Digital Commons Network^™

Maternal Iron Deficiency Programs Rat Offspring Hypertension In Relation To Renin-Angiotensin System And Oxidative Stress, Ya-Hui Chang, Wan-Hsuan Chen, Chung-Hao Su, Hong-Ren Yu, You-Lin Tain, Li-Tung Huang, Jiunn-Ming Sheen

Faculty, Staff and Student Publications

Hypertension is an important public health challenge, affecting up to 30-50% of adults worldwide. Several epidemiological studies indicate that high blood pressure originates in fetal life-the so-called programming effect or developmental origin of hypertension. Iron-deficiency anemia has become one of the most prevalent nutritional problems globally. Previous animal experiments have shown that prenatal iron-deficiency anemia adversely affects offspring hypertension. However, the underlying mechanism remains unclear. We used a maternal low-iron diet Sprague Dawley rat model to study changes in blood pressure, the renal renin-angiotensin system, oxidative stress, inflammation, and sodium transporters in adult male offspring. Our study revealed that 16-week-old …

Slc12a8 In The Lateral Hypothalamus Maintains Energy Metabolism And Skeletal Muscle Functions During Aging, Naoki Ito, Ai Takatsu, Hiromi Ito, Yuka Koike, Kiyoshi Yoshioka, Yasutomi Kamei, Shin-Ichiro Imai

2020-Current year OA Pubs

Sarcopenia and frailty are urgent socio-economic problems worldwide. Here we demonstrate a functional connection between the lateral hypothalamus (LH) and skeletal muscle through Slc12a8, a recently identified nicotinamide mononucleotide transporter, and its relationship to sarcopenia and frailty. Slc12a8-expressing cells are mainly localized in the LH. LH-specific knockdown of Slc12a8 in young mice decreases activity-dependent energy and carbohydrate expenditure and skeletal muscle functions, including muscle mass, muscle force, intramuscular glycolysis, and protein synthesis. LH-specific Slc12a8 knockdown also decreases sympathetic nerve signals at neuromuscular junctions and β2-adrenergic receptors in skeletal muscle, indicating the importance of the LH-sympathetic nerve-β2-adrenergic receptor axis. LH-specific overexpression …

Targeting De Novo Lipogenesis And The Lands Cycle Induces Ferroptosis In Kras-Mutant Lung Cancer, Caterina Bartolacci, Cristina Andreani, Gonçalo Vale, Stefano Berto, Margherita Melegari, Anna Colleen Crouch, Dodge L Baluya, George Kemble, Kurt Hodges, Jacqueline Starrett, Katerina Politi, Sandra L Starnes, Daniele Lorenzini, Maria Gabriela Raso, Luisa M Solis Soto, Carmen Behrens, Humam Kadara, Boning Gao, Ignacio I Wistuba, John D Minna, Jeffrey G Mcdonald, Pier Paolo Scaglioni

Faculty, Staff and Student Publications

Mutant KRAS (KM), the most common oncogene in lung cancer (LC), regulates fatty acid (FA) metabolism. However, the role of FA in LC tumorigenesis is still not sufficiently characterized. Here, we show that KMLC has a specific lipid profile, with high triacylglycerides and phosphatidylcholines (PC). We demonstrate that FASN, the rate-limiting enzyme in FA synthesis, while being dispensable in EGFR-mutant or wild-type KRAS LC, is required for the viability of KMLC cells. Integrating lipidomic, transcriptomic and functional analyses, we demonstrate that FASN provides saturated and monounsaturated FA to the Lands cycle, the process remodeling oxidized phospholipids, such as PC. Accordingly, …

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

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

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

Regulated Dicing Of Pre-Mir-144 Via Reshaping Of Its Terminal Loop., Renfu Shang, Dmitry A Kretov, Scott I Adamson, Thomas Treiber, Nora Treiber, Jeffrey Vedanayagam, Jeffrey H Chuang, Gunter Meister, Daniel Cifuentes, Eric C Lai

