Search Results (583)

As the size of the elderly population increases, the need for an improved understanding of what leads to the age-related decline in physiological function continues to grow. SAMP8 mice were selected for their accelerated aging phenotype. The low levels of glyoxalase 1 (Glo1), the main enzyme that removes the reactive dicarbonyl methylglyoxal (MGO), in the cerebral cortex of SAMP8 mice prompted us to produce the first transgenic mice overexpressing Glo1 against the SAMP8 background, aimed at rescuing the accelerated aging phenotype. Selected health and biochemical endpoints were assessed in ten-month-old SAMP8 mice overexpressing Glo1. Glo1 overexpression increased median survival in males (21%) and females (4.6%), which was associated with better memory performance. Glo1 overexpression also increased synaptic markers (synaptophysin and SNAP25) as well as markers of mitochondrial function (NDUFB8, SDHB) and negative modulators of oxytosis/ferroptosis (NQO1, FTH1, and GPx4) in the cerebral cortex. For all parameters analyzed, the effect of Glo1 overexpression was more pronounced in males. Overall, the data support the beneficial effects of overexpressing Glo1 in multiple tissues, especially in SAMP8 males, suggesting a possible gender effect of MGO in aging. Both modulation of oxytosis/ferroptosis and mitochondrial metabolism warrant further investigation as potential mechanisms underlying the improved health span of Glo1 mice. Full article

Brain ischemia is a severe condition caused by reduced cerebral blood flow, leading to the disruption of ion gradients in brain tissue. This imbalance triggers spreading depolarizations, which are waves of neuronal and glial depolarization propagating through the gray matter. Microelectrode arrays (MEAs) are essential for real-time monitoring of these electrophysiological processes both in vivo and in vitro, but their sensitivity and signal quality are critical for accurate detection of extracellular brain activity. In this study, we evaluate the performance of a flexible microelectrode array based on gold-coated zinc oxide nanorods (ZnO NRs), referred to as nano-fMEA, specifically for high-fidelity electrophysiological recording under pathological conditions. Acute mouse brain slices were tested under two ischemic models: oxygen–glucose deprivation (OGD) and hyperkalemia. The nano-fMEA demonstrated significant improvements in event detection rates and in capturing subtle fluctuations in neural signals compared to flat fMEAs. This enhanced performance is primarily attributed to an optimized electrode–tissue interface that reduces impedance and improves charge transfer. These features enabled the nano-fMEA to detect weak or transient electrophysiological events more effectively, making it a valuable platform for investigating neural dynamics during metabolic stress. Overall, the results underscore the promise of ZnO NRs in advancing electrophysiological tools for neuroscience research. Full article

Background/objectives: Being overweight increases the predisposition to obesity and type 2 diabetes (T2D), which significantly elevate stroke risk and the likelihood of severe post-stroke disability. Dietary nitrate (NO₃⁻) supplementation can mitigate obesity and metabolic impairments, making it a promising approach to halt overweight people from developing overt obesity/T2D, thereby potentially also improving stroke outcome. We determined whether NO3⁻ supplementation prevents overweight mice from progressing into obesity and T2D and whether this intervention improves stroke outcome. Methods: An overweight condition was induced via 6 weeks of a high-fat diet (HFD), after which animals were randomized to either a HFD or a HFD with NO₃⁻ supplementation. After 24 weeks, when HFD-mice without NO₃⁻ developed obesity and T2D, all animals were subjected to transient middle cerebral artery occlusion and stroke outcome was assessed via behavioral testing and infarct size. The effect of NO₃⁻ on post-stroke neuroinflammation, neurogenesis, and neovascularization was analyzed by immunohistochemistry. Results: Sustained NO₃⁻ supplementation in overweight mice did not prevent obesity or insulin resistance. However, it attenuated weight gain, prevented hyperglycemia, and significantly improved functional recovery after stroke, without affecting infarct size. Moreover, NO₃⁻ decreased post-stroke neuroinflammation by reducing microglial infiltration. NO₃⁻ did not affect stroke-induced neurogenesis or vascularization. Conclusion: These results highlight the potential of NO₃⁻ supplementation to prevent metabolic impairment in the overweight population and improve stroke prognosis in this large group of people at risk of stroke and severe stroke sequelae. Full article

