Search Results (865)

Gut microbial metabolites play a crucial role in modulating cognitive function. In a previous animal study, oral administration of Lactiplantibacillus plantarum MWFLp-182 (L. plantarum MWFLp-182) significantly increased inosine levels in both the serum and feces of D-galactose (D-gal)-induced mice, which was accompanied by improved cognitive performance. Building on this finding, we further investigated the neuroprotective mechanisms of inosine derived from L. plantarum MWFLp-182 in alleviating D-gal-induced neuronal damage in HT-22 cells. Reverse transcription-quantitative PCR (RT-qPCR) was used to analyze the addition of inosine (250 μg/mL, 500 μg/mL), which considerably reduces oxidative stress induced by D-gal (20 mg/mL), on the regulation of mRNA expression of the nuclear factor erythroid 2-related factor (Nrf2)/hemeoxygenase 1 (HO-1) signaling pathway factors. Compared to the D-gal group, the inosine-treated group exhibited a 4.3-fold and 8.7-fold increase in HO-1 and Nrf2 levels, respectively. Furthermore, inosine alleviates neuroinflammation by modulating the mRNA expression of the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response protein 88 (MyD88)/nuclear factor kappa B (NF-κB) signaling pathway. Compared to the D-gal group, the inosine-treated group showed reductions of 41.75%, 28.29%, and 32.17% in TLR4, MyD88, and NF-κB levels, respectively. Moreover, immunofluorescence staining revealed that inosine exhibits anti-apoptotic properties by enhancing the levels of neurotrophic factors, including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), while simultaneously lowering the expression of the pro-apoptotic protein bcl-2-associated X (Bax). These findings suggest that inosine, a differentially expressed metabolite identified in a probiotic-intervention mouse model, alleviates D-gal-induced neuronal damage in HT-22 cells by modulating oxidative, inflammatory, and apoptotic pathways, providing mechanistic insights into the neuroprotective effects of this metabolite. Full article

Chronic inflammation constitutes a well-established driver of colorectal carcinogenesis, yet the molecular circuitry linking inflammatory receptor signalling to tumour cell survival remains incompletely delineated. Here we demonstrate that the HMG-CoA reductase inhibitors atorvastatin and rosuvastatin modulate inflammatory survival pathways in colorectal cancer cells in a manner consistent with targeted interference with the protease-activated receptor 2 (PAR-2)–extracellular signal-regulated kinase (ERK)–tumour necrosis factor-α (TNF-α) signalling axis. Using lipopolysaccharide-stimulated HT-29 and Caco-2 cells as complementary models of inflammatory colorectal malignancy, we show that both statins selectively attenuate PAR-2 expression at the protein and transcript levels while leaving structurally related PAR-1 unaffected. This pattern of receptor modulation is accompanied by suppression of total ERK1/2 expression, ERK1/2 phosphorylation, and the transcriptional target DUSP6, together with attenuation of TNF-α secretion. Importantly, these signaling shifts are associated with dual apoptotic programs; the extrinsic pathway, reflected by transcriptional upregulation and proteolytic activation of caspase-8; and the intrinsic mitochondrial pathway, evidenced by reciprocal modulation of Bcl-2 family proteins favoring Bax over Bcl-2. Both pathways converge upon activation of executioner caspase-3 and an increase in Annexin V-defined apoptotic fractions, indicating re-engagement of programmed cell death under inflammatory stress. Notably, rosuvastatin consistently demonstrates superior potency across signaling endpoints, achieving comparable biological effects at lower concentrations than atorvastatin. Collectively, these data indicate that clinically deployed statins target the PAR-2–ERK axis and are associated with re-activation of apoptotic pathways in inflammatory colorectal cancer models, while leaving open the possibility that additional statin-responsive networks contribute to their pro-apoptotic effects. This mechanistic framework provides biological plausibility for epidemiologic observations linking statin use with reduced colorectal cancer risk and improved outcomes, and supports further translational evaluation of PAR-2-directed statin strategies in colorectal malignancy. Full article

