Cell Biology Commons^™

Foxs1 Is Increased In Liver Fibrosis And Regulates Tgfβ Responsiveness And Proliferation Pathways In Human Hepatic Stellate Cells, Evelyn A. Bates, Zachary A. Kipp, Wang-Hsin Lee, Genesee J. Martinez, Lauren Weaver, Kathryn N. Becker, Sally Pauss, Justin F. Creeden, Garrett B. Anspach, Robert N. Helsley, Mei Xu, Maria E. C. Bruno, Marlene E. Starr, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Liver fibrosis commences with liver injury stimulating transforming growth factor beta (TGFβ) activation of hepatic stellate cells (HSCs), causing scarring and irreversible damage. TGFβ induces expression of the transcription factor Forkhead box S1 (FOXS1) in hepatocytes and may have a role in the pathogenesis of hepatocellular carcinoma (HCC). To date, no studies have determined how it affects HSCs. We analyzed human livers with cirrhosis, HCC, and a murine fibrosis model and found that FOXS1 expression is significantly higher in fibrotic livers but not in HCC. Next, we treated human LX2 HSC cells with TGFβ to activate fibrotic pathways, and FOXS1 …

Mir-27a-3p Regulates Intestinal Cell Proliferation And Differentiation Through Wnt/Β-Catenin Signalling, Chang Li, Yuning Zhou, Yinping Jiang, Zhijie Yin, Heidi L. Weiss, Qingding Wang, B. Mark Evers

Markey Cancer Center Faculty Publications

Intestinal stem cells differentiate into absorptive enterocytes, characterised by increased brush border enzymes such as intestinal alkaline phosphatase (IAP), making up the majority (95%) of the terminally differentiated cells in the villus. Loss of integ- rity of the intestinal epithelium plays a key role in inflammatory diseases and gastro- intestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differenti- ation. Repression of endogenous miR-27a-3p leads to increased enterocyte differen- tiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell …

Cell Aggregation Activates Small Gtpase Rac1 And Induces Cd44 Cleavage By Maintaining Lipid Raft Integrity, Dong Li, Younhee Park, Hami Hemati, Xia Liu

Markey Cancer Center Faculty Publications

Lipid rafts are highly ordered membrane domains that are enriched in cholesterol and glycosphingolipids and serve as major platforms for signal transduction. Cell detachment from the extracellular matrix (ECM) triggers lipid raft disruption and anoikis, which is a barrier for cancer cells to metastasize. Compared to single circulating tumor cells (CTCs), our recent studies have demonstrated that CD44-mediatd cell aggregation enhances the stemness, survival and metastatic ability of aggregated cells. Here, we investigated whether and how lipid rafts are involved in CD44-mediated cell aggregation. We found that cell detachment, which mimics the condition when tumor cells detach from the ECM …

Loss Of Carnitine Palmitoyltransferase 1a Reduces Docosahexaenoic Acid-Containing Phospholipids And Drives Sexually Dimorphic Liver Disease In Mice, Mikala M. Zelows, Corissa Cady, Nikitha Dharanipragada, Anna E. Mead, Zachary A. Kipp, Evelyn A. Bates, Venkateshwari Varadharajan, Rakhee Banerjee, Se-Hyung Park, Nathan R. Shelman, Harrison A. Clarke, Tara R. Hawkinson, Terrymar Medina, Ramon C. Sun, Todd A. Lydic, Terry D. Hinds, Jr., J. Mark Brown, Samir Softic, Gregory A. Graf, Robert N. Helsley

Saha Cardiovascular Research Center Faculty Publications

Background and aims: Genome and epigenome wide association studies identified variants in carnitine palmitoyltransferase 1a (CPT1a) that associate with lipid traits. The goal of this study was to determine the role of liver-specific CPT1a on hepatic lipid metabolism.

