Single Cell Rna-Sequencing Dissects Proliferation Of Pancreatic Beta Cells

Background: The decreasing pancreatic beta cell mass in patients with type 2 diabetes mellitus is a critical problem and increasing the beta cell mass would be one of the strategies for its treatment. However, little is known about the mechanism of beta cell proliferation in adult. In addition, since pancreatic beta cells are heterogeneous and proliferating beta cells are in a small population, the analysis using bulk pancreatic islets has limitations. To clarify the further molecular mechanism of beta cell proliferation, we addressed the gene regulation of proliferating beta cells at single cell level. Methods: Young (8 weeks) and old (1 year) C57BL/6 mice were performed partial pancreatectomy (PPTx), and conducted 3 analyses; 1) immunohistochemistry for proliferating beta cells with BrdU staining, 2) conventional bulk RNA-sequencing (bulk RNA-seq) of isolated pancreatic islets from young or old mice with PPTx or without PPTx (control) to examine the impact of aging and stimulation by resection, 3) single cell RNA-seq to highlight gene expression profiles of proliferating beta cells. Results: In young mice, the proliferation of beta cells was highly induced by PPTx. On the contrary, the proliferation in old PPTx mice was much less than young PPTx. The bulk RNA-seq followed by gene ontology analysis demonstrated that genes related to DNA replication and cell cycle regulation were specifically up-regulated in young PPTx. The scRNA-seq could sort beta cells with Ins1 and Ins2 expression from the other endocrine cells like alpha, delta and PP cells, and identified the cells with high expressions of Pcna and Ccnb1 in the beta cells. By the motif analysis, we further identified candidate transcription factors that activate genes specific for the proliferating cells. Conclusion: We found genes specific for proliferating beta cells and identified candidate regulators to activate the proliferation of beta cells. Disclosure H. Tatsuoka: None. D. Yabe: Advisory Panel; Self; Abbott. Research Support; Self; Astellas Pharma Inc. Speaker's Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Eli Lilly and Company, Merck Sharp & Dohme Corp., Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi K.K., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited. S. Sakamoto: None. A. Watanabe: None. R. Usui: None. S. Tokumoto: None. A. Botagarova: None. D. Ootani: None. H. Goto: None. M. Fauzi: None. M. Ogura: Research Support; Self; Takeda Pharmaceutical Company Limited. Speaker's Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Daiichi Sankyo Company, Limited, Eli Lilly and Company, Kyowa Hakko Kirin Co., Ltd., Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi, Takeda Pharmaceutical Company Limited. N. Inagaki: Research Support; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Japan Tobacco Inc., Kyowa Hakko Kirin Co., Ltd., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Ono Pharmaceutical Co., Ltd., Sanofi, Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited.