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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 -
Purinergic Signalling Jun 2024Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease. The prevalent features of AD pathogenesis are the appearance of β-amyloid (Aβ) plaques... (Review)
Review
Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease. The prevalent features of AD pathogenesis are the appearance of β-amyloid (Aβ) plaques and neurofibrillary tangles, which cause microglial activation, synaptic deficiency, and neuronal loss. Microglia accompanies AD pathological processes and is also linked to cognitive deficits. Purinergic signaling has been shown to play a complex and tight interplay with the chemotaxis, phagocytosis, and production of pro-inflammatory factors in microglia, which is an important mechanism for regulating microglia activation. Here, we review recent evidence for interactions between AD, microglia, and purinergic signaling and find that the purinergic P2 receptors pertinently expressed on microglia are the ionotropic receptors P2X4 and P2X7, and the subtypes of P2YRs expressed by microglia are metabotropic receptors P2Y, P2Y, P2Y, and P2Y. The adenosine P1 receptors expressed in microglia include AR, AR, and AR. Among them, the activation of P2X4, P2X7, and adenosine A, A receptors expressed in microglia can aggravate the pathological process of AD, whereas P2Y, P2Y, P2Y, and P2Y receptors expressed by microglia can induce neuroprotective effects. However, AR activation also has a strong neuroprotective effect and has a significant anti-inflammatory effect in chronic neuroinflammation. These receptors regulate a variety of pathophysiological processes in AD, including APP processing, Aβ production, tau phosphorylation, neuroinflammation, synaptic dysfunction, and mitochondrial dysfunction. This review also provides key pharmacological advances in purinergic signaling receptors.
PubMed: 38910192
DOI: 10.1007/s11302-024-10029-8 -
International Journal of Biological... Jun 2024The Rab proteins primarily regulate vesicular transport between membrane-bound organelles and are important for innate immune. However, there is currently a lack of...
The Rab proteins primarily regulate vesicular transport between membrane-bound organelles and are important for innate immune. However, there is currently a lack of studies on crustaceans regarding Rab proteins, particularly core Rabs. We identified a Rab11 gene from Procambarus clarkii (PcRab11) and evaluated its potential involvement in immune response. The results showed PcRab11 was 1789 bp long, with an open reading frame of 645 bp encoding 211 amino acids and an estimated molecular weight of 23.8 kDa. Sequence analysis revealed its remarkable evolutionary conservation. The PcRab11 was widely expressed in various tissues, with highest levels in hepatopancreas, and localized within the cell cytoplasm. Upon infection with white spot syndrome virus (WSSV) or Aeromonas veronii, the expression of PcRab11 in immune organs was significantly induced. Furthermore, silencing PcRab11 reduced phagocytosis-related genes expression and haemocytes' phagocytic activity to FITC-labeled A. veronii, as well as decreased mortality and death time in WSSV or A. veronii infected P. clarkii. Additionally, the potential protein interaction between PcRab11 and 14-3-3ε was identified in haemocytes. Overall, our findings provided evidence for the involvement of Rab11 in P. clarkii's immune response, establishing a foundation to explore the immune role of core Rab proteins in crustaceans' innate immune system.
PubMed: 38909733
DOI: 10.1016/j.ijbiomac.2024.133299 -
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 -
Journal of Endodontics Jun 2024The repair process of periradicular tissues depends, among other factors, on the properties of endodontic cements. One of the main cells involved in this process are...
INTRODUCTION
The repair process of periradicular tissues depends, among other factors, on the properties of endodontic cements. One of the main cells involved in this process are macrophages.
MATERIALS AND METHODS
Murine peritoneal macrophages obtained from C57BL/6 (MBL6) and BALB/c (MBalb) mice, respectively, were cultured with capillaries containing or not Endosequence BC Sealer® (BC), Sealer Plus BC® (MK), Bio C Sealer (Ang) and MTA®. Cell viability was measured by trypan blue and MTT methods at 24, 48 and 72 hours. Cell adhesion, phagocytosis of S. boulardii, production of reactive oxygen species (ROS), nitric oxide (NO), and the cytokines TNF-α and TGF-β, were also evaluated. The data were analysed using the ANOVA test (p<0.05).
RESULTS
Cell viability was similar between bioceramic sealers and MTA (p>0.05). There was no statistical difference between both macrophages when adherence and phagocytose were assayed. The presence of inflammation stimulus significantly altered the production of ROS by MBL6 macrophages in contact with the cements. The production of TGF-β was similar for both lineages of macrophages.
CONCLUSIONS
This study shows that the evaluated bioceramic cements do not interfere with MBL6 and MBalb macrophages adhesion, phagocytic capacity, as well as TGF-β production. The cements stimulated the production of ROS by MBL6 macrophages in response to induced inflammation, potentially favouring the elimination of residual pathogens.
PubMed: 38908681
DOI: 10.1016/j.joen.2024.06.008 -
International Journal of Biological... Jun 2024CD47, a cell surface protein known for inhibiting phagocytosis, plays a critical role in the tumor microenvironment (TME) and is a potential biomarker for cancer....
CD47, a cell surface protein known for inhibiting phagocytosis, plays a critical role in the tumor microenvironment (TME) and is a potential biomarker for cancer. However, directly applying αCD47, a hydrophilic macromolecular antibody that targets CD47, in vivo for cancer detection can have adverse effects on normal cells, cause systemic toxicities, and lead to resistance against anti-cancer therapies. In this study, we developed a novel complex incorporating aluminum-based metal-organic frameworks (Al-MOF) loaded with indocyanine green (ICG), αCD47, and resiquimod (R848), a hydrophobic small molecule Toll-like receptor 7/8 (TLR7/8) agonist. Upon activation with an infrared 808 nm laser, the nanocomposites exhibited photothermal effects that triggered the release of the loaded reagents, induced ROS production, and induced changes in the TME. This led to the polarization of immune-suppressive M2 macrophages towards an immune-stimulatory M1 phenotype, promoted dendritic cell (DC) maturation, and enabled mature DCs to facilitate antigen presentation, T-cell activation, and critical roles in tumor immunity. Furthermore, in vivo imaging successfully detected the specific binding of αCD47 with CD47 on tumor cells. Overall, the complex composed of αCD47 antibody and toll-like receptor agonist showed promising efficacy in both tumor diagnosis and therapy, providing a potential strategy for detecting early lung cancer and modulating the tumor microenvironment for improved treatment outcomes.
PubMed: 38908646
DOI: 10.1016/j.ijbiomac.2024.133322