Farnesyl thiosalicylic acid prevents iNOS induction triggered by lipopolysaccharide via suppression of iNOS mRNA transcription in murine macrophages

Investigation of the interaction between S-isoalkyl derivatives of the thiosalicylic acid and human serum albumin

S-isoalkyl derivatives of thiosalicylic acid (isopropyl-(L1), isobutyl-(L2) and isoamyl-(L3)) were selected in order to investigate the binding interaction with the human serum albumin (HSA) using different spectroscopic methods and molecular docking simulation. Association constants and number of binding sites were used to analyze the quenching mechanism. The experimental results showed that the fluorescence quenching of HSA by L1, L2 and L3 occurs because of static quenching and that binding processes were spontaneous, with the leading forces in bonding by hydrogen bonding, hydrophobic interactions, and electrostatic interactions. Fluorescence spectroscopy, UV-Vis spectroscopy and synchronous fluorescence spectroscopy showed that ligands (L1, L2 and L3) can bind to HSA and that the binding of ligands induced some microenvironmental and conformational changes in HSA. The calculated distance between the donor and the acceptor according to fiFörster's theory confirms the energy transfer efficiency between the acceptor and HSA. Results of site marker competitive experiments showed that the tested compounds bind to HSA in domain IIA (Site I). Molecular dynamics and docking calculations demonstrated that L3 binds to the Sudlow site I of HSA with lower values of binding energies compared to L1 and L2, indicating the formation of the most stable ligand-HSA complex. Understanding the binding mechanisms of S-isoalkyl derivatives of the thiosalicylic acid to HSA may provide valuable data for the future studies of their biological activity and application as potential antitumor drugs.

Repurposing High-Throughput Screening Reveals Unconventional Drugs with Antimicrobial and Antibiofilm Potential Against Methicillin-Resistant Staphylococcus aureus from a Cystic Fibrosis Patient

Background/Objectives: Antibiotic therapy faces challenges from rising acquired and biofilm-related antibiotic resistance rates. High resistance levels to commonly used antibiotics have been observed in methicillin-resistant Staphylococcus aureus (MRSA) strains among cystic fibrosis (CF) patients, indicating an urgent need for new antibacterial agents. This study aimed to identify potential novel therapeutics with antibacterial and antibiofilm activities against an MRSA CF strain by screening, for the first time, the Drug Repurposing Compound Library (MedChem Express). Methods/Results: Among the 3386 compounds, a high-throughput screening-based spectrophotometric approach identified 2439 (72%), 654 (19.3%), and 426 (12.6%) drugs active against planktonic cells, biofilm formation, and preformed biofilm, respectively, although to different extents. The most active hits were 193 (5.7%), against planktonic cells, causing a 100% growth inhibition; 5 (0.14%), with excellent activity against biofilm formation (i.e., reduction ≥ 90%); and 4, showing high activity (i.e., 60% ≤ biofilm reduction < 90%) against preformed biofilms. The potential hits belonged to several primary research areas, with "cancer" being the most prevalent. After performing a literature review to identify other, already published biological properties that could be relevant to the CF lung environment (i.e., activity against other CF pathogens, and anti-inflammatory and anti-virulence potential), the most interesting hits were the following: 5-(N,N-Hexamethylene)-amiloride (diuretic), Toremifene (anticancer), Zafirlukast (antiasthmatic), Fenretide (anticancer), and Montelukast (antiasthmatic) against planktonic S. aureus cells; Hemin against biofilm formation; and Heparin, Clemastine (antihistaminic), and Bromfenac (nonsteroidal anti-inflammatory) against established biofilms. Conclusions: These findings warrant further in vitro and in vivo studies to confirm the potential of repurposing these compounds for managing lung infections caused by S. aureus in CF patients.

Photodynamic hemostatic silk fibroin film with photo-controllable modulation of macrophages for bacteria-infected wound healing

