Biological Phenomena, Cell Phenomena, and Immunity Commons^™

Cells And Networks In Flux: Rethinking Ontogenesis And Pathogenesis, Mark L. Tykocinski

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Organ and tissue functions emerge from the coordinated activity of cell networks. Therapeutics that act on pathogenic cell networks, modulating their cellular interplay, follow naturally. Over several decades, our laboratory has developed a series of approaches for rewiring cell networks, culminating in a class of cell surface-directed signal converter proteins (SCPs) that do so by modulating juxtacrine and autocrine signaling in and among their nodal cells. A first such SCP has now produced encouraging clinical data for cancer immunotherapy. Yet, these early network-directed fusion proteins rest on a deliberately simplified picture: discrete end-cell types plugged into graphically tractable networks. That …

Mitochondria-Er Contact Sites (Mercs) In The Cell Cycle: Molecular Architecture And Functional Remodeling Across Cellular States, Eduardo Silva-Pavez, Bruno Torres-Gonzalez, Michelle Sotomayor, Benjamín Cartes-Saavedra, Dorian V. Ziegler, Yessia Hidalgo-Fadic, Ulises Ahumada-Castro

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondria–endoplasmic reticulum (ER) contact sites (MERCS) are nanoscopic, dynamic platforms integrating metabolism, signaling, and stress responses to regulate cell fate. These nanoscopic interfaces remodel continuously to meet the demands of proliferating, quiescent, and senescent cells. We synthesize evidence that MERCS actively coordinate local Ca2+ signaling, non-vesicular lipid transfer, and proteostasis to shape mitochondrial function and cellular homeostasis. We discuss how MERCS architecture changes across the cell cycle and during arrest, distinguishing adaptive from maladaptive remodeling, and consider therapeutic potential in aging and age-related disease.

Distinct Transcriptional Regulation Of The Wnt And Tgfβ Signaling Families Associated With Wound Healing And Fibrotic Outcomes To Lens Injury, Catherine Lalman, Kylie R. Stabler, Joshua Disatham, Lisa A. Brennan, Marc Kantorow, Janice L. Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Posterior capsule opacification (PCO) is a fibrotic complication of cataract surgery caused by aberrant repair of residual lens cells. It remains unclear how the lens injury response shifts toward a pathological repair process. Here, we performed a transcriptional analysis of two major pro-fibrotic pathways, the TGF-β superfamily and Wnt signaling pathways to determine how they are differentially regulated during regenerative wound healing versus fibrosis in a lens injury model. For these studies, RNA sequencing was performed on an ex vivo lens explant system that models post-surgical healing within regenerative and fibrotic microenvironments, from 0 to 3 days post-injury. Fibrotic conditions …

Astrocytes Expressing Mutant Hnrnpa1 Induce Non-Cell-Autonomous Motor Neuron Death, Qinxue Wu, Xionghao Liu, Tingting Zhang, Shiquan Cui, Bo Huang, Cao Huang, Qilin Cao, Xu-Gang Xia, Hongxia Zhou

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Pathogenic mutation of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) is causative to amyotrophic lateral sclerosis (ALS). Neuron death resulting from pathogenic hnRNPA1 may not require its presence across all pertinent cells types, including neurons, glia, and muscles. Rather, the exclusive presence of pathogenic hnRNPA1 in a specific cell type, such as astrocytes, may suffice to substantially alter cellular functions. Consequently, this alteration initiates abnormal interaction within intricate neuron-glia networks, culminating in non-cell-autonomous motor neuron death. To investigate the pivotal role of non-cell-autonomous neuron death in hnRNPA1-associated ALS, we developed transgenic rats overexpressing mutant hnRNPA1 in specifically astrocytes. The confined overexpression of …

Neovascular Pruning By Ido1 Inhibitors Can Potentiate Immunogenic Cytotoxicity Of Ischemia-Targeted Agents To Synergistically Enhance Anti-Pd-1 Responsiveness, Shih-Chun Shen, Souvik Dey, James B. Duhadaway, Erika Sutanto-Ward, Maurice T. Hampton, Serguei V. Kozlov, George C. Prendergast, Alexander J. Muller

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Strategies for deploying indoleamine 2,3-dioxygenase 1 (IDO1)-targeted therapies for use against cancer have focused on IDO1's role in promoting peripheral immune tolerance that shields tumors from effector T cells. However, preclinical investigation of both primary and metastatic tumor development in the lungs has uncovered a previously unappreciated role for IDO1 in directing a counterregulatory response to interferon (IFN)-γ that realigns the local inflammatory environment to promote tumor neovascularization. Understanding how to therapeutically leverage the ability of IDO1 inhibitors to subvert inflammatory neovascularization within the tumor microenvironment has potential ramifications for future clinical development of these compounds.

