Medicine and Health Sciences Commons^™

Glycative Stress Disrupts The Mitochondrial-Lysosome Axis And Promotes Geroconversion In Aging Cardiomyocytes, Diana Bou-Teen, Simonas Valiuska, Elisabet Miro-Casas, Chiara Rubeo, Elena Bonzon-Kulichenko, Zuzana Nichtova, Celia Fernandez-Sanz, Javier Inserte, Antonio Rodriguez-Sinovas, Begoña Benito, Eduard Ródenas-Alesina, Jesús Vázquez, Ignacio Ferreira-González, Marisol Ruiz-Meana

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Aging is a major risk factor for heart failure, yet the molecular mechanisms linking cardiac aging to the inflammatory pathophysiology of heart failure remain elusive. Mitochondrial dysfunction and defective organelle quality control are emerging hallmarks of the aging heart, but their biochemical underpinnings are poorly defined. Using comprehensive glycomics, we found that cardiac mitochondria from physiologically aged mice (≥ 20 months) are the major intracellular reservoirs of advanced glycation end products (AGEs), derived primarily from the chemical attack of some α-oxoaldehydes on proteins. This was associated with mild mitochondrial dysfunction and structural remodeling. Lysosomes in aged hearts were enlarged, more …

Mist: A Hierarchical Bayesian Framework For Detecting Differential Dna Methylation Dynamics In Single-Cell Data, Daoyu Duan, Wenjing Ma, Wen Tang, Hao Wu, Liangliang Zhang, Hao Feng

Faculty, Staff and Student Publications

Recent advancements in single-cell DNA methylation (scDNAm) sequencing technologies have enabled the profiling of epigenetic landscapes at unprecedented resolution, offering insights into cellular heterogeneity, differentiation and evolution. Trajectory inference, which orders cells along pseudotime, allows researchers to track genomics changes across continuous cell states and identify key loci exhibiting differential methylation. However, no methods currently exist to model methylation changes along pseudotime in scDNAm data. Here, we present a hierarchical Bayesian framework for scDNAm data analysis. Our method, named mist (methylation inference for single-cell along trajectory), models stage-specific biological variations, identifies genomic features with significant methylation changes along pseudotime, and …

Pkmζ-Kibra Interactions, Molecular Turnover, And Memory, Changchi Hsieh, David A Cano, Panayiotis Tsokas, James E Cottrell, André Antonio Fenton, Harel Shouval, Todd Charlton Sacktor

Faculty, Staff and Student Publications

How can the molecules that strengthen synaptic connections maintain memory in the face of molecular turnover? Our previous work showed that persistent interaction between the postsynaptic scaffolding protein, KIBRA, and the autonomously active PKC isoform, PKMζ, is crucial for maintaining synaptic long-term potentiation (LTP) and memory lasting at least a month. This duration is longer than the lifespans of individual KIBRA and PKMζ molecules. Biophysical modeling of the interaction suggests oligomers of KIBRA-PKMζ dimers, but not individual dimers or monomers, can overcome molecular turnover by continuously incorporating newly synthesized KIBRA and PKMζ, replacing those that have degraded. Here we used …

Megakaryocyte And Platelet Thrombospondin-1 Regulates Matrix Remodeling By Stabilizing Basement Membrane Col6a1 In Lung Injury, Hernán F Peñaloza, Atish Gheware, Ananya Gupta, Donovan Watza, Anupam Kumari, Zeyu Xiong, Pooja Bhojraj, Jae-Sung Kim, Bo-Ram Jin, Kyunghee Choi, Matthew R Rosengart, Jaehyung Cho, Janet S Lee, Et Al.

2020-Current year OA Pubs

An early event after lung injury is extracellular matrix (ECM) remodeling and the formation of a provisional matrix. While megakaryocytes and platelets (Mgk/plt) play important roles in hemostasis, their impact on the matrix in lung injury is not fully understood. Using lung intravital microscopy, 3D large area scanning with multiphoton confocal hybrid imaging, and label-free quantitative proteomics, the matricellular protein thrombospondin-1 (TSP1) arising from Mgk/plt protects the lung from alveolar injury. Mgk/plt cell-specific Thbs1 knockout (cKO) mice show increased alveolar barrier disruption with exaggerated neutrophil-mediated injury. The cKO mice exhibit striking extracellular matrix re-organization with reduction in basement membrane matrix …

