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Bhutto IA, McLeod DS, Thomson BR, Lutty GA, Edwards MM. Visualization of choroidal vasculature in pigmented mouse eyes from experimental models of AMD. Exp Eye Res 2024; 238:109741. [PMID: 38056552 PMCID: PMC10872330 DOI: 10.1016/j.exer.2023.109741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/22/2023] [Accepted: 11/26/2023] [Indexed: 12/08/2023]
Abstract
A variety of techniques exist to investigate retinal and choroidal vascular changes in experimental mouse models of human ocular diseases. While all have specific advantages, a method for evaluating the choroidal vasculature in pigmented mouse eyes has been more challenging especially for whole mount visualization and morphometric analysis. Here we report a simple, reliable technique involving bleaching pigment prior to immunostaining the vasculature in whole mounts of pigmented mouse choroids. Eyes from healthy adult pigmented C57BL/6J mice were used to establish the methodology. The retina and anterior segment were separated from the choroid. The choroid with retinal pigment epithelial cells (RPE) and sclera was soaked in 1% ethylenediaminetetraacetic acid (EDTA) to remove the RPE. Tissues were fixed in 2% paraformaldehyde (PFA) in phosphate-buffered saline (PBS). Choroids were subjected to melanin bleaching with 10% hydrogen peroxide (H2O2) at 55 °C for 90 min, washed in PBS and then immunostained with anti-podocalyxin antibody to label vascular endothelium followed by Cy3-AffiniPure donkey anti-goat IgG at 4 °C overnight. Images of immunostained bleached choroids were captured using a Zeiss 710 confocal microscope. In addition to control eyes, this method was used to analyze the choroids from subretinal sodium iodate (NaIO3) RPE atrophy and laser-induced choroidal neovascularization (CNV) mouse models. The H2O2 pretreatment effectively bleached the melanin, resulting in a transparent choroid. Immunolabeling with podocalyxin antibody following bleaching provided excellent visualization of choroidal vasculature in the flat perspective. In control choroids, the choriocapillaris (CC) displayed different anatomical patterns in peripapillary (PP), mid peripheral (MP) and far peripheral (FP) choroid. Morphometric analysis of the vascular area (VA) revealed that the CC was most dense in the PP region (87.4 ± 4.3% VA) and least dense in FP (79.9 ± 6.7% VA). CC diameters also varied depending on location from 11.4 ± 1.97 mm in PP to 15.1 ± 3.15 mm in FP. In the NaIO3-injected eyes, CC density was significantly reduced in the RPE atrophic regions (50.7 ± 5.8% VA in PP and 45.8 ± 6.17% VA in MP) compared to the far peripheral non-atrophic regions (82.8 ± 3.8% VA). CC diameters were significantly reduced in atrophic regions (6.35 ± 1.02 mm in PP and 6.5 ± 1.2 mm in MP) compared to non-atrophic regions (14.16 ± 2.12 mm). In the laser-induced CNV model, CNV area was 0.26 ± 0.09 mm2 and luminal diameters of CNV vessels were 4.7 ± 0.9 mm. Immunostaining on bleached choroids with anti-podocalyxin antibody provides a simple and reliable tool for visualizing normal and pathologic choroidal vasculature in pigmented mouse eyes for quantitative morphometric analysis. This method will be beneficial for examining and evaluating the effects of various treatment modalities on the choroidal vasculature in mouse models of ocular diseases such as age-related macular degeneration, and degenerative genetic diseases.
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Affiliation(s)
- Imran A Bhutto
- Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - D Scott McLeod
- Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Benjamin R Thomson
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg SOM, Chicago, IL, USA
| | - Gerard A Lutty
- Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Malia M Edwards
- Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Radu P, Zurzu M, Paic V, Bratucu M, Garofil D, Tigora A, Georgescu V, Prunoiu V, Pasnicu C, Popa F, Surlin P, Surlin V, Strambu V. CD34-Structure, Functions and Relationship with Cancer Stem Cells. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59050938. [PMID: 37241170 DOI: 10.3390/medicina59050938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/08/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023]
Abstract
The CD34 protein was identified almost four decades ago as a biomarker for hematopoietic stem cell progenitors. CD34 expression of these stem cells has been exploited for therapeutic purposes in various hematological disorders. In the last few decades, studies have revealed the presence of CD34 expression on other types of cells with non-hematopoietic origins, such as interstitial cells, endothelial cells, fibrocytes, and muscle satellite cells. Furthermore, CD34 expression may also be found on a variety of cancer stem cells. Nowadays, the molecular functions of this protein have been involved in a variety of cellular functions, such as enhancing proliferation and blocking cell differentiation, enhanced lymphocyte adhesion, and cell morphogenesis. Although a complete understanding of this transmembrane protein, including its developmental origins, its stem cell connections, and other functions, is yet to be achieved. In this paper, we aimed to carry out a systematic analysis of the structure, functions, and relationship with cancer stem cells of CD34 based on the literature overview.
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Affiliation(s)
- Petru Radu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Mihai Zurzu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Vlad Paic
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Mircea Bratucu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Dragos Garofil
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Anca Tigora
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
| | - Valentin Georgescu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
| | - Virgiliu Prunoiu
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
- Oncological Institute "Prof. Dr. Alexandru Trestioreanu", 022328 Bucharest, Romania
| | - Costin Pasnicu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Florian Popa
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
| | - Petra Surlin
- Department of Periodontology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania
| | - Valeriu Surlin
- Sixth Department of Surgery, University of Medicine and Pharmacy of Craiova, Craiova Emergency Clinical 7 Hospital, 200642 Craiova, Romania
| | - Victor Strambu
- General Surgery Department, Carol Davila Nephrology Hospital Bucharest, 020021 Bucharest, Romania
- Tenth Department of Surgery, University of Medicine and Pharmacy "Carol Davila" Bucharest, 050474 Bucharest, Romania
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Amo L, Díez-García J, Tamayo-Orbegozo E, Maruri N, Larrucea S. Podocalyxin Expressed in Antigen Presenting Cells Promotes Interaction With T Cells and Alters Centrosome Translocation to the Contact Site. Front Immunol 2022; 13:835527. [PMID: 35711462 PMCID: PMC9197222 DOI: 10.3389/fimmu.2022.835527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/02/2022] [Indexed: 11/25/2022] Open
Abstract
Podocalyxin (PODXL), a cell surface sialomucin expressed in diverse types of normal and malignant cells, mediates cellular adhesion to extracellular matrix and cell-to-cell interaction. A previous study reported the expression of PODXL protein on monocytes undergoing macrophage differentiation, yet the expression of this molecule in other antigen presenting cells (APCs) and its function in the immune system still remain undetermined. In this study, we report that PODXL is expressed in human monocyte-derived immature dendritic cells at both the mRNA and protein levels. Following dendritric cells maturation using pro-inflammatory stimuli, PODXL expression level decreased substantially. Furthermore, we found that PODXL expression is positively regulated by IL-4 through MEK/ERK and JAK3/STAT6 signaling pathways. Our results revealed a polarized distribution of PODXL during the interaction of APCs with CD4+ T cells, partially colocalizing with F-actin. Notably, PODXL overexpression in APCs promoted their interaction with CD4+ T cells and CD8+ T cells and decreased the expression of MHC-I, MHC-II, and the costimulatory molecule CD86. In addition, PODXL reduced the translocation of CD4+ T-cell centrosome toward the APC-contact site. These findings suggest a regulatory role for PODXL expressed by APCs in immune responses, thus representing a potential target for therapeutic blockade in infection and cancer.
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Affiliation(s)
- Laura Amo
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Javier Díez-García
- Microscopy Facility, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Estíbaliz Tamayo-Orbegozo
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Natalia Maruri
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, Barakaldo, Spain
| | - Susana Larrucea
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
- *Correspondence: Susana Larrucea,
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Asano T, Suzuki H, Kaneko MK, Kato Y. Epitope Mapping of a Cancer-Specific Anti-Podocalyxin Monoclonal Antibody (PcMab-60) Using Enzyme-Linked Immunosorbent Assay and Surface Plasmon Resonance. Monoclon Antib Immunodiagn Immunother 2021; 40:227-232. [PMID: 34678093 DOI: 10.1089/mab.2021.0030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Podocalyxin (PODXL) is a type I transmembrane sialoglycoprotein that is overexpressed in human cancers, including breast, oral, and lung. PODXL promotes tumor progression, and its expression is associated with poor prognosis. Since PODXL is expressed in normal cells, including kidney podocytes and vascular endothelial cells (VECs), cancer-specific monoclonal antibodies (mAbs) are necessary to reduce the adverse effects of antibody therapy on PODXL-expressing cancers. Previously, we established a cancer-specific mAb against PODXL, PcMab-60 (mouse IgM, kappa), by immunizing mice with soluble PODXL produced by LN229 glioblastoma cells. PcMab-60 reacted with PODXL-expressing cancer cells, but did not react with VECs. In this study, we investigated an epitope of PcMab-60 using flow cytometry, surface plasmon resonance (SPR), and enzyme-linked immunosorbent assay (ELISA). The results of SPR revealed that the PcMab-60 epitope consisted of Thr105, Arg109, Gly110, Gly111, Gly112, Ser113, Gly114, Asn115, Pro116, and Thr117. In contrast, the results of ELISA revealed that the PcMab-60 epitope consisted of Arg109, Gly110, Gly111, Gly112, Ser113, Gly114, Asn115, and Pro116. These results demonstrate the cancer-specific epitope, which was recognized by PcMab-60.
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Affiliation(s)
- Teizo Asano
- Department of Antibody Drug Development and Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroyuki Suzuki
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mika K Kaneko
- Department of Antibody Drug Development and Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development and Tohoku University Graduate School of Medicine, Sendai, Japan.,Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
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Podocalyxin in Normal Tissue and Epithelial Cancer. Cancers (Basel) 2021; 13:cancers13122863. [PMID: 34201212 PMCID: PMC8227556 DOI: 10.3390/cancers13122863] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022] Open
Abstract
Podocalyxin (PODXL), a glycosylated cell surface sialomucin of the CD34 family, is normally expressed in kidney podocytes, vascular endothelial cells, hematopoietic progenitors, mesothelium, as well as a subset of neurons. In the kidney, PODXL functions primarily as an antiadhesive molecule in podocyte epithelial cells, regulating adhesion and cell morphology, and playing an essential role in the development and function of the organ. Outside the kidney, PODXL plays subtle roles in tissue remodelling and development. Furthermore, many cancers, especially those that originated from the epithelium, have been reported to overexpress PODXL. Collective evidence suggests that PODXL overexpression is linked to poor prognosis, more aggressive tumour progression, unfavourable treatment outcomes, and possibly chemoresistance. This review summarises our current knowledge of PODXL in normal tissue function and epithelial cancer, with a particular focus on its underlying roles in cancer metastasis, likely involvement in chemoresistance, and potential use as a diagnostic and prognostic biomarker.
