Pseudotime Ordering Single-Cell Transcriptomic ofβCells Pancreatic Islets in Health and Type 2 Diabetes

βcells are defined by the ability to produce and secret insulin.Recent studies have evaluated that human pancreaticβcells are heterogeneous and demonstrated the transcript alterations ofβcell subpopulation in diabetes.Single-cell RNA sequence(scRNA-seq)analysis helps us to refine the cell types signatures and understand the role of theβcells during metabolic challenges and diseases.Here,we construct the pseudotime trajectory ofβcells from publicly available scRNA-seq data in health and type 2 diabetes(T2D)based on highly dispersed and highly expressed genes using Monocle2.We identified three major states including 1)Normal branch,2)Obesity-like branch and 3)T2D-like branch based on biomarker genes and genes that give rise to bifurcation in the trajectory.βcell function-maintain-related genes,insulin expression-related genes,and T2D-related genes enriched in three branches,respectively.Continuous pseudotime spectrum might suggest thatβcells transition among different states.The application of pseudotime analysis is conducted to clarify the different cell states,providing novel insights into the pathology ofβcells in T2D.