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Li Z, Jiang YY, Long C, Peng X, Tao J, Pu Y, Yue R. Bridging metabolic syndrome and cognitive dysfunction: role of astrocytes. Front Endocrinol (Lausanne) 2024; 15:1393253. [PMID: 38800473 PMCID: PMC11116704 DOI: 10.3389/fendo.2024.1393253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/25/2024] [Indexed: 05/29/2024] Open
Abstract
Metabolic syndrome (MetS) and cognitive dysfunction pose significant challenges to global health and the economy. Systemic inflammation, endocrine disruption, and autoregulatory impairment drive neurodegeneration and microcirculatory damage in MetS. Due to their unique anatomy and function, astrocytes sense and integrate multiple metabolic signals, including peripheral endocrine hormones and nutrients. Astrocytes and synapses engage in a complex dialogue of energetic and immunological interactions. Astrocytes act as a bridge between MetS and cognitive dysfunction, undergoing diverse activation in response to metabolic dysfunction. This article summarizes the alterations in astrocyte phenotypic characteristics across multiple pathological factors in MetS. It also discusses the clinical value of astrocytes as a critical pathologic diagnostic marker and potential therapeutic target for MetS-associated cognitive dysfunction.
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Affiliation(s)
- Zihan Li
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ya-yi Jiang
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Caiyi Long
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xi Peng
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jiajing Tao
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yueheng Pu
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Rensong Yue
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Clinical Medical School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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2
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Pauziene N, Ranceviene D, Rysevaite-Kyguoliene K, Inokaitis H, Saburkina I, Plekhanova K, Sabeckiene D, Sabeckis I, Martinaityte R, Pilnikovaite E, Pauza DH. Comparative analysis of intracardiac neural structures in the aged rats with essential hypertension. Anat Rec (Hoboken) 2023; 306:2313-2332. [PMID: 36342958 DOI: 10.1002/ar.25109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/16/2022] [Accepted: 10/09/2022] [Indexed: 11/09/2022]
Abstract
Persistent arterial hypertension initiates cardiac autonomic imbalance and alters cardiac tissues. Previous studies have shown that neural component contributes to arterial hypertension etiology, maintenance, and progression and leads to brain damage, peripheral neuropathy, and remodeling of intrinsic cardiac neural plexus. Recently, significant structural changes of the intracardiac neural plexus were demonstrated in young prehypertensive and adult hypertensive spontaneously hypertensive rats (SHR), yet structural alterations of intracardiac neural plexus that occur in the aged SHR remain undetermined. Thus, we analyzed the impact of uncontrolled arterial hypertension in old (48-52 weeks) SHR and the age-matched Wistar-Kyoto rats (WKY). Intrinsic cardiac neural plexus was examined using a combination of immunofluorescence confocal microscopy and transmission electron microscopy in cardiac sections and whole-mount preparations. Our findings demonstrate that structural changes of intrinsic cardiac neural plexus caused by arterial hypertension are heterogeneous and may support recent physiological implications about cardiac denervation occurring together with the hyperinnervation of the SHR heart. We conclude that arterial hypertension leads to (i) the decrease of the neuronal body area, the thickness of atrial nerves, the number of myelinated nerve fibers, unmyelinated axon area and cumulative axon area in the nerve, and the density of myocardial nerve fibers, and (ii) the increase in myelinated nerve fiber area and density of neuronal bodies within epicardiac ganglia. Despite neuropathic alterations of myelinated fibers were exposed within intracardiac nerves of both groups, SHR and WKY, we consider that the determined significant changes in structure of intrinsic cardiac neural plexus were predisposed by arterial hypertension.
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Affiliation(s)
| | | | | | | | - Inga Saburkina
- Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | | | - Ignas Sabeckis
- Lithuanian University of Health Sciences, Kaunas, Lithuania
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Ben-Shabat M, Awad-Igbaria Y, Sela S, Gross B, Yagil Y, Yagil C, Palzur E. Predisposition to cortical neurodegenerative changes in brains of hypertension prone rats. J Transl Med 2023; 21:51. [PMID: 36707861 PMCID: PMC9881299 DOI: 10.1186/s12967-023-03916-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Substantial evidence suggests that hypertension is a significant risk factor for cognitive decline. However, it is unclear whether the genetic predisposition to hypertension is also associated with cellular dysfunction that promotes neurodegeneration. METHODS Changes in blood pressure were evaluated following dietary salt-loading or administration of a regular diet in Sabra Normotensive (SBN/y) and Sabra Hypertension-prone rats (SBH/y). We performed quantitative RT-PCR and immunofluorescence staining in brain cortical tissues before salt loading and 6 and 9 months after salt loading. To examine the expression of brain cortical proteins involved in the gene regulation (Histone Deacetylase-HDAC2; Histone Acetyltransferase 1-HAT1), stress response (Activating Transcription Factor 4-ATF4; Eukaryotic Initiation Factor 2- eIF2α), autophagy (Autophagy related 4A cysteine peptidase- Atg4a; light-chain 3-LC3A/B; mammalian target of rapamycin complex 1- mTORC1) and apoptosis (caspase-3). RESULTS Prior to salt loading, SBH/y compared to SBN/y expressed a significantly higher level of cortical HAT1 (protein), Caspase-3 (mRNA/protein), LC3A, and ATF4 (mRNA), lower levels of ATG4A (mRNA/protein), LC3A/B, HDAC2 (protein), as well as a lower density of cortical neurons. Following dietary salt loading, SBH/y but not SBN/y developed high blood pressure. In hypertensive SBH/y, there was significant upregulation of cortical HAT1 (protein), Caspase-3 (protein), and eIF2α ~ P (protein) and downregulation of HDAC2 (protein) and mTORC1 (mRNA), and cortical neuronal loss. CONCLUSIONS The present findings suggest that genetic predisposition to hypertension is associated in the brain cortex with disruption in autophagy, gene regulation, an abnormal response to cellular stress, and a high level of cortical apoptosis, and could therefore exacerbate cellular dysfunction and thereby promote neurodegeneration.
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Affiliation(s)
- Moti Ben-Shabat
- grid.415839.2Research Institute of Galilee Medical Center, Nahariya, Israel ,grid.22098.310000 0004 1937 0503Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel ,grid.415839.2Neurology Department, Galilee Medical Center, Nahariya, Israel
| | - Yaseen Awad-Igbaria
- grid.415839.2Research Institute of Galilee Medical Center, Nahariya, Israel ,grid.22098.310000 0004 1937 0503Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Shifra Sela
- grid.415839.2Research Institute of Galilee Medical Center, Nahariya, Israel ,grid.415839.2Neurology Department, Galilee Medical Center, Nahariya, Israel
| | - Bella Gross
- grid.415839.2Research Institute of Galilee Medical Center, Nahariya, Israel ,grid.415839.2Neurology Department, Galilee Medical Center, Nahariya, Israel
| | - Yoram Yagil
- Laboratory for Molecular Medicine, Barzilai University Medical Center, Ashkelon, Israel ,grid.7489.20000 0004 1937 0511Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheba, Israel
| | - Chana Yagil
- Laboratory for Molecular Medicine, Barzilai University Medical Center, Ashkelon, Israel ,grid.7489.20000 0004 1937 0511Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheba, Israel
| | - Eilam Palzur
- grid.415839.2Research Institute of Galilee Medical Center, Nahariya, Israel
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Ghozy S, Reda A, Varney J, Elhawary AS, Shah J, Murry K, Sobeeh MG, Nayak SS, Azzam AY, Brinjikji W, Kadirvel R, Kallmes DF. Neuroprotection in Acute Ischemic Stroke: A Battle Against the Biology of Nature. Front Neurol 2022; 13:870141. [PMID: 35711268 PMCID: PMC9195142 DOI: 10.3389/fneur.2022.870141] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 04/21/2022] [Indexed: 12/22/2022] Open
Abstract
Stroke is the second most common cause of global death following coronary artery disease. Time is crucial in managing stroke to reduce the rapidly progressing insult of the ischemic penumbra and the serious neurologic deficits that might follow it. Strokes are mainly either hemorrhagic or ischemic, with ischemic being the most common of all types of strokes. Thrombolytic therapy with recombinant tissue plasminogen activator and endovascular thrombectomy are the main types of management of acute ischemic stroke (AIS). In addition, there is a vital need for neuroprotection in the setting of AIS. Neuroprotective agents are important to investigate as they may reduce mortality, lessen disability, and improve quality of life after AIS. In our review, we will discuss the main types of management and the different modalities of neuroprotection, their mechanisms of action, and evidence of their effectiveness after ischemic stroke.
