Medicine and Health Sciences Commons^™

Identification Of Dual Strn-Ntrk2 Rearrangements In A High Grade Sarcoma, With Good Clinical Response To First-Line Larotrectinib Therapy, Ruihe Lin, Atrayee Basu Mallick, Zi-Xuan Wang, Phd, Scot Andrew Brown, Bo Lu, Md, Wei Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Among the three NTRK genes, NTRK2 possesses a tremendous structural complexity and involves tumorigenesis of several types of tumors. To date, only STRN and RBPMS are identified in the fusion with NTRK2 in adult soft tissue tumors. More recently, the highly selective Trk tyrosine kinases inhibitors, including larotrectinib and entrectinib, have shown significant efficacy for treating tumors harboring NTRK fusions and were approved by FDA.

CASE PRESENTATION: We report a case of sarcoma in a 35-year-old female harboring two STRN-NTRK2 gene fusions, with a good clinical response to first-line larotrectinib treatment. Core biopsy of the 16.5 cm gluteal mass …

Sexual Dimorphism In Bidirectional Sr-Mitochondria Crosstalk In Ventricular Cardiomyocytes, Richard T Clements, Radmila Terentyeva, Shanna Hamilton, Paul M L Janssen, Karim Roder, Benjamin Y Martin, Fruzsina Perger, Timothy G Schneider, Zuzana Nichtova, Anindhya S Das, Roland Veress, Beth S Lee, Do-Gyoon Kim, Gideon Koren, Matthew S Stratton, György Csordás, Federica Accornero, Andriy E Belevych, Sandor Gyorke, Dmitry Terentyev

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Calcium transfer into the mitochondrial matrix during sarcoplasmic reticulum (SR) Ca²⁺ release is essential to boost energy production in ventricular cardiomyocytes (VCMs) and match increased metabolic demand. Mitochondria from female hearts exhibit lower mito-[Ca²⁺] and produce less reactive oxygen species (ROS) compared to males, without change in respiration capacity. We hypothesized that in female VCMs, more efficient electron transport chain (ETC) organization into supercomplexes offsets the deficit in mito-Ca²⁺ accumulation, thereby reducing ROS production and stress-induced intracellular Ca²⁺ mishandling. Experiments using mitochondria-targeted biosensors confirmed lower mito-ROS and mito-[Ca²⁺] in female rat VCMs challenged …

Micu1 Occludes The Mitochondrial Calcium Uniporter In Divalent-Free Conditions, Macarena Rodríguez-Prados, Elena Berezhnaya, Maria Teresa Castromonte, Sergio L. Menezes-Filho, Melanie Paillard, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial Ca2+ uptake is mediated by the mitochondrial uniporter complex (mtCU) that includes a tetramer of the pore-forming subunit, MCU, a scaffold protein, EMRE, and the EF-hand regulatory subunit, MICU1 either homodimerized or heterodimerized with MICU2/3. MICU1 has been proposed to regulate Ca2+ uptake via the mtCU by physically occluding the pore and preventing Ca2+ flux at resting cytoplasmic [Ca2+] (free calcium concentration) and to increase Ca2+ flux at high [Ca2+] due to cooperative activation of MICUs EF-hands. However, mtCU and MICU1 functioning when its EF-hands are unoccupied by Ca2+ is poorly studied due to technical limitations. To overcome this …

Corneal Injury Is Associated With Stromal And Vascular Alterations Within Cranial Dura Mater, Olga V. Glinskii, Vladislav V. Glinsky, Leike Xie, Filiz Bunyak, Vladimir V. Glinskii, Sunilima Sinha, Suneel Gupta, Renato V. Iozzo, Rajiv R. Mohan

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The cornea and cranial dura mater share sensory innervation. This link raises the possibility that pathological impulses mediated by corneal injury may be transmitted to the cranial dura, trigger dural perivascular/connective tissue nociceptor responses, and induce vascular and stromal alterations affecting dura mater blood and lymphatic vessel functionality. In this study, using a mouse model, we demonstrate for the first time that two weeks after the initial insult, alkaline injury to the cornea leads to remote pathological changes within the coronal suture area of the dura mater. Specifically, we detected significant pro-fibrotic changes in the dural stroma, as well as …

Transcriptomic Changes Predict Metabolic Alterations In Lc3 Associated Phagocytosis In Aged Mice, Anuradha Dhingra, John W. Tobias, Nancy J. Philp, Kathleen Boesze-Battaglia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

LC3b (Map1lc3b) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b to promote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes, such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells, utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis, and neuroprotection. In a mouse model of retinal lipid steatosis-mice lacking LC3b (LC3b−/−), we observed increased lipid deposition, metabolic dysregulation, …

Opa1 Disease-Causing Mutants Have Domain-Specific Effects On Mitochondrial Ultrastructure And Fusion, Benjamín Cartes-Saavedra, Daniel Lagos, Josefa Macuada, Duxan Arancibia, Florence Burté, Marcela K. Sjöberg-Herrera, María Estela Andrés, Rita Horvath, Patrick Yu-Wai-Man, György Hajnóczky, Verónica Eisner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Inner mitochondrial membrane fusion and cristae shape depend on optic atrophy protein 1, OPA1. Mutations in OPA1 lead to autosomal dominant optic atrophy (ADOA), an important cause of inherited blindness. The Guanosin Triphosphatase (GTPase) and GTPase effector domains (GEDs) of OPA1 are essential for mitochondrial fusion; yet, their specific roles remain elusive. Intriguingly, patients carrying OPA1 GTPase mutations have a higher risk of developing more severe multisystemic symptoms in addition to optic atrophy, suggesting pathogenic contributions for the GTPase and GED domains, respectively. We studied OPA1 GTPase and GED mutations to understand their domain-specific contribution to protein function by analyzing …

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain …

Supporting A Culture Of Patient Safety: Resident-Led Patient Safety Event Reviews In A Pathology Residency Training Program, Catherine Tucker, Rebecca C. Jaffe,, Allison F Goldberg

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Patient safety is a critical component of quality patient care at any healthcare institution. In order to support a culture of patient safety, and in the context of a hospital-wide patient safety initiative at our institution, we have created and implemented a new patient safety curriculum within our training program. The curriculum is embedded in an introductory course for first-year residents, in which residents gain an understanding of the multifaceted role of the pathologist in patient care. The patient safety curriculum is a resident-centered event review process and includes 1) identification and reporting of a patient safety event, 2) event …

Estimated Impact Of Low Isolate Numbers On The Reliability Of Cumulative Antibiogram Data, Christian Tran, John Hargy, Bryan Hess, Matthew Pettengill

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Antibiograms are cumulative reports of antimicrobial susceptibility results that are used to guide the selection of empirical antibiotic therapy. Although Clinical and Laboratory Standards Institute (CLSI) guidelines recommend including only organisms that have at least 30 isolates in an antibiogram, previous studies demonstrated that adherence to this recommendation is highly variable. This paper aims to model the impact of small sample sizes on expected levels of error in cumulative antibiograms by comparing percent susceptibility results for random samples to those of the larger, entire data set. The results demonstrate relatively high error rates when utilizing low numbers of isolates in …

Complexity Of Progranulin Mechanisms Of Action In Mesothelioma, Elisa Ventura, Christopher Xie, Simone Buraschi, Antonino Belfiore, Renato V. Iozzo, Antonio Giordano, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: Mesothelioma is an aggressive disease with limited therapeutic options. The growth factor progranulin plays a critical role in several cancer models, where it regulates tumor initiation and progression. Recent data from our laboratories have demonstrated that progranulin and its receptor, EphA2, constitute an oncogenic pathway in bladder cancer by promoting motility, invasion and in vivo tumor formation. Progranulin and EphA2 are expressed in mesothelioma cells but their mechanisms of action are not well defined. In addition, there are no data establishing whether the progranulin/EphA2 axis is tumorigenic for mesothelioma cells.

Methods: The expression of progranulin in various mesothelioma cell …

Data Supporting The Roles Of Bap1, Sting, And Ifn-Β In Isgf3 Activation In Ccrcc, Lauren E Langbein, Eleonora Sementino, Zhijiu Zhong, Wei Jiang, Li Li, Joseph R Testa, Haifeng Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The data presented in this article are companion materials to our manuscript titled "BAP1 maintains HIF-dependent interferon beta induction to suppress tumor growth in clear cell renal cell carcinoma" (Langbein et al., 2022), where we investigated the downstream effects of BAP1 (BRCA1-associated protein 1) expression in clear cell renal cell carcinoma (ccRCC) cell lines and mouse xenograft models. In the manuscript, we showed that BAP1 upregulates STING (stimulator of interferon genes) expression and activity in ccRCC cells, leading to IFN-β transcription and activation of interferon stimulated gene factor 3 (ISGF3), the transcription factor that mediates the effects of type I …

