title: Dynamic Proteomic Analysis of Pancreatic Mesenchyme Reveals Novel Factors That Enhance Human Embryonic Stem Cell to Pancreatic Cell Differentiation.
abstract: Current approaches in human embryonic stem cell (hESC) to pancreatic beta cell differentiation have largely been based on knowledge gained from developmental studies of the epithelial pancreas, while the potential roles of other supporting tissue compartments have not been fully explored. One such tissue is the pancreatic mesenchyme that supports epithelial organogenesis throughout embryogenesis. We hypothesized that detailed characterization of the pancreatic mesenchyme might result in the identification of novel factors not used in current differentiation protocols. Supplementing existing hESC differentiation conditions with such factors might create a more comprehensive simulation of normal development in cell culture. To validate our hypothesis, we took advantage of a novel transgenic mouse model to isolate the pancreatic mesenchyme at distinct embryonic and postnatal stages for subsequent proteomic analysis. Refined sample preparation and analysis conditions across four embryonic and prenatal time points resulted in the identification of 21,498 peptides with high-confidence mapping to 1,502 proteins. Expression analysis of pancreata confirmed the presence of three potentially important factors in cell differentiation: Galectin-1 (LGALS1), Neuroplastin (NPTN), and the Laminin α-2 subunit (LAMA2). Two of the three factors (LGALS1 and LAMA2) increased expression of pancreatic progenitor transcript levels in a published hESC to beta cell differentiation protocol. In addition, LAMA2 partially blocks cell culture induced beta cell dedifferentiation. Summarily, we provide evidence that proteomic analysis of supporting tissues such as the pancreatic mesenchyme allows for the identification of potentially important factors guiding hESC to pancreas differentiation.
authors.affiliation: Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Holger A
authors.initials: HA
authors.lastname: Russ
authors.affiliation: Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA ; Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Limor
authors.initials: L
authors.lastname: Landsman
authors.affiliation: Bioinformatics and High-Throughput Analysis Laboratory and High-Throughput Analysis Core, Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, WA 98105, USA.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Moss
authors.affiliation: Bioinformatics and High-Throughput Analysis Laboratory and High-Throughput Analysis Core, Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, WA 98105, USA ; Predictive Analytics, Seattle Children's Hospital, Seattle, WA 98105, USA ; Data-Enabled Life Sciences Alliance (DELSA), Seattle, WA 98105, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Higdon
authors.affiliation: Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Renee L
authors.initials: RL
authors.lastname: Greer
authors.affiliation: Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Kaihara
authors.affiliation: Bioinformatics and High-Throughput Analysis Laboratory and High-Throughput Analysis Core, Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, WA 98105, USA.
authors.forename: Randy
authors.initials: R
authors.lastname: Salamon
authors.affiliation: Bioinformatics and High-Throughput Analysis Laboratory and High-Throughput Analysis Core, Center for Developmental Therapeutics, Seattle Children's Research Institute, Seattle, WA 98105, USA ; Predictive Analytics, Seattle Children's Hospital, Seattle, WA 98105, USA ; Data-Enabled Life Sciences Alliance (DELSA), Seattle, WA 98105, USA ; Department of Biomedical Informatics & Medical Education and Pediatrics, Medical School, University of Washington, Seattle, WA 98101, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kolker
authors.affiliation: Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hebrok