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Yorgancı A, Halici Ozturk F, Hancerliogullari N, Çandar T, Caglar AT, Ozgu-Erdinc AS. The role of serum podocalyxin levels in recurrent pregnancy loss. Eur J Obstet Gynecol Reprod Biol 2021; 260:114-117. [PMID: 33765479 DOI: 10.1016/j.ejogrb.2021.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To measure serum levels of podocalyxin (PODXL) in recurrent miscarriages as a marker of vascular endothelial dysfunction. STUDY DESIGN In this case-control study, women who were hospitalized for singleton first-trimester pregnancy terminations due to missed abortion, anembryonic pregnancy, and inevitable abortion were included. There were 24 patients who were admitted for the first pregnancy termination, 39 patients who were admitted for recurrent pregnancy loss (RPL), and 25 fetal cardiac activity positive patients as the control group. Demographic features, medical and obstetric histories were recorded. The measurements of serum PODXL were done by a human enzyme-linked immunosorbent assay kit. RESULTS Serum PODXL levels were found to be significantly higher in the RPL group than the control group and the first time miscarriage group (13.82 [10.09-113.54] vs. 11.78 [9.25-48.80], p = 0.016 and 13.82 [10.09-113.54] vs. 11.99 [8.20-20.47], p = 0.003; respectively). Serum PODXL levels were not statistically significantly different between the first miscarriage and the control group (p = 0.62). There were positive correlation between serum PODXL levels and the number of gravida and the number of miscarriages (r = 0.217, p = 0.042, and r = 0.291, p = 0.006; respectively). CONCLUSION Recurrent miscarriage patients had higher serum levels of PODXL than both normal pregnancies and first-time miscarriages. Our results suggest that maternal endothelial dysfunction might have a role in recurrent pregnancy losses.
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Affiliation(s)
- Ayçağ Yorgancı
- Department of Obstetrics and Gynecology, Ministry of Health Ankara City Hospital, Ankara, Turkey.
| | - Filiz Halici Ozturk
- Division of Perinatology, Department of Obstetrics and Gynecology, Ministry of Health Ankara City Hospital, Ankara, Turkey
| | - Necati Hancerliogullari
- Department of Obstetrics and Gynecology, Ministry of Health Ankara City Hospital, Ankara, Turkey
| | - Tuba Çandar
- Department of Biochemistry, Ufuk University Faculty of Medicine, Turkey
| | - Ali Turhan Caglar
- Division of Perinatology, Department of Obstetrics and Gynecology, University of Health Sciences Etlik Zübeyde Hanım Women's Health Education and Research Hospital, Ankara, Turkey
| | - A Seval Ozgu-Erdinc
- Department of Obstetrics and Gynecology, Ministry of Health Ankara City Hospital, Ankara, Turkey
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7
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Tamayo-Orbegozo E, Amo L, Díez-García J, Amutio E, Riñón M, Alonso M, Arana P, Maruri N, Larrucea S. Emerging Role of Podocalyxin in the Progression of Mature B-Cell Non-Hodgkin Lymphoma. Cancers (Basel) 2020; 12:cancers12020396. [PMID: 32046309 PMCID: PMC7072361 DOI: 10.3390/cancers12020396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/03/2020] [Accepted: 02/06/2020] [Indexed: 02/06/2023] Open
Abstract
Mature B-cell non-Hodgkin lymphoma (B-NHL) constitutes a group of heterogeneous malignant lymphoproliferative diseases ranging from indolent to highly aggressive forms. Although the survival after chemo-immunotherapy treatment of mature B-NHL has increased over the last years, many patients relapse or remain refractory due to drug resistance, presenting an unfavorable prognosis. Hence, there is an urgent need to identify new prognostic markers and therapeutic targets. Podocalyxin (PODXL), a sialomucin overexpressed in a variety of tumor cell types and associated with their aggressiveness, has been implicated in multiple aspects of cancer progression, although its participation in hematological malignancies remains unexplored. New evidence points to a role for PODXL in mature B-NHL cell proliferation, survival, migration, drug resistance, and metabolic reprogramming, as well as enhanced levels of PODXL in mature B-NHL. Here, we review the current knowledge on the contribution of PODXL to tumorigenesis, highlighting and discussing its role in mature B-NHL progression.
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Affiliation(s)
- Estíbaliz Tamayo-Orbegozo
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (E.T.-O.); (L.A.)
| | - Laura Amo
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (E.T.-O.); (L.A.)
| | - Javier Díez-García
- Microscopy Facility, Biocruces Bizkaia Health Research Institute, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain;
| | - Elena Amutio
- Blood Cancer Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain;
| | - Marta Riñón
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (M.R.); (M.A.); (P.A.); (N.M.)
| | - Marta Alonso
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (M.R.); (M.A.); (P.A.); (N.M.)
| | - Paula Arana
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (M.R.); (M.A.); (P.A.); (N.M.)
| | - Natalia Maruri
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (M.R.); (M.A.); (P.A.); (N.M.)
| | - Susana Larrucea
- Regulation of the Immune System Group, Biocruces Bizkaia Health Research Institute, Hospital Universitario Cruces, Plaza de Cruces 12, 48903 Barakaldo, Bizkaia, Spain; (M.R.); (M.A.); (P.A.); (N.M.)
- Correspondence:
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8
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El-Ashmawy HM, Selim FO, Hosny TAM, Almassry HN. Association of serum podocalyxin levels with peripheral arterial disease in patients with type 2 diabetes. J Diabetes Complications 2019; 33:495-499. [PMID: 31097305 DOI: 10.1016/j.jdiacomp.2019.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/17/2019] [Accepted: 04/06/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Renal podocalyxin is a marker for kidney diseases. Previous studies have shown the expression of serum podocalyxin (s-Podxl) in the endothelial cells of blood vessels. We aimed to investigate the association between s-podxl levels and peripheral arterial disease (PAD) in subjects with type 2 diabetes (T2DM). SUBJECTS AND METHODS Serum Podxl levels were analyzed in 69 subjects with normal glucose tolerance and PAD (NGT-PAD), 120 subjects with T2DM and PAD (D-PAD) and 36 subjects with T2DM without PAD (D-NPAD). RESULTS In D-PAD Patients, s-Podxl was significantly higher (17.67 ± 20.7 ng/mL) than in D-NPAD subjects (9.97 ± 5.34 ng/mL; P < 0.001). Subjects with NGT-PAD had significantly higher s-Podxl levels (15.34 ± 18.21 ng/mL), than D-NPAD patients (P < 0.001). Subjects with D-PAD and medial calcific sclerosis (MCS) had significantly higher s-Podxl levels compared to the same group but without MCS (P < 0.02). In D-PAD patients, MCS (P = 0.003) and glycosylated hemoglobin (P < 0.001) were the two variables that had the strongest prediction for s-Podxl as revealed by regression analysis. Multivariate regression showed that an increase of one standard deviation in s-Podxl was associated with an odds ratio of 3.4 (95% confidence interval = 2.2-4.6, P < 0.001) for the prevalence of PAD. CONCLUSIONS This is the first study showing an association between s-Podxl and PAD in patients with T2DM. S-Podxl was higher in D-PAD patients than in D-NPAD subjects. In NGT-PAD patients, s-Podxl was also higher than in D-NPAD patients. In patients with D-PAD, s-Podxl was positively associated with MCS.
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Affiliation(s)
- Hazem M El-Ashmawy
- Department of Internal Medicine, Zagazig University, Faculty of Medicine, Egypt.
| | - Fayrouz O Selim
- Department of Internal Medicine, Zagazig University, Faculty of Medicine, Egypt
| | - Thoraya A M Hosny
- Department of Clinical Pathology, Zagazig University, Faculty of Medicine, Egypt
| | - Hosam N Almassry
- Department of Radio-diagnosis, Zagazig University, Faculty of Medicine, Egypt
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9
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Caterson B, Melrose J. Keratan sulfate, a complex glycosaminoglycan with unique functional capability. Glycobiology 2018; 28:182-206. [PMID: 29340594 PMCID: PMC5993099 DOI: 10.1093/glycob/cwy003] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 12/20/2017] [Accepted: 01/08/2018] [Indexed: 12/19/2022] Open
Abstract
From an evolutionary perspective keratan sulfate (KS) is the newest glycosaminoglycan (GAG) but the least understood. KS is a sophisticated molecule with a diverse structure, and unique functional roles continue to be uncovered for this GAG. The cornea is the richest tissue source of KS in the human body but the central and peripheral nervous systems also contain significant levels of KS and a diverse range of KS-proteoglycans with essential functional roles. KS also displays important cell regulatory properties in epithelial and mesenchymal tissues and in bone and in tumor development of diagnostic and prognostic utility. Corneal KS-I displays variable degrees of sulfation along the KS chain ranging from non-sulfated polylactosamine, mono-sulfated and disulfated disaccharide regions. Skeletal KS-II is almost completely sulfated consisting of disulfated disaccharides interrupted by occasional mono-sulfated N-acetyllactosamine residues. KS-III also contains highly sulfated KS disaccharides but differs from KS-I and KS-II through 2-O-mannose linkage to serine or threonine core protein residues on proteoglycans such as phosphacan and abakan in brain tissue. Historically, the major emphasis on the biology of KS has focused on its sulfated regions for good reason. The sulfation motifs on KS convey important molecular recognition information and direct cell behavior through a number of interactive proteins. Emerging evidence also suggest functional roles for the poly-N-acetyllactosamine regions of KS requiring further investigation. Thus further research is warranted to better understand the complexities of KS.
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Affiliation(s)
- Bruce Caterson
- Connective Tissue Biology Laboratories, School of Biosciences, College of Biological & Life Sciences, Cardiff University, Cardiff, Wales, UK
| | - James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute of Medical Research, Northern Sydney Local Health District, St. Leonards, NSW, Australia
- Sydney Medical School, Northern, The University of Sydney, Royal North Shore Hospital, St. Leonards, NSW, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
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10
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Shoji M, Takemoto M, Kobayashi K, Shoji T, Mori S, Sagara JI, Kurosawa H, Hirayama Y, Sakamoto K, Ishikawa T, Koshizaka M, Maezawa Y, Yokote K. Serum podocalyxin levels correlate with carotid intima media thickness, implicating its role as a novel biomarker for atherosclerosis. Sci Rep 2018; 8:245. [PMID: 29321582 PMCID: PMC5762903 DOI: 10.1038/s41598-017-18647-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 12/15/2017] [Indexed: 12/05/2022] Open
Abstract
Podocalyxin is a cell surface sialomucin, which is expressed in not only glomerular podocytes but also vascular endothelial cells. Urinary podocalyxin is used as a marker for glomerular disease. However, there are no reports describing serum podocalyxin (s-Podxl) levels. Therefore, the association between s-Podxl levels and clinical parameters were examined with 52 patients. s-Podxl level was evaluated using enzyme-linked immunosorbent assay. The median s-Podxl level was 14.2 ng/dL (interquartile range: 10.8–22.2 ng/dL). There were significant correlations (correlation coefficient: r > 0.2) of s-Podxl levels with carotid intima media thickness (IMT) (r = 0.30, p = 0.0307). Multiple logistic regression analysis showed that s-Podxl levels remained significantly associated with carotid IMT > 1 mm (OR: 1.15; 95% CI 1.02–1.31, p = 0.026) after adjustments for traditional cardiovascular risk factors such as age, sex, current smoking status, hypertension, dyslipidemias, and diabetes. In conclusion, s-Podxl is independently associated with carotid IMT and might be used as a novel biomarker for cardiovascular disease.
