Endocrinology, Diabetes, and Metabolism Commons^™

Circadian Clock Control Of Mrtf/Srf Pathway Suppresses Beige Adipocyte Thermogenic Recruitment, Xuekai Xiong, Weini Li, Ruya Liu, Pradip Saha, Vijay Yechoor, Ke Ma

Faculty, Staff and Students Publications

The morphological transformation of adipogenic progenitors into mature adipocytes requires dissolution of actin cytoskeleton with loss of myocardin-related transcription factor (MRTF)/serum response factor (SRF) activity. Circadian clock confers temporal control in adipogenic differentiation, while the actin cytoskeleton-MRTF/SRF signaling transduces extracellular physical niche cues. Here, we define a novel circadian transcriptional control involved in actin cytoskeleton-MRTF/SRF signaling cascade that modulates beige fat thermogenic function. Key components of actin dynamic-MRTF/SRF pathway display circadian regulation in beige fat depot. The core clock regulator, brain and muscle arnt-like 1 (Bmal1), exerts direct transcriptional control of genes within the actin dynamic-MRTF/SRF cascade that impacts actin …

Mapping The Metabolic Reprogramming Induced By Sodium-Glucose Cotransporter 2 Inhibition, Aviram Kogot-Levin, Yael Riahi, Ifat Abramovich, Ofri Mosenzon, Bella Agranovich, Liat Kadosh, Rachel Ben-Haroush Schyr, Doron Kleiman, Liad Hinden, Erol Cerasi, Danny Ben-Zvi, Ernesto Bernal-Mizrachi, Joseph Tam, Eyal Gottlieb, Gil Leibowitz

Faculty, Staff and Student Publications

Diabetes is associated with increased risk for kidney disease, heart failure, and mortality. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) prevent these adverse outcomes; however, the mechanisms involved are not clear. We generated a roadmap of the metabolic alterations that occur in different organs in diabetes and in response to SGLT2i. In vivo metabolic labeling with 13C-glucose in normoglycemic and diabetic mice treated with or without dapagliflozin, followed by metabolomics and metabolic flux analyses, showed that, in diabetes, glycolysis and glucose oxidation are impaired in the kidney, liver, and heart. Treatment with dapagliflozin failed to rescue glycolysis. SGLT2 inhibition increased glucose oxidation …

The Effect Of A Pharmaceutical Ghrelin Agonist On Lifespan In C57bl/6j Male Mice: A Controlled Experiment, Kathryn A Kaiser, Inga Kadish, Thomas Van Groen, Daniel L Smith, Stephanie Dickinson, Beate Henschel, Erik S Parker, Andrew W Brown, David B Allison

Children’s Nutrition Research Center Staff Publications

Interventions for animal lifespan extension like caloric restriction (CR) have identified physiologic and biochemical pathways related to hunger and energy-sensing status as possible contributors, but mechanisms have not been fully elucidated. Prior studies using ghrelin agonists show greater food intake but no effect on lifespan in rodent models. This experiment in male C57BL/6J mice tested the influence of ghrelin agonism for perceived hunger, in the absence of CR, on longevity. Mice aged 4 weeks were allowed to acclimate for 2 weeks prior to being assigned (N = 60/group). Prior to lights off daily (12:12 cycle), animals were fed a ghrelin …

Exposure To Pcb126 During The Nursing Period Reversibly Impacts Early-Life Glucose Tolerance, Brittany Breon Rice, Keegan W. Sammons, Sara Y. Ngo Tenlep, Madeline T. Weltzer, Leryn J. Reynolds, Cetewayo S. Rashid, Hollie I. Swanson, Kevin J. Pearson

Markey Cancer Center Faculty Publications

Polychlorinated biphenyls (PCBs) are persistent environmental organic pollutants known to have detrimental health effects. Using a mouse model, we previously demonstrated that PCB126 exposure before and during pregnancy and throughout the perinatal period adversely affected offspring glucose tolerance and/or body composition profiles. The purpose of this study was to investigate the glucose tolerance and body composition of offspring born to dams exposed to PCB126 during the nursing period only. Female ICR mice were bred, and half of the dams were exposed to either vehicle (safflower oil) or 1 μmole PCB126 per kg of body weight via oral gavage on postnatal …