Faculty Research 2022

Although the route to generate microRNAs (miRNAs) is often depicted as a linear series of sequential and constitutive cleavages, we now appreciate multiple alternative pathways as well as diverse strategies to modulate their processing and function. Here, we identify an unusually profound regulatory role of conserved loop sequences in vertebrate pre-mir-144, which are essential for its cleavage by the Dicer RNase III enzyme in human and zebrafish models. Our data indicate that pre-mir-144 dicing is positively regulated via its terminal loop, and involves the ILF3 complex (NF90 and its partner NF45/ILF2). We provide further evidence that this regulatory switch involves …

Sirpα Mediates Igf1 Receptor In Cardiomyopathy-Induced By Chronic Kidney Disease, Sandhya S Thomas, Jiao Wu, Giovanni Davogustto, Michael W Holliday, Kristin Eckel-Mahan, Daniela Verzola, Giacomo Garibotto, Zhaoyong Hu, William E Mitch, Heinrich Taegtmeyer

Faculty, Staff and Student Publications

BACKGROUND: Chronic kidney disease (CKD) is characterized by increased myocardial mass despite near-normal blood pressure, suggesting the presence of a separate trigger. A potential driver is SIRPα (signal regulatory protein alpha)-a mediator impairing insulin signaling. The objective of this study is to assess the role of circulating SIRPα in CKD-induced adverse cardiac remodeling.

METHODS: SIRPα expression was evaluated in mouse models and patients with CKD. Specifically, mutant, muscle-specific, or cardiac muscle-specific SIRPα KO (knockout) mice were examined after subtotal nephrectomy. Cardiac function was assessed by echocardiography. Metabolic responses were confirmed in cultured muscle cells or cardiomyocytes.

RESULTS: We demonstrate that …

Myt1l In The Making: Emerging Insights On Functions Of A Neurodevelopmental Disorder Gene, Jiayang Chen, Allen Yen, Colin P Florian, Joseph D Dougherty

2020-Current year OA Pubs

Large scale human genetic studies have shown that loss of function (LoF) mutations in MYT1L are implicated in neurodevelopmental disorders (NDDs). Here, we provide an overview of the growing number of published MYT1L patient cases, and summarize prior studies in cells, zebrafish, and mice, both to understand MYT1L's molecular and cellular role during brain development and consider how its dysfunction can lead to NDDs. We integrate the conclusions from these studies and highlight conflicting findings to reassess the current model of the role of MYT1L as a transcriptional activator and/or repressor based on the biological context. Finally, we highlight additional …

Advanced-Stage Melanoma At Presentation Following The Peak Of The Pandemic: A Covid-19 Cancer Canary In A Coal Mine, Ryan Lamm, Md, Walker Lyons, Md, Winnie So, Rn, Alliric I. Willis, Md, Facs, Msph

Department of Surgery Faculty Papers

Background: For melanoma patients, timely identification and tumor thickness are directly correlated with outcomes. COVID-19 impacted both patients' ability and desire to see physicians. We sought to identify whether the pandemic correlated with changes in melanoma thickness at presentation and subsequent treatment timeline.

Methods: Retrospective chart review was performed on patients who underwent surgery for melanoma in an academic center surgical oncology practice from May 2019 to September 2021. Patients were split into two cohorts: "pre-pandemic" from May 2019 to May 2020 and "pandemic," after May 2020, representing when these patients received their initial diagnostic biopsy. Demographic and melanoma-specific variables …

A Phospholipid Mimetic Targeting Lrh-1 Ameliorates Colitis, Suzanne G Mays, Emma H D'Agostino, Autumn R Flynn, Xiangsheng Huang, Guohui Wang, Xu Liu, Elizabeth J Millings, C Denise Okafor, Anamika Patel, Michael L Cato, Jeffery L Cornelison, Diana Melchers, René Houtman, David D Moore, John W Calvert, Nathan T Jui, Eric A Ortlund

Faculty, Staff and Students Publications

Phospholipids are ligands for nuclear hormone receptors (NRs) that regulate transcriptional programs relevant to normal physiology and disease. Here, we demonstrate that mimicking phospholipid-NR interactions is a robust strategy to improve agonists of liver receptor homolog-1 (LRH-1), a therapeutic target for colitis. Conventional LRH-1 modulators only partially occupy the binding pocket, leaving vacant a region important for phospholipid binding and allostery. Therefore, we constructed a set of molecules with elements of natural phospholipids appended to a synthetic LRH-1 agonist. We show that the phospholipid-mimicking groups interact with the targeted residues in crystal structures and improve binding affinity, LRH-1 transcriptional activity, …

