Phagosomes Of Cells Research Articles

Da_Tracker: Automated workflow for high throughput single cell and single phagosome tracking in infected cells.

Time-lapse microscopy has emerged as a crucial tool in cell biology, facilitating a deeper understanding of dynamic cellular processes. While existing tracking tools have proven effective in detecting and monitoring objects over time, the quantification of signals within these tracked objects often faces implementation constraints. In the context of infectious diseases, the quantification of signals at localized compartments within the cell and around intracellular pathogens can provide even deeper insight into the interactions between the pathogen and host cell organelles. Existing quantitative analysis at a single-phagosome level remains limited and dependent on manual tracking methods. We developed a near-fully automated workflow that performs with limited bias, high-throughput cell segmentation and quantitative tracking of both single cell and single bacterium/phagosome within multi-channel, z-stack, time-lapse confocal microscopy videos. We took advantage of the PyImageJ library to bring Fiji functionality into a Python environment and combined deep-learning-based segmentation from Cellpose with tracking algorithms from Trackmate. The 'da_tracker' workflow provides a versatile toolkit of functions for measuring relevant signal parameters at the single-cell level (such as velocity or bacterial burden) and at the single-phagosome level (i.e. assessment of phagosome maturation over time). Its capabilities in both single-cell and single-phagosome quantification, its flexibility and open-source nature should assist studies that aim to decipher for example the pathogenicity of bacteria and the mechanism of virulence factors that could pave the way for the development of innovative therapeutic approaches.

Exploring Infantile Epileptic Spasm Syndrome: A Proteomic Analysis of Plasma Using the Data-Independent Acquisition Approach.

This study aimed to identify characteristic proteins in infantile epileptic spasm syndrome (IESS) patients' plasma, offering insights into potential early diagnostic biomarkers and its underlying causes. Plasma samples were gathered from 60 patients with IESS and 40 healthy controls. Data-independent acquisition proteomic analysis was utilized to identify differentially expressed proteins (DEPs). These DEPs underwent functional annotation through Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Gene set enrichment analysis (GSEA) was employed for both GO (GSEA-GO) and KEGG (GSEA-KEGG) analyses to examine the gene expression profiles. Receiver operating characteristic (ROC) curves assessed biomarkers' discriminatory capacity. A total of 124 DEPs were identified in IESS patients' plasma, mainly linked to pathways, encompassing chemokines, cytokines, and oxidative detoxification. GSEA-GO and GSEA-KEGG analyses indicated significant enrichment of genes associated with cell migration, focal adhesion, and phagosome pathways. ROC curve analysis demonstrated that the combination of PRSS1 and ACTB, PRSS3, ACTB, and PRSS1 alone exhibited AUC values exceeding 0.7. This study elucidated the significant contribution of cytokines, chemokines, oxidative detoxification, and phagosomes to the IESS pathogenesis. The combination of PRSS1 and ACTB holds promise as biomarkers for the early diagnosis of IESS.

Immune features revealed by single-cell RNA and single-cell TCR/BCR sequencing in patients with rheumatoid arthritis receiving COVID-19 booster vaccination.

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, have profoundly affected human health. Booster COVID-19 vaccines have demonstrated significant efficacy in reducing infection and severe cases. However, the effects of booster COVID-19 vaccines on key immune cell subsets and their responses in rheumatoid arthritis (RA) are not well understood. By using single-cell RNA sequencing (scRNA-seq) combined with scTCR/BCR-seq analysis, a total of 8 major and 27 minor cell clusters were identified from paired peripheral blood mononuclear cells (PBMCs) which were collected 1 week before and 4 weeks after booster vaccination in stable RA patients. Booster vaccination only had limited impact on the composition and proportions of PBMCs cell clusters. CD8+ cytotoxic T cells (CD8+T_CTL) showed a trend toward an increase after vaccination, while naive B cells and conventional dendritic cells (cDCs) showed a trend toward a decrease. Transcriptomic changes were observed after booster vaccination, primarily involving T/B cell receptor signaling pathways, phagosome, antigen processing and presenting, and viral myocarditis pathways. Interferon (IFN) and pro-inflammatory response gene sets were slightly upregulated across most major cell subpopulations in COVID-19 booster-vaccinated RA individuals. Plasma neutralizing antibody titers significantly increased after booster COVID-19 vaccination (p = 0.037). Single-cell TCR/BCR analysis revealed increased B cell clone expansion and repertoire diversity postvaccination, with no consistent alterations in T cells. Several clonotypes of BCRs and TCRs were identified to be significantly over-represented after vaccination, such as IGHV3-15 and TRBV28. Our study provided a comprehensive single-cell atlas of the peripheral immune response and TCR/BCR immune repertoire profiles to inactivated SARS-CoV-2 booster vaccination in RA patients, which helps us to understand vaccine-induced immune responses better.

Ecological effects of biochar-supported nanoscale zero-valent iron on Eisenia foetida in cadmium-contaminated soil: Oxidative stress, DNA damage, gene expression and transcriptomics analysis

Biochar-supported nanoscale zero-valent iron (nZVI@BC) has been widely used in heavy metal contaminated soil for remediation. However, studies on the soil ecological effects of nZVI@BC were rare. In this study, nZVI@BC was synthesized by the liquid phase reduction and GnZVI@BC was prepared by a green synthesis method which was reduced by green tea extract instead of NaBH4. Earthworms (Eisenia foetida) as indicator organisms were exposed to Cd-contaminated soil. The immobilization effects and enrichment in earthworms of Cd were measured. Besides, oxidative stress, DNA damage, gene expression and transcriptomics of earthworms were deeply explored. The results indicated that the immobilization efficiency of BC, nZVI@BC and GnZVI@BC for Cd was 76.01%, 85.49%, and 80.76%, respectively. The effects of Cd on superoxide dismutase, glutathione S-transferase, peroxidase, and catalase in earthworms reduced, reactive oxygen species and malondialdehyde contents decreased, and DNA damage was relieved. In addition, the gene toxicity of Cd to earthworms was restrained, and the genes expression of sod, cat and gst tended to be stable. With nZVI@BC, the main pathways affected by the differential genes were cellular oxidative phosphorylation and transforming growth factor-β signaling pathways. With GnZVI@BC, there were mainly structure of the cell phagosome, metabolism of taurine, hypotaurine, and alanine processes. This study will provide references for ecological risk assessment of nZVI@BC in practical applications.

NOTCH2 sensitizes the chondrocyte to the inflammatory response of tumor necrosis factor α

Notch regulates the immune and inflammatory response and has been associated with the pathogenesis of osteoarthritis in humans and preclinical models of the disease. Notch2tm1.1Ecan mice harbor a NOTCH2 gain-of-function and are sensitized to osteoarthritis, but the mechanisms have not been explored. We examined the effects of tumor necrosis factor α (TNFα) in chondrocytes from Notch2tm1.1Ecan mice and found that NOTCH2 enhanced the effect of TNFα on Il6 and Il1b expression. Similar results were obtained in cells from a conditional model of NOTCH2 gain-of-function, Notch22.1Ecan mice, and following the expression of the NOTCH2 intracellular domain invitro. Recombination signal-binding protein for immunoglobulin Kappa J region partners with the NOTCH2 intracellular domain to activate transcription; in the absence of Notch signaling it inhibits transcription, and Rbpj inactivation in chondrocytes resulted in Il6 induction. Although TNFα induced IL6 to a greater extent in the context of NOTCH2 activation, there was a concomitant inhibition of Notch target genes Hes1, Hey1, Hey2, and Heyl. Electrophoretic mobility shift assay demonstrated displacement of recombination signal-binding protein for immunoglobulin Kappa J region from DNA binding sites by TNFα explaining the increased Il6 expression and the concomitant decrease in Notch target genes. NOTCH2 enhanced the effect of TNFα on NF-κB signaling, and RNA-Seq revealed increased expression of pathways associated with inflammation and the phagosome in NOTCH2 overexpressing cells in the absence and presence of TNFα. Collectively, NOTCH2 has important interactions with TNFα resulting in the enhanced expression of Il6 and inflammatory pathways in chondrocytes.

