Geriatrics Commons^™

Surgical Removal Of Implanted Microchips To Correct Mri Susceptibility Artifacts In Mice, Elizabeth Hipskind, Nicole Hernandez, Sydney Fox, Tina Manirambona, Rita Schack, Brian Gibson, Robia G Pautler

Center on Aging Staff Publications

Purpose: Implanted microchips are becoming increasingly common in research for animal identification and have been adopted by commercial vendors for some mouse strains. However, they often contain metal components, which generate magnetic susceptibility artifacts on MR images. Despite this, some microchips are marketed as MR-compatible, even though they are likely to affect image quality.

Methods: We assessed the impact of a radiofrequency identification microchip on MR images of the mouse brain and present a method for precise surgical removal. A handheld magnet was used to locate and stabilize the microchips during removal. Mice were imaged before and after microchip removal. …

Peritoneal Immunosurgery: Immunotherapy Augmented Surgery For The Treatment Of Peritoneal Cancers, Ada I Ozcan, Arianexys Aquino López, Mary K Mckenna, Malcolm K Brenner, Alastair M Thompson

Faculty, Staff and Students Publications

Peritoneal malignancy often indicates disruptions in multiple physiological systems resulting from widespread cancer. The heterogenous origin and dynamic nature of peritoneal cancer make it difficult to treat with standard approaches that fit into guidelines. We describe how successful treatment should address the underlying pathology, the systemic response to surgical treatments and target the immune perturbations that facilitate the establishment and propagation of this multifaceted disease.

Muscle Rev-Erb Controls Time-Dependent Adaptations To Chronic Exercise In Mice, Jidong Liu, Fang Xiao, Abhinav Choubey, Udhaya Kumar S, Yanxiang Wang, Sungguan Hong, Tingting Yang, Husniye Gul Otlu, Ege Sanem Oturmaz, Emanuele Loro, Yuxiang Sun, Pradip Saha, Tejvir S Khurana, Li Chen, Xinguo Hou, Zheng Sun

Center on Aging Staff Publications

The best time of the day for chronic exercise training and the mechanism underlying the timing effects is unclear. Here, we show that low-intensity, low-volume treadmill training in mice before sleep yields greater benefits than after waking for muscle contractile performance and systemic glucose tolerance. Baseline muscle performance also exhibits diurnal variations, with higher strength but lower endurance before sleep than after waking. Muscle-specific knockout of circadian clock genes Rev-erbα/β (Rev-MKO) in male mice eradicates the diurnal variations in both training and baseline conditions without affecting muscle mass, mitochondrial content, food intake, or spontaneous activities. Multi-omics and metabolic measurements reveal …

Reduction Of Neuronal Activity Mediated By Blood-Vessel Regression In The Adult Brain, Xiaofei Gao, Xing-Jun Chen, Meng Ye, Jun-Liszt Li, Nannan Lu, Di Yao, Bo Ci, Fei Chen, Lijun Zheng, Yating Yi, Shiwen Zhang, Zhanying Bi, Xinwei Gao, Yuanlei Yue, Tingbo Li, Jiafu Lin, Ying-Chao Shi, Kaibin Shi, Nicholas E Propson, Yubin Huang, Katherine Poinsatte, Zhaohuan Zhang, Dale B Bosco, Shi-Bing Yang, Ralf H Adams, Volkhard Lindner, Fen Huang, Long-Jun Wu, Hui Zheng, Simon Hippenmeyer, Ann M Stowe, Bo Peng, Marta Margeta, Qingchun Guo, Xiaoqun Wang, Qiang Liu, Jakob Körbelin, Martin Trepel, Hui Lu, Guoen Cai, Bo O Zhou, Bo Shen, Ying-Mei Lu, Wenzhi Sun, Jie-Min Jia, Feng Han, Hu Zhao, Robert M Bachoo, Woo-Ping Ge

Center on Aging Staff Publications

The brain vasculature supplies neurons with glucose and oxygen, but little is known about how vascular plasticity contributes to brain function. Using longitudinal in vivo imaging, we report that a substantial proportion of blood vessels in the adult mouse brain sporadically occlude and regress. Their regression proceeds through sequential stages of blood-flow occlusion, endothelial cell collapse, relocation or loss of pericytes, and retraction of glial endfeet. Regressing vessels are found to be widespread in mouse, monkey and human brains. We further reveal that blood vessel regression cause a reduction of neuronal activity due to a dysfunction in mitochondrial metabolism and …

