(747.5) Mapping and specific viral targeting of peripheral pancreatic innervation

Poster Board Number: E394

Maria Jimenez Gonzalez (Icahn School of Medicine at Mount Sinai), Rosemary Li (Icahn School of Medicine at Mount Sinai), Lisa Pomeranz (Rockefeller University), Alexandra Alvarsson (Icahn School of Medicine at Mount Sinai), Roberta Marongiu (Weill Cornell Medicine), Rollie Hampton (Icahn School of Medicine at Mount Sinai), Rupangi Vasavada (City of Hope), Gary Schwartz (Albert Einstein College of Medicine), Sarah Stanley (Icahn School of Medicine at Mount Sinai)

Neuronal inputs from central nervous system (CNS) are essential in regulating pancreatic endocrine function. It has been shown that perturbation of CNS activity alters pancreatic hormone release. CNS and peripheral organs constantly communicate through the peripheral nervous system (PNS), which can be divided into autonomic efferent (parasympathetic and sympathetic) and afferent sensory nervous systems. While we know that the pancreas is densely innervated by the PNS, we lack a comprehensive map of peripheral ganglia providing inputs to the pancreas. These data could provide crucial information about pancreatic function. Published studies suggest parasympathetic inputs to the pancreas lower blood glucose by enhancing insulin secretion. On the other hand, sympathetic action results in increased blood glucose levels by stimulating glucagon secretion and inhibiting insulin.  However, these studies are based on electrical stimulation or transection of peripheral splachnic and vagal nerves that may affect the activity of other metabolically active organs (liver,stomach, intestine,). Highly targeted modulation of specific pancreatic nerve activity in health and pancreatic diseases requires new approaches.

In the present project, we provide a detailed map of the distribution of peripheral pancreas-innervating neurons using retrograde tracing, tissue clearing and 3D imaging techniques (Idisco+). We show that a substantial pancreatic innervation (Fig 1b) with significant neuronal populations in sympathetic, parasympathetic and sensory ganglia projecting to pancreatic tissue (Fig 1 c,d). In addition, we achieved targeted gene delivery to specific pancreatic efferent and afferent pathways by optimizing adeno-associated viral serotypes (AAV), promoters, titers and delivery (Fig2 a-d). By utilizing our optimized approach, we show that highly targeted chemogenetic neural activation of intrapancreatic parasympathetic cholinergic neurons increased plasma insulin and significantly improved glucose tolerance in male mice (Fig 2 e,f). Additionally, using a dual viral strategy to specifically target pancreas-projecting sympathetic neurons, we demonstrated that targeted activation of pancreas-projecting sympathetic neurons impaired glucose tolerance in male mice (Fig 2g,h).

Our innovative viral approaches allow highly targeted gene expression and neuromodulation of defined pancreatic nerves. These methodologies will allow examination of functional roles of pancreatic parasympathetic and sympathetic innervation in glucose metabolism as well as in digestion (exocrine function). Our work also allow for future studies to determine the specific contribution of pancreatic innervation to metabolic diseases, pancreatic inflammation and cancer.

Support or Funding Information

AA is supported by the Charles H. Revson Foundation (Grant No. 18-25) and a postdoctoral scholarship from Swedish Society for Medical Research (SSMF). RFH is supported in part by NIH Training Grant 32 T32GM007280. This work was supported by the American Diabetes Association Pathway to Stop Diabetes Grant 33 ADA #1-17-ACE-31, and in part by grants from the National Institutes of Health (R01NS097184, OT2OD024912), Department of Defense (W81XWH-20-1-0345 and Discovery Award # W81XWH-20-1-0156) and Alexander and Alexandrine Sinsheimer Scholar Award.

AA is supported by the Charles H. Revson Foundation (Grant No. 18-25) and a postdoctoral scholarship from Swedish Society for Medical Research (SSMF). RFH is supported in part by NIH Training Grant 32 T32GM007280. This work was supported by the American Diabetes Association Pathway to Stop Diabetes Grant 33 ADA #1-17-ACE-31, and in part by grants from the National Institutes of Health (R01NS097184, OT2OD024912), Department of Defense (W81XWH-20-1-0345 and Discovery Award # W81XWH-20-1-0156) and Alexander and Alexandrine Sinsheimer Scholar Award.





Mapping of the pancreas peripheral innervation .a) Scheme. DRG: Dorsal Root Ganglia, CG: Coeliac Ganglia, NG: Nodose ganglia, IPG: Intrapancreatic Ganglia. B) Mouse pancreas cleared,  sympathetic marker TH (Tyrosine Hydroxilase), parasympathetic marker vAChT (vesicular acetylcholine transporter) and INS (insulin). c) Cholera toxin β (CTβ) labelled pancreas-projecting neurons in cleared peripheral ganglia after intrapancreatic injections of CTβ. d) Quantification of CTβ+  neurons  per ganglia.; a) CG mCherry+ neurons, after intrapancreatic injection of AAV(9, 8, 6,rg). b) mCherry+  quantification c) AAV serotypes in IPG d) Quantification. e) Chemogenetic AAV8-hSyn-DIO-hM3Gq-mCherry in Chat-CRE mice.  mCherry+ in IPG. f) Activation of cholinergic neurons (CNO, ip) improves glucose tolerance in Gq  and enhances insulin secretion. g) Dual injection to target pancreatic CG sympathetic neurons. h) mCherry+ expression. Sympathetic activation impairs glucose tolerance in Gq.