Dysregulated magnesium (Mg²⁺) homeostasis contributes to colorectal cancer (CRC), yet its context-dependent function within the tumor microenvironment remains unresolved. This study aimed to determine how sustained low and high extracellular Mg²⁺ environments affect CRC spheroid (SP) growth and Mg²⁺ homeostasis using HT-29 SPs. We analyzed Mg²⁺ flux, the expression of Mg²⁺ transporters (e.g., Transient Receptor Potential Melastatin (TRPM) 6), viability, apoptotic and autophagic markers, and phospho-/oxidoproteomic alterations. Both Mg²⁺ extremes destabilized SP architecture, reduced viability, and induced apoptosis and autophagy, with SPs displaying heightened vulnerability relative to 2D cultures. Mg²⁺ stress impaired Mg²⁺ influx and eliminated adaptive transporter regulation in SPs. Loss of membrane TRPM6/7 heterodimers, driven by altered phosphorylation (e.g., TRPM6 Serine 141, Serine 1252, Threonine 1851) and elevated oxidation (e.g., Methionine 1755), suppressed channel activity. High Mg²⁺ caused profound metabolic failure despite increased total Mg²⁺, reflecting functional Mg²⁺ deficiency. CRC spheroids are acutely susceptible to Mg²⁺ imbalance due to collapsed transporter homeostasis and post-translational inhibition of Mg²⁺ channels. These findings reveal a targetable metabolic vulnerability and support the therapeutic potential of localized Mg²⁺ modulation in CRC. Full article

Vitamin D is involved in immune regulation through effects on innate and adaptive immune responses mediated by vitamin D receptor activation within immune cells. Experimental and translational studies support its role in promoting regulatory T-cell activity, modulating Th1/Th17 responses, and influencing autoantibody production. At the population level, low serum 25-hydroxyvitamin D concentrations are consistently associated with an increased risk of autoimmune diseases, including autoimmune thyroid disorders such as Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), suggesting a potential preventive association. In contrast, clinical evidence from interventional studies in patients with established disease is heterogeneous. Although vitamin D supplementation has been associated with reductions in thyroid autoantibody titers in some studies—particularly in patients with HT and baseline vitamin D deficiency—consistent effects on thyroid function, disease progression, or relapse prevention have not been demonstrated. Overall, current evidence supports vitamin D deficiency as a potentially modifiable risk marker rather than a confirmed disease-modifying therapeutic target in autoimmune thyroid diseases, highlighting the need for further studies focused on clinically meaningful outcomes. Full article

Chronic ethanol exposure and genetic factors interact to drive neuroadaptations in alcohol use disorders (AUD). However, the system-level coordination of molecular responses across brain regions remains unclear. The 5-HT system and BDNF are key regulators of neuroplasticity in alcoholism. The 5-HT₇ receptor modulates both behavior and serotonin signaling. We investigated midbrain 5-HT₇ overexpression in C57BL/6 mice given 5-week ethanol access. Our results showed complex, region-specific changes in 5-HT and BDNF signaling, as well as selective behavioral alterations. Ethanol abolished the antidepressant-like effect of 5-HT₇ overexpression and increased anxiety-like behavior, without affecting baseline locomotion or novel object recognition. At the molecular level, ethanol suppressed 5-HT₇-mediated CREB/BDNF signaling and differentially regulated 5-HT_1A and 5-HT_2A expression across regions. To extract general principles, we used integrative systems analysis based on population-averaged generalized estimating equations (GEE), and mapped effects in the (t₁, t₂) plane. We identified two regularities: first, regional specificity of responses, and second, divergence across regulatory levels, with opposing effects more frequent at the mRNA level and concordant effects more common at the protein level. These findings suggest that neuroadaptation to combined 5-HT₇ and ethanol factors follows region- and level-specific rules, rather than a single global program, underscoring the value of integrative analysis. Full article

Background/Objectives: Combination therapy for schizophrenia may exacerbate side effects mediated by multiple brain receptors. This study aimed to elucidate the pharmacodynamic and pharmacokinetic interactions between chlorpromazine and risperidone. We investigated dopamine 2 (D₂), serotonin 2A (5-HT_2A), histamine 1 (H₁), and muscarinic acetylcholine (mACh) receptor occupancy in the brain as well as pharmacokinetic interactions after oral administration of chlorpromazine and risperidone in rats. Methods: Rats were orally administered chlorpromazine, risperidone, or their combination. A tracer cocktail solution was injected intravenously to measure multiple receptor occupancies simultaneously. Tracer and drug concentrations in the brain tissue and plasma were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: Receptor occupancy increased in a dose-dependent manner. The doses required for 70% D₂ receptor occupancy were 4.5 mg/kg for chlorpromazine and 1.5 mg/kg for risperidone. Co-administration of chlorpromazine (4.5 mg/kg) and risperidone (1.5 mg/kg) resulted in an increase in D₂ and 5-HT_2A receptor occupancy to approximately 90%. Risperidone alone caused a transient increase in H₁ receptor occupancy to 80%, while co-administration increased mACh receptor occupancy to 60%. Co-administration with chlorpromazine significantly increased the plasma concentrations of risperidone and its metabolite, paliperidone, and decreased the oral clearance of risperidone by 5.9-fold. Conclusions: Co-administration of chlorpromazine and risperidone increases the occupancy of D₂, 5-HT_2A, and mACh receptors in the rat brain and increases the plasma concentrations of risperidone and paliperidone, suggesting a potential risk of enhanced adverse effects due to both pharmacokinetic and pharmacodynamic interactions involving target and non-target brain receptors. Full article

Background: Suppressor of Cytokine Signalling 6 (SOCS6) is a cytokine signalling suppressor that regulates receptor tyrosine kinase pathways by promoting degradation of signalling proteins, thereby controlling cell growth and survival. One of these tyrosine kinase receptors, Erythropoietin Receptor (EPOR), plays a critical role in CRC progression by enhancing tumour metabolism, angiogenesis, proliferation, and growth. This study investigates the molecular mechanisms governing SOCS6’s role in CRC pathogenesis using in vitro cell models and examines its interaction with EPOR expression following gene knockdown. Methods: Bioinformatics interaction between SOCS6 and EPOR were investigated using molecular visualization. HT-29 and COLO 320DM colorectal cancer cells were transfected with SOCS6 siRNA followed by measurement of SOCS6 and EPOR expression levels by qRT-PCR. The selected knockdown concentration was used in functional assays assessing cell viability, colony formation, migration, apoptosis, and invasion. Results: Bioinformatic results showed interaction between SOCS6 and EPOR through polar bonds. Furthermore, SOCS6 silencing increased cell viability and colony formation in both cell lines and significantly enhanced migration in COLO 320DM cells. Active caspase-3 levels were elevated markedly in HT-29 cells post SOCS6 knockdown, consistent with caspase-3’s reported oncogenic role in CRC. Moreover, EPOR knockdown selectively altered SOCS6 expression in HT-29 cells, indicating a regulatory feedback loop. EPOR silencing elevated cell viability at 24 h in both cell lines but caused a significant decrease in COLO 320DM cells at 72 h. Conclusions: These findings identify the SOCS6–EPOR axis as a potential target for personalized CRC therapy, supporting SOCS6’s tumour-suppressive and diagnostic roles. Full article

Background: Neuroblastoma is the most common extracranial solid malignancy in infants and children. High-risk neuroblastoma patients are commonly treated with temozolomide (TMZ), which typically exhibits a poor therapeutic response. Serotonin, also known as 5-hydroxytryptamine (5-HT), plays various essential functions in the human body. In the central nervous system, it serves as a neurotransmitter. Beyond its physiological roles, 5-HT has recently been identified as a potential growth factor for several human tumors, including gliomas and carcinoid tumors. Recent literature has demonstrated that 5-HT receptor antagonists can inhibit the growth of cancer cells. Furthermore, both 5-HT receptors and their antagonists have been identified as potential anticancer agents, suggesting their significance in the development of new treatment strategies. Objectives: The primary aim of this study was to examine the effects of 5-HT and 5-HT antagonists on tumor (neuroblastoma (SH-SY5Y)) and healthy cells (microglia (HMC3)) and determine the impact of their interaction with the anticancer agent TMZ on cell proliferation/viability and migration. Methods: The study explored the interaction between 5-HT, the 5-HT antagonist granisetron (GRN), the anticancer agent TMZ, and their combinations, specifically assessing their influence on cell proliferation, viability, and migration. Results: As a result, the single and combined applications of 5-HT, TMZ, and GRN, a 5-HT antagonist, inhibited cell growth and proliferation in SH-SY5Y, causing decreased cell viability. Additionally, the combination of 5-HT and GRN increased the efficacy of TMZ. Conclusions: The study findings revealed that 5-HT and 5-HT antagonists may have therapeutic effects by exhibiting antiproliferative effects in SH-SY5Y cells at high concentrations. Full article

Growing evidence suggests that psychiatric disorders are characterized by a prolonged inflammatory state, which may influence the efficacy of compounds targeting serotonin. Serotonin is a key signaling molecule in neuroplasticity of the adult hippocampus and involved in antidepressant action. Recent in vitro studies indicate the neurotransmitter may also facilitate the response to inflammation and potentially modulate microglial function towards neuroprotection. Using Tph2^−/− rats depleted of brain serotonin, we examined microglial expression of various serotonin receptors (5-HTRs) in vivo in both the hippocampus and prefrontal cortex and assessed mRNA levels of cytokines and brain-derived neurotrophic factor (BDNF). We observed age-dependent and region-specific gene expression of 5-HTRs on sorted microglia, paralleling changes in BDNF signaling, especially with 5-HT2b. Notably, both 5-HT2b and BDNF expression in the hippocampus was significantly upregulated in the absence of brain serotonin. Our data indicate distinct roles of 5-HTR subtypes in early network formation (5-HT1b, 5-HT5b) and in the response to endogenous changes (5-HT2b, 5-HT5a). Understanding serotonin–microglia interplay could offer therapeutic insights into the maintenance of mood via brain–immune cell interactions. Full article

