ADAM10-Mediated Ectodomain Shedding Is an Essential Driver of Podocyte Damage

2021 ◽  
pp. ASN.2020081213
Author(s):  
Marlies Sachs ◽  
Sebastian Wetzel ◽  
Julia Reichelt ◽  
Wiebke Sachs ◽  
Lisa Schebsdat ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Wnt Signaling Pathway ◽  
Immunogold Electron Microscopy ◽  
Ectodomain Shedding ◽  
Dependent Manner ◽  
Podocyte Injury ◽  
Filtration Barrier ◽  
Adam10 Expression

BackgroundPodocytes embrace the glomerular capillaries with foot processes, which are interconnected by a specialized adherens junction to ultimately form the filtration barrier. Altered adhesion and loss are common features of podocyte injury, which could be mediated by shedding of cell-adhesion molecules through the regulated activity of cell surface–expressed proteases. A Disintegrin and Metalloproteinase 10 (ADAM10) is such a protease known to mediate ectodomain shedding of adhesion molecules, among others. Here we evaluate the involvement of ADAM10 in the process of antibody-induced podocyte injury.MethodsMembrane proteomics, immunoblotting, high-resolution microscopy, and immunogold electron microscopy were used to analyze human and murine podocyte ADAM10 expression in health and kidney injury. The functionality of ADAM10 ectodomain shedding for podocyte development and injury was analyzed, in vitro and in vivo, in the anti-podocyte nephritis (APN) model in podocyte-specific, ADAM10-deficient mice.ResultsADAM10 is selectively localized at foot processes of murine podocytes and its expression is dispensable for podocyte development. Podocyte ADAM10 expression is induced in the setting of antibody-mediated injury in humans and mice. Podocyte ADAM10 deficiency attenuates the clinical course of APN and preserves the morphologic integrity of podocytes, despite subepithelial immune-deposit formation. Functionally, ADAM10-related ectodomain shedding results in cleavage of the cell-adhesion proteins N- and P-cadherin, thus decreasing their injury-related surface levels. This favors podocyte loss and the activation of downstream signaling events through the Wnt signaling pathway in an ADAM10-dependent manner.ConclusionsADAM10-mediated ectodomain shedding of injury-related cadherins drives podocyte injury.

scholarly journals Eap1p, an Adhesin That Mediates Candida albicans Biofilm Formation In Vitro and In Vivo

2007 ◽  
Vol 6 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Fang Li ◽  
Michael J. Svarovsky ◽  
Amy J. Karlsson ◽  
Joel P. Wagner ◽  
Karen Marchillo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Adhesion ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Gene Dosage ◽  
Venous Catheter ◽  
Flow Chamber ◽  
Dependent Manner

ABSTRACT Candida albicans is the leading cause of systemic fungal infections in immunocompromised humans. The ability to form biofilms on surfaces in the host or on implanted medical devices enhances C. albicans virulence, leading to antimicrobial resistance and providing a reservoir for infection. Biofilm formation is a complex multicellular process consisting of cell adhesion, cell growth, morphogenic switching between yeast form and filamentous states, and quorum sensing. Here we describe the role of the C. albicans EAP1 gene, which encodes a glycosylphosphatidylinositol-anchored, glucan-cross-linked cell wall protein, in adhesion and biofilm formation in vitro and in vivo. Deleting EAP1 reduced cell adhesion to polystyrene and epithelial cells in a gene dosage-dependent manner. Furthermore, EAP1 expression was required for C. albicans biofilm formation in an in vitro parallel plate flow chamber model and in an in vivo rat central venous catheter model. EAP1 expression was upregulated in biofilm-associated cells in vitro and in vivo. Our results illustrate an association between Eap1p-mediated adhesion and biofilm formation in vitro and in vivo.

scholarly journals tRNA-Derived Fragments in Podocytes with Adriamycin-Induced Injury Reveal the Potential Mechanism of Idiopathic Nephrotic Syndrome

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shanwen Li ◽  
Yiwen Liu ◽  
Xiaowei He ◽  
Xiagang Luo ◽  
Huimin Shi ◽  
...  
Keyword(s):  
Nephrotic Syndrome ◽  
Signaling Pathway ◽  
Idiopathic Nephrotic Syndrome ◽  
Wnt Signaling Pathway ◽  
Differentially Expressed ◽  
Ras Signaling ◽  
Potential Mechanism ◽  
Significant Differential Expression ◽  
Podocyte Injury ◽  
Filtration Barrier

