scholarly journals Protein complexes that control renal epithelial polarity

2011 ◽  
Vol 300 (3) ◽  
pp. F589-F601 ◽  
Author(s):  
Jay Pieczynski ◽  
Ben Margolis
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Kidney Development ◽  
Protein Complexes ◽  
Basolateral Membrane ◽  
Protein Activity ◽  
Mesenchymal Transition ◽  
Apicobasal Polarity ◽  
Mesenchymal To Epithelial Transition ◽  
And Function ◽  
Crumbs Complex

Establishment of epithelial apicobasal polarity is crucial for proper kidney development and function. In recent years, there have been important advances in our understanding of the factors that mediate the initiation of apicobasal polarization. Key among these are the polarity complexes that are evolutionarily conserved from simple organisms to humans. Three of these complexes are discussed in this review: the Crumbs complex, the Par complex, and the Scribble complex. The apical Crumbs complex consists of three proteins, Crumbs, PALS1, and PATJ, whereas the apical Par complex consists of Par-3, Par-6, and atypical protein kinase C. The lateral Scribble complex consists of Scribble, discs large, and lethal giant larvae. These complexes modulate kinase and small G protein activity such that the apical and basolateral complexes signal antagonistically, leading to the segregation of the apical and basolateral membranes. The polarity complexes also serve as scaffolds to direct and retain proteins at the apical membrane, the basolateral membrane, or the intervening tight junction. There is plasticity in apicobasal polarity, and this is best seen in the processes of epithelial-to-mesenchymal transition and the converse mesenchymal-to-epithelial transition. These transitions are important in kidney disease as well as kidney development, and modulation of the polarity complexes are critical for these transitions.

scholarly journals Key role for EphB2 receptor in kidney fibrosis

2021 ◽  
Vol 135 (17) ◽  
pp. 2127-2142
Author(s):  
Zhimin Huang ◽  
Simeng Liu ◽  
Anna Tang ◽  
Laith Al-Rabadi ◽  
Mark Henkemeyer ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Kidney Development ◽  
Ischemia Reperfusion ◽  
Kidney Tissue ◽  
Kidney Injury ◽  
Regulation Of Expression ◽  
Kidney Fibrosis ◽  
Mesenchymal Transition ◽  
Renal Tubular ◽  
And Function

Abstract Erythropoietin producing hepatocellular (Eph)–Eph receptor interacting (Ephrin) receptor–ligand signaling has been implicated in the development of tissue fibrosis, though it has not been well defined in the kidney. We detected substantial up-regulation of expression and phosphorylation of the EphB2 receptor tyrosine kinase in fibrotic kidney tissue obtained both from mice subjected to the unilateral renal ischemia–reperfusion (IR) model at 14 days and in patients suffering from chronic kidney disease (CKD). Knockout (KO) mice lacking EphB2 expression exhibited a normal renal structure and function, indicating no major role for this receptor in kidney development or action. Although IR injury is well-known to cause tissue damage, fibrosis, and renal dysfunction, we found that kidneys from EphB2KO mice showed much less renal tubular injury and retained a more preserved renal function. IR-injured kidneys from EphB2 KOs exhibited greatly reduced fibrosis and inflammation compared with injured wildtype (WT) littermates, and this correlated with a significant reduction in renal expression of profibrotic molecules, inflammatory cytokines, NADPH oxidases, and markers for cell proliferation, tubular epithelial-to-mesenchymal transition (EMT), myofibroblast activation, and apoptosis. A panel of 760 fibrosis-associated genes were further assessed, revealing that 506 genes in WT mouse kidney following IR injury changed their expression. However, 70.9% of those genes were back to or close to normal in expression when EphB2 was deleted. These data indicate that endogenous EphB2 expression and signaling are abnormally activated after kidney injury and subsequently contribute to the development of renal fibrosis via regulation of multiple profibrotic pathways.

scholarly journals The dark-side of the outside: how extracellular heat shock proteins promote cancer

2021 ◽  
Author(s):  
Laura Seclì ◽  
Federica Fusella ◽  
Lidia Avalle ◽  
Mara Brancaccio
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Epithelial To Mesenchymal Transition ◽  
Dark Side ◽  
Migration And Invasion ◽  
Protein Activity ◽  
Tumour Immunity ◽  
Mesenchymal Transition ◽  
Cancer Hallmarks ◽  
Shock Proteins

