Medicine and Health Sciences Commons^™

Structures Of Channelrhodopsin Paralogs In Peptidiscs Explain Their Contrasting K+ And Na+ Selectivities, Takefumi Morizumi, Kyumhyuk Kim, Hai Li, Elena G Govorunova, Oleg A Sineshchekov, Yumei Wang, Lei Zheng, Éva Bertalan, Ana-Nicoleta Bondar, Azam Askari, Leonid S Brown, John L Spudich, Oliver P Ernst

Faculty, Staff and Student Publications

Kalium channelrhodopsin 1 from Hyphochytrium catenoides (HcKCR1) is a light-gated channel used for optogenetic silencing of mammalian neurons. It selects K+ over Na+ in the absence of the canonical tetrameric K+ selectivity filter found universally in voltage- and ligand-gated channels. The genome of H. catenoides also encodes a highly homologous cation channelrhodopsin (HcCCR), a Na+ channel with >100-fold larger Na+ to K+ permeability ratio. Here, we use cryo-electron microscopy to determine atomic structures of these two channels embedded in peptidiscs to elucidate structural foundations of their dramatically different cation selectivity. Together with structure-guided mutagenesis, we show …

Loss Of Function Mutation In Ank Causes Aberrant Mineralization And Acquisition Of Osteoblast-Like-Phenotype By The Cells Of The Intervertebral Disc, Takashi Ohnishi, Victoria Tran, Kimheak Sao, Pranay Ramteke, William Querido, Ruteja A. Barve, Koen Van De Wetering, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

Pathological mineralization of intervertebral disc is debilitating and painful and linked to disc degeneration in a subset of human patients. An adenosine triphosphate efflux transporter, progressive ankylosis (ANK) is a regulator of extracellular inorganic pyrophosphate levels and plays an important role in tissue mineralization. However, the function of ANK in intervertebral disc has not been fully explored. Herein we analyzed the spinal phenotype of Ank mutant mice (ank/ank) with attenuated ANK function. Micro-computed tomography and histological analysis showed that loss of ANK function results in the aberrant annulus fibrosus mineralization and peripheral disc fusions with cranial to caudal progression in …

Metastatic Infiltration Of Nervous Tissue And Periosteal Nerve Sprouting In Multiple Myeloma-Induced Bone Pain In Mice And Human, Marta Diaz-Delcastillo, Oana Palasca, Tim T Nemler, Didde M Thygesen, Norma A Chávez-Saldaña, Juan A Vázquez-Mora, Lizeth Y Ponce Gomez, Lars Juhl Jensen, Holly Evans, Rebecca E Andrews, Aritri Mandal, David Neves, Patrick Mehlen, James P Caruso, Patrick M Dougherty, Theodore J Price, Andrew Chantry, Michelle A Lawson, Thomas L Andersen, Juan M Jimenez-Andrade, Anne-Marie Heegaard

Faculty, Staff and Student Publications

Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with …

Metastatic Infiltration Of Nervous Tissue And Periosteal Nerve Sprouting In Multiple Myeloma-Induced Bone Pain In Mice And Human, Marta Diaz-Delcastillo, Oana Palasca, Tim T Nemler, Didde M Thygesen, Norma A Chávez-Saldaña, Juan A Vázquez-Mora, Lizeth Y Ponce Gomez, Lars Juhl Jensen, Holly Evans, Rebecca E Andrews, Aritri Mandal, David Neves, Patrick Mehlen, James P Caruso, Patrick M Dougherty, Theodore J Price, Andrew Chantry, Michelle A Lawson, Thomas L Andersen, Juan M Jimenez-Andrade, Anne-Marie Heegaard

Faculty, Staff and Student Publications

Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with …

Βii-Spectrin Is Required For Synaptic Positioning During Retinal Development, Debalina Goswami-Sewell, Caitlin Bagnetto, Cesiah C Gomez, Joseph T Anderson, Akash Maheshwari, Elizabeth Zuniga-Sanchez

Faculty, Staff and Students Publications

Neural circuit assembly is a multistep process where synaptic partners are often born at distinct developmental stages, and yet they must find each other and form precise synaptic connections with one another. This developmental process often relies on late-born neurons extending their processes to the appropriate layer to find and make synaptic connections to their early-born targets. The molecular mechanism responsible for the integration of late-born neurons into an emerging neural circuit remains unclear. Here, we uncovered a new role for the cytoskeletal protein βII-spectrin in properly positioning presynaptic and postsynaptic neurons to the developing synaptic layer. Loss of βII-spectrin …

Local And Long-Distance Organization Of Prefrontal Cortex Circuits In The Marmoset Brain, Akiya Watakabe, David C Van Essen, Et Al.

2020-Current year OA Pubs

The prefrontal cortex (PFC) has dramatically expanded in primates, but its organization and interactions with other brain regions are only partially understood. We performed high-resolution connectomic mapping of the marmoset PFC and found two contrasting corticocortical and corticostriatal projection patterns: "patchy" projections that formed many columns of submillimeter scale in nearby and distant regions and "diffuse" projections that spread widely across the cortex and striatum. Parcellation-free analyses revealed representations of PFC gradients in these projections' local and global distribution patterns. We also demonstrated column-scale precision of reciprocal corticocortical connectivity, suggesting that PFC contains a mosaic of discrete columns. Diffuse projections …

Loss Of Function Mutation In Ank Causes Aberrant Mineralization And Acquisition Of Osteoblast-Like-Phenotype By The Cells Of The Intervertebral Disc, Takashi Ohnishi, Victoria Tran, Kimheak Sao, Pranay Ramteke, William Querido, Ruteja A Barve, Koen Van De Wetering, Makarand V Risbud

2020-Current year OA Pubs

Pathological mineralization of intervertebral disc is debilitating and painful and linked to disc degeneration in a subset of human patients. An adenosine triphosphate efflux transporter, progressive ankylosis (ANK) is a regulator of extracellular inorganic pyrophosphate levels and plays an important role in tissue mineralization. However, the function of ANK in intervertebral disc has not been fully explored. Herein we analyzed the spinal phenotype of Ank mutant mice (ank/ank) with attenuated ANK function. Micro-computed tomography and histological analysis showed that loss of ANK function results in the aberrant annulus fibrosus mineralization and peripheral disc fusions with cranial to caudal progression in …

Isoflurane Conditioning-Induced Delayed Cerebral Ischemia Protection In Subarachnoid Hemorrhage-Role Of Inducible Nitric Oxide Synthase, Meizi Liu, Keshav Jayaraman, Aaron J Norris, Ahmed Hussein, James W Nelson, Jogender Mehla, Deepti Diwan, Ananth Vellimana, Yousef Abu-Amer, Gregory J Zipfel, Umeshkumar Athiraman

2020-Current year OA Pubs

Background Recent evidence implicates inflammation as a key driver in delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH). Inducible nitric oxide synthase (iNOS) is one of the known major mediators of inflammation. We previously showed that an inhalational anesthetic, isoflurane, provides strong protection against delayed cerebral ischemia after SAH. Our current study aims to define the role of iNOS in isoflurane conditioning-induced protection against delayed cerebral ischemia in a mouse model of SAH. Methods and Results The experiments used 10- to 14-week-old male wild-type (C57BL/6) and iNOS global knockout mice. Anesthetic conditioning was initiated 1 hour after SAH with isoflurane …

The Checkpoint Inhibitor Pd-1h/Vista Controls Osteoclast-Mediated Multiple Myeloma Bone Disease, Jing Fu, Shirong Li, Huihui Ma, Jun Yang, Gabriel M Pagnotti, Lewis M Brown, Stephen J Weiss, Markus Y Mapara, Suzanne Lentzsch

Faculty, Staff and Student Publications

Multiple myeloma bone disease is characterized by the development of osteolytic bone lesions. Recent work identified matrix metalloproteinase 13 as a myeloma-derived fusogen that induces osteoclast activation independent of its proteolytic activity. We now identify programmed death-1 homolog, PD-1H, as the bona fide MMP-13 receptor on osteoclasts. Silencing PD-1H or using Pd-1h-/- bone marrow cells abrogates the MMP-13-enhanced osteoclast fusion and bone-resorptive activity. Further, PD-1H interacts with the actin cytoskeleton and plays a necessary role in supporting c-Src activation and sealing zone formation. The critical role of PD-1H in myeloma lytic bone lesions was confirmed using a Pd-1h-/- myeloma bone …

