Medicine and Health Sciences Commons^™

Estradiol Mediates Colonic Epithelial Protection In Aged Mice After Stroke And Is Associated With Shifts In The Gut Microbiome, Juneyoung Lee, Pedram Peesh, Victoria Quaicoe, Chunfeng Tan, Anik Banerjee, Patrick Mooz, Bhanu P Ganesh, Joseph Petrosino, Robert M Bryan, Louise D Mccullough, Venugopal Reddy Venna

Journal Articles

The gut is a major source of bacteria and antigens that contribute to neuroinflammation after brain injury. Colonic epithelial cells (ECs) are responsible for secreting major cellular components of the innate defense system, including antimicrobial proteins (AMP) and mucins. These cells serve as a critical regulator of gut barrier function and maintain host-microbe homeostasis. In this study, we determined post-stroke host defense responses at the colonic epithelial surface in mice. We then tested if the enhancement of these epithelial protective mechanisms is beneficial in young and aged mice after stroke. AMPs were significantly increased in the colonic ECs of young …

Mechanopathology Of Biofilm-Like Mycobacterium Tuberculosis Cords, Richa Mishra, Melanie Hannebelle, Vishal P Patil, Anaëlle Dubois, Cristina Garcia-Mouton, Gabriela M Kirsch, Maxime Jan, Kunal Sharma, Nicolas Guex, Jessica Sordet-Dessimoz, Jesus Perez-Gil, Manu Prakash, Graham W Knott, Neeraj Dhar, John D Mckinney, Vivek V Thacker

Journal Articles

Mycobacterium tuberculosis (Mtb) cultured axenically without detergent forms biofilm-like cords, a clinical identifier of virulence. In lung-on-chip (LoC) and mouse models, cords in alveolar cells contribute to suppression of innate immune signaling via nuclear compression. Thereafter, extracellular cords cause contact-dependent phagocyte death but grow intercellularly between epithelial cells. The absence of these mechanopathological mechanisms explains the greater proportion of alveolar lesions with increased immune infiltration and dissemination defects in cording-deficient Mtb infections. Compression of Mtb lipid monolayers induces a phase transition that enables mechanical energy storage. Agent-based simulations demonstrate that the increased energy storage capacity is sufficient for the formation …

A Novel Machine-Learning Framework Based On A Hierarchy Of Dispute Models For The Identification Of Fish Species Using Multi-Mode Spectroscopy, Mitchell Sueker, Amirreza Daghighi, Alireza Akhbardeh, Nicholas Mackinnon, Gregory Bearman, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M Tabb, Jiahleen B Roungchun, Rosalee S Hellberg, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Hossein Kashani Zadeh

Journal Articles

Seafood mislabeling rates of approximately 20% have been reported globally. Traditional methods for fish species identification, such as DNA analysis and polymerase chain reaction (PCR), are expensive and time-consuming, and require skilled technicians and specialized equipment. The combination of spectroscopy and machine learning presents a promising approach to overcome these challenges. In our study, we took a comprehensive approach by considering a total of 43 different fish species and employing three modes of spectroscopy: fluorescence (Fluor), and reflectance in the visible near-infrared (VNIR) and short-wave near-infrared (SWIR). To achieve higher accuracies, we developed a novel machine-learning framework, where groups of …

Iron Overload Induces Cerebral Endothelial Senescence In Aged Mice And In Primary Culture In A Sex-Dependent Manner, Brian Noh, Maria Pilar Blasco-Conesa, Syed Mushfiqur Rahman, Sheelu Monga, Rodney Ritzel, Gary Guzman, Yun-Ju Lai, Bhanu Priya Ganesh, Akihiko Urayama, Louise D Mccullough, Jose Felix Moruno-Manchon

Journal Articles

Iron imbalance in the brain negatively affects brain function. With aging, iron levels increase in the brain and contribute to brain damage and neurological disorders. Changes in the cerebral vasculature with aging may enhance iron entry into the brain parenchyma, leading to iron overload and its deleterious consequences. Endothelial senescence has emerged as an important contributor to age-related changes in the cerebral vasculature. Evidence indicates that iron overload may induce senescence in cultured cell lines. Importantly, cells derived from female human and mice generally show enhanced senescence-associated phenotype, compared with males. Thus, we hypothesize that cerebral endothelial cells (CEC) derived …