Massive hemorrhage and chronic wounds caused by bacterial infections after trauma are significant challenges in clinical practice. An ideal hemostatic wound dressing should simultaneously manage bleeding and prevent bacterial infections and also hold excellent biocompatibility and bioactivities to successfully modulate immune microenvironments to promote wound healing. In this study, a silk fibroin-based light-responsive film was demonstrated to possess effective capacity of light-induced non-compressible hemostasis on liver hemorrhage and tail bleeding in vivo by binding with blood platelets to promote the clotting cascade. The blood loss of the rats was significantly less after C-MASiF films were applied, which were 1223.33 ± 347.9 mg (liver trauma) and 363.33 ± 60.28 mg (tail trimming). Importantly, the films exhibited photo-controllable modulation activity on macrophages through repeated near-infrared irradiation to regulate the immune microenvironment to enhance photodynamic antibacterial therapy. Moreover, the light-responsive silk fibroin film effectively promoted Staphylococcus aureus infected burn wound healing in vivo. The quantity of residual bacteria in the wound sites of mice in the C-MASiF films group (0.05 ± 0.0047 × 108 CFU mL-1) was considerably less than that in the control group (3.18 ± 0.75 × 108 CFU mL-1), and the wound area in the C-MASiF group (78.03% ± 4.12%) was considerably smaller than that in the control group (60.33% ± 8.81%) after 14 days. Overall, this light-responsive silk fibroin film can provide a powerful strategy for wound healing of burns.

Recent progress of porphyrin metal-organic frameworks for combined photodynamic therapy and hypoxia-activated chemotherapy

Nanoscale metal-organic frameworks integrated with porphyrins (Por-nMOFs) have emerged as efficient nanoplatforms for photodynamic therapy (PDT), which relies on the conversion of molecular oxygen into cytotoxic singlet oxygen. However, the hypoxic microenvironment within tumors significantly limits the efficacy of PDT. To address this challenge, researchers have explored various strategies to either alter or exploit the hypoxic conditions in tumors. One such strategy involves leveraging the porous structure of Por-nMOFs to load hypoxia-activated prodrugs (HAPs) like tirapazamine (TPZ), thereby utilizing the tumor's intrinsic hypoxic environment to trigger a chemotherapeutic effect that synergizes with PDT. Advances in nanoscience have enabled the development of porphyrin-based nMOFs capable of simultaneously loading both porphyrin photosensitizers and TPZ, ensuring effective release within cancer cells under high-phosphate conditions. The subsequent activation of co-loaded TPZ, by the tumor's own hypoxic microenvironment, and that created during PDT, facilitates a combined PDT and chemotherapy approach. This method not only enhances the suppression of cancer cell proliferation but also improves control over tumor metastasis while mitigating the negative impact of hypoxia on singular Por-nMOFs in PDT. This review summarizes recent advances in Por-nMOFs research, focusing on the design strategies for enhancing water dispersibility, circulatory stability, and targeting specificity through post-synthetic modifications. Additionally, this review highlights the bioapplication of Por-nMOFs by integrating TPZ chemotherapy and other therapeutic modalities to combat hypoxic and metastatic malignancies. We anticipate that this review will inspire further research into Por-nMOFs and advance their application in biomedicine.

Porphyrin-engineered nanoscale metal-organic frameworks: enhancing photodynamic therapy and ferroptosis in oncology

Photodynamic therapy and ferroptosis induction have risen as vanguard oncological interventions, distinguished by their precision and ability to target vulnerabilities in cancer cells. Photodynamic therapy's non-invasive profile and selective cytotoxicity complement ferroptosis' unique mode of action, which exploits iron-dependent lipid peroxidation, offering a pathway to overcome chemoresistance with lower systemic impact. The synergism between photodynamic therapy and ferroptosis is underscored by the depletion of glutathione and glutathione peroxidase four inhibitions by photodynamic therapy-induced reactive oxygen species, amplifying lipid peroxidation and enhancing ferroptotic cell death. This synergy presents an opportunity to refine cancer treatment by modulating redox homeostasis. Porphyrin-based nanoscale metal-organic frameworks have unique hybrid structures and exceptional properties. These frameworks can serve as a platform for integrating photodynamic therapy and ferroptosis through carefully designed structures and functions. These nanostructures can be engineered to deliver multiple therapeutic modalities simultaneously, marking a pivotal advance in multimodal cancer therapy. This review synthesizes recent progress in porphyrin-modified nanoscale metal-organic frameworks for combined photodynamic therapy and ferroptosis, delineating the mechanisms that underlie their synergistic effects in a multimodal context. It underscores the potential of porphyrin-based nanoscale metal-organic frameworks as advanced nanocarriers in oncology, propelling the field toward more efficacious and tailored cancer treatments.

Glomerular injury induced by vinyl carbamate in A/J inbred mice: a novel model of membranoproliferative glomerulonephritis

Ethyl carbamate (EC) is a process contaminant found in fermented foods and alcoholic beverages. Metabolic conversion of ethyl carbamate generates vinