Search Results (1,066)

Mouse models of genetic diseases are important research tools. However, the genetic background of the mouse strain can significantly influence how a genetic mutation is expressed. Studies on preclinical models of phenylketonuria (PKU), an inherited metabolic disorder, have used two strains, BTBR and C57Bl/6, created via a chemically induced point mutation in the gene encoding the enzyme phenylalanine hydroxylase (BTBR^enu2 and C57^enu2, respectively). Despite having the same levels of hyperphenylalaninemia (HPA), published results indicate differences in neural and behavioral phenotypes between the two backgrounds. To explore this difference further, the current study examines the genome-wide transcriptome of the prefrontal cortex (pFC), the brain region which is the most vulnerable to the negative effects of HPA. Regardless of the strain, the enu2 mutation upregulated the expression of several aminoacyl-tRNA synthetases and eukaryotic translation initiation factors, suggesting an essential modification in the protein translation process and supporting the downregulation of gene programs related to myelination. Accordingly, we deepened the exploration of cognitive dysfunctions in C57^enu2− mice, showing a previously unreported working memory impairment under increasing information load. These findings identify convergent pFC molecular and cognitive alterations induced by HPA across distinct genetic backgrounds, providing clinically relevant insights into mechanisms that may contribute to executive dysfunctions in PKU. Full article

Identifying probiotics that modulate the gut–brain axis is vital for non-pharmacological Alzheimer’s disease (AD) therapy. Through a staged screening from transgenic Drosophila to a D-galactose/AlCl₃-induced murine model, Lactobacillus acidophilus LA4 and Lacticaseibacillus paracasei F5 were prioritized for their ability to improve climbing indices and reduce Aβ deposition and AChE activity. In AD mice, LA4 and F5 significantly ameliorated cognitive deficits and anxiety-like behaviors. Mechanistically, both strains reduced hippocampal Aβ_1–42 and p-Tau levels, inhibited AChE, suppressed pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), and enhanced antioxidant enzymes (SOD, GSH-Px). 16S rRNA analysis revealed restored Firmicutes/Bacteroidetes ratios and enrichment of SCFA-producers (Muribaculaceae, Dubosiella). Metabolomics highlighted remodeled purine and arginine pathways, with strain-specific effects on primary bile acid biosynthesis/sphingolipid metabolism (LA4) and butanoate metabolism/nicotinate and nicotinamide metabolism (F5). Consequently, LA4 and F5 alleviate AD pathology by restructuring microbial and metabolic profiles, thereby mitigating neuroinflammation and oxidative stress. These findings confirm the potential of specific probiotics as functional food ingredients for the prevention and adjuvant treatment of neurodegenerative diseases. Full article

The treatment of depression is an uphill battle due to the low efficiency and delayed clinical response of antidepressants and the fact that most of them cause numerous side effects. Psychobiotics, probiotics that affect brain function and confer mental health benefits, emerged as a promising ally showing protective effects against depressive- and anxiety-like behaviors in various animal models of depression. There is rapidly accumulating evidence that psychobiotics show protective effects at the molecular level as well, affecting several pathophysiological processes implicated in depression. This narrative review summarizes preclinical insights into molecular changes related to the hypothalamic-pituitary-adrenal (HPA) axis, peripheral inflammation, neuroinflammation, neurotransmission and tryptophan metabolism underlying psychobiotic-driven mitigation of depressive and anxiety symptoms in stress-based, corticosterone-induced and inflammation-induced animal models of depression. Research evidence indicates that psychobiotics normalize the activity of the HPA axis, decrease levels of inflammatory mediators in the intestine, circulation, and brain, normalize the levels of neurotransmitters and their receptors, and regulate tryptophan metabolism in various animal models of depression. The main setbacks in this field are the extensive diversity of studied probiotic strains, which are often insufficiently characterized, and the lack of mechanistic studies in animal models. However, despite these challenges, further study of psychobiotics in the pursuit of supportive therapies for depressive disorders is firmly grounded. Full article

