Madina Makhmutova1, Jonathan Weitz2, Alejandro Tamayo2, Elizabeth Pereira3, Maria Boulina4, Joana Almaça2, Rayner Rodriguez-Diaz5, Alejandro Caicedo6. 1. Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, Florida. Electronic address: m.makhmutova@med.miami.edu. 2. Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida. 3. Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida. 4. Analytical Imaging Core Facility, Miller School of Medicine, University of Miami. 5. Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, Florida. 6. Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, Florida; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida; Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, Florida. Electronic address: acaicedo@med.miami.edu.
Abstract
BACKGROUND AND AIMS: Destroying visceral sensory nerves impacts pancreatic islet function, glucose metabolism, and diabetes onset, but how islet endocrine cells interact with sensory neurons has not been studied. METHODS: We characterized the anatomical pattern of pancreatic sensory innervation by combining viral tracing, immunohistochemistry, and reporter mouse models. To assess the functional interactions of β-cells with vagal sensory neurons, we recorded Ca2+ responses in individual nodose neurons in vivo while selectively stimulating β-cells with chemogenetic and pharmacologic approaches. RESULTS: We found that pancreatic islets are innervated by vagal sensory axons expressing Phox2b, substance P, calcitonin-gene related peptide, and the serotonin receptor 5-HT3R. Centrally, vagal neurons projecting to the pancreas terminate in the commissural nucleus of the solitary tract. Nodose neurons responded in vivo to chemogenetic stimulation of β-cells and to pancreas infusion with serotonin, but were not sensitive to insulin. Responses to chemogenetic and pharmacologic stimulation of β-cells were blocked by a 5-HT3R antagonist and were enhanced by increasing serotonin levels in β-cells. We further confirmed directly in living pancreas slices that sensory terminals in the islet were sensitive to serotonin. CONCLUSIONS: Our study establishes that pancreatic β-cells communicate with vagal sensory neurons, likely using serotonin signaling as a transduction mechanism. Serotonin is coreleased with insulin and may therefore convey information about the secretory state of β-cells via vagal afferent nerves.
BACKGROUND AND AIMS: Destroying visceral sensory nerves impacts pancreatic islet function, glucose metabolism, and diabetes onset, but how islet endocrine cells interact with sensory neurons has not been studied. METHODS: We characterized the anatomical pattern of pancreatic sensory innervation by combining viral tracing, immunohistochemistry, and reporter mouse models. To assess the functional interactions of β-cells with vagal sensory neurons, we recorded Ca2+ responses in individual nodose neurons in vivo while selectively stimulating β-cells with chemogenetic and pharmacologic approaches. RESULTS: We found that pancreatic islets are innervated by vagal sensory axons expressing Phox2b, substance P, calcitonin-gene related peptide, and the serotonin receptor 5-HT3R. Centrally, vagal neurons projecting to the pancreas terminate in the commissural nucleus of the solitary tract. Nodose neurons responded in vivo to chemogenetic stimulation of β-cells and to pancreas infusion with serotonin, but were not sensitive to insulin. Responses to chemogenetic and pharmacologic stimulation of β-cells were blocked by a 5-HT3R antagonist and were enhanced by increasing serotonin levels in β-cells. We further confirmed directly in living pancreas slices that sensory terminals in the islet were sensitive to serotonin. CONCLUSIONS: Our study establishes that pancreatic β-cells communicate with vagal sensory neurons, likely using serotonin signaling as a transduction mechanism. Serotonin is coreleased with insulin and may therefore convey information about the secretory state of β-cells via vagal afferent nerves.
Authors: M Jimenez-Gonzalez; R Li; L E Pomeranz; A Alvarsson; R Marongiu; R F Hampton; M G Kaplitt; R C Vasavada; G J Schwartz; S A Stanley Journal: Nat Biomed Eng Date: 2022-07-14 Impact factor: 29.234
Authors: Jonathan Robert Weitz; Herve Tiriac; Tatiana Hurtado de Mendoza; Alexis Wascher; Andrew M Lowy Journal: Cancers (Basel) Date: 2021-10-05 Impact factor: 6.639