Zhaoyang Jiang, n/a
Intern
Zionsville Community High School, United States
Disclosure information not submitted.
Yunlong Liu, Ph.D.
Director, Center for Computational Biology & Bioinformatics
Indiana University School of Medicine, United States
Disclosure information not submitted.
Title: MiRNA Activity Reveal Mediators of Translation Shutdown in Sepsis-Associated Acute Kidney Injury
Introduction: Acute kidney injury is a common yet poorly understood sequela of sepsis with high mortality. Our group focuses on understanding the cellular and molecular mediators of sepsis-associated acute kidney injury (sAKI). We have previously shown that the critical event leading to sAKI is translation shutdown. We hypothesize that single-cell microRNA activity (miR) will aid in understanding the cellular and molecular mediators of translation shutdown leading to sAKI.
Methods: scRNAseq was performed on murine kidney tissue at baseline (untreated, 0 hr) and after endotoxin injection spanning early and late sepsis/recovery (up to 48 hrs). The data and normalized-QC’d Seurat object were downloaded from NCBI's GEO database: GSE151658. Data were analyzed with R, and miReact used to infer miR activities from mRNA expression. Activities corresponding with miRBase miR annotations were used for downstream analyses and re-clustered by inferred miR activities. Differential miR activities analysis across time points were performed with one-way ANOVA, Bonferroni adjustment for multiple testing. Downstream enrichment analyses were performed (FDR < 0.05) on Mienturnet API and transcription factor-miR interactions with TransmiR database.
Results: miR activity clustering differed between the proximal, distal tubule, and immune cells. Most renal cell types in the kidney showed significant changes in miR activity at the 16 hr time point. Patterns of miR activities in later time points differed between cell types, with epithelial cells returning to baseline profiles by 27 hours, while immune cells did not return to baseline beyond 27 hours. In the S1-proximal tubule (PT), miR-12205, miR-1948, miR-218-1 were found to have regulatory interactions with ATF4, a key transcription factor involved in translation shutdown. miR-96, specific to the S3-PT interacts with Stat3, Smad2, and Smad4, implying this miR as an integral mediator in S3-PT recovery.
Conclusions: miR activity computational pipelines afford a high-dimensional level of analysis into low-depth datasets such as scRNASeq, affording high-resolution insight into cell-specific molecular mediators of sAKI. Future studies will focus on the validation of genetic targets and their assessment as potential therapeutic targets for recovery from sAKI.