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Affiliation(s)
- Mayumi Shoji
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
| | - Minoru Takemoto
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan. .,School of Medicine, International University of Health and Welfare, Department of Diabetes, Metabolism and Endocrinology, 4-3 Kozunomori, Narita-shi, Chiba, 286-8686, Japan.
| | - Kazuki Kobayashi
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Asahi Chuo Hospital, 1326, Ino, Asahi-shi, Chiba, 289-2511, Japan
| | - Toshihiro Shoji
- Department of Cardiology, Chiba Emergency Medical Center, Chiba, 3-32-1, Isobe, Mihama-ku, Chiba-shi, Chiba, 261-0012, Japan
| | - Satoka Mori
- Life Inovation Research Institute, Denka Co., Ltd, 3-5-1, Asahi-Machi, Machida-City, Tokyo, 194-0023, Japan
| | - Jun-Ichi Sagara
- Life Inovation Research Institute, Denka Co., Ltd, 3-5-1, Asahi-Machi, Machida-City, Tokyo, 194-0023, Japan
| | - Hiroyuki Kurosawa
- R&D Center, Denka Seikne Co., Ltd, 1359-1, Kagamida, Kigoshi, Gosen-City, Niigata, 959-1695, Japan
| | - Yoshiaki Hirayama
- R&D Center, Denka Seikne Co., Ltd, 1359-1, Kagamida, Kigoshi, Gosen-City, Niigata, 959-1695, Japan
| | - Kenichi Sakamoto
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
| | - Takahiro Ishikawa
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
| | - Masaya Koshizaka
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
| | - Yoshiro Maezawa
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
| | - Koutaro Yokote
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan.,Department of Medicine, Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba, 260-8670, Japan
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11
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Horrillo A, Porras G, Ayuso MS, González-Manchón C. Loss of endothelial barrier integrity in mice with conditional ablation of podocalyxin (Podxl) in endothelial cells. Eur J Cell Biol 2016; 95:265-76. [PMID: 27289182 DOI: 10.1016/j.ejcb.2016.04.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 11/29/2022] Open
Abstract
Podocalyxin (Podxl) has an essential role in the development and function of the kidney glomerular filtration barrier. It is also expressed by vascular endothelia but perinatal lethality of podxl(-/-) mice has precluded understanding of its function in adult vascular endothelial cells (ECs). In this work, we show that conditional knockout mice with deletion of Podxl restricted to the vascular endothelium grow normally but most die spontaneously around three months of age. Histological analysis showed a nonspecific inflammatory infiltrate within the vessel wall frequently associated with degenerative changes, and involving vessels of different caliber in one or more organs. Podxl-deficient lung EC cultures exhibit increased permeability to dextran and macrophage transmigration. After thrombin stimulation, ECs lacking Podxl showed delayed recovery of VE-cadherin cell contacts, persistence of F-actin stress fibers, and sustained phosphorylation of the ERM complex and activation of RhoA, suggesting a failure in endothelial barrier stabilization. The results suggest that Podxl has an essential role in the regulation of endothelial permeability by influencing the mechanisms involved in the restoration of endothelial barrier integrity after injury.
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Affiliation(s)
- Angélica Horrillo
- Department of Cellular and Molecular Medicine, Centre of Biological Research-CIB, CSIC, Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Gracia Porras
- Department of Cellular and Molecular Medicine, Centre of Biological Research-CIB, CSIC, Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Matilde S Ayuso
- Department of Cellular and Molecular Medicine, Centre of Biological Research-CIB, CSIC, Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Consuelo González-Manchón
- Department of Cellular and Molecular Medicine, Centre of Biological Research-CIB, CSIC, Madrid, Spain; CIBER de Enfermedades Raras (CIBERER), Madrid, Spain.
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12
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Chijiiwa Y, Moriyama T, Ohuchida K, Nabae T, Ohtsuka T, Miyasaka Y, Fujita H, Maeyama R, Manabe T, Abe A, Mizuuchi Y, Oda Y, Mizumoto K, Nakamura M. Overexpression of microRNA-5100 decreases the aggressive phenotype of pancreatic cancer cells by targeting PODXL. Int J Oncol 2016; 48:1688-700. [PMID: 26892887 DOI: 10.3892/ijo.2016.3389] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/21/2016] [Indexed: 11/05/2022] Open
Abstract
Metastasis is the main cause of cancer-associated death, and metastasis of pancreatic cancer remains difficult to treat because of its aggressiveness. MicroRNAs (miRNAs) play crucial roles in the regulation of various human transcripts, and many miRNAs have been reported to correlate with cancer metastasis. We identified an anti-metastatic miRNA, miR-5100, by investigating differences in miRNA profiling between highly metastatic pancreatic cancer cells and their parental cells. Overexpression of miR-5100 inhibited colony formation (P<0.05), cell migration (P<0.0001) and invasion (P<0.0001) of pancreatic cancer cells. In addition, we identified a possible target of miR-5100, podocalyxin-like 1 (PODXL), and demonstrated miR-5100 directly binds to the 3' untranslated region of PODXL and post-transcriptionally regulates its expression in pancreatic cancer cells. Silencing PODXL resulted in diminished cell migration (P<0.0001) and invasion (P<0.05). We also clarified the close relationship between expression of PODXL in human pancreatic cancer specimens and liver metastasis (P=0.0003), and determined that post-operative survival was longer in the low-PODXL expression group than in the high-PODXL expression group (P<0.05). These results indicate that miR-5100 and PODXL have considerable therapeutic potential for anti-metastatic therapy and could be potential indicators for cancer metastases in patients with pancreatic cancer.
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Affiliation(s)
- Yoshiro Chijiiwa
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Taiki Moriyama
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kenoki Ohuchida
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toshinaga Nabae
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takao Ohtsuka
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshihiro Miyasaka
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hayato Fujita
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryo Maeyama
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tatsuya Manabe
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsushi Abe
- Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yusuke Mizuuchi
- Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshinao Oda
- Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | | | - Masafumi Nakamura
- Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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13
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Amo L, Tamayo-Orbegozo E, Maruri N, Eguizabal C, Zenarruzabeitia O, Riñón M, Arrieta A, Santos S, Monge J, Vesga MA, Borrego F, Larrucea S. Involvement of platelet-tumor cell interaction in immune evasion. Potential role of podocalyxin-like protein 1. Front Oncol 2014; 4:245. [PMID: 25309871 PMCID: PMC4160963 DOI: 10.3389/fonc.2014.00245] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/26/2014] [Indexed: 11/13/2022] Open
Abstract
Besides their essential role in hemostasis and thrombosis, platelets are involved in the onset of cancer metastasis by interacting with tumor cells. Platelets release secretory factors that promote tumor growth, angiogenesis, and metastasis. Furthermore, the formation of platelet-tumor cell aggregates in the bloodstream provides cancer cells with an immune escape mechanism by protecting circulating malignant cells from immune-mediated lysis by natural killer (NK) cells. Platelet-tumor cell interaction is accomplished by specific adhesion molecules, including integrins, selectins, and their ligands. Podocalyxin-like protein 1 (PCLP1) is a selectin-ligand protein in which overexpression has been associated with several aggressive cancers. PCLP1 expression enhances cell adherence to platelets in an integrin-dependent process and through the interaction with P-selectin expressed on activated platelets. However, the involvement of PCLP1-induced tumor-platelet interaction in tumor immune evasion still remains unexplored. The identification of selectin ligands involved in the interaction of platelets with tumor cells may provide help for the development of effective therapies to restrain cancer cell dissemination. This article summarizes the current knowledge on molecules that participate in platelet-tumor cell interaction as well as discusses the potential role of PCLP1 as a molecule implicated in tumor immune evasion.
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Affiliation(s)
- Laura Amo
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | - Estíbaliz Tamayo-Orbegozo
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | - Natalia Maruri
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | | | - Olatz Zenarruzabeitia
- Immunopathology Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | - Marta Riñón
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | - Arantza Arrieta
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
| | - Silvia Santos
- Basque Center for Transfusion and Human Tissues , Galdakao , Spain
| | - Jorge Monge
- Basque Center for Transfusion and Human Tissues , Galdakao , Spain
| | | | - Francisco Borrego
- Immunopathology Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain ; Ikerbasque, Basque Foundation for Science , Bilbao , Spain
| | - Susana Larrucea
- Regulation of the Immune System Group, BioCruces Health Research Institute, Hospital Universitario Cruces , Barakaldo , Spain
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14
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Palacios de Franco Y, Velazquez K, Segovia N, Acosta C, Yanosky D, Franco Palacios YV, Ramos A, Franco Palacios CR. Urinary podocalyxin as a marker of preeclampsia in a Hispanic population. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2014; 6:115-124. [PMID: 25057338 PMCID: PMC4106648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 05/29/2014] [Indexed: 06/03/2023]
Abstract
BACKGROUND Preeclampsia is associated with significant materno-fetal morbidity and mortality. Podocyturia due to podocyte damage seems to be associated with the disease. The objective of this study was to evaluate the usefulness of urinary podocalyxin as a marker of preeclampsia in a Hispanic population. METHODS 63 patients were studied. 25 patients had preeclampsia/eclampsia (PE-E). 38 patients had normal pregnancies and served as control group. 24 hour proteinuria, urine protein/creatinine (UPC), urinary podocalyxin and perinatal outcomes were measured. A Podocalyxin ELISA test was used to detect podocyturia. RESULTS Mean age (years), mean±SD was 30.5±5.4 in normal patients vs 30.6±5.8 in PE-E, p=0.98. Median gestational age (weeks) was, 38 (range 21-42) for normal pregnancies and 36 (range 24-40) for patients with PE-E, <0.001. Urine podocalyxin/creatinine on admission (ng/mg), median [IQR] in normal patients was 55.9 [29.4, 74.9] vs 109.7 [63.8, 234.1] in PE-E, p=0.001. After adjusting for admission proteinuria, urinary podocalyxin remained independently associated with preeclampsia: OR=1.0040 (95% CI 1.0003-1.0078), p=0.03. There was low to moderate correlation between UPC and urinary podocalyxin, Spearman's =0.31, p=0.01. In PE-E, post-partum urine podocalyxin was lower, median [IQR]: 69.7 [32.7, 184.8] p=0.19 vs admission. There was a trend towards more podocyturia and proteinuria in patients with eclampsia, comparing to those with preeclampsia. There was no association observed between podocyturia and neonatal mortality, IUGR or Apgar scores. CONCLUSIONS Significantly higher levels of urinary podocalyxin are seen in preeclampsia/eclampsia. They tend to normalize after delivery.
