Identification of differentially expressed genes and their functional activity in rat vascular tissues

Abstract

This thesis presents an intricate exploration into the cellular and molecular diversity within the vascular system, emphasizing the critical roles of ion channels and G-protein-coupled receptors, including P2X and P2Y receptors, across different arterial territories. Utilizing a Wistar rat model, the study meticulously investigates the heterogeneity in gene expression among mesenteric, aortic, and pulmonary arteries. It aims to uncover the intrinsic gene signatures unique to each vascular bed, to understand the implications of diverse gene expressions on vascular function, and to offer insights that could refine therapeutic approaches for vascular disorders. Whole-Genome expression profiling was utilized to investigate differentially expressed genes (DEGs) in different tissues from mesenteric, aortic, and pulmonary arteries. with a particular focus on comparing different vascular beds. Bioinformatic analyses were performed to examine DEGs and the gene ontology of common DEGs. The study particularly focused on six candidate genes whose expression levels were meticulously validated through quantitative polymerase chain reaction (qPCR) to ensure the precision of our gene expression analysis. Additionally, Gene Ontology analysis was utilized to identify significant enrichments in clusters related to various pathways, highlighting the intricate nature of vascular physiology. The functional consequences of these DEGs were further examined using wire-myography, which provided insights into the varied contractile phenotypes of arteries. This variability was shown to be dependent on the order and susceptible to modulation by pharmacological agents in whole tissue assays, underscoring the complexity of vascular responses. The analysis identified 16,814 DEGs across the examined vascular tissues, underscoring significant molecular heterogeneity inherent to distinct vascular regions. This molecular diversity, characteristic of each arterial bed, reveals unique gene expression patterns that are foundational to understanding the intricate nature of vascular physiology. Notably, variations in gene changes related to ion channels across tissues were observed, with Gene Ontology analysis indicating significant enrichment in clusters associated with diverse physiological pathways. All six selected candidate genes P2X2, P2X4, P2X6, P2Y12, P2Y13, and P2Y14, demonstrated differential expression patterns across the arterial samples, reinforcing the bioinformatic assessment's findings. Moreover, the study elucidated that arteries exhibit a varied contractile phenotype, which is order-dependent and subject to modulation by pharmacological interactions, as evidenced in whole tissue assays. The investigation into mesenteric, aortic, and pulmonary arteries has unveiled distinct gene expression profiles, illuminating the molecular diversity that underpins the physiology of different arterial beds. This foundational understanding of vascular physiology opens new avenues for the development of innovative therapeutic strategies targeting vascular diseases. The differences in gene expression identified across these vascular regions hold significant promise for the future of medical treatment, potentially serving as key markers for screening and identifying prospective therapeutic candidates.