Approach and results: Male and female liver-specific knockout (LKO) and littermate controls were placed on a low-fat or high-fat diet (60% kcal fat) for 15 weeks. Mice were necropsied after a 16 h fast, and tissues were collected for lipidomics, matrix-assisted laser desorption ionization mass spectrometry imaging, kinome analysis, RNA-sequencing, and protein expression by immunoblotting. Female LKO mice had increased serum alanine …

Cyclin D1 Extensively Reprograms Metabolism To Support Biosynthetic Pathways In Hepatocytes, Heng Wu, Betsy T. Kren, Andrew N. Lane, Teresa A. Cassel, Richard M. Higashi, Teresa Whei-Mei Fan, George S. Scaria, Laurie L. Shekels, Mark A. Klein, Jeffrey H. Albrecht

Markey Cancer Center Faculty Publications

Cell proliferation requires metabolic reprogramming to accommodate biosynthesis of new cell components, and similar alterations occur in cancer cells. However, the mechanisms linking the cell cycle machinery to metabolism are not well defined. Cyclin D1, along with its main partner cyclindependent kinase 4 (Cdk4), is a pivotal cell cycle regulator and driver oncogene that is overexpressed in many cancers. Here, we examine hepatocyte proliferation to define novel effects of cyclin D1 on biosynthetic metabolism. Metabolomic studies reveal that cyclin D1 broadly promotes biosynthetic pathways including glycolysis, the pentose phosphate pathway, and the purine and pyrimidine nucleotide synthesis in hepatocytes. Proteomic …

Distinct Camp Signaling Microdomains Differentially Regulate Melanosomal Ph And Pigmentation, Maftuna Yusupova, Dalee Zhou, Jaewon You, Jeydi Gonzalez-Guzman, Megha B. Ghanta, Hong Pu, Zalfa Abdel-Malek, Qiuying Chen, Steven S. Gross, John August D'Orazio, Shosuke Ito, Kazumasa Wakamatsu, Melissa L. Harris, Jonathan H. Zippin

Markey Cancer Center Faculty Publications

cAMP signaling is a well-established regulator of melanin synthesis. Two distinct cAMP signaling pathways—the transmembrane adenylyl cyclase pathway, activated primarily by the MC1R, and the soluble adenylyl cyclase (sAC) pathway—affect melanin synthesis. The sAC pathway affects melanin synthesis by regulating melanosomal pH, and the MC1R pathway affects melanin synthesis by regulating gene expression and post-translational modifications. However, whether MC1R genotype affects melanosomal pH is poorly understood. We now report that loss of function MC1R does not affect melanosomal pH. Thus, sAC signaling appears to be the only cAMP signaling pathway that regulates melanosomal pH. We also addressed whether MC1R genotype …

Inhibition Of Mitochondrial Fission Activates Glycogen Synthesis To Support Cell Survival In Colon Cancer, Sumati Raj Hasani, Lyndsay E. A. Young, Warren Van Nort, Moumita Banerjee, Dylan R. Rivas, Jinhwan Kim, Xiaopeng Xiong, Ramon C. Sun, Matthew S. Gentry, Hiromi Sesaki, Tianyan Gao

Markey Cancer Center Faculty Publications

Metabolic reprogramming has been recognized as one of the major mechanisms that fuel tumor initiation and progression. Our previous studies demonstrate that activation of Drp1 promotes fatty acid oxidation and downstream Wnt signaling. Here we investigate the role of Drp1 in regulating glycogen metabolism in colon cancer. Knockdown of Drp1 decreases mitochondrial respiration without increasing glycolysis. Analysis of cellular metabolites reveals that the levels of glucose-6-phosphate, a precursor for glycogenesis, are significantly elevated whereas pyruvate and other TCA cycle metabolites remain unchanged in Drp1 knockdown cells. Additionally, silencing Drp1 activates AMPK to stimulate the expression glycogen synthase 1 (GYS1) mRNA …

Phosphatidic Acid Binding To Patched Contributes To The Inhibition Of Smoothened And Hedgehog Signaling In Drosophila Wing Development, Jie Zhang, Yajuan Liu, Chi Wang, Craig W. Vander Kooi, Jianhang Jia