Altered Expression Of Glycobiology-Related Genes In Parkinson’S Disease Brain, Jay S Schneider, Garima Singh

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The precise mechanisms initiating and perpetuating the cellular degeneration in Parkinson's disease (PD) remain unclear. There is decreased expression of the main brain gangliosides, and GM1 ganglioside in particular, in the PD brain along with decreased expression of the genes coding for the glycosyltranferase and the sialyltransferase responsible for the synthesis of these brain gangliosides. However, potentially important pathogenic mechanisms contributing to the neurodegeneration in PD may also include altered levels of expression of genes involved in glycosylation, sialylation and sphingolipid synthesis and metabolism. Although various studies have described pathological lipid and glycolipid changes in PD brain, there have been …

Genome-Scale Metabolic Modeling Reveals Sequential Dysregulation Of Glutathione Metabolism In Livers From Patients With Alcoholic Hepatitis, Alexandra Manchel, Radhakrishnan Mahadevan, Ramon Bataller, Jan B. Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Alcoholic hepatitis (AH) is the most severe form of alcoholic liver disease for which there is no efficacious treatment aiding most patients. AH manifests differently in individuals, with some patients showing debilitating symptoms more so than others. Previous studies showed significant metabolic dysregulation associated with AH. Therefore, we sought to analyze how the activity of metabolic pathways differed in the liver of patients with varying degrees of AH severity. We utilized a genome-scale metabolic modeling approach that allowed for integration of a generic human cellular metabolic model with specific RNA-seq data corresponding to healthy and multiple liver disease states to …

Capture At The Er-Mitochondrial Contacts Licenses Ip, Máté Katona, Ádám Bartók, Zuzana Nichtova, György Csordás, Elena Berezhnaya, David Weaver, Arijita Ghosh, Péter Várnai, David I. Yule, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Endoplasmic reticulum-mitochondria contacts (ERMCs) are restructured in response to changes in cell state. While this restructuring has been implicated as a cause or consequence of pathology in numerous systems, the underlying molecular dynamics are poorly understood. Here, we show means to visualize the capture of motile IP3 receptors (IP3Rs) at ERMCs and document the immediate consequences for calcium signaling and metabolism. IP3Rs are of particular interest because their presence provides a scaffold for ERMCs that mediate local calcium signaling, and their function outside of ERMCs depends on their motility. Unexpectedly, in a cell model with little ERMC Ca2+ coupling, IP3Rs …

Pi3k Isoform-Specific Regulation Of Leader And Follower Cell Function For Collective Migration And Proliferation In Response To Injury, Morgan D Basta, A. Menko, Janice L Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

To ensure proper wound healing it is important to elucidate the signaling cues that coordinate leader and follower cell behavior to promote collective migration and proliferation for wound healing in response to injury. Using an ex vivo post-cataract surgery wound healing model we investigated the role of class I phosphatidylinositol-3-kinase (PI3K) isoforms in this process. Our findings revealed a specific role for p110α signaling independent of Akt for promoting the collective migration and proliferation of the epithelium for wound closure. In addition, we found an important role for p110α signaling in orchestrating proper polarized cytoskeletal organization within both leader and …

Bap1 Maintains Hif-Dependent Interferon Beta Induction To Suppress Tumor Growth In Clear Cell Renal Cell Carcinoma., Lauren Langbein, Rayan El Hajjar, Shen He, Eleonora Sementino, Zhijiu Zhong, Wei Jiang, Benjamin E Leiby, Li Li, Robert G Uzzo, Joseph R Testa, Haifeng Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BRCA1-associated protein 1 (BAP1) is a deubiquitinase that is mutated in 10-15% of clear cell renal cell carcinomas (ccRCC). Despite the association between BAP1 loss and poor clinical outcome, the critical tumor suppressor function(s) of BAP1 in ccRCC remains unclear. Previously, we found that hypoxia-inducible factor 2α (HIF2α) and BAP1 activate interferon-stimulated gene factor 3 (ISGF3), a transcription factor activated by type I interferons and a tumor suppressor in ccRCC xenograft models. Here, we aimed to determine the mechanism(s) through which HIF and BAP1 regulate ISGF3. We found that in ccRCC cells, loss of the von Hippel-Lindau tumor suppressor (VHL) …

