Quantitative Characterization of the Neuropeptide Level Changes in Dorsal Horn and Dorsal Root Ganglia Regions of the Murine Itch Models

Abstract

Chronic itch can be extremely devastating and, in many cases, difficult to treat. One challenge in treating itch disorders is the limited understanding of the multitude of chemical players involved in the communication of itch sensation from the peripheral to the central nervous system. Neuropeptides are intercellular signaling molecules that are known to be involved in the transmission of itch signals from primary afferent neurons, which detect itch in the skin, to higher-order circuits in the spinal cord and brain. To investigate the role of neuropeptides in transmitting itch signals, we generated two mouse models of chronic itchAcetone–Ether–Water (AEW, dry skin) and calcipotriol (MC903, atopic dermatitis). For peptide identification and quantitation, we analyzed the peptide content of dorsal root ganglia (DRG) and dorsal horn (DH) tissues from chronically itchy mice using liquid chromatography coupled to tandem mass spectrometry. De novo-assisted database searching facilitated the identification and quantitation of 335 peptides for DH MC903, 318 for DH AEW, 266 for DRG MC903, and 271 for DRG AEW. Of these quantifiable peptides, we detected 30 that were differentially regulated in the tested models, after accounting for multiple testing correction (q ≤ 0.1). These include several peptide candidates derived from neuropeptide precursors, such as proSAAS, protachykinin-1, proenkephalin, and calcitonin gene-related peptide, some of them previously linked to itch. The peptides identified in this study may help elucidate our understanding about these debilitating disorders. Data are available via ProteomeXchange with identifier PXD015949.

Sarkoidozlu hastalarda plazma protaşikinin-1 (TAC1) düzeyleri

“…peptides, such as proenkephalin-A, proSAAS, protein AF1q, secretogranin-1, thioredoxin and calcitonin gene-related peptide have been detected at measurable level so far, one of which is TAC1 [16]. In the present study, plasma TAC1 levels of sarcoidosis patients and healthy control subjects were found as 1124.25±1117.25 ng/L, 1319.37±1357.38 ng/L, respectively.…”

Mass Spectrometry Measurements of Neuropeptides: From Identification to Quantitation

“…Here, quantitation is performed at the MS1 level and the area of the peptide XIC is compared across replicates (53). This method of untargeted NP quantitation has been employed by various groups to study NP profiles in different physiological models, including migraine, chronic itch, and feeding behavior (26,54,55). generated by searching Orbitrap-tandem MS (MS/MS) results for pooled tissues against a peptide database.…”