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling controls growth and patterning during embryonic development and homeostasis in adult tissues. Hh binding to the receptor Patched (Ptc) elicits intracellular signaling by relieving Ptc-mediated inhibition of the transmembrane protein Smoothened (Smo). We uncovered a role for the lipid phosphatidic acid (PA) in the regulation of the Hh pathway in Drosophila melanogaster. Deleting the Ptc C-terminal tail or mutating the predicted PA-binding sites within it prevented Ptc from inhibiting Smo in wing discs and in cultured cells. The C-terminal tail of Ptc directly interacted with PA in vitro, an association that was reduced by Hh, and increased …

Regulated Translocation Of Neutral Sphingomyelinase-2 To The Plasma Membrane Drives Insulin Resistance In Steatotic Hepatocytes, Salim S. El-Amouri, Alexander A. Karakashian, Erhard Bieberich, Mariana N. Nikolova‑Karakashian

Markey Cancer Center Faculty Publications

Abstract Obesity-associated diabetes is linked to the accumulation of ceramide in various organs, including the liver. The exact mechanisms by which ceramide contributes to diabetic pathology are unclear, but one proposed scenario is that ceramide accumulation may inhibit insulin signaling pathways. It is unknown however whether the excess ceramide is generated proximal to the insulin receptor, that is, at the plasma membrane (PM), where it could affect the insulin signaling pathway directly, or the onset of insulin resistance is due to ceramide- induced mitochondrial dysfunction and/or lipotoxicity. Using hepatic cell lines and primary cultures, gain- and loss- of function approach, …

Stat3 Modulates Cd4+ T Mitochondrial Dynamics And Function In Aging, Emelia Zukowski, Marco Sannella, Jack Donato Rockhold, Gabriella Kalantar, Jingting Yu, Sara Santacruz-Calvo, Madison K. Kuhn, Nasun Hah, Ling Ouyang, Tzu-Wen Wang, Lyanne Murphy, Heather Marszalkowski, Kaleigh Gibney, Micah J. Drummond, Elizabeth A. Proctor, Hatice Hasturk, Barbara S. Nikolajczyk, Leena P. Bharath

Markey Cancer Center Faculty Publications

Aging promotes numerous intracellular changes in T cells that impact their effector function. Our data show that aging promotes an increase in the localization of STAT3 to the mitochondria (mitoSTAT3), which promotes changes in mitochondrial dynamics and function and T-cell cytokine production. Mechanistically, mitoSTAT3 increased the activity of aging T-cell mitochondria by increasing complex II. Limiting mitoSTAT3 using a mitochondria-targeted STAT3 inhibitor, Mtcur-1 lowered complex II activity, prevented age-induced changes in mitochondrial dynamics and function, and reduced Th17 inflammation. Exogenous expression of a constitutively phosphorylated form of STAT3 in T cells from young adults mimicked changes in mitochondrial dynamics and …

Asparagine Restriction Enhances Cd8+ T Cell Metabolic Fitness And Antitumoral Functionality Through An Nrf2-Dependent Stress Response, J. N. Rashida Gnanaprakasam, Bhavana Kushwaha, Lingling Liu, Xuyong Chen, Siwen Kang, Tingting Wang, Teresa A. Cassel, Christopher M. Adams, Richard M. Higashi, David A. Scott, Gang Xin, Zihai Li, Jun Yang, Andrew N. Lane, Teresa Whei-Mei Fan, Ji Zhang, Ruoning Wang

Markey Cancer Center Faculty Publications

Robust and effective T cell immune surveillance and cancer immunotherapy require proper allocation of metabolic resources to sustain energetically costly processes, including growth and cytokine production. Here, we show that asparagine (Asn) restriction on CD8+ T cells exerted opposing effects during activation (early phase) and differentiation (late phase) following T cell activation. Asn restriction suppressed activation and cell cycle entry in the early phase while rapidly engaging the nuclear factor erythroid 2-related factor 2 (NRF2)-dependent stress response, conferring robust proliferation and effector function on CD8+ T cells during differentiation. Mechanistically, NRF2 activation in CD8+ T cells conferred by Asn restriction …

Long-Term Monitoring Of Clodronate In Equine Hair Using Liquid Chromatography-Tandem Mass Spectrometry, Heather K. Knych, D. S. Mckemie, S. Yim, S. D. Stanley, R. M. Arthur

