusses these phenotypic variations as well as describing the known longevity genes in long-lived mutant mice and the molecular mechanisms specifying longevity. We anticipate that these mouse studies will ultimately provide clues about how to delay the aging and prolong lifespan, and help to develop therapies for healthier human aging.
Collapse
Affiliation(s)
- Yi-Fan Chen
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, 155 Li-Nong St, Sec 2, Peitou, Taipei 112, Taiwan
| | | | | | | |
Collapse
|
42
|
Abstract
Insulin-like growth factor I (IGF-I) belongs to an ancient family of hormones already present in early invertebrates. The insulin family is well characterized in mammals, although new members have been described recently. Since its characterization over 50 years ago, IGF-I has been considered a peptide mostly involved in the control of body growth and tissue remodeling. Currently, its most prominent recognized role is as a quasi-universal cytoprotectant. This role connects IGF-I with regulation of lifespan and with cancer, two areas of very active research in relation to this peptide. In the brain, IGF-I was formerly considered a neurotrophic factor involved in brain growth, as many other neurotrophic factors. Other aspects of the neurobiology of IGF-I are gradually emerging and suggest that this growth factor has a prominent role in brain function as a whole. During development IGF-I is abundantly expressed in many areas, whereas once the brain is formed its expression is restricted to a few regions and in very low quantities. However, the adult brain appears to have an external input from serum IGF-I, where this anabolic peptide is abundant. Thus, serum IGF-I has been proven to be an important modulator of brain activity, including higher functions such as cognition. Many of these functions can be ascribed to its tissue-remodeling activity as IGF-I modulates adult neurogenesis and angiogenesis. Other activities are cytoprotective; indeed, IGF-I can be considered a key neuroprotective peptide. Still others pertain to the functional characteristics of brain cells, such as cell excitability. Through modulation of membrane channels and neurotransmission, IGF-I impinges directly on neuronal plasticity, the cellular substrate of cognition. However, to fully understand the role of IGF-I in the brain, we have to sum the actions of locally produced IGF-I to those of serum IGF-I, and this is still pending. Thus, an integrated view of the role played by IGF-I in the brain is not yet possible. An operational approach to overcome this limitation would be to consider IGF-I as a signal coupling environmental influences on body metabolism with brain function. Or in a more colloquial way, we may say that IGF-I links body "fitness" with brain fitness, providing a mechanism to the roman saying "mens sana in corpore sano."
Collapse
|
43
|
Holländer GA, Krenger W, Blazar BR. Emerging strategies to boost thymic function. Curr Opin Pharmacol 2010; 10:443-53. [PMID: 20447867 DOI: 10.1016/j.coph.2010.04.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 04/06/2010] [Accepted: 04/06/2010] [Indexed: 11/28/2022]
Abstract
The thymus constitutes the primary lymphoid organ for the generation of T cells. Its function is particularly susceptible to various negative influences ranging from age-related involution to atrophy as a consequence of malnutrition, infection or harmful iatrogenic influences such as chemotherapy and radiation. The loss of regular thymus function significantly increases the risk for infections and cancer because of a restricted capacity for immune surveillance. In recent years, thymus-stimulatory, thymus-regenerative, and thymus-protective strategies have been developed to enhance and repair thymus function in the elderly and in individuals undergoing hematopoietic stem cell transplantation. These strategies include the use of sex steroid ablation, the administration of growth and differentiation factors, the inhibition of p53, and the transfer of T cell progenitors to alleviate the effects of thymus dysfunction and consequent T cell deficiency.
Collapse
Affiliation(s)
- Georg A Holländer
- Laboratory of Pediatric Immunology, Department of Biomedicine, University of Basel, The University Children's Hospital (UKBB), Mattenstrasse 28, 4058 Basel, Switzerland.
| | | | | |
Collapse
|
44
|
Conover CA, Bale LK, Mader JR, Mason MA, Keenan KP, Marler RJ. Longevity and age-related pathology of mice deficient in pregnancy-associated plasma protein-A. J Gerontol A Biol Sci Med Sci 2010; 65:590-9. [PMID: 20351075 DOI: 10.1093/gerona/glq032] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The pregnancy-associated plasma protein-A knockout (PAPP-A KO) mouse is a model of reduced local insulin-like growth factor (IGF)-I activity with normal circulating IGF-I levels. In this study, PAPP-A KO mice had significantly increased mean (27%), median (27%), and maximum (35%) life span compared with wild-type (WT) littermates. End-of-life pathology indicated that the incidence of neoplastic disease was not significantly different in the two groups of mice; however, it occurred in older aged PAPP-A KO compared with WT mice. Furthermore, PAPP-A KO mice were less likely to show degenerative changes of age. Scheduled pathologies at 78, 104, and 130 weeks of age indicated that WT mice, in general, had more degenerative changes and tumors earlier than PAPP-A KO mice. This was particularly true for abnormalities in heart, testes, brain, kidney, spleen, and thymus. In summary, the major contributors to the extended life span of PAPP-A KO mice are delayed occurrence of fatal neoplasias and decreased incidence of age-related degenerative changes.
