• Preclinical Development of Anti-Cancer Drugs from Natural Products.

      Huang, Ying; Sun, Qing (2014)
      Cancer has been and will continue to be the common concern in the United States and worldwide. As a conventional treatment to fight cancer, new anti-cancer drugs with more efficiency and less toxicity are extremely required. In this study, we have identified two novel compounds with anti-cancer properties from two traditional Chinese medicinal plants. One is Lappaol F that was extracted from the seeds of the plant Actium Lapp L., which has been used in China for centuries as anti-viral and anti-bacterial medicine. Another is M-9 that was extracted from the stem of Marsdenia tenacissima,a plant that has been applied to treat inflammation and cancer in China. Our results showed that Lappaol F inhibited cancer cell growth by regulating a series of cell cycle related proteins and inducing cell cycle arrest at G1 and/or G2 phase. p21 played a critical role in Lappaol F-induced cyclin B1 and cyclin-dependent kinase 1 (CDK1) suppression as well as G2arrest. Lappaol F also induced cell death in a number of cancer cells through caspases activation. Lappaol F-mediated cell growth inhibition was p53-independent. Notably, results from animal studies showed that Lappaol F effectively inhibited tumor growth in vivo, while being well tolerated by the mice. Thus, Lappaol F has a strong potential to be developed as a novel anti-cancer chemotherapeutic. Our studies showed that M-9 successfully sensitized several tumor cells but not non-tumorigenic cells to paclitaxel (Taxol) treatment. Additionally, M-9 reversed chemotherapeutic resistance in a number of multidrug resistant cells. Further results suggested that M-9 functioned, at least to a certain extent, via inhibiting drug efflux by competitively binding to P-glycoprotein (P-gp), a protein that accounts for multidrug resistance. Importantly, results from the in vivostudies demonstrated that M-9 strongly enhanced Taxol-induced growth suppression against xenografts derived from HeLa cells. Moreover, mice tolerated the treatment of Taxol and M-9 well. Therefore, M-9 is a novel chemosensitizer candidate to overcome P-gp-mediated multidrug resistance. Taken together, our studies provide a solid basis for further development of these two compounds as anti-cancer remedies.
    • Presentation of Self in MySpace.com an Online Social Networking Site

      Perretta, Heather (2007-05-01)
      This ethnographic study explores the presentation of self on MySpace.com, an online social networking website. One hundred MySpace.com profile pages were analyzed to discover how users complete and manipulate the MySpace template to create a virtual presentation of self. The one hundred profile pages represented fifty stated female users and fifty stated male users. Each page was archived and coded based on the elements present that were viewable by the public. All users were selected at random using the website search tool and a random number generator. The work of Erving Goffman in his 1959 book, The Presentation of Self in Everyday Life, is the theoretical foundation for the this study. Analysis of the profile pages sampled indicates that most users studied modify the default template and add various elements from textual information to pictures, music, and video clips to the profile pages and create a virtual presentation of self on MySpace.com.
    • Prezi v. PowerPoint: Finding the right tool for the job

      White, Nicloe L. (2011-08-01)
      The purpose of this project is to determine which presentation tool works best to deliver a clear, concise message to an audience. The tools being studied are PowerPoint, the standard, slidebased presentation tool, and Prezi, the newer, non-linear software tool. A presentation was created in Prezi using the same content and multi-media as the original PowerPoint presentation. The principles of Human Centered Design Theory were used as a guide to analyze each tool. Research was further triangulated by creating two groups and showing both presentations to each. Each group then had to answer survey questions about the presentations. Finally, using volunteers from both survey groups a focus group was formed to further discuss both presentations and their reactions to each one.
    • The Process of Redesigning and Redeveloping a University Website in the Face of Organizational Change

      Rau, Erika E (2005-05-01)
      This case study analyzes the process of redesigning and redeveloping a university website. An in-depth exploration of decision-making processes, organizational structure, working relationships, communication during change, and the impact these issues have on the process during the beginning stages of the website redesign is examined. Brenda Dervin’s SenseMaking theory is applied and was the key theory that led the research. Tushman and Nadler’s Information Processing theory and Daft and Lengel’s Information Processing and Organizational Design theory was also analyzed and related to this redesign process.
    • Professional Practice in Design a Massive Open Online Course

