Effects of activating mTORC2/Akt signaling pathway on dopaminergic neurons and behaviors in 6-hydroxydopamin model mice / 解剖学报

Objective To explore the effect of activation of mammalian target of rapmycin complex 2(mTORC2)/Akt signaling pathway on dopaminergic neurons and behavior in 6-hydroxydopamine (6-OHDA) model mice and its possible mechanism. Methods Selecting 36 mice which The Nestin-CreERTM and ROSA26-LacZ reporter genes were detected at the same time in 3-month-old male C57BL/6J mice weighing 20-25 g divideng them into 4 gruops, NS+ corn oil group, 6-OHDA+corn oil group, 6-OHDA+PP242 group and 6-OHDA+A-443654 group, and 6-OHDA was injected into the right striatum of the brain to replicate the Parkinson’s disease (PD) model of mice, and then daily intraperitoneal injection of mTORC2/Akt signaling pathway agonist A-443654 or inhibitor PP242. Serum interleukin-1β (IL-1β) and tumor necrosis factor-α(TNF-α)levels were measured by enzyme-linked immunosorbent assay. Immunohistochemistry and immunofluorescence staining were performed to investigate the change of microglia, dopaminergic neurons as well as neural progenitor cells (NPCs). Western blotting was used to detect the expression of related protein of mTORC2/Akt signaling pathway including rictor, p-Akt and regulated in development and DNA dgmage responses 1(REDD1) and the interaction between them were verified by immunoprecipitation. Finally, the behavioral performance of each group of mice was observed. Results With the activation of microglia and the increase of inflammatory factors in PD model mice, the number of dopaminergic neurons in the substantia nigra(SN) decreased significantly, and the motor function of the mice was impaired, but the number of NPCs increased significantly compared with the control mice, mTORC2/Akt signaling pathway related protein expression was also significantly up-regulated. A-443654 treatment further up-regulated the expression of these proteins, meanwhile the indicators mentioned above were ameliorated. However, the inhibitor PP242 treatment group showed completely opposite result with the agonist group. Conclusion A-443654 can promote the proliferation of NPCs and the number of new-born dopaminergic neurons by up-regulating related proteins of mTORC2/Akt signaling pathway, and reducing the activation of microglia and the level of inflammation factors, which ultimately lead to the amelioration of SN-striatal dopaminergic neurons and behavioral performance in PD model mice.

Effect and molecular mechanism of mammalian target of rapamycin complex 2 / Akt signaling pathway on 6-hydroxydopamine-treated SH-SY5Y cell model / 解剖学报

[Abstract] Objective To study whether the regulation of mammalian target of rapamycin complex 2(mTORC2) / Akt signaling pathway has a protective effect on SH-SY5Y cell line damaged by 6-hydroxydopamine (6-OHDA), and to clarify its molecular mechanism. Methods SH-SY5Y cells treated with retinoic acid (RA) were given 6-OHDA, mTORC2 signaling pathway inhibitor PP242 and agonist A-443654 respectively. The changes of cell number in each group were investigated by immunofluorescent staining; The total protein was extracted and the expression level and interaction of key proteins in mTORC2 signaling pathway were determined by Western blotting and co-immunoprecipitation (CoIP); The apoptosis rate of cells in each group was detected by flow cytometry. At the same time, the co-culture Parkinson’ s disease (PD) model was made using SH-SY5Y cell line and Bv-2 cell line; MTT colorimetric method was used to detect the cell viability of each group; ELISA was used to detect the content of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in cell culture supernatant. Results The number of tyrosine hydroxylase(TH) / proliferating cell nuclear antigen (PCNA) / hochest-, TH / 5-bronmo-2’ -deoxyuridine(BrdU) -labeled positive cells in 6-OHDA-lesioned PD cell model group was significantly lower than that in the normal group; The apoptosis rate was higher; The expression of Rictor, p-Akt and regulated in DNA damage and development 1(REDD1) was increased; There was an interaction between Rictor and p-Akt or REDD1; The cell viability was significantly reduced in the co-culture model; the content of TNF-α and IL-β increased in the cell culture supernatant. With further up-regulation of the abovementioned protein expressions, the cell survival, apoptosis and pro-inflammatory cytokine levels in A-443654 group were significantly ameliorated, while PP242 group showed the opposite changes. Conclusion A-443654 activates mTORC2 signaling pathway by p-Akt, which increases the expression of Rictor and REDD1 protein. These changes contribute to the amelioration in cell survival rate, apoptosis rate, and the proliferation and differentiation and decreasion of apoptosis rate of SH-SY5Y cells. These result improved 6-OHDA-induced cell damage and inhibited the release of pro-inflammatory cytokines.

