1
|
Sarkala HB, Jahanshahi M, Dolatabadi LK, Namavar MR. G-CSF improved the memory and dendritic morphology impairments in the hippocampal CA1 pyramidal neurons after brain ischemia in the male rats. Metab Brain Dis 2023; 38:2573-2581. [PMID: 37728699 DOI: 10.1007/s11011-023-01286-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 09/01/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUND Stroke remains the leading cause of death and disability in the world. A new potential treatment for stroke is the granulocyte colony-stimulating factor (G-CSF), which exerts neuroprotective effects through multiple mechanisms. Memory impairment is the most common cognitive problem after a stroke. The suggested treatment for memory impairments is cognitive rehabilitation, which is often ineffective. The hippocampus plays an important role in memory formation. This project aimed to study the effect of G-CSF on memory and dendritic morphology of hippocampal CA1 pyramidal neurons after middle cerebral artery occlusion (MCAO)in rats. METHODS Male Sprague-Dawley rats were divided into three groups: the sham, control (MCAO + Vehicle), and treatment (MCAO + G-CSF) groups. G-CSF (50 µg/kg S.C) was administered at 6, 24, and 48 h after brain ischemia induction. The passive avoidance task to evaluate learning and memory was performed on days 6 and 7 post-ischemia. Seven days after MCAO, the brain was removed and the hippocampal slices were stained with Golgi. After that, the neurons were analyzed for dendritic morphology and maturity. OUTCOMES The data showed that stroke was associated with a significant impairment in the acquisition and retention of passive avoidance tasks, while the G-CSF improved learning and memory loss. The dendritic length, arborization, spine density, and mature spines of the hippocampus CA1 neurons were significantly reduced in the control group, and treatment with G-CSF significantly increased these parameters. CONCLUSION G-CSF, even with three doses, improved learning and memory deficits, and dendritic morphological changes in the CA1 hippocampal neurons resulted from brain ischemia.
Collapse
Affiliation(s)
- Hamzeh Badeli Sarkala
- Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Jahanshahi
- Neuroscience Research Center, Department of Anatomy, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran
| | - Leila Kamali Dolatabadi
- Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
- Alzahra Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Reza Namavar
- Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
- Clinical Neurology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| |
Collapse
|
2
|
Different changes in pre- and postsynaptic components in the hippocampal CA1 subfield after transient global cerebral ischemia. Brain Struct Funct 2021; 227:345-360. [PMID: 34626230 DOI: 10.1007/s00429-021-02404-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022]
Abstract
To date, ischemia-induced damage to dendritic spines has attracted considerable attention, while the possible effects of ischemia on presynaptic components has received relatively less attention. To further examine ischemia-induced changes in pre- and postsynaptic specializations in the hippocampal CA1 subfield, we modeled global cerebral ischemia with two-stage 4-vessel-occlusion in rats, and found that three postsynaptic markers, microtubule-associated protein 2 (MAP2), postsynaptic density protein 95 (PSD95), and filamentous F-actin (F-actin), were all substantially decreased in the CA1 subfield after ischemia/reperfusion (I/R). Although no significant change was detected in synapsin I, a presynaptic marker, in the CA1 subfield at the protein level, confocal microscopy revealed that the number and size of synapsin I puncta were significantly changed in the CA1 stratum radiatum after I/R. The size of synapsin I puncta became slightly, but significantly reduced on Day 1.5 after I/R. From Days 2 to 7 after I/R, the number of synapsin I puncta became moderately decreased, while the size of synapsin I puncta was significantly increased. Interestingly, some enlarged puncta of synapsin I were observed in close proximity to the dendritic shafts of CA1 pyramidal cells. Due to the more substantial decrease in the number of F-actin puncta, the ratio of synapsin I/F-actin puncta was significantly increased after I/R. The decrease in synapsin I puncta size in the early stage of I/R may be the result of excessive neurotransmitter release due to I/R-induced hyperexcitability in CA3 pyramidal cells, while the increase in synapsin I puncta in the later stage of I/R may reflect a disability of synaptic vesicle release due to the loss of postsynaptic contacts.