For more than a century, pathology has served as a cornerstone of modern medicine, relying primarily on static microscopic assessment of tissue morphology—such as H&E staining—which remains the “gold standard” for disease diagnosis. However, this conventional paradigm provides only a snapshot of disease states and often fails to capture their dynamic evolution and complex functional mechanisms. Moreover, animal models are constrained by marked interspecies differences, creating a persistent gap in translational research. To overcome these limitations, we propose the concept of New Pathophysiology, a research framework that transcends purely morphological descriptions and aims to resolve functional dynamics in real time. This approach integrates Organ-on-a-Chip (OOC) technology, multi-omics analyses, and artificial intelligence to reconstruct the entire course of disease initiation and to enable personalized medicine. In this review, we first outline the foundations and limitations of traditional pathology and animal models. We then systematically summarize more than one hundred existing OOC disease models across multiple organs—including the kidney, liver, and brain. Finally, we elaborate on how OOC technologies are reshaping the study of key pathological processes such as inflammation, metabolic dysregulation, and fibrosis by converting them into dynamic, mechanistic disease models, and we propose future perspectives in the field. This review adopts a relatively uncommon classification strategy based on pathological mechanisms (mechanism-based), rather than organ-based categorization, allowing readers to recognize shared principles underlying different diseases. Moreover, the focus of this work is not on emphasizing iteration or replacement of existing approaches, but on preserving past achievements from a historical perspective, with an emphasis on overcoming current limitations and enabling new advances. Full article

Guanidinoacetate methyltransferase (GAMT) is an essential enzyme in the biosynthesis of creatine, an important molecule in energy recycling. GAMT loss of function leads to GAMT deficiency (GAMT-D), an autosomal recessive disorder resulting in low creatine levels and the accumulation of a toxic intermediate, guanidinoacetate (GAA). GAMT-D patients present with intellectual disability and epilepsy, emphasizing the detrimental consequences of disturbed creatine metabolisms in the central nervous system (CNS). Current treatments are not curative and may not restore creatine metabolism in the brain. Here, we present a proof-of concept study testing the first CNS-directed, Adeno-associated virus serotype 9 (AAV9)-based gene therapy for the treatment of GAMT-D. the delivery of GAMT construct to cellular models of GAMT-D effectively restored protein and mRNA expression of GAMT while increasing intracellular creatine content and decreasing GAA accumulation. In murine models of GAMT-D, treatment with scAAV9.hGAMT, delivered intrathecally, resulted in increased creatine content as well as significant decreases in GAA accumulation in the CNS and peripheral organs. Overall, we found that scAAV9.hGAMT represents a promising gene therapy for treating GAMT-D, warranting further investigation in animal models to determine an appropriate therapeutic window for both efficacy and safety that allows for translation into human patients in the future. Full article

Neurodegenerative diseases (NDDs), including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), are becoming more prevalent and still lack effective disease-modifying therapies (DMTs). However, translational efficiency remains critically low. For example, a ClinicalTrials.gov analysis of AD programs (2002–2012) estimated ~99.6% attrition, while PD programs (1999–2019) achieved an overall success rate of ~14.9%. In vitro platforms are assessed, ranging from immortalized neuronal lines and primary cultures to human-induced pluripotent stem cell (iPSC)-derived neurons/glia, neuron–glia co-cultures (including neuroinflammation paradigms), 3D spheroids, organoids, and blood–brain barrier (BBB)-on-chip systems. Complementary in vivo toxin, pharmacological, and genetic models are discussed for systems-level validation and central nervous system (CNS) exposure realism. The therapeutic synthesis focuses on AD, covering symptomatic drugs, anti-amyloid immunotherapies, tau-directed approaches, and repurposed drug classes that target metabolism, neuroinflammation, and network dysfunction. This review links experimental models to translational decision-making, focusing primarily on AD and providing a brief comparative context from other NDDs. It also covers emerging targeted protein degradation (PROTACs). Key priorities include neuroimmune/neurovascular human models, biomarker-anchored adaptive trials, mechanism-guided combination DMTs, and CNS PK/PD-driven development for brain-directed degraders. Full article

Background: Alzheimer’s disease (AD) features progressive cognitive decline and amyloid-beta (Aβ) accumulation. Insulin resistance in type 2 diabetes mellitus (T2DM) is increasingly recognised as a mechanistic link between metabolic dysfunction and neurodegeneration. Although sodium–glucose cotransporter-2 inhibitors (SGLT2is) have established glycaemic and cardioprotective benefits, their neuroprotective role remains less well defined. Objectives: This systematic review examines animal studies on the neuroprotective effects of SGLT2i in T2DM and AD models. Methods: A literature search was conducted across the Web of Science, Scopus, and PubMed databases, covering January 2014 to November 2024. Heterogeneity was assessed with I², and data were pooled using fixed-effects models, reported as standardised mean differences with 95% confidence intervals. We focus on spatial memory performance as measured by the Morris Water Maze (MWM) test, including escape latency and time spent in the target quadrant, as the primary endpoints. The secondary endpoints of Aβ accumulation, oxidative stress, and inflammatory markers were also analysed and summarised. Results: Twelve studies met the inclusion criteria for this review. A meta-analysis showed that SGLT2i treatment significantly improved spatial memory by reducing the escape latency in both T2DM and AD models. In addition, SGLT2i yielded a significant improvement in spatial memory, as indicated by an increased target quadrant time for both T2DM and AD. Furthermore, SGLT2i reduced Aβ accumulation in the hippocampus and cortex, which met the secondary endpoint; the treatment also lessened oxidative stress and inflammatory markers in animal brains. Conclusions: Our findings indicate that SGLT2is confer consistent neuroprotective benefits in experimental T2DM and AD models. Full article

