Digital Commons Network^™

Concurrent Tb And Hiv Therapies Control Tb Reactivation During Co-Infection But Not Chronic Immune Activation, Riti Sharan, Yi Zou, Bindu Singh, Vinay Shivanna, Edward J Dick, Shannan Hall-Ursone, Xi Luo, Guanlin Guo, Shabaana A Khader, Xavier Alvarez, Jyothi Rengarajan, Zhao Lai, Smriti Mehra, Hulin Wu, Deepak Kaushal

Faculty, Staff and Student Publications

Most HIV-negative individuals exposed to Mycobacterium tuberculosis (Mtb) control infection as latent TB infection (LTBI), but HIV co-infection greatly increases progression to tuberculosis (TB), the leading cause of death in people living with HIV (PLHIV). Although combination antiretroviral therapy (cART) reduces LTBI reactivation, immune control of Mtb is not fully restored, as shown by persistent TB incidence in PLHIV on cART. In macaques, skewed pulmonary effector memory CD4⁺ T-cell (TEM) responses and new TB lesions persist despite cART. We hypothesize that concurrent anti-TB therapy with cART would improve bacterial control and immune restoration compared to cART alone. Using …

Agpat2 Acts At The Crossroads Of Lipid Biosynthesis And Drp1-Mediated Er Morphogenesis, Yoshihiro Adachi, Mauricio Torres, Allen H Hunter, Woo Jung Cho, Meixia Pan, Xianlin Han, Guangwei Du, Ling Qi, Miho Iijima, Hiromi Sesaki

Faculty, Staff and Student Publications

The morphology of the endoplasmic reticulum (ER), characterized by central sheets and peripheral tubules, is controlled by membrane-shaping proteins. However, the role of lipids in ER morphogenesis remains elusive, despite the ER being the major site for lipid synthesis. Here, by examining the role of eighteen phosphatidic acid (PA)-generating enzymes in ER morphology, we identify lysophosphatidic acid acyltransferase 2 (AGPAT2) as a critical factor in mouse and human cells. AGPAT2 produces PA in the glycerophospholipid/triacylglycerol biosynthesis pathway, and its mutations cause congenital generalized lipodystrophy. We find that AGPAT2-generated PA drives ER tubulation through gene knockout, 3D structural analysis by FIB-SEM, …

Sex-Specific Angiogenic Responses In Endothelial Cells-Role Of The Pluripotency Factor Oct4, Junchul Shin, Junyoung Hong, Iuliia Molokotina, Irene Krukovets, Ellin Kim, Svyatoslav Tkachenko, Eugene Podrez, Tatiana V Byzova, Olga A Cherepanova

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The study investigates the sex-specific effects of the pluripotency factor OCT4 deficiency in endothelial cells (ECs) on angiogenesis. OCT4 is known for its role in embryonic stem cells, but we recently found that it plays a protective role in ECs during atherosclerosis. Herein, we utilized cultured mouse aortic ECs (MAECs) and several in vivo models, including skin wounding, melanoma tumor implantation, and hindlimb ischemia, to explore the role of OCT4 in angiogenesis in both male and female mice. Our findings revealed significant sexual dimorphism in wild type mice, along with sex differences in responses to OCT4 deficiency across all three …

Structural Basis Of Panx1 Permeation And Positive Modulation By Mefloquine, Yangyang Li, Zheng Ruan, Junuk Lee, Ian Orozco, Edward Zhou, Juan Du, Wei Lü

Department of Biochemistry and Molecular Biology Faculty Papers

Purinergic signaling relies on ATP release through exocytosis and large-pore channels. Large-pore channels permeate both small anions like chloride and large signaling molecules like ATP, but how this broad cargo selectivity is structurally controlled remains elusive. Here we investigate PANX1, a prototypical large-pore channel, and uncover structural plasticity at the extracellular entrance formed by seven tryptophan (W74) residues. The W74 sidechains are flexible, sampling conformations that range from a constricted state permissive only to chloride to a dilated state compatible with ATP. These states are coupled to variable cation-π interactions between W74 and arginine 75 (R75), suggesting a mechanism for …

Delayed Delivery Of Antibiotics By Ultrasound-Mediated Rupture Of Polylactic Acid Pockets: In Vitro And In Vivo Studies, Selin Isguven Billmyer, Priscilla Machado, Ryan Tomlinson, Lauren J. Delaney, Ji-Bin Liu, Alexander H Harris, Eric Mclaughlin, Noreen J. Hickok, Flemming Forsberg

Department of Radiology Faculty Papers

Surgical site infections are a devastating complication of instrumented orthopaedic surgery, particularly in the spine. Bacterial biofilms, once formed on the implant surfaces, exhibit antibiotic tolerance and immune escape, which lead to treatment challenges. Up to 9% of instrumented spine surgeries result in infection, despite the use of systemic antibiotics and local, powdered antibiotics for prophylaxis. The bacteria that survive the initial prophylaxis may be susceptible to a second, high dose of antibiotic prophylaxis prior to establishing at the site. Hence, we designed a local drug delivery system consisting of polylactic acid (PLA) film pockets that can be noninvasively triggered …

Seed Amplification Of Msa Alpha-Synuclein Aggregates Preserves The Biological And Structural Properties Of Brain-Derived Aggregates, Fei Wang, Victor Banerjee, Carla Barria, Santiago Ramirez, Tyler Allison, Damian Gorski, Haley Evans, Quynh Nguyen, Danielle Harrison, Rabab Al-Lahham, Nicole De Gregorio Carbonell, Michelle Pinho, Sanne Kaalund, Jonas Folke, Susana Aznar, Luis Concha-Marambio, Mohd Ishtikhar, Venkata Kps Mallampalli, Sandra Pritzkow, Mohammad Shahnawaz, Matthew L Baker, Irina Serysheva, Claudio Soto

Faculty, Staff and Student Publications

Parkinson's disease (PD), Dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), are characterized by the misfolding and aggregation of alpha-synuclein (αSyn). Compelling evidence showed that αSyn aggregates exist as distinct conformational strains in different synucleinopathies. Recently, we reported that the αSyn Seed Amplification Assay (αSyn-SAA) can amplify and distinguish αSyn strains from PD and MSA. In this study, we investigate whether MSA-seeded, SAA-amplified αSyn fibrils retain the biological and structural properties of the αSyn seeds present in MSA brains. We study the biological activities of both brain-derived and SAA-amplified αSyn aggregates using an αSyn "biosensor" cell model and …

Tgfbr2 Coordinates The Endometrial Response To Estrogen, Regulating Endometrial Hyperplasia And Fertility, Sydney E Parks, Suni Tang, Anna Catherine Unser, Ananya L Bhonsley, Eunbi M Chung, Peixin Jiang, Audrey Savolainen, Vanessa J Joseph, Dominique I Cope, Ramya P Masand, Renata Prunskaite-Hyyryläinen, Diana Monsivais

Faculty, Staff and Students Publications

Proper endometrial function is critical for establishing and maintaining healthy pregnancies, as well as preventing the pathogenesis of conditions such as endometrial hyperplasia and endometrial cancer. The TGFβ signaling pathway regulates key aspects of endometrial biology, although the direct effects of many individual receptors remain unstudied. In this study, we characterize the role of TGFβR2 within the endometrium using a progesterone receptor-cre conditional knock-out mouse model (Tgfbr2flox/flox;Pgrcre/+; “Tgfbr2 cKO”). We found that conditional deletion of TGFβR2 resulted in female infertility, endometrial hyperplasia, altered estrogen and progesterone response, and, only in bred females, reproductive tract …

Glycoside Hydrolase-Mediated Glucomannan Catabolism In Segatella Copri, A Target Of Microbiota-Directed Foods For Malnourished Children, Cyrus Zhou, Matthew C Hibberd, Evan M Lee, Suzanne Henrissat, Marie A Crane, Jiye Cheng, Michael J Barratt, Jeffrey I Gordon, Et Al.

