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Swegen A, Grupen CG, Gibb Z, Baker MA, Ruijter‐Villani M, Smith ND, Stout TAE, Aitken RJ. From Peptide Masses to Pregnancy Maintenance: A Comprehensive Proteomic Analysis of The Early Equine Embryo Secretome, Blastocoel Fluid, and Capsule. Proteomics 2017; 17. [DOI: 10.1002/pmic.201600433] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 07/19/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Aleona Swegen
- Priority Research Centre in Reproductive Science University of Newcastle Callaghan NSW Australia
| | - Christopher G. Grupen
- Faculty of Veterinary Science School of Life and Environmental Sciences University of Sydney Camden NSW Australia
| | - Zamira Gibb
- Priority Research Centre in Reproductive Science University of Newcastle Callaghan NSW Australia
| | - Mark A. Baker
- Priority Research Centre in Reproductive Science University of Newcastle Callaghan NSW Australia
| | - Marta Ruijter‐Villani
- Department of Equine Sciences Faculty of Veterinary Medicine Utrecht University Utrecht the Netherlands
| | - Nathan D. Smith
- Analytical and Biomolecular Research Facility University of Newcastle Callaghan NSW Australia
| | - Tom A. E. Stout
- Department of Equine Sciences Faculty of Veterinary Medicine Utrecht University Utrecht the Netherlands
| | - R. John Aitken
- Priority Research Centre in Reproductive Science University of Newcastle Callaghan NSW Australia
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Storm T, Christensen EI, Christensen JN, Kjaergaard T, Uldbjerg N, Larsen A, Honoré B, Madsen M. Megalin Is Predominantly Observed in Vesicular Structures in First and Third Trimester Cytotrophoblasts of the Human Placenta. J Histochem Cytochem 2016; 64:769-784. [PMID: 27798286 DOI: 10.1369/0022155416672210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/30/2016] [Indexed: 12/31/2022] Open
Abstract
The membrane receptor megalin is crucial for normal fetal development. Besides its expression in the developing fetus, megalin is also expressed in the human placenta. Similar to its established function in the kidney proximal tubules, placental megalin has been proposed to mediate uptake of vital nutrients. However, details of megalin expression, subcellular localization, and function in the human placenta remain to be established. By immunohistochemical analyses of first trimester and term human placenta, we showed that megalin is predominantly expressed in cytotrophoblasts, the highly proliferative cells in placenta. Only limited amounts of megalin could be detected in syncytiotrophoblasts and least in term placenta syncytiotrophoblasts. Immunocytochemical analyses furthermore showed that placental megalin associates with structures of the endolysosomal apparatus. Combined, our results clearly place placental megalin in the context of endocytosis and trafficking of ligands. However, due to the limited expression of megalin in syncytiotrophoblasts, especially in term placenta, it appears that the main role for placental megalin is not to mediate uptake of nutrients from the maternal bloodstream, as previously proposed. In contrast, our results point toward novel and complex functions for megalin in the cytotrophoblasts. Thus, we propose that the perception of placental megalin localization and function should be revised.
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Affiliation(s)
- Tina Storm
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
| | - Erik I Christensen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
| | - Julie Nelly Christensen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
| | - Tine Kjaergaard
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
| | - Niels Uldbjerg
- Department of Clinical Medicine-Obstetrics and Gynaecology, Aarhus University Hospital, Skejby, Denmark (NU)
| | - Agnete Larsen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
| | - Bent Honoré
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark (TS, EIC, JNC, TK, AL, BH, MM)
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Wyatt AR, Cater JH, Ranson M. PZP and PAI-2: Structurally-diverse, functionally similar pregnancy proteins? Int J Biochem Cell Biol 2016; 79:113-117. [PMID: 27554634 DOI: 10.1016/j.biocel.2016.08.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 01/30/2023]
Abstract
Pregnancy zone protein (PZP) and plasminogen activator inhibitor type 2 (PAI-2) are two multifunctional proteins that are elevated in normal pregnancy and numerous other inflammatory states. Both proteins were originally identified as protease inhibitors, but current evidence supports the notion that they may also function as modulators of T-helper cells and/or extracellular chaperones. Exacerbated inflammation, fibrinolytic disturbances and misfolded proteins are all implicated in the pathology of preeclampsia, a leading cause of maternal and foetal mortality and morbidity. Notably, reduced levels of PZP or PAI-2 are associated with preeclampsia and clarification of their diverse functions in normal pregnancy could provide much needed insight regarding the pathogenesis of this disorder. Given that inflammation and protein misfolding underlie the pathology of a very large number of disorders, the contributions of PZP and PAI-2 to extracellular proteostasis and immunoregulation could be broad-reaching.
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Affiliation(s)
- Amy R Wyatt
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522, Australia; School of Biological Sciences, University of Wollongong, Wollongong 2522, Australia
| | - Jordan H Cater
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522, Australia; School of Biological Sciences, University of Wollongong, Wollongong 2522, Australia
| | - Marie Ranson
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522, Australia; School of Biological Sciences, University of Wollongong, Wollongong 2522, Australia.
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4
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Gilardoni MB, Ceschin DG, Sahores MM, Oviedo M, Gehrau RC, Chiabrando GA. Decreased Expression of the Low-density Lipoprotein Receptor-related Protein-1 (LRP-1) in Rats with Prostate Cancer. J Histochem Cytochem 2016; 51:1575-80. [PMID: 14623925 DOI: 10.1177/002215540305101201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of this work was to evaluate by immunohistochemistry (IHC) the expression of both LRP-1 and urokinase-type plasminogen activator receptor (uPAR) at different developmental stages of rat prostate disease by using a prostate cancer model previously developed in our laboratory. We found that LRP-1 was weakly expressed in normal prostates and in rats with hyperplastic glands. The expression of this receptor increased and correlated with the degree of premalignant lesions (PIN I, II, and III). The IHC for uPAR in normal prostates and in premalignant lesions showed a score of immunostaining that correlated with the expression of LRP-1. On the other hand, in prostates with adenocarcinomas and undifferentiated carcinomas, LRP-1 was undetectable or weakly detected, whereas uPAR showed a significantly higher level of expression. Based on the IHC results in rat prostates with premalignant and malignant lesions and considering that LRP-1, by mediating the internalization of uPAR, is involved in the regulation of extracellular matrix remodeling and cell migration, we conclude that a decreased expression of LRP-1 could be involved with the increasing activation of plasminogen activators shown in cancers.
