A Descriptive Pilot Study of Endothelial Transcriptomic Responses to Extended Lactate Exposure In Vitro

Lactate is increasingly recognized as a signaling molecule capable of modulating gene expression and vascular function. This descriptive pilot study investigated the effects of different lactate concentrations (0 mM, 10 mM, 20 mM, and 30 mM) and exposure times (1 h, 3 h, and 6 h) on the transcriptomic responses of human umbilical vein endothelial cells (HUVECs). Using next-generation RNA sequencing, an unbiased genome-wide analysis was performed, followed by focused examination of genes relevant to endothelial biology, calcium signaling, and glycocalyx integrity. Results showed that there was no statistically significant effect of lactate concentration on the expression of the examined genes. In contrast, prolonged incubation time was associated with differential expression of KLF2, KLF4, FOXO1, CD34, and VCAM1. These findings suggest that exposure time, rather than lactate concentration, may be associated with endothelial gene expression patterns under static conditions. This exploratory pilot study provides preliminary transcriptomic observations and highlights the need for further mechanistic investigations including functional and protein-level analyses.