Medical Cell Biology Commons^™

Intermembrane Coupling Between Bcl-Xl And The Ip3 Receptor Supports Local Ca2+ Transfer At Er-Mitochondrial Contacts, Arijita Ghosh, David Weaver, Chi Li, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Bcl-xL, an anti-apoptotic Bcl-2 family protein, engages laterally with Bak/Bax in the outer mitochondrial membrane (OMM) to inhibit apoptosis and interacts with the IP₃ receptor Ca²⁺ channels (IP3Rs) in the endoplasmic reticulum (ER) membrane to control Ca²⁺ release. It is unknown if OMM-localized Bcl-xL can also interact in trans with IP3Rs at ER-mitochondrial contacts to form a tethering complex that supports IP3R-mediated local Ca²⁺ transfer from ER to mitochondria. We establish that IP3R-mitochondria Ca²⁺ signal propagation depends on Bcl-xL. By targeting Bcl-xL specifically to different subcellular compartments, we find that OMM-localized Bcl-xL increases the efficacy …

An Inf2-Dependent Actin-Mediated Step In Inositol 1,4,5-Trisphosphate Receptor Cluster Formation And Activity, Maite R. Zavala, Amrapali Ghosh, Suresh K. Joseph, Rajarshi Chakrabarti

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Intracellular calcium signaling plays a vital role in regulating various cellular processes including gene regulation, motility, metabolism, and cell death. Inositol 1,4,5-trisphosphate receptors (IP3Rs) on the endoplasmic reticulum (ER) are a major cation channel that regulates stimulus-induced calcium release from the ER. While several molecular players regulate the activity of IP3R, its regulation by actin filaments was uncharacterized. Here, we show that actin filaments polymerized by the specific actin nucleator INF2 facilitate agonist-induced IP3R activity. Our results demonstrate that INF2-mediated actin filaments regulate the formation and/or stability of IP3R clusters on the ER that have been previously shown to be …

Routine Transfusion Of Rh(D)-Positive Rbcs To Rh(D)-Negative Patients Designated As Do Not Resuscitate Conserves Rh(D)-Negative Red Blood Cell Inventory, Julie Katz Karp, Jovanna Everetts, Juliana Guarente, Angelica Vivero, Tiffany Bohr, Mary Harach

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background: A minority of blood donors are Rh(D)-negative, and Rh(D)-negative red blood cell (RBC) products are often overutilized. As such, Rh(D)-negative RBCs may be difficult to maintain in blood bank inventory.

Study design and methods: We changed our blood bank laboratory policy to approve non-alloimmunized Rh(D)-negative patients to receive Rh(D)-positive RBCs for routine transfusion under defined criteria. Those criteria included Rh(D)-negative males (all ages) and females (aged >50 years) who were designated as do not resuscitate (DNR), either with or without intubation, in the electronic medical record.

Results: From August 15, 2024 through August 15, 2025, a total of 204 …

Maackia Amurensis Seed Lectin Structure And Sequence Comparison With Other M. Amurensis Lectins, Ashok R. Nayak, Cayla J. Holdcraft, Ariel C. Yin, Rachel E. Nicoletto, Caifeng Zhao, Haiyan Zheng, Dmitry Temiakov, Gary S. Goldberg

Department of Biochemistry and Molecular Biology Faculty Papers

Maackia amurensis lectins, including MASL, MAA, and MAL2, are widely utilized in biochemical and medicinal research. However, the structural and functional differences between these lectins have not been defined. Here, we present a high-resolution cryo-EM structure of MASL revealing that its tetrameric assembly is directed by two intersubunit disulfide bridges. These bridges, formed by C272 residues, are central to the dimer-of-dimers assembly of a MASL tetramer. This cryo-EM structure also identifies residues involved in stabilizing the dimer interface, multiple glycosylation sites, and calcium and manganese atoms in the sugar-binding pockets of MASL. Notably, our analysis reveals that Y250 in the …

Adult Zymosan Re-Exposure Exacerbates The Molecular Alterations In The Brainstem Rostral Ventromedial Medulla Of Rats With Early Life Zymosan-Induced Cystitis, Bhavana Talluri, Sankar Addya, Maia Terashvili, Bidyut K. Medda, Anjishnu Banerjee, Reza Shaker, Jyoti N. Sengupta, Banani Banerjee