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Affiliation(s)
- Sherief Ghozy
- Department of Neuroradiology, Mayo Clinic, Rochester, MN, United States.,Nuffield Department of Primary Care Health Sciences and Department for Continuing Education (EBHC Program), Oxford University, Oxford, United Kingdom
| | - Abdullah Reda
- Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Joseph Varney
- School of Medicine, American University of the Caribbean, Philipsburg, Sint Maarten
| | | | - Jaffer Shah
- Medical Research Center, Kateb University, Kabul, Afghanistan
| | | | - Mohamed Gomaa Sobeeh
- Faculty of Physical Therapy, Sinai University, Cairo, Egypt.,Faculty of Physical Therapy, Cairo University, Giza, Egypt
| | - Sandeep S Nayak
- Department of Internal Medicine, NYC Health + Hospitals/Metropolitan, New York, NY, United States
| | - Ahmed Y Azzam
- Faculty of Medicine, October 6 University, Giza, Egypt
| | - Waleed Brinjikji
- Department of Neurosurgery, Mayo Clinic Rochester, Rochester, MN, United States
| | | | - David F Kallmes
- Department of Neuroradiology, Mayo Clinic, Rochester, MN, United States
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Tomassoni D, Martinelli I, Moruzzi M, Micioni Di Bonaventura MV, Cifani C, Amenta F, Tayebati SK. Obesity and Age-Related Changes in the Brain of the Zucker Lepr fa/fa Rats. Nutrients 2020; 12:E1356. [PMID: 32397542 PMCID: PMC7284640 DOI: 10.3390/nu12051356] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/02/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023] Open
Abstract
Metabolic syndrome (MetS) is an association between obesity, dyslipidemia, hyperglycemia, hypertension, and insulin resistance. A relationship between MetS and vascular dementia was hypothesized. The purpose of this work is to investigate brain microanatomy alterations in obese Zucker rats (OZRs), as a model of MetS, compared to their counterparts lean Zucker rats (LZRs). 12-, 16-, and 20-weeks-old male OZRs and LZRs were studied. General physiological parameters and blood values were measured. Immunochemical and immunohistochemical techniques were applied to analyze the brain alterations. The morphology of nerve cells and axons, astrocytes and microglia were investigated. The blood-brain barrier (BBB) changes occurring in OZRs were assessed as well using aquaporin-4 (AQP4) and glucose transporter protein-1 (GLUT1) as markers. Body weight gain, hypertension, hyperglycemia, and hyperlipidemia were found in OZRs compared to LZRs. In the frontal cortex and hippocampus, a decrease of neurons was noticeable in the older obese rats in comparison to their age-matched lean counterparts. In OZRs, a reduction of neurofilament immunoreaction and gliosis was observed. The BBB of older OZRs revealed an increased expression of AQP4 likely related to the development of edema. A down-regulation of GLUT1 was found in OZRs of 12 weeks of age, whereas it increased in older OZRs. The behavioral analysis revealed cognitive alterations in 20-week-old OZRs. Based on these results, the OZRs may be useful for understanding the mechanisms through which obesity and related metabolic alterations induce neurodegeneration.
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Affiliation(s)
- Daniele Tomassoni
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032 Camerino, Italy;
| | - Ilenia Martinelli
- School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 9, 62032 Camerino, Italy; (I.M.); (M.V.M.D.B.); (F.A.)
| | - Michele Moruzzi
- Department of Medicine, University of Leipzig, Liebigstraße 21, 04103 Leipzig, Germany;
| | | | - Carlo Cifani
- School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 9, 62032 Camerino, Italy; (I.M.); (M.V.M.D.B.); (F.A.)
| | - Francesco Amenta
- School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 9, 62032 Camerino, Italy; (I.M.); (M.V.M.D.B.); (F.A.)
| | - Seyed Khosrow Tayebati
- School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 9, 62032 Camerino, Italy; (I.M.); (M.V.M.D.B.); (F.A.)
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Micioni Di Bonaventura MV, Martinelli I, Moruzzi M, Micioni Di Bonaventura E, Giusepponi ME, Polidori C, Lupidi G, Tayebati SK, Amenta F, Cifani C, Tomassoni D. Brain alterations in high fat diet induced obesity: effects of tart cherry seeds and juice. Nutrients 2020; 12:E623. [PMID: 32120798 PMCID: PMC7146216 DOI: 10.3390/nu12030623] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/22/2020] [Accepted: 02/25/2020] [Indexed: 12/22/2022] Open
Abstract
Evidence suggests that obesity adversely affects brain function. High body mass index, hypertension, dyslipidemia, insulin resistance, and diabetes are risk factors for increasing cognitive decline. Tart cherries (PrunusCerasus L.) are rich in anthocyanins and components that modify lipid metabolism. This study evaluated the effects of tart cherries on the brain in diet-induced obese (DIO) rats. DIO rats were fed with a high-fat diet alone or in association with a tart cherry seeds powder (DS) and juice (DJS). DIO rats were compared to rats fed with a standard diet (CHOW). Food intake, body weight, fasting glycemia, insulin, cholesterol, and triglycerides were measured. Immunochemical and immunohistochemical techniques were performed. Results showed that body weight did not differ among the groups. Blood pressure and glycemia were decreased in both DS and DJS groups when compared to DIO rats. Immunochemical and immunohistochemical techniques demonstrated that in supplemented DIO rats, the glial fibrillary acid protein expression and microglial activation were reduced in both the hippocampus and in the frontal cortex, while the neurofilament was increased. Tart cherry intake modified aquaporin 4 and endothelial inflammatory markers. These findings indicate the potential role of this nutritional supplement in preventing obesity-related risk factors, especially neuroinflammation.
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Affiliation(s)
| | - Ilenia Martinelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Michele Moruzzi
- Department of Medicine, University of Leipzig, Liebigstraße 21, 04103 Leipzig, Germany
| | | | - Maria Elena Giusepponi
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Carlo Polidori
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Giulio Lupidi
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Seyed Khosrow Tayebati
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Francesco Amenta
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Daniele Tomassoni
- School of Biosciences and Veterinary Medicine, University of Camerino, via Gentile III da Varano, 62032 Camerino, Italy
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7
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Li Y, Liu J, Gao D, Wei J, Yuan H, Niu X, Zhang Q. Age-related changes in hypertensive brain damage in the hippocampi of spontaneously hypertensive rats. Mol Med Rep 2016; 13:2552-60. [PMID: 26846626 PMCID: PMC4768967 DOI: 10.3892/mmr.2016.4853] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 01/06/2016] [Indexed: 02/07/2023] Open
Abstract
The aim of the present study was to investigate the age-related alterations in hypertensive brain damage in the hippocampi of spontaneously hypertensive rats (SHR) and the underlying mechanisms. Aging resulted in a significant increase in the number of activated astrocytes and apoptotic cells in the SHR group, which was accompanied by increased expression of oxidative stress markers (iNOS and gp47phox) and apoptotic regulatory proteins (Bax and caspase-3). In addition, the expression of PPAR-γ and Bcl-2 were progressively reduced with increasing age in the SHR group. The 32 and 64-week-old SHRs exhibited significantly increased numbers of apoptotic cells, oxidative stress markers and pro-apoptotic proteins compared with age-matched WKY rats, which was accompanied by reduced expression of PPAR-γ. Compared with the 16 and 32-week-old WKY group, the 64-week-old WKY rats exhibited increased oxidative stress and pro-apoptotic markers, and increased levels apoptotic cells. In conclusion, the present study indicated that both aging and hypertension enhanced brain damage and oxidative stress injury in the hippocampi of SHRs, indicated by an increased presence of apoptotic cells and astrocytes. In addition, reduced expression of PPAR-γ may contribute to the age-related brain damage in SHRs.
