Peptidomic Identification and Biological Validation of Neuroendocrine Regulatory Peptide-1 and -2

Abstract

Recent advances in peptidomics have enabled the identification of previously uncharacterized peptides. However, sequence information alone does not allow us to identify candidates for bioactive peptides. To increase an opportunity to discover bioactive peptides, we have focused on C-terminal amidation, a post-translational modification shared by many bioactive peptides. We analyzed peptides secreted from human medullary thyroid carcinoma TT cells that produce amidated peptides, and we identified two novel amidated peptides, designated neuroendocrine regulatory peptide (NERP)-1 and NERP-2. NERPs are derived from distinct regions of the neurosecretory protein that was originally identified as a product of a nerve growth factorresponsive gene in PC12 cells. Mass spectrometric analysis of the immunoprecipitate using specific antibodies as well as reversed phase-high performance liquid chromatography coupled with radioimmunoassay analysis of brain extract demonstrated the endogenous presence of NERP-1 and NERP-2 in the rat. NERPs are abundant in the paraventricular and supraoptic nuclei of the rat hypothalamus and colocalized frequently with vasopressin but rarely with oxytocin. NERPs dose-dependently suppressed vasopressin release induced by intracerebroventricular injection of hypertonic NaCl or angiotensin II in vivo. NERPs also suppressed basal and angiotensin II-induced vasopressin secretion from hypothalamic explants in vitro. Bioactivity of NERPs required C-terminal amidation. Anti-NERP IgGs canceled plasma vasopressin reduction in response to water loading, indicating that NERPs could be potent endogenous suppressors of vasopressin release. These findings suggest that NERPs are novel modulators in body fluid homeostasis.

Chronic intracerebroventricular injection of TLQP-21 prevents high fat diet induced weight gain in fast weight-gaining mice

“…Upon processing by the neuroendocrine-specific prohormone convertases PC1/3 and PC2, VGF may yield a number of peptides that are stored in dense core granules and secreted through regulated pathways [66]. Up to now, six VGFpeptides were shown to modulate with a remarkable peptide-specific selectivity, a diverse range of biological functions such as synaptic plasticity, apoptosis, sexual antidepressant-like behavior and inflammatory pain [2,7,10,11,35,37,58,63,64,65,70].…”

Selective expression of TLQP-21 and other VGF peptides in gastric neuroendocrine cells and modulation by feeding

“…In cells and tissues, proteolytic processing yields diverse peptides, including some of low MW, which were preferentially released by various stimuli (Possenti et al 1989, Trani et al 1995. These include peptides encompassing the VGF C-terminal portion, TLQP-21 and TLQP-62 peptides, and the recently identified peptides NERP-1 and -2 (Trani et al 2002, Bartolomucci et al 2007, Yamaguchi et al 2007, Bozdagi et al 2008. While vgf gene expression is distinctly modulated in multiple models and conditions (Levi et al 2004), differential processing and modulation of VGF peptides have been shown so far in the pituitary (Brancia et al 2005), adrenal glands (D'Amato et al 2008) and pancreas (Cocco et al 2007).…”

“…The vgf gene (non-acronymic) and its peptide products are proposed neuroendocrine regulators affecting food intake and/or energy balance (Salton et al 2000, Levi et al 2004, as well as other functions including water balance (Yamaguchi et al 2007).…”

The Cannabinoid CB1/CB2 Agonist WIN55212.2 Promotes Oligodendrocyte Differentiation In Vitro and Neuroprotection During the Cuprizone‐Induced Central Nervous System Demyelination

“…Vgf is a component of the chromogranin/secretogranin family 47, 48 actively involved in amyotrophic lateral sclerosis (ALS) neuroprotection 49. Because it is described that declined levels of this bioactive peptide (Vgf) could promote neurodegeneration 50, further investigation of these aspects is required.…”