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Beenken A, Cerutti G, Brasch J, Guo Y, Sheng Z, Erdjument-Bromage H, Aziz Z, Robbins-Juarez SY, Chavez EY, Ahlsen G, Katsamba PS, Neubert TA, Fitzpatrick AWP, Barasch J, Shapiro L. Structures of LRP2 reveal a molecular machine for endocytosis. Cell 2023; 186:821-836.e13. [PMID: 36750096 PMCID: PMC9993842 DOI: 10.1016/j.cell.2023.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/29/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023]
Abstract
The low-density lipoprotein (LDL) receptor-related protein 2 (LRP2 or megalin) is representative of the phylogenetically conserved subfamily of giant LDL receptor-related proteins, which function in endocytosis and are implicated in diseases of the kidney and brain. Here, we report high-resolution cryoelectron microscopy structures of LRP2 isolated from mouse kidney, at extracellular and endosomal pH. The structures reveal LRP2 to be a molecular machine that adopts a conformation for ligand binding at the cell surface and for ligand shedding in the endosome. LRP2 forms a homodimer, the conformational transformation of which is governed by pH-sensitive sites at both homodimer and intra-protomer interfaces. A subset of LRP2 deleterious missense variants in humans appears to impair homodimer assembly. These observations lay the foundation for further understanding the function and mechanism of LDL receptors and implicate homodimerization as a conserved feature of the LRP receptor subfamily.
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Affiliation(s)
- Andrew Beenken
- Division of Nephrology, Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Gabriele Cerutti
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Julia Brasch
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Yicheng Guo
- Aaron Diamond AIDS Research Center, Columbia University, New York, NY 10032, USA
| | - Zizhang Sheng
- Aaron Diamond AIDS Research Center, Columbia University, New York, NY 10032, USA
| | - Hediye Erdjument-Bromage
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Zainab Aziz
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Estefania Y Chavez
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Goran Ahlsen
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Phinikoula S Katsamba
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Thomas A Neubert
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Anthony W P Fitzpatrick
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.
| | - Jonathan Barasch
- Division of Nephrology, Department of Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Columbia University George M. O'Brien Urology Center, New York, NY 10032, USA.
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Aaron Diamond AIDS Research Center, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA.
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2
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Mentzel S, Dijkman HB, van Son JP, Wetzels JF, Assmann KJ. In vivo antibody-mediated modulation of aminopeptidase A in mouse proximal tubular epithelial cells. J Histochem Cytochem 1999; 47:871-80. [PMID: 10375375 DOI: 10.1177/002215549904700704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aminopeptidase A (APA) is one of the many renal hydrolases. In mouse kidney, APA is predominantly expressed on the brush borders and sparsely on the basolateral membranes of proximal tubular epithelial cells. However, when large amounts of monoclonal antibodies (MAbs) against APA were injected into mice, we observed strong binding of the MAbs to the basolateral membranes, whereas the MAbs bound only transiently to the brush borders of the proximal tubular epithelial cells. In parallel, APA itself disappeared from the brush borders by both endocytosis and shedding, whereas it was increasingly expressed on the basolateral sides. Using ultrastructural immunohistology, we found no evidence for transcellular transport of endocytosed APA to the basolateral side of the proximal tubular epithelial cells. The absence of transcellular transport was confirmed by experiments in which we used a low dose of the MAbs. Such a low dose did not result in binding of the MAbs to the brush borders and had no effect on the presence of APA in the brush borders of the proximal tubular epithelial cells. In these experiments we still could observe binding of the MAbs to the basolateral membranes in parallel with the local appearance of APA. In addition, treatment of mice with chlorpromazine, a calmodulin antagonist that interferes with cytoskeletal function, largely inhibited the MAb-induced modulation of APA. Our studies suggest that injection of MAbs to APA specifically interrupts the normal intracellular traffic of this enzyme in proximal tubular epithelial cells. This intracellular transport is dependent on the action of cytoskeletal proteins.