A New Ferrocene Derivative Blocks K-Ras Localization And Function By Oxidative Modification At His95, Kristen M Rehl, Jayaraman Selvakumar, Rhonda L Pitsch, Don Hoang, Kuppuswamy Arumugam, Sean W Harshman, Alemayehu A Gorfe, Kwang-Jin Cho

Journal Articles

Ras proteins are membrane-bound GTPases that regulate essential cellular processes at the plasma membrane (PM). Constitutively active mutations of K-Ras, one of the three Ras isoforms in mammalian cells, are frequently found in human cancers. Ferrocene derivatives, which elevate cellular reactive oxygen species (ROS), have shown to block the growth of non-small cell lung cancers harboring oncogenic mutant K-Ras. Here, we tested a novel ferrocene derivative on the growth of pancreatic ductal adenocarcinoma and non-small cell lung cancer. Our compound, which elevated cellular ROS levels, inhibited the growth of K-Ras-driven cancers, and abrogated the PM binding and signaling of K-Ras …

Interplay Of Hypoxia-Inducible Factors And Oxygen Therapy In Cardiovascular Medicine, Yafen Liang, Wei Ruan, Yandong Jiang, Richard Smalling, Xiaoyi Yuan, Holger K Eltzschig

Journal Articles

Mammals have evolved to adapt to differences in oxygen availability. Although systemic oxygen homeostasis relies on respiratory and circulatory responses, cellular adaptation to hypoxia involves the transcription factor hypoxia-inducible factor (HIF). Given that many cardiovascular diseases involve some degree of systemic or local tissue hypoxia, oxygen therapy has been used liberally over many decades for the treatment of cardiovascular disorders. However, preclinical research has revealed the detrimental effects of excessive use of oxygen therapy, including the generation of toxic oxygen radicals or attenuation of endogenous protection by HIFs. In addition, investigators in clinical trials conducted in the past decade have …

Cd13 Facilitates Immune Cell Migration And Aggravates Acute Injury But Promotes Chronic Post-Stroke Recovery, Justin N Nguyen, Eric C Mohan, Gargee Pandya, Uzma Ali, Chunfeng Tan, Julia K Kofler, Linda Shapiro, Sean P Marrelli, Anjali Chauhan

Journal Articles

Introduction

Acute stroke leads to the activation of myeloid cells. These cells express adhesion molecules and transmigrate to the brain, thereby aggravating injury. Chronically after stroke, repair processes, including angiogenesis, are activated and enhance post-stroke recovery. Activated myeloid cells express CD13, which facilitates their migration into the site of injury. However, angiogenic blood vessels which play a role in recovery also express CD13. Overall, the specific contribution of CD13 to acute and chronic stroke outcomes is unknown.

Methods

CD13 expression was estimated in both mice and humans after the ischemic stroke. Young (8–12 weeks) male wild-type and global CD13 knockout …

Stabilizing Histamine Release In Gut Mast Cells Mitigates Peripheral And Central Inflammation After Stroke, Maria P Blasco Conesa, Frank W Blixt, Pedram Peesh, Romeesa Khan, Janelle Korf, Juneyoung Lee, Gayathri Jagadeesan, Alexander Andersohn, Tushar K Das, Chunfeng Tan, Claudia Di Gesu, Gabriela Delevati Colpo, Jose Félix Moruno-Manchón, Louise D Mccullough, Robert Bryan, Bhanu P Ganesh

Journal Articles

Stroke is the most common cause of long-term disability and places a high economic burden on the global healthcare system. Functional outcomes from stroke are largely determined by the extent of ischemic injury, however, there is growing recognition that systemic inflammatory responses also contribute to outcomes. Mast cells (MCs) rapidly respond to injury and release histamine (HA), a pro-inflammatory neurotransmitter that enhances inflammation. The gut serves as a major reservoir of HA. We hypothesized that cromolyn, a mast cell stabilizer that prevents the release of inflammatory mediators, would decrease peripheral and central inflammation, reduce MC trafficking to the brain, and …

Sepsis Exacerbates Alzheimer’S Disease Pathophysiology, Modulates The Gut Microbiome, Increases Neuroinflammation And Amyloid Burden, Vijayasree V Giridharan, Celso S G Catumbela, Carlos Henrique R Catalão, Juneyoung Lee, Bhanu P Ganesh, Fabricia Petronilho, Felipe Dal-Pizzol, Rodrigo Morales, Tatiana Barichello

