Medical Molecular Biology Commons^™

Notch Signaling Regulates The Secretion Of Pro-Metastatic Factors In Extracellular Vesicles In Liposarcoma, Menchus Quan, Yi-Kai Liu, Ying Zhao, Madeline Kay, Kai Sun, Timothy P Gavin, Raphael E Pollock, W Andy Tao, Shihuan Kuang

The Brown Foundation: Institute of Molecular Medicine

Notch signaling is an emerging regulator of liposarcoma (LPS), but its role in mediating communication with the tumor microenvironment (TME) is unclear. Here, we investigate how Notch activation (NICD overexpression) alters the proteomes of LPS-derived extracellular vesicles (EVs). We used quantitative mass spectrometry to profile the EV proteome in multiple contexts: cultured LPS cells, LPS tumor, circulating EVs of LPS-bearing mice, and human LPS samples. We found that Notch signaling increases the secretion of EV proteins that favor tumor progression and metastasis but suppresses immune responses in murine LPS cells. Overlapping murine and human LPS data identifies 18 proteins that …

Myeloid Mmp14 Couples Extracellular Proteolysis To Inflammatory And Metabolic Remodeling During Obesity, Long J Shao, Fathima Elizondo, Feng Gao, Elizabeth L Lieu, Bharati Reddi, Maryam Elizondo, Iqbal Mahmud, Kristin Eckel-Mahan, Philipp E Scherer, Xin Ge, Huaizhu Wu, Sean Hartig, Kai Sun

The Brown Foundation: Institute of Molecular Medicine

Macrophages orchestrate tissue remodeling, inflammation, and metabolic dysfunction in obesity, but the role of macrophage-intrinsic extracellular proteolysis in immunometabolic regulation remains unclear. Matrix metalloproteinase-14 (MMP14), a membrane-bound protease, is strongly induced during monocyte-to-macrophage differentiation and further elevated in adipose tissue macrophages from high-fat diet (HFD)-fed mice. Pharmacological inhibition or myeloid-specific deletion of Mmp14 impaired macrophage differentiation, proliferation, migration, phagocytosis, and inflammatory activation in response to obesity-associated adipose tissue signals. Mechanistically, MMP14 promoted inflammatory programming by increasing endotrophin generation and enhancing TLR4-NFκB signaling. MMP14 also reprogrammed macrophage lipid metabolism by suppressing lipolysis and promoting lipid accumulation, altering metabolic communication with neighboring …

Unbiased Avidity-Based Isolation Of Antigen-Specific T Cells, Amanda Montoya, Meredith L Frank, Peixin Jiang, Hui Nie, Minying Zhang, Emily Bontekoe, Jared K Slone, Ludovica L Posta, Sofia Rosy Caterina Sorice, Tina Cascone, Maura Gillison, Don L Gibbons, Jianjun Zhang, Eleonora Dondossola, Lydia Kavraki, Pamela L Wenzel, John V Heymach, Alexandre Reuben

The Brown Foundation: Institute of Molecular Medicine

Background: Cancer immunotherapies have significantly improved treatment efficacy and patient survival by exploiting antigen-specific T cells to eliminate cancer cells. However, current approaches for identifying and isolating antigen-specific T cells typically require prior knowledge of target antigens, limiting discovery, and reducing the ability to consistently detect rare tumor-reactive T cells. We therefore sought to develop an unbiased platform for the identification and enrichment of antigen-specific T cells using naturally processed and presented tumor antigens.

Methods: We developed ATTACH (Assessment of T cells Tethered to Antigen Class I Histocompatibility), a microfluidic platform that applies controlled shear stress and leverages tumor cells …

Functional Characterization Of Uhrf1 Variants In Facilitating Dna Methylation, Bigang Liu, Kaila Nayvelt, Swanand Hardikar, Kimie Kondo, Marcos R Estecio, Xiaodong Cheng, Taiping Chen

The Brown Foundation: Institute of Molecular Medicine

Ubiquitin-like with plant homeodomain (PHD) and really interesting new gene (RING) finger domains 1 (UHRF1) is essential for DNA methylation inheritance. However, the functional impacts of several natural and engineered UHRF1 variants are either insufficiently characterized or obscured by conflicting results, with some discrepancies likely stemming from cellular toxicity and adaptive responses induced by DNA methylation changes. In this study, we utilized mouse embryonic stem cells (mESCs)-which uniquely tolerate the complete loss of DNA methylation-to evaluate the functional consequences of clinical mutations, isoform variation, and epitope tagging. Using rescue experiments in Uhrf1-deficient mESCs, we characterized two UHRF1 mutations identified in …

Microglial Swell1 Deficiency Drives Male-Specific Seizure Vulnerability But Paradoxical Neuroprotection Through Impaired Phagocytosis, Abhijeet S Barath, Aastha Dheer, Laura Montier, Mekenzie M Peshoff, Emily Dale, Flavia Goche, Thanh Thanh Le Nguyen, Mastura Akter, Fangfang Qi, Dimitrios Kleidonas, Lauren Harris, Sarah A Jewanee, Anthony D Umpierre, Dale B Bosco, Koichiro Haruwaka, Rajan Sah, Long-Jun Wu, Rongzhuo Hua, Tejaswani Datla

The Brown Foundation: Institute of Molecular Medicine

The discovery of genes encoding the volume-regulated anion channel (VRAC) has enabled detailed exploration of its cell type-specific roles in the brain. LRRC8A (SWELL1) is the essential VRAC subunit. We observed seizure-induced, subunit-specific changes in microglial VRAC expression and investigated its function using conditional KO (cKO) of LRRC8A in microglia. SWELL1 cKO mice exhibited a male-specific increase in kainate-induced seizure severity, yet showed paradoxical neuroprotection against seizure-associated neuronal loss. Mechanistically, SWELL1 deletion led to a cell-autonomous reduction in microglial density and decreased release of VRAC-permeable neuroactive metabolites, including taurine, GABA, and glutamate in culture. Additionally, impaired phagocytic kinetics and reduced …

Monoclonal Antibodies Targeting Pcdh7 Inhibit Tumor Growth And Enhance Immune Responses In Kras-Mutant Non-Small Cell Lung Cancer, Nicole Novaresi, Poorva Ghosh, Shayna Thomas-Jardin, Hui Deng, Xuejun Fan, Zhiqiang Ku, Wei Xiong, Xiaorong Zhou, Jingfei Zhu, Huiyu Li, Mahesh S Padanad, Bethany Smith, Chul Ahn, John D Minna, Zhiqiang An, Ningyan Zhang, Kathryn A O'Donnell

The Brown Foundation: Institute of Molecular Medicine

We identified an important oncogenic role for protocadherin 7 (PCDH7), a cell surface protein frequently overexpressed in lung adenocarcinoma and associated with poor clinical outcome. Pcdh7 depletion reduces tumor burden and prolongs survival in KrasLSL-G12D; Tp53fl/fl mice. These findings nominate this cell surface protein as an actionable therapeutic target and highlight the therapeutic potential of PCDH7 inhibition for non–small cell lung cancer. We report the development and characterization of high-affinity anti-PCDH7 monoclonal antibodies (mAbs) that inhibit downstream mitogen-activated protein kinase (MAPK) pathway activation and suppress tumor growth in multiple mutant KRAS–driven models. A lead mAb (mAb7) sensitized tumors …

Amc-F1 Regulates Mitochondria-Autophagy Crosstalk Independent Of Nutrient Stress, Yuqin Wang, Raksha K Rao, Trung Vu, Ayano Sekine, Zhengmei Mao, Nami Mccarty

