Digital Commons Network^™

Short-Wavelength Light Sensitivity Of Circadian, Pupillary, And Visual Awareness In Humans Lacking An Outer Retina, Farhan H. Zaidi, Joseph T. Hull, Stuart N. Peirson, Katharina Wulff, Daniel Aeschbach, Joshua J. Gooley, George C. Brainard, Kevin Gregory-Evans, Joseph F. Rizzo Iii, Charles A. Czeisler, Russell G. Foster, Merrick J. Moseley, Steven W. Lockley

Department of Neurology Faculty Papers

As the ear has dual functions for audition and balance, the eye has a dual role in detecting light for a wide range of behavioral and physiological functions separate from sight. These responses are driven primarily by stimulation of photosensitive retinal ganglion cells (pRGCs) that are most sensitive to short-wavelength ( approximately 480 nm) blue light and remain functional in the absence of rods and cones. We examined the spectral sensitivity of non-image-forming responses in two profoundly blind subjects lacking functional rods and cones (one male, 56 yr old; one female, 87 yr old). In the male subject, we found …

Direct Inhibition Of Cdk9 Blocks Hiv-1 Replication Without Preventing T Cell Activation In Primary Human Peripheral Blood Lymphocytes, Dominic Salerno, Muneer G Hasham, Renee Marshall Demarest, Judit Garriga, Alexander Y Tsygankov, Xavier Graña

Rowan-Virtua School of Osteopathic Medicine Departmental Research

HIV-1 transcription is essential for the virus replication cycle. HIV-1 Tat is a viral transactivator that strongly stimulates the processivity of RNA polymerase II (RNAPII) via recruitment of the cyclin T1/CDK9 positive transcription elongation factor, which phosphorylates the C-terminal domain (CTD) of RNAPII. Consistently, HIV-1 replication in transformed cells is very sensitive to direct CDK9 inhibition. Thus, CDK9 could be a potential target for anti-HIV-1 therapy. A clearer understanding of the requirements for CDK9 activity in primary human T cells is needed to assess whether the CDK9-dependent step in HIV-1 transcription can be targeted clinically. We have investigated the effects …

How To Prevent Perioperative Myocardial Injury: The Conundrum Continues, Jian-Zhong Sun, David Maguire

Department of Anesthesiology Faculty Papers

BACKGROUND: Perioperative myocardial injury (PMI) remains a major cause of perioperative morbidity and mortality but clinical strategies to prevent PMI are still uncertain.

METHODS AND RESULTS: We comprehensively searched PubMed for major research articles concerning clinical strategies to prevent PMI. The key findings are as follows: (1) the American College of Cardiology/American Heart Association guideline update for perioperative cardiovascular evaluation for noncardiac surgery is very useful to stratify cardiac risk preoperatively; (2) cardiac troponin has emerged as a biomarker to diagnose postoperative PMI and to predict clinical outcomes; (3) coronary revascularization before noncardiac surgery probably would provide cardiac protection in …

Aoa Symposium. Orthopaedists Partnering With Other Physicians To Provide Musculoskeletal Care., Alan Hilibrand, Kurt P Spindler, Scott D Boden

Rothman Institute Papers

No abstract provided.

Modulation Of Tgf-Beta Signaling By Proinflammatory Cytokines In Articular Chondrocytes., Jorge A. Roman-Blas, David G. Stokes, Sergio A. Jimenez

Department of Medicine Faculty Papers

OBJECTIVE: The normal structure and function of articular cartilage are the result of a precisely balanced interaction between anabolic and catabolic processes. The transforming growth factor-beta (TGF-beta) family of growth factors generally exerts an anabolic or repair response; in contrast, proinflammatory cytokines such as interleukin 1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) exert a strong catabolic effect. Recent evidence has shown that IL-1beta, and TNF-alpha, and the TGF-beta signaling pathways share an antagonistic relationship. The aim of this study was to determine whether the modulation of the response of articular chondrocytes to TGF-beta by IL-1beta or TNF-alpha signaling pathways …

