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Laukka JJ, Kain KM, Rathnam AS, Sohi J, Khatib D, Kamholz J, Stanley JA. Altered high-energy phosphate and membrane metabolism in Pelizaeus–Merzbacher disease using phosphorus magnetic resonance spectroscopy. Brain Commun 2022; 4:fcac202. [PMID: 36003325 PMCID: PMC9396944 DOI: 10.1093/braincomms/fcac202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 06/06/2022] [Accepted: 08/04/2022] [Indexed: 11/14/2022] Open
Abstract
Pelizaeus–Merzbacher disease is an X-linked recessive leucodystrophy of the central nervous system caused by mutations affecting the major myelin protein, proteolipid protein 1. The extent of the altered in vivo neurochemistry of protein, proteolipid protein 1 duplications, the most common form of Pelizaeus–Merzbacher disease, is, however, poorly understood. Phosphorus magnetic resonance spectroscopy is the only in vivo technique that can assess the biochemistry associated with high-energy phosphate and membrane phospholipid metabolism across different cortical, subcortical and white matter areas. In this cross-sectional study, whole-brain, multi-voxel phosphorus magnetic resonance spectroscopy was acquired at 3 T on 14 patients with Pelizaeus–Merzbacher disease with protein, proteolipid protein 1 duplications and 23 healthy controls (all males). Anabolic and catabolic levels of membrane phospholipids (phosphocholine and phosphoethanolamine, and glycerophosphoethanolamine and glycerophosphocholine, respectively), as well as phosphocreatine, inorganic orthophosphate and adenosine triphosphate levels relative to the total phosphorus magnetic resonance spectroscopy signal from 12 different cortical and subcortical areas were compared between the two groups. Independent of brain area, phosphocholine, glycerophosphoethanolamine and inorganic orthophosphate levels were significantly lower (P = 0.0025, P < 0.0001 and P = 0.0002) and phosphocreatine levels were significantly higher (P < 0.0001) in Pelizaeus–Merzbacher disease patients compared with controls. Additionally, there was a significant group-by-brain area interaction for phosphocreatine with post-hoc analyses demonstrating significantly higher phosphocreatine levels in patients with Pelizaeus–Merzbacher disease compared with controls across multiple brain areas (anterior and posterior white matter, superior parietal lobe, posterior cingulate cortex, hippocampus, occipital cortex, striatum and thalamus; all P ≤ 0.0042). Phosphoethanolamine, glycerophosphoethanolamine and adenosine triphosphate levels were not significantly different between groups. For the first-time, widespread alterations in phosphorus magnetic resonance spectroscopy metabolite levels of Pelizaeus–Merzbacher disease patients are being reported. Specifically, increased high-energy phosphate storage levels of phosphocreatine concomitant with decreased inorganic orthophosphate across multiple areas suggest a widespread reduction in the high-energy phosphate utilization in Pelizaeus–Merzbacher disease, and the membrane phospholipid metabolite deficits suggest a widespread degradation in the neuropil content/maintenance of patients with Pelizaeus–Merzbacher disease which includes axons, dendrites and astrocytes within cortex and the myelin microstructure and oligodendrocytes within white matter. These results provide greater insight into the neuropathology of Pelizaeus–Merzbacher disease both in terms of energy expenditure and membrane phospholipid metabolites. Future longitudinal studies are warranted to investigate the utility of phosphorus magnetic resonance spectroscopy as surrogate biomarkers in monitoring treatment intervention for Pelizaeus–Merzbacher disease.