Molecular Insights Into The Regulation Of Gnptαβ By Lyset, Xi Yang, Balraj Doray, Danielle Henn, Varsha Venkatarangan, Benjamin C Jennings, Zhongzheng Dong, Jiaxuan Liang, Weichao Zhang, Bokai Zhang, Linchen Yu, Liang Chen, Stuart Kornfeld, Ming Li

2020-Current year OA Pubs

In vertebrates, newly synthesized lysosomal enzymes traffic to lysosomes through the mannose-6-phosphate (M6P) pathway. The Golgi membrane protein LYSET was recently discovered to regulate lysosome biogenesis by controlling the level of GlcNAc-1-phosphotransferase (GNPT). However, its working mechanism remained unclear. In this study, we demonstrate that LYSET is a two-transmembrane protein essential for GNPT stability, cleavage by Site-1 Protease (S1P), and enzymatic activity. We reconcile conflicting models by showing that LYSET enhances GNPT cleavage and prevents its mislocalization to lysosomes for degradation. We further establish that LYSET achieves this by interacting with GOLPH3 and retromer complexes to anchor the LYSET-GNPT complex …

Underexplored Maternal Microbiomes: Immune, Metabolic, And Microbial Pathways Shaping Pregnancy Outcomes, Rafael Tomoya Michita, Nicole Jimenez, Melissa M Herbst-Kralovetz, Indira U Mysorekar

Faculty, Staff and Students Publications

Maternal microbial ecosystems play critical roles in shaping reproductive physiology and pregnancy outcomes. During the pre-conception and prenatal periods, these communities modulate maternal physiology by regulating immune tolerance, nutrient metabolism, and susceptibility to pregnancy complications such as preterm birth, hypertensive disorders, and gestational diabetes. While the gut microbiota has been extensively studied, the roles of cervicovaginal, urinary, respiratory, oral, and upper reproductive tract microbiomes remain less clear. In this minireview, we synthesize current knowledge on these underexplored maternal microbiomes, with an emphasis on the cervicovaginal and urinary microbiota and their interactions with the placenta and fetus. We discuss cross-niche microbial …

Differential Contributions Of Clpx And Clpp To Pulmonary Virulence In Classical And Hypervirulent Klebsiella Pneumoniae, Nathan M Lin, Emily C Marino, Jordan M Schlotmann, David A Rosen

2020-Current year OA Pubs

No abstract provided.

Crossing The Finish Line Towards A Disease-Modifying Treatment For Angelman Syndrome, Matthew C Judson, Jason J Yi, Et Al.

2020-Current year OA Pubs

Recent progress in the development of genetic therapies promises that impactful treatments for single-gene neurodevelopmental disorders are imminent. But can derailed neurodevelopmental processes be mended after broken genes are replaced or otherwise restored? The results of ongoing clinical trials for Angelman syndrome will soon yield answers to this pressing question, yet the trials face significant obstacles. Here we identify insights needed to aid the quest for a disease-modifying Angelman syndrome therapy, which could serve as a roadmap for the expeditious development of genetic therapies for other single-gene neurodevelopmental disorders.

Translation Of Expanded Cgg Repeats In Lrp12 Associated Oculopharyngodistal Myopathy, Chengcheng Li, Jil A Daw, Sara K Pittman, Connor J Maltby, Hidetoshi Sakurai, Peter K Todd, Conrad C Weihl

2020-Current year OA Pubs

Oculopharyngodistal myopathy (OPDM) is characterized by ptosis, ophthalmoparesis, dysphagia, and distal weakness. Myopathological features include rimmed vacuoles and intranuclear inclusions. OPDM is associated with a pathogenic CGG repeat expansions in the 5'UTR of LRP12, NOTCH2NLC, GIPC1, RILPL1 and ABCD3. Translation of the repeat in the glycine reading frame has been demonstrated for expansions in FMR1, NOTCH2NLC and GIPC1. To assess for a similar phenomenon with LRP12, we expressed normal or expanded CGG repeats in the context of the 5'UTR of LRP12, upstream of a green fluorescent protein (GFP) in the three repeat reading frames. Repeat dependent translation occurs exclusively in …

A New Chromosome-Level Genome Assembly For Western Painted Turtle Chrysemys Picta Bellii, A Model For Extreme Physiological Adaptations, Junhao Chen, John R Bermingham Jr, Patrick Minx, Milinn Kremitzky, Zhenguo Lin, Daniel E Warren