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Affiliation(s)
- Yali Li
- Department of Rehabilitation, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Jian Liu
- Department of Physiology, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Dengfeng Gao
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Jin Wei
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Haifeng Yuan
- Department of Rehabilitation, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Xiaolin Niu
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
| | - Qiaojun Zhang
- Department of Rehabilitation, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
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López-Gil X, Amat-Roldan I, Tudela R, Castañé A, Prats-Galino A, Planas AM, Farr TD, Soria G. DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests. Front Aging Neurosci 2014; 6:167. [PMID: 25100993 PMCID: PMC4107676 DOI: 10.3389/fnagi.2014.00167] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/30/2014] [Indexed: 01/09/2023] Open
Abstract
The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm3 isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.
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Affiliation(s)
- Xavier López-Gil
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain
| | | | - Raúl Tudela
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain ; Group of Biomedical Imaging of the University of Barcelona, CIBER de Bioingenieria, Biomateriales y Nanomedicina Barcelona, Spain
| | - Anna Castañé
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC) Barcelona, Spain ; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII Madrid, Spain
| | - Alberto Prats-Galino
- Human Anatomy and Embryology Unit, Laboratory of Surgical NeuroAnatomy, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain
| | - Anna M Planas
- Department of Brain Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC) Barcelona, Spain
| | - Tracy D Farr
- Department of Experimental Neurology, Center for Stroke Research Berlin Charité, Berlin, Germany
| | - Guadalupe Soria
- Experimental 7T MRI Unit, IDIBAPS, Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona, Spain ; Group of Biomedical Imaging of the University of Barcelona, CIBER de Bioingenieria, Biomateriales y Nanomedicina Barcelona, Spain
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9
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Tikhonoff V, Mazza A, Casiglia E, Pessina AC. Role of manidipine in the management of patients with hypertension. Expert Rev Cardiovasc Ther 2014; 2:815-27. [PMID: 15500427 DOI: 10.1586/14779072.2.6.815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Manidipine is a third-generation dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. In clinical studies, manidipine has been shown to significantly lower office and 24-h blood pressure compared with placebo in patients with essential hypertension. The resulting reduction in blood pressure is maintained over 24 h, with preservation of the circadian blood pressure pattern; its blood pressure-lowering capacity appears to be similar to that of other calcium antagonists. In elderly patients with mild-to-moderate essential hypertension, manidipine is able to significantly decrease blood pressure compared with placebo for up to 3 years of treatment. The drug also significantly lowers blood pressure in patients with hypertension and concomitant Type 2 diabetes mellitus or renal impairment, and is devoid of adverse metabolic effects. It is well-tolerated with few untoward adverse effects related to vasodilation. In particular, manidipine appears to have less potential for pedal edema than other calcium channel blockers.
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Affiliation(s)
- Valérie Tikhonoff
- University of Padova, Department of Clinical and Experimental Medicine, Via Giustiniani No. 2, I-35128 Padova, Italy.
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10
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Neuroprotective activity of thioctic acid in central nervous system lesions consequent to peripheral nerve injury. BIOMED RESEARCH INTERNATIONAL 2013; 2013:985093. [PMID: 24527432 PMCID: PMC3914604 DOI: 10.1155/2013/985093] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 11/21/2022]
Abstract
Peripheral neuropathies are heterogeneous disorders presenting often with hyperalgesia and allodynia. This study has assessed if chronic constriction injury (CCI) of sciatic nerve is accompanied by increased oxidative stress and central nervous system (CNS) changes and if these changes are sensitive to treatment with thioctic acid. Thioctic acid is a naturally occurring antioxidant existing in two optical isomers (+)- and (−)-thioctic acid and in the racemic form. It has been proposed for treating disorders associated with increased oxidative stress. Sciatic nerve CCI was made in spontaneously hypertensive rats (SHRs) and in normotensive reference cohorts. Rats were untreated or treated intraperitoneally for 14 days with (+/−)-, (+)-, or (−)-thioctic acid. Oxidative stress, astrogliosis, myelin sheets status, and neuronal injury in motor and sensory cerebrocortical areas were assessed. Increase of oxidative stress markers, astrogliosis, and neuronal damage accompanied by a decreased expression of neurofilament were observed in SHR. This phenomenon was more pronounced after CCI. Thioctic acid countered astrogliosis and neuronal damage, (+)-thioctic acid being more active than (+/−)- or (−)-enantiomers. These findings suggest a neuroprotective activity of thioctic acid on CNS lesions consequent to CCI and that the compound may represent a therapeutic option for entrapment neuropathies.
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11
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Dunn KM, Nelson MT. Neurovascular signaling in the brain and the pathological consequences of hypertension. Am J Physiol Heart Circ Physiol 2013; 306:H1-14. [PMID: 24163077 DOI: 10.1152/ajpheart.00364.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The execution and maintenance of all brain functions are dependent on a continuous flow of blood to meet the metabolic needs of the tissue. To ensure the delivery of resources required for neural processing and the maintenance of neural homeostasis, the cerebral vasculature is elaborately and extensively regulated by signaling from neurons, glia, interneurons, and perivascular nerves. Hypertension is associated with impaired neurovascular regulation of the cerebral circulation and culminates in neurodegeneration and cognitive dysfunction. Here, we review the physiological processes of neurovascular signaling in the brain and discuss mechanisms of hypertensive neurovascular dysfunction.
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Affiliation(s)
- Kathryn M Dunn
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, Vermont; and
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12
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Daulatzai MA. Neurotoxic Saboteurs: Straws that Break the Hippo’s (Hippocampus) Back Drive Cognitive Impairment and Alzheimer’s Disease. Neurotox Res 2013; 24:407-59. [DOI: 10.1007/s12640-013-9407-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/06/2013] [Accepted: 06/17/2013] [Indexed: 12/29/2022]
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Brain activity of thioctic Acid enantiomers: in vitro and in vivo studies in an animal model of cerebrovascular injury. Int J Mol Sci 2013; 14:4580-95. [PMID: 23443159 PMCID: PMC3634420 DOI: 10.3390/ijms14034580] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 02/19/2013] [Accepted: 02/20/2013] [Indexed: 01/27/2023] Open
Abstract
Oxidative stress is an imbalance between the production of free radicals and antioxidant defense mechanisms, potentially leading to tissue damage. Oxidative stress has a key role in the development of cerebrovascular and/or neurodegenerative diseases. This phenomenon is mainly mediated by an enhanced superoxide production by the vascular endothelium with its consequent dysfunction. Thioctic, also known as alpha-lipoic acid (1,2-dithiolane-3-pentanoic acid), is a naturally occurring antioxidant that neutralizes free radicals in the fatty and watery regions of cells. Both the reduced and oxidized forms of the compound possess antioxidant ability. Thioctic acid has two optical isomers designated as (+)- and (−)-thioctic acid. Naturally occurring thioctic acid is the (+)-thioctic acid form, but the synthetic compound largely used in the market for stability reasons is a mixture of (+)- and (−)-thioctic acid. The present study was designed to compare the antioxidant activity of the two enantiomers versus the racemic form of thioctic acid on hydrogen peroxide-induced apoptosis in a rat pheochromocytoma PC12 cell line. Cell viability was evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and free oxygen radical species (ROS) production was assessed by flow cytometry. Antioxidant activity of the two enantiomers and the racemic form of thioctic acid was also evaluated in spontaneously hypertensive rats (SHR) used as an in vivo model of increased oxidative stress. A 3-h exposure of PC12 cells to hydrogen peroxide (H2O2) significantly decreased cell viability and increased levels of intracellular ROS production. Pre-treatment with racemic thioctic acid or (+)-enantiomer significantly inhibited H2O2-induced decrease in cell viability from the concentration of 50 μmol/L and 20 μmol/L, respectively. Racemic thioctic acid and (+)-salt decreased levels of intracellular ROS, which were unaffected by (−)-thioctic acid. In the brain of SHR, the occurrence of astrogliosis and neuronal damage, with a decreased expression of neurofilament 200 kDa were observed. Treatment of SHR for 30 days with (+)-thioctic acid reduced the size of astrocytes and increased the neurofilament immunoreaction. The above findings could contribute to clarify the role played by thioctic acid in central nervous system injury related to oxidative stress. The more pronounced effect of (+)-thioctic acid observed in this study may have practical therapeutic implications worthy of being investigated in further preclinical and clinical studies.
