丹参与电针对脑缺血再灌注损伤大鼠GFAP和iNOS表达的影响

目的:观察脑缺血再灌注损伤后大鼠脑胶质原纤维酸性蛋白(GFAP)及诱导型一氧化氮合酶(iNOS)的表达,以及丹参与电针对其表达的影响。方法:将60只SD大鼠随机分为假手术组、模型组、丹参组、电针组、丹参+电针组,采用大脑中动脉线栓法建立脑缺血再灌注模型。造模后,丹参组给予丹参注射液5g/kg腹腔注射,电针组刺激"百会"、"大椎"穴,疏密波,频率2~15Hz,持续30min,丹参+电针组给予丹参注射液腹腔注射和电针,各组治疗均每天1次,连续4d。进行神经功能缺损评分、干湿重法测脑组织含水量,采用HE染色观察脑组织的病理形态学变化,免疫组织化学染色法检测各组大鼠纹状体GFAP、iNOS的表达。结果:模型组神经功能缺损评分和脑组织含水量均明显高于假手术组(P<0.01);与模型组比较,丹参组、电针组、丹参+电针组神经功能缺损评分和脑组织含水量均显著降低(P<0.05或P<0.01),并且丹参+电针组的评分和含水量显著低于丹参组、电针组(P<0.05或P<0.01);HE染色显示的病理形态学改变与上述一致。模型组GFAP、iNOS的表达均明显高于假手术组(P<0.01);与模型组比较,丹参组、电针组、丹参+电针组GFAP、iNOS的表达均明显降低(P<0.05或P<0.01),并且丹参+电针组的表达明显低于丹参组、电针组(P<0.05或P<0.01)。结论:丹参和电针对脑缺血再灌注损伤有神经保护作用,可能与其抑制星型胶质细胞的过度活化,降低iNOS的表达有关,且二者合用效果更佳。

Effects of P2Y_1 receptor on glial fibrillary acidic protein and glial cell line-derived neurotrophic factor production of astrocytes under ischemic condition and the related signaling pathways

Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Neurogenesis by Activation of Inherent Neural Stem Cells in the Rat Hippocampus after Cerebral Infarction

Objective To investigate the changes of neural stem cells (NSCs) in the rat hippocampus after cerebral infarction (CI) and to evaluate the neurogenesis caused by the activation of NSCs. Methods CI models of rats were made and rats were assigned to 6 groups: sham-operated, 1 day, 3 days, 7 days, 14 days, and 28 days after CI. The dynamic expression of bromodeoxyuridine (BrdU), polysialylated neural cell adhesion molecule (PSA-NCAM), glial fibrillary acidic protein (GFAP), and neuronal nuclear antigen (NeuN) were determined by immunohistochemistry and immunofluorescence staining. BrdU was used to mark the proliferated NSCs. PSA-NCAM was used to mark the plasticity of activated NSCs. GFAP and NeuN were used to mark the differentiated NSCs. Results Compared with the controls, the number of BrdU+ cells in the hippocampus increased significantly at 1 day after CI (P<0.05), reached peak at 7 days after CI (P<0.05), decreased but still elevated compared with the controls at 14 days after CI (P<0.05), and nearly unchanged at 28 days after CI. The number of BrdU+/PSA-NCAM+ cells increased significantly at 7 days after CI (P<0.05), reached peak at 14 days after CI (P<0.05), and decreased but still elevated compared with the controls at 28 days after CI (P<0.05). The number of BrdU+/PSA-NCAM+ cells was equal to 60% of the number of BrdU+ cells in all the same period. The number of BrdU+/NeuN+ cells in the hippocampus increased significantly at 14 days after CI (P<0.05) and reached peak at 28 day after CI (P<0.05). The number of BrdU+/GFAP+cells in the hippocampus nearly unchanged after CI. Conclusion CI can stimulate the proliferation of inherent NSCs, and most proliferated NSCs may differentiate into neurons and represent neural plasticity.