The Brown Foundation: Institute of Molecular Medicine

Mitochondria and autophagy are fundamental yet distinct regulators of cellular homeostasis. Here, we identify AMC-F1 (Autophagy-Mitochondria Coupling Factor 1; formerly TRIM44) as a central integrator of mitochondrial bioenergetics and autophagy. Using Amcf1 knockout and knock-in mouse models, we demonstrate that AMC-F1 bidirectionally regulates these pathways: its loss reduces mitochondrial respiration and autophagic flux, whereas its overexpression promotes mitochondrial elongation and increases autophagy independently of nutrient stress. Transcriptomic analyses reveal AMC-F1-dependent regulation of mitochondrial biogenesis programs that engage autophagy, involving mitochondrial respiratory chain complex genes under basal conditions and mitochondrial organization factors under starvation-induced autophagy. Although dispensable under homeostasis, this coupling …

An Obligatory Role For Agrp Neurons In Maintaining Body Temperature During Time-Restricted Feeding, Cunjin Su, Jing Cai, Yuanzhong Xu, Benjamin R Arenkiel, Qingchun Tong

The Brown Foundation: Institute of Molecular Medicine

Homeotherms maintain a steady body temperature through thermoregulation, a process critical for survival during fasting, in which the brain has to defend energy-costly body temperature while reducing energy expenditure to conserve energy reserve; however, the neural basis for defending body temperature remains unclear. Here, we demonstrated that AgRP neuron lesion led to lethality during time-restricted feeding on chow but not on HFD, and caused no obvious impact on HFD-induced obesity or obesity-reducing responses to glucagon-like peptide-1 receptor agonism. The lesion disrupted adaptive feeding behaviors during time-restricted feeding and reduced motivational feeding on chow. Notably, the lethality was caused by hypothermia …

Selective And Differential Roles Of Pvhcrh Neurotransmitters In Diet-Induced Obesity In Mice, Zhiying Jiang, Yuhan Cao, Michelle He, Cunjin Su, Runzhou Yang, Maojie Yang, Jing Cai, Hongli Li, Yuanzhong Xu, Shi-Bin Li, Hiroshi Yamaguchi, Luis De Lecea, Benjamin R Arenkiel, Qingchun Tong

The Brown Foundation: Institute of Molecular Medicine

Stress and diet are known to synergistically promote risks of obesity but the underlying neural basis remains elusive. Corticotropin-releasing hormone neurons in the paraventricular hypothalamus (PVHCRH) are stress responsive and release both CRH and glutamate. Here we generated a mouse model with gain or loss of release in CRH or glutamate from PVHCRH neurons. While these models showed no changes in body weight when fed chow, they exhibited contrasting effects when fed high-fat high-caloric diets (HFD). Whereas disrupting glutamate release from PVHCRH neurons led to diet-induced obesity (DIO), that of CRH caused no impact. Conversely, augmented CRH release led to …

Claudins Interact With Lilrb Immune Inhibitory Receptors To Promote Myeloid Immunosuppression In Cancer, Xiaoye Liu, Ryan Huang, Zhiqiang Ku, Jingjing Xie, Heyu Chen, Yubo He, Qi Lou, Chengcheng Zhang, Xing Yang, Cheryl Lewis, Jade Homsi, Ankit Gupta, Lei Dong, Kenian Chen, Annabel Tu, Liming Du, Hailong Yu, Qing Hu, Meng Fang, Bufan Li, A E M Adan Khan, Caroline Simith, Samuel John, Lin Xu, Ningyan Zhang, Zhiqiang An, Cheng Cheng Zhang

The Brown Foundation: Institute of Molecular Medicine

The mechanisms underlying tumor cell-myeloid cell interactions in the tumor microenvironment (TME) remain unclear, and predictive biomarkers for patient response to myeloid checkpoint blockade are lacking. This study identified specific binding between tight junction claudins (CLDNs) and leukocyte immunoglobulin-like receptor subfamily B2 (LILRB2) and LILRB5. In multiple human cancer cohorts, the spatial proximity of LILRB2-positive macrophages to CLDN-expressing cancer cells correlated with clinical outcomes, highlighting this spatial relationship as a potential biomarker. In syngeneic LILRB2-transgenic and humanized mouse models, CLDN18.2-LILRB2 interactions triggered bidirectional signaling, enhanced the immunosuppressive activity of myeloid cells, and accelerated tumor progression. These effects were reversed by …