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Affiliation(s)
- S Mentzel
- Departments of Pathology, Division of Nephrology, University Hospital Nijmegen, Nijmegen, The Netherlands
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3
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Mentzel S, van Son JP, Dijkman HB, Wetzels JF, Assmann KJ. Induction of albuminuria in mice: synergistic effect of two monoclonal antibodies directed to different domains of aminopeptidase A. Kidney Int 1999; 55:1335-47. [PMID: 10200998 DOI: 10.1046/j.1523-1755.1999.00362.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Aminopeptidase A is an enzyme that is present on podocytes and is involved in the degradation of angiotensin II. In previous studies in mice, we administered single monoclonal antibodies directed against aminopeptidase A. We observed that only monoclonal antibodies that inhibited aminopeptidase A enzyme activity caused albuminuria. METHODS In this study, the effects of the combined injections of two monoclonal anti-aminopeptidase A antibodies (mAbs) were studied, using a combination of anti-aminopeptidase A mAbs that were directed against two different domains involved in the aminopeptidase A enzyme activity (ASD-3 or ASD-37) and an anti-aminopeptidase A mAb not related to the enzyme active site (ASD-41). RESULTS An injection of the combinations ASD-3/37 (total 4 mg, 1:1 ratio) and ASD-37/41 (total 4 mg, 1:1 ratio) in doses that do not cause albuminuria when given alone (4 mg) induced massive albuminuria at day 1 after injection. The combination ASD-3/41 had no effect. This albuminuria was not dependent on systemic immune mediators of inflammation and could not merely be related to a blockade of aminopeptidase A enzyme activity. However, a correlation was observed between the induction of albuminuria and the aggregation of the mAbs injected and aminopeptidase A on the podocytes. An injection of the combinations ASD-3/37 or ASD-37/41 did not cause an increase in systemic blood pressure. The treatment with a combination of enalapril and losartan lowered blood pressure (53 +/- 10 vs. 90 +/- 3 mm Hg in untreated mice) and reduced the acute albuminuria by 55% (11,145 +/- 864 vs. 24,517 +/- 2448 micrograms albumin/18 hr in untreated mice). However, similar effects were observed using triple therapy. Therefore, the reduction of albuminuria by the combined treatment of enalapril/losartan seems to be the consequence of the reduction in the systemic blood pressure. These findings argue against a specific role for angiotensin II in this model. CONCLUSIONS The combined injection of two mAbs directed against different domains of aminopeptidase A induces a massive albuminuria in mice, which is not merely dependent on angiotensin II. We hypothesize that the direct binding of mAbs to at least two pathogenic domains on aminopeptidase A triggers the podocyte to release mediators that are involved in the observed albuminuria.
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Affiliation(s)
- S Mentzel
- Department of Pathology, University Hospital Nijmegen, The Netherlands.