2020-Current year OA Pubs

Evidence is emerging that perturbed postnatal gut microbiota development is causally related to childhood undernutrition. Clinical trials in undernourished Bangladeshi children found that a polysaccharide-rich, microbiota-directed complementary food (MDCF-2) designed to repair this perturbation produced superior ponderal and linear growth compared to a standard ready-to-use supplementary food. Subsequent analyses disclosed several candidate bioactive polysaccharides in the MDCF and their bacterial targets, notably strains of

The Breakdown Of Neurovascular Barriers: Molecular Mechanisms Of Tight Junction Dysfunction, Sowmya Shree Gopal, Mandeep Kaur, Sophie Lanzkron, Amit K. Srivastava

Department of Medicine Faculty Papers

The central nervous system (CNS) relies on tightly regulated barriers to maintain homeostasis and protect neural tissue from blood-borne toxins, pathogens, and inflammatory mediators. Tight junctions (TJs) are critical components of the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB), forming selective paracellular seals that regulate molecular trafficking. These structures comprise transmembrane proteins and cytoplasmic scaffolding proteins, which anchor TJs to the actin cytoskeleton. The spatial organization and function of TJs are dynamically regulated by calcium-dependent signaling, phosphorylation events, and G-protein-mediated pathways, which govern their assembly, disassembly, and response to physiological and pathological stimuli. The integrity of TJ complexes is …

Myocardial Lipin1 Protects The Heart Against Ischemic Injury By Preserving Lipid Homeostasis, Jiaxi Guo, Brian N. Finck, Et Al.

2020-Current year OA Pubs

Impaired cardiac lipid metabolism has been reported to cause heart failure. Lipin1, a multifunctional protein, is a phosphatidate phosphatase that generates diacylglycerol from phosphatidic acid and a transcriptional cofactor that regulates lipid metabolism-related gene expression. Here, we investigated the roles of lipin1 in cardiac remodeling after myocardial infarction (MI). The expression levels of lipin1 significantly decreased in cardiomyocytes of the human failing heart and murine ischemic myocardium. Cardiomyocyte-specific Lpin1 knockout (cKO) mice showed left ventricle enlargement and reduced fractional shortening after MI, compared with control mice. This was accompanied by elevated cardiac fibrosis, accumulation of reactive oxygen species, and increased …

Liver Injury In A Preclinical Model Of Short Bowel Syndrome Is Associated With Impaired Autophagy, Daniel M Alligood, Alex Park, Kerry Swanson, Naima Pyarali, Evan Mayse, David M Alvarado, Xiuli Liu, Jae-Sung Kim, Nicholas O Davidson, Deborah C Rubin, Jun Guo, Brad W Warner

2020-Current year OA Pubs

Critical for cellular maintenance and repair, autophagy recycles damaged or redundant cellular components. Dysregulated autophagy is associated with progressive cellular injury in various liver pathologies. However, the role of autophagy in intestinal failure-associated liver disease has not previously been investigated. Using a preclinical murine model of short bowel syndrome, we explored the role of autophagy impairment at early and late time points. Regardless of sex, small bowel resected (SBR) mice demonstrated significant liver injury compared to sham controls, exhibiting elevated serum transaminases, altered liver histology, and increased mRNA expression of endoplasmic reticulum stress marker (Ddit3) and oxidative stress marker (Nqo1). …

Insm1 Governs A Neuronal Progenitor State That Drives Glioblastoma In A Human Stem Cell Model, Patrick A Desouza, Matthew Ishahak, Xuan Qu, Colin Mccornack, Devi Annamalai, Diane D Mao, Rajanikanth Vangipurapu, Yiwei Fu, Alexandre T Vessoni, Ryan T Cleary, Rowland H Han, Punn Augsornworawat, Timothy Woodiwiss, Darby Agovino, Braxton Sizemore, Jessica Kline, Maryam Borhani-Haghighi, Hao Chen, Sangami Pugazenthi, Hiroko Yano, Ting Wang, Luis F Z Batista, Jeffrey R Millman, Albert H Kim

2020-Current year OA Pubs

Glioblastoma is a lethal brain cancer marked by functional plasticity driven by tumor cell-intrinsic mutations and their interplay with developmental programs. To investigate how canonical glioblastoma mutations promote functional plasticity, we have developed an isogenic human neural stem cell (NSC) model of glioblastoma by sequential addition of TERT promoter, TP53, and PDGFRA point mutations. TP53 loss-of-function increases TERT expression during serial mutagenesis, but only triple mutant NSCs reliably form lethal brain tumors in vivo that recapitulate glioblastoma. Tumor cell evolution triggers stress-related metabolic changes and transitions toward a neuronal progenitor network driven by transcription factor INSM1. INSM1 is highly expressed …