Journal Articles

While our understanding of the molecular biology of Alzheimer's disease (AD) has grown, the etiology of the disease, especially the involvement of peripheral infection, remains a challenge. In this study, we hypothesize that peripheral infection represents a risk factor for AD pathology. To test our hypothesis, APP/PS1 mice underwent cecal ligation and puncture (CLP) surgery to develop a polymicrobial infection or non-CLP surgery. Mice were euthanized at 3, 30, and 120 days after surgery to evaluate the inflammatory mediators, glial cell markers, amyloid burden, gut microbiome, gut morphology, and short-chain fatty acids (SCFAs) levels. The novel object recognition (NOR) task …

Pirh2-Dependent Dna Damage In Neurons Induced By The G-Quadruplex Ligand Pyridostatin, Rocio Diaz Escarcega, Abhijeet A Patil, Jose F Moruno-Manchon, Akihiko Urayama, Sean P Marrelli, Nayun Kim, David Monchaud, Louise D Mccullough, Andrey S Tsvetkov

Journal Articles

Noncanonical base pairing between four guanines (G) within single-stranded G-rich sequences leads to formation of а G-quartet. Self-stacking of G-quartets results in a columnar four-stranded DNA structure known as the G-quadruplex (G4 or G4-DNA). In cancer cells, G4-DNA regulates multiple DNA-dependent processes, including transcription, replication, and telomere function. How G4s function in neurons is poorly understood. Here, we performed a genome-wide gene expression analysis (RNA-Seq) to identify genes modulated by a G4-DNA ligand, pyridostatin (PDS), in primary cultured neurons. PDS promotes stabilization of G4 structures, thus allowing us to define genes directly or indirectly responsive to G4 regulation. We found …

X, But Not Y, Chromosomal Complement Contributes To Stroke Sensitivity In Aged Animals, Shaohua Qi, Conelius Ngwa, Abdullah Al Mamun, Sharmeen Romana, Ting Wu, Sean P Marrelli, Arthur P Arnold, Louise D Mccullough, Fudong Liu

Journal Articles

Post-menopausal women become vulnerable to stroke and have poorer outcomes and higher mortality than age-matched men, and previous studies suggested that sex chromosomes play a vital role in mediating stroke sensitivity in the aged. It is unknown if this is due to effects of the X or Y chromosome. The present study used the XY* mouse model (with four genotypes: XX and XO gonadal females and XY and XXY gonadal males) to compare the effect of the X vs. Y chromosome compliment in stroke. Aged (18-20 months) and gonadectomized young (8-12 weeks) mice were subjected to a 60-min middle cerebral …

Evaluation Of The Effectiveness Of Foot-And-Mouth Disease Vaccination Of Animals In The Buffer Zone Of The Republic Of Armenia In 2016–2020, Satenik Kharatyan, Khachik Sargsyan, Hasmik Elbakyan, Tigran Markosyan, Pertsh Tumanyan, Varduhi Hakobyan, Vazgen Sargsyan, Manvel Badalyan, Gayane Chobanyan, Jenna E Achenbach

Journal Articles

BACKGROUND: Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used for limiting the spread of infection. Armenia shares a border with both Turkey and Iran where FMD is endemic, making vaccination an important component of Armenia's control strategy. Additionally, Armenian veterinary services utilize both passive and active monitoring for prevention control.

METHODS: We sought to determine the immune status of animals vaccinated against FMD and to evaluate the effectiveness of our vaccination policy in Armenia. This was conducted in three regions including Shirak, Armavir, and Ararat Region which are located in the …

Tmem27 Suppresses Tumor Development By Promoting Ret Ubiquitination, Positioning, And Degradation, Qianjin Guo, Zi-Ming Cheng, Hector Gonzalez-Cantú, Matthew Rotondi, Gabriela Huelgas-Morales, Purushoth Ethiraj, Zhijun Qiu, Jonathan Lefkowitz, Wan Song, Bethany N Landry, Hector Lopez, Cynthia M Estrada-Zuniga, Shivi Goyal, Mohammad Aasif Khan, Timothy J Walker, Exing Wang, Faqian Li, Yanli Ding, Lois M Mulligan, Ricardo C T Aguiar, Patricia L M Dahia

