Puerarin reduces intracellular Ca2+ concentration and upregulates BDNF to protect hippocampal neurons in vascular dementia rats / 西安交通大学学报(医学版)

【Objective】 To observe the effect of puerarin on the concentration of Ca2+ and the expression of brain derived neurotrophic factor (BDNF) in hippocampal neurons of vascular dementia (VD) rats so as to explore the mechanism of puerarin in protecting nerve cells. 【Methods】 Male SD rats were randomly divided into sham operation group, model group, and puerarin intervention group. The vascular dementia model was established by ligating bilateral common carotid arteries at intervals of 3 days. Two weeks after the operation, the learning and memory abilities of the rats were evaluated by Morris water maze, and the expression of BDNF in the hippocampus of the rats was detected by immunohistochemistry and Western blotting. The mean fluorescence intensity was measured by flow cytometry to represent the intracellular free Ca2+ concentration. 【Results】 In the puerarin intervention group, the rats’ escape latency in Morris water maze was significantly shortened, the expression of BDNF in the hippocampus was significantly increased, and the concentration of Ca2+ in hippocampal neurons was decreased. Compared with the model group, the difference was statistically significant (all P<0.05). 【Conclusion】 Puerarin has neuroprotective effect on VD rats, and its mechanism may be related to the decrease of Ca2+ concentration in hippocampal neurons and the up-regulation of BDNF expression.

Research advances on neural cell senescence and cellular senescence models / 中华老年医学杂志

As terminally differentiated cells, neurons undergo aging with specific patterns.Understanding the characteristics of neural cell senescence and associated aging models is helpful to select appropriate models for the study of nervous system senescence.

Activation of PPARγ pathway enhances cellular anti-oxidant capacity to protect long-term cultured primary rat neural cells from apoptosis / 南方医科大学学报

OBJECTIVE@#To study the protective effect of enhanced peroxisome proliferator activated receptor γ (PPARγ) pathway against apoptosis of long-term cultured primary nerve cells.@*METHODS@#A natural aging model was established in primary rat nerve cells by long-term culture for 22 days. The cells were divided into control group, 0.1, 1.0, 5.0, and 10 μmol/L GW9662 intervention groups, and 0.1, 1.0, 5.0, and 10 μmol/L pioglitazone intervention groups. The cell viability was assessed using MTT assay and the cell morphological changes were observed after the treatments to determine the optimal concentrations of GW9662 and pioglitazone. Double immunofluorescence labeling and flow cytometry were used to observe the changes in the number of viable cells and cell apoptosis following the treatments; immunocytochemical staining was used to assess the changes in the anti-oxidation ability of the treated cells.@*RESULTS@#The optimal concentrations of GW9662 and pioglitazone determined based on the cell viability and morphological changes were both 1 μmol/L. Compared with the control group, GW9662 treatment significantly lowered while pioglitazone significantly increased the total cell number and nerve cell counts ( < 0.05), and nerve cells in the cell cultures maintained a constant ratio at about 80% in all the groups ( > 0.05). GW9662 significantly enhanced while pioglitazone significantly lowered the cell apoptosis rates compared with the control group ( < 0.05). GW9662 obviously lowered SOD activity and GSH content in G group ( < 0.05) and increased MDA content in the cells ( < 0.05), and pioglitazone resulted in reverse changes in SOD, GSH and MDA contents in the cells ( < 0.05).@*CONCLUSIONS@#Activation of PPARγ pathway protects long-term cultured primary nerve cells by enhancing cellular anti-oxidant capacity and reducing cell apoptosis, suggesting a potential strategy for anti-aging treatment of the nervous system through intervention of the PPARγ pathway.

Expression of vascular endothelial growth factor and microvessel density in different brain regions in aged rats / 中南大学学报(医学版)

Objective:To observe the distribution of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in different brain regions in aged rats and determine the role of VEGF and MVD in the aging process of the nervous system. Methods:We observed the expression of VEGF and MVD in different parts of rat brain in the 3- month group and 30-month group with immunohistochemical technique. Results:Compared with the 3-month group, the 30-month group showed fewer VEGF-positive cells and MVD in the brain (P<0.01), and the number varied signiifcantly in different brain regions(P<0.01). The motor cortex region contained more VEGF-positive cells and MVD than the hippocampus and cerebellum. Conclusion:VEGF-positive cells and MVD are decreased in every brain region of aged rats, and the motor cortex region contains more positive cells, suggesting exogenous VEGF may enhance the formation of microvessels and delay the aging of the nervous system.

Effect of erythropoietin on activities of antioxidant enzymes in the brain tissue of aged rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of erythropoietin (EPO) on the activities of antioxidant enzymes, namely catalase (CAT) and glutathione peroxidase (GSH-Px) in the brain tissues of aged rats.</p><p><b>METHODS</b>Thirty SD rats were randomly divided into normal control, aging model, and recombinant human erythropoietin (rhEPO) treatment groups (n=10). Morris water maze was used to compare the behavioral indexes. The rats were then sacrificed to observe Nissl bodies in the hippocampal neurons with Nissl staining and test the activities of CAT and GSH-Px in the brain tissues.</p><p><b>RESULTS</b>Compared with the control group, the aging rats showed significantly deteriorated learning and memory abilities (P<0.05), which were improved obviously by rhEPO treatment (P<0.05). The number of Nissl bodies in the neurons was reduced in the aging rats compared with that in the control group, and rhEPO treatment increased the number of Nissle bodies but failed to restore the control level. The aging rats also showed significantly lowered activities of CAT and GSH-Px in the brain tissue (P<0.05), which were increased significantly after rhEPO treatment (P<0.05).</p><p><b>CONCLUSION</b>EPO can enhance the activities of the antioxidant enzymes in the brain tissues of aged rats to increase the antioxidant capacity and produces an anti-aging effect.</p>

Expression of hypoxia inducible factor-1alpha and erythropoietin in the hippocampus of aging rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the expression of hypoxia inducible factor-1alpha (HIF-1alpha) and erythropoietin in the hippocampus of aging rats, and to investigate the role of HIF-1alpha and erythropoietin in the aging of nervous system.@*METHODS@#The expression of Nissl body, HIF-1alpha, and erythropoietin in the CA1 region of the hippocampus in different months was observed by Nissl staining and immunohistochemical technique.@*RESULTS@#Nerve cells became bigger and appeared sparse, and the Nissl bodies decreased with age. HIF-1alpha positive cells increased significantly with age in the CA1 region of the hippocampus (P<0.05). The expression of erythropoietin presented a parabola with aging in the CA1 region of the hippocampus. The increase from 3 to 18 months and the reduction from 18 to 30 months of erythropoietin positive cells had statistical significance (both P<0.05).@*CONCLUSION@#HIF-1alpha and erythropoietin are parallelly incremental before middle age, and are separated after middle age, suggesting decreased activity of HIF-1alpha and recession of protein synthesis function may be the main reasons for decreased expression of erythropoietin in the brain during aging. Strengthened endogenous HIF-1alpha activity and supply of exogenous erythropoietin may delay the aging of the nervous system.