Telomerase Knockout In Myeloid Cells Predisposes Mice To Foam Cell Formation, Dyslipidemia, Lung Fibrosis, And Cardiac Dysfunction, Zhanguo Gao, Yongmei Yu, David Wiggins, Eva M Sevick-Muraca, Mikhail G Kolonin

The Brown Foundation: Institute of Molecular Medicine

Aging-associated changes in myeloid cells are incompletely understood. One of the culprits of aging is the downregulation of the Tert gene coding for the catalytic subunit of telomerase. Studies of mouse models with Tert knockout (KO) in specific cells have revealed the importance of the telomere-independent noncanonical function of TERT in supporting mitochondrial metabolism and protection from cell senescence. To investigate the role of TERT in myeloid cells (MCs), we analyzed mice with Tert KO in the LysM+ lineage, indelibly labeled with membrane green fluorescent protein (mG). Macrophage numbers and properties in various organs were compared. Changes in the vasculature, …

Molecular Characterization Of Humanized Apoe Mouse Models Reveals Source And Genotype Dependent Differences, Na Wang, Gefei Yu, Zhen Wang, Alla Alnobani, Suren Jeevaratnam, Xue Zhang, Meghan Mcreynolds, Yuzhou Chang, Fangfang Qi, William Tauer, Cassandra Rosenberg, Melissa Wren, Tadafumi C Ikezu, Yuka A Martens, Minghui Wang, Bin Zhang, Gregory W Carter, Michael Sasner, David M Holtzman, Junmin Peng, Long-Jun Wu, Takahisa Kanekiyo, Chia-Chen Liu, Guojun Bu

The Brown Foundation: Institute of Molecular Medicine

Background

Humanized APOE targeted-replacement (TR) mice are essential tools for studying apoE isoform effects in Alzheimer’s disease (AD) and other apoE-related disorders. Despite their widespread use, existing APOE mouse models, generated with different gene targeting strategies, have not been directly compared in terms of apoE isoform expression, lipid profiles, and transcriptomic signatures. Such differences could impact how we interpret APOE genotype-related outcomes, as well as related underlying molecular mechanisms.

Methods

We conducted a comprehensive molecular comparison of humanized APOE mouse models from three sources: Taconic Biosciences (TAC), the Cure Alzheimer’s Fund (CAF), and The Jackson Laboratory (JAX). We assessed apoE …

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 …

Gh Alters Lymphatic Vessels In Female Mice And Stat5 Phosphorylation In Human Lymphatic Endothelial Cells, Christopher Walsh, Emily Scott, Elise Wagner, Jerome Walsh, Shashank Reddy, Arshad Ahmad, Reetobrata Basu, Eva Sevick-Muraca, Rich Brody, Uday Sandbhor, Sebastian Neggers, John J Kopchick

The Brown Foundation: Institute of Molecular Medicine

Disruption of lymphatic function underlies a broad spectrum of inflammatory and metabolic disorders, yet the hormonal pathways that regulate lymphatic biology remain poorly defined. GH, which is implicated in similar disease states, has an unclear role in lymphatic homeostasis. To address this gap, we investigated how chronic alterations in GH signaling alter lymphatic structure and function. Using transgenic mouse lines with increased, decreased, or absent GH action, we quantified the effect of GH on lymphatic pumping rate and lymphangiogenic remodeling during wound healing using near-infrared fluorescent imaging. We also measured markers of lymphatic endothelial cells using Western blot and immunohistochemistry …

Mucin 5ac Modulates Cancer-Associated Fibroblast Heterogeneity Through Epigenetic Reprogramming Of Precursor Cells, Rachel J. Kehrberg, Namita Bhyravbhatla, Zahraa Wajih Alsafwani, Xiaoqi Li, Gopalakrishnan Natarajan, Imran Khan, Randall E. Brand, Maneesh Jain, Surinder K. Batra, Sushil Kumar

