101
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Affiliation(s)
- Jurgen A.H.R. Claassen
- From the Department of Geriatric Medicine, Donders Institute for Brain, Cognition, and Behaviour, Radboud Alzheimer Center, Radboud University Medical Center, Nijmegen, The Netherlands
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102
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Tong XK, Hamel E. Simvastatin restored vascular reactivity, endothelial function and reduced string vessel pathology in a mouse model of cerebrovascular disease. J Cereb Blood Flow Metab 2015; 35:512-20. [PMID: 25564230 PMCID: PMC4348394 DOI: 10.1038/jcbfm.2014.226] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/14/2014] [Accepted: 11/20/2014] [Indexed: 01/02/2023]
Abstract
Cerebrovascular dysfunction seen in Alzheimer's disease (AD) and vascular dementia (VaD) is multifaceted and not limited to the amyloid-β (Aβ) pathology. It encompasses structural alterations in the vessel wall, degenerating capillaries (string vessels), vascular fibrosis and calcification, features recapitulated in transgenic mice that overexpress transforming growth factor-β1 (TGF mice). We recently found that simvastatin rescued Aβ-mediated cerebrovascular and cognitive deficits in a transgenic mouse model of AD. However, whether simvastatin can counteract Aβ-independent deficits remains unknown. Here, we evaluated the effects of simvastatin in aged TGF mice on cerebrovascular reactivity and structure, and on cognitive performance. Simvastatin restored baseline levels of nitric oxide (NO), NO-, and KATP channel-mediated dilations and endothelin-1-induced contractions. Simvastatin significantly reduced vasculopathy with arteriogenic remodeling and string vessel pathology in TGF mice. In contrast, simvastatin did not lessen gliosis, and the cerebrovascular levels of pro-fibrotic proteins and calcification markers remained elevated after treatment. The TGF mice displayed subtle cognitive decline that was not affected by simvastatin. Our results show potent benefits of simvastatin on endothelial- and smooth muscle cell-mediated vasomotor responses, endothelial NO synthesis and in preserving capillary integrity. We conclude that simvastatin could be indicated in the treatment of cerebrovascular dysfunction associated with VaD and AD.
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Affiliation(s)
- Xin-Kang Tong
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada
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103
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Marcelo A, Bix G. The potential role of perlecan domain V as novel therapy in vascular dementia. Metab Brain Dis 2015; 30:1-5. [PMID: 24964971 DOI: 10.1007/s11011-014-9576-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/13/2014] [Indexed: 10/25/2022]
Abstract
Vascular dementia (VaD) is the second most common cause of dementia and leads to a decline in cognitive thinking via conditions that lead to blockage or reduced blood flow to the brain. It is a poorly understood disease, and the changes that occur are often linked to other types of dementia such as Alzheimer's disease. To date, there are no approved therapies or drugs to treat the symptoms of VaD, even though there is some evidence of drugs approved for Alzheimer's that might have some benefit in patients diagnosed with VaD. The altered blood flow that precedes VaD may result in compensatory mechanisms, such as angiogenesis, to increase blood flow in the brain. Angiogenesis, the process of new blood vessel formations from pre-existing ones, involves several pro-angiogenic factors such as vascular endothelial growth factor (VEGF) and is regulated by a variety of growth factors from neurons, astrocytes, and pericytes in the brain as well the extracellular matrix (ECM). The ECM highly regulates angiogenesis and other processes in the brain. One such ECM component is the heparan sulfate proteoglycan perlecan and its bioactive region, Domain V (DV). Here we discuss the potential role of DV as a novel therapy to treat VaD.
