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2017

Autophagy

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Full-Text Articles in Medicine and Health Sciences

Intrinsic And Innate Defenses Of Neurons: Détente With The Herpesviruses, Lynn Enquist, David A. Leib Oct 2017

Intrinsic And Innate Defenses Of Neurons: Détente With The Herpesviruses, Lynn Enquist, David A. Leib

Dartmouth Scholarship

Neuroinvasive herpesviruses have evolved to efficiently infect and establish latency in neurons. The nervous system has limited capability to regenerate, so immune responses therein are carefully regulated to be nondestructive, with dependence on atypical intrinsic and innate defenses. In this article we review studies of some of these noncanonical defense pathways and how herpesvirus gene products counter them, highlighting the contributions that primary neuronal in vitro models have made to our understanding of this field.


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 Sep 2017

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 …


Thiamine Deficiency And Neurodegeneration: The Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, And Autophagy, Dexiang Liu, Zunji Ke, Jia Luo Sep 2017

Thiamine Deficiency And Neurodegeneration: The Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, And Autophagy, Dexiang Liu, Zunji Ke, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Thiamine (vitamin B1) is an essential nutrient and indispensable for normal growth and development of the organism due to its multilateral participation in key biochemical and physiological processes. Humans must obtain thiamine from their diet since it is synthesized only in bacteria, fungi, and plants. Thiamine deficiency (TD) can result from inadequate intake, increased requirement, excessive deletion, and chronic alcohol consumption. TD affects multiple organ systems, including the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems. In the brain, TD causes a cascade of events including mild impairment of oxidative metabolism, neuroinflammation, and neurodegeneration, which are commonly observed in …


Hsp27 And Chemotherapy-Induced Autophagy As Biomarkers In Osteosarcoma, John Andrew Livingston Aug 2017

Hsp27 And Chemotherapy-Induced Autophagy As Biomarkers In Osteosarcoma, John Andrew Livingston

Dissertations & Theses (Open Access)

Survival for patients with osteosarcoma has not improved for > 30 years. Despite aggressive multi-agent chemotherapy combined with surgical resection, a significant fraction of patients with localized disease relapse after optimal treatment. We evaluated the occurrence of cytoplasmic LC3B (light chain 3B)-positive puncta (a marker of autophagy) and presence of HSP27 (heat shock protein 27) in cancer cells within pre-treatment biopsy, post-treatment surgical resection, and metastatic osteosarcoma specimens by immunohistochemistry in 260 patients. LCB3+ puncta expression was seen in 34% of pre-treatment. 50% of resection, and 67% of metastasis samples. Sixty-six percent of all specimens were scored positive for HSP27 (85% …


Mechanisms Underlying The Sensitivity And Resistance Of Gastric Cancer Cells To Met Inhibitors, Rebecca Schroeder Aug 2017

Mechanisms Underlying The Sensitivity And Resistance Of Gastric Cancer Cells To Met Inhibitors, Rebecca Schroeder

Dissertations & Theses (Open Access)

MET amplification has been clinically credentialed as a therapeutic target in gastric cancer, but the molecular mechanisms underlying sensitivity and resistance to MET inhibitors are still not well understood. Using whole-genome mRNA expression profiling, we identified autophagy as a top molecular pathway that was activated by the MET inhibitor crizotinib in drug-sensitive human gastric cancer cells, and functional studies confirmed that crizotinib increased autophagy levels in the drug sensitive cells in a concentration-dependent manner. We then used chemical and molecular approaches to inhibit autophagy in order to define its role in cell death. The clinically available inhibitor of autophagy, chloroquine, …


Lack Of Evidence For Involvement Of Tonebp And Hyperosmotic Stimulus In Induction Of Autophagy In The Nucleus Pulposus., Chao Liu, Hyowon Choi, Zariel I. Johnson, Jiwei Tian, Irving Shapiro, Makarand V Risbud Jul 2017

Lack Of Evidence For Involvement Of Tonebp And Hyperosmotic Stimulus In Induction Of Autophagy In The Nucleus Pulposus., Chao Liu, Hyowon Choi, Zariel I. Johnson, Jiwei Tian, Irving Shapiro, Makarand V Risbud

Department of Orthopaedic Surgery Faculty Papers

Nucleus pulposus (NP) cells reside in a physiologically hyperosmotic environment within the intervertebral disc. TonEBP/NFAT5 is an osmo-sensitive transcription factor that controls expression of genes critical for cell survival under hyperosmotic conditions. A recent report on NP and studies of other cell types have shown that hyperosmolarity triggers autophagy. However, little is known whether such autophagy induction occurs through TonEBP. The goal of this study was to investigate the role of TonEBP in hyperosmolarity-dependent autophagy in NP. Loss-of-function studies showed that autophagy in NP cells was not TonEBP-dependent; hyperosmolarity did not upregulate autophagy as previously reported. NP tissue of haploinsufficient …


