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Full-Text Articles in Medicine and Health Sciences

Basement Membrane Damage By Ros- And Jnk-Mediated Mmp2 Activation Drives Macrophage Recruitment To Overgrown Tissue, Neha Diwanji, Andreas Bergmann Jul 2020

Basement Membrane Damage By Ros- And Jnk-Mediated Mmp2 Activation Drives Macrophage Recruitment To Overgrown Tissue, Neha Diwanji, Andreas Bergmann

Open Access Articles

Macrophages are a major immune cell type infiltrating tumors and promoting tumor growth and metastasis. To elucidate the mechanism of macrophage recruitment, we utilize an overgrowth tumor model ("undead" model) in larval Drosophila imaginal discs that are attached by numerous macrophages. Here we report that changes to the microenvironment of the overgrown tissue are important for recruiting macrophages. First, we describe a correlation between generation of reactive oxygen species (ROS) and damage of the basement membrane (BM) in all neoplastic, but not hyperplastic, models examined. ROS and the stress kinase JNK mediate the accumulation of matrix metalloproteinase 2 (Mmp2), damaging ...


Expression Of Mitochondrial Membrane-Linked Sab Determines Severity Of Sex-Dependent Acute Liver Injury, Sanda Win, Robert W. M. Min, Christopher Q. Chen, Jun Zhang, Yibu Chen, Meng Li, Ayako Suzuki, Manal F. Abdelmalek, Ying Wang, Mariam Aghajan, Filbert W. M. Aung, Anna Mae Diehl, Roger J. Davis, Tin A. Than, Neil Kaplowitz Sep 2019

Expression Of Mitochondrial Membrane-Linked Sab Determines Severity Of Sex-Dependent Acute Liver Injury, Sanda Win, Robert W. M. Min, Christopher Q. Chen, Jun Zhang, Yibu Chen, Meng Li, Ayako Suzuki, Manal F. Abdelmalek, Ying Wang, Mariam Aghajan, Filbert W. M. Aung, Anna Mae Diehl, Roger J. Davis, Tin A. Than, Neil Kaplowitz

University of Massachusetts Medical School Faculty Publications

SAB is an outer membrane docking protein for JNK mediated impaired mitochondrial function. Deletion of Sab in hepatocytes inhibits sustained JNK activation and cell death. Current work demonstrated that increasing SAB enhanced the severity of APAP liver injury. Female mice were resistant to liver injury and exhibited markedly decreased hepatic SAB protein expression versus males. The mechanism of SAB repression involved a pathway from ERalpha to p53 expression which induced miR34a-5p. miR34a-5p targeted the Sab mRNA coding region, repressing SAB expression. Fulvestrant or p53 knockdown decreased miR34a-5p and increased SAB in females leading to increased injury from APAP and TNF ...


Atf6alpha Impacts Cell Number By Influencing Survival, Death And Proliferation, Rohit B. Sharma, Jarin T. Snyder, Laura C. Alonso Sep 2019

Atf6alpha Impacts Cell Number By Influencing Survival, Death And Proliferation, Rohit B. Sharma, Jarin T. Snyder, Laura C. Alonso

Open Access Articles

BACKGROUND: A growing body of literature suggests the cell-intrinsic activity of Atf6alpha during ER stress responses has implications for tissue cell number during growth and development, as well as in adult biology and tumorigenesis [1]. This concept is important, linking the cellular processes of secretory protein synthesis and endoplasmic reticulum stress response with functional tissue capacity and organ size. However, the field contains conflicting observations, especially notable in secretory cell types like the pancreatic beta cell.

SCOPE OF REVIEW: Here we summarize current knowledge of the basic biology of Atf6alpha, along with the pleiotropic roles Atf6alpha plays in cell life ...


Activation Of The Apoptotic Pathway During Prolonged Prometaphase Blocks Daughter Cell Proliferation, Yumi Uetake, Greenfield Sluder Nov 2018

Activation Of The Apoptotic Pathway During Prolonged Prometaphase Blocks Daughter Cell Proliferation, Yumi Uetake, Greenfield Sluder

Radiology Publications

When untransformed human cells spend >1.5 hr. in prometaphase under standard culture conditions, all daughters arrest in G1 despite normal division of their mothers. We investigate what happens during prolonged prometaphase that leads to daughter cell arrest in the absence of DNA damage. We find that progressive loss of anti-apoptotic MCL-1 activity and oxidative stress act in concert to partially activate the apoptosis pathway resulting in the delayed death of some daughters and senescence for the rest. At physiological oxygen levels, longer prometaphase durations are needed for all daughters to arrest. Partial activation of apoptosis during prolonged prometaphase leads ...


Till Death Do Us Part: The Marriage Of Autophagy And Apoptosis., Katrina F Cooper May 2018

Till Death Do Us Part: The Marriage Of Autophagy And Apoptosis., Katrina F Cooper

School of Osteopathic Medicine Faculty Scholarship

Autophagy is a widely conserved catabolic process that is necessary for maintaining cellular homeostasis under normal physiological conditions and driving the cell to switch back to this status quo under times of starvation, hypoxia, and oxidative stress. The potential similarities and differences between basal autophagy and stimulus-induced autophagy are still largely unknown. Both act by clearing aberrant or unnecessary cytoplasmic material, such as misfolded proteins, supernumerary and defective organelles. The relationship between reactive oxygen species (ROS) and autophagy is complex. Cellular ROS is predominantly derived from mitochondria. Autophagy is triggered by this event, and by clearing the defective organelles effectively ...


