Isabella Melena

Program: Molecular Cell Biology

Current advisor: Jing W. Hughes, MD, PhD

Undergraduate university: Drury University, 2019

Enrollment year: 2022

Research summary
The primary cilium is a sensory and signaling organelle on the surface of eukaryotic cells, responsive to a wide range of extracellular inputs. Our lab focuses on ciliary control of hormone secretion from the islet of Langerhans.

The primary cilium is a sensory and signaling organelle on the surface of eukaryotic cells, responsive to a wide range of extracellular inputs. The ciliary membrane sequesters a very specific pool of signaling proteins, including G protein coupled receptors (GPCRs) and tyrosine kinase family receptors. These receptors are coupled to ion channels and adenylyl cyclases that upon agonist activation trigger local Ca2+ and cAMP influxes that send signals to the cell body. Studies in kidney cells and neurons have shown that cells interpret ciliary versus extraciliary signals differently and primary cilia are viewed as an essential signaling microdomain. This model is untested in pancreatic islets. Our lab published the seminal study showing that primary cilia regulate beta cell insulin secretion from pancreatic islets via islet paracrine signaling. Our current research seeks to understand the mechanisms of primary cilia control of paracrine signaling in pancreatic islets.

Graduate publications
Sviben S, Polino AJ, Melena IL, Hughes JW. 2024 Immuno-scanning electron microscopy of islet primary cilia. J Cell Sci, 137(20)::jcs262038. PMCID: PMC11166453

Bjornstad P, Choi YJ, Platnick C, Gross S, Narongkiatikhun P, Melena I, Remmers L, Baca M, Schutte G, Dobbs T, Vigers T, Pyle L, Driscoll L, Tommerdahl K, Kendrick J, Looker HC, Dart A, Cherney D, van Raalte DH, Srivastava A, Li L, Prasad P, Saulnier P, Nelson RG, Johnson RJ, Nadeau KJ; Bjornstad Lab. 2024 Insulin Secretion, Sensitivity, and Kidney Function in Young Individuals With Type 2 Diabetes. Diabetes Care, 47(3):409-17. PMCID: PMC10909687

Polino AJ, Sviben S, Melena I, Piston DW, Hughes JW. 2023 Scanning electron microscopy of human islet cilia. Proc Natl Acad Sci USA, 120(22):e2302624120. PMCID: