Effects of pyrroloquinoline quinine on oxidative stress-induced apoptosis of Schwann cells and its mechanism / 中华整形外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effects of Pyrroloquinoline quinine (PQQ) on hydrogen peroxide-induced apoptosis of Schwann cells (SCs) and its mechanism.</p><p><b>METHODS</b>SCs were isolated and cultured in vitro, and identified by S-100 immunofluorescence staining. The cultured SCs were divided into control group, hydrogen peroxide-treated group, hydrogen peroxide and PQQ treated groups. The intracellular superoxide dismutase (SOD) and malondialdehyde (MDA) content was detected; the apoptotic rate of SCs induced by hydrogen peroxide was determined by flow cytometry assay. The Hoechst33342 staining was used to detect the nuclear fragmentation and apoptotic nuclear condensation of SCs; the Rhodamine123 staining was used to detect the changes of mitochondrial membrane potential in SCs, the Western blot analysis was used to detect the expression of Bcl-2 in hydrogen peroxide induced SCs.</p><p><b>RESULTS</b>The SOD activity was significantly decreased and MDA level was increased in H2O2 induced SCs (P < 0.05), after addition of PQQ, the SOD content increased and MDA content decreased (P < 0.05). Flow cytometry results showed that the early apoptotic rate was 58.8% in H2O2 induced SCs, which has significant difference compared with the control group (P < 0.05), after addition of 10, 50, 100 nmol/L PQQ, the apoptotic rates were reduced to 33.7%, 18.7%, 3.9% respectively, showing significantly different with injured group (P < 0.05). Hoechst 33342 staining showed that H2O2 induced SCs had typical morphological characteristics, such as uptake of nuclear chromatin, nuclear shrinkage, nuclear fragmentation phenomenon. The proportion of apoptotic cells after PQQ treatment reduced. Rhodamine staining results showed that the H2O2 induced mitochondrial membrane potential reduction in SCs, which was reversed by addition of PQQ. Western blot analysis showed that the expression of Bcl-2 was decreased in H2O2 induced SCs, while it increased significantly after addition of PQQ (P < 0.05).</p><p><b>CONCLUSION</b>PQQ has a protective effect on oxidative stress-induced apoptosis of SCs.</p>