Kimmel Cancer Center Papers, Presentations, and Grand Rounds

Recent evidence suggests that the descending modulatory pathways from the brainstem rostral ventromedial medulla (RVM) are important for bladder inflammatory pain. This study aimed to identify the long-term molecular changes in RVM neurons due to early life cystitis during neuronal development and the effect of reexposure later in adulthood. RVM tissues from two treatment protocols were used: (1) neonatal zymosan exposures with acute adult rechallenge (RC) and (2) only neonatal zymosan exposures (NRC). RNAseq analysis showed upregulation of several genes associated with synaptic plasticity (Grin1, Grip2, Notch1, Arc, and Scn2b) in the cystitis groups compared to controls in both protocols. …

Refining The Optimal Caf Cluster Marker For Predicting Tme-Dependent Survival Expectancy And Treatment Benefits In Nsclc Patients, Kai Li, Rui Wang, Guo-Wei Liu, Zi-Yang Peng, Ji-Chang Wang, Guo-Dong Xiao, Shou-Ching Tang, Ning Du, Jia Zhang, Jing Zhang, Hong Ren, Xin Sun, Yi-Ping Yang, Da-Peng Liu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The tumor microenvironment (TME) plays a pivotal role in the onset, progression, and treatment response of cancer. Among the various components of the TME, cancer-associated fibroblasts (CAFs) are key regulators of both immune and non-immune cellular functions. Leveraging single-cell RNA sequencing (scRNA) data, we have uncovered previously hidden and promising roles within this specific CAF subgroup, paving the way for its clinical application. However, several critical questions persist, primarily stemming from the heterogeneous nature of CAFs and the use of different fibroblast markers in various sample analyses, causing confusion and hindrance in their clinical implementation. In this groundbreaking study, we …

Proteoglycans Of Basement Membranes: Crucial Controllers Of Angiogenesis, Neurogenesis, And Autophagy, Maurizio Mongiat, Gabriel Pascal, Evelina Poletto, Davion M. Williams, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Anti-angiogenic therapy is an established method for the treatment of several cancers and vascular-related diseases. Most of the agents employed target the vascular endothelial growth factor A, the major cytokine stimulating angiogenesis. However, the efficacy of these treatments is limited by the onset of drug resistance. Therefore, it is of fundamental importance to better understand the mechanisms that regulate angiogenesis and the microenvironmental cues that play significant role and influence patient treatment and outcome. In this context, here we review the importance of the three basement membrane heparan sulfate proteoglycans (HSPGs), namely perlecan, agrin and collagen XVIII. These HSPGs are …

Neuroendocrine Gene Subsets Are Uniquely Dysregulated In Prostate Adenocarcinoma, Nicole M. Naranjo, Anne Kennedy, Anna Testa, Cecilia E. Verrillo, Adrian D. Altieri, Rhonda Kean, D. Craig Hooper, Jindan Yu, Jonathan Zhao, Oliver Abinader, Maxwell W. Pickles, Adam Hawkins, William Kevin Kelly, Ramkrishna Mitra, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Prostate cancer has heterogeneous growth patterns, and its prognosis is the poorest when it progresses to a neuroendocrine phenotype. Using bioinformatic analysis, we evaluated RNA expression of neuroendocrine genes in a panel of five different cancer types: prostate adenocarcinoma, breast cancer, kidney chromophobe, kidney renal clear cell carcinoma and kidney renal papillary cell carcinoma. Our results show that specific neuroendocrine genes are significantly dysregulated in these tumors, suggesting that they play an active role in cancer progression. Among others, synaptophysin (SYP), a conventional neuroendocrine marker, is upregulated in prostate adenocarcinoma (PRAD) and breast cancer (BRCA). Our analysis shows that SYP …

Clearing The Light Path: Proteoglycans And Their Important Roles In The Lens And Cornea, Mary Ann Stepp, A. Sue Menko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Some of the earliest studies of glycans were performed on mammalian corneas and lenses with many of the key concepts we currently recognize as being fundamental to our understanding of basic cell biology arising from these studies. Proteoglycans and their GAG side chains are essential components of the ECM of the lens capsule. They also are present in the anterior corneal epithelial basement membrane and the posterior (Decemet's) basement membrane, and they organize collagen fiber diameters and spacing in the corneal stroma to maintain stromal clarity. Studies using genetically engineered mice and characterization of spontaneously arising mutations in genes controlling …

