BCL-xL/BCL2L1 is a critical anti-apoptotic protein that promotes the survival of differentiating pancreatic cells from human pluripotent stem cells

• Published in: Cell death & disease Vol. 11; no. 5; p. 378
• Main Authors: Loo, Larry Sai Weng, Soetedjo, Andreas Alvin Purnomo, Lau, Hwee Hui, Ng, Natasha Hui Jin, Ghosh, Soumita, Nguyen, Linh, Krishnan, Vidhya Gomathi, Choi, Hyungwon, Roca, Xavier, Hoon, Shawn, Teo, Adrian Kee Keong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.05.2020; Springer Nature B.V
• Subjects: 13/100; 631/136/142; 631/532/1360; Antibodies; Apoptosis; Apoptosis - physiology; Bcl-2 protein; Bcl-x protein; bcl-X Protein - metabolism; Beta cells; Biochemistry; Bioenergetics; Biomedical and Life Sciences; Caspase 3 - metabolism; Cell Biology; Cell Culture; Cell differentiation; Cell Differentiation - physiology; Cell fate; Cell proliferation; Cell Proliferation - physiology; Gene expression; Glycolysis; Humans; Immunology; Life Sciences; Oxidative phosphorylation; Pancreas; Pancreatic Neoplasms - metabolism; Phenotypes; Phosphorylation; Pluripotency; Pluripotent Stem Cells - cytology; Pluripotent Stem Cells - metabolism; Proto-Oncogene Proteins c-bcl-2 - metabolism; Ribonucleic acid; RNA; Stem cells
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-020-2589-7

The differentiation of human pluripotent stem cells into pancreatic cells involves cellular proliferation and apoptosis during cell fate transitions. However, their implications for establishing cellular identity are unclear. Here, we profiled the expression of BCL-2 family of proteins during pancreatic specification and observed an upregulation of BCL-xL, downregulation of BAK and corresponding downregulation of cleaved CASP3 representative of apoptosis. Experimental inhibition of BCL-xL reciprocally increased apoptosis and resulted in a decreased gene expression of pancreatic markers despite a compensatory increase in anti-apoptotic protein BCL-2. RNA-Seq analyses then revealed a downregulation of multiple metabolic genes upon inhibition of BCL-xL. Follow-up bioenergetics assays revealed broad downregulation of both glycolysis and oxidative phosphorylation when BCL-xL was inhibited. Early perturbation of BCL-xL during pancreatic specification also had subsequent detrimental effects on the formation of INS + pancreatic beta-like cells. In conclusion, the more differentiated pancreatic progenitors are dependent on anti-apoptotic BCL-xL for survival, whereas the less differentiated pancreatic progenitors that survived after WEHI-539 treatment would exhibit a more immature phenotype. Therefore, modulation of the expression level of BCL-xL can potentially increase the survival and robustness of pancreatic progenitors that ultimately define human pancreatic beta cell mass and function.