Search Results (1,869)

Antibody-dependent enhancement (ADE) is a well-established mechanism of pathology in several viral diseases, but its relevance in COVID-19 is not yet recognized. Although several studies in humans have shown an association between antibody responses and disease severity, long term studies addressing the presence of antibodies before infection and their neutralization capacity are needed to establish ADE. Mechanistic studies have determined that the entry of SARS-CoV-2 into host cells can be mediated by immune complexes through Fcγ receptors or by favoring ACE2 conformation. However, the impact on viral replication is not clear. There is evidence for enhancing effects of immune complexes on Fcγ receptor-mediated effector mechanisms and cytokine secretion after modulation of cell signaling in immune cells, specially by antibodies with altered glycosylation, which points to ADE that can contribute to COVID-19 pathology. However, more studies are needed to determine the impact of antibodies both in naturally infected and vaccinated subjects, which can lead to their use as a prognostic marker and increase vaccine safety. Full article

Traumatic brain injury (TBI) leads to persistent pro-inflammatory microglial activation implicated in neurodegeneration. Idebenone, a coenzyme Q10 analogue that interacts with both mitochondria and the tyrosine kinase adaptor SHC1, inhibits aspects of microglial activation in vitro. We used the NanoString neuropathology Panel to test the hypothesis that idebenone post-treatment mitigates TBI-pathology-associated acute gene expression changes by moderating the pro-inflammatory microglial response to injury. Controlled cortical impact to adult male mice increased the microglial activation signature in the peri-lesional cortex at 24 h post-TBI. Unexpectedly, several microglial signature genes upregulated by TBI were further increased by post-injury idebenone administration. However, idebenone significantly attenuated TBI-mediated perturbations to gene expression associated with behavior, particularly in the gene ontology–biological process (GO:BP) pathways “ephrin receptor signaling” and “dopamine metabolic process”. Gene co-expression analysis correlated levels of microglial complement component 1q (C1q) and the neurotrophin receptor gene Ntrk1 to large (>3-fold) TBI-induced decreases in dopamine receptor genes Drd1 and Drd2 that were mitigated by idebenone treatment. Bioinformatics analysis identified SUZ12 as a candidate transcriptional regulator of idebenone-modified gene expression changes. Overall, the results suggest that idebenone may enhance TBI-induced microglial number within the first 24 h of TBI and identify ephrin-A and dopamine signaling as novel idebenone targets. Full article

This study investigated the role of exosomes in the pathological processes of gouty arthritis (GA), with the aim of clarifying their mechanistic role and pathological significance in the onset and progression of GA. Using a rat model of GA established through potassium oxonate and yeast gavage combined with intra-articular monosodium urate (MSU) injection, we isolated and characterized plasma exosomes using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Differential exosomal protein expression was analyzed using 4D label-free proteomics technology, followed by GO and KEGG enrichment analyses, and protein–protein interaction (PPI) network construction to identify core targets. In vivo experiments measured the expression levels of CTSD in synovial tissues and joint fluid, as well as HPRT1 in renal tissues, while in vitro experiments involved co-culturing NRK cells with exosomes to validate target protein expression. The results indicated that serum uric acid levels were significantly elevated in the model group (p < 0.01), accompanied by pronounced joint swelling and inflammation. Exosome characterization confirmed their typical bilayer membrane structure and the expression of marker proteins (CD63/TSG101). Proteomic analysis identified 40 differentially expressed proteins (12 upregulated and 28 downregulated) enriched in pathways such as complement and coagulation cascades, autophagy, lysosomal function, and purine metabolism. In vivo and in vitro experiments demonstrated significantly increased CTSD expression (p < 0.05/p < 0.01) and decreased HPRT1 expression (p < 0.05/p < 0.01) in the model group, suggesting that exosomes are involved in the occurrence and development of GA by regulating purine metabolism and lysosomal dysfunction. These findings offer new insights into disease mechanisms and potential therapeutic targets. Full article

