scholarly journals Mitotic Centromere-Associated Kinesin (MCAK/KIF2C) Regulates Cell Migration and Invasion by Modulating Microtubule Dynamics and Focal Adhesion Turnover

Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5673
Author(s):  
Ha Hyung Moon ◽  
Nina-Naomi Kreis ◽  
Alexandra Friemel ◽  
Susanne Roth ◽  
Dorothea Schulte ◽  
...  
Keyword(s):  
Cell Motility ◽  
Molecular Mechanisms ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Focal Adhesions ◽  
Protein Composition ◽  
Cell Types ◽  
Migration And Invasion ◽  
And Migration ◽  
Cytoskeleton Dynamics

The microtubule (MT) cytoskeleton is crucial for cell motility and migration by regulating multiple cellular activities such as transport and endocytosis of key components of focal adhesions (FA). The kinesin-13 family is important in the regulation of MT dynamics and the best characterized member of this family is the mitotic centromere-associated kinesin (MCAK/KIF2C). Interestingly, its overexpression has been reported to be related to increased metastasis in various tumor entities. Moreover, MCAK is involved in the migration and invasion behavior of various cell types. However, the precise molecular mechanisms were not completely clarified. To address these issues, we generated CRISPR/dCas9 HeLa and retinal pigment epithelium (RPE) cell lines overexpressing or downregulating MCAK. Both up- or downregulation of MCAK led to reduced cell motility and poor migration in malignant as well as benign cells. Specifically, it’s up- or downregulation impaired FA protein composition and phosphorylation status, interfered with a proper spindle and chromosome segregation, disturbed the assembly and disassembly rate of FA, delayed cell adhesion, and compromised the plus-tip dynamics of MTs. In conclusion, our data suggest MCAK act as an important regulator for cell motility and migration by affecting the actin-MT cytoskeleton dynamics and the FA turnover, providing molecular mechanisms by which deregulated MCAK could promote malignant progression and metastasis of tumor cells.

scholarly journals CIB2 regulates mTORC1 signaling and is essential for autophagy and visual function

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Saumil Sethna ◽  
Patrick A. Scott ◽  
Arnaud P. J. Giese ◽  
Todd Duncan ◽  
Xiaoying Jian ◽  
...  
Keyword(s):  
Visual Function ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Negative Regulator ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Mtorc1 Signaling ◽  
Marked Accumulation

AbstractAge-related macular degeneration (AMD) is a multifactorial neurodegenerative disorder. Although molecular mechanisms remain elusive, deficits in autophagy have been associated with AMD. Here we show that deficiency of calcium and integrin binding protein 2 (CIB2) in mice, leads to age-related pathologies, including sub-retinal pigment epithelium (RPE) deposits, marked accumulation of drusen markers APOE, C3, Aβ, and esterified cholesterol, and impaired visual function, which can be rescued using exogenous retinoids. Cib2 mutant mice exhibit reduced lysosomal capacity and autophagic clearance, and increased mTORC1 signaling—a negative regulator of autophagy. We observe concordant molecular deficits in dry-AMD RPE/choroid post-mortem human tissues. Mechanistically, CIB2 negatively regulates mTORC1 by preferentially binding to ‘nucleotide empty’ or inactive GDP-loaded Rheb. Upregulated mTORC1 signaling has been implicated in lymphangioleiomyomatosis (LAM) cancer. Over-expressing CIB2 in LAM patient-derived fibroblasts downregulates hyperactive mTORC1 signaling. Thus, our findings have significant implications for treatment of AMD and other mTORC1 hyperactivity-associated disorders.

