Medicine and Health Sciences Commons^™

Increased Intermembrane Space [Ca2+] Drives Mitochondrial Structural Damage In Cpvt, Shanna Hamilton, Radmila Terentyeva, Roland Veress, Fruzsina Perger, Zuzana Nichtova, Mark Bannister, Jinxi Wang, Sage Quiggle, Rachel Battershell, Matthew Gorr, Sandor Györke, Bum-Rak Choi, Christopher George, Andriy Belevych, György Csordás, Dmitry Terentyev

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Mitochondrial dysfunction caused by abnormally high RyR2 (ryanodine receptor) activity is a common finding in cardiovascular diseases. Mechanisms linking RyR2 gain of function with mitochondrial remodeling remain elusive. We hypothesized that RyR2 hyperactivity in cardiac disease increases [Ca 2+ ] in the mitochondrial intermembrane space (IMS) and activates the Ca 2+ -sensitive protease calpain, driving remodeling of mitochondrial cristae architecture through cleavage of structural protein OPA1 (optic atrophy protein 1).

METHODS: We generated a highly arrhythmogenic rat model of catecholaminergic polymorphic ventricular tachycardia, induced by RyR2 gain-of-function mutation S2236L(Ser2336Leu)(+/-) . We created a new biosensor to measure IMS-[Ca2+ ] …

A Mouse Model Of Lipoatrophy Reveals Relationships Between Beige Fat Appearance And Female Fertility, Elizabeth S Anaya, William Dion, Pradip K Saha, Aaron R Cox, Evelyn De Groot, Avery A Ahmed, Jessica B Felix, Bokai Zhu, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

White adipose tissue (WAT) performs vital metabolic and endocrine functions, but roles in female reproduction remain understudied and poorly understood. Here, we report that female mice experiencing progressive lipoatrophy after knockout of Ubc9 in adipocytes (Ubc9fKO) displayed disrupted estrous cycles, reduced ovarian reserve, and subfertility. During aging, female Ubc9fKO mice lose subcutaneous WAT more quickly than their male counterparts and weigh less than littermate controls. Subcutaneous WAT excised from female Ubc9fKO mice strongly enriched for thermogenesis genes generally associated with metabolic benefits. Female Ubc9fKO mice exhibited hypermetabolism and accumulated thermogenic, Uncoupling Protein 1-expressing beige fat cells in residual subcutaneous WAT …

Fgf13 Regulates Vgsc-Independent Cardiomyocyte Impulse Propagation Via Cx43 Trafficking, Lala Tanmoy Das, Mattia Malvezzi, Aravind R Gade, Maiko Matsui, Margaret Mckay, Eric Q Wei, Matea J Zelich, Keon Mazdisnian, Jared Kushner, Bi-Xing Chen, Isabella Distefano, Daniel Roybal, Lin Yang, Lisa Stoll, James C Lo, Marian Kalocsay, Fadi G Akar, Steven O Marx, Geoffrey S Pitt

Faculty, Staff and Student Publications

Background: FHF (fibroblast growth factor homologous factor) variants associate with arrhythmias. Although FHFs are best characterized as regulators of voltage-gated sodium channel (VGSC) gating, recent studies suggest broader, non-VGSC-related functions, including regulation of Cx43 (connexin 43) gap junctions and hemichannels, mechanisms that have generally been understudied or disregarded.

Methods: We assessed cardiac conduction and cardiomyocyte action potentials in mice with constitutive cardiac-specific Fgf13 ablation (cFgf13KO) while targeting Cx43 gap junctions and hemichannels pharmacologically. We characterized FGF13 regulation of Cx43 abundance and subcellular distribution. With proximity labeling proteomics, we investigated novel candidate mechanisms underlying FGF13 regulation of Cx43. …

Yap-Induced Glycolysis Drives Fibroinflammation And Disrupts Fibroblast Fidelity, Chang-Ru Tsai, Lin Liu, Yi Zhao, Jong H Kim, Paulo Czarnewski, Rich Gang Li, Fansen Meng, Mingjie Zheng, Jeffrey Steimle, Xiaolei Zhao, Francisco Grisanti, Zheng Sun, Jun Wang, Md Abul Hassan Samee, Xiao Li, James F Martin

Faculty, Staff and Students Publications

Background: Separation of the pulmonic and systemic circulation is essential for terrestrial life, and mammals have evolved distinct cardiac chambers with specialized structures and functions. Transcriptomics profiling revealed cellular heterogeneity between heart chambers. However, the mechanisms underlying chamber-specific transcriptomic and metabolic differences-and their functional significance-remain poorly understood. The Hippo/YAP (yes-associated protein) pathway is a conserved signaling network that regulates diverse cellular processes. The Hippo kinases inhibit YAP in cardiac fibroblasts (CF) to restrict fibrosis and inflammation. Nonetheless, how YAP regulates the metabolic microenvironment during homeostasis and fibroinflammation remains unclear.

Methods: We investigated YAP and glycolysis activity in the 4 cardiac …

Protein-Protein Interaction–Interfering Peptide Rescues Dysregulated Nmda Receptor Signaling, Robert E. Featherstone, Hongbin Li, Ameet S. Sengar, Karin E. Borgmann-Winter, Olya Melnychenko, Lindsey M. Crown, Ray L. Gifford, Felix Amirfathi, Anamika Banerjee, Aivi Tran, Krishna Parekh, Margaret Heller, Wenyu Zhang, Robert J. Gallop, Adam D. Marc, Pragya Komal, Michael W. Salter, Steven J. Siegel, Chang-Gyu Hahn

Farber Institute for Neuroscience Faculty Papers

The complex and heterogeneous genetic architecture of neuropsychiatric illnesses compels us to look beyond individual risk genes for therapeutic strategies and target the interactive dynamics and convergence of their protein products. A mechanistic substrate for convergence of synaptic neuropsychiatric risk genes are protein-protein interactions (PPIs) in the N-methyl-D-aspartate receptor (NMDAR) complex. NMDAR hypofunction in schizophrenia is associated with hypoactivity of Src kinase, resulting from convergent alterations in PPIs of Src with its partners. Of these, the association of Src with PSD-95, which inhibits the activity of this kinase in the NMDAR complex, is known to be increased in schizophrenia. Here, …

Discovery Of A Small Molecule Tlr3 Agonist Adjuvant, Branden Lee, Danica Dong, Etsuro Nanishi, John Mark Awad, Kimia Abedi, Yoshine Saito, Francesco Borriello, Soumik Barman, Byron Brook, Aisling Kelly, Manisha Menon, Constance Marques-Mourlet, Maansi Gupta, Ida Lister, Chiwoo Oh, Kevin Lyskawa, Morgan Goetz, Kristina Walker, Wing Ki Cheng, Spencer Brightman, Pankaj Sharma, Timothy O'Meara, Katherine Chew, Daniel Vieira, Kevin Ryff, Cali Sweitzer, Sanya Thomas, Simon Van Haren, Matthew Pettengill, Hyuk-Soo Seo, Sirano Dhe-Paganon, Wei Zhang, Ofer Levy, David Dowling

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Pattern-recognition receptor (PRR) agonists are valuable agents across multiple medical applications, from vaccinology to immune-oncology. However, well-defined and potent small molecule agonists for many PRRs still await discovery and development. Screening of chemical libraries of ~200,000 small molecules for maturation of human monocytic cells by quantifying NF-κB activation and cell adherence was completed. From this screen, we selected a thiazole benzamide derivative, PVP-057, for its robust immunomodulatory properties, low toxicity profile, and concentration-dependent activity. In vitro investigation of pathway and receptor activation reveals that PVP-057 is a Toll-like receptor 3 (TLR3) agonist. As a single-component adjuvant, administered intramuscularly or intradermally …

Revealing The Nervous System Requirements Of Alzheimer Disease Risk Genes In Drosophila, Jennifer M Deger, Shabab B Hannan, Mingxue Gu, Colleen E Strohlein, Lindsey D Goodman, Sasidhar Pasupuleti, Zahid Shaik, Liwen Ma, Yarong Li, Jiayang Li, Morgan C Stephens, Michal Tyrlík, Zhandong Liu, Ismael Al-Ramahi, Juan Botas, Chad A Shaw, Oguz Kanca, Hugo J Bellen, Joshua M Shulman

Faculty, Staff and Students Publications

Most Alzheimer disease (AD) susceptibility genes have poorly understood roles in the central nervous system (CNS). To address this gap, we systematically characterized 100 conserved candidate AD risk genes using a cross-species strategy in the fruit fly, Drosophila melanogaster. Genes were prioritized based primarily on human functional genomic evidence. We generated custom loss-of-function alleles for each of the conserved fly orthologs. Most of the genes are expressed in the adult brain, including 24 neuron- and 13 glia-specific expression patterns. Overall, we identify 50 candidate AD risk gene homologs with requirements for CNS structure or function, including 18 whose loss of …

Restoration Of Sfrp3 Preserves The Neural Stem Cell Pool And Spatial Discrimination Ability In A Mouse Model Of Alzheimer's Disease, Chia-Hsuan Fu, Jin Park, Umberto Tosi, Francisco A Blanco, Manuel Silva-Pérez, Kavitha Muralidharan, Jason C You, Minjung Lee, Gabriel S Stephens, Xiaohong Zhang, Yi Zheng, Helen Scharfman, Kimberley F Tolias, Jeannie Chin

Faculty, Staff and Students Publications

Individuals with Alzheimer's disease (AD) have an increased incidence of seizures, which worsen cognitive decline. Using a transgenic mouse model of AD neuropathology that exhibits spontaneous seizures, we previously found that seizure activity stimulates and accelerates depletion of the hippocampal neural stem cell (NSC) pool, which was associated with deficits in neurogenesis-dependent spatial discrimination. However, the precise molecular mechanisms that drive seizure-induced activation and depletion of NSCs are unclear. Here, using mice of both sexes, we performed RNA-sequencing on the hippocampal dentate gyrus and identified differentially expressed regulators of neurogenesis in the Wnt signaling pathway that regulates many aspects of …

A Distinct Pp2a Subunit Regulates Local Protein Phosphorylation At The Axon Initial Segment, Andrew P Anderson, Sanghyun Kim, Allison J Melton, Xiaoyun Ding, Wei Zhang, Alexander B Saltzman, Anna Malovannaya, Matthew N Rasband, Yudong Gao

Faculty, Staff and Students Publications

Protein phosphorylation plays a crucial role in regulating the cytoskeletal and membrane proteins at the axon initial segment (AIS). However, our knowledge of AIS-specific kinases and phosphatases is very limited. Here, we report the identification of a protein phosphatase 2A (PP2A) B55 regulatory subunit enriched at the AIS in mice: Ppp2r2c. Our results demonstrate that PP2A-B55 subunits exhibit substantial heterogeneity in their subcellular localization and function. Notably, the Ppp2r2c subunit is selectively concentrated at the AIS, and this enrichment is driven by its unique structure. Utilizing a microelectrode array system (MEA), we show that Ppp2r2c modulates neuronal activity during in …

Resolving The Mysteries Of Brain Clearance And Immune Surveillance, Jonathan Kipnis, Et Al.

2020-Current year OA Pubs

Recent advances are transforming our understanding of brain fluid dynamics, highlighting cerebrospinal fluid (CSF) flow as a key process in brain waste clearance. While debates persist regarding its anatomical pathways and regulatory mechanisms, certain core principles have become widely accepted. CSF influx occurs primarily along periarterial spaces, solute clearance follows multiple routes, and glymphatic and meningeal lymphatic systems are functionally connected. Brain clearance is influenced by vascular pulsation, neural activity, and sleep. Immune cells at brain-border niches both monitor solute efflux and modulate flow, linking brain clearance to neuroimmune interactions. A deeper understanding of brain clearance could unlock new therapeutic …

Hif-2-Dependent Regulation Of Pthrp And Paraneoplastic Hypercalcemia In Aggressive Clear-Cell Renal Cell Carcinoma, Arijit Mal, Bingqing Xie, Zane Gray, Charlotte Small, Susmita G Ramanand, Yunpeng Gao, Vanina Toffessi Tcheuyap, Sashi Debnath, Alana Christie, Jeffrey Miyata, Brooklyn Jackson, Hua Zhong, Boning Gao, Jay Lohrey, Naim M Maalouf, Sangeetha M Reddy, John D Minna, Ivan Pedrosa, Xiankai Sun, Ram S Mani, Payal Kapur, James Brugarolas

Faculty, Staff and Student Publications

Renal cell carcinoma (RCC) patients with hypercalcemia (HC) have worse outcomes. HC often involves PTHrP, and the role of HIF-2 is incompletely understood. Leveraging RCC tumorgraft (TG) models of HC, which were characterized by tumor cell autonomous inflamatory/immune signatures, we show that HIF-2 inhibition with PT2399 frequently normalized calcium, downregulated circulating PTHrP and reduced HIF-2 binding to the PTHLH (PTHrP) promoter. Likely contributing to the selective induction of PTHrP in a subset of HIF-2-dependent tumors, the PTHLH locus was generally more accessible in TG(HC). However, PTHLH chromatin accessibility was grossly unaffected by PT2399, unlike elsewhere (including EPO locus in a …