Innate Immunity As Mediator Of Cell Death And Inflammation In Alcoholic Liver Disease, Arvin Iracheta-Vellve Nov 2017

Innate Immunity As Mediator Of Cell Death And Inflammation In Alcoholic Liver Disease, Arvin Iracheta-Vellve

GSBS Dissertations and Theses

Central driving forces in the pathogenesis of liver disease are hepatocyte death and immune cell-driven inflammation. The interplay between outcomes, stemming from these two major cell types, is present from the earliest ethanol exposure, and are both determinants in advanced stages of liver disease particularly in alcoholic liver disease (ALD). The complexities associated with advanced ALD are many and therapies are limited. Due to the liver’s role in ethanol metabolism and filtering gut-derived products, it is becoming increasingly clear that innate immunity plays a central role in triggering activation of cell death and inflammatory pathways in ALD. We identified ...


Exploiting Dna Repair And Er Stress Response Pathways To Induce Apoptosis In Glioblastoma Multiforme: A Dissertation, Jessica L. Weatherbee Aug 2016

Exploiting Dna Repair And Er Stress Response Pathways To Induce Apoptosis In Glioblastoma Multiforme: A Dissertation, Jessica L. Weatherbee

GSBS Dissertations and Theses

Glioblastoma multiforme (GBM) is a deadly grade IV brain tumor characterized by a heterogeneous population of cells that are drug resistant, aggressive, and infiltrative. The current standard of care, which has not changed in over a decade, only provides GBM patients with 12-14 months survival post diagnosis. We asked if the addition of a novel endoplasmic reticulum (ER) stress inducing agent, JLK1486, to the standard chemotherapy, temozolomide (TMZ), which induces DNA double strand breaks (DSBs), would enhance TMZ’s efficacy. Because GBMs rely on the ER to mitigate their hypoxic environment and DNA repair to fix TMZ induced DSBs, we ...


The Physiological Stress Response Caused By Hypoxia And Reperfusion Injury In Striped Bass (Morone Saxatilis) And Nile Tilapia (Oreochromis Niloticus), Amanda C. Reynolds Jan 2015

The Physiological Stress Response Caused By Hypoxia And Reperfusion Injury In Striped Bass (Morone Saxatilis) And Nile Tilapia (Oreochromis Niloticus), Amanda C. Reynolds

Electronic Theses and Dissertations

Approximately five million people in the United States are affected by cardiovascular related diseases yearly contributing to 300,000 annual deaths, making CVD the leading cause of mortality worldwide. It has been suggested that apoptosis (programmed cell death) contributes to the pathogenesis of cardiovascular diseases. When blood flow is reduced or cut off from the heart, usually by a thrombus, this results in oxygen deprivation (hypoxia) to the cardiomyocytes (heart cells). In response to this hypoxic stress, cardiomyocytes will undergo apoptosis. Since many species of fish can survive levels of hypoxia that would be fatal to mammals, fish are an ...


Cellular And Molecular Mechanisms Of Chemical-Induced Ovarian Toxicity, Shanthi Ganesan Jan 2014

Cellular And Molecular Mechanisms Of Chemical-Induced Ovarian Toxicity, Shanthi Ganesan

Graduate Theses and Dissertations

The ovary is the ovum-producing female reproductive organ composed of follicles at different stages of development. Chemicals which selectively damage large growing or antral follicles only temporarily interrupt reproductive function because these follicles can be replaced by recruitment from the greater pool of primordial follicles. However, chemicals that destroy oocytes contained in primordial follicles can cause permanent infertility and premature ovarian failure (early menopause in women), since once a primordial follicle is destroyed, it cannot be replaced. We hypothesized that ovotoxic chemicals can bind to DNA to induce DNA damage and that the ovarian cells activate DNA repair, cell cycle ...


Dose-Dependent Thresholds Of 10-Ns Electric Pulse Induced Plasma Membrane Disruption And Cytotoxicity In Multiple Cell Lines, Bennett L. Ibey, Caleb C. Roth, Andrei G. Pakhomov, Joshua A. Bernhard, Gerald J. Wilmink, Olga N. Pakhomova Jan 2011

Dose-Dependent Thresholds Of 10-Ns Electric Pulse Induced Plasma Membrane Disruption And Cytotoxicity In Multiple Cell Lines, Bennett L. Ibey, Caleb C. Roth, Andrei G. Pakhomov, Joshua A. Bernhard, Gerald J. Wilmink, Olga N. Pakhomova

Bioelectrics Publications

In this study, we determined the LD50 (50% lethal dose) for cell death, and the ED50 (50% of cell population staining positive) for propidium (Pr) iodide uptake, and phosphatidylserine (PS) externalization for several commonly studied cell lines (HeLa, Jurkat, U937, CHO-K1, and GH3) exposed to 10-ns electric pulses (EP). We found that the LD50 varied substantially across the cell lines studied, increasing from 51 J/g for Jurkat to 1861 J/g for HeLa. PS externalized at doses equal or lower than that required for death in all cell lines ranging from 51 J/g in Jurkat, to 199 J ...


The Role Of Fas And Fas Ligand In Apoptosis During Regression Of The Corpus Luteum, Sharon Roughton Jan 1997

The Role Of Fas And Fas Ligand In Apoptosis During Regression Of The Corpus Luteum, Sharon Roughton

Theses : Honours

Apoptosis, a form of physiological cell death, has been found to occur during regression of the corpus luteum (Juengel etal, 1993; Dharmarajan etal, 1994). The pathways involved in this process, however, have yet to be specified. One possible mediator of corpus luteum regression is the Fas (or AP0-1 or CD95) receptor, a transmembrane protein which induces apoptosis in the cell when ligated. In order to further confirm this hypolhesis, the present study establishes and quantitates the presence and regulation of Fas receptor and Fas ligand (Fasl) in the rat corpus luteum during pregnancy and post-partum. The animals used were sexually ...