Collapse
|
3
|
Memory deficits and hippocampal inflammation in cerebral hypoperfusion and reperfusion in male rats: Neuroprotective role of vanillic acid. Life Sci 2018; 211:126-132. [PMID: 30195619 DOI: 10.1016/j.lfs.2018.08.065] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 08/20/2018] [Accepted: 08/27/2018] [Indexed: 11/20/2022]
Abstract
Ischemic stroke is one of the leading causes of neurological deterioration and mortality worldwide. Neuroprotective strategies are being investigated to minimize cognitive deficits after ischemic events. Here we investigated the neuroprotective potential of vanillic acid (VA) in an animal model of transient bilateral common carotid artery occlusion and reperfusion (BCCAO/R). Adult male Wistar rats (250-300 g) were randomly divided in 4 groups and submitted to either cerebral hypoperfusion-reperfusion or a sham surgery after two-weeks of pretreatment with VA and/or normal saline. To induce the animal model of hypoperfusion, bilateral common carotid arteries were occluded (2VO model) for 30 min, followed by 72 h of reperfusion. Subsequently, their cognitive performance was evaluated in a Morris water maze (MWM) test, and also hippocampi were removed for ELISA assays and TUNEL staining test. The results showed that 2VO significantly reduced the spatial memory performance in MWM. As well as, BCCAO/R increased the level of IL-6, TNF-α and TUNEL positive cells, and also decreased the contents of IL-10 in the hippocampus of vehicle- pretreated groups as compared to the sham-operated groups. Furthermore, 14 consecutive days pretreatment with VA significantly restored the spatial memory, decreased the levels of IL-6, TNF-α and TUNEL positive cells and also increased the IL-10 levels in the hippocampi of the BCCAO/R rats. VA alone did not show any change neither in the status of various cytokines nor behavioral and TUNEL staining tests over sham values. Our data confirm that VA could potentially serve as a novel, promising, and accessible neuroprotective agent against cerebrovascular insufficiency states and vascular dementia.
Collapse
|
4
|
Cui X, Fu Z, Wang M, Nan X, Zhang B. Pitavastatin treatment induces neuroprotection through the BDNF-TrkB signalling pathway in cultured cerebral neurons after oxygen-glucose deprivation. Neurol Res 2018; 40:391-397. [PMID: 29544396 DOI: 10.1080/01616412.2018.1447318] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVES Along with their lipid-lowering effect, statins have been reported to have neuroprotective function in both in vivo and in vitro models of neurodegenerative diseases. We conducted this study in order to uncover the he neuroprotective effect of the lipophilic statin pitavastatin (PTV) and investigate the underlying molecular mechanisms using primary cultured cerebral neurons exposed to oxygen-glucose deprivation (OGD). METHODS The primary cultured cerebral neurons were randomly assigned into four groups: the control group, the pitavastatin treatment group, the OGD group and the OGD + pitavastatin treatment group. The pitavastatin's concentration were set as follows: 1μM, 15μM, 30μM. After 3 hours OGD treatment, we use MTT method to assessment cell viability, immunofluorescence to observe neuron morphology and western blot method analysis the BDNF, TrkB. RESULTS PTV at concentrations of 1 μM and 15 μM elevated the survival rate of cortical neurons exposed to OGD, whereas 30 μM PTV did not show such an effect. Moreover, PTV promoted neuronal dendrite growth at concentrations of 1 μM and 15 μM. Increased expression levels of brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) were observed in both of the following two scenarios: when neurons were treated with PTV for 48 hours and when PTV was added after the OGD procedure. CONCLUSION Pitavastatin treatment induces neuroprotection in cultured cerebral neurons after oxygen-glucose deprivation this neuroprotection induced by PTV involves the BDNF-TrkB signalling pathway.
Collapse
Affiliation(s)
- Xiaoyan Cui
- a Department of Neurology , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Zhenqiang Fu
- a Department of Neurology , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Menghan Wang
- a Department of Neurology , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Xiaofei Nan
- c School of Information and Engineering , Zhengzhou University , Zhengzhou , China
| | - Boai Zhang
- a Department of Neurology , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China.,b Institute of Clinical Medical Research , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| |
Collapse
|
5
|
Li X, Liu RZ, Zeng Q, Huang ZH, Zhang JD, Liu ZL, Zeng J, Xiao H. 3'-Daidzein sulfonate sodium protects against memory impairment and hippocampal damage caused by chronic cerebral hypoperfusion. Neural Regen Res 2018; 13:1561-1567. [PMID: 30127116 PMCID: PMC6126135 DOI: 10.4103/1673-5374.237119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
3′-Daidzein sulfonate sodium (DSS) is a new synthetic water-soluble compound derived from daidzein, a soya isoflavone that plays regulatory roles in neurobiology. In this study, we hypothesized that the regulatory role of DSS in neurobiology exhibits therapeutic effects on hippocampal damage and memory impairment. To validate this hypothesis, we established rat models of chronic cerebral hypoperfusion (CCH) by the permanent occlusion of the common carotid arteries using the two-vessel occlusion method. Three weeks after modeling, rat models were intragastrically administered 0.1, 0.2, and 0.4 mg/kg DSS, once a day, for 5 successive weeks. The Morris water maze test was performed to investigate CCH-induced learning and memory deficits. TUNEL assay was used to analyze apoptosis in the hippocampal CA1, CA3 regions and dentate gyrus. Hematoxylin-eosin staining was performed to observe the morphology of neurons in the hippocampal CA1, CA3 regions and dentate gyrus. Western blot analysis was performed to investigate the phosphorylation of PKA, ERK1/2 and CREB in the hippocampal PKA/ERK1/2/CREB signaling pathway. Results showed that DSS treatment greatly improved the learning and memory deficits of rats with CCH, reduced apoptosis of neurons in the hippocampal CA1, CA3 regions and dentate gyrus, and increased the phosphorylation of PKA, ERK1/2, and CREB in the hippocampus. These findings suggest that DSS protects against CCH-induced memory impairment and hippocampal damage possibly through activating the PKA/ERK1/2/CREB signaling pathway.
