Medical Cell Biology Commons^™

A Twist To The Kirby-Bauer Disk Diffusion Susceptibility Test: An Accessible Laboratory Experiment Comparing Haloferax Volcanii And Escherichia Coli Antibiotic Susceptibility To Highlight The Unique Cell Biology Of Archaea, Heather Schiller, Criston Young, Stefan Schulze, Manuela Tripepi, Mechthild Pohlschroder

College of Life Sciences Faculty Papers

Archaea, once thought to only live in extreme environments, are present in many ecosystems, including the human microbiome, and they play important roles ranging from nutrient cycling to bioremediation. Yet this domain is often overlooked in microbiology classes and rarely included in laboratory exercises. Excluding archaea from high school and undergraduate curricula prevents students from learning the uniqueness and importance of this domain. Here, we have modified a familiar and popular microbiology experiment-the Kirby-Bauer disk diffusion antibiotic susceptibility test-to include, together with the model bacterium Escherichia coli, the model archaeon Haloferax volcanii. Students will learn the differences and similarities between …

Reactive Oxygen Species Reprogram Macrophages To Suppress Antitumor Immune Response Through The Exosomal Mir-155-5p/Pd-L1 Pathway, Xiang Li, Shaomin Wang, Wei Mu, Jennifer Barry, Anna Han, Richard L Carpenter, Bing-Hua Jiang, Stephen C Peiper, M G Mahoney, A E Aplin, Hong Ren, Jun He

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: Cancer cells have an imbalance in oxidation-reduction (redox) homeostasis. Understanding the precise mechanisms and the impact of the altered redox microenvironment on the immunologic reaction to tumors is limited.

Methods: We isolated exosomes from ovarian cancer cells through ultracentrifuge and characterized by Western-blots and Nanoparticle Tracking Analysis. 2D, 3D-coculture tumor model, and 3D live cell imaging were used to study the interactions between tumor cells, macrophages and CD3 T cells in vitro. The role of exosomal miR-155-5p in tumor growth was evaluated in xenograft nude mice models and immune-competent mice models. Flow cytometry and flow sorting were used to …

Novel Oncogenic Transcription Factor Cooperation In Rb-Deficient Cancer, Amy C. Mandigo, Ayesha A Shafi, Jennifer J Mccann, Wei Yuan, Talya Laufer, Denisa Bogdan, Lewis Gallagher, Emanuela Dylgjeri, Galina Semenova, Irina A Vasilevskaya, M J Schiewer, Chris M Mcnair, Johann S De Bono, Karen E Knudsen

Department of Cancer Biology Faculty Papers

The retinoblastoma tumor suppressor (RB) is a critical regulator of E2F-dependent transcription, controlling a multitude of protumorigenic networks including but not limited to cell-cycle control. Here, genome-wide assessment of E2F1 function after RB loss in isogenic models of prostate cancer revealed unexpected repositioning and cooperation with oncogenic transcription factors, including the major driver of disease progression, the androgen receptor (AR). Further investigation revealed that observed AR/E2F1 cooperation elicited novel transcriptional networks that promote cancer phenotypes, especially as related to evasion of cell death. These observations were reflected in assessment of human disease, indicating the clinical relevance of the AR/E2F1 cooperome …

Microbial Cell Factory Of Baccatin Iii Preparation In Escherichia Coli By Increasing Dbat Thermostability And In Vivo Acetyl-Coa Supply, Jia-Jun Huang, Tao Wei, Zhi-Wei Ye, Qian-Wang Zheng, Bing-Hua Jiang, Wen-Feng Han, An-Qi Ye, Pei-Yun Han, Li-Qiong Guo, Jun-Fang Lin

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Given the rapid development of genome mining in this decade, the substrate channel of paclitaxel might be identified in the near future. A robust microbial cell factory with gene dbat, encoding a key rate-limiting enzyme 10-deacetylbaccatin III-10-O-transferase (DBAT) in paclitaxel biosynthesis to synthesize the precursor baccatin III, will lay out a promising foundation for paclitaxel de novo synthesis. Here, we integrated gene dbat into the wild-type Escherichia coli BW25113 to construct strain BWD01. Yet, it was relatively unstable in baccatin III synthesis. Mutant gene dbat S189V with improved thermostability was screened out from a semi-rational mutation library …

Opa1 Modulates Mitochondrial Ca 2+ Uptake Through Er-Mitochondria Coupling, Benjamín Cartes-Saavedra, Josefa Macuada, Daniel Lagos, Duxan Arancibia, María E Andrés, Patrick Yu-Wai-Man, György Hajnóczky, Verónica Eisner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Autosomal Dominant Optic Atrophy (ADOA), a disease that causes blindness and other neurological disorders, is linked to OPA1 mutations. OPA1, dependent on its GTPase and GED domains, governs inner mitochondrial membrane (IMM) fusion and cristae organization, which are central to oxidative metabolism. Mitochondrial dynamics and IMM organization have also been implicated in Ca2+ homeostasis and signaling but the specific involvements of OPA1 in Ca2+ dynamics remain to be established. Here we studied the possible outcomes of OPA1 and its ADOA-linked mutations in Ca2+ homeostasis using rescue and overexpression strategies in Opa1-deficient and wild-type murine embryonic fibroblasts (MEFs), respectively and in …

Extracellular Mechanotransduction, Stephen J. Haller, Andrew T. Dudley

Journal Articles: Genetics, Cell Biology & Anatomy

We highlight the force-sensing function of extracellular matrix and present a complementary mechanotransduction paradigm.

Mintruls: Prediction Of Mirna-Mrna Target Site Interactions Using Regularized Least Square Method, Sushil Kumar Shakyawar, Siddesh Southekal, Chittibabu Guda

Journal Articles: Genetics, Cell Biology & Anatomy

Identification of miRNA-mRNA interactions is critical to understand the new paradigms in gene regulation. Existing methods show suboptimal performance owing to inappropriate feature selection and limited integration of intuitive biological features of both miRNAs and mRNAs. The present regularized least square-based method, mintRULS, employs features of miRNAs and their target sites using pairwise similarity metrics based on free energy, sequence and repeat identities, and target site accessibility to predict miRNA-target site interactions. We hypothesized that miRNAs sharing similar structural and functional features are more likely to target the same mRNA, and conversely, mRNAs with similar features can be targeted by …

Phytochemical Constituents Of Aquilaria Malaccensis Leaf Extract And Their Anti-Inflammatory Activity Against Lps/Ifn-Γ-Stimulated Raw 264.7 Cell Line, Eman Ramadan, Manar A. Eissa, Yumi Z. H-Y Hashim, Dina M. El-Kersh

Pharmacy

This study aims to identify the major phytochemical constituents in Aquilaria malaccensis (Thymelaeaceae) ethanolic leaf extract (ALEX-M) and elucidate their ability to suppress nitric oxide (NO) production from a murine macrophage-like cell line (RAW 264.7) stimulated by lipopolysaccharide (LPS) and interferon-γ (IFN-γ). Dichloromethane (DCM) and ethyl acetate (EtOAc) fractions of ALEX-M were subjected to column chromatography. Eight known compounds were isolated for the first time from this species. Compounds were identified using spectroscopic techniques (IR, UV, HRESIMS, and 1D and 2D NMR). Anti-inflammatory activity of both extract and isolated compounds were investigated in vitro. The fractions offered the isolation of …

Extracellular Matrix Guidance Of Autophagy: A Mechanism Regulating Cancer Growth, Carolyn Chen, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The extracellular matrix (ECM) exists as a dynamic network of biophysical and biochemical factors that maintain tissue homeostasis. Given its sensitivity to changes in the intra- and extracellular space, the plasticity of the ECM can be pathological in driving disease through aberrant matrix remodelling. In particular, cancer uses the matrix for its proliferation, angiogenesis, cellular reprogramming and metastatic spread. An emerging field of matrix biology focuses on proteoglycans that regulate autophagy, an intracellular process that plays both critical and contextual roles in cancer. Here, we review the most prominent autophagic modulators from the matrix and the current understanding of the …

Monitoring The Systemic Immune System To Understand And Improve The Efficacy Of Immunotherapy For Metastatic Osteosarcoma, Justin Edward Markel

Graduate Theses, Dissertations, and Problem Reports

Osteosarcoma (OS) is a complex tumor with no effective targeted therapies due to its genomic heterogeneity and pleomorphism. The immune response it creates, particularly against metastatic lesions, is considerable; however, various suppressive mechanisms induced by the tumor prohibit its effectiveness. The presence of infiltrating lymphocytes suggests that therapeutic disinhibition through checkpoint blockade could increase antitumor immunity, though none have been successful in clinical trials. The complexities of the immune response to OS tumors have yet to be unraveled; however, there is evidence to suggest that cell-mediated immunity (CMI, specifically T cells, Natural Killer [NK] cells, and myeloid-lineage cells [MLCs]) plays …

