Proteomic profiling of Pachyonychia congenita plantar callus

Abstract

Callus samples from the ball and the arch of the foot, collected on tape circles, were compared by shotgun proteomic profiling. Pachyonychia congenita subjects were sampled who exhibited a mutation in KRT6A, KRT6B, KRT6C, KRT16 or KRT17, and the proteins were digested and analyzed by tandem mass spectrometry. In comparison with samples from unaffected control subjects, those from subjects with KRT6A or KRT16 mutations displayed the most differences in profile from normal, while those from subjects with KRT6C or KRT17 mutations showed few differences from normal. The profiles from subjects with KRT6B mutations were intermediate in protein profile differences. Degree of departure from the normal profile could be estimated by expression of numerous proteins in callus from the ball of the foot that were consistently different. By contrast, the protein profile from the arch of the foot was hardly affected. The results provide a foundation for noninvasive monitoring of the efficacy of treatments with quantitative assessment of departure from the normal phenotype.

Human stratum corneum proteomics reveals cross‐linking of a broad spectrum of proteins in cornified envelopes

“…Samples of epidermal squames were collected with CuDerm D110 D‐Squame Pro 2.2 cm adhesive circles from the forearms of 3 male and 3 female healthy individuals with informed consent (University of California Davis IRB#217868‐14) and eluted from the tapes as previously described . Some samples were processed with reduction and alkylation for mass spectrometry without fractionation, while others were separated into SDS‐dithioerythritol insoluble (envelope) and solubilized fractions .…”

“…Peptides were subjected to LC‐MS/MS analysis on a Thermo Scientific Q Exactive Plus Orbitrap mass spectrometer essentially as previously described . Intensity‐based absolute quantitation (iBAQ) values of samples analysed were used to calculate the relative molar amount of each protein .…”

Loricrin Confers Photoprotective Function against UVB in Corneocytes

“…Loricrin knockout (LKO) mice have impaired crosslinking of CE proteins (Rice et al, 2017), and total epidermal sheets were solubilized with a buffer containing sodium dodecyl sulfate and beta-mercaptoethanol to probe the FLG-repeat sequence (Yuspa et al, 1989) in the soluble protein fraction. As we previously described (Koch et al, 2000), LKO mice showed weaker signals in the monomeric 28-kDa FLG bands but stronger signals in the multimeric FLG bands (Figure 1a).…”

“…As we previously described (Koch et al, 2000), LKO mice showed weaker signals in the monomeric 28-kDa FLG bands but stronger signals in the multimeric FLG bands (Figure 1a). On the other hand, reflecting reduced gglutamyl lysine isopeptide crosslinks in the absence of LOR (Rice et al, 2017), SC from LKO mice showed smaller insoluble pellets compared with those from wild-type mice (Figure 1b). LKO mice showed higher amounts of both the monomeric and multimeric FLG bands compared with those from wildtype mice, as well as in the lowmolecular-weight bands that correspond to FLG breakdown peptides ( Figure 1c).…”

Corneocyte proteomics: Applications to skin biology and dermatology

“…[37, 38] Comparisons with samples from unaffected control subjects revealed the protein profiles were most altered in samples from individuals with KRT6 or KRT16 mutations, while those from KRT6C or KRT17 mutations displayed few protein alterations. [39] The degree of departure from normal generally fit the observed severity of the syndrome for the keratin gene categories. Although not clearly contributing to understanding the mechanism of pain generation, a debilitating symptom, the results do provide a quantitative basis for noninvasive monitoring of treatment effectiveness.…”