Idiopathic nephrotic syndrome (INS) is a disease involving injury to podocytes in the glomerular filtration barrier, and its specific causes have not been elucidated. Transfer RNA-derived fragments (tRFs), products of precise tRNA cleavage, have been indicated to play critical roles in various diseases. Currently, there is no relevant research on the role of tRFs in INS. This study intends to explore the changes in and importance of tRFs during podocyte injury in vitro and to further analyze the potential mechanism of INS. Differentially expressed tRFs in the adriamycin-treated group were identified by high-throughput sequencing and further verified by quantitative RT-PCR. In total, 203 tRFs with significant differential expression were identified, namely, 102 upregulated tRFs and 101 downregulated tRFs (q<0.05, ∣log2FC∣≥2). In particular, AS-tDR-008924, AS-tDR-011690, tDR-003634, AS-tDR-013354, tDR-011031, AS-tDR-001008, and AS-tDR-007319 were predicted to be involved in podocyte injury by targeting the Gpr, Wnt, Rac1, and other genes. Furthermore, gene ontology analysis showed that these differential tRFs were strongly associated with podocyte injury processes such as protein binding, cell adhesion, synapses, the actin cytoskeleton, and insulin-activate receptor activity. KEGG pathway analysis predicted that they participated in the PI3K-Akt signaling pathway, Wnt signaling pathway, and Ras signaling pathway. It was reported that these pathways contribute to podocyte injury. In conclusion, our study revealed that changes in the expression levels of tRFs might be involved in INS. Seven of the differentially expressed tRFs might play important roles in the process of podocyte injury and are worthy of further study.

scholarly journals Ultrastructural localization of E-cadherin cell adhesion molecule on the cytoplasmic membrane of keratinocytes in vivo and in vitro.

1994 ◽  
Vol 42 (10) ◽  
pp. 1333-1340 ◽  
Author(s):  
Y Horiguchi ◽  
F Furukawa ◽  
M Fujita ◽  
S Imamura
Keyword(s):  
Cell Adhesion ◽  
Free Surface ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Cytoplasmic Membrane ◽  
Ultrastructural Localization ◽  
In Vivo Studies ◽  
E Cadherin

We examined the ultrastructural localization of E (epithelial)-cadherin cell adhesion molecules by immunoperoxidase electron microscopy on the epithelium of mouse intestine, epidermis of human skin, and cultured human keratinocytes. The in vivo studies demonstrated that E-cadherin was present at the intermediate junction but not at the desmosome of the mouse intestinal single epithelium, and was found on the cytoplasmic membranes of keratinocytes with condensation in the intercellular space of the desmosomes, except for the basal surface of the basal cells. In vitro studies demonstrated that keratinocytes cultured in medium containing a low Ca2+ concentration (0.1 mM) lacked the tight connection through desmosomes, and that E-cadherin showed diffuse distribution and dot-like accumulation around the free surface of the cytoplasmic membrane. In culture medium containing a high concentration of Ca2+ (0.6 mM), keratinocytes formed desmosomal adhesion structures in which E-cadherin was accumulated. The free surface of the keratinocytes in this medium showed weaker distribution and a lesser amount of dot-like accumulation of E-cadherin than that in a low Ca2+ condition. These findings suggest that the distribution pattern of the E-cadherin cell adhesion molecules on the keratinocytes is different from that on the single epithelium of the intestine, and that E-cadherin on the cytoplasmic membrane of the keratinocytes shifts to the desmosomes under physiological conditions, participating in adhesion in association with other desmosomal cadherins.

scholarly journals Tyrosine Phosphorylation at a Site Highly Conserved in the L1 Family of Cell Adhesion Molecules Abolishes Ankyrin Binding and Increases Lateral Mobility of Neurofascin

1997 ◽  
Vol 137 (3) ◽  
pp. 703-714 ◽  
Author(s):  
Timothy D. Garver ◽  
Qun Ren ◽  
Shmuel Tuvia ◽  
Vann Bennett
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Phosphorylation ◽  
Adhesion Molecules ◽  
Tyrosine Kinases ◽  
Cell Adhesion Molecules ◽  
Protein Tyrosine Kinase ◽  
Neuroblastoma Cells ◽  
Cytoplasmic Domain ◽  
Lateral Mobility