2020-Current year OA Pubs

The western painted turtle, Chrysemys picta bellii, has the greatest tolerance to anoxia of any tetrapod studied to date. These turtles reside in the northern United States and southern Canada, and survive months of anoxia while submerged in ice-locked ponds and bogs. Reference genomes provide an important resource for elucidating the molecular bases for such unique physiological traits. The initial reference genome for this species, published in 2013, is highly fragmented, thereby limiting downstream analyses and biological interpretation. We created a new and improved assembly by combining PacBio HiFi, 10 × Genomics Chromium, Hi-C sequence data and Bionano optical mapping …

Bi-Allelic Variants In Nrdc Cause A Neurodevelopmental Disorder Characterized By Neonatal Lethality, Microcephaly, And Brain Abnormalities, Davut Pehlivan, Abigail Sandoval, Reza Maroofian, François Lecoquierre, Aisha M Al Shamsi, Gyu S Lee, Osman Yesilbas, Preston Taylor, Matthew B Mcdougal, Vahid Bahrambeigi, Omid Aryani, Juan Felipe Ramirez, Khalid Hama Salih, Chadi Al Alam, Heba Morsy, Haytham Hussien, Tarek Omar, Ibrahim M Abdelrazek, Anne Claire Brehin, Dana Marafi, Tugba Kalayci, Jubran Abu Rahma, Jawabreh Kassem Talbeya, Husein Dabbah, Eric Verspyck, Toktam Moosavian, Jawid M Fatih, Tadahiro Mitani, Gulsen Akay, Daniel G Calame, Anne-Marie Guerrot, Wendy K Chung, Henry Houlden, James R Lupski, Adel Shalata, Wan Hee Yoon

Faculty, Staff and Students Publications

Nardilysin (NRDC) plays a role in multiple cellular functions in diverse cellular compartments, including ectodomain shedding in the plasma membrane, as well as chaperoning a key Krebs cycle enzyme in mitochondria. We had previously reported limited clinical information from two individuals with homozygous frameshift variants in NRDC. With inclusion of previously published individuals, here we report 14 individuals (10 females, four males) from nine unrelated families carrying homozygous NRDC pathogenic variants. Common clinical features include severe to profound developmental delay/intellectual disability (12/12), microcephaly (13/13), prematurity (5/13), lethality in the first 3 years of life (9/14), seizures (7/11), joint contractures (4/8), …

Brd4-Mediated Er Membrane Contact Creates Functionally Distinct Mitochondrial Subtypes, Brandon Chen, Rachel M Guerra, David J Pagliarini, Et Al.

2020-Current year OA Pubs

Inter-organellar communication is critical for cellular metabolism. One of the most abundant inter-organellar interactions occurs at the endoplasmic reticulum and mitochondria contact sites (ERMCSs). However, an understanding of the mechanisms governing ERMCS regulation and their roles in cellular metabolism is limited by a lack of tools that permit temporal induction and reversal. Through screening approaches, we identified fedratinib, an FDA-approved drug that dramatically increases ERMCS abundance by inhibiting the epigenetic modifier BRD4. Fedratinib rapidly and reversibly modulates mitochondrial and ER morphology, induces a distinct ER-mitochondria envelopment structure, and alters metabolic homeostasis. Moreover, ERMCS modulation depends on mitochondrial electron transport chain …

Modulating Alternative Splicing Of Mecp2 Is A Potential Therapeutic Strategy For Rett Syndrome, Harini P Tirumala, Li Wang, Yan Li, Sameer S Bajikar, Ashley G Anderson, Wei Wang, Alexander J Trostle, Mahla Zahabiyon, Aleksandar Bajic, Jean J Kim, Hu Chen, Zhandong Liu, Huda Y Zoghbi

Faculty, Staff and Students Publications

Rett syndrome (RTT) is a neurological disorder caused by loss-of-function mutations in methyl CpG binding protein 2 (MECP2), a transcriptional regulator essential for maintenance of normal neuronal function. The current FDA-approved treatment for RTT, Trofinetide, mildly alleviates some symptoms. In contrast, re-introducing MeCP2 or increasing its amount through transgenesis in mouse RTT models improves most neurological phenotypes and enhances survival. Here, we devised a therapeutic strategy to moderately increase MeCP2 protein by modulating the alternative splicing of MECP2 to switch the less efficiently translated e2 to the more efficiently translated e1 isoform. We deleted Mecp2 exon 2 (unique …