Kathryn V. Holmes: A Career Of Contributions To The Coronavirus Field, Aurelio Bonavia, Samuel R Dominguez, Gabriela Dveksler, Sara Gagneten, Megan Howard, Scott Jeffers, Zhaohui Qian, Mary Kathryn Smith, Larissa B Thackray, Dina B Tresnan, David E Wentworth, David R Wessner, Richard K Williams, Tanya A Miura

2020-Current year OA Pubs

Over the past two years, scientific research has moved at an unprecedented rate in response to the COVID-19 pandemic. The rapid development of effective vaccines and therapeutics would not have been possible without extensive background knowledge on coronaviruses developed over decades by researchers, including Kathryn (Kay) Holmes. Kay's research team discovered the first coronavirus receptors for mouse hepatitis virus and human coronavirus 229E and contributed a wealth of information on coronaviral spike glycoproteins and receptor interactions that are critical determinants of host and tissue specificity. She collaborated with several research laboratories to contribute knowledge in additional areas, including coronaviral pathogenesis, …

Paclitaxel And Urolithin A Prevent Histamine-Induced Neurovascular Breakdown Alike, In An, Srijayaprakash Uppada, Dianxiong Zou, Erin M Scott, Gladys Ko, Stephen Pflugfelder, M N V Ravi Kumar, Raghu Ganugula

Faculty, Staff and Students Publications

Neurovascular eye problems are better prevented than managed or treated. Despite growing concern of occurrence in aging populations and development secondary to diseases such as diabetes and hypertension, we currently have very few options to tackle this global problem. Creating effective and high-throughput screening strategies is as important as the intervention itself. Here, we present for the first time a robust ex vivo rat eye model of histamine-induced vascular damage for investigating the therapeutic potential of paclitaxel (PTX) and urolithin A (UA) as alternatives to dexamethasone for preventing vascular damage in the retina. Extensive loss of vascularization and apoptosis were …

Acrylamide Inhibits Long-Term Potentiation And Learning Involving Microglia And Pro-Inflammatory Signaling, Yukitoshi Izumi, Chika Fujii, Kazuko A O'Dell, Charles F Zorumski

2020-Current year OA Pubs

Acrylamide is a chemical used in various industries and a product following high-temperature cooking of vegetables containing asparagine. Environmental or dietary exposure to acrylamide could impair cognitive function because of its neurotoxicity. Using rat hippocampal slices, we tested whether acrylamide alters induction of long-term potentiation (LTP), a cellular model of learning and memory. We hypothesized that acrylamide impairs cognitive function via activation of pro-inflammatory cytokines because robust upregulation of NLRP3 inflammasome has been reported. Although acrylamide up to 3 mM did not alter basal synaptic transmission, incubation with 10 μM or acute administration of 100 μM acrylamide inhibited induction of …

Hippo-Taz Signaling Is The Master Regulator Of The Onset Of Triple-Negative Basal-Like Breast Cancers, Hirotoshi Soyama, Miki Nishio, Junji Otani, Toshiko Sakuma, Shintaro Takao, Shigeo Hara, Takaaki Masuda, Koshi Mimori, Shinya Toyokuni, John P Lydon, Kazuwa Nakao, Hiroshi Nishina, Takumi Fukumoto, Tomohiko Maehama, Akira Suzuki

Faculty, Staff and Students Publications

A universal oncogenic driver of basal-like breast cancer (BLBC) has resisted identification. We show that continuous transcriptional coactivator with PDZ-binding motif (TAZ) activation in precancerous murine luminal cells generates luminal cancers that later become BLBCs. Subsequent TP53 alteration, a feature of invasive human BLBCs, accelerates tumor progression. Because BLBC development is inhibited by TAZ inactivation in vivo, our work provides a sound rationale for targeting Hippo-TAZ signaling as therapy for human BLBC. Our mouse model of BLBC represents a powerful tool for evaluating such drugs.