A Novel Inhibitory Mechanism Of Mitochondrion-Dependent Apoptosis By A Herpesviral Protein, Pinghui Feng, Chengyu Liang, Young C. Shin, Xiaofei E, Weijun Zhang, Robyn Gravel, Ting-Ting Wu, Ren Sun, Edward Usherwood, Jae U. Jung

Dartmouth Scholarship

Upon viral infection, cells undergo apoptosis as a defense against viral replication. Viruses, in turn, have evolved elaborate mechanisms to subvert apoptotic processes. Here, we report that a novel viral mitochondrial anti-apoptotic protein (vMAP) of murine gamma-herpesvirus 68 (gammaHV-68) interacts with Bcl-2 and voltage-dependent anion channel 1 (VDAC1) in a genetically separable manner. The N-terminal region of vMAP interacted with Bcl-2, and this interaction markedly increased not only Bcl-2 recruitment to mitochondria but also its avidity for BH3-only pro-apoptotic proteins, thereby suppressing Bax mitochondrial translocation and activation. In addition, the central and C-terminal hydrophobic regions of vMAP interacted with VDAC1. …

Neurogranin Controls The Spatiotemporal Pattern Of Postsynaptic Ca2+/Cam Signaling, Yoshihisa Kubota, John A Putkey, M Neal Waxham

Faculty, Staff and Student Publications

Neurogranin (Ng) is a postsynaptic IQ-motif containing protein that accelerates Ca(2+) dissociation from calmodulin (CaM), a key regulator of long-term potentiation and long-term depression in CA1 pyramidal neurons. The exact physiological role of Ng, however, remains controversial. Two genetic knockout studies of Ng showed opposite outcomes in terms of the induction of synaptic plasticity. To understand its function, we test the hypothesis that Ng could regulate the spatial range of action of Ca(2+)/CaM based on its ability to accelerate the dissociation of Ca(2+) from CaM. Using a mathematical model constructed on the known biochemistry of Ng, we calculate the cycle …

Pre-Mrna Secondary Structures Influence Exon Recognition, Michael Hiller, Zhaiyi Zhang, Rolf Backofen, Stefan Stamm

Molecular and Cellular Biochemistry Faculty Publications

The secondary structure of a pre-mRNA influences a number of processing steps including alternative splicing. Since most splicing regulatory proteins bind to single-stranded RNA, the sequestration of RNA into double strands could prevent their binding. Here, we analyzed the secondary structure context of experimentally determined splicing enhancer and silencer motifs in their natural pre-mRNA context. We found that these splicing motifs are significantly more single-stranded than controls. These findings were validated by transfection experiments, where the effect of enhancer or silencer motifs on exon skipping was much more pronounced in single-stranded conformation. We also found that the structural context of …

Discovery Of Platelet-Type 12-Human Lipoxygenase Selective Inhibitors By High-Throughput Screening Of Structurally Diverse Libraries., Joshua D. Deschamps, Jeffrey T. Gautschi, Stephanie Whitman, Tyler A. Johnson, Nadine C. Gassner, Phillip Crews, Theodore R. Holman

Natural Sciences and Mathematics | Faculty Scholarship

Human lipoxygenases (hLO) have been implicated in a variety of diseases and cancers and each hLO isozyme appears to have distinct roles in cellular biology. This fact emphasizes the need for discovering selective hLO inhibitors for both understanding the role of specific lipoxygenases in the cell and developing pharmaceutical therapeutics. To this end, we have modified a known lipoxygenase assay for high-throughput (HTP) screening of both the National Cancer Institute (NCI) and the UC Santa Cruz marine extract library (UCSC-MEL) in search of platelet-type 12-hLO (12-hLO) selective inhibitors. The HTP screen led to the characterization of five novel 12-hLO inhibitors …

Adaptive Radiotherapy Planning On Decreasing Gross Tumor Volumes As Seen On Megavoltage Computed Tomography Images., Curtis Woodford, Slav Yartsev, R. Dar, Glenn Bauman, Jacob Van Dyk

Oncology Publications

PURPOSE: To evaluate gross tumor volume (GTV) changes for patients with non-small-cell lung cancer by using daily megavoltage (MV) computed tomography (CT) studies acquired before each treatment fraction on helical tomotherapy and to relate the potential benefit of adaptive image-guided radiotherapy to changes in GTV.