Tfeb-Mediated Lysosomal Exocytosis Alleviates High-Fat Diet-Induced Lipotoxicity In The Kidney, Jun Nakamura, Takeshi Yamamoto, Yoshitsugu Takabatake, Tomoko Namba-Hamano, Satoshi Minami, Atsushi Takahashi, Jun Matsuda, Shinsuke Sakai, Hiroaki Yonishi, Shihomi Maeda, Sho Matsui, Isao Matsui, Takayuki Hamano, Masatomo Takahashi, Maiko Goto, Yoshihiro Izumi, Takeshi Bamba, Miwa Sasai, Masahiro Yamamoto, Taiji Matsusaka, Fumio Niimura, Motoko Yanagita, Shuhei Nakamura, Tamotsu Yoshimori, Andrea Ballabio, Yoshitaka Isaka

Duncan NRI Faculty and Staff Publications

Obesity is a major risk factor for end-stage kidney disease. We previously found that lysosomal dysfunction and impaired autophagic flux contribute to lipotoxicity in obesity-related kidney disease, in both humans and experimental animal models. However, the regulatory factors involved in countering renal lipotoxicity are largely unknown. Here, we found that palmitic acid strongly promoted dephosphorylation and nuclear translocation of transcription factor EB (TFEB) by inhibiting the mechanistic target of rapamycin kinase complex 1 pathway in a Rag GTPase-dependent manner, though these effects gradually diminished after extended treatment. We then investigated the role of TFEB in the pathogenesis of obesity-related kidney …

Dual-Specificity Phosphatases 22-Deficient T Cells Contribute To The Pathogenesis Of Ankylosing Spondylitis, Ming-Han Chen, Huai-Chia Chuang, Yi-Chen Yeh, Chung-Tei Chou, Tse-Hua Tan

Children’s Nutrition Research Center Staff Publications

Background: Dual-specificity phosphatases (DUSPs) can dephosphorylate both tyrosine and serine/threonine residues of their substrates and regulate T cell-mediated immunity and autoimmunity. The aim of this study was to investigate the potential roles of DUSPs in ankylosing spondylitis (AS).

Methods: Sixty AS patients and 45 healthy controls were enrolled in this study. Associations of gene expression of 23 DUSPs in peripheral T cells with inflammatory cytokine gene expression and disease activity of AS were analyzed. Finally, we investigated whether the characteristics of AS are developed in DUSP-knockout mice.

Results: The mRNA levels of DUSP4, DUSP5, DUSP6, DUSP7, and DUSP14 in peripheral …

Hepatocytes Demarcated By Ephb2 Contribute To The Progression Of Nonalcoholic Steatohepatitis, Yang Xiao, Kirill Batmanov, Wenxiang Hu, Kun Zhu, Alexander Y Tom, Dongyin Guan, Chunjie Jiang, Lan Cheng, Sam J Mccright, Eric C Yang, Matthew R Lanza, Yifan Liu, David A Hill, Mitchell A Lazar

Faculty, Staff and Students Publications

Current therapeutic strategies for treating nonalcoholic steatohepatitis (NASH) have failed to alleviate liver fibrosis, which is a devastating feature leading to hepatic dysfunction. Here, we integrated single-nucleus transcriptomics and epigenomics to characterize all major liver cell types during NASH development in mice and humans. The bifurcation of hepatocyte trajectory with NASH progression was conserved between mice and humans. At the nonalcoholic fatty liver (NAFL) stage, hepatocytes exhibited metabolic adaptation, whereas at the NASH stage, a subset of hepatocytes was enriched for the signatures of cell adhesion and migration, which were mainly demarcated by receptor tyrosine kinase ephrin type B receptor …

Genome-Wide Screening Reveals The Genetic Basis Of Mammalian Embryonic Eye Development, Justine M Chee, Louise Lanoue, Dave Clary, Kendall Higgins, Lynette Bower, Ann Flenniken, Ruolin Guo, David J Adams, Fatima Bosch, Robert E Braun, Steve D M Brown, H-J Genie Chin, Mary E Dickinson, Chih-Wei Hsu, Michael Dobbie, Xiang Gao, Sanjeev Galande, Anne Grobler, Jason D Heaney, Yann Herault, Martin Hrabe De Angelis, Fabio Mammano, Lauryl M J Nutter, Helen Parkinson, Chuan Qin, Toshi Shiroishi, Radislav Sedlacek, J-K Seong, Ying Xu, Brian Brooks, Colin Mckerlie, K C Kent Lloyd, Henrik Westerberg, Ala Moshiri

Faculty, Staff and Students Publications

BACKGROUND: Microphthalmia, anophthalmia, and coloboma (MAC) spectrum disease encompasses a group of eye malformations which play a role in childhood visual impairment. Although the predominant cause of eye malformations is known to be heritable in nature, with 80% of cases displaying loss-of-function mutations in the ocular developmental genes OTX2 or SOX2, the genetic abnormalities underlying the remaining cases of MAC are incompletely understood. This study intended to identify the novel genes and pathways required for early eye development. Additionally, pathways involved in eye formation during embryogenesis are also incompletely understood. This study aims to identify the novel genes and pathways …

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 …

Pgc-1Α Senses The Cbc Of Pre-Mrna To Dictate The Fate Of Promoter-Proximally Paused Rnapii, Xavier Rambout, Hana Cho, Roméo Blanc, Qing Lyu, Joseph M Miano, Joe V Chakkalakal, Geoffrey M Nelson, Hari K Yalamanchili, Karen Adelman, Lynne E Maquat

Children’s Nutrition Research Center Staff Publications

PGC-1α is well established as a metazoan transcriptional coactivator of cellular adaptation in response to stress. However, the mechanisms by which PGC-1α activates gene transcription are incompletely understood. Here, we report that PGC-1α serves as a scaffold protein that physically and functionally connects the DNA-binding protein estrogen-related receptor α (ERRα), cap-binding protein 80 (CBP80), and Mediator to overcome promoter-proximal pausing of RNAPII and transcriptionally activate stress-response genes. We show that PGC-1α promotes pausing release in a two-arm mechanism (1) by recruiting the positive transcription elongation factor b (P-TEFb) and (2) by outcompeting the premature transcription termination complex Integrator. Using mice …

Adar1 Deletion Causes Degeneration Of The Exocrine Pancreas Via Mavs-Dependent Interferon Signaling, Dhwani N Rupani, Fredrik I Thege, Vidhi Chandra, Hajar Rajaei, Robert W Cowan, Sonja M Wörmann, Olivereen Le Roux, Prerna Malaney, Sara L Manning, Jack Hashem, Jennifer Bailey-Lundberg, Andrew D Rhim, Florencia Mcallister

Faculty, Staff and Student Publications

Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-binding protein that deaminates adenosine (A) to inosine (I). A-to-I editing alters post-transcriptional RNA processing, making ADAR1 a crucial regulator of gene expression. Consequently, Adar1 has been implicated in organogenesis. To determine the role of Adar1 in pancreatic development and homeostasis, we conditionally deleted Adar1 from the murine pancreas (Ptf1aCre/+; Adar1Fl/Fl). The resulting mice had stunted growth, likely due to malabsorption associated with exocrine pancreatic insufficiency. Analyses of pancreata revealed ductal cell expansion, heightened interferon-stimulated gene expression and an increased influx of immune cells. Concurrent deletion of Adar1 and Mavs, a …

Exposure To Pcb126 During The Nursing Period Reversibly Impacts Early-Life Glucose Tolerance, Brittany B. Rice, Keegan W. Sammons, Sara Y. Ngo Tenlep, Madeline T. Weltzer, Leryn J. Reynolds, Cetewayo S. Rashid, Hollie I. Swanson, Kevin J. Pearson