Anti-Mir-93-5p Therapy Prolongs Sepsis Survival By Restoring The Peripheral Immune Response, Mihnea P Dragomir, Enrique Fuentes-Mattei, Melanie Winkle, Keishi Okubo, Recep Bayraktar, Erik Knutsen, Aiham Qdaisat, Meng Chen, Yongfeng Li, Masayoshi Shimizu, Lan Pang, Kevin Liu, Xiuping Liu, Simone Anfossi, Huanyu Zhang, Ines Koch, Anh M Tran, Swati Mohapatra, Anh Ton, Mecit Kaplan, Matthew W Anderson, Spencer J Rothfuss, Robert Silasi, Ravi S Keshari, Manuela Ferracin, Cristina Ivan, Cristian Rodriguez-Aguayo, Gabriel Lopez-Berestein, Constantin Georgescu, Pinaki P Banerjee, Rafet Basar, Ziyi Li, David Horst, Catalin Vasilescu, Maria Teresa S Bertilaccio, Katayoun Rezvani, Florea Lupu, Sai-Ching Yeung, George A Calin

Faculty, Staff and Student Publications

Sepsis remains a leading cause of death for humans and currently has no pathogenesis-specific therapy. Hampered progress is partly due to a lack of insight into deep mechanistic processes. In the past decade, deciphering the functions of small noncoding miRNAs in sepsis pathogenesis became a dynamic research topic. To screen for new miRNA targets for sepsis therapeutics, we used samples for miRNA array analysis of PBMCs from patients with sepsis and control individuals, blood samples from 2 cohorts of patients with sepsis, and multiple animal models: mouse cecum ligation puncture-induced (CLP-induced) sepsis, mouse viral miRNA challenge, and baboon Gram+ and …

Nerve Transfer For Restoration Of Lower Motor Neuron-Lesioned Bladder, Urethral, And Anal Sphincter Function In A Dog Model. Part 3. Nicotinic Receptor Characterization, Nagat Frara, Mary F. Barbe, Dania Giaddui, Danielle S. Porreca, Alan S. Braverman, Ekta Tiwari, Attia Ahmad, Justin M. Brown, Benjamin R. Johnston, Stanley F. Bazarek, Michael R. Ruggieri

Department of Neurology Faculty Papers

Very little is known about the physiological role of nicotinic receptors in canine bladders, although functional nicotinic receptors have been reported in bladders of many species. Utilizing in vitro methods, we evaluated nicotinic receptors mediating bladder function in dogs: control (9 female and 11 male normal controls, 5 sham operated), Decentralized (9 females, decentralized 6–21 mo), and obturator-to-pelvic nerve transfer reinnervated (ObNT-Reinn; 9 females; decentralized 9–13 mo, then reinnervated with 8–12 mo recovery). Muscle strips were collected, mucosa-denuded, and mounted in muscle baths before incubation with neurotransmitter antagonists, and contractions to the nicotinic receptor agonist epibatidine were determined. Strip response …

Anoctamin 4 Channel Currents Activate Glucose-Inhibited Neurons In The Mouse Ventromedial Hypothalamus During Hypoglycemia, Longlong Tu, Jonathan C Bean, Yang He, Hailan Liu, Meng Yu, Hesong Liu, Nan Zhang, Na Yin, Junying Han, Nikolas A Scarcelli, Kristine M Conde, Mengjie Wang, Yongxiang Li, Bing Feng, Peiyu Gao, Zhao-Lin Cai, Makoto Fukuda, Mingshan Xue, Qingchun Tong, Yongjie Yang, Lan Liao, Jianming Xu, Chunmei Wang, Yanlin He, Yong Xu