Occupational health monitoring in demolition environments requires precise detection of blast-dust-induced pulmonary pathologies. However, it is often hindered by challenges such as contaminated imaging biomarkers, limited access to medical resources in mining areas, and opaque AI-based diagnostic models. This study presents a novel computational framework that combines industrial-grade robustness with clinical interpretability for the diagnosis of pulmonary nodules. We propose a hybrid framework that integrates morphological purification techniques (multi-step filling and convex hull operations) with multi-dimensional features fusion (radiomics + lightweight deep features). To enhance computational efficiency and interpretability, we design a soft voting ensemble classifier, eliminating the need for complex deep learning architectures. On the LIDC-IDRI dataset, our model achieved an AUC of 0.99 and an accuracy of 0.97 using standard clinical-grade hardware, outperforming state-of-the-art (SOTA) methods while requiring fewer computational resources. Ablation studies, feature weight maps, and normalized mutual information heatmaps confirm the robustness and interpretability of the model, while uncertainty quantification metrics such as the Brier score and Expected Calibration Error (ECE) better validate the model’s clinical applicability and prediction stability. This approach effectively achieves resource-accuracy co-optimization, maintaining low computational costs, and is highly suitable for resource-constrained clinical environments. The modular design of our framework also facilitates extensions to other medical imaging domains without the need for high-end infrastructure. Full article

SARS-CoV-2 can cause neurological issues, including cognitive dysfunction in COVID-19 survivors. Endothelial dysfunction, a key mechanism in COVID-19, is also a risk factor for vascular dementia (VaD). Reduced nitric oxide (NO) bioavailability is a pathogenic factor of endothelial dysfunction and platelet aggregation in COVID-19 patients, and endothelial NO synthase (eNOS) levels decline with advancing age, a risk factor for both COVID-19 morbidity and VaD. SARS-CoV-2 also induces cellular senescence and senescence-associated secretory phenotype (SASP). We hypothesized that eNOS deficiency would worsen neuroinflammation, senescence, blood–brain barrier (BBB) permeability, and hypercoagulability in eNOS-deficient mice. Six-month-old eNOS^+/− (pre-cognitively impaired experimental VaD) and wild-type (WT) male mice were infected with mouse-adapted (MA10) SARS-CoV-2. Mice were evaluated for weight loss, viral load, and markers of inflammation and senescence 3 days post-infection. eNOS^+/− mice showed more weight loss (~15%) compared to WT mice (~5%) and increased inflammatory markers (Ccl2, Cxcl9, Cxcl10, IL-1β, and IL-6) and senescence markers (p53 and p21). They also exhibited higher microglial activation (Iba1) and increased plasma coagulation and BBB permeability, despite comparable lung viral loads and absence of virus in the brain. This is the first experimental evidence demonstrating that eNOS deficiency exacerbates SARS-CoV-2-induced morbidity, neuroinflammation, and brain senescence, linking eNOS to COVID-19-related neuropathology. Full article

Astaxanthin (ASX) is a xanthophyll carotenoid mainly derived from marine microalgae such as Haematococcus pluvialis and Chlorella zofingiensis, as well as the yeast Phaffia rhodozyma. Its chemical nature structure, rich in conjugated double bonds, carbonyl, and hydroxyl groups, confers potent antioxidant and anti-inflammatory properties. ASX modulates oxidative stress via the PI3K/Akt-Nrf2 pathway and suppresses NF-κB-mediated inflammatory responses, reducing cytokine levels such as TNF-α, IL-6, and iNOS. ASX exerts dual apoptotic effects, cytoprotective in non-transformed cells and pro-apoptotic in cancer cells through p53 activation. Sustainable extraction techniques, especially supercritical CO₂, have improved its industrial applicability. Recent findings highlight ASX’s role in stem cell biology, enhancing proliferation, supporting lineage-specific differentiation, and protecting against oxidative and inflammatory damage, which is a crucial issue for regenerative medicine applications. These multifaceted molecular effects support ASX’s therapeutic potential in chronic diseases, including diabetes, cardiovascular pathologies, and cancer. This review outlines ASX’s natural sources, extraction methods, and biological mechanisms, emphasizing its application in oxidative stress- and inflammation-related conditions. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) pandemic that devastated the world. While this is a respiratory virus, one feature of the SARS-CoV-2 infection was recognized to cause pathogenesis of other organs. Because the membrane fusion protein of SARS-CoV-2, the spike protein, binds to its major host cell receptor angiotensin-converting enzyme 2 (ACE2), which regulates a critical mediator of cardiovascular diseases, angiotensin II, COVID-19 is largely associated with vascular pathologies. The present study examined the pulmonary vasculature of COVID-19 patients using large sample sizes and provides mechanistic information through histological observations. We studied 56 postmortal lung samples from COVID-19 patients. The comparative group consisted of 17 postmortal lung samples from patients who died of influenza A virus subtype H1N1. The examination of 56 autopsy lung samples showed thickened vascular walls of small pulmonary arteries after 14 days of disease compared to H1N1 influenza patients who died before the COVID-19 pandemic started. Pulmonary vascular remodeling in COVID-19 patients was associated with hypertrophy of the smooth muscle layer, perivascular fibrosis, edema and lymphostasis, inflammatory infiltration, perivascular hemosiderosis, and neoangiogenesis. We found a correlation between the duration of hospital stay and the thickness of the muscular layer of the pulmonary arterial walls. These results demonstrate that COVID-19 significantly affected the pulmonary vasculature in fatal-course patients, also suggesting the need for careful follow-up in non-fatal cases, at risk of pulmonary hypertension. Full article