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Affiliation(s)
- Aileen Marcelo
- Sanders-Brown Center on Aging, Department of Anatomy and Neurobiology and Department of Neurology, University of Kentucky, 430 Sanders Brown Building, 800 S. Limestone Street, Lexington, KY, 40536-0230, USA
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104
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Jellinger KA. Pathogenesis and treatment of vascular cognitive impairment. Neurodegener Dis Manag 2014; 4:471-90. [DOI: 10.2217/nmt.14.37] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
SUMMARY Vascular cognitive impairment (VCI) defines a continuum of disorders ranging from mild cognitive impairment to full-blown dementia, attributable to cerebrovascular causes. Major morphological types – multi-infarct encephalopathy, strategic infarct type, subcortical arteriosclerotic leukoencephalopathy, multilacunar state, postischemic encephalopathy – result from systemic, cardiac and local large or small vessel disease. Cognitive decline is commonly caused by widespread small cerebrovascular lesions (CVLs) affecting regions/networks essential for cognition, memory and behavior. CVLs often coexist with Alzheimer-type and other pathologies, which interact in promoting dementia, but in many nondemented elderly individuals, mixed brain pathologies are also present. Due to the high variability of CVLs, no validated clinical and neuropathological criteria for VCI are available. Cholinesterase inhibitors and memantine produce small cognitive improvement but without essential effect. Antihypertensive treatment, cardiovascular control and lifestyle modifications reducing vascular risk factors are essential. Given its growing health, social and economic burden, prevention and treatment of VCI are a major challenge of neuroscience.
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105
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Is Alzheimer's disease related to metabolic syndrome? A Wnt signaling conundrum. Prog Neurobiol 2014; 121:125-46. [PMID: 25084549 DOI: 10.1016/j.pneurobio.2014.07.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/17/2014] [Accepted: 07/23/2014] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, affecting more than 36 million people worldwide. AD is characterized by a progressive loss of cognitive functions. For years, it has been thought that age is the main risk factor for AD. Recent studies suggest that life style factors, including nutritional behaviors, play a critical role in the onset of dementia. Evidence about the relationship between nutritional behavior and AD includes the role of conditions such as obesity, hypertension, dyslipidemia and elevated glucose levels. The coexistence of some of these cardio-metabolic risk factors is generally known as metabolic syndrome (MS). Some clinical studies support the role of MS in the onset of AD. However, the cross-talk between the molecular signaling implicated in these disorders is unknown. In the present review, we focus on the molecular correlates that support the relationship between MS and the onset of AD. We also discuss relevant issues such as the role of leptin, insulin and renin-angiotensin signaling in the brain and the possible role of Wnt signaling in both MS and AD. We discuss the evidence supporting the use of ob/ob mice, high-fructose diets, aortic coarctation-induced hypertension and Octodon degus, which spontaneously develops β-amyloid deposits and metabolic derangements, as suitable animal models to address the relationships between MS and AD. Finally, we examine emergent data supporting the role of Wnt signaling in the modulation of AD and MS, implicating this pathway as a therapeutic target in both conditions.
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106
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Franco R, Cedazo-Minguez A. Successful therapies for Alzheimer's disease: why so many in animal models and none in humans? Front Pharmacol 2014; 5:146. [PMID: 25009496 PMCID: PMC4070393 DOI: 10.3389/fphar.2014.00146] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/03/2014] [Indexed: 11/29/2022] Open
Abstract
Peering into the field of Alzheimer’s disease (AD), the outsider realizes that many of the therapeutic strategies tested (in animal models) have been successful. One also may notice that there is a deficit in translational research, i.e., to take a successful drug in mice and translate it to the patient. Efforts are still focused on novel projects to expand the therapeutic arsenal to “cure mice.” Scientific reasons behind so many successful strategies are not obvious. This article aims to review the current approaches to combat AD and to open a debate on common mechanisms of cognitive enhancement and neuroprotection. In short, either the rodent models are not good and should be discontinued, or we should extract the most useful information from those models. An example of a question that may be debated for the advancement in AD therapy is: In addition to reducing amyloid and tau pathologies, would it be necessary to boost synaptic strength and cognition? The debate could provide clues to turn around the current negative output in generating effective drugs for patients. Furthermore, discovery of biomarkers in human body fluids, and a clear distinction between cognitive enhancers and disease modifying strategies, should be instrumental for advancing in anti-AD drug discovery.