Cyclin D1 Restrains Oncogene-Induced Autophagy By Regulating The Ampk-Lkb1 Signaling Axis., Mathew C. Casimiro, Gabriele Disante, Agnese Di Rocco, Emanuele Loro, Claudia Pupo, Timothy G. Pestell, Sara Bisetto, Marco A. Velasco-Velázquez, Xuanmao Jiao, Zhiping Li, Christine M. Kusminski, Erin L. Seifert, Chenguang Wang, Daniel Ly, Bin Zheng, Che-Hung Shen, Philipp E. Scherer, Richard Pestell Jul 2017

Cyclin D1 Restrains Oncogene-Induced Autophagy By Regulating The Ampk-Lkb1 Signaling Axis., Mathew C. Casimiro, Gabriele Disante, Agnese Di Rocco, Emanuele Loro, Claudia Pupo, Timothy G. Pestell, Sara Bisetto, Marco A. Velasco-Velázquez, Xuanmao Jiao, Zhiping Li, Christine M. Kusminski, Erin L. Seifert, Chenguang Wang, Daniel Ly, Bin Zheng, Che-Hung Shen, Philipp E. Scherer, Richard Pestell

Department of Cancer Biology Faculty Papers

Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 …


Light Dependent Endolysosomal Defects In A Photoreceptor Model Of Alzheimer's Disease, Michelle S. Smith May 2017

Light Dependent Endolysosomal Defects In A Photoreceptor Model Of Alzheimer's Disease, Michelle S. Smith

Undergraduate Honors Theses

Alzheimer’s disease (AD) is a neurodegenerative disease which is the 6th leading cause of death in the US. AD pathology is thought to be linked to the accumulation and aggregation of toxic proteins, amyloid-beta and tau. AD development and neurodegeneration is proposed to be caused by the toxic effects of these protein accumulations, specifically amyloid-beta, as postulated by the amyloid-cascade hypothesis. To study the relationship between amyloid-beta and overall neuronal health, a study was carried out using an amyloid-expressing fruit fly photoreceptor model. Using this model, toxicity of amyloid in a stressed lysosomal system induced by light, an established …


The Regulation Of Rotavirus–Infected Ht29.F8 And Ma104 Cells Treated With Arachidin 1 Or Arachidin 3, Caleb M. Witcher May 2017

The Regulation Of Rotavirus–Infected Ht29.F8 And Ma104 Cells Treated With Arachidin 1 Or Arachidin 3, Caleb M. Witcher

Electronic Theses and Dissertations

Rotavirus (RV) infections cause severe life threatening diarrhea in young children and immunocompromised individuals. Several effective vaccines have been developed for young children but are not protective against all strains of RV, and there are no anti-RV therapeutics. Our laboratory has discovered a decrease in the number of infectious simian RV particles (SA114f) in human intestinal cell line, HT29.f8 cells with the addition of either of two stilbenoids, arachidin-1 (A1) or arachidin-3 (A3). This suggests effects on the host cell and RV replication. We examined the cellular effects of human RV strain (Wa) on a human intestinal cell line (HT29.f8) …


The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton May 2017

The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton

Dissertations & Theses (Open Access)

DIRAS3 is a maternally imprinted tumor suppressor gene that is downregulated by multiple mechanisms across several tumor types. When re-expressed, DIRAS3 decreases proliferation, inhibits motility, and induces autophagy and tumor dormancy. DIRAS3 encodes a 26 kDa small GTPase with 60% homology to Ras and Rap, differing from oncogenic Ras family members by a 34-amino acid N-terminal extension that is required for its tumor suppressive function in ovarian cancer. By assessing the structure-function relationship, I found that DIRAS3 inhibits Ras-induced transformation and is a natural antagonist of Ras/MAPK signaling. DIRAS3 binds directly to Ras and disrupts cluster formation inhibiting the activation …


Targeting Autophagy To Improve Efficacy Of Cdk4/6 Inhibition In Breast Cancer, Smruthi Vijayaraghavan May 2017

Targeting Autophagy To Improve Efficacy Of Cdk4/6 Inhibition In Breast Cancer, Smruthi Vijayaraghavan

Dissertations & Theses (Open Access)