Background: Hypometabolism of the thalamus has been reported in epilepsy patients. This study aimed to investigate the prognostic value of thalamic metabolic activity in children with epilepsy. Methods: A total of 200 children with epilepsy and 237 children without epilepsy (sex- and age-matched control group) underwent 18F-FDG PET/CT in this study. Localization of the interictal hypometabolic epileptic focus was performed visually. Bilateral thalamic metabolic activity was evaluated qualitatively (thalamic FDG uptake in relation to the cerebral cortex) and semi-quantitatively (SUV max, normalized SUV (ratio to ipsilateral cerebellum), and absolute asymmetric index (AAI). Results: A total of 133 patients (66.5%) with epilepsy showed cerebral cortical hypometabolism in the interictal 18F-FDG PET study; there were 76 patients on the right side, 55 patients on the left side, and two patients on both sides. Of these 133 patients, 45 also had visually observed asymmetric hypometabolism in the thalamus. Semi-quantitatively, asymmetry was more prominent in epileptic patients. AAI was a more sensitive variable than other variables. Average AAIs were 3.89% and 7.36% in the control and epilepsy patients, respectively. Metabolic activity in the thalami was significantly reduced in epileptic patients compared to the control group. Associated hypometabolism of the ipsilateral thalamus was observed in 66.5% of epileptic patients with a focal cortical defect semi-quantitatively. Overall, 61 out of 200 patients showed thalamus hypometabolism. Some 51 out of 61 patients (83.6%) with thalamus hypometabolism showed refractory disease; however, the refractory disease was noted in 90 out of 139 (64.7%) patients without thalamus hypometabolism. Brain surgery was performed in 86 epileptic patients (43%). Some 35 out of 86 patients had thalamus hypometabolism. Recurrence of epilepsy was observed more in patients with thalamus hypometabolism (48% vs. 25%), with p ≤ 0.01. Conclusion: This study suggests that patients with thalamus metabolic abnormalities may be more medically resistant to therapy and less responsive to surgical treatments. Therefore, the thalamus metabolic abnormality could be used as a prognostic sign in pediatric epilepsy. Recent studies have also suggested that incorporating thalamic metabolic data into clinical workflows may improve the stratification of treatment-resistant epilepsy in children. Full article

Background/Objectives: Niemann-Pick disease Type C (NPC) represents an autosomal recessive disorder with an incidence rate of 1 in 100,000 live births that belongs to the lysosomal storage diseases (LSDs). NPC is characterized by the abnormal accumulation of unesterified cholesterol, in addition to being an autosomal recessive inherited pathology, which belongs to LSDs. It occurs in 95% of cases due to mutations in the NPC1 gene, while 5% of cases are due to mutations in the NPC2 gene. In the cerebral cortex (CC), the disease shows lipid inclusions, increased cholesterol and multiple sphingolipids in neuronal membranes, and protein aggregates such as hyperphosphorylated tau, α-Synuclein, TDP-43, and β-amyloid peptide. Mitochondrial damage and oxidative stress are some alterations at the cellular level in NPC. Therefore, the aim of this work was to determine the gene expression profile in the CC of NPC1 mice in order to identify altered molecular pathways that may be related to the pathophysiology of the disease. Methods: In this study, we performed a microarray analysis of a 22,000-gene chip from the cerebral cortex of an NPC mutant mouse compared to a WT mouse. Subsequently, we performed a bioinformatic analysis in which we found groups of dysregulated genes, and their expression was corroborated by qPCR. Finally, we performed Western blotting to determine the expression of proteins probably dysregulated. Results: We found groups of dysregulated genes in the cerebral cortex of the NPC mouse involved in the ubiquitination, fatty acid metabolism, differentiation and development, and underexpression in genes with mitochondrial functions, which could be involved in intrinsic apoptosis reported in NPC, in addition, we found a generalized deregulation in the cortical circadian rhythm pathway, which could be related to the depressive behavior that has even been reported in NPC patients. Conclusions: Recognizing that there are changes in the expression of genes related to ubiquitination, mitochondrial functions, and cortical circadian rhythm in the NPC mutant mouse lays the basis for targeting treatments to new potential therapeutic targets. Full article

Hypoxia represents a critical environmental stressor in aquaculture, significantly disrupting aquatic organisms’ physiological homeostasis and thereby constraining the sustainable development of aquaculture industries. To elucidate the mechanisms underlying hypoxia-induced metabolic regulation in aquatic species, this study employed hybrid yellow catfish (Pelteobagrus vachelli ♀ × Leiocassis longirostris ♂) as a model organism to systematically investigate the multidimensional physiological responses in brain, liver, and muscle tissues under hypoxia (0.7 mg/L) and reoxygenation (7.0 mg/L) conditions. Through qRT-PCR and enzymatic activity analyses, we comprehensively assessed molecular alterations associated with oxygen sensing (HIF-1α gene), respiratory metabolism (PFKL, HK1, PK, CS, and LDHA genes and corresponding enzyme activities), oxidative stress (SOD1, SOD2, GSH-PX, and CAT genes, along with LPO, MDA, PCO, T-SOD, GSH-PX, and CAT levels), apoptosis (Caspase-3, Bax/Bcl-2), inflammatory response (IL-1β, IKKβ), and mitochondrial function (COXIV, PGC-1α, ATP5A1). Key findings demonstrated pronounced HIF-1α activation across all examined tissues. Hepatic tissues exhibited adaptive metabolic reprogramming from aerobic to anaerobic metabolism, whereas cerebral tissues displayed suppressed anaerobic glycolysis during prolonged hypoxia, and muscular tissues manifested concurrent inhibition of both glycolytic and aerobic metabolic pathways. Notably, skeletal muscle exhibited marked oxidative stress accompanied by mitochondrial dysfunction, exacerbated inflammation, and apoptosis activation during hypoxia/reoxygenation cycles. This study delineates tissue-specific adaptive mechanisms to hypoxia in yellow catfish, providing theoretical foundations for both piscine hypoxia physiology research and aquaculture practices. Full article

X-linked adrenoleukodystrophy (ALD) is an inherited metabolic disorder that can cause adrenal insufficiency and cerebral ALD (cALD) in childhood. Early detection prevents adverse health outcomes and can be achieved by newborn screening (NBS) followed by monitoring disease progression. However, monitoring is associated with high costs. This study evaluates the cost–effectiveness of NBS for ALD in The Netherlands compared to no screening using a health economic model. A decision tree combined with a Markov model was developed to estimate societal costs, including screening costs, healthcare costs, and productivity losses of parents, and health outcomes over an 18-year time horizon. Model parameters were derived from the literature and expert opinion. A probabilistic sensitivity analysis (PSA) was performed to assess uncertainty. The screening costs of detecting one ALD case by NBS was EUR 40,630. Until the age of 18 years, the total societal cost per ALD case was EUR 120,779 for screening and EUR 62,914 for no screening. Screening gained an average of 1.7 QALYs compared with no screening. This resulted in an incremental cost–effectiveness ratio (ICER) of EUR 34,084 per QALY gained for screening compared to no screening. Although the results are sensitive to uncertainty surrounding costs and effectiveness due to limited data, NBS for ALD is likely to be cost–effective using a willingness-to-pay (WTP) threshold of EUR 50,000– EUR 80,000 per QALY gained. Full article

Backgrounds/Objective: The impact of metabolic disturbances induced by an unbalanced diet on cognitive decline in mid-life is now widely observed, although the mechanisms are not well identified. Here we report that glutamatergic vasoactive pathways are a key feature of high-fat-diet (HFD)-induced neurogliovascular uncoupling in mice. Methods: C57Bl6/J mice are fed either with normal diet (ND) or high-fat diet (HFD) during 6 or 12 months and characterized for metabolic status. Cerebral vascular tree from pial to intraparenchymal arteries, is investigated with Halpern’s arteriography and with differential interference contrast infrared imaging of brain slices. Results: A 70% alteration in the myogenic tone of the basilar artery is observed as early as 6 months (M6) after the HFD. Infrared imaging revealed a 77% reduction in the glutamate-induced vasodilation of intraparenchymal arterioles appearing after 12 months (M12) of the HFD. The respective contributions of enzymes involved in glutamatergic pathways were altered as a function of HFD and time. The decrease in astrocytic COX I observed at M6 was followed by a loss of neuronal COX II and a compensatory action of NOS at M12. Conclusions: This HFD-induced neurogliovascular uncoupling pathway offers therapeutic targets to consider for improving cerebral vasoactive functions while preventing peripheral metabolic disturbances. Full article