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Tayebati SK, Tomassoni D, Amenta F. Spontaneously hypertensive rat as a model of vascular brain disorder: microanatomy, neurochemistry and behavior. J Neurol Sci 2012; 322:241-9. [PMID: 22726353 DOI: 10.1016/j.jns.2012.05.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/23/2012] [Indexed: 11/28/2022]
Abstract
Arterial hypertension is the main risk factor for stroke and plays a role in the development of vascular cognitive impairment (VCI) and vascular dementia (VaD). An association between hypertension and reduced cerebral blood flow and VCI is documented and arterial hypertension in midlife is associated with a higher probability of cognitive impairment. These findings suggest that arterial hypertension is a main cause of vascular brain disorder (VBD). Spontaneously hypertensive rat (SHR) is the rat strain most extensively investigated and used for assessing hypertensive brain damage and treatment of it. They are normotensive at birth and at 6months they have a sustained hypertension. Time-dependent rise of arterial blood pressure, the occurrence of brain atrophy, loss of nerve cells and glial reaction are phenomena shared to some extent with hypertensive brain damage in humans. SHR present changes of some neurotransmitter systems that may have functional and behavioral relevance. An impaired cholinergic neurotransmission characterizes SHR, similarly as reported in patients affected by VaD. SHR are also characterized by a dopaminergic hypofunction and noradrenergic hyperactivity similarly as occurs in attention-deficit with hyperactivity disorder (ADHD). Microanatomical, neurochemical and behavioral data on SHR are in favor of the hypothesis that this strain is a suitable model of VBD. Changes in catecholaminergic transmission put forward SHR as a possible model of ADHD as well. Hence SHR could represent a multi-faced model of two important groups of pathologies, VBD and ADHD. As for most models, researchers should always consider that SHR offer some similarities with corresponding human pathologies, but they do not suffer from the same disease. This paper reviews the main microanatomical, neurochemical and behavioral characteristics of SHR with particular reference as an animal model of brain vascular injury.
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Affiliation(s)
- Seyed Khosrow Tayebati
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy.
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Goo MJ, Choi SM, Kim SH, Ahn BO. Protective effects of acetyl-L-carnitine on neurodegenarative changes in chronic cerebral ischemia models and learning-memory impairment in aged rats. Arch Pharm Res 2012; 35:145-54. [PMID: 22297753 DOI: 10.1007/s12272-012-0116-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 07/14/2011] [Accepted: 07/25/2011] [Indexed: 11/30/2022]
Abstract
This study investigated the effects of acetyl-L-carnitine (ALC) in secondarily-induced cerebral chronic ischemia models using rats with permanent ligation of bilateral common carotid arteries (BCCL) and spontaneously hypertensive rats (SHR). Additionally, we used normal aged rats as a primary dementia model. Chronic ALC administration at 100 mg/kg (p.o.) for 4 weeks significantly attenuated neurodegenerative changes. In groups receiving 50 mg/kg or 100 mg/kg, ALC inhibited the active astrocyte increase in cerebral tissues of both BCCL and SHR models. In BCCL rats, ALC administration (50 mg/kg or 100 mg/kg, p.o.) resulted in significant promotion of glutathione levels in brain tissues. We also confirmed behavioral improvement after ALC treatment (100 mg/kg for 8 weeks, p.o.) on learning-memory function using aged rats (18 months old) in a passive avoidance task and preservation of CA1 pyramidal neurons was coincided on histopathological observation. In conclusion, chronic ALC administration may ameliorate cerebral ischemia progress after a cerebrovascular disorder as well as spontaneous ageing-related cerebral dysfunction via hippocampal protection.
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Affiliation(s)
- Moon-Jung Goo
- Preclinical Research Laboratories, Dong-A Pharmaceutical Company, Yongin 446-905, Korea.
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Vicario A, del Sueldo MA, Zilberman JM, Cerezo GH. Cognitive evolution in hypertensive patients: a six-year follow-up. Vasc Health Risk Manag 2011; 7:281-5. [PMID: 21603597 PMCID: PMC3096508 DOI: 10.2147/vhrm.s18777] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Several studies have examined the links between hypertension, vascular damage, and cognitive impairment. The functions most commonly involved seem to be those associated with memory and executive function. AIMS 1) to report the cognitive evolution in a cohort of hypertensive patients, 2) to identify the affected domains, and 3) to correlate the results obtained with blood pressure measurements. MATERIALS AND METHODS Observational 6-year follow-up cohort study including both males and females aged≥65 and ≤80 years, and hypertensive patients under treatment. Patients with a history of any of the following conditions were excluded: stroke, transient ischemic attack, diabetes mellitus, atrial fibrillation, cardiac surgery, dementia, or depression. Four neurocognitive evaluations were performed (at baseline and every 2 years). The tests used evaluated memory and executive function domain. Blood pressure was measured on every cognitive evaluation. RESULTS Sixty patients were followed for 76.4±2.8 months. The average age at baseline was 72.5±4.2 and 77.9±4.6 at 6 years (65% were women). Two patients were lost to follow up (3.3%) and 8 patients died (13.3%).The density incidence for dementia was 0.6% patients per year (pt/y) (n=3) and for depression was 1.6% pt/y (n=12). No changes were observed in either memory impairment or the Mini Mental State Examination (MMSE) results (p=ns) during follow-up. A progressive impairment of the executive function was shown regardless of the blood pressure measurements. CONCLUSION 1) the incidence of dementia doubled to general population, 2) the initial memory impairment did not change during the evaluation period, 3) cognitive impairment worsened in the areas related to executive function (prefrontal cortex) regardless of the adequacy of anti-hypertensive treatment and blood pressure values.
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Affiliation(s)
- Augusto Vicario
- Department of Internal Medicine, Cardiovascular Division, Hospital Español de Buenos Aires, Argentina.
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18
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Expression of aquaporins 1 and 4 in the brain of spontaneously hypertensive rats. Brain Res 2010; 1325:155-63. [PMID: 20156423 DOI: 10.1016/j.brainres.2010.02.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 02/05/2010] [Accepted: 02/06/2010] [Indexed: 11/20/2022]
Abstract
Aquaporins (AQP) 1 and 4 are water channel proteins localized respectively at the level of the blood-cerebrospinal fluids (CSF) and blood brain (BBB) barriers. These barriers represent the sites of exchange between blood and nervous tissue and between blood, choroid plexus and CSF in brain ventricles respectively. Damage of these barriers may alter transfer of substances between blood and nervous tissue. In spontaneously hypertensive rats (SHR) chronic hypertension may induce BBB dysfunction and pronounced defects in the integrity of the blood-CSF barrier. AQP1 is expressed in the apical membrane of choroid plexus epithelium. AQP4 is expressed by astrocyte foot processes near blood vessels. The present study has assessed the expression of AQP1 and AQP4 in the brain of SHR in pre-hypertensive (2 months of age), developing hypertension (4 months of age) and established hypertension (6 months of age) stages. Age-matched Wistar-Kyoto (WKY) rats were used as normotensive reference group. AQP1 expression is increased in choroid plexus epithelium of 6-month-old SHR. An increased expression of AQP4 was found in frontal cortex, striatum, and hippocampus of 4- and 6-month-old SHR compared to younger cohorts and age-matched WKY rats. These findings suggest that the increase in AQP expression may alter fluid exchange in BBB and/or in blood-CSF barrier. This situation in case of an acute or excessively elevated rise of blood pressure can promote BBB changes causing the brain damage occurring in this animal model of hypertension.
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Neuroprotective effect of treatment with galantamine and choline alphoscerate on brain microanatomy in spontaneously hypertensive rats. J Neurol Sci 2009; 283:187-94. [DOI: 10.1016/j.jns.2009.02.349] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Tomassoni D, Lanari A, Silvestrelli G, Traini E, Amenta F. Nimodipine and Its Use in Cerebrovascular Disease: Evidence from Recent Preclinical and Controlled Clinical Studies. Clin Exp Hypertens 2009; 30:744-66. [DOI: 10.1080/10641960802580232] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Is the brain the essential in hypertension? Neuroimage 2009; 47:914-21. [PMID: 19410005 DOI: 10.1016/j.neuroimage.2009.04.072] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 04/24/2009] [Accepted: 04/24/2009] [Indexed: 02/07/2023] Open
Abstract
The brain is typically considered a target for late stage hypertensive disease due to the high prevalence of stroke among hypertensive patients. Research is reviewed, however, that suggests that the brain is implicated in the initiation of high blood pressure and is itself altered by early disease processes. A substantial literature establishes neural control of the vasculature and kidney as candidate etiological factors in essential hypertension. This research, largely done in animals, is now supplemented by behavioral and brain imaging studies in humans. This review suggests that the brain and vasculature may be independently and concurrently targeted by the factors inducing essential hypertension. Early stage hypertension is associated with cognitive deficits, altered cerebral blood flow support for cognitive processing, and decreased grey matter in specific cortical regions. Pharmacological reversal of hypertension is less successful in patients with premature brain aging and fails to reverse either the progression of functional or structural changes within the cerebral cortex. Furthermore, magnetic resonance imaging Blood Oxygen Level-Dependent (BOLD) responses during psychological challenge differ between normotensive individuals at risk and those not at risk for hypertension because of their exaggerated blood pressure responses to psychological challenge. Further examination of mechanisms of action and early influences of the disease on the brain are required to understand the pathophysiological mechanisms having concurrent influences on the brain and the peripheral vasculature.
