OMICS Analyses Unraveling Related Gene and Protein-Driven Molecular Mechanisms Underlying PACAP 38-Induced Neurite Outgrowth in PC12 Cells

Abstract

The study aimed to understand mechanism/s of neuronal outgrowth in the rat adrenal-derived pheochromocytoma cell line (PC12) under pituitary adenylate cyclase-activating polypeptide (PACAP) treatment. Neurite projection elongation was suggested to be mediated via Pac1 receptor-mediated dephosphorylation of CRMP2, where GSK-3β, CDK5, and Rho/ROCK dephosphorylated CRMP2 within 3 h after addition of PACAP, but the dephosphorylation of CRMP2 by PACAP remained unclear. Thus, we attempted to identify the early factors in PACAP-induced neurite projection elongation via omics-based transcriptomic (whole genome DNA microarray) and proteomic (TMT-labeled liquid chromatography-tandem mass spectrometry) analyses of gene and protein expression profiles from 5–120 min after PACAP addition. The results revealed a number of key regulators involved in neurite outgrowth, including known ones, called ‘Initial Early Factors’, e.g., genes Inhba, Fst, Nr4a1,2,3, FAT4, Axin2, and proteins Mis12, Cdk13, Bcl91, CDC42, including categories of ‘serotonergic synapse, neuropeptide and neurogenesis, and axon guidance’. cAMP signaling and PI3K-Akt signaling pathways and a calcium signaling pathway might be involved in CRMP2 dephosphorylation. Cross-referencing previous research, we tried to map these molecular components onto potential pathways, and we may provide important new information on molecular mechanisms of neuronal differentiation induced by PACAP. Gene and protein expression data are publicly available at NCBI GSE223333 and ProteomeXchange, identifier PXD039992.

The Potential of the Nose-to-Brain Delivery of PACAP for the Treatment of Neuronal Disease

“…Besides its neuroprotective effects, PACAP promotes brain repair through stimulation of neurogenesis, synaptic plasticity and angiogenesis [ 13 , 54 , 55 ]. This regenerative effect is essentially due to the ability of PACAP to stimulate the expression of genes such as brain-derived neurotrophic factor (BDNF), solute carrier family 16 member 7 (Slc16a7), neuronal differentiation 1 (NEUROD1), vascular endothelial growth factor A (VEGFA), homer scaffold protein 1 (HOMER 1), diazepam-binding inhibitor (DBI/ACBP), and sirtuin 3, as well as others [ 14 ].…”