Digital Commons Network^™

Branched-Chain Amino Acid Accumulation Fuels The Senescence-Associated Secretory Phenotype, Yaosi Liang, Christopher Pan, Tao Yin, Lu Wang, Xia Gao, Ergang Wang, Holly Quang, De Huang, Lianmei Tan, Kun Xiang, Yu Wang, Peter B Alexander, Qi-Jing Li, Tso-Pang Yao, Zhao Zhang, Xiao-Fan Wang

Faculty, Staff and Students Publications

The essential branched-chain amino acids (BCAAs) leucine, isoleucine, and valine play critical roles in protein synthesis and energy metabolism. Despite their widespread use as nutritional supplements, BCAAs' full effects on mammalian physiology remain uncertain due to the complexities of BCAA metabolic regulation. Here a novel mechanism linking intrinsic alterations in BCAA metabolism is identified to cellular senescence and the senescence-associated secretory phenotype (SASP), both of which contribute to organismal aging and inflammation-related diseases. Altered BCAA metabolism driving the SASP is mediated by robust activation of the BCAA transporters Solute Carrier Family 6 Members 14 and 15 as well as downregulation …

Optimizing Immunogenicity And Product Presentation Of A Sars-Cov-2 Subunit Vaccine Composition: Effects Of Delivery Route, Heterologous Regimens With Self-Amplifying Rna Vaccines, And Lyophilization, William R Lykins, Jeroen Pollet, Jessica A White, Brian Keegan, Leroy Versteeg, Ulrich Strych, Wen-Hsiang Chen, Raodoh Mohamath, Gabi Ramer-Denisoff, Sierra Reed, Christina Renshaw, Samuel Beaver, Alana Gerhardt, Emily A Voigt, Mark A Tomai, Robert Sitrin, Robert K M Choy, Frederick J Cassels, Peter J Hotez, Maria Elena Bottazzi, Christopher B Fox

Faculty, Staff and Students Publications

INTRODUCTION: Dozens of vaccines have been approved or authorized internationally in response to the ongoing SARS-CoV-2 pandemic, covering a range of modalities and routes of delivery. For example, mucosal delivery of vaccines via the intranasal (i.n.) route has been shown to improve protective mucosal responses in comparison to intramuscular (i.m.) delivery. As we gain knowledge of the limitations of existing vaccines, it is of interest to understand if changes in product presentation or combinations of multiple vaccine modalities can further improve immunological outcomes.

METHODS: We investigated a commercial-stage SARS-CoV-2 receptor binding domain (RBD) antigen adjuvanted with a clinical-stage TLR-7/8 agonist …

The Forkhead Transcription Factor Foxj1 Controls Vertebrate Olfactory Cilia Biogenesis And Sensory Neuron Differentiation, Dheeraj Rayamajhi, Steven L. Brody, Et Al.

2020-Current year OA Pubs

In vertebrates, olfactory receptors localize on multiple cilia elaborated on dendritic knobs of olfactory sensory neurons (OSNs). Although olfactory cilia dysfunction can cause anosmia, how their differentiation is programmed at the transcriptional level has remained largely unexplored. We discovered in zebrafish and mice that Foxj1, a forkhead domain-containing transcription factor traditionally linked with motile cilia biogenesis, is expressed in OSNs and required for olfactory epithelium (OE) formation. In keeping with the immotile nature of olfactory cilia, we observed that ciliary motility genes are repressed in zebrafish, mouse, and human OSNs. Strikingly, we also found that besides ciliogenesis, Foxj1 controls the …

Stat1 Employs Myeloid Cell-Extrinsic Mechanisms To Regulate The Neutrophil Response And Provide Protection Against Invasive Klebsiella Pneumoniae Lung Infection, Shekina Gonzalez-Ferrer, Zeyu Xiong, Atish Gheware, Janet S Lee, Et Al.

2020-Current year OA Pubs

Klebsiella pneumoniae (KP) is an extracellular Gram-negative bacterium that causes infections in the lower respiratory and urinary tracts and the bloodstream. STAT1 is a master transcription factor that acts to maintain T cell quiescence under homeostatic conditions. Although STAT1 helps defend against systemic spread of acute KP intrapulmonary infection, whether STAT1 regulation of T cell homeostasis impacts pulmonary host defense during acute bacterial infection and injury is less clear. Using a clinical KP respiratory isolate and a pneumonia mouse model, we found that STAT1 deficiency led to an early neutrophil-dominant transcriptional profile and neutrophil recruitment in the lung preceding widespread …

Neurosteroids Mediate And Modulate The Effects Of Pro-Inflammatory Stimulation And Toll-Like Receptors On Hippocampal Plasticity And Learning, Yukitoshi Izumi, Kazuko A. O'Dell, Anil G. Cashikar, Steven M. Paul, Douglas F. Covey, Steven J. Mennerick, Charles F. Zorumski

2020-Current year OA Pubs

Pro-inflammatory changes contribute to multiple neuropsychiatric illnesses. Understanding how these changes are involved in illnesses and identifying strategies to alter inflammatory responses offer paths to potentially novel treatments. We previously found that acute pro-inflammatory stimulation with high (μg/ml) lipopolysaccharide (LPS) for 10-15 min dampens long-term potentiation (LTP) in the hippocampus and impairs learning. Effects of LPS involved non-canonical inflammasome signaling but were independent of toll-like receptor 4 (TLR4), a known LPS receptor. Low (ng/ml) LPS also inhibits LTP when administered for 2-4 h, and here we report that this LPS exposure requires TLR4. We also found that effects of low …

Revolutionizing Psoriasis Topical Treatment: Enhanced Efficacy Through Ceramide/Phospholipid Composite Cerosomes Co-Delivery Of Cyclosporine And Dithranol: In-Vitro, Ex-Vivo, And In-Vivo Studies, Sammar Fathy Elhabal, Nashwa Abdelaal, Saeed A S Al-Zuhairy, Mohamed Fathi Mohamed Elrefai, Mohamed Mansour Khalifa, Mohammad Ahmad Khasawneh, Ahmed Mohsen Elsaid Hamdan, Passant M Mohie, Rania A Gad, Soad L Kabil, Mohamed Kandeel El-Ashery, Bhaskara R Jasti, Nahla A Elzohairy, Nehal Elfar, Tayseer Elnawawy, Fatma E Hassan, Mohamed Ahmed El-Nabarawi

Faculty, Staff and Students Publications

PURPOSE: Improving the treatment of psoriasis is a serious challenge today. Psoriasis is an immune-mediated skin condition affecting 125 million people worldwide. It is commonly treated with cyclosporine-A (CsA) and dithranol (DTH). CsA suppresses the activation of T-cells, immune cells involved in forming psoriatic lesions. Meanwhile, DTH is a potent anti-inflammatory and anti-proliferative drug that effectively reduces the severity of psoriasis symptoms such as redness, scaling, and skin thickness. CsA and DTH belong to BCS class II with limited oral bioavailability. We aim to develop a drug delivery system for topical co-delivery of CsA and DTH, exploring its therapeutic potential. …

Leishmania Major Surface Components And Dkk1 Signalling Via Lrp6 Promote Migration And Longevity Of Neutrophils In The Infection Site, Olivia C Ihedioha, Haley Q Marcarian, Anutr Sivakoses, Stephen M Beverley, Diane Mcmahon-Pratt, Alfred L M Bothwell

2020-Current year OA Pubs

BACKGROUND: Host-related factors highly regulate the increased circulation of neutrophils during

RESULTS: In this study, we further explored the potential role of DKK1-LRP6 signalling in the migration and longevity of activated neutrophils in the infection site using BALB/c mice with PMNs deficient in LRP6 (LRP6

CONCLUSION: Our results suggest that DKK1 signalling and

Delayed Macrophage Targeting By Clodronate Liposomes Worsens The Progression Of Cytokine Storm Syndrome, Kunjan Khanna, Emily Eul, Hui Yan, Roberta Faccio

2020-Current year OA Pubs

Excessive macrophage activation and production of pro-inflammatory cytokines are hallmarks of the Cytokine Storm Syndrome (CSS), a lethal condition triggered by sepsis, autoimmune disorders, and cancer immunotherapies. While depletion of macrophages at disease onset protects from lethality in an infection-induced CSS murine model, patients are rarely diagnosed early, hence the need to characterize macrophage populations during CSS progression and assess the therapeutic implications of macrophage targeting after disease onset. In this study, we identified MHCII

