| Abstrakt: |
Objective To preliminarily investigate the role of the Ras-related C3 botulinum toxin substrate 3 (RAC3) in type 1 diabetes mellitus (T1DM) and dendritic cells (DC). Methods Patients with T1DM were enrolled from the Guangdong Type 1 Diabetes Translational Medicine Study from 2011 to 2016. Healthy controls were volunteers with normal glucose tolerance who visited the Third Affiliated Hospital of Sun Yat-sen University from 2011 to 2016. Whole exome sequencing was performed in the screening stage, and genotyping was performed in the validation stage among all participants. CRISPR/Cas9 gene editing technology was used to construct the RAC3 whole-body knock-out (KO) mouse model on C57BL/6 mouse background. Polymerase chain reaction (PCR), quantitative real-time PCR (qRT-PCR), and Western blotting assay were used to verify that RAC3 was knocked out on DNA, RNA and protein level. Flow cytometry was used to compare the differentiation ratio of DC and the expression levels of maturation and activation indicators, such as major histocompatibility complex-II (MHC II), CD86 and CD80, between RAC3 KO mice and wild-type (WT) littermate control mice (3 mice in each group). Logistic regression was used to compare the frequency distributions of the alleles between case and control groups. Intergroup comparisons were conducted by independent-samples t-tests. Results A total of 72 patients with T1DM and 487 healthy controls were included in the screening stage, and 122 patients with T1DM and 577 healthy controls were included in the validation stage. The results in the screening stage showed that the frequencies of the T allele of RAC3 rs4969478 in patients with T1DM were higher than that in healthy controls [7.64% (11/144) and 1.13% (11/974), respectively, OR=9.38, P<0.001]. The results in the validation stage also showed that the frequencies of the T allele of RAC3 rs4969478 in patients with T1DM were increased compared to the healthy controls [4.50% (11/244) vs. 1.13% (13/1 154), respectively, OR=4.14, P<0.01]. There was no significant difference in the percentage of differentiated DC between WT mice and RAC3 KO mice (85.6%±1.1% vs. 83.3%±0.25%, respectively, P=0.08). There was no significant difference in the expression levels of maturation and activation indicators (such as MHC II, CD86 and CD80) in DC between WT mice and RAC3 KO mice (P>0.05). Conclusion Genetic studies suggest that RAC3 may be a susceptibility gene for human T1DM, but it may not be involved in the pathogenesis of T1DM via DC. [ABSTRACT FROM AUTHOR] |