Evaluation of Galleria mellonella immune response as a key step toward plastic degradation

BackgroundPlastic's remarkable durability presents a significant challenge for our planet, leading to widespread environmental damage. However, some organisms, such as Galleria mellonella larvae, have shown a unique capability to consume and degrade plastic, offering potential solutions to plastic pollution. In this study, we investigated the response of G. mellonella larvae to different diets, including artificial diet (AD), polyethylene low density mixed with AD (PELD + AD), and PELD alone. Using various microscopy techniques, we examined the larvae's hemocyte hemogram and mid-gut characteristics to understand their immune response and digestive system when exposed to plastic.ResultsThe results revealed that PELD-only feeding negatively impacted hemocyte immunity, resulting in a significant decrease in total hemocyte counts compared to AD and AD + PELD feeding. Moreover, plastic consumption induced differential hemocyte alterations, affecting specific cell types. The presence of phagosomes in larval hemocytes and mid-gut cells during PELD-only feeding suggested active involvement in plastic breakdown.ConclusionsThese findings highlight the potential of G. mellonella larvae as a model organism to study responses to pollutants, emphasizing the urgent need to address plastic pollution's global threat. Further investigation is warranted to explore larval deformities, weight loss, and appetite changes, potentially influencing mortality rates and enzyme biochemistry. Understanding the impacts of plastic ingestion on G. mellonella larvae is crucial to develop effective strategies for mitigating plastic pollution's ecological implications.

Ameliorative effect of Alangium chinense (Lour.) Harms on rheumatoid arthritis by reducing autophagy with targeting regulate JAK3-STAT3 and COX-2 pathways

Ethnopharmacological relevanceAlangium chinense has been used as traditional folk medicine for centuries to treat rheumatoid arthritis (RA) by Guizhou Miao nationality with remarkable clinical effect. But the mechanism of its anti-RA is not fully clarified. Aim of the studyTo explore the effect and underlying mechanism of A. chinense against RA. Material and methodsRA rats were induced by CII/IFA, and oral administrated with or without ethyl acetate extracts of Alangium chinense (ACEE) and tripterygium glycosides (GTW). Then arthritis scores, inflammatory factors in serum and histological evaluation were evaluated to assess the degree of joints disease. Proteomics were conducted via LC-MS/MS to clarify the mechanism of ACEE preliminarily, and further examined by immunohistochemistry, immunofluorescence, western botting, and molecular docking. ResultsACEE decreased joints swelling, cell abscission and necrosis of joint tissues arthropathy of RA rats, and attenuated expression of TNF-α, IL-1β, IL-6, PGE2, TGF-β. Meanwhile, differentially expressed proteins in the ACEE treated groups were observed, which were involved in RA, spliceosome, cell adhesion molecules, phagosome and lysosome signaling pathways. Moreover, ACEE significantly ameliorated arthropathy, suppressed JAK-STAT pathway (JAK3, p-JAK3, STAT3, iNOS, RANKL), COX-2 pathway (COX-2, TNF-α, IL-6I, L-1β, 5-LOX), and autophagic signaling pathway (LC3-Ⅰ, LC3-Ⅱ, p62, mTOR). But it showed little effect on the expression of COX-1, JAK1, JAK2, TyK2. ConclusionIt is the first evidence that A. chinense significantly ameliorates RA, and the underlying immune mechanism involves reducing autophagy with targeting regulate JAK3-STAT3 and COX-2 pathways.

Dissecting Phagosomal Pattern Recognition Receptor-Dependent Signaling and Antigen MHC-II Presentation from Phagosomes in MurineDendritic Cells.

Phagosomal pattern recognition receptor signaling promotes phagosome maturation and additional immune pathways such as proinflammatory cytokine secretion and antigen MHC-II presentation in antigen-presenting cells. In the present chapter, we describe procedures to assess these pathways in murinedendritic cells, professional phagocytes positioned at the interface between innate and adaptive immune responses. The assays described herein follow proinflammatory signaling by biochemical and immunological assays as well as antigen presentation of the model antigen Eα by immunofluorescence followed by flow cytometry.

Proteome analysis of Ehrlichia chaffeensis containing phagosome membranes revealed the presence of numerous bacterial and host proteins.

