[The extracellular signal-regulated kinase was promoted by pyrroloquinoline quinine in cultured Schwann cells].

OBJECTIVE: To investigate the effect of mitogen-activated protein kinase (MEK) kinase cascade, extracellular signal-regulated kinase (ERK1/2) signal pathway on Schwann cells proliferation promoted by Pyrroloquinoline Quinine (PQQ) and its molecular mechanisms. METHODS: Schwann cells were cultured and purified in vitro. The purity was identified by S-100. Different time and concentration of PQQ was added into culture medium. The expression of ERK1/2 and phosphorylated-ERK1/2 was detected by western blot. The expression of p-ERK1/2 after blocking of MEK signal pathway by specific inhibitor PD98059 was detected by western blot. RESULTS: Morphological change was observed in PQQ treated Schwann cells. 1-500 nmol/L PQQ could up-regulate the expression of p-ERK1/2, and 1000 nmol/L had no effects, while 10 000 nmol/L exhibited inhibitory effect (P < 0.05). p-ERK1/2 increased to peak 1 h after PQQ added, and this up-regulation of p-ERK1/2 was inhibited by PD98059 (P < 0.05). CONCLUSIONS: PQQ could affect morphology of Schwann cells and activation of ERK1/2. MEK inhibitor PD98059 could, block this activation. It suggests that MEK/ERK signal pathway should be involved in Schwann cells proliferation promoted by PQQ.