Role of Lipids in Brain Injury and Diseases

Multiplatform Lipid Analysis of the Brain of Aging Mice by Mass Spectrometry

Lipids are critical to brain structure and function, accounting for approximately 50% of its dry weight. However, the impact of aging on brain lipids remains poorly characterized. To address this, here we applied three complementary mass spectrometry techniques: multiple reaction monitoring (MRM) profiling, untargeted liquid chromatography tandem mass spectrometry (LC-MS/MS), and desorption electrospray ionization-MS imaging (DESI-MSI). We used brains from mice of three age groups: adult (3-4 months), middle-aged (10 months), and old (19-21 months). Phospholipids such as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol were more abundant, while phosphatidylinositol and phosphatidylserine were reduced in old mice compared to adults or middle-aged mice. Key lipids such as polyunsaturated fatty acids, including DHA, AA, HexCer, SHexCer, and SM, were among the most abundant lipids in aged brains. DESI-MSI revealed spatial lipid distribution patterns consistent with findings from MRM profiling and LC-MS/MS. Integration of lipidomic data with the recently published proteomics data from the same tissues highlighted changes in proteins and phosphorylation levels of several proteins associated with Cer, HexCer, FA, PI, SM, and SHexCer metabolism, aligning with the multiplatform lipid surveillance. These findings shed insight into age-dependent brain lipid changes and their potential contribution to age-related cognitive decline.

Characterizing circulating biomarkers for childhood dementia disorders: A scoping review of clinical trials

Childhood dementias, a group of neurological disorders are characterised by neurocognitive decline, with physical and psychosocial impacts for individuals. With therapy available for <5 ​% of childhood dementias, there is a high level of unmet need. Integration of biomarkers in clinical trials are important to characterize distinctive biological activities and interrogate targets for therapeutic development. This study reviewed four clinical trial registries to examine circulating biomarkers in childhood dementias. Findings from 262 studies were synthesized across 49/72 (68 ​%) childhood dementia disorders. Disease-related biomarkers were associated with 1) the primary pathophysiology 2) downstream pathogenic events 3) drug-related pharmacokinetics, safety and/or tolerability. The predominant biological measures were metabolites linked to the primary pathophysiological pathway (102 measures, 185 studies), while use of cytoskeletal proteins (3 measures, 15 studies), inflammatory mediators (19 measures, 24 studies), oxidative stress-related analytes (15 measures, 8 studies), neurotransmitters or related neuro-metabolites (3 measures, 5 studies) were limited. A range of potential biomarkers are used in clinical trials; however, their use is inconsistent and under utilised among conditions. Development of a panel of biomarkers has potential to interrogate and link shared biological pathways across the heterogeneity of childhood dementias to exert a significant impact for the development of disease-modifying therapies.

Visualization of Efavirenz-Induced Lipid Alterations in the Mouse Brain Using MALDI Mass Spectrometry Imaging

This article highlights experimental procedures and troubleshooting tips for the utilization of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) methods for detecting and visualizing lipid alterations in the mouse brain tissue in response to efavirenz (EFV) treatment. To investigate drug-induced adverse effects, it is becoming increasingly important to understand the spatial alterations of lipid molecules in the target organs. EFV is a non-nucleoside reverse transcriptase inhibitor commonly used for HIV treatment in combination with other antiretrovirals. Importantly, EFV is a drug that is included in the World Health Organization's list of essential medications. However, EFV is known to be associated with neurotoxicity. To date, the mechanisms underlying EFV-induced neurotoxicity have not been fully elucidated. Therefore, it is important to gain understanding of the effect of EFV on the brain. It is known that the brain is composed of different neuroanatomical regions that are abundant in lipids. Described here is the use of a chemical imaging strategy, MALDI MSI, to detect, identify, and visualize the spatial localization of several lipid species across the brain tissue sections along with their alterations in response to EFV treatment. The set of protocols consists of three major parts: lipid detection, identification, and tissue imaging. Lipid detection includes testing different chemical matrices and how they facilitate the detection of analytes, which is then followed by identification. Collision-induced dissociation is employed to verify the identity of the lipid molecules. Lastly, tissue imaging experiments are performed to generate the spatial localization profiles of the lipids. The protocols described in this article can be employed to spatially visualize alterations in the lipid molecules in response to drug treatment. © 2025 Wiley Periodicals LLC. Basic Protocol 1: MALDI mass spectrometry (MALDI MS) profiling experiments for detection of lipids Basic Protocol 2: MALDI MS imaging of lipid molecules in mouse brain tissues Basic Protocol 3: MALDI MS data processing and analysis.

Common lipidomic signatures across distinct acute brain injuries in patient outcome prediction

Lipidomic alterations have been associated with various neurological diseases. Examining temporal changes in serum lipidomic profiles, irrespective of injury type, reveals promising prognostic indicators. In this longitudinal prospective observational study, serum samples were collected early (46 ± 24 h) and late (142 ± 52 h) post-injury from 70 patients with ischemic stroke, aneurysmal subarachnoid hemorrhage, and traumatic brain injury that had outcomes dichotomized as favorable (modified Rankin Scores (mRS) 0-3) and unfavorable (mRS 4-6) three months post-injury. Lipidomic profiling of 1153 lipids, analyzed using statistical and machine learning methods, identified 153 lipids with late-stage significant outcome differences. Supervised machine learning pinpointed 12 key lipids, forming a combinatory prognostic equation with high discriminatory power (AUC 94.7 %, sensitivity 89 %, specificity 92 %; p < 0.0001). Enriched functions of the identified lipids were related to sphingolipid signaling, glycerophospholipid metabolism, and necroptosis (p < 0.05, FDR-corrected). The study underscores the dynamic nature of lipidomic profiles in acute brain injuries, emphasizing late-stage distinctions and proposing lipids as significant prognostic markers, transcending injury types. These findings advocate further exploration of lipidomic changes for a comprehensive understanding of pathobiological roles and enhanced prediction for recovery trajectories.

Neuroprotective and neuroregenerative drugs after severe traumatic brain injury : A narrative review from a clinical perspective

Traumatic brain injuries cause enormous individual and socioeconomic burdens. Survivors frequently struggle with motor handicaps as well as impaired cognition and emotion. In addition to the primary mechanical brain damage, complex secondary mechanisms are the main drivers of functional impairment. Many of these pathophysiological mechanisms are now well known: excitotoxic amino acids, breakdown of the blood-brain barrier, neuroinflammation with subsequent damage to cell organelles and membranes, cerebral edema, and apoptotic processes triggering neuronal death; however, paracrine resilience factors may counteract these processes. Specific neuroprotective and neuroregenerative intensive care therapies are few. This review highlights medical approaches aimed at mitigating secondary damage and promoting neurotrophic processes in severe traumatic brain injury. Some pharmacologic attempts that appeared very promising in experimental settings have had disappointing clinical results (progesterone, cyclosporine A, ronopterin, erythropoietin, dexanabinol). Thus, the search for drugs that can effectively limit ongoing posttraumatic neurological damage is ongoing. Some medications appear to be beneficial: N‑methyl-D-aspartate receptor (NMDA) antagonists (esketamine, amantadine, Mg++) reduce excitotoxicity and statins and cerebrolysin are known to counteract neuroinflammation. By supporting the impaired mitochondrial energy supply, oxidative processes are inhibited and neuroregenerative processes, such as neurogenesis, angiogenesis and synaptogenesis are promoted by citicoline and cerebrolysin. First clinical evidence shows an improvement in cognitive and thymopsychic outcomes, underlined by own clinical experience combining different therapeutic approaches. Accordingly, adjuvant treatment with neuroprotective substances appears to be a promising option, although more randomized prospective studies are still needed.

Comparative brain metabolomics reveals shared and distinct metabolic alterations in Alzheimer's disease and progressive supranuclear palsy

BACKGROUND

Metabolic dysregulation is a hallmark of neurodegenerative diseases, including Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). Although metabolic dysregulation is a common link between these two tauopathies, a comprehensive brain metabolic comparison of the diseases has not yet been performed.

METHODS

We analyzed 342 postmortem brain samples from the Mayo Clinic Brain Bank and examined 658 metabolites in the cerebellar cortex and the temporal cortex between the two tauopathies.

RESULTS

Our findings indicate that both diseases display oxidative stress associated with lipid metabolism, mitochondrial dysfunction linked to lysine metabolism, and an indication of tau-induced polyamine stress response. However, specific to AD, we detected glutathione-related neuroinflammation, deregulations of enzymes tied to purines, and cognitive deficits associated with vitamin B.

DISCUSSION

Our findings underscore vast alterations in the brain's metabolome, illuminating shared neurodegenerative pathways and disease-specific traits in AD and PSP.

HIGHLIGHTS

First high-throughput metabolic comparison of Alzheimer's diesease (AD) versus progressive supranuclear palsy (PSP) in brain tissue. Cerebellar cortex (CER) shows substantial AD-related metabolic changes, despite limited proteinopathy. AD impacts both CER and temporal cortex (TCX); PSP's changes are primarily in CER. AD and PSP share metabolic alterations despite major pathological differences.