Dendritic Cells Overcome Cre/Lox Induced Gene Deficiency By Siphoning Cytosolic Material From Surrounding Cells, Christopher H. Herbst, Aurélie Bouteau, Evelin J. Menykő, Zhen Qin, Ervin Gyenge, Qingtai Su, Vincent Cooper, Neil A. Mabbott, Botond Z. Igyártó

Department of Microbiology and Immunology Faculty Papers

In a previous report, keratinocytes were shown to share their gene expression profile with surrounding Langerhans cells (LCs), influencing LC biology. Here, we investigated whether transferred material could substitute for lost gene products in cells subjected to Cre/Lox conditional gene deletion. We found that in human Langerin-Cre mice, epidermal LCs and CD11b+CD103+ mesenteric DCs overcome gene deletion if the deleted gene was expressed by neighboring cells. The mechanism of material transfer differed from traditional antigen uptake routes, relying on calcium and PI3K, being susceptible to polyguanylic acid inhibition, and remaining unaffected by inflammation. Termed intracellular monitoring, this process was specific …

Two-Pore Channel-2 And Inositol Trisphosphate Receptors Coordinate Ca2+ Signals Between Lysosomes And The Endoplasmic Reticulum, Yu Yuan, Vikas Arige, Ryo Saito, Qianru Mu, Gabriela C. Brailoiu, Gustavo J.S. Pereira, Stephen R. Bolsover, Marco Keller, Franz Bracher, Christian Grimm, Eugen Brailoiu, Jonathan S. Marchant, David I. Yule, Sandip Patel

College of Pharmacy Faculty Papers

Lysosomes and the endoplasmic reticulum (ER) are Ca2+ stores mobilized by the second messengers NAADP and IP3, respectively. Here, we establish Ca2+ signals between the two sources as fundamental building blocks that couple local release to global changes in Ca2+. Cell-wide Ca2+ signals evoked by activation of endogenous NAADP-sensitive channels on lysosomes comprise both local and global components and exhibit a major dependence on ER Ca2+ despite their lysosomal origin. Knockout of ER IP3 receptor channels delays these signals, whereas expression of lysosomal TPC2 channels accelerates them. High-resolution Ca2+ imaging reveals elementary events upon TPC2 opening and signals coupled to …

Xtx101, A Tumor-Activated, Fc-Enhanced Anti-Ctla-4 Monoclonal Antibody, Demonstrates Tumor-Growth Inhibition And Tumor-Selective Pharmacodynamics In Mouse Models Of Cancer, Kurt A. Jenkins, Miso Park, Magali Pederzoli-Ribeil, Ugur Eskiocak, Parker Johnson, Wilson Guzman, Megan Mclaughlin, Deborah Moore-Lai, Caitlin O'Toole, Zhen Liu, Benjamin Nicholson, Veronica Flesch, Huawei Qiu, Tim Clackson, Ronan C. O'Hagan, Ulrich Rodeck, Margaret Karow, Jennifer O'Neil, John C. Williams

Department of Dermatology and Cutaneous Biology Faculty Papers

INTRODUCTION: The clinical benefit of the anti-CTLA-4 monoclonal antibody (mAb) ipilimumab has been well established but limited by immune-related adverse events, especially when ipilimumab is used in combination with anti-PD-(L)1 mAb therapy. To overcome these limitations, we have developed XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4 mAb.

METHODS: XTX101 consists of an anti-human CTLA-4 mAb covalently linked to masking peptides that block the complementarity-determining regions, thereby minimizing the mAb binding to CTLA-4. The masking peptides are designed to be released by proteases that are typically dysregulated within the tumor microenvironment (TME), resulting in activation of XTX101 intratumorally. Mutations within the Fc region …

Targeting The Αvβ3/Ngr2 Pathway In Neuroendocrine Prostate Cancer, Anna Testa, Fabio Quaglia, Nicole M. Naranjo, Cecilia E. Verrillo, Christopher D. Shields, Stephen Lin, Maxwell W. Pickles, Drini F. Hamza, Tami Von Schalscha, David A. Cheresh, Benjamin E Leiby, Qin Liu, Jianyi Ding, William K. Kelly, D. Craig Hooper, Eva Corey, Edward F. Plow, Dario C. Altieri, Lucia R. Languino