Dnmt3a Regulates Murine Megakaryocyte-Biased Hematopoietic Stem Cell Fate Decisions, Sarah M Waldvogel, Virginia Camacho, Dandan Fan, Anna G Guzman, Alejandra Garcia-Martell, Elmira Khabusheva, Jacey Rodriguez Pridgen, Josephine De La Fuente, Rachel Rau, Ashlyn G Laidman, Maria N Barrachina, Estelle Carminita, Justin A Courson, Michael R Williamson, Joanne I Hsu, Chun-Wei Chen, Jaime Reyes, Subhashree Pradhan, Rolando E Rumbaut, Alan R Burns, Benjamin Deneen, Jianzhong Su, Kellie R Machlus, Margaret A Goodell

Center on Aging Staff Publications

Hematopoietic stem cells (HSCs) are defined by their capacity to regenerate all main components of peripheral blood, but individual HSCs exhibit a range of preferences for generating downstream cell types. Their propensities are thought to be epigenetically encoded, but few differential regulatory mechanisms have been identified. In this work, we explored the role of DNA methyltransferase 3A (DNMT3A) in the megakaryocyte-biased HSC population, which is thought to reside at the top of the hematopoietic hierarchy. We demonstrate that heterozygous loss of DNMT3A (Dnmt3a+/-) in these megakaryocyte-biased HSCs has distinct consequences compared with the rest of the HSC pool. These megakaryocyte-biased …

Clonal Dynamics And Somatic Evolution Of Haematopoiesis In Mouse, Chiraag D Kapadia, Nicholas Williams, Kevin J Dawson, Caroline Watson, Matthew J Yousefzadeh, Duy Le, Kudzai Nyamondo, Sreeya Kodavali, Alex Cagan, Sarah Waldvogel, Xiaoyan Zhang, Josephine De La Fuente, Daniel Leongamornlert, Emily Mitchell, Marcus A Florez, Krzysztof Sosnowski, Rogelio Aguilar, Alejandra Martell, Anna Guzman, David Harrison, Laura J Niedernhofer, Katherine Y King, Peter J Campbell, Jamie Blundell, Margaret A Goodell, Jyoti Nangalia

Center on Aging Staff Publications

Haematopoietic stem cells maintain blood production throughout life1. Although extensively characterized using the laboratory mouse, little is known about clonal selection and population dynamics of the haematopoietic stem cell pool during murine ageing. We isolated stem cells and progenitors from young and old mice, identifying 221,890 somatic mutations genome-wide in 1,845 single-cell-derived colonies. Mouse stem cells and progenitors accrue approximately 45 somatic mutations per year, a rate only approximately threefold greater than human progenitors despite the vastly different organismal sizes and lifespans. Phylogenetic patterns show that stem and multipotent progenitor cell pools are established during embryogenesis, after which …

Inhibition Of Soluble Epoxide Hydrolase Confers Neuroprotection And Restores Microglial Homeostasis In A Tauopathy Mouse Model, Shuo Wang, Chuangye Qi, Chetan Rajpurohit, Baijayanti Ghosh, Wen Xiong, Baiping Wang, Yanyan Qi, Sung Hee Hwang, Bruce D Hammock, Hongjie Li, Li Gan, Hui Zheng

Center on Aging Staff Publications

Background: The epoxyeicosatrienoic acids (EETs) are derivatives of the arachidonic acid metabolism with anti-inflammatory activities. However, their efficacy is limited due to the rapid hydrolysis by soluble epoxide hydrolase (sEH). Inhibition of sEH has been shown to stabilize the EETs and reduce neuroinflammation in Aβ mouse models of Alzheimer's disease (AD). However, the role of the sEH-EET signaling pathway in other CNS cell types and neurodegenerative conditions are less understood.