      LaBella, Sharon (2013-05-01)
      This thesis project is the development of a massive open online course (MOOC), an open access course available to anyone with an internet connection. The course title for this MOOC is Professional Practice in Design and focuses on career development skills for a student enrolled in a college design program. Not all design programs offer instruction on these topics and the student gains an advantage in the workplace with this course instruction. The methodology selected is that of the xMOOC which mirrors the instruction found in a traditional on campus course with the instructor giving a lecture and then assessing students learning with assignments and tests. The conclusions found that in contrast to other xMOOCs, provided by such organizations as Coursera and edX where thousands of students participate at one time, this course would require an enrollment cap. Additionally, it was found offering a MOOC through a college program for tuition credit could potentially result in more consistent student engagement and participation. Finally, MOOCs are new to the online learning environment and there are a number of unanswered questions about topics such as, a business model for organizations offering courses, the ability to continue to offer open access courses for free and the acceptance by colleges and employers.
    • Prototyping a Mobile App for Pregnancy During the COVID-19 Pandemic: Using Information Design to Strengthen Information Landscapes

      Stam, Kathryn; Thesis Advisor; Banner, Phylise; Second reader; Woodworth, Anna (2021-05)
      When the COVID-19 pandemic struck the United States in early 2020, pregnant people faced challenges unlike what would be expected while pregnant during “normal times.” Studies found this population to be overwhelmed by rampant misinformation or a lack of information, decreased access to health care, and uncertain social support. This project investigates and addresses the preferences of pregnant people by designing a prototype of a mobile application that seeks to increase both accessibility and availability of credible information about pregnancy and postpartum during the COVID-19 pandemic. Methods include a literature review, questionnaires, interviews, personas, current app research, wireframing, and prototyping. They identify a gap in the mobile app toolbox for navigable, credible information on COVID-19 for pregnant and recently pregnant people. They also find that, contra to the goals of the project, it isn’t feasible to incorporate into the app a social support feature, due to the potential for misinformation. The project also concludes that a successful mobile application employs information design to lessen the cognitive load of users and to integrate their geographic confines; elements that support a user’s agency also strengthen the user’s information landscape. Further research ascertaining the specifics of what might be needed to make an app usable for particular marginalized or underserved populations is still needed. Finally, one of the more intriguing questions raised by this project might be how to integrate the social support identified as an important need by pregnant people into an app that values the integrity of information.
    • Psychoactive substance use disorders in adults with attention deficit hyperactivity disorder (ADHD): effects of ADHD and psychiatric comorbidity

      Biederman, J; Wilens, T; Mick, E; Milberger, S; Spencer, T J; Faraone, Stephen V. (American Psychiatric Association Publishing, 1995-11)
      Objective: The authors evaluated the association between attention deficit hyperactivity disorder (ADHD) and psychoactive substance use disorders in adults with ADHD, attending to comorbidity with mood, anxiety, and antisocial disorders. It was hypothesized that psychiatric comorbidity would be a risk factor for psychoactive substance use disorders. Method: Findings for 120 referred adults with a clinical diagnosis ofchildhood-onset ADHD were compared with those for non-ADHD adult comparison subjects (N=268). All childhood and adult diagnoses were obtained by structured psychiatric interviews for DSM-III-R. Rı ıiiIt.ıi There was a significantly higher lifetime risk for psychoactive substance use disorders in the ADHD adults than in the comparison subjects (52% versus 27%). Although the two groups did not differ in the rate ofalcohol use disorders, the ADHD adults had significantly higher rates ofdrug and drug plus alcohol use disorders than the comparison subjects. ADHD significantly increased the risk for substance use disorders independently ofpsychiatric comorbidity. Antisocial disorders significantly increased the risk for substance use disorders independently ofADHD status. Mood and anxiety disorders increased the risk for substance use disorders in both the ADHD and comparison subjects, but more demonstrably in the comparison subjects. Conclusions: Although psychiatric comorbidity increased the risk for psychoactive substance use disorders in adults with ADHD, by itself ADHD was a significant risk factor for substance use disorders. More information is needed to further delineate risk and protective factors mediating the development of substance use disorders in persons with ADHD.
    • A Qualitative Study on Web Product Development: Based on Experiences of Professionals

      Plano, Krista A. (2011-08-01)
      The purpose of this thesis is to discuss experiences of web professionals and how these professionals interact with one another and with clients to create web products. I used relevant literature and qualitative research to present the themes that exist in the production of web products. When I began my thesis I was ans aspiring Web Project Manager with minimal experience in the digital field and decided to research the experiences of web professionals to learn about the process of creating web-based products from beginning to end. Research and interviews provided information on the steps involved in web product development: I learned that the steps are dependent on the scope of a project and the requirements of stakeholders, clients, and users. I conducted semi-structured, in-depth interviews with seven professionals and extracted themes that include making a functional team, professional roles, the merging roles of web developer and web designer, problem solving, marketing strategies, the process, team interaction, client relations, and products versus projects. Professionals discussed experiences related to team and client interaction that help define the overall development process and answer the research question, how do web professionals create web products? I learned that these steps vary and overlap depending on experiences and professional roles.
    • Rab4acontrol over metabolism and mTOR drives disease progression in Systemic Lupus Erythematosus

      Perl, Andras; Huang, Nick (2020-05-15)
      Endosomal trafficking is key to intercellular communication and metabolic regulation of immunological development. Rab4a, an endosomal trafficker, is elevated in lupus T cells and polymorphisms of the Rab4a gene have been linked to disease susceptibility. Here, we report the constitutive activation of Rab4a increases susceptibility and severity to lupus nephritis in the genetic SLE1.2.3. model of lupus and is corrected by the deletion of Rab4a in T cells. Alternatively, in a pristane model of induced autoimmunity, the deletion of Rab4a in T cells magnifies the pulmonary manifestations of diffuse alveolar hemorrhage that is otherwise protected by the constitutive activation of Rab4a. Rab4a mediates these changes through control over mTOR, mitochondrial function and homeostasis, and immunological development. In particular, inactivation of Rab4a in T cells reduces expression of activation signals, mitochondrial mass and electrochemical potential. Alterations to Rab4a activity drives the aberrant development and function of anti-inflammatory regulatory T cells and pro-inflammatory double-negative T cells. These data provide new insights into the regulation of metabolism and immunological development through endosomal trafficking. As such, the targeting of Rab4a is a novel therapeutic approach in the treatment of autoimmune diseases such as lupus, which has lacked new targeted therapeutics for more than half a century.
    • RASD2, MYH9, and CACNG2 Genes at Chromosome 22q12 Associated with the Subgroup of Schizophrenia with Non-Deficit in Sustained Attention and Executive Function

      Liu, Yu-Li; Fann, Cathy Shen-Jang; Liu, Chih-Min; Chen, Wei J.; Wu, Jer-Yuarn; Hung, Shuen-Iu; Chen, Chun-Houh; Jou, Yuh-Shan; Liu, Shi-Kai; Hwang, Tzung-Jeng; et al. (Elsevier BV, 2008-11)
      Background: In a previous linkage study of schizophrenia that included Taiwanese samples, the marker D22S278 (22q12.3) was significantly linked to schizophrenia (p .001). Methods: We conducted fine mapping of the implicated genomic region, with 47 validated single nucleotide polymorphism (SNP) markers around 1 Mb of D22S278, in a Taiwanese sample of 218 pedigrees with at least 2 siblings affected with schizophrenia. We examined the association of these SNPs and their haplotypes with schizophrenia and with subgroups defined by the presence and absence of deficits in sustained attention as assessed by undegraded and degraded continuous performance tests (CPTs). We also examined subgroups defined by deficits in categories achieved in the Wisconsin Card Sort Test (WCST). Results: Three of five candidate vulnerability genes (RASD2, APOL5, MYH9, EIF3S7, and CACNG2), which had marginally significant associations with schizophrenia, had significant associations with schizophrenic patients who did not have deficits in sustained attention on the undegraded CPT (RASD2 gene SNP rs736212; p .0008 with single locus analysis) and the degraded CPT (MYH9 gene haplotype 1-1-1-1 of SNP rs3752463 - rs1557540 - rs713839 - rs739097; p .0059 with haplotype analysis). We also found a significant association for patients who showed no deficits in executive function as measured by categories achieved in the WCST (CACNG2 gene haplotype 2-1-1-1 of SNP rs2267360 - rs140526 - rs1883987 - rs916269; p .0163 with haplotype analysis). Conclusions: The genes RASD2, MYH9, and CACNG2 might be vulnerability genes for neuropsychologically defined subgroups of schizophrenic patients.
    • Rational design of a genetically encoded fluorescent protein color switch using a modular, entropy-driven mechanism

      Loh, Stewart; John, Anna (2022-06)
      Engineered protein conformational switches have applications in cellular and in vitro biosensing, molecular diagnostics and artificial signaling systems in synthetic biology. They broadly consist of an input module and an output module that communicate via a conformational change. The overarching goal of this thesis is to tackle two major challenges in protein switch design - signal transduction, by coupling a target recognition domain to an output domain to produce a robust change in signal in addition to modularity, which allows the facile creation of sensors binding novel targets. Here, we attempted to test a rational design strategy that exploits two key protein engineering principles (1) loop entropy, by which long insertions into a loop of a host protein destabilizes the host due to an entropic cost associated with loop closure unless the inserted sequence adopts a folded structure; and (2) alternate frame folding (AFF), which allows a protein - green fluorescent protein variants(GFP), in this case - to switch between two mutually exclusive folds. Toward this goal, we first studied the effect of loop entropy at two different insertion sites in a GFP variant (chapter 2) using a well-characterized ribose binding protein as the input domain. We provide stability measurements using circular dichroism and fluorescence data to support our hypothesis of the application of the loop entropy principle in a GFP beta barrel scaffold. To provide a proof-of-concept of the combination of loop entropy and the AFF mechanism in a genetically encodable GFP scaffold, we chose an unstable, circularly permuted FK506-binding protein (cpFKBP) as the input recognition domain and inserted it in one of the two mutually exclusive folds of the GFP-AFF fusion protein (chapter 3). Upon addition of ligand, binding induced folding of the cpFKBP domain effects a conformational change in which the tenth beta strand of GFP exchanges, replacing Thr203 (green state) with Tyr203 (yellow state). We confirmed this mechanism in vitro by a ratiometric change in fluorescence output and observed that the process is slow and irreversible. We elucidate the biophysical principles underlying this mechanism by using denaturant and temperature to modulate the relative populations of the two folds in vitro. We also observed a faster and higher intensiometric response in mammalian cells which may be attributed to an alternate mechanism. We then harnessed this intensiometric response in a single fold of the fluorescent protein combined with a previously engineered monobody scaffold capable of binding a variety of targets (chapter 4). Altogether this work may have the potential to create a novel class of fluorescent protein biosensors comparable to existing single fluorescent protein-based biosensors currently available.
    • Rational Design of Protein-Based Biosensors Using Engineered Binding-Induced Conformational Switches