Deregulation of the cell cycle machinery is a hallmark of cancer, leading to aberrant proliferation and tumorigenesis. The crucial role of the CDK4/6-Cyclin D pathway has led to the development and FDA approval (palbociclib, ribociclib) of CDK4/6 inhibitors for the treatment of advanced estrogen receptor positive breast cancer. However, three major clinical challenges remain: i) adverse events leading to discontinuation of therapy and ii) lack of reliable biomarkers to identify responsive patients and iii) acquired resistance to CDK4/6 inhibitors. Previous in vitro studies have shown that palbociclib mediated CDK4/6 inhibition induces G1 arrest and senescence in ER+ breast cancer cells, …


Characterization Of A Mutant Oncolytic Adenovirus And The Role Of Jnk In Enhancing Virotherapy., Stephen L. Wechman May 2017

Characterization Of A Mutant Oncolytic Adenovirus And The Role Of Jnk In Enhancing Virotherapy., Stephen L. Wechman

Electronic Theses and Dissertations

Oncolytic adenoviruses (Ads) have great therapeutic potential for lung cancer treatment. Cancer selective E1b-deleted Ads are safe; however, their clinical cancer therapeutic efficacy remains limited. The limited efficacy of Ad virotherapy is due to many factors including inefficient cancer cell lysis, Ad release and spread. Progress in overcoming these barriers to Ad virotherapy are hampered by limited knowledge of the genes associated with enhanced Ad release and spread and the dearth of understanding of the mechanisms by which E1b-deleted Ads cause cancer cell lysis. The role of c-JNK n- terminal kinase (JNK) phosphorylation in this process remains unknown. …


Mitochondria Initiate And Regulate Sarcopenia, Stephen E. Alway, Junaith S. Mohamed, Matthew J. Myers Apr 2017

Mitochondria Initiate And Regulate Sarcopenia, Stephen E. Alway, Junaith S. Mohamed, Matthew J. Myers

Clinical and Translational Science Institute

We present the hypothesis that an accumulation of dysfunctional mitochondria initiates a signaling cascade leading to motor neuron and muscle fiber death and culminating in sarcopenia. Interactions between neural and muscle cells that contain dysfunctional mitochondria exacerbate sarcopenia. Preventing sarcopenia will require identifying mitochondrial sources of dysfunction that are reversible.


Adipocytes Activate Mitochondrial Fatty Acid Oxidation And Autophagy To Promote Tumor Growth In Colon Cancer, Yang-An Wen, Xiaopeng Xing, Jennifer W. Harris, Yekaterina Y. Zaytseva, Mihail I. Mitov, Dana L. Napier, Heidi L. Weiss, B. Mark Evers, Tianyan Gao Feb 2017

Adipocytes Activate Mitochondrial Fatty Acid Oxidation And Autophagy To Promote Tumor Growth In Colon Cancer, Yang-An Wen, Xiaopeng Xing, Jennifer W. Harris, Yekaterina Y. Zaytseva, Mihail I. Mitov, Dana L. Napier, Heidi L. Weiss, B. Mark Evers, Tianyan Gao

Markey Cancer Center Faculty Publications

Obesity has been associated with increased incidence and mortality of a wide variety of human cancers including colorectal cancer. However, the molecular mechanism by which adipocytes regulate the metabolism of colon cancer cells remains elusive. In this study, we showed that adipocytes isolated from adipose tissues of colon cancer patients have an important role in modulating cellular metabolism to support tumor growth and survival. Abundant adipocytes were found in close association with invasive tumor cells in colon cancer patients. Co-culture of adipocytes with colon cancer cells led to a transfer of free fatty acids that released from the adipocytes to …


Autophagy Is Involved In Hdac6 Mediated Ciliary Loss, And Increases Malignancy In Cholangiocarcinoma Models, Estanislao Peixoto, Stephanie Holtorf, Kristen Thelen M. Thelen, Maria J. Lorenzo Pisarello, Nicholas F. Larusso, Sujeong Jin, Sergio A. Gradilone Jan 2017

Autophagy Is Involved In Hdac6 Mediated Ciliary Loss, And Increases Malignancy In Cholangiocarcinoma Models, Estanislao Peixoto, Stephanie Holtorf, Kristen Thelen M. Thelen, Maria J. Lorenzo Pisarello, Nicholas F. Larusso, Sujeong Jin, Sergio A. Gradilone

Hepatobiliary Cancers: Pathobiology and Translational Advances

No abstract provided.


