Medicine and Health Sciences Commons^™

Segmental Trans-Endplate Pedicle Screws Do Not Induce Spinal Deformity In A Porcine Model, Taylor R Johnson, Talissa O Generoso, Christine Farnsworth, Amishi Jobanputra, Jonathan H Wen, Austin J Stoner, Arianne Salunga, Vivian Ho, Miranda Guzman, David Berry, Vidyadhar Upasani, John S Vorhies

Faculty, Staff and Student Publications

Purpose: Growth modulation is an established technique for limb deformity correction and is increasingly applied to spinal deformities. While distraction-based posterior and anterior compressive methods have been explored, spinal growth modulation through fixation across vertebral growth centers remains unstudied. We hypothesized that unilateral trans-endplate screws-spinal epiphysiodesis trajectory (SET) screws-could induce partial anterior growth arrest and promote scoliotic deformity in a porcine model.

Methods: Four male piglets (two experimental, two control) underwent unilateral posterior spinal instrumentation at four lower thoracic levels at eight weeks of age. Experimental animals received trans-endplate SET screws; controls received pedicle screws. Radiographs obtained three months postoperatively …

Antidepressant-Like Effects Of Extinction Learning As An Animal Model Of Behavioral Therapy, Jing Liu, Sarah E Bulin, David A Morilak

Faculty, Staff and Student Publications

Exposure-based behavioral therapy, the most effective treatment for posttraumatic stress disorder (PTSD), also reduces depressive symptoms. However, neurobiological mechanisms underlying the beneficial effects of exposure-based behavioral therapy on depression remain unknown. Our lab has established fear extinction as a rat model of exposure therapy to investigate the mechanisms underlying its therapeutic behavioral effects in chronically stressed rats. In this study, we demonstrated that extinction learning reduced immobility in the forced-swim test and reversed chronic stress-induced reduction in sucrose preference. Chemogenetic inactivation of pyramidal neurons in the ventral medial prefrontal cortex (vmPFC) prevented these antidepressant-like effects of extinction. Extinction learning enhanced …

Computational Modeling Meets 3d Bioprinting: Emerging Synergies In Cardiovascular Disease Modeling, Tanmay Mukherjee, Mehdi Salar Amoli, Sarah Rezapourdamanab, Lama Rita El Shammas, Martin L Tomov, Emilio A Mendiola, Vahid Serpooshan, Reza Avazmohammadi

Faculty, Staff and Student Publications

Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, underscoring the need for improved strategies in diagnosis, treatment, and disease modeling. Traditional in vitro models often fall short in replicating human CV physiology, prompting efforts to advance cardiac tissue engineering and computational modeling. Among these, three-dimensional (3D) bioprinting has emerged as a transformative tool, enabling the creation of biomimetic CV constructs that more faithfully replicate native tissue structure and function. However, challenges persist in achieving appropriate mechanical properties and long-term performance of engineered CV constructs. Computational modeling offers powerful solutions to assist with these challenges, providing predictive insights into …

Estrogen As A Therapeutic Agent: Targeting Endotheliopathy And Coagulopathy In Trauma, Niruktha Raghavan, Mira Patel, Bryan A Cotton, Julia Coleman, Donald Jenkins

Faculty, Staff and Student Publications

Background: Traumatic injury remains a leading cause of death, often due to uncontrolled hemorrhage and trauma-induced coagulopathy (TIC). TIC is critically triggered by the endotheliopathy of trauma, involving endothelial cell injury and glycocalyx degradation. Despite conventional advances, the stable casualty rate underscores the urgent need for new precision resuscitation strategies that acknowledge factors like biological sex.

Design: The central hypothesis is that estrogen confers a survival advantage in hormonally active females through a dual action: endothelial cell stabilization (halting glycocalyx shedding) and its inherent procoagulant effect. The analysis assesses the therapeutic potential of both exogenous estrogen and female-derived blood products …

A Covalent Allosteric Molecular Glue Suppresses Nrf2-Dependent Cancer Growth, Nilotpal Roy, Ilah Bok, Harit Panda, Dhaval P Bhatt, Emily M Wilkerson, Soma Saeidi, Paul Zolkind, Michael B Major, Et Al.