Heart failure with preserved ejection fraction (HFpEF) is increasingly recognized as a systemic disorder, often coexisting with chronic obstructive pulmonary disease (COPD). This study aims to identify the shared pathogenic mechanisms between HFpEF and COPD and validate them in an experimental HFpEF model. Transcriptomic datasets from HFpEF cardiac tissue and COPD lung tissue were analyzed using differentially expressed gene (DEG) analysis, weighted gene co-expression network analysis (WGCNA), and functional enrichment analysis. Key genes were identified through least absolute shrinkage and selection operator (LASSO) regression. Immune cell infiltration was assessed using xCell and CIBERSORT, and single-cell RNA sequencing (scRNA-seq) was utilized to determine gene expression patterns across different cell populations. A high-fat diet and N[w]-nitro-L-arginine methyl ester (L-NAME)-induced HFpEF mouse model was established, and the expression of SESN3 and autophagy-related markers was evaluated in both cardiac and pulmonary tissues using immunofluorescence, quantitative PCR (qPCR), Western blotting (WB), and transmission electron microscopy. DEG and WGCNA analyses identified 1243 and 131 core genes in HFpEF and COPD, respectively. Functional enrichment analysis highlighted autophagy as a common regulatory pathway in both conditions. Among the nine intersecting genes, SESN3 was identified as a key candidate through LASSO regression. Immune infiltration analysis and scRNA-seq further demonstrated the involvement of SESN3 in both cardiac and pulmonary pathophysiology. In vivo experiments showed that HFpEF mice exhibited significant lung injury. Furthermore, SESN3 upregulation and autophagy dysregulation were observed in both heart and lung tissues, supporting a potential systemic role of SESN3-mediated autophagy in HFpEF-related pulmonary alterations. This study suggests that SESN3-mediated autophagy may represent a shared mechanism between HFpEF and COPD. Our findings suggest that HFpEF may be associated with pulmonary alterations beyond cardiac dysfunction alone. These results provide novel insights into the potential multi-organ involvement in HFpEF and support the role of SESN3 as a shared molecular target in both cardiac and pulmonary pathologies. Full article

The proteolytic processing of the SARS-CoV-2 spike glycoprotein by host cell membrane-associated proteases is a key step in both the entry of the invading virus into the cell and the release of the newly generated viral particles from the infected cell. Because of the critical importance of this step for the viral infectivity cycle, it has been a target of extensive efforts aimed at identifying highly specific protease inhibitors as potential antiviral agents. An alternative strategy to disrupt the pre-fusioviden processing of the SARS-CoV-2 S glycoprotein aims to protect the substrate rather than directly inhibit the proteases. In this work, we focused on furin, a serine protease located primarily in the Golgi apparatus, but also present on the cell membrane. Its cleavage site within the S glycoprotein is located within the stalk region of the latter and comprises an arginine-rich segment (SPRRARS), which fits the definition of the Cardin–Weintraub glycosaminoglycan recognition motif. Native mass spectrometry (MS) measurements confirmed the binding of a hexadecameric peptide representing the loop region at the S1/S2 interface and incorporating the furin cleavage site (FCS) to heparin fragments of various lengths, as well as unfractionated heparin (UFH), although at the physiological ionic strength, only UFH remains tightly bound to the FCS. The direct LC/MS monitoring of FCS digestion with furin revealed a significant impact of both heparin fragments and UFH on the proteolysis kinetics, although only the latter had IC50 values that could be considered physiologically relevant (0.6 ± 0.1 mg/mL). The results of this work highlight the importance of the long-range and relatively non-specific electrostatic interactions in modulating physiological and pathological processes and emphasize the multi-faceted role played by heparin in managing coronavirus infections. Full article

