Major depression accompanied with inflammation and multiple cytokines alterations: Evidences from clinical patients to macaca fascicularis and LPS-induced depressive mice model

•The levels of IL-6, IL-8, MCP-1 and VEGF were elevated in the serum of MDD patients and NOD macaca fascicularis.•The aLPS and cLPS depressed mice displayed higher serum concentrations of IL-6 and VEGF than these in control mice.•The prefrontal cortex of the LPS-treated mice showed increased expressions of IL-6 and VEGF.•The IL-6 and VEGF may as predictive biomarkers for novel diagnostic as well as therapeutic of depression.•The hypothalamus may as a key brain region involve in the inflammation related depressive-like behaviors.