METHODS AND MATERIALS: Seventeen patients were prescribed 30 fractions of radiotherapy on helical tomotherapy for non-small-cell lung cancer at London Regional Cancer Program from Dec 2005 to March 2007. The GTV was contoured on the daily MVCT studies of each patient. Adapted plans were created using merged MVCT-kilovoltage CT image sets to investigate the advantages …

Micro Rna 145 Targets The Insulin Receptor Substrate-1 And Inhibits The Growth Of Colon Cancer Cells, Bin Shi, Laura Sepp-Lorenzino, Marco Prisco, Peter Linsley, Tiziana Deangelis, Renato Baserga

Department of Cancer Biology Faculty Papers

The insulin receptor substrate-1 (IRS-1), a docking protein for both the type 1 insulin-like growth factor receptor (IGF-IR) and the insulin receptor, is known to send a mitogenic, anti-apoptotic, and anti-differentiation signal. Several micro RNAs (miRs) are suggested by the data base as possible candidates for targeting IRS-1. We show here that one of the miRs predicted by the data base, miR145, whether transfected as a synthetic oligonucleotide or expressed from a plasmid, causes down-regulation of IRS-1 in human colon cancer cells. IRS-1 mRNA is not decreased by miR145, while it is down-regulated by an siRNA targeting IRS-1. Targeting of …

Developing "Human Functioning And Rehabilitation Research" From The Comprehensive Perspective., Gerold Stucki, Jan Dietrich Reinhardt, Gunnar Grimby, John Melvin

Department of Rehabilitation Medicine Faculty Papers

With the International Classification of Functioning, Disability and Health (ICF) the World Health Organization (WHO) has prepared the ground for a comprehensive understanding of Human Functioning and Rehabilitation Research, integrating the biomedical perspective on impairment with the social model of disability. This poses a number of old and new challenges regarding the enhancement of adequate research capacity. Here we will summarize approaches to address these challenges with respect to 3 areas: the organization of Human Functioning and Rehabilitation Research into distinct scientific fields, the development of suitable academic training programmes and the building of university centres and collaboration networks.

Human Tob, An Antiproliferative Transcription Factor, Is A Poly(A)-Binding Protein-Dependent Positive Regulator Of Cytoplasmic Mrna Deadenylation, Nader Ezzeddine, Tsung-Cheng Chang, Wenmiao Zhu, Akio Yamashita, Chyi-Ying A Chen, Zhenping Zhong, Yukiko Yamashita, Dinghai Zheng, Ann-Bin Shyu

Faculty, Staff and Student Publications

In mammalian cells, mRNA decay begins with deadenylation, which involves two consecutive phases mediated by the PAN2-PAN3 and the CCR4-CAF1 complexes, respectively. The regulation of the critical deadenylation step and its relationship with RNA-processing bodies (P-bodies), which are thought to be a site where poly(A)-shortened mRNAs get degraded, are poorly understood. Using the Tet-Off transcriptional pulsing approach to investigate mRNA decay in mouse NIH 3T3 fibroblasts, we found that TOB, an antiproliferative transcription factor, enhances mRNA deadenylation in vivo. Results from glutathione S-transferase pull-down and coimmunoprecipitation experiments indicate that TOB can simultaneously interact with the poly(A) nuclease complex CCR4-CAF1 and …

Is A 3-Mm Intrafractional Margin Sufficient For Daily Image-Guided Intensity-Modulated Radiation Therapy Of Prostate Cancer?, Adam D Melancon, Jennifer C O'Daniel, Lifei Zhang, Rajat J Kudchadker, Deborah A Kuban, Andrew K Lee, Rex M Cheung, Renaud De Crevoisier, Susan L Tucker, Wayne D Newhauser, Radhe Mohan, Lei Dong

Faculty, Staff and Student Publications

PURPOSE: To determine whether a 3-mm isotropic target margin adequately covers the prostate and seminal vesicles (SVs) during administration of an intensity-modulated radiation therapy (IMRT) treatment fraction, assuming that daily image-guided setup is performed just before each fraction.