2020-Current year OA Pubs

UNLABELLED: The NRF2 transcription factor is constitutively active in cancer, in which it functions to maintain oxidative homeostasis and reprogram cellular metabolism. NRF2-active tumors exhibit NRF2 dependency and resistance to chemotherapy/radiotherapy (RT). In this study, we characterize VVD-065, a first-in-class NRF2 inhibitor that acts via an unprecedented allosteric molecular glue mechanism. In the absence of stress or mutation, NRF2 is rapidly degraded by the Kelch-like ECH-associated protein 1 (KEAP1)-cullin3 (CUL3) ubiquitin-ligase complex. VVD-065 specifically and covalently engages Cys151 on KEAP1, which in turn promotes KEAP1-CUL3 complex formation, leading to enhancement of NRF2 degradation. Previously reported Cys151-directed compounds decrease KEAP1-CUL3 interactions …

Adaptive Evolution Of Gene Regulatory Networks In Mammalian Neocortex, Zhuo Li, Linda J Richards, Et Al.

2020-Current year OA Pubs

Mammals have evolved a more complex brain, exemplified by the transformation of the single-layer dorsal cortex of excitatory projection neurons (ExNs) in ancestors into a multilayered cerebral neocortex

Preterm Birth Increases Susceptibility To Hyperglycemia-Induced Kidney Injury With Sex-Specific Differences In Structural And Molecular Responses, Rachel K Dailey, Aleksandra Cwiek, Logan C Hamil, Sage Timberline, Ayyappa Kumar Sista Kameshwar, Masako Suzuki, Jaya Isaac, Kimberly Deronde, Mark Conaway, Kevin M Bennett, Edwin J Baldelomar, Matthew R Hoch, Kimberly J Reidy, Jennifer R Charlton

2020-Current year OA Pubs

BACKGROUND: Preterm birth increases the long-term risk of diabetes and chronic kidney disease (CKD), yet its impact on diabetic kidney disease (DKD) is unclear. We previously showed that male preterm mice with diabetes develop early features of DKD, including reduced podocyte density, decreased renin expression, activation of angiogenesis pathways, and impaired endothelial-podocyte signaling. Here, we examine whether preterm birth similarly accelerates DKD progression in female mice and compare structural and transcriptomic outcomes in the females to the prior male cohort to assess sex-specific differences.

METHODS: Preterm mice were delivered by Caesarean section at 19 days post conception (dpc) and term …

Primary Cilia Regulate Glp-1 Signaling In Pancreatic Β Cells, Isabella Melena, Jeong Hun Jo, Shannon E Townsend, Samantha Adamson Digruccio, Xinhang Dong, Lifei Zhu, Jonathan Campbell, Jing W Hughes

2020-Current year OA Pubs

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are mainstay therapies for diabetes and obesity, acting in part by enhancing glucose-dependent insulin secretion. While the primary cilium is a known signaling compartment for certain G-protein coupled receptors (GPCRs), its role in the β-cell response to incretins remains undefined. Here, we show that primary cilia are essential for full GLP-1R signaling. Loss of β-cell cilia in mouse and human islets severely impaired GLP-1-potentiated insulin secretion, an effect preceded by blunted whole-cell cAMP and Ca

Maternal Fish Intake In The Year Prior To Conception And Birth Defects, National Birth Defects Prevention Study, 1997-2011, Dorothy Kim Waller, Zeyu Miao, Renata H Benjamin, Richard Finnell, Nithya Lakshmi Mohan Dass, Eirini Nestoridi, Marcia C De Oliveira Otto, Julie Peterson, Tunu Ramadhani, Mark A Canfield

Faculty, Staff and Students Publications

Background: Epidemiologic data on the association between maternal fish intake and birth defects are sparse. Our objective was to assess associations between maternal fish intake and 52 different birth defects, most of which have not been assessed previously.