METHODS: Pulmonary metastases …

Potential Role Of Csf Cytokine Profiles In Discriminating Infectious From Non-Infectious Cns Disorders., Danielle Fortuna, D. Craig Hooper, Amity L. Roberts, Larry A. Harshyne, Michelle Nagurney, Mark T. Curtis

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Current laboratory testing of cerebrospinal fluid (CSF) does not consistently discriminate between different central nervous system (CNS) disease states. Rapidly distinguishing CNS infections from other brain and spinal cord disorders that share a similar clinical presentation is critical. New approaches focusing on aspects of disease biology, such as immune response profiles that can have stimulus-specific attributes, may be helpful. We undertook this preliminary proof-of-concept study using multiplex ELISA to measure CSF cytokine levels in various CNS disorders (infections, autoimmune/demyelinating diseases, lymphomas, and gliomas) to determine the potential utility of cytokine patterns in differentiating CNS infections from other CNS diseases. Both …

A Simple And Accurate Rule-Based Modeling Framework For Simulation Of Autocrine/Paracrine Stimulation Of Glioblastoma Cell Motility And Proliferation By L1cam In 2-D Culture., Justin Caccavale, David Fiumara, Michael Stapf, Liedeke Sweitzer, Hannah J. Anderson, Jonathan Gorky, Prasad Dhurjati, Deni S. Galileo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Glioblastoma multiforme (GBM) is a devastating brain cancer for which there is no known cure. Its malignancy is due to rapid cell division along with high motility and invasiveness of cells into the brain tissue. Simple 2-dimensional laboratory assays (e.g., a scratch assay) commonly are used to measure the effects of various experimental perturbations, such as treatment with chemical inhibitors. Several mathematical models have been developed to aid the understanding of the motile behavior and proliferation of GBM cells. However, many are mathematically complicated, look at multiple interdependent phenomena, and/or use modeling software not freely available to the research …

Positional Information Generated By Spatially Distributed Signaling Cascades., Javier Muñoz-García, Zoltan Neufeld, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile …

Smc3 Knockdown Triggers Genomic Instability And P53-Dependent Apoptosis In Human And Zebrafish Cells., Giancarlo Ghiselli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The structural maintenance of chromosome 3 (SMC3) protein is a constituent of a number of nuclear multimeric protein complexes that are involved in DNA recombination and repair in addition to chromosomal segregation. Overexpression of SMC3 activates a tumorigenic cascade through which mammalian cells acquire a transformed phenotype. This has led us to examine in depth how SMC3 level affects cell growth and genomic stability. In this paper the effect of SMC3 knockdown has been investigated. RESULTS: Mammalian cells that are SMC3 deficient fail to expand in a clonal population. In order to shed light on the underlying mechanism, experiments …

The Use Of Time-Resolved Fluorescence Imaging In The Study Of Protein Kinase C Localisation In Cells., Christopher D Stubbs, Stanley W Botchway, Simon J Slater, Anthony W Parker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Two-photon-excitation fluorescence lifetime imaging (2P-FLIM) was used to investigate the association of protein kinase C alpha (PKCalpha) with caveolin in CHO cells. PKCalpha is found widely in the cytoplasm and nucleus in most cells. Upon activation, as a result of increased intracellular Ca2+ and production of DAG, through G-protein coupled-phospholipase C signalling, PKC translocates to a variety of regions in the cell where it phosphorylates and interacts with many signalling pathways. Due to its wide distribution, discerning a particular interaction from others within the cell is extremely difficult. RESULTS: Fluorescence energy transfer (FRET), between GFP-PKCalpha and DsRed-caveolin, was used …

Hinderin, A Five-Domains Protein Including Coiled-Coil Motifs That Binds To Smc3., Chirag A Patel, Giancarlo Ghiselli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The structural maintenance of chromosome proteins SMC1 and SMC3 play an important role in the maintenance of chromosomal integrity by preventing the premature separation of the sister chromatids at the onset of anaphase. The two proteins are constitutive components of the multimeric complex cohesin and form dimers by interacting at their central globular regions. RESULTS: In order to identify proteins that by binding to SMC3 may interfere with the protein dimerization process, a human cDNA library was screened by the yeast two-hybrid system by using the hinge region of SMC3 as bait. This has lead to the identification of …