Innervation of adult kidney (Human and mouse)
We plan to identify genes that are expressed in sensory nerves that innervate the kidney and determine the identity and cellular diversity of kidney specific sensory neurons. We will further use 3D high resolution imaging on human and mouse kidney thick sections to understand the relationship between sensory and motor nerve fibers with their distinct target sites in kidney cell types. Peripheral sensory neuropathy and autonomic neuropathy are well recognized sequelae of diabetic neuropathy. Diabetes is one of the most common cause of kidney failure. Is kidney a target site of diabetic neuropathy that could explain progressive kidney failure? If so knowledge of genes important in kidney innervation and thereby interacting with kidney parenchyma will be critical to gain insights into the role of kidney nerves in chronic kidney disease and insights into designing drugs for modulating the regulation of kidney nervous system and homeostasis. The molecular identity of sensory neurons involved in cross talk with kidney in healthy and disease states are not known due to limited availability in humans and technically challenging in model systems. We will generate high depth single cell transcription data using FACS-seq of retrogradely labeled kidney projecting sensory neurons from dorsal root ganglia and nodose ganglia. Kidneys will be injected with retrograde tracer, labeled neurons collected by FACS and subjected to plate-based sequencing using methods we have developed. After quality check with key nociceptive markers we will determine neuronal diversity, enrichment of kidney neurons genes compared to non kidney innervating sensory neurons, potential heterotypic interactions with kidney parenchyma and validate 3 most enriched kidney sensory genes. Using a panel of neurochemical, neurotrophic growth factor receptor antibodies and genetically labeled nociceptors determine types of renal nerve fibers and their target innervation sites using 3D high resolution microscopy on adult human kidney tissue. With this as a bench mark, future dues in diabetic nephropathy will be done to understand the relationship between the kidney nerves and different stages of diabetic kidney disease.