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Affiliation(s)
- Mónica B Gilardoni
- Departamento de Bioquímica Clínica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Cao C, Pressman EK, Cooper EM, Guillet R, Westerman M, O'Brien KO. Placental heme receptor LRP1 correlates with the heme exporter FLVCR1 and neonatal iron status. Reproduction 2014; 148:295-302. [PMID: 24947444 DOI: 10.1530/rep-14-0053] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
LDL receptor-related protein 1 (LRP1) is a transmembrane receptor highly expressed in human placenta. It was recently found to be the receptor for heme and its plasma-binding protein hemopexin (Hx) and is integral to systemic heme clearance. Little is known about systemic concentrations of Hx during pregnancy and whether maternal Hx and placental LRP1 contributes to fetal iron (Fe) homeostasis during pregnancy. We hypothesized that placental LRP1 would be upregulated in maternal/neonatal Fe insufficiency and would be related to maternal circulating Hx. Placental LRP1 expression was assessed in 57 pregnant adolescents (14-18 years) in relationship with maternal and cord blood Fe status indicators (hemoglobin (Hb), serum ferritin, transferrin receptor), the Fe regulatory hormone hepcidin and serum Hx. Hx at mid-gestation correlated positively with Hb at mid-gestation (r=0.35, P=0.02) and Hx at delivery correlated positively with cord hepcidin (r=0.37, P=0.005). Placental LRP1 protein expression was significantly higher in women who exhibited greater decreases in serum Hx from mid-gestation to term (r=0.28, P=0.04). Significant associations were also found between placental LRP1 protein with cord hepcidin (r=-0.29, P=0.03) and placental heme exporter feline leukemia virus C receptor 1 (r=0.34, P=0.03). Our data are consistent with a role for placental heme Fe utilization in supporting fetal Fe demands.
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Affiliation(s)
- Chang Cao
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
| | - Eva K Pressman
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
| | - Elizabeth M Cooper
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
| | - Ronnie Guillet
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
| | - Mark Westerman
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
| | - Kimberly O O'Brien
- Division of Nutritional SciencesCornell University, 230 Savage Hall, Ithaca, New York 14853, USASchool of MedicineUniversity of Rochester, Rochester, New York, USAIntrinsic LifeSciencesLa Jolla, California, USA
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Saunders RD, Nakajima ST, Rai SN, Pan J, Gercel-Taylor C, Taylor DD. Alterations in antibody subclass immune reactivity to trophoblast-derived fetal fibronectin and α2-macroglobulin in women with recurrent pregnancy loss. Am J Reprod Immunol 2012; 68:438-49. [PMID: 22935024 DOI: 10.1111/j.1600-0897.2012.01182.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 07/02/2012] [Indexed: 11/26/2022] Open
Abstract
PROBLEM Increasing evidence supports the involvement of complex antibody-mediated immunologic events at the decidua-trophoblast interface. Our objective is to define the humoral immune responses of pregnant women with a history of recurrent pregnancy loss (RPL) compared with gestation-age-matched and non-pregnant controls in terms of trophoblast-derived antigenic targets and IgG subclasses. METHOD OF STUDY Immunoprecipitation and Western immunoblotting were performed to characterize IgG subclass reactivity to Sw.71 trophoblast-derived fetal fibronectin and alpha-2-macroglobulin, using serum obtained from first-trimester pregnant RPL subjects, gestation-age-matched controls, and non-pregnant controls. RESULTS Using a generalized linear model, sera from women with a history of RPL exhibited increased IgG(3) immunoreactivity to trophoblast-derived fetal fibronectin and alpha-2-macroglobulin compared with controls (P < 0.001 and P < 0.001, respectively). CONCLUSION IgG(3) reactivity in women with RPL may play a significant role in aberrant immune-regulatory mechanisms in early pregnancy. Further investigations into the role of autoantibodies against trophoblast-derived proteins in implantation and pregnancy are warranted.
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Affiliation(s)
- Rhiana D Saunders
- Department of Obstetrics, Gynecology, and Women's Health, University of Louisville, KY, USA.
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Ludvigsen M, Jacobsen C, Maunsbach AB, Honoré B. Identification and characterization of novel ERC-55 interacting proteins: Evidence for the existence of several ERC-55 splicing variants; including the cytosolic ERC-55-C. Proteomics 2009; 9:5267-87. [DOI: 10.1002/pmic.200900321] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Barrera DI, Matheus LM, Stigbrand T, Arbeláez LF. Proteolytic hydrolysis and purification of the LRP/alfa-2-macroglobulin receptor domain from α-macroglobulins. Protein Expr Purif 2007; 53:112-8. [PMID: 17257854 DOI: 10.1016/j.pep.2006.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Revised: 12/06/2006] [Accepted: 12/08/2006] [Indexed: 10/23/2022]
Abstract
A new, easier and efficient purification method, using Sephacryl and DEAE-Sephacel, of the C-terminal fragment of two alpha-macroglobulins, alpha(2)-M and PZP, is presented. Two larger peptides were identified for each protein as the C-terminal fragment, with molecular weights of approximately 30 kDa and the N-terminal sequences were determined to be SSTQDTV for alpha(2)-M and VALHLS for PZP. The smaller peptides with molecular weights of 18 kDa correspond to a shorter C-terminal sequence of these proteins, and they were determined to be EEFPFA for alpha(2)-M and ALKVQTV for PZP, with no interfering sequences detected. The results confirmed the discriminatory capacity of the purification procedure and the purity of the fragments. This new methodology facilitates biological studies of alpha-macroglobulins, and will enable elucidation of the role the C-terminal region may exert to eliminate alpha-macroglobulin-proteinases complexes from the circulation by the LRP/receptor.
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Affiliation(s)
- Daniel Iván Barrera
- Grupo de Investigación en Biomoléculas, Universidad de Pamplona, Pamplona, Colombia
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Shimizu M, Jinbo T, Kashiwazaki N, Kuribayashi T, Nomura M, Yamamoto S. Transplacental transport of alpha 2-macroglobulin (alpha 2M) and induction of alpha 2M in maternal and neonatal rats with acute inflammation. Exp Anim 2002; 51:361-5. [PMID: 12221929 DOI: 10.1538/expanim.51.361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The aims of this study were to investigate transplacental transport of alpha 2-macroglobulin (alpha 2M) in rats in rats and to examine the degree of alpha 2M induction in maternal and neonatal rats with acute inflammation. Serum was collected from healthy pregnant CD (IGS) rats, neonates of the pregnant rats and their cord blood. Additional serum samples were obtained from pregnant rats inoculated with an inflammatory agent, turpentine oil, their neonates and cord blood, and neonates inoculated with turpentine oil. The serum levels of alpha 2M were measured by means of an enzyme-linked immunosorbent assay. The average serum levels of alpha 2M in healthy neonates and cord blood were about 380 micrograms/ml. Serum a2M level in neonates inoculated with turpentine oil averaged about 580 micrograms/ml. Serum alpha 2M levels in maternal rats inoculated with turpentine oil, neonates from those rats and their cord blood were elevated, the values being 2,000 micrograms/ml or higher. It was demonstrated that induction of alpha 2M in neonatal rats was lower than in maternal rats when inoculated with turpentine oil. These results suggest that alpha 2M is transplacentally transported from maternal rats to fetal ones.
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Affiliation(s)
- Makoto Shimizu
- Laboratory of Immunology, College of Environmental and Health Sciences, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan
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Chiabrando GA, Vides MA, Sánchez MC. Differential binding properties of human pregnancy zone protein- and alpha2-macroglobulin-proteinase complexes to low-density lipoprotein receptor-related protein. Arch Biochem Biophys 2002; 398:73-8. [PMID: 11811950 DOI: 10.1006/abbi.2001.2659] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human pregnancy zone protein (PZP) is a major pregnancy-associated plasma protein strongly related to alpha2-macroglobulin (alpha2-M). Both alpha-macroglobulins (alpha-Ms) covalently bind proteinases, which is accompanied by the exposure of carboxy terminal receptor recognition domains important for the rapid clearance from the circulation and tissues. It is accepted that the molecule responsible for the clearance of alpha2-M- and PZP-proteinase complexes is the low-density lipoprotein receptor-related protein (LRP). Although both alpha-M-proteinase complexes bind to the same receptor, differences in the binding properties have been reported. In addition, although it is known that the binding of alpha2-M-proteinase complexes to LRP can be blocked by Ni2+, the effect on PZP-proteinase has never been examined. In order to investigate differences in the binding properties of both alpha-Ms to the receptor, we purified LRP from human placenta by affinity chromatography and then analyzed the specificity and affinity of binding of alpha2-M- and PZP-proteinase complexes to the receptor by enzyme immunoassay. Our results clearly established that although both alpha-M-proteinase complexes specifically bind to LRP, PZP-chymotrypsin complexes bind to the receptor with lesser apparent affinity (Kd approximately equal 320 nM) than alpha2-M-chymotrypsin complexes (Kd approximately equal 40 nM). We also demonstrated that Ni2+ blocks the binding of alpha2-M-chymotrypsin complexes, but not PZP-chymotrypsin complexes, to LRP. These data suggest that the binding to LRP involves conformational differences between both alpha-Ms in a region immediately upstream of the carboxy terminal receptor recognition domain. The possibility that PZP-proteinase complexes interact with other receptors not available to alpha2-M-proteinase complexes could be considered.
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Affiliation(s)
- G A Chiabrando
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina.
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Hilpert J, Vorum H, Burmeister R, Spoelgen R, Grishkovskaya I, Misselwitz R, Nykjaer A, Willnow TE. Efficient eukaryotic expression system for authentic human sex hormone-binding globulin. Biochem J 2001; 360:609-15. [PMID: 11736650 PMCID: PMC1222263 DOI: 10.1042/0264-6021:3600609] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sex hormone-binding globulin (SHBG) is the main carrier for androgens and oestrogens in humans. It mediates the transport of steroid hormones in the circulation and testicular fluid, and regulates their bioavailability to steroid-responsive tissues. In addition, the protein interacts with membrane receptors expressed in target tissues. Binding to the receptors is suspected to facilitate the uptake of steroid hormones and/or elicit cellular signal transduction. The identity of the SHBG receptor has not yet been resolved, in part due to a lack of sufficient quantities of authentic SHBG for receptor purification and molecular characterization. We have successfully addressed this problem by establishing an episomal expression system in human embryonic kidney cells that produces 5 mg of fully active human SHBG per litre. The recombinant protein resembles native SHBG in terms of structure, glycosylation pattern and steroid-binding activity. Moreover, the protein interacts with plasma membranes in steroid target tissues, an activity not observed with SHBG from other recombinant expression systems. Thus our studies have removed an important obstacle to the further elucidation of the role SHBG plays in steroid hormone action.
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Affiliation(s)
- J Hilpert
- Max-Delbrueck-Center for Molecular Medicine, Robert-Roessle-Strasse 10, D-13125 Berlin, Germany
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Sánchez MC, Chiabrando GA, Vides MA. Pregnancy zone protein-tissue-type plasminogen activator complexes bind to low-density lipoprotein receptor-related protein (LRP). Arch Biochem Biophys 2001; 389:218-22. [PMID: 11339811 DOI: 10.1006/abbi.2001.2329] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tissue-type plasminogen activator (t-PA), is a serine proteinase that catalyzes the initial and rate-limiting step in the fibrinolytic cascade. Its plasma activity is determined by the rate of release into the bloodstream, the rate of inhibition by plasminogen-activator inhibitor type 1 (PAI-1) and the rate of hepatic clearance. Two receptor systems contribute to the clearance of t-PA: the mannose receptor and the low-density lipoprotein receptor-related protein (LRP) that removes free t-PA as well as t-PA-PAI-1 complexes from the blood. During pregnancy a significant rise in the plasma levels of pregnancy zone protein (PZP) is observed, while alpha(2)-macroglobulin (alpha(2)-M) remains constant. Interestingly, the fibrinolytic activity is decreased during this period. In this context, we have recently demonstrated the in vitro formation of PZP-t-PA complexes. Here, we purified LRP from human placenta by affinity chromatography and then analyzed the binding specificity and affinity of PZP-proteinase complexes to the receptor by enzyme immunoassay (EIA). Our results clearly established that the binding of PZP-t-PA complexes to LRP was specific, saturable, and with K(d) = 337 +/- 31 nM. Moreover, by using the same EIA, we further observed that this binding was inhibited by receptor-associated protein. These data suggest that PZP, by binding to t-PA and promoting its clearance via LRP, might contribute in vivo to the downregulation of the fibrinolytic activity during pregnancy.
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Affiliation(s)
- M C Sánchez
- Departamento de Bioquímica Clínica, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
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Abstract
We recently reported the identification of human calumenin, a novel Ca(2+) binding, transformation-sensitive and secreted protein [Vorum et al. (1998) Biochim. Biophys. Acta 1386, 121-131; Vorum et al. (1999) Exp. Cell Res. 248, 473-481] belonging to the family of multiple EF-hand proteins of the secretory pathway that include reticulocalbin, ERC-55, Cab45 and crocalbin. In order to further investigate the extracellular functions of calumenin we immobilized the recombinant protein to a column. After application of a placental tissue extract we were able to elute one protein that interacts with calumenin in the presence of Ca(2+). Amino acid sequencing identified this protein as serum amyloid P component (SAP). Furthermore, we verified and characterized the calumenin-SAP interaction by the surface plasmon resonance technique. The findings indicate that calumenin may participate in the immunological defense system and could be involved in the pathological process of amyloidosis that leads to formation of amyloid deposits seen in different types of tissues.