MATERIALS AND METHODS: In-room computed tomographic (CT) scans were acquired immediately before and after a daily treatment fraction in 46 patients with prostate cancer. An eight-field IMRT plan was designed using the pre-fraction CT with a 3-mm margin and subsequently recalculated on the post-fraction CT. For convenience of comparison, dose plans were scaled to full course of treatment (75.6 Gy). Dose coverage …

Sirtuins, Nuclear Hormone Receptor Acetylation And Transcriptional Regulation, James R. Whittle, Michael J. Powell, Vladimir M. Popov, L. Andrew Shirley, Chenguang Wang, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Endocrine signaling via nuclear receptors (NRs) is known to play an important role in normal physiology as well as in human tumor progression. Hormones regulate gene expression by altering local chromatin structure and, thereby, accessibility of transcriptional co-regulators to DNA. Recently it has been shown that non-histone proteins involved in hormone signaling, such as nuclear receptors and NR co-activators, are regulated by acetylation, resulting in their altered transcriptional activity. NAD-dependent protein deacetylases, the sirtuins (Sir2-related enzymes), directly modify NRs. Because sirtuins have been shown to regulate tumor cellular growth, aging, metabolic signaling and endocrine hormone signaling, they might play a …

Induction Of Insulin Secretion In Engineered Liver Cells By Nitric Oxide, Latha Muniappan, Sabire Özcan

Molecular and Cellular Biochemistry Faculty Publications

BACKGROUND: Type 1 Diabetes Mellitus results from an autoimmune destruction of the pancreatic beta cells, which produce insulin. The lack of insulin leads to chronic hyperglycemia and secondary complications, such as cardiovascular disease. The currently approved clinical treatments for diabetes mellitus often fail to achieve sustained and optimal glycemic control. Therefore, there is a great interest in the development of surrogate beta cells as a treatment for type 1 diabetes. Normally, pancreatic beta cells produce and secrete insulin only in response to increased blood glucose levels. However in many cases, insulin secretion from non-beta cells engineered to produce insulin occurs …

Nicotinamide Riboside Kinase Structures Reveal New Pathways To Nad+, Wolfram Tempel, Wael M. Rabeh, Katrina L. Bogan, Peter Belenky, Marzena Wojcik, Heather F. Seidle, Lyudmila Nedyalkova, Tianle Yang, Anthony A. Sauve, Hee-Won Park, Charles Brenner

Dartmouth Scholarship

The eukaryotic nicotinamide riboside kinase (Nrk) pathway, which is induced in response to nerve damage and promotes replicative life span in yeast, converts nicotinamide riboside to nicotinamide adenine dinucleotide (NAD+) by phosphorylation and adenylylation. Crystal structures of human Nrk1 bound to nucleoside and nucleotide substrates and products revealed an enzyme structurally similar to Rossmann fold metabolite kinases and allowed the identification of active site residues, which were shown to be essential for human Nrk1 and Nrk2 activity in vivo. Although the structures account for the 500-fold discrimination between nicotinamide riboside and pyrimidine nucleosides, no enzyme feature was identified to recognize …

Versatile Applications Of Transcriptional Pulsing To Study Mrna Turnover In Mammalian Cells, Chyi-Ying A Chen, Yukiko Yamashita, Tsung-Cheng Chang, Akio Yamashita, Wenmiao Zhu, Zhenping Zhong, Ann-Bin Shyu