Collapse
Affiliation(s)
- Xiao Li
- Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Rui-Zhen Liu
- Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Qi Zeng
- Department of Ultrasound, First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Zhi-Hua Huang
- Gannan Medical University, Ganzhou, Jiangxi Province, China
| | | | - Zong-Liang Liu
- Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Jing Zeng
- Gannan Medical University, Ganzhou, Jiangxi Province, China
| | - Hai Xiao
- Department of Pathology, First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi Province, China
| |
Collapse
|
6
|
Electroacupuncture Ameliorates Learning and Memory and Improves Synaptic Plasticity via Activation of the PKA/CREB Signaling Pathway in Cerebral Hypoperfusion. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:7893710. [PMID: 27829866 PMCID: PMC5088321 DOI: 10.1155/2016/7893710] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/18/2016] [Indexed: 12/19/2022]
Abstract
Electroacupuncture (EA) has shown protective effects on cognitive decline. However, the underlying molecular mechanisms are ill-understood. The present study was undertaken to determine whether the cognitive function was ameliorated in cerebral hypoperfusion rats following EA and to investigate the role of PKA/CREB pathway. We used a rat 2-vessel occlusion (2VO) model and delivered EA at Baihui (GV20) and Dazhui (GV14) acupoints. Morris water maze (MWM) task, electrophysiological recording, Golgi silver stain, Nissl stain, Western blot, and real-time PCR were employed. EA significantly (1) ameliorated the spatial learning and memory deficits, (2) alleviated long-term potentiation (LTP) impairment and the reduction of dendritic spine density, (3) suppressed the decline of phospho-CREB (pCREB) protein, brain-derived neurotrophic factor (BDNF) protein, and microRNA132 (miR132), and (4) reduced the increase of p250GAP protein of 2VO rats. These changes were partially blocked by a selective protein kinase A (PKA) inhibitor, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide (H89), suggesting that the PKA/CREB pathway is potentially involved in the effects of EA. Moreover, any significant damage to the pyramidal cell layer of CA1 subregion was absent. These results demonstrated that EA could ameliorate learning and memory deficits and alleviate hippocampal synaptic plasticity impairment of cerebral hypoperfusion rats, potentially mediated by PKA/CREB signaling pathway.
Collapse
|
7
|
Wang Z, Fan J, Wang J, Li Y, Duan D, Du G, Wang Q. Chronic cerebral hypoperfusion induces long-lasting cognitive deficits accompanied by long-term hippocampal silent synapses increase in rats. Behav Brain Res 2016; 301:243-52. [PMID: 26756439 DOI: 10.1016/j.bbr.2015.12.047] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 12/29/2015] [Accepted: 12/29/2015] [Indexed: 11/26/2022]
Abstract
Synaptic dysfunction underlies cognitive deficits induced by chronic cerebral hypoperfusion (CCH). There are silent synapses in neural circuits, but the effect of CCH on silent synapses is unknown. The present study was designed to explore learning and memory deficits and dynamic changes in silent synapses by direct visualization in a rat model of CCH. Adult male Sprague-Dawley rats were subjected to permanent bilateral common carotid artery occlusion (BCCAO) to reproduce CCH. Learning and memory effects were examined at 1, 4, 12, and 24 weeks after BCCAO. In addition, immunofluorescent confocal microscopy was used to detect AMPA and N-methyl-d-aspartate receptors colocalized with synaptophysin, and Golgi-Cox staining was used to observe dendritic spine density. We found that BCCAO rats exhibited recognition memory deficits from 4 weeks; spatial learning and memory, as well as working memory impairment began at 1 week and persistent to 24 weeks after surgery. Following BCCAO, the percentage of silent synapses increased by 29.81-55.08% compared with the controls at different time points (P<0.001). Compared with control groups, dendritic spine density in the CA1 region of BCCAO groups significantly decreased (P<0.001). Thus, the present study suggests that CCH can induce long-lasting cognitive deficits and long-term increase in the number of silent synapses. Furthermore, the decrease in dendritic spine density was correlated with the decrease in the number of functional synapses. The results suggest a potential mechanism by which CCH can induce learning and memory deficits.
