Folliculin Haploinsufficiency Causes Cellular Dysfunction of Pleural Mesothelial Cells

Abstract Birt–Hogg–Dubé syndrome (BHDS), an autosomal dominant inheritance disease caused by folliculin (FLCN) mutations, is associated with lung cysts and spontaneous pneumothorax. The possibility of FLCN haploinsufficiency in pleural mesothelial cells (PMCs) contributing to development of pneumothorax has not yet been clarified. Electron microscopy revealed exposed intercellular boundaries between PMCs on visceral pleura and decreased electron density around the adherens junctions in BHDS. To characterize cellular function of PMCs in BHDS patients (BHDS-PMCs), during surgery for pneumothorax, we established the flow cytometry-based methods of isolating high-purity PMCs from pleural lavage fluid. BHDS-PMCs showed impaired cell attachment and a significant decrease in proliferation and migration, but a significant increase in apoptosis compared with PMCs from primary spontaneous pneumothorax (PSP) patients (PSP-PMCs). Microarray analysis using isolated PMCs revealed a significant alteration in the expression of genes belonging to Gene Ontology terms “cell-cell adhesion junction” and “cell adhesion molecule binding”. Gene set enrichment analysis demonstrated that CDH1, encoding E-cadherin, was identified in the down-regulated leading edge of a plot in BHDS-PMCs. AMPK and LKB1 activation were significantly impaired in BHDS-PMCs compared with PSP-PMCs. Our findings indicate that FLCN haploinsufficiency may affect the E-cadherin-LKB1-AMPK axis and lead to abnormal cellular function in BHDS-PMCs.

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Folliculin haploinsufficiency causes cellular dysfunction of pleural mesothelial cells

Scientific Reports ◽

10.1038/s41598-021-90184-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shouichi Okamoto ◽

Hiroki Ebana ◽

Masatoshi Kurihara ◽

Keiko Mitani ◽

Etsuko Kobayashi ◽

...

Keyword(s):

Cell Adhesion ◽

Spontaneous Pneumothorax ◽

Cell Attachment ◽

Leading Edge ◽

Cellular Function ◽

Mesothelial Cells ◽

Gene Set Enrichment Analysis ◽

Lung Cysts ◽

Pleural Mesothelial Cells ◽

E Cadherin

AbstractBirt–Hogg–Dubé syndrome (BHDS), an autosomal dominant inheritance disease caused by folliculin (FLCN) mutations, is associated with lung cysts and spontaneous pneumothorax. The possibility of FLCN haploinsufficiency in pleural mesothelial cells (PMCs) contributing to development of pneumothorax has not yet been clarified. Electron microscopy revealed exposed intercellular boundaries between PMCs on visceral pleura and decreased electron density around the adherens junctions in BHDS. To characterize cellular function of PMCs in BHDS patients (BHDS-PMCs), during surgery for pneumothorax, we established the flow cytometry-based methods of isolating high-purity PMCs from pleural lavage fluid. BHDS-PMCs showed impaired cell attachment and a significant decrease in proliferation and migration, but a significant increase in apoptosis compared with PMCs from primary spontaneous pneumothorax (PSP) patients (PSP-PMCs). Microarray analysis using isolated PMCs revealed a significant alteration in the expression of genes belonging to Gene Ontology terms “cell–cell adhesion junction” and “cell adhesion molecule binding”. Gene set enrichment analysis demonstrated that CDH1, encoding E-cadherin, was identified in the down-regulated leading edge of a plot in BHDS-PMCs. AMPK and LKB1 activation were significantly impaired in BHDS-PMCs compared with PSP-PMCs. Our findings indicate that FLCN haploinsufficiency may affect the E-cadherin-LKB1-AMPK axis and lead to abnormal cellular function in BHDS-PMCs.

