Obesity is a common, serious, and costly disease that affects 33% of US citizens and 37% of VA patients. Although therapeutic treatments remain elusive, recent scientific evidence has pointed to enteroendocrine cells - sensory cells of the gut - as potential solutions. These cells are known to secrete several neuropeptides that are potent inducers of satiety, like cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), and their sensory mechanisms have been the subject of intensive investigation. However, how these cells transduce their sensory signals onto neurons and other cells is largely unknown. We recently developed novel transgenic mouse models to study these cells by expressing enhanced green fluorescent protein (eGFP) in CCK- or PYY-containing cells. The eGFP models allowed us to discover that enteroendocrine cells have prominent basal cytoplasmic processes with similar features to neuronal axons. These basal cytoplasmic processes, we found, directly connect to neuronal afferents and efferents innervating the gut mucosa. The present proposal is designed to elucidate the function of this connection. Our central hypothesis is that basal cytoplasmic processes are essential in the exchange of molecular information between enteroendocrine cells and sensory neurons. This hypothesis is built on preliminary data produced in the PI's laboratory and will be tested by pursuing the following specific aims: ? Aim 1 is to characterize the connection between enteroendocrine cells and sensory neurons ? Aim 2 is to determine how the formation of enteroendocrine cell cytoplasmic processes is regulated ? Aim 3 is to define the effects of diet-induced obesity on the neuro-enteroendocrine connection We anticipate that the characterization of gut neuroendocrine signaling will facilitate the development of strategies to modulate the transmission of sensory information from enteroendocrine cells to neurons and vice versa. Because these sensory signals ultimately participate in the regulation of food intake and appetite, elucidating the mechanisms that regulate this connection can provide novel therapeutic approaches to treat obesity.

Public Health Relevance

Obesity is a common, serious, and costly disease that affects 33% of US citizens and 37% of VA patients. Recent evidence has pointed to enteroendocrine cells - sensory cells of the gut - as potential solutions. These cells secrete neuropeptides [e.g., cholecystokinin (CCK) and peptide YY (PYY)] that are potent inducers of satiety, and their sensory mechanisms have been the subject of intensive investigation. However, how these cells communicate with other cells is largely unknown. We recently discovered that CCK and PYY cells have unique cellular processes that extend to neurons in the gut. We believe these processes allow enteroendocrine cells to communicate with neurons through direct cell-to-cell synaptic connections. We anticipate that characterization of gut neuroendocrine signaling will facilitate the development of strategies to regulate food intake and ultimately provide novel approaches to treat obesity.

Agency
National Institute of Health (NIH)
Institute
Veterans Affairs (VA)
Type
Non-HHS Research Projects (I01)
Project #
1I01BX002230-01A1
Application #
8635645
Study Section
Gastroenterology (GAST)
Project Start
2014-04-01
Project End
2018-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
1
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Durham VA Medical Center
Department
Type
DUNS #
City
Durham
State
NC
Country
United States
Zip Code
27705
Romac, Joelle M-J; Shahid, Rafiq A; Swain, Sandip M et al. (2018) Piezo1 is a mechanically activated ion channel and mediates pressure induced pancreatitis. Nat Commun 9:1715
Liddle, Rodger A (2018) Parkinson's disease from the gut. Brain Res 1693:201-206
Ye, Lihua; Liddle, Rodger A (2017) Gastrointestinal hormones and the gut connectome. Curr Opin Endocrinol Diabetes Obes 24:9-14
Morozko, Eva L; Nishio, Ayako; Ingham, Neil J et al. (2015) ILDR1 null mice, a model of human deafness DFNB42, show structural aberrations of tricellular tight junctions and degeneration of auditory hair cells. Hum Mol Genet 24:609-24
Bohórquez, Diego; Haque, Fariha; Medicetty, Satish et al. (2015) Correlative Confocal and 3D Electron Microscopy of a Specific Sensory Cell. J Vis Exp :e52918
Bohórquez, Diego V; Shahid, Rafiq A; Erdmann, Alan et al. (2015) Neuroepithelial circuit formed by innervation of sensory enteroendocrine cells. J Clin Invest 125:782-6
Bohórquez, Diego V; Liddle, Rodger A (2015) The gut connectome: making sense of what you eat. J Clin Invest 125:888-90
Bohórquez, Diego V; Samsa, Leigh A; Roholt, Andrew et al. (2014) An enteroendocrine cell-enteric glia connection revealed by 3D electron microscopy. PLoS One 9:e89881
La Sala, Michael S; Hurtado, Maria D; Brown, Alicia R et al. (2013) Modulation of taste responsiveness by the satiation hormone peptide YY. FASEB J 27:5022-33