CD99 as surface anchor for human islet endocrine cell purification.

Rat and human beta cell proteomes were quantified by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), searching for cell surface markers. In human beta cells, CD99 (cluster of differentiation 99) was ranked among the plasma membrane proteins that combine a high molar abundance with a relative degree of selectivity for the endocrine cells of the islets of Langerhans. Therefore, the applicability of CD99 as anchor for islet endocrine cell purification was investigated.

Potential of UCHL1 as biomarker for destruction of pancreatic beta cells.

Unlabelled: There is a clinical need for plasma tests for real-time detection of beta cell destruction, as surrogate endpoint in islet transplantation and immunoprevention trials in type 1 diabetes. This study reports on the use of label-free LC-MS/MS proteomics for bottom-up selection of candidate biomarkers. Ubiquitin COOH-terminal hydrolase 1 (UCHL1) was identified as abundant protein in rat and human beta cells, showing promising beta cell-selectivity, and was selected for further validation in standardized toxicity models.