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Biology subjects

Markiewitz, D.

Publications and source records attributed to Markiewitz, D..

2 recordsLinked to original sources

Characterizing Gene Regulatory Network Ensembles in Kidney Injury and Repair

The inference of gene regulatory networks (GRNs) from single-cell RNAseq data allows for mechanistic characterization of the different cell states and their dynamics in complex biological processes. While numerous algorithms have been proposed to infer GRNs from single-cell transcriptomic data, multiple network solutions may explain the same dataset, posing a challenge for biologically meaningful interpretation. Here, we use the Reasoning Engine for Interaction Networks (RE:IN), a computational tool based on formal reasoning, to characterize GRN ensembles in the context of acute kidney injury (AKI). To this end, we applied RE:IN to a single-cell RNAseq dataset from a mouse ischemiareperfusion injury (IRI) model, focusing on distinct proximal tubule cell states related to kidney injury and repair. We first created an Abstract Boolean Net-work (ABN) model for the kidney using RE:IN and synthesized an ensemble of consistent network solutions. Then, we visualized the ensemble in latent space using Principal Components Analysis (PCA) and discovered four distinct GRN families compatible with the input gene expression and regulatory constraints. Finally, we identified two specific network substructures that discern between the four different network families. This study provides a methodology for characterizing and interpreting GRN heterogeneity in complex processes such as tissue development, disease, and repair.

systems biology↗

Dynamics of cell states and alternative splicing following kidney ischemia-reperfusion injury

The progression of kidney damage in chronic kidney disease (CKD) involves multiple post-injury stages and complex cellular and molecular mechanisms that are not yet fully understood. In our study we set to characterize the dynamics of mRNA splicing following kidney injury. To this end, we analyzed publicly available bulk RNA-seq data covering nine time points following a kidney ischemia-reperfusion injury (IRI) mouse experiment. Using topic modeling we discerned five distinct temporal phases corresponding to the following cell states: "early injury response", "injury", "repairing", "failed recovery", and "healthy proximal tubule". Additionally, we discovered a set of genes that are alternatively spliced between selected time points associated with these cell states, some of which are related to injury, stress, EMT, and apoptosis. Finally, we found several putative splicing regulators that are differentially expressed between the different time points and whose binding motifs are enriched in the vicinity of alternatively spliced exons, indicating that they may play critical roles in mRNA splicing dynamics following kidney injury and repair. These findings enhance our understanding of the molecular mechanisms involved in kidney injury and repair, offering potential avenues for developing targeted therapeutic strategies for acute kidney injury (AKI) and its progression to CKD.

genomics↗