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Highly aggressive, metastatic, neuroendocrine prostate cancer, which typically develops from prostate cancer cells acquiring resistance to androgen deprivation therapy, is associated with limited treatment options and hence poor prognosis. We have previously demonstrated that the αVβ3 integrin is over-expressed in neuroendocrine prostate cancer. We now show that LM609, a monoclonal antibody that specifically targets the human αVβ3 integrin, hinders the growth of neuroendocrine prostate cancer patient-derived xenografts in vivo. Our group has recently identified a novel αVβ3 integrin binding partner, NgR2, responsible for regulating the expression of neuroendocrine markers and for inducing neuroendocrine differentiation in prostate cancer cells. Through in …

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 …

Gene Signature Reveals Decreased Sox10-Dependent Transcripts In Malignant Cells From Immune Checkpoint Inhibitor-Resistant Cutaneous Melanomas, Timothy J. Purwin, Signe Caksa, Ahmet Sacan, Claudia Capparelli, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Evidence is mounting for cross-resistance between immune checkpoint and targeted kinase inhibitor therapies in cutaneous melanoma patients. Since the loss of the transcription factor, SOX10, causes tolerance to MAPK pathway inhibitors, we used bioinformatic techniques to determine if reduced SOX10 expression/activity is associated with immune checkpoint inhibitor resistance. We integrated SOX10 ChIP-seq, knockout RNA-seq, and knockdown ATAC-seq data from melanoma cell models to develop a robust SOX10 gene signature. We used computational methods to validate this signature as a measure of SOX10-dependent activity in independent single-cell and bulk RNA-seq SOX10 knockdown, cell line panel, and MAPK inhibitor drug-resistant datasets. Evaluation …

Increased Sirt3 Combined With Parp Inhibition Rescues Motor Function Of Sbma Mice, David R. Garcia Castro, Joseph R. Mazuk, Erin M. Heine, Daniel Simpson, R. Seth Pinches, Caroline Lozzi, Kathryn Hoffman, Phillip Morrin, Dylan Mathis, Maria V. Lebedev, Elyse Nissley, Kang Hoo Han, Tyler Farmer, Diane E. Merry, Qiang Tong, Maria Pennuto, Heather L. Montie

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease with substantial mitochondrial and metabolic dysfunctions. SBMA is caused by polyglutamine (polyQ) expansion in the androgen receptor (AR). Activating or increasing the NAD+-dependent deacetylase, SIRT3, reduced oxidative stress and death of cells modeling SBMA. However, increasing diminished SIRT3 in AR100Q mice failed to reduce acetylation of the SIRT3 target/antioxidant, SOD2, and had no effect on increased total acetylated peptides in quadriceps. Yet, overexpressing SIRT3 resulted in a trend of motor recovery, and corrected TCA cycle activity by decreasing acetylation of SIRT3 target proteins. We sought to boost blunted SIRT3 activity …

Tumor Matrix Stiffness Provides Fertile Soil For Cancer Stem Cells, Sadegh Safaei, Roya Sajed, Ahmad Shariftabrizi, Shima Dorafshan, Leili Saeednejad Zanjani, Masoumeh Dehghan Manshadi, Zahra Madjd, Roya Ghods

Kimmel Cancer Center Papers, Presentations, and Grand Rounds

Matrix stiffness is a mechanical characteristic of the extracellular matrix (ECM) that increases from the tumor core to the tumor periphery in a gradient pattern in a variety of solid tumors and can promote proliferation, invasion, metastasis, drug resistance, and recurrence. Cancer stem cells (CSCs) are a rare subpopulation of tumor cells with self-renewal, asymmetric cell division, and differentiation capabilities. CSCs are thought to be responsible for metastasis, tumor recurrence, chemotherapy resistance, and consequently poor clinical outcomes. Evidence suggests that matrix stiffness can activate receptors and mechanosensor/mechanoregulator proteins such as integrin, FAK, and YAP, modulating the characteristics of tumor cells …

Targeting The Vulnerabilities Of Oncogene Activation, Christina Huang, Jack L. Arbiser

Student Papers, Posters & Projects

No abstract provided.