Astrocytes Promote Progression Of Breast Cancer Metastases To The Brain Via A Kiss1-Mediated Autophagy., Natalya Kaverina, Anton V Borovjagin, Zaira Kadagidze, Anatoly Baryshnikov, Maria Baryshnikova, Dmitry Malin, Dhimankrishhna Ghosh, Nameeta Shah, Danny R Welch, Patrik Gabikian, Apollon Karseladze, Charles Cobbs, Ilya V Ulasov Jan 2017

Astrocytes Promote Progression Of Breast Cancer Metastases To The Brain Via A Kiss1-Mediated Autophagy., Natalya Kaverina, Anton V Borovjagin, Zaira Kadagidze, Anatoly Baryshnikov, Maria Baryshnikova, Dmitry Malin, Dhimankrishhna Ghosh, Nameeta Shah, Danny R Welch, Patrik Gabikian, Apollon Karseladze, Charles Cobbs, Ilya V Ulasov

Articles, Abstracts, and Reports

Formation of metastases, also known as cancer dissemination, is an important stage of breast cancer (BrCa) development. KISS1 expression is associated with inhibition of metastases development. Recently we have demonstrated that BrCa metastases to the brain exhibit low levels of KISS1 expression at both mRNA and protein levels. By using multicolor immunofluorescence and coculture techniques here we show that normal adult astrocytes in the brain are capable of promoting metastatic transformation of circulating breast cancer cells localized to the brain through secretion of chemokine CXCL12. The latter was found in this study to downregulate KISS1 expression at the post-transcriptional level …


Autophagy In Mitochondrial Quality Control And Proteotoxicity In Neurons, Matthew Redmann Jan 2017

Autophagy In Mitochondrial Quality Control And Proteotoxicity In Neurons, Matthew Redmann

All ETDs from UAB

Parkinson’s disease (PD) is the 2nd most common neurodegenerative disorder with aging as a significant risk factor. Sharing with aging brains, postmortem PD brains exhibit cellular deficits including autophagic dysfunction, mitochondrial dysfunction, and intracellular protein aggregates of alpha-synuclein. This dissertation will focus on the interplay between these key disease features. To that end, we coupled primary cortical neuronal cultures from either rats or mice with Seahorse extracellular flux, metabolomics and biochemical techniques. Autophagy is an important cell recycling program responsible for the clearance of damaged proteins and organelles. Bafilomycin A1 and chloroquine are compounds that inhibit autophagy by targeting the …


Activation Of Ampk To Diminish Sepsis-Induced Lung Injury, Nathaniel Bone Jan 2017

Activation Of Ampk To Diminish Sepsis-Induced Lung Injury, Nathaniel Bone

All ETDs from UAB

Sepsis is the most frequent cause of death of hospitalized patients in modern ICUs. Severe infection, trauma, hemorrhage, burns, and surgery are significant causes of multi-organ injury and immune dysfunction that in turn primes for a high risk of secondary lung infections. In addition to detrimental inflammation, sepsis is linked to loss of metabolic plasticity due to mitochondrial dysfunction in immune cells and lung tissue. In particular, mitochondrial failure in lungs of critically ill septic patients is correlated with high mortality rates. We proposed that AMP-activated protein kinase (AMPK) activation, a major bioenergetic sensor and metabolic regulator, is a plausible …


Post-Transcriptional Regulation Of Autophagy By The 5’-3’ Mrna Decay Pathway In Saccharomyces Cerevisiae, Matthew Weaver Jan 2017

Post-Transcriptional Regulation Of Autophagy By The 5’-3’ Mrna Decay Pathway In Saccharomyces Cerevisiae, Matthew Weaver

All ETDs from UAB

The process of bulk degradation of cytoplasmic contents, called macroautophagy or simply autophagy, is a heavily conserved cellular process from yeast to humans. In yeast, it involves more than 30 different autophagy related genes (ATG) that coordinate the process of building a double membrane vesicle, called the autophagosome, that fuses with the vacuole to allow degradation and recycling of its contents. This process can also be selective, involving the recruitment of the autophagic machinery to specific organelles. In this work, we used RNA sequencing (RNA-seq) to identify a subset of ATG genes that are heavily upregulated in response to nitrogen …


Proteoglycan Neofunctions: Regulation Of Inflammation And Autophagy In Cancer Biology., Liliana Schaefer, Claudia Tredup, Maria A. Gubbiotti, Renato V. Iozzo Jan 2017

Proteoglycan Neofunctions: Regulation Of Inflammation And Autophagy In Cancer Biology., Liliana Schaefer, Claudia Tredup, Maria A. Gubbiotti, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inflammation and autophagy have emerged as prominent issues in the context of proteoglycan signaling. In particular, two small, leucine-rich proteoglycans, biglycan and decorin, play pivotal roles in the regulation of these vital cellular pathways and, as such, are intrinsically involved in cancer initiation and progression. In this minireview, we will address novel functions of biglycan and decorin in inflammation and autophagy, and analyze new emerging signaling events triggered by these proteoglycans, which directly or indirectly modulate these processes. We will critically discuss the dual role of proteoglycan-driven inflammation and autophagy in tumor biology, and delineate the potential mechanisms through which …