Upregulation of N-acetylaspartic acid induces oxidative stress to contribute in disease pathophysiology

A new approach towards highly sensitive detection of endogenous N-acetylaspartic acid, N-acetylglutamic acid, and N-acetylaspartylglutamic acid in brain tissues based on strong anion exchange monolith microextraction coupled with UHPLC-MS/MS

A novel in-tube solid-phase microextraction coupled with an ultra-high performance liquid chromatography-mass spectrometry method has been established for simultaneous quantification of three crucial brain biomarkers N-acetylaspartic acid (NAA), N-acetylglutamic acid (NAG), and N-acetylaspartylglutamic acid (NAAG). A polymer monolith with quaternary ammonium as the functional group was designed and exhibited efficient enrichment of target analytes through strong anion exchange interaction. Under the optimized conditions, the proposed method displayed wide linear ranges (0.1-80 nM for NAA and NAG, 0.2-160 nM for NAAG) with good precision (RSDs were lower than 15%) and low limits of detection (0.019-0.052 nM), which is by far the most sensitive approach for NAA, NAG, and NAAG determination. Furthermore, this approach has been applied to measure the target analytes in mouse brain samples, and endogenous NAA, NAG, and NAAG were successfully detected and quantified from only around 5 mg of cerebral cortex, cerebellum, and hippocampus. Compared with existing methods, the newly developed method in the current study provides highest sensitivity and lowest sample consumption for NAA, NAG, and NAAG measurements, which would potentially be utilized in determining and tracking these meaningful brain biomarkers in diseases or treatment processes, benefiting the investigations of pathophysiology and treatment of brain disorders.

Pd2Spermine as an Alternative Therapeutics for Cisplatin-Resistant Triple-Negative Breast Cancer

Cisplatin (cDDP) resistance is a matter of concern in triple-negative breast cancer therapeutics. We measured the metabolic response of cDDP-sensitive (S) and -resistant (R) MDA-MB-231 cells to Pd2Spermine(Spm) (a possible alternative to cDDP) compared to cDDP to investigate (i) intrinsic response/resistance mechanisms and (ii) the potential cytotoxic role of Pd2Spm. Cell extracts were analyzed by untargeted nuclear magnetic resonance metabolomics, and cell media were analyzed for particular metabolites. CDDP-exposed S cells experienced enhanced antioxidant protection and small deviations in the tricarboxylic acid cycle (TCA), pyrimidine metabolism, and lipid oxidation (proposed cytotoxicity signature). R cells responded more strongly to cDDP, suggesting a resistance signature of activated TCA cycle, altered AMP/ADP/ATP and adenine/uracil fingerprints, and phospholipid biosynthesis (without significant antioxidant protection). Pd2Spm impacted more markedly on R/S cell metabolisms, inducing similarities to cDDP/S cells (probably reflecting high cytotoxicity) and strong additional effects indicative of amino acid depletion, membrane degradation, energy/nucleotide adaptations, and a possible beneficial intracellular γ-aminobutyrate/glutathione-mediated antioxidant mechanism.

Metabolomic Signatures of Alzheimer's Disease Indicate Brain Region-Specific Neurodegenerative Progression

Pathological mechanisms contributing to Alzheimer's disease (AD) are still elusive. Here, we identified the metabolic signatures of AD in human post-mortem brains. Using 1H NMR spectroscopy and an untargeted metabolomics approach, we identified (1) metabolomic profiles of AD and age-matched healthy subjects in post-mortem brain tissue, and (2) region-common and region-unique metabolome alterations and biochemical pathways across eight brain regions revealed that BA9 was the most affected. Phenylalanine and phosphorylcholine were mainly downregulated, suggesting altered neurotransmitter synthesis. N-acetylaspartate and GABA were upregulated in most regions, suggesting higher inhibitory activity in neural circuits. Other region-common metabolic pathways indicated impaired mitochondrial function and energy metabolism, while region-unique pathways indicated oxidative stress and altered immune responses. Importantly, AD caused metabolic changes in brain regions with less well-documented pathological alterations that suggest degenerative progression. The findings provide a new understanding of the biochemical mechanisms of AD and guide biomarker discovery for personalized risk prediction and diagnosis.