Faculty, Staff and Student Publications

Development of transcriptional pulsing approaches using the c-fos and Tet-off promoter systems greatly facilitated studies of mRNA turnover in mammalian cells. However, optimal protocols for these approaches vary for different cell types and/or physiological conditions, limiting their widespread application. In this study, we have further optimized transcriptional pulsing systems for different cell lines and developed new protocols to facilitate investigation of various aspects of mRNA turnover. We apply the Tet-off transcriptional pulsing strategy to investigate ARE-mediated mRNA decay in human erythroleukemic K562 cells arrested at various phases of the cell cycle by pharmacological inhibitors. This application facilitates studies of the …

Computational Identification And Functional Validation Of Regulatory Motifs In Cartilage-Expressed Genes, Sherri R Davies, Li-Wei Chang, Debabrata Patra, Xiaoyun Xing, Karen Posey, Jacqueline Hecht, Gary D Stormo, Linda J Sandell

Faculty, Staff and Student Publications

Chondrocyte gene regulation is important for the generation and maintenance of cartilage tissues. Several regulatory factors have been identified that play a role in chondrogenesis, including the positive transacting factors of the SOX family such as SOX9, SOX5, and SOX6, as well as negative transacting factors such as C/EBP and delta EF1. However, a complete understanding of the intricate regulatory network that governs the tissue-specific expression of cartilage genes is not yet available. We have taken a computational approach to identify cis-regulatory, transcription factor (TF) binding motifs in a set of cartilage characteristic genes to better define the transcriptional regulatory …

Regulation Of Mucin Gene Expression By Creb Via A Nonclassical Retinoic Acid Signaling Pathway, Seung-Wook Kim, Jeong Soo Hong, Seung-Hee Ryu, Wen-Cheng Chung, Joo-Heon Yoon, Ja Seok Koo

Faculty, Staff and Student Publications

Vitamin A and its metabolite retinoic acid (RA) are essential elements for normal lung development and the differentiation of lung epithelial cells. We previously showed that RA rapidly activated cyclic AMP response element-binding protein (CREB) in a nonclassical manner in normal human tracheobronchial epithelial (NHTBE) cells. In the present study, we further demonstrated that this nonclassical signaling of RA on the activation of CREB plays a critical role in regulating the expression of airway epithelial cell differentiation markers, the MUC2, MUC5AC, and MUC5B genes. We found that RA rapidly activates the protein kinase Calpha isozyme and transmits the activation signal …

Mutations In The Cofilin Partner Aip1/Wdr1 Cause Autoinflammatory Disease And Macrothrombocytopenia, Benjamin T Kile, Athanasia D Panopoulos, Roslynn A Stirzaker, Douglas F Hacking, Lubna H Tahtamouni, Tracy A Willson, Lisa A Mielke, Katya J Henley, Jian-Guo Zhang, Ian P Wicks, William S Stevenson, Paquita Nurden, Stephanie S Watowich, Monica J Justice

Faculty, Staff and Student Publications

A pivotal mediator of actin dynamics is the protein cofilin, which promotes filament severing and depolymerization, facilitating the breakdown of existing filaments, and the enhancement of filament growth from newly created barbed ends. It does so in concert with actin interacting protein 1 (Aip1), which serves to accelerate cofilin's activity. While progress has been made in understanding its biochemical functions, the physiologic processes the cofilin/Aip1 complex regulates, particularly in higher organisms, are yet to be determined. We have generated an allelic series for WD40 repeat protein 1 (Wdr1), the mammalian homolog of Aip1, and report that reductions in Wdr1 function …

Downregulation Of Rap1gap Contributes To Ras Transformation, Oxana Tsygankova, Gregory V. Prendergast, Kanchan Puttaswamy, Yan Wang, Michael D. Feldman, Hongbin Wang, Marcia S. Brose, Judy L. Meinkoth