Using Gnotobiotic Mice To Decipher Effects Of Gut Microbiome Repair In Undernourished Children On Tuft And Goblet Cell Function, Yi Wang, Hao-Wei Chang, Jiye Cheng, Daniel M Webber, Hannah M Lynn, Matthew C Hibberd, Clara Kao, Ishita Mostafa, Tahmeed Ahmed, Michael J Barratt, Jeffrey I Gordon

2020-Current year OA Pubs

Studies have implicated perturbations in the postnatal development of the gut microbiome as a contributing factor to childhood undernutrition. Compared to a standard ready-to-use supplementary food, a microbiome-directed complementary food (MDCF-2) designed to repair these perturbations produced superior improvements in ponderal and linear growth in clinical trials of Bangladeshi children with moderate acute malnutrition. Here, "reverse translation" experiments are performed where intact fecal microbiomes collected from trial participants before and at the end of treatment are introduced into female gnotobiotic mice just after delivery of their pups. Pups received diets designed to resemble those consumed by children in the trials …

Adrenomedullin Overexpression Protects Mice From Experimental Bronchopulmonary Dysplasia And Associated Pulmonary Hypertension, Shyam Thapa, Poonam Sarkar, M Waleed Gaber, Roberto Barrios, Madhulata Chauhan, Chandrasekhar Yallampalli, Binoy Shivanna

Faculty, Staff and Students Publications

Bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH) or BPD-PH is a lung disease of infants with significant morbidity. Adrenomedullin (Adm) is an angiogenic peptide that signals through calcitonin receptor-like receptor (Calcrl) and receptor activity modifying protein 2 (RAMP2). Adm deficiency potentiates hyperoxia-induced experimental BPD-PH in mice; however, whether Adm overexpression can mitigate this lung disease is unclear. Thus, we tested the hypothesis that Adm overexpression attenuates hyperoxia (HO)-induced murine experimental BPD-PH by using a novel transgenic mouse that overexpresses Adm globally (Admhi/hi mice). One-day-old Admhi/hi mice or their wild-type littermates (Adm+/+ mice) were exposed to …

Rbm8a Deficiency Causes Hematopoietic Defects By Modulating Wnt/Pcp Signaling, Agnese Kocere, Elena Chiavacci, Charlotte Soneson, Seth T Jacobson, Emma N Harrison, Kevin Manuel Méndez-Acevedo, Jacalyn S Macgowan, Harrison H Wells, Max S Hiltabidle, Azhwar Raghunath, Jordan A Shavit, Daniela Panáková, Margot L K Williams, Mark D Robinson, Christian Mosimann, Alexa Burger

Faculty, Staff and Students Publications

Thrombocytopenia-Absent Radius (TAR) syndrome is a rare congenital condition with reduced platelets, forelimb anomalies, and variable heart and kidney defects. TAR syndrome is caused by mutations in RBM8A/Y14, a component of the exon junction complex. How perturbing a general mRNA-processing factor causes the selective TAR Syndrome phenotypes remains unknown. Here, we connect zebrafish rbm8a perturbation to early hematopoietic defects via attenuated non-canonical Wnt/Planar Cell Polarity (PCP) signaling. In hypomorphic rbm8a zebrafish, we observe a reduction of cd41-positive thrombocytes. rbm8a-mutant zebrafish accumulate mRNAs with retained introns, including non-canonical Wnt/PCP pathway components resulting in convergent extension defects. We found that reduced rbm8a …

Exploration Of Zileuton Protective Mechanisms Against Vancomycin-Associated Nephrotoxicity, Cole S Hudson, James E Smith, Rongjin Sun, Linh T Vuong, Luan D Truong, David Sheikh-Hamad, Masayuki Nigo, Ming Hu, Vincent H Tam

Faculty, Staff and Students Publications

Vancomycin is one of the most commonly used parenteral antibiotics for treating drug-resistant bacterial infections, however, it is hindered by nephrotoxicity. We previously demonstrated that zileuton could delay the onset of vancomycin-associated nephrotoxicity in rats. Here, we sought to understand the mechanism(s) of zileuton renal protection. Sprague-Dawley rats were administered vancomycin (200 mg/kg) and zileuton (1 and 4 mg/kg) daily for 10 days. After 3 days, kidneys were collected from select animals for histopathological analysis of renal injury. Single-dose vancomycin serum pharmacokinetics and renal tissue spatial distribution with adjuvant zileuton were evaluated. In vitro, proximal tubular cells were exposed …