Human Movement Studies & Special Education Faculty Publications

Polychlorinated biphenyls (PCBs) are persistent environmental organic pollutants known to have detrimental health effects. Using a mouse model, we previously demonstrated that PCB126 exposure before and during pregnancy and throughout the perinatal period adversely affected offspring glucose tolerance and/or body composition profiles. The purpose of this study was to investigate the glucose tolerance and body composition of offspring born to dams exposed to PCB126 during the nursing period only. Female ICR mice were bred, and half of the dams were exposed to either vehicle (safflower oil) or 1 µmole PCB126 per kg of body weight via oral gavage on postnatal …

TCf21 Marks Visceral Adipose Mesenchymal Progenitors And Functions As A Rate-Limiting Factor During Visceral Adipose Tissue Development, Qianglin Liu, Chaoyang Li, Buhao Deng, Peidong Gao, Leshan Wang, Yuxia Li, Mohammad Shiri, Fozi Alkaifi, Junxing Zhao, Jacqueline M. Stephens, Constantine A. Simintiras, Joseph Francis, Jiangwen Sun, Xing Fu

Computer Science Faculty Publications

Distinct locations of different white adipose depots suggest anatomy-specific developmental regulation, a relatively understudied concept. Here, we report a population of Tcf21 lineage cells (Tcf21 LCs) present exclusively in visceral adipose tissue (VAT) that dynamically contributes to VAT development and expansion. During development, the Tcf21 lineage gives rise to adipocytes. In adult mice, Tcf21 LCs transform into a fibrotic or quiescent state. Multiomics analyses show consistent gene expression and chromatin accessibility changes in Tcf21 LC, based on which we constructed a gene-regulatory network governing Tcf21 LC activities. Furthermore, …

Receptor-Interacting Protein 1 And 3 Kinase Activity Are Required For High-Fat Diet Induced Liver Injury In Mice, Xiaoqin Wu, Rakesh K Arya, Emily Huang, Megan R Mcmullen, Laura E Nagy

Faculty, Staff and Student Publications

BACKGROUND: The RIP1-RIP3-MLKL-mediated cell death pathway is associated with progression of non-alcohol-associated fatty liver/steatohepatitis (NAFL/NASH). Previous work identified a critical role for MLKL, the key effector regulating necroptosis, but not RIP3, in mediating high fat diet-induced liver injury in mice. RIP1 and RIP3 have active N-terminus kinase domains essential for activation of MLKL and subsequent necroptosis. However, little is known regarding domain-specific roles of RIP1/RIP3 kinase in liver diseases. Here, we hypothesized that RIP1/RIP3 kinase activity are required for the development of high fat diet-induced liver injury.

METHODS:Rip1K45A/K45A and Rip3K51A/K51A kinase-dead mice on a C57BL/6J background and their littermate …

Randomization, Design And Analysis For Interdependency In Aging Research: No Person Or Mouse Is An Island, Daniella E Chusyd, Steven N Austad, Stephanie L Dickinson, Keisuke Ejima, Gary L Gadbury, Lilian Golzarri-Arroyo, Richard J Holden, Yasaman Jamshidi-Naeini, Doug Landsittel, Tapan Mehta, J Michael Oakes, Arthur H Owora, Greg Pavela, Javier Rojo, Michael W Sandel, Daniel L Smith, Colby J Vorland, Pengcheng Xun, Roger Zoh, David B Allison

Children’s Nutrition Research Center Staff Publications

Investigators traditionally use randomized designs and corresponding analysis procedures to make causal inferences about the effects of interventions, assuming independence between an individual's outcome and treatment assignment and the outcomes of other individuals in the study. Often, such independence may not hold. We provide examples of interdependency in model organism studies and human trials and group effects in aging research and then discuss methodologic issues and solutions. We group methodologic issues as they pertain to (1) single-stage individually randomized trials; (2) cluster-randomized controlled trials; (3) pseudo-cluster-randomized trials; (4) individually randomized group treatment; and (5) two-stage randomized designs. Although we present …

Human Islet Amyloid Polypeptide (Hiapp) Protofibril-Specific Antibodies For Detection And Treatment Of Type 2 Diabetes, Angelina S Bortoletto, W Vallen Graham, Gabriella Trout, Alessandra Bonito-Oliva, Manija A Kazmi, Jing Gong, Emily Weyburne, Brandy L Houser, Thomas P Sakmar, Ronald J Parchem

