P1305: HSA_CIRC_0001599 REGULATES IL18 LEVELS IN AGVHD VIA CERNA MECHANISM

Abstract

Background: AGVHD (acute graft-versus-host disease) is one of the major complications after hematopoietic stem cell transplantation, and severe aGVHD not only seriously affects the outcome of transplantation but also may pose a threat to the patient’s life.The gastrointestinal system is one of the areas most strongly affected by aGVHD. Aims: This study was dedicated to investigating the pathogenic mechanism of hsa_circ_0001599 in intestinal acute graft-versus-host disease (aGVHD). Methods: Four patients with intestinal aGVHD and four healthy volunteers were invited to have peripheral blood drawn early in the morning on an empty stomach. After treatment, peripheral blood mononuclear cells (PBMCs) were obtained, and after further testing and purification, RNAs that met the experimental requirements were obtained from them. After screening circRNAs with abnormal expression levels by high-throughput sequencing as well as data processing, the levels of specific circRNAs in 20 patients were verified by qRT-PCR. Then, the ceRNA interaction network was constructed by bioinformatics analysis using GO, KEGG and miRanda. Finally, clinical patients’ correlations were analyzed to determine the sensitivity and specificity of disease-related indicators for disease diagnosis. Results: 1. High-throughput sequencing results showed that a total of 330 circRNAs showed bidirectional expression in the aGVHD group relative to the HC group, of which 8 were up-regulated and 322 were down-regulated (FC≥2.0, P≤0.05) (Figure 1 A). 2. PCR validation of high level expression of hsa_circ_0001599 The PCR results showed that the mean expression level of hsa_circ_0001599 in the aGVHD group was more than twice that of the control group. (Figure 1 B) 3. Analysis of differentially expressed genes involved in intestinal aGVHD and pathway prediction Analysis by GO and KEGG enrichment indicated that the upregulation of circRNA expression may have an impact on the pathogenesis of intestinal aGVHD (Figure 1 C). 4. Construction of circRNA-miRNA-mRNA interaction network The hsa_circ_0001599-targeted mRNA: IL18 was predicted using miRanda, TargetScan and other databases, and the ceRNA interaction network was constructed (Figure 1 D). 5. We analyzed the relationship between clinical characteristics, hsa_circ_0001599 and IL18 in 15 patients with intestinal aGVHD. The results showed that the level of hsa_circ_0001599 was positively correlated with IL18 level in intestinal aGVHD patients.(R2=0.832, P<0.05). (Figure 1 E) Image:Summary/Conclusion: The aberrant expression of hsa_circ_0001599 in PBMCs may be a new diagnostic marker and therapeutic target for intestinal aGVHD.