Nrf2 pathways in neuroprotection: Alleviating mitochondrial dysfunction and cognitive impairment in aging

Mitochondrial dysfunction and cognitive impairment are widespread phenomena among the elderly, being crucial factors that contribute to neurodegenerative diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular defense systems, including that against oxidative stress. As such, increased Nrf2 activity may serve as a strategy to avert mitochondrial dysfunction and cognitive decline. Scientific data on Nrf2-mediated neuroprotection was collected from PubMed, Google Scholar, and Science Direct, specifically addressing mitochondrial dysfunction and cognitive impairment in older people. Search terms included "Nrf2", "mitochondrial dysfunction," "cognitive impairment," and "neuroprotection." Studies focusing on in vitro and in vivo models and clinical investigations were included to review Nrf2's therapeutic potential comprehensively. The relative studies have demonstrated that increased Nrf2 activity could improve mitochondrial performance, decrease oxidative pressure, and mitigate cognitive impairment. To a large extent, this is achieved through the modulation of critical cellular signalling pathways such as the Keap1/Nrf2 pathway, mitochondrial biogenesis, and neuroinflammatory responses. The present review summarizes the recent progress in comprehending the molecular mechanisms regarding the neuroprotective benefits mediated by Nrf2 through its substantial role against mitochondrial dysfunction and cognitive impairment. This review also emphasizes Nrf2-target pathways and their contribution to cognitive function improvement and rescue from mitochondria-related abnormalities as treatment strategies for neurodegenerative diseases that often affect elderly individuals.

Brain-wide alterations revealed by spatial transcriptomics and proteomics in COVID-19 infection

Understanding the pathophysiology of neurological symptoms observed after severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is essential to optimizing outcomes and therapeutics. To date, small sample sizes and narrow molecular profiling have limited the generalizability of findings. In this study, we profiled multiple cortical and subcortical regions in postmortem brains of patients with coronavirus disease 2019 (COVID-19) and controls with matched pulmonary pathology (total n = 42) using spatial transcriptomics, bulk gene expression and proteomics. We observed a multi-regional antiviral response without direct active SARS-CoV2 infection. We identified dysregulation of mitochondrial and synaptic pathways in deep-layer excitatory neurons and upregulation of neuroinflammation in glia, consistent across both mRNA and protein. Remarkably, these alterations overlapped substantially with changes in age-related neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Our work, combining multiple experimental and analytical methods, demonstrates the brain-wide impact of severe acute/subacute COVID-19, involving both cortical and subcortical regions, shedding light on potential therapeutic targets within pathways typically associated with pathological aging and neurodegeneration.

Serum lipidome associates with neuroimaging features in patients with traumatic brain injury

Acute traumatic brain injury (TBI) is associated with substantial abnormalities in lipid biology, including changes in the structural lipids that are present in the myelin in the brain. We investigated the relationship between traumatic microstructural changes in white matter from magnetic resonance imaging (MRI) and quantitative lipidomic changes from blood serum. The study cohort included 103 patients from the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study. Diffusion tensor fitting generated fractional anisotropy (FA) and mean diffusivity (MD) maps for the MRI scans while ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry was applied to analyze the lipidome. Increasing severity of TBI was associated with higher MD and lower FA values, which scaled with different lipidomic signatures. There appears to be consistent patterns of lipid changes associating with the specific microstructure changes in the CNS white matter, but also regional specificity, suggesting that blood-based lipidomics may provide an insight into the underlying pathophysiology of TBI.

Low-Dose Radiation Induces Alterations in Fatty Acid and Tyrosine Metabolism in the Mouse Hippocampus: Insights from Integrated Multiomics

In recent years, there has been a drastic surge in neurological disorders with sporadic cases contributing more than ever to their cause. Radiation exposure through diagnostic or therapeutic routes often results in neurological injuries that may lead to neurodegenerative pathogenesis. However, the underlying mechanisms regulating the neurological impact of exposure to near-low doses of ionizing radiation are not known. In particular, the neurological changes caused by metabolomic reprogramming have not yet been elucidated. Hence, in the present study, C57BL/6 mice were exposed to a single whole-body X-ray dose of 0.5 Gy, and 14 days post-treatment, the hippocampus was subjected to metabolomic analysis. The hippocampus of the irradiated animals showed significant alterations in 15 metabolites, which aligned with altered tyrosine, phenylalanine, and alpha-linolenic acid metabolism and the biosynthesis of unsaturated fatty acids. Furthermore, a multiomics interaction network comprising metabolomics and RNA sequencing data analysis provided insights into gene-metabolite interactions. Tyrosine metabolism was revealed to be the most altered, which was demonstrated by the interaction of several crucial genes and metabolites. The present study revealed the regulation of low-dose radiation-induced neurotoxicity at the metabolomic level and its implications for the pathogenesis of neurological disorders. The present study also provides novel insights into metabolomic pathways altered following near-low-dose IR exposure and its link with neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

Valorization of Pig Brains for Prime Quality Oil: A Comparative Evaluation of Organic-Solvent-Based and Solvent-Free Extractions

Pig processing industries have produced large quantities of by-products, which have either been discarded or used to make low-value products. This study aimed to provide recommendations for manufacturing edible oil from pig brains, thereby increasing the value of pork by-products. The experiment compared non-solvent extraction methods, specifically wet rendering and aqueous saline, to a standard solvent extraction method, the Bligh and Dyer method, for extracting oil from pig brains. The yield, color, fatty acid profile, a number of lipid classes, and lipid stability against lipolysis and oxidation of the pig brain oil were comprehensively compared, and the results revealed that these parameters varied depending on the extraction method. The wet rendering process provided the highest extracted oil yield (~13%), followed by the Bligh and Dyer method (~7%) and the aqueous saline method (~2.5%). The Bligh and Dyer method and wet rendering techniques produced a translucent yellow oil; however, an opaque light-brown-red oil was found in the aqueous saline method. The Bligh and Dyer method yielded the oil with the highest phospholipid, cholesterol, carotenoid, tocopherol, and free fatty acid contents (p < 0.05). Although the Bligh and Dyer method recovered the most unsaturated fatty acids, it also recovered more trans-fatty acids. Aqueous saline and wet rendering procedures yielded oil with low FFA levels (<1 g/100 g). The PV of the oil extracted using all methods was <1 meq/kg; however, the Bligh and Dyer method had a significant TBARS content (7.85 mg MDA equivalent/kg) compared to aqueous saline (1.75 mg MDA equivalent/kg) and wet rendering (1.14 mg MDA equivalent/kg) (p < 0.05). FTIR spectra of the pig brain oil revealed the presence of multiple components in varying quantities, as determined by chemical analysis experiments. Given the higher yield and lipid stability and the lower cholesterol and trans-fatty acid content, wet rendering can be regarded as a simple and environmentally friendly method for safely extracting quality edible oil from pig brains, which may play an important role in obtaining financial benefits, nutrition, the zero-waste approach, and increasing the utilization of by-products in the meat industry.

Enhancement of weak signals by applying a suppression method to high-intense methyl and methylene signals of lipids in NMR spectroscopy

Lipids play crucial roles in human biology, serving as energy stores, cell membranes, hormone production, and signaling molecules. Accordingly, their study under lipidomics has advanced the study of living organisms. 1-Dimensional (D) and 2D NMR methods, particularly 1D 1H and 2D 1H-1H Total Correlation Spectroscopy (TOCSY), are commonly used in lipidomics for quantification and structural identification. However, these NMR methods suffer from low sensitivity, especially in cases of low concentrated molecules such as protons attached to hydroxy, esters, aliphatic, or aromatic unsaturated carbons. Such molecules are common in complex mixtures such as dairy products and plant oils. On the other hand, lipids have highly populated fractions of methyl and methylene groups that result in intense peaks that overwhelm lower peaks and cause inhomogeneities in 2D TOCSY spectra. In this study, we applied a method of suppression to suppress these intense peaks of methyl and methylene groups to detect weaker peaks. The suppression method was investigated on samples of cheese, butter, a mixture of lipids, coconut oil, and olive oil. A significant improvement in peak sensitivity and visibility of cross-peaks was observed, leading to enhanced comparative quantification and structural identification of a greater number of lipids. Additionally, the enhanced sensitivity reduced the time required for the qualitative and comparative quantification of other lipid compounds and components. This, in turn, enables faster and more reliable structural identification and comparative quantification of a greater number of lipids. Additionally, it reduces the time required for the qualitative, and comparative quantification due to the enhancement of sensitivity.