Interaction between VEGF and Calcium-Independent Phospholipase A2in Proliferation and Migration of Retinal Pigment Epithelium

2012 ◽  
Vol 37 (6) ◽  
pp. 500-507 ◽  
Author(s):  
Anne Katrine Kehler ◽  
Cammilla Andersen ◽  
Jens Rovelt Andreasen ◽  
Rupali Vohra ◽  
Nanna Junker ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
And Migration ◽  
Proliferation And Migration

scholarly journals Pathogenic Effects of Mineralocorticoid Pathway Activation in Retinal Pigment Epithelium

2021 ◽  
Vol 22 (17) ◽  
pp. 9618
Author(s):  
Jérémie Canonica ◽  
Min Zhao ◽  
Tatiana Favez ◽  
Emmanuelle Gelizé ◽  
Laurent Jonet ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Retinal Pigment Epithelium ◽  
Barrier Function ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Diseases ◽  
Mesenchymal Transition ◽  
Rpe Cells ◽  
Pathway Activation ◽  
And Migration

Glucocorticoids are amongst the most used drugs to treat retinal diseases of various origins. Yet, the transcriptional regulations induced by glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) activation in retinal pigment epithelium cells (RPE) that form the outer blood–retina barrier are unknown. Levels of endogenous corticoids, ligands for MR and GR, were measured in human ocular media. Human RPE cells derived from induced pluripotent stem cells (iRPE) were used to analyze the pan-transcriptional regulations induced by aldosterone—an MR-specific agonist, or cortisol or cortisol + RU486—a GR antagonist. The retinal phenotype of transgenic mice that overexpress the human MR (P1.hMR) was analyzed. In the human eye, the main ligand for GR and MR is cortisol. The iRPE cells express functional GR and MR. The subset of genes regulated by aldosterone and by cortisol + RU-486, and not by cortisol alone, mimics an imbalance toward MR activation. They are involved in extracellular matrix remodeling (CNN1, MGP, AMTN), epithelial–mesenchymal transition, RPE cell proliferation and migration (ITGB3, PLAUR and FOSL1) and immune balance (TNFSF18 and PTX3). The P1.hMR mice showed choroidal vasodilation, focal alteration of the RPE/choroid interface and migration of RPE cells together with RPE barrier function alteration, similar to human retinal diseases within the pachychoroid spectrum. RPE is a corticosteroid-sensitive epithelium. MR pathway activation in the RPE regulates genes involved in barrier function, extracellular matrix, neural regulation and epithelial differentiation, which could contribute to retinal pathology.

Degradation of extracellular ATP by the retinal pigment epithelium

2005 ◽  
Vol 289 (3) ◽  
pp. C617-C624 ◽  
Author(s):  
David Reigada ◽  
Wennan Lu ◽  
Xiulan Zhang ◽  
Constantin Friedman ◽  
Klara Pendrak ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Adenosine Diphosphate ◽  
Cell Types ◽  
P2y Receptors ◽  
Extracellular Atp ◽  
Pcr Analysis ◽  
Subretinal Space ◽  
Rpe Cells ◽  
Mrs 2179

Stimulation of ATP or adenosine receptors causes important physiological changes in retinal pigment epithelial (RPE) cells that may influence their relationship to the adjacent photoreceptors. While RPE cells have been shown to release ATP, the regulation of extracellular ATP levels and the production of dephosphorylated purines is not clear. This study examined the degradation of ATP by RPE cells and the physiological effects of the adenosine diphosphate (ADP) that result. ATP was readily broken down by both cultured human ARPE-19 cells and the apical membrane of fresh bovine RPE cells. The compounds ARL67156 and βγ-mATP inhibited this degradation in both cell types. RT-PCR analysis of ARPE-19 cells found mRNA message for multiple extracellular degradative enzymes; ectonucleotide pyrophosphatase/phosphodiesterase eNPP1, eNPP2, and eNPP3; the ectoATPase ectonucleoside triphosphate diphosphohydrolase NTPDase2, NTPDase3, and some message for NTPDase1. Considerable levels of ADP bathed RPE cells, consistent with a role for NTPDase2. ADP and ATP increased levels of intracellular Ca2+. Both responses were inhibited by thapsigargin and P2Y1 receptor inhibitor MRS 2179. Message for both P2Y1 and P2Y12 receptors was detected in ARPE-19 cells. These results suggest that extracellular degradation of ATP in subretinal space can result in the production of ADP. This ADP can stimulate P2Y receptors and augment Ca2+ signaling in the RPE.