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4
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Ranganathan S, Knaak C, Morales CR, Argraves WS. Identification of low density lipoprotein receptor-related protein-2/megalin as an endocytic receptor for seminal vesicle secretory protein II. J Biol Chem 1999; 274:5557-63. [PMID: 10026171 DOI: 10.1074/jbc.274.9.5557] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The low density lipoprotein receptor-related protein-2/megalin (LRP-2) is an endocytic receptor that is expressed on the apical surfaces of epithelial cells lining specific regions of the male and female reproductive tracts. In the present study, immunohistochemical staining revealed that LRP-2 is also expressed by epithelial cells lining the ductal region and the ampulla of the rat seminal vesicle. To identify LRP-2 ligands in the seminal vesicle, we probed seminal vesicle fluid with 125I-labeled LRP-2 in a gel-blot overlay assay. A 100-kDa protein (under non-reducing conditions) was found to bind the radiolabeled receptor. The protein was isolated and subjected to protease digestion, and the proteolytic fragments were subjected to mass spectroscopic sequence analysis. As a result, the 100-kDa protein was identified as the seminal vesicle secretory protein II (SVS-II), a major constituent of the seminal coagulum. Using purified preparations of SVS-II and LRP-2, solid-phase binding assays were used to show that the SVS-II bound to the receptor with high affinity (Kd = 5.6 nM). The binding of SVS-II to LRP-2 was inhibited using a known antagonist of LRP-2 function, the 39-kDa receptor-associated protein RAP. Using a series of recombinant subfragments of SVS-II, the LRP-2 binding site was mapped to a stretch of repeated 13-residue modules located in the central portion of the SVS-II polypeptide. To evaluate the ability of LRP-2 to mediate 125I-SVS-II endocytosis and lysosomal degradation, ligand clearance assays were performed using differentiated mouse F9 cells, which express high levels of LRP-2. Radiolabeled SVS-II was internalized and degraded by the cells, and both processes were inhibited by antibodies to LRP-2 or by RAP. The results indicate that LRP-2 binds SVS-II and can mediate its endocytosis leading to lysosomal degradation.
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Affiliation(s)
- S Ranganathan
- Cell Biology and Anatomy Department, Medical University of South Carolina, Charleston, South Carolina 29425-2204, USA
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Hammad SM, Ranganathan S, Loukinova E, Twal WO, Argraves WS. Interaction of apolipoprotein J-amyloid beta-peptide complex with low density lipoprotein receptor-related protein-2/megalin. A mechanism to prevent pathological accumulation of amyloid beta-peptide. J Biol Chem 1997; 272:18644-9. [PMID: 9228033 DOI: 10.1074/jbc.272.30.18644] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Apolipoprotein J (apoJ) has been shown to be the predominant amyloid beta-peptide (Abeta)-binding protein in cerebrospinal fluid. We have previously demonstrated that the endocytic receptor low density lipoprotein receptor-related protein-2/megalin (LRP-2), which is expressed by choroid plexus epithelium and ependymal cells lining the brain ventricles and neural tube, binds and mediates cellular uptake of apoJ (Kounnas, M. Z., Loukinova, E. B., Stefansson, S., Harmony, J. A., Brewer, B., Strickland, D. K., and Argraves, W. S. (1995) J. Biol. Chem. 270, 13070-13075). In the present study, we evaluated the ability of apoJ to mediate binding of Abeta1-40-apoJ complex to LRP-2 in vitro. Immunoblot analysis showed that incubation of apoJ with Abeta1-40 resulted in the formation of Abeta1-40-apoJ complex and the inhibition of the formation of Abeta1-40 aggregates. Using an enzyme-linked immunosorbent assay, an estimated dissociation constant (Kd) of 4.8 nM was derived for the interaction between Abeta1-40 and apoJ. Enzyme-linked immunosorbent assay was also used to study the interaction of the Abeta1-40-apoJ complex with LRP-2. The results showed that Abeta alone did not bind directly to LRP-2; however, when Abeta1-40 was combined with apoJ to form a complex, binding to LRP-2 took place. The binding interaction could be blocked by inclusion of the receptor-associated protein, an antagonist of apoJ binding to LRP-2. When LRP-2-expressing cells were given 125I-Abeta1-40, cellular uptake of the radiolabeled peptide was promoted by co-incubation with apoJ. When the cells were provided purified 125I-Abeta1-40-apoJ complex, the complex was internalized and degraded, and both processes were inhibited with polyclonal LRP-2 antibodies. Furthermore, chloroquine treatment inhibited the cellular degradation of the complex. The data indicate that apoJ facilitates Abeta1-40 binding to LRP-2 and that the receptor mediates cellular clearance of Abeta1-40-apoJ complex leading to lysosomal degradation of Abeta1-40. The findings support the possibility that LRP-2 can act in vivo to mediate clearance of the complex from biological fluids such as cerebrospinal fluid and thereby play a role in the regulation of Abeta accumulation.