Collapse
Affiliation(s)
- Zhiqiang Wang
- The Graduate Management Team, The Third Military Medical University, Chongqing 400038, China; Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Jin Fan
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Jian Wang
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Yuxia Li
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Dan Duan
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Guo Du
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China
| | - Qingsong Wang
- Department of Neurology, Chengdu Military General Hospital, Chengdu 610083, China.
| |
Collapse
|
8
|
Li N, Gu Z, Li Y, Fu X, Wang J, Bai H. A modified bilateral carotid artery stenosis procedure to develop a chronic cerebral hypoperfusion rat model with an increased survival rate. J Neurosci Methods 2015; 255:115-21. [DOI: 10.1016/j.jneumeth.2015.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/03/2015] [Accepted: 08/04/2015] [Indexed: 12/18/2022]
|
9
|
Bayat M, Sharifi MD, Haghani M, Shabani M. Enriched environment improves synaptic plasticity and cognitive deficiency in chronic cerebral hypoperfused rats. Brain Res Bull 2015; 119:34-40. [PMID: 26474515 DOI: 10.1016/j.brainresbull.2015.10.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/02/2015] [Accepted: 10/07/2015] [Indexed: 12/12/2022]
Abstract
Recent studies have indicated that environmental enrichment (EE) increases the sensorial and social stimulations and leads to strengthened plastic changes in the brain. In models of chronic cerebral hypoperfusion, the ability of an EE to restore the cognition depends on hippocampal synaptic plasticity. The mechanisms for this effect have not, however, been adequately studied. Thus, the aim of the present study was to evaluate the neuroprotective effects and underlying mechanism of environmental enrichment by assessment of spatial memory tasks as well as parameters of synaptic plasticity in rats subjected to occlusion of the bilateral common carotid arteries (2-VO) model. Male Sprague-Dawley rats were used in this study. The model group was established by occlusion of the bilateral common carotid arteries. The animals were tested for learning, memory performance and synaptic plasticity using Morris water maze (MWM), 8-arm Radial Maze (RM), and field potential recording, respectively. The rats subjected to 2-VO in EE exhibited a significantly lower number of working errors and reference errors in RM. Moreover, the enriched environment recovered the memory performance of hypoperfused rats and decreased the swimming time to reach the platform in MWM. In addition, conditions of the environment did not have any effect on baseline synaptic transmission and presynaptic plasticity, but housing the animals in EE rescued the impairment of LTP induction induced by 2-VO. These results suggest that EE ameliorates the LTP and spatial memory impairment induced by 2-VO. Our data indicated that the LTP recovery by EE in the rat models of 2-VO is probably mediated by post-synaptic mechanisms.
Collapse
Affiliation(s)
- Mahnaz Bayat
- Department of Physiology, International Branch, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Mohammad Davood Sharifi
- Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Masoud Haghani
- Histomorphometry and Stereology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran; Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Mohammad Shabani
- Kerman Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
| |
Collapse
|
10
|
Kim DH, Choi BR, Jeon WK, Han JS. Impairment of intradimensional shift in an attentional set-shifting task in rats with chronic bilateral common carotid artery occlusion. Behav Brain Res 2015; 296:169-176. [PMID: 26365458 DOI: 10.1016/j.bbr.2015.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/25/2015] [Accepted: 09/07/2015] [Indexed: 01/08/2023]
Abstract
Studies of rats with chronic bilateral common carotid artery occlusion (BCCAo), an animal model for vascular dementia (VaD), have reported hippocampus-dependent memory impairment and associated neuropathologies. Patients with VaD also experience attentional shifting dysfunction. However, animal models of VaD have not been used to study attentional function. Therefore, the present study examined attentional function in rats with BCCAo, using attentional set-shifting task (ASST) that required rats to choose a food-baited pot from 2 possible pots. ASST included 6 consecutive sessions including simple discrimination, compound discrimination, intradimensional shifting, extradimensional shifting, and reversals. The BCCAo rats were significantly slower at learning the intradimensional set-shifting task compared to control rats. Previous studies have demonstrated that the cingulate cortex and medial prefrontal cortex are critical to intradimensional and extradimensional set-shifting, respectively. Additionally, inflammatory responses and neuronal dysfunction were observed in rats with chronic BCCAo. In addition, OX-6 positive microglia significantly increased in the forceps minor white matter of BCCAo rats, and glutamate decarboxylase signals co-localized with NeuN were reduced in the anterior cingulate cortex of BCCAo rats, compared to control rats. Impaired neuronal and GABAergic neuronal integrity in the anterior cingulate cortex, damage to white matter, and attentional impairments observed in BCCAo rats suggest dysfunction of brain structures that are associated with attentional impairments observed in patients with VaD.