Mass Spectrometry Imaging Reveals Region-Specific Lipid Alterations in the Mouse Brain in Response to Efavirenz Treatment

Efavirenz (EFV) is a commonly used drug to treat human immunodeficiency virus infection and is known to exert adverse effects on the brain. Although it is known that EFV is associated with abnormal plasma lipid levels, the changes in the spatial localization of individual lipid molecules in brain tissue following EFV treatment are yet to be explored. In this study, we employed a matrix-assisted laser desorption/ionization mass spectrometry imaging approach to determine region-specific lipid alterations in mouse brains following EFV treatment. We detected unique spatial localization patterns of phosphatidylcholine (PC), sphingomyelin (SM), ceramide phosphoinositol (PI-Cer), and hexosylceramide (HexCer) molecules in the mouse brain. Interestingly, PC(32:0), PC(38:5), and SM(36:1;O2) showed high abundance in the hippocampus region, whereas PI-Cer(38:8) exhibited low abundance in the hippocampus region of the EFV-treated mouse brains. Additionally, we observed low abundance of PC(38:6), PC(40:6), and PI-Cer(40:3) in the thalamus region of the EFV-treated mouse brains. Furthermore, SM(40:1;O2), SM(42:2;O2), SM(42:1;O2), SM(43:2;O2), and SM(43:1;O2) exhibited their accumulation in the corpus callosum region of the EFV-treated mouse brains as compared to controls. However, HexCer(42:1;O3) exhibited depletion in the corpus callosum region in response to EFV treatment. To characterize the expression patterns of proteins, including lipid metabolizing enzymes, in response to EFV treatment, mass spectrometry-based proteomics was utilized. From these, the expression levels of 12 brain proteins were found to be significantly decreased following EFV treatment. Taken together, these multiomics data provide important insights into the effects of EFV on brain lipid metabolism.

Oxidative Stress in Cerebral Ischemia/Reperfusion Injury

Oxidative stress in cerebral ischemia/reperfusion injury (CIRI) involves reactive oxygen and nitrogen species (ROS and RNS). Despite efficient antioxidant pathways in the brain, hypoxia triggers the production of oxygen free radicals and downregulates ATP, which leads to oxidative stress. Sources of free radicals during CIRI include Ca²⁺-dependent enzymes, phospholipid degradation and mitochondrial enlargement. Upon reperfusion, the abrupt increase of oxygen triggers a massive radical production via enzymes like xantin oxidase (XO), phospholipase A2 (PLA2) and oxide synthases (OS). These enzymes play an essential role in neuronal damage by excitotoxicity, lipoperoxidation, nitrosylation, inflammation and programmed cell death (PCD). Endothelial nitric oxide synthase (eNOS) decreases as compared to neuronal nitric oxide synthase (nNOS). This is associated with neuronal damage, endothelial inflammation, apoptosis and oxidative stress. Strategies promoting activation of eNOS while inhibiting nNOS could offer neuroprotective benefits in CIRI. Understanding and targeting these pathways could mitigate brain damage in ischemia/reperfusion events. Clinically, tissue plasminogen activator (t-PA) has been shown to restore cerebral blood flow. However, serious side effects have been described, including hemorrhagic transformation. Different treatments are currently under investigation to avoid I/R injury. Baicalin has been reported as a potential agent that could improve t-PA adverse effects, which have to do with peroxynitrite synthesis and matrix metalloproteinase (MMP) expression. In this review, CIRI and interventions in oxidative stress are addressed. Special attention is paid to efficient antioxidant mechanisms in the brain and the production of free radicals, especially nNOS-derived nitric oxide (NO). The primary purpose is to describe accessible radical pathways with the activity of Ca²⁺-dependent oxidative enzymes, leading to membrane phospholipids and mitochondrial breakdown. <strong>Key</strong><strong>w</strong><strong>ords</strong>Oxidative stress; cerebral ischemia/reperfusion; nitric oxide; reactive oxygen species; nitric oxide synthase

Sphingolipid changes in mouse brain and plasma after mild traumatic brain injury at the acute phases

BACKGROUND

Traumatic brain injury (TBI) causes neuroinflammation and can lead to long-term neurological dysfunction, even in cases of mild TBI (mTBI). Despite the substantial burden of this disease, the management of TBI is precluded by an incomplete understanding of its cellular mechanisms. Sphingolipids (SPL) and their metabolites have emerged as key orchestrators of biological processes related to tissue injury, neuroinflammation, and inflammation resolution. No study so far has investigated comprehensive sphingolipid profile changes immediately following TBI in animal models or human cases. In this study, sphingolipid metabolite composition was examined during the acute phases in brain tissue and plasma of mice following mTBI.

METHODS

Wildtype mice were exposed to air-blast-mediated mTBI, with blast exposure set at 50-psi on the left cranium and 0-psi designated as Sham. Sphingolipid profile was analyzed in brain tissue and plasma during the acute phases of 1, 3, and 7 days post-TBI via liquid-chromatography-mass spectrometry. Simultaneously, gene expression of sphingolipid metabolic markers within brain tissue was analyzed using quantitative reverse transcription-polymerase chain reaction. Significance (P-values) was determined by non-parametric t-test (Mann-Whitney test) and by Tukey's correction for multiple comparisons.

RESULTS

In post-TBI brain tissue, there was a significant elevation of 1) acid sphingomyelinase (aSMase) at 1- and 3-days, 2) neutral sphingomyelinase (nSMase) at 7-days, 3) ceramide-1-phosphate levels at 1 day, and 4) monohexosylceramide (MHC) and sphingosine at 7-days. Among individual species, the study found an increase in C18:0 and a decrease in C24:1 ceramides (Cer) at 1 day; an increase in C20:0 MHC at 3 days; decrease in MHC C18:0 and increase in MHC C24:1, sphingomyelins (SM) C18:0, and C24:0 at 7 days. Moreover, many sphingolipid metabolic genes were elevated at 1 day, followed by a reduction at 3 days and an absence at 7-days post-TBI. In post-TBI plasma, there was 1) a significant reduction in Cer and MHC C22:0, and an increase in MHC C16:0 at 1 day; 2) a very significant increase in long-chain Cer C24:1 accompanied by significant decreases in Cer C24:0 and C22:0 in MHC and SM at 3 days; and 3) a significant increase of C22:0 in all classes of SPL (Cer, MHC and SM) as well as a decrease in Cer C24:1, MHC C24:1 and MHC C24:0 at 7 days.

CONCLUSIONS

Alterations in sphingolipid metabolite composition, particularly sphingomyelinases and short-chain ceramides, may contribute to the induction and regulation of neuroinflammatory events in the early stages of TBI, suggesting potential targets for novel diagnostic, prognostic, and therapeutic strategies in the future.

The investigation of the molecular changes during lipopolysaccharide-induced systemic inflammation on rat hippocampus by using FTIR spectroscopy

The aim of this study is to reveal the molecular changes accompanying the neuronal hyper-excitability during lipopolysaccharide (LPS)-induced systemic inflammation on rat hippocampus using Fourier transform infrared (FTIR) spectroscopy. For this aim, the body temperature of Wistar albino rats administered LPS or saline was recorded by radiotelemetry. The animals were decapitated when their body temperature began to decrease by 0.5°C after LPS treatment and the hippocampi of them were examined by FTIR spectroscopy. The results indicated that systemic inflammation caused lipid peroxidation, an increase in the amounts of lipids, proteins and nucleic acids, a decrease in membrane order, an increase in membrane dynamics and changes in the secondary structure of proteins. Principal component analysis successfully separated control and LPS-treated groups. In conclusion, significant structural, compositional and functional alterations occur in the hippocampus during systemic inflammation and these changes may have specific characteristics which can lead to neuronal hyper-excitability.

HR/MS-based lipidome analysis of rat brain modulated by tolcapone

Lipids play key roles in the body, influencing cellular regulation, function, and signalling. Tolcapone, a potent catechol-O-methyltransferase (COMT) inhibitor described to enhance cognitive performance in healthy subjects, was previously shown to impact fatty acid β-oxidation and oxidative phosphorylation. However, its impact on the brain lipidome remains unexplored. Hence, this study aimed to assess how tolcapone affects the lipidome of the rat pre-frontal cortex (PFC), a region of the brain highly relevant to tolcapone therapeutic effect, while evaluating its influence on operant behaviour. Tolcapone at 20 mg/kg was chronically administered to Wistar rats during a behavioural task and an untargeted liquid chromatography high-resolution mass spectrometry (LC-HR/MS) approach was employed to profile lipid species. The untargeted analysis identified 7227 features, of which only 33% underwent statistical analysis following data pre-processing. The results revealed an improved cognitive performance and a lipidome remodelling promoted by tolcapone. The lipidomic analysis showed 32 differentially expressed lipid species in tolcapone-treated animals (FC ≥ 1.2, p-value ≤ 0.1), and among these several triacylglycerols, cardiolipins and N-acylethanolamine (NAE 16:2) were found upregulated whereas fatty acids, hexosylceramides, and several phospholipids including phosphatidylcholines and phosphatidylethanolamines were downregulated. These preliminary findings shed light on tolcapone impact on lipid pathways within the brain. Although tolcapone improved cognitive performance and literature suggests the significance of lipids in cognition, this study did not conclusively establish that lipids directly drove or contributed to this outcome. Nevertheless, it underscores the importance of lipid modulation and encourages further exploration of tolcapone-associated mechanisms in the central nervous system (CNS).

Depicting the molecular features of suicidal behavior: a review from an "omics" perspective

Background Suicide is one of the leading global causes of death. Behavior patterns from suicide ideation to completion are complex, involving multiple risk factors. Advances in technologies and large-scale bioinformatic tools are changing how we approach biomedical problems. The "omics" field may provide new knowledge about suicidal behavior to improve identification of relevant biological pathways associated with suicidal behavior. Methods We reviewed transcriptomic, proteomic, and metabolomic studies conducted in blood and post-mortem brains from individuals who experienced suicide or suicidal behavior. Omics data were combined using systems biology in silico, aiming at identifying major biological mechanisms and key molecules associated with suicide. Results Post-mortem samples of suicide completers indicate major dysregulations in pathways associated with glial cells (astrocytes and microglia), neurotransmission (GABAergic and glutamatergic systems), neuroplasticity and cell survivor, immune responses and energy homeostasis. In the periphery, studies found alterations in molecules involved in immune responses, polyamines, lipid transport, energy homeostasis, and amino and nucleic acid metabolism. Limitations We included only exploratory, non-hypothesis-driven studies; most studies only included one brain region and whole tissue analysis, and focused on suicide completers who were white males with almost none confounding factors. Conclusions We can highlight the importance of synaptic function, especially the balance between the inhibitory and excitatory synapses, and mechanisms associated with neuroplasticity, common pathways associated with psychiatric disorders. However, some of the pathways highlighted in this review, such as transcriptional factors associated with RNA splicing, formation of cortical connections, and gliogenesis, point to mechanisms that still need to be explored.

Omega-3 supplementation improves depressive symptoms, cognitive function and niacin skin flushing response in adolescent depression: A randomized controlled clinical trial

BACKGROUND

Depressive disorder in adolescents is a major health problem with inadequate treatment. Omega-3 (ω3) polyunsaturated fatty acids are a promising adjuvant therapy in adult depression. The primary objective of this study was to investigate the efficacy of adjuvant ω3 treatment on depressive symptoms in adolescent depression. Secondarily, we explored the effects of ω3 on cognitive function and memory and niacin skin flushing response (NSFR), as their robust associations with adolescent depression.

METHODS

A total of 71 adolescents with depression (aged 13-24; 59.2 % female) were randomly assigned to receive ω3 plus Paxil (n = 34) or Paxil alone (n = 37) for 12 weeks. Primary outcome was depression severity according to scores on Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes were cognitive function and memory, and NSFR.

RESULTS

Significant improvements in depressive symptoms over time (p = 0.00027 at week 12) were observed in the ω3 + Paxil group compared with Paxil group. Additionally, in the ω3 + Paxil group, significant improvements in memory over time, and greater cognitive function and NSFR were also observed compared with the Paxil group; the NSFR was negatively correlated with MADRS scores at baseline.

LIMITATIONS

The trial was open label; thus, the outcome measures should be viewed as preliminary since inherent bias in outcomes due to the potential of a placebo effect.

CONCLUSIONS

Our results demonstrate that adjuvant ω3 treatment is effective for reducing depressive symptoms as well as improving cognitive function, memory and the NSFR; these results suggest ω3 is a promising adjuvant treatment for adolescent depression.

Recommendations for reproducibility of cerebrospinal fluid extracellular vesicle studies

Cerebrospinal fluid (CSF) is a clear, transparent fluid derived from blood plasma that protects the brain and spinal cord against mechanical shock, provides buoyancy, clears metabolic waste and transports extracellular components to remote sites in the brain. Given its contact with the brain and the spinal cord, CSF is the most informative biofluid for studies of the central nervous system (CNS). In addition to other components, CSF contains extracellular vesicles (EVs) that carry bioactive cargoes (e.g., lipids, nucleic acids, proteins), and that can have biological functions within and beyond the CNS. Thus, CSF EVs likely serve as both mediators of and contributors to communication in the CNS. Accordingly, their potential as biomarkers for CNS diseases has stimulated much excitement for and attention to CSF EV research. However, studies on CSF EVs present unique challenges relative to EV studies in other biofluids, including the invasive nature of CSF collection, limited CSF volumes and the low numbers of EVs in CSF as compared to plasma. Here, the objectives of the International Society for Extracellular Vesicles CSF Task Force are to promote the reproducibility of CSF EV studies by providing current reporting and best practices, and recommendations and reporting guidelines, for CSF EV studies. To accomplish this, we created and distributed a world-wide survey to ISEV members to assess methods considered 'best practices' for CSF EVs, then performed a detailed literature review for CSF EV publications that was used to curate methods and resources. Based on responses to the survey and curated information from publications, the CSF Task Force herein provides recommendations and reporting guidelines to promote the reproducibility of CSF EV studies in seven domains: (i) CSF Collection, Processing, and Storage; (ii) CSF EV Separation/Concentration; (iii) CSF EV Size and Number Measurements; (iv) CSF EV Protein Studies; (v) CSF EV RNA Studies; (vi) CSF EV Omics Studies and (vii) CSF EV Functional Studies.

Oxidative Stress is a New Avenue for Treatment of Neuropsychiatric Disorders: Hype of Hope?

The biochemical integrity of the brain is critical in maintaining normal central nervous system (CNS) functions. One of the factors that plays an important role in causing biochemical impairment of the brain is known as oxidative stress. Oxidative stress is generally defined as the excessive formation of free radicals relative to antioxidant defenses. The brain is particularly susceptible to oxidative stress because of its high oxygen consumption and lipid-rich content. Therefore, oxidative stress damage is associated with abnormal CNS function. Psychiatric disorders are debilitating diseases. The underlying pathophysiology of psychiatric disorders is poorly defined and may involve the interplay of numerous clinical factors and mechanistic mechanisms. Considerable evidence suggests that oxidative stress plays a complex role in several neuropsychiatric disorders, including anxiety, bipolar disorder, depression, obsessivecompulsive disorder, panic disorder, and schizophrenia. To address these issues, we reviewed the literature and considered the role of oxidative stress as one of the first pathological changes in the course of neuropsychiatric disorders, which should receive more attention in future research.

Maternal High Fat Diet in Lactation Impacts Hypothalamic Neurogenesis and Neurotrophic Development, Leading to Later Life Susceptibility to Obesity in Male but Not Female Mice

Early life nutrition can reprogram development and exert long-term consequences on body weight regulation. In mice, maternal high-fat diet (HFD) during lactation predisposed male but not female offspring to diet-induced obesity when adult. Molecular and cellular changes in the hypothalamus at important time points are examined in the early postnatal life in relation to maternal diet and demonstrated sex-differential hypothalamic reprogramming. Maternal HFD in lactation decreased the neurotropic development of neurons formed at the embryo stage (e12.5) and impaired early postnatal neurogenesis in the hypothalamic regions of both males and females. Males show a larger increased ratio of Neuropeptide Y (NPY) to Pro-opiomelanocortin (POMC) neurons in early postnatal neurogenesis, in response to maternal HFD, setting an obese tone for male offspring. These data provide insights into the mechanisms by which hypothalamic reprograming by early life overnutrition contributes to the sex-dependent susceptibility to obesity in adult life in mice.

Nutritional efficacy of Astaxanthin in modulating orexin peptides and fatty acid level during adult life of rats exposed to perinatal undernutrition stress

Perinatal undernutrition stress predisposes several disorders in adult life, which could be programed using nutraceuticals. However, the effect of perinatal undernutrition stress on orexin peptides, brain lipids, and its amelioration by a potent antioxidant (Astaxanthin) needs exploration. The present study focussed on the effect of perinatal undernutrition stress on brain fatty acid levels, Orexin peptides A and B, and its amelioration by Astaxanthin.Twenty-four male Wistar rats (Rattus norvegicus) were allocated to four groups (n = 6) as Normal, Perinatally Undernourished (UN), Astaxanthin treated (AsX, 12mg/kg), and perinatally Undernourished-but-Astaxanthin treated (UNA), and are allowed to grow for 1, 6 and 12 months. The fatty acid and orexin peptides A & B at different brain parts were measured and compared. Orexin peptides were assessed using an ELISA kit. Fatty acid levels were estimated using HP 5890 gas chromatograph. Data were analyzed by ANOVA followed by Tukey's posthoc test. P < 0.05 was considered significant.The hair cortisol, Orexin-A, and B were significantly increased (p < 0.001) in the UN group compared to normal and were modulated significantly by AsX in the UNA group. Undernutrition stress during the perinatal period altered the lipid profile, Total SFA, Total MUFA, Total n-3 PUFA, Total n-6 PUFA, n-3: n-6 PUFA, which Astaxanthin effectively modulated at 6 and 12 months of postnatal life. There was no difference between DHA and AA ratio. These results indicate that nutritional enrichment with Astaxanthin during the perinatal period positively contributes to adult health. Further, the mechanism of regulation of brain chemistry by Astaxanthin is warranted.

Lipid droplets in Zika neuroinfection: Potential targets for intervention?

Lipid droplets (LD) are evolutionarily conserved lipid-enriched organelles with a diverse array of cell- and stimulus-regulated proteins. Accumulating evidence demonstrates that intracellular pathogens exploit LD as energy sources, replication sites, and part of the mechanisms of immune evasion. Nevertheless, LD can also favor the host as part of the immune and inflammatory response to pathogens. The functions of LD in the central nervous system have gained great interest due to their presence in various cell types in the brain and for their suggested involvement in neurodevelopment and neurodegenerative diseases. Only recently have the roles of LD in neuroinfections begun to be explored. Recent findings reveal that lipid remodelling and increased LD biogenesis play important roles for Zika virus (ZIKV) replication and pathogenesis in neural cells. Moreover, blocking LD formation by targeting DGAT-1 in vivo inhibited virus replication and inflammation in the brain. Therefore, targeting lipid metabolism and LD biogenesis may represent potential strategies for anti-ZIKV treatment development. Here, we review the progress in understanding LD functions in the central nervous system in the context of the host response to Zika infection.

Synapse-Specific Defects in Synaptic Transmission in the Cerebellum of W246G Mutant ELOVL4 Rats-a Model of Human SCA34

Elongation of very long fatty acids-4 (ELOVL4) mediates biosynthesis of very long chain-fatty acids (VLC-FA; ≥28 carbons). Various mutations in this enzyme result in spinocerebellar ataxia-34 (SCA34). We generated a rat model of human SCA34 by knock-in of a naturally occurring c.736T>G, p.W246G mutation in the Elovl4 gene. Our previous analysis of homozygous W246G mutant ELOVL4 rats (MUT) revealed early-onset gait disturbance and impaired synaptic transmission and plasticity at parallel fiber-Purkinje cell (PF-PC) and climbing fiber-Purkinje cell (CF-PC) synapses. However, the underlying mechanisms that caused these defects remained unknown. Here, we report detailed patch-clamp recordings from Purkinje cells that identify impaired synaptic mechanisms. Our results show that miniature EPSC (mEPSC) frequency is reduced in MUT rats with no change in mEPSC amplitude, suggesting a presynaptic defect of excitatory synaptic transmission on Purkinje cells. We also find alterations in inhibitory synaptic transmission as miniature IPSC (mIPSC) frequency and amplitude are increased in MUT Purkinje cells. Paired-pulse ratio is reduced at PF-PC synapses but increased at CF-PC synapses in MUT rats, which along with results from high-frequency stimulation suggest opposite changes in the release probability at these two synapses. In contrast, we identify exaggerated persistence of EPSC amplitude at CF-PC and PF-PC synapses in MUT cerebellum, suggesting a larger readily releasable pool (RRP) at both synapses. Furthermore, the dendritic spine density is reduced in MUT Purkinje cells. Thus, our results uncover novel mechanisms of action of VLC-FA at cerebellar synapses, and elucidate the synaptic dysfunction underlying SCA34 pathology.SIGNIFICANCE STATEMENT Very long chain-fatty acids (VLC-FA) are an understudied class of fatty acids that are present in the brain. They are critical for brain function as their deficiency caused by mutations in elongation of very long fatty acids-4 (ELOVL4), the enzyme that mediates their biosynthesis, results in neurologic diseases including spinocerebellar ataxia-34 (SCA34), neuroichthyosis, and Stargardt-like macular dystrophy. In this study, we investigated the synaptic defects present in a rat model of SCA34 and identified defects in presynaptic neurotransmitter release and dendritic spine density at synapses in the cerebellum, a brain region involved in motor coordination. These results advance our understanding of the synaptic mechanisms regulated by VLC-FA and describe the synaptic dysfunction that leads to motor incoordination in SCA34.

Comparative brain metabolomics reveals shared and distinct metabolic alterations in Alzheimer's disease and progressive supranuclear palsy

Metabolic dysregulation is a hallmark of neurodegenerative diseases, including Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). While metabolic dysregulation is a common link between these two tauopathies, a comprehensive brain metabolic comparison of the diseases has not yet been performed. We analyzed 342 postmortem brain samples from the Mayo Clinic Brain Bank and examined 658 metabolites in the cerebellar cortex and the temporal cortex between the two tauopathies. Our findings indicate that both diseases display oxidative stress associated with lipid metabolism, mitochondrial dysfunction linked to lysine metabolism, and an indication of tau-induced polyamine stress response. However, specific to AD, we detected glutathione-related neuroinflammation, deregulations of enzymes tied to purines, and cognitive deficits associated with vitamin B. Taken together, our findings underscore vast alterations in the brain's metabolome, illuminating shared neurodegenerative pathways and disease-specific traits in AD and PSP.

Alzheimer's-Associated Upregulation of Mitochondria-Associated ER Membranes After Traumatic Brain Injury

Traumatic brain injury (TBI) can lead to neurodegenerative diseases such as Alzheimer's disease (AD) through mechanisms that remain incompletely characterized. Similar to AD, TBI models present with cellular metabolic alterations and modulated cleavage of amyloid precursor protein (APP). Specifically, AD and TBI tissues display increases in amyloid-β as well as its precursor, the APP C-terminal fragment of 99 a.a. (C99). Our recent data in cell models of AD indicate that C99, due to its affinity for cholesterol, induces the formation of transient lipid raft domains in the ER known as mitochondria-associated endoplasmic reticulum (ER) membranes ("MAM" domains). The formation of these domains recruits and activates specific lipid metabolic enzymes that regulate cellular cholesterol trafficking and sphingolipid turnover. Increased C99 levels in AD cell models promote MAM formation and significantly modulate cellular lipid homeostasis. Here, these phenotypes were recapitulated in the controlled cortical impact (CCI) model of TBI in adult mice. Specifically, the injured cortex and hippocampus displayed significant increases in C99 and MAM activity, as measured by phospholipid synthesis, sphingomyelinase activity and cholesterol turnover. In addition, our cell type-specific lipidomics analyses revealed significant changes in microglial lipid composition that are consistent with the observed alterations in MAM-resident enzymes. Altogether, we propose that alterations in the regulation of MAM and relevant lipid metabolic pathways could contribute to the epidemiological connection between TBI and AD.

Central nervous system sulfatide deficiency as a causal factor for bladder disorder in Alzheimer's disease

BACKGROUND

Despite being a brain disorder, Alzheimer's disease (AD) is often accompanied by peripheral organ dysregulations (e.g., loss of bladder control in late-stage AD), which highly rely on spinal cord coordination. However, the causal factor(s) for peripheral organ dysregulation in AD remain elusive.

METHODS

The central nervous system (CNS) is enriched in lipids. We applied quantitative shotgun lipidomics to determine lipid profiles of human AD spinal cord tissues. Additionally, a CNS sulfatide (ST)-deficient mouse model was used to study the lipidome, transcriptome and peripheral organ phenotypes of ST loss.

RESULTS

We observed marked myelin lipid reduction in the spinal cord of AD subjects versus cognitively normal individuals. Among which, levels of ST, a myelin-enriched lipid class, were strongly and negatively associated with the severity of AD. A CNS myelin-specific ST-deficient mouse model was used to further identify the causes and consequences of spinal cord lipidome changes. Interestingly, ST deficiency led to spinal cord lipidome and transcriptome profiles highly resembling those observed in AD, characterized by decline of multiple myelin-enriched lipid classes and enhanced inflammatory responses, respectively. These changes significantly disrupted spinal cord function and led to substantial enlargement of urinary bladder in ST-deficient mice.

CONCLUSIONS

Our study identified CNS ST deficiency as a causal factor for AD-like lipid dysregulation, inflammation response and ultimately the development of bladder disorders. Targeting to maintain ST levels may serve as a promising strategy for the prevention and treatment of AD-related peripheral disorders.

Application of Lipidomics in Psychiatry: Plasma-Based Potential Biomarkers in Schizophrenia and Bipolar Disorder

In this study, we obtained a lipidomic profile of plasma samples from drug-naïve patients with schizophrenia (SZ) and bipolar disorder (BD) in comparison to healthy controls. The sample cohort consisted of 30 BD and 30 SZ patients and 30 control individuals. An untargeted lipidomics strategy using liquid chromatography coupled with high-resolution mass spectrometry was employed to obtain the lipid profiles. Data were preprocessed, then univariate (t-test) and multivariate (principal component analysis and orthogonal partial least squares discriminant analysis) statistical tools were applied to select differential lipids, which were putatively identified. Afterward, multivariate receiver operating characteristic tests were performed, and metabolic pathway networks were constructed, considering the differential lipids. Our results demonstrate alterations in distinct lipid pathways, especially in glycerophospholipids, sphingolipids and glycerolipids, between SZ and BD patients. The results obtained in this study may serve as a basis for differential diagnosis, which is crucial for effective treatment and improving the quality of life of patients with psychotic disorders.

