1696-P: PBMC of Recent-Onset Patients with Type 1 Diabetes Present a Differential Gene Expression Profile

Abstract

Introduction: Type 1 diabetes is characterized by the autoimmune destruction of insulin-secreting β-cells, mediated by T auto reactive infiltrating cells, inflammatory cytokines and immunological mechanisms. However, little is known about the expression of genes and pathways dysregulated in peripheral blood mononuclear cells of patients with T1D. Objective: to investigate the gene expression profiles of circulating PBMC in recent-onset T1D patients (up to 6 months of diagnosis) in comparison with controls in the context of putative disease-related pathobiological processes and pathways. Methods: expression of mRNA from PBMC of 20 T1D patients, 15.8±8.6 years and age-matched 20 healthy controls, 14.7±6.7 years, (p>0.05) was evaluated with the Whole Human Genome Microarray Agilent and analyzed by GeneSpring with a fold change cutoff of 1.5 and adjusted P value <0.05; pathways analysis was performed with the software IPA. Results: 326 genes were differentially expressed between T1D patients and controls, being 204 (63%) upregulated, and 122 (37%) downregulated in T1D. Interactions between the differentially expressed genes evidenced expression patterns of 24 networks. The most significantly enriched canonical pathways were namely ErbB (erythroblastic leukemia viral oncogene) signaling, micropinocytosis signaling, savage pathways of pyrimidine ribonucleotides and hepathocyte growth factor in descending order of significance. The up-regulated protein targets within these signaling pathways were NEK2, PLK1, ATM, PRKCD, CCND1, NRG2 and those down regulated were AREG, CDC42 and CDADC1. Conclusion: The majority of upregulated genes of patients with T1D was related to cell cycle control, mitotic progression, proliferation and DNA repair, probably related to changes in PBMC metabolism and function due to DNA damage associated with hyperglycemia. The lower expression of AREG and CDC42 can be related to reduce immunosuppressive activity of regulatory T cells and B cell functions. Disclosure A. Santos: None. C. Chevillard: None. N. Gonfinetti: None. F. Bertonha: None. C. Moreira-Filho: None. J. Kalil: None. E. Cunha-Neto: None. M. Silva: None. Funding European Foundation for the Study of Diabetes; São Paulo Research Foundation