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The Journal of Clinical Investigation Jun 2024Neutrophil infiltration occurs in a variety of liver diseases, but it is unclear how neutrophils and hepatocytes interact. Neutrophils generally use granule proteases to...
Neutrophil infiltration occurs in a variety of liver diseases, but it is unclear how neutrophils and hepatocytes interact. Neutrophils generally use granule proteases to digest phagocytosed bacteria and foreign substances or neutralize them in neutrophil extracellular traps. In certain pathological states, granule proteases play a destructive role against the host as well. More recently, non-destructive actions of neutrophil granule proteins have been reported, such as modulation of tissue remodeling and metabolism. Here we report a completely different mechanism by which neutrophils act non-destructively, by inserting granules directly into hepatocytes. Specifically, elastase-containing granules were transferred to hepatocytes where elastase selectively degraded intracellular calcium channels to reduce cell proliferation without cytotoxicity. In response, hepatocytes increased expression of serpin E2 and A3, which inhibited elastase activity. Elastase insertion was seen in patient specimens of alcohol-associated hepatitis, and the relationship between elastase-mediated ITPR2 degradation and reduced cell proliferation was confirmed in mouse models. Moreover, neutrophils from patients with alcohol-associated hepatitis were more prone to degranulation and more potent in reducing calcium channel expression than neutrophils from healthy subjects. This non-destructive and reversible action on hepatocytes defines a previously unrecognized role for neutrophils in the transient regulation of epithelial calcium signaling mechanisms.
PubMed: 38916955
DOI: 10.1172/JCI171691 -
Microbiology Spectrum Jun 2024Tuberculosis (TB) is a leading cause of death among infectious diseases worldwide due to latent TB infection, which is the critical step for the successful pathogenic...
UNLABELLED
Tuberculosis (TB) is a leading cause of death among infectious diseases worldwide due to latent TB infection, which is the critical step for the successful pathogenic cycle. In this stage resides inside the host in a dormant and antibiotic-tolerant state. Latent TB infection can also lead to multisystemic diseases because invades virtually all organs, including ocular tissues. Ocular tuberculosis (OTB) occurs when the dormant bacilli within the ocular tissues reactivate, originally seeded by hematogenous spread from pulmonary TB. Histological evidence suggests that retinal pigment epithelium (RPE) cells play a central role in immune privilege and in protection from antibiotic effects, making them an anatomical niche for invading . RPE cells exhibit high tolerance to environmental redox stresses, allowing phagocytosed bacilli to maintain viability in a dormant state. However, the microbiological and metabolic mechanisms determining the interaction between the RPE intracellular environment and phagocytosed are largely unknown. Here, liquid chromatography-mass spectrometry metabolomics were used to illuminate the metabolic state within RPE cells reprogrammed to harbor dormant bacilli and enhance antibiotic tolerance. Timely and accurate diagnosis as well as efficient chemotherapies are crucial in preventing the poor visual outcomes of OTB patients. Unfortunately, the efficacy of current methods is highly limited. Thus, the results will lead to propose a novel therapeutic option to synthetically kill the dormant inside the RPE cells by modulating the phenotypic state of and laying the foundation for a new, innovative regimen for treating OTB.
IMPORTANCE
Understanding the metabolic environment within the retinal pigment epithelium (RPE) cells altered by infection with and mycobacterial dormancy is crucial to identify new therapeutic methods to cure ocular tuberculosis. The present study showed that RPE cellular metabolism is altered to foster intracellular to enter into the dormant and drug-tolerant state, thereby blunting the efficacy of anti-tuberculosis chemotherapy. RPE cells serve as an anatomical niche as the cells protect invading bacilli from antibiotic treatment. LC-MS metabolomics of RPE cells after co-treatment with HO and infection showed that the intracellular environment within RPE cells is enriched with a greater level of oxidative stress. The antibiotic tolerance of intracellular within RPE cells can be restored by a metabolic manipulation strategy such as co-treatment of antibiotic with the most downstream glycolysis metabolite, phosphoenolpyruvate.
PubMed: 38916325
DOI: 10.1128/spectrum.00788-24 -
BioRxiv : the Preprint Server For... Jun 2024Immune cells elicit a continuum of transcriptional and functional states after spinal cord injury (SCI). In mammals, inefficient debris clearance and chronic...