Transformation Of Autophagic Sqstm1 Droplets To Sqstm1-Dependent P-Bodies, Evelina Valionyte, Elizabeth R. Barrow, Chris R. Baxter, Sharon Herath, Shouqing Luo

Peninsula Medical School

SQSTM1/p62 droplets play crucial roles in droplets-based macroautophagy/autophagy including selective autophagy and bulk autophagy. We observed that under several stress milieus, SQSTM1 droplets entirely colocalize with P-body markers, and these stress-induced SQSTM1 droplets contain mRNAs. We thus determined that under certain stress conditions, autophagic SQSTM1 droplets are converted to a type of enlarged P-bodies, designated SQSTM1/p62-dependent P-bodies (pd-PBs). Stress-enhanced SQSTM1 droplet formation drives the nucleation of pd-PBs through the interaction between SQSTM1 and the RNA-binding protein DDX6. Furthermore, pd-PBs sequester PYCARD, facilitating the assembly of NLRP3 inflammasomes, and in turn induce inflammation-related cytotoxicity. Our study suggests that under stress settings, …

Inhibition Of Src-3 As A Potential Therapeutic Strategy For Aggressive Mantle Cell Lymphoma, Imani Bijou, Yang Liu, Dong Lu, Jianwei Chen, Shelby Sloan, Lapo Alinari, David M Lonard, Bert W O'Malley, Michael Wang, Jin Wang

Faculty, Staff and Students Publications

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel …

Female Titin Mutant Mice Outperform Young And Old Males, Reese Ger

Scripps Senior Theses

Exercise performance is widely believed to generally be maximal among young males. However, little research has been conducted to investigate the impact of sex or age on muscle performance. This study investigated the effects of sex and age on forelimb and all limb grip strength performance in wildtype and titin mutant mice. Titin is the largest known protein, with known involvement in muscle function. The mice in this study were Ttn∆112-158 with a 75% deletion to the PEVK region of titin. Based on limited existing research, we hypothesized that wildtype mice would outperform all Ttn∆112-158 mice, males would outperform females …

Folate Regulation Of Planar Cell Polarity Pathway And F-Actin Through Folate Receptor Alpha, Xiao Han, Xuanye Cao, Robert M Cabrera, Paula Andrea Pimienta Ramirez, Ying Linda Lin, Bogdan J Wlodarczyk, Cuilian Zhang, Richard H Finnell, Yunping Lei

Faculty, Staff and Students Publications

Folate deficiency contribute to neural tube defects (NTDs) which could be rescued by folate supplementation. However, the underlying mechanisms are still not fully understood. Besides, there is considerable controversy concerning the forms of folate used for supplementation. To address this controversy, we prepared culture medium with different forms of folate, Folic acid (FA) and 5-methyltetrahydrofolate(5mTHF), at concentration of 5uM, 500nM, 50nM and folate free, respectively. Mouse embryonic fibroblasts (MEFs) were treated with different folates continuously for three passages and cell proliferation and F-actin was monitored. We determined that compared to 5mTHF, FA showed stronger effects on promoting cell proliferation and …

Neutrophil-Derived Activin-A Moderates Their Pro-Netotic Activity And Attenuates Collateral Tissue Damage Caused By Influenza A Virus Infection, Georgios Divolis, Evgenia Synolaki, Athanasia Doulou, Ariana Gavriil, Christina C Giannouli, Anastasia Apostolidou, Martyn L Foster, Martin M Matzuk, Panagiotis Skendros, Ioanna-Evdokia Galani, Paschalis Sideras

Faculty, Staff and Students Publications

BACKGROUND: Pre-neutrophils, while developing in the bone marrow, transcribe the Inhba gene and synthesize Activin-A protein, which they store and release at the earliest stage of their activation in the periphery. However, the role of neutrophil-derived Activin-A is not completely understood.

METHODS:To address this issue, we developed a neutrophil-specific Activin-A-deficient animal model (S100a8-Cre/Inhba fl/fl mice) and analyzed the immune response to Influenza A virus (IAV) infection. More specifically, evaluation of body weight and lung mechanics, molecular and cellular analyses of bronchoalveolar lavage fluids, flow cytometry and cell sorting of lung cells, as well as histopathological analysis of lung tissues, …

Transcriptomic Profiling Of Thymic Dysregulation And Viral Tropism After Neonatal Roseolovirus Infection, Andrei Belean, Eden Xue, Benjamin Cisneros, Elisha D O Roberson, Michael A Paley, Tarin M Bigley

2020-Current year OA Pubs

INTRODUCTION: Herpesviruses, including the roseoloviruses, have been linked to autoimmune disease. The ubiquitous and chronic nature of these infections have made it difficult to establish a causal relationship between acute infection and subsequent development of autoimmunity. We have shown that murine roseolovirus (MRV), which is highly related to human roseoloviruses, induces thymic atrophy and disruption of central tolerance after neonatal infection. Moreover, neonatal MRV infection results in development of autoimmunity in adult mice, long after resolution of acute infection. This suggests that MRV induces durable immune dysregulation.

METHODS: In the current studies, we utilized single-cell RNA sequencing (scRNAseq) to study …

Mapping Of A Hybrid Insulin Peptide In The Inflamed Islet Β-Cells From Nod Mice, Janet M Wenzlau, Orion J Peterson, Anthony N Vomund, James E Dilisio, Anita Hohenstein, Kathryn Haskins, Xiaoxiao Wan

2020-Current year OA Pubs

There is accumulating evidence that pathogenic T cells in T1D recognize epitopes formed by post-translational modifications of β-cell antigens, including hybrid insulin peptides (HIPs). The ligands for several CD4 T-cell clones derived from the NOD mouse are HIPs composed of a fragment of proinsulin joined to peptides from endogenous β-cell granule proteins. The diabetogenic T-cell clone BDC-6.9 reacts to a fragment of C-peptide fused to a cleavage product of pro-islet amyloid polypeptide (6.9HIP). In this study, we used a monoclonal antibody (MAb) to the 6.9HIP to determine when and where HIP antigens are present in NOD islets during disease progression …

Hyperbaric Oxygen Augments Susceptibility To C. Difficile Infection By Impairing Gut Microbiota Ability To Stimulate The Hif-1Α-Il-22 Axis In Ilc3, José L Fachi, Laís P Pral, Helder C Assis, Sarah Oliveira, Vinícius R Rodovalho, Jefferson A C Dos Santos, Mariane F Fernandes, Valquíria A Matheus, Renata Sesti-Costa, Paulo J Basso, Marina Flóro E Silva, Niels O S Câmara, Selma Giorgio, Marco Colonna, Marco A R Vinolo

2020-Current year OA Pubs

Hyperbaric oxygen (HBO) therapy is a well-established method for improving tissue oxygenation and is typically used for the treatment of various inflammatory conditions, including infectious diseases. However, its effect on the intestinal mucosa, a microenvironment known to be physiologically hypoxic, remains unclear. Here, we demonstrated that daily treatment with hyperbaric oxygen affects gut microbiome composition, worsening antibiotic-induced dysbiosis. Accordingly, HBO-treated mice were more susceptible to

Cep120 Is Essential For Kidney Stromal Progenitor Cell Growth And Differentiation, Ewa Langner, Tao Cheng, Eirini Kefaloyianni, Charles Gluck, Baolin Wang, Moe R Mahjoub

2020-Current year OA Pubs

Mutations in genes that disrupt centrosome structure or function can cause congenital kidney developmental defects and lead to fibrocystic pathologies. Yet, it is unclear how defective centrosome biogenesis impacts renal progenitor cell physiology. Here, we examined the consequences of impaired centrosome duplication on kidney stromal progenitor cell growth, differentiation, and fate. Conditional deletion of the ciliopathy gene Cep120, which is essential for centrosome duplication, in the stromal mesenchyme resulted in reduced abundance of interstitial lineages including pericytes, fibroblasts and mesangial cells. These phenotypes were caused by a combination of delayed mitosis, activation of the mitotic surveillance pathway leading to apoptosis, …

Select Gut Microbiota Impede Rotavirus Vaccine Efficacy, Vu L Ngo, Yanling Wang, Yadong Wang, Zhenda Shi, Robert Britton, Jun Zou, Sasirekha Ramani, Baoming Jiang, Andrew T Gewirtz

Faculty, Staff and Students Publications

BACKGROUND & AIMS: The protection provided by rotavirus (RV) vaccines is highly heterogeneous among individuals. We hypothesized that microbiota composition might influence RV vaccine efficacy.