Combined targeted and untargeted high-resolution mass spectrometry analyses to investigate metabolic alterations in pompe disease

INTRODUCTION

Pompe disease is a rare, lysosomal disorder, characterized by intra-lysosomal glycogen accumulation due to an impaired function of α-glucosidase enzyme. The laboratory testing for Pompe is usually performed by enzyme activity, genetic test, or urine glucose tetrasaccharide (Glc4) screening by HPLC. Despite being a good preliminary marker, the Glc4 is not specific for Pompe.

OBJECTIVE

The purpose of the present study was to develop a simple methodology using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for targeted quantitative analysis of Glc₄ combined with untargeted metabolic profiling in a single analytical run to search for complementary biomarkers in Pompe disease.

METHODS

We collected 21 urine specimens from 13 Pompe disease patients and compared their metabolic signatures with 21 control specimens.

RESULTS

Multivariate statistical analyses on the untargeted profiling data revealed Glc₄, creatine, sorbitol/mannitol, L-phenylalanine, N-acetyl-4-aminobutanal, N-acetyl-L-aspartic acid, and 2-aminobenzoic acid as significantly altered in Pompe disease. This panel of metabolites increased sample class prediction (Pompe disease versus control) compared with a single biomarker.

CONCLUSION

This study has demonstrated the potential of combined acquisition methods in LC-HRMS for Pompe disease investigation, allowing for routine determination of an established biomarker and discovery of complementary candidate biomarkers that may increase diagnostic accuracy, or improve the risk stratification of patients with disparate clinical phenotypes.

Antisense Oligonucleotide Therapy for the Nervous System: From Bench to Bedside with Emphasis on Pediatric Neurology

Antisense oligonucleotides (ASOs) are disease-modifying agents affecting protein-coding and noncoding ribonucleic acids. Depending on the chemical modification and the location of hybridization, ASOs are able to reduce the level of toxic proteins, increase the level of functional protein, or modify the structure of impaired protein to improve function. There are multiple challenges in delivering ASOs to their site of action. Chemical modifications in the phosphodiester bond, nucleotide sugar, and nucleobase can increase structural thermodynamic stability and prevent ASO degradation. Furthermore, different particles, including viral vectors, conjugated peptides, conjugated antibodies, and nanocarriers, may improve ASO delivery. To date, six ASOs have been approved by the US Food and Drug Administration (FDA) in three neurological disorders: spinal muscular atrophy, Duchenne muscular dystrophy, and polyneuropathy caused by hereditary transthyretin amyloidosis. Ongoing preclinical and clinical studies are assessing the safety and efficacy of ASOs in multiple genetic and acquired neurological conditions. The current review provides an update on underlying mechanisms, design, chemical modifications, and delivery of ASOs. The administration of FDA-approved ASOs in neurological disorders is described, and current evidence on the safety and efficacy of ASOs in other neurological conditions, including pediatric neurological disorders, is reviewed.

Sánchez B, León C, Nozal L, Mora-Rodríguez JM, Castro F, Crego AL, Díaz-Laviada I. Metabolic fingerprinting of chemotherapy-resistant prostate cancer stem cells. An untargeted metabolomic approach by liquid chromatography-mass spectrometry

Chemoresistance is one of the most important challenges in cancer therapy. The presence of cancer stem cells within the tumor may contribute to chemotherapy resistance since these cells express high levels of extrusion pumps and xenobiotic metabolizing enzymes that inactivate the therapeutic drug. Despite the recent advances in cancer cell metabolism adaptations, little is known about the metabolic adaptations of the cancer stem cells resistant to chemotherapy. In this study, we have undertaken an untargeted metabolomic analysis by liquid chromatography–high-resolution spectrometry combined with cytotoxicity assay, western blot, quantitative real-time polymerase chain reaction (qPCR), and fatty acid oxidation in a prostate cancer cell line resistant to the antiandrogen 2-hydroxiflutamide with features of cancer stem cells, compared to its parental androgen-sensitive cell line. Metabolic fingerprinting revealed 106 out of the 850 metabolites in ESI+ and 67 out of 446 in ESI- with significant differences between the sensitive and the resistant cell lines. Pathway analysis performed with the unequivocally identified metabolites, revealed changes in pathways involved in energy metabolism as well as posttranscriptional regulation. Validation by enzyme expression analysis indicated that the chemotherapy-resistant prostate cancer stem cells were metabolically dormant with decreased fatty acid oxidation, methionine metabolism and ADP-ribosylation. Our results shed light on the pathways underlying the entry of cancer cells into dormancy that might contribute to the mechanisms of drug resistance.

Metabolic alterations in the visual pathway of retinitis pigmentosa rats: A longitudinal multimodal magnetic resonance imaging study with histopathological validation

Because retinitis pigmentosa (RP) has been shown to cause degenerative changes in the entire visual pathway, there is an urgent need to perform longitudinal assessments of RP-induced degeneration and identify imaging protocols to detect this degeneration as early as possible. In this study, we assessed a transgenic rat model of RP by using complementary noninvasive magnetic resonance imaging techniques, namely, proton magnetic resonance spectroscopy (¹ H-MRS), to investigate the metabolic changes in RP. Our study demonstrated decreased concentrations and ratios to creatine (Cr) of N-acetylaspartate (NAA), glutamate (Glu), γ-aminobutyric acid (GABA), and taurine (Tau), whereas myo-inositol (Ins) and choline (Cho) were increased in the visual cortex of Royal College of Surgeons (RCS) rats compared with control rats (p < 0.05). Furthermore, with the progression of RP, the concentrations of NAA, Glu, GABA, and Tau, and the ratios of GABA/Cr and Tau/Cr significantly decreased over time, whereas the concentrations of Ins and Cho and the ratio of Ins/Cr significantly increased over time (p < 0.05). In addition, in RCS rats, NAA/Cr decreased significantly from 3 to 4 months postnatal (p < 0.001), and Cho/Cr increased significantly from 4 to 5 months postnatal (p = 0.005). Meanwhile, the ¹ H-MRS indicators in 5-month postnatal RCS rats could be confirmed by immunohistochemical staining. In conclusion, with the progression of RP, the metabolic alterations in the visual cortex indicated progressive reprogramming with the decrease of neurons and axons, accompanied by the proliferation of gliocytes.

Neurometabolite Changes in Hyperthyroid Patients Before and After Antithyroid Treatment: An in vivo 1H MRS Study

Purpose: Patients with hyperthyroidism have frequent neuropsychiatric symptoms such as lack of attention, concentration, poor memory, impaired executive functions, depression, and anxiety. These neurocognitive impairments such as memory, attention, and executive functions appear to be associated with dysfunction in brain regions. This study was conducted to investigate the metabolic changes in the brain subcortical regions, i.e., posterior parietal cortex and dorsolateral prefrontal cortex (DLPFC), in patients with hyperthyroidism before and after antithyroid treatment using proton magnetic resonance spectroscopy (¹H MRS). Materials and Methods: We collected neuropsychological and ¹H MRS data from posterior parietal cortex and DLPFC, in both control (N = 30) and hyperthyroid (N = 30) patients. In addition, follow-up data were available for 19 patients treated with carbimazole for 30 weeks. The relative ratios of the neurometabolites were calculated using the Linear Combination Model (LCModel). Analysis of co-variance using Bonferroni correction was performed between healthy controls and hyperthyroid patients, and a paired t-test was applied in patients at baseline and follow-up. Spearman's rank-order correlation was used to analyze bivariate associations between thyroid hormone levels and metabolite ratios, and the partial correlation analysis was performed between neuropsychological scores and metabolite ratios, with age and sex as covariates, in the patients before and after treatment. Results: Our results revealed a significant decrease in choline/creatine [glycerophosphocholine (GPC) + phosphocholine (PCh)/creatine (tCr)] in both the posterior parietal cortex and DLPFC in hyperthyroid patients, and these changes were reversible after antithyroid treatment. The posterior parietal cortex also showed significantly reduced glutamate/creatine (Glu/tCr), (glutamate + glutamine)/creatine (Glx/tCr), and increased glutathione/creatine (GSH/tCr) ratios in the hyperthyroid patients over control subjects. In DLPFC, only (N-acetyl aspartate + N-acetyl aspartyl-glutamate)/creatine (NAA + NAAG)/tCr was increased in the hyperthyroid patients. After antithyroid treatment, (GPC + PCh)/tCr increased, and Glx/tCr decreased in both brain regions in the patients at follow-up. Gln/tCr in the posterior parietal cortex was decreased in patients at follow-up. Interestingly, (GPC + PCh)/tCr in DLPFC showed a significantly inverse correlation with free tri-iodothyronine (fT3) in hyperthyroid patients at baseline, whereas NAA/tCr showed positive correlations with fT3 and free thyroxine (fT4) in hyperthyroid patients before and after antithyroid treatment, in the posterior parietal cortex. In DLPFC, only (NAA + NAAG)/tCr showed positive correlations with fT3 and fT4 in the patients before treatment. Conclusion: The overall findings suggest that all the brain metabolite changes were not completely reversed in the hyperthyroid patients after antithyroid treatment, even after achieving euthyroidism.

The natural history of Canavan disease: 23 new cases and comparison with patients from literature

Background

Canavan disease (CD, MIM # 271900) is a rare and devastating leukodystrophy of early childhood. To identify clinical features that could serve as endpoints for treatment trials, the clinical course of CD was studied retrospectively and prospectively in 23 CD patients. Results were compared with data of CD patients reported in three prior large series. Kaplan Meier survival analysis including log rank test was performed for pooled data of 82 CD patients (study cohort and literature patients).

Results

Onset of symptoms was between 0 and 6 months. Psychomotor development of patients was limited to abilities that are usually gained within the first year of life. Macrocephaly became apparent between 4 and 18 months of age. Seizure frequency was highest towards the end of the first decade. Ethnic background was more diverse than in studies previously reported. A CD severity score with assessment of 11 symptoms and abilities was developed.

Conclusions

Early hallmarks of CD are severe psychomotor disability and macrocephaly that develop within the first 18 months of life. While rare in the first year of life, seizures increase in frequency over time in most patients. CD occurs more frequently outside Ashkenazi Jewish communities than previously reported. Concordance of phenotypes between siblings but not patients with identical ASPA mutations suggest the influence of yet unknown modifiers. A CD severity score may allow for assessment of CD disease severity both retrospectively and prospectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-020-01659-3.

Ketogenic diet alleviates colitis by reduction of colonic group 3 innate lymphoid cells through altering gut microbiome

Accumulating evidence suggests that ketogenic diets (KDs) mediate the rise of circulating ketone bodies and exert a potential anti-inflammatory effect; however, the consequences of this unique diet on colitis remain unknown. We performed a series of systematic studies using a dextran sulfate sodium (DSS) animal model of inflammatory colitis. Animals were fed with a KD, low-carbohydrate diet (LCD), or normal diet (ND). Germ-free mice were utilized in validation experiments. Colon tissues were analyzed by transcriptome sequencing, RT2 profiler PCR array, histopathology, and immunofluorescence. Serum samples were analyzed by metabolic assay kit. Fecal samples were analyzed by 16S rRNA gene sequencing, liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. We observed that KD alleviated colitis by altering the gut microbiota and metabolites in a manner distinct from LCD. Quantitative diet experiments confirmed the unique impact of KD relative to LCD with a reproducible increase in Akkermansia, whereas the opposite was observed for Escherichia/Shigella. After colitis induction, the KD protected intestinal barrier function, and reduced the production of RORγt⁺CD3⁻ group 3 innate lymphoid cells (ILC3s) and related inflammatory cytokines (IL-17α, IL-18, IL-22, Ccl4). Finally, fecal microbiota transplantation into germ-free mice revealed that the KD- mediated colitis inhibition and ILC3 regulation were dependent on the modification of gut microbiota. Taken together, our study presents a global view of microbiome-metabolomics changes that occur during KD colitis treatment, and identifies the regulation of gut microbiome and ILC3s as novel targets involving in IBD dietary therapy.

The Tryptophan/Kynurenine Pathway: A Novel Cross-Talk between Nutritional Obesity, Bariatric Surgery and Taste of Fat

Diet-induced obesity (DIO) reduces the orosensory perception of lipids in rodents and in some humans. Although bariatric surgery partially corrects this alteration, underlying mechanisms remain poorly understood. To explore whether metabolic changes might explain this fat taste disturbance, plasma metabolome analyses, two-bottle choice tests and fungiform papillae (Fun) counting were performed in vertical sleeve gastrectomized (VSG) mice and sham-operated controls. An exploratory clinic study was also carried out in adult patients undergone a VSG. In mice, we found that (i) the VSG reduces both the plasma neurotoxic signature due to the tryptophan/kynurenine (Trp/Kyn) pathway overactivation and the failure of fat preference found in sham-operated DIO mice, (ii) the activity of Trp/Kyn pathway is negatively correlated to the density of Fun, and (iii) the pharmacological inhibition of the Kyn synthesis mimics in non-operated DIO mice the positive effects of VSG (i.e., decrease of Kyn synthesis, increase of Fun number, improvement of the fat taste perception). In humans, a reduction of the plasma Kyn level is only found in patients displaying a post-surgery improvement of their fat taste sensitivity. Altogether these data provide a plausible metabolic explanation to the degradation of the orosensory lipid perception observed in obesity.

Clinical and biochemical characteristics of patients with ornithine transcarbamylase deficiency

BACKGROUND

Ornithine transcarbamylase deficiency (OTCD) is pleomorphic congenital hyperammonemia, in which the prognosis of the patient is determined both by genotype and environmental factors. This study investigated the clinical and biochemical characteristics of OTCD patients with different prognosis.

METHOD

Of 35 OTCD patients, six males deceased at the first disease-onset, 17 males survived and had controllable ammonia levels after treatment, and 12 females survived through the first disease-onset but had intractable hyperammonemia and high mortality. Fasting blood samples from patients collected at three disease stages were used for the analysis of amino acid (AA) profile, acylcarnitine profile, and micronutrients. Differences in profiles between patients and healthy controls and within patient groups were studied.

RESULTS

All OTCD patients had accumulation of glutamine, homocitrulline, lysine, glutamate, cystathionine, and pipecolic acid, as well as deficiency of citrulline, tryptophan, threonine, and carnitine. For male non-survivors, most other AAs and long-chain acylcarnitines were elevated at disease onset, of which the levels of creatine, N-acetylaspartic acid, and homoarginine were remarkably high. Male survivors and female patients had most other AAs at low to normal levels. Compared with male survivors, female patients had much lower protein-intolerance, as indicated by significantly lower levels of protein consumption indicators, including essential AAs, 1-methylhistidine, acylcarnitines et al., but high levels of ammonia. Female patients still had significantly higher levels of citrulline, homocitrulline, and citrulline/arginine compared to male survivors.

CONCLUSION

Unique profiles were observed in each group of OTCD patients, indicating specific physiological changes that happened to them.

Investigation of Early Death-Induced Changes in Rat Brain by Solid Phase Microextraction via Untargeted High Resolution Mass Spectrometry: In Vivo versus Postmortem Comparative Study

Analysis of brain samples obtained postmortem remains a standard approach in neuroscience, despite often being suboptimal for inferring roles of small molecules in the pathophysiology of brain diseases. Sample collection and preservation further hinders conclusive interpretation of biomarker analysis in autopsy samples. We investigate purely death-induced changes affecting rat hippocampus in the first hour of postmortem interval (PMI) by means of untargeted liquid chromatography-mass spectrometry-based metabolomics. The unique possibility of sampling the same brain area of each animal both in vivo and postmortem was enabled by employing solid phase microextraction (SPME) probes. Four millimeter probes coated with mixed mode extraction phase were used to sample awake, freely roaming animals, with 2 more sampling events performed after death. Significant changes in brain neurochemistry were found to occur as soon as 30 min after death, further progressing with increasing PMI, evidenced by relative changes in levels of metabolites and lipids. These included species from several distinct groups, which can be classified as engaged in energy metabolism-related processes, signal transduction, neurotransmission, or inflammatory response. Additionally, we perform thorough analysis of interindividual variability in response to death, which provides insights into how this aspect can obscure conclusions drawn from an untargeted study at single metabolite and pathway level. The results suggest high demand for systematic studies examining the PMI time course with in vivo sampling as a starting point to eliminate artifacts in the form of neurochemical changes assumed to occur in vivo.

Plasma N-acetylaspartate: Development and validation of a quantitative assay based on HPLC-MS-MS and sample derivatization

N-acetylaspartate is a human endogenous compound synthesized by neurons, which is involved in neuronal metabolism. It is used as a marker in brain magnetic resonance spectroscopy to investigate several neurological and metabolic disorders, that can be related to a variation of its concentration with respect to reference values. N-acetylaspartate is present also in biological fluids, such as plasma, urine, and cerebrospinal fluid, where it can be quantified. Here we describe the development and validation, in compliance with the EMA guidelines, of a novel assay method for the quantification of N-acetylaspartate in plasma based on tandem mass spectrometry coupled to liquid chromatography. Its peculiarity lies in the fact that sample preparation includes an esterification step, which significantly improves the chromatographic performances and, consequently, also the method sensitivity, reproducibility and accuracy. Instrumental LLOQ is 0.06 ng/mL, i.e. at least 300 times lower than the medium N-acetylaspartate concentration in samples, accuracy is in the range 98-103%, while precision lies between 1 and 3%. The method robustness was tested in about 1000 injections of plasma samples, 96 of which were used also to assess the reference ranges in control subjects (16.46-63.40 ng/mL). Controls were then compared to plasma samples from type 2 diabetic patients. Contrary to brain magnetic resonance spectroscopy, which demonstrated a decrease in the N-acetylaspartate levels in right frontal and parieto-temporal region of type 2 diabetic patients, plasma analysis showed no statistical difference with respect to controls. However, the method here described can be profitably used in studies concerning different disorders with CNS involvement, as confirmed by reports available in the literature.

Rag1 immunodeficiency-induced early aging and senescence in zebrafish are dependent on chronic inflammation and oxidative stress

In mammals, recombination activating gene 1 (RAG1) plays a crucial role in adaptive immunity, generating a vast range of immunoglobulins. Rag1^−/− zebrafish (Danio rerio) are viable and reach adulthood without obvious signs of infectious disease in standard nonsterile conditions, suggesting that innate immunity could be enhanced to compensate for the lack of adaptive immunity. By using microarray analysis, we confirmed that the expression of immunity‐ and apoptosis‐related genes was increased in the rag1^−/− fish. This tool also allows us to notice alterations of the DNA repair and cell cycle mechanisms in rag1^−/− zebrafish. Several senescence and aging markers were analyzed. In addition to the lower lifespan of rag1^−/− zebrafish compared to their wild‐type (wt) siblings, rag1^−/− showed a higher incidence of cell cycle arrest and apoptosis, a greater amount of phosphorylated histone H2AX, oxidative stress and decline of the antioxidant mechanisms, an upregulated expression and activity of senescence‐related genes and senescence‐associated β‐galactosidase, respectively, diminished telomere length, and abnormal self‐renewal and repair capacities in the retina and liver. Metabolomic analysis also demonstrated clear differences between wt and rag1^−/− fish, as was the deficiency of the antioxidant metabolite l‐acetylcarnitine (ALCAR) in rag1^−/− fish. Therefore, Rag1 activity does not seem to be limited to V(D)J recombination but is also involved in senescence and aging. Furthermore, we confirmed the senolytic effect of ABT‐263, a known senolytic compound and, for the first time, the potential in vivo senolytic activity of the antioxidant agent ALCAR, suggesting that this metabolite is essential to avoid premature aging.