Faculty, Staff and Student Publications

Glucose is the basic fuel essential for maintenance of viability and functionality of all cells. However, some neurons - namely, glucose-inhibited (GI) neurons - paradoxically increase their firing activity in low-glucose conditions and decrease that activity in high-glucose conditions. The ionic mechanisms mediating electric responses of GI neurons to glucose fluctuations remain unclear. Here, we showed that currents mediated by the anoctamin 4 (Ano4) channel are only detected in GI neurons in the ventromedial hypothalamic nucleus (VMH) and are functionally required for their activation in response to low glucose. Genetic disruption of the Ano4 gene in VMH neurons reduced blood …

Apoe-Ε4 Synergizes With Sleep Disruption To Accelerate Aβ Deposition And Aβ-Associated Tau Seeding And Spreading, Chanung Wang, Aishwarya Nambiar, Michael R. Strickland, Choonghee Lee, Samira Parhizkar, Alec C. Moore, Erik S. Musiek, Jason D. Ulrich, David M. Holtzman

2020-Current year OA Pubs

Alzheimer's disease (AD) is the most common cause of dementia. The APOE-ε4 allele of the apolipoprotein E (APOE) gene is the strongest genetic risk factor for late-onset AD. The APOE genotype modulates the effect of sleep disruption on AD risk, suggesting a possible link between apoE and sleep in AD pathogenesis, which is relatively unexplored. We hypothesized that apoE modifies Aβ deposition and Aβ plaque-associated tau seeding and spreading in the form of neuritic plaque-tau (NP-tau) pathology in response to chronic sleep deprivation (SD) in an apoE isoform-dependent fashion. To test this hypothesis, we used APPPS1 mice expressing human APOE-ε3 …

Deletion Of Taf1 And Taf5 In Zebrafish Capitulate Cardiac And Craniofacial Abnormalities Associated With Tafopathies Through Perturbations In Metabolism, Jamison Leid, Ryan Gray, Peter Rakita, Andrew L Koenig, Rohan Tripathy, James A J Fitzpatrick, Charles Kaufman, Lilianna Solnica-Krezel, Kory J Lavine

2020-Current year OA Pubs

Intellectual disability is a neurodevelopmental disorder that affects 2-3% of the general population. Syndromic forms of intellectual disability frequently have a genetic basis and are often accompanied by additional developmental anomalies. Pathogenic variants in components of TATA-binding protein associated factors (TAFs) have recently been identified in a subset of patients with intellectual disability, craniofacial hypoplasia, and congenital heart disease. This syndrome has been termed as a TAFopathy and includes mutations in TATA binding protein (TBP), TAF1, TAF2, and TAF6. The underlying mechanism by which TAFopathies give rise to neurodevelopmental, craniofacial, and cardiac abnormalities remains to be defined. Through a forward …

The Cerebellum Contributes To Generalized Seizures By Altering Activity In The Ventral Posteromedial Nucleus, Jaclyn Beckinghausen, Joshua Ortiz-Guzman, Tao Lin, Benjamin Bachman, Luis E Salazar Leon, Yu Liu, Detlef H Heck, Benjamin R Arenkiel, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Thalamo-cortical networks are central to seizures, yet it is unclear how these circuits initiate seizures. We test whether a facial region of the thalamus, the ventral posteromedial nucleus (VPM), is a source of generalized, convulsive motor seizures and if convergent VPM input drives the behavior. To address this question, we devise an in vivo optogenetic mouse model to elicit convulsive motor seizures by driving these inputs and perform single-unit recordings during awake, convulsive seizures to define the local activity of thalamic neurons before, during, and after seizure onset. We find dynamic activity with biphasic properties, raising the possibility that heterogenous …

Lrp1 Is Essential For Lethal Rift Valley Fever Hepatic Disease In Mice, Madeline M Schwarz, Safder S Ganaie, Annie Feng, Griffin Brown, Tenzin Yangdon, J Michael White, Ryan M Hoehl, Cynthia M Mcmillen, Rachael E Rush, Kaleigh A Connors, Xiaoxia Cui, Daisy W Leung, Takeshi Egawa, Gaya K Amarasinghe, Amy L Hartman