Faculty, Staff and Student Publications

Although abundant in well-differentiated rat thyroid cells, Rap1GAP expression was extinguished in a subset of human thyroid tumor-derived cell lines. Intriguingly, Rap1GAP was downregulated selectively in tumor cell lines that had acquired a mesenchymal morphology. Restoring Rap1GAP expression to these cells inhibited cell migration and invasion, effects that were correlated with the inhibition of Rap1 and Rac1 activity. The reexpression of Rap1GAP also inhibited DNA synthesis and anchorage-independent proliferation. Conversely, eliminating Rap1GAP expression in rat thyroid cells induced a transient increase in cell number. Strikingly, Rap1GAP expression was abolished by Ras transformation. The downregulation of Rap1GAP by Ras required the …

Selective Repression Of Retinoic Acid Target Genes By Rip140 During Induced Tumor Cell Differentiation Of Pluripotent Human Embryonal Carcinoma Cells, Kelly C. Heim, Kristina A. White, Dexin Deng, Craig R. Tomlinson, Jason Moore, Sarah Freemantle, Michael Spinella

Dartmouth Scholarship

The use of retinoids as anti-cancer agents has been limited due to resistance and low efficacy. The dynamics of nuclear receptor coregulation are incompletely understood. Cell-and context-specific activities of nuclear receptors may be in part due to distinct coregulator complexes recruited to distinct subsets of target genes. RIP140 (also called NRIP1) is a ligand-dependent corepressor that is inducible with retinoic acid (RA). We had previously shown that RIP140 limits RA induced tumor cell differentiation of embryonal carcinoma; the pluriopotent stem cells of testicular germ cell tumors. This implies that RIP140 represses key genes required for RA-mediated tumor cell differentiation. Identification …

Microvascular Endothelial Cells Express A Phosphatidylserine Receptor: A Functionally Active Receptor For Phosphatidylserine-Positive Erythrocytes, Yamaja Setty, Suhita Gayen Betal

Department of Pediatrics Faculty Papers

Phosphatidylserine (PS)-positive erythrocytes adhere to endothelium and subendothelial matrix components. While thrombospondin mediates these inter-actions, it is unknown whether PS-associated erythrocyte-endothelial adhesion occurs in the absence of plasma ligands. Using ionophore-treated PS-expressing control HbAA erythrocytes, we demonstrate that PS-positive erythrocytes adhered to human lung microendothelial cells in the absence of plasma ligands, that this adhesion was enhanced following endothelial activation with IL-1alpha, TNF-alpha, LPS, hypoxia, and heme, and that this adhesive interaction was selective to erythrocyte PS. We next explored whether microendothelial cells express an adhesion receptor that recognizes cell surface-expressed PS (PSR) similar to that expressed on activated macrophages. …

Recent Advances In Cancer Stem/Progenitor Cell Research: Therapeutic Implications For Overcoming Resistance To The Most Aggressive Cancers., M. Mimeault, Ralph Hauke, Parmender P. Mehta, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers. This review summarizes recent advances in our understanding of the cellular origin and molecular mechanisms at the basis of cancer initiation and progression as well as the heterogeneity of cancers arising from the malignant transformation of adult stem/progenitor cells. We describe the critical functions provided by several growth factor cascades, including epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), stem cell factor (SCF) receptor (KIT), hedgehog and Wnt/beta-catenin signalling pathways that …

Receiver Operating Characteristic And Location Analysis Of Simulated Near-Infrared Tomography Images, Xiaomei Song, Brian W. Pogue, Hamid Dehghani, Shudong Jiang, Keith D. Paulsen, Tor D. Tosteson

Dartmouth Scholarship

Receiver operating characteristic (ROC) analysis was performed on simulated near-infrared tomography images, using both human observer and contrast-to-noise ratio (CNR) computational assessment, for application in breast cancer imaging. In the analysis, a nonparametric approach was applied for estimating the ROC curves. Human observer detection of objects had superior capability to localize the presence of heterogeneities when the objects were small with high contrast, with a minimum detectable threshold of CNR near 3.0 to 3.3 in the images. Human observers were able to detect heterogeneities in the images below a size limit of 4 mm, yet could not accurately find the …