Simultaneously inhibiting beta-amyloid protein (Aβ) aggregation and reducing metal ion overload in the brain is a promising strategy for treating Alzheimer’s disease (AD). Aloe emodin (AE) is one of the major components of the traditional Chinese medicine rhubarb. Based on its reported pharmacological effects and its structural affinity for metal ions, this study aims to explore the potential of AE in improving AD pathology. Through the injection of Aβ or copper-Aβ complex in the bilateral hippocampus of rats, we constructed two kinds of nontransgenic animal models. Behavioral tests were used to evaluate cognitive impairment, and the effects of AE on neuronal damage and Aβ deposition were measured via Nissl staining and immunohistochemistry. Furthermore, we detected copper content in the serum and brain tissues as well as some biochemical indexes of Aβ cascade pathology in the brain tissues of model rats to explore the mechanism of action. AE treatment decreased copper accumulation and regulated Aβ metabolism in the brain of model rats, thereby improving Aβ deposition, memory impairment, hippocampal nerve cell damage, and related biochemical indicators. AE ameliorated the AD pathology of the model rats by targeting copper-induced Aβ toxicity, revealing a mechanism of action by which AE may exhibit good clinical efficacy in treating AD. Full article

As global population aging accelerates, the growing burden of age-related diseases is driving a shift in medical research from single-disease treatment to interventions targeting the aging process itself. Organ-specific interventions have emerged as a promising strategy to modulate systemic aging. Among organs, the brain, muscle, and gut have attracted particular attention due to their central roles in neural regulation, metabolic homeostasis, and immune balance. In this review, we focus on these three key organs, systematically summarizing their roles and regulatory mechanisms in organismal aging and discussing how exercise influences the aging process by affecting these organs. Crucially, we propose a novel “local-to-global” regulatory model, positing that preserving homeostasis in these specific tissues is sufficient to orchestrate systemic anti-aging effects. This work represents a conceptual advance by providing the theoretical rationale to move beyond non-specific systemic treatments toward precise, organ-targeted interventions. Full article

Background/Objectives: Mitochondrial dysfunction is a major cause of brain injury in patients with primary mitochondrial disease. New mitochondrial therapeutics and non-invasive tools for efficacy monitoring are urgently needed. To these ends, succinate prodrug NV354 (methyl 3-[(2-acetylaminoethylthio)carbonyl]propionate) and diffuse optical techniques are promising. In this proof-of-concept study, we characterize NV354’s effects on microdialysis metrics of cerebral metabolism in a swine model of mitochondrial dysfunction and assess the associations of diffuse optical metrics with mitochondrial dysfunction and metabolic improvement. Methods: One-month-old swine received a four-hour co-infusion of rotenone with either the succinate prodrug NV354 (n = 5) or placebo (n = 5). Rotenone is a mitochondrial complex I inhibitor. Before and during co-infusion, cerebral metabolism was probed with microdialysis and diffuse optics. Microdialysis acquired interstitial lactate and pyruvate levels invasively, while diffuse optics measured changes in oxygen extraction fraction (OEF) and oxidized cytochrome-c-oxidase concentration (oxCCO). Results: Interstitial lactate continually increased in the placebo group (p < 0.01), but lactate levels plateaued in the NV354 group (p = 0.90). oxCCO also increased in the placebo group (p = 0.05), but OEF remained constant (p = 0.80). In the NV354 group, oxCCO increased (p < 0.01) while OEF decreased (p < 0.01). Conclusions: Microdialysis results suggest that NV354 treatment can increase oxygen metabolism in large animals with mitochondrial dysfunction. The optical oxCCO metric was also sensitive to metabolic changes induced by rotenone and NV354 administration. Full article