Parvovirus B19 (B19V) is a human ssDNA virus with ample pathogenic potential. It is characterized by a selective tropism for erythroid progenitor cells (EPC), exerting a cytotoxic effect with blockade of erythropoiesis. In our work, we investigated both viral and cellular expression profile in the course of infection of EPCs cultures via mRNA high throughput sequencing technology (HTS) and a dedicated bioinformatic pipeline, reconstructing both the viral and cellular transcriptome and their variations. A productive infection was confirmed as restricted to EPCs expressing mature differentiation markers and the specific receptor for virus VP1u region. mRNA HTS reconstructed the viral transcriptome in terms of localization and abundance of the different mRNA species, detailing the differential expression profile of B19V among early or late times in the course of infection. Analysis of cellular transcriptome indicated that variation was mainly driven by the cellular differentiation process, with the virus impacting to a lesser level, but still clearly separating infected vs. non-infected profiles. At early times post-infection, variations were typical of cellular sensing of viral infection and aimed at the induction of an antiviral state. At later times in the course of infection, the cellular population showed induction of an inflammatory response, related to TNF and IL-10, and a transition to adaptive immunity with evidence of upregulation of genes involved in MHC-II presentation. This dual-transcriptome analysis on infected EPCs population can lay the ground for future research aimed at a better definition of the pathogenetic mechanisms of B19V. Full article

The renin–angiotensin–aldosterone system (RAAS) is essential for controlling blood pressure and maintaining fluid balance, driving significant structural changes throughout the cardiovascular system, including the heart and blood vessels. As a result, the RAAS is a key therapeutic target for various chronic cardiovascular diseases, ranging from arterial hypertension (AH) to heart failure (HF). In this review, one of our objectives is to describe the new evidence over the last 4 years regarding the RAAS. Moreover, we pay attention to the structure and function of the angiotensin II type 1 receptor (AT1R) and its role in hypertension, as well as define its active site. Later, we discuss the most potent, selective inhibitors of AT1 receptors, based on in vitro and in vivo experiments, from 2020 to 2024. Large peptide molecules, small non-peptide-like molecules, and sartan derivatives are analyzed. The low IC₅₀ values of the entities that do not resemble sartans showcase the vast chemical space that can be explored for the creation of more potent antihypertensive medications. We have also employed computational chemistry tools in order to identify key molecular interactions between the compounds of the literature studied in order to elucidate the underlying reasons why these different molecules exhibit variations in their binding energies and overall potency. Full article

Prolonged periods of sailing may contribute to the development of functional constipation, which can significantly impair an individual’s work efficiency. Currently, the efficacy of Bifidobacteria in treating functional constipation is gaining recognition. However, since the therapeutic effects of Bifidobacteria are strain-specific, further research is required on strains isolated from pre-voyage fecal samples. This study examines the role of gut microbiota in post-stroke constipation, aiming to identify specific microbial biomarkers for the development of targeted therapeutic strategies. B. adolescentis was identified through metagenomic analysis and subsequently isolated for validation. In the experimental group (EG), C57BL/6J mice received fecal suspension treatment following a 12-day navigation period, which was subsequently followed by a 12-day oral administration of B. adolescentis. After treatment, EG significantly improved fecal volume, intestinal motility, and goblet cells; reversed microbial ecological imbalance; reduced pathogens (E. coli and Klebsiella) by restoring arginine/bile acid metabolism, decreasing Tauro-ursodeoxycholic acid (TUDCA) content, 5-Hydroxytryptamine 4 Receptor (5-HT4R)/Slc8a1 signaling, and Ca²⁺ signaling pathway; and restoring beneficial species (B. adolescentis, Pseudomonas aeruginosa). This study provides new insights into probiotics in improving human intestinal health. Full article

It has been demonstrated that prolonged exposure to stress engenders a plethora of neuropsychiatric, immune and metabolic disorders. However, its pathophysiology transcends the conventional hypothalamic–pituitary–adrenal (HPA) axis. This review addresses the central question of how integrated neural and microbial pathways regulate stress responses and resilience. We present a model in which the parasympathetic nervous system (particularly the vagus nerve) and the gut microbiota interact to form a bidirectional neuroimmune network that modulates the HPA axis, immune function, neurotransmitter balance, and metabolic adaptation. Key molecular pathways include nitric oxide synthesis via the classical nitric oxide synthase (NOS)-dependent and microbiota-mediated nitrate–nitrite routes, inducible nitric oxide synthase (iNOS) regulation, nuclear factor erythroid 2-related factor 2 (Nrf2) signalling, lysosomal function, autophagy and the cholinergic anti-inflammatory reflex. Other pathways include the gamma-aminobutyric acid (GABA) and serotonin (5-HT) systems, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signalling, polyamine metabolism and peroxisome proliferator-activated receptor gamma (PPARγ). Intermittent hypoxia training (IHT) enhances mitochondrial function, oxidative stress responses, autonomic balance and gut microbiota composition. This promotes parasympathetic activity and stress resilience that is tailored to the individual. These adaptations support the concept of personalised stress response profiles based on hypoxic adaptability. Clinical implications include combining IHT with vagus nerve stimulation, probiotics, dietary strategies, and stress reduction techniques. Monitoring vagal tone and microbiota composition could also serve as predictive biomarkers for personalised interventions in stress-related disorders. This integrative framework highlights the therapeutic potential of targeting the parasympathetic system and the gut microbiota to modulate stress. Full article

Background/Objectives: The therapeutic potential of selective trace amine-associated receptor 1 (TAAR1) agonists has been established in multiple animal models of depression and anxiety. PTSD is a debilitating psychiatric disorder frequently characterized by anxiety and often comorbid with major depressive disorder. Complex PTSD represents an even more severe clinical presentation, emerging from prolonged or repeated exposure to traumatic events. Recent studies indicate that TAAR1 agonists can attenuate anxiety-like behaviors in experimental models of PTSD; however, the molecular mechanisms underlying this effect remain poorly understood. In this study, we evaluated whether TAAR1 agonism modulates PTSD-related neurochemical and molecular changes within the hippocampus and striatum. Methods: Post-traumatic stress was modeled using predator stress, a validated experimental paradigm relevant to complex PTSD. Treatment consisted of intraperitoneal administration of the TAAR1 agonist LK00764. Monoamine neurotransmitters and their metabolites were quantified, and the expression of genes implicated in noradrenergic, dopaminergic, and serotonergic signaling pathways was assessed. In addition, gene network reconstruction was performed using artificial intelligence to identify TAAR1-dependent regulatory interactions. Results: Treatment with a TAAR1 agonist fully prevented behavioral abnormalities in the experimental model of complex PTSD. Neurochemical analyses revealed decreased 5-HT levels in the hippocampus and reduced dopamine and metabolite concentrations in the striatum following TAAR1 agonism. Moreover, TAAR1 activation was associated with increased expression of the neurotrophic factor BDNF in the striatum. Gene network reconstruction identified a distinct molecular hub within the PTSD network, comprising TAAR1-coexpressed genes, their encoded proteins, and interconnected signaling pathways, suggesting a tightly regulated feedback loop. Conclusions: These findings provide novel evidence that TAAR1 agonists exert protective effects against complex PTSD-related behavioral and neurochemical abnormalities. The reconstructed TAAR1-centered gene network offers mechanistic insight into receptor-dependent regulation of monoaminergic signaling and neuroplasticity, supporting further exploration of TAAR1 agonists as promising therapeutic candidates for PTSD. Full article

Serotonin receptors, in particular 5-HT_1A and 5-HT_2A receptors, are important molecular targets for the central nervous system (CNS) disorders, such as schizophrenia, depression, anxiety disorders, memory deficits, and many others. Here, we present structural and pharmacological evaluation of a serotonin receptor ligand, SERAAK2, identified in a structure-based virtual screening campaign. Molecular docking studies revealed that SERAAK2 binds with its molecular targets via Asp3.32 as the main anchoring point, which is typical for orthosteric ligands of aminergic GPCRs. Molecular dynamics simulations confirmed the stability of the ligand binding poses in the studied receptors. MMGBSA calculations were in accordance with the receptor in vitro binding affinity studies, which indicated that SERAAK2 is a potent ligand of 5-HT_1A and 5-HT_2A receptors. It was also found that SERAAK2 displays favorable ADMET parameters. The demonstrated anxiolytic- and antidepressant-like effects of SERAAK2 in animal models, which may involve its interaction with 5-HT_1A receptors, warrant further studies to confirm these activities and elucidate the underlying mechanisms. Full article