AbstractIn addition to exerting several essential house-keeping activities in the cell, heat shock proteins (HSPs) are crucial players in a well-structured molecular program activated in response to stressful challenges. Among the different activities carried out by HSPs during emergency, they reach the extracellular milieu, from where they scout the surroundings, regulate extracellular protein activity and send autocrine and paracrine signals. Cancer cells permanently experience stress conditions due to their altered equilibrium and behaviour, and constantly secrete heat shock proteins as a result. Other than supporting anti-tumour immunity, extracellular heat shock proteins (eHSPs), can also exacerbate cancer cell growth and malignancy by sustaining different cancer hallmarks. eHSPs are implicated in extracellular matrix remodelling, resistance to apoptosis, promotion of cell migration and invasion, induction of epithelial to mesenchymal transition, angiogenesis and activation of stromal cells, supporting ultimately, metastasis dissemination. A broader understanding of eHSP activity and contribution to tumour development and progression is leading to new opportunities in the diagnosis and treatment of cancer.

scholarly journals PPAR-gamma induced AKT3 expression increases levels of mitochondrial biogenesis driving prostate cancer

Oncogene ◽  
2021 ◽  
Vol 40 (13) ◽  
pp. 2355-2366
Author(s):  
Laura C. A. Galbraith ◽  
Ernest Mui ◽  
Colin Nixon ◽  
Ann Hedley ◽  
David Strachan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Biogenesis ◽  
Nuclear Export ◽  
Epithelial To Mesenchymal Transition ◽  
Ppar Gamma ◽  
Peroxisome Proliferator ◽  
Serine Threonine Kinase ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mesenchymal Transition ◽  
And Function

AbstractPeroxisome Proliferator-Activated Receptor Gamma (PPARG) is one of the three members of the PPAR family of transcription factors. Besides its roles in adipocyte differentiation and lipid metabolism, we recently demonstrated an association between PPARG and metastasis in prostate cancer. In this study a functional effect of PPARG on AKT serine/threonine kinase 3 (AKT3), which ultimately results in a more aggressive disease phenotype was identified. AKT3 has previously been shown to regulate PPARG co-activator 1 alpha (PGC1α) localisation and function through its action on chromosome maintenance region 1 (CRM1). AKT3 promotes PGC1α localisation to the nucleus through its inhibitory effects on CRM1, a known nuclear export protein. Collectively our results demonstrate how PPARG over-expression drives an increase in AKT3 levels, which in turn has the downstream effect of increasing PGC1α localisation within the nucleus, driving mitochondrial biogenesis. Furthermore, this increase in mitochondrial mass provides higher energetic output in the form of elevated ATP levels which may fuel the progression of the tumour cell through epithelial to mesenchymal transition (EMT) and ultimately metastasis.

scholarly journals Molecular mechanisms underpinning sarcomas and implications for current and future therapy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Victoria Damerell ◽  
Michael S. Pepper ◽  
Sharon Prince
Keyword(s):  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Treatment Strategies ◽  
Mesenchymal Transition ◽  
Mesenchymal To Epithelial Transition ◽  
Cells Of Origin ◽  
Novel Treatment Strategies ◽  
Future Therapy

AbstractSarcomas are complex mesenchymal neoplasms with a poor prognosis. Their clinical management is highly challenging due to their heterogeneity and insensitivity to current treatments. Although there have been advances in understanding specific genomic alterations and genetic mutations driving sarcomagenesis, the underlying molecular mechanisms, which are likely to be unique for each sarcoma subtype, are not fully understood. This is in part due to a lack of consensus on the cells of origin, but there is now mounting evidence that they originate from mesenchymal stromal/stem cells (MSCs). To identify novel treatment strategies for sarcomas, research in recent years has adopted a mechanism-based search for molecular markers for targeted therapy which has included recapitulating sarcomagenesis using in vitro and in vivo MSC models. This review provides a comprehensive up to date overview of the molecular mechanisms that underpin sarcomagenesis, the contribution of MSCs to modelling sarcomagenesis in vivo, as well as novel topics such as the role of epithelial-to-mesenchymal-transition (EMT)/mesenchymal-to-epithelial-transition (MET) plasticity, exosomes, and microRNAs in sarcomagenesis. It also reviews current therapeutic options including ongoing pre-clinical and clinical studies for targeted sarcoma therapy and discusses new therapeutic avenues such as targeting recently identified molecular pathways and key transcription factors.

scholarly journals miRNA proxy approach reveals hidden functions of glycosylation

2015 ◽  
Vol 112 (23) ◽  
pp. 7327-7332 ◽  
Author(s):  
Tomasz Kurcon ◽  
Zhongyin Liu ◽  
Anika V. Paradkar ◽  
Christopher A. Vaiana ◽  
Sujeethraj Koppolu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Epithelial To Mesenchymal Transition ◽  
Biological Function ◽  
Regulatory Elements ◽  
Rapid Identification ◽  
Mesenchymal Transition ◽  
Disease States ◽  
Mesenchymal To Epithelial Transition ◽  
Genes Encoding ◽  
Target Network