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CD13 tethers the IQGAP1-ARF6-EFA6 complex to the plasma membrane to promote ARF6 activation, β1 integrin recycling, and cell migration

Science Signaling ◽

10.1126/scisignal.aav5938 ◽

2019 ◽

Vol 12 (579) ◽

pp. eaav5938 ◽

Cited By ~ 6

Author(s):

Mallika Ghosh ◽

Robin Lo ◽

Ivan Ivic ◽

Brian Aguilera ◽

Veneta Qendro ◽

...

Keyword(s):

Plasma Membrane ◽

Cell Migration ◽

Cell Adhesion ◽

Cell Attachment ◽

Leading Edge ◽

Small Gtpase ◽

Β1 Integrin ◽

Recycling Endosomes ◽

Cellular Processes ◽

Early Endosomes

Cell attachment to the extracellular matrix (ECM) requires a balance between integrin internalization and recycling to the surface that is mediated by numerous proteins, emphasizing the complexity of these processes. Upon ligand binding in various cells, the β1 integrin is internalized, traffics to early endosomes, and is returned to the plasma membrane through recycling endosomes. This trafficking process depends on the cyclical activation and inactivation of small guanosine triphosphatases (GTPases) by their specific guanine exchange factors (GEFs) and their GTPase-activating proteins (GAPs). In this study, we found that the cell surface antigen CD13, a multifunctional transmembrane molecule that regulates cell-cell adhesion and receptor-mediated endocytosis, also promoted cell migration and colocalized with β1 integrin at sites of cell adhesion and at the leading edge. A lack of CD13 resulted in aberrant trafficking of internalized β1 integrin to late endosomes and its ultimate degradation. Our data indicate that CD13 promoted ARF6 GTPase activity by positioning the ARF6-GEF EFA6 at the cell membrane. In migrating cells, a complex containing phosphorylated CD13, IQGAP1, GTP-bound (active) ARF6, and EFA6 at the leading edge promoted the ARF6 GTPase cycling and cell migration. Together, our findings uncover a role for CD13 in the fundamental cellular processes of receptor recycling, regulation of small GTPase activities, cell-ECM interactions, and cell migration.

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Cryopreservation-Induced Nonattachment of Human Hepatocytes: Role of Adhesion Molecules

Cell Transplantation ◽

10.3727/000000007783465000 ◽

2007 ◽

Vol 16 (6) ◽

pp. 639-647 ◽

Cited By ~ 47

Author(s):

Claire Terry ◽

Robin D. Hughes ◽

Ragai R. Mitry ◽

Sharon C. Lehec ◽

Anil Dhawan

Keyword(s):

Cell Adhesion ◽

Adhesion Molecules ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Cell Attachment ◽

Human Hepatocytes ◽

Β1 Integrin ◽

Gene And Protein Expression ◽

A Cell ◽

E Cadherin

Good quality cryopreserved human hepatocytes are becoming an important source for clinical hepatocyte transplantation. However, the process of cryopreservation leads to both structural and functional impairment of hepatocytes. The aim of this study was to investigate the mechanisms of cryopreservation-induced nonattachment in human hepatocytes. Hepatocytes were cryopreserved after isolation from unused donor liver tissue. Cell attachment to collagen-coated plates was measured. A cDNA gene array system for 96 cell adhesion-related molecules was used to determine mRNA expression in fresh and cryopreserved hepatocytes. Two cell adhesion molecule proteins were investigated further: β1-integrin, a cell-matrix adhesion molecule, and E-cadherin, a cell–cell adhesion molecule. Attachment efficiency was significantly decreased after cryopreservation of human hepatocytes. Twenty-two genes were downregulated after cryopreservation including integrins, cadherins, catenins, and matrix metalloproteinases (MMPs). β1-Integrin gene and protein expression were significantly decreased in cultured cryopreserved hepatocytes compared to fresh hepatocytes. There was a significant correlation between loss of β1-integrin and attachment in cryopreserved cells. Degradation of E-cadherin was increased in cryopreserved hepatocytes. The process of cryopreservation leads to downregulation of cell adhesion molecules at the gene and the cellular level. New cryopreservation protocols are needed to prevent these effects on cell attachment.