METHODS: First, we examined the potential of segmented filamentous bacteria (SFB) colonization to influence RV vaccine efficacy in mice. Next, we probed the influence of human microbiomes on RV vaccination via administering mice fecal microbial transplants (FMTs) from children with robust or minimal RV vaccine responsiveness. Post-FMT, mice were subjected to RV vaccination followed by RV challenge.

RESULTS: SFB colonization induced a phenotype that was reminiscent of RV vaccine failure (ie, failure to generate RV …

Control Of Acute Myeloid Leukemia And Generation Of Immune Memory In Vivo Using Amv564, A Bivalent Bispecific Cd33 X Cd3 T Cell Engager, Linda G. Eissenberg, Julie K. Ritchey, Michael P. Rettig, Dilan A. Patel, Kiran Vij, Feng Gao, Victoria Smith, Tae H Han, John F. Dipersio

2020-Current year OA Pubs

Off-the-shelf immunotherapeutics that suppress tumor growth and provide durable protection against relapse could enhance cancer treatment. We report preclinical studies on a CD33 x CD3 bivalent bispecific diabody, AMV564, that not only suppresses tumor growth, but also facilitates memory responses in a mouse model of acute myelogenous leukemia (AML). Mechanistically, a single 5-day treatment with AMV564 seems to reduce tumor burden by redirection of T cells, providing a time window for allogeneic or other T cells that innately recognize tumor antigens to become activated and proliferate. When the concentration of bispecific becomes negligible, the effector: target ratio has also shifted, …

Comparative Exploration Of Mammalian Deafness Gene Homologues In The Drosophila Auditory Organ Shows Genetic Correlation Between Insect And Vertebrate Hearing, Daniel C Sutton, Jonathan C Andrews, Dylan M Dolezal, Ye Jin Park, Hongjie Li, Daniel F Eberl, Shinya Yamamoto, Andrew K Groves

Faculty, Staff and Students Publications

Johnston's organ, the Drosophila auditory organ, is anatomically very different from the mammalian organ of Corti. However, recent evidence indicates significant cellular and molecular similarities exist between vertebrate and invertebrate hearing, suggesting that Drosophila may be a useful platform to determine the function of the many mammalian deafness genes whose underlying biological mechanisms are poorly characterized. Our goal was a comprehensive screen of all known orthologues of mammalian deafness genes in the fruit fly to better understand conservation of hearing mechanisms between the insect and the fly and ultimately gain insight into human hereditary deafness. We used bioinformatic comparisons to …

Β2-Glycoprotein I Promotes The Clearance Of Circulating Mitochondria, Swapan Kumar Dasgupta, Jahnavi Gollamudi, Stefanie Rivera, Ross A Poche, Rolando E Rumbaut, Perumal Thiagarajan

Faculty, Staff and Students Publications

β2-glycoprotein I (β2-Gp1) is a cardiolipin-binding plasma glycoprotein. It is evolutionarily conserved from invertebrates, and cardiolipin-bound β2-Gp1 is a major target of antiphospholipid antibodies seen in autoimmune disorders. Cardiolipin is almost exclusively present in mitochondria, and mitochondria are present in circulating blood. We show that β2-Gp1 binds to cell-free mitochondria (CFM) in the circulation and promotes its phagocytosis by macrophages at physiological plasma concentrations. Exogenous CFM had a short circulation time of less than 10 minutes in mice. Following infusion of CFM, β2-Gp1-deficient mice had significantly higher levels of transfused mitochondria at 5 minutes (9.9 ± 6.4 pg/ml versus 4.0 …

Traversing The Bench To Bedside Journey For Inkt Cell Therapies, Julie O'Neal, Melissa Mavers, Reyka G Jayasinghe, John F Dipersio