Tick-transmitted Ehrlichia chaffeensis, the causative agent for human monocytic ehrlichiosis, resides and multiplies within a host cell phagosome. Infection progression of E. chaffeensis includes internalization into a host cell by host cell membrane fusion events following engulfment leading to the formation of E. chaffeensis containing vacuole (ECV). Revealing the molecular composition of ECV is important in understanding the host cellular processes, evasion of host defense pathways and in defining host-pathogen interactions. ECVs purified from infected host cells were analyzed to define both host and bacterial proteomes associated with the phagosome membranes. About 160 bacterial proteins and 2,683 host proteins were identified in the ECV membranes. The host proteins included predominantly known phagosome proteins involved in phagocytic trafficking, fusion of vesicles, protein transport, Ras signaling pathway and pathogenic infection. Many highly expressed proteins were similar to the previously documented proteins of phagosome vacuole membranes containing other obligate pathogenic bacteria. The finding of many bacterial membrane proteins is novel; they included multiple outer membrane proteins, such as the p28-Omps, the 120 kDa protein, preprotein translocases, lipoproteins, metal binding proteins, and chaperonins, although the presence of ankyrin repeat proteins, several Type I and IV secretion system proteins is anticipated. This study demonstrates that ECV membrane is extensively modified by the pathogen. This study represents the first and the most comprehensive description of ECV membrane proteome. The identity of many host and Ehrlichia proteins in the ECV membrane will be a valuable to define pathogenic mechanisms critical for the replication of the pathogen within macrophages.

Salmonella enterica Infections Are Disrupted by Two Small Molecules That Accumulate within Phagosomes and Differentially Damage Bacterial Inner Membranes.

ABSTRACTGram-negative bacteria have a robust cell envelope that excludes or expels many antimicrobial agents. However, during infection, host soluble innate immune factors permeabilize the bacterial outer membrane. We identified two small molecules that exploit outer membrane damage to access the bacterial cell. In standard microbiological media, neither compound inhibited bacterial growth nor permeabilized bacterial outer membranes. In contrast, at micromolar concentrations, JAV1 and JAV2 enabled the killing of an intracellular human pathogen, Salmonella enterica serovar Typhimurium. S. Typhimurium is a Gram-negative bacterium that resides within phagosomes of cells from the monocyte lineage. Under broth conditions that destabilized the lipopolysaccharide layer, JAV2 permeabilized the bacterial inner membrane and was rapidly bactericidal. In contrast, JAV1 activity was more subtle: JAV1 increased membrane fluidity, altered reduction potential, and required more time than JAV2 to disrupt the inner membrane barrier and kill bacteria. Both compounds interacted with glycerophospholipids from Escherichia coli total lipid extract-based liposomes. JAV1 preferentially interacted with cardiolipin and partially relied on cardiolipin production for activity, whereas JAV2 generally interacted with lipids and had modest affinity for phosphatidylglycerol. In mammalian cells, neither compound significantly altered mitochondrial membrane potential at concentrations that killed S. Typhimurium. Instead, JAV1 and JAV2 became trapped within acidic compartments, including macrophage phagosomes. Both compounds improved survival of S. Typhimurium-infected Galleria mellonella larvae. Together, these data demonstrate that JAV1 and JAV2 disrupt bacterial inner membranes by distinct mechanisms and highlight how small, lipophilic, amine-substituted molecules can exploit host soluble innate immunity to facilitate the killing of intravesicular pathogens.

Proteasomal degradation within endocytic organelles can mediate antigen cross- presentation

During MHC-I-restricted antigen processing peptides generated by cytosolic proteasomes are translocated by the Transporter associated with Antigen Processing (TAP) into the endoplasmic reticulum, where they bind to newly synthesized MHC-I molecules. Dendritic cells and other cell types can also generate MHC-I complexes with peptides derived from internalized proteins, a process called cross-presentation. Here we show that active proteasomes within cross-presenting cell phagosomes can generate these peptides. Active proteasomes are detectable within endocytic compartments in mouse bone marrow-derived dendritic cells. In TAP-deficient mouse dendritic cells cross-presentation is enhanced by the introduction of human b 2 m, increasing surface expression of MHC-I and suggesting a role for recycling MHC-I molecules. In addition, surface MHC-I is reduced by proteasome inhibition but can be stabilized by the addition of a specific peptide, consistent with constitutive proteasomedependent but TAP-independent peptide loading in the endocytic pathway. Introduction of Rab-GTPase mutants that restrain phagosome maturation increases proteasome recruitment and enhances TAP-independent cross-presentation. Phagosomal/endosomal binding of peptides locally generated by proteasomes allows cross-presentation to generate MHC-I-peptide complexes identical to those produced by conventional antigen processing.