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Affiliation(s)
- Ylbe Palacios de Franco
- Catholic University of Asuncion School of MedicineAsuncion, Paraguay
- Department of Obstetrics and Gynecology, Instituto de Prevision Social (IPS) HospitalAsuncion, Paraguay
| | - Karina Velazquez
- Department of Laboratory Medicine, Instituto de Prevision Social (IPS) HospitalAsuncion, Paraguay
| | - Natalia Segovia
- Department of Clinical Immunology, Instituto de Prevision Social (IPS) HospitalAsuncion, Paraguay
| | - Carolina Acosta
- Department of Obstetrics and Gynecology, Instituto de Prevision Social (IPS) HospitalAsuncion, Paraguay
| | - Deborah Yanosky
- Department of Obstetrics and Gynecology, Instituto de Prevision Social (IPS) HospitalAsuncion, Paraguay
| | - Ylbe V Franco Palacios
- Department of Obstetrics and Gynecology, Complete Care Health Network, South Jersey General HospitalVineland, NJ. USA
| | - Amanda Ramos
- Department of Gynecology and Obstetrics, Johns Hopkins HospitalBaltimore, MD. USA
| | - Carlos R Franco Palacios
- Department of Nephrology, Affiliated Community Medical Centers, Rice Memorial HospitalWillmar, MN. USA
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15
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Expression of caveolin-1 and podocalyxin in rat lungs challenged with 2-kDa macrophage-activating lipopeptide and Flt3L. Cell Tissue Res 2014; 356:207-16. [PMID: 24419512 DOI: 10.1007/s00441-013-1771-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 11/14/2013] [Indexed: 10/25/2022]
Abstract
Caveolin-1 is one of the important regulators of vascular permeability in inflamed lungs. Podocalyxin is a CD34 protein expressed on vascular endothelium and has a role in podocyte development in the kidney. Few data are available on the expression of caveolin-1 and podocalyxin in lungs challenged with Toll-like receptor 2 (TLR2) agonists such as mycoplasma-derived macrophage activating lipopeptide or with immune modulators such as Fms-like tyrosine kinase receptor-3 ligand (Flt3L), which expands dendritic cell populations in the lung. Because of the significance of pathogen-derived molecules that act through TLR2 and of the role of immune modulators in lung physiology, we examine the immunohistochemical expression of caveolin-1 and podocalyxin in lungs from rats challenged with a 2-kDa macrophage-activating lipopeptide (MALP-2) and Flt3L. Normal rat lungs expressed caveolin-1 in alveolar septa, vascular endothelium and airway epithelium, especially along the lateral borders of epithelial cells but not in alveolar macrophages. MALP-2 and Flt3L decreased and increased, respectively, the expression of caveolin-1. Caveolin-1 expression seemed to increase in microvessels in bronchiole-associated lymphoid tissue (BALT) in Flt3L-challenged lungs but not in normal or MALP-2-treated lungs. Podocalyxin was absent in the epithelium and alveolar macrophages but was present in the vasculature of control, Flt3L- and MALP-2-treated rats. Compared with control and MALP-2-treated rats, Flt3L-treated lungs showed greater expression of podocalyxin in BALT vasculature and at the interface of monocytes and the endothelium. These immunohistochemical data describing the altered expression of caveolin-1 and podocalyxin in lungs treated with MALP-2 or Flt3L encourage further mechanistic studies on the role of podocalyxin and caveolin-1 in lung inflammation.
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16
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Larsson AH, Nodin B, Syk I, Palmquist I, Uhlén M, Eberhard J, Jirström K. Podocalyxin-like protein expression in primary colorectal cancer and synchronous lymph node metastases. Diagn Pathol 2013; 8:109. [PMID: 23819542 PMCID: PMC3751142 DOI: 10.1186/1746-1596-8-109] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/25/2013] [Indexed: 11/10/2022] Open
Abstract
Aims Previous studies have shown that membranous expression of podocalyxin-like protein (PODXL) is associated with poor prognosis in colorectal cancer (CRC). In this study, we compared PODXL expression in primary CRC and synchronous lymph node metastases. We further analyzed whether its expression changed in rectal tumours after neoadjuvant radiation therapy. Methods and results The studied cohort consists of 73 consecutive patients from the South-Swedish Colorectal Cancer Biobank. Immunohistochemical PODXL expression was examined on full-face sections from all primary tumours and all 140 available lymph node metastases from 31 cases. Membranous PODXL expression was denoted in 18/73 (24,7%) primary tumours, with a high concordance between primary and metastatic lesions. While all negative primary tumours had negative metastases, some PODXL positive primaries had a varying proportion of positive and negative metastatic lymph nodes. PODXL expression was also found to be mainly unaltered in pre- and post-irradiation surgically resected tumour specimens in rectal cancer patients (n=16). Conclusions The findings in this study suggest that analysis of PODXL expression in the primary tumour is sufficient for its use as a prognostic and treatment predictive biomarker in CRC, also in patients with metastatic disease. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9014177329634352
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Affiliation(s)
- Anna H Larsson
- Department of Clinical Sciences, Division of Pathology, Lund University, Skåne University Hospital, SE-221 85 Lund, Sweden.
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17
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Dallas MR, Chen SH, Streppel MM, Sharma S, Maitra A, Konstantopoulos K. Sialofucosylated podocalyxin is a functional E- and L-selectin ligand expressed by metastatic pancreatic cancer cells. Am J Physiol Cell Physiol 2012; 303:C616-24. [PMID: 22814396 DOI: 10.1152/ajpcell.00149.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Selectin-mediated interactions in the vasculature promote metastatic spread by facilitating circulating tumor cell binding to selectin-expressing host cells. Therefore, identifying the selectin ligand(s) on tumor cells is critical to the prevention of blood-borne metastasis. A current challenge is to distinguish between structures expressed by circulating tumor cells that can bind selectins in vitro from the functional ligands whose depletion suppresses selectin-dependent binding under flow in vivo. Interestingly, podocalyxin (PODXL), which can bind E- and L-selectin, is upregulated in a number of cancers, including those of the breast, colon, and pancreas. In this work, we show that metastatic pancreatic cancer cells overexpress PODXL compared with nonmalignant pancreatic epithelial cells. We further demonstrate via tissue microarray that 69% of pancreatic ductal adenocarcinomas stain positive for PODXL. In cases of focal expression, positive staining is restricted to the invasive front of primary tumors. By combining immunoblot, immunodepletion, short-hairpin RNA-mediated gene silencing, and flow-based adhesion assays, we evaluated the functional role of sialofucosylated PODXL in selectin-mediated adhesion under flow. Our data indicate that sialofucosylated PODXL is a functional E- and L-selectin ligand expressed by metastatic pancreatic cancer cells, as specific depletion of this molecule from the cell surface significantly interferes with selectin-dependent interactions. Cumulatively, these data support a correlation between sialofucosylated PODXL expression and enhanced binding to selectins by metastatic pancreatic cancer cells and offer additional perspective on the upregulation of PODXL in aggressive cancers.
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Affiliation(s)
- Matthew R Dallas
- Dept. of Chemical and Biomolecular Engineering, Johns Hopkins Univ., Baltimore, MD 21218, USA
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18
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The anti-adhesive mucin podocalyxin may help initiate the transperitoneal metastasis of high grade serous ovarian carcinoma. Clin Exp Metastasis 2012; 29:239-52. [DOI: 10.1007/s10585-011-9446-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 12/22/2011] [Indexed: 01/04/2023]
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19
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Pericacho M, Alonso-Martín S, Larrucea S, González-Manchón C, Fernández D, Sánchez I, Ayuso MS, Parrilla R. Diminished thrombogenic responses by deletion of the Podocalyxin Gene in mouse megakaryocytes. PLoS One 2011; 6:e26025. [PMID: 22016802 PMCID: PMC3189243 DOI: 10.1371/journal.pone.0026025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 09/15/2011] [Indexed: 11/19/2022] Open
Abstract
Podocalyxin (Podxl) is a type I membrane sialoprotein of the CD34 family, originally described in the epithelial glomerular cells of the kidney (podocytes) in which it plays an important function. Podxl can also be found in megakaryocytes and platelets among other extrarenal places. The surface exposure of Podxl upon platelet activation suggested it could play some physiological role. To elucidate the function of Podxl in platelets, we generated mice with restricted ablation of the podxl gene in megakaryocytes using the Cre-LoxP gene targeting methodology. Mice with Podxl-null megakaryocytes did not show any apparent phenotypical change and their rates of growth, life span and fertility did not differ from the floxed controls. However, Podxl-null mice showed prolonged bleeding time and decreased platelet aggregation in response to physiological agonists. The number, size-distribution and polyploidy of Podxl-null megakaryocytes were similar to the floxed controls. Podxl-null platelets showed normal content of surface receptors and normal activation by agonists. However, the mice bearing Podxl-null platelets showed a significant retardation in the ferric chloride-induced occlusion of the carotid artery. Moreover, acute thrombosis induced by the i.v. injection of sublethal doses of collagen and phenylephrine produced a smaller fall in the number of circulating platelets in Podxl-null mice than in control mice. In addition, perfusion of uncoagulated blood from Podxl-null mice in parallel flow chamber showed reduced adhesion of platelets and formation of aggregates under high shear stress. It is concluded that platelet Podxl is involved in the control of hemostasis acting as a platelet co-stimulator, likely due to its pro-adhesive properties.
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Affiliation(s)
| | - Sonia Alonso-Martín
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
| | - Susana Larrucea
- Laboratorio de Inmunología, Hospital de Cruces, Baracaldo, Spain
| | - Consuelo González-Manchón
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | | | - Inés Sánchez
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
| | - Matilde S. Ayuso
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Roberto Parrilla
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
- * E-mail:
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20
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Vitureira N, Andrés R, Pérez-Martínez E, Martínez A, Bribián A, Blasi J, Chelliah S, López-Doménech G, De Castro F, Burgaya F, McNagny K, Soriano E. Podocalyxin is a novel polysialylated neural adhesion protein with multiple roles in neural development and synapse formation. PLoS One 2010; 5:e12003. [PMID: 20706633 PMCID: PMC2919383 DOI: 10.1371/journal.pone.0012003] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2010] [Accepted: 06/30/2010] [Indexed: 12/21/2022] Open
Abstract
Neural development and plasticity are regulated by neural adhesion proteins, including the polysialylated form of NCAM (PSA-NCAM). Podocalyxin (PC) is a renal PSA-containing protein that has been reported to function as an anti-adhesin in kidney podocytes. Here we show that PC is widely expressed in neurons during neural development. Neural PC interacts with the ERM protein family, and with NHERF1/2 and RhoA/G. Experiments in vitro and phenotypic analyses of podxl-deficient mice indicate that PC is involved in neurite growth, branching and axonal fasciculation, and that PC loss-of-function reduces the number of synapses in the CNS and in the neuromuscular system. We also show that whereas some of the brain PC functions require PSA, others depend on PC per se. Our results show that PC, the second highly sialylated neural adhesion protein, plays multiple roles in neural development.