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Affiliation(s)
- S M Hammad
- Cell Biology and Anatomy Department, Medical University of South Carolina, Charleston, South Carolina 29425-2204, USA
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6
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Yamaguchi N, Plant C, Biancone L, Bachovchin W, McCluskey R, Andres G. In vivo modulation of CD26 (dipeptidyl peptidase IV) in the mouse: effects of polyreactive and monoreactive antibodies. Transplantation 1996; 62:973-85. [PMID: 8878393 DOI: 10.1097/00007890-199610150-00017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We previously reported that intravenous injections in rabbits or guinea pigs of divalent antibodies to purified protein or carbohydrate antigens located mainly on endothelial cells induce acute pulmonary edema, which is often lethal. Surviving animals develop resistance to the injurious effect of subsequent injection of antibodies (adaptation), associated with shedding of antigen-antibody complexes from endothelial cells. In the present study, we investigated and compared in mice the effects of 3-day multiple injections of two different rabbit antibody (IgG) preparations against antigens expressed mainly at the surface of epithelial cells. The first preparation contained antibodies to a single transmembrane protein, CD26 (dipeptidyl peptidase IV [DPP IV]) (monoreactive anti-DPP IV IgG); the second contained antibodies against multiple antigens of the renal tubular brush border (BB), including DPP IV (polyreactive anti-BB IgG). Both IgG preparations caused loss of DPP IV from the organs studied, as shown by reduction in enzyme activity in tissue homogenates and by immunofluorescence microscopy, which showed loss of DPP IV from cell surface. However, the monoreactive anti-DPP IV IgG induced considerably greater reduction than polyreactive anti-BB IgG. Loss of DPP IV from the cell surface probably occurred by shedding of immune complexes into vascular and extravascular fluids, including bile and urine. The results may have relevance to hyperacute rejection of xenografts, as from pigs to primates. Since human natural antibodies that bind to porcine cells are polyreactive, a new prophylactic strategy for hyperacute rejection might be based on down-regulation of the major xenogeneic antigen, alpha-galactosyl, by injecting donor animals with monoreactive alpha-galactosyl antibodies before transplantation.
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Affiliation(s)
- N Yamaguchi
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
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Hjälm G, Murray E, Crumley G, Harazim W, Lundgren S, Onyango I, Ek B, Larsson M, Juhlin C, Hellman P, Davis H, Akerström G, Rask L, Morse B. Cloning and sequencing of human gp330, a Ca(2+)-binding receptor with potential intracellular signaling properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 239:132-7. [PMID: 8706697 DOI: 10.1111/j.1432-1033.1996.0132u.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We present here the complete primary structure of human gp330, the human variant of the principal kidney autoantigen causing Heymann membranous glomerulonephritis in rats. The deduced 4655 amino acid residues give a calculated molecular mass of 519636 Da for the mature protein and consists of a probable 25-amino-acid N-terminal signal peptide sequence, an extracellular region of 4398 amino acids, a single transmembrane-spanning domain of 23 amino acids, and an intracellular C-terminal region of 209 amino acid residues. Three types of cysteine-rich repeats characteristic of the low density lipoprotein receptor (LDLR) superfamily are present in human gp330. In the extracellular region, there are a total of 36 LDLR ligand-binding repeats, comprising four distinct domains, 16 growth factor repeats separated by eight YWTD spacer regions, and one epidermal growth factor-like repeat. No consensus cleavage sequence for the processing endoprotease furin is detected in human gp330. The intracellular tail contains not only two copies of the F(X)NPXY coated-pit mediated internalization signal characteristic of LDLR superfamily members, but also intriguing and potentially functional motifs including several Src-homology 3 recognition motifs, one Src-homology 2 recognition motif for the p85 regulatory subunit of phosphatidylinositol 3-kinase, and additional sites for protein kinase C, casein kinase II and cAMP-/cGMP-dependent protein kinase. There is approximately 77% amino acid identity between human and rat gp330 with minor differences between the extracellular and intracellular regions. Recently gp330 has been implicated in Ca2+ regulation in the parathyroid, the placenta, and the renal tubule, but its overall physiological and pathological role still remains uncertain.