2020-Current year OA Pubs

Rift Valley fever virus (RVFV) is an emerging arbovirus found in Africa. While RVFV is pantropic and infects many cells and tissues, viral replication and necrosis within the liver play a critical role in mediating severe disease. The low-density lipoprotein receptor-related protein 1 (Lrp1) is a recently identified host factor for cellular entry and infection by RVFV. The biological significance of Lrp1, including its role in hepatic disease in vivo, however, remains to be determined. Because Lrp1 has a high expression level in hepatocytes, we developed a mouse model in which Lrp1 is specifically deleted in hepatocytes to test how …

Unique Transcriptional Profiles Underlie Osteosarcomagenesis Driven By Different P53 Mutants, Dhruv Chachad, Lalit R Patel, Carlos Vera Recio, Rasoul Pourebrahim, Elizabeth M Whitley, Wenyi Wang, Xiaoping Su, An Xu, Dung-Fang Lee, Guillermina Lozano

Faculty, Staff and Student Publications

Missense mutations in the DNA binding domain of p53 are characterized as structural or contact mutations based on their effect on the conformation of the protein. These mutations show gain-of-function (GOF) activities, such as promoting increased metastatic incidence compared with p53 loss, often mediated by the interaction of mutant p53 with a set of transcription factors. These interactions are largely context specific. To understand the mechanisms by which p53 DNA binding domain mutations drive osteosarcoma progression, we created mouse models, in which either the p53 structural mutant p53R172H or the contact mutant p53R245W are expressed specifically in osteoblasts, yielding osteosarcoma …

Bicc1 Drives Pancreatic Cancer Progression By Inducing Vegf-Independent Angiogenesis, Chongbiao Huang, Hui Li, Yang Xu, Chao Xu, Huizhi Sun, Zengxun Li, Yi Ge, Hongwei Wang, Tiansuo Zhao, Song Gao, Xiuchao Wang, Shengyu Yang, Peiqing Sun, Zhe Liu, Jing Liu, Antao Chang, Jihui Hao

Faculty, Staff and Student Publications

VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors. Nevertheless, pancreatic adenocarcinoma (PAAD) cells can reinstate tumor angiogenesis via activation of VEGF-independent pathways, thereby conferring resistance to VEGF inhibitors. Bioinformatic analysis showed that BICC1 was one of the top genes involved in the specific angiogenesis process of PAAD. The analysis of our own cohort confirmed that BICC1 was overexpressed in human PAAD tissues and was correlated to increased microvessel density and tumor growth, and worse prognosis. In cells and mice with xenograft tumors, BICC1 facilitated angiogenesis in pancreatic cancer in a VEGF-independent …

Molecular Dissection And Testing Of Prss37 Function Through Lc-Ms/Ms And The Generation Of A Prss37 Humanized Mouse Model, Courtney Sutton, Kaori Nozawa, Katarzyna Kent, Alexander Saltzman, Mei Leng, Sureshbabu Nagarajan, Anna Malovannaya, Masahito Ikawa, Thomas X Garcia, Martin M Matzuk

Faculty, Staff and Students Publications

The quest for a non-hormonal male contraceptive pill for men still exists. Serine protease 37 (PRSS37) is a sperm-specific protein that when ablated in mice renders them sterile. In this study we sought to examine the molecular sequelae of PRSS37 loss to better understand its molecular function, and to determine whether human PRSS37 could rescue the sterility phenotype of knockout (KO) mice, allowing for a more appropriate model for drug molecule testing. To this end, we used CRISPR-EZ to create mice lacking the entire coding region of Prss37, used pronuclear injection to create transgenic mice expressing human PRSS37, intercrossed these …

Adenosine Metabolized From Extracellular Atp Ameliorates Organ Injury By Triggering A2br Signaling, Taha Kelestemur, Zoltán H Németh, Pal Pacher, Jennet Beesley, Simon C Robson, Holger K Eltzschig, György Haskó

Faculty, Staff and Student Publications

BACKGROUND: Trauma and a subsequent hemorrhagic shock (T/HS) result in insufficient oxygen delivery to tissues and multiple organ failure. Extracellular adenosine, which is a product of the extracellular degradation of adenosine 5' triphosphate (ATP) by the membrane-embedded enzymes CD39 and CD73, is organ protective, as it participates in signaling pathways, which promote cell survival and suppress inflammation through adenosine receptors including the A