Methods: Here we investigated the mechanisms and functional role of the sEH-EET axis in tauopathy by treating PS19 mice with a small molecule sEH inhibitor TPPU and by crossing the …

The Havcr1-Centric Host Factor Network Drives Zika Virus Vertical Transmission, Wenzhe Yu, Jun Tao, Hongmin Cao, Wanshan Zheng, Beiang Zhang, Yue Zhang, Peiqun Xu, Yiwei Zhang, Xuan Liu, Yinan Wang, Han Cai, Gang Liu, Fan Liu, Haibin Wang, Haiyan Zhao, Indira U Mysorekar, Xiaoqian Hu, Bin Cao

Center on Aging Staff Publications

Zika virus (ZIKV) vertical transmission results in devastating congenital malformations and pregnancy complications; however, the specific receptor and host factors facilitating ZIKV maternal-fetal transmission remain elusive. Here, we employ a genome-wide CRISPR screening and identify multiple placenta-intrinsic factors modulating ZIKV infection. Our study unveils that hepatitis A virus cellular receptor 1 (HAVCR1) serves as a primary receptor governing ZIKV entry in placental trophoblasts. The GATA3-HAVCR1 axis regulates heterogeneous cell tropism in the placenta. Notably, placenta-specific Havcr1 deletion in mice significantly impairs ZIKV transplacental transmission and associated adverse pregnancy outcomes. Mechanistically, the immunoglobulin variable-like domain of HAVCR1 binds to ZIKV via …

Quantitative Profiling Ph Heterogeneity Of Acidic Endolysosomal Compartments Using Fluorescence Lifetime Imaging Microscopy, Dinghuan Deng, Youchen Guan, Ayse Sena Mutlu, Baiping Wang, Shihong Max Gao, Hui Zheng, Meng C Wang

Center on Aging Staff Publications

The endolysosomal system plays a crucial role in maintaining cellular homeostasis and promoting organism fitness. The pH of its acidic compartments is a crucial parameter for proper function, and it is dynamically influenced by both intracellular and environmental factors. Here, we present a method based on fluorescence lifetime imaging microscopy (FLIM) for quantitatively analyzing the pH profiles of acidic endolysosomal compartments in diverse types of primary mammalian cells and in live organism Caenorhabditis elegans. This FLIM-based method exhibits high sensitivity in resolving subtle pH differences, thereby revealing heterogeneity within a cell and across cell types. This method enables rapid …

Human Embryonic Genetic Mosaicism And Its Effects On Development And Disease, Sarah M Waldvogel, Jennifer E Posey, Margaret A Goodell

Center on Aging Staff Publications

Nearly every mammalian cell division is accompanied by a mutational event that becomes fixed in a daughter cell. When carried forward to additional cell progeny, a clone of variant cells can emerge. As a result, mammals are complex mosaics of clones that are genetically distinct from one another. Recent high-throughput sequencing studies have revealed that mosaicism is common, clone sizes often increase with age and specific variants can affect tissue function and disease development. Variants that are acquired during early embryogenesis are shared by multiple cell types and can affect numerous tissues. Within tissues, variant clones compete, which can result …

Pkmyt1 Is A Marker Of Treatment Response And A Therapeutic Target For Cdk4/6 Inhibitor-Resistance In Er+ Breast Cancer, Anran Chen, Beom-Jun Kim, Aparna Mitra, Craig T Vollert, Jonathan T Lei, Diana Fandino, Meenakshi Anurag, Matthew V Holt, Xuxu Gou, Jacob B Pilcher, Matthew P Goetz, Donald W Northfelt, Susan G Hilsenbeck, C Gary Marshall, Marc L Hyer, Robert Papp, Shou-Yun Yin, Carmine De Angelis, Rachel Schiff, Suzanne A W Fuqua, Cynthia X Ma, Charles E Foulds, Matthew J Ellis

Faculty, Staff and Students Publications

Endocrine therapies (ET) with cyclin-dependent kinase 4/6 (CDK4/6) inhibition are the standard treatment for estrogen receptor-α-positive (ER+) breast cancer, however drug resistance is common. In this study, proteogenomic analyses of patient-derived xenografts (PDXs) from patients with 22 ER+ breast cancer demonstrated that protein kinase, membrane-associated tyrosine/threonine one (PKMYT1), a WEE1 homolog, is estradiol (E2) regulated in E2-dependent PDXs and constitutively expressed when growth is E2-independent. In clinical samples, high PKMYT1 mRNA levels associated with resistance to both ET and CDK4/6 inhibition. The PKMYT1 inhibitor lunresertib (RP-6306) with gemcitabine selectively and synergistically reduced the viability of ET and palbociclib-resistant ER+ breast …