Human Collagen Krox Up-Regulates Type I Collagen Expression In Normal And Scleroderma Fibroblasts Through Interaction With Sp1 And Sp3 Transcription Factors., Magdalini Kypriotou, Gallic Beauchef, Christos Chadjichristos, Russell Widom, Emmanuelle Renard, Sergio A. Jimenez, Joseph Korn, François-Xavier Maquart, Thierry Oddos, Otto Von Stetten, Jean-Pierre Pujol, Philippe Galéra

Department of Medicine Faculty Papers

Despite several investigations, the transcriptional mechanisms that regulate the expression of both type I collagen genes (COL1A1 and COL1A2) in either physiological or pathological situations, such as scleroderma, are not completely known. We have investigated the role of hc-Krox transcription factor on type I collagen expression by human dermal fibroblasts. hc-Krox exerted a stimulating effect on type I collagen protein synthesis and enhanced the corresponding mRNA steady-state levels of COL1A1 and COL1A2 in foreskin fibroblasts (FF), adult normal fibroblasts (ANF), and scleroderma fibroblasts (SF). Forced hc-Krox expression was found to up-regulate COL1A1 transcription through a -112/-61-bp sequence in FF, ANF, …

Human Muc4 Mucin Induces Ultra-Structural Changes And Tumorigenicity In Pancreatic Cancer Cells., N. Moniaux, P. Chaturvedi, G. C. Varshney, Jane L. Meza, J. F. Rodriguez-Sierra, J-P Aubert, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

MUC4 is a type-1 transmembrane glycoprotein and is overexpressed in many carcinomas. It is a heterodimeric protein of 930 kDa, composed of a mucin-type subunit, MUC4alpha, and a membrane-bound growth factor-like subunit, MUC4beta. MUC4 mRNA contains unique 5' and 3' coding sequences along with a large variable number of tandem repeat (VNTR) domain of 7-19 kb. A direct association of MUC4 overexpression has been established with the degree of invasiveness and poor prognosis of pancreatic cancer. To understand the precise role of MUC4 in pancreatic cancer, we engineered a MUC4 complementary DNA construct, mini-MUC4, whose deduced protein (320 kDa) is …

Molecular Determinants Of Mg2+ And Ca2+ Permeability And Ph Sensitivity In Trpm6 And Trpm7*S, Mingjiang Li, Jianyang Du, Jianmin Jiang, William J. Ratzan, Li-Ting Su, Loren W. Runnels, Lixia Yue

UCHC Articles - Research

The channel kinases TRPM6 and TRPM7 have recently been discovered to play important roles in Mg²⁺ and Ca²⁺ homeostasis, which is critical to both human health and cell viability. However, the molecular basis underlying these channels’ unique Mg²⁺ and Ca²⁺ permeability and pH sensitivity remains unknown. Here we have created a series of amino acid substitutions in the putative pore of TRPM7 to evaluate the origin of the permeability of the channel and its regulation by pH. Two mutants of TRPM7, E1047Q and E1052Q, produced dramatic changes in channel properties. The I–V relations of E1052Q and …

Defective Dna Base Excision Repair In Brain From Individuals With Alzheimer's Disease And Amnestic Mild Cognitive Impairment, Lior Weissman, Dong-Gyu Jo, Martin M. Sørensen, Nadja C. De Souza-Pinto, William R. Markesbery, Mark P. Mattson, Vilhelm A. Bohr

Pathology and Laboratory Medicine Faculty Publications

Oxidative stress is thought to play a role in the pathogenesis of Alzheimer's disease (AD) and increased oxidative DNA damage has been observed in brain tissue from AD patients. Base excision repair (BER) is the primary DNA repair pathway for small base modifications such as alkylation, deamination and oxidation. In this study, we have investigated alterations in the BER capacity in brains of AD patients. We employed a set of functional assays to measure BER activities in brain tissue from short post-mortem interval autopsies of 10 sporadic AD patients and 10 age-matched controls. BER activities were also measured in brain …