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Affiliation(s)
- G Hjälm
- Department of Bone Metabolism, Rhône-Poulenc Rorer Central Research, Collegeville PA, USA
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Stefansson S, Chappell DA, Argraves KM, Strickland DK, Argraves WS. Glycoprotein 330/low density lipoprotein receptor-related protein-2 mediates endocytosis of low density lipoproteins via interaction with apolipoprotein B100. J Biol Chem 1995; 270:19417-21. [PMID: 7642623 DOI: 10.1074/jbc.270.33.19417] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The ability of glycoprotein 330/low density lipoprotein receptor-related protein-2 (LRP-2) to function as a lipoprotein receptor was investigated using cultured mouse F9 teratocarcinoma cells. Treatment with retinoic acid and dibutyryl cyclic AMP, which induces F9 cells to differentiate into endoderm-like cells, produced a 50-fold increase in the expression of LRP-2. Levels of the other members of the low density lipoprotein (LDL) receptor (LDLR) family, including LDLR, the very low density lipoprotein receptor, and LRP-1, were reduced. When LDL catabolism was examined in these cells, it was found that the treated cells endocytosed and degraded at 10-fold higher levels than untreated cells. The increased LDL uptake coincided with increased LRP-2 activity of the treated cells, as measured by uptake of both 125I-labeled monoclonal LRP-2 antibody and the LRP-2 ligand prourokinase. The ability of LDL to bind to LRP-2 was demonstrated by solid-phase binding assays. This binding was inhibitable by LRP-2 antibodies, receptor-associated protein (the antagonist of ligand binding for all members of the LDLR family), or antibodies to apoB100, the major apolipoprotein component of LDL. In cell assays, LRP-2 antibodies blocked the elevated 125I-LDL internalization and degradation observed in the retinoic acid/dibutyryl cyclic AMP-treated F9 cells. A low level of LDL endocytosis existed that was likely mediated by LDLR since it could not be inhibited by LRP-2 antibodies, but was inhibited by excess LDL, receptor-associated protein, or apoB100 antibody. The results indicate that LRP-2 can function to mediate cellular endocytosis of LDL, leading to its degradation. LRP-2 represents the second member of the LDLR family identified as functioning in the catabolism of LDL.
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Affiliation(s)
- S Stefansson
- Biochemistry Department, J.H. Holland Laboratory, American Red Cross, Rockville, Maryland 20855, USA
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Kounnas MZ, Stefansson S, Loukinova E, Argraves KM, Strickland DK, Argraves WS. An overview of the structure and function of glycoprotein 330, a receptor related to the alpha 2-macroglobulin receptor. Ann N Y Acad Sci 1994; 737:114-23. [PMID: 7944141 DOI: 10.1111/j.1749-6632.1994.tb44305.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- M Z Kounnas
- Department of Biochemistry, J. H. Holland Laboratory, American Red Cross, Rockville, Maryland 20855
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Zheng G, Bachinsky DR, Abbate M, Andres G, Brown D, Stamenkovic I, Niles JL, McCluskey RT. gp330: receptor and autoantigen. Ann N Y Acad Sci 1994; 737:154-62. [PMID: 7944145 DOI: 10.1111/j.1749-6632.1994.tb44309.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- G Zheng
- Department of Pathology, Harvard Medical School, Massachusetts
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Vergleichende immunhistochemische und lectinhistochemische Untersuchungen an den Ependymzellen und den Epithelien der Plexus choroidei. Acta Histochem 1987. [DOI: 10.1016/s0065-1281(87)80030-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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