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Affiliation(s)
- H Vorum
- Department of Medical Biochemistry, Ole Worms Allé, Building 170, University of Aarhus, DK-8000, Aarhus C, Denmark
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Wheal HV, Chen Y, Mitchell J, Schachner M, Maerz W, Wieland H, Van Rossum D, Kirsch J. Molecular mechanisms that underlie structural and functional changes at the postsynaptic membrane during synaptic plasticity. Prog Neurobiol 1998; 55:611-40. [PMID: 9670221 DOI: 10.1016/s0301-0082(98)00026-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The synaptic plasticity that is addressed in this review follows neurodegeneration in the brain and thus has both structural as well as functional components. The model of neurodegeneration that has been selected is the kainic acid lesioned hippocampus. Degeneration of the CA3 pyramidal cells results in a loss of the Schaffer collateral afferents innervating the CA1 pyramidal cells. This is followed by a period of structural plasticity where new synapses are formed. These are associated with changes in the numbers and shapes of spines as well as changes in the morphometry of the dendrites. It is suggested that this synaptogenesis is responsible for an increase in the ratio of NMDA to AMPA receptors mediating excitatory synaptic transmission at these synapses. Changes in the temporal and spatial properties of these synapses resulted in an altered balance between LTP and LTD. These properties together with a reduction in the inhibitory drive increased the excitability of the surviving CA1 pyramidal cells which in turn triggered epileptiform bursting activity. In this review we discuss the insights that may be gained from studies of the underlying molecular machinery. Developments in one of the collections of the cogs in this machinery has been summarized through recent studies characterizing the roles of neural recognition molecules in synaptic plasticity in the adult nervous systems of vertebrates and invertebrates. Such investigations of neural cell adhesion molecules, cadherins and amyloid precursor protein have shown the involvement of these molecules on the morphogenetic level of synaptic changes, on the one hand, and signal transduction effects, on the other. Further complex cogs are found in the forms of the low-density lipoprotein receptor (LDL-R) family of genes and their ligands play pivotal roles in the brain development and in regulating the growth and remodelling of neurones. Evidence is discussed for their role in the maintenance of cognitive function as well as Alzheimer's. The molecular mechanisms responsible for the clustering and maintenance of transmitter receptors at postsynaptic sites are the final cogs in the machinery that we have reviewed. Postsynaptic densities (PSD) from excitatory synapses have yielded many cytoskeletal proteins including actin, spectrin, tubulin, microtubule-associated proteins and calcium/calmodulin-dependent protein kinase II. Isolated PSDs have also been shown to be enriched in AMPA, kainate and NMDA receptors. However, recently, a new family of proteins, the MAGUKs (for membrane-associated guanylate kinase) has emerged. The role of these proteins in clustering different NMDA receptor subunits is discussed. The MAGUK proteins are also thought to play a role in synaptic plasticity mediated by nitric oxide (NO). Both NMDA and non-NMDA receptors are highly clustered at excitatory postsynaptic sites in cortical and hippocampal neurones but have revealed differences in their choice of molecular components. Both GABAA and glycine (Gly) receptors mediate synaptic inhibition in the brain and spinal cord. Whilst little is known about how GABAA receptors are localized in the postsynaptic membrane, considerable progress has been made towards the elucidation of the molecular mechanisms underlying the formation of Gly receptors. It has been shown that the peripheral membrane protein gephyrin plays a pivotal role in the formation of Gly receptor clusters most likely by anchoring the receptor to the subsynaptic cytoskeleton. Evidence for the distribution as well as function of gephyrin and Gly receptors is discussed. Postsynaptic membrane specializations are complex molecular machinery subserving a multitude of functions in the proper communication between neurones. Despite the fact that only a few key players have been identified it will be a fascinating to watch the story as to how they contribute to structural and functional plasticity unfold.
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Affiliation(s)
- H V Wheal
- Neuroscience Research Group, School of Biological Sciences, University of Southampton, U.K..
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Douglas GC, Moreira-Cali P, King BF, Lonnerdal B. Uptake of125I-labelled α2-macroglobulin and albumin by human placental syncytiotrophoblast in vitro. J Cell Biochem 1998. [DOI: 10.1002/(sici)1097-4644(19980315)68:4<427::aid-jcb3>3.0.co;2-s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hatzopoulos AK, Rigotti A, Rosenberg RD, Krieger M. Temporal and spatial pattern of expression of the HDL receptor SR-BI during murine embryogenesis. J Lipid Res 1998. [DOI: 10.1016/s0022-2275(20)33289-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Li Y, Wood N, Parsons PG, Yellowlees D, Donnelly PK. Expression of alpha2-macroglobulin receptor/low density lipoprotein receptor-related protein on surfaces of tumour cells: a study using flow cytometry. Cancer Lett 1997; 111:199-205. [PMID: 9022147 DOI: 10.1016/s0304-3835(96)04520-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
alpha2-Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha2 MR/LRP) is a multifunctional cell surface receptor that binds and endocytoses several structurally and functionally distinct ligands. Very little is known about the expression and function of alpha2 MR/LRP in tumour cells. The aim of this study was to quantify the number of alpha2 MR/LRP on surfaces of human tumour cells by flow cytometry. Using human alpha2 MR/LRP monoclonal antibody 8G1, human peripheral blood lymphocytes (negative control cells), monocytes (positive control cells), human neonatal foreskin fibroblast cells (NFF) (positive control cells), three human breast cancer cell lines (BT-20, T-47D, and MCF-7), two human ovarian tumour cell lines (JAM, and CI80-13S), and five human melanomas (MM418c1, MM253c1, A2058, MM138, MM370) were indirectly labelled with goat anti-mouse IgFITC. The fluorescent signals of stained cells were measured by flow cytometry. Using Quantum Simply Cellular bead standards, the number of alpha2 MR/LRP binding sites per cell was assessed. The flow cytometric method to quantify of alpha2 MR/LRP described here is simple and reliable. All the human tumour cell lines so far examined express alpha2 MR/LRP at different levels from approximately 300 to approximately 10000 sites per cell.
