Résumé
Objective To investigate the expression and role of Huntingtin-associated protein-1 (HAP-1) in the process of valproate acid (VP A) inducing neural stem cells (NSCs) into neurons. Methods The hippocampus NSCs of SD rats were isolated and cultured, Real-time PCR and Western blotting were used to detect HAP-1 mRNA and protein expression at day 0, day 1, day 3 and day 5 during the induction of VPA on NSCs differentiation into neurons ; Real-time PCR was used to detect the expression level of HAP-1 mRNA in multiple tissues of adult SD rats, as well as NSCs, neurons and astrocytes. After applying small interfering RNA technology to down-regulate the expression of HAP-1 mRNA in NSCs, Real-time PCR was used to detect the mRNA expression levels of neuron-specific molecules stathmin-2 ( Stmn-2), neuronal differentiation-1 (Neurod-1), microtubule-associated protein-2 (Map-2) and synapsin-1 (Syn-1), and Western blotting was used to detect the protein expression levels of neuron-specific marker β-tubulin III (Tuj-1). Immunofluorescence was used to detect the proportion of NSCs differentiated into Tuj-1 positive neurons, and to observe the development of neurons. Results At day 1 and day 3 after VPA treatment, the expression of HAP-1 mRNA and protein in the VPA group was significantly up-regulated; HAP-1 mRNA was predominantly expressed in the hippocampus, and its expression was higher in neurons, followed by NSCs, and minimally in astrocytes. After down-regulating HAP-1 with small interference technology, the proportion of NSCs differentiated into Tuj-1 positive neurons reduced, and neuron development became worse. Conclusion VPA may promote the differentiation of NSCs into neurons by up-regulating HAP-1 expression.
Résumé
Objective To study the effect of docosahexaenoic acid ( DHA ) and eicosapentaenoic acid (EPA) on cognition impairment and huntingtin associated protein 1 ( HAP1 ) expression in hippocampus of rat model with Alzheimer' s disease(AD). Methods Forty healthy Sprague-Dawley rats were randomly divided into control group, AD group, DHA group and EPA group on average. Alcl3 was injected intraperitoneally and D-galac tose was injected into subcutaneous to establish the model of rat with AD. ABC method of immunohistochemistry was used to observe the expression level of HAP1 in the hippocampus. Morris water maze was used to study the spatial learning and memory in rats. Results Compared with control group,the HAP1-positive neurons of hippo campus decreased and poorer performance in Morris water maze test was observed in AD group. Compared with AD group, DHA and EPA treatments significantly caused the decreases in escape latency and searching distance in the Morris water maze test. The number of HAP1- positive cells in DG region of DHA group(43.57 ±6.14) increased obviously compared with AD group( 28.56 ± 4.23 ) (P ＜ 0.05 ＝. Conclusion The immunoreactivities of HAP1 decrease in hippocampus of AD rat. The applications of DHA and EPA in AD rats significantly improve the ability of learning and memory;and the mechanisms may be related to the decrease of HAP1 expressions in hippocampus.
Résumé
Objective To observe the ultrastructure location of Huntingtin-associated protein 1(HAP1) in rat adrenal medulla and the effect of cold stress on the expression of HAP1 in rat adrenal medulla. Methods Fourteen healthy male Wistar rats were used in the present study and among them two rats were used for immune electron microscopy and twelve rats for cold stress experiment. In the cold stress experiment, animals were divided into control and cold groups randomly with six rats in each group. During the experiment, rats were housed in a room at the temperature of 4℃ for 12 hours and then immunohistochemistry and Western blotting were used to measure the expression of HAP1 in adrenal medulla. Results By using the immune electron microscopy, the results showed HAP1 was located on the external membrane of secretory vesicles of adrenal medulla and their membranous organelles. The expression of HAP1 in adrenal medulla of cold group significantly decreased as compared with that of control group ( P <0.01). Conclusion HAP1 might be related with the adrenal medulla cells endocrine granula and involved in the transmission and release of adrenaline or noradrenaline in secretory granule.