Lipid Mediated Brain Disorders: A Perspective

The brain, one of the most resilient organs of the body is highly enriched in lipid content, suggesting the essential role of lipids in brain physiological activities. Lipids constitute an important structural part of the brain and act as a rich source of metabolic energy. Besides, lipids in their bioactive form (known as bioactive lipids) play an essential signaling and regulatory role, facilitating neurogenesis, synaptogenesis, and cell-cell communication. Brain lipid metabolism is thus a tightly regulated process. Any alteration/dysregulation of lipid metabolism greatly impact brain health and activity. Moreover, since central nervous system (CNS) is the most metabolically active system and lacks an efficient antioxidative defence system, it acts as a hub for the production of reactive oxygen species (ROS) and subsequent lipid peroxidation. These peroxidation events are reported during pathological changes such as neuronal tissue injury and inflammation. Present review is a modest attempt to gain insights into the role of dysregulated bioactive lipid levels and lipid oxidation status in the pathogenesis and progression of neurodegenerative disorders. This may open up new avenues exploiting lipids as the therapeutic targets for improving brain health, and treatment of nervous system disorders.

Systematic untargeted UHPLC-Q-TOF-MS based lipidomics workflow for improved detection and annotation of lipid sub-classes in serum

INTRODUCTION AND OBJECTIVE

Taking into consideration the challenges of lipid analytics, present study aims to design the best high-throughput workflow for detection and annotation of lipids.

MATERIAL AND METHODS

Serum lipid profiling was performed on CSH-C18 and EVO-C18 columns using UHPLC Q-TOF-MS and generated lipid features were annotated based on m/z and fragment ion using different software.

RESULT AND DISCUSSION

Better detection of features was observed in CSH-C18 than EVO-C18 with enhanced resolution except for Glycerolipids (triacylglycerols) and Sphingolipids (sphingomyelin).

CONCLUSION

The study revealed an optimized untargeted Lipidomics-workflow with comprehensive lipid profiling (CSH-C18 column) and confirmatory annotation (LipidBlast).

Role of Lipids in Regulation of Neuroglial Interactions

Lipids comprise an extremely heterogeneous group of compounds that perform a wide variety of biological functions. Traditional view of lipids as important structural components of the cell and compounds playing a trophic role is currently being supplemented by information on the possible participation of lipids in signaling, not only intracellular, but also intercellular. The review article discusses current data on the role of lipids and their metabolites formed in glial cells (astrocytes, oligodendrocytes, microglia) in communication of these cells with neurons. In addition to metabolic transformations of lipids in each type of glial cells, special attention is paid to the lipid signal molecules (phosphatidic acid, arachidonic acid and its metabolites, cholesterol, etc.) and the possibility of their participation in realization of synaptic plasticity, as well as in other possible mechanisms associated with neuroplasticity. All these new data can significantly expand our knowledge about the regulatory functions of lipids in neuroglial relationships.

Machine Learning Analysis of the Cerebrovascular Thrombi Lipidome in Acute Ischemic Stroke

ABSTRACT

OBJECTIVE: The aim of this study was to identify a signature lipid profile from cerebral thrombi in acute ischemic stroke (AIS) patients at the time of ictus. METHODS: We performed untargeted lipidomics analysis using liquid chromatography-mass spectrometry on cerebral thrombi taken from a nonprobability, convenience sampling of adult subjects (≥18 years old, n = 5) who underwent thrombectomy for acute cerebrovascular occlusion. The data were classified using random forest, a machine learning algorithm. RESULTS: The top 10 metabolites identified from the random forest analysis were of the glycerophospholipid species and fatty acids. CONCLUSION: Preliminary analysis demonstrates feasibility of identification of lipid metabolomic profiling in cerebral thrombi retrieved from AIS patients. Recent advances in omic methodologies enable lipidomic profiling, which may provide insight into the cellular metabolic pathophysiology caused by AIS. Understanding of lipidomic changes in AIS may illuminate specific metabolite and lipid pathways involved and further the potential to develop personalized preventive strategies.

Citicoline for the Management of Patients with Traumatic Brain Injury in the Acute Phase: A Systematic Review and Meta-Analysis

BACKGROUND

Citicoline or CDP-choline is a neuroprotective/neurorestorative drug used in several countries for the treatment of traumatic brain injury (TBI). Since the publication of the controversial COBRIT, the use of citicoline has been questioned in this indication, so it was considered necessary to undertake a systematic review and meta-analysis to evaluate whether citicoline is effective in the treatment of patients with TBI.

METHODS

A systematic search was performed on OVID-Medline, EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Ferrer databases, from inception to January 2021, to identify all published, unconfounded, comparative clinical trials of citicoline in the acute phase of head-injured patients- that is, treatment started during the first 24 h. We selected studies on complicated mild, moderate, and severe head-injured patients according to the score of the Glasgow Coma Scale (GCS). The primary efficacy measure was independence at the end of the scheduled clinical trial follow-up.

RESULTS

In total, 11 clinical studies enrolling 2771 patients were identified by the end. Under the random-effects model, treatment with citicoline was associated with a significantly higher rate of independence (RR, 1.18; 95% CI = 1.05-1.33; I2, 42.6%). The dose of citicoline or the administration route had no effect on outcomes. Additionally, no significant effects on mortality were found, and no safety concerns were noticed.

CONCLUSIONS

This meta-analysis indicates some beneficial effects of citicoline's increasing the number of independent patients with TBI. The most important limitation of our meta-analysis was the presumed heterogeneity of the studies included.

REGISTRATION

PROSPERO CRD42021238998.

Sevoflurane Exposure of Clinical Doses in Pregnant Rats Induces Vcan Changes without Significant Neural Apoptosis in the Offspring

Background and Objectives: Sevoflurane is a commonly used inhalational anaesthetic in clinics. Prolonged exposure to sevoflurane can induce significant changes in lipid metabolism and neuronal damage in the developing brain. However, the effect of exposure of pregnant rats to clinical doses of sevoflurane remains unclear. Materials and Methods: Twenty-eight pregnant rats were randomly and equally divided into sevoflurane exposure (S) group, control (C) and a blank group at gestational day (G) 18; Rats in S group received 2% sevoflurane with 98% oxygen for 6 h in an anesthetizing chamber, while C group received 100% oxygen at an identical flow rate for 6 h in an identical chamber. Partial least squares discriminant analysis (PLS-DA), ultra performance liquid chromatography/time-of-flight mass spectrometry(UPLC/TOF-MS) and MetaboAnalyst were used to analysis acquire metabolomics profiles, and immunohistochemical changes of neuronalapoptosis in hippocampus and cortex of neonatal rats were also analyzed. Results: This study aimed to explore lipidomics and transcriptomics changes related to 2% sevoflurane exposure for 6 h in the developing brains of newborn offspring rats. Ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOF-MS) and RNA sequencing (RNA-seq) analyses were used to acquire metabolomics and transcriptomics profiles. We used RNA-seq to analyse the expression of the coding and non-coding transcripts in neural cells of the cerebral cortex. No significant differences in arterial oxygen tension (PaO₂), arterial carbon dioxide tension (PaCO₂), or arterial blood gas were found between the groups. The relative standard deviation (RSD) of retention times was <1.53%, and the RSDs of peak areas ranged from 2.13% to 8.51%. Base peak chromatogram (BPC) profiles showed no differences between the groups. We evaluated the partial least square-discriminant analysis (PLS-DA) model. In negative ion mode, R2X was over 70%, R2Y was over 93%, and Q2 (cum) was over 80%. Cell apoptosis was not remarkably enhanced by TUNEL and haematoxylin and eosin (HE) staining in the sevoflurane-exposed group compared to the control group (p > 0.05). Glycerophospholipid (GP) and sphingolipid metabolism disturbances might adversely influence neurodevelopment in offspring. The expression of mRNAs (Vcan gene, related to neuronal development, function and repair) of the sevoflurane group was significantly increased in the differential genes by qRT-PCR verification. Conclusions: GP and sphingolipid metabolism homeostasis may be potential therapeutic approaches against inhalational anaesthetic-induced neurodegenerative disorders. Meanwhile, sevoflurane-induced Vcan changes indicated some lipidomic and transcriptomic changes, even if neural cell apoptosis was not significantly changed in the usual clinical dose of sevoflurane exposure.

Citicoline: pharmacological and clinical review, 2022 update

This review is based on the previous one published in 2016 (Secades JJ. Citicoline: pharmacological and clinical review, 2016 update. Rev Neurol 2016; 63 (Supl 3): S1-S73), incorporating 176 new references, having all the information available in the same document to facilitate the access to the information in one document. This review is focused on the main indications of the drug, as acute stroke and its sequelae, including the cognitive impairment, and traumatic brain injury and its sequelae. There are retrieved the most important experimental and clinical data in both indications.