Methods: Using logistic regression, data was analyzed for 29,242 mothers of infants with birth defects and 10,973 mothers of control infants who participated in the National Birth Defects Prevention Study (NBDPS) and delivered between 1997 and 2011. We focused on associations between mothers who reported high fish intake of 2 or more servings of fish per week for the year prior to …

Dolutegravir Developmental Toxicity Is Mitigated By Magnesium And Folate In Zebrafish Embryos, Robert M Cabrera, Ahmed Mohamed, Ryoko Minowa, Katheryn A Neugebauer, Daniel A Gorelick

Faculty, Staff and Students Publications

Integrase strand transfer inhibitors have transformed human immunodeficiency virus (HIV) therapy, yet the widely prescribed drug dolutegravir (DTG) has been linked to developmental toxicity, and its teratogenic mechanism remains unclear. Here, we used zebrafish to dissect DTG toxicity during early vertebrate development. DTG exposure from 2-4 h post-fertilization (hpf) to 24 hpf produced high mortality and abnormal morphology. Co-treatment with folates partially restored normal morphology, whereas calcium had no effect. Strikingly, supplementation with magnesium (Mg) partially rescued DTG-exposed embryos, implicating Mg availability in protection. In competitive binding assays, Mg increased binding of folate to purified folate receptor (FOLR1) by 30% …

The Right Time For A Synapse To Change: Windows And Mechanisms Of Multiday Training Trials, Rong-Yu Liu, Yili Zhang, Roberta Calvo, Paul Smolen, John H Byrne

Faculty, Staff and Student Publications

Although learning over multiple days is more effective than a single day of training, the underlying cellular mechanisms of repeated training trials remain poorly understood. With a combination of empirical and computational approaches, we determined a critical time window for a second stimulus block of a multiday training protocol to augment long-term synaptic facilitation (LTF) of the Aplysia sensorimotor synapse and long-term enhancement of neuronal excitability (LTEE), two cellular correlates of learning and memory. A second stimulus block delivered 24 h after the first block significantly enhanced LTF and LTEE, but was without effect at 18 or 32 h. This …

Yap Induces A Prorenewal Metabolic State In Cardiomyocytes, Lin Liu, Jeffrey D Steimle, Chang-Ru Tsai, Fansen Meng, Yuka Morikawa, Yi Zhao, Sandra Carmichael, Xiao Li, James F Martin

Faculty, Staff and Students Publications

BACKGROUND: Cardiomyocytes, as highly specialized and differentiated somatic cells, possess a limited capacity for renewal. Neonatal rodents possess the ability to regenerate cardiomyocytes after injury; however, this regenerative capacity declines rapidly with cardiomyocyte maturation, suggesting an inhibitory network between cellular maturation and cardiomyocyte proliferation. Maturing cardiomyocytes undergo a metabolic shift from predominantly glycolysis in the neonatal state to increased fatty acid oxidation in the mature state, which poses a barrier to cardiomyocyte proliferation and cardiac regenerative repair. YAP, a transcriptional cofactor regulated by the Hippo signaling pathway, promotes cardiac regenerative repair. We investigated the role of YAP in mediating metabolic …

B Cell Expression Of An Enzymatic Intermediary In Ether Lipid Biosynthesis Promotes Antibody Responses And Germinal Center Size, Sung Hoon Cho, Marissa A Jones, Kaylor Meyer, David M Anderson, Sergiy Chetyrkin, M Wade Calcutt, Richard M Caprioli, Clay F Semenkovich, Mark R Boothby

2020-Current year OA Pubs

The qualities of antibody (Ab) responses provided by B lymphocytes and their plasma cell (PC) descendants are crucial facets of responses to vaccines and microbes. Metabolic processes and products regulate aspects of B cell proliferation and differentiation into germinal center (GC) and PC states along with Ab diversification. However, there is little information about lymphoid-cell-intrinsic functions of enzymes that mediate ether lipid biosynthesis. Imaging mass spectrometry (IMS) results had indicated that concentrations of a number of these phospholipids were substantially enhanced in GC compared to the background average in spleens, but it was unclear if biosynthesis in B cells was …