Faculty, Staff and Students Publications

Type 2 diabetes mellitus (T2D) is a major public health concern and is characterized by sustained hyperglycemia due to insulin resistance and destruction of insulin-producing β cells. One pathological hallmark of T2D is the toxic accumulation of human islet amyloid polypeptide (hIAPP) aggregates. Monomeric hIAPP is a hormone normally co-secreted with insulin. However, increased levels of hIAPP in prediabetic and diabetic patients can lead to the formation of hIAPP protofibrils, which are toxic to β cells. Current therapies fail to address hIAPP aggregation and current screening modalities do not detect it. Using a stabilizing capping protein, monoclonal antibodies (mAbs) can …

Analysis Of Genome-Wide Knockout Mouse Database Identifies Candidate Ciliopathy Genes, Kendall Higgins, Bret A Moore, Zorana Berberovic, Hibret A Adissu, Mohammad Eskandarian, Ann M Flenniken, Andy Shao, Denise M Imai, Dave Clary, Louise Lanoue, Susan Newbigging, Lauryl M J Nutter, David J Adams, Fatima Bosch, Robert E Braun, Steve D M Brown, Mary E Dickinson, Michael Dobbie, Paul Flicek, Xiang Gao, Sanjeev Galande, Anne Grobler, Jason D Heaney, Yann Herault, Martin Hrabe De Angelis, Hsian-Jean Genie Chin, Fabio Mammano, Chuan Qin, Toshihiko Shiroishi, Radislav Sedlacek, J-K Seong, Ying Xu, Impc Consortium, K C Kent Lloyd, Colin Mckerlie, Ala Moshiri

Faculty, Staff and Students Publications

We searched a database of single-gene knockout (KO) mice produced by the International Mouse Phenotyping Consortium (IMPC) to identify candidate ciliopathy genes. We first screened for phenotypes in mouse lines with both ocular and renal or reproductive trait abnormalities. The STRING protein interaction tool was used to identify interactions between known cilia gene products and those encoded by the genes in individual knockout mouse strains in order to generate a list of "candidate ciliopathy genes." From this list, 32 genes encoded proteins predicted to interact with known ciliopathy proteins. Of these, 25 had no previously described roles in ciliary pathobiology. …

Anti-Diabetic Effects Of Glp1 Analogs Are Mediated By Thermogenic Interleukin-6 Signaling In Adipocytes, Absalon D Gutierrez, Zhanguo Gao, Vala Hamidi, Liang Zhu, Karla Bermudez Saint Andre, Kayla Riggs, Monika Ruscheinsky, Hongyu Wang, Yongmei Yu, Charles Miller, Hernan Vasquez, Heinrich Taegtmeyer, Mikhail G Kolonin

Faculty, Staff and Student Publications

Mechanisms underlying anti-diabetic effects of GLP1 analogs remain incompletely understood. We observed that in prediabetic humans exenatide treatment acutely induces interleukin-6 (IL-6) secretion by monocytes and IL-6 in systemic circulation. We hypothesized that GLP1 analogs signal through IL-6 in adipose tissue (AT) and used the mouse model to test if IL-6 receptor (IL-6R) signaling underlies the effects of the GLP1-IL-6 axis. We show that liraglutide transiently increases IL-6 in mouse circulation and IL-6R signaling in AT. Metronomic liraglutide treatment resulted in AT browning and thermogenesis linked with STAT3 activation. IL-6-blocking antibody treatment inhibited STAT3 activation in AT and suppressed liraglutide-induced …

Pancreatic Tumor Microenvironmental Acidosis And Hypoxia Transform Gold Nanorods Into Cell-Penetrant Particles For Potent Radiosensitization, Pradipta Ranjan Rauta, Yuri Mackeyev, Keith Sanders, Joseph B K Kim, Valeria V Gonzalez, Yasmin Zahra, Muhammad A Shohayeb, Belal Abousaida, Geraldine V Vijay, Okan Tezcan, Paul Derry, Anton V Liopo, Eugene R Zubarev, Rickey Carter, Pankaj Singh, Sunil Krishnan