METHODS: T/HS shock was induced by blood withdrawal from the femoral artery in wild-type, global knockout (CD39, CD73, A

RESULTS: T/HS upregulated the expression of CD39, CD73, and the A

CONCLUSION: In conclusion, the CD39-CD73-A

Adenosine Metabolized From Extracellular Atp Ameliorates Organ Injury By Triggering A2br Signaling, Taha Kelestemur, Zoltán H Németh, Pal Pacher, Jennet Beesley, Simon C Robson, Holger K Eltzschig, György Haskó

Faculty, Staff and Student Publications

BACKGROUND: Trauma and a subsequent hemorrhagic shock (T/HS) result in insufficient oxygen delivery to tissues and multiple organ failure. Extracellular adenosine, which is a product of the extracellular degradation of adenosine 5' triphosphate (ATP) by the membrane-embedded enzymes CD39 and CD73, is organ protective, as it participates in signaling pathways, which promote cell survival and suppress inflammation through adenosine receptors including the A

METHODS: T/HS shock was induced by blood withdrawal from the femoral artery in wild-type, global knockout (CD39, CD73, A

RESULTS: T/HS upregulated the expression of CD39, CD73, and the A

CONCLUSION: In conclusion, the CD39-CD73-A

Genomic Landscape Of Down Syndrome-Associated Acute Lymphoblastic Leukemia, Zhenhua Li, Ti-Cheng Chang, Jacob J Junco, Meenakshi Devidas, Yizhen Li, Wenjian Yang, Xin Huang, Dale J Hedges, Zhongshan Cheng, Mary Shago, Andrew J Carroll, Nyla A Heerema, Julie Gastier-Foster, Brent L Wood, Michael J Borowitz, Lauren Sanclemente, Elizabeth A Raetz, Stephen P Hunger, Eleanor Feingold, Tracie C Rosser, Stephanie L Sherman, Mignon L Loh, Charles G Mullighan, Jiyang Yu, Gang Wu, Philip J Lupo, Karen R Rabin, Jun J Yang

Faculty, Staff and Students Publications

Trisomy 21, the genetic cause of Down syndrome (DS), is the most common congenital chromosomal anomaly. It is associated with a 20-fold increased risk of acute lymphoblastic leukemia (ALL) during childhood and results in distinctive leukemia biology. To comprehensively define the genomic landscape of DS-ALL, we performed whole-genome sequencing and whole-transcriptome sequencing (RNA-Seq) on 295 cases. Our integrated genomic analyses identified 15 molecular subtypes of DS-ALL, with marked enrichment of CRLF2-r, IGH::IGF2BP1, and C/EBP altered (C/EBPalt) subtypes compared with 2257 non-DS-ALL cases. We observed abnormal activation of the CEBPD, CEBPA, and CEBPE genes in 10.5% of DS-ALL cases via a …

Effects Of Nalcn-Encoded Na+ Leak Currents On The Repetitive Firing Properties Of Scn Neurons Depend On K+-Driven Rhythmic Changes In Input Resistance, Nien-Du Yang, Rebecca L Mellor, Tracey O Hermanstyne, Jeanne M Nerbonne

2020-Current year OA Pubs

Neurons in the suprachiasmatic nucleus (SCN) generate circadian changes in the rates of spontaneous action potential firing that regulate and synchronize daily rhythms in physiology and behavior. Considerable evidence suggests that daily rhythms in the repetitive firing rates (higher during the day than at night) of SCN neurons are mediated by changes in subthreshold potassium (K

Mct4-Dependent Lactate Secretion Suppresses Antitumor Immunity In Lkb1-Deficient Lung Adenocarcinoma, Yu Qian, Ana Galan-Cobo, Irene Guijarro, Minghao Dang, David Molkentine, Alissa Poteete, Fahao Zhang, Qi Wang, Jing Wang, Edwin Parra, Apekshya Panda, Jacy Fang, Ferdinandos Skoulidis, Ignacio I Wistuba, Svena Verma, Taha Merghoub, Jedd D Wolchok, Kwok-Kin Wong, Ralph J Deberardinis, John D Minna, Natalie I Vokes, Catherine B Meador, Justin F Gainor, Linghua Wang, Alexandre Reuben, John V Heymach