The Polymerized Protein Response (Ppr) Is Activated By Genetic Variants That Polymerize In The Er And Is Mediated By Nfκbp50, Admire Munanairi, David A Rudnick, Jiansheng Huang, David H Perlmutter

2020-Current year OA Pubs

In previous studies we have shown that accumulation of the polymerogenic variant ATZ that causes α1-antitrypsin deficiency (ATD) activates NFκB DNA binding. Here we discovered that this response, which we are naming the polymerized protein response (PPR), is characterized by NFκB p50 homodimers, distinct from the p50/p65 heterodimers in the canonical NFκB inflammatory response and the unfolded protein response (UPR). The PPR is also activated by other disease associated variants that polymerize in the ER whereas disease-associated variants that do not form polymers activate p50/p65 heterodimers and UPR. The PPR elicits a unique gene expression profile, including changes that stabilize …

An Atlas Of Human Siglecs Integrates Expression, Affinity, And Cis/Trans Sialoglycan Recognition Profiles, Shani Leviatan Ben-Arye, Edward N Schmidt, Zeinab Jame-Chenarboo, Claire Guetta-Oz, Fahima Mozaneh, Jaesoo Jung, Kelli A Mccord, Ronit Rosenfeld, Kan Zhong, Hongzhi Cao, Hai Yu, Xi Chen, Lori J West, Matthew S Macauley, Vered Padler-Karavani

Faculty, Staff and Students Publications

All living cells have a sugar-coat that facilitates communication. Sialic acids cap mammalian glycans and are recognized by immune cells through sialic acid-binding immunoglobulin-like lectins (Siglecs) that regulate signaling by their cytoplasmic motifs. Inconsistent reports of Siglecs expression and sialoglycan recognition limit their therapeutic potential. Here we investigate 14 functional human Siglecs for their expression, glycan interactions and affinities. SIGLEC mRNA is broad in blood-derived monocytes and dendritic cells, restricted in natural-killer/B cells and absent in T cells, with similar Siglec-proteins expression in splenocytes. Binding to 114 glycans across 274 glycan microarrays, 220 splenocytes-assays and 132 cell-based arrays, reveal Siglecs …

Dual Membrane-Spanning Anti-Sigma 2 Controls Omv Biogenesis And Colonization Fitness In Bacteroides Thetaiotaomicron, Evan J Pardue, Tengfei Zhong, Nichollas E Scott, Biswanath Jana, Wandy Beatty, Juan C Ortiz-Marquez, Mohammed Kaplan, Clay Jackson-Litteken, Mario F Feldman

2020-Current year OA Pubs

UNLABELLED:

IMPORTANCE: Dual membrane-spanning anti-sigma factors (Dma) are a novel class of regulatory proteins found solely among Bacteroidota. Previous studies demonstrated the importance of Dma1 in vesiculation, but the overall role of the Dma family in Bacteroides physiology remains poorly understood. Here, we show that Dma2 modulates vesiculation and the expression of select polysaccharide utilization loci (PULs) that target host-associated glycans

Rhesus Macaques With An Opa1 Mutation Demonstrate Features Of Autosomal Dominant Optic Atrophy, Tracy N Jaggers, Ana Ripolles-Garcia, Ala Moshiri, Brett D Story, Jun Wang, Rui Chen, Lucy G Moore, Leandro B C Teixeira, Jaeho Shim, Ana C Raposo, Maria Isabel Casanova, Sophie M Le, Sangwan Park, Laura J Young, Soohyun Kim, Karolina P Roszak, Vanessa Ureno, Paige M Karpinen, Nayeli Echeverria, Monica Ardon, Brian C Leonard, Marguerite Knipe, Eliza Bliss-Moreau, Brad Fortune, J Timothy Stout, Jeffrey Rogers, Nicholas Marsh-Armstrong, Sara M Thomasy