Journal Articles: Biochemistry & Molecular Biology

Pancreatic cancer (PC) is characterized by extensive desmoplasia, with heterogeneous cancer-associated fibroblasts (CAFs) as a major component. However, the contribution of distinct precursor cells to CAF heterogeneity remains poorly defined. This study investigated the role of Muc5ac in modulating CAF heterogeneity by maturing precursor cells, including adipose-derived mesenchymal stem cells (AD-MSCs), bone marrow-derived MSCs (BM-MSCs), and pancreatic stellate cells (PSCs), into different CAF subsets. RNA sequencing of precursor cells treated with conditioned media from Muc5ac-proficient or -deficient cancer cells revealed distinct transcriptional profiles. Muc5ac significantly modulated the expression of Dnmts and Tets in AD-MSCs, promoting the acquisition of extracellular matrix …

Ddt Exposure Induces Microglial Activation And Disease-Associated Microglial Signatures: Relevance To Mechanisms Of Alzheimer’S Disease, Isha Mhatre-Winters, Aseel Eid, Nicole Blum, Yoonhee Han, Ferass M Sammoura, Long-Jun Wu, Jason R Richardson

The Brown Foundation: Institute of Molecular Medicine

Background: Alzheimer's disease (AD) is characterized by the presence of amyloid-β plaques, neurofibrillary tangles, and neuroinflammation. Previously, we reported that serum levels of dichlorodiphenyldichloroethylene (DDE), the primary metabolite of the pesticide dichlorodiphenyltrichloroethane (DDT), were significantly higher in AD patients compared to age-matched controls and that DDT exposure worsened AD pathology in animal models.

Objective: Here, we investigated the effect of DDT on neuroinflammation in primary mouse microglia (PMG) and C57BL/6J mice.

Methods: DDT-induced inflammatory and disease-associated microglial (DAM) gene expression were determined in PMG by qPCR and immunocytochemistry, with and without pretreatment with the sodium channel antagonist tetrodotoxin (TTX). Furthermore, …

Estrogen-Related Receptor Alpha Promotes Skeletal Muscle Regeneration And Mitigates Muscular Dystrophy, Thi Thu Hao Nguyen, Ya Xiang Huang, Svitlana Poliakova, Citu Citu, Eira Mann, Danesh H Sopariwala, Zhongming Zhao, Ashok Kumar, Vihang A Narkar

The Brown Foundation: Institute of Molecular Medicine

Skeletal muscle regeneration in chronic muscle diseases such as Duchenne Muscular Dystrophy (DMD) has remained clinically unsurmountable. Estrogen‐related receptor alpha (ERRα) plays a critical role in adult skeletal muscle metabolism and exercise fitness. Whether ERRα activation can drive muscle regeneration and mitigate dystrophy in DMD is not known. We have investigated ERRα signaling in pre‐clinical models of acute muscle injury and DMD. ERRα is induced in differentiating C2C12 myoblast and regenerating muscle. ERRα silencing suppressed proliferation and differentiation in C2C12 myoblasts. RNA sequencing revealed that angiogenic factor and proliferation genes were downregulated by ERRα knockdown in proliferating cells, whereas oxidative …

Escape Of Kdm6a From X Chromosome Is Detrimental To Ischemic Brains Via Irf5 Signaling, Conelius Ngwa, Afzal Misrani, Kanaka Valli Manyam, Yan Xu, Shaohua Qi, Romana Sharmeen, Juneyoung Lee, Long-Jun Wu, Louise Mccullough, Fudong Liu

The Brown Foundation: Institute of Molecular Medicine

The role of chromatin biology and epigenetics in disease progression is gaining increasing recognition. Genes that escape X chromosome inactivation (XCI) can impact neuroinflammation through epigenetic mechanisms. Our previous study has suggested that the X escapee genes Kdm6a and Kdm5c are involved in microglial activation after stroke in aged mice. However, the underlying mechanisms remain unclear. We hypothesized that Kdm6a/5c demethylate H3K27Me3/H3K4Me3 in microglia, respectively, and mediate the transcription of interferon regulatory factor 5 (IRF5) and IRF4, leading to microglial pro-inflammatory responses and exacerbated stroke injury. Aged (17–20 months) Kdm6a/5c microglial conditional knockout (CKO) female mice (one allele of the …

