Isoforms of soluble vascular endothelial growth factor in stress-related mental disorders: a cross-sectional study

Abstract

Vascular endothelial growth factor (VEGF) has been implicated in the pathophysiology of stress-related mental disorders. However, VEGF levels have seldom been compared across mental disorders and never by isoforms. Pathophysiological processes involving leakage of astrocyte-derived extracellular vesicles (EVs) across the blood–brain barrier could be associated with VEGF levels in patients with stress-related mental disorders. This cross-sectional study compared plasma levels of VEGF121, VEGF165, and VEGF121 + VEGF165 (VEGFtotal) in patients with stress-induced exhaustion disorder (SED) (n = 31), patients with major depressive disorder (MDD) (n = 31), and healthy controls (n = 61). It also analyzed the correlation between VEGF and astrocyte-derived EVs in plasma. An enzyme-linked immunosorbent assay (ELISA) was used to measure VEGF121 and VEGF165 in citrate plasma, and flow cytometry was used to measure astrocyte-derived EVs in plasma. The mean concentration of soluble VEGF121 (sVEGF121) was significantly higher in patients with SED than healthy controls (P = 0.043). Mean sVEGF165 was significantly lower in patients with MDD than patients with SED (P = 0.004) or healthy controls (P = 0.037). Mean sVEGFtotal was significantly higher in patients with SED than in patients with MDD (P = 0.021) and also higher in patients with SED than healthy controls (P = 0.040). Levels of sVEGF121 were positively correlated with levels of astrocyte-derived EVs only in patients with SED (P = 0.0128). The same was true of levels of sVEGFtotal and astrocyte-derived EVs (P = 0.0046). Differing levels of VEGF isoforms may reflect different pathophysiological mechanisms in SED and MDD. Further research is needed to better understand the potential roles of VEGF isoforms and astrocyte-derived EVs in mental disorders.