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Affiliation(s)
- Nathalia Vitureira
- Institute for Research in Biomedicine, Parc Cientific de Barcelona, Barcelona, Spain
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21
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Alonso-Martin S, Nowakowski A, Larrucea S, Fernández D, Vilar-Egea M, Ayuso MS, Parrilla R. Overexpression of podocalyxin in megakaryocytes and platelets decreases the bleeding time and enhances the agonist-induced aggregation of platelets. Thromb Res 2010; 125:e300-5. [PMID: 20223501 DOI: 10.1016/j.thromres.2010.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 02/05/2010] [Accepted: 02/10/2010] [Indexed: 11/27/2022]
Abstract
Podocalyxin (PODXL) is a 145KDa sialoprotein abundantly expressed in the glycocalix of the intraglomerular kidney epithelial cells, essential in maintaining a normal renal function. PODXL is also found in vascular endothelial cells, megakaryocytes and platelets. The function of PODXL in platelets is ignored; however, its surface exposure upon platelet activation suggests its participation in controlling the hemostasis. We have generated mice (pralphaIIb-PODXL) overexpressing PODXL specifically in megakaryocytes , either alone or as a fusion protein with green fluorescent protein. The transgenic mice showed a phenotype characterized by decreased bleeding time, mild rebleeding and enhanced platelets aggregation upon agonist stimulation. The cytohematological exams as well as the prothrombin time (PT) and (APTT) tests did not differ from the control group. The biochemical analysis showed only a discrete hyperlipemia and a rise in plasma uric acid levels in the transgenic mice. The present data seem to indicate that PODXL may act as a costimulator of agonists in the activation of platelets and formation of a stable thrombus.
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Affiliation(s)
- Sonia Alonso-Martin
- Department of Physiopathology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040-Madrid, Spain
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Nowakowski A, Alonso-Martín S, González-Manchón C, Larrucea S, Fernández D, Vilar M, Cerdán S, Ayuso MS, Parrilla R. Ventricular enlargement associated with the panneural ablation of the podocalyxin gene. Mol Cell Neurosci 2010; 43:90-7. [DOI: 10.1016/j.mcn.2009.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 09/14/2009] [Accepted: 09/25/2009] [Indexed: 10/20/2022] Open
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Agarwal N, Lippmann ES, Shusta EV. Identification and expression profiling of blood-brain barrier membrane proteins. J Neurochem 2009; 112:625-35. [PMID: 19895664 DOI: 10.1111/j.1471-4159.2009.06481.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Blood-brain barrier (BBB) membrane proteins play crucial roles in the proper functioning of the BBB as well as in disease progression. Previously, we developed a novel approach for identifying membrane proteins expressed at the BBB, which we referred to as multiplex expression cloning. In this study, the proteome coverage of the multiplex expression cloning approach was expanded to allow the identification of a total of 30 BBB membrane proteins that are diverse in function and abundance. To unveil those membrane proteins that are enriched at the BBB and hence partially responsible for some of its unique characteristics, the transcript abundance levels for all 30 BBB membrane proteins were compared with those found in microvessels derived from lung, liver, heart, and kidney. Such quantitative PCR profiling of RNA samples from laser capture microdissected microvessels revealed that the transcripts for five membrane proteins, namely Lutheran glycoprotein, carbonic anhydrase IV, uncoupling protein 2, podocalyxin, and solute carrier family 38, member 5, were BBB selective, in that expression was elevated in brain microvessels when compared with all of the vascular beds tested. Many other membrane protein transcripts, whereas not as BBB-restricted, showed selective expression within subsets of tissues indicating other potential parallels and contrasts between vascular beds in the body. The identification of BBB membrane proteins could help better understand the molecular mechanisms responsible for BBB function and those with selective expression may have utility for BBB-targeted therapies.
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Affiliation(s)
- Nitin Agarwal
- Department of Chemical and Biological Engineering, University of Wisconsin - Madison, Madison, Wisconsin 53706, USA
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24
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Abstract
Podocalyxin, a sialomucin most closely related to CD34 and endoglycan, is expressed by kidney podocytes, hematopoietic progenitors, vascular endothelia, and a subset of neurons; aberrant expression has recently been implicated in a range of cancers. Through interactions with several intracellular proteins and at least one extracellular ligand, podocalyxin regulates both adhesion and cell morphology. In the developing kidney, podocalyxin plays an essential role in the formation and maintenance of podocyte foot processes, and its absence results in perinatal lethality. Podocalyxin expression in the hematopoietic system correlates with cell migration and the seeding of new hematopoietic tissues. In addition, it is abnormally expressed in subsets of breast, prostate, liver, pancreatic, and kidney cancer as well as leukemia. Strikingly, it is often associated with the most aggressive cases, and it is likely involved in metastasis. Thus, a thorough investigation of the normal activities of podocalyxin may facilitate the development of new cancer treatment strategies.
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Affiliation(s)
- Julie S Nielsen
- The Biomedical Research Centre, Vancouver, British Columbia, Canada
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25
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Abstract
For almost 30 years, the cell-surface protein CD34 has been widely used as a marker to assist in the identification and Summary isolation of hematopoietic stem cells (HSCs) and progenitors in preparation for bone-marrow transplantation. In addition, it has increasingly been used as a marker to help identify other tissue-specific stem cells, including muscle satellite cells and epidermal precursors. Despite its utility as a stem-cell marker, however, the function of CD34 has remained remarkably elusive. This is probably because: (1) it is subject to a range of tissue-specific post-transcriptional and post-translational modifications that are expected to alter its function dramatically; (2) the simple interpretation of CD34 gain- and loss-of-function experiments has been confounded by the overlapping expression of the two recently discovered CD34-related proteins podocalyxin and endoglycan; and (3) there has been a glaring lack of robust in vitro and in vivo functional assays that permit the structural and functional analysis of CD34 and its relatives. Here, we provide a brief review of the domain structure, genomic organization, and tissue distribution of the CD34 family. We also describe recent insights from gain- and loss-of-function experiments and improved assays, which are elucidating a fascinating role for these molecules in cell morphogenesis and migration.
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Affiliation(s)
- Julie S Nielsen
- Trev and Joyce Deeley Research Centre, British Columbia Cancer Agency, 2410 Lee Avenue, Victoria, BC, Canada V8R 6V5
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Abstract
The ability to form epithelial lumina is a central architectural characteristic of virtually all organs and indispensable for their function. Ontogenetically, the kidney is one of the best-characterized organs, but concepts of the regulated formation of its hollow epithelial structures are still emerging. Epithelial cell lines provide the opportunity to study molecular mechanisms in simplified assays modeling cyst and tube formation. In these systems, several groups have identified molecules implicated in lumen formation, and their downregulation results in either multiple-lumen or no-lumen phenotypes. On the basis of these phenotypes, we propose a working model, assigning proteins to groups with similar functions. Defects within these specific protein groups lead to distinct epithelial phenotypes. Studies of mesenchymal-to-epithelial transition underline the importance of these protein groups, but converting these basic models of lumen formation to an understanding of the mesenchymal to tubule formation during kidney development is still challenging.
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Affiliation(s)
- Marc A Schlüter
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Testa JE, Chrastina A, Li Y, Oh P, Schnitzer JE. Ubiquitous yet distinct expression of podocalyxin on vascular surfaces in normal and tumor tissues in the rat. J Vasc Res 2009; 46:311-24. [PMID: 19142011 DOI: 10.1159/000189792] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 07/16/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The vasculature has become an important target in the development of therapies for increasing numbers of human diseases, yet there are few reliable markers available to identify the endothelium in rodent models. We have characterized the expression, subcellular localization and accessibility of the rat pan-endothelial marker podocalyxin (podxl) using a newly developed monoclonal antibody (mAb), G278. METHODS podxl expression and accessibility to binding by G278 were determined in the rat by a variety of experimental approaches. RESULTS mAb G278 reliably immunostained blood vessels of all types and of every size in fresh-frozen, fixed-frozen and paraffin-embedded sections of all tissues, but did not stain lymphatic vessels. Western blotting, in vivo imaging and biodistribution analyses demonstrated that the highest levels of endothelial podxl were found in the lung and heart. We also determined that podxl is not enriched in caveolae and that its expression can be modulated in the tumor microenvironment. CONCLUSION Our study shows that podxl is a better identifier of rat endothelia than are some of the more commonly used markers and that mAb G278 is a robust antibody for use not only in identifying rat blood vessels but also as a tool to elucidate podxl function.
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Maltby S, Hughes MR, Zbytnuik L, Paulson RF, McNagny KM. Podocalyxin selectively marks erythroid-committed progenitors during anemic stress but is dispensable for efficient recovery. Exp Hematol 2008; 37:10-8. [PMID: 19004540 DOI: 10.1016/j.exphem.2008.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 09/10/2008] [Accepted: 09/11/2008] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Podocalyxin expression on Ter119(+) erythroblasts is induced following administration of erythropoietin (Epo) or phenylhydrazine treatment, but is notably absent on committed erythroid progenitors during homeostatic red cell turnover. Following high-dose Epo administration in vivo, podocalyxin surface expression is upregulated, in part, via a signal transducers and activators of transcription 5-dependent pathway and this expression has been postulated to play a role in the release of reticulocytes from hematopoietic organs into the periphery under conditions of increased erythropoietic rate. Here we have thoroughly addressed this hypothesis and further examined the expression profile of podocalyxin during Epo-induced erythroblast expansion and stress erythropoiesis. MATERIALS AND METHODS Following Epo induction, progenitor cells were sorted to characterize podocalyxin expression during stress. In addition, as podocalyxin-deficient mice die perinatally, we used chimeric mice reconstituted with wild-type or podocalyxin-deficient hematopoietic cells to analyze differences in response to high dose Epo administration and chemically induced anemia. RESULTS Podocalyxin surface expression is rapidly upregulated in response to stress and marks early erythroid progenitors and erythroblasts. Despite loss of podocalyxin, chimeras exhibit normal basal erythropoiesis and no differences in erythroid progenitor proportions in the spleen and marrow in response to Epo. Further, podocalyxin is dispensable for efficient recovery from models of anemia. CONCLUSIONS We demonstrate that podocalyxin is a highly specific marker of stress-induced blast-forming unit erythroid and colony-forming unit erythroid progenitors in mouse bone marrow and spleen. In addition, our findings suggest that podocalyxin is not necessary for efficient erythroblast expansion, erythroid differentiation, or reticulocyte release in response to Epo stimulation in vivo.
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Affiliation(s)
- Steven Maltby
- The Biomedical Research Centre, The University of British Columbia, Vancouver, Canada
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Skoberne A, Konieczny A, Schiffer M. Glomerular epithelial cells in the urine: what has to be done to make them worthwhile? Am J Physiol Renal Physiol 2008; 296:F230-41. [PMID: 18842819 DOI: 10.1152/ajprenal.90507.2008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The significance of the native urine sediment in the differential of glomerular diseases needs no further comment. However, the question arises whether it could be useful to develop a more specific diagnostic approach to identify the origin of renal epithelial cells that can be detected in the urine sediments as well. Especially the detection of podocytes in the urine could be a valuable noninvasive method to get information about the disease activity or disease type and could be used as a follow-up after a biopsy in an outpatient setting. So far, there are only a few studies that analyzed the clinical relevance of renal epithelial cells in the urine systematically or prospectively. The reason for this could be the nature of the material since it will remain unclear whether detachment and changes in the urine milieu have a direct effect on the expression of marker proteins on the detected cells. Dedifferentiation or transdifferentiation of cells that goes along with changed marker expression is certainly also part of the underlying disease process. This review summarizes the available information on marker proteins that have been successfully used in the diagnostic of "podocytes" in the urine. Furthermore, it gives an overview of marker expression on podocytes in situ in development and disease and examines the role of glomerular epithelial shedding in the urine at the interface of basic science and clinical medicine.