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Affiliation(s)
- Y Li
- Department of Surgery, North Queensland Clinical School, University of Queensland, Townsville, Australia
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18
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da Silva GC, Teixeira N, Bell SC. Major secretory product of the mesometrial decidua in the rat, a variant of alpha-2-macroglobulin, binds insulin-like growth factor I via a protease-dependent mechanism. Mol Reprod Dev 1996; 44:103-10. [PMID: 8722698 DOI: 10.1002/(sici)1098-2795(199605)44:1<103::aid-mrd12>3.0.co;2-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Decidualization-associated protein (DAP), the quantitatively major secretory product of the mesometrial decidua in the rat, is a pl variant of the liver-derived acute-phase reactant, alpha-2-macroglobulin (alpha 2M). Alpha 2M, a broad spectrum protease inhibitor, has been demonstrated in the human to bind a variety of cytokines and growth factors. In humans, the quantitatively major secretory product of decidual tissue is an insulin-like growth factor (IGF) binding protein. In this study, we have therefore tested the ability of liver- and decidual-derived alpha 2M in the rat to bind IGF-I. Alpha 2M purified from acute-phase plasma and DAP purified from cytosolic extracts of decidual tissue and medium from tissue incubations both bound radiolabeled IGF-I. The binding of IGF-I was principally dependent upon the coincubation of the protein with a proteinase. Therefore, it occurred during the conversion of the "slow" to the "fast" form of alpha 2M. Pretreatment with proteinase to produce the fast form before addition of the IGF-I reduced the binding. Binding was enhanced at a ratio protein:proteinase of 1:1. Results from gel electrophoretic analysis were consistent with the covalent linkage of IGF-I to alpha 2M during the cleavage of the "bait region." A saturable displacement by increasing concentrations of unlabeled IGF-I suggested high affinity interaction. Under conditions of demonstrated binding to purified proteins binding in acute-phase plasma, decidual tissue extracts and tissue incubation medium were associated with a high molecular weight species which was confirmed to represent alpha 2M and DAP, respectively. Our studies demonstrate that IGF-I may now be added to the list of regulatory peptides which alpha 2M may bind and that, in rat decidua, DAP may represent the functional homolog of decidual IGFBP-1 in the human and regulate growth factor function during placental development.
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Affiliation(s)
- G C da Silva
- Department of Biochemistry, Faculty of Pharmacy, Oporto University, Portugal
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19
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Woollett LA. Origin of cholesterol in the fetal golden Syrian hamster: contribution of de novo sterol synthesis and maternal-derived lipoprotein cholesterol. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)39154-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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20
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Kjøller L, Simonsen AC, Ellgaard L, Andreasen PA. Differential regulation of urokinase-type-1 inhibitor complex endocytosis by phorbol esters in different cell lines is associated with differential regulation of alpha 2-macroglobulin receptor and urokinase receptor expression. Mol Cell Endocrinol 1995; 109:209-17. [PMID: 7664984 DOI: 10.1016/0303-7207(95)03504-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Complex between urokinase and its type-1 inhibitor (uPA-PAI-1) may, when bound to the urokinase receptor (uPAR), be endocytosed by an ensuing binding of the complex to the multiligand receptors alpha (2)-macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2MR/LRP) and glycoprotein 330 (gp330). We have found that phorbol esters regulate endocytosis of uPA-PAI-1 differently in different cell lines. In COS-1 cells, expressing uPAR and high levels of alpha 2MR/LRP under basal conditions, phorbol esters cause a time-dependent decrease in endocytosis concomitantly with a parallel down-regulation of alpha 2MR/LRP expression. An up-regulation of uPAR expression was also observed. General endocytosis via the clathrin-coated pit pathway was not affected by PMA treatment, as judged from measurements of transferrin endocytosis. In LLC-PK1 cells, expressing alpha 2MR/LRP but not uPAR under basal conditions, phorbol esters transiently increase endocytosis in parallel with a transient induction of uPAR expression, while there was virtually no change in alpha 2MR/LRP expression. Differential regulation of endocytosis therefore seems to be caused by differential regulation of the receptors, with either the alpha 2MR/LRP-level (in COS)-1 cells) or the uPAR-level (in LLC-PK1 cells) being rate-limiting.
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Affiliation(s)
- L Kjøller
- Department of Molecular Biology, University of Aarhus, Denmark
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21
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Arbelaez L, Jensen P, Stigbrand T. Proteinases from the fibrinolytic and coagulation systems: Analyses of binding to pregnancy zone protein, a pregnancy-associated plasma proteinase inhibitor. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0268-9499(08)80044-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Delain E, Barray M, Pochon F, Gliemann J, Moestrup SK. Electron microscopic visualization of the human alpha 2-macroglobulin receptor and its interaction with alpha 2-macroglobulin/chymotrypsin complex. Ann N Y Acad Sci 1994; 737:202-11. [PMID: 7524397 DOI: 10.1111/j.1749-6632.1994.tb44313.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- E Delain
- Laboratoire de Microscopie Cellulaire et Moléculaire, Institut Gustave Roussy, Villejuif, France
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23
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Moestrup SK. The alpha 2-macroglobulin receptor and epithelial glycoprotein-330: two giant receptors mediating endocytosis of multiple ligands. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1197:197-213. [PMID: 7518253 DOI: 10.1016/0304-4157(94)90005-1] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- S K Moestrup
- Department of Medical Biochemistry, University of Aarhus, Denmark
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24
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Lorent K, Overbergh L, Delabie J, Van Leuven F, Van den Berghe H. Distribution of mRNA coding for alpha-2-macroglobulin, the murinoglobulins, the alpha-2-macroglobulin receptor and the alpha-2-macroglobulin receptor associated protein during mouse embryogenesis and in adult tissues. Differentiation 1994; 55:213-23. [PMID: 7514554 DOI: 10.1046/j.1432-0436.1994.5530213.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The distribution of mRNA coding for the members of the wide-spectrum proteinase scavenging system of the alpha-2-macroglobulin family was examined in the mouse: Alpha-2-macroglobulin (MAM), the murinoglobulins (MUG), the alpha-2-macroglobulin receptor (alpha 2MR) and the receptor associated protein, the heparin binding protein-44 (alpha 2MRAP/HBP-44), a component of unknown function. The results demonstrate that MAM is expressed in the mouse embryo exclusively in the liver and not before day 13 of gestation. MUG mRNA was never detected during embryogenesis. On the other hand, both the alpha 2MR and the alpha 2MRAP/HBP-44 messages were present throughout all embryonal stages examined. The distribution of the alpha 2MR mRNA was widespread in most tissues, with stronger signals observed in developing mouse brain, in whisker follicles and in the perifollicular mesenchyme, in lung, liver, kidney, intestine and placenta. The alpha 2MRAP/HBP-44 mRNA was detected predominantly in brain, lung, liver, kidney and placenta. Interestingly, within each tissue the cellular distribution of the alpha 2MR and alpha 2MRAP/HBP-44 mRNA was quite different with the most remarkable extremes observed in kidney and in placenta. The implication of these observations for receptor expression and function are discussed. Northern analysis of adult tissues extended these observations: major signals for MAM and MUG were seen only in liver, while the expression of the alpha 2MR and the alpha 2MRAP/HBP-44 was widespread with highest levels of the 15-kb alpha 2MR mRNA in liver. Kidney was the most abundant source of alpha 2MRAP/HBP-44 mRNA with the 1.8- and 3.6-kb mRNAs, derived from the same gene by alternative mRNA splicing, present in nearly constant ratios in most tissues, except in testis. The notable absence of expression of MAM in the first half of gestation indicates that during this period the receptor is scavenging for proteinases complexed to MAM derived from the maternal circulation or is being used for endocytosis of the other documented ligands, such as plasminogen activator complexes or apolipoprotein E-containing lipoprotein particles.
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Affiliation(s)
- K Lorent
- Center for Human Genetics, Katholieke Universiteit Leuven, Belgium
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25
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Jensen PH, Lorand L, Ebbesen P, Gliemann J. Type-2 plasminogen-activator inhibitor is a substrate for trophoblast transglutaminase and factor XIIIa. Transglutaminase-catalyzed cross-linking to cellular and extracellular structures. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 214:141-6. [PMID: 8099547 DOI: 10.1111/j.1432-1033.1993.tb17906.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Plasminogen-activator inhibitor type-2 (PAI-2), a serine-proteinase inhibitor, suppresses fibrinolysis by blocking both urokinase and tissue-type plasminogen activators. The 43-kDa PAI-2 molecule is an abundant cytosolic protein in certain cell types, but can upon appropriate stimulation be secreted as an approximately 60-70-kDa glycoprotein. However, in trophoblast membranes PAI-2 activity is associated with large covalent complexes (Jensen, P. H., Nykjaer, P., Andreasen P. A., Lund, L., Astedt, B. Lecander, I & Gliemann, J. (1989) Biochim. Biophys. Acta 986, 135-140). This study shows that PAI-2 can act as a substrate for both tissue transglutaminase and activated plasma factor XIII. In the presence of Ca2+, either of these will catalyze the incorporation of primary amines, such as putrescine, into PAI-2. Moreover, in reactions with tissue transglutaminase, PAI-2 homopolymers and, in conjunction with other biological substrates, heteropolymers were observed. As judged by the test of incorporating 125I-urokinase into SDS-resistant 125I-urokinase/PAI-2 complexes, polymerized PAI-2 retained its inhibitory activity. Furthermore, syncytiotrophoblast microvillous membranes and trophoblast detergent extracts incorporated 125I-PAI-2 into large structures in a reaction inhibited by putrescine and a synthetic inhibitor of transglutaminase. Trophoblast transglutaminase was identified as a tissue transglutaminase by non-denaturing gel electrophoresis and dansylcadaverine activity staining, fibronectin binding and Western blotting with a specific antibody. The transglutaminase-catalyzed and Ca(2+)-dependent anchoring of PAI-2 to extracellular membrane structures might have the purpose of focally regulating fibrinolysis.
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Affiliation(s)
- P H Jensen
- Institute of Medical Biochemistry, University of Aarhus, Denmark
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26
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Herz J, Clouthier DE, Hammer RE. LDL receptor-related protein internalizes and degrades uPA-PAI-1 complexes and is essential for embryo implantation. Cell 1992; 71:411-21. [PMID: 1423604 DOI: 10.1016/0092-8674(92)90511-a] [Citation(s) in RCA: 447] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The low density lipoprotein receptor-related protein (LRP) is a large multifunctional clearance receptor that has been implicated in the hepatic uptake of chylomicron remnants and in the removal of protease-inhibitor complexes from the circulation and from the extracellular space. Disruption of the LRP gene in mice blocks development of LRP-/- embryos around the implantation stage. The expression pattern of LRP in the postimplantation stage embryo is identical to that of urokinase, a plasminogen activator that confers invasive properties to migrating cells. We demonstrate that LRP mediates uptake and degradation of urokinase-type plasminogen activator-plasminogen activator inhibitor 1 complexes and propose that the inability of the giant cells to remove the inactive protease complexes from their surfaces interferes with implantation of the embryo.
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Affiliation(s)
- J Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235
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27
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Gåfvels M, Coukos G, Sayegh R, Coutifaris C, Strickland D, Strauss J. Regulated expression of the trophoblast alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein. Differentiation and cAMP modulate protein and mRNA levels. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)36822-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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28
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Moestrup SK, Gliemann J, Pallesen G. Distribution of the alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein in human tissues. Cell Tissue Res 1992; 269:375-82. [PMID: 1423505 DOI: 10.1007/bf00353892] [Citation(s) in RCA: 320] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The hepatic alpha 2-macroglobulin receptor (alpha 2MR)/low density lipoprotein receptor-related protein (LRP) binds and endocytoses alpha 2-macroglobulin-proteinase complexes in plasma. In addition, it binds lipoproteins, a novel 40 kDa protein, and complexes between plasminogen activators and plasminogen activator inhibitor type-1. This study shows, for the first time, the tissue distribution of alpha 2MR/LRP as determined by immunohistochemistry with specific monoclonal antibodies. The analysis revealed alpha 2MR/LRP-expression in a restricted spectrum of cell types, including neurons and astrocytes in the central nervous system, epithelial cells of the gastrointestinal tract, smooth muscle cells, fibroblasts, Leydig cells in testis, granulosa cells in ovary, and dendritic interstitial cells of kidney. Monocyte-derived cells displayed marked alpha 2MR/LRP expression in the phagocytes of liver, lung and lymphoid tissues, but no or low expression in antigen-presenting cells including Langerhans' cells of the skin. The high abundance of alpha 2MR/LRP in certain cell types of most organs suggests two main routes for alpha 2MR/LRP-mediated ligand clearance: (1) systemic removal in liver of circulating ligands, and (2) non-hepatic interstitial removal in different organs, including the brain.
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Affiliation(s)
- S K Moestrup
- Institute of Medical Biochemistry, Aarhus University, Denmark
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29
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Moestrup SK, Hokland P. Surface expression of the alpha 2-macroglobulin receptor on human malignant blood cells. Leuk Res 1992; 16:227-34. [PMID: 1560672 DOI: 10.1016/0145-2126(92)90060-k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The surface expression of the alpha 2-macroblobulin receptor (alpha 2MR), detected by a monoclonal antibody, A2MR alpha-2, was determined on mononuclear blood cells from 90 cases of malignant blood disease. Flow cytometric analyses combined with immunoblotting and ligand binding experiments revealed that alpha 2MR was expressed on malignant cells from patients with acute and chronic myelomonocytic leukemias, while no significant expression was found on malignant cells from acute and chronic lymphatic leukemia, lymphomas, plasma cell leukemias or hairy cell leukemia. In acute myeloid leukemia, alpha 2MR was expressed in 50% of the M4-M5 cases, but only in three of thirty of the morphologically undifferentiated or non-monocytic cases (M1-M3 and M6). In chronic myelomonocytic leukemia five of seven cases were alpha 2MR-positive, while only one of seven cases of chronic myeloid leukemia was positive. The monocytic nature of the hematopoietic cells reacting with A2MR alpha 2 was further confirmed by a close correlation with CD14 surface expression.