The Hippo Pathway Regulates Axis Formation And Morphogenesis In Hydra, Maria Brooun, Willi Salvenmoser, Catherine Dana, Marius Sudol, Robert Steele, Bert Hobmayer, Helen Mcneill

2020-Current year OA Pubs

How did cells of early metazoan organisms first organize themselves to form a body axis? The canonical Wnt pathway has been shown to be sufficient for induction of axis in Cnidaria, a sister group to Bilateria, and is important in bilaterian axis formation. Here, we provide experimental evidence that in cnidarian

Sox9 Directs Divergent Epigenomic States In Brain Tumor Subtypes, Debosmita Sardar, Hsiao-Chi Chen, Amanda Reyes, Srinidhi Varadharajan, Antrix Jain, Carrie Mohila, Rachel Curry, Brittney Lozzi, Kavitha Rajendran, Alexis Cervantes, Kwanha Yu, Ali Jalali, Ganesh Rao, Stephen C Mack, Benjamin Deneen

Duncan NRI Faculty and Staff Publications

Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations; however, the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here, we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). Using our autochthonous mouse models, we found that Sox9 suppresses HGG growth and expands associated H3K27ac states, while promoting ZFTA-RELA (ZR

Cranial Base Synchondrosis Lacks Pthrp-Expressing Column-Forming Chondrocytes, Shawn A Hallett, Annabelle Zhou, Curtis Herzog, Ariel Arbiv, Wanida Ono, Noriaki Ono

Faculty, Staff and Student Publications

The cranial base contains a special type of growth plate termed the synchondrosis, which functions as the growth center of the skull. The synchondrosis is composed of bidirectional opposite-facing layers of resting, proliferating, and hypertrophic chondrocytes, and lacks the secondary ossification center. In long bones, the resting zone of the epiphyseal growth plate houses a population of parathyroid hormone-related protein (PTHrP)-expressing chondrocytes that contribute to the formation of columnar chondrocytes. Whether PTHrP+ chondrocytes in the synchondrosis possess similar functions remains undefined. Using Pthrp-mCherry knock-in mice, we found that PTHrP+ chondrocytes predominantly occupied the lateral wedge-shaped area of the synchondrosis, unlike …

Α-Synuclein Conformational Plasticity: Physiologic States, Pathologic Strains, And Biotechnological Applications, Amanda Li, Cyrus Rastegar, Xiaobo Mao

2020-Current year OA Pubs

α-Synuclein (αS) is remarkable for both its extensive conformational plasticity and pathologic prion-like properties. Physiologically, αS may populate disordered monomeric, helically folded tetrameric, or membrane-bound oligomeric states. Pathologically, αS may assemble into toxic oligomers and subsequently fibrils, the prion-like transmission of which is implicated in a class of neurodegenerative disorders collectively termed α-synucleinopathies. Notably, αS does not adopt a single "amyloid fold", but rather exists as structurally distinct amyloid-like conformations referred to as "strains". The inoculation of animal models with different strains induces distinct pathologies, and emerging evidence suggests that the propagation of disease-specific strains underlies the differential pathologies observed …

Neuronal Activity Induces Glucosylceramide That Is Secreted Via Exosomes For Lysosomal Degradation In Glia, Liping Wang, Guang Lin, Zhongyuan Zuo, Yarong Li, Seul Kee Byeon, Akhilesh Pandey, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

Recessive variants in GBA1 cause Gaucher disease, a prevalent form of lysosome storage disease. GBA1 encodes a lysosomal enzyme that hydrolyzes glucosylceramide (GlcCer) into glucose and ceramide. Its loss causes lysosomal dysfunction and increased levels of GlcCer. We generated a null allele of the Drosophila ortholog Gba1b by inserting the Gal4 using CRISPR-Cas9. Here, we show that Gba1b is expressed in glia but not in neurons. Glial-specific knockdown recapitulates the defects found in Gba1b mutants, and these can be rescued by glial expression of human GBA1. We show that GlcCer is synthesized upon neuronal activity, and it is transported …

Impairing Proliferation Of Glioblastoma Multiforme With Cd44+ Selective Conjugated Polymer Nanoparticles, Dorota Lubanska, Sami Alrashed, Gage T. Mason, Fatima Nadeem, Angela Awada, Mitchell Dipasquale, Alexandra Sorge, Aleena Malik, Monika Kojic, Mohamed A. R Soliman, Ana C. De Carvalho, Abdalla Shamisa, Swati Kulkarni, Drew Marquardt, Lisa A. Porter, Simon Rondeau-Gagné