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Affiliation(s)
- Andrej Skoberne
- Division of Nephrology, University Medical Centre Ljubljana, Ljublijana, Slovenia, Germany
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30
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Podocalyxin expression in malignant astrocytic tumors. Biochem Biophys Res Commun 2008; 374:394-8. [PMID: 18639524 DOI: 10.1016/j.bbrc.2008.07.049] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 07/11/2008] [Indexed: 11/23/2022]
Abstract
Podocalyxin is an anti-adhesive mucin-like transmembrane sialoglycoprotein that has been implicated in the development of aggressive forms of cancer. Podocalyxin is also known as keratan sulfate (KS) proteoglycan. Recently, we revealed that highly sulfated KS or another mucin-like transmembrane sialoglycoprotein podoplanin/aggrus is upregulated in malignant astrocytic tumors. The aim of this study is to examine the relationship between podocalyxin expression and malignant progression of astrocytic tumors. In this study, 51 astrocytic tumors were investigated for podocalyxin expression using immunohistochemistry, Western blot analysis, and quantitative real-time PCR. Immunohistochemistry detected podocalyxin on the surface of tumor cells in six of 14 anaplastic astrocytomas (42.9%) and in 17 of 31 glioblastomas (54.8%), especially around proliferating endothelial cells. In diffuse astrocytoma, podocalyxin expression was observed only in vascular endothelial cells. Podocalyxin might be associated with the malignant progression of astrocytic tumors, and be a useful prognostic marker for astrocytic tumors.
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Larrucea S, Butta N, Arias-Salgado EG, Alonso-Martin S, Ayuso MS, Parrilla R. Expression of podocalyxin enhances the adherence, migration, and intercellular communication of cells. Exp Cell Res 2008; 314:2004-15. [PMID: 18456258 DOI: 10.1016/j.yexcr.2008.03.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 03/06/2008] [Accepted: 03/06/2008] [Indexed: 11/25/2022]
Abstract
Podocalyxin (PODXL) is an anti-adhesive glycoprotein expressed abundantly in the epithelial cells of kidney glomeruli. In contrast, we report herein that expression of podocalyxin(GFP) (PODXL(GFP)) in CHO cells increased the adherence to immobilized fibronectin, spreading, and migration. The transient knockdown of PODXL or the expression of PODXL lacking the cytosolic carboxyterminal domain (PODXL-Delta(451)) inhibited cell adherence. Moreover, the effect of PODXL was prevented by the ectodomain of podocalyxin (PODXL-Delta(429)), by RGD peptides, or by inhibitors of the vitronectin receptor (alphavbeta3). CHO-PODXL(GFP) also showed adherence to human vascular endothelial cells (HUVEC), exhibiting polarization of granular PODXL and emission of long and thin, spike-like, protrusions with PODXL granules progressing along. We found PODXL colocalized with beta1 integrins at membrane ruffle regions on the leading edge of the cell and a blocking beta1 mAb prevented the spreading of cells. PODXL was also associated with submembrane actin in lamellipodia ruffles, or with vinculin at cell protrusions. The proadhesive effects of PODXL were absent in sialic acid deficient O-glycomutant CHO cells. To conclude, we present evidence indicating that human PODXL enhances the adherence of cells to immobilized ligands and to vascular endothelial cells through a mechanism(s) dependent on the activity of integrins.
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Affiliation(s)
- Susana Larrucea
- Department of Physiopathology, Centro de Investigaciones Biológicas (CSIC), Spain
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32
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Sizemore S, Cicek M, Sizemore N, Ng KP, Casey G. Podocalyxin increases the aggressive phenotype of breast and prostate cancer cells in vitro through its interaction with ezrin. Cancer Res 2007; 67:6183-91. [PMID: 17616675 DOI: 10.1158/0008-5472.can-06-3575] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Podocalyxin is an anti-adhesive transmembrane sialomucin that has been implicated in the development of more aggressive forms of breast and prostate cancer. The mechanism through which podocalyxin increases cancer aggressiveness remains poorly understood but may involve the interaction of podocalyxin with ezrin, an established mediator of metastasis. Here, we show that overexpression of podocalyxin in MCF7 breast cancer and PC3 prostate cancer cell lines increased their in vitro invasive and migratory potential and led to increased expression of matrix metalloproteases 1 and 9 (MMP1 and MMP9). Podocalyxin expression also led to an increase in mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) activity. To determine the role of ezrin in these podocalyxin-dependent phenotypic events, we first confirmed that podocalyxin formed a complex with ezrin in MCF7 and PC3 cells. Furthermore, expression of podocalyxin was associated with a changed ezrin subcellular localization and increased ezrin phosphorylation. Transient knockdown of ezrin protein abrogated MAPK and PI3K signaling as well as MMP expression and invasiveness in cancer cells overexpressing podocalyxin. These findings suggest that podocalyxin leads to increased in vitro migration and invasion, increased MMP expression, and increased activation of MAPK and PI3K activity in MCF7 and PC3 cells through its ability to form a complex with ezrin.
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Affiliation(s)
- Steven Sizemore
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Krtil J, Pláteník J, Kazderová M, Tesar V, Zima T. Culture methods of glomerular podocytes. Kidney Blood Press Res 2007; 30:162-74. [PMID: 17502717 DOI: 10.1159/000102520] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Indexed: 12/29/2022] Open
Abstract
Podocytes (glomerular visceral epithelial cells) cover the exterior surface of the glomerular capillaries and contribute to the glomerular filtration membrane. Failure of podocyte function is involved in the progression of chronic glomerular disease; accordingly, research interest into podocyte biology is driven by the need for better protection and perhaps recovery of these cells in renal diseases. This review aims at summarizing available techniques for podocyte cell cultures from both the past and present, with special attention to the currently used methods. The establishment of classical primary cultures is based on isolation of glomeruli by differential sieving. Plating of glomeruli onto a collagen surface is followed by an outgrowth of cobblestone-like cells that, after replating, differentiate into arborized, mature podocytes. Currently, the majority of research studies use immortalized podocytic cell lines most often derived from transgenic mice bearing a conditional immortalizing gene. The podocytes can also be collected and cultured from healthy or diseased animal or patient urine. The urinary podocytes obtained from subjects with active glomerulopathies display higher proliferation potential and viability in vitro, perhaps due to disease-induced transdifferentiation. Finally, a list of phenotypic markers useful for identification and characterization of the cultured podocytic elements is provided.
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Affiliation(s)
- J Krtil
- Institute of Medical Biochemistry, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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Rodríguez RB, Butta N, Larrucea S, Alonso S, Parrilla R. Production and characterization of murine monoclonal antibodies against human podocalyxin. ACTA ACUST UNITED AC 2007; 68:407-17. [PMID: 17092254 DOI: 10.1111/j.1399-0039.2006.00692.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Podocalyxin (podxl) is a protein with a peptide bone of approximately 55.5 kDa that undergoes a post-translational glycosylation, yielding a final molecular mass from approximately 145 to approximately 200 kDa. This protein is normally found covering the vascular side of the epithelial glomerular cells, the podocytes, and its presence is essential to maintain a normal renal function. It has also been reported in other cells and tissues although its function has not been yet clarified. The carboxy-terminal intracellular domain of podxl is nearly 100% identical in most species; however, the ectodomain shows considerable variations although the cysteine residues are conserved. Detection of this protein is elusive, most likely due to differences in post-translational modifications. We aimed at producing murine monoclonal antibodies against human podxl. Immunization with Chinese hamster ovarian -hpodxl-green fluorescence protein live cells yielded five different monoclonal antibodies that were characterized by enzyme-linked immunosorbent assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis/western blot, flow cytometry, immunohistochemistry, and immunoprecipitation. The different behavior of these antibodies suggests that some of them may react against epitopes masked by different glycosylated protein moieties.
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Affiliation(s)
- R B Rodríguez
- Department of Physiopathology and Human Molecular Genetics, Centro de Investigaciones Biológicas (CSIC), 28040-Madrid, Spain
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35
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Nielsen JS, Graves ML, Chelliah S, Vogl AW, Roskelley CD, McNagny KM. The CD34-related molecule podocalyxin is a potent inducer of microvillus formation. PLoS One 2007; 2:e237. [PMID: 17311105 PMCID: PMC1796660 DOI: 10.1371/journal.pone.0000237] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Accepted: 01/30/2007] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Podocalyxin is a CD34-related transmembrane protein involved in hematopoietic cell homing, kidney morphogenesis, breast cancer progression, and epithelial cell polarization. Although this sialomucin has been shown to block cell adhesion, the mechanisms involved remain enigmatic. It has, however, been postulated that the adaptor proteins NHERF-1 and 2 could regulate apical targeting of Podocalyxin by linking it to the actin cytoskeleton. PRINCIPAL FINDINGS Here, in contrast, we find that full-length Podocalyxin acts to recruit NHERF-1 to the apical domain. Moreover, we show that ectopic expression of Podocalyxin in epithelial cells leads to microvillus formation along an expanded apical domain that extends laterally to the junctional complexes. Removal of the C-terminal PDZ-binding domain of Podocalyxin abolishes NHERF-1 recruitment but, surprisingly, has no effect on the formation of microvilli. Instead, we find that the extracellular domain and transmembrane region of Podocalyxin are sufficient to direct recruitment of filamentous actin and ezrin to the plasma membrane and induce microvillus formation. CONCLUSIONS/SIGNIFICANCE Our data suggest that this single molecule can modulate NHERF localization and, independently, act as a key orchestrator of apical cell morphology, thereby lending mechanistic insights into its multiple roles as a polarity regulator, tumor progression marker, and anti-adhesin.
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Affiliation(s)
- Julie S. Nielsen
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marcia L. Graves
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shierley Chelliah
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - A. Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Calvin D. Roskelley
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kelly M. McNagny
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- * To whom correspondence should be addressed. E-mail:
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Lin WL, Pang VF, Liu CH, Chen JY, Shen KF, Lin YY, Yu CY, Hsu YH, Jou TS. Pleomorphic extra-renal manifestation of the glomerular podocyte marker podocalyxin in tissues of normal beagle dogs. Histochem Cell Biol 2006; 127:399-414. [PMID: 17180683 DOI: 10.1007/s00418-006-0252-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2006] [Indexed: 11/26/2022]
Abstract
Podocalyxin (PC) was initially identified as a major sialoprotein on the apical surface of glomerular podocytes to perform the filtration barrier function. Later, it was reported to be expressed in endothelial cells, megakaryotes/platelets, and hemangioblasts, the common progenitor cells of the hematopoietic and endothelial cells. Recently, increasing numbers of reports have indicated that PC is not merely a molecule restricted at renal glomerulus, angiogenic or hematopoietic system. To further elucidate the expression pattern and address the possible physiological role of PC in adult mammals, we conducted an extensive study by immunohistochemistry and immunofluorescence staining on various tissues of healthy adult beagle dogs. By combinatory usage of two different anti-podocalyxin antibodies recognizing distinct epitopes in PC, we have demonstrated that (1) PC is expressed in renal tubules, mesothelium, myocardium, striated muscles in tongue, esophagus and extraocular region, myoepithelial cells in esophagus and salivary glands, neurons, and ependyma, etc.; (2) there are at least three forms of PC proteins, depending upon the accessibility of two different PC antibodies, expressed in different organs/systems; and (3) a particular form of PC is distributed in a vesicle-like compartment in certain organs/systems, such as the central nervous system.
