1 research outputs found
Peptidomic Profiling of Secreted Products from Pancreatic Islet Culture Results in a Higher Yield of Full-length Peptide Hormones than Found using Cell Lysis Procedures
Peptide Hormone Acquisition through
Smart Sampling Technique-Mass
Spectrometry (PHASST-MS) is a peptidomics platform that employs high
resolution liquid chromatography–mass spectrometry (LC–MS)
techniques to identify peptide hormones secreted from <i>in vitro</i> or <i>ex vivo</i> cultures enriched in endocrine cells.
Application of the methodology to the study of murine pancreatic islets
has permitted evaluation of the strengths and weaknesses of the approach,
as well as comparison of our results with published islet studies
that employed traditional cellular lysis procedures. We found that,
while our PHASST-MS approach identified fewer peptides in total, we
had greater representation of intact peptide hormones. The technique
was further refined to improve coverage of hydrophilic as well as
hydrophobic peptides and subsequently applied to human pancreatic
islet cultures derived from normal donors or donors with type 2 diabetes.
Interestingly, in addition to the expected islet hormones, we identified
alpha-cell-derived bioactive GLP-1, consistent with recent reports
of paracrine effects of this hormone on beta-cell function. We also
identified many novel peptides derived from neurohormonal precursors
and proteins related to the cell secretory system. Taken together,
these results suggest the PHASST-MS strategy of focusing on cellular
secreted products rather than the total tissue peptidome may improve
the probability of discovering novel bioactive peptides and also has
the potential to offer important new insights into the secretion and
function of known hormones