Faculty, Staff and Students Publications

Autosomal dominant optic atrophy (ADOA) is an inherited optic neuropathy primarily caused by mutations in OPA1. We identified and defined a spontaneous nonhuman primate (NHP) model of ADOA using rhesus macaques heterozygous for a missense mutation (OPA1A8S). With ocular examinations, ophthalmic imaging, electroretinography, histopathology, immunohistochemistry, and transmission electron microscopy (TEM), we documented retinal nerve fiber layer (RNFL) thinning, retinal ganglion cell (RGC) loss and dysfunction, OPA1 mislocalization, and reduced axonal mitochondrial density in affected macaques. Our investigation revealed substantial phenotypic variability among affected macaques, shedding light on the pathogenesis of ADOA. The retinas were evaluated using techniques …

Functional Requirement For Dicer Helicase Arginine Methylation In 26 G Sirna Biogenesis And Oocyte Meiotic Program, Nick Newkirk, Shin-Yu Chen, Tokiko Furuta, Kenneth A Trimmer, Leilei Shi, Sabrina Stratton, Hongyuan Li, Xiaodong Cheng, Mark T Bedford, Swathi Arur

The Brown Foundation: Institute of Molecular Medicine

Spatiotemporal regulation of Dicer is essential for small RNA biogenesis and fertility, yet how its helicase domain is controlled remains unclear. Using Caenorhabditis elegans, we identify a regulatory role for the arginine-rich GRARR motif within helicase domain motif VI of DCR-1. Mutating conserved arginines in this sequence disrupts maternal 26 G endo-siRNA production, impairs oocyte meiosis I and II, and reduces fertility. Biochemically, an asymmetrically dimethylated DCR-1 GRA[R495*]R peptide enhances interaction with ERI-5, a tandem-Tudor protein in the ERIC complex, while loss of DCR-1(R495) diminishes this interaction in vivo. Genetically, eri-5 deletion phenocopies the dcr-1 R495K mutant, supporting a functional …

Enhancing Inference Of Differential Gene Expression In Metatranscriptomes From Human Microbial Communities, Evan M Lee, Nathan P Mcnulty, Matthew C Hibberd, Jiye Cheng, Kazi Ahsan, Hao-Wei Chang, Barak A Cohen, Jeffrey I Gordon

2020-Current year OA Pubs

Metatranscriptomic (MTX) sequencing quantifies gene expression from the collective genomes of microbial communities (microbiomes), enabling assessment of functional activity rather than functional potential. While differential expression testing is essential for RNA-sequencing analysis, current metatranscriptomic approaches have only been benchmarked on simulated data, resulting in a lack of standard practices for analysis of real datasets. Here, we use mock communities (defined mixtures of microbial cells with known properties) to quantitatively assess robustness and susceptibility of current approaches to various confounders including organisms' low relative abundance, differential abundance, low prevalence, global transcriptional output changes, and compositional effects. We show that no current …

Maternal Inflammation Alters Nuclear And Mitochondrial Dna Methylation Patterns In Neonatal Brain Monocytes, Andrew Ebenezer, Jonathan Hicks, Brooke Hollander, Alexander Hone, Mona Batish, Robert Akins, Adam Marsh, Elizabeth Wright-Jin

Department of Medicine Faculty Papers

Neonatal hypoxic ischemic encephalopathy (HIE) is a common birth complication that can cause death or lifelong disabling conditions like cerebral palsy, epilepsy, and autism. It is well established that maternal infection and inflammation are significant risk factors for HIE but reasons for this increase in neurological risk to the offspring remain unknown. Inflammation or infection are associated with epigenetic changes and may contribute to the increased risk of neurodevelopmental disability in exposed offspring. Here, we analyzed and compared DNA methylation patterns in brain monocytes isolated from control, maternal immune activation (MIA), and an inflammation sensitized HIE (IS-HIE) CF-1 mouse model …