This paper presents evidence that a member of the L1 family of ankyrin-binding cell adhesion molecules is a substrate for protein tyrosine kinase(s) and phosphatase(s), identifies the highly conserved FIGQY tyrosine in the cytoplasmic domain as the principal site of phosphorylation, and demonstrates that phosphorylation of the FIGQY tyrosine abolishes ankyrin-binding activity. Neurofascin expressed in neuroblastoma cells is subject to tyrosine phosphorylation after activation of tyrosine kinases by NGF or bFGF or inactivation of tyrosine phosphatases with vanadate or dephostatin. Furthermore, both neurofascin and the related molecule Nr-CAM are tyrosine phosphorylated in a developmentally regulated pattern in rat brain. The FIGQY sequence is present in the cytoplasmic domains of all members of the L1 family of neural cell adhesion molecules. Phosphorylation of the FIGQY tyrosine abolishes ankyrin binding, as determined by coimmunoprecipitation of endogenous ankyrin and in vitro ankyrin-binding assays. Measurements of fluorescence recovery after photobleaching demonstrate that phosphorylation of the FIGQY tyrosine also increases lateral mobility of neurofascin expressed in neuroblastoma cells to the same extent as removal of the cytoplasmic domain. Ankyrin binding, therefore, appears to regulate the dynamic behavior of neurofascin and is the target for regulation by tyrosine phosphorylation in response to external signals. These findings suggest that tyrosine phosphorylation at the FIGQY site represents a highly conserved mechanism, used by the entire class of L1-related cell adhesion molecules, for regulation of ankyrin-dependent connections to the spectrin skeleton.

Expression of ROR1 in Chronic Lymphocytic Leukemia Cells Enhances Cells Survival by Wnt5a Signaling.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 340-340
Author(s):  
Liguang Chen ◽  
Li Tang ◽  
Tetsu Fukuda ◽  
Thomas J. Kipps
Keyword(s):  
Tyrosine Kinase ◽  
Human Serum ◽  
Cell Survival ◽  
Cho Cells ◽  
Wnt Signaling Pathway ◽  
Leukemia Cell ◽  
Chinese Hamster ◽  
Type I ◽  
Dependent Manner

Abstract ROR1 is a type I membrane-receptor tyrosine kinase with intracellular tyrosine kinase domains and extracellular Frizzled-like cysteine-rich domains (CRDs) and kringle domains, which are common to receptors of members of the Wnt-family. We found that ROR1 might serve as an orphan receptor for Wnt5a, which can activate NF-κB via a non-canonical Wnt-signaling pathway. In prior studies we found that CLL cells expressed ROR1 and high-levels of Wnt3, Wnt5b, Wnt6, Wnt10a, Wnt14, and Wnt16, but not Wnt5a, which is found expressed on dendritic cells and other stromal cells that can support leukemia-cell survival in vitro, and presumably in vivo. As such, we examined whether cells could support the survival of CLL cells in a Wnt5a-dependent manner. For this we cultured CLL cells alone or together with Chinese Hamster Ovary (CHO) cells or CHO transduced to express Wnt5a (CHO-Wnt5a) and monitored the viability of CLL cells over time. We found that the viability of CLL cells co-cultured with CHO cells or CHO-Wnt5a cells was greater than that of CLL cells cultured alone. However the viability of CLL cells co-cultured for two days with CHO-Wnt5a cells (71% ± 18% S.D) was significantly greater than that of CLL cells co-cultured with CHO cells (45% ± 17% S.D) (N=10, P<0.01). The capacity of CHO-Wnt5a to enhance the viability of CLL cells relative to that of CHO cells could be neutralized by anti-ROR1 antisera generated in patients who received autologous CLL cells transduced to express the CD40-ligand (CD154), but not by normal human serum or pre-treatment human serum. CHO cells transduced to express ROR1, but not CHO cells transduced with a control vector, could absorb the capacity of the anti-ROR1 antisera to bind ROR1 and removed its capacity to neutralize the capacity of CHO-Wnt5a cells to provide for a protecive advantage over CHO cells for CLL cell survival in vitro. These studies provide the first evidence that the survival of CLL cells can be enhanced by cells expressing Wnt5a, let alone Wnt factors in general, and might account in part for the enhanced survival of CLL cells in tissue microenvironments containing cells that express Wnt5a. Conceivably, the anti-ROR1 antibodies induced by autologous CLL cells transduced to express CD154, or the administration of antibodies or antagonists that can inhibit Wnt5a-ROR1 signaling, could have therapeutic activity in patients with CLL.