      Loh, Stewart; ZHENG, HUIMEI (2014)
      Biosensor development continues to be driven by the growing need to accurately detect and monitor analytes with many biotechnology, clinical, agriculture, and military applications. With their well-established capacity for molecular recognition, proteins are the go-to choice of binding elements in many conventional sensor designs. Switchable proteins offer the potential of integrating analyte binding and signal transduction within a single molecule, thus reducing the need for complex and expensive detection equipment and opening the door to miniaturization and in vivo applications. The principal challenge is that the majority of natural binding proteins do not undergo a large-scale change in conformation upon target binding. This work describes two complementary protein design strategies for the rational conversion of ordinary binding proteins into ligand induced conformational switches for biosensing purposes. In the first approach, we applied the Alternate Frame Folding (AFF) mechanism to the human sulfiredoxin (hSrx) and the fibronectin (FN3) monobody scaffold towards the creation of an ATP biosensor and a customizable biosensor platform, respectively. In a second novel approach, the Protein Fragment Exchange (FREX) mechanism was demonstrated in a proof-of principle study that converts the FN3 scaffold into a biosensor, capable of genetic encoding and application in mammalian cells. While these designs were based on well established principles of protein folding and thermodynamics, the results obtained from these studies also offer important insights regarding protein sequence-structure-function relationships.
    • Reading from an Electronic Reading Device versus Hardcopy Text

      Hue, Jennifer E. (2013-06-24)
      The use of electronic reading devices has become more prevalent. Many individuals of all ages are using personal electronic readers (e.g., Kindle, Nook, E-Reader) in place of hardcopy printed materials. Previous work in our laboratory has demonstrated that symptoms when reading from a computer screen are significantly greater than those experienced when reading printed text. Accordingly, the aim of the present study was to examine both symptoms and task performance when reading from a Kindle e-reading device, and to compare the findings with those from hardcopy, printed materials.
    • Reconstitution and Characterization of RNA Polymerase I Upstream Activating Factor.

      Knutson, Bruce; Smith, Marissa (2018)
      RNA polymerase I (Pol I) transcription of the ribosomal DNA (rDNA) is the first and one of the most critical steps in ribosome biosynthesis. Pol I transcription initiation is coordinated by four Pol I factors that include the Upstream Activating Factor (UAF), TATA-binding protein (TBP), Core Factor (CF), and Rrn3. These factors work together to recruit Pol I to the rDNApromoter and to initiate transcription.UAF is a six-subunit complex composed of Rrn9, Rrn5, Uaf30, Rrn10, and histones H3 and H4.To investigate the importance of each UAF subunit in UAF complex formation and complex integrity, we developed a recombinant Escherichia coli-based system to coexpress and purify transcriptionally active UAF complex. Here, we found that no single subunit is required for UAF assembly, including histones H3 and H4. We also demonstrate that histone H3 is able to interact with each UAF-specific subunit. Last, wedetermined the stoichiometry of the subunits of the UAF complex, revealing there are two copies of histoneH3 and one copy of the remaining UAF subunits, including histone H4. Together, our results provide a new model suggesting that UAF contains a hybrid H3–H4 tetramer-like subcomplex.The results from this thesiswill help to reveal key mechanisms in Pol Itranscription activation.
    • Redesigning Adirondack Adventures: Analyzing Crowd Culture to Develop Social Media Marketing Strategies

      McFadden, Hannah (2016-12-01)
      The purpose of this thesis is to analyze present day crowd culture to better understand consumer behaviors and engagement to help redesign the brand and marketing strategy for Adirondack Adventures, a small white water rafting business in upstate New York. With small businesses struggling to take full advantage of social media platforms and the potential they offer, consumers and potential customers are left disengaged and consequently uninterested. By researching the correlation between Web 2.0 technology and the emergence of crowd culture it is my goal to develop a social media marketing strategy for Adirondack Adventures that will help establish their brand, increase their exposure, and grow their customer base to become a top competitor in their industry.
    • REELIN SIGNALING COORDINATES DENDRITICINITIATION AND CELLULAR POSITIONING BY NEURITESTABILIZATION