Neuropathological Hallmarks During The Chronic Phase Of Ischemic Stroke In Mice And Humans, Romeesa Khan, Gary Guzman, Trang Do, Patrick Devlin, John Ahn, Chunfeng Tan, Venugopal Reddy Venna, Sean P Marrelli, Haniyeh Koochak, Claudia M Di Gesù, Anthony Flores, Louise D Mccullough, Rodney M Ritzel

Faculty, Staff and Student Publications

Background: Advances in acute stroke care, including endovascular thrombectomy and improved neurocritical management, have increased survival after ischemic stroke. However, stroke remains a leading cause of long-term disability, with many survivors experiencing persistent neurological and cognitive impairments. The chronic neurological consequences of stroke, particularly its potential to accelerate brain aging, remain poorly understood.

Methods: We examined chronic neurobehavioral changes at 2 and 6 months after middle cerebral artery occlusion in male C57Bl/6 mice. Behavioral assessments included the open field test (OFT), novel object recognition test (NORT), fear conditioning (FC), nesting activity, and tail suspension testing. Transcriptomic profiling was performed using …

Inflammation- And Resolution-Programmed Myeloid Circuits Govern Therapeutic Resistance In Epithelial And Mesenchymal Triple-Negative Breast Cancer, Liqun Yu, Charlotte Rivas, Fengshuo Liu, Yichao Shen, Ling Wu, Zhan Xu, Yunfeng Ding, Xiaoxin Hao, Weijie Zhang, Hilda L Chan, Jun Liu, Bo Wei, Yang Gao, Luis Becerra-Dominguez, Yi-Hsuan Wu, Siyue Wang, Tobie D Lee, Xuan Li, Xiang Chen, David G Edwards, Xiang H-F Zhang

Faculty, Staff and Students Publications

Single-cell analysis of human triple-negative breast cancer revealed heterogeneous macrophage populations with opposing phenotypes - proinflammatory and proresolution of inflammation. Paradoxically, both subsets accumulated in therapy-refractory residual tumors but showed inverse correlations across patients, suggesting mutually exclusive resistance mechanisms. Inflammatory macrophages localized preferentially to epithelial-like tumors, whereas proresolution macrophages were enriched in mesenchymal-like tumors. Mouse models faithfully recapitulated these patterns. After chemoimmunotherapy, mesenchymal-like tumors expanded proresolution macrophages through phagocytosis/efferocytosis, ω-3 fatty acid uptake, and resolvin production. Macrophage-secreted C1q emerged as a principal antagonist of T cell function by targeting mitochondria and inducing metabolic dysfunction. By contrast, epithelial-like tumors accumulated inflammatory …

Sex-Specific Autosomal Susceptibility Loci In Systemic Sclerosis: A Genome-Wide Association Study, Inmaculada Rodriguez-Martin, Martin Kerick, Carlos Rangel-Peláez, Carlos Rosa-Baez, Gonzalo Borrego-Yaniz, Lourdes Ortiz-Fernández, Alfredo Guillen-Del-Castillo, Carmen P Simeón-Aznar, José Luis Callejas, Oliver Distler, Susanna M Proudman, Mandana Nikpour, Nicolas Hunzelmann, Jeska K De Vries-Bouwstra, Ariane L Herrick, Yannick Allanore, Marta E Alarcón-Riquelme, Lorenzo Beretta, Shervin Assassi, Christopher P Denton, Maureen D Mayes, Javier Martin, Marialbert Acosta-Herrera

Faculty, Staff and Student Publications

Background: Systemic sclerosis is an immune-mediated inflammatory disease with marked sex differences in prevalence and severity. Although genome-wide association studies (GWAS) have advanced the understanding of systemic sclerosis genetics, sex-aware approaches remain scarce. We aimed to address this gap by examining autosomal sex-specific genetic factors in systemic sclerosis.