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Phorbol ester-induced scattering of HT-29 human intestinal cancer cells is associated with down-modulation of E-cadherin

Journal of Cell Science ◽

10.1242/jcs.106.2.513 ◽

1993 ◽

Vol 106 (2) ◽

pp. 513-521

Author(s):

M. Fabre ◽

A. Garcia de Herreros

Keyword(s):

Cell Adhesion ◽

Phorbol Ester ◽

Cell Attachment ◽

Cell Aggregation ◽

Tumor Promoter ◽

High Concentration ◽

High Calcium ◽

Ht 29 ◽

E Cadherin ◽

Cell Cell

The effects of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on the growth characteristics of the colon cancer cell line HT-29 M6 were studied. TPA induced the scattering of proliferative HT-29 M6 cells: in the presence of the phorbol ester, HT-29 M6 colonies scattered and the cells acquired a flatter aspect with diminished cell-cell contacts. This effect of TPA required a persistent activation of PK-C and was accompanied by a slight decrease (30%) in the growth rate. Modifications by TPA of two scattering associated properties of these cells were also detected: TPA decreased cell-to-cell aggregation and enhanced the cellular attachment to matrix substrata (collagen, laminin). The decrease in cell-to-cell adhesion was correlated with a loss of cellular E-cadherin as evidenced by immunofluorescence or immunoblotting with a specific monoclonal antibody. Cell scattering was dependent on the extracellular concentration of Ca2+; an increase from 1.6 to 10 mM in the concentration of this ion completely blocked the morphological effects of TPA as well as its action on cell aggregation. This high concentration of Ca2+ also prevented the down modulation of E-cadherin as determined by immunofluorescence. However, the TPA-induced increase in cell attachment to the matrix was not affected by high calcium. These findings support the importance of altered cell-cell adhesion in the process of scattering and provide a good system for the study of down modulation of E-cadherin, a protein involved in the control of cell growth, differentiation and invasion of epithelial cells.

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Regulation of Rap1 activity by RapGAP1 controls cell adhesion at the front of chemotaxing cells

The Journal of Cell Biology ◽

10.1083/jcb.200705068 ◽

2007 ◽

Vol 179 (5) ◽

pp. 833-843 ◽

Cited By ~ 44

Author(s):

Taeck J. Jeon ◽

Dai-Jen Lee ◽

Susan Lee ◽

Gerald Weeks ◽

Richard A. Firtel

Keyword(s):

Cell Adhesion ◽

Cell Attachment ◽

Leading Edge ◽

Cell Cortex ◽

Temporal Regulation ◽

Attachment Sites ◽

Edge Defects ◽

Mediate Cell ◽

Guanosine Triphosphatase ◽

Rap1 Activation

Spatial and temporal regulation of Rap1 is required for proper myosin assembly and cell adhesion during cell migration in Dictyostelium discoideum. Here, we identify a Rap1 guanosine triphosphatase–activating protein (GAP; RapGAP1) that helps mediate cell adhesion by negatively regulating Rap1 at the leading edge. Defects in spatial regulation of the cell attachment at the leading edge in rapGAP1− (null) cells or cells overexpressing RapGAP1 (RapGAP1OE) lead to defective chemotaxis. rapGAP1− cells have extended chemoattractant-mediated Rap1 activation kinetics and decreased MyoII assembly, whereas RapGAP1OE cells show reciprocal phenotypes. We see that RapGAP1 translocates to the cell cortex in response to chemoattractant stimulation and localizes to the leading edge of chemotaxing cells via an F-actin–dependent pathway. RapGAP1 localization is negatively regulated by Ctx, an F-actin bundling protein that functions during cytokinesis. Loss of Ctx leads to constitutive and uniform RapGAP1 cortical localization. We suggest that RapGAP1 functions in the spatial and temporal regulation of attachment sites through MyoII assembly via regulation of Rap1–guanosine triphosphate.

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