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MESH Headings
- Animals
- Antibodies, Monoclonal
- Cell Differentiation/physiology
- Humans
- Immunoblotting
- Immunophenotyping
- Leukemia/blood
- Leukemia, Erythroblastic, Acute/blood
- Leukemia, Monocytic, Acute/blood
- Leukemia, Myeloid, Acute/blood
- Leukemia, Myelomonocytic, Acute/blood
- Leukemia, Promyelocytic, Acute/blood
- Low Density Lipoprotein Receptor-Related Protein-1
- Mice
- Mice, Inbred BALB C
- Monocytes/metabolism
- Monocytes/ultrastructure
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/blood
- Receptors, Immunologic/metabolism
- Receptors, Immunologic/physiology
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Affiliation(s)
- S K Moestrup
- Institute of Physiology, Aarhus University, Denmark
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30
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Delain E, Pochon F, Barray M, Van Leuven F. Ultrastructure of alpha 2-macroglobulins. ELECTRON MICROSCOPY REVIEWS 1992; 5:231-81. [PMID: 1374655 DOI: 10.1016/0892-0354(92)90012-f] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
New results concerning the ultrastructure of human alpha 2-macroglobulin (alpha 2M) molecules are presented in connection and comparison with the historical, the current and our own most recent, even unpublished results on the structure and function of alpha 2M and related proteins. The electron microscopic approach uses classical negative staining, combined with the new imaging mode "Electron Energy Loss Spectroscopy", which provides unusual contrast, resolution and readability of the electron micrographs. Immuno- and cryoelectron microscopy, as well as image processing has provided new data necessary to the building of tentative 3D models of the molecule. A model for the native tetrameric alpha 2M is described for the first time, and tries to explain and gather the various observations, sometimes contradictory, taken from different laboratories. A revised version for a model of the methylamine- and proteinase-transformed forms of alpha 2M is also shown. The probable positions of the bait regions and the thiol esters are given on both models. We confirm that alpha 2M is a twin trap capable of inactivating one or two proteinases by partial immobilization. Preliminary results on the production of crystals of alpha 2M-chymotrypsin complexes are also presented. A critical analysis of our models is presented in comparison with others. The technical limitations reached with some techniques and some possible extensions of future research in the field are also presented.
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Affiliation(s)
- E Delain
- Laboratoire de microscopie cellulaire et moléculaire, Centre National de la Recherche Scientifique (CNRS), Institut Gustave Roussy, Villejuif, France
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31
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Affiliation(s)
- P Bischof
- Department of Obstetrics and Gynaecology, University of Geneva, Switzerland
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32
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Devriendt K, Van den Berghe H, Cassiman JJ, Marynen P. Primary structure of pregnancy zone protein. Molecular cloning of a full-length PZP cDNA clone by the polymerase chain reaction. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1088:95-103. [PMID: 1989698 DOI: 10.1016/0167-4781(91)90157-h] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A full-length cDNA clone of the human pregnancy zone protein (PZP) was cloned from the hepatocellular carcinoma cell line Hep3B. Based on the exon sequences of the PZP gene (Devriendt et al. (1989) Gene 81, 325-334; Marynen et al., unpublished data), primer pairs were designed to amplify six overlapping fragments of the PZP cDNA. The obtained cDNA is 4609 bp long and contains an open reading frame coding for 1482 amino acids, including a signal peptide of 25 amino acid residues. Comparison with the published partial PZP amino acid sequence (Sottrup-Jensen et al. (1984) Proc. Natl. Acad. Sci. USA 81, 7353-7357) and the PZP genomic sequences confirmed the identity as a PZP cDNA. 71% of the corresponding amino acid residues in PZP and human alpha 2-macroglobulin (alpha 2M) are identical and all cysteine residues are conserved. A typical internal thiol ester site and a bait domain were identified. A Pro/Thr polymorphism was identified at amino acid position 1180, and an A/G nucleotide polymorphism at bp 4097.
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Affiliation(s)
- K Devriendt
- Center for Human Genetics, University of Leuven, Belgium
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33
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Moestrup SK, Kaltoft K, Petersen CM, Pedersen S, Gliemann J, Christensen EI. Immunocytochemical identification of the human alpha 2-macroglobulin receptor in monocytes and fibroblasts: monoclonal antibodies define the receptor as a monocyte differentiation antigen. Exp Cell Res 1990; 190:195-203. [PMID: 2209723 DOI: 10.1016/0014-4827(90)90185-d] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The alpha 2-macroglobulin receptor was recently purified from rat liver and human placenta. Three different monoclonal antibodies have now been raised against the human receptor and expression of the 440-kDa receptor protein is demonstrated in human placenta, fibroblasts, liver, and monocytes by immunoblot analysis. Flow cytometric studies showed that anti-alpha 2-macroglobulin receptor monoclonal antibodies bind to 90-100% of the blood monocyte population and not to other blood cells. This defines the alpha 2-macroglobulin receptor as a monocyte differentiation antigen, different from any of the classified leucocyte cluster determinants. Electron microscopic gold immunocytochemistry revealed the subcellular distribution of the receptor in human cultured monocytes and fibroblasts. In these cells, 18-33% of the gold particles were found on the outside of the plasma membrane, and in fibroblasts, especially, in coated invaginations. The intracellular receptors were mainly distributed in vesicles and tubular structures.
