Localization of the mRNA encoding prolyl endopeptidase in the rat brain and pituitary

Abstract

Prolyl endopeptidase (EC 3.4.21.26, PEP), a serine protease that hydrolyzes peptides at the carboxyl side of proline residues, is involved in the breakdown of several proline-containing neuropeptides and, thus, may contribute to the regulation of behavioral activities. In this study, the distribution of PEP mRNA was investigated in the central nervous system and pituitary of rat by means of quantitative reverse transcriptase-polymerase chain reaction analysis and in situ hybridization histochemistry. High densities of PEP transcripts were found in cerebellar Purkinje and granule cells, within most hypothalamic nuclei, in pyramidal neurons of the Ammon's horn, in granule cells of the dentate gyrus, and within the basolateral complex of the amygdala. Moderate levels of PEP mRNA were observed in layers 3-5 of the cerebral cortex, the anterior thalamic group, the septal region, the substantia nigra, the magnocellular neurons of the red nucleus, and the motor nuclei of the cranial nerves. Low concentrations of PEP mRNA were detected in the deep mesencephalic nuclei, the reticular formation, the pretectum, and the tectum. A high density of PEP mRNA was found in the intermediate and the anterior lobes of the pituitary, while the neural lobe was devoid of labeling. In several brain regions, the distribution pattern of PEP mRNA overlapped that of various neuropeptide receptors, suggesting that PEP is actually involved in the inactivation of regulatory neuropeptides.

Hypothalamic prolyl endopeptidase (PREP) regulates pancreatic insulin and glucagon secretion in mice

“…In the central nervous system, Prep mRNA was found in the hypothalamus (Fig. 1A), hippocampus, and cortex (5,6). Within the hypothalamus, higher expression of Prep mRNA was detected in the ventromedial nucleus (VMH) (Fig.…”

“…In humans and rodents it is highly expressed in the brain (2), including the cortex, striatum, hypothalamus, hippocampus, and amygdala (3)(4)(5)(6). The physiological role of PREP remains elusive (7).…”

Localization and subcellular distribution of prolyl oligopeptidase in the mouse placenta

“…However, the studies did not include the ovary and placenta for the assay and one report indicated that the ovary contained higher POP activity than the brain in the mouse (Ohta et al, 1992). In addition, many reports have suggested that POP enzymatic activity is not necessarily consistent with its mRNA level and protein amount (Bellemère et al, 2004;Garcia-Horsman et al, 2007;Irazusta et al, 2001;Myöhänen et al, 2007Myöhänen et al, , 2008a, possibly due to post-transcriptional or post-translational modifications or the existence of endogenous POP inhibitors (Salers, 1994;Soeda et al, 1985). Thus, what we can say from the current study is that at least in the mouse, POP mRNA is expressed at higher levels in the ovary and placenta than the brain.…”

VPAC2Receptors Mediate Vasoactive Intestinal Peptide-Induced Neuroprotection against Neonatal Excitotoxic Brain Lesions in Mice

“…In situ hybridization was performed as described previously (Bellemère et al, 2004). Briefly, sections were acetylated, treated with 0.2% Triton X-100 and covered with prehybridization buffer [50% formamide, 0.6 M NaCl, 10 mM Tris-HCl, pH 7.5, 0.02% Ficoll, 0.02% polyvinylpyrollidone, 0.02% bovine serum albumin (BSA), 1 mM EDTA, pH 8.0, 550 g/ml denatured salmon sperm DNA, and 50 g/ml yeast tRNA].…”