WT1-interacting protein and ZO-1 translocate into podocyte nuclei after puromycin aminonucleoside treatment

2005 ◽  
Vol 289 (2) ◽  
pp. F431-F441 ◽  
Author(s):  
Maribel Rico ◽  
Amitava Mukherjee ◽  
Martha Konieczkowski ◽  
Leslie A. Bruggeman ◽  
R. Tyler Miller ◽  
...  
Keyword(s):  
Adherens Junctions ◽  
Slit Diaphragm ◽  
Cell Junctions ◽  
Puromycin Aminonucleoside ◽  
Glomerular Diseases ◽  
Podocyte Injury ◽  
Interacting Protein ◽  
Filtration Barrier ◽  
Cell Cell

Podocyte differentiation is required for normal glomerular filtration barrier function and is regulated by the transcription factor WT1. We identified WT1-interacting protein (WTIP) and hypothesized that it functions as both a scaffold for slit diaphragm proteins and a corepressor of WT1 transcriptional activity by shuttling from cell-cell junctions to the nucleus after injury. Endogenous WTIP colocalizes with zonula occludens-1 (ZO-1) in cultured mouse podocyte adherens junctions. To model podocyte injury in vitro, we incubated differentiated podocytes with puromycin aminonucleoside (PAN; 100 μg/ml) for 24 h, which disassembled cell-cell contacts, rearranged actin cytoskeleton, and caused process retraction. Podocyte synaptopodin expression diminished after PAN treatment, consistent with podocyte dedifferentiation in some human glomerular diseases. To assess podocyte function, we measured albumin flux across differentiated podocytes cultured on collagen-coated Transwell filters. Albumin transit across PAN-treated cells increased to levels observed with undifferentiated podocytes. Consistent with our hypothesis, WTIP, as well as ZO-1, translocated from podocyte adherens junctions to nuclei in PAN-treated cells. Because WTIP is a transcriptional corepressor for WT1, we examined the effect of PAN on expression of retinoblastoma binding protein Rbbp7 (also known as RbAp46), a WT1 target gene expressed in S-shaped bodies during nephrogenesis. Rbbp7 expression in PAN-treated podocytes was reduced compared with untreated cells. In conclusion, WTIP translocates from cell-cell junctions to the nucleus in PAN-treated podocytes. We suggest that WTIP monitors slit diaphragm protein assembly and shuttles into the nucleus after podocyte injury, translating changes in slit diaphragm structure into altered gene expression and a less differentiated phenotype.

scholarly journals Fibrinogen in equine pregnancy as a mediator of cell adhesion, an epigenetic and functional investigation

2019 ◽  
Author(s):  
Danielle M Grant ◽  
Alysson Macedo ◽  
Derek Toms ◽  
Claudia Klein
Keyword(s):  
Dna Methylation ◽  
Cell Adhesion ◽  
Tumor Stroma ◽  
Transcript Abundance ◽  
Metastatic Potential ◽  
Adhesion Assay ◽  
Dependent Manner ◽  
Clotting Cascade ◽  
Functional Investigation

Abstract Preimplantation equine embryos synthesize and secrete fibrinogen, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. This study investigated the hypothesis that conceptus-derived fibrinogen mediates cell adhesion during fixation. On day 21 of pregnancy, five integrin subunits, including ITGA5, ITGB1, ITGAV, and ITGB1, displayed significantly higher transcript abundance than on day 16 of pregnancy. Endometrial epithelial cells adhered to fibrinogen in an integrin-dependent manner in an in vitro cell adhesion assay. Bilaminar trophoblast and allantochorion expressed fibrinogen transcript, indicating that fibrinogen expression persists past fixation. Preimplantation-phase endometrium, conceptuses, and microcotyledonary tissue expressed components of the clotting cascade regulating fibrin homeostasis, leaving open the possibility that fibrinogen is converted to fibrin. Fibrinogen is likely to have functions beyond mediating cell adhesion, such trapping growth factors and triggering signaling cascades, and has remarkable parallels to the expression of fibrinogen by some tumors. The deposition of fibrinogen within tumor stroma is characteristic of breast carcinoma, and tumor-derived fibrinogen has been implicated in the metastatic potential of circulating tumor cells. DNA methylation of the fibrinogen locus in equine conceptuses was examined in comparison to liver and endometrium, and across the full gene cluster, was significantly higher for endometrium than liver and conceptus. DNA methylation of regulatory regions did not differ between liver and conceptus, and was significantly lower than in endometrium. These results, therefore, support the hypothesis of DNA methylation being a regulator of fibrinogen expression in the conceptus.

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