Effect of recombination signal binding protein for immunoglobulin Kappa J region on the proliferation and differentiation of CD133-positive ependymal cells / 解剖学报

Objective To explore the effect of recombination signal binding protein for immunoglobulin Kappa J region (RBP-Jκ) on the proliferation and differentiation of CD133￣positive ependymal cells and its possible mechanism. Methods RBP-Jκ in CD133-positive ependymal cells of lateral ventricle was interfered with siRNA in the fetuses of embryos which were isolated from 12-day pregnant Institute of Cancer Research(ICR) mouse (3 mice) and knocked out in CD133-CreER

Allopregnanolone protecting cell line SH-SY5Y against 6-hydroxydopamine-induced lesion / 解剖学报

Objective To clarify the protective effect of allopregnanolone (APα) on cell line SH-SY5Y damaged by 6-hydroxydopamine (6-OHDA) and its possible molecular mechanism. Methods 6-OHDA, APα, γ-aminobutyric acid A receptor (GABAAR) antagonist, voltage-gated L-type Ca2

Allopregnanolone restores dopaminergic neurons and motor performance in Parkinson’s disease mice and its molecular mechanisms / 解剖学报

[ Abstract] Objective To investigate the effects of allopregnanolone (APα) on the dopaminergic neurons in substantia nigra, striatal dopaminergic neural fibers and behavioral performance in Parkinson’ s disease (PD) model mice, as well as its possible molecular mechanisms. Methods C57BL / 6 adult male mice with 20-25 g at 3-month old (n = 90) were successively injected with 6-hydroxydopamine (6-OHDA) to generate a PD animal model. APα and its receptor γ-aminobutyric acid A receptor (GABAAR) antagonist—bicuculline (Bic) were successively injected. ELISA was used to detect the APα or dopamine concentration in the serum, cerebral cortex and striatum. The number of tyrosine hydroxylase (TH) in the substantia nigra (SN) and striatal dopaminergic neural projections were examined by immunohistochemical staining. The expression levels of GABAAR in membrane fractions and Ca

Effect of curcumin on the learning, memory and hippocampal Ca+/CaMK II level in senescence-accelerated mice / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore effect of curcumin in different concentrations on learning and memory of senescence-accelerated mice (SAM) and their possible mechanisms.</p><p><b>METHODS</b>Mice were randomly divided into six groups: the SAMR1 normal control group, the SAMP8 model control group, the SAMP8 + solvent (the peanut oil) control group, SAMP8 + low, middle and high dose curcumin groups. Mice were gastrogavage for 25 successive days. On the next day of ending the experiment, changes of learning and memory in mice of each group were observed by Morris water maze. The hippocampal [Ca2+] was determined. Expressions of hippocampal calmodulin-dependent protein kinase II (CaMK II) and Calmodulin (CaM) mRNA were detected using Western blot and reverse transcription polymerase chain reaction (RT-PCR) respectively.</p><p><b>RESULTS</b>The latency to find the hidden platform was remarkably prolonged, the hippocampal [Ca2+]i was markedly increased, the expression of CaMK II in the hippocampal membrane and the level of hippocampal CaM mRNA were significantly reduced in the SAMP8-model control group (P < 0.05, P < 0.01). The latency to find the hidden platform was remarkably shortened in the SAMP8 + middle dose curcumin and the SAMP8 + high dose curcumin groups (P < 0.01). The hippocampal [Ca2+]i was markedly lowered, the expression of CaMK II in the hippocampal membrane and the level of hippocampal CaM mRNA obviously increased in the SAMP8 + low, middle and high dose curcumin groups (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>Curcumin could improve learning and memory Ca2+/capacities of SAM by lowering hippocampal [Ca2+] overload, increase the hippocampal CaM mRNA level and CaMK II expression in the hippocampal dose-dependently.</p>

Effect of Rhizoma curcumae oil on the learning and memory in rats exposed to chronic hypoxia and the possible mechanisms / 生理学报

The effect of Rhizoma curcumae oil on the learning and memory in rats exposed to chronic hypoxia and the possible mechanisms were investigated. The rats were divided randomly into 5 groups (14 animals in each group): control, chronic hypoxia, chronic hypoxia with low (5 mg/kg body weight), middle (10 mg/kg body weight) and high (20 mg/kg body weight) concentrations of Rhizoma curcumae oil injection. The animals undergoing chronic hypoxia were exposed to hypoxia in a hypoxic chamber containing 10% O(2) and 5% CO(2) for 10 h/d, lasting 28 d. Morris water maze (MWM) test was used to obtain the scores of leaning and memory. The superoxide dismutase (SOD) activity and malonaldehyde (MDA) content were determined in the serum and hippocampus as well as [Ca(2+)](i) in the hippocampus. The expression of phosphorylated Ca(2+)/calmodulin-dependent protein kinase II (p-CaMKII) in the hippocampus was evaluated by using immunohistochemistry and Western blot. Compared with the control group, the chronic hypoxia group showed the following changes: (1) The escape latency to the hidden platform was remarkably prolonged (P<0.05); (2) The content of MDA and [Ca(2+)](i) were obviously higher, but the activity of SOD and the expression of p-CaMKII were significantly lower (P<0.05, P<0.01). Compared with the chronic hypoxia group, groups with Rhizoma curcumae oil injection had the following changes: (1) The escape latency to the hidden platform was remarkably shorter in 10, 20 mg/kg body weight groups (P<0.05); (2) The content of MDA and [Ca(2+)](i) were markedly decreased in 5, 10, 20 mg/kg body weight groups (P<0.05, P<0.01), but the activity of SOD in the serum and the expression of p-CaMKII were significantly higher in 10, 20 mg/kg body weight groups (P<0.05, P<0.01). The results showed that the capacity of learning and memory was degraded following chronic hypoxia. The decrease in MDA content and [Ca(2+)](i) and (or) the increase in SOD activity and p-CaMKII expression might participate in the enhancing effect on learning and memory induced by Rhizoma curcumae oil.

Study on angle and depth of needle insertion in acupuncture at Zusanli (ST 36) / 中国针灸

<p><b>OBJECTIVE</b>To provide an appropriate angle and depth of needle insertion in acupuncture at Zusanli (ST 36) and avoid injuring the nerve and blood vessel and exert the most effect.</p><p><b>METHODS</b>Eighty adult lower-limb samples were used to dissect and observe the relative layered structures and adjoining important nerves and blood vessels in needling Zusanli (ST 36) according to the national standard.</p><p><b>RESULTS</b>The needling depth from the skin to the interosseous membrane and from the skin to posterior border of tibialis posterior is (2.22 +/- 0.31) cm and (4.42 +/- 0.53) cm, respectively. There are flabellate branches of anterior tibial arteries and deep peroneal nerves around the needle in the superficial layer of interosseous membrane. The vessel and nerve bundles containing tibial nerve and posterior tibial vessels can be touched when the needle body past through tibialis posterior.</p><p><b>CONCLUSION</b>It is recommended that ideal average depth of acupuncture is 2.22 cm and the maximum depth is 4.42 cm for oblique needling Zusanli (ST 36). When it is injected, the needle should be perpendicularly inserted or deviated slightly to the direction of tibia and paralleled to medial surface of tibia. And the safe needling depth is generally less than 5 cm. The point of the body surface between tibialis anterior and extensor digitorum longus at 3 cun below Dubi (ST 35) is also an effectively stimulating point.</p>