Background: Alzheimer’s disease (AD), a progressive brain disorder, is the most common form of dementia and necessitates the development of effective intervention strategies. Ginseng-Natto composite fermentation products (GN) have demonstrated beneficial bioactivities in mouse models of AD; however, the underlying mechanism of action through which GN ameliorates AD requires further elucidation. Methods: Mice received daily intragastric administration of low- or high-dose GN for 4 weeks, followed by intraperitoneal injection of scopolamine to induce the AD model. The pharmacological effects of GN were systematically evaluated using the Morris water maze test, ELISA, and H&E staining. To further investigate the underlying mechanisms, 16S rRNA gene sequencing and metabolomics were employed to analyze the regulatory effects of GN on the gut–brain axis. Additionally, Western blotting was performed to assess the impact of GN on blood–brain barrier (BBB) integrity. Results: GN intervention significantly ameliorated cognitive deficits and attenuated neuropathological injury in AD mice, restoring the brain levels of acetylcholine (ACh), acetylcholinesterase (AChE), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) to normal ranges. GN reshaped the gut microbiota by promoting beneficial bacteria and inhibiting pro-inflammatory strains. It also regulated key metabolic pathways related to amino acid and unsaturated fatty acid metabolism. This metabolic remodeling restored the compromised BBB integrity by upregulating tight junction proteins (ZO-1, Occludin and Claudin-1). Conclusions: Our findings demonstrate that GN ameliorates AD through a gut-to-brain pathway, mediated by reshaping the microbiota-metabolite axis and repairing the BBB. Thus, GN may represent a promising intervention candidate for AD. Full article

Background/Objectives: Glucose Transporter 1 Deficiency Syndrome (GLUT1-DS) is a neurodevelopmental disorder caused by mutations in the gene encoding glucose transporter 1 (GLUT1), which leads to impaired glucose transport into the brain and is characterized by drug-resistant epilepsy. Limited glucose supply disrupts neuronal and astrocytic energy homeostasis, but how hypometabolism translates into network hyperexcitability remains poorly understood. Here, we used induced pluripotent stem cells (iPSCs)-derived brain organoids to examine how reduced metabolic substrate availability shapes epileptiform dynamics in human neuronal circuits from GLUT1-DS. Methods: Brain organoids were generated from a healthy donor or a GLUT1-DS patient and interfaced with multielectrode arrays (MEA) for recording of neuronal activity. A unified Python (v3.10)-based analytical pipeline was developed to quantify spikes, bursts, and power spectral density (PSD) across frequency bands of neuronal activity. Organoids were challenged with reduced glucose, pentylenetetrazol (PTZ), potassium chloride (KCl), and tetrodotoxin (TTX) to assess metabolic and pharmacological modulation of excitability. Results: GLUT1-DS organoids exhibited elevated baseline hyperexcitability compared to healthy control, characterized by increased spike rates, prolonged bursts, increased spikes per burst, and elevated PSD. Reduced glucose availability further amplified these features selectively in GLUT1-DS. Conclusions: Human brain organoids reproduce the pathological coupling between hypometabolism and hyperexcitability in GLUT1-DS. Our platform provides a mechanistic model and quantification tool for evaluating metabolic and anti-epileptic therapeutic strategies. Full article

Background: Alcohol use disorder (AUD) is associated with chronic heavy or repeated binge alcohol abuse, which can cause alcohol-related brain damage (ARBD) marked by neurobehavioral, cognitive, and motor deficits. The anterior frontal lobe and cerebellar vermis are two of the major targets of ARBD in humans with AUD and in experimental alcohol exposed models. Alcohol’s neurotoxic and neurodegenerative effects include impairments in signaling through insulin and insulin-like growth factor (IGF) pathways that regulate energy metabolism. This human AUD study was inspired by a recent report suggesting that dysfunction of the frontal lobe incretin network in experimental ARBD is linked to known impairments in brain insulin/IGF signaling. Objective: The overarching goal was to investigate whether AUD is associated with dysfunction of the brain’s incretin network, focusing on the cerebellum and frontal lobe. Methods: Fresh frozen postmortem cerebellar vermis and anterior frontal lobe tissues from adult male AUD (n = 6) and control (n = 6) donors were processed for protein extraction. Duplex enzyme-linked immunosorbent assays (ELISAs) were used to assess immunoreactivity to neurofilament light chain (NfL) as a marker of neurodegeneration. A multiplex ELISA was used to measure immunoreactivity to a panel of gut hormones, including incretin polypeptides. Results: AUD was associated with significantly increased NfL immunoreactivity in both the cerebellar vermis and anterior frontal lobe. However, the patterns of AUD-related alterations in gut hormone immunoreactivity differed regionally. AUD reduced pancreatic polypeptide immunoreactivity in the cerebellar vermis, and GIP, GLP-1, leptin, and ghrelin in the frontal lobe. Conclusions: (1) Increased NfL may serve as a useful biomarker of neurodegeneration in AUD. (2) AUD’s adverse effects on neuroendocrine signaling networks differ in the cerebellar vermis and anterior frontal region, although both are significant targets of ARBD. (3) The finding of AUD-associated reductions in frontal lobe GIP and GLP-1 suggests that therapeutic targeting with incretin receptor agonists may help restore energy metabolism and neurobehavioral and cognitive functions linked to their networks. Full article

Background/Objectives: Alzheimer’s disease (AD) is a neurodegenerative disorder in which altered microvascular circulation participates in the pathogenesis. The lack of therapeutic treatments for AD makes the development of strategies aimed at preventing or delaying the disease onset urgent. In recent years, several studies have highlighted that a diet rich in antioxidants and anti-inflammatory compounds may positively impact AD development. In this study, we assessed the impact of a diet enriched with Acebuche (ACE) oil, an extra-virgin olive oil particularly rich in antioxidants and anti-inflammatory compounds, on AD progression in the 5xFAD mouse model. Methods: After weaning, wild-type (WT) and 5xFAD mice received the standard or the ACE oil-enriched diet. At 2, 4 and 6 months, the effects of the diet were evaluated on AD-related microvascular aberrancies, beta-amyloid (Aβ) formation, hypoxic state, blood–brain barrier (BBB) alterations, neuroinflammation and cognitive impairment. Metabolic parameters were also evaluated. Results: In 5xFAD mice, the ACE oil-enriched diet prevented alterations in cerebral microcirculation. Moreover, Aβ accumulation, downregulation of Aβ-degrading enzymes, hypoxia, BBB breakdown, neuroinflammation, and cognitive deficits were delayed by the ACE oil-enriched diet. However, some of these effects were reduced at 6 months, in concomitance with systemic metabolic changes, such as hepatic steatosis, evidenced in both WT and 5xFAD mice receiving the ACE oil-enriched diet. Conclusions: Overall, the present results represent proof of concept for the validity of early dietary interventions in AD prevention. Full article

Background: Unhealthy diets characterized by high salt, fat, and fructose content are established risk factors for metabolic and cardiovascular disorders and may have indirect effects on cognitive function. However, the combined impact of a high-salt, high-fat, and high-fructose diet (HSHFHFD) on systemic physiology and brain health remains to be fully elucidated. Methods: Sprague-Dawley (SD) rats received a customized high-salt, high-fat diet supplemented with 30% fructose water for 18 weeks. Physiological and brain parameters were assessed, in combination with multi-omics analyses including brain proteomics and metabolomics, serum metabolomics, and gut microbiota profiling. Results: HSHFHFD significantly elevated blood glucose, blood pressure, and serum levels of TG, TC, and LDL in rats. Serum metabolomic profiling identified over 100 differentially abundant metabolites in the Model group. Proteomics, metabolomics, and gut microbiome integration revealed pronounced alterations in both brain proteomic and metabolomic profiles, with 155 differentially expressed proteins associated with glial cell proliferation and 65 differential metabolites linked to fatty acid and amino acid metabolism, among others. Experimental validation confirmed marked upregulation of GFAP and Bax protein, concomitant with downregulation of ZO-1 and occludin. Furthermore, HSHFHFD perturbed the CREB signaling pathway, leading to diminished BDNF expression. The levels of inflammatory factors, including IL-6, IL-10, IL-1β and TNFα, were significantly elevated in the brain. Oxidative stress was evident, as indicated by elevated malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) activity, and altered NAD⁺/NADH ratio. Additionally, HSHFHFD significantly reduced the abundance of beneficial gut bacteria, including Lactobacillus, Romboutsia, and Monoglobus. Conclusions: HSHFHFD-induced depletion of gut Lactobacillus spp. may disrupt the linoleic acid metabolic pathway and gut–brain axis homeostasis, leading to the impairment of neuroprotective function, blood–brain barrier dysfunction, and exacerbated neuroinflammation and oxidative stress in the brain. These effects potentially increase the susceptibility of rats to neurodegenerative disorders. Full article