Quantitative Top-Down Mass Spectrometry Identifies Proteoforms Differentially Released during Mechanical Stimulation of Mouse Skin

Mechanotransduction refers to the
processes whereby mechanical
stimuli are converted into electrochemical signals that allow for
the sensation of our surrounding environment through touch. Despite
its fundamental role in our daily lives, the molecular and cellular
mechanisms of mechanotransduction are not yet well-defined. Previous
data suggest that keratinocytes may release factors that activate
or modulate cutaneous sensory neuron terminals, including small molecules,
lipids, peptides, proteins, and oligosaccharides. This study presents
a first step toward identifying soluble mediators of keratinocyte-sensory
neuron communication by evaluating the potential for top-down mass
spectrometry to identify proteoforms released during 1 min of mechanical
stimulation of mouse skin from naı̈ve animals. Overall,
this study identified 47 proteoforms in the secretome of mouse hind
paw skin, of which 14 were differentially released during mechanical
stimulation, and includes proteins with known and previously unknown
relevance to mechanotransduction. Finally, this study outlines a bioinformatic
workflow that merges output from two complementary analysis platforms
for top-down data and demonstrates the utility of this workflow for
integrating quantitative and qualitative data.