Immune cells elicit a continuum of transcriptional and functional states after spinal cord injury (SCI). In mammals, inefficient debris clearance and chronic inflammation impede recovery and overshadow pro-regenerative immune functions. We found that, unlike mammals, zebrafish SCI elicits transient immune activation and efficient debris clearance, without causing chronic inflammation. Single-cell transcriptomics and inducible genetic ablation showed zebrafish macrophages are highly phagocytic and required for regeneration. Cross-species comparisons between zebrafish and mammalian macrophages identified ( ) as a macrophage-enriched zebrafish gene. Genetic deletion of zebrafish impairs phagocytosis and regeneration, causes aberrant and chronic immune activation, and can be rescued by transplanting wild-type immune precursors into mutants. Conversely, genetic expression of human accelerates debris clearance and regeneration by reprogramming myeloid precursors into activated phagocytes. This study establishes a central requirement for elevated phagocytic capacity to achieve innate spinal cord repair.
PubMed: 38915507
DOI: 10.1101/2024.06.11.598515 -
BioRxiv : the Preprint Server For... Jun 2024Patients with cutaneous T cell lymphoma (CTCL) experience high morbidity and mortality due to skin infections and sepsis, but the causative immune defect is unclear. We...
Patients with cutaneous T cell lymphoma (CTCL) experience high morbidity and mortality due to skin infections and sepsis, but the causative immune defect is unclear. We previously identified high levels of LAIR2, a decoy protein for the inhibitory receptor LAIR1, in advanced CTCL. Mice do not have a LAIR2 homolog, so we used knock-out (KO) mice to model LAIR2 overexpression. In a model of subcutaneous skin infection, KO mice had significantly larger abscesses and areas of dermonecrosis compared to WT. KO exhibited a pattern of increased inflammatory responses in infection and sterile immune stimulation, including increased production of proinflammatory cytokines and myeloid chemokines, neutrophil ROS, and collagen/ECM remodeling pathways. Notably, KO infected skin had a similar bacterial burden and neutrophils and monocytes had equivalent phagocytosis compared to WT. These findings support a model in which lack of LAIR1 signaling causes an excessive inflammatory response that does not improve infection control. CTCL skin lesions harbored similar patterns of increased expression in cytokine and collagen/ECM remodeling pathways, suggesting that high levels of LAIR2 in CTCL recapitulates KO, causing inflammatory tissue damage and compromising host defense against infection.
PubMed: 38915487
DOI: 10.1101/2024.06.13.598864 -
International Journal of Nanomedicine 2024Ginsenoside Rg3 (Rg3) and Panax notoginseng saponins (PNS) can be used for ischemic stroke treatment, however, the lack of targeting to the ischemic region limits the...
PURPOSE
Ginsenoside Rg3 (Rg3) and Panax notoginseng saponins (PNS) can be used for ischemic stroke treatment, however, the lack of targeting to the ischemic region limits the therapeutic effect. To address this, we leveraged the affinity of macrophage membrane proteins for inflamed brain microvascular endothelial cells to develop a macrophage membrane-cloaked liposome loaded with Rg3 and PNS (MM-Lip-Rg3/PNS), which can precisely target brain lesion region through intranasal administration.
METHODS
MM-Lip-Rg3/PNS was prepared by co-extrusion method and was performed by characterization, stability, surface protein, and morphology. The cellular uptake, immune escape ability, and blood-brain barrier crossing ability of MM-Lip-Rg3/PNS were studied in vitro. The in vivo brain targeting, biodistribution and anti-ischemic efficacy of MM-Lip-Rg3/PNS were evaluated in MACO rats, and we determined the diversity of the nasal brain pathway through the olfactory nerve blockade model in rats. Finally, the pharmacokinetics and brain targeting index of MM-Lip-Rg3/PNS were investigated.
RESULTS
Our results indicated that MM-Lip-Rg3/PNS was spherical with a shell-core structure. MM-Lip-Rg3/PNS can avoid mononuclear phagocytosis, actively bind to inflammatory endothelial cells, and have the ability to cross the blood-brain barrier. Moreover, MM-Lip-Rg3/PNS could specifically target ischemic sites, even microglia, increase the cumulative number of drugs in the brain, improve the inflammatory environment of the brain, and reduce the infarct size. By comparing olfactory nerve-blocking rats with normal rats, it was found that there are direct and indirect pathways for nasal entry into the brain. Pharmacokinetics demonstrated that MM-Lip-Rg3/PNS exhibited stronger brain targeting and prolonged drug half-life.
CONCLUSION
MM-Lip-Rg3/PNS might contribute to the accumulation of Rg3 and PNS in the ischemic brain area to improve treatment efficacy. This biomimetic nano-drug delivery system provides a new and promising strategy for the treatment of ischemic stroke.
Topics: Animals; Liposomes; Administration, Intranasal; Ischemic Stroke; Rats; Male; Ginsenosides; Blood-Brain Barrier; Macrophages; Drug Delivery Systems; Rats, Sprague-Dawley; Tissue Distribution; Brain; Biomimetic Materials; Saponins; Mice
PubMed: 38911498
DOI: 10.2147/IJN.S458656 -
Experimental and Therapeutic Medicine Aug 2024(CF) is known for its anti-inflammatory, antioxidant and antibacterial activities. However, there is a lack of research on its other pharmacological properties. In the...
(CF) is known for its anti-inflammatory, antioxidant and antibacterial activities. However, there is a lack of research on its other pharmacological properties. In the present study, the bifunctional roles of CF in 3T3-L1 and RAW264.7 cells were investigated, focusing on its anti-obesity and immunostimulatory effects. In 3T3-L1 cells, CF effectively mitigated the accumulation of lipid droplets and triacylglycerol. Additionally, CF downregulated the peroxisome proliferator-activated receptor (PPAR)-γ and CCAAT/enhancer-binding protein α protein levels; however, this effect was impeded by the knockdown of β-catenin using β-catenin-specific small interfering RNA. Consequently, CF-mediated inhibition of lipid accumulation was also decreased. CF increased the protein levels of adipose triglyceride lipase and phosphorylated hormone-sensitive lipase, while decreasing those of perilipin-1. Moreover, CF elevated the protein levels of phosphorylated AMP-activated protein kinase and PPARγ coactivator 1-α. In RAW264.7 cells, CF enhanced the production of pro-inflammatory mediators, such as nitric oxide (NO), inducible NO synthase, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α, and increased their phagocytic capacities. Inhibition of Toll-like receptor (TLR)-4 significantly reduced the effects of CF on the production of pro-inflammatory mediators and phagocytosis, indicating its crucial role in facilitating these effects. CF-induced increase in the production of pro-inflammatory mediators was controlled by the activation of c-Jun N-terminal kinase (JNK) and nuclear factor (NF)-κB pathways, and TLR4 inhibition attenuated the phosphorylation of these kinases. The results of the pesent study suggested that CF inhibits lipid accumulation by suppressing adipogenesis and inducing lipolysis and thermogenesis in 3T3-L1 cells, while stimulating macrophage activation via the activation of JNK and NF-κB signaling pathways mediated by TLR4 in RAW264.7 cells. Therefore, CF simultaneously exerts both anti-obesity and immunostimulatory effects.
PubMed: 38911047
DOI: 10.3892/etm.2024.12604 -
BMC Musculoskeletal Disorders Jun 2024To analyze the characteristics of PEEK rods retrieved in vivo, specifically their wear and deformation, biodegradability, histocompatibility, and mechanical properties.
PURPOSE
To analyze the characteristics of PEEK rods retrieved in vivo, specifically their wear and deformation, biodegradability, histocompatibility, and mechanical properties.
METHOD
Six PEEK rods were retrieved from revision surgeries along with periprosthetic tissue. The retrieved PEEK rods were evaluated for surface damage and internal changes using Micro-CT, while light and electron microscopy were utilized to determine any histological changes in periprosthetic tissues. Patient history was gathered from medical records. Two intact and retrieved PEEK rods were used for fatigue testing analysis by sinusoidal load to the spinal construct.
RESULTS
All implants showed evidence of plastic deformation around the screw-rod interface, while the inner structure of PEEK rods appeared unchanged with no visible voids or cracks. Examining images captured through light and electron microscopy indicated that phagocytosis of macrophages around PEEK rods was less severe in comparison to the screw-rod interface. The results of an energy spectrum analysis suggested that the distribution of tissue elements around PEEK rods did not differ significantly from normal tissue. During fatigue testing, it was found that the retrieved PEEK rods cracked after 1.36 million tests, whereas the intact PEEK rods completed 5 million fatigue tests without any failure.
CONCLUSION
PEEK rods demonstrate satisfactory biocompatibility, corrosion resistance, chemical stability, and mechanical properties. Nevertheless, it is observed that the indentation at the junction between the nut and the rod exhibits relatively weak strength, making it susceptible to breakage. As a precautionary measure, it is recommended to secure the nut with a counter wrench, applying the preset torque to prevent overtightening.
Topics: Humans; Polymers; Ketones; Benzophenones; Pedicle Screws; Female; Male; Polyethylene Glycols; Middle Aged; Device Removal; Materials Testing; Aged; Biocompatible Materials; Prosthesis Failure; Reoperation
PubMed: 38909212
DOI: 10.1186/s12891-024-07600-0 -
Ferroptosis inhibitor improves outcome after early and delayed treatment in mild spinal cord injury.Acta Neuropathologica Jun 2024We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and...