Faculty, Staff and Student Publications

Inactivating STK11/LKB1 mutations are genomic drivers of primary resistance to immunotherapy in KRAS-mutated lung adenocarcinoma (LUAD), although the underlying mechanisms remain unelucidated. We find that LKB1 loss results in enhanced lactate production and secretion via the MCT4 transporter. Single-cell RNA profiling of murine models indicates that LKB1-deficient tumors have increased M2 macrophage polarization and hypofunctional T cells, effects that could be recapitulated by the addition of exogenous lactate and abrogated by MCT4 knockdown or therapeutic blockade of the lactate receptor GPR81 expressed on immune cells. Furthermore, MCT4 knockout reverses the resistance to PD-1 blockade induced by LKB1 loss in syngeneic …

Myc Regulates Csf1 Expression Via Microrna 17/20a To Modulate Tumor-Associated Macrophages In Osteosarcoma, Bikesh K Nirala, Tajhal D Patel, Lyazat Kurenbekova, Ryan Shuck, Atreyi Dasgupta, Nino Rainusso, Cristian Coarfa, Jason T Yustein

Faculty, Staff and Students Publications

Osteosarcoma (OS) is the most common primary bone tumor of childhood. Approximately 20%-30% of OSs carry amplification of chromosome 8q24, which harbors the oncogene c-MYC and correlates with a poor prognosis. To understand the mechanisms that underlie the ability of MYC to alter both the tumor and its surrounding tumor microenvironment (TME), we generated and molecularly characterized an osteoblast-specific Cre-Lox-Stop-Lox-c-MycT58A p53fl/+ knockin genetically engineered mouse model (GEMM). Phenotypically, the Myc-knockin GEMM had rapid tumor development with a high incidence of metastasis. MYC-dependent gene signatures in our murine model demonstrated significant homology to the human hyperactivated MYC OS. We established that …

Endothelial Cell Cd36 Regulates Membrane Ceramide Formation, Exosome Fatty Acid Transfer And Circulating Fatty Acid Levels, V S Peche, T A Pietka, M Jacome-Sosa, D Samovski, H Palacios, G Chatterjee-Basu, A C Dudley, W Beatty, G A Meyer, I J Goldberg, N A Abumrad

2020-Current year OA Pubs

Endothelial cell (EC) CD36 controls tissue fatty acid (FA) uptake. Here we examine how ECs transfer FAs. FA interaction with apical membrane CD36 induces Src phosphorylation of caveolin-1 tyrosine-14 (Cav-1Y14) and ceramide generation in caveolae. Ensuing fission of caveolae yields vesicles containing FAs, CD36 and ceramide that are secreted basolaterally as small (80-100 nm) exosome-like extracellular vesicles (sEVs). We visualize in transwells EC transfer of FAs in sEVs to underlying myotubes. In mice with EC-expression of the exosome marker emeraldGFP-CD63, muscle fibers accumulate circulating FAs in emGFP-labeled puncta. The FA-sEV pathway is mapped through its suppression by CD36 depletion, blocking …

Vitamin B2 Enables Regulation Of Fasting Glucose Availability, Peter M Masschelin, Pradip Saha, Scott A Ochsner, Aaron R Cox, Kang Ho Kim, Jessica B Felix, Robert Sharp, Xin Li, Lin Tan, Jun Hyoung Park, Liping Wang, Vasanta Putluri, Philip L Lorenzi, Alli M Nuotio-Antar, Zheng Sun, Benny Abraham Kaipparettu, Nagireddy Putluri, David D Moore, Scott A Summers, Neil J Mckenna, Sean M Hartig

Faculty, Staff and Students Publications

Flavin adenine dinucleotide (FAD) interacts with flavoproteins to mediate oxidation-reduction reactions required for cellular energy demands. Not surprisingly, mutations that alter FAD binding to flavoproteins cause rare inborn errors of metabolism (IEMs) that disrupt liver function and render fasting intolerance, hepatic steatosis, and lipodystrophy. In our study, depleting FAD pools in mice with a vitamin B2-deficient diet (B2D) caused phenotypes associated with organic acidemias and other IEMs, including reduced body weight, hypoglycemia, and fatty liver disease. Integrated discovery approaches revealed B2D tempered fasting activation of target genes for the nuclear receptor PPARα, including those required for gluconeogenesis. We also found …