Emerging Tick-Borne Disease Risk In An Urban Center Of Harris County, Texas, Alisa Nelson, Michelle Downey, Maya Murry, Brianna Weber, Erik Aguirre, Richard Scott Mccrea, Jerrod Mims, Max Vigilant, Courtney Standlee, Kristy O Murray, Alex Kneubehl, Eric L Brown, Heather T Essigmann, Sarah M Gunter

Faculty, Staff and Students Publications

Background: Tick-borne diseases are an endemic and emerging public health concern in the United States. Ongoing tick range expansion, invasive species, and newly identified pathogens are rapidly altering disease epidemiology. Surveillance is critical to understanding vector ecology and disease risk. Harris County, Texas, with nearly five million residents and diverse ecological zones, offers a unique setting to study local tick dynamics.

Methods: From January 2021 to December 2022, we conducted weekly tick surveillance across 63 sites in Harris County (City of Houston), Texas. Ticks were morphologically identified and tested for Rickettsia, Borrelia, Ehrlichia, and Anaplasma via real-time PCR. Samples positive …

The Microstructure Of Metastatic Bone Lesions Suggests Tumor Mediated Alterations In Bone Mineralization, Hanwen Fan, Zhan Xu, Carla Berrospe Rodriguez, Noah Dover, Andrei Demkov, Morgan Lilly, Guillermo Aguilar, Larry J Suva, Xiang H-F Zhang, Yuxiao Zhou

Faculty, Staff and Students Publications

Breast, prostate and lung cancer cells frequently metastasize to bone, leading to disruption of the bone microstructure. This study utilized mechanical testing coupled with micro-CT imaging, digital volume correlation (DVC), and atomic force microscopy (AFM) nanomechanical testing to examine the mechanical property variations in mouse long bones (tibia) with metastatic lung cancer cell involvement, spanning from the whole-bone scale to the microstructural level. In addition, we also investigated how metastatic invasion alters the morphology of hydroxyapatite nanocrystals in bone at the nanometer scale. The biochemical composition within metastatic lesions was assessed using Raman spectroscopy and correlated with AFM mechanical testing …

Cross-Species Standardised Cortico-Subcortical Tractography, Stephania Assimopoulos, Shaun Warrington, Davide Folloni, Katherine Bryant, Ali-Reza Mohammadi-Nejad, Wei Tang, Saad Jbabdi, Sarah R Heilbronner, Rogier B Mars, Stamatios N Sotiropoulos

Faculty, Staff and Students Publications

Despite their importance for brain function, cortico-subcortical white matter tracts are under-represented in diffusion magnetic resonance imaging tractography studies. Their non-invasive mapping is more challenging and less explored compared to other major cortico-cortical bundles. We introduce a set of standardised tractography protocols for delineating tracts between the cortex and various deep subcortical structures, including the caudate, putamen, amygdala, thalamus, and hippocampus. To enable comparative studies, our protocols are designed for both human and macaque brains. We demonstrate how tractography reconstructions follow topographical principles obtained from tracers in the macaque and how these translate to humans. We show that the proposed …

Ataxia-Telangiectasia Mutated Activation Mediates Transforming Growth Factor Beta Signaling In Acetaminophen-Induced Liver Injury In Mice, Matthew Mcmillin, Christopher S Chu, Elaina Williams, Juliet Venter, Kiersten Bell, Anca D Petrescu, Patrick Mireles, Sharon Demorrow

Faculty and Staff Publications

Acetaminophen (APAP) overdose is associated with increased transforming growth factor beta 1 (TGFβ1) signaling and elevated oxidative stress, which exacerbate DNA damage. TGFβ1 has been shown to regulate ataxia-telangiectasia mutated (ATM) signaling and DNA repair in other cell types. This study investigates the DNA damage response (DDR) during APAP-induced liver injury, focusing on ATM-mediated regulation of TGFβ1 signaling. APAP administration in vitro and in vivo resulted in DNA damage, increased ATM signaling, accumulation of γH2AX, and activation of phosphorylated ataxia telangiectasia mutated (pATM) and phosphorylated checkpoint kinase 2 (pChk2). Pretreatment with an ATM inhibitor, KU55933, attenuated APAP-induced hepatocyte damage and …

