Identification and quantification of neuropeptides in naïve mouse spinal cord using mass spectrometry reveals [des-Ser1]-cerebellin as a novel modulator of nociception

Authors

  • Jie Su,

    1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
    Search for more papers by this author
    • These authors contributed equally to this work.
  • Katalin Sandor,

    1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
    Search for more papers by this author
    • These authors contributed equally to this work.
  • Karl Sköld,

    1. Research and Development, Denator AB, Uppsala, Sweden
    2. Department of Medical Sciences, Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
    Search for more papers by this author
  • Tomas Hökfelt,

    1. Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
    Search for more papers by this author
  • Camilla I. Svensson,

    1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
    Search for more papers by this author
  • Kim Kultima

    Corresponding author
    1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
    2. Department of Medical Sciences, Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
    • Address correspondence and reprint requests to Dr Kim Kultima, Department of Medical Sciences, Uppsala University, Akademiska sjukhuset, 3tr, SE-751 85 Uppsala, Sweden, E-mail: Kim.Kultima@medsci.uu.se

    Search for more papers by this author

Abstract

Neuropeptide transmitters involved in nociceptive processes are more likely to be expressed in the dorsal than the ventral horn of the spinal cord. This study was designed to examine the relative distribution of neuropeptides between the dorsal and ventral spinal cord in naïve mice using liquid chromatography, high-resolution mass spectrometry. We identified and relatively quantified 36 well-characterized full-length neuropeptides and an additional 168 not previously characterized peptides. By extraction with organic solvents we identified seven additional full-length neuropeptides. The peptide [des-Ser1]-cerebellin (desCER), originating from cerebellin precursor protein 1 (CBLN1), was predominantly expressed in the dorsal horn. Immunohistochemistry showed the presence of CBLN1 immunoreactivity with a punctate cytoplasmic pattern in neuronal cell bodies throughout the spinal gray matter. The signal was stronger in the dorsal compared to the ventral horn, with most CBLN1 positive cells present in outer laminae II/III, colocalizing with calbindin, a marker for excitatory interneurons. Intrathecal injection of desCER induced a dose-dependent mechanical hypersensitivity but not heat or cold hypersensitivity. This study provides evidence for involvement of desCER in nociception and provides a platform for continued exploration of involvement of novel neuropeptides in the regulation of nociceptive transmission.

image

Neuropeptides involved in nociceptive processes are more likely to be expressed in the dorsal than the ventral horn of spinal cord. Well-characterized full-length neuropeptides as well as uncharacterized neuropeptides were quantified by mass spectrometry. The CBLN1-derived peptide [des-Ser1]-cerebellin (desCER) is predominantly expressed in the dorsal horn, and intrathecal injection of desCER induced a dose-dependent mechanical hypersensitivity.

Ancillary