2020-Current year OA Pubs

Invariant natural killer T (iNKT) cells are immune cells that harness properties of both the innate and adaptive immune system and exert multiple functions critical for the control of various diseases. Prevention of graft-versus-host disease (GVHD) by iNKT cells has been demonstrated in mouse models and in correlative human studies in which high iNKT cell content in the donor graft is associated with reduced GVHD in the setting of allogeneic hematopoietic stem cell transplants. This suggests that approaches to increase the number of iNKT cells in the setting of an allogeneic transplant may reduce GVHD. iNKT cells can also induce …

Ddr2-Regulated Arginase Activity In Ovarian Cancer-Associated Fibroblasts Promotes Collagen Production And Tumor Progression, Favour A Akinjiyan, Zainab Ibitoye, Peinan Zhao, Leah P Shriver, Gary J Patti, Gregory D Longmore, Katherine C Fuh

2020-Current year OA Pubs

Ovarian cancer has poor survival outcomes particularly for advanced stage, metastatic disease. Metastasis is promoted by interactions of stromal cells, such as cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME), with tumor cells. CAFs play a key role in tumor progression by remodeling the TME and extracellular matrix (ECM) to result in a more permissive environment for tumor progression. It has been shown that fibroblasts, in particular myofibroblasts, utilize metabolism to support ECM remodeling. However, the intricate mechanisms by which CAFs support collagen production and tumor progression are poorly understood. In this study, we show that the fibrillar collagen receptor, …

Lung Infection With Classical Klebsiella Pneumoniae Strains Establishes Robust Macrophage-Dependent Protection Against Heterologous Reinfection, Joseph J Mackel, Casey L G Mick, Emily Guo, David A Rosen

2020-Current year OA Pubs

At present, there is no approved vaccine for prevention of infection by the opportunistic bacterium Klebsiella pneumoniae (Kp); success in treating these infections is increasingly challenged by the spread of antibiotic resistance. Preclinical investigation of adaptive immunity elicited by lung infection with live classical Kp may reveal host mechanisms of protection against this pathogen. Here, we utilize multiple virulent classical Kp strains to demonstrate that following lung infection, surviving wild-type mice develop protective immunity against both homologous and heterologous (heterotypic) reinfection. For Kp strains with low capacity to disseminate from the lung, this immunity is B-cell-independent. We further demonstrate that …

Targeting Of Oncogenic Aaa-Atpase Trip13 Reduces Progression Of Pancreatic Ductal Adenocarcinoma, Farrukh Afaq, Sumit Agarwal, Prachi Bajpai, Sameer Al Diffalha, Hyung-Gyoon Kim, Shajan Peter, Moh'd Khushman, Subhash C Chauhan, Priyabrata Mukherjee, Sooryanarayana Varambally, Upender Manne

2020-Current year OA Pubs

Thyroid hormone receptor-interacting protein 13 (TRIP13) is involved in cancer progression, but its role in pancreatic ductal adenocarcinoma (PDAC) is unknown. Thus, we assessed the expression, functional role, and mechanism of action of TRIP13 in PDAC. We further examined the efficacy of TRIP13 inhibitor, DCZ0415, alone or in combination with gemcitabine on malignant phenotypes, tumor progression, and immune response. We found that TRIP13 was overexpressed in human PDACs relative to corresponding normal pancreatic tissues. TRIP13 knockdown or treatment of PDAC cells with DCZ0415 reduced proliferation and colony formation, and induced G2/M cell cycle arrest and apoptosis. Additionally, TRIP13 knockdown or …

A Structure-Function Analysis Of Hepatocyte Arginase 2 Reveals Mitochondrial Ureahydrolysis As A Determinant Of Glucose Oxidation, Yiming Zhang, Jiameng Sun, Henry D Wasserman, Joshua A Adams, Cassandra B Higgins, Shannon C Kelly, Louise Lantier, Brian J Debosch

2020-Current year OA Pubs

BACKGROUND & AIMS: Restoring hepatic and peripheral insulin sensitivity is critical to prevent or reverse metabolic syndrome and type 2 diabetes. Glucose homeostasis comprises in part the complex regulation of hepatic glucose production and insulin-mediated glucose uptake and oxidation in peripheral tissues. We previously identified hepatocyte arginase 2 (Arg2) as an inducible ureahydrolase that improves glucose homeostasis and enhances glucose oxidation in multiple obese, insulin-resistant models. We therefore examined structure-function determinants through which hepatocyte Arg2 governs systemic insulin action and glucose oxidation.