Faculty, Staff and Student Publications

Coating nanoparticles with stealth epilayers increases circulation time by evading opsonization, macrophage phagocytosis, and reticuloendothelial sequestration. However, this also reduces internalization by cancer cells upon reaching the tumor. We designed gold nanorods (GNRs) with an epilayer that retains stealth properties in circulation but transforms spontaneously in the acidotic tumor microenvironment to a cell-penetrating particle. We used a customized stoichiometric ratio of l-glutamic acid and l-lysine within an amphiphilic polymer of poly(l-glutamic acid-co-l-lysine), or P(Glu-co-Lys), to effect this transformation in acidotic environments. P(Glu-co-Lys)-GNRs were internalized by cancer cells to facilitate potent in vitro radiosensitization. When administered intravenously in mice, they accumulate …

Aging-Associated Regγ Proteasome Decline Predisposes To Tauopathy, Jialu Tu, Haiyang Zhang, Ting Yang, Yun Liu, Solomon Kibreab, Yunpeng Zhang, Liangcai Gao, Robb E Moses, Bert W O'Malley, Jianru Xiao, Xiaotao Li

Faculty, Staff and Students Publications

The REGγ-20S proteasome is an ubiquitin- and ATP-independent degradation system, targeting selective substrates, possibly helping to regulate aging. The studies we report here demonstrate that aging-associated REGγ decline predisposes to decreasing tau turnover, as in a tauopathy. The REGγ proteasome promotes degradation of human and mouse tau, notably phosphorylated tau and toxic tau oligomers that shuttle between the cytoplasm and nuclei. REGγ-mediated proteasomal degradation of tau was validated in 3- to 12-month-old REGγ KO mice, REGγ KO;PS19 mice, and PS19 mice with forebrain conditional neuron-specific overexpression of REGγ (REGγ OE) and behavioral abnormalities. Coupled with tau accumulation, we found …

Desmoglein-2 Is Important For Islet Function And Β-Cell Survival, Kay K. Myo Min, Darling Rojas-Canales, Daniella Penko, Mark Denichilo, Michaelia P. Cockshell, Charlie B. Ffrench, Emma J. Thompson, Olof Asplund, Christopher J. Drogemuller, Rashmi B. Prasad, Leif Groop, Shane T Grey, Helen E. Thomas, Thomas Loudovaris, Thomas W. Kay, My G. Mahoney, Claire F. Jessup, P. Toby Coates, Claudine S. Bonder

Department of Dermatology and Cutaneous Biology Faculty Papers

Type 1 diabetes is a complex disease characterized by the lack of endogenous insulin secreted from the pancreatic β-cells. Although β-cell targeted autoimmune processes and β-cell dysfunction are known to occur in type 1 diabetes, a complete understanding of the cell-to-cell interactions that support pancreatic function is still lacking. To characterize the pancreatic endocrine compartment, we studied pancreata from healthy adult donors and investigated a single cell surface adhesion molecule, desmoglein-2 (DSG2). Genetically-modified mice lacking Dsg2 were examined for islet cell mass, insulin production, responses to glucose, susceptibility to a streptozotocin-induced mouse model of hyperglycaemia, and ability to cure diabetes …

Rna Binding Protein Rbm46 Regulates Mitotic-To-Meiotic Transition In Spermatogenesis, Baomei Qian, Yang Li, Ruoyu Yan, Shenglin Han, Zhiwen Bu, Jie Gong, Bangjin Zheng, Zihan Yuan, Sen Ren, Qing He, Jinwen Zhang, Chen Xu, Ruilin Wang, Zheng Sun, Mingyan Lin, Jian Zhou, Lan Ye

Faculty, Staff and Students Publications

Meiosis entry during spermatogenesis requires reprogramming from mitotic to meiotic gene expression profiles. Transcriptional regulation has been extensively studied in meiosis entry, but gain of function for master transcription factors is insufficient to down-regulate mitotic genes. RNA helicase YTHDC2 and its partner MEIOC emerge as essential posttranscriptional regulators of meiotic entry. However, it is unclear what governs the RNA binding specificity of YTHDC2/MEIOC. Here, we identified RNA binding protein RBM46 as a component of the YTHDC2/MEIOC complex. Testis-specific Rbm46 knockout in mice causes infertility with defective mitotic-to-meiotic transition, phenocopying global Ythdc2 or Meioc knockout. RBM46 binds to 3′ UTR of …