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Temma T, Kuge Y, Sano K, Kamihashi J, Obokata N, Kawashima H, Magata Y, Saji H. PET O-15 cerebral blood flow and metabolism after acute stroke in spontaneously hypertensive rats. Brain Res 2008; 1212:18-24. [DOI: 10.1016/j.brainres.2008.03.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2007] [Revised: 03/15/2008] [Accepted: 03/18/2008] [Indexed: 11/24/2022]
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Uys JDK, Hattingh SM, Stein DJ, Daniels WMU. Large scale hippocampal cellular distress may explain the behavioral consequences of repetitive traumatic experiences--a proteomic approach. Neurochem Res 2008; 33:1724-34. [PMID: 18307038 DOI: 10.1007/s11064-008-9615-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 01/30/2008] [Indexed: 01/22/2023]
Abstract
Early life traumatic experiences are associated with psychopathology in adulthood. This may be due in part to the effects of trauma on hippocampal development and protein expression. The purpose of the study was to investigate the effects of early life trauma and adult re-stress on ventral hippocampal protein expression. Adolescent rats (n = 19) were subjected to a triple stressor on post-natal day 28 followed 7 days later by the first re-stress session and 25 days later (post-natal day 60 = adulthood) by the second re-stress session. Ventral hippocampi were collected on post-natal day 68 for protein expression determinations using protein arrays and 2D-gel electrophoresis with liquid chromatography tandem mass spectrometry. Compared to controls, traumatized animals showed an increase in Ca(2+) homeostatic proteins, dysregulated signaling pathways and energy metabolism enzymes, cytoskeletal protein changes, a decrease in neuroplasticity regulators, energy metabolism enzymes and an increase in apoptotic initiator proteins. These results indicate the extensive impact of trauma on adult brain development and behavior.
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Affiliation(s)
- Joachim D K Uys
- Division of Medical Physiology, Department of Biomedical Sciences, University of Stellenbosch, Tygerberg Campus, Francie van Zijl Avenue, Parow Valley, 7505, Cape Town, Western Cape, South Africa
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24
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Lanari A, Silvestrelli G, De Dominicis P, Tomassoni D, Amenta F, Parnetti L. Arterial hypertension and cognitive dysfunction in physiologic and pathologic aging of the brain. ACTA ACUST UNITED AC 2007; 16:158-64. [PMID: 17483667 DOI: 10.1111/j.1076-7460.2007.06502.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Arterial hypertension is the most important modifiable cerebrovascular risk factor; its relationship with cerebrovascular disease is continuous, consistent, and independent. Different and probably converging pathophysiologic mechanisms explain the role of arterial hypertension in causing cognitive dysfunction in pathologic aging of the brain, specifically, vascular dementia and Alzheimer's disease.
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Affiliation(s)
- Alessia Lanari
- Section of Neurology, University of Perugia, Perugia, Italy
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25
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Kronenberg G, Lippoldt A, Kempermann G. Two genetic rat models of arterial hypertension show different mechanisms by which adult hippocampal neurogenesis is increased. Dev Neurosci 2007; 29:124-33. [PMID: 17148955 DOI: 10.1159/000096217] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Accepted: 03/28/2006] [Indexed: 12/29/2022] Open
Abstract
To investigate strain differences and genetic effects on different aspects of neurogenesis, we compared young adult spontaneously hypertensive/hyperactive rats (SHR) and stroke-prone SHR (SHRSP) with the genetic control WKY strain. In both hypertensive/hyperactive strains, the number of newly generated neurons and the number of lineage-determined cells as detected by doublecortin (DCX) immunoreactivity were significantly increased. SHRSP had significantly more DCX-positive cells than the other groups. Whereas cell proliferation as measured by Ki67 expression was increased in SHR, we found no difference between SHRSP and WKY. In summary, we found increased net neurogenesis in both hypertensive/hyperactive strains. However, this phenotype was based on different mechanisms in the course of neuronal development: cell proliferation in SHR and cell survival in SHRSP. In addition, we found that within strains the number of DCX-positive cells was not predictive of the net number of new neurons and that the increase in neurogenesis was not significantly correlated with blood pressure in SHR and WKY. However, in both SHR and SHRSP, cell proliferation showed an association with blood pressure recordings.
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Affiliation(s)
- Golo Kronenberg
- Max Delbruck Center for Molecular Medicine (MDC) Berlin-Buch, Germany
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26
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Tomassoni D, Avola R, Mignini F, Parnetti L, Amenta F. Effect of treatment with choline alphoscerate on hippocampus microanatomy and glial reaction in spontaneously hypertensive rats. Brain Res 2006; 1120:183-90. [PMID: 16989788 DOI: 10.1016/j.brainres.2006.08.068] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 08/17/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
The influence of long term treatment with choline alphoscerate on microanatomy of hippocampus and glial reaction was assessed in spontaneously hypertensive rats (SHR) used as an animal model of cerebrovascular disease. Choline alphoscerate is a cholinergic precursor, which has shown to be effective in countering cognitive symptoms in forms of dementia disorders of degenerative, vascular or combined origin. Male spontaneously hypertensive rats (SHR) aged 6 months and age-matched normotensive Wistar-Kyoto (WKY) rats were treated for 8 weeks with an oral daily dose of 100 mg/kg of choline alphoscerate, 285 mg/kg of phosphatidylcholine (lecithin) or vehicle. On the hippocampus of different animal groups, nerve cell number and GFAP-immunoreactive astrocytes were assessed by neuroanatomical, immunochemical and immunohistochemical techniques associated with quantitative analysis. Treatment with choline alphoscerate countered nerve cell loss and glial reaction primarily in the CA1 subfields and in the dentate gyrus of the hippocampus of SHR. Phosphatidylcholine did not affect hypertension-dependent changes in hippocampal microanatomy. Both compounds did not affect blood pressure values in SHR. These data suggest that choline alphoscerate may play a role in the countering hippocampal changes induced by cerebrovascular involvement. The observation that treatment with choline alphoscerate attenuates the extent of glial reaction in the hippocampus of SHR suggests also that the compound may afford neuroprotection in this animal model of vascular brain damage.
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Affiliation(s)
- Daniele Tomassoni
- Sezione di Anatomia Umana, Dipartimento di Medicina Sperimentale e Sanità Pubblica,Università di Camerino, Camerino, Italy
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27
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Turner CP, Miller R, Smith C, Brown L, Blackstone K, Dunham SR, Strehlow R, Manfredi M, Slocum P, Iverson K, West M, Ringler SL, Berry ZC. Widespread Neonatal Brain Damage following Calcium Channel Blockade. Dev Neurosci 2006; 29:213-31. [PMID: 16921238 DOI: 10.1159/000095221] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 04/04/2006] [Indexed: 01/05/2023] Open
Abstract
An abundance of evidence exists that shows calcium channel blockade promotes injury in cultured neurons. However, few studies have addressed the in vivo toxicity of such agents. We now show that the L-type calcium channel antagonist nimodipine promotes widespread and robust injury throughout the neonatal rat brain, in an age-dependent manner. Using both isolated neuronal as well as brain slice approaches, we address mechanisms behind such injury. These expanded studies show a consistent pattern of injury using a variety of agents that lower intracellular calcium. Collectively, these observations indicate that postnatal brain development represents a transitional period for still developing neurons, from being highly sensitive to reductions in intracellular calcium to being less vulnerable to such changes. These observations directly relate to current therapeutic strategies targeting neonatal brain injury.