An Acetylation-Dependent Switch Underlies Host Disease Tolerance During Streptococcal Infection, Sumit Kumar Paudel, Sowmya Gannavaram, Michael G Caparon, Wei Xu

2020-Current year OA Pubs

Building on our finding that Streptococcus pyogenes pyruvate dehydrogenase (PDH) suppresses host disease tolerance (DT) via short-chain fatty acid (SCFA)-mediated modulation of host acetyl-CoA and IL-10 levels, we characterize the global transcriptomic and epigenetic mechanisms underlying this immunometabolic manipulation. Combining new histological and ultrastructural analyses with an in-depth re-analysis of single-cell and bulk RNA-seq datasets to more comprehensively characterize the DT response, we show that PDH deficiency is associated with broad immunologic rewiring, characterized by intracellular bacterial containment within phagocytes, expansion of pro-resolving myeloid cells, and altered cell-cell communication. Metabolic analysis of ΔPdh-infected tissues revealed a shift away from acetyl-CoA …

A Neural Circuit Framework For Economic Choice: From Building Blocks Of Valuation To Compositionality In Multitasking, Aldo Battista, Camillo Padoa-Schioppa, Xiao-Jing Wang

2020-Current year OA Pubs

Value-guided decisions are a cornerstone of cognition, yet the underlying circuit-level mechanisms remain elusive. We used reinforcement learning to train recurrent neural network models endowed with Dale's law on a battery of economic choice tasks, which revealed a two-stage computational framework. First, value estimation occurs at the input level, where learned weights store subjective preferences and approximate the non-linear multiplication of reward magnitude and probability to yield expected values. This feedforward mechanism enables generalization to novel choice options. Second, option values are compared within the recurrent network, where specific connectivity patterns mediate robust winner-take-all decisions, with both excitatory and inhibitory …

Ectopic B Lymphocyte Follicles Exacerbate Ischemic Brain Damage Via Mif-Cd74/Cxcr4 And Interferon Signaling, Sheng Yang, Hang Zhang, Lu-Lu Xu, Luo-Qi Zhou, Yun-Hui Chu, Lian Chen, Xiao-Wei Pang, Lu-Yang Zhang, Li-Fang Zhu, Ming-Hao Dong, Ke Shang, Jun Xiao, Long-Jun Wu, Wei Wang, Dai-Shi Tian, Chuan Qin

Faculty, Staff and Student Publications

Neuroinflammation, encompassing both innate and adaptive immune responses, plays a crucial role in ischemic stroke. Although B lymphocytes are central to adaptive immunity, their contributions to ischemic stroke remain poorly understood. Here, we demonstrated that B lymphocytes accumulate in ischemic lesions, forming germinal center-like structures at the later stage after stroke, which mainly depended on in situ proliferation. This accumulation correlated with worsened neuroinflammation and ischemic injury, whereas B cell depletion reduced chronic brain damage during stroke. Mechanistically, microglia recruited B cells into ischemic lesions through MIF-CD74/CXCR4 signaling during the early phase of stroke, while IFN-related pathways in B cells …

Activin A Secretion By Muscle-Repairing Macrophages Induces Heterotopic Ossification In Mice, Wenqiang Yin, Kazuo Okamoto, Asuka Terashima, Warunee Pluemsakunthai, Takehito Ono, Taku Ito-Kureha, Shizuo Akira, Yoshinobu Hashizume, Roland Baron, Satoshi Ueha, Kouji Matsushima, Martin M Matzuk, Yuji Mishina, Hiroshi Takayanagi

Faculty, Staff and Students Publications

The immune system is not only essential for host defense, but it is also involved in tissue maintenance and disease pathogenesis. Macrophages play a key role in tissue repair, fibrosis, and tumorigenesis, but the mechanisms underlying their multifunctionality have not been fully explored. Here, we identified Mrep (Ly6ChiCX3CR1loPDPN+CD9+) as a crucial subset of macrophages for muscle regeneration after muscle injury. Muscle regeneration required Mrep-derived activin A, which was produced via the TLR4/TIR domain-containing adapter-inducing interferon-β/TANK-binding kinase 1/interferon regulatory factor 3/7 signaling pathway in response to muscle injury. Mrep exerted pathological effects by secreting activin A in a model of genetically …