Prolonged Exposure To Food Odors Suppresses Feeding Via An Olfactory Bulb-To-Hypothalamus Circuit, Yao Liu, Hailan Liu, Huey-Xian Kelly Wong, Niccole Auld, Kristine M Conde, Yongxiang Li, Meng Yu, Yue Deng, Qingzhuo Liu, Xing Fang, Mengjie Wang, Yuhan Shi, Olivia Z Ginnard, Yuxue Yang, Longlong Tu, Hesong Liu, Jonathan C Bean, Junying Han, Megan E Burt, Sanika V Jossy, Yongjie Yang, Chunmei Wang, Qingchun Tong, Benjamin R Arenkiel, Hongjie Li, Yong Xu, Yang He

The Brown Foundation: Institute of Molecular Medicine

Olfactory perception of food odors is a key determinant of eating behavior, including triggering appetite, facilitating food seeking and influencing food choice. While transient food-related olfactory cues stimulate appetite and provoke cravings in states of hunger, emerging evidence implies that prolonged and sustained exposure to food-derived odor (FO) suppresses feeding. However, the mechanisms by which olfaction induces hypophagia remain elusive. In this study, we show that prolonged FO exposure significantly suppresses food intake in male mice. We identified a subset of neurons in the ventral subiculum (vSub) that are specifically activated by FO. We further discovered that these FO-activated neurons …

Regional Heterogeneity Of The Blood-Brain Barrier, Marie Blanchette, Kaja Bajc, Benjamin D Gastfriend, Caterina P Profaci, Nadine Ruderisch, Cayce E Dorrier, Guo Zhong, Raquel Cuevas-Diaz Duran, Sean S Harvey, Iris H Garcia-Pak, Lucija Pintarić, Manon Leclerc, Louise Reveret, Vincent Émond, Annette Wang, Deepti Pant, Linus T Tsai, Frédéric Calon, Nina Isoherranen, Sean P Palecek, Eric V Shusta, Jiaqian Wu, Richard Daneman

The Brown Foundation: Institute of Molecular Medicine

The blood-brain barrier (BBB), formed by specialized endothelial cells (ECs), regulates the extracellular composition of the central nervous system (CNS). Little is known about whether there are regional specializations of the BBB that may control the function of specific neural circuits. We use single cell RNA-seq to characterize ECs from nine CNS regions in male mice: cortex, hippocampus, cerebellum, spinal cord, striatum, thalamus, hypothalamus, midbrain, and medulla/pons. Although there is a core BBB transcriptional profile, there are significant regional specializations. Stra6, a retinoid transporter, is highly enriched in the BBB of the nucleus accumbens shell (ShNAc) and ventral cochlear nucleus, …

The Microrna Mir-30a Blocks Adipose Tissue Fibrosis Accumulation In Obesity, Michael J Bolt, Sung Yun Jung, Kang Ho Kim, Kai Sun, Huaizhu Wu, Samuel Klein, Sean M Hartig

Faculty, Staff and Student Publications

White adipose tissue (WAT) fibrosis occurring in obesity contributes to the inflammatory and metabolic comorbidities of insulin resistance and type 2 diabetes, yet the mechanisms involved remain poorly understood. Here, we report a role for the broadly conserved miRNA miR-30a as a regulator of WAT fibrosis and systemic glucose metabolism. Mice modified to express miR-30a at elevated levels in adipose tissues maintain insulin sensitivity coupled with reduced fatty liver disease when fed a high-fat diet. These effects were attributable to cell-autonomous functions of miR-30a that potently increase expression of adipocyte-specific genes. Proteomic screening revealed miR-30a limits profibrotic programs in subcutaneous …

Inactivation Of The Fusobacterium Nucleatum Rnf Complex Reduces Fada-Mediated Amyloid Formation And Tumor Development, Yi-Wei Chen, Hung Ton-That

Faculty, Staff and Student Publications

The Gram-negative anaerobe Fusobacterium nucleatum is an oral oncobacterium that promotes colorectal cancer (CRC) development with the amyloid-forming cell surface adhesin FadA integral to CRC tumorigenesis. We describe here molecular genetic studies uncovering a novel mode of metabolic regulation of FadA-mediated tumor formation by a highly conserved respiratory enzyme known as the Rnf complex. First, we show that genetic disruption of Rnf, via rnfC deletion, significantly reduces the level of fadA transcript, accompanied by a near-complete abolishment of the precursor form of FadA (pFadA), reduced assembly of FadA at the mature cell pole, and severe defects in the osmotic stress-induced …

177lu-Labeled Antibody-Drug Conjugate: A Dual-Mechanistic Treatment Modality In Solid Tumors, Aiko Yamaguchi, Chisato M Yamazaki, Yasuaki Anami, Summer Y Y Ha, Wei Xiong, Robert T Ta, Ningyan Zhang, H Charles Manning, Zhiqiang An, Kyoji Tsuchikama

The Brown Foundation: Institute of Molecular Medicine

To explore the potential of site-selectively radiolabeled antibody-drug conjugates (ADC) against solid tumors, we constructed and evaluated radiolabeled ADCs equipped with lutetium-177 (177Lu) and a membrane-permeable antimitotic agent. Site-selective 177Lu-labeled ADCs [anti-trophoblast cell-surface antigen 2 (TROP2) 177Lu-DTPA ADCs or anti-HER2 177Lu-DO3A ADCs], a 177Lu-labeled homogeneous radioimmunoconjugate (homogeneous RIC), and 177Lu-labeled conventional RIC (heterogeneous RIC) were constructed. We confirmed that 177Lu-labeled ADCs and the homogeneous RIC were obtained with high homogeneity and defined chelator/payload-to-antibody ratios. Next, we performed biodistribution studies and treatment efficacy studies in xenograft mouse models bearing orthotopic breast tumors. Compared with the heterogeneous RIC, the 177Lu-DTPA TROP2 ADC …

Identification And Functional Assessment Of Candidate Causal Cis-Regulatory Variants Underlying Electrocardiographic Qt Interval Gwas Loci, Supraja Kadagandla, Lavanya Gunamalai, Dongwon Lee, Ashish Kapoor

The Brown Foundation: Institute of Molecular Medicine

Background: Identifying causal variants among tens or hundreds of associated variants at each locus in genome-wide association studies is challenging. As the vast majority of genome-wide association studies variants are noncoding, sequence variation at cis-regulatory elements (CREs) affecting transcriptional expression of specific genes is a widely accepted molecular hypothesis. Following this hypothesis, combined with the observation that open chromatin is a universal hallmark of all types of CREs, we aimed to identify candidate causal cis-regulatory variants underlying QT interval genome-wide association studies loci.

Methods: Common variants in high linkage disequilibrium with genome-wide significant variants were identified using variant …

Optogenetic Activation Of Cortical Microglia Promotes Neuronal Activity And Pain Hypersensitivity, Min-Hee Yi, Yi Liu, Yong U Liu, Jinkyung Lee, Priyanka Hanumaihgari, Sebastian Parusel, Dale B Bosco, Lingxiao Wang, Jiaying Zheng, Wu Shi, Lattawat Eauchai, Supin Chompoopong, Christine L Hunt, Long-Jun Wu

The Brown Foundation: Institute of Molecular Medicine

Chronic pain following peripheral nerve injury is accompanied by increased neuronal activity in the somatosensory cortex. However, whether and how cortical microglia contribute to these changes is less understood. To this end, we applied an optogenetic strategy to specifically target cortical microglia and investigate their function in behavioral pain sensitization. We found that optogenetic activation of microglia in the primary somatosensory cortex (S1) via red-activated channelrhodopsin (ReaChR) triggered pain hypersensitivity and affective-motivational responses in mice. Remarkably, S1-targeted optogenetic stimulation increased microglial landscape changes and ATP release. In addition, optogenetic stimulation altered the microglial proteomic profile, upregulated neuronal c-Fos expression, and …