Neurosurgery Articles

Glioblastoma is one of the most aggressive types of cancer with success of therapy being hampered by the existence of treatment resistant populations of stem-like Tumour Initiating Cells (TICs) and poor blood-brain barrier drug penetration. Therapies capable of effectively targeting the TIC population are in high demand. Here, we synthesize spherical diketopyrrolopyrrole-based Conjugated Polymer Nanoparticles (CPNs) with an average diameter of 109 nm. CPNs were designed to include fluorescein-conjugated Hyaluronic Acid (HA), a ligand for the CD44 receptor present on one population of TICs. We demonstrate blood-brain barrier permeability of this system and concentration and cell cycle phase-dependent selective uptake …

Impairing Proliferation Of Glioblastoma Multiforme With Cd44+ Selective Conjugated Polymer Nanoparticles, Dorota Lubanska, Sami Alrashed, Gage T Mason, Fatima Nadeem, Angela Awada, Mitchell Dipasquale, Alexandra Sorge, Aleena Malik, Monika Kojic, Mohamed A R Soliman, Ana C Decarvalho, Abdalla Shamisa, Swati Kulkarni, Drew Marquardt, Lisa A Porter, Simon Rondeau-Gagné

Faculty, Staff and Student Publications

Glioblastoma is one of the most aggressive types of cancer with success of therapy being hampered by the existence of treatment resistant populations of stem-like Tumour Initiating Cells (TICs) and poor blood-brain barrier drug penetration. Therapies capable of effectively targeting the TIC population are in high demand. Here, we synthesize spherical diketopyrrolopyrrole-based Conjugated Polymer Nanoparticles (CPNs) with an average diameter of 109 nm. CPNs were designed to include fluorescein-conjugated Hyaluronic Acid (HA), a ligand for the CD44 receptor present on one population of TICs. We demonstrate blood-brain barrier permeability of this system and concentration and cell cycle phase-dependent selective uptake …

Cd11bhigh B Cells Increase After Stroke And Regulate Microglia: Cd11bhigh B Cells Increase After Stroke And Regulate Mg, Janelle M Korf, Pedram Honarpisheh, Eric C Mohan, Anik Banerjee, Maria P Blasco-Conesa, Parisa Honarpisheh, Gary U Guzman, Romeesa Khan, Bhanu P Ganesh, Amy L Hazen, Juneyoung Lee, Aditya Kumar, Louise D Mccullough, Anjali Chauhan

Faculty, Staff and Student Publications

Recent studies have highlighted the deleterious contributions of B cells to post-stroke recovery and cognitive decline. Different B cell subsets have been proposed based on expression levels of transcription factors (e.g. T-bet) as well as specific surface proteins. CD11b (α-chain of integrin) is expressed by several immune cell types and is involved in regulation of cell motility, phagocytosis, and other essential functions of host immunity. Although B cells express CD11b, the CD11b^high subset of B cells has not been well characterized, especially in immune dysregulation seen with aging and after stroke. Here, we investigate the role of CD11b^{high …}

Infiltration Of Peripheral Immune Cells Into The Olfactory Bulb In A Mouse Model Of Acute Nasal Inflammation, Hinami Asano, Sanae Hasegawa-Ishii, Ken Arae, Aki Obara, Geoffroy Laumet, Robert Dantzer, Atsuyoshi Shimada

Faculty, Staff and Student Publications

Chronic nasal inflammation induces robust olfactory bulb (OB) atrophy in mice. Here we examined initial events that occur in the OB after bilateral intranasal administration of lipopolysaccharide, focusing on the olfactory nerve fibers and meninges. We analyzed the time course of OB and meninges inflammation using histological and biochemical approaches. Within 12 h, we observed increased chemokine expression and transient infiltration of peripheral immune cells into the OB, resulting in the development of pro-inflammatory status in the OB. Meningeal immunity was activated. Resident microglia produced anti-inflammatory cytokines within 24 h. These could be the initial events that lead to OB …