Methods: Based on a chromosomal definition of sex, we conducted a sex-stratified autosomal meta-analysis of GWAS in systemic sclerosis. We retrieved patient-level and control data from a previous GWAS for systemic sclerosis and newly recruited participants from an international multicentre collaboration (data cutoff June 1, 2024). Adult patients (aged ≥18 years) were …

Dapk2 Regulates Pkm2 Phosphorylation At Threonine 45 To Facilitate Disturbed Flow-Induced Atherosclerosis, Shuai Guo, Long Xu, Yixin Chen, Yuan Zhao, Yuting Zhang, Runfa Yu, Kaixiang Cao, Litao Wang, Wenjia Ai, Jiang-Yun Luo, Lu Lu, Jun He, Yuan Zhou, Li Wang, Andrew H Baker, Yuqing Huo, Yiming Xu

Faculty, Staff and Students Publications

Background: Oscillatory shear stress (OSS), resulting from disturbed blood flow, is implicated in atherosclerotic plaque formation by incompletely understood mechanisms. This study aims to elucidate the involvement of death-associated protein kinase (DAPK) 2 in OSS-induced endothelial cell (EC) activation and atherosclerosis.

Methods: Publicly available resources, including genome-wide microarray, RNA sequencing, and single-cell RNA sequencing, were utilized to identify key OSS-sensitive regulatory factors. Techniques such as mass spectrometry, immunoprecipitation, proximity ligation assay, and RNA sequencing were employed to identify pyruvate kinase M2 (PKM2) as the binding protein of DAPK2 and determine the specific site of PKM2 phosphorylation by DAPK2. To assess …

Synthetic Lethality Of Decitabine Plus Atr Inhibition For Tp53-Mutated Aml, Jeremy T Baeten, Sumedha Agashe, Imene Tabet, Jack T Wooldridge, Amber Carter, Jamie N Butler, Christopher A Miller, Nicole Helton, Annabel Quinet, Kimberly B Johansson, Yichan Yang, Geoffrey L Uy, Alessandro Vindigni, Daniel C Link

2020-Current year OA Pubs

TP53 mutations are found in 10% to 15% of myeloid neoplasms and are associated with a dismal prognosis. Although hypomethylating agents (HMAs), such as decitabine, are active in TP53-mutated myeloid neoplasms (TP53-MN), mutation clearance is rarely complete and nearly all patients relapse. Molecular determinants of response to HMAs in TP53-MN are poorly understood. Here, we show that decitabine induces replicative stress with decreased replication fork progression, induction of single-strand DNA breaks, and activation of the ataxia telangiectasia mutated-Rad3-related (ATR) pathway. Resolution of decitabine-induced replication stress is impaired in TP53-mutated acute myeloid leukemia (AML) cells, representing a potential therapeutic vulnerability. Indeed, …

Herpes Simplex Virus Type 1 R-Loops Are Targets For Apobec-Mediated Mutagenesis, Márton Miskei, Dóra Varga, Lilla Hornyák, Éva Sipos, Éva Nagy, Qiuzhen Li, Zsolt Karányi, Zoltán Szabó, Rachel Deweerd, Abby M Green, Dávid Szüts, Eszter Csoma, Lóránt Székvölgyi

2020-Current year OA Pubs

APOBEC3 enzymes are key effectors of antiviral immunity that introduce mutations into viral genomes. We show that viral R-loops serve as preferred substrates for APOBEC3-mediated mutagenesis during herpes simplex virus type 1 (HSV-1) infection. APOBEC3 enzymes are recruited to viral R-loops, generating clustered C-to-T mutations in genes critical for viral assembly. Importantly, R-loops alone are not mutagenic, and APOBEC3 enzymes do not edit HSV-1 without an R-loop; mutagenesis occurs when R-loops and APOBEC3 enzymes interact. These findings identify endogenous R-loops formed during the HSV-1 life cycle as focal vulnerabilities and highlight R-loop-APOBEC3 coupling as a mechanism for antiviral mutagenesis.

