Life Sciences Commons^™

Genetic Modification Of Human Mesenchymal Stem Cells Helps To Reduce Adiposity And Improve Glucose Tolerance In An Obese Diabetic Mouse Model., Sabyasachi Sen, Cleyton C Domingues, Carol Rouphael, Cyril Chou, Chul Kim, Nagendra Yadava

Medicine Faculty Publications

INTRODUCTION: Human mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into fat, muscle, bone and cartilage cells. Exposure of subcutaneous abdominal adipose tissue derived AD-MSCs to high glucose (HG) leads to superoxide accumulation and up-regulation of inflammatory molecules. Our aim was to inquire how HG exposure affects MSCs differentiation and whether the mechanism is reversible.

METHODS: We exposed human adipose tissue derived MSCs to HG (25 mM) and compared it to normal glucose (NG, 5.5 mM) exposed cells at 7, 10 and 14 days. We examined mitochondrial superoxide accumulation (Mitosox-Red), cellular oxygen consumption rate (OCR, Seahorse) and gene …

Endothelin-B Receptor Activation In Astrocytes Regulates The Rate Of Oligodendrocyte Regeneration During Remyelination., Timothy R. Hammond, Brian Mcellin, Paul D Morton, Matthew Raymond, Jeff Dupree, Vittorio Gallo

Medicine Faculty Publications

Reactive astrogliosis is an essential and ubiquitous response to CNS injury, but in some cases, aberrant activation of astrocytes and their release of inhibitory signaling molecules can impair endogenous neural repair processes. Our lab previously identified a secreted intercellular signaling molecule, called endothelin-1 (ET-1), which is expressed at high levels by reactive astrocytes in multiple sclerosis (MS) lesions and limits repair by delaying oligodendrocyte progenitor cell (OPC) maturation. However, as ET receptors are widely expressed on neural cells, the cell- and receptor-specific mechanisms of OPC inhibition by ET-1 action remain undefined. Using pharmacological approaches and cell-specific endothelin receptor (EDNR) ablation, …

Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez

Genomics and Precision Medicine Faculty Publications

The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated …

The Role Of The Pleckstrin Homology Domain-Containing Protein Ckip-1 In Activation Of P21-Activated Kinase 1 (Pak1), Yong-Bae Kim, Yong Jae Shin, Adhiraj Roy, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

Upon growth factor stimulation, PAK1 is recruited to the plasma membrane and activated by a mechanism that requires its phosphorylation at S223 by the protein kinase CK2. However, the upstream signaling molecules that regulate this phosphorylation event are not clearly defined. Here, we demonstrate a major role of the CK2α-interacting protein CKIP-1 in activation of PAK1. CK2α, CKIP-1 and PAK1 are translocated to membrane ruffles in response to the epidermal growth factor (EGF), where CKIP-1 mediates the interaction between CK2α, and PAK1 in a PI3K-dependent manner. Consistently, we observe that PAK1 mediates phosphorylation and modulation of the activity of p41-Arc, …

Topbp1 Governs Hematopoietic Stem/Progenitor Cells Survival In Zebrafish Definitive Hematopoiesis., Lei Gao, Dantong Li, Ke Ma, Wenjuan Zhang, Tao Xu, Wenge Zhu, +12 Additional Authors

Biochemistry and Molecular Medicine Faculty Publications

In vertebrate definitive hematopoiesis, nascent hematopoietic stem/progenitor cells (HSPCs) migrate to and reside in proliferative hematopoietic microenvironment for transitory expansion. In this process, well-established DNA damage response pathways are vital to resolve the replication stress, which is deleterious for genome stability and cell survival. However, the detailed mechanism on the response and repair of the replication stress-induced DNA damage during hematopoietic progenitor expansion remains elusive. Here we report that a novel zebrafish mutantcas003 with nonsense mutation in topbp1 gene encoding topoisomerase II β binding protein 1 (TopBP1) exhibits severe definitive hematopoiesis failure. Homozygous topbp1cas003 mutants manifest reduced number of HSPCs …

Targeting Il13ralpha2 Activates Stat6-Tp63 Pathway To Suppress Breast Cancer Lung Metastasis, Panagiotis Papageorgis, Sait Ozturk, Arthur W. Lambert, Christiana M. Neophytou, Alexandros Tzatsos, Chen K. Wong, Sam Thiagalingam, Andreas I. Constantinou

Anatomy and Regenerative Biology Faculty Publications

Introduction

Basal-like breast cancer (BLBC) is an aggressive subtype often characterized by distant metastasis, poor patient prognosis, and limited treatment options. Therefore, the discovery of alternative targets to restrain its metastatic potential is urgently needed. In this study, we aimed to identify novel genes that drive metastasis of BLBC and to elucidate the underlying mechanisms of action.