Changes of learning, memory and levels of CaMKII, CaM mRNA, CREB mRNA in the hippocampus of chronic multiple-stressed rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The effect of chronic stress on cognitive functions has been one of the hot topic in neuroscience. But there has been much controversy over its mechanism. Such single stressor applied in the past could not simulate complicated living circumstances that people confronted with. The aim of this study was to investigate the effects of chronic multiple-stress on learning and memory as well as on the levels of calcium/calmodulin-dependent protein kinase II (CaMKII), calmodulin (CaM) mRNA, and cAMP-response element binding protein (CREB) mRNA in the hippocampus of rats.</p><p><b>METHODS</b>The rats were divided randomly into stressed and control groups. The stressed group was given chronic multiple-stress for 6 weeks to set up a chronic multiple-stressed model. The rats' performance of spatial learning and memory was tested using Morris Water Maze (MWM) and Y-maze. Meanwhile, the expressions of CaMKII, CaM mRNA and CREB mRNA of rats' hippocampus were detected by immunohistochemistry, Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. In addition, the width of synaptic cleft and the thickness of post-synaptic densities (PSD) were observed in the hippocampal CA3 region of rats by electron microscopy.</p><p><b>RESULTS</b>After exposure to chronic multiple-stress for 6 weeks, the ability of learning and memory of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). The width of synaptic cleft was smaller and the thickness of PSD was larger in the hippocampal CA3 region of the stressed group than in that of the control group (P < 0.01). The CaMK II immunostaining of the stressed group was stronger than that of the control group in the stratum radiatum and oriens of the hippocampal CA1 and CA3, especially in the stratum oriens. Quantitative analysis indicated that the expression of CaMK II, CaM mRNA, and CREB mRNA in the hippocampus of the stressed group was higher than that of the control group (P < 0.05, P < 0.01).</p><p><b>CONCLUSIONS</b>The capacity of learning and memory can be enhanced after chronic multiple-stress. The increased levels of CaMK II, CaM mRNA, and CREB mRNA may contribute to the enhancing effect of chronic multiple-stress on learning and memory.</p>

Chronic multiple stress enhances learning and memory capability in rats / 生理学报

The present study aimed at investigating the effects of chronic multiple stress on learning and memory functions of rats. Adult male Wistar rats were randomly divided into stressed and control groups. Rats in the stressed group were irregularly and alternately exposed to the situation of vertical revolution, sleep deprivation, noise stimulation, and night illumination 6 h per day for 6 weeks to prepare a chronic multiple stressed model. Learning and memory performance of rats was measured by using Morris water maze first and Y-maze afterwards. Neurons in the dentate gyrus(DG), CA3 and CA1 regions of the hippocampus were stained by using Cresyl violet method and counted. The results showed that: (1) After chronic multiple stress, compared with the control rats, the escape latency to the hidden platform in Morris water maze was significantly shortened in stressed rats. In stressed and control groups, the escape latency periods were (15.89+/-9.15) s and (27.30+/-12.51) s, respectively, indicating that spatial memory of the stressed rats was stronger than that of the control ones. In brightness-darkness discrimination learning in the Y- maze, the correct trials and correct percentage of entering safe arm was remarkably increased in the stressed rats, the correct rates of stressed and control groups were (79.01+/-1.23)% and (66.12+/-1.61)%, respectively, indicating that brightness-darkness discrimination learning ability of the stressed rats was better than that of the control ones. (2) After chronic multiple stress, nerve cell density in DG, CA1 and CA3 of the hippocampus in stressed rats was higher than that of the control group, the cell densities in DG, CA1 and CA3 of the stressed and the control group were (223.78+/-26.52), (112.07+/-14.23) and (105.55+/-18.12) as well as (199.13+/-15.36), (92.89+/-13.69), and (89.02+/-15.77) respectively. These results suggest that the chronic multiple stress may enhance the capability of spatial memory and brightness-darkness discrimination learning of rats. Possible reasons for the chronic multiple stress-induced learning and memory enhancement of rats were also discussed.