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Affiliation(s)
- Jeremy J Laukka
- Department of Medical Education, University of Toledo College of Medicine and Life Sciences , Toledo, OH , USA
- Department of Neurology, University of Toledo College of Medicine and Life Sciences , Toledo, OH , USA
| | - Kevin M Kain
- College of Osteopathic Medicine, Kansas City University , Kansas City, MO , USA
| | | | - Jasloveleen Sohi
- Department of Neurology, Center for Molecular Medicine and Genetics, Wayne State University School of Medicine , MI , USA
| | - Dalal Khatib
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine , Detroit, MI , USA
| | - John Kamholz
- Department of Neurology, Center for Molecular Medicine and Genetics, Wayne State University School of Medicine , MI , USA
- Department of Neurology, University of Iowa Carver College of Medicine , Iowa City, IA , USA
| | - Jeffrey A Stanley
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine , Detroit, MI , USA
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Haszto CS, Stanley JA, Iyengar S, Prasad KM. Regionally Distinct Alterations in Membrane Phospholipid Metabolism in Schizophrenia: A Meta-analysis of Phosphorus Magnetic Resonance Spectroscopy Studies. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 5:264-280. [PMID: 31748123 DOI: 10.1016/j.bpsc.2019.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND Existing data on altered membrane phospholipid metabolism in schizophrenia are diverse. We conducted a meta-analysis of studies of phosphorus magnetic resonance spectroscopy, a noninvasive imaging approach that can assess molecular biochemistry of cortex by measuring phosphomonoester (PME) and phosphodiester (PDE) levels, which can provide evidence of altered biochemical processes involved in neuropil membrane expansion and contraction in schizophrenia. METHODS We analyzed PME and PDE data in the frontal and temporal lobes in subjects with schizophrenia from 24 peer-reviewed publications using the MAVIS package in R by building random- and fixed-effects models. Heterogeneity of effect sizes, effects of publication bias, and file drawer analysis were also assessed. RESULTS Subjects with schizophrenia showed lower PME levels in the frontal regions (p = .008) and elevated PDE levels in the temporal regions (p < .001) with significant heterogeneity. We noted significant publication bias and file drawer effect for frontal PME and PDE and temporal PDE levels, but not for temporal PME levels. Fail-safe analysis estimated that a high number of negative studies were required to provide nonsignificant results. CONCLUSIONS Despite methodological differences, these phosphorus magnetic resonance spectroscopy studies demonstrate regionally specific imbalance in membrane phospholipid metabolism related to neuropil in subjects with schizophrenia compared with control subjects reflecting neuropil contraction. Specifically, decreased PME levels in the frontal regions and elevated PDE levels in the temporal regions provide evidence of decreased synthesis and increased degradation of neuropil membrane, respectively. Notwithstanding significant heterogeneity and publication bias, a large number of negative studies are required to render the results of this meta-analysis nonsignificant. These findings warrant further postmortem and animal studies.
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Affiliation(s)
- Connor S Haszto
- Kenneth Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jeffrey A Stanley
- Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, Michigan
| | - Satish Iyengar
- Department of Statistics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Konasale M Prasad
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Veterans Affairs Pittsburgh Health System, Pittsburgh, Pennsylvania.
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Niendam TA, Ray KL, Iosif AM, Lesh TA, Ashby SR, Patel PK, Smucny J, Ferrer E, Solomon M, Ragland JD, Carter CS. Association of Age at Onset and Longitudinal Course of Prefrontal Function in Youth With Schizophrenia. JAMA Psychiatry 2018; 75:1252-1260. [PMID: 30285056 PMCID: PMC6583034 DOI: 10.1001/jamapsychiatry.2018.2538] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 07/08/2018] [Indexed: 01/19/2023]
Abstract
Importance The extent of cognitive deterioration after schizophrenia (SZ) onset is poorly understood because prior longitudinal studies used small samples of older individuals with established illness. Objective To examine the association of age at onset and subsequent longitudinal course of prefrontal activity during the first 2 years of illness in youths with SZ and healthy control participants (HCs). Design, Setting, and Participants This naturalistic, longitudinal, functional magnetic resonance imaging (fMRI) study included patients with recent-onset SZ and HCs aged 12 to 25 years enrolled in an ongoing study of cognition in recent-onset psychosis in the Sacramento, California, area from October 13, 2004, through June 25, 2013. Participants completed clinical assessments and an established measure of cognitive control, the AX Continuous Performance Task (AX-CPT), during fMRI at baseline and at 6-, 12-, and 24-month follow-up. Whole-brain, voxelwise, and an a priori dorsolateral prefrontal cortex (DLPFC) region of interest analyses were performed. Group differences in developmental trajectories were examined by focusing on behavioral performance (d'-context) and cognitive control-associated brain activity. The association of antipsychotic medication and clinical factors were also examined. Data were analyzed from April 15, 2015, through August 29, 2017. Main Outcomes and Measures Primary outcomes included group differences (HC vs SZ) in behavioral performance (d'-context from AX-CPT) and brain activity for cue B-A trials of the AX-CPT in an a priori DLPFC region of interest at baseline and across the age span. Secondary analysis examined the influence of antipsychotics on behavioral performance and DLPFC activity. Results Among the sample of 180 participants (66.1% male; mean [SD] age at baseline, 19.2 [3.2] years), 87 patients with SZ (mean [SD] age, 19.6 [3.0] years) showed impaired performance compared with 93 HCs (mean [SD] age, 18.8 [3.4] years) across the age span (estimated difference [SE], -0.571 [0.12], d'-context; P < .001). Patients with SZ showed reduced activation in the DLPFC and parietal cortex (false discovery rate cluster corrected to P < .05) compared with HCs under conditions of high cognitive control at baseline. Region-of-interest analysis showed reduced activation in the DLPFC bilaterally for patients with SZ, with a trajectory that paralleled that of HCs across the age span (left DLPFC β [SE] estimates, 0.409 [0.165] for the HC group and -0.285 [0.130] for the SZ group [main effect of group, P = .03]; right DLPFC β [SE] estimates, 0.350 [0.103] for the HC group and -0.469 [0.157] for the SZ group [P = .003]). Antipsychotic medication, clinical symptoms, and global functioning were associated with SZ performance. Conclusions and Relevance During the initial 1 to 2 years after illness onset, young individuals with SZ showed deficits in DLPFC activation and cognitive control, with developmental trajectories comparable to those of HCs. Younger age at onset was not associated with reduced cognition or activation. For individuals contributing to longitudinal analysis, results suggest that young patients do not show deterioration or disruption of ongoing brain development in the initial years after illness onset.
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Affiliation(s)
- Tara A. Niendam
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
| | - Kimberly L. Ray
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
- Department of Psychology, The University of Texas at Austin
| | - Ana-Maria Iosif
- Division of Biostatistics, Department of Public Health Sciences, University of California, Davis, Sacramento
| | - Tyler A. Lesh
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
| | - Stefania R. Ashby
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
- Department of Psychology, University of Oregon, Eugene
| | - Pooja K. Patel
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
- Department of Psychology, UCLA (University of California, Los Angeles), Westwood
| | - Jason Smucny
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
| | - Emilio Ferrer
- Department of Psychology, University of California, Davis, Sacramento
| | - Marjorie Solomon
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
- MIND Institute, University of California, Davis, Sacramento
| | - J. Daniel Ragland
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
| | - Cameron S. Carter
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Sacramento
- Center for Neuroscience, University of California, Davis, Sacramento
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Neuropil contraction in relation to Complement C4 gene copy numbers in independent cohorts of adolescent-onset and young adult-onset schizophrenia patients-a pilot study. Transl Psychiatry 2018; 8:134. [PMID: 30026462 PMCID: PMC6053402 DOI: 10.1038/s41398-018-0181-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 05/14/2018] [Indexed: 02/08/2023] Open
Abstract
A recent report suggested Complement 4 (C4A) gene copy numbers (GCN) as risk factors for schizophrenia. Rodent model showed association of C4 with synaptic pruning suggesting its pathophysiological significance (Sekar, A. et al. (2016)). We, therefore, predicted that C4A GCN would be positively correlated with neuropil contraction in the human brain among schizophrenia patients showing more prominent correlations in ventral regions among young adults and dorsal regions among adolescents since neuromaturation progresses dorsoventrally. Whole-brain, multi-voxel, in vivo phosphorus magnetic resonance spectroscopy (31P MRS) assessed neuropil changes by estimating levels of membrane phospholipid (MPL) precursors and catabolites. Increased MPL catabolites and/or decreased MPL precursors indexed neuropil contraction. Digital droplet PCR-based assay was used to estimate C4A and C4B GCN. We evaluated two independent cohorts (young adult-onset early-course schizophrenia (YASZ = 15) and adolescent-onset schizophrenia (AOSZ = 12) patients), and controls matched for each group, n = 22 and 15, respectively. Separate forward stepwise linear regression models with Akaike information Criterion were built for MPL catabolites and precursors. YASZ cohort: Consistent with the rodent model (Sekar, A. et al. 2016)), C4A GCN positively correlated with neuropil contraction (increased pruning/decreased formation) in the inferior frontal cortex and inferior parietal lobule. AOSZ cohort: C4A GCN positively correlated with neuropil contraction in the dorsolateral prefrontal cortex and thalamus. Exploratory analysis of C4B GCN showed positive correlation with neuropil contraction in the cerebellum and superior temporal gyrus among YASZ while AOSZ showed neuropil contraction in the prefrontal and subcortical structures. Thus, C4A and C4B GCN are associated with neuropil contraction in regions often associated with schizophrenia, and may be neuromaturationally dependent.
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Raz N, Daugherty AM. Pathways to Brain Aging and Their Modifiers: Free-Radical-Induced Energetic and Neural Decline in Senescence (FRIENDS) Model - A Mini-Review. Gerontology 2017; 64:49-57. [PMID: 28858861 DOI: 10.1159/000479508] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/15/2017] [Indexed: 12/19/2022] Open
Abstract
In this mini-review, we survey the extant literature on brain aging, with the emphasis on longitudinal studies of neuroanatomy, including regional brain volumes and white matter microstructure. We assess the impact of vascular, metabolic, and inflammatory risk factors on the trajectories of change in regional brain volumes and white matter properties, as well as the relationships between neuroanatomical and physiological changes and their influence on cognitive performance. We examine these findings in the context of current biological theories of aging and propose the means of integrating noninvasive measures - spectroscopic indices of brain energy metabolism and regional iron deposits - as valuable proxies for elucidating the basic neurobiology of human brain aging. In a brief summary of the recent findings pertaining to age-related changes in the brain structure and their impact on cognition, we discuss the role of vascular, metabolic, and inflammatory risk factors in shaping the trajectories of change. Drawing on the extant biological theories of aging and mindful of the brain's role as a disproportionately voracious energy consumer in mammals, we emphasize the importance of the fundamental bioenergetic mechanisms as drivers of age-related changes in brain structure and function. We sketch out a model that builds on the conceptualization of aging as an expression of cumulative cellular damage inflicted by reactive oxygen species and ensuing declines in energy metabolism. We outline the ways and means of adapting this model, Free-Radical-Induced Energetic and Neural Decline in Senescence (FRIENDS), to human aging and testing it within the constraints of noninvasive neuroimaging.
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Affiliation(s)
- Naftali Raz
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
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Upadhyay A, Joshi V, Amanullah A, Mishra R, Arora N, Prasad A, Mishra A. E3 Ubiquitin Ligases Neurobiological Mechanisms: Development to Degeneration. Front Mol Neurosci 2017; 10:151. [PMID: 28579943 PMCID: PMC5437216 DOI: 10.3389/fnmol.2017.00151] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/04/2017] [Indexed: 01/08/2023] Open
Abstract
Cells regularly synthesize new proteins to replace old or damaged proteins. Deposition of various aberrant proteins in specific brain regions leads to neurodegeneration and aging. The cellular protein quality control system develop various defense mechanisms against the accumulation of misfolded and aggregated proteins. The mechanisms underlying the selective recognition of specific crucial protein or misfolded proteins are majorly governed by quality control E3 ubiquitin ligases mediated through ubiquitin-proteasome system. Few known E3 ubiquitin ligases have shown prominent neurodevelopmental functions, but their interactions with different developmental proteins play critical roles in neurodevelopmental disorders. Several questions are yet to be understood properly. How E3 ubiquitin ligases determine the specificity and regulate degradation of a particular substrate involved in neuronal proliferation and differentiation is certainly the one, which needs detailed investigations. Another important question is how neurodevelopmental E3 ubiquitin ligases specifically differentiate between their versatile range of substrates and timing of their functional modulations during different phases of development. The premise of this article is to understand how few E3 ubiquitin ligases sense major molecular events, which are crucial for human brain development from its early embryonic stages to throughout adolescence period. A better understanding of these few E3 ubiquitin ligases and their interactions with other potential proteins will provide invaluable insight into disease mechanisms to approach toward therapeutic interventions.
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Affiliation(s)
- Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology JodhpurJodhpur, India
| | - Vibhuti Joshi
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology JodhpurJodhpur, India
| | - Ayeman Amanullah
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology JodhpurJodhpur, India
| | - Ribhav Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology JodhpurJodhpur, India
| | - Naina Arora
- School of Basic Sciences, Indian Institute of Technology MandiMandi, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology MandiMandi, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology JodhpurJodhpur, India
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Prasad KM, Burgess AM, Keshavan MS, Nimgaonkar VL, Stanley JA. Neuropil pruning in Early-Course Schizophrenia: Immunological, Clinical, and Neurocognitive Correlates. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2016; 1:528-538. [PMID: 28255578 PMCID: PMC5328666 DOI: 10.1016/j.bpsc.2016.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Neuropathological studies suggest neuropil reduction in schizophrenia. Altered synaptic pruning is proposed to underlie neuropil reduction. Underlying factors and clinical correlates of synaptic pruning are poorly understood. Using phosphorus magnetic resonance spectroscopy (31P MRS), it is feasible to assess membrane phospholipid (MPL) metabolites in the brain that specifically and sensitively reflect neuropil expansion (elevated MPL precursors) or contraction (elevated MPL catabolites). METHODS We examined MPL metabolites and their cognitive, clinical and immunologic correlates among 28 early-course schizophrenia individuals (illness duration 1.99±1.33 years; antipsychotic-naïve=18) and 21 controls. We acquired whole-brain multi-voxel 31P MRS data from 12 unique brain regions. Interleukin-6 and C-reactive protein (CRP) were assayed in the serum. Generalized linear mixed models examined case-control differences in MPL metabolites in these regions correcting for multiple testing. Partial correlations accounting for multiple tests examined the relationship of Interleukin-6 and CRP levels with MPL metabolite levels. RESULTS MPL catabolite levels were increased in the thalamus in schizophrenia compared to controls. Interleukin-6 and CRP levels did not show case-control differences. Interleukin-6 levels positively correlated with MPL catabolite levels in the thalamus after correcting for multiple tests. The left thalamus MPL catabolite levels correlated negatively with sustained attention (corrected p=0.039). DISCUSSION Elevated MPL catabolites in the thalamus suggest increased neuropil contraction that may be related to excessive synaptic pruning. The thalamic neuropil contraction is associated with Interleukin-6 levels suggesting central pathogenic mechanisms for the inflammatory mediators. Correlation of increased thalamic MPL catabolite levels with cognitive impairments suggests clinical correlates of neuropil contraction.
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Stanley JA. The impact of magnetic resonance spectroscopy in elucidating the role of apolipoprotein E ε4 in preclinical Alzheimer's disease. Biol Psychiatry 2014; 75:672-3. [PMID: 24731694 DOI: 10.1016/j.biopsych.2014.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 11/15/2022]
Affiliation(s)
- Jeffrey A Stanley
- Department of Psychiatry & Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan.
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Altered development of the dorsolateral prefrontal cortex in chromosome 22q11.2 deletion syndrome: an in vivo proton spectroscopy study. Biol Psychiatry 2012; 72:684-91. [PMID: 22633947 PMCID: PMC3440535 DOI: 10.1016/j.biopsych.2012.04.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 02/02/2023]
Abstract
BACKGROUND Chromosome 22q11.2 deletion syndrome (22q11DS), the most common microdeletion in humans, is associated with multiple medical features, almost universal cognitive deficits, and a high risk of schizophrenia. The metabolic basis of the psychological/psychiatric features is not well understood. Volumetric brain imaging studies have shown that gray matter abnormalities in the dorsolateral prefrontal cortex (DLPFC), an area that is believed to be integral for higher neurocognition, as well as being involved in schizophrenia, are associated with the psychological manifestations. However, studies have not characterized any possible metabolite alterations within the DLPFC of children with 22q11DS and their correlations with the psychological findings. METHODS We conducted a short echo time, single-voxel, in vivo proton spectroscopy study involving children with 22q11DS (n = 26) and matched control subjects (n = 23). RESULTS Absolute N-acetylaspartate (NAA) levels from the DLPFC were significantly elevated in children with 22q11DS compared with control subjects and the elevations were associated with poor global functioning and higher rates of comorbid attention-deficit/hyperactivity disorder. Children with 22q11DS had a lack of an age-associated decrease in NAA levels, a trend seen in the control subjects. However, the results did not remain statistically significant after corrections for multiple comparisons were made. CONCLUSIONS These findings represent the first report of proton spectroscopy in children with 22q11DS. The elevated DLPFC NAA levels and the lack of decreasing trends in NAA with age in the 22q11DS group relative to control subjects suggest an alteration in cortical development. Also, such neuronal dysmaturation is associated with psychopathology in children with 22q11DS.
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Igarashi M, Ma K, Gao F, Kim HW, Rapoport SI, Rao JS. Disturbed choline plasmalogen and phospholipid fatty acid concentrations in Alzheimer's disease prefrontal cortex. J Alzheimers Dis 2011; 24:507-17. [PMID: 21297269 PMCID: PMC3175096 DOI: 10.3233/jad-2011-101608] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by brain deposition of senile (neuritic) plaques containing amyloid-β, neurofibrillary tangles, synaptic loss, neuroinflammation, and overexpression of arachidonic acid (AA, 20:4n-6) metabolizing enzymes. Lipid concentration changes have been reported in different brain regions, but often partially or as a percent of the total concentration. In this study, we measured absolute concentrations (per gram wet weight) of a wide range of lipids in postmortem prefrontal cortex (Brodmann area 9) from 10 AD patients and 9 non-AD controls. Mean total brain lipid, phospholipid, cholesterol, and triglyceride concentrations did not differ significantly between AD and controls. There was a significant 73% decrease in plasmalogen choline, but no difference in other measured phospholipids. Fatty acid concentrations in total phospholipid did not differ from control. However, docosahexaenoic acid (DHA, 22:6n-3) was reduced in ethanolamine glycerophospholipid and choline glycerophospholipid, but increased in phosphatidylinositol. AA was reduced in choline glycerophospholipid, but increased in phosphatidylinositol, while docosatetraenoic acid (22:4n-6), an AA elongation product, was reduced in total brain lipid, cholesteryl ester and triglyceride. These lipid changes, which suggest extensive membrane remodeling, may contribute to membrane instability and synaptic loss in AD and reflect neuroinflammation.
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Affiliation(s)
- Miki Igarashi
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
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Zimmerman ME, Lipton RB, Pan JW, Hetherington HP, Verghese J. MRI- and MRS-derived hippocampal correlates of quantitative locomotor function in older adults. Brain Res 2009; 1291:73-81. [PMID: 19631621 DOI: 10.1016/j.brainres.2009.07.043] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 07/08/2009] [Accepted: 07/15/2009] [Indexed: 11/28/2022]
Abstract
Gait measures have been shown to predict cognitive decline and dementia in older adults. Investigation of the neurobiology associated with locomotor function is needed to elucidate this relationship with cognitive abilities. This study aimed to examine magnetic resonance imaging (MRI; hippocampal volume)- and proton magnetic resonance spectroscopy (MRS; N-acetylaspartate to creatine (NAA/Cr) ratios)-derived hippocampal correlates of quantitative gait function (swing time (seconds), stride length (cm), and stride length variability (standard deviation)) in a subset of 48 nondemented older adults (24 males; mean age=81 years) drawn from the Einstein Aging Study, a community-based sample of individuals over the age of 70 residing in Bronx, New York. Linear regression analyses controlling for age were used to examine hippocampal volume and neurochemistry as predictors of gait function. We found that stride length was associated with hippocampal volume (beta=0.36, p=0.03; overall model R(2)=0.33, p=0.01), but not hippocampal neurochemistry (beta=0.09, p=0.48). Stride length variability was more strongly associated with hippocampal NAA/Cr (beta=-0.38, p=0.01; overall model R(2)=0.14, p=0.04) than hippocampal volume (beta=-0.33, p=0.08). Gait swing time was not significantly related to any neuroimaging measure. These relationships remained significant after accounting for memory and clinical gait impairments. These findings suggest that nondemented older adults exhibit increased stride length variability that is associated with lower levels of hippocampal neuronal metabolism, but not hippocampal volume. Conversely, decreased stride length is associated with smaller hippocampal volumes, but not hippocampal neurochemistry. Distinct neurobiological hippocampal substrates may support decreased stride length and increased stride length variability in older adults.
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Affiliation(s)
- Molly E Zimmerman
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, 1165 Morris Park Avenue, Room 343, Bronx, NY 10461, USA.
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Simultaneous in vivo positron emission tomography and magnetic resonance imaging. Proc Natl Acad Sci U S A 2008; 105:3705-10. [PMID: 18319342 DOI: 10.1073/pnas.0711622105] [Citation(s) in RCA: 226] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Positron emission tomography (PET) and magnetic resonance imaging (MRI) are widely used in vivo imaging technologies with both clinical and biomedical research applications. The strengths of MRI include high-resolution, high-contrast morphologic imaging of soft tissues; the ability to image physiologic parameters such as diffusion and changes in oxygenation level resulting from neuronal stimulation; and the measurement of metabolites using chemical shift imaging. PET images the distribution of biologically targeted radiotracers with high sensitivity, but images generally lack anatomic context and are of lower spatial resolution. Integration of these technologies permits the acquisition of temporally correlated data showing the distribution of PET radiotracers and MRI contrast agents or MR-detectable metabolites, with registration to the underlying anatomy. An MRI-compatible PET scanner has been built for biomedical research applications that allows data from both modalities to be acquired simultaneously. Experiments demonstrate no effect of the MRI system on the spatial resolution of the PET system and <10% reduction in the fraction of radioactive decay events detected by the PET scanner inside the MRI. The signal-to-noise ratio and uniformity of the MR images, with the exception of one particular pulse sequence, were little affected by the presence of the PET scanner. In vivo simultaneous PET and MRI studies were performed in mice. Proof-of-principle in vivo MR spectroscopy and functional MRI experiments were also demonstrated with the combined scanner.
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Hoyer S, Riederer P. Alzheimer disease--no target for statin treatment. A mini review. Neurochem Res 2006; 32:695-706. [PMID: 17063393 DOI: 10.1007/s11064-006-9168-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 09/11/2006] [Indexed: 10/24/2022]
Abstract
Nosologically, Alzheimer disease (AD) is not a single disorder. A minority of around 400 families worldwide can be grouped as hereditary in origin, whereas the majority of all Alzheimer cases (approx. 25 million worldwide) are sporadic in origin. In the pathophysiology of the latter type, a number of susceptibility genes contribute to the disease among which are allelic abnormalities of the apolipoprotein E4 gene pointing to a link between disturbed cholesterol metabolism and sporadic AD. Cholesterol is a main component of membrane composition enriched in microdomains and is functionally linked to the proteolytic processing of amyloid precursor protein (APP). In sporadic AD, a marked diminution of both membrane phospholipids and cholesterol has been found. Evidence has been provided that high plasma cholesterol may protect from AD. In contrast to these well documented abnormalities observed in AD patients, it was assumed that an elevated cholesterol concentration might favour the generation of beta-amyloid and, thus, AD. However, a series of in vitro-and in vivo-studies did not provide evidence for the assumption that an enhanced cholesterol concentration increased betaA4-production. A harsh reduction of membrane cholesterol only caused a "beneficial" effect of APP metabolism. However, this experimentally induced condition may not be compatible to sporadic AD. The application of statins in sporadic AD did not yield results to assume that this therapeutic strategy may prevent or treat successfully sporadic AD.
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Affiliation(s)
- Siegfried Hoyer
- Department of Pathology, University of Heidelberg, Im Neuenheimer Feld 220/221, D-69120 Heidelberg, Germany.
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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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15
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Pettegrew JW, Panchalingam K, Hamilton RL, McClure RJ. Brain membrane phospholipid alterations in Alzheimer's disease. Neurochem Res 2001; 26:771-82. [PMID: 11565608 DOI: 10.1023/a:1011603916962] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Studies have demonstrated alterations in brain membrane phospholipid metabolite levels in Alzheimer's disease (AD). The changes in phospholipid metabolite levels correlate with neuropathological hallmarks of the disease and measures of cognitive decline. This 31P nuclear magnetic resonance (NMR) study of Folch extracts of autopsy material reveals significant reductions in AD brain levels of phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns), and elevations in sphingomyelin (SPH) and the plasmalogen derivative of PtdEtn. In the superior temporal gyrus, there were additional reductions in the levels of diphosphatidylglycerol (DPG) and phosphatidic acid (PtdA). The findings are present in 3/3 as well as 3/4 and 4/4 apolipoprotein E (apoE) genotypes. The AD findings do not appear to reflect non-specific neurodegeneration or the presence of gliosis. The present findings could possibly contribute to an abnormal membrane repair in AD brains which ultimately results in synaptic loss and the aggregation of A beta peptide.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry. School of Medicine, University of Pittsburgh, Pennsylvania, USA.
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