Methods

An unbiased approach using gene expression profiling of a BLBC progression model and in silicoleveraging of pre-existing tumor transcriptomes were used to uncover metastasis-promoting genes. Lentiviral-mediated knockdown of interleukin-13 receptor alpha 2 (IL13Ralpha2) coupled with whole-body in vivo bioluminescence imaging was …

Klf4-Sqstm1/P62-Associated Prosurvival Autophagy Contributes To Carfilzomib Resistance In Multiple Myeloma Models., Irene Riz, Teresa S. Hawley, Robert G. Hawley

Anatomy and Regenerative Biology Faculty Publications

Multiple myeloma (MM) is an incurable clonal plasma cell malignancy. Because of a high rate of immunoglobulin synthesis, the endoplasmic reticulum of MM cells is subjected to elevated basal levels of stress. Consequently, proteasome inhibitors, which exacerbate this stress by inhibiting ubiquitin-proteasome-mediated protein degradation, are an important new class of chemotherapeutic agents being used to combat this disease. However, MM cells still develop resistance to proteasome inhibitors such as carfilzomib. Toward this end, we have established carfilzomib-resistant derivatives of MM cell lines. We found that resistance to carfilzomib was associated with elevated levels of prosurvival autophagy, and Kruppel-like factor 4 …

Radium-223 For The Treatment Of Castration-Resistant Prostate Cancer, Joelle El-Amm, Jeanny B. Aragon-Ching

Medicine Faculty Publications

The vast majority of patients with metastatic castration-resistant prostate cancer (mCRPC) develop bone metastases. Bone metastases are a source of significant morbidity and affect quality of life in these patients. Several bone-targeting agents are approved for the treatment of bone metastases in prostate cancer, including bisphosphonates, denosumab, and radiopharmaceuticals. Radium-223 is a novel first-in-class alpha-emitting radiopharmaceutical that has been approved for treatment of patients with mCRPC with bone metastases. Radium-223 delivers cytotoxic radiation to the sites of bone metastases and offers the advantage of minimal myelosuppression. The landmark Phase III ALSYMPCA trial demonstrated that, in addition to providing bone-related palliation, …

Translation Initiation Complex Eif4f Is A Therapeutic Target For Dual Mtor Kinase Inhibitors In Non-Hodgkin Lymphoma., Christos Demosthenous, Jing Jing Han, Mary J Stenson, Matthew J Maurer, Linda E Wellik, Brian Link, Kristen Hege, Ahmet Dogan, Eduardo Sotomayor, Thomas Witzig, Mamta Gupta

Medicine Faculty Publications

Deregulated mRNA translation has been implicated in disease development and in part is controlled by a eukaryotic initiation complex eIF4F (composed of eIF4E, eIF4G and eIF4A). We demonstrate here that the cap bound fraction from lymphoma cells was enriched with eIF4G and eIF4E indicating that lymphoma cells exist in an activated translational state. Moreover, 77% (110/142) of diffuse large B cell lymphoma tumors expressed eIF4E and this was associated with an inferior event free survival. Over-expression of wild-type eIF4E (eIF4E(WT)) but not cap-mutant eIF4E (eIF4E(cap mutant)) increased the activation of the eIF4F complex. Treatment with the active-site dual mTOR inhibitor …

Pharmaceutical Integrated Stress Response Enhancement Protects Oligodendrocytes And Provides A Potential Multiple Sclerosis Therapeutic., Sharon W Way, Joseph R Podojil, Benjamin L Clayton, Anita Zaremba, Tassie L Collins, Rejani B Kunjamma, Andrew P Robinson, Pedro Brugarolas, Robert H. Miller, Stephen D Miller, Brian Popko

Anatomy and Regenerative Biology Faculty Publications

Oligodendrocyte death contributes to the pathogenesis of the inflammatory demyelinating disease multiple sclerosis (MS). Nevertheless, current MS therapies are mainly immunomodulatory and have demonstrated limited ability to inhibit MS progression. Protection of oligodendrocytes is therefore a desirable strategy for alleviating disease. Here we demonstrate that enhancement of the integrated stress response using the FDA-approved drug guanabenz increases oligodendrocyte survival in culture and prevents hypomyelination in cerebellar explants in the presence of interferon-γ, a pro-inflammatory cytokine implicated in MS pathogenesis. In vivo, guanabenz treatment protects against oligodendrocyte loss caused by CNS-specific expression of interferon-γ. In a mouse model of MS, experimental …

