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Principal Investigator: MICHAEL P CZECH
Organization: UNIV OF MASSACHUSETTS MED SCH WORCESTER
Fiscal Year: 2020
Award: $582,900
Funding agency: National Institute of Diabetes and Digestive and Kidney Diseases
Abstract
The overarching long term goal of our laboratory is to understand and exploit how adipose tissues
exert powerful control over whole body glucose tolerance and insulin sensitivity. Small amounts of
mouse brown (BAT) or human “Beige” adipocytes transplanted into recipient mice can improve glucose
homeostasis, highlighting the importance of understanding mechanisms of adipose browning. Based on the
knowledge that intermediates of the de novo lipogenesis (DNL) pathway display potent signaling
functions (e.g., Acetyl CoA as substrate for histone acetylation, transcriptional regulation) and that adipocyte
DNL is highly regulated by obesity, fasting, cold exposure, and exercise, we hypothesize that adipocyte DNL is
a major regulatory node in metabolism. We aim to interrogate this concept by perturbing this DNL pathway
through selective KO of DNL enzymes ATP citrate lyase (ACLY) and fatty acid synthase (FASN). Our
preliminary data encourage this approach by revealing that FASN KO upregulates adipocyte
neurotrophic factor Neuregulin 4 (Nrg4) and enhances expansion of sWAT sympathetic neurons (SNS),
even at thermo-neutrality (30C). Thus, DNL metabolites (Acetyl CoA, Malonyl CoA) or DNL product
(Palmitoyl CoA) appear to be intimately linked to controlling adipose SNS activity, adipose energy expenditure
and whole body glucose homeostasis. Based on these data, this project seeks to determine the cellular
and molecular mechanisms whereby adipocytes can signal to localized SNS neurons and promote the
development of Beige adipocytes in sWAT. Aim 1 will determine whether Beige adipocytes in iAdFASNKO
mice are derived by direct “conversion” of mature white to beige adipocytes OR by paracrine signaling to
induce differentiation of progenitor cells to Beige adipocytes. To address underlying mechanisms, Aim 2 will
determine whether Nrg4 (and Negr1, which may also be upregulated) mediates the effect of FASN-depleted
adipocytes to cause expansion of the SNS in vivo. This Aim is based on exciting preliminary data showing
that conditioned media from such adipocytes cause marked neurite outgrowth in PC-12 neurons in
vitro, which is inhibited by Nrg4 silencing. New technology we developed will be used to delete adipocyte
Nrg4 and Negr1 using CRISPR-based nanoparticles prior to implantation into recipient mice and analysis of
their effects on SNS innervation. Finally, Aim 3 tests whether adipocyte DNL intermediate metabolites Acetyl
CoA/Malonyl CoA in iAdFASNKO mice initiate signaling to cause Nrg4 expression and SNS expansion. These
adipocyte metabolites in iAdFASNKO mice, and their acetylation and malonylation of cellular proteins, will be
reversed by KO of ATP citrate Lyase (ACLY), which generates the Acetyl CoA, in double KO mice. Identifying
the DNL intermediates that modulate adipocyte function will enable defining their underlying mechanisms.
Together, these experiments have high potential to define novel signaling pathways driven by DNL
metabolites that regulate adipose browning and new therapeutic strategies for type 2 diabetes.