Collapse
Affiliation(s)
- Dong-Hee Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Bo-Ryoung Choi
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Won Kyung Jeon
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea
| | - Jung-Soo Han
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea.
| |
Collapse
|
11
|
Li CJ, Lu Y, Zhou M, Zong XG, Li C, Xu XL, Guo LJ, Lu Q. Activation of GABAB receptors ameliorates cognitive impairment via restoring the balance of HCN1/HCN2 surface expression in the hippocampal CA1 area in rats with chronic cerebral hypoperfusion. Mol Neurobiol 2014; 50:704-20. [PMID: 24838625 DOI: 10.1007/s12035-014-8736-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 04/29/2014] [Indexed: 11/30/2022]
Abstract
Hyperpolarization-activated cyclic-nucleotide-gated cation nonselective (HCN) channels are involved in the pathology of nervous system diseases. HCN channels and γ-aminobutyric acid (GABA) receptors can mutually co-regulate the function of neurons in many brain areas. However, little is known about the co-regulation of HCN channels and GABA receptors in the chronic ischemic rats with possible features of vascular dementia. Protein kinase A (PKA) and TPR containing Rab8b interacting protein (TRIP8b) can modulate GABAB receptors cell surface stability and HCN channel trafficking, respectively, and adaptor-associated kinase 1 (AAK1) inhibits the function of the major TRIP8b-interacting protein adaptor protein 2 (AP2) via phosphorylating the AP2 μ2 subunit. Until now, the role of these regulatory factors in chronic cerebral hypoperfusion is unclear. In the present study, we evaluated whether and how HCN channels and GABAB receptors were pathologically altered and investigated neuroprotective effects of GABAB receptors activation and cross-talk networks between GABAB receptors and HCN channels in the hippocampal CA1 area in chronic cerebral hypoperfusion rat model. We found that cerebral hypoperfusion for 5 weeks by permanent occlusion of bilateral common carotid arteries (two-vessel occlusion, 2VO) induced marked spatial and nonspatial learning and memory deficits, significant neuronal loss and decrease in dendritic spine density, impairment of long-term potentiation (LTP) at the Schaffer collateral-CA1 synapses, and reduction of surface expression of GABAB R1, GABAB R2, and HCN1, but increase in HCN2 surface expression. Meanwhile, the protein expression of TRIP8b (1a-4), TRIP8b (1b-2), and AAK1 was significantly decreased. Baclofen, a GABAB receptor agonist, markedly improved the memory impairment and alleviated neuronal damage. Besides, baclofen attenuated the decrease of surface expression of GABAB R1, GABAB R2, and HCN1, but downregulated HCN2 surface expression. Furthermore, baclofen could restore expression of AAK1 protein and significantly increase p-PKA, TRIP8b (1a-4), TRIP8b (1b-2), and p-AP2 μ2 expression. Those findings suggested that, under chronic cerebral hypoperfusion, activation of PKA could attenuate baclofen-induced decrease in surface expression of GABAB R1 and GABAB R2, and activation of GABAB receptors not only increased the expression of TRIP8b (1a-4) and TRIP8b (1b-2) but also regulated the function of TRIP8b via AAK1 and p-AP2 μ2, which restored the balance of HCN1/HCN2 surface expression in rat hippocampal CA1 area, and thus ameliorated cognitive impairment.
Collapse
Affiliation(s)
- Chang-jun Li
- Department of Pharmacology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
12
|
LEÓN R, PAVÓN N, PENTÓN G, ALMAGUER W, MARÍN J, CRUZ A, LORIGADOS L, BLANCO L, ESTUPIÑÁN B, MERCERON D, MACÍAS L, BERGADO J. Experimental Model of Cerebral Hypoperfusion Produced Memory-learning Deficits, and Modifications in Gene Expression. ACTA BIOLÓGICA COLOMBIANA 2014. [DOI: 10.15446/abc.v20n1.40976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|