A Functional Link Between Lariat Debranching Enzyme And The Intron-Binding Complex Is Defective In Non-Photosensitive Trichothiodystrophy, Brittany A Townley, Luke Buerer, Ning Tsao, Albino Bacolla, Fadhel Mansoori, Timur Rusanov, Nathanial Clark, Negar Goodarzi, Nicolas Schmidt, Sridhar Nonavinkere Srivatsan, Hua Sun, Reilly A Sample, Joshua R Brickner, Drew Mcdonald, Miaw-Sheue Tsai, Matthew J Walter, David F Wozniak, Alex S Holehouse, Vladimir Pena, John A Tainer, William G Fairbrother, Nima Mosammaparast

Faculty, Staff and Student Publications

The pre-mRNA life cycle requires intron processing; yet, how intron-processing defects influence splicing and gene expression is unclear. Here, we find that TTDN1/MPLKIP, which is encoded by a gene implicated in non-photosensitive trichothiodystrophy (NP-TTD), functionally links intron lariat processing to spliceosomal function. The conserved TTDN1 C-terminal region directly binds lariat debranching enzyme DBR1, whereas its N-terminal intrinsically disordered region (IDR) binds the intron-binding complex (IBC). TTDN1 loss, or a mutated IDR, causes significant intron lariat accumulation, as well as splicing and gene expression defects, mirroring phenotypes observed in NP-TTD patient cells. A Ttdn1-deficient mouse model recapitulates intron-processing defects and certain …

Targeting Gbm With An Oncolytic Picornavirus Svv-001 Alone And In Combination With Fractionated Radiation In A Novel Panel Of Orthotopic Pdx Models, Huiyuan Zhang, Yuchen Du, Lin Qi, Sophie Xiao, Frank K Braun, Mari Kogiso, Yulun Huang, Frank Huang, Aalaa Abdallah, Milagros Suarez, Sekar Karthick, Nabil M Ahmed, Vita S Salsman, Patricia A Baxter, Jack M Su, Daniel J Brat, Paul L Hellenbeck, Wan-Yee Teo, Akash J Patel, Xiao-Nan Li

Faculty, Staff and Students Publications

BACKGROUND: Animal models representing different molecular subtypes of glioblastoma multiforme (GBM) is desired for developing new therapies. SVV-001 is an oncolytic virus selectively targeting cancer cells. It's capacity of passing through the blood brain barrier makes is an attractive novel approach for GBM.

MATERIALS AND METHODS: 23 patient tumor samples were implanted into the brains of NOD/SCID mice (1 × 105 cells/mouse). Tumor histology, gene expression (RNAseq), and growth rate of the developed patient-derived orthotopic xenograft (PDOX) models were compared with the originating patient tumors during serial subtransplantations. Anti-tumor activities of SVV-001 were examined in vivo; and therapeutic efficacy validated …

Tiam1 Coordinates Synaptic Structural And Functional Plasticity Underpinning The Pathophysiology Of Neuropathic Pain, Lingyong Li, Qin Ru, Yungang Lu, Xing Fang, Guanxing Chen, Ali Bin Saifullah, Changqun Yao, Kimberley F Tolias

Faculty, Staff and Students Publications

Neuropathic pain is a common, debilitating chronic pain condition caused by damage or a disease affecting the somatosensory nervous system. Understanding the pathophysiological mechanisms underlying neuropathic pain is critical for developing new therapeutic strategies to treat chronic pain effectively. Tiam1 is a Rac1 guanine nucleotide exchange factor (GEF) that promotes dendritic and synaptic growth during hippocampal development by inducing actin cytoskeletal remodeling. Here, using multiple neuropathic pain animal models, we show that Tiam1 coordinates synaptic structural and functional plasticity in the spinal dorsal horn via actin cytoskeleton reorganization and synaptic NMDAR stabilization and that these actions are essential for the …