Journal Articles

The TMEM127 gene encodes a transmembrane protein of poorly known function that is mutated in pheochromocytomas, neural crest-derived tumors of adrenomedullary cells. Here, we report that, at single-nucleus resolution, TMEM127-mutant tumors share precursor cells and transcription regulatory elements with pheochromocytomas carrying mutations of the tyrosine kinase receptor RET. Additionally, TMEM127-mutant pheochromocytomas, human cells, and mouse knockout models of TMEM127 accumulate RET and increase its signaling. TMEM127 contributes to RET cellular positioning, trafficking, and lysosome-mediated degradation. Mechanistically, TMEM127 binds to RET and recruits the NEDD4 E3 ubiquitin ligase for RET ubiquitination and degradation via TMEM127 C-terminal PxxY motifs. Lastly, increased cell …

The Circadian Nobiletin-Ror Axis Suppresses Adipogenic Differentiation And Iκbα/Nf-Κb Signaling In Adipocytes, Eunju Kim, Kazuaki Mawatari, Seung-Hee Yoo, Zheng Chen

Journal Articles

Obesity is a known risk factor for metabolic diseases and is often associated with chronic inflammation in adipose tissue. We previously identified the polyethoxylated flavonoid Nobiletin (NOB) as a circadian clock modulator that directly binds to and activates the ROR receptors in the core oscillator, markedly improving metabolic fitness in obese mice. Here, we show that NOB enhanced the oscillation of core clock genes in differentiated 3T3-L1 adipocytes, including ROR target genes such as Bmal1, Cry1, Dec1, and Dec2. NOB inhibited lipid accumulation in 3T3-L1 and SVF cells, concomitant with the dysregulated circadian expression of adipogenic …

Argininosuccinate Lyase Deficiency Causes Blood-Brain Barrier Disruption Via Nitric Oxide-Mediated Dysregulation Of Claudin Expression, Jordan Kho, Urszula Polak, Ming-Ming Jiang, John D Odom, Jill V Hunter, Saima M Ali, Lindsay C Burrage, Sandesh Cs Nagamani, Robia G Pautler, Hannah P Thompson, Akihiko Urayama, Zixue Jin, Brendan Lee

Journal Articles

Nitric oxide (NO) is a critical signaling molecule that has been implicated in the pathogenesis of neurocognitive diseases. Both excessive and insufficient NO production have been linked to pathology. Previously, we have shown that argininosuccinate lyase deficiency (ASLD) is a novel model system to investigate cell-autonomous, nitric oxide synthase-dependent NO deficiency. Humans with ASLD are at increased risk for developing hyperammonemia due to a block in ureagenesis. However, natural history studies have shown that individuals with ASLD have multisystem disease including neurocognitive deficits that can be independent of ammonia. Here, using ASLD as a model of NO deficiency, we investigated …

Sexually Dimorphic Extracellular Vesicle Responses After Chronic Spinal Cord Injury Are Associated With Neuroinflammation And Neurodegeneration In The Aged Brain, Yun Li, Niaz Khan, Rodney M Ritzel, Zhuofan Lei, Samantha Allen, Alan I Faden, Junfang Wu

Journal Articles

Background

Medical advances have made it increasingly possible for spinal cord injury (SCI) survivors to survive decades after the insult. But how SCI affects aging changes and aging impacts the injury process have received limited attention. Extracellular vesicles (EVs) are recognized as critical mediators of neuroinflammation after CNS injury, including at a distance from the lesion site. We have previously shown that SCI in young male mice leads to robust changes in plasma EV count and microRNA (miR) content. Here, our goal was to investigate the impact of biological sex and aging on EVs and brain after SCI.

Methods

Young …

Enhanced Cerebroprotection Of Xenon-Loaded Liposomes In Combination With Rtpa Thrombolysis For Embolic Ischemic Stroke., Tao Peng, Keith Booher, Melanie R Moody, Xing Yin, Jaroslaw Aronowski, David D Mcpherson, Sean I Savitz, Hyunggun Kim, Shao-Ling Huang

Journal Articles

Xenon (Xe) has shown great potential as a stroke treatment due to its exceptional ability to protect brain tissue without inducing side effects. We have previously developed Xe-loaded liposomes for the ultrasound-activated delivery of Xe into the cerebral region and demonstrated their therapeutic efficacy. At present, the sole FDA-approved thrombolytic agent for stroke treatment is recombinant tissue plasminogen activator (rtPA). In this study, we aimed to investigate the potential of combining Xe-liposomes with an intravenous rtPA treatment in a clinically relevant embolic rat stroke model. We evaluated the combinational effect using an in vitro clot lysis model and an in …