Integrated multi-omics analysis of Huntington disease identifies pathways that modulate protein aggregation

Huntington disease (HD) is a neurodegenerative disease associated with polyglutamine expansion in the protein huntingtin (HTT). Although the length of the polyglutamine repeat correlates with age at disease onset and severity, psychological, cognitive and behavioral complications point to the existence of disease modifiers. Mitochondrial dysfunction and metabolic deregulation are both associated with the HD but, despite multi-omics characterization of patients and model systems, their mechanisms have remained elusive. Systems analysis of multi-omics data and its validation by using a yeast model could help to elucidate pathways that modulate protein aggregation. Metabolomics analysis of HD patients and of a yeast model of HD was, therefore, carried out. Our analysis showed a considerable overlap of deregulated metabolic pathways. Further, the multi-omics analysis showed deregulated pathways common in human, mice and yeast model systems, and those that are unique to them. The deregulated pathways include metabolic pathways of various amino acids, glutathione metabolism, longevity, autophagy and mitophagy. The addition of certain metabolites as well as gene knockouts targeting the deregulated metabolic and autophagy pathways in the yeast model system showed that these pathways do modulate protein aggregation. Taken together, our results showed that the modulation of deregulated pathways influences protein aggregation in HD, and has implications for progression and prognosis. This article has an associated First Person interview with the first author of the paper.

MicroRNA: A Linking between Astrocyte Dysfunction, Mild Cognitive Impairment, and Neurodegenerative Diseases

Simple Summary

Neurodegenerative diseases are complex neurological disorders with a high incidence worldwide in older people, increasing hospital visits and requiring expensive treatments. As a precursor phase of neurodegenerative diseases, cognitive impairment needs to be studied to understand the factors that influence its development and improve patients’ quality of life. The present review compiles possible factors and biomarkers for diagnosing mild cognitive impairment based on the most recent studies involving miRNAs. These molecules can direct the gene expression in multiple cells, affecting their behavior under certain conditions, such as stressing factors. This review encourages further research into biomarkers that identify cognitive impairment in cellular models such as astrocytes, which are brain cells capable of maintaining the optimal conditions for the central nervous system functioning.

Abstract

The importance of miRNAs in cellular processes and their dysregulation has taken significant importance in understanding different pathologies. Due to the constant increase in the prevalence of neurodegenerative diseases (ND) worldwide and their economic impact, mild cognitive impairment (MCI), considered a prodromal phase, is a logical starting point to study this public health problem. Multiple studies have established the importance of miRNAs in MCI, including astrocyte regulation during stressful conditions. Additionally, the protection mechanisms exerted by astrocytes against some damage in the central nervous system (CNS) lead to astrocytic reactivation, in which a differential expression of miRNAs has been shown. Nevertheless, excessive reactivation can cause neurodegeneration, and a clear pattern defining the equilibrium point between a neuroprotective or detrimental astrocytic phenotype is unknown. Therefore, the miRNA expression has gained significant attention to understand the maintenance of brain balance and improve the diagnosis and treatment at earlier stages in the ND. Here, we provide a comprehensive review of the emerging role of miRNAs in cellular processes that contribute to the loss of cognitive function, including lipotoxicity, which can induce chronic inflammation, also considering the fundamental role of astrocytes in brain homeostasis.

Brain lipidomics: From functional landscape to clinical significance

Lipids are crucial components of cellular function owing to their role in membrane formation, intercellular signaling, energy storage, and homeostasis maintenance. In the brain, lipid dysregulations have been associated with the etiology and progression of neurodegeneration and other neurological pathologies. Hence, brain lipids are emerging as important potential targets for the early diagnosis and prognosis of neurological diseases. This review aims to highlight the significance and usefulness of lipidomics in diagnosing and treating brain diseases. We explored lipid alterations associated with brain diseases, paying attention to organ-specific characteristics and the functions of brain lipids. As the recent advances in brain lipidomics would have been impossible without advances in analytical techniques, we provide up-to-date information on mass spectrometric approaches and integrative analysis with other omic approaches. Last, we present the potential applications of lipidomics combined with artificial intelligence techniques and interdisciplinary collaborative research for treating brain diseases with clinical heterogeneities.

Synergistic effects of epigallocatechin gallate and l-theanine in nerve repair and regeneration by anti-amyloid damage, promoting metabolism, and nourishing nerve cells

Green tea has significant protective activity on nerve cells, but the mechanism of action is unclear. Epigallocatechin gallate (EGCG) and N-ethyl-L-glutamine (L-theanine) are the representative functional components of green tea (Camellia sinensis). In this study, an AD model of Aβ_25–35-induced differentiated neural cell line PC12 cells was established to study the synergistic effect of EGCG and L-theanine in protecting neural cells. The results showed that under Aβ_25–35 stress conditions, mitochondria and axons degenerated, and the expression of cyclins was up-regulated, showing the gene and protein characteristics of cellular hyperfunction. EGCG + L-theanine inhibited inflammation and aggregate formation pathways, significantly increased the percentage of G0/G1 in the cell cycle, downregulated the expression of proteins such as p-mTOR, Cyclin D1, and Cyclin B1, upregulated the expression of GAP43, Klotho, p-AMPK, and other proteins, promoted mitochondrial activity and energy metabolism, and had repair and regeneration effects on differentiated nerve cells. The synergistic mechanism study showed that under the premise that EGCG inhibits amyloid stress and inflammation and promotes metabolism, L-theanine could play a nourish nerve effect. EGCG + L-theanine keeps differentiated nerve cells in a quiescent state, which is beneficial to the repair and regeneration of nerve cells. In addition, EGCG + L-theanine maintains the high-fidelity structure of cellular proteins. This study revealed for the first time that the synergistic effect of EGCG with L-theanine may be an effective way to promote nerve cell repair and regeneration and slow down the progression of AD. Our findings provide a new scientific basis for the relationship between tea drinking and brain protection.

Evidences of the radiofrequency exposure on the antioxidant status, potentially contributing to the inflammatory response and demyelination in rat brain

Present study exhibited the oxidative potential of microwave radiation (MWR) leading to the neurodegeneration in rats. Wistar rats were exposed at 2100 MHz frequency for 4 h/day, 5 days/week/3 months. Animals were exposed at an estimated specific absorption rate (0.453 W/kg) and power density (8.237 µW/m²). After exposure irradiated group was compared with control group. Results indicated that microwave exposure significantly increased the levels of serological triglycerides and cholesterol. Oxidative stress is observed through alteration of glutathione homeostasis followed by activated inflammatory response further confirmed by pro and anti-inflammatory cytokines in the exposed group. Histopathological assessments and electron microscopic observation confirmed a significant change in the myelination pattern and cellular organelles in the brain of exposed animals. Taking everything into account it can be concluded that chronic exposure of 2100-MHz frequency caused oxidative stress, which leads to neural damage and demyelination and may affect neural communication.

Dietary Inulin Supplementation Affects Specific Plasmalogen Species in the Brain

Plasmalogens (Pls) are glycerophospholipids that play critical roles in the brain. Evidence supports the role of diet and that of the gut microbiota in regulating brain lipids. We investigated the impact of dietary intake of inulin—a soluble fiber used as prebiotic—on the Pl content of the cortex in mice. No global modification in the Pl amounts was observed when evaluated by gas chromatographic analysis of dimethyl acetals (DMAs). However, the analysis of individual molecular species of Pls by liquid chromatography revealed a reduced abundance of major species of ethanolamine Pls (PlsEtn)―PE(P-18:0/22:6) and PE(P-34:1)―in the cortex of mice fed a diet supplemented with inulin. DMA and expression levels of genes (Far-1, Gnpat, Agps, Pla2g6 and Tmem86b) encoding key enzymes of Pl biosynthesis or degradation were not altered in the liver and in the cortex of mice exposed to inulin. In addition, the fatty acid profile and the amount of lyso forms derived from PlsEtn were not modified in the cortex by inulin consumption. To conclude, inulin affects the brain levels of major PlsEtn and further investigation is needed to determine the exact molecular mechanisms involved.

Arachidonic Acid Cascade and Eicosanoid Production Are Elevated While LTC4 Synthase Modulates the Lipidomics Profile in the Brain of the HIVgp120-Transgenic Mouse Model of NeuroHIV

BACKGROUND

Combination antiretroviral therapy (cART) has transformed HIV infection from a terminal disease to a manageable chronic health condition, extending patients' life expectancy to that of the general population. However, the incidence of HIV-associated neurocognitive disorders (HANDs) has persisted despite virological suppression. Patients with HIV display persistent signs of immune activation and inflammation despite cART. The arachidonic acid (AA) cascade is an important immune response system responsible for both pro- and anti-inflammatory processes.

METHODS

Lipidomics, mRNA and Western blotting analysis provide valuable insights into the molecular mechanisms surrounding arachidonic acid metabolism and the resulting inflammation caused by perturbations thereof.