St6galnac-I Regulates Tumor Cell Sialylation Via Nectin2/Muc5ac-Mediated Immunosuppression And Angiogenesis In Non-Small Cell Lung Cancer, Muthamil Iniyan Appadurai, Sanjib Chaudhary, Ashu Shah, Gopalakrishnan Natarajan, Zahraa W. Alsafwani, Parvez Khan, Dhananjay D. Shinde, Subodh M. Lele, Lynette M. Smith, Mohd W. Nasser, Surinder K. Batra, Apar Kishor Ganti, Imayavaramban Lakshmanan

Journal Articles: Biochemistry & Molecular Biology

Glycosylation controls immune evasion, tumor progression, and metastasis. However, how tumor cell sialylation regulates immune evasion remains poorly characterized. ST6GalNAc-I, a sialyltransferase that conjugates sialic acid to the glycans in glycoproteins, was overexpressed in an aggressive-type KPA (KrasG12D/+ Trp53R172H/+ Ad-Cre) lung adenocarcinoma (LUAD) model and patient samples. Proteomic and biochemical analysis indicated that ST6GalNAc-I mediated NECTIN2 sialylation in LUAD cells. ST6GalNAc-I-deficient tumor cells cocultured with T cells were more susceptible to T cell-mediated tumor cell killing, indicating a key role for NECTIN2 in T cell dysfunction. Mice injected with St6galnac-I-knockdown syngeneic cells showed reduced lung tumor incidence and Nectin2/Tigit-associated immunosuppression. …

Maternal Dysbiosis Produces Long-Lasting Behavioral Changes In Offspring, Nagireddy Putluri, Venugopal R Venna, Louise D Mccullough

Faculty, Staff and Student Publications

Advanced maternal age (AMA) is defined as a pregnancy in a woman older than 35 years of age. AMA increases the risk for both maternal and neonatal complications, including miscarriage and stillbirth. AMA has also been linked to neurodevelopmental and neuropsychiatric disorders in the offspring. Recent studies have found that age-associated compositional shifts in the gut microbiota contribute to altered microbial metabolism and enhanced inflammation in the host. We investigated the specific contribution of the maternal microbiome on pregnancy outcomes and offspring behavior by recolonizing young female mice with aged female microbiome prior to pregnancy. We discovered that pre-pregnancy colonization …

Dependence Of Mitochondrial Calcium Signalling And Dynamics On The Disaggregase, Clpb, Donato D'Angelo, Víctor H. Sánchez-Vázquez, Benjamín Cartes-Saavedra, Denis Vecellio Reane, Ryan R. Cupo, Hilda Delgado De La Herran, Giorgia Ghirardo, James Shorter, Ron A. Wevers, Saskia B. Wortmann, Fabiana Perocchi, Rosario Rizzuto, Anna Raffaello, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cells utilize protein disaggregases to avoid abnormal protein aggregation that causes many diseases. Among these, caseinolytic peptidase B protein homolog (CLPB) is localized in the mitochondrial intermembrane space and linked to human disease. Upon CLPB loss, MICU1 and MICU2, regulators of the mitochondrial calcium uniporter complex (mtCU), and OPA1, a main mediator of mitochondrial fusion, become insoluble but the functional outcome remains unclear. In this work we demonstrate that CLPB is required to maintain mitochondrial calcium signalling and fusion dynamics. CLPB loss results in altered mtCU composition, interfering with mitochondrial calcium uptake independently of cytosolic calcium and mitochondrial membrane potential. …

Islet Single-Cell Transcriptomic Profiling During Obesity-Induced Beta Cell Expansion In Female Mice, Peter M Masschelin, Scott A Ochsner, Sean M Hartig, Neil J Mckenna, Aaron R Cox

Faculty, Staff and Student Publications

Targeting beta cell proliferation is an appealing approach to restore glucose control in type 1 diabetes. However, the underlying mechanisms of beta cell proliferation remain incompletely understood, limiting identification of new therapeutic targets. Obesity is a naturally occurring process that potently induces human and rodent beta cell replication, representing an ideal model to study mechanisms of beta cell proliferation. We showed previously acute whole-body