Platelet-Derived Exerkine Cxcl4/Platelet Factor 4 Rejuvenates Hippocampal Neurogenesis And Restores Cognitive Function In Aged Mice, Odette Leiter, David Brici, Stephen J Fletcher, Xuan Ling Hilary Yong, Jocelyn Widagdo, Nicholas Matigian, Adam B Schroer, Gregor Bieri, Daniel G Blackmore, Perry F Bartlett, Victor Anggono, Saul A Villeda, Tara L Walker

Journal Articles

The beneficial effects of physical activity on brain ageing are well recognised, with exerkines, factors that are secreted into the circulation in response to exercise, emerging as likely mediators of this response. However, the source and identity of these exerkines remain unclear. Here we provide evidence that an anti-geronic exerkine is secreted by platelets. We show that platelets are activated by exercise and are required for the exercise-induced increase in hippocampal precursor cell proliferation in aged mice. We also demonstrate that increasing the systemic levels of the platelet-derived exerkine CXCL4/platelet factor 4 (PF4) ameliorates age-related regenerative and cognitive impairments in …

Enhanced Cerebroprotection Of Xenon-Loaded Liposomes In Combination With Rtpa Thrombolysis For Embolic Ischemic Stroke, Tao Peng, Keith Booher, Melanie R Moody, Xing Yin, Jaroslaw Aronowski, David D Mcpherson, Sean I Savitz, Hyunggun Kim, Shao-Ling Huang

Journal Articles

Xenon (Xe) has shown great potential as a stroke treatment due to its exceptional ability to protect brain tissue without inducing side effects. We have previously developed Xe-loaded liposomes for the ultrasound-activated delivery of Xe into the cerebral region and demonstrated their therapeutic efficacy. At present, the sole FDA-approved thrombolytic agent for stroke treatment is recombinant tissue plasminogen activator (rtPA). In this study, we aimed to investigate the potential of combining Xe-liposomes with an intravenous rtPA treatment in a clinically relevant embolic rat stroke model. We evaluated the combinational effect using an in vitro clot lysis model and an in …

Monoallelic Variation In Dhx9, The Gene Encoding The Dexh-Box Helicase Dhx9, Underlies Neurodevelopment Disorders And Charcot-Marie-Tooth Disease, Daniel G Calame, Tianyu Guo, Chen Wang, Lillian Garrett, Angad Jolly, Moez Dawood, Alina Kurolap, Noa Zunz Henig, Jawid M Fatih, Isabella Herman, Haowei Du, Tadahiro Mitani, Lore Becker, Birgit Rathkolb, Raffaele Gerlini, Claudia Seisenberger, Susan Marschall, Jill V Hunter, Amanda Gerard, Alexis Heidlebaugh, Thomas Challman, Rebecca C Spillmann, Shalini N Jhangiani, Zeynep Coban-Akdemir, Seema Lalani, Lingxiao Liu, Anya Revah-Politi, Alejandro Iglesias, Edwin Guzman, Evan Baugh, Nathalie Boddaert, Sophie Rondeau, Clothide Ormieres, Giulia Barcia, Queenie K G Tan, Isabelle Thiffault, Tomi Pastinen, Kazim Sheikh, Suur Biliciler, Davide Mei, Federico Melani, Vandana Shashi, Yuval Yaron, Mary Steele, Emma Wakeling, Elsebet Østergaard, Lusine Nazaryan-Petersen, Undiagnosed Diseases Network, Francisca Millan, Teresa Santiago-Sim, Julien Thevenon, Ange-Line Bruel, Christel Thauvin-Robinet, Denny Popp, Konrad Platzer, Pawel Gawlinski, Wojciech Wiszniewski, Dana Marafi, Davut Pehlivan, Jennifer E Posey, Richard A Gibbs, Valerie Gailus-Durner, Renzo Guerrini, Helmut Fuchs, Martin Hrabě De Angelis, Sabine M Hölter, Hoi-Hung Cheung, Shen Gu, James R Lupski