RESULTS

Here, we report the presence of inflammatory eicosanoids in the brains of a transgenic mouse model of NeuroHIV that expresses soluble HIV-1 envelope glycoprotein in glial cells (HIVgp120tg mice). Additionally, we report that the effect of LTC4S knockout in HIVgp120tg mice resulted in the sexually dimorphic transcription of COX- and 5-LOX-related genes. Furthermore, the absence of LTC4S suppressed ERK1/2 and p38 MAPK signaling activity in female mice only. The mass spectrometry-based lipidomic profiling of these mice reveals beneficial alterations to lipids in the brain.

CONCLUSION

Targeting the AA cascade may hold potential in the treatment of neuroinflammation observed in NeuroHIV and HANDs.

Evidence of methylphenidate effect on mitochondria, redox homeostasis, and inflammatory aspects: Insights from animal studies

Methylphenidate (MPH) is a central nervous system (CNS) stimulant known for its effectiveness in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), a neuropsychiatric condition that has a high incidence in childhood and affects behavior and cognition. However, the increase in its use among individuals who do not present all the diagnostic criteria for ADHD has become a serious public health problem since the neurological and psychiatric consequences of this unrestricted use are not widely known. In addition, since childhood is a critical period for the maturation of the CNS, the high prescription of MPH for preschool children also raises several concerns. This review brings new perspectives on how MPH (in different doses, routes of administration and ages) affects the CNS, focusing on animal studies that evaluated changes in mitochondrial (bioenergetics), redox balance and apoptosis, as well as inflammatory parameters. MPH alters brain energy homeostasis, increasing glucose consumption and impairing the activity of enzymes in the Krebs cycle and electron transport chain, as well as ATP levels and Na⁺,K⁺-ATPase activity. MPH induces oxidative stress, increasing the levels of reactive oxygen and nitrogen species and altering enzymatic and non-enzymatic antioxidant defenses, which, consequently, is related to damage to proteins, lipids, and DNA. Among the harmful effects of MPH, studies also demonstrate its ability to induce inflammation as well as alter the apoptosis pathway. It is important to highlight that age, treatment time, administration route, and dose are factors that can influence MPH effects. However, young animals seem to be more susceptible to damage caused by MPH. It is possible that changes in mitochondrial function and markers of status oxidative, apoptosis and inflammation may be exerting important mechanisms associated with MPH toxicity and, therefore, the unrestricted use of this drug can cause brain damage.

Spectroscopic Evaluation of the Potential Neurotoxic Effects of a New Candidate for Anti-Seizure Medication-TP-315 during Chronic Administration (In Vivo)

The aim of this study was to investigate the potential neurotoxic effect of the new anti-seizure medication candidate—5-(3-chlorophenyl)-4-hexyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (TP-315), after chronic administration to mice. TP-315 was administered to mice intraperitoneally for 14 days. At 24 h post the last injection, animals were decapitated, their brains were acquired, flash-frozen in liquid nitrogen and cut into 10 µm slices. The FT-IR chemical imaging technique was used for the investigation of the potential neurotoxic effect in the cerebral cortex and hippocampus. The effect on the lipidomic and proteomic profile and on oxidative stress was investigated. The results showed no statistically significant changes in the above-mentioned parameters. TP-315 seems to pose no neurotoxic effect on the mouse brain after chronic use, therefore, its use should be safe.

Changes in the Cerebrospinal Fluid and Plasma Lipidome in Patients with Rett Syndrome

Rett syndrome (RTT) is defined as a rare disease caused by mutations of the methyl-CpG binding protein 2 (MECP2). It is one of the most common causes of genetic mental retardation in girls, characterized by normal early psychomotor development, followed by severe neurologic regression. Hitherto, RTT lacks a specific biomarker, but altered lipid homeostasis has been found in RTT model mice as well as in RTT patients. We performed LC-MS/MS lipidomics analysis to investigate the cerebrospinal fluid (CSF) and plasma composition of patients with RTT for biochemical variations compared to healthy controls. In all seven RTT patients, we found decreased CSF cholesterol levels compared to age-matched controls (n = 13), whereas plasma cholesterol levels were within the normal range in all 13 RTT patients compared to 18 controls. Levels of phospholipid (PL) and sphingomyelin (SM) species were decreased in CSF of RTT patients, whereas the lipidomics profile of plasma samples was unaltered in RTT patients compared to healthy controls. This study shows that the CSF lipidomics profile is altered in RTT, which is the basis for future (functional) studies to validate selected lipid species as CSF biomarkers for RTT.

Genetic Inactivation of Free Fatty Acid Receptor 3 Impedes Behavioral Deficits and Pathological Hallmarks in the APPswe Alzheimer's Disease Mouse Model

The free fatty acid FFA3 receptor (FFA3R) belongs to the superfamily of G-protein-coupled receptors (GPCRs). In the intestine and adipose tissue, it is involved in the regulation of energy metabolism, but its function in the brain is unknown. We aimed, first, to investigate the expression of the receptor in the hippocampus of Alzheimer disease (AD) patients at different stages of the disease and, second, to assess whether genetic inactivation of the Ffar3 gene could affect the phenotypic features of the APP_swe mouse model. The expression of transcripts for FFA receptors in postmortem human hippocampal samples and in the hippocampus of wild-type and transgenic mice was analyzed by RT-qPCR. We generated a double transgenic mouse, FFA3R^−/−/APP_swe, to perform cognition studies and to assess, by immunoblotting Aβ and tau pathologies and the differential expression of synaptic plasticity-related proteins. For the first time, the occurrence of the FFA3R in the human hippocampus and its overexpression, even in the first stages of AD, was demonstrated. Remarkably, FFA3R^−/−/APP_swe mice do not have the characteristic memory impairment of 12-month-old APP_swe mice. Additionally, this newly generated transgenic line does not develop the most important Alzheimer’s disease (AD)-related features, such as amyloid beta (Aβ) brain accumulations and tau hyperphosphorylation. These findings are accompanied by increased levels of the insulin-degrading enzyme (IDE) and lower activity of the tau kinases GSK3β and Cdk5. We conclude that the brain FFA3R is involved in cognitive processes and that its inactivation prevents AD-like cognitive decline and pathological hallmarks.

Dopamine D2 receptor signaling in the brain modulates circadian liver metabolomic profiles

SignificanceWe analyzed the liver metabolome of mice deficient in the expression of the dopamine D2 receptor (D2R) in striatal medium spiny neurons (iMSN-D2RKO) and found profound changes in the liver circadian metabolome compared to control mice. Additionally, we show activation of dopaminergic circuits by acute cocaine administration in iMSN-D2RKO mice reprograms the circadian liver metabolome in response to cocaine. D2R signaling in MSNs is key for striatal output and essential for regulating the first response to the cellular and rewarding effects of cocaine. Our results suggest changes in dopamine signaling in specific striatal neurons evoke major changes in liver physiology. Dysregulation of liver metabolism could contribute to an altered allostatic state and therefore be involved in continued use of drugs.

Sult2b1 deficiency exacerbates ischemic stroke by promoting pro-inflammatory macrophage polarization in mice

Rationale: Stroke is a leading causes of human death worldwide. Ischemic damage induces the sterile neuroinflammation, which directly determines the recovery of patients. Lipids, a major component of the brain, significantly altered after stroke. Cholesterol sulfate, a naturally occurring analog of cholesterol, can directly regulate immune cell activation, indicating the possible involvement of cholesterol metabolites in neuroinflammation. Sulfotransferase family 2b member 1 (Sult2b1) is the key enzyme that catalyzes the synthesis of cholesterol sulfate. This study aimed to investigate the function of Sult2b1 and cholesterol sulfate in the neuroinflammation after ischemic stroke.

Methods and Results: Sult2b1^-/- and wild-type mice were subjected to transient middle cerebral artery occlusion. Our data showed that Sult2b1^-/- mice had larger infarction and worse neurological scores. To determine whether immune cells were involved in the worsening stroke outcome in Sult2b1^-/- mice, bone marrow transplantation, immune cell depletion, and adoptive monocyte transfer were performed. Combined with CyTOF and immunofluorescence techniques, we demonstrated that after stroke, the peripheral monocyte-derived macrophages were the dominant cell type promoting the pro-inflammatory status in Sult2b1^-/-mice. Using primary bone marrow-derived macrophages, we showed that cholesterol sulfate could attenuate the pro-inflammatory polarization of macrophages under both normal and oxygen-glucose deprivation conditions by regulating the levels of nicotinamide adenine dinucleotide phosphate (NADPH), reactive oxygen species (ROS), and activating the AMP-activated protein kinase (AMPK) - cAMP responsive element-binding protein (CREB) signaling pathway.

Conclusions:Sult2b1^-/- promoted the polarization of macrophages into pro-inflammatory status. This trend could be attenuated by adding cholesterol sulfate, which promotes the polarization of macrophages into anti-inflammatory status by metabolic regulation. In this study, we established an inflammation-metabolism axis during the macrophage polarization after ischemic stroke.