Developing a model to assess the contribution of cytokeratin 19-expressing cells during multipotent stromal cell-induced islet regeneration
Abstract
Previously, pharmacological activation of Wnt-signaling in human bone marrow-derived multipotent stromal cells (hMSC) generated conditioned media (CM) that promoted β-cell regeneration in streptozotocin-treated mice. Ductal-derived endocrine progenitors, which have been shown to generate β-cells following pancreatic injury, represent a candidate for the ‘signal-receiving cell’. Ductal (CK19+) cells from mice pancreata obtained by purification of live Dolichos Biflorus Agglutinin lectin+ cells and cultured in minimal media supplemented with Untreated, Wnt-activated, or Wnt-inhibited CM demonstrated a significantly increased proportion of EdU+/CK19+ cells following 48-hours of supplementation but no endocrine phenotype acquisition. Lineage-tracing CK19-CreERT;Ai9(RCL-tdT) mice treated with tamoxifen (single dose) demonstrated specific labeling of pancreatic CK19+ cells. Streptozotocin treatment (60 mg/kg/day, 5 days) resulted in decreased β-cell mass, islet density, and insulin+ cell frequency, as well as impaired glucose tolerance and increased pancreatic leukocyte infiltration. This model will be used in future studies to lineage-trace CK19+ cell contribution during hMSC CM-induced islet regeneration.