Journal Articles

DExD/H-box RNA helicases (DDX/DHX) are encoded by a large paralogous gene family; in a subset of these human helicase genes, pathogenic variation causes neurodevelopmental disorder (NDD) traits and cancer. DHX9 encodes a BRCA1-interacting nuclear helicase regulating transcription, R-loops, and homologous recombination and exhibits the highest mutational constraint of all DDX/DHX paralogs but remains unassociated with disease traits in OMIM. Using exome sequencing and family-based rare-variant analyses, we identified 20 individuals with de novo, ultra-rare, heterozygous missense or loss-of-function (LoF) DHX9 variant alleles. Phenotypes ranged from NDDs to the distal symmetric polyneuropathy axonal Charcot-Marie-Tooth disease (CMT2). Quantitative Human Phenotype Ontology (HPO) …

Probiotic-Derived Ecto-5'-Nucleotidase Produces Anti-Inflammatory Adenosine Metabolites In Treg-Deficient Scurfy Mice, Yuying Liu, Shabba A Armbrister, Beanna Okeugo, Tingting W Mills, Rhea C Daniel, Jee-Hwan Oh, Jan-Peter Van Pijkeren, Evelyn S Park, Zeina M Saleh, Sharmistha Lahiri, Stefan Roos, Jmarc Rhoads

Journal Articles

Probiotic Limosilactobacillus reuteri DSM 17938 (DSM 17938) prolongs the survival of Treg-deficient scurfy (SF) mice and reduces multiorgan inflammation by a process requiring adenosine receptor 2A (A2A) on T cells. We hypothesized that L. reuteri-derived ecto-5’-nucleotidase (ecto-5’NT) activity acts to generate adenosine, which may be a central mediator for L. reuteri protection in SF mice. We evaluated DSM 17938–5’NT activity and the associated adenosine and inosine levels in plasma, gut, and liver of SF mice. We examined orally fed DSM 17938, DSM 17938Δ5NT (with a deleted 5’NT gene), and DSM 32846 (BG-R46) (a naturally selected strain derived from DSM …

The Gpcr-Gαs-Pka Signaling Axis Promotes T Cell Dysfunction And Cancer Immunotherapy Failure, Victoria H Wu, Bryan S Yung, Farhoud Faraji, Robert Saddawi-Konefka, Zhiyong Wang, Alexander T Wenzel, Miranda J Song, Meghana S Pagadala, Lauren M Clubb, Joshua Chiou, Sanju Sinha, Marin Matic, Francesco Raimondi, Thomas S Hoang, Rebecca Berdeaux, Dario A A Vignali, Ramiro Iglesias-Bartolome, Hannah Carter, Eytan Ruppin, Jill P Mesirov, J Silvio Gutkind

Journal Articles

Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable responses. G-protein-coupled receptors (GPCRs) are the most intensively studied drug targets but are underexplored in immuno-oncology. Here, we cross-integrated large singe-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of Gαs-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, β1AR and β2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted Gαs–DREADD to activate …

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

Journal Articles

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 that K+ versus Na+ …

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

Journal Articles

UNLABELLED: 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 …

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

Journal Articles

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

Inhibition Of Autophagy In Microglia And Macrophages Exacerbates Innate Immune Responses And Worsens Brain Injury Outcomes, Nivedita Hegdekar, Chinmoy Sarkar, Sabrina Bustos, Rodney M Ritzel, Marie Hanscom, Prarthana Ravishankar, Deepika Philkana, Junfang Wu, David J Loane, Marta M Lipinski

Journal Articles

Excessive and prolonged neuroinflammation following traumatic brain injury (TBI) contributes to long-term tissue damage and poor functional outcomes. However, the mechanisms contributing to exacerbated inflammatory responses after brain injury remain poorly understood. Our previous work showed that macroautophagy/autophagy flux is inhibited in neurons following TBI in mice and contributes to neuronal cell death. In the present study, we demonstrate that autophagy is also inhibited in activated microglia and infiltrating macrophages, and that this potentiates injury-induced neuroinflammatory responses. Macrophage/microglia-specific knockout of the essential autophagy gene Becn1 led to overall increase in neuroinflammation after TBI. In particular, we observed excessive activation of …

Free Ferrous Ions Sustain Activity Of Mammalian Stearoyl-Coa Desaturase-1, Jiemin Shen, Gang Wu, Brad S Pierce, Ah-Lim Tsai, Ming Zhou

