Vascular remodeling outcomes in human arteriovenous fistula maturation are associated to long non-coding RNA expression

Arteriovenous fistulas (AVFs) are the preferred vascular access for haemodialysis in patients with chronic kidney disease (CKD), yet approximately 50% fail to mature adequately within six weeks after surgery. This high failure rate remains a major clinical challenge, primarily due to maladaptive vascular remodeling in response to arterial pressure and blood flow and kinetics.

To investigate transcriptomic changes underlying AVF maturation and failure, we integrated two independent bulk RNA sequencing datasets from patients undergoing a two-stage brachio-basilic AVF procedure. Vein tissue collected at the first surgical stage, and matched AVF tissue was obtained six weeks later during the second stage. Maturation was defined by an intraoperative AVF diameter ≥6 mm. All samples were patient-paired and sequenced to an average depth of ~40 million base pair reads. After quality control, normalization, and differential expression analysis using DESeq2, we performed pathway enrichment and vascular cell-type marker profiling.

We focused on long non-coding RNAs (lncRNAs), filtering for transcripts with absolute log₂ fold change ≥0.5, adjusted p-value ≤0.05, and expression ≥1 TPM. Candidate lncRNAs were further prioritized through an integrative profiling strategy incorporating vascular cell-type enrichment, murine synteny, isoform complexity, proximity to differentially expressed protein-coding genes, functional literature, vascular GWAS associations, and correlation with AVF diameter.

This approach identified several high-confidence lncRNAs, eleven of which were selected for validation via qPCR in an independent cohort. Expression analysis showed lncRNAs 1–6 were enriched in smooth muscle cells and fibroblasts, while lncRNAs 7-11 were broadly expressed. Functional annotation linked these lncRNAs to vascular processes including smooth muscle phenotype switching, endothelial activation, and oxidative stress.

qRT-PCR confirmed significant upregulation of lncRNAs 1 (p = 0.0021), 2 (p = 0.029), 6 (p = 0.0326), and 7 (p = 0.0264) and a significant downregulation of lncRNA 11 (p = 0.0327) in failed versus matured AVFs. Functional knockdown of these lncRNAs reduced vascular cell migration and modulated senescence- and inflammation-related pathways.

These findings highlight novel lncRNA signatures involved in AVF failure.