Complement C3ar Signaling: Immune And Metabolic Modulation And Its Impact On Alzheimer’S Disease, Manasee Gedam, Hui Zheng

Center on Aging Staff Publications

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia among the elderly population. Despite its widespread prevalence, our comprehension of the intricate mechanisms governing the pathogenesis of the disease remains incomplete, posing a challenge for the development of efficient therapies. Pathologically characterized by the presence of amyloid β plaques and neurofibrillary tau tangles, AD is also accompanied by the hyperactivation of glial cells and the immune system. The complement cascade, the evolutionarily conserved innate immune pathway, has emerged as a significant contributor to AD. This review focuses on one of the complement components, the …

Advances In Immunocompetent Mouse And Rat Models, Wen Bu, Yi Li

Center on Aging Staff Publications

Rodent models of breast cancer have played critical roles in our understanding of breast cancer development and progression as well as preclinical testing of cancer prevention and therapeutics. In this article, we first review the values and challenges of conventional genetically engineered mouse (GEM) models and newer iterations of these models, especially those with inducible or conditional regulation of oncogenes and tumor suppressors. Then, we discuss nongermline (somatic) GEM models of breast cancer with temporospatial control, made possible by intraductal injection of viral vectors to deliver oncogenes or to manipulate the genome of mammary epithelial cells. Next, we introduce the …

Txnrd1 Drives The Innate Immune Response In Senescent Cells With Implications For Age-Associated Inflammation, Xue Hao, Bo Zhao, Martina Towers, Liping Liao, Edgar Luzete Monteiro, Xin Xu, Christina Freeman, Hongzhuang Peng, Hsin-Yao Tang, Aaron Havas, Andrew V Kossenkov, Shelley L Berger, Peter D Adams, David W Speicher, David Schultz, Ronen Marmorstein, Kenneth S Zaret, Rugang Zhang

Faculty, Staff and Student Publications

Sterile inflammation, also known as 'inflammaging', is a hallmark of tissue aging. Cellular senescence contributes to tissue aging, in part, through the secretion of proinflammatory factors collectively known as the senescence-associated secretory phenotype (SASP). The genetic variability of thioredoxin reductase 1 (TXNRD1) is associated with aging and age-associated phenotypes such as late-life survival, activity of daily living and physical performance in old age. TXNRD1's role in regulating tissue aging has been attributed to its enzymatic role in cellular redox regulation. Here, we show that TXNRD1 drives the SASP and inflammaging through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) …

Tfeb-Vacuolar Atpase Signaling Regulates Lysosomal Function And Microglial Activation In Tauopathy, Baiping Wang, Heidi Martini-Stoica, Chuangye Qi, Tzu-Chiao Lu, Shuo Wang, Wen Xiong, Yanyan Qi, Yin Xu, Marco Sardiello, Hongjie Li, Hui Zheng

Center on Aging Staff Publications

Transcription factor EB (TFEB) mediates gene expression through binding to the coordinated lysosome expression and regulation (CLEAR) sequence. TFEB targets include subunits of the vacuolar ATPase (v-ATPase), which are essential for lysosome acidification. Single-nucleus RNA sequencing of wild-type and PS19 (Tau) transgenic mice expressing the P301S mutant tau identified three unique microglia subclusters in Tau mice that were associated with heightened lysosome and immune pathway genes. To explore the lysosome-immune relationship, we specifically disrupted the TFEB-v-ATPase signaling by creating a knock-in mouse line in which the CLEAR sequence of one of the v-ATPase subunits, Atp6v1h, was mutated. CLEAR mutant exhibited …

Age-Associated Temporal Decline In Butyrate-Producing Bacteria Plays A Key Pathogenic Role In The Onset And Progression Of Neuropathology And Memory Deficits In 3×Tg-Ad Mice, Paula M Chilton, Smita S Ghare, Benjamin T Charpentier, Scott A Myers, Aakarsha V Rao, Joseph F Petrosino, Kristi L Hoffman, John C Greenwell, Neetu Tyagi, Jyotirmaya Behera, Yali Wang, Lucy J Sloan, Jingwen Zhang, Christopher B Shields, Gregory E Cooper, Leila Gobejishvili, Scott R Whittemore, Craig J Mcclain, Shirish S Barve

Faculty, Staff and Students Publications

Alterations in the gut-microbiome-brain axis are increasingly being recognized to be involved in Alzheimer's disease (AD) pathogenesis. However, the functional consequences of enteric dysbiosis linking gut microbiota and brain pathology in AD progression remain largely undetermined. The present work investigated the causal role of age-associated temporal decline in butyrate-producing bacteria and butyrate in the etiopathogenesis of AD. Longitudinal metagenomics, neuropathological, and memory analyses were performed in the 3×Tg-AD mouse model. Metataxonomic analyses showed a significant temporal decline in the alpha diversity marked by a decrease in butyrate-producing bacterial communities and a concurrent reduction in cecal butyrate production. Inferred metagenomics analysis …

Aging Differentially Affects Axonal Autophagosome Formation And Maturation, Heather Tsong, Erika Lf Holzbaur, Andrea Kh Stavoe

Faculty, Staff and Student Publications

Misregulation of neuronal macroautophagy/autophagy has been implicated in age-related neurodegenerative diseases. We compared autophagosome formation and maturation in primary murine neurons during development and through aging to elucidate how aging affects neuronal autophagy. We observed an age-related decrease in the rate of autophagosome formation leading to a significant decrease in the density of autophagosomes along the axon. Next, we identified a surprising increase in the maturation of autophagic vesicles in neurons from aged mice. While we did not detect notable changes in endolysosomal content in the distal axon during early aging, we did observe a significant loss of acidified vesicles …

Oleoylethanolamide Facilitates Pparα And Tfeb Signaling And Attenuates Aβ Pathology In A Mouse Model Of Alzheimer’S Disease, Michele M Comerota, Manasee Gedam, Wen Xiong, Feng Jin, Lisheng Deng, Meng C Wang, Jin Wang, Hui Zheng

Faculty, Staff and Students Publications

BACKGROUND: Age is the strongest risk factor for the development of Alzheimer's disease (AD). Besides the pathological hallmarks of β-amyloid (Aβ) plaques and neurofibrillary tangles, emerging evidence demonstrates a critical role of microglia and neuroinflammation in AD pathogenesis. Oleoylethanolamide (OEA) is an endogenous lipid amide that has been shown to promote lifespan and healthspan in C. elegans through regulation of lysosome-to-nucleus signaling and cellular metabolism. The goal of our study was to determine the role of OEA in the mediation of microglial activity and AD pathology using its stable analog, KDS-5104.

METHODS: We used primary microglial cultures and genetic and …

Naive T Cells Inhibit The Outgrowth Of Intractable Antigen-Activated Memory T Cells: Implications For T-Cell Immunotherapy, Sandhya Sharma, Mae Woods, Naren U Mehta, Tim Sauer, Kathan S Parikh, Michael Schmuck-Henneresse, Huimin Zhang, Birju Mehta, Malcolm K Brenner, Helen E Heslop, Cliona M Rooney

Faculty, Staff and Students Publications

BACKGROUND: The wider application of T cells targeting viral tumor-antigens via their native receptors is hampered by the failure to expand potent tumor-specific T cells from patients. Here, we examine reasons for and solutions to this failure, taking as our model the preparation of Epstein-Barr virus (EBV)-specific T cells (EBVSTs) for the treatment of EBV-positive lymphoma. EBVSTs could not be manufactured from almost one-third of patients, either because they failed to expand, or they expanded, but lacked EBV specificity. We identified an underlying cause of this problem and established a clinically feasible approach to overcome it.

METHODS: CD45RO+CD45RA- memory compartment …

Ultralow-Dose Binary Oncolytic/Helper-Dependent Adenovirus Promotes Antitumor Activity In Preclinical And Clinical Studies, Daniel Wang, Caroline E Porter, Bora Lim, Amanda Rosewell Shaw, Catherine S Robertson, Mae L Woods, Ya Xu, Greyson G W Biegert, Daisuke Morita, Tao Wang, Bambi J Grilley, Helen Heslop, Malcolm K Brenner, Masataka Suzuki

Faculty, Staff and Students Publications

We show that a binary oncolytic/helper-dependent adenovirus (CAdVEC) that both lyses tumor cells and locally expresses the proinflammatory cytokine IL-12 and PD-L1 blocking antibody has potent antitumor activity in humanized mouse models. On the basis of these preclinical studies, we treated four patients with a single intratumoral injection of an ultralow dose of CAdVEC (NCT03740256), representing a dose of oncolytic adenovirus more than 100-fold lower than used in previous trials. While CAdVEC caused no significant toxicities, it repolarized the tumor microenvironment with increased infiltration of CD8 T cells. A single administration of CAdVEC was associated with both locoregional and abscopal …

High Pulse Pressure Impairs Cerebral Artery Endothelial Function In Young, But Not Old, Mice, Nick R Winder, Emily H Reeve, Elise K Kronquist, Aleena Khurana, Byron Lee, Thuan Nguyen, Grant D Henson, Ashley E Walker

Faculty, Staff and Student Publications

One of the hallmarks of vascular aging is increased pulse pressure. This elevated pulse pressure is associated with deleterious effects on cerebral vascular function; however, it is unknown if age modulates the susceptibility to high pulse pressure. To examine the effects of age on the cerebral artery response to pulse pressure, we studied isolated cerebral arteries collected from young (6.1 ± 0.2 mo) and old (26.7 ± 0.5 mo) male C57BL/6 mice. Isolated cerebral arteries were exposed ex vivo to static pressure, low pulse pressure (25 mmHg), and high pulse pressure (50 mmHg). In cerebral arteries from young mice, endothelium-dependent …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Neuronal Signal-Regulatory Protein Alpha Drives Microglial Phagocytosis By Limiting Microglial Interaction With Cd47 In The Retina, Danye Jiang, Courtney A Burger, Viktor Akhanov, Justine H Liang, Robert D Mackin, Nicholas E Albrecht, Pilar Andrade, Dorothy P Schafer, Melanie A Samuel

Center on Aging Staff Publications

Microglia utilize their phagocytic activity to prune redundant synapses and refine neural circuits during precise developmental periods. However, the neuronal signals that control this phagocytic clockwork remain largely undefined. Here, we show that neuronal signal-regulatory protein alpha (SIRPα) is a permissive cue for microglial phagocytosis in the developing murine retina. Removal of neuronal, but not microglial, SIRPα reduced microglial phagocytosis, increased synpase numbers, and impaired circuit function. Conversely, prolonging neuronal SIRPα expression extended developmental microglial phagocytosis. These outcomes depended on the interaction of presynaptic SIRPα with postsynaptic CD47. Global CD47 deficiency modestly increased microglial phagocytosis, while CD47 overexpression reduced it. …

Post-Developmental Plasticity Of The Primary Rod Pathway Allows Restoration Of Visually Guided Behaviors, Yan Cao, Diego Fajardo, Debbie Guerrero-Given, Melanie A Samuel, Toshihisa Ohtsuka, Shannon E Boye, Naomi Kamasawa, Kirill A Martemyanov

Center on Aging Staff Publications

Formation of neural circuits occurs in a programmed fashion, but proper activity in the circuit is essential for refining the organization necessary for driving complex behavioral tasks. In the retina, sensory deprivation during the critical period of development is well known to perturb organization of the visual circuit making the animals unable to use vision for behavior. However, the extent of plasticity, molecular factors involved and malleability of individual channels in the circuit to manipulations outside of the critical period are not well understood. In this study we selectively disconnected and reconnected rod photoreceptors in mature animals after completion of …

Non-Canonical Odor Coding In The Mosquito, Margaret Herre, Olivia V Goldman, Tzu-Chiao Lu, Gabriela Caballero-Vidal, Yanyan Qi, Zachary N Gilbert, Zhongyan Gong, Takeshi Morita, Saher Rahiel, Majid Ghaninia, Rickard Ignell, Benjamin J Matthews, Hongjie Li, Leslie B Vosshall, Meg A Younger

Center on Aging Staff Publications

Aedes aegypti mosquitoes are a persistent human foe, transmitting arboviruses including dengue when they feed on human blood. Mosquitoes are intensely attracted to body odor and carbon dioxide, which they detect using ionotropic chemosensory receptors encoded by three large multi-gene families. Genetic mutations that disrupt the olfactory system have modest effects on human attraction, suggesting redundancy in odor coding. The canonical view is that olfactory sensory neurons each express a single chemosensory receptor that defines its ligand selectivity. We discovered that Ae. aegypti uses a different organizational principle, with many neurons co-expressing multiple chemosensory receptor genes. In vivo electrophysiology demonstrates …