Journal Articles

Mammalian stearoyl-CoA desaturase-1 (SCD1) introduces a double-bond to a saturated long-chain fatty acid in a reaction catalyzed by a diiron center. The diiron center is well-coordinated by conserved histidine residues and is thought to remain with the enzyme. However, we find here that SCD1 progressively loses its activity during catalysis and becomes fully inactive after about nine turnovers. Further studies show that the inactivation of SCD1 is due to the loss of an iron (Fe) ion in the diiron center and that the addition of free ferrous ions (Fe

An Erk5-Nrf2 Axis Mediates Senescence-Associated Stemness And Atherosclerosis, Jun-Ichi Abe, Masaki Imanishi, Shengyu Li, Aijun Zhang, Kyung Ae Ko, Venkata S K Samanthapudi, Ling-Ling Lee, Angelica Paniagua Bojorges, Young Jin Gi, Brian P Hobbs, Anita Deswal, Joerg Herrmann, Steven H Lin, Eduardo N Chini, Ying H Shen, Keri L Schadler, Thi-Hong-Minh Nguyen, Anisha A Gupte, Cielito Reyes-Gibby, Sai-Ching J Yeung, Rei J Abe, Elizabeth A Olmsted-Davis, Sunil Krishnan, Robert Dantzer, Nicolas L Palaskas, John P Cooke, Henry J Pownall, Momoko Yoshimoto, Keigi Fujiwara, Dale J Hamilton, Jared K Burks, Guangyu Wang, Nhat-Tu Le, Sivareddy Kotla

Journal Articles

BACKGROUND: ERK5 (extracellular signal-regulated kinase 5) is a dual kinase transcription factor containing an N-terminal kinase domain and a C-terminal transcriptional activation domain. Many ERK5 kinase inhibitors have been developed and tested to treat cancer and inflammatory diseases. However, recent data have raised questions about the role of the catalytic activity of ERK5 in proliferation and inflammation. We aimed to investigate how ERK5 reprograms myeloid cells to the proinflammatory senescent phenotype, subsequently leading to atherosclerosis.

METHODS: A ERK5 S496A (dephosphorylation mimic) knock in (KI) mouse model was generated using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic …

Blm Overexpression As A Predictive Biomarker For Chk1 Inhibitor Response In Parp Inhibitor–Resistant Brca-Mutant Ovarian Cancer, Nitasha Gupta, Tzu-Ting Huang, Jayakumar R Nair, Daniel An, Grant Zurcher, Erika J Lampert, Ann Mccoy, Ashley Cimino-Mathews, Elizabeth M Swisher, Marc R Radke, Christina M Lockwood, Jonathan B Reichel, Chih-Yuan Chiang, Kelli M Wilson, Ken Chih-Chien Cheng, Darryl Nousome, Jung-Min Lee

Journal Articles

Poly(ADP-ribose) polymerase inhibitors (PARPis) have changed the treatment paradigm in breast cancer gene (BRCA)–mutant high-grade serous ovarian carcinoma (HGSC). However, most patients eventually develop resistance to PARPis, highlighting an unmet need for improved therapeutic strategies. Using high-throughput drug screens, we identified ataxia telangiectasia and rad3-related protein/checkpoint kinase 1 (CHK1) pathway inhibitors as cytotoxic and further validated the activity of the CHK1 inhibitor (CHK1i) prexasertib in PARPi-sensitive and -resistant BRCA-mutant HGSC cells and xenograft mouse models. CHK1i monotherapy induced DNA damage, apoptosis, and tumor size reduction. We then conducted a phase 2 study (NCT02203513) of prexasertib …

A Novel Specific Aptamer Targets Cerebrovascular Endothelial Cells After Ischemic Stroke, Heng Hu, Silin Wu, Tae Jin Lee, Aaron M Gusdon, Yuxin Liu, Huimahn A Choi, Xuefang Sophie Ren

Journal Articles

Cell specific-targeted therapy (CSTT) for acute ischemic stroke remains underdeveloped. Cerebrovascular endothelial cells (CECs) are key components of the blood-brain barrier and are the first brain cells affected by ischemic stroke. After stroke, CEC injury causes insufficient energy supply to neurons and leads to cytotoxic and vasogenic brain edema. Aptamers are short single-stranded RNA or DNA molecules that can bind to specific ligands for cell specific delivery. The expression of vascular cell adhesion molecule-1 (VCAM-1) is increased on CECs after stroke. Herein, we report that an RNA-based VCAM-1-aptamer can specifically target CECs in stroke brains following transient middle cerebral artery …