Neuroprotective effects of genistein on SH-SY5Y cells overexpressing A53T mutant α-synuclein.

Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson's disease. However, the mechanism underlying this action remains unknown. This study investigated human SH-SY5Y cells overexpressing the A53T mutant of α-synuclein. Four groups of cells were assayed: a control group (without any treatment), a genistein group (incubated with 20 µM genistein), a rotenone group (treated with 50 µM rotenone), and a rotenone + genistein group (incubated with 20 µM genistein and then treated with 50 µM rotenone). A lactate dehydrogenase release test confirmed the protective effect of genistein, and genistein remarkably reversed mitochondrial oxidative injury caused by rotenone. Western blot assays showed that BCL-2 and Beclin 1 levels were markedly higher in the genistein group than in the rotenone group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling revealed that genistein inhibited rotenone-induced apoptosis in SH-SY5Y cells. Compared with the control group, the expression of NFE2L2 and HMOX1 was significantly increased in the genistein + rotenone group. However, after treatment with estrogen receptor and NFE2L2 channel blockers (ICI-182780 and ML385, respectively), genistein could not elevate NFE2L2 and HMOX1 expression. ICI-182780 effectively prevented genistein-mediated phosphorylation of NFE2L2 and remarkably suppressed phosphorylation of AKT, a protein downstream of the estrogen receptor. These findings confirm that genistein has neuroprotective effects in a cell model of Parkinson's disease. Genistein can reduce oxidative stress damage and cell apoptosis by activating estrogen receptors and NFE2L2 channels.

[Comparative study on the brain protection in patients of traumatic cerebral infarction treated with bloodletting at Jing-well points and semen coicis].

OBJECTIVE: To verify the effect of bloodletting therapy at Jing-well points and semen coicis on patients with traumatic cerebral infarction. METHODS: Ninety patients were randomized into a bloodletting therapy at Jing-well points group (bloodletting group), a semen coicis group and a comprehensive therapy group, 30 cases in each one. The conventional basic medication was applied in all of the three groups. In the bloodletting group, the bloodletting therapy was done at twelve Jing-well points with three-edged needle, 3 drops of blood required at each one, three times a day. In the semen coicis group, the semen coicis preparation was applied via nasal feeding or oral administration, 90 g each day, three times a day. In the comprehensive therapy group, the bloodletting therapy at twelve Jing-well points and semen coicis preparation were used in combination and the methods were same as the above two groups. After 4 weeks of treatment, the efficacy was assessed with nerve function defectscale (NDS). Fugl-Meyer scale of the upper and lower limb function was used to evaluate the motor function of the affected limbs of the patients before and after treatment. RESULTS: The scores of Fugl-Meyer scale of the upper and lower limb function were increased apparently after treatment in the patients of every group (P < 0.01, P < 0.05). The score increase was much more obvious in the bloodletting group and the comprehensive therapy group as compared with the semen coicis group (all P < 0.01). The result in the comprehensive therapy group was superior to the bloodletting group (all P < 0.05). The total effective rates of NDS in the comprehensive therapy group, bloodletting group and semen coicis group were 96.7% (29/30), 83.3% (25/30) and 76.7% (23/30) separately. The result in the comprehensive therapy group was higher apparently than those in the bloodletting group and semen coicis group separately (both P < 0.05). The result in the bloodletting group was better than that in the semen coicis group (P < 0.05). CONCLUSION: The bloodletting therapy at Jing-well points and semen coicis alleviate apparently nerve function defect, improve the motor function of the affected limbs and achieve the better efficacy.

Tropism mechanism of stem cells targeting injured brain tissues by stromal cell-derived factor-1.

OBJECTIVE: To explore the role and function of stromal cell-derived factor-1 (SDF-1) in stem cells migrating into injured brain area. METHODS: Rat-derived nerve stem cells (NSCs) were isolated and cultured routinely. Transwell system was used to observe the migration ability of NSCs into injured nerve cells. Immunocytochemistry was used to explore the expression of chemotactic factor receptor-4 (CXCR-4) in NSCs. In vivo, we applied immunofluorescence technique to observe the migration of NSCs into injured brain area. Immunofluorescence technique and Western blotting were used to test expression level of SDF-1. After AMD3100 (a special chemical blocker) blocking CXCR-4, the migration ability of NSCs was tested in vivo and in vitro, respectively. RESULTS: NSCs displayed specific tropism for injured nerve cells or traumatic brain area in vivo and in vitro. The expression level of SDF-1 in traumatic brain area increased remarkably and the expression level of CXCR-4 in the NSCs increased simultaneously. After AMD3100 blocking the expression of CXCR-4, the migration ability of NSCs decreased significantly both in vivo and in vitro. CONCLUSIONS: SDF-1 may play a key role in stem cells migrating into injured brain area through specially combining with CXCR-4.

Stem cells modified by brain-derived neurotrophic factor to promote stem cells differentiation into neurons and enhance neuromotor function after brain injury.

OBJECTIVE: To promote stem cells differentiation into neurons and enhance neuromotor function after brain injury through brain-derived neurotrophic factor (BDNF) induction. METHODS: Recombinant adenovirus vector was applied to the transfection of BDNF into human-derived umbilical cord mesenchymal stem cells (UCMSCs). Enzyme linked immunosorbent assay (ELISA) was used to determine the secretion phase of BDNF. The brain injury model of athymic mice induced by hydraulic pressure percussion was established for transplantation of stem cells into the edge of injury site. Nerve function scores were obtained, and the expression level of transfected and non-transfected BDNF, proportion of neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and the number of apoptosis cells were compared respectively. RESULTS: The BDNF expression achieved its stabilization at a high level 72 hours after gene transfection. The mouse obtained a better score of nerve function, and the proportion of the NSE-positive cells increased significantly (P<0.05), but GFAP-positive cells decreased in BDNF-UCMSCs group compared with the other two groups (P<0.05). At the site of high expression of BDNF, the number of apoptosis cells decreased markedly. CONCLUSION: BDNF gene can promote the differentiation of the stem cells into neurons rather than glial cells, and enhance neuromotor function after brain injury.