Vascular calcification is a critical pathological hallmark of cardiovascular diseases. Although previous studies have indicated that M1 macrophages significantly promote calcification, the exact underlying mechanisms remain unclear. This study examined whether semaphorin 4D (Sema4D), a class IV semaphorin involved in atherosclerosis development, is secreted by M1 macrophages and contributes to the calcification of vascular smooth muscle cells (VSMCs). We observed elevated expression and secretion of Sema4D in both M1 and M2 macrophages, with significantly higher levels in M1-polarized cells. M1 macrophages promoted VSMC calcification in both co-culture and conditioned medium systems, as evidenced by increased alkaline phosphatase activity, enhanced calcium deposition, and upregulation of osteogenic markers. Notably, neutralization of Sema4D in M1 conditioned medium using pepinemab, an anti-Sema4D antibody, effectively attenuated VSMC calcification induced by M1 macrophages. Conversely, supplementation of conditioned medium with recombinant Sema4D enhanced calcification and osteogenic signaling in VSMCs, further supporting the pro-calcifying role of Sema4D. Collectively, these findings highlight macrophage-derived Sema4D as a pivotal regulator of vascular calcification and a promising therapeutic target. Full article

A hallmark of type 2 diabetes mellitus (T2DM) is the presence of abundant amyloid deposits composed of amyloid polypeptide (amylin) within the pancreatic islets of Langerhans. Given its high prevalence among diabetic individuals, human amylin fibrillization has long been considered a key pathogenic factor in T2DM. Co-secreted with insulin, amylin can misfold and aggregate, inducing β-cell toxicity, impairing insulin secretion, and accelerating disease progression. Emerging evidence also indicates that amylin accumulates in the brains of patients with Alzheimer’s disease, where it may interact with amyloid-β (Aβ) to promote neurodegeneration. Although the underlying mechanisms remain under investigation, amylin aggregates have been shown to disrupt mitochondrial function, trigger endoplasmic reticulum stress, and activate the NLRP3 inflammasome. Additionally, T2DM-associated cerebrovascular alterations may compound cognitive decline. This review, based on a comprehensive literature search across major biomedical databases up to January 2025, synthesizes current evidence on amylin as a molecular link between metabolic and neurodegenerative disorders. We highlight pancreatic β-cell amylin aggregation as a potential early marker of dementia risk in T2DM and examine its relationship with proteostasis-associated proteins. Finally, we discuss emerging diagnostic and therapeutic strategies targeting amylin pathology, offering new perspectives on preventing or delaying neurodegeneration in individuals with T2DM. Full article

The coronavirus disease 2019 (COVID-19) pandemic has been linked to long-term neurological effects with multifaceted complications of neurodegenerative diseases. Several studies have found that pathological changes in transactive response DNA-binding protein of 43 kDa (TDP-43) are involved in these cases. This review explores the causal interactions between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and TDP-43 from multiple perspectives. Some viral proteins of SARS-CoV-2 have been shown to induce pathological changes in TDP-43 through its cleavage, aggregation, and mislocalization. SARS-CoV-2 infection can cause liquid−liquid phase separation and stress granule formation, which accelerate the condensation of TDP-43, resulting in host RNA metabolism disruption. TDP-43 has been proposed to interact with SARS-CoV-2 RNA, though its role in viral replication remains to be fully elucidated. This interaction potentially facilitates viral replication, while viral-induced oxidative stress and protease activity accelerate TDP-43 pathology. Evidence from both clinical and experimental studies indicates that SARS-CoV-2 infection may contribute to long-term neurological sequelae, including amyotrophic lateral sclerosis-like and frontotemporal dementia-like features, as well as increased phosphorylated TDP-43 deposition in the central nervous system. Biomarker studies further support the link between TDP-43 dysregulation and neurological complications of long-term effects of COVID-19 (long COVID). In this review, we presented a novel integrative framework of TDP-43 pathology, bridging a gap between SARS-CoV-2 infection and mechanisms of neurodegeneration. These findings underscore the need for further research to clarify the TDP-43-related neurodegeneration underlying SARS-CoV-2 infection and to develop therapeutic strategies aimed at mitigating long-term neurological effects in patients with long COVID. Full article

Dendritic cells (DCs) are critical regulators of immune homeostasis, balancing tolerance and immunity through antigen presentation and T cell modulation. While the influence of hypoxia (<2% O₂) on DC function in pathological settings is well-documented, the impact of physiological O₂ levels remains underexplored. This study investigates the role of physioxia (4% O₂) in programming mature DCs toward a tolerogenic phenotype compared to atmospheric conditions (21% O₂) typically present in in vitro assays. DC cultures generated under 4% O₂ exhibited a reduced monocyte-to-DC transformation rate, increased lactate production, a semi-mature surface marker profile, and increased surface expression of the tolerance-associated marker ILT4. T cell priming was altered only when atmospheric DCs were co-cultured under physioxia, suggesting an O₂-dependent threshold for immunostimulatory capacity. These findings highlight the complexity of O₂-dependent mechanisms in DC-T cell interactions, revealing a delicate balance between tolerance and immunogenicity. Our results underscore the need for physiologically relevant O₂ conditions in DC research to better reflect in vivo behavior and inform immunotherapy design. Overall, this study advances understanding of how microenvironmental cues shape DC biology, with implications for immune tolerance, autoimmunity, and cancer immunotherapy. Full article