Regulation Of The Protease Activity For The Mitochondrial Omi/Htra2, Simon Larson

Honors Undergraduate Theses

Human High Temperature requirement A2 (HtrA2) also known as Omi, is a serine protease located in the mitochondria with an important function in both cell survival and death. My results show the proteolytic activity of Omi/HtrA2 varies under different conditions. I characterized the optimal condition for Omi/HtrA2 protease activity using an in vitro assay system. Additionally, I identified a new allosteric regulation of Omi/HtrA2 through interaction with a specific substrate, the MUL1 protein. MUL1 is a multifunctional E3 ubiquitin ligase anchored in the outer mitochondrial membrane with domains both inside mitochondria and in the cytoplasm. The data shown here strongly …

Crosstalk Between Hippo And Rb Tumour Suppressor Pathways In Ovarian Cancer, Fatmata Sesay

Theses and Dissertations

The cell cycle is a highly regulated process that ensures the timely and accurate division of cells. Events of the normal cell cycle fall under two categories - positive and negative regulatory mechanisms. The first category, positive regulatory machinery, includes active protein complexes of cyclins in association with their partnering cyclin-dependent kinases (cyclin/CDK), which mediate series of phosphorylation events that relay a cell cycle progression from one stage to the next. The second category, the negative regulatory mechanisms, include the checkpoint controls consisting of the retinoblastoma (RB) family of proteins, some of which can form a transcriptional repressor complex DREAM. …

The Effect Of Creatine On Immortalized Schwann Cell Proliferation, Peyton Kimmel, Caitlyn Henry, Angela Asirvatham

Student Research Poster Presentations 2022

Creatine is an important component of the high-energy phosphate transfer to regulate cellular levels of ATP. The functions of creatine supplementation are well studied in the muscular and skeletal system, however the impact of creatine in the nervous system, specifically Schwann cells, is relatively unknown. Schwann cell growth in vitro is facilitated by heregulin, a neuron secreted growth factor, and forskolin, a pharmacological agent that activates cAMP. In peripheral nervous system injuries, recovery time is based around Schwann cell’s ability to proliferate and differentiate, and it is unknown what role creatine plays in this process. It was hypothesized that increasing …

Anthracyclines Attenuate The Nrf1-Mediated Bounce-Back Response, Bader Albalawi

Theses and Dissertations

Proteasome inhibitors, such as carfilzomib, are FDA-approved to treat multiple myeloma and mantle cell lymphoma. Unfortunately, proteasome inhibitors have only produced clinically significant results in patients with hematologic cancers, despite their predicted pan-cancer utility, and even hematologic cancer types frequently show intrinsic and acquired resistance.

One proposed mechanism responsible for the proteasome inhibitors' shortcomings is the NRF1-mediated bounce-back response. Identification of drugs that can potentiate the action of proteasome inhibitors could overcome resistance in patients with hematologic cancers and expand proteasome inhibitors' use to treat solid tumors. Our previous studies have identified anthracyclines as potential compounds that interfere with the …

Barriers And Facilitators Of Availability Of Hydroxyurea For Sickle Cell Disease In Tanzania; A Qualitative Study Of Pharmaceutical Manufacturers, Importers, And Regulators, Hamu J. Mlyuka, Manase Kilonzi, Ritah F. Mutagonda, Lulu Chirande, Wigilya P. Mikomangwa, David T. Myemba, Godfrey Sambayi, Dorkasi L. Mwakawanga, Joyce Ndunguru, Paschal Ruggajo

Internal Medicine, East Africa

Despite three decades of proven safety and effectiveness of hydroxyurea in modifying sickle cell disease (SCD), its accessibility is limited in Sub-Saharan Africa, which shares 75% of the world’s SCD burden. Therefore, it is time to explore the barriers and facilitators for manufacturing and importation of hydroxyurea for SCD in Tanzania. This was qualitative research that employed a case study approach. Purposive sampling followed by an in-depth interview (IDI) using a semi-structured questionnaire aspired by data saturation enabled us to gather data from 10 participants. The study participants were people with more than three years of experience in pharmaceuticals importation, …

Comparative Analysis Of Gene Expression Patterns For Oral Epithelial Cell Functions In Periodontitis, Octavio A Gonzalez, Sreenatha Kirakodu, Linh M Nguyen, Luis Orraca, Michael J Novak, Janis Gonzalez-Martinez, Jeffrey L Ebersole

Journal Articles

The structure and function of epithelial cells are critical for the construction and maintenance of intact epithelial surfaces throughout the body. Beyond the mechanical barrier functions, epithelial cells have been identified as active participants in providing warning signals to the host immune and inflammatory cells and in communicating various detailed information on the noxious challenge to help drive specificity in the characteristics of the host response related to health or pathologic inflammation. Rhesus monkeys were used in these studies to evaluate the gingival transcriptome for naturally occurring disease samples (GeneChip® Rhesus Macaque Genome Array) or for ligature-induced disease (GeneChip® Rhesus …

Uveitis-Mediated Immune Cell Invasion Through The Extracellular Matrix Of The Lens Capsule, Jodirae Dedreu, Sonali Pal-Ghosh, Mary J Mattapallil, Rachel R Caspi, Mary Ann Stepp, A Sue Menko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

While the eye is considered an immune privileged site, its privilege is abrogated when immune cells are recruited from the surrounding vasculature in response to trauma, infection, aging, and autoimmune diseases like uveitis. Here, we investigate whether in uveitis immune cells become associated with the lens capsule and compromise its privilege in studies of C57BL/6J mice with experimental autoimmune uveitis. These studies show that at D14, the peak of uveitis in these mice, T cells, macrophages, and Ly6G/Ly6C+ immune cells associate with the lens basement membrane capsule, burrow into the capsule matrix, and remain integrated with the capsule as immune …

Interferon Gamma Release Assay Mitogen Responses In Covid-19, Dagan Coppock, Claire E. Zurlo, Jenna M. Meloni, Sara L. Goss, John J. Zurlo, Matthew A. Pettengill

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background

Elevated cytokine release and T cell exhaustion have been associated with COVID-19 disease severity. T cell activity may be indirectly measured through interferon gamma release assays (IGRAs), which use mitogen stimulation of T lymphocytes as a positive control. In our institution, an unexpectedly high rate of indeterminate IGRAs was noted in COVID-19–positive patients. We aimed to evaluate the clinical characteristics associated with indeterminate IGRA results and the difference in mitogen responses between COVID-19–positive and COVID-19–negative patients.

Methods

We reviewed all patients, regardless of COVID status, who were admitted between March 1, 2020, and May 31, 2020, and for whom …

Sox10 Requirement For Melanoma Tumor Growth Is Due, In Part, To Immune-Mediated Effects, Sheera Rosenbaum, Manoela Tiago, Signe Caksa, Claudia Capparelli, Timothy J. Purwin, Gaurav Kumar, Mckenna Glasheen, Danielle Pomante, Daniel Kotas, I Chervoneva, A E Aplin

Department of Cancer Biology Faculty Papers

Developmental factors may regulate the expression of immune modulatory proteins in cancer, linking embryonic development and cancer cell immune evasion. This is particularly relevant in melanoma because immune checkpoint inhibitors are commonly used in the clinic. SRY-box transcription factor 10 (SOX10) mediates neural crest development and is required for melanoma cell growth. In this study, we investigate immune-related targets of SOX10 and observe positive regulation of herpesvirus entry mediator (HVEM) and carcinoembryonic-antigen cell-adhesion molecule 1 (CEACAM1). Sox10 knockout reduces tumor growth in vivo, and this effect is exacerbated in immune-competent models. Modulation of CEACAM1 expression but not HVEM elicits modest …

Atrx Inactivation And Idh1-R132h Drive Preferential Sensitivity To Proton Vs. X-Ray Radiotherapy In Glioma Stem Cells, Ángel Adrián Garcés

Dissertations & Theses (Open Access)

Background: Glioma Stem Cells (GSCs) are self-renewable, treatment resistant cells in the glioma tumor mass known to promote tumor development. In contrast to traditional photon-based radiation therapy (XRT), proton radiation therapy (PRT) may induce more complex DNA damage and therefore might have the potential to eliminate GSCs. Although previous studies have individually linked IDH mutations, specifically IDH1^R132H, and ATRX inactivating mutations to improved patient outcomes and suppressed DNA damage repair compared to their respective wild-types, the mechanisms by which these two genetic alterations interact in GSCs treated with PRT compared to XRT are currently unknown. We hypothesize that …