Unreliable Automated Complete Blood Count Results: Causes, Recognition, And Resolution, Gene Gulati, Guldeep Uppal, Jerald Z. Gong

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Automated hematology analyzers generate accurate complete blood counts (CBC) results on nearly all specimens. However, every laboratory encounters, at times, some specimens that yield no or inaccurate result(s) for one or more CBC parameters even when the analyzer is functioning properly and the manufacturer's instructions are followed to the letter. Inaccurate results, which may adversely affect patient care, are clinically unreliable and require the attention of laboratory professionals. Laboratory professionals must recognize unreliable results, determine the possible cause(s), and be acquainted with the ways to obtain reliable results on such specimens. We present a concise overview of the known causes …

Glucose Uptake By Glut1 In Photoreceptors Is Essential For Outer Segment Renewal And Rod Photoreceptor Survival, Lauren L. Daniele, John Y.S. Han, Ivy S Samuels, Ravikiran Komirisetty, Nikhil Mehta, Jessica L Mccord, Minzhong Yu, Yekai Wang, Kathleen Boesze-Battaglia, Brent A Bell, Jianhai Du, Neal S Peachey, Nancy J. Philp

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Photoreceptors consume glucose supplied by the choriocapillaris to support phototransduction and outer segment (OS) renewal. Reduced glucose supply underlies photoreceptor cell death in inherited retinal degeneration and age-related retinal disease. We have previously shown that restricting glucose transport into the outer retina by conditional deletion of Slc2a1 encoding GLUT1 resulted in photoreceptor loss and impaired OS renewal. However, retinal neurons, glia, and the retinal pigment epithelium play specialized, synergistic roles in metabolite supply and exchange, and the cell-specific map of glucose uptake and utilization in the retina is incomplete. In these studies, we conditionally deleted Slc2a1 in a pan-retinal or …

Patient With Multiple Genetically Distinct Thyroid Nodules Including Papillary Thyroid Carcinoma Harboring Novel Ywhag-Braf Fusion, Ruihe Lin, Zi-Xuan Wang, Elizabeth Cottrill, Nitika Badjatia, Stacey Gargano

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Next-generation sequencing (NGS) analysis of thyroid samples aids in risk stratification of cytologically indeterminate nodules and contributes to our understanding of molecular mechanisms in thyroid neoplasia. Several genes, including BRAF, RAS, and EIF1AX, are known to play a role in thyroid tumorigenesis. Here we report a case of papillary thyroid carcinoma (PTC) in which a single lesion harbored a novel YWHAG-BRAF fusion and EIF1AX mutation and displayed mixed morphological findings. The patient is a 74-year-old female with multiple incidentally discovered thyroid nodules, two of which were sampled by ultrasound-guided fine needle aspiration (FNA). Cytologic diagnosis for both nodules was suspicious …

Altered Genome-Wide Hippocampal Gene Expression Profiles Following Early Life Lead Exposure And Their Potential For Reversal By Environmental Enrichment, Garima Singh, V Singh, T Kim, A Ertel, W Fu, J S Schneider

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Early life lead (Pb) exposure is detrimental to neurobehavioral development. The quality of the environment can modify negative influences from Pb exposure, impacting the developmental trajectory following Pb exposure. Little is known about the molecular underpinnings in the brain of the interaction between Pb and the quality of the environment. We examined relationships between early life Pb exposure and living in an enriched versus a non-enriched postnatal environment on genome-wide transcription profiles in hippocampus CA1. RNA-seq identified differences in the transcriptome of enriched vs. non-enriched Pb-exposed animals. Most of the gene expression changes associated with Pb exposure were reversed by …

A Mathematical Model Of Glut1 Modulation In Rods And Rpe And Its Differential Impact In Cell Metabolism, Andrea Aparicio, Erika T Camacho, Nancy J. Philp, Stephen A Wirkus

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

We present a mathematical model of key glucose metabolic pathways in two cells of the human retina: the rods and the retinal pigmented epithelium (RPE). Computational simulations of glucose transporter 1 (GLUT1) inhibition in the model accurately reproduce experimental data from conditional knockout mice and reveal that modification of GLUT1 expression levels of both cells differentially impacts their metabolism. We hypothesize that, under glucose scarcity, the RPE’s energy producing pathways are altered in order to preserve its functionality, impacting the photoreceptors’ outer segment renewal. On the other hand, when glucose is limited in the rods, aerobic glycolysis is preserved, which …

Bacille Calmette-Guérin Vaccine Reprograms Human Neonatal Lipid Metabolism In Vivo And In Vitro, Joann Diray-Arce, Asimenia Angelidou, Kristoffer Jarlov Jensen, Maria Giulia Conti, Rachel S Kelly, Matthew Pettengill, Mark Liu, Simon D Van Haren, Scott D Mcculloch, Greg Michelloti, Olubukola Idoko, Tobias R Kollmann, Beate Kampmann, Hanno Steen, Al Ozonoff, Jessica Lasky-Su, Christine S Benn, Ofer Levy

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Vaccines have generally been developed with limited insight into their molecular impact. While systems vaccinology enables characterization of mechanisms of action, these tools have yet to be applied to infants, who are at high risk of infection and receive the most vaccines. Bacille Calmette-Guérin (BCG) protects infants against disseminated tuberculosis (TB) and TB-unrelated infections via incompletely understood mechanisms. We employ mass-spectrometry-based metabolomics of blood plasma to profile BCG-induced infant responses in Guinea-Bissau in vivo and the US in vitro. BCG-induced lysophosphatidylcholines (LPCs) correlate with both TLR-agonist- and purified protein derivative (PPD, mycobacterial antigen)-induced blood cytokine production in vitro, raising the …

Gm1 Ganglioside Modifies Microglial And Neuroinflammatory Responses To Α-Synuclein In The Rat Aav-A53t Α-Synuclein Model Of Parkinson's Disease, Jay S Schneider, Garima Singh, Courtney K. Williams, Vikrant Singh

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Among the pathological events associated with the dopaminergic neurodegeneration characteristic of Parkinson's disease (PD) are the accumulation of toxic forms of α-synuclein and microglial activation associated with neuroinflammation. Although numerous other processes may participate in the pathogenesis of PD, the two factors mentioned above may play critical roles in the initiation and progression of dopamine neuron degeneration in PD. In this study, we employed a slowly progressing model of PD using adeno-associated virus-mediated expression of human A53T α-synuclein into the substantia nigra on one side of the brain and examined the microglial response in the striatum on the injected side …

Patterns Of Crystallin Gene Expression In Differentiation State Specific Regions Of The Embryonic Chicken Lens, Zhiwei Ma, Daniel Chauss, Joshua Disatham, Xiaodong Jiao, Lisa Ann Brennan, A Sue Menko, Marc Kantorow, J Fielding Hejtmancik

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Purpose: Transition from lens epithelial cells to lens fiber cell is accompanied by numerous changes in gene expression critical for lens transparency. We identify expression patterns of highly prevalent genes including ubiquitous and enzyme crystallins in the embryonic day 13 chicken lens.

Methods: Embryonic day 13 chicken lenses were dissected into central epithelial cell (EC), equatorial epithelial cell (EQ), cortical fiber cell (FP), and nuclear fiber cell (FC) compartments. Total RNA was prepared, subjected to high-throughput unidirectional mRNA sequencing, analyzed, mapped to the chicken genome, and functionally grouped.

Results: A total of 77,097 gene-specific transcripts covering 17,450 genes were expressed, …

The Pro-Fibrotic Response Of Mesenchymal Leader Cells To Lens Wounding Involves Hyaluronic Acid, Its Receptor Rhamm, And Vimentin, A. Sue Menko, Alison Romisher, Janice L Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Hyaluronic Acid/Hyaluronan (HA) is a major component of the provisional matrix deposited by cells post-wounding with roles both in regulating cell migration to repair a wound and in promoting a fibrotic outcome to wounding. Both are mediated through its receptors CD44 and RHAMM. We now showed that HA is present in the provisional matrix assembled on the substrate surface in a lens post-cataract surgery explant wound model in which mesenchymal leader cells populate the wound edges to direct migration of the lens epithelium across the adjacent culture substrate onto which this matrix is assembled. Inhibiting HA expression with 4-MU blocked …

68-Year Old Man With Progressive Weakness And Ventilator Dependent Respiratory Failure: A Case Report Of Sporadic Late Onset Nemaline Myopathy, P. Kirupaharan, Daniel Kramer, Alan Gandler, Lawrence C. Kenyon, Ross Summer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: Neuromuscular pathologies must be considered when caring for patients with persistent or progressive respiratory failure. Pertinent disease states may involve skeletal muscles of respiration or associated neurologic structures including motor neurons, peripheral neurons and the neuromuscular junction. Diagnosis may require pulmonary function testing, neurophysiologic studies, imaging, and/or muscle biopsy.

