Poster #050, City of Hope
Spliced Xbp1 is essential for maintaining beta cell mass
Mentors: Lu Ding, PhD, PI: Yingfeng Deng, PhD
Islet β-cells secrete insulin to maintain glucose homeostasis, and a reduction in β-cell mass will lead to diabetes. β-cells are highly sensitive to endoplasmic reticulum (ER) stress due to constant insulin synthesis and secretion. The X-box binding protein spliced (Xbp1s), the most conserved unfolded protein response (UPR) transducer, helps cells restore ER homeostasis under ER stress. However, the exact change of β-cell mass in Xbp1s knockout mice (Xbp1sKO) remains unknown. Here, we performed immunofluorescence staining for insulin (β-cells), glucagon (α-cells), Ki67 (cell proliferation), and TUNEL (apoptosis), followed by image analysis using ImageJ to quantify β-cell mass, β-cell-to-α-cell ratio, β-cell proliferation, and β-cell apoptosis in WT, Het and Xbp1sKO mice. These analyses allow us to determine the role of Xbp1s in regulating β-cell mass by looking at cell differentiation, proliferation, and apoptosis. We anticipate that these results will complement ongoing research involving the prevention of diabetes.