Cd11b Suppresses Tlr Activation Of Nonclassical Monocytes To Reduce Primary Graft Dysfunction After Lung Transplantation, Melissa Querrey, Stephen Chiu, Emilia Lecuona, Qiang Wu, Haiying Sun, Megan Anderson, Megan Kelly, Sowmya Ravi, Alexander V. Misharin, Daniel Kreisel, Ankit Bharat, G. R. Scott Budinger

2020-Current year OA Pubs

Primary graft dysfunction (PGD) is the leading cause of postoperative mortality in lung transplant recipients and the most important risk factor for development of chronic lung allograft dysfunction. The mechanistic basis for the variability in the incidence and severity of PGD between lung transplant recipients is not known. Using a murine orthotopic vascularized lung transplant model, we found that redundant activation of Toll-like receptors 2 and 4 (TLR2 and -4) on nonclassical monocytes activates MyD88, inducing the release of the neutrophil attractant chemokine CXCL2. Deletion of Itgam (encodes CD11b) in nonclassical monocytes enhanced their production of CXCL2 and worsened PGD, …

Slitrk2 Variants Associated With Neurodevelopmental Disorders Impair Excitatory Synaptic Function And Cognition In Mice, Salima El Chehadeh, Dorothy K Grange, Et Al

2020-Current year OA Pubs

SLITRK2 is a single-pass transmembrane protein expressed at postsynaptic neurons that regulates neurite outgrowth and excitatory synapse maintenance. In the present study, we report on rare variants (one nonsense and six missense variants) in SLITRK2 on the X chromosome identified by exome sequencing in individuals with neurodevelopmental disorders. Functional studies showed that some variants displayed impaired membrane transport and impaired excitatory synapse-promoting effects. Strikingly, these variations abolished the ability of SLITRK2 wild-type to reduce the levels of the receptor tyrosine kinase TrkB in neurons. Moreover, Slitrk2 conditional knockout mice exhibited impaired long-term memory and abnormal gait, recapitulating a subset of …

Gut Bacterial Isoamylamine Promotes Age-Related Cognitive Dysfunction By Promoting Microglial Cell Death, Yun Teng, Jingyao Mu, Fangyi Xu, Xiangcheng Zhang, Mukesh K Sriwastva, Qiaohong M Liu, Xiaohong Li, Chao Lei, Kumaran Sundaram, Xin Hu, Lifeng Zhang, Juw Won Park, Jae Yeon Hwang, Eric C Rouchka, Xiang Zhang, Jun Yan, Michael L Merchant, Huang-Ge Zhang

Faculty, Staff and Student Publications

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. …

The Testis-Specific E3 Ubiquitin Ligase Rnf133 Is Required For Fecundity In Mice, Kaori Nozawa, Yoshitaka Fujihara, Darius J Devlin, Ricardo E Deras, Katarzyna Kent, Irina V Larina, Kohei Umezu, Zhifeng Yu, Courtney M Sutton, Qiuji Ye, Laura K Dean, Chihiro Emori, Masahito Ikawa, Thomas X Garcia, Martin M Matzuk

Faculty, Staff and Students Publications

BACKGROUND: Ubiquitination is a post-translational modification required for a number of physiological functions regulating protein homeostasis, such as protein degradation. The endoplasmic reticulum (ER) quality control system recognizes and degrades proteins no longer needed in the ER through the ubiquitin-proteasome pathway. E2 and E3 enzymes containing a transmembrane domain have been shown to function in ER quality control. The ER transmembrane protein UBE2J1 is a E2 ubiquitin-conjugating enzyme reported to be essential for spermiogenesis at the elongating spermatid stage. Spermatids from Ube2j1 KO male mice are believed to have defects in the dislocation step of ER quality control. However, associated …

Renin-Angiotensin System In Huntington's Disease: Evidence From Animal Models And Human Patients, Lucas M Kangussu, Natalia P Rocha, Priscila A C Valadão, Thatiane C G Machado, Kívia B Soares, Julliane V Joviano-Santos, Leigh B Latham, Gabriela D Colpo, Ana Flávia Almeida-Santos, Erin Furr Stimming, Ana Cristina Simões E Silva, Antônio L Teixeira, Aline Silva Miranda, Cristina Guatimosim