Decorin Deficiency Promotes D-Galactose-Induced Skeletal Muscle Atrophy And Fibrosis By Regulating Itgb1/Akt/Mtor Signalling Pathway, Xiaoqin Luo, Mengxue Zhang, Lili Chen, Ruichang Wang, Jiabing Lian, Zhe Yang, Renato V. Iozzo, Jin Wang, Yan Zhang, Xiuli Bi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Primary sarcopenia is an age-associated disorder with progressive and generalised loss of skeletal muscle strength and mass. Skeletal muscle fibrosis is one of the significant pathological manifestations of age-associated sarcopenia. Decorin, a small dermatan-sulfate proteoglycan, participates in extracellular matrix assembly. In numerous studies, the involvement of decorin is not restricted to matrix structural proteins, and it also affects a diverse variety of biological functions like cell growth, adhesion, migration, proliferation and differentiation. Additionally, it modulates the process of inflammation and fibrillogenesis. Based on these preclinical evidences, we hypothesised that decorin may potentially play an important role in skeletal muscles …

Bypassing Cisplatin Resistance In Nrf2 Hyperactivated Head And Neck Cancer Through Effective Pi3kinase Targeting, Pedram Yadollahi, Kelli A Mccord, Yang Li, Hussam Dayoub, Kalil Saab, Fonma Essien, Sean Hyslop, Emerald Kan, Kazi M Ahmed, Parker R Kirby, Vasanta Putluri, Chandra Shekar R Ambati, Karthik Reddy Kami Reddy, Patricia Castro, Heath D Skinner, Cristian Coarfa, William K Decker, Abdullah A Osman, Rutulkumar Patel, Jeffrey N Myers, Stephen Y Lai, Nagireddy Putluri, Faye M Johnson, Mitchell J Frederick, William H Hudson, Vlad C Sandulache

Faculty, Staff and Students Publications

Background: For patients with head and neck squamous cell carcinoma (HNSCC), failure of definitive radiation combined with cisplatin nearly universally results in death. Although hyperactivation of the Nrf2 pathway can drive radiation and cisplatin resistance along with suppressed anti-tumor immunity, treatment-refractory HNSCC tumors may retain sensitivity to targeted agents secondary to synergistic lethality with other oncogenic drivers (e.g., NOTCH1 mutations).

Methods: Using state of the science mechanistic, metabolomic and spatial transcriptomic approaches combined with preclinical models of HNSCC, we tested whether a novel PI3K inhibitor, gedatolisib, can bypass hyperactivation of the Nrf2 pathway.

Results: The PI3K pathway is activated in …

Ddt Exposure Induces Microglial Activation And Disease-Associated Microglial Signatures: Relevance To Mechanisms Of Alzheimer’S Disease, Isha Mhatre-Winters, Aseel Eid, Nicole Blum, Yoonhee Han, Ferass M Sammoura, Long-Jun Wu, Jason R Richardson

The Brown Foundation: Institute of Molecular Medicine

Background: Alzheimer's disease (AD) is characterized by the presence of amyloid-β plaques, neurofibrillary tangles, and neuroinflammation. Previously, we reported that serum levels of dichlorodiphenyldichloroethylene (DDE), the primary metabolite of the pesticide dichlorodiphenyltrichloroethane (DDT), were significantly higher in AD patients compared to age-matched controls and that DDT exposure worsened AD pathology in animal models.

Objective: Here, we investigated the effect of DDT on neuroinflammation in primary mouse microglia (PMG) and C57BL/6J mice.

Methods: DDT-induced inflammatory and disease-associated microglial (DAM) gene expression were determined in PMG by qPCR and immunocytochemistry, with and without pretreatment with the sodium channel antagonist tetrodotoxin (TTX). Furthermore, …

Surgical Removal Of Implanted Microchips To Correct Mri Susceptibility Artifacts In Mice, Elizabeth Hipskind, Nicole Hernandez, Sydney Fox, Tina Manirambona, Rita Schack, Brian Gibson, Robia G Pautler

Center on Aging Staff Publications

Purpose: Implanted microchips are becoming increasingly common in research for animal identification and have been adopted by commercial vendors for some mouse strains. However, they often contain metal components, which generate magnetic susceptibility artifacts on MR images. Despite this, some microchips are marketed as MR-compatible, even though they are likely to affect image quality.