scholarly journals KCNQ5/Kv7.5 potassium channel expression and subcellular localization in primate retinal pigment epithelium and neural retina

2011 ◽  
Vol 301 (5) ◽  
pp. C1017-C1026 ◽  
Author(s):  
Xiaoming Zhang ◽  
Dongli Yang ◽  
Bret A. Hughes
Keyword(s):  
Visual Information ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Basal Membrane ◽  
Cell Types ◽  
Neural Retina ◽  
Pcr Analysis ◽  
Rod Photoreceptor ◽  
Rpe Cells ◽  
Channel Expression

Previous studies identified in retinal pigment epithelial (RPE) cells an M-type K+ current, which in many other cell types is mediated by channels encoded by KCNQ genes. The aim of this study was to assess the expression of KCNQ genes in the monkey RPE and neural retina. Application of the specific KCNQ channel blocker XE991 eliminated the M-type current in freshly isolated monkey RPE cells, indicating that KCNQ subunits contribute to the underlying channels. RT-PCR analysis revealed the expression of KCNQ1, KCNQ4, and KCNQ5 transcripts in the RPE and all five KCNQ transcripts in the neural retina. At the protein level, KCNQ5 was detected in the RPE, whereas both KCNQ4 and KCNQ5 were found in neural retina. In situ hybridization in frozen monkey retinal sections revealed KCNQ5 gene expression in the ganglion cell layer and the inner and outer nuclear layers of the neural retina, but results in the RPE were inconclusive due to the presence of melanin. Immunohistochemistry revealed KCNQ5 in the inner and outer plexiform layers, in cone and rod photoreceptor inner segments, and near the basal membrane of the RPE. The data suggest that KCNQ5 channels contribute to the RPE basal membrane K+ conductance and, thus, likely play an important role in active K+ absorption. The distribution of KCNQ5 in neural retina suggests that these channels may function in the shaping of the photoresponses of cone and rod photoreceptors and the processing of visual information by retinal neurons.

scholarly journals X-linked Inhibitor of Apoptosis Protein (XIAP) Mediates Cancer Cell Motility via Rho GDP Dissociation Inhibitor (RhoGDI)-dependent Regulation of the Cytoskeleton

2011 ◽  
Vol 286 (18) ◽  
pp. 15630-15640 ◽  
Author(s):  
Jinyi Liu ◽  
Dongyun Zhang ◽  
Wenjing Luo ◽  
Yonghui Yu ◽  
Jianxiu Yu ◽  
...  
Keyword(s):  
Cell Motility ◽  
Cancer Cell ◽  
Actin Polymerization ◽  
Molecular Mechanisms ◽  
Biological Behavior ◽  
Migration And Invasion ◽  
Inhibitor Of Apoptosis ◽  
Inhibitor Of Apoptosis Protein ◽  
Apoptosis Protein ◽  
Gdp Dissociation Inhibitor

X-linked inhibitor of apoptosis protein (XIAP) overexpression has been found to be associated with malignant cancer progression and aggression in individuals with many types of cancers. However, the molecular basis of XIAP in the regulation of cancer cell biological behavior remains largely unknown. In this study, we found that a deficiency of XIAP expression in human cancer cells by either knock-out or knockdown leads to a marked reduction in β-actin polymerization and cytoskeleton formation. Consistently, cell migration and invasion were also decreased in XIAP-deficient cells compared with parental wild-type cells. Subsequent studies demonstrated that the regulation of cell motility by XIAP depends on its interaction with the Rho GDP dissociation inhibitor (RhoGDI) via the XIAP RING domain. Furthermore, XIAP was found to negatively regulate RhoGDI SUMOylation, which might affect its activity in controlling cell motility. Collectively, our studies provide novel insights into the molecular mechanisms by which XIAP regulates cancer invasion and offer a further theoretical basis for setting XIAP as a potential prognostic marker and specific target for treatment of cancers with metastatic properties.

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