Autophagy in lung infections with three common atypical pathogens

Autophagy is a lysosomal mediated catabolic process that helps maintain cell balance and survival under extracellular or intracellular stress by degrading different cytoplasmic components. Autophagy is also a significant way for the body to defend pathogen invasion, which is swallowed by the phagosomes of host cells. When the phagosomes mature, they form autophagosomes, which are fused with lysosomes to form autophagolysosomes. Autophagolysosomes degrade due to the action of various hydrolases and remove pathogens at the same time. By interfering with the autophagy level of host cells, pulmonary atypical pathogens can escape from the host cells and be cleared by autophagy, and reproduce in host cells, finally reaching the goal of infecting the host. This article presented a brief review of recent studies on the relationship between infection and autophagy of three common atypical pathogens in the lung.

Transcriptome Changes and Potential Immunotoxicity Analysis in RAW264.7 Macrophages Caused by Bisphenol F.

As a viable substitute for bisphenol A (BPA), BPF has been widely used in the plastic industry and daily consumer goods, resulting in its detection in humans at a comparable concentration. Evidence reveals that BPF and BPA may have similar toxic effects due to their similar structures. However, there is less information about BPF and its latent implications on the immune system, which is associated with many disorders. In this study, the in vitro toxicity of BPF on RAW264.7 macrophages was explored. The cells were treated with different concentrations of BPF (5, 10, 20, 50, 100, and 200 μM), the cell viability and apoptosis were detected, the gene expression profile was analyzed by whole-transcriptome sequencing, and the mRNA levels were detected by qRT-PCR. The results showed a high concentration of BPF could significantly reduce the survival rate of RAW264.7 macrophages. Although the medium concentration (20–50 μM) of BPF seemed to have no impact on the cell activity of macrophages, it caused the occurrence of apoptosis. The results of differential transcription showed that compared with the control group, 121 genes were upregulated and 82 genes were downregulated in the BPF group. The significantly changed gene functions were mainly concentrated in cell cycle, phagosome, lysosome, and antigen processing and presentation. These findings provide valuable information for correctly understanding the immunotoxicity risk of BPF and may help to improve the hazard identification of bisphenol compounds.

Deficiency in Lyst function leads to accumulation of secreted proteases and reduced retinal adhesion.

Chediak–Higashi syndrome, caused by mutations in the Lysosome Trafficking Regulator (Lyst) gene, is a recessive hypopigmentation disorder characterized by albinism, neuropathies, neurodegeneration, and defective immune responses, with enlargement of lysosomes and lysosome-related organelles. Although recent studies have suggested that Lyst mutations impair the regulation of sizes of lysosome and lysosome-related organelle, the underlying pathogenic mechanism of Chediak–Higashi syndrome is still unclear. Here we show striking evidence that deficiency in LYST protein function leads to accumulation of photoreceptor outer segment phagosomes in retinal pigment epithelial cells, and reduces adhesion between photoreceptor outer segment and retinal pigment epithelial cells in a mouse model of Chediak–Higashi syndrome. In addition, we observe elevated levels of cathepsins, matrix metallopeptidase (MMP) 3 and oxidative stress markers in the retinal pigment epithelium of Lyst mutants. Previous reports showed that impaired degradation of photoreceptor outer segment phagosomes causes elevated oxidative stress, which could consequently lead to increases of cysteine cathepsins and MMPs in the extracellular matrix. Taken together, we conclude that the loss of LYST function causes accumulation of phagosomes in the retinal pigment epithelium and elevation of several extracellular matrix-remodeling proteases through oxidative stress, which may, in turn, reduce retinal adhesion. Our work reveals previously unreported pathogenic events in the retinal pigment epithelium caused by Lyst deficiency. The same pathogenic events may be conserved in other professional phagocytic cells, such as macrophages in the immune system, contributing to overall Chediak–Higashi syndrome pathology.

VASP boosts protrusive activity of macroendocytic cups and drives phagosome rocketing after internalization

Ena/VASP proteins are powerful actin polymerases that drive the processive elongation of actin filaments. Members of this protein family have been implicated in a variety of important cellular processes including axon guidance, cell migration and adhesion. However, the specific function of these proteins in macroendocytosis, comprising macropinocytosis and phagocytosis remain rather poorly understood. Here, we used the professional phagocyte Dictyostelium discoideum to address the function and dynamics of its only family member VASP in macroendocytosis. Confocal time-lapse imaging revealed that VASP localized prominently in a circumferential narrow band at the advancing rim of the phagocytic cup followed by its aperture-like convergence upon particle internalization. Loss of VASP resulted in substantial defects in both, macropinocytosis of bulk fluid and phagocytosis of yeast particles. Consistently, VASP-deficiency coincided with diminished speed of the protruding rim and an impaired internalization rate. Most intriguingly, after cup closure, VASP condensed at the distal side of internalized phagosomes and initiated localized de-novo actin assembly to propel the phagosome by an actin-rich comet deeper into the cell, resembling intracellular movement of rocketing Listeria cells. In line with these findings, travelled distance and speed of rocketing phagosomes in VASP-deficient cells were markedly impaired.

Targeted killing of tumor cells based on isoelectric point suitable nanoceria-rod with high oxygen vacancies.

Nanozymes have great potential applications in tumor treatment due to their good stability, high biocompatibility, easy preparation and versatility. However, it remains a challenge to design highly active nanozymes with tumor cell targeting. Herein, three nanoceria structures (nanoceria-rod; nanoceria polyhedra, abbreviated as nanoceria-poly.; and nanoceria-cube) with different surface oxygen vacancy concentrations are designed. Among them, nanoceria-rod shows the highest enzyme activity and tumor cell toxicity because of its highest concentration of oxygen vacancies on the surface. Further study shows that nanoceria-rod can selectively enter tumor cells because nanoceria-rod with a suitable isoelectric point (IEP) remains positively charged in the acidic microenvironment of the tumor but negatively charged in the physiological microenvironment of normal cells. Nanoceria-rod distributes in lysosomes and phagosomes to produce reactive oxygen species (ROS) in tumor cells. Finally, the mitochondrial membrane potential (MMP) was reduced, which caused cell apoptosis. This study provides an interesting new tumor-targeting therapy method, which could also be extended to other drug nanocarriers and diagnostic imaging nanomaterials for tumors.

Identification of hub genes in chronic pancreatitis and analysis of association with pancreatic cancer via bioinformatic analysis.

Chronic pancreatitis (CP), a fibroinflammatory disease, is a potential risk factor for pancreatic cancer. This study attempted to identify and analyze the key genes involved in CP development and their association with pancreatic cancer. The GSE41418 dataset was obtained from the Gene Expression Omnibus database. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed on common differentially expressed genes. A protein-protein interaction network was constructed by using the STRING database. The expression and prognostic value of hub genes in pancreatic cancer were analyzed by Gene Expression Profiling Interactive Analysis (GEPIA) and UALCAN databases. The results showed that the upregulated genes primarily focused on the cell cycle, DNA replication, and phagosome activity. The PPI network was composed of 184 nodes and 925 edges. The 10 hub genes were screened by CytoHubba, of which CCNB2, CDC6, CDK1 and CKS2 were observed to be differentially expressed in pancreatic cancer with CP, and all of them were detrimental to overall survival and recurrence-free survival of pancreatic cancer. In this study, we employed bioinformatic analysis to determine that CCNB2, CDC6, CDK1 and CKS2 may be key genes in the development of CP and pancreatic cancer.

Convergent molecular mechanisms underlying cognitive impairment in mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder caused by pathogenic variants in the iduronate-2-sulfatase gene (IDS), responsible for the degradation of glycosaminoglycans (GAGs) heparan and dermatan sulfate. IDS enzyme deficiency results in the accumulation of GAGs within cells and tissues, including the central nervous system (CNS). The progressive neurological outcome in a representative number of MPSII patients (neuronopathic form) involves cognitive impairment, behavioral difficulties, and regression in developmental milestones. In an attempt to dissect part of the influence of axon guidance instability over the cognitive impairment presentation in MPS II, we used brain expression data, network propagation, and clustering algorithm to prioritize in the human interactome a disease module associated with the MPS II context. We identified new candidate genes and pathways that act in focal adhesion, integrin cell surface, laminin interactions, ECM proteoglycans, cytoskeleton, and phagosome that converge into functional mechanisms involved in early neural circuit formation defects and could indicate clues about cognitive impairment in patients with MPSII. Such molecular changes during neurodevelopment may precede the morphological and clinical evidence, emphasizing the importance of an early diagnosis and directing the development of potential drug leads. Furthermore, our data also support previous hypotheses pointing to shared pathogenic mechanisms in some neurodegenerative diseases.

Bacillus subtilis Attenuates Hepatic and Intestinal Injuries and Modulates Gut Microbiota and Gene Expression Profiles in Mice Infected with Schistosoma japonicum

Parasitic infection can induce pathological injuries and impact the gut microbiota diversity and composition of the host. Bacillus subtilis is a nonpathogenic and noninvasive probiotic bacterium for humans and other animals, playing an important role in improving the host immune system’s ability to respond to intestinal and liver diseases and modulating gut microbiota. However, whether B. subtilis can impact biological functions in Schistosoma japonicum–infected mice is unclear. This study used oral administration (OA) of B. subtilis to treat mice infected with S. japonicum. We evaluated changes in the gut microbiota of infected mice using 16 S rRNA gene sequencing and differentially expressed gene profiles using transcriptome sequencing after OA B. subtilis. We found that OA B. subtilis significantly attenuated hepatic and intestinal pathological injuries in infected mice. The gut microbiota of mice were significantly altered after S. japonicum infection, while OA B. subtilis remodel the diversity and composition of gut microbiomes of infected mice. We found that the S. japonicum–infected mice with OA B. subtilis had an overabundance of the most prevalent bacterial genera, including Bacteroides, Enterococcus, Lactobacillus, Blautia, Lachnoclostridium, Ruminiclostridium, and Enterobacter. Transcriptomic analysis of intestinal tissues revealed that OA B. subtilis shaped the intestinal microenvironment of the host responding to S. japonicum infection. Differentially expressed genes were classified into KEGG pathways between S. japonicum–infected mice and those without included cell adhesion molecules, intestinal immune network for IgA production, hematopoietic cell lineage, Fc epsilon RI signaling pathway, Th1 and Th2 cell differentiation, Th17 cell differentiation, calcium signaling pathway, Fc gamma R-mediated phagocytosis, chemokine signaling pathway, phospholipase D signaling pathway, NF-kappa B signaling pathway, B cell receptor signaling pathway, pancreatic secretion, and phagosome. In conclusion, our findings showed that OA B. subtilis alleviates pathological injuries and regulates gene expression, implying that B. subtilis supplementation may be a potential therapeutic strategy for schistosomiasis. Our study may highlight the value of probiotics as a beneficial supplementary therapy during human schistosomiasis, but further studies are needed.

Real‐Time Simultaneous Imaging of Acidification and Proteolysis in Single Phagosomes Using Bifunctional Janus‐Particle Probes

AbstractThe digestion of pathogens inside phagosomes by immune cells occurs through a sequence of reactions including acidification and proteolysis, but how the reactions are orchestrated in the right order is unclear due to a lack of methods to simultaneously measure more than one reaction in phagosomes. Here we report a bifunctional Janus‐particle probe to simultaneously monitor acidification and proteolysis in single phagosomes in live cells. Each probe consists of a pH reporter and a proteolysis reporter that are spatially separated but function concurrently. Using the Janus probes, we found the acidic pH needed to initiate and maintain proteolysis, revealing the mechanism for the sequential occurrence of both reactions during pathogen digestion. We showed how bacterium‐derived lipopolysaccharides alter the acidification and proteolysis in phagosomes. This study showcases Janus‐particle probes as a generally applicable tool for monitoring multiple reactions in intracellular vesicles.