Poly(Adp-Ribose) Glycohydrolase Enforces P21 Degradation Via Deparylation To Promote Gastric Cancer Progression, Yangchan Hu, Qimei Bao, Yixing Huang, Yan Wang, Xin Zhao, Junjun Nan, Yuxin Meng, Mingcong Deng, Yuancong Li, Zirui Zhuang, Hanyi He, Dan Zu, Yuke Zhong, Chunkai Zhang, Bing Wang, Ran Li, Yanhua He, Qihan Wang, Min Liu, John A Tainer, Yin Shi, Xiangdong Cheng, Ji Jing, Zu Ye

Faculty, Staff and Student Publications

Dysregulation of cell cycle checkpoints is a cancer hallmark, with ubiquitination-controlled protein stability playing a pivotal role. Although p21, a key cyclin-dependent kinase inhibitor, is tightly regulated by ubiquitin-mediated degradation, the key upstream modulators of its ubiquitination remain incompletely defined. Here, we identify poly(ADP-ribose) glycohydrolase (PARG) as a regulator of p21 stability in gastric cancer (GC) cells. We show that PARG expression is markedly upregulated in GC tissues and correlates with poor patient prognosis. Functional assays revealed that genetic depletion of PARG triggers G2/M phase arrest and impairs GC cell proliferation. Mechanistically, we demonstrate that PARG loss enhances p21 PARylation, …

Mechanometabolism Instructs Hematopoietic Stem Cell Specification, Paulina D Horton, Alina Syed, Michelle Winkler, Abishek B Vaidya, Michael Rariden, Neha Arora, Yong Zhou, Michihiro Kobayashi, Momoko Yoshimoto, Hyun Jung Lee, Hyun-Eui Kim, John P Hagan, Catherine Denicourt, Travis I Moore, Pamela L Wenzel

Faculty, Staff and Student Publications

Mechanical force generated by blood flow stimulates emergence of the first hematopoietic stem cells (HSCs) that populate the blood system. Force drives the transition of HSC precursors from an endothelial to hematopoietic identity, yet the molecular regulation of this fate switch remains poorly understood. We report that shear stress triggers adaptation in mitochondrial composition, ultrastructure, and function, which are essential for hematopoietic fate and engraftment potential. Shear stress remodels mitochondria in hemogenic endothelium by promoting mitochondrial gene transcription and protein synthesis. Laminar flow selectively initiates translation of 5' terminal polypyrimidine (5'TOP) motif-containing transcripts, which commonly encode ribosome and translation machinery. …

The Relationship Between Apparent Potentiation And The Magnitude Of The Control Response, Joe Henry Steinbach, Gustav Akk

2020-Current year OA Pubs

The effect of a potentiating drug on ion channel function is typically evaluated by comparing current responses to the control agonist in the presence and absence of the potentiator. Differences in ratios of responses are then taken as proof of distinct potentiation properties when comparing modulation by different compounds. In these experiments, the concentration of the agonist is typically kept low to generate a small fractional control response. The precise relative magnitude of the control response is, however, not standardized among labs and can range from a concentration producing a response equal to just 2% of maximal (EC2) to over …

Histone Demethylase Jmjd1a Protects Mice From Enteric Bacterial Infection By Upregulating Ccl8 Expression To Recruit Macrophages And Cd4+ T Cells, Guifang Lin, Lichun Yang, Shuyan Jiang, Yong Zhang, Ping Luo, Weihua Li, Jianming Xu, Gongpeng Xiong, Chundong Yu, Wenbo Chen

Faculty, Staff and Students Publications

Jumonji domain-containing 1A (JMJD1A, also known as KDM3A) is a histone demethylase that specifically demethylates H3K9me1/2 to enhance gene expression. The roles of JMJD1A in many physiological and pathological processes have been revealed. However, it is unclear whether JMJD1A is involved in host defense against enteric pathogen infection. In this study, we found that enteric infection with C. rodentium induced JMJD1A expression in colonic epithelial cells at the transcriptional level partly mediated by IRF1. After C. rodentium infection, JMJD1A-/- mice exhibited increased mortality, colonic injury, and C. rodentium load and systemic spread, suggesting that JMJD1A protects host against C. rodentium …

Distributed Battery-Free Bioelectronic Implants With Improved Network Power Transfer Efficiency Via Magnetoelectrics, Joshua E Woods, Fatima Alrashdan, Ellie C Chen, Wendy Tan, Mathews John, Lukas Jaworski, Drew Bernard, Allison Post, Angel Moctezuma-Ramirez, Abdelmotagaly Elgalad, Alexander G Steele, Sean M Barber, Philip J Horner, Amir H Faraji, Dimitry G Sayenko, Mehdi Razavi, Jacob T Robinson

Faculty, Staff and Students Publications

Networks of miniature implants could enable simultaneous sensing and stimulation at different locations in the body, such as the heart and central or peripheral nervous system. This capability would support precise disease tracking and treatment or enable prosthetic technologies with many degrees of freedom. However, wireless power and data transfer are often inefficient through biological tissues, particularly as the number of implanted devices increases. Here we show that magnetoelectric wireless data and power transfer supports a network of millimetre-sized bioelectronic implants in which system efficiency improves with additional devices. We demonstrate wireless, battery-free networks ranging from one to six implants, …

The Evolving Therapeutic Landscape Of Pcsk9 Inhibition, Brett S Mansfield, Yakubu Bene-Alhasan, Christie M Ballantyne, Frederick J Raal

Faculty, Staff and Students Publications

Cardiovascular disease remains the leading cause of death worldwide with low density lipoprotein being a major, yet modifiable, risk factor. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a central role in regulating low density lipoprotein (LDL) receptor expression. Naturally occurring loss-of-function variants in the PCSK9 gene result in lifelong lower LDL cholesterol (LDL-C) levels and significantly lower risk of atherosclerotic cardiovascular disease (ASCVD), providing strong genetic validation of PCSK9 as a therapeutic target. This insight has driven the development of therapies directed at PCSK9 for the management of hypercholesterolaemia, particularly in patients who fail to meet LDL-C targets despite maximally …

Toward Scientific Rigor: Setting Standards For Indirect Calorimetry Analysis And Reporting, Elizabeth L Lieu, Mark A Herman, Sean M Hartig

Faculty, Staff and Students Publications

Indirect calorimetry determines energy expenditure by measuring respiratory gas exchange. The approach is based on the principle that nutrient metabolism consumes O2 and produces CO2 and water in predictable ratios that can be compared with heat production. Due to the impracticality and high cost of direct calorimetry, indirect calorimetry is the major approach for modern metabolic studies in preclinical models. Despite the broad adoption of this method in rodent phenotyping, the field has lacked standardized methods for analyzing, representing, and sharing these data, limiting scientific progress. The recent review in Nature Metabolism by the International Indirect Calorimetry Consensus Committee (IICCC) …

Diversity And Immune Dynamics Of Choroid Plexus Macrophages Are Shaped By Distinct Developmental Origins, Siling Du, Khai M Nguyen, Alina Ulezko Antonova, Jose L Fachi, Patrick Fernandes Rodrigues, Alice Verdiani, Martina Molgora, Igor Smirnov, Jasmin Herz, Tornike Mamuladze, Jennifer Ponce, Amanda Swain, Mattia Bugatti, Susan Gilfillan, Marina Cella, William Vermi, Jonathan Kipnis, Marco Colonna, Simone Brioschi

The Brown Foundation: Institute of Molecular Medicine

The choroid plexus forms a key barrier and signaling interface between the brain and peripheral circulation, yet its immune landscape remains incompletely understood. Using single-cell transcriptomics combined with lineage and spatial tracing methods, we identified three biologically distinct populations of choroid plexus macrophages, defined by differential expression of CD163, MHCII or CD9. These subsets arise from separate hematopoietic waves, occupy distinct anatomical niches and differentially rely on CSF1 and IL-34 for survival. We found that TGFβ signaling is essential to maintain their tissue-specific identities, and deletion of Tgfbr2 in these cells induces broad phenotypic reprogramming. During neuroinflammation, choroid plexus macrophages …

Glutamatergic Dysfunction Of Astrocytes In Paraventricular Nucleus Of Thalamus Contributes To Adult Anxiety Susceptibility In Adolescent Ethanol Exposed Mice, Aubrey Bennett, Hyunjung Kim, David Thomas, Peter Biggs, Roxan Ara, Asamoah Bosomtwi, Seungwoo Kang

The Brown Foundation: Institute of Molecular Medicine

Repeated ethanol exposure during adolescence increases adult anxiety risk, but the underlying mechanisms remain unclear. The paraventricular nucleus of the thalamus (PVT) has been considered a hub for controlling anxiety and is affected by experiences from early life. Thus, this study investigated how adolescent intermittent repeated ethanol exposure (AIE) affects the PVT activities and anxiety-related behaviors in adulthood. We found that AIE triggers anxiety-like behaviors and parallelly exhibited elevated firing rates and increased calcium signaling in the PVT neurons compared to control counterpart mice. Chemogenetic inhibition of PVT neurons reduced anxiety-like behaviors in AIE-treated animals, confirming PVT's role in adolescent …