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Affiliation(s)
- Wei-Ling Lin
- Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7, Chung-Shan S. Road, Taipei, 100, Taiwan
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Schopperle WM, DeWolf WC. The TRA-1-60 and TRA-1-81 human pluripotent stem cell markers are expressed on podocalyxin in embryonal carcinoma. Stem Cells 2006; 25:723-30. [PMID: 17124010 DOI: 10.1634/stemcells.2005-0597] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have previously identified the cell adhesion protein podocalyxin expressed in a human pluripotent stem cell, embryonal carcinoma (EC), which is a malignant germ cell. Podocalyxin is a heavily glycosylated membrane protein with amino acid sequence homology to the hematopoietic stem cell marker CD34. Since the initial discovery of podocalyxin in a cancerous stem cell, numerous new studies have identified podocalyxin in many different human cancers and in embryonic stem cells lines (ES) derived from human embryos. Embryonal carcinoma, as do all human pluripotent stem cells, expresses TRA-1-60 and TRA-1-81 antigens, and although their molecular identities are unknown, they are commonly used as markers of undifferentiated pluripotent human stem cells. We report here that purified podocalyxin from embryonal carcinoma has binding activity with the TRA-1-60 and TRA-1-81 antibodies. Embryonal carcinoma cells treated with retinoic acid undergo differentiation and lose the TRA-1-60/TRA-1-81 markers from their plasma membrane surface. We show that podocalyxin is modified in the retinoic acid-treated cells and has an apparent molecular mass of 170 kDa on protein blots as compared with the apparent 200-kDa molecular weight form of podocalyxin expressed in untreated cells. Furthermore, the modified form of podocalyxin no longer reacts with the TRA-1-60/TRA-1-81 antibodies. Thus, embryonal carcinoma expresses two distinct forms of podocalyxin, and the larger version is a molecular carrier of the human stem cell-defining antigens TRA-1-60 and TRA-1-81.
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Affiliation(s)
- William M Schopperle
- Department of Surgery, Beth Israel Deaconess Medical Center, RW-875, 330 Brookline Ave., Boston, MA 02215, USA.
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38
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Furness SGB, McNagny K. Beyond mere markers: functions for CD34 family of sialomucins in hematopoiesis. Immunol Res 2006. [PMID: 16720896 DOI: 10.1385/ir: 34: 1: 13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
CD34, podocalyxin, and endoglycan are members of a family of single-pass transmembrane proteins that show distinct expression on early hematopoietic precursors and vascular-associated tissue. In spite of the fact that the expression of CD34 on these early progenitors has been known for over 20 yr and used clinically in hematopoietic stem cell transplantation for more than 15 yr, little is known about its exact role or function. More recently, CD34 expression has been shown to distinguish activated early progenitors from quiescent cells. With the subsequent identification of podocalyxin and endoglycan as related family members also expressed on early progenitor cells, attention is slowly shifting toward understanding how these molecules might contribute to progenitor function and behavior. In this review we examine the existing evidence and propose testable models to reveal the importance of these molecules for stem and progenitor cell function.
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Furness SGB, McNagny K. Beyond mere markers: functions for CD34 family of sialomucins in hematopoiesis. Immunol Res 2006; 34:13-32. [PMID: 16720896 DOI: 10.1385/ir:34:1:13] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 12/28/2022]
Abstract
CD34, podocalyxin, and endoglycan are members of a family of single-pass transmembrane proteins that show distinct expression on early hematopoietic precursors and vascular-associated tissue. In spite of the fact that the expression of CD34 on these early progenitors has been known for over 20 yr and used clinically in hematopoietic stem cell transplantation for more than 15 yr, little is known about its exact role or function. More recently, CD34 expression has been shown to distinguish activated early progenitors from quiescent cells. With the subsequent identification of podocalyxin and endoglycan as related family members also expressed on early progenitor cells, attention is slowly shifting toward understanding how these molecules might contribute to progenitor function and behavior. In this review we examine the existing evidence and propose testable models to reveal the importance of these molecules for stem and progenitor cell function.
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40
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Vitureira N, McNagny K, Soriano E, Burgaya F. Pattern of expression of the podocalyxin gene in the mouse brain during development. Gene Expr Patterns 2005; 5:349-54. [PMID: 15661640 DOI: 10.1016/j.modgep.2004.10.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Revised: 10/08/2004] [Accepted: 10/10/2004] [Indexed: 12/21/2022]
Abstract
We studied the expression pattern of the major renal protein Podocalyxin during the development of mouse brain using in situ hybridization. Podocalyxin mRNA was widely expressed at least from E14, the first age we studied, and expression remained high until adulthood. The highest levels of expression were postnatal. Podocalyxin expression was particularly elevated in the cortical plate, the hippocampus and cerebellum, and in several basal forebrain nuclei.
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Affiliation(s)
- Nathalia Vitureira
- IRBB/PCB, Barcelona Science Park and Department of Cell Biology, University of Barcelona, Josep Samitier 1-5, Barcelona E-08028, Spain
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41
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Doyonnas R, Nielsen JS, Chelliah S, Drew E, Hara T, Miyajima A, McNagny KM. Podocalyxin is a CD34-related marker of murine hematopoietic stem cells and embryonic erythroid cells. Blood 2005; 105:4170-8. [PMID: 15701716 DOI: 10.1182/blood-2004-10-4077] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Podocalyxin/podocalyxin-like protein 1 [PCLP1]/thrombomucin/MEP21 is a CD34-related sialomucin. We have performed a detailed analysis of its expression during murine development and assessed its utility as a marker of hematopoietic stem cells (HSCs) and their more differentiated progeny. We find that podocalyxin is highly expressed by the first primitive hematopoietic progenitors and nucleated red blood cells to form in the embryonic yolk sac. Likewise, podocalyxin is expressed by definitive multilineage hematopoietic progenitors and erythroid precursors in fetal liver. The level of podocalyxin expression gradually declines with further embryo maturation and reaches near-background levels at birth. This is followed by a postnatal burst of expression that correlates with the seeding of new hematopoietic progenitors to the spleen and bone marrow. Shortly thereafter, podocalyxin expression gradually declines, and by 4 weeks postpartum it is restricted to a rare population of Sca-1(+), c-kit(+), lineage marker(-) (Lin(-)) cells in the bone marrow. These rare podocalyxin-expressing cells are capable of serially reconstituting myeloid and lymphoid lineages in lethally irradiated recipients, suggesting they have HSC activity. In summary, we find that podocalyxin is a marker of embryonic HSCs and erythroid cells and of adult HSCs and that it may be a valuable marker for the purification of these cells for transplantation.
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Affiliation(s)
- Regis Doyonnas
- The Biomedical Research Centre, University of British Columbia, 2222 Health Sciences Mall, Vancouver, Canada V6T 1Z3
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42
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Somasiri A, Nielsen JS, Makretsov N, McCoy ML, Prentice L, Gilks CB, Chia SK, Gelmon KA, Kershaw DB, Huntsman DG, McNagny KM, Roskelley CD. Overexpression of the anti-adhesin podocalyxin is an independent predictor of breast cancer progression. Cancer Res 2004; 64:5068-73. [PMID: 15289306 DOI: 10.1158/0008-5472.can-04-0240] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Podocalyxin is a CD34-related cell surface molecule with anti-adhesive qualities. We probed a tissue microarray (n = 272) linked to long-term outcome data and found that podocalyxin was highly overexpressed in a distinct subset of invasive breast carcinomas (n = 15; 6%). Univariate disease-specific (P < 0.01) and multivariate regression (P < 0.0005) analyses indicated that this overexpression is an independent indicator of poor outcome. Forced podocalyxin expression perturbed cell junctions between MCF-7 breast carcinoma cells, and it caused cell shedding from confluent monolayers. Therefore, podocalyxin overexpression is a novel predictor of breast cancer progression that may contribute to the process by perturbing tumor cell adhesion.
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Affiliation(s)
- Aruna Somasiri
- Department of Anatomy and Cell Biology, University of British Columbia, 2177 Wesbrook Mall, Vancouver, BC, Canada V6T 1Z3
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43
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Economou CG, Kitsiou PV, Tzinia AK, Panagopoulou E, Marinos E, Kershaw DB, Kerjaschki D, Tsilibary EC. Enhanced podocalyxin expression alters the structure of podocyte basal surface. J Cell Sci 2004; 117:3281-94. [PMID: 15226400 DOI: 10.1242/jcs.01163] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Glomerular basement membrane (GBM) and podocalyxin are essential for podocyte morphology. We provide evidence of functional interconnections between basement membrane components (collagen IV and laminin), the expression of podocalyxin and the morphology of human glomerular epithelial cells (podocytes). We demonstrated that GBM and laminin, but not collagen IV, up-regulated the expression of podocalyxin. Scanning electron microscopy revealed that laminin induced a modified morphology of podocytes with process formation, which was more extensive in the presence of GBM. Under high magnification, podocytes appeared ruffled. Using transmission electron microscopy we observed that raised areas occurred in the basal cell surface. Furthermore, the presence of anti-podocalyxin antibody increased the extent of adhesion and spreading of podocytes to both collagen IV and laminin, thus podocalyxin apparently inhibits cell-matrix interactions. We also performed adhesion and spreading assays on podocytes grown under increased glucose concentration (25 mM). Under these conditions, the expression of podocalyxin was almost totally suppressed. The cells adhered and spread to basement membrane components but there was no increase in the extent of adhesion and spreading in the presence of anti-podocalyxin antibody, or ruffling of the cell edges. Additionally, in podocytes expressing podocalyxin, the presence of anti-podocalyxin antibody partially reversed the inhibition of adhesion to collagen IV provoked by anti-β1 integrin antibody, thus podocalyxin should compete with β1-related cell adhesion. We suggest that the observed podocalyxin-mediated inhibition of binding to the matrix could be in part responsible for the specialized conformation of the basal surface of podocytes.