Actin Dysregulation Induces Neuroendocrine Plasticity And Immune Evasion: A Vulnerability Of Small Cell Lung Cancer, Yoojeong Seo, Shengzhe Zhang, Jinho Jang, Kyung-Pil Ko, Kee-Beom Kim, Yuanjian Huang, Dong-Wook Kim, Bongjun Kim, Gengyi Zou, Jie Zhang, Sohee Jun, Wonhong Chu, Nicole A Kirk, Ye Eun Hwang, Young Ho Ban, Shilpa S Dhar, Joseph M Chan, Min Gyu Lee, Charles M Rudin, Kwon-Sik Park, Jae-Il Park

Faculty, Staff and Student Publications

Small cell lung cancer (SCLC) is an aggressive malignancy with limited therapeutic options. Capping protein inhibiting regulator of actin dynamics (CRACD) that promotes actin polymerization, is frequently inactivated in SCLC. However, the role of CRACD loss in SCLC is unknown. Here we show that CRACD depletion drives neuroendocrine (NE) cell plasticity and immune evasion in SCLC. Mechanistically, CRACD inactivation disrupts actin organization, leading to suppression of Yap1-NOTCH signaling and subsequent NE gene upregulation. Simultaneously, CRACD loss drives EZH2-mediated histone methylation via nuclear actin disruption, leading to repression of MHC-I genes and depletion of CD8⁺ T cells. Consequently, CRACD-downregulated tumors exhibit …

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. …

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+ ] …

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 …

Pitx2 Dosage-Dependent Changes In Pacemaker Cell State Underlie Sinus Node Dysfunction And Atrial Arrhythmias, Lieve E Van Der Maarel, M Ridwane Mungroo, Otto J Mulleners, Mathilde R Rivaud, Arie O Verkerk, Karel Van Duijvenboden, Freek H T Tiel Groenestege, Jeffrey D Steimle, Lianne Fokkert, Corrie De Gier-De Vries, Mischa Klerk, Arie R Boender, James F Martin, Bjarke Jensen, Gerard J J Boink, Harsha D Devalla, Vincent M Christoffels

Faculty, Staff and Students Publications

Physiologically relevant increases in transcription factor dosage and their role in development and disease remain largely unexplored. Genomic deletions upstream of the Paired-like homeodomain transcription factor gene (PITX2), identified in patients with sinus node dysfunction and atrial fibrillation and modeled in mice (delB), rewire the local epigenetic landscape, increasing PITX2 expression. Here, we demonstrate that pacemaker cardiomyocytes in the embryonic delB sinus node ectopically express PITX2 at physiological dosages in a heterogeneous pattern. The prenatal delB sinus node forms discrete subdomains showing PITX2 dosage-dependent mild or severe loss of pacemaker cardiomyocyte identity. Respective subdomain sizes and severity of sinus node …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Impact Of Antibody Fc Engineering On Translational Pharmacology, And Safety: Insights From Industry Case Studies., Frank R Brennan, J Ryan Polli, Jean Sathish, Melissa Ramones, Babette Wolf, Tilman Schlothauer, Shirley J Peters, Curtis C Maier, Changhua Ji, David L Wensel, Derrick Witcher, Patricia C Ryan, T Scott Manetz, Adriano Flora, Brian Soper, Birgit Fogal, Lindsey Dzielak, Xiaoting Wang, Prathap Nagaraja Shastri, Karen Price, Michael Doyle, Nidhi Sharda, Mary Struthers, Maximilian Brinkhaus, Bianca Balbino, Eric Stefanich, Masaki Honda, Jan Terje Andersen, Shermaine Mitchell-Ryan, David P Humphreys

Faculty Research 2025

Therapeutic monoclonal antibodies (mAbs) are often designed to not only bind targets via their antigen-binding domains (Fabs) but to also engage with cell surface receptors, FcγRs and FcRn, through their Fc regions, which may result in a variety of functional outcomes, including antibody- dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), complement-dependent cytotoxicity (CDC) and alteration of circulating half-lives. Engineering the Fc regions to achieve desirable pharmacology and pharmacokinetics is a widely adopted strategy in drug development. Fc regions can be modified through amino acid substitutions and glycoengineering, resulting in enhanced or reduced effector functions, preferential binding to FcR subtypes, …