Methods: We assessed the impact of a radiofrequency identification microchip on MR images of the mouse brain and present a method for precise surgical removal. A handheld magnet was used to locate and stabilize the microchips during removal. Mice were imaged before and after microchip removal. …

Loss Of The Lysosomal Protein Cln3 Triggers C-Abl-Dependent Yap1 Pro-Apoptotic Signaling, Neuza Domingues, Alessia Calcagni', Sofia Freire, Joana Pires, Ricardo Casqueiro, Ivan L Salazar, Niculin Joachim Herz, Tuong Huynh, Katarzyna Wieciorek, Tiago Fleming Outeiro, Henrique Girão, Ira Milosevic, Andrea Ballabio, Nuno Raimundo

Duncan NRI Faculty and Staff Publications

Batten disease is characterized by early-onset blindness, juvenile dementia and death within the second decade of life. The most common genetic cause are mutations in CLN3, encoding a lysosomal protein. Currently, no therapies targeting disease progression are available, largely because its molecular mechanisms remain poorly understood. To understand how CLN3 loss affects cellular signaling, we generated human CLN3 knock-out cells (CLN3-KO) and performed RNA-seq analysis. Our multi-dimensional analysis reveals the transcriptional regulator YAP1 as a key factor in remodeling the transcriptome in CLN3-KO cells. YAP1-mediated pro-apoptotic signaling is also increased as a consequence of CLN3 functional loss in retinal pigment …

From Bladder To Brain: How You Know When It’S Time To Go, Anne M J Verstegen, Kara L Marshall

Duncan NRI Faculty and Staff Publications

The decision to urinate relies on assessing bladder fullness and context to determine an appropriate time and place to go. Any disruption in this interoceptive process results in frequent and sometimes debilitating consequences in daily life. Recent work has uncovered key pathways and brain regions that contribute to the sense of bladder stretch and the control of urinary reflexes, but many open questions remain. Here, we review the known mechanisms that convey sensory information from the bladder to the brain and back down again, and we highlight the knowledge gaps and opportunities for better understanding this system, which will be …

Revisiting Soluble Guanylate Cyclase Pharmacology: Additive Potential Of Stimulators And Activators, Alexandra Petraina, Mahmoud H Elbatreek, Christopher T Neullens, Theodora Saridaki, Vu Thao-Vi Dao, Rebecca D Szepanowski, Emil Martin, Wolfgang Sippl, Ana I Casas, Harald H H W Schmidt

Faculty, Staff and Student Publications

Nitric oxide (NO) is a key gasotransmitter that binds to soluble guanylate cyclase (sGC), thereby stimulating cGMP production. Under disease conditions, reactive oxygen species disrupt this signaling by either: (1) scavenging NO, or (2) promoting heme-free, NO-insensitive apo-sGC due to impaired heme incorporation or oxidative damage. To counteract these conditions, two pharmacological approaches have emerged: sGC stimulators, which allosterically enhance sGC sensitivity to low NO levels; and sGC activators, which directly activate apo-sGC (heme-free sGC) by binding to its empty heme pocket, inducing a conformation that mimics NO-bound sGC. Thus, sGC stimulators are thought to target only sGC. Instead, we …

Tumor Intrinsic Mettl5 Modulates Atf4 Translation To Prevent T Cell-Induced Ferroptosis In Ovarian Cancer, Jiakai Hou, Cheng-Wei Ju, Nicholas A Egan, Yanjun Wei, Yunfei Wang, Minghao Dang, Tianyi Zhou, Leilei Shi, Ningbo Zheng, Si Chen, Ashley M Guerrero, Xiaofang Liang, Wanfu Wu, Areej Akhtar, Chitra Dhiman, Debanwita Roy Burman, Andro E Gerges, Mason D Flores, Han Li, Li-Sheng Zhang, Marleen Kok, Xiaobo Mao, Linghua Wang, Qin Feng, Yiwen Chen, Sanghoon Lee, Daniel J Mcgrail, Nidhi Sahni, Chuan He, Amir A Jazaeri, Weiyi Peng

Faculty, Staff and Student Publications

Poor clinical responses to immune checkpoint blockade (ICB) observed in ovarian cancer (OC) highlight an unmet need to understand the mechanisms driving immune evasion in this disease. To address this, an integrative analysis is conducted by combining in vitro genome‐wide immune screens, in vivo ICB screens, and clinical data mining, and METTL5 is identified as a crucial OC‐intrinsic factor that promotes immune resistance. Immunologically “cold” OC tumors and poor responders to ICB exhibit elevated METTL5 expression. Mechanistically, knocking out (KO) METTL5 in OC disrupts ATF4 translation by altering 18S rRNA m6A levels, leading to the downregulation of SLC7A11 and SLC3A2 …