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MESH Headings
- Amino Acids, Diamino/metabolism
- Animals
- Antibodies, Monoclonal/chemistry
- Basement Membrane/physiology
- Blotting, Northern
- Blotting, Western
- Cell Adhesion
- Cell Proliferation
- Cell Separation
- Cells, Cultured
- Collagen Type IV/metabolism
- DNA, Complementary/metabolism
- Densitometry
- Diabetes Mellitus, Experimental/metabolism
- Epithelial Cells/metabolism
- Flow Cytometry
- Glucose/metabolism
- Humans
- Immunohistochemistry
- Integrin beta1/metabolism
- Laminin/chemistry
- Laminin/metabolism
- Membrane Proteins/metabolism
- Microscopy, Electron, Scanning
- Microscopy, Electron, Transmission
- Microscopy, Fluorescence
- Phosphoproteins/metabolism
- Protein Binding
- Proteins/metabolism
- RNA/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Sialoglycoproteins/biosynthesis
- Sialoglycoproteins/metabolism
- Up-Regulation
- Zonula Occludens-1 Protein
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Affiliation(s)
- Constantinos G Economou
- Institute of Biology, National Center for Scientific Research, Demokritos, Agia Paraskevi, 15310 Athens, Greece
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Kruse JJCM, te Poele JAM, Velds A, Kerkhoven RM, Boersma LJ, Russell NS, Stewart FA. Identification of differentially expressed genes in mouse kidney after irradiation using microarray analysis. Radiat Res 2004; 161:28-38. [PMID: 14680399 DOI: 10.1667/rr3097] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Irradiation of the kidney induces dose-dependent, progressive renal functional impairment, which is partly mediated by vascular damage. The molecular mechanisms underlying the development of radiation-induced nephropathy are unclear. Given the complexity of radiation-induced responses, microarrays may offer new opportunities to identify a wider range of genes involved in the development of radiation injury. The aim of the present study was to determine whether microarrays are a useful tool for identifying time-related changes in gene expression and potential mechanisms of radiation-induced nephropathy. Microarray experiments were performed using amplified RNA from irradiated mouse kidneys (1 x 16 Gy) and from sham-irradiated control tissue at different intervals (1-30 weeks) after irradiation. After normalization procedures (using information from straight-color, color-reverse and self-self experiments), the differentially expressed genes were identified. Control and repeat experiments were done to confirm that the observations were not artifacts of the array procedure (RNA amplification, probe synthesis, hybridizations and data analysis). To provide independent confirmation of microarray data, semi-quantitative PCR was performed on a selection of genes. At 1 week after irradiation (before the onset of vascular and functional damage), 16 genes were significantly up-regulated and 9 genes were down-regulated. During the period of developing nephropathy (10 to 20 weeks), 31 and 42 genes were up-regulated and 9 and 4 genes were down-regulated. At the later time of 30 weeks, the vast majority of differentially expressed genes (191 out of 203) were down-regulated. Potential genes of interest included TSA-1 (also known as Ly6e) and Jagged 1 (Jag1). Increased expression of TSA-1, a member of the Ly-6 family, has previously been reported in response to proteinuria. Jagged 1, a ligand for the Notch receptor, is known to play a role in angiogenesis, and is particularly interesting in the context of radiation-induced vascular injury. The present study demonstrates the potential of microarrays to identify changing patterns of gene expression in irradiated kidney. Further studies will be required to evaluate functional involvement of these genes in vascular-mediated normal tissue injury.
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Affiliation(s)
- Jacqueline J C M Kruse
- The Netherlands Cancer Institute, Division of Experimental Therapy (H6),Amsterdam, The Netherlands
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45
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Kerosuo L, Juvonen E, Alitalo R, Gylling M, Kerjaschki D, Miettinen A. Podocalyxin in human haematopoietic cells. Br J Haematol 2004; 124:809-18. [PMID: 15009070 DOI: 10.1111/j.1365-2141.2004.04840.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Podocalyxin-like protein (PCLP) is a sialomucin-type membrane protein structurally related to CD34 and endoglycan. It was first described in glomerular podocytes and endothelial cells. In mice, PCLP is present in haemangioblasts, and in both chicken and mice it is a marker of early haematopoietic stem cells and lineage-restricted haematopoietic progenitors. Its expression decreases during differentiation of haematopoietic cells. Of mature blood cells, only chicken and rat thrombocytes express PCLP protein. PCLP expression in human haematopoietic cells has not been studied. Here we demonstrate PCLP mRNA in human CD34+ cells, in lineage committed erythroid, megakaryocyte and myeloid progenitors, in K562 leukaemia cells, and in peripheral blood leucocytes. The mRNA expression level was higher in developing cells than in mature leucocytes. By Northern blotting and cDNA sequencing, the haematopoietic and renal PCLP mRNAs were identical. Of the mobilized CD34+ cells, 28% (mean; range 14-61%) expressed PCLP protein and the majority of PCLP+ cells were CD117+. Almost all of the K562 cells expressed PCLP protein. Surprisingly, PCLP protein was not detected in any mature blood cells. These results suggest that human PCLP may be a valuable marker for a subset of haematopoietic stem cells.
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Affiliation(s)
- Laura Kerosuo
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Finland
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46
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47
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Schopperle WM, Kershaw DB, DeWolf WC. Human embryonal carcinoma tumor antigen, Gp200/GCTM-2, is podocalyxin. Biochem Biophys Res Commun 2003; 300:285-90. [PMID: 12504081 DOI: 10.1016/s0006-291x(02)02844-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We previously characterized a peanut agglutinin-binding tumor antigen, gp200, a surface membrane glycoprotein expressed on human embryonal carcinoma, a malignant stem cell of testicular tumors. Gp200 is remarkably similar to another embryonal carcinoma antigen, GCTM-2, a cell differentiation marker that is also detected in blood of testis cancer patients, yet neither molecular identity is known. We now report the identity of gp200 as podocalyxin. Protein sequence results of gp200 peptides match with podocalyxin sequence. Furthermore, two distinct monoclonal antibodies, specific for podocalyxin, react positively with gp200. Therefore, gp200 is a testicular tumor form of podocalyxin, a surface membrane glycoprotein that was originally discovered as a scaffolding extracellular matrix protein of kidney podocyte cells. Podocalyxin is also expressed on subsets of hematopoietic cells where it has a putative function as a cell adhesion protein. This is the first report of podocalyxin expression on malignant cells.
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Affiliation(s)
- W Michael Schopperle
- Division of Urology, Urological Research Laboratory, Beth Israel Deaconess Medical Center, Dana 838, 330 Brookline Ave., Boston, MA 02115, USA.
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48
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Rantanen M, Palmén T, Pätäri A, Ahola H, Lehtonen S, Aström E, Floss T, Vauti F, Wurst W, Ruiz P, Kerjaschki D, Holthöfer H. Nephrin TRAP mice lack slit diaphragms and show fibrotic glomeruli and cystic tubular lesions. J Am Soc Nephrol 2002; 13:1586-94. [PMID: 12039988 DOI: 10.1097/01.asn.0000016142.29721.22] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The molecular mechanisms maintaining glomerular filtration barrier are under intensive study. This study describes a mutant Nphs1 mouse line generated by gene-trapping. Nephrin, encoded by Nphs1, is a structural protein of interpodocyte filtration slits crucial for formation of primary urine. Nephrin(trap/trap) mutants show characteristic features of proteinuric disease and die soon after birth. Morphologically, fibrotic glomeruli with distorted structures and cystic tubular lesions were observed, but no prominent changes in the branching morphogenesis of the developing collecting ducts could be found. Western blotting and immunohistochemical analyses confirmed the absence of nephrin in nephrin(trap/trap) glomeruli. The immunohistochemical staining showed also that the interaction partner of nephrin, CD2-associated protein (CD2AP), and the slit-diaphragm-associated protein, ZO-1alpha (-), appeared unchanged, whereas the major anionic apical membrane protein of podocytes, podocalyxin, somewhat punctate as compared with the wild-type (wt) and nephrin(wt/trap) stainings. Electron microscopy revealed that >90% of the podocyte foot processes were fused. The remaining interpodocyte junctions lacked slit diaphragms and, instead, showed tight adhering areas. In the heterozygote glomeruli, approximately one third of the foot processes were fused and real-time RT-PCR showed >60% decrease of nephrin-specific transcripts. These results show an effective nephrin gene elimination, resulting in a phenotype that resembles human congenital nephrotic syndrome. Although the nephrin(trap/trap) mice can be used to study the pathophysiology of the disease, the heterozygous mice may provide a useful model to study the gene dose effect of this crucial protein of the glomerular filtration barrier.
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Affiliation(s)
- Maija Rantanen
- Biomedicum, Molecular Medicine, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
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49
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Li Y, Li J, Straight SW, Kershaw DB. PDZ domain-mediated interaction of rabbit podocalyxin and Na(+)/H(+) exchange regulatory factor-2. Am J Physiol Renal Physiol 2002; 282:F1129-39. [PMID: 11997330 DOI: 10.1152/ajprenal.00131.2001] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The transmembrane sialoglycoprotein podocalyxin is thought to be essential in the fine interdigitating foot process structure of the podocyte. The intracellular COOH-terminal amino acids Asp-Thr-His-Leu (DTHL) of podocalyxin comprise a putative ligand for a type I PSD95-Dlg-zona occludens-1 (PDZ) domain. A 20-amino acid synthetic peptide containing this motif was used to screen a cDNA library, and clones of rabbit Na(+)/H(+) exchange regulatory factor-2 (NHERF-2) were obtained. In vitro analysis demonstrated that each PDZ domain of NHERF-2 could bind podocalyxin independently. NHERF-2 coprecipitated from glomerular extracts with podocalyxin, and podocalyxin and NHERF-2 colocalized in the glomerular capillary loops, indicating that podocalyxin and NHERF-2 may interact in vivo. Podocalyxin peptide missing the terminal leucine (-DTHL) failed to interact with NHERF-2 in vitro. Podocalyxin localized to the apical membrane of transfected Madin-Darby canine kidney (MDCK) cells. However, mutant podocalyxin (missing a functional DTHL COOH-terminal motif) showed cytoplasmic and apical membrane localization in transfected cells and was also less stable at the apical membrane, as assessed by confocal microscopy and biotinylation studies. Mutant podocalyxin did lower the transepithelial resistance of MDCK cell monolayers, albeit to a lesser extent than full-length podocalyxin. We conclude that podocalyxin can interact with both PDZ domains of NHERF-2 and that this interaction requires the intact COOH terminus of podocalyxin, which is also responsible for the efficient apical localization of podocalyxin in transfected MDCK cells. These results suggest that the interaction of podocalyxin with NHERF-2 may function to efficiently retain podocalyxin at the apical surface of the podocyte and provide a mechanism linking podocalyxin to the actin cytoskeleton.
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Affiliation(s)
- Yong Li
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan 48109-0676, USA
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50
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Li J, Li Y, Brophy PD, Kershawt DB. Gene structure and alternative splicing of murine podocalyxin: a member of the CD34 sialomucin family. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 2001; 12:407-12. [PMID: 11913788 DOI: 10.3109/10425170109084466] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Podocalyxin is a sialoglycoprotein of the glomerular podocytes, vascular endothelial cells, platelets, and hemopoietic stem cells. The function of podocalyxin is unknown, but it contains most of the protein bound sialic acid in the glomerulus and is considered vital in the structure and function of the glomerular filtration apparatus. The murine podocalyxin full-length cDNA has been determined and is 5,318 base pairs. The gene localizes to chromosome 6B1 by FISH analysis and contains eight major exons with one additional alternatively spliced exon. The alternatively spliced isoform of podocalyxin codes for a truncated intracellular domain and is expressed in a tissue specific pattern in parallel with full-length podocalyxin. The organization of the gene structure of murine podocalyxin is similar to the murine CD34 gene and suggests a distant evolutionary relationship to CD34.
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Affiliation(s)
- J Li
- Department of Pediatrics and Communicable Disease, University of Michigan, Ann Arbor 48109 USA
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