      Olson, Eric; O’Dell, Ryan (2015)
      The laminar organization characteristic of the adult mammalian neocortex is a product of the precise coordination of neuronal proliferation, migration, and differentiation. Among these processes, the biological signals controlling apical dendrite initiation and targeting are not completely understood.The secreted ligand Reelin is a largeextracellular matrix glycoprotein localized to the axonal plexus of themarginal zone, and mutations areassociated with severe disruptions in cellular organization in laminated brain regions. Although the Reelin signaling pathway has been traditionally describedas a modulator of neuronal migration, recent evidence suggests Reelin controlsneuronal orientation and subsequent dendritogenesis into the overlying marginal zoneduring a period of early cortical development known as preplate splitting.To explicitly characterize how Reelin coordinates the transition between migration and dendritogenesis and controls polarized apical dendrite initiation and growth, an ex uteroexplant model of early cortical developmentwas used for fixed tissue and multiphoton live imaging analysis. Our investigations revealed the apical dendrite of cortical neurons emerges via direct transformation of the leading process during terminal translocation.Both throughoutand after this migratory phase, the dendriticarbor demonstrated significant increases in growth and branching, typically initiatedafter leading process entryinto the Reelin-rich marginal zone.In the absence of Reelin signaling, mutant cortices demonstrated a significant proportion of neurons that successfully translocated, but showed unstable arbors and marginal zone avoidance after migration arrest. Application of exogenous Reelin protein rescued dendritekinetics and polarity within4 hours, resultinginthe retraction of tangentially orienteddendritessimultaneous with the extension of a highly branched,apicallyoriented primary process. These findings suggesta precise role of Reelin signaling in early cortical development in proper neuronal polarization and stabledendrite outgrowth into the marginal zone, an area otherwiseexclusionary for dendrites. Furthermore, it is suggested that appropriate dendritic arbor elaborationinto the marginal zone may not only promote terminal translocation, but also definesthe final position of migration arrest.Thisbody of work thus offers an important advancement in understanding Reelin’s role in polarized dendritic outgrowth and the subsequent knock-on effectsassociated withperturbationsof this signaling pathway.
    • Reelin Signaling in Oligodendrocyte Progenitor Cell Migration

      Osterhout, Donna; BHATTI, HARNEET (2016)
      Oligodendroglial progenitor cells (OPCs) are the precursors to the myelinating oligodendrocytes in the central nervous system (CNS). These cells are produced in the ventral neuroepithelium at later stages of cortical development, migrating into the cortex where they contact axons and differentiate, ultimately forming a myelin membrane. During the process of differentiation, OPCs undergo significant morphological changes, extending many processes which will make contact with axons. Once in contact with an axon, the oligodendrocyte process expands and begins to form the myelin membrane which will ensheathe the axon. Reelin is a highly conserved secretory glycoprotein, which has acritical role in directing neuronal migration. Reelin orchestrates the proper cortical layer formation and neuronal organization during brain development. In the absence of Reelin, the cerebral crotex is disorganized, with inverted cortical layers, generating devastating biological effects. Reelin acts through several cellular receptors, activating numerous downstream effectors and complex signaling cascades. If elements of the Reelin signalling pathway are disrupted,similar defects in migration can occur.Oligodendroglial cells, from the early progenitor cells to the mature myelinating cells secrete Reelin, but also express a receptor for Reelin and criticalelements of the intracellular Reelin signaling pathways. It is not known if these cells canrespond to Reelin. In this thesis, we examined the effects of Reelin on oligodendroglial cells, using both in vitroand in vivomethods. We demostrate a potentialrole for Reelin in modulating oligodendrocyte migration, but also identify a novel aspect ofReelin signalling in the biology of oligodendroglia.
    • REGULATION AND FUNCTION OF TUMOR SUPPRESSOR ECRG2 IN RELATION TO DNA DAMAGE AND MICROTUBULE DYNAMICS IN HUMAN MALIGNANCIES

