Multiomic deep delve of synthesis and secretion processes in a model peptidergic system

Abstract

The cell bodies of hypothalamic magnocellular neurones are densely packed in the hypothalamic supraoptic nucleus (SON) whereas their axons project to the anatomically discrete posterior pituitary gland. We have taken advantage of this unique anatomical structure to establish proteome and phosphoproteome dynamics in neuronal cell bodies and axonal terminals in response to physiological stimulation. We have found that proteome and phosphoproteome responses are very different between somatic and axonal neuronal compartments, indicating the need of each cell domain to differentially adapt. In particular, changes in the phosphoproteome in the cell body are involved in the reorganisation of the cytoskeleton and in axonal terminals the regulation of synaptic and secretory processes. We have identified that prohormone precursors including vasopressin and oxytocin are phosphorylated in axonal terminals and become hyperphosphorylated following stimulation. By multi-omic integration of transcriptome and proteomic data we identify changes to proteins present in afferent inputs to this nucleus.

Isoflurane Rapidly Modifies Synaptic and Cytoskeletal Phosphoproteomes of the Supraoptic Nucleus of the Hypothalamus and the Cortex

“…The phosphorylation state change (ΔPs) value calculation was performed as described [17, 21]. Briefly, the ΔPs values for protein isoforms encoded by the same gene were determined by the sum of log2FC of all phosphorylated peptides with statistically significant changes (FDR <0.05) in both CC and SON when comparing the control and isoflurane-treated groups.…”

“…Phosphoproteome analysis by nano-LC mass spectrometry (LC-MS/MS) and data processing were performed at the Bristol Proteomics Facility, University of Bristol as described [17]. Statistical significance was determined using Welch's T tests between the conditions of interest.…”

Osmoadaptive GLP-1R signalling in hypothalamic neurones inhibits antidiuretic hormone synthesis and release

“…We show that WD does not increase Fos expression in Gcg neurones in the NTS compared to control and rehydration, rather expression appeared to decrease ( Figure 4 F). In our recent SON proteomics study GCG abundance was similarly not altered by WD ([ 52 ], Figure 4 G). This is consistent with the decrease to Gcg expression.…”