Collapse
Affiliation(s)
- Cheryl A Conover
- The Division of Endocrinology and Metabolism, Department of Medicine, Mayo Clinic, 200 First Street SW, 5-194 Joseph, Rochester, MN 55905, USA.
| | | | | | | | | | | |
Collapse
|
45
|
Newman AB, Walter S, Lunetta KL, Garcia ME, Slagboom PE, Christensen K, Arnold AM, Aspelund T, Aulchenko YS, Benjamin EJ, Christiansen L, D'Agostino RB, Fitzpatrick AL, Franceschini N, Glazer NL, Gudnason V, Hofman A, Kaplan R, Karasik D, Kelly-Hayes M, Kiel DP, Launer LJ, Marciante KD, Massaro JM, Miljkovic I, Nalls MA, Hernandez D, Psaty BM, Rivadeneira F, Rotter J, Seshadri S, Smith AV, Taylor KD, Tiemeier H, Uh HW, Uitterlinden AG, Vaupel JW, Walston J, Westendorp RGJ, Harris TB, Lumley T, van Duijn CM, Murabito JM. A meta-analysis of four genome-wide association studies of survival to age 90 years or older: the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. J Gerontol A Biol Sci Med Sci 2010; 65:478-87. [PMID: 20304771 DOI: 10.1093/gerona/glq028] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Genome-wide association studies (GWAS) may yield insights into longevity. METHODS We performed a meta-analysis of GWAS in Caucasians from four prospective cohort studies: the Age, Gene/Environment Susceptibility-Reykjavik Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Longevity was defined as survival to age 90 years or older (n = 1,836); the comparison group comprised cohort members who died between the ages of 55 and 80 years (n = 1,955). In a second discovery stage, additional genotyping was conducted in the Leiden Longevity Study cohort and the Danish 1905 cohort. RESULTS There were 273 single-nucleotide polymorphism (SNP) associations with p < .0001, but none reached the prespecified significance level of 5 x 10(-8). Of the most significant SNPs, 24 were independent signals, and 16 of these SNPs were successfully genotyped in the second discovery stage, with one association for rs9664222, reaching 6.77 x 10(-7) for the combined meta-analysis of CHARGE and the stage 2 cohorts. The SNP lies in a region near MINPP1 (chromosome 10), a well-conserved gene involved in regulation of cellular proliferation. The minor allele was associated with lower odds of survival past age 90 (odds ratio = 0.82). Associations of interest in a homologue of the longevity assurance gene (LASS3) and PAPPA2 were not strengthened in the second stage. CONCLUSION Survival studies of larger size or more extreme or specific phenotypes may support or refine these initial findings.
Collapse
Affiliation(s)
- Anne B Newman
- Department of Epidemiology, Graduate School of Public Health, 130 North Bellefield Avenue, Suite 500, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Swindell WR, Masternak MM, Bartke A. In vivo analysis of gene expression in long-lived mice lacking the pregnancy-associated plasma protein A (PappA) gene. Exp Gerontol 2010; 45:366-74. [PMID: 20197085 DOI: 10.1016/j.exger.2010.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/16/2010] [Accepted: 02/18/2010] [Indexed: 01/15/2023]
Abstract
Mice lacking the pregnancy-associated plasma protein A (PappA) gene exhibit diminished localized IGF-1 bioavailability and a 30% increase in mean life span. However, it is uncertain which tissues exhibit reduced IGF-1 signals in the PappA(-/-) mouse, and whether effects of this mutation parallel those of mutations that diminish IGF-1 in serum. Across a panel of 21 tissues, we used RT-PCR to evaluate the effects of the PappA(-/-) mutation on expression of Igfbp5, which served as an in vivo indicator of IGF-1 signaling. Among these tissues, expression of Igfbp5 was significantly reduced by PappA(-/-) only in kidney. A broader survey of IGF-associated genes in six organs identified five other genes responsive to PappA(-/-) in kidney, with stronger effects in this organ relative to other tissues. Renal expression of Irs1 and Mt1 was increased by PappA(-/-) as well as by mutations that reduce IGF-1 in serum (i.e., Ghr(-/-), Pit1(dw/dw) and Prop1(df/df)), and we demonstrate that expression of these genes is regulated by growth hormone-treatment and calorie restriction. These results provide in vivo data on an important new model of mammalian aging, and characterize both similar and contrasting expression patterns between long-lived mice with reduced local IGF-1 availability and diminished IGF-1 in serum.