Kras Inhibition Activates An Actionable Cd24 "Do Not Eat Me" Signal In Pancreatic Cancer, Yongkun Wei, Minghui Liu, Er-Yen Yen, Jun Yao, Zhenzhen Xun, Phuoc T Nguyen, Xiaofei Wang, Zecheng Yang, Abdelrahman Yousef, Dean Pan, Yanqing Jin, Ching-Fei Li, Madelaine S Theardy, Jangho Park, Yiming Cai, Mitsunobu Takeda, Matthew Vasquez, Elizabeth M Park, David H Peng, Yong Zhou, Hong Zhao, Timothy P Heffernan, Andrea Viale, Huamin Wang, Stephanie S Watowich, Han Liang, Dan Zhao, Ronald A Depinho, Wantong Yao, Haoqiang Ying

Faculty, Staff and Student Publications

KRASG12C inhibitors (G12Ci) have produced encouraging, albeit modest and transient, clinical benefit in pancreatic ductal adenocarcinoma (PDAC). Identifying and targeting resistance mechanisms to G12Ci treatment is therefore crucial. To better understand the function of KRASG12C and possible G12Ci bypass mechanisms, we developed an autochthonous KRASG12C-driven PDAC model. Compared to the classical KRASG12D PDAC model, the G12C model exhibits slower tumor growth, yet similar histopathological and molecular features. Aligned with clinical experience, G12Ci treatment of KRASG12C tumors produced modest impact despite stimulating a ‘hot’ tumor immune microenvironment. Immunoprofiling revealed that CD24, a ‘don’t eat me’ signal, is significantly upregulated on cancer …

Evidence For Improved Dna Repair In The Long-Lived Bowhead Whale, Denis Firsanov, Max Zacher, Xiao Tian, Todd L Sformo, Yang Zhao, Gregory Tombline, J Yuyang Lu, Zhizhong Zheng, Luigi Perelli, Enrico Gurreri, Li Zhang, Jing Guo, Anatoly Korotkov, Valentin Volobaev, Seyed Ali Biashad, Zhihui Zhang, Johanna Heid, Alexander Y Maslov, Shixiang Sun, Zhuoer Wu, Jonathan Gigas, Eric C Hillpot, John C Martinez, Minseon Lee, Alyssa Williams, Abbey Gilman, Nicholas Hamilton, Ekaterina Strelkova, Ena Haseljic, Avnee Patel, Maggie E Straight, Nalani Miller, Julia Ablaeva, Lok Ming Tam, Chloé Couderc, Michael R Hoopmann, Robert L Moritz, Shingo Fujii, Amandine Pelletier, Dan J Hayman, Hongrui Liu, Yuxuan Cai, Anthony K L Leung, Zhengdong Zhang, C Bradley Nelson, Lisa M Abegglen, Joshua D Schiffman, Vadim N Gladyshev, Carlo C Maley, Mauro Modesti, Giannicola Genovese, Mirre J P Simons, Jan Vijg, Andrei Seluanov, Vera Gorbunova

Faculty, Staff and Student Publications

At more than 200 years, the maximum lifespan of the bowhead whale exceeds that of all other mammals. The bowhead is also the second-largest animal on Earth1, reaching over 80,000 kg. Despite its very large number of cells and long lifespan, the bowhead is not highly cancer-prone, an incongruity termed Peto’s paradox2. Here, to understand the mechanisms that underlie the cancer resistance of the bowhead whale, we examined the number of oncogenic hits required for malignant transformation of whale primary fibroblasts. Unexpectedly, bowhead whale fibroblasts required fewer oncogenic hits to undergo malignant transformation than human fibroblasts. …

Periostin Promotes Sarcoma Growth By Promoting Tumor-Associated Macrophage Migration And Differentiation, Jin-Fen Xiao, Kristin Ishaya, Emily Y Ko, Annaliese Fowler, Marina T Broz, Jlenia Guarnerio

Faculty, Staff and Student Publications

Soft-tissue sarcomas (STS) are characterized by abundant extracellular matrix (ECM) deposition, yet the functional contribution of specific ECM components remains poorly understood. In this study, we identify periostin (POSTN), a matricellular protein, as a regulator of sarcoma progression and the tumor immune microenvironment. Analysis of human sarcoma datasets revealed that high POSTN expression correlates with poor prognosis and elevated expression of ECM-related and myeloid cell–associated genes. In murine genetic models of sarcoma, tumors expressing high levels of Postn displayed enhanced expression of ECM genes and monocyte-recruiting cytokines. Functional silencing of Postnin vivo reduced tumor growth without altering tumor cell …