We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and functional loss in the acute and chronic periods after spinal cord injury (SCI) in young, adult, female mice. Phagocytosis of red blood cells at sites of hemorrhage is the main source of iron derived from hemoglobin after SCI. Expression of hemeoxygenase-1 that induces release of iron from heme, is increased in spinal cord macrophages 7 days after injury. While iron is stored safely in ferritin in the injured spinal cord, it can, however, be released by NCOA4-mediated shuttling of ferritin to autophagosomes for degradation (ferritinophagy). This leads to the release of redox active iron that can cause free radical damage. Expression of NCOA4 is increased after SCI, mainly in macrophages. Increase in the ratio of redox active ferrous (Fe) to ferric iron (Fe) is also detected after SCI by capillary electrophoresis inductively coupled mass spectrometry. These changes are accompanied by other hallmarks of ferroptosis, i.e., deficiency in various elements of the antioxidant glutathione (GSH) pathway. We also detect increases in enzymes that repair membrane lipids (ACSL4 and LPCAT3) and thus promote on-going ferroptosis. These changes are associated with increased levels of 4-hydroxynonenal (4-HNE), a toxic lipid peroxidation product. Mice with mild SCI (30 kdyne force) treated with the ferroptosis inhibitor (UAMC-3203-HCL) either early or delayed times after injury showed improvement in locomotor recovery and secondary damage. Cerebrospinal fluid and serum samples from human SCI cases show evidence of increased iron storage (ferritin), and other iron related molecules, and reduction in GSH. Collectively, these data suggest that ferroptosis contributes to secondary damage after SCI and highlights the possible use of ferroptosis inhibitors to treat SCI.
Topics: Ferroptosis; Animals; Spinal Cord Injuries; Mice; Female; Mice, Inbred C57BL; Iron; Treatment Delay
PubMed: 38907771
DOI: 10.1007/s00401-024-02758-2 -
A deep learning approach for automatic recognition of abnormalities in the cytoplasm of neutrophils.Computers in Biology and Medicine Jun 2024This study aims to develop and evaluate NeuNN, a system based on convolutional neural networks (CNN) and generative adversarial networks (GAN) for the automatic...
BACKGROUND AND OBJECTIVES
This study aims to develop and evaluate NeuNN, a system based on convolutional neural networks (CNN) and generative adversarial networks (GAN) for the automatic identification of normal neutrophils and those containing several types of inclusions or showing hypogranulation.
METHODS
From peripheral blood smears, a set of 5605 digital images was obtained with neutrophils belonging to seven categories: Normal neutrophils (NEU), Hypogranulated (HYP) or containing cryoglobulins (CRY), Döhle bodies (DB), Howell-Jolly body-like inclusions (HJBLI), Green-blue inclusions of death (GBI) and phagocytosed bacteria (BAC). The dataset utilized in this study has been made publicly available. The class of GBI was augmented using synthetic images generated by GAN. The NeuNN classification model is based on an EfficientNet-B7 architecture trained from scratch.
RESULTS
NeuNN achieved an overall performance of 94.3% accuracy on the test data set. Performance metrics, including sensitivity, specificity, precision, F1-Score, Jaccard index, and Matthews correlation coefficient indicated overall values of 94%, 99.1%, 94.3%, 94.3%, 89.6%, and 93.6%, respectively.
CONCLUSIONS
The proposed approach, combining data augmentation and classification techniques, allows for automated identification of morphological findings in neutrophils, such us inclusions or hypogranulation. The system can be used as a support tool for clinical pathologists to detect these specific abnormalities with clinical relevance.
PubMed: 38905894
DOI: 10.1016/j.compbiomed.2024.108691 -
MedComm Jul 2024Type 2 diabetes mellitus (T2DM) and periodontitis (PD) have intricated connections as chronic inflammatory diseases. While the immune response is a key factor that...
Type 2 diabetes mellitus (T2DM) and periodontitis (PD) have intricated connections as chronic inflammatory diseases. While the immune response is a key factor that accounts for their association, the underlying mechanisms remain unclear. To gain a deeper understanding of the connection, we conducted research using a multiomics approach. We generated whole genome and methylation profiling array data from the periodontium of PD patients with DM (PDDM) and without DM to confirm genetic and epigenetic changes. Independent bulk and single-cell RNA sequencing data were employed to verify the expression levels of hypo-methylated genes. We observed a gradual rise in C>T base substitutions and hypomethylation in PD and PDDM patients compared with healthy participants. Furthermore, specific genetic and epigenetic alterations were prominently associated with the Fc-gamma receptor-mediated phagocytosis pathway. The upregulation of these genes was confirmed in both the periodontal tissues of PD patients and the pancreatic tissues of T2DM patients. Through single-cell RNA analysis of peripheral blood mononuclear cells, substantial upregulation of Fc-gamma receptors and related genes was particularly identified in monocytes. Our findings suggest that targeting the Fc-gamma signaling pathway in monocytes holds promise as a potential treatment strategy for managing systemic complications associated with diabetes.
PubMed: 38903536
DOI: 10.1002/mco2.620