Diffusion MRI and MR spectroscopy reveal microstructural and metabolic brain alterations in chronic mild stress exposed rats: A CMS recovery study

Chronic mild stress (CMS) induced depression elicits several debilitating symptoms and causes a significant economic burden on society. High variability in the symptomatology of depression poses substantial impediment to accurate diagnosis and therapy outcome. CMS exposure induces significant metabolic and microstructural alterations in the hippocampus (HP), prefrontal cortex (PFC), caudate-putamen (CP) and amygdala (AM), however, recovery from these maladaptive changes are limited and this may provide negative effects on the therapeutic treatment and management of depression. The present study utilized anhedonic rats from the unpredictable CMS model of depression to study metabolic recovery in the ventral hippocampus (vHP) and microstructural recovery in the HP, AM, CP, and PFC. The study employed 1H MR spectroscopy (1H MRS) and in-vivo diffusion MRI (d-MRI) at the age of week 18 (week 1 post CMS exposure) week 20 (week 3 post CMS) and week 25 (week 8 post CMS exposure) in the anhedonic group, and at the age of week 18 and week 22 in the control group. The d-MRI data have provided an array of diffusion tensor metrics (FA, MD, AD, and RD), and fast kurtosis metrics (MKT, WL and WT). CMS exposure induced a significant metabolic alteration in vHP, and significant microstructural alterations were observed in the HP, AM, and PFC in comparison to the age match control and within the anhedonic group. A significantly high level of N-acetylaspartate (NAA) was observed in vHP at the age of week 18 in comparison to age match control and week 20 and week 25 of the anhedonic group. HP and AM showed significant microstructural alterations up to the age of week 22 in the anhedonic group. PFC showed significant microstructural alterations only at the age of week 18, however, most of the metrics showed significantly higher value at the age of week 20 in the anhedonic group. The significantly increased NAA concentration may indicate impaired catabolism due to astrogliosis or oxidative stress. The significantly increased WL in the AM and HP may indicate hypertrophy of AM and reduced volume of HP. Such metabolic and microstructural alterations could be useful in disease diagnosis and follow-up treatment intervention in depression and similar disorders.

Metabolomics and neuroanatomical evaluation of post-mortem changes in the hippocampus

Understanding the human brain is the ultimate goal in neuroscience, but this is extremely challenging in part due to the fact that brain tissue obtained from autopsy is practically the only source of normal brain tissue and also since changes at different levels of biological organization (genetic, molecular, biochemical, anatomical) occur after death due to multiple mechanisms. Here we used metabolomic and anatomical techniques to study the possible relationship between post-mortem time (PT)-induced changes that may occur at both the metabolomics and anatomical levels in the same brains. Our experiments have mainly focused on the hippocampus of the mouse. We found significant metabolomic changes at 2 h PT, whereas the integrity of neurons and glia, at the anatomical/ neurochemical level, was not significantly altered during the first 5 h PT for the majority of histological markers.

Gene Therapy for the Treatment of Neurological Disorders: Metabolic Disorders

Metabolic disorders comprise a large group of heterogeneous diseases ranging from very prevalent diseases such as diabetes mellitus to rare genetic disorders like Canavan Disease. Whether either of these diseases is amendable by gene therapy depends to a large degree on the knowledge of their pathomechanism, availability of the therapeutic gene, vector selection, and availability of suitable animal models. In this book chapter, we review three metabolic disorders of the central nervous system (CNS; Canavan Disease, Niemann-Pick disease and Phenylketonuria) to give examples for primary and secondary metabolic disorders of the brain and the attempts that have been made to use adeno-associated virus (AAV) based gene therapy for treatment. Finally, we highlight commonalities and obstacles in the development of gene therapy for metabolic disorders of the CNS exemplified by those three diseases.

A thematic review of scientific and family interests in Canavan Disease: where are the developmentalists?

BACKGROUND

Canavan Disease is a degenerative neurological condition resulting in a spongy deterioration of the brain. Much research has been conducted by the medical community regarding this condition, but little research can be found in the psychological literature.

METHOD

A review of the scientific literature related to Canavan Disease using the Psychinfo and PubMed databases was conducted covering a 5-year span from 2006 through 2011. Concurrently, a review of parent initiated topics found on the most popular Canavan Disease Internet discussion board was conducted for comparison purposes.

RESULTS

When comparing the topics discussed and information sought among parents with the themes noted in the extant scientific literature, researchers found an exceedingly small overlap between the two communities of interest. In the scientific literature, published research on Canavan Disease focused on three areas: the biochemistry of Canavan Disease, diagnosis and genetic counselling, and clinical therapeutic approaches in Canavan Disease. Of the 42 unique topics raised on a popular Internet discussion board, however, only three (7%) fell into the category of diagnosis and genetic counselling, none (0%) fell into the category of the biochemistry of Canavan Disease, and four fell into the category of clinical therapeutic approaches in Canavan Disease (10%). Of the four posts addressing clinical therapeutic approaches to Canavan Disease, only one post truly overlapped with the topics addressed by the scientific community. Worded differently, while these three categories comprise 100% of the extant scientific literature regarding Canavan Disease, they comprise only 17% of the parent-raised topics. The remaining 83% of parent-raised topics addressed concerns not currently being focusing upon by the scientific community, namely, non-medical practical issues, information regarding specific characteristics of Canavan Disease, non-medical developmental and quality of life issues, and day-to-day developmental and medical concerns.

CONCLUSION

By comparing the extant literature on Canavan Disease with the topics of interest raised by parents and caregivers, it seems clear that there is a significant 'underlap' of topics raised by these two communities of interest, one that may reflect a lack of sensitivity on the part of the scientific community to meet the needs of this population of knowledge seekers. It is the suggestion of these authors that developmental psychology may be the appropriate scientific field within which to address this need and fill this gap in the current literature.

Neurometabolite concentration and clinical features of chronic alcohol use: a proton magnetic resonance spectroscopy study

Chronic, heavy alcohol consumption may affect the concentration of neurometabolites assessed with proton magnetic resonance spectroscopy ((1)H-MRS). We investigated the largest sample reported to date (N=213) with the primary goal of determining how specific clinical features impact neurometabolite concentrations in an anterior cingulate gray matter voxel. This community-dwelling sample included both treatment-seeking and non-treatment-seeking individuals. A healthy control group (N=66) was matched for age and education. In multivariate analyses predicting neurometabolite concentrations, the heavy drinking group had greater concentrations overall. An age by group interaction was noted, as group difference across neurometabolites increased with age. More years drinking, but not more drinks per drinking day (DPDD), predicted greater concentrations of choline-containing compounds (Cho), creatine-phosphocreatine (Cre), glutamate-glutamine (Glx), and N-acetyl-aspartate (NAA). The effects of other clinical variables (depression, cigarette smoking, marijuana use) were negligible. After controlling for DPDD and years drinking, treatment-seeking status had no impact on neurometabolites. In the very oldest portion of the sample (mean age=50), however, a negative relationship was seen between NAA and years drinking. These results suggest that the nature of neurometabolite abnormalities in chronic heavy drinkers may vary as a function of duration of abuse.

Aspartoacylase deficiency in the white matter of human immunodeficiency virus encephalitis: novel mechanism in axonal damage

Aspartoacylase/aminoacylase II (ASPA/ACY II) is mainly synthesized in oligodendrocytes to contribute in myelin synthesis. Although axonal damage is seen in the brain with human immunodeficiency virus encephalitis (HIVE), ASPA contribution in the pathology is not known. Immunostaining study showed that ASPA protein is reduced in the white matter of patients with HIVE compared to the control. Western blot study further confirmed ASPA deficiency in the HIVE brain compared to the control. This paper suggests that HIVE condition affects ASPA to contribute in myelin loss/axonal damage seen in the disease.