Immune Phenotype Of The Cd4+ T Cells In The Aged Lymphoid Organs And Lacrimal Glands, Claudia M Trujillo-Vargas, Kelsey E Mauk, Humberto Hernandez, Rodrigo G De Souza, Zhiyuan Yu, Jeremias G Galletti, Jana Dietrich, Friedrich Paulsen, Cintia S De Paiva

Faculty, Staff and Students Publications

Aging is associated with a massive infiltration of T lymphocytes in the lacrimal gland. Here, we aimed to characterize the immune phenotype of aged CD4+ T cells in this tissue as compared with lymphoid organs. To perform this, we sorted regulatory T cells (Tregs, CD4+CD25+GITR+) and non-Tregs (CD4+CD25negGITRneg) in lymphoid organs from female C57BL/6J mice and subjected these cells to an immunology NanoString® panel. These results were confirmed by flow cytometry, live imaging, and tissue immunostaining in the lacrimal gland. Importantly, effector T helper 1 (Th1) genes were highly upregulated on aged Tregs, including the master regulator Tbx21. Among …

Isolation And Rna Sequencing Of Single Nuclei From Drosophila Tissues, Colleen N Mclaughlin, Yanyan Qi, Stephen R Quake, Liqun Luo, Hongjie Li

Center on Aging Staff Publications

Many insect cells are encapsulated within the exoskeleton and cannot be dissociated intact, making them inaccessible to single-cell transcriptomic profiling. We have used single-nucleus RNA sequencing to extract transcriptomic information from multiple Drosophila tissues. Here, we describe procedures for the (1) dissociation of single nuclei, (2) isolation of single nuclei using two popular cell sorters, and (3) preparation of libraries for Smart-seq2 and 10× Genomics. This protocol enables generation of high-quality transcriptomes from single nuclei and can be applied to other species.

For complete details on the use and execution of this protocol, please refer to McLaughlin et al. (2021) …

Exercise Intolerance In Older Adults With Heart Failure With Preserved Ejection Fraction: Jacc State-Of-The-Art Review, Ambarish Pandey, Sanjiv J Shah, Javed Butler, Dean L Kellogg, Gregory D Lewis, Daniel E Forman, Robert J Mentz, Barry A Borlaug, Marc A Simon, Julio A Chirinos, Roger A Fielding, Elena Volpi, Anthony J A Molina, Mark J Haykowsky, Flora Sam, Bret H Goodpaster, Alain G Bertoni, Jamie N Justice, James P White, Jingzhone Ding, Scott L Hummel, Nathan K Lebrasseur, George E Taffet, Iraklis I Pipinos, Dalane Kitzman

Faculty, Staff and Students Publications

Exercise intolerance (EI) is the primary manifestation of chronic heart failure with preserved ejection fraction (HFpEF), the most common form of heart failure among older individuals. The recent recognition that HFpEF is likely a systemic, multiorgan disorder that shares characteristics with other common, difficult-to-treat, aging-related disorders suggests that novel insights may be gained from combining knowledge and concepts from aging and cardiovascular disease disciplines. This state-of-the-art review is based on the outcomes of a National Institute of Aging-sponsored working group meeting on aging and EI in HFpEF. We discuss aging-related and extracardiac contributors to EI in HFpEF and provide the …

Macrocyclic Immunoproteasome Inhibitors As A Potential Therapy For Alzheimer's Disease, Min Jae Lee, Deepak Bhattarai, Hyeryung Jang, Ahreum Baek, In Jun Yeo, Seongsoo Lee, Zachary Miller, Sukyeong Lee, Jin Tae Hong, Dong-Eun Kim, Wooin Lee, Kyung Bo Kim

Faculty, Staff and Students Publications

Previously, we reported that immunoproteasome (iP)-targeting linear peptide epoxyketones improve cognitive function in mouse models of Alzheimer's disease (AD) in a manner independent of amyloid β. However, these compounds' clinical prospect for AD is limited due to potential issues, such as poor brain penetration and metabolic instability. Here, we report the development of iP-selective macrocyclic peptide epoxyketones prepared by a ring-closing metathesis reaction between two terminal alkenes attached at the P2 and P3/P4 positions of linear counterparts. We show that a lead macrocyclic compound DB-60 (