UK CARES Faculty Publications

Given the potential for long-term inhibition of bone remodeling/healing and detrimental effects to horses in training, bisphosphonates are tightly regulated in horseracing. Hair has proven to be an effective matrix for detection of drug administration to horses and has been particularly effective in detecting drugs for a long period of time post administration. Thus, hair may prove to be a useful matrix for detection of administration of this class of drugs. The objective of the current study was to develop an assay and assess the usefulness of hair as a matrix for long-term detection of clodronate to horses. Seven horses …

Integrative Analysis Of Mendelian Randomization And Gene Expression Profiles Reveals A Null Causal Relationship Between Adiponectin And Diabetic Retinopathy, Ao Zhang, Hui Wu, Chi Wang, Suyan Tian

Markey Cancer Center Faculty Publications

Observational studies have been conducted to investigate the correlation between adiponectin and diabetic retinopathy (DR), but no consistent relationship has been established. In this study, we employed an integrative analysis that combined Mendelian randomization (MR) and bioinformatics analyses to comprehensively explore the association between DR and adiponectin, aiming to provide a unified answer of their relationship. Using the inverse-variance weighted (IVW) method, the odd ratio (OR) of developing DR per 1 mg/dL increment in genetically predicted log- transformed adiponectin concentration was estimated to be 0.949 (P = 0.557). Other robust MR methods produced consistent results, confirming the absence of a …

Noncovalent Interactions That Tune The Reactivities Of The Flavins In Bifurcating Electron Transferring Flavoprotein, María González-Viegas, Rajiv K. Kar, Anne-Frances Miller, Maria-Andrea Mroginski

Markey Cancer Center Faculty Publications

Bifurcating electron transferring flavoproteins (Bf-ETFs) tune chemically identical flavins to two contrasting roles. To understand how, we used hybrid quantum mechanical molecular mechanical calculations to characterize noncovalent interactions applied to each flavin by the protein. Our computations replicated the differences between the reactivities of the flavins: the electron transferring flavin ( ETflavin) was calculated to stabilize anionic semiquinone (ASQ) as needed to execute its single-electron transfers, whereas the Bf flavin (Bfflavin) was found to disfavor the ASQ state more than does free flavin and to be less susceptible to reduction. The stability of ETflavin ASQ was attributed in part to …

Serum Amyloid A Augments The Atherogenic Effects Of Cholesteryl Ester Transfer Protein, Ailing Ji, Andrea C. Trumbauer, Victoria P. Noffsinger, Frederick C. De Beer, Nancy R. Webb, Lisa R. Tannock, Preetha Shridas

Saha Cardiovascular Research Center Faculty Publications

Serum amyloid A (SAA) is predictive of CVD in humans and causes atherosclerosis in mice. SAA has many proatherogenic effects in vitro. However, HDL, the major carrier of SAA in the circulation, masks these effects. The remodeling of HDL by cholesteryl ester transfer protein (CETP) liberates SAA restoring its proinflammatory activity. Here, we investigated whether deficiency of SAA suppresses the previously described proatherogenic effect of CETP. ApoE¡/¡ mice and apoE¡/¡ mice deficient in the three acute-phase isoforms of SAA (SAA1.1, SAA2.1, and SAA3; “apoE¡/¡ SAA-TKO”) with and without adeno-associated virus-mediated expression of CETP were studied. There was no effect of …

Impact Of The Dimethyl Sulfoxide Reductase Superfamily On The Evolution Of Biogeochemical Cycles, Michael Wells, Minjae Kim, Denise M. Akob, Partha Basu, John F. Stolz

UK CARES Faculty Publications

The dimethyl sulfoxide reductase (or MopB) family is a diverse assemblage of enzymes found throughout Bacteria and Archaea. Many of these enzymes are believed to have been present in the last universal common ancestor (LUCA) of all cellular lineages. However, gaps in knowledge remain about how MopB enzymes evolved and how this diversification of functions impacted global biogeochemical cycles through geologic time. In this study, we perform maximum likelihood phylogenetic analyses on manually curated comparative genomic and metagenomic data sets containing over 47,000 distinct MopB homologs. We demonstrate that these enzymes constitute a catalytically and mechanistically diverse superfamily defined not …

