Evidences for correlation between the reduced VCAM-1 expression and hyaluronan synthesis during cellular senescence of human mesenchymal stem cells

► VCAM-1 expression was markedly decreased during long-term culture of MSCs. ► The VCAM-1 expression was restored by applying hyaluronan to the culture. ► Hyaluronan level was also greatly reduced in the senescent MSCs, mainly due to decreased expression of hyaluronan synthases. ► Knock-down of hyaluronan synthase genes resulted in decreased expression of VCAM-1. ► Hyaluronan-supplemented culture of MSC will compensate the adverse effects induced by its decreased synthesis.