The intestinal health and functionality of animals play pivotal roles in nutrient digestion and absorption, as well as in maintaining defense against pathogenic invasions. These biological processes are modulated by various determinants, including husbandry conditions, dietary composition, and gut microbial ecology. The excessive use of anthropogenic antibiotics may disrupt intestinal microbiota composition, potentially leading to dysbiosis that directly compromises host homeostasis. While Lactobacillus species are recognized for their immunomodulatory properties, their precise mechanisms in regulating host anti-inflammatory gene expression and influencing mucosal layer maturation, particularly regarding E. coli colonization resistance, require further elucidation. To investigate the regulatory mechanisms of Lactobacillus in relation to intestinal architecture and function during E. coli infection, we established a colonic infection model using Bal b/c mice, conducting systematic analyses of intestinal morphology, inflammatory mediator profiles, and microbial community dynamics. Our results demonstrate that Lactobacillus supplementation (Pediococcus acidilactici) effectively mitigated E. coli O78-induced enteritis, with co-administration during infection facilitating the restoration of physiological parameters, including body mass, intestinal histoarchitecture, and microbial metabolic functions. Microbiome profiling revealed that the Lactobacillus intervention significantly elevated Lactococcus abundance while reducing Weissella populations (p < 0.05), concurrently enhancing metabolic pathways related to nutrient assimilation and environmental signal processing (including translation mechanisms, ribosomal biogenesis, amino acid transport metabolism, and energy transduction systems; p < 0.05). Mechanistically, Lactobacillus administration attenuated E. coli-induced intestinal pathology through multiple pathways: downregulating pro-inflammatory cytokine expression (IL-1β, IL-1α, and TNF-α), upregulating epithelial junctional complexes (Occludin, Claudin-1, and ZO-1), and stimulating mucin biosynthesis (MUC1 and MUC2; p < 0.05). These modifications collectively enhanced mucosal barrier integrity and promoted epithelial maturation. This investigation advances our comprehension of microbiota–host crosstalk during enteropathogenic infections under probiotic intervention, offering valuable insights for developing novel nutritional strategies and microbial management protocols in animal husbandry. Full article

Introduction: Coronavirus (CoV) is an extremely contagious, enveloped positive-single-stranded RNA virus, which has become a global pandemic that causes several illnesses in humans and animals. Hence, it is necessary to investigate viral-induced reactions across diverse hosts. Herein, we propose utilizing naturally secreted extracellular vesicles (EVs), mainly focusing on exosomes to examine virus–host responses following CoV infection. Exosomes are small membrane-bound vesicles originating from the endosomal pathway, which play a pivotal role in intracellular communication and physiological and pathological processes. We suggested that CoV could impact EV formation, content, and diverse immune responses in vitro. Methods: In this study, we infected A-72, which is a canine fibroblast cell line, with a feline coronavirus (FCoV) and canine coronavirus (CCoV) independently in an exosome-free media at 0.001 multiplicity of infection (MOI), with incubation periods of 48 and 72 h. The cell viability was significantly downregulated with increased incubation time following FCoV and CCoV infection, which was identified by performing the 3-(4,5-dimethylthiazo-1-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. After the infection, EVs were isolated through ultracentrifugation, and the subsequent analysis involved quantifying and characterizing the purified EVs using various techniques. Results: NanoSight particle tracking analysis (NTA) verified that EV dimensions fell between 100 and 200 nm at both incubation periods. At both periods, total protein and RNA levels were significantly upregulated in A-72-derived EVs following FCoV and CCoV infections. However, total DNA levels were gradually upregulated with increased incubation time. Dot blot analysis indicated that the expression levels of ACE2, IL-1β, Flotillin-1, CD63, caspase-8, and Hsp90 were modified in A-72-derived EVs following both CoV infections. Conclusions: Our results indicated that FCoV and CCoV infections could modulate the EV production and content, which could play a role in the development of viral diseases. Investigating diverse animal CoV will provide in-depth insight into host exosome biology during CoV infection. Hence, our findings contribute to the comprehension and characterization of EVs in virus–host interactions during CoV infection. Full article