      Huang, Ying; Patel, Harsh (2020)
      phageal Cancer-Related Gene 2 (ECRG2) is a novel tumor suppressor which is frequently mutated or downregulated in multiple human cancers. Previous studies have demonstrated that ECRG2 inhibits growth of cancer cells by inducing apoptotic death. However, the molecular basis of its regulation and involvement in DNA damage response remain to be elucidated. The function of tumor suppressor p53 in cellular response to stress conditions, such as DNA damage, has been well-established. In the present study, we report for the first time, that ECRG2 is a novel pro-apoptotic transcriptional target of p53 and ECRG2 expression is induced by DNA damage in a p53-dependent manner. Moreover, we demonstrate that disruption of ECRG2 leads to reduced apoptosis and improved survival following the treatment with DNA damage-inducing anticancer agent despite p53 activation in cancer cells. Significantly, we characterized a natural variant in ECRG2promoter (rs3214447) that is found in the genomes of ~38.5% of world population and showed that ECRG2 promoter with rs3214447 variant is defective in responding to p53 and DNA damage. Thus, ECRG2 is an important executor of p53-mediated apoptosis in response to DNA damage. We also report a novel biological function of ECRG2 and demonstrate that ECRG2 interacts with and stabilizes microtubules. ECRG2 was shown to protect the microtubules against the destabilization induced by cold and nocodazole treatment. In addition, we show that ECRG2 increases acetylation of microtubules, which is associated with more stable microtubules. Importantly, we demonstrate that ECRG2 disruption give rise to increased cell proliferation by elevated activation of Akt. Taken together, our findings ascribe a novel function to ECRG2 in the regulation of microtubule dynamics and cancer cell proliferation. ECRG2-mediated tumor suppressor activities elucidated in this dissertation are clinically significant. Our database analyses reveal that cancer patients with lower ECRG2expression in their tumors had poor prognosis and reduced disease-free survival as compared to their counterparts. These observations suggest that loss of ECRG2 expression and function confers survival advantage to cancer cells. Collectively, this dissertation highlights novel aspects of ECRG2 regulation and function in cancer cell sensitivity to DNA damage-inducing anticancer therapy, microtubule dynamics and cell proliferation.
    • REGULATION OF CELLULAR BIOENERGETICS IN CNS DEMYELINATING DISEASE

      Massa, Paul T.; Minchenberg, Scott (2017)
      Multiple Sclerosis (MS) is a debilitating neurological disease characterized by sclerotic inflammatory demyelination of the white matter tracts in the central nervous system (CNS). There is no “cure” for MS but rather disease modifying treatments that decrease relapse rates and slow disease progression. Due to the lack of insight into the pathogenesis of MS, animal models have been developed to study demyelination in the CNS. Two widely used models of demyelination are experimental autoimmune encephalomyelitis (EAE), and Theiler’s murine encephalomyelitis virus (TMEV). Our studies focused on TMEV mediated demyelination, which was dependent on the expression of the protein tyrosine phosphate SHP-1. SHP-1 is a major negative regulator of cytokine/growth factor signaling and a global deficiency triggers an acute macrophage mediated demyelination in C3H mice. SHP-1 deficient mice are also highly susceptible to systemic inflammation and dysmyelination. Our overall goal was to identify how SHP-1 is mediating susceptibility to inflammatory demyelination. We first demonstrated that SHP-1 deficient oligodendrocytes had increased reactive oxygen species (ROS) production resulting in downregulation of myelin gene expression and oxidation of myelin, a common finding in MS patients. To determine a source of the ROS we investigated how SHP-1 controls metabolic pathways as ROS production is tightly linked to metabolism. To determine how SHP-1 impacts bioenergetics, oligodendrocyte glycolytic and mitochondrial metabolism were quantified using the Seahorse XFe96 analyzer. We determined that SHP-1 enhances oligodendrocyte metabolism, which correlates with its ability to suppress STAT1 activity in oligodendrocytes. We corroborated these results via activation of STAT1 in oligodendrocytes with the proinflammatory cytokine IFN-γ recapitulating the metabolic defects in SHP-1 deficient oligodendrocytes. Based the role of SHP-1 in oligodendrocyte bioenergetics and the importance of macrophage-derived cytokine production during demyelination; we investigated a role for SHP-1 in macrophage bioenergetics. In macrophages, enhanced glycolysis drives activation and proinflammatory cytokine production. TMEV infection specifically induced glycolysis in GM-CSF-derived macrophages lacking SHP-1. This finding may explain why SHP-1 confers susceptibility to macrophage-mediated demyelination after TMEV infection. Overall we demonstrate a novel role for SHP-1 in controlling oligodendrocyte and macrophage bioenergetics that is highly relevant in expanding our understanding of CNS demyelinating disease.