Cytometric Characterization Of Circulating Tumor Cells Captured By Microfiltration And Their Correlation To The Cellsearch(®) Ctc Test., Daniel L Adams, Steingrimur Stefansson, Christian Haudenschild, Stuart S Martin, Monica Charpentier, Saranya Chumsri, Massimo Cristofanilli, Cha-Mei Tang, R Katherine Alpaugh

Pathology Faculty Publications

Recent studies reporting hundreds, to thousands, of circulating tumor cells (CTCs) in the blood of cancer patients have raised questions regarding the prevalence of CTCs, as enumerated by the CellSearch(®) CTC Test. Although CellSearch has been shown to consistently detect clinically relevant CTCs; the ability to only capture EpCAM positive cells has led to speculation that it captures limited subsets of CTCs. In contrast, alternative approaches to CTC isolation are often cited as capturing large numbers of CTCs from patient blood. Not surprisingly the number of cells isolated by alternative approaches show poor correlations when compared to CellSearch, even when …

The Use Of Stem Cells In Burn Wound Healing: A Review, Fadi Ghieh, Rosalyn A. Jurjus, Amir Ibrahim, Alice Gerges Geagea, Hisham Daouk, Bassel El Baba, Sana Cham, Michel Matar, Wadih Zein, Abdo Jurjus

Anatomy and Regenerative Biology Faculty Publications

Burn wound healing involves a series of complex processes which are subject to intensive investigations to improve the outcomes, in particular, the healing time and the quality of the scar. Burn injuries, especially severe ones, are proving to have devastating effects on the affected patients. Stem cells have been recently applied in the field to promote superior healing of the wounds. Not only have stem cells been shown to promote better and faster healing of the burn wounds, but also they have decreased the inflammation levels with less scar progression and fibrosis. This review aims to highlight the beneficial therapeutic …

Clinical Significance Of A Point Mutation In Dna Polymerase Beta (Polb) Gene In Gastric Cancer., Xiaohui Tan, Hongyi Wang, Guangbin Luo, Shuyang Ren, Wenmei Li, Jiantao Cui, Harindarpal S. Gill, Sidney W. Fu, Youyong Lu

Medicine Faculty Publications

Gastric cancer (GC) is a major cause of global cancer mortality. Genetic variations in DNA repair genes can modulate DNA repair capability and, consequently, have been associated with risk of developing cancer. We have previously identified a T to C point mutation at nucleotide 889 (T889C) in DNA polymerase beta (POLB) gene, a key enzyme involved in base excision repair in primary GCs. The purpose of this study was to evaluate the mutation and expression of POLB in a larger cohort and to identify possible prognostic roles of the POLB alterations in GC. Primary GC specimens and their matched normal …

Once Upon A Microscopic Slide: The Story Of Histology, Inaya Hussein, Mohamad Raad, Rawan Safa, Rosalyn A. Jurjus, Abdo Jurjus

Anatomy and Regenerative Biology Faculty Publications

For centuries, histology has maintained its remarkable place in the medical curriculum. However, its teaching has been influenced by the new technological advancement that has reshaped medicine teaching into a more modern student-friendly form. Since its inception in the 18th century, the discipline of histology has progressed hand in hand with the advancements in microscopy and microscopic technologies, including immunohistochemistry. In the traditional curriculum of USA medical schools, especially after the first Flexner’s report of 1910, histology was considered as very essential topic for a physician studying the “Art and Science” of medicine. In this era, the teaching relied more …

Nitric Oxide Generating/Releasing Materials, Honying Liang, Parimala Nacharaju, Adam J. Friedman, Joel Friedman

Dermatology Faculty Publications

Harnessing the impressive therapeutic potential of nitric oxide (NO) remains an ongoing challenge. This paper describes several of the current strategies both with respect to the underlying chemistry and physics and to the applications where they have shown promise. Included in this overview are molecular systems such as NONOates that release NO through chemical reactions and delivery vehicles such as nanoparticles that can generate, store, transport and deliver NO and related bioactive forms of NO such as nitrosothiols. Although there has been much positive movement, it is clear that we are only at the early stages of knowing how to …

May Circulating Micrornas Be Gastric Cancer Diagnostic Biomarkers?, Xiaoling Wu, Xiaohui (Jane) Tan, Sidney W. Fu

Medicine Faculty Publications

Gastric cancer (GC) is the third leading cause of cancer-related deaths. More than 80% of the diagnosis was made at the advanced stages of the disease, highlighting the urgent demand for novel biomarkers that can be used for early detection. Recently, a number of studies suggest that circulating microRNAs (miRNAs) could be potential biomarkers for GC diagnosis. Cancer-related circulating miRNAs, as well as tissue miRNAs, provide a hopeful prospect of detecting GC at early stages, and the prospective participation of miRNAs in biomarker development will enhance the sensitivity and specificity of diagnostic tests for GC. As miRNAs in blood are …