Low-Coverage Whole-Genome Sequencing Facilitates Accurate And Cost-Effective Haplotype Reconstruction In Complex Mouse Crosses., Samuel J Widmayer, Lydia K Wooldridge, Emily Swanzey, Mary Barter, Chrystal M Snow, Michael C Saul, Qingchang Meng, Beth L Dumont, Laura G Reinholdt, Daniel M Gatti

Faculty Research 2025

The search for the underlying genetic contributions to complex traits and diseases relies on accurate genetic data from populations of interest. Outbred populations, like the Diversity Outbred (DO), are commonly genotyped using commercial SNP arrays, such as the Giga Mouse Universal Genotyping Array (GigaMUGA). However, array genotypes are expensive to collect, subject to significant ascertainment bias, and too sparse to capture the genetic structure of highly recombined mouse crosses. We investigated the efficacy of sequencing-based genotyping by comparing genotyping results between the GigaMUGA, double-digest restriction-site associated DNA sequencing (ddRADseq), and low-coverage whole-genome sequencing (lcWGS). We aligned reads at ~ 1× …

Pak1 Inhibitor Nvs-Pak1-1 Preserves Dendritic Spines In Amyloid/Tau Exposed Neurons And 5xfad Mice., Tao Yang, Hasi Huhe, Sean-Paul Williams, Sukhneet Kaur, Yeonglong Albert Ay, Zachary W Davis-Gilbert, Gregory Cary, Carolyn Paisie, Robert R Butler, Jesse Wiley, Ranjita Betarbet, Haian Fu, Duc Duong, Nicholas T Seyfried, Karina Leal, Gregory W. Carter, Aled Edwards, Allan I Levey, Jacob L Capener, David H Drewry, Mohammad A Hossain, Hans J Oh, Alison D Axtman, Stacey J Sukoff Rizzo, Frank M Longo, The Emory-Sage-Sgc-Jax Treat-Ad Center

Faculty Research 2025

INTRODUCTION: Synaptic spine loss in Alzheimer's disease (AD) contributes to cognitive decline. p21-activated kinase 1 (PAK1), a regulator of spine integrity, is aberrantly activated in AD. We investigated whether PAK1 inhibition might preserve dendritic spines in vitro and in vivo.

METHODS: Oligomeric amyloid beta (oAβ) or tau (oTau) were applied to hippocampal neurons ± NVS-PAK1-1, a selective PAK1 inhibitor. NVS-PAK1-1 was orally administered to 5xFAD mice. The effects of NVS-PAK1-1 treatment on PAK1 activity, spine density, and the proteome were assessed using phospho-PAK1 (pPAK1) western blotting, Golgi staining, and mass spectrometry for proteomic analyses.

RESULTS: NVS-PAK1-1 prevented oAβ and oTau-induced …

Integrated Phenotypic And Proteomic Screening Identifies Top-Tier Alzheimer's Disease Therapeutic Targets., Gregory Cary, Qianjin Li, Jesse C Wiley, Carolyn Paisie, Yuhong Du, Elizabeth L Zoeller, Duc Duong, Haian Fu, Nicholas T Seyfried, Allan I Levey, Ranjita Betarbet, Gregory W. Carter, The Emory-Sage-Sgc-Jax Treat-Ad Center

Faculty Research 2025

INTRODUCTION: Alzheimer's disease (AD) is a complex neurodegenerative disorder. Hundreds of therapeutic targets have been nominated through genetic and multi-omic studies, but effective prioritization remains a major bottleneck.

METHODS: We applied an integrative screening framework to assess 29 candidate targets from risk-enriched biological domains. Using disease-relevant murine BV2 microglial cell lines with stable Psen2 knockdown, we performed small interfering RNA-mediated perturbations followed by cellular phenotypic assays and quantitative proteomics.

RESULTS: Twenty-five candidate targets significantly altered at least one phenotype, with stronger effects in Psen2 knockdown cells. Integrated proteomic analyses identified several perturbations that reversed AD-associated molecular patterns. Five targets-Ap2a2, Pdhb, …