Loss Of Peroxiredoxin Iv Protects Mice From Azoxymethane/Dextran Sulfate Sodium-Induced Colorectal Cancer Development, Pratik Thapa, Hong Jiang, Na Ding, Yanning Hao, Aziza Alshahrani, Eun Young Lee, Junichi Fujii, Qiou Wei

Markey Cancer Center Faculty Publications

Peroxiredoxin IV (Prx4), a typical two-cysteine-containing member of the peroxidase family, functions as an antioxidant to maintain cellular redox homeostasis through the reduction of reactive oxygen species (ROS) via cycles of oxidation–reduction reactions. Under oxidative stress, all Prxs including Prx4 are inactivated as their catalytic cysteines undergo hyperoxidation, and hyperoxidized two-cysteine Prxs can be exclusively repaired and revitalized through the reduction cycle catalyzed by sulfiredoxin (Srx). Previously, we showed that Prx4 is a preferred substrate of Srx, and knockout of Srx in mice leads to resistance to azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon carcinogenesis. To further understand the significance of the …

Critical Role Of The Sulfiredoxin-Peroxiredoxin Iv Axis In Urethane-Induced Non-Small Cell Lung Cancer, Yanning Hao, Hong Jiang, Pratik Thapa, Na Ding, Aziza Alshahrani, Junichi Fujii, Michel B. Toledano, Qiou Wei

Markey Cancer Center Faculty Publications

Non-small cell lung cancer (NSCLC), the most common type of lung cancer, etiologically associates with tobacco smoking which mechanistically contributes to oxidative stress to facilitate the occurrence of mutations, oncogenic transformation and aberrantly activated signaling pathways. Our previous reports suggested an essential role of Sulfiredoxin (Srx) in promoting the development of lung cancer in humans, and was causally related to Peroxiredoxin IV (Prx4), the major downstream substrate and mediator of Srx-enhanced signaling. To further explore the role of the Srx-Prx4 axis in de novo lung tumorigenesis, we established Prx4−/− and Srx−/−/Prx4−/− mice in pure FVB/N background. Together with wild-type litter …

Exploring The Molecular Basis Of Touch: A Comparative Analysis Of Gene Expression In Sensory Corpuscle-Rich And Corpuscle-Poor Skin Regions In The Duck, Thomas Hart

Theses and Dissertations--Biology

Cutaneous touch is facilitated by discrete cellular complexes composed of non-neuronal cells associated with mechanoreceptor neuron endings. The non-neuronal cells of these cutaneous end organ complexes (CEOCs) are believed to contribute to touch, but their role in touch sensation remains unclear. To better understand the function of CEOC cells, we sought to characterize the transcriptional profile of CEOC-rich tissue and identify genes expressed in CEOC cells. Bill skin of the tactile foraging Pekin duck (Anas platyrhynchos) is dense with CEOCs, specifically the avian analogs of mammalian Pacinian and Meissner corpuscles, while corpuscles in duck foot skin are scarce. Using RNA …

Best3-Mediated Mekk2/3 Activation: A Novel Therapeutic Target In Aortopathies, Tatiana Zyrianova, Benjamin Lopez, Kathlyn Zou, Charles Gu, Dayna Pham, Sriharsha Talapaneni, Christopher M. Waters, Riccardo Olcese, Andreas Schwingshackl

Saha Cardiovascular Research Center Faculty Publications

Influenza-A virus (IAV) infects yearly an estimated one billion people worldwide, resulting in 300,000–650,000 deaths. Preventive vaccination programs and antiviral medications represent the mainstay of therapy, but with unacceptably high morbidity and mortality rates, new targeted therapeutic approaches are urgently needed. Since inflammatory processes are commonly associated with measurable changes in the cell membrane potential (Em), we investigated whether Em hyperpolarization via TREK-1 (K2P 2.1) K þ channel activation can protect against influenza-A virus (IAV)-induced pneumonia. We infected mice with IAV, which after 5 days caused 10–15% weight loss and a decrease in spontaneous activity, representing a clinically relevant infection. …