Faculty, Staff and Student Publications

The Renin-Angiotensin System (RAS) is expressed in the central nervous system and has important functions that go beyond blood pressure regulation. Clinical and experimental studies have suggested that alterations in the brain RAS contribute to the development and progression of neurodegenerative diseases. However, there is limited information regarding the involvement of RAS components in Huntington's disease (HD). Herein, we used the HD murine model, (BACHD), as well as samples from patients with HD to investigate the role of both the classical and alternative axes of RAS in HD pathophysiology. BACHD mice displayed worse motor performance in different behavioral tests alongside …

Γ-Secretase Promotes Drosophila Postsynaptic Development Through The Cleavage Of A Wnt Receptor, Lucas J Restrepo, Alison T Depew, Elizabeth R Moese, Stephen R Tymanskyj, Michael J Parisi, Michael A Aimino, Juan Carlos Duhart, Hong Fei, Timothy J Mosca

Farber Institute for Neuroscience Faculty Papers

Developing synapses mature through the recruitment of specific proteins that stabilize presynaptic and postsynaptic structure and function. Wnt ligands signaling via Frizzled (Fz) receptors play many crucial roles in neuronal and synaptic development, but whether and how Wnt and Fz influence synaptic maturation is incompletely understood. Here, we show that Fz2 receptor cleavage via the γ-secretase complex is required for postsynaptic development and maturation. In the absence of γ-secretase, Drosophila neuromuscular synapses fail to recruit postsynaptic scaffolding and cytoskeletal proteins, leading to behavioral deficits. Introducing presenilin mutations linked to familial early-onset Alzheimer's disease into flies leads to synaptic maturation phenotypes …

Metabolic Requirement For Got2 In Pancreatic Cancer Depends On Environmental Context, Samuel A Kerk, Lin Lin, Amy L Myers, Damien J Sutton, Anthony Andren, Peter Sajjakulnukit, Li Zhang, Yaqing Zhang, Jennifer A Jiménez, Barbara S Nelson, Brandon Chen, Anthony Robinson, Galloway Thurston, Samantha B Kemp, Nina G Steele, Megan T Hoffman, Hui-Ju Wen, Daniel Long, Sarah E Ackenhusen, Johanna Ramos, Xiaohua Gao, Zeribe C Nwosu, Stefanie Galban, Christopher J Halbrook, David B Lombard, David R Piwnica-Worms, Haoqiang Ying, Marina Pasca Di Magliano, Howard C Crawford, Yatrik M Shah, Costas A Lyssiotis

Faculty, Staff and Student Publications

Mitochondrial glutamate-oxaloacetate transaminase 2 (GOT2) is part of the malate-aspartate shuttle, a mechanism by which cells transfer reducing equivalents from the cytosol to the mitochondria. GOT2 is a key component of mutant KRAS (KRAS*)-mediated rewiring of glutamine metabolism in pancreatic ductal adenocarcinoma (PDA). Here, we demonstrate that the loss of GOT2 disturbs redox homeostasis and halts proliferation of PDA cells in vitro. GOT2 knockdown (KD) in PDA cell lines in vitro induced NADH accumulation, decreased Asp and α-ketoglutarate (αKG) production, stalled glycolysis, disrupted the TCA cycle, and impaired proliferation. Oxidizing NADH through chemical or genetic means resolved the redox imbalance …

Interchromosomal Interaction Of Homologous Stat92e Alleles Regulates Transcriptional Switch During Stem-Cell Differentiation., Matthew Antel, Romir Raj, Madona Y G Masoud, Ziwei Pan, Sheng Li, Barbara G Mellone, Mayu Inaba

Faculty Research 2022

Pairing of homologous chromosomes in somatic cells provides the opportunity of interchromosomal interaction between homologous gene regions. In the Drosophila male germline, the Stat92E gene is highly expressed in a germline stem cell (GSC) and gradually downregulated during the differentiation. Here we show that the pairing of Stat92E is always tight in GSCs and immediately loosened in differentiating daughter cells, gonialblasts (GBs). Disturbance of Stat92E pairing by relocation of one locus to another chromosome or by knockdown of global pairing/anti-pairing factors both result in a failure of Stat92E downregulation, suggesting that the pairing is required for the decline in transcription. …