Immunotherapy For Type 1 Diabetes Mellitus By Adjuvant-Free Schistosoma Japonicum-Egg Tip-Loaded Asymmetric Microneedle Patch (Stamp), Haoming Huang, Dian Hu, Zhuo Chen, Jiarong Xu, Rengui Xu, Yusheng Gong, Zhengming Fang, Ting Wang, Wei Chen

Faculty, Staff and Student Publications

BACKGROUND: Type 1 diabetes mellitus (T1DM) is an autoimmune disease mediated by autoreactive T cells and dominated by Th1 response polarization. Insulin replacement therapy faces great challenges to this autoimmune disease, requiring highly frequent daily administration. Intriguingly, the progression of T1DM has proven to be prevented or attenuated by helminth infection or worm antigens for a relatively long term. However, the inevitable problems of low safety and poor compliance arise from infection with live worms or direct injection of antigens. Microneedles would be a promising candidate for local delivery of intact antigens, thus providing an opportunity for the clinical immunotherapy …

Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 Regulates Hepatic Fuel Metabolism, Brittany A Stork, Adam Dean, Andrea R Ortiz, Pradip Saha, Nagireddy Putluri, Maricarmen D Planas-Silva, Iqbal Mahmud, Kimal Rajapakshe, Cristian Coarfa, Stefan Knapp, Philip L Lorenzi, Bruce E Kemp, Benjamin E Turk, John W Scott, Anthony R Means, Brian York

Faculty, Staff and Students Publications

OBJECTIVE: The liver is the primary internal metabolic organ that coordinates whole body energy homeostasis in response to feeding and fasting. Genetic ablation or pharmacological inhibition of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) has been shown to significantly improve hepatic health and peripheral insulin sensitivity upon overnutrition with high fat diet. However, the precise molecular underpinnings that explain this metabolic protection have remained largely undefined.

METHODS: To characterize the role of CaMKK2 in hepatic metabolism, we developed and challenged liver-specific CaMKK2 knockout (CaMKK2

RESULTS: Consistent with previous findings, we show that hepatic CaMKK2 ablation significantly improves indices of peripheral insulin …

A Role For Insulin-Like Growth Factor 1 In The Generation Of Epileptic Spasms In A Murine Model, Carlos J Ballester-Rosado, John T Le, Trang T Lam, Carrie A Mohila, Sandi Lam, Anne E Anderson, James D Frost, John W Swann

Faculty, Staff and Students Publications

Objective: Infantile spasms are associated with a wide variety of clinical conditions, including perinatal brain injuries. We have created a model in which prolonged infusion of tetrodotoxin (TTX) into the neocortex, beginning in infancy, produces a localized lesion and reproduces the behavioral spasms, electroencephalogram (EEG) abnormalities, and drug responsiveness seen clinically. Here, we undertook experiments to explore the possibility that the growth factor IGF-1 plays a role in generating epileptic spasms.

Methods: We combined long-term video EEG recordings with quantitative immunohistochemical and biochemical analyses to unravel IGF-1's role in spasm generation. Immunohistochemistry was undertaken in surgically resected tissue from infantile …

Regulation Of Age-Associated Insulin Resistance By Mt1-Mmp-Mediated Cleavage Of Insulin Receptor, Xuanming Guo, Pallavi Asthana, Susma Gurung, Shuo Zhang, Sheung Kin Ken Wong, Samane Fallah, Chi Fung Willis Chow, Sijia Che, Lixiang Zhai, Zening Wang, Xin Ge, Zhixin Jiang, Jiayan Wu, Yijing Zhang, Xiaoyu Wu, Keyang Xu, Cheng Yuan Lin, Hiu Yee Kwan, Aiping Lyu, Zhongjun Zhou, Zhao-Xiang Bian, Hoi Leong Xavier Wong

Faculty, Staff and Student Publications

Insulin sensitivity progressively declines with age. Currently, the mechanism underlying age-associated insulin resistance remains unknown. Here, we identify membrane-bound matrix metalloproteinase 14 (MT1-MMP/MMP14) as a central regulator of insulin sensitivity during ageing. Ageing promotes MMP14 activation in insulin-sensitive tissues, which cleaves Insulin Receptor to suppress insulin signaling. MT1-MMP inhibition restores Insulin Receptor expression, improving insulin sensitivity in aged mice. The cleavage of Insulin Receptor by MT1-MMP also contributes to obesity-induced insulin resistance and inhibition of MT1-MMP activities normalizes metabolic dysfunctions in diabetic mouse models. Conversely, overexpression of MT1-MMP in the liver reduces the level of Insulin Receptor, impairing hepatic insulin …

Tomatoes, Lycopene, And Prostate Cancer: What Have We Learned From Experimental Models?, Nancy E Moran, Jennifer M Thomas-Ahner, Lei Wan, Krystle E Zuniga, John W Erdman, Steven K Clinton

Children’s Nutrition Research Center Staff Publications

Human epidemiology suggests a protective effect of tomatoes or tomato phytochemicals, such as lycopene, on prostate cancer risk. However, human epidemiology alone cannot reveal causal relations. Laboratory animal models of prostate cancer provide opportunities to investigate hypotheses regarding dietary components in precisely controlled, experimental systems, contributing to our understanding of diet and cancer risk relations. We review the published studies evaluating the impact of tomatoes and/or lycopene in preclinical models of prostate carcinogenesis and tumorigenesis. The feeding of tomatoes or tomato components demonstrates anti-prostate cancer activity in both transplantable xenograft models of tumorigenesis and models of chemically- and genetically-driven carcinogenesis. …

An Exercise-Inducible Metabolite That Suppresses Feeding And Obesity, Veronica L Li, Yang He, Kévin Contrepois, Hailan Liu, Joon T Kim, Amanda L Wiggenhorn, Julia T Tanzo, Alan Sheng-Hwa Tung, Xuchao Lyu, Peter-James H Zushin, Robert S Jansen, Basil Michael, Kang Yong Loh, Andrew C Yang, Christian S Carl, Christian T Voldstedlund, Wei Wei, Stephanie M Terrell, Benjamin C Moeller, Rick M Arthur, Gareth A Wallis, Koen Van De Wetering, Andreas Stahl, Bente Kiens, Erik A Richter, Steven M Banik, Michael P Snyder, Yong Xu, Jonathan Z Long

Children’s Nutrition Research Center Staff Publications

Exercise confers robust protection against obesity, type 2 diabetes, and other cardiometabolic diseases.1–5 However, the molecular and cellular mechanisms that mediate the metabolic benefits of physical activity remain unclear.6 Here we show that exercise stimulates production of Lac-Phe, a blood-borne signaling metabolite that suppresses feeding and obesity. Lac-Phe biosynthesis from lactate occurs in CNDP2+ cells including immune cells, epithelial cells, and mesenchymal stem cells localized to diverse organs. In diet-induced obese mice, pharmacological elevation of circulating Lac-Phe reduces food intake without affecting movement or energy expenditure. Chronic administration of Lac-Phe decreases adiposity and body weight and …

Circadian Disruption Of Hippocampus In An Early Senescence Male Mouse Model, Jennifer A Davis, Jodi R Paul, Mugdha V Mokashi, Stefani A Yates, Daniel J Mount, Hira A Munir, Lacy K Goode, Martin E Young, David B Allison, Karen L Gamble

Children’s Nutrition Research Center Staff Publications

Age-related cognitive decline and disruptions in circadian rhythms are growing problems as the average human life span increases. Multiple strains of the senescence-accelerated mouse (SAM) show reduced life span, and the SAMP8 strain in particular has been well documented to show cognitive deficits in behavior as well as a bimodal pattern of circadian locomotor activity. However, little is known about circadian regulation within the hippocampus of these strains of mice. Here we test the hypothesis that in this early senescence model, disruption of the molecular circadian clock in SAMP8 animals drives disrupted behavior and physiology. We found normal rhythms in …