Background and clinical significance: Acute reduction in vigilance is a frequent reason for emergency department admissions, especially among the elderly. While intracranial causes or infections with fluid depletion are often responsible, there remain cases where imaging, laboratory tests, and clinical examination fail to provide a clear diagnosis. Case presentation: A 91-year-old woman was presented to the emergency department with recurrent episodes of somnolence to deep coma. On admission, her vital signs were stable, and cerebral CT imaging revealed no intracranial pathology. Laboratory analyses, including blood gas measurements, were unremarkable. Empirical treatment for possible intoxications with benzodiazepines or opioids using flumazenil and naloxone had no effect. An Addison’s crisis was considered but excluded following methylprednisolone administration without improvement in consciousness. Eventually, an isolated elevation of serum ammonia was identified as the cause of the reduced vigilance. Further investigation linked the hyperammonemia to abnormal intestinal bacterial colonization, likely due to a prior ureteroenterostomy. There was no evidence of liver dysfunction, thus classifying the condition as non-hepatic hyperammonemia. Therapy was initiated with rifaximin, supported by aggressive laxative regimens. Ammonia levels and vital parameters were closely monitored. The patient’s condition improved gradually, with serum ammonia levels returning to normal and cognitive function fully restored. Conclusions: This case highlights an uncommon cause of coma due to non-hepatic hyperammonemia in the absence of liver disease, emphasizing the diagnostic challenge when standard evaluations are inconclusive. It underscores the need for broad differential thinking in emergency settings and the importance of considering rare metabolic disturbances as potential causes of altered mental status. Full article

Early-life brain injuries are major causes of long-term neurodevelopmental disorders such as cerebral palsy. Emerging evidence suggests these injuries can alter the gut microbiota composition, intestinal integrity, and neuroinflammatory responses. This systematic review evaluated the impact of early-life brain injuries on the gut microbiota in rodent models. A scientific literature search was conducted across Medline/PubMed, Web of Science, Scopus, and Embase. Initially, 7419 records were identified, and 21 eligible studies were included. Eligible studies focused on evaluating the microbiota alterations and related gut–brain axis markers at the neonatal or post-weaning stages. The data extraction and synthesis followed PRISMA guidelines. Most studies reported gut dysbiosis characterized by a decreased abundance of Bacteroidetes, and Lactobacillus. Alterations were associated with an increased gut permeability, reduced tight junction proteins, and elevated pro-inflammatory cytokines. Several studies showed reduced levels of short-chain fatty acids and metabolic pathway disruptions. Brain outcomes included neuroinflammation, white matter injury, altered gene expression, and impaired structural integrity. These results suggest that early-life brain injury induces complex alterations in the gut microbiota and its metabolic products, which may contribute to systemic and neuroinflammatory processes. Understanding these interactions offers insights into the pathophysiology of neurodevelopmental disorders and highlights the gut–brain axis as a potential target for early interventions. Full article

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by difficulty with social communication, behavior, and sensory integration. With its prevalence rising worldwide in recent decades, understanding and mitigating the origins of ASD has become a priority. Though its etiology is multifactorial, the current research highlights two major contributors, genetic susceptibilities and environmental inflammatory exposures, leading to oxidative stress during critical developmental periods. We explore how genetic variations, including those affecting cerebral folate metabolism, and various inflammatory triggers, including exposure to inflammatory agents during both the fetal and post-fetal period, intersect to influence the development of ASD, giving rise to specific symptoms seen in autism. Full article