Engineering Of Genetically Encoded Programmable Calcium Channel Inhibitory Binders, Xiaoxuan Liu, Sher Ali, Tien-Hung Lan, Decheng Wang, Brendan Mckee, Tatsuki Nonomura, Siyao Liu, Feng Zhao, Michael X Zhu, Yun Huang, Qing Deng, Guolin Ma, Yubin Zhou

Faculty, Staff and Student Publications

Store-operated Ca2+ release-activated Ca2+ (CRAC) channels, composed of STIM and ORAI, are essential for immune and developmental processes, and their dysregulation underlies channelopathies such as Stormorken syndrome. Here, we report the engineering of genetically encoded CRAC channel inhibitory binders (CRABs) derived from the ORAI C-terminal tail. Guided by deep mutational scanning, we optimize a membrane-anchored CRAB variant that potently inhibits Ca2+ influx and NFAT signaling, and rescues thrombocytopenia-like phenotypes in a zebrafish model of Stormorken syndrome. To enable tunable inhibition, we further design oligomeric, optogenetic (Opto-CRAB), and chemogenetic (Chemo-CRAB) variants, providing graded and real-time control of CRAC activity. Chemo-CRAB further …

Adipocytes Signal To Recruit Specific Mrnas From Surrounding Cells To Restore Expression Deficits, Clair Crewe, Snigdha Tiash, Yun-Ling Pai, Marjori Russo, Saket Awadhesbhai Patel, Yi-Cian Zheng, Alex Larkin, Chun-Kan Chen, Et Al.

2020-Current year OA Pubs

Extracellular vesicles (EVs) are nano-sized, membrane-delimited, particles released by cells that carry signaling macromolecules. A major pathway of EV production is potentiated by neutral sphingomyelinase 2 (SMPD3/nSMAse2), an enzyme that generates ceramide from sphingomyelin. In our attempt to study this pathway in adipocytes of male mice, we discover that the elimination of SMPD3 from adipocytes in vivo triggers a signal to surrounding immune cell-like preadipocytes to release EVs that carry SMPD3 mRNA. This results in a widespread increase in SMPD3 mRNA in purified null adipocytes without a change in the transcripts of other enzymes involved in ceramide metabolism. These results …

Constitutive Ampk Activation Prevents Hepatocellular Carcinoma Development Through Inhibition Of Hnf4Α Activity, Zhen Sun, Bernard Linares, Cassidy Urdiales, Fiyad Alsarmi, Boyuan Sang, Nagireddy Putluri, Jeanine L Van Nostrand

Faculty, Staff and Students Publications

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality and is largely driven by metabolic disorders such as obesity and type 2 diabetes. The AMP-activated protein kinase (AMPK) is a master regulator of metabolism, and its activation has been proposed as a therapeutic strategy for treating metabolic disorders. However, although AMPK activity is down-regulated in HCC, the precise role of AMPK in HCC development has not been clearly delineated. Here, we investigated the ability of constitutive AMPK activation to prevent HCC development using a constitutively active AMPK transgenic mouse model and a pharmacological AMPK activator. We observed that AMPK …

A Multidomain Peptide Hydrogel-Liposome Composite For Controlled Release Of A Cyclic Dinucleotide In Oral Cancer, Joseph W R Swain, Andrea H Molina, Gemalene M Sunga, Danielle Chew-Martinez, Neeraja Dharmaraj, Alejandra Cobos Perez, Arghadip Dey, Ephraim J Vázquez-Rosado, Simon Young, Jeffrey D Hartgerink

Faculty, Staff and Student Publications

While immunotherapy is a promising treatment strategy for cancer, the majority of head and neck squamous cell carcinoma (HNSCC) patients treated with single-agent immunotherapy do not respond. Therefore, researchers are investigating combination treatments with immunostimulatory molecules that can maximize anti-tumor responses. Cyclic dinucleotides (CDNs) are STING agonists that hold promise in combination approaches, but they require frequent intratumoral administration when used in both preclinical models of HNSCC and clinical trials. To reduce administration frequency, we have created a peptide hydrogel–liposome composite system, K2-Lip(CDN), for local and prolonged availability of CDN. We investigated the loading limits of cationic liposomes in both …