Articles by Reni Ajoy in JoVE
Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy Chun Austin Changou1,2,3, Reni Ajoy4,5, Szu-Yi Chou4,5,6 1The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, 2Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, 3Core Facility, Taipei Medical University, 4The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, 5Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, 6TMU research center for Neurotrauma and Neuroregeneration, College of Medical Science and Technology, Taipei Medical University This protocol describes a technique for observation of real-time Green Fluorescence Protein (GFP) tagged Glucose Transporter 4 (GLUT4) protein trafficking upon insulin stimulation and characterization of the biological role of CCR5 in the insulin–GLUT4 signaling pathway with Deconvolution Microscopy.
Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain Reni Ajoy1,2, Szu-Yi Chou1,2,3 1The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research, 2Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, 3TMU research center for Neurotrauma and Neuroregeneration, College of Medical Science and Technology, Taipei Medical University This protocol studies the role of chemokine (C-C motif) ligand 5 (CCL5) in the hypothalamus by delivering an antagonist, MetCCL5, into the mouse brain using a micro-osmotic pump brain infusion system. This transient inhibition of CCL5 activity interrupted hypothalamic insulin signaling, leading to glucose intolerance and peripheral systemic insulin sensitivity.
Other articles by Reni Ajoy on PubMed
CCL5/RANTES Contributes to Hypothalamic Insulin Signaling for Systemic Insulin Responsiveness Through CCR5 Scientific Reports. | Pubmed ID: 27898058 Many neurodegenerative diseases are accompanied by metabolic disorders. CCL5/RANTES, and its receptor CCR5 are known to contribute to neuronal function as well as to metabolic disorders such as type 2 diabetes mellitus, obesity, atherosclerosis and metabolic changes after HIV infection. Herein, we found that the lack of CCR5 or CCL5 in mice impaired regulation of energy metabolism in hypothalamus. Immunostaining and co-immunoprecipitation revealed the specific expression of CCR5, associated with insulin receptors, in the hypothalamic arcuate nucleus (ARC). Both ex vivo stimulation and in vitro tissue culture studies demonstrated that the activation of insulin, and PI3K-Akt pathways were impaired in CCR5 and CCL5 deficient hypothalamus. The inhibitory phosphorylation of insulin response substrate-1 at Ser302 (IRS-1(S302)) but not IRS-2, by insulin was markedly increased in CCR5 and CCL5 deficient animals. Elevating CCR5/CCL5 activity induced GLUT4 membrane translocation and reduced phospho-IRS-1(S302) through AMPKα-S6 Kinase. Blocking CCR5 using the antagonist, (Met)CCL5, abolished the de-phosphorylation of IRS-1(S302) and insulin signal activation. In addition, intracerebroventricular delivery of (Met)CCL5 interrupted hypothalamic insulin signaling and elicited peripheral insulin responsiveness and glucose intolerance. Taken together, our data suggest that CCR5 regulates insulin signaling in hypothalamus which contributes to systemic insulin sensitivity and glucose metabolism.