Metabolic Reprogramming Driven By Ezh2 Inhibition Depends On Cell–Matrix Interactions, Teresa W-M Fan, Jahid M. M. Islam, Richard M. Higashi, Penghui Lin, Christine F. Brainson, Andrew N. Lane

Markey Cancer Center Faculty Publications

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Poly- comb Repressive Complex 2 (PRC2), catalyzes the trimethyla- tion of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 in- hibition can be achieved with the FDA-approved drug EPZ- 6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems in- fluences this blockade in terms of growth-related metabolic functions. Here, we show that …

Bilirubin Levels Are Negatively Correlated With Adiposity In Obese Men And Women, And Its Catabolized Product, Urobilin, Is Positively Associated With Insulin Resistance, Zachary A. Kipp, Mei Xu, Evelyn A. Bates, Wang-Hsin Lee, Philip A. Kern, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Bilirubin levels in obese humans and rodents have been shown to be lower than in their lean counterparts. Some studies have proposed that the glucuronyl UGT1A1 enzyme that clears bilirubin from the blood increases in the liver with obesity. UGT1A1 clearance of bilirubin allows more conjugated bilirubin to enter the intestine, where it is catabolized into urobilin, which can be then absorbed via the hepatic portal vein. We hypothesized that when bilirubin levels are decreased, the urobilin increases in the plasma of obese humans, as compared to lean humans. To test this, we measured plasma levels of bilirubin and urobilin, …

Dysregulated Polycomb Repressive Complex 2 Contributes To Chronic Obstructive Pulmonary Disease By Rewiring Stem Cell Fate, Aria Byrd, Xufeng Qu, Alexsandr Lukyanchuk, Jinpeng Liu, Fan Chen, Kassandra J. Naughton, Tanner Ducote, Xiulong Song, Hannah Bowman, Yanming Zhao, Abigail R Edgin, Chi Wang, Jinze Liu, Christine Fillmore Brainson

Markey Cancer Center Faculty Publications

Aberrant lung cell differentiation is a hallmark of many lung diseases including chronic obstructive pulmonary disease (COPD). The EZH2-containing Polycomb Repressive Complex 2 (PRC2) regulates embryonic lung stem cell fate, but its role in adult lung is obscure. Histological analysis of patient tissues revealed that loss of PRC2 activity was correlated with aberrant bronchiolar cell differentiation in COPD lung. Histological and single-cell RNA-sequencing analyses showed that loss of EZH2 in mouse lung organoids led to lowered self- renewal capability, increased squamous morphological development, and marked shifts in progenitor cell populations. Evaluation of in vivo models revealed that heterozygosity of Ezh2 …

Extracellular Vesicle Distribution And Localization In Skeletal Muscle At Rest And Following Disuse Atrophy, Ahmed Ismaeel, Douglas W. Van Pelt, Zachary Hettinger, Xu Fu, Christopher I. Richards, Timothy A. Butterfield, Jonathan J. Petrocelli, Ivan J. Vechetti Jr., Amy L. Confides, Micah J. Drummond, Esther E. Dupont-Versteegden

Markey Cancer Center Faculty Publications

Background Skeletal muscle (SkM) is a large, secretory organ that produces and releases myokines that can have autocrine, paracrine, and endocrine effects. Whether extracellular vesicles (EVs) also play a role in the SkM adaptive response and ability to communicate with other tissues is not well understood. The purpose of this study was to investigate EV biogenesis factors, marker expression, and localization across cell types in the skeletal muscle. We also aimed to investigate whether EV concentrations are altered by disuse atrophy.

Methods To identify the potential markers of SkM‑derived EVs, EVs were isolated from rat serum using density gradient ultracentrifugation, …

The Link Between Intracellular Calcium Signaling And Exosomal Pd-L1 In Cancer Progression And Immunotherapy, Rakibul Alam, Mizanur Rahman, Zhiguo Li

Markey Cancer Center Faculty Publications

Exosomes are small membrane vesicles containing microRNA, RNA, DNA fragments, and proteins that are transferred from donor cells to recipient cells. Tumor cells release exo- somes to reprogram the factors associated with the tumor microenvironment (TME) causing tu- mor metastasis and immune escape. Emerging evidence revealed that cancer cell-derived exosomes carry immune inhibitory molecule program death ligand 1 (PD-L1) that binds with re- ceptor program death protein 1 (PD-1) and promote tumor progression by escaping immune response. Currently, some FDA-approved monoclonal antibodies are clinically used for cancer treatment by blocking PD-1/PD-L1 interaction. Despite notable treatment outcomes, some pa- tients show …