Collapse
Affiliation(s)
- William R Swindell
- University of Michigan, Department of Pathology and Geriatrics Center, Ann Arbor, MI 48109-2200, USA.
| | | | | |
Collapse
|
47
|
Chen JH, Tarry-Adkins JL, Heppolette CAA, Palmer DB, Ozanne SE. Early-life nutrition influences thymic growth in male mice that may be related to the regulation of longevity. Clin Sci (Lond) 2009; 118:429-38. [PMID: 19874273 DOI: 10.1042/cs20090429] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nutrition and growth rate during early life can influence later health and lifespan. We have demonstrated previously that low birthweight, resulting from maternal protein restriction during pregnancy followed by catch-up growth in rodents, was associated with shortened lifespan, whereas protein restriction and slow growth during lactation increased lifespan. The underlying mechanisms by which these differences arise are unknown. In the present study, we report that maternal protein restriction in mice influences thymic growth in early adult life. Offspring of dams fed a low-protein diet during lactation (PLP offspring) had significant thymic growth from 21 days to 12 weeks of age, whereas this was not observed in control mice or offspring of dams fed a low-protein diet during pregnancy (recuperated offspring). PCNA (proliferating-cell nuclear antigen) and SIRT1 (silent information regulator 1) protein levels at 21 days of age were significantly higher in the thymus from both PLP mice (P<0.001 and P<0.05 respectively) and recuperated mice (P<0.001 and P<0.01 respectively) compared with controls. At 12 weeks, PLP mice maintained a higher SIRT1 level, whereas PCNA was decreased in the thymus from recuperated offspring. This suggests that mitotic activity was initially enhanced in the thymus from both PLP and recuperated offspring, but remained sustained into adulthood only in PLP mice. The differential mitotic activity in the thymus from PLP and recuperated mice appeared to be influenced by changes in sex hormone concentrations and the expression of p53, p16, the androgen receptor, IL-7 (interleukin-7) and the IL-7 receptor. In conclusion, differential thymic growth may contribute to the regulation of longevity by maternal diet.
Collapse
Affiliation(s)
- Jian-Hua Chen
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, U.K.
| | | | | | | | | |
Collapse
|
48
|
Swindell WR. Genes and gene expression modules associated with caloric restriction and aging in the laboratory mouse. BMC Genomics 2009; 10:585. [PMID: 19968875 PMCID: PMC2795771 DOI: 10.1186/1471-2164-10-585] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 12/07/2009] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Caloric restriction (CR) counters deleterious effects of aging and, for most mouse genotypes, increases mean and maximum lifespan. Previous analyses of microarray data have identified gene expression responses to CR that are shared among multiple mouse tissues, including the activation of anti-oxidant, tumor suppressor and anti-inflammatory pathways. These analyses have provided useful research directions, but have been restricted to a limited number of tissues, and have focused on individual genes, rather than whole-genome transcriptional networks. Furthermore, CR is thought to oppose age-associated gene expression patterns, but detailed statistical investigations of this hypothesis have not been carried out. RESULTS Systemic effects of CR and aging were identified by examining transcriptional responses to CR in 17 mouse tissue types, as well as responses to aging in 22 tissues. CR broadly induced the expression of genes known to inhibit oxidative stress (e.g., Mt1, Mt2), inflammation (e.g., Nfkbia, Timp3) and tumorigenesis (e.g., Txnip, Zbtb16). Additionally, a network-based investigation revealed that CR regulates a large co-expression module containing genes associated with the metabolism and splicing of mRNA (e.g., Cpsf6, Sfpq, Sfrs18). The effects of aging were, to a considerable degree, similar among groups of co-expressed genes. Age-related gene expression patterns characteristic of most mouse tissues were identified, including up regulation of granulin (Grn) and secreted phosphoprotein 1 (Spp1). The transcriptional association between CR and aging varied at different levels of analysis. With respect to gene subsets associated with certain biological processes (e.g., immunity and inflammation), CR opposed age-associated expression patterns. However, among all genes, global transcriptional effects of CR were only weakly related to those of aging. CONCLUSION The study of aging, and of interventions thought to combat aging, has much to gain from data-driven and unbiased genomic investigations. Expression patterns identified in this analysis characterize a generalized response of mammalian cells to CR and/or aging. These patterns may be of importance in determining effects of CR on overall lifespan, or as factors that underlie age-related disease. The association between CR and aging warrants further study, but most evidence indicates that CR does not induce a genome-wide "reversal" of age-associated gene expression patterns.
Collapse
Affiliation(s)
- William R Swindell
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
| |
Collapse
|