Effects of pyrroloquinoline quinone on proliferation and expression of c-fos, c-jun, CREB and PCNA in cultured Schwann cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of pyrroloquinoline quinine (PQQ) on proliferation and expression of c-fos, c-jun, CREB and PCNA in cultured Schwann cells.</p><p><b>METHODS</b>Schwann cells were cultured and purified in vitro. The purity of Schwann cells was identified by immunofluorescence of S-100. After synchronization of cell cycle by serum-free medium, different concentration of PQQ (0,1, 10, 100, 1,000, 10,000 nmol/L) were added into culture medium for 72 h. Flow cytometry was used to determine cell cycle. The content of c-fos, c-jun, and CREB mRNA were detected by RT-PCR, and the expression of PCNA protein was detected by Western blot.</p><p><b>RESULTS</b>After PQQ treatment, the percentage of cells in G0/G1 phase decreased and the percentage of cells in S and G2/M phase increased. After treated by PQQ at concentration of 1-10,000nmol/L, content of c-fos,c-jun,CREB mRNA was increased by 0.33,0.42 and 0. 52 fold (P < 0. 05). However, at concentration of 1 000 nmol/L, there was no difference in mRNAs content when compare to control (P >0.05). And it showed a decline at concentration of 10,000 nmol/L (P < 0.05). PCNA protein expression was up-regulated at PQQ concentration of 1-100 nmol/L. At 100 nmol/L, the expression increased by 1.17 fold (P < 0.05); However, at 1,000 nmol/L, there was no difference in PCNA expression when compared to control. And 10,000 nmol/L of PQQ inhibited the expression of PCNA (P < 0.05).</p><p><b>CONCLUSIONS</b>When treated with PQQ at concentration of 10-100 nmol/L, the proliferation of Schwann cells increased and the expression of c-fos,c-jun, CREB and PCNA was up-regulated.</p>

The roles of PI3K/Akt pathway in proliferation of Schwann cells promoted by pyrroloquinoline quinone / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the roles of PI3K/Akt signal pathway in Schwann cells proliferation promoted by pyrroloquinoline quinone (PQQ).</p><p><b>METHODS</b>Schwann cells were cultured and purified in vitro. The purity was identified by immunofluorescence of S-100; the expression of Akt and phosphorylated-Akt (p-Akt) were detected by western blot, and the expression of p-Akt after blocking the PI3K signal transduction pathway by PI3K inhibitor wortmannin was detected by western blot.</p><p><b>RESULTS</b>Morphological change was observed in PQQ-treated Schwann cells, p-Akt was detected 30 min after PQQ treated, reached the peak at 4 h, and disappeared 12 h later. 1-100 nmol/L PQQ could up-regulate the expression of p-Akt; this up-regulated expression of p-Akt was inhibited by wortmannin (P<0.05).</p><p><b>CONCLUSIONS</b>PQQ could affect morphology of Schwann cells and activation of Akt. It indicates that PI3K/Akt signal pathway might be involved in Schwann cells proliferation promoted by PQQ.</p>

The extracellular signal-regulated kinase was promoted by pyrroloquinoline quinine in cultured Schwann cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>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.</p>

Pyrroloquinoline quinone enhances regeneration of transected sciatic nerve in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect of pyrroloquinoline quinone (PQQ) on nerve regeneration of transected sciatic nerve in animal models.</p><p><b>METHODS</b>Forty SD rats weighing 220-240 g were randomized into a PQQ group (n = 20) and a control group (n = 20). Each animal underwent sciatic nerve transection operation. After the operation, PQQ 0.5 ml (250 microg/Kg) was injected at the operation site in the PQQ group, while the same volume of normal saline was delivered in the control group. Nerve functional evaluation, electrophysiological index recording were carried out according to the experimental design. Newly generated nerve specimens were harvested 12 weeks postoperatively for morphological studies.</p><p><b>RESULTS</b>In the PQQ group there was a good nerve regeneration and the sciatic nerve function, sciatic nerve function index, electrophysiological index and morphological appearance were superior to the control group (P < 0.05).</p><p><b>CONCLUSIONS</b>PQQ has a remarkable effect in enhancing nerve regeneration of transected peripheral nerve.</p>