RESUMO
Objective: To research the effect of matrine on the proliferation and migration of HepG2 cells through extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Methods: HepG2 cell was selected and divided into blank control group, experimental group (matrine 1, 2, and 4 mg/mL), and positive control group (PD98059, ERK1/2 inhibitor). MTT measure was used to detect the effective time and concentration which matrine inhibits HepG2 cells. After 24 h, the effect of effective concentration of matrine on the of morphological changing HepG2 cells was observed. The invasion ability was assayed by transwell method, the expression of ERK1/2 and pERK1/2 were detected through Western blot, and reverse transcription polymerase chain reaction was used to test the expression level of ERK1/2 mRNA. Results: With the increase of matrine concentration, the number of adherent HepG2 cells gradually decreased, the morphologic changes gradually became spherical, some cell morphology was incomplete, and even cell fragments appeared. The proliferation and invasion ability of HepG2 cells decreased. The expression of ERK1/2, pERK1/2, and ERK1/2 mRNA downregulated with the increase of matrine concentration (P < 0.05). Conclusion: Matrine inhibits the proliferation and migration of HepG2 cells by downregulating the ERK1/2 signaling pathway.
RESUMO
The effects of magnetic stimulation on spinal cord injury-induced migration of white matter astrocytes were studied using an established animal model. Ethidium bromide was injected into the dorsal spinal cord funiculus of adult Sprague-Dawley rats on the left side at T10-11. Animals then received 1.52 Tesla-pulsed magnetic stimulation for 5 min at different frequencies (0-20 Hz) for 14 consecutive days. Selected animals received the non-competitive MEK1/2 inhibitor U0126 (10 μM), prior to stimulation at 10 Hz. Lesion volumes were measured in hematoxylin/eosin-stained sections. Expression of glial fibrillary acidic protein (GFAP), microtubule associated protein-2 (MAP-2) and extra-cellular signal-regulated kinase1/2 (ERK1/2) near the epicenter of injury was examined by Western blotting with quantification using an image analysis system. Lesion volumes decreased and GFAP and p-ERK1/2 expression increased with increasing magnetic stimulation frequency (0-10 Hz). MAP-2 expression was not affected at any frequency. Pretreatment with U0126 reduced GFAP and ERK1/2 expression and increased lesion volumes in response to stimulation at 10 Hz. It is concluded that magnetic stimulation increases the migration of astrocytes to spinal cord lesions. Activation of the ERK1/2 signaling pathway is proposed to mediate astrocyte migration and glial scar formation in response to spinal cord injury.