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Full-Text Articles in Medical Sciences
Suppression Of Pi3k Signaling Is Linked To Autophagy Activation And The Spatiotemporal Induction Of The Lens Organelle Free Zone, Rifah Gheyas, Ramon Ortega-Alvarez, Daniel Chauss, Marc Kantorow, A. Menko
Suppression Of Pi3k Signaling Is Linked To Autophagy Activation And The Spatiotemporal Induction Of The Lens Organelle Free Zone, Rifah Gheyas, Ramon Ortega-Alvarez, Daniel Chauss, Marc Kantorow, A. Menko
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
The terminal steps of lens cell differentiation require elimination of all organelles to create a central Organelle Free Zone (OFZ) that is required for lens function of focusing images on the retina. Previous studies show that the spatiotemporal elimination of these organelles during development is autophagy-dependent. We now show that the inhibition of PI3K signaling in lens organ culture results in the premature induction of autophagy within 24 h, including a significant increase in LAMP1+ lysosomes, and the removal of lens organelles from the center of the lens. Specific inhibition of just the PI3K/Akt signaling axis was directly linked to …
The Role Of Decorin Proteoglycan In Mitophagy., Thomas Neill, Renato V. Iozzo
The Role Of Decorin Proteoglycan In Mitophagy., Thomas Neill, Renato V. Iozzo
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Proteoglycans are emerging as critical regulators of intracellular catabolism. This rise in prominence has transformed our basic understanding and alerted us to the existence of non-canonical pathways, independent of nutrient deprivation, that potently control the autophagy downstream of a cell surface receptor. As a member of the small leucine-rich proteoglycan gene family, decorin has single-handedly pioneered the connection between extracellular matrix signaling and autophagy regulation. Soluble decorin evokes protracted endothelial cell autophagy via Peg3 and breast carcinoma cell mitophagy via mitostatin by interacting with VEGFR2 or the MET receptor tyrosine kinase, respectively. In this paper, we give a mechanistic perspective …
The Role Of Decorin And Biglycan Signaling In Tumorigenesis, Valentina Diehl, Lisa Sophie Huber, Jonel Trebicka, Malgorzata Wygrecka, Renato V. Iozzo, Liliana Schaefer
The Role Of Decorin And Biglycan Signaling In Tumorigenesis, Valentina Diehl, Lisa Sophie Huber, Jonel Trebicka, Malgorzata Wygrecka, Renato V. Iozzo, Liliana Schaefer
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
The complex and adaptive nature of malignant neoplasm constitute a major challenge for the development of effective anti-oncogenic therapies. Emerging evidence has uncovered the pivotal functions exerted by the small leucine-rich proteoglycans, decorin and biglycan, in affecting tumor growth and progression. In their soluble forms, decorin and biglycan act as powerful signaling molecules. By receptor-mediated signal transduction, both proteoglycans modulate key processes vital for tumor initiation and progression, such as autophagy, inflammation, cell-cycle, apoptosis, and angiogenesis. Despite of their structural homology, these two proteoglycans interact with distinct cell surface receptors and thus modulate distinct signaling pathways that ultimately affect cancer …
Catabolic Degradation Of Endothelial Vegfa Via Autophagy, Thomas Neill, Carolyn Chen, Simone Buraschi, Renato V. Iozzo
Catabolic Degradation Of Endothelial Vegfa Via Autophagy, Thomas Neill, Carolyn Chen, Simone Buraschi, Renato V. Iozzo
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Extracellular matrix-evoked angiostasis and autophagy within the tumor microenvironment represent two critical, but unconnected, functions of the small leucine-rich proteoglycan, decorin. Acting as a partial agonist of vascular endothelial growth factor 2 (VEGFR2), soluble decorin signals via the energy sensing protein, AMP-activated protein kinase (AMPK), in the autophagic degradation of intracellular vascular endothelial growth factor A (VEGFA). Here, we discovered that soluble decorin evokes intracellular catabolism of endothelial VEGFA that is mechanistically independent of mTOR, but requires an autophagic regulator, paternally expressed gene 3 (PEG3). We found that administration of autophagic inhibitors such as chloroquine or bafilomycin A1, or depletion …
Metabolic Reprogramming Of Murine Cardiomyocytes During Autophagy Requires The Extracellular Nutrient Sensor Decorin., Maria A. Gubbiotti, Erin L. Seifert, Ulrich Rodeck, Jan B. Hoek, Renato V. Iozzo
Metabolic Reprogramming Of Murine Cardiomyocytes During Autophagy Requires The Extracellular Nutrient Sensor Decorin., Maria A. Gubbiotti, Erin L. Seifert, Ulrich Rodeck, Jan B. Hoek, Renato V. Iozzo
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
The extracellular matrix is a master regulator of tissue homeostasis in health and disease. Here we examined how the small, leucine-rich, extracellular matrix proteoglycan decorin regulates cardiomyocyte metabolism during fasting in vivo. First, we validated in Dcn-/- mice that decorin plays an essential role in autophagy induced by fasting. High-Throughput metabolomics analyses of cardiac tissue in Dcn-/- mice subjected to fasting revealed striking differences in the hexosamine biosynthetic pathway resulting in aberrant cardiac O-β-N-Acetylglycosylation as compared with WT mice. Functionally, Dcn-/- mice maintained cardiac function at a level comparable with nonfasted animals whereas fasted WT mice showed …
Decorin-Evoked Paternally Expressed Gene 3 (Peg3) Is An Upstream Regulator Of The Transcription Factor Eb (Tfeb) In Endothelial Cell Autophagy., Thomas Neill, Catherine Sharpe, Rick T. Owens, Renato V. Iozzo
Decorin-Evoked Paternally Expressed Gene 3 (Peg3) Is An Upstream Regulator Of The Transcription Factor Eb (Tfeb) In Endothelial Cell Autophagy., Thomas Neill, Catherine Sharpe, Rick T. Owens, Renato V. Iozzo
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Macroautophagy is a fundamental and evolutionarily conserved catabolic process that eradicates damaged and aging macromolecules and organelles in eukaryotic cells. Decorin, an archetypical small leucine-rich proteoglycan, initiates a protracted autophagic program downstream of VEGF receptor 2 (VEGFR2) signaling that requires paternally expressed gene 3 (PEG3). We have discovered that PEG3 is an upstream transcriptional regulator of transcription factor EB (TFEB), a master transcription factor of lysosomal biogenesis, for decorin-evoked endothelial cell autophagy. We found a functional requirement of PEG3 for TFEB transcriptional induction and nuclear translocation in human umbilical vein endothelial and PAER2 cells. Mechanistically, inhibiting VEGFR2 or AMP-activated protein …
The Role Of Perlecan And Endorepellin In The Control Of Tumor Angiogenesis And Endothelial Cell Autophagy., Stephen Douglass, Atul Goyal, Renato V. Iozzo
The Role Of Perlecan And Endorepellin In The Control Of Tumor Angiogenesis And Endothelial Cell Autophagy., Stephen Douglass, Atul Goyal, Renato V. Iozzo
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
During tumor growth and angiogenesis there is a dynamic remodeling of tissue architecture often accompanied by the release of extracellular matrix constituents full of biological activity. One of the key constituents of the tumor microenvironment is the large heparan sulfate proteoglycan perlecan. This proteoglycan, strategically located at cell surfaces and within basement membranes, is a well-defined pro-angiogenic molecule when intact. However, when partially processed by proteases released during cancer remodeling and invasion, the C-terminal fragment of perlecan, known as endorepellin, has opposite effects than its parent molecule. Endorepellin is a potent inhibitor of angiogenesis by exerting a dual receptor antagonism …