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Affiliation(s)
- S K Moestrup
- Institute of Physiology, University of Aarhus, Denmark
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34
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Moestrup SK, Kaltoft K, Sottrup-Jensen L, Gliemann J. The human alpha 2-macroglobulin receptor contains high affinity calcium binding sites important for receptor conformation and ligand recognition. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38389-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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35
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Differential inhibition of transforming growth factor beta 1 and beta 2 activity by alpha 2-macroglobulin. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39246-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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36
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Ashcom JD, Tiller SE, Dickerson K, Cravens JL, Argraves WS, Strickland DK. The human alpha 2-macroglobulin receptor: identification of a 420-kD cell surface glycoprotein specific for the activated conformation of alpha 2-macroglobulin. J Biophys Biochem Cytol 1990; 110:1041-8. [PMID: 1691187 PMCID: PMC2116111 DOI: 10.1083/jcb.110.4.1041] [Citation(s) in RCA: 234] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Ligand affinity chromatography was used to purify a cell surface alpha 2-macroglobulin (alpha 2M) receptor. Detergent extracts of human placenta were applied to an affinity matrix consisting of alpha 2M, previously reacted with methylamine, coupled to Sepharose. Elution with EDTA specifically released polypeptides with apparent molecular masses of 420 and 39 kD. In some preparations, small amounts of a 90-kD polypeptide were observed. The 420- and 39-kD polypeptides appear specific for the forms of alpha 2M activated by reaction with proteinases or methylamine and do not bind to an affinity matrix consisting of native alpha 2M coupled to Sepharose. Separation of these two polypeptides was accomplished by anion exchange chromatography, and binding activity was exclusively associated with the 420-kD polypeptide. The purified 420-kD protein binds to the conformationally altered forms of alpha 2M that are known to specifically interact with alpha 2M receptors and does not bind to native alpha 2M. Binding of the 420-kD polypeptide to immobilized wheat germ agglutinin indicates that this polypeptide is a glycoprotein. The cell surface localization of the 420-kD glycoprotein was confirmed by affinity chromatography of extracts from surface radioiodinated fibroblasts. These properties suggest that the 420-kD polypeptide is a cell surface receptor for the activated forms of alpha 2M.
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Affiliation(s)
- J D Ashcom
- Biochemistry Department, Holland Laboratory, American Red Cross, Rockville, Maryland 20855
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37
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Jensen PH, Nykjaer A, Andreasen PA, Lund LR, Astedt B, Lecander I, Gliemann J. Urokinase binds to a plasminogen activator inhibitor type-2-like molecule in placental microvillous membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 986:135-40. [PMID: 2819091 DOI: 10.1016/0005-2736(89)90282-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Placental microvillous membranes exhibited saturable binding of urokinase-type plasminogen activator with plateau achieved by 30 min at 4 degrees C and 10 min at 37 degrees C. The binding was essentially irreversible. The capacity was about 8 pmol urokinase per mg membrane protein. Half-maximal displacement of 125I-labelled urokinase was achieved with about 1.0 nM unlabelled urokinase when using 75 micrograms membrane protein/ml. 125I-labelled urokinase did not bind when treated with diisopropylfluorophosphate to block the catalytic activity. Single-chain urokinase (prourokinase), devoid of catalytic activity, did not bind. Catalytically active tissue-type plasminogen activator did compete with 125I-labelled urokinase for binding although less efficiently than urokinase. Binding activity remained in the 100,000 x g pellet after treatment of the membranes with 3 M KCl, alkaline stripping at pH 12 or extraction by the detergent Triton X-100. The binding was essentially blocked by antibodies against plasminogen activator inhibitor-type-2 (PAI-2). Sodium dodecyl sulfate polyacrylamide gel electrophoresis of solubilized membranes with bound 125I-labelled urokinase showed that the urokinase-PAI-2 complexes largely migrated in fractions corresponding to a very large Mr although no clearly defined peaks were observed. It is suggested that PAI-2 occurs in a form anchored to syncytiotrophoblast microvilli, possibly to the cytoskeleton.
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Affiliation(s)
- P H Jensen
- Institute of Physiology, University of Aarhus, Denmark
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Devriendt K, Zhang J, van Leuven F, van den Berghe H, Cassiman JJ, Marynen P. A cluster of alpha 2-macroglobulin-related genes (alpha 2 M) on human chromosome 12p: cloning of the pregnancy-zone protein gene and an alpha 2M pseudogene. Gene X 1989; 81:325-34. [PMID: 2478422 DOI: 10.1016/0378-1119(89)90193-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The characterization of two alpha 2-macroglobulin (alpha 2M)-related genomic clones, isolated from two human genomic libraries by use of alpha 2M cDNA [Kan et al., Proc. Natl. Acad. Sci. USA 82 (1985) 2282-2286] as a probe, is reported. Sequence comparison of the clone EPZP6 with the human alpha 2M cDNA revealed the presence of five exons with the proper splice signals. Alignment of the corresponding amino acid (aa) sequence of these exons with the published partial pregnancy-zone protein (PZP) aa sequence (Sottrup-Jensen et al., Proc. Natl. Acad. Sci. USA 81 (1984) 7353-7357] showed a perfect match, thereby identifying EPZP6 as a PZP genomic clone. The clone MPAM16 showed a considerable degree of sequence conservation when compared to the human alpha 2M cDNA sequence, and several putative exons were identified. However, a frame-shift mutation leading to a premature stop codon was found in the coding sequence, classifying this gene as an alpha 2M pseudogene. Human alpha 2M, PZP and the related pseudogene were mapped to the human chromosome 12p12-13, with the help of gene-specific probes and in situ hybridization. This result was confirmed in Southern-blot experiments with DNA from a human-Ltk- mouse somatic-cell hybrid containing only a human isochromosome 12p in a mouse background.
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Affiliation(s)
- K Devriendt
- Center for Human Genetics, University of Leuven, Belgium
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Jensen PH, Moestrup SK, Gliemann J. Purification of the human placental alpha 2-macroglobulin receptor. FEBS Lett 1989; 255:275-80. [PMID: 2477279 DOI: 10.1016/0014-5793(89)81105-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The alpha 2-macroglobulin receptor was solubilized from human placental membranes, purified and characterized. Affinity cross-linking of labelled ligand to intact membranes showed a receptor size compatible with 400-500 kDa. The membranes were solubilized in 3-[(3-cholamidopropyl)dimethylammonio]propane sulfonate (CHAPS) and affinity chromatography was performed using Sepharose-immobilized alpha 2-macroglobulin-methylamine with elution in buffer containing 2 mM EDTA, pH 6.0. SDS-PAGE of the resulting receptor preparation showed a predominant approx. 440 kDa band (reducing conditions) and some minor accompanying proteins of 70-90 kDa and 40 kDa. The yield was 400-800 micrograms receptor preparation per placenta. The receptor preparation immobilized on nitrocellulose bound the alpha 2-macroglobulin-trypsin complex with a dissociation constant of about 400 pM. 125I-iodinated receptor preparation bound almost quantitatively to Sepharose-immobilized alpha 2-macroglobulin-methylamine in the presence of CHAPS alone, and bound 70-80% in the presence of 0.2% SDS. The labelled proteins were separated in the presence of 0.2% SDS by gel filtration or SDS-PAGE (unboiled samples). The 440 kDa protein accounted for the major part of the binding, although some approx. 80 kDa proteins, perhaps proteolytic degradation products, also showed binding activity.
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Affiliation(s)
- P H Jensen
- Institute of Physiology, University of Aarhus, Denmark
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Sottrup-Jensen L. α-Macroglobulins: structure, shape, and mechanism of proteinase complex formation. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)80094-1] [Citation(s) in RCA: 300] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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