Glycosylation, the most abundant posttranslational modification, holds an unprecedented capacity for altering biological function. Our ability to harness glycosylation as a means to control biological systems is hampered by our inability to pinpoint the specific glycans and corresponding biosynthetic enzymes underlying a biological process. Herein we identify glycosylation enzymes acting as regulatory elements within a pathway using microRNA (miRNA) as a proxy. Leveraging the target network of the miRNA-200 family (miR-200f), regulators of epithelial-to-mesenchymal transition (EMT), we pinpoint genes encoding multiple promesenchymal glycosylation enzymes (glycogenes). We focus on three enzymes, beta-1,3-glucosyltransferase (B3GLCT), beta-galactoside alpha-2,3-sialyltransferase 5 (ST3GAL5), and (alpha-N-acetyl-neuraminyl-2,3-beta-galactosyl-1,3)-N-acetylgalactosaminide alpha-2,6-sialyltransferase 5 (ST6GALNAC5), encoding glycans that are difficult to analyze by traditional methods. Silencing these glycogenes phenocopied the effect of miR-200f, inducing mesenchymal-to-epithelial transition. In addition, all three are up-regulated in TGF-β–induced EMT, suggesting tight integration within the EMT-signaling network. Our work indicates that miRNA can act as a relatively simple proxy to decrypt which glycogenes, including those encoding difficult-to-analyze structures (e.g., proteoglycans, glycolipids), are functionally important in a biological pathway, setting the stage for the rapid identification of glycosylation enzymes driving disease states.

scholarly journals Snail1: A Transcriptional Factor Controlled at Multiple Levels

2019 ◽  
Vol 8 (6) ◽  
pp. 757 ◽  
Author(s):  
Josep Baulida ◽  
Víctor M. Díaz ◽  
Antonio García de Herreros
Keyword(s):  
Gene Transcription ◽  
Epithelial To Mesenchymal Transition ◽  
Transcriptional Repressor ◽  
Transcriptional Factor ◽  
Protein Modifications ◽  
Mesenchymal Transition ◽  
Fibroblast Activation ◽  
Multiple Levels ◽  
And Function ◽  
Snail1 Expression

Snail1 transcriptional factor plays a key role in the control of epithelial to mesenchymal transition and fibroblast activation. As a consequence, Snail1 expression and function is regulated at multiple levels from gene transcription to protein modifications, affecting its interaction with specific cofactors. In this review, we describe the different elements that control Snail1 expression and its activity both as transcriptional repressor or activator.

scholarly journals Epiblast integrity requires CLASP and Dystroglycan-mediated microtubule anchoring to the basal cortex

2013 ◽  
Vol 202 (4) ◽  
pp. 637-651 ◽  
Author(s):  
Yukiko Nakaya ◽  
Erike W. Sukowati ◽  
Guojun Sheng
Keyword(s):  
Basement Membrane ◽  
Epithelial To Mesenchymal Transition ◽  
Transmembrane Protein ◽  
Basolateral Membrane ◽  
Cortical Microtubule ◽  
Molecular Regulation ◽  
Mesenchymal Transition ◽  
Binding Partner ◽  
Mesoderm Formation ◽  
Lateral Localization

Amniote epiblast cells differentiate into mesoderm and endoderm lineages during gastrulation through a process called epithelial-to-mesenchymal transition (EMT). Molecular regulation of gastrulation EMT is poorly understood. Here we show that epiblast epithelial status was maintained by anchoring microtubules to the basal cortex via CLIP-associated protein (CLASP), a microtubule plus-end tracking protein, and Dystroglycan, a transmembrane protein that bridges the cytoskeleton and basement membrane (BM). Mesoderm formation required down-regulation of CLASP and Dystroglycan, and reducing CLASP activity in pregastrulation epiblast cells caused ectopic BM breakdown and disrupted epiblast integrity. These effects were mediated through the CLASP-binding partner LL5. Live-imaging using EB1–enhanced GFP (eGFP) revealed that reducing CLASP and LL5 levels in the epiblast destabilized basal microtubules. We further show that Dystroglycan is localized to basolateral membrane in epiblast cells. Basal but not lateral localization of Dystroglycan was regulated by CLASP. We propose that epiblast–BM interaction requires CLASP- and Dystroglycan-mediated cortical microtubule anchoring, the disruption of which initiates gastrulation EMT.

scholarly journals The Transcription Factor Elf3 Is Essential for a Successful Mesenchymal to Epithelial Transition

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 858 ◽  
Author(s):  
Burcu Sengez ◽  
Ilkin Aygün ◽  
Huma Shehwana ◽  
Neslihan Toyran ◽  
Sanem Tercan Avci ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Expression Profiles ◽  
Biological Processes ◽  
Comprehensive Understanding ◽  
Mesenchymal Transition ◽  
Mesenchymal To Epithelial Transition ◽  
Strong Candidate ◽  
Acute Changes ◽  
Epithelial State ◽  
E Cadherin

The epithelial to mesenchymal transition (EMT) and the mesenchymal to epithelial transition (MET) are two critical biological processes that are involved in both physiological events such as embryogenesis and development and also pathological events such as tumorigenesis. They present with dramatic changes in cellular morphology and gene expression exhibiting acute changes in E-cadherin expression. Despite the comprehensive understanding of EMT, the regulation of MET is far from being understood. To find novel regulators of MET, we hypothesized that such factors would correlate with Cdh1 expression. Bioinformatics examination of several expression profiles suggested Elf3 as a strong candidate. Depletion of Elf3 at the onset of MET severely impaired the progression to the epithelial state. This MET defect was explained, in part, by the absence of E-cadherin at the plasma membrane. Moreover, during MET, ELF3 interacts with the Grhl3 promoter and activates its expression. Our findings present novel insights into the regulation of MET and reveal ELF3 as an indispensable guardian of the epithelial state. A better understanding of MET will, eventually, lead to better management of metastatic cancers.

scholarly journals Notch-Jagged signalling can give rise to clusters of cells exhibiting a hybrid epithelial/mesenchymal phenotype

2016 ◽  
Vol 13 (118) ◽  
pp. 20151106 ◽  
Author(s):  
Marcelo Boareto ◽  
Mohit Kumar Jolly ◽  
Aaron Goldman ◽  
Mika Pietilä ◽  
Sendurai A. Mani ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Tumour Progression ◽  
Cell Communication ◽  
Notch Signalling ◽  
Circulating Tumour Cells ◽  
Mesenchymal Phenotype ◽  
Mesenchymal Transition ◽  
Mesenchymal To Epithelial Transition ◽  
Key Players

Metastasis can involve repeated cycles of epithelial-to-mesenchymal transition (EMT) and its reverse mesenchymal-to-epithelial transition. Cells can also undergo partial transitions to attain a hybrid epithelial/mesenchymal (E/M) phenotype that allows the migration of adhering cells to form a cluster of circulating tumour cells. These clusters can be apoptosis-resistant and possess an increased metastatic propensity as compared to the cells that undergo a complete EMT (mesenchymal cells). Hence, identifying the key players that can regulate the formation and maintenance of such clusters may inform anti-metastasis strategies. Here, we devise a mechanism-based theoretical model that links cell–cell communication via Notch-Delta-Jagged signalling with the regulation of EMT. We demonstrate that while both Notch-Delta and Notch-Jagged signalling can induce EMT in a population of cells, only Jagged-dominated Notch signalling, but not Delta-dominated signalling, can lead to the formation of clusters containing hybrid E/M cells. Our results offer possible mechanistic insights into the role of Jagged in tumour progression, and offer a framework to investigate the effects of other microenvironmental signals during metastasis.

scholarly journals ZEB1 insufficiency causes corneal endothelial cell state transition and altered cellular processing

2019 ◽  
Author(s):  
Ricardo F. Frausto ◽  
Doug D. Chung ◽  
Payton M. Boere ◽  
Vinay S. Swamy ◽  
Huong N.V. Duong ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Cell Lineage ◽  
Corneal Dystrophy ◽  
State Transitions ◽  
Cellular Phenotype ◽  
Mesenchymal Transition ◽  
Cell State ◽  
Functional Studies ◽  
Mesenchymal To Epithelial Transition ◽  
Integral Role

ABSTRACTThe zinc finger e-box binding homeobox 1 (ZEB1) transcription factor is a master regulator of the epithelial to mesenchymal transition (EMT), and of the reverse mesenchymal to epithelial transition (MET) processes. ZEB1 plays an integral role in mediating cell state transitions during cell lineage specification, wound healing and disease. EMT/MET are characterized by distinct changes in molecular and cellular phenotype that are generally context-independent. Posterior polymorphous corneal dystrophy (PPCD), associated with ZEB1 insufficiency, provides a new biological context in which to understand and evaluate the classic EMT/MET paradigm. PPCD is characterized by a cadherin-switch and transition to an epithelial-like transcriptomic and cellular phenotype, which we study in a cell-based model of PPCD generated using CRISPR-Cas9-mediated ZEB1 knockout in corneal endothelial cells (CEnCs). Transcriptomic and functional studies support the hypothesis that CEnC undergo a MET-like transition in PPCD, termed endothelial to epithelial transition (EnET), and lead to the conclusion that EnET may be considered a corollary to the classic EMT/MET paradigm.

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