The enzymatic formation of kynurenic acid (KYNA), a neuromodulator metabolite of the kynurenine pathway (KP) of tryptophan metabolism, in the mammalian brain is widely attributed to kynurenine aminotransferase II (KATII). However, an alternative biosynthetic route, involving the conversion of D-kynurenine (D-KYN) to KYNA by D-amino acid oxidase (D-AAO), may play a role as well. In the present study, we first confirmed that purified D-AAO efficiently converted D-KYN—but not L-KYN—to KYNA. We then examined KYNA formation from D-KYN (100 µM) in vitro, using tissue homogenates from several human brain regions. KYNA was generated in all areas, with D-AAO-specific production being most effective by far in the cerebellum. Next tested in homogenates from rat cerebellum, KYNA neosynthesis was significantly reduced by D-AAO inhibition, whereas KATII inhibition had no effect. Finally, KYNA production was assessed by in vivo microdialysis in rat cerebellum. Local D-KYN perfusion, alone and in combination with inhibitors of D-AAO (kojic acid) or aminotransferases (AOAA), caused a substantive increase in extracellular KYNA levels. This effect was attenuated dose-dependently by micromolar concentrations of kojic acid, whereas co-perfusion of AOAA (1 mM) was ineffective. Together, our findings indicate that D-AAO should be considered a major contributor to KYNA production in the cerebellum, highlighting region-specific qualitative differences in cerebral KYNA metabolism. Full article

Background/Objectives: Abnormal brain glycerolipid metabolism has been reported for Alzheimer’s disease (AD). This includes both diacylglycerols (DGs) and monogalactosyl-DGs (MGDGs), which are elevated in AD subjects. While DGs are also elevated in subjects with mild cognitive impairment (MCI), MGDGs have not yet been examined at this early stage of cognitive impairment. Methods: MGDG, triacylglycerol (TG), and ether glycerolipid levels in the cerebral cortex gray matter of controls, MCI, and non-demented Alzheimer’s neuropathology (NDAN) subjects were monitored by high-resolution mass spectrometry (<2 ppm mass error). Results: MGDG, MGDG ether, DG ether, and TG levels were elevated in the cerebral cortex of MCI but not NDAN subjects. Conclusions: A diverse array of glycerolipids was elevated in MCI subjects, suggesting a role in cognitive dysfunction. This suggestion is further supported by the maintenance of normal glycerolipid levels in NDAN subjects with amyloid accumulation but not cognitive deficits. Our data clearly indicate that while complex lipid alterations occur in MCI subjects, relative to controls 20 years younger, no such lipid alterations occur in NDAN subjects. While amyloid deposition in MCI is not involved in the observed lipid alterations, other ongoing neuropathologies may contribute to changes in lipid dynamics and vice versa. Full article

Background: Elevated levels of methylmalonic acid (MMA) are observed in the bodily fluids and tissues of patients with methylmalonic aciduria, a metabolic disorder characterized by manifestations such as vomiting, lethargy, muscle weakness, seizures, and coma. Objectives and Methods: To better understand the neuropathological mechanisms underlying this condition, we investigated the effects of intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of MMA on antioxidant defenses, citric acid cycle functioning, and glial reactivity in the cerebral cortex and striatum of Wistar rats. Amino acid levels were also quantified. Results: i.p. and i.c.v. administration of MMA decreased reduced glutathione levels and altered the activities of different antioxidant enzymes in the cortex and striatum. The activity of the citric acid cycle enzyme succinate dehydrogenase was diminished in both brain regions by i.p. and i.c.v. administration. Citrate synthase, isocitrate dehydrogenase, and malate dehydrogenase activities were further inhibited in the striatum. Furthermore, the i.p. administration increased glial fibrillary acidic protein (GFAP) and glucose transporter 1 (GLUT1) levels, whereas i.c.v. administration elevated GFAP and ionized calcium-binding adaptor molecule 1 (IBA1) levels in the striatum, suggesting glial activation. In contrast, no significant changes in glial markers were detected in the cortex. Moreover, synaptophysin levels remained unaltered in both regions. Finally, i.p. administration increased glutamate, glycine, and serine levels and reduced tyrosine concentrations in the striatum. Conclusions: Our findings indicate that oxidative stress, bioenergetic dysfunction, and glial reactivity induced by MMA may contribute to the neurological deficits observed in methylmalonic aciduria. Full article