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Affiliation(s)
- C P Turner
- Department of Neurobiology and Anatomy, Wake Forest University Medical School, Medical Center Boulevard, Winston-Salem, NC 27157-1010, USA.
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Abstract
Deciphering the secret of successful aging depends on understanding the patterns and biological underpinnings of cognitive and behavioral changes throughout adulthood. That task is inseparable from comprehending the workings of the brain, the physical substrate of behavior. In this review, we summarize the extant literature on age-related differences and changes in brain structure, including postmortem and noninvasive magnetic resonance imaging (MRI) studies. Among the latter, we survey the evidence from volumetry, diffusion-tensor imaging, and evaluations of white matter hyperintensities (WMH). Further, we review the attempts to elucidate the mechanisms of age-related structural changes by measuring metabolic markers of aging through magnetic resonance spectroscopy (MRS). We discuss the putative links between the pattern of brain aging and the pattern of cognitive decline and stability. We then present examples of activities and conditions (hypertension, hormone deficiency, aerobic fitness) that may influence the course of normal aging in a positive or negative fashion. Lastly, we speculate on several proposed mechanisms of differential brain aging, including neurotransmitter systems, stress and corticosteroids, microvascular changes, calcium homeostasis, and demyelination.
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Affiliation(s)
- Naftali Raz
- Department of Psychology and Institute of Gerontology, Wayne State University, 87 East Ferry St., 226 Knapp Building, Detroit, MI 48202, USA.
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Zhang Y, Wen L, Cheng B. Effect of [Ca2+]i and neuronal mitochondria transmembrane potentials in hippocampus of murine cytomegalovirus infected mice. JOURNAL OF HUAZHONG UNIVERSITY OF SCIENCE AND TECHNOLOGY. MEDICAL SCIENCES = HUA ZHONG KE JI DA XUE XUE BAO. YI XUE YING DE WEN BAN = HUAZHONG KEJI DAXUE XUEBAO. YIXUE YINGDEWEN BAN 2006; 26:211-2. [PMID: 16850749 DOI: 10.1007/bf02895818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To explore the effect of [Ca2+]i and neuronal mitochondria transmembrane potentials in hippocampus of murine cytomegalovirus (MCMV) infected mice, newborn Balb/c mice were randomly divided into two groups: a virus inoculated group and a control group. After 56 days, single cell of hippocampus was isolated, and mitochondria transmembrane potentials and the intracellular free calcium level [Ca2+]i in hippocampus were measured by means of flow cytometry (FCM). Compared with the control group, the mitochondria transmembrane potentials was decreased (P<0.01) and the intracellular free calcium level [Ca2+]i was increased (P<0.01) in inoculated group. The dysfunction of [Ca2+]i and mitochondria transmembrane potentials in hippocampus may play an important role in the functional disorders in CMV-infected CNS.
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Affiliation(s)
- Ying Zhang
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Avola R, Di Tullio MA, Fisichella A, Tayebati SK, Tomassoni D. Glial fibrillary acidic protein and vimentin expression is regulated by glucocorticoids and neurotrophic factors in primary rat astroglial cultures. Clin Exp Hypertens 2004; 26:323-33. [PMID: 15195687 DOI: 10.1081/ceh-120034137] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The neurotrophic factors epidermal growth factor (EGF), basic fibroblast growth factor, (bFGF), insulin-like growth factor I (IGF-I) and insulin (INS) regulate neural and astroglial cell functions. Glucocorticoids may influence the metabolism of astroglial compartment and are key hormones in neurodegenerative events. This study was designed to assess the interactions between growth factors and dexamethasone (DEX) on cytoskeletal proteins (GFAP and vimentin) expression in 25 days in vitro (DIV) astrocyte cultures. An increase in GFAP and vimentin expression was observed after 12 h pretreatment with bFGF and subsequent treatment for 60 h with DEX. GFAP immunoreactivity was decreased after 24 h progression growth factors (EGF, IGF-I and INS) addition, when compared to control 36 h DEX and bFGF-pretreated cultures for the last 12 h. Vimentin immunoreactivity was decreased after 12 h bFGF pretreatment and subsequent 60 h DEX addition in astrocyte cultures compared to 12 h bFGF-pretreated ones. Pretreatment for 36 h with DEX plus bFGF in the last 12 h and subsequent treatment for 24 h with DMEM (Dulbecco's modified Eagle medium; DMEM) + BSA (bovine serum albumine) (harvesting), or with progression growth factors (EGF, IGF-I or INS) alone or two of them together, stimulated GFAP expression, compared to untreated controls. Immunochemical analysis of the mitogen-activated protein kinase ERK2 suggests an involvement of this enzyme in the control of GFAP expression. The above findings support the view of an interactive and complex dialogue between growth factors and glucocorticoids during astroglial cell proliferation and maturation in culture. This may have implications in therapeutic approach of neurologic disorders associated with astrogliosis, including cerebrovascular disease.
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Affiliation(s)
- Roberto Avola
- Sezione di Biochimica e Biologia Molecolare, Dipartimento di Scienze Chimiche, Università di Catania, Catania, Italy.
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Tomassoni D, Avola R, Di Tullio MA, Sabbatini M, Vitaioli L, Amenta F. Increased expression of glial fibrillary acidic protein in the brain of spontaneously hypertensive rats. Clin Exp Hypertens 2004; 26:335-50. [PMID: 15195688 DOI: 10.1081/ceh-120034138] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Astrogliosis, consisting in astroglial proliferation and increased expression of the specific cytoskeletal protein glial fibrillary acid protein (GFAP) is common in several situations of brain damage. Arterial hypertension, which induces cerebrovascular changes, can cause also brain damage, neurodegeneration and dementia (vascular dementia). This study was designed to assess astroglial reaction in different brain areas (frontal cortex, occipital cortex, hippocampus and striatum) of spontaneously hypertensive rats (SHR) in the pre-hypertensive phase (2 months of age), in the developing phase of hypertension (4 months of age) and in established hypertension (6 months of age). SHR were compared to age-matched normotensive Wistar-Kyoto (WKY) rats. Analysis included reverse transcription-polymerase chain reaction (RT-PCR) of GFAP mRNA, GFAP immunochemistry (Western blot analysis) and immunohistochemistry. A significant increase of GFAP mRNA and an increase of GFAP immunoreactivity were noticeable in different brain areas of SHR compared to normotensive WKY rats at 6, but not at 2 or 4 months of age. Immunohistochemistry revealed a numerical augmentation (hyperplasia) and an increase in size (hypertrophy) of GFAP-immunoreactive astrocytes in frontal cortex, occipital cortex and striatum of SHR. In the hippocampus of SHR only a numerical increase of GFAP-immunoreactive astrocytes was found. These finding demonstrating the occurrence of astrogliosis in the brain of SHR with established hypertension suggest that hypertension induces a condition of brain suffering enough to increase biosynthesis and expression of GFAP similarly as reported in several neurodegenerative disorders and in brain ischemia.
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Affiliation(s)
- Daniele Tomassoni
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy
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Mignini F, Vitaioli L, Sabbatini M, Tomassoni D, Amenta F. The cerebral cortex of spontaneously hypertensive rats: a quantitative microanatomical study. Clin Exp Hypertens 2004; 26:287-303. [PMID: 15195685 DOI: 10.1081/ceh-120034135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The morphology of cerebral cortex was investigated in male spontaneously hypertensive rats (SHR) aged 2, 4 and 6 months (pre-hypertensive, developing hypertension and established hypertension respectively) and in age-matched normotensive Wistar-Kyoto (WKY) rats using quantitative microanatomical techniques. Analysis included frontal and occipital cortex as a paradigm of motor and sensory cerebrocortical areas respectively. Values of systolic pressure were slightly higher in 2-month-old SHR compared to age-matched WKY rats and augmented progressively with increasing age in SHR. In frontal cortex of SHR a decrease of nerve cell number and of cortical volume was observed in layers V and VI of 4- and 6- month-old SHR, and in layers I-IV of 6- month-old SHR. In occipital cortex a decrease of the number of nerve cells and of cortical volume was observed in layers V and VI of 2-, 4-, 6- month-old SHR, and in layers I-IV of 6-month-old SHR. Numerical decrease of neurons in SHR affected to a greater extent occipital cortex than frontal cortex. An increase in the number of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes (hyperplasia) as well as in the mean immune reaction area (hypertrophy) was found in the two cerebrocortical areas investigated of 6-month-old SHR. The occurrence of apoptosis and/or necrosis identified using the terminal deoxyribo-nucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) technique was also observed in frontal and occipital cortex of 6-month-old SHR, but not of younger cohorts. These findings indicate the development of microanatomical changes in the cerebral cortex of SHR, the extent of which increases parallel with the progression of hypertension. The occurrence of cerebrocortical apoptosis and/or necrosis as well as the obvious astrogliosis occurring in established hypertension may account for the increased risk of vascular dementia that represents a specific trait of complicated hypertension.