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Affiliation(s)
- Rafael Franco
- Division of Neurosciences, Centro de Investigación Médica Aplicada, Universidad de Navarra Pamplona, Spain ; Department of Biochemistry and Molecular Biology, Faculty of Biology, Universitat de Barcelona Barcelona, Spain
| | - Angel Cedazo-Minguez
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet Huddinge, Sweden
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107
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108
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Bossers WJR, Scherder EJA, Boersma F, Hortobágyi T, van der Woude LHV, van Heuvelen MJG. Feasibility of a combined aerobic and strength training program and its effects on cognitive and physical function in institutionalized dementia patients. A pilot study. PLoS One 2014; 9:e97577. [PMID: 24844772 PMCID: PMC4028210 DOI: 10.1371/journal.pone.0097577] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/17/2014] [Indexed: 12/13/2022] Open
Abstract
Objectives We examined the feasibility of a combined aerobic and strength training program in institutionalized dementia patients and studied the effects on cognitive and physical function. Methods Thirty-three patients with dementia, recruited from one nursing home, participated in this non-randomized pilot study (25 women; age = 85.2±4.9 years; Mini Mental State Examination = 16.8±4.0). In phase 1 of the study, seventeen patients in the Exercise group (EG) received a combined aerobic and strength training program for six weeks, five times per week, 30 minutes per session, in an individually supervised format and successfully concluded the pre and posttests. In phase 2 of the study, sixteen patients in the Social group (SG) received social visits at the same frequency, duration, and format and successfully concluded the pre and posttests. Results Indices of feasibility showed that the recruitment and adherence rate, respectively were 46.2% and 86.3%. All EG patients completed the exercise program according to protocol without adverse events. After the six-week program, no significant differences on cognitive function tests were found between the EG and SG. There was a moderate effect size in favor for the EG for the Visual Memory Span Forward; a visual attention test. There were significant differences between groups in favor for the EG with moderate to large effects for the physical tests Walking Speed (p = .003), Six-Minute Walk Test (p = .031), and isometric quadriceps strength (p = .012). Conclusions The present pilot study showed that it is feasible to conduct a combined aerobic and strength training program in institutionalized patients with dementia. The selective cognitive visual attention improvements and more robust changes in motor function in favor of EG vs. SG could serve as a basis for large randomized clinical trials. Trial Registration trialregister.nl 1230
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Affiliation(s)
- Willem J. R. Bossers
- University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands
- * E-mail:
| | - Erik J. A. Scherder
- University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands
- VU University, Department of Clinical Neuropsychology, Amsterdam, The Netherlands
| | - Froukje Boersma
- University of Groningen, University Medical Center Groningen, Department of General Practice, Elderly Care Medicine, Groningen, The Netherlands
| | - Tibor Hortobágyi
- University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands
| | - Lucas H. V. van der Woude
- University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands
- University of Groningen, University Medical Center Groningen, Center for Rehabilitation, Groningen, The Netherlands
| | - Marieke J. G. van Heuvelen
- University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands
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109
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Abstract
In recent years, emerging evidence has linked vitamin D not only to its known effects on calcium and bone metabolism, but also to many chronic illnesses involving neurocognitive decline. The importance of vitamin D3 in reducing the risk of these diseases continues to increase due to the fact that an increasing portion of the population in developed countries has a significant vitamin D deficiency. The older population is at an especially high risk for vitamin D deficiency due to the decreased cutaneous synthesis and dietary intake of vitamin D. Recent studies have confirmed an association between cognitive impairment, dementia, and vitamin D deficiency. There is a need for well-designed randomized trials to assess the benefits of vitamin D and lifestyle interventions in persons with mild cognitive impairment and dementia.
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Affiliation(s)
- Mathias Schlögl
- University Center for Medicine of Aging Basel, University of Basel, Basel, Switzerland
| | - Michael F Holick
- Department of Medicine, Section of Endocrinology, Nutrition, and Diabetes, Vitamin D, Skin, and Bone Research Laboratory, Boston University Medical Center, Boston, MA, USA
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