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 …

Pimt Is A Novel And Potent Suppressor Of Endothelial Activation, Chen Zhang, Zhifu Guo, Wennan Liu, Kyosuke Kazama, Louis Hu, Xiaobo Sun, Lu Wang, Hyoungjoo Lee, Lin Lu, Xiao-Feng Yang, Ross Summer, Jianxin Sun

Division of Pulmonary, Allergy, and Critical Care Medicine Faculty Papers

Proinflammatory agonists provoke the expression of cell surface adhesion molecules on endothelium in order to facilitate leukocyte infiltration into tissues. Rigorous control over this process is important to prevent unwanted inflammation and organ damage. Protein L-isoaspartyl O-methyltransferase (PIMT) converts isoaspartyl residues to conventional methylated forms in cells undergoing stress-induced protein damage. The purpose of this study was to determine the role of PIMT in vascular homeostasis. PIMT is abundantly expressed in mouse lung endothelium and PIMT deficiency in mice exacerbated pulmonary inflammation and vascular leakage to LPS(lipopolysaccharide). Furthermore, we found that PIMT inhibited LPS-induced toll-like receptor signaling through its interaction …

Cold Atmospheric Pressure Plasma-Antibiotic Synergy In Pseudomonas Aeruginosa Biofilms Is Mediated Via Oxidative Stress Response, Jordanne-Amee Maybin, Thomas P. Thompson, Padrig B. Flynn, Timofey Skvortsov, Noreen J. Hickok, Theresa A. Freeman, Brendan F. Gilmore

Department of Orthopaedic Surgery Faculty Papers

Cold atmospheric-pressure plasma (CAP) has emerged as a potential alternative or adjuvant to conventional antibiotics for the treatment of bacterial infections, including those caused by antibiotic-resistant pathogens. The potential of sub-lethal CAP exposures to synergise conventional antimicrobials for the eradication of Pseudomonas aeruginosa biofilms is investigated in this study. The efficacy of antimicrobials following or in the absence of sub-lethal CAP pre-treatment in P. aeruginosa biofilms was assessed. CAP pre-treatment resulted in an increase in both planktonic and biofilm antimicrobial sensitivity for all three strains tested (PAO1, PA14, and PA10548), with both minimum inhibitory concentrations (MICs) and minimum biofilm eradication …

Parp Inhibitors For The Treatment Of Brca1/2-Mutated Metastatic Breast Cancer: A Systematic Review And Meta-Analysis, Ranju Kunwor, Daniel P. Silver, Maysa Abu-Khalaf

Kimmel Cancer Center Faculty Papers

BACKGROUND: The PARP inhibitors (PARPis) olaparib and talazoparib are currently approved for the treatment of deleterious germline BRCA1/2-mutated (gBRCA+) metastatic breast cancer (MBC). These approvals were based on improvements in progression-free survival (PFS) observed in two randomized controlled trials (RCTs). Other PARPis, such as veliparib and niraparib, have also been studied. We conducted this meta-analysis of RCTs to assess the PFS and overall survival (OS) benefits of PARPis in gBRCA + MBC.

METHODS: We performed a systematic search for RCTs using the Cochrane Library, PubMed, Embase, and Web of Science databases up to March 2021. Only phase II and III …

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, …

Cellular Heterogeneity And Stem Cells Of Vascular Endothelial Cells In Blood Vessel Formation And Homeostasis: Insights From Single-Cell Rna Sequencing, Taku Wakabayashi, Hisamichi Naito

Wills Eye Hospital Papers

Vascular endothelial cells (ECs) that constitute the inner surface of blood vessels are essential for new vessel formation and organ homeostasis. ECs display remarkable phenotypic heterogeneity across different organs and the vascular tree during angiogenesis and homeostasis. Recent advances in single cell RNA sequencing (scRNA-seq) technologies have allowed a new understanding of EC heterogeneity in both mice and humans. In particular, scRNA-seq has identified new molecular signatures for arterial, venous and capillary ECs in different organs, as well as previously unrecognized specialized EC subtypes, such as the aerocytes localized in the alveolar capillaries of the lung. scRNA-seq has also revealed …

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 …

Toll-Like Receptor 4 Signaling In Osteoblasts Is Required For Load-Induced Bone Formation In Mice, Ibtesam Rajpar, Gaurav Kumar, Paolo Fortina, Ryan E. Tomlinson

Department of Orthopaedic Surgery Faculty Papers

In mature bone, NGF is produced by osteoblasts following mechanical loading and signals through resident sensory nerves expressing its high affinity receptor, neurotrophic tyrosine kinase receptor type 1 (TrkA), to support bone formation. Here, we investigated whether osteoblastic expression of Toll-like receptor 4 (TLR4), a key receptor in the NF-κB signaling pathway, is required to initiate NGF-TrkA signaling required for load-induced bone formation. Although Tlr4 conditional knockout mice have normal skeletal mass and strength in adulthood, the loss of TLR4 signaling significantly reduced lamellar bone formation following loading. Inhibition of TLR4 signaling reduced Ngf expression in primary osteoblasts and RNA …