METHODS: To do this, we generated mice expressing wild-type murine Arg2, enzymatically inactive Arg2 (Arg2

RESULTS: We show …

Beta Cell Primary Cilia Mediate Somatostatin Responsiveness Via Sstr3, Samantha E Adamson, Zipeng A Li, Jing W Hughes

2020-Current year OA Pubs

Somatostatin is a paracrine modulator of insulin secretion and beta cell function with pleotropic effects on glucose homeostasis. The mechanism of somatostatin-mediated communication between delta and beta cells is not well-understood, which we address in this study via the ciliary somatostatin receptor 3 (SSTR3). Primary cilia are membrane organelles that act as signaling hubs in islets by virtue of their subcellular location and enrichment in signaling proteins such as G-protein coupled receptors (GPCRs). We show that SSTR3, a ciliary GPCR, mediates somatostatin suppression of insulin secretion in mouse islets. Quantitative analysis of calcium flux using a mouse model of genetically …

Genetic Inactivation Of Β-Catenin Is Salubrious, Whereas Its Activation Is Deleterious In Desmoplakin Cardiomyopathy, Melis Olcum, Siyang Fan, Leila Rouhi, Sirisha Cheedipudi, Benjamin Cathcart, Hyun-Hwan Jeong, Zhongming Zhao, Priyatansh Gurha, Ali J Marian

Faculty, Staff and Student Publications

AIMS: Mutations in the DSP gene encoding desmoplakin, a constituent of the desmosomes at the intercalated discs (IDs), cause a phenotype that spans arrhythmogenic cardiomyopathy (ACM) and dilated cardiomyopathy. It is typically characterized by biventricular enlargement and dysfunction, myocardial fibrosis, cell death, and arrhythmias. The canonical wingless-related integration (cWNT)/β-catenin pathway is implicated in the pathogenesis of ACM. The β-catenin is an indispensable co-transcriptional regulator of the cWNT pathway and a member of the IDs. We genetically inactivated or activated β-catenin to determine its role in the pathogenesis of desmoplakin cardiomyopathy.

METHODS AND RESULTS: The Dsp gene was conditionally deleted in …

P53r245w Mutation Fuels Cancer Initiation And Metastases In Nash-Driven Liver Tumorigenesis, Denada Dibra, Mihai Gagea, Yuan Qi, Gilda P Chau, Xiaoping Su, Guillermina Lozano

Faculty, Staff and Student Publications

Obesity is a significant global health concern. Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH) are common risk factors for hepatocellular carcinoma (HCC) and are closely associated with metabolic comorbidities, including obesity and diabetes. The TP53 tumor suppressor is the most frequently mutated gene in liver cancers, with half of these alterations being missense mutations. These mutations produce highly abundant proteins in cancer cells which have both inhibitory effects on wildtype (WT) p53, and gain-of-function (GOF) activities that contribute to tumor progression. A Western diet increases p53 activity in the liver. To elucidate the functional consequences of Trp53 mutations in …

Triobp Modulates Β-Catenin Signaling By Regulation Of Mir-29b In Idiopathic Pulmonary Fibrosis, Lan Wang, Wenyu Zhao, Cong Xia, Shuaichen Ma, Zhongzheng Li, Ningdan Wang, Linke Ding, Yaxuan Wang, Lianhui Cheng, Huibing Liu, Juntang Yang, Yajun Li, Ivan Rosas, Guoying Yu

Faculty, Staff and Students Publications

Idiopathic pulmonary fibrosis (IPF) is a fatal and devastating lung disease of unknown etiology, described as the result of multiple cycles of epithelial cell injury and fibroblast activation. Despite this impressive increase in understanding, a therapy that reverses this form of fibrosis remains elusive. In our previous study, we found that miR-29b has a therapeutic effect on pulmonary fibrosis. However, its anti-fibrotic mechanism is not yet clear. Recently, our study identified that F-Actin Binding Protein (TRIOBP) is one of the target genes of miR-29b and found that deficiency of TRIOBP increases resistance to lung fibrosis in vivo. TRIOBP knockdown inhibited …