Conserved Novel Interactions Between Post-Replicative Repair And Mismatch Repair Proteins Have Differential Effects On Dna Repair Pathways, Anna K. Miller

Theses and Dissertations--Toxicology and Cancer Biology

DNA mismatch repair (MMR) is the DNA repair mechanism that repairs base-base mispairs and small insertions and deletions remaining after replication. MMR is also required for apoptosis after certain types of exogenous DNA damage that result in damage-associated mispairs. The basic MMR mechanism is well understood; however, proteins associated with MMR continue to be identified. The roles of these interacting proteins in MMR are largely unknown. We have identified the yeast protein Rad5 as a novel interactor of the critical MMR proteins Msh2 and Mlh1. Rad5 is a DNA helicase and E3 ubiquitin ligase involved in post-replicative repair. However, to …

Elucidating The Functional Importance Of Peroxiredoxin Iv In Prostate Cancer And Its Secretion Mechanism, Na Ding

Theses and Dissertations--Toxicology and Cancer Biology

Prostate cancer is the most common and second leading cause of cancer death in men. Prevailing theories state that inflammation may drive prostate carcinogenesis via oxidative stress and the generation of reactive oxygen species (ROS) that induce somatic mutagenesis. Since high proliferating cells or cancer cells exhibit aberrant metabolism to satisfy the needs of energy for rapid cell proliferation, they also generate high levels of ROS which stimulates the expression of cellular antioxidants to overcome the dysregulation of redox homeostasis through the regulation of redox-sensitive transcription factors. Among different antioxidants, peroxiredoxin (Prx) family proteins are the highly conserved and mostly …

Elucidating The Role Of Polycomb Repressive Complex 2 In Lung Stem Cell Fate And Lung Disease, Aria Byrd

Theses and Dissertations--Toxicology and Cancer Biology

The average human lungs take ~22,000 breaths and inhale ~2,000 gallons of air each day. This organ is the primary conduit for the transfer of oxygen to the internal organs, making it crucial for the sustainment of life. Consequently, mechanical malfunction of the lungs and/or pollution of inhaled air negatively impact internal organ function and ultimately put survival in jeopardy. Epigenetics, by nature, is a plastic phenomenon in which environmental stimuli influence short term, long term, and generational gene expression patterns. Chronic exposure of harmful stimuli to the lung epithelium has also been shown to alter epigenetic pathways, engender aberrant …

Sex Dimorphism In Hematopoiesis And Bone Marrow Niche, Xiaojing Cui

Theses and Dissertations--Toxicology and Cancer Biology

Hematopoietic stem cells (HSC), which are a rare population of cells existing in human circulating blood and bone marrow, can form the whole-blood system by their self-renewal capacity and differentiation ability. Sex dimorphism can be found in hematopoietic stem and progenitor cells, and in the development of hematopoietic lineages. Also, males are at higher risk and have a worse prognosis for most hematologic malignancies than females. Under normal conditions, the number of circulating progenitor cells in women is lower than in men. Furthermore, female mice have a higher rate of HSC division than male mice. A dramatic gender difference exists …

Metabolic Diversity Among Fibroblasts From Regenerating And Non-Regenerating Mammals, Ebenezer Aryee

Theses and Dissertations--Biology

Regeneration is a wound repair process that terminates in the restoration of tissue function and structure. Fibroblasts play pivotal roles in regenerative and fibrotic wound repair. Reports of extensive regenerative ability in mammals have been historically rare, but more recently spiny mice (Acomys) have emerged as a bona fide model of complex tissue regeneration. Recent work has indicated that fibroblasts from regenerators (Acomys and Oryctolagus) are more resistant to reactive oxygen species (ROS)-induced senescence compared to non-regenerating species, suggesting the influence of intrinsic cellular states on the fate of wound repair. Determining the basal metabolic signature …