Lipids Grease The Chain Of Cancer Progression, Joseph Rupert, Pham Hong Anh Cao, Daniel E Frigo, Mikhail G Kolonin

The Brown Foundation: Institute of Molecular Medicine

The role of lipids in cancer progression has become a fervent area of exploration. The crosstalk of tumors with adipose tissue is a complex but well-regulated orchestration of signaling pathways, lipid transporters, and enzymes. They regulate fatty acid synthesis, their deposition into lipid droplets (LDs) as triglycerides, induction of lipolysis, shuttling lipids across cells, and their systemic trafficking, modification, and catabolism. For the latter, lipid oxidation has emerged as a metabolic process of particular clinical importance. Products of lipid processing can become secondary messengers, contribute to reactive oxygen species (ROS) generation, stimulate the production of antioxidants, and, if left unchecked, …

Non-Synaptic Function And Localization Of Syntaxin-Binding Protein 1 In A Mouse Model Of Stxbp1-Related Epileptic Encephalopathy, Tao Yang, Rajat Banerjee, Yamei Deng, Sheetal Jahagirdar, Joo Hyun Kim, Wu Chen, Mingshan Xue, Alexey I Nesvizhskii, Michael D Uhler, Jack M Parent, Yu Wang

Duncan NRI Faculty and Staff Publications

Objective: De novo mutations in the syntaxin-binding protein 1 (STXBP1), encoded by STXBP1, are among the most prevalent causes of variable neurodevelopmental disorders, including epileptic encephalopathy, developmental delay, and movement disorders. Although STXBP1 has been proposed as a critical presynaptic protein controlling synaptic vesicle exocytosis, clinical phenotypes also suggest that its biological function could be more diverse.

Methods: The expression pattern of STXBP1 was studied using immunostaining in vitro and in vivo. Synaptosome isolation was performed to investigate the synaptic and non-synaptic localization of STXBP1 in the brain. STXBP1 immunoprecipitation followed by mass spectrometry (MS) was conducted to identify protein …

Pharmacokinetic Modeling Strategies For Dynamic Hyperpolarized Urea Imaging, Keith A Michel, Collin J Harlan, Christopher M Walker, Matthew E Merritt, Yunyun Chen, Stephen Y Lai, James A Bankson

Faculty, Staff and Student Publications

Purpose: To evaluate pharmacokinetic modeling methods for quantification of tissue perfusion/permeability with hyperpolarized 13C urea.

Methods: Three models for quantitative analysis of dynamic HP urea imaging data were proposed and evaluated in numerical simulations and a thyroid cancer mouse model. A multicompartment model resembling the extended Tofts model for DCE-MRI (Model I) and two simplified models were used. The simplified models each eliminate a volume parameter representing vascular (Model II) or impermeable cellular space (Model III). Signal curves were generated from Model I, and models were fit to these synthetic data to quantify the effects of acquisition settings, bias in …

Rab4 Spatially And Functionally Converges With Rab7 In The Degradative Endolysosomal Network, Stephen M Farmer, Shiyu Xu, Yue Yu, Xin Ye, Haoyi Yang, Jing Cai, Beatriz Rios, Wen-Wen Lin, Daniela Covarrubias, Vicky Chuong, Lili Ye, German Zylberberg, Charissa Wang, Erin Furr-Stimming, Qingchun Tong, Oguz Kanca, Hugo J Bellen, Travis I Moore, Sheng Zhang

Faculty, Staff and Students Publications

Rab GTPases are key regulators of endosomal trafficking in eukaryotes. In mammalian cells, Rab4 and Rab7 were shown to localize to distinct compartments, with Rab4 on early endosomes for fast recycling and Rab7 on late endosomes for degradation. Here, we show that in Drosophila, endogenous Rab4 and Rab7 extensively colocalize across tissues and developmental stages. Recruited to the same compartments through mechanisms that do not require the activity of the other, they have opposing effects on endolysosomal size: Rab4 overexpression or Rab7 impairment leads to enlarged endolysosomes, whereas Rab4 loss or constitutively active Rab7 reduces their sizes. Rab4 deficiency suppresses …