Journal: bioRxiv
Article Title: Integration of Alzheimer’s GWAS, 3D genomics, and single-cell CRISPRi non-coding screen implicates causal variants in a microglial enhancer regulating TSPAN14
doi: 10.1101/2025.04.01.646442
Figure Lengend Snippet: a: Schematic of the screen. Three sgRNAs were designed to target each of 74 candidate regulatory regions (CREs) from our V2G mapping effort. We created a CRISPRi helper line expressing dCas9-KRAB in HMC3 cells and transduced it with a lentiviral pool of the sgRNAs at low MOI so that most cells would only receive a single perturbation. After selection and expansion, we performed scRNA-seq with 10x Genomics. Upon successful targeting of a CRE using CRISPRi, we anticipate RNA expression knockdown of the target gene. b, c, d: QQ plots from SCEPTRE differential expression analysis showing b ) good calibration, c) significant signal, and d ) volcano plot of the hits. These plots refer to the V2G “union” analysis. e , f , g : a candidate region containing three AD-associated SNPs (rs7080009, rs1870138, and rs1870137) regulates TSPAN14 expression in microglial but not in neuronal cells. CRISPRi ( e ) and CRISPRa ( f ) were performed in HMC3 cells stably expressing dCas9-KRAB and dCas9-VPR, respectively, via lentiviral delivery of three gRNAs targeting the region (T1, T2, and T3) and three non-targeting control guides (N1, N2, and N3). TSPAN14 expression was assessed by qPCR (N=3; bar plots show mean TSPAN14 expression with SEM error bars normalized to their respective control line with no guide. Significance by one-way ANOVA followed by pairwise t-test. ** P <5×10 −5 ; * P <0.05. A similar CRISPRi experiment was performed in the neuronal ReNcell VM line, showing no effect on TSPAN14 expression ( c ). P: a guide targeting TSPAN14 promoter was used as a positive control.
Article Snippet: The HiFi cloning approach (NEBuilder HiFi DNA Assembly Master Mix, cat# E2621S) was implemented to clone a PCR amplified TSPAN14 enhancer region encompassing rs7080009, rs1870138 and rs1870137 (hg19 coordinates: chr10:82,268,673-82,270,263, 1,591bp) in two different plasmids which would be used for dual luciferase reporter assays: pNL[Nlucp/minP/hygro] (Promega; custom-made) containing a minimal promoter (minP) and the Nanoluc reporter cassette (the pNL-minP plasmid), and pGL4.10[luc2] (Promega) containing the endogenous promoter of the TSPAN14 gene, which was digested out of a commercially available plasmid (Genecopoeia, cat# HPRM34820-PF02) using restriction endonucleases EcoRI (NEB, cat# R3101S) and SacI (NEB, cat# R3156S) (the resulting plasmid: pGL4.10-TSPAN14promoter), and the firefly luciferase reporter cassette (the resulting plasmid: pGL4.10-TSPAN14promoter/enhancer).
Techniques: Expressing, Selection, RNA Expression, Knockdown, Stable Transfection, Control, Positive Control