Terms: <3'5'-cyclic ester of AMP><ATP Citrate (pro-3S)-Lyase><ATP Citrate (pro-S)-Lyase><ATP Citrate Lyase><ATP citrate pro3s lyase><ATP-Dependent Citrate Lyase><Acetyl CoA><Acetyl Coenzyme A><Acetylation><Address><Adenosine Cyclic 3',5'-Monophosphate><Adenosine Cyclic Monophosphate><Adenosine, cyclic 3',5'-(hydrogen phosphate)><Adipocytes><Adipose Cell><Adipose tissue><Adult-Onset Diabetes Mellitus><Antibodies><Appearance><Autoregulation><Brown Adipose Tissue><Brown Fat><CRISPR><CRISPR/Cas system><Caloric Restriction><Cell Body><Cell Communication and Signaling><Cell Components><Cell Signaling><Cell Structure><Cells><Cellular Structures><Characteristics><Citrate Cleavage Enzyme><Clustered Regularly Interspaced Short Palindromic Repeats><Cyclic AMP><Data><Denervation><Development><EC 2.3.1.85><Energy Expenditure><Energy Metabolism><Enzyme Gene><Enzymes><Exercise><Fasting><Fat Cells><Fats><Fatty Acid Synthetase Complex><Fatty Acids><Fatty Tissue><Fatty acid glycerol esters><Fatty-acid synthase><Goals><Health><Hexadecanoyl CoA><Hibernating Gland><Histone Acetylation><Homeostasis><Human><Implant><In Vitro><Intermediary Metabolism><Intracellular Communication and Signaling><KO mice><Ketosis-Resistant Diabetes Mellitus><Kinetics><Knock-out Mice><Knockout Mice><Knowledge><Laboratories><Lentivirinae><Lentivirus><Link><Lipocytes><Malonyl CoA><Malonyl Coenzyme A><Mature Lipocyte><Mature fat cell><Maturity-Onset Diabetes Mellitus><Mediating><Metabolic><Metabolic Diseases><Metabolic Disorder><Metabolic Processes><Metabolism><Mice><Mice Mammals><Modern Man><Molecular><Murine><Mus><NIDDM><Nerve Cells><Nerve Unit><Neural Cell><Neurites><Neurocyte><Neurons><Non-Insulin Dependent Diabetes><Non-Insulin-Dependent Diabetes Mellitus><Noninsulin Dependent Diabetes><Noninsulin Dependent Diabetes Mellitus><Null Mouse><Obesity><PC-12><PC12 Cells><Palmitoyl CoA><Palmitoyl Coenzyme A><Palmityl CoA><Paracrine Communication><Paracrine Signaling><Pathway interactions><Pheochromocytoma Cell Line><Physiologic><Physiological><Physiological Homeostasis><Progenitor Cells><Proteins><Publishing><Recombinant Proteins><Resolution><Role><S-acetate Coenzyme A><S-hexadecanoate Coenzyme A><Signal Pathway><Signal Transduction><Signal Transduction Systems><Signaling><Slow-Onset Diabetes Mellitus><Solid><Stable Diabetes Mellitus><Subfamily lentivirinae><T2 DM><T2D><T2DM><Technology><Testing><Thesaurismosis><Time><Transcription Regulation><Transcriptional Control><Transcriptional Regulation><Transplantation><Type 2 Diabetes Mellitus><Type 2 diabetes><Type II Diabetes Mellitus><Type II diabetes><Tyrosine 3-Monooxygenase><Tyrosine Hydroxylase><Virus-Lenti><adenosine 3'5' monophosphate><adipocyte development><adipocyte differentiation><adipogenesis><adipose><adiposity><adult onset diabetes><base><biological signal transduction><blood glucose regulation><cAMP><caloric restricted><calorically restricted><calorie restricted><calorie restriction><citrate pro3s lyase><corpulence><corpulency><corpulentia><developmental><experiment><experimental research><experimental study><fasted><fasts><fatty acid oxidation><glucose control><glucose homeostasis><glucose regulation><glucose tolerance><implantation><improved><in vivo><innervation><insulin sensitivity><ketosis resistant diabetes><lipid biosynthesis><lipogenesis><maturity onset diabetes><metabolism disorder><nano particle><nano-sized particle><nanoparticle><nanosized particle><nerve supply><neuregulin-4><neuronal><neuronal growth><neurotrophic factor><neurotrophin><neutrophin><new technology><new therapeutic approach><new therapeutic intervention><new therapeutic strategies><new therapy approaches><novel><novel technologies><novel therapeutic approach><novel therapeutic intervention><novel therapy approach><obese><obese people><obese person><obese population><palmitoylation><pathway><pheochromocytoma 12 cell line><response><shRNA><short hairpin RNA><small hairpin RNA><social role><stem cells><transplant><type 2 DM><type II DM><type two diabetes><white adipose tissue><yellow adipose tissue>