Type 1 Diabetes Risk Variants Alter the Transcriptional Profile of Beta Cells

GWAS studies have identified a number of SNPs connected to the development of type 1 diabetes (T1D). It is unclear how these variants confer risk for T1D development and whether this is based on direct effects on the beta cell, or whether the systemic inflammatory environment is detrimental to the beta cell. Using CRISPR mediated homology directed repair (Life Technologies), T1D risk variants rs10517086 and rs1534422 were introduced into the BRIN-BD11 beta cell line and the Jurkat T-cell line. Experiments were conducted in BRIN-BD11 cells expressing each variant and in native BRIN-BD11 cells treated with conditioned media from Jurkat cells expressing each variant. ApoTox GloTM (Promega) was used to assess cell viability, cytotoxicity and apoptosis. In all instances, cell viability and cytotoxicity were unchanged following the introduction of the two variants. However, rs1534422 significantly (P<0.01) increased apoptosis in BRIN-BD11 cells. This was not observed when BRIN-BD11 cells were treated with Jurkat condition media. In all instances, modest reductions (P<0.05) in glucose-stimulated insulin secretion were observed (Insulin ELISA, Mercodia). Expression of beta cell markers (ABCC8, KCNJ11, KCNQ1, SCL2A2, GCK, HNF1A, PDX1, NKX6.1 NGN3) was examined by qPCR (Roche Lightcycler). Irrespective of whether BRIN-BD11 cells were exposed to Jurkat conditioned media or not, induction of rs10517086 or rs1534422 caused significant (P<0.05-0.001) reductions in the expression of all genes examined with two exceptions: both HNF1A and ABCC8 were significantly upregulated (P<0.001). The transcriptional profiles of BRIN-BD11 cells were remarkably similar regardless of whether rs10517086 and rs1534422 were directly induced in BRIN-BD11 cells or whether they were exposed to conditioned media from Jurkat cells expressing the variants. This suggests that soluble secreted factors arising from the expression of these variants may drive the changes observed in the function of BRIN-BD11 cells. Disclosure W. Ratajczak: None. S. Atkinson: None. C. Kelly: None. Funding European Union Regional Development Fund; European Union Sustainable Competitiveness Programme for Northern Ireland; Northern Ireland Public Health Agency; Ulster University; Northern Ireland Department of Employment and Learning