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Affiliation(s)
- Fiorenzo Mignini
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy
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Tomassoni D, Bellagamba G, Postacchini D, Venarucci D, Amenta F. Cerebrovascular and brain microanatomy in spontaneously hypertensive rats with streptozotocin-induced diabetes. Clin Exp Hypertens 2004; 26:305-21. [PMID: 15195686 DOI: 10.1081/ceh-120034136] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The influence of hypertension associated with diabetes on cerebrovascular and frontal cortex or hippocampus microanatomy was investigated in 20-week-old spontaneously hypertensive rats (SHR) in which diabetes was induced by treatment with streptozotocin (STZ) and in control or STZ-diabetic age-matched normotensive Wistar Kyoto (WKY) rats. At the beginning of experiment, systolic pressure values were similar in WKY rats either control, or exposed to STZ and remarkably higher in control or STZ-treated SHR. Systolic pressure values increased in the different animal groups examined along the course of experiment. Blood glucose levels were increased in either STZ-WKY rats or -SHR compared to WKY rats and SHR respectively. The main changes occurring in pial and intracerebral arteries of SHR and STZ-SHR were thickening of the arterial wall accompanied by luminal narrowing. In medium sized pial arteries of STZ-WKY rats luminal narrowing and a decreased thickness of arterial wall were noticeable. Intracerebral arteries of STZ-WKY diabetic rats showed a not homogeneous sensitivity of different sized branches. The volume of zones III and IV of frontal cortex was decreased in SHR and STZ-SHR compared to control WKY rats. The number of nerve cells in these cerebrocortical layers was decreased to a similar extent in SHR. STZ-WKY rats or STZ-SHR compared to control WKY rats. In dentate gyrus, followed by the CA1 subfield of hippocampus, decreased volume and number of neurons were found in SHR and STZ-SHR compared to control WKY rats. The occurrence of astrogliosis was observed in hypertensive, diabetic or hypertensive plus diabetic rats. The above findings indicate the occurrence of cerebrovascular and brain microanatomical changes in SHR and to a lesser extent in STZ-diabetic rats compared to control normotensive and normoglicemic WKY rats. Association of hypertension and diabetes caused more pronounced changes than in the single disease models. These results support the view that hypertension and diabetes affect the structure of cerebrovascular tree and of brain and that association of the two diseases results in an increased risk of target-organ damage, involving brain.
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Affiliation(s)
- Daniele Tomassoni
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy
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Vega E, Gómez-Villalobos MDJ, Flores G. Alteration in dendritic morphology of pyramidal neurons from the prefrontal cortex of rats with renovascular hypertension. Brain Res 2004; 1021:112-8. [PMID: 15328038 DOI: 10.1016/j.brainres.2004.06.042] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2004] [Indexed: 10/26/2022]
Abstract
We have studied, in the rat, the dendritic morphological changes of the pyramidal neurons of the medial part of the prefrontal cortex induced by the chronic effect of high blood pressure. Renovascular hypertension was induced using a silver clip on the renal artery by surgery. The morphology of the pyramidal neurons from the medial part of the prefrontal cortex was investigated in these animals. The blood pressure was measured to confirm the increase in the arterial blood pressure. After 16 weeks of increase in the arterial blood pressure, the animals were sacrificed by overdoses of sodium pentobarbital and perfused intracardially with a 0.9% saline solution. The brains were removed, processed by the Golgi-Cox stain method and analyzed by the Sholl method. The dendritic morphology clearly showed that the hypertensive animals had an increase (32%) in the dendritic length of the pyramidal cells with a decrease (50%) in the density of dendritic spines when compared with sham animals. The branch-order analysis showed that the animals with hypertension exhibit more dendritic arborization at the level of the first to fourth branch order. This result suggests that renovascular hypertension may in part affect the dendritic morphology in this limbic structure, which may implicate cognitive impairment in hypertensive patients.
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Affiliation(s)
- Elenia Vega
- Escuela de Biología, Universidad Autónoma de Puebla, Puebla, México
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Lehohla M, Kellaway L, Russell VA. NMDA receptor function in the prefrontal cortex of a rat model for attention-deficit hyperactivity disorder. Metab Brain Dis 2004. [PMID: 15214504 DOI: 10.1023/b: mebr.0000027415.75432.ad] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The spontaneously hypertensive rat (SHR) is an accepted model for attention-deficit hyperactivity disorder (ADHD) since it displays the major symptoms of ADHD (hyperactivity, impulsivity, and poor performance in tasks that require sustained attention). We have previously shown that glutamate activation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors released significantly more norepinephrine from SHR prefrontal cortex slices than control Wistar-Kyoto (WKY) rats. The aim of this study was to determine whether N-methyl-D-aspartate (NMDA) receptor function is disturbed in the prefrontal cortex of SHR. Prefrontal cortex slices were incubated with 45Ca2+ in the presence or absence of 100 microM NMDA for 2 min. Activation of NMDA receptors stimulated significantly less Ca2+ uptake into prefrontal cortex slices of SHR than control WKY (2.8 +/- 0.17 vs. 3.7 +/- 0.38 nmol/mg protein, respectively, P < 0.05). Basal Ca2+ uptake into SHR slices was not significantly different from WKY. These findings are consistent with suggestions that the intracellular concentration of calcium is elevated and therefore the concentration gradient that drives calcium into the cell is decreased in SHR compared to WKY. Impaired NMDA receptor function in the prefrontal cortex of SHR could give rise to impaired cognition and an inability to sustain attention.
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Affiliation(s)
- Molupe Lehohla
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Lehohla M, Kellaway L, Russell VA. NMDA receptor function in the prefrontal cortex of a rat model for attention-deficit hyperactivity disorder. Metab Brain Dis 2004; 19:35-42. [PMID: 15214504 DOI: 10.1023/b:mebr.0000027415.75432.ad] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The spontaneously hypertensive rat (SHR) is an accepted model for attention-deficit hyperactivity disorder (ADHD) since it displays the major symptoms of ADHD (hyperactivity, impulsivity, and poor performance in tasks that require sustained attention). We have previously shown that glutamate activation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors released significantly more norepinephrine from SHR prefrontal cortex slices than control Wistar-Kyoto (WKY) rats. The aim of this study was to determine whether N-methyl-D-aspartate (NMDA) receptor function is disturbed in the prefrontal cortex of SHR. Prefrontal cortex slices were incubated with 45Ca2+ in the presence or absence of 100 microM NMDA for 2 min. Activation of NMDA receptors stimulated significantly less Ca2+ uptake into prefrontal cortex slices of SHR than control WKY (2.8 +/- 0.17 vs. 3.7 +/- 0.38 nmol/mg protein, respectively, P < 0.05). Basal Ca2+ uptake into SHR slices was not significantly different from WKY. These findings are consistent with suggestions that the intracellular concentration of calcium is elevated and therefore the concentration gradient that drives calcium into the cell is decreased in SHR compared to WKY. Impaired NMDA receptor function in the prefrontal cortex of SHR could give rise to impaired cognition and an inability to sustain attention.
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Affiliation(s)
- Molupe Lehohla
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Korf ESC, White LR, Scheltens P, Launer LJ. Midlife blood pressure and the risk of hippocampal atrophy: the Honolulu Asia Aging Study. Hypertension 2004; 44:29-34. [PMID: 15159381 DOI: 10.1161/01.hyp.0000132475.32317.bb] [Citation(s) in RCA: 194] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hippocampal atrophy (HA) is usually attributed to the neurofibrillary tangles and neuritic plaques of Alzheimer disease. However, the hippocampus is vulnerable to global ischemia, which may lead to atrophy. We investigated the association of midlife blood pressure (BP) and late-life HA in a sample of Japanese-American men born between 1900 and 1919. BP was measured on 3 occasions between 1965 and 1971. In 1994 to 1996 a subsample underwent magnetic resonance imaging (MRI) of the brain. Hippocampal volume was estimated by manually drawing regions of interest on relevant scan slices; HA was defined as the lowest quartile of hippocampal volume. Also assessed on the MRI were cortical and subcortical infarcts, lacunes, and white matter hyperintensities. The risk (OR, 95% CI) was estimated for HA associated with systolic (<140 versus > or =140 mm Hg) and diastolic (<90 versus > or =90 mm Hg) BP and with antihypertensive treatment. Analyses were adjusted for sociodemographic factors, other cardiovascular risk factors, apolipoprotein E allele, and correlated brain pathology. Those never treated with antihypertensive medication had a significantly increased risk for HA (OR 1.7; CI=1.12; 2.65). The nontreated subjects with high systolic BP had an increased risk (OR=1.98; CI=0.89; 4.39) for HA. Results were similar for untreated men with high diastolic BP (OR=3.51; CI=1.26; 9.74). In conclusion, treatment with antihypertensive treatment modifies the association of BP and HA, such that high levels of BP adversely affect the hippocampus in persons never treated with antihypertensives.
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Affiliation(s)
- Esther S C Korf
- Department of Neurology and Alzheimer Center, Universiteit Medical Center, Amsterdam, The Netherlands
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Tayebati SK, Di Tullio MA, Amenta F. Effect of Treatment with the Cholinesterase Inhibitor Rivastigmine on Vesicular Acetylcholine Transporter and Choline Acetyltransferase in Rat Brain. Clin Exp Hypertens 2004; 26:363-73. [PMID: 15195690 DOI: 10.1081/ceh-120034140] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A decline of cholinergic neurotransmission probably contributes to cognitive dysfunction occurring in Alzheimer's disease (AD) and vascular dementia (VaD). Acetylcholinesterase (AChE)/cholinesterase (ChE) inhibitors are the only drugs authorized for symptomatic treatment of AD and are also under investigation for VaD. The present study has investigated the influence of two doses of the AChE inhibitor rivastigmine (0.625 mg/Kg/day and 2.5 mg/Kg/day) on vesicular acetylcholine transporter (VAChT) and on choline acetyltransferase (ChAT) expression in frontal cortex, hippocampus, striatum and cerebellum of normotensive and spontaneously hypertensive rats (SHR). Cholinergic markers were assessed by immunochemical (Western blotting) and immunohistochemical techniques. In frontal cortex and striatum of normotensive rats, treatment with the lower dose (0.625 mg/Kg/day) of rivastigmine had no effect on VAChT immunoreactivity and increased slightly ChAT protein immunoreactivity. The higher dose (2.5 mg/Kg/day) of the compound increased significantly VAChT and ChAT protein immunoreactivity. In hippocampus rivastigmine induced a concentration-dependent increase of VAChT protein expression and no significant changes of ChAT protein expression. A similar pattern of VAChT and ChAT protein expression was observed in control SHR, whereas treatment of SHR with rivastigmine induced a more pronounced increase of VAChT protein immunoreactivity in frontal cortex, hippocampus and striatum compared to normotensive rats. Our data showing an increase of VAChT after treatment with rivastgmine further support the notion of an enhancement of cholinergic neurotransmission by AChE/ChE inhibitors. The observation of a greater expression of this cholinergic marker in SHR suggest that AChE inhibition may provide beneficial effects on cholinergic neurotransmission in an animal model of VaD.
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Affiliation(s)
- Seyed Khosrow Tayebati
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy.
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Amenta F, Tomassoni D. Treatment with Nicardipine Protects Brain in an Animal Model of Hypertension‐Induced Damage. Clin Exp Hypertens 2004; 26:351-61. [PMID: 15195689 DOI: 10.1081/ceh-120034139] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Control of blood pressure protects from the development of cerebrovascular lesions and vascular dementia (VaD). This study has assessed the influence of treatment with the dihydropyridine-type Ca2+ antagonist nicardipine on brain microanatomical changes in spontaneously hypertensive rats (SHR). SHR were treated from 16th to 26th week of age with hypotensive (3 mg/Kg/day) or non-hypotensive (0.1 mg/Kg/day) doses of nicardipine, with the non-dihydropyridine-type vasodilator hydralazine (10 mg/kg/day) or with vehicle (control group). Untreated age-matched Wistar Kyoto (WKY) rats were used as a normotensive reference group. Brain volume, number of neurons, glial fibrillary-acidic protein (GFAP)-immunoreactive astrocytes and neurofilament 200 KDa (NFP)-immunoreactivity (IR) were assessed in frontal and occipital cortex, hippocampus and striatum. A decrease of volume and number of nerve cells and a loss of NFP-IR was found in the frontal and occipital cortex and in the CA1 subfield of hippocampus and in the striatum of SHR. Treatment with nicardipine countered microanatomical changes occurring in SHR, whereas hydralazine displayed a less pronounced effect. Comparatively, the non-hypotensive dose of nicardipine was less active than the hypotensive one. The observation that equihypotensive doses of nicardipine or hydralazine did not protect brain in the same way from hypertensive brain damage suggests that lowering blood pressure is per se not enough for affording neuroprotection. The demonstration of neuroprotective effect of nicardipine suggests an use of the compound in situations in which hypertension is accompanied by the risk of brain damage.
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Affiliation(s)
- Francesco Amenta
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy.
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Amenta F, Di Tullio MA, Tomassoni D. Arterial hypertension and brain damage--evidence from animal models (review). Clin Exp Hypertens 2003; 25:359-80. [PMID: 12940473 DOI: 10.1081/ceh-120023545] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hypertension is an important risk factor for cerebrovascular disease including stroke and has also a role in the development of vascular cognitive impairment (VCI) and vascular dementia (VaD). Research on pathophysiology and treatment of hypertensive brain damage may benefit from the availability of animal models. This paper has reviewed the main animal models of hypertension in which brain damage is documented. Spontaneously hypertensive rats (SHR) represent the animal model more largely used. In these rats cerebrovascular changes, brain atrophy, loss of nerve cells in cerebrocortical areas, and glial reaction were documented. Several changes observed in SHR are similar to those found by in vivo imaging studies in essential hypertensives. It is documented that brain gets benefit from lowering abnormally elevated blood pressure and that reduction of hypertension protects brain from stroke and probably reduces the incidence of VaD. The influence of anti-hypertensive treatment on brain structure and function in animal models of hypertension is reviewed. Among classes of drugs investigated, dihydropyridine-type Ca2+ antagonists were those with a most documented protective effect on hypertensive brain damage. Limits and perspectives in the use of animal models for assessing brain damage caused by hypertension and protection from it are discussed.
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Affiliation(s)
- Francesco Amenta
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy.
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Frishman WH. Are antihypertensive agents protective against dementia? A review of clinical and preclinical data. HEART DISEASE (HAGERSTOWN, MD.) 2002; 4:380-6. [PMID: 12441015 DOI: 10.1097/00132580-200211000-00007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the United States, the size of the population of persons aged 65 years or older is expected to double within the next 30 years, resulting in a marked increase in the prevalence of dementia. Hypertension is a risk factor for cognitive impairment and dementia in addition to cerebrovascular morbidity and mortality. The evidence for a connection between high blood pressure in midlife and dementia in late life comes from numerous longitudinal studies. A placebo-controlled, double-blind, randomized trial involving 2,418 patients aged 60 years or older with isolated systolic hypertension demonstrated that active treatment based on the dihydropyridine calcium antagonist nitrendipine with the addition of enalapril, hydrochlorothiazide, or both if needed to control systolic blood pressure to <150 mmHg, significantly reduced not only stroke and cardiovascular complications but also the incidence of vascular dementia and Alzheimer's disease. Several trials of antihypertensive treatment are ongoing to confirm this important finding. The newer dihydropyridine calcium antagonists lacidipine and lercanidipine are effective and well tolerated in the treatment of hypertension. In animal models, these newer agents also have been shown to prevent the progression of hypertensive microvascular damage. Their neuroprotective effects offer possible unique advantages in the management of hypertension.
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Affiliation(s)
- William H Frishman
- Department of Medicine, New York Medical College, Westchester Medical Center, Valhalla, New York 10595, USA.
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