Case presentation: A 68-year-old male was transferred to our intensive care unit (ICU) for management of ventilator dependent respiratory failure. Upon further historical review, he described gradually worsening gait instability and muscle weakness, which was previously attributed to vascular Parkinsonism in the setting of known cerebrovascular disease. Upon arrival to …

Uncontrolled Mitochondrial Calcium Uptake Underlies The Pathogenesis Of Neurodegeneration In Micu1-Deficient Mice And Patients, Raghavendra Singh, Adam Bartok, Melanie Paillard, Ashley L. Tyburski, Melanie B Elliott, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Dysregulation of mitochondrial Ca2+ homeostasis has been linked to neurodegenerative diseases. Mitochondrial Ca2+ uptake is mediated via the calcium uniporter complex that is primarily regulated by MICU1, a Ca2+-sensing gatekeeper. Recently, human patients with MICU1 loss-of-function mutations were diagnosed with neuromuscular and cognitive impairments. While studies in patient-derived cells revealed altered mitochondrial calcium signaling, the neuronal pathogenesis was difficult to study. To fill this void, we created a neuron-specific MICU1-KO mouse model. These animals show progressive, abnormal motor and cognitive phenotypes likely caused by the degeneration of motor neurons in the spinal cord and the cortex. We found increased susceptibility …

Fluorescence Imaging Detection Of Nanodomain Redox Signaling Events At Organellar Contacts, David M. Booth, Péter Várnai, Suresh K Joseph, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

This protocol describes how to visualize, detect, and analyze redox signals (oxidative bursts) at the ER-mitochondrial interface. It uses drug-inducible crosslinking to target the genetically encoded glutathione redox sensor Grx1roGFP2 to organellar contact sites to measure local redox changes associated with transient depolarizations of the mitochondrial membrane potential (flickers). The strategy allows imaging of the oxidized to reduced glutathione ratio (GSSG:GSH) in subcellular regions below the diffraction limit with good temporal resolution and minimum phototoxicity. Moreover, the strategy also applies to diverse parameters including pH, H2O2, and Ca2+.

Suppression Of Pi3k Signaling Is Linked To Autophagy Activation And The Spatiotemporal Induction Of The Lens Organelle Free Zone, Rifah Gheyas, Ramon Ortega-Alvarez, Daniel Chauss, Marc Kantorow, A. Menko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The terminal steps of lens cell differentiation require elimination of all organelles to create a central Organelle Free Zone (OFZ) that is required for lens function of focusing images on the retina. Previous studies show that the spatiotemporal elimination of these organelles during development is autophagy-dependent. We now show that the inhibition of PI3K signaling in lens organ culture results in the premature induction of autophagy within 24 h, including a significant increase in LAMP1+ lysosomes, and the removal of lens organelles from the center of the lens. Specific inhibition of just the PI3K/Akt signaling axis was directly linked to …

Human Endothelial Cells Promote Arsenic-Transformed Lung Epithelial Cells To Induce Tumor Growth And Angiogenesis Through Interleukin-8 Induction, Lei Zhao, Yi-Fang Wang, Jie Liu, Bing-Hua Jiang, Ling-Zhi Liu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Arsenic exposure is associated with lung cancer. Angiogenesis is essential for tumor development. However, the role and mechanism of human vascular endothelial cells in tumor growth and angiogenesis induced by arsenic-transformed bronchial epithelial (As-T) cells remain to be elucidated. In this study, we found that endothelial cells significantly increased As-T cell-induced tumor growth compared to those induced by As-T cells alone. To understand the molecular mechanism, we found that endothelial cells co-cultured with As-T cells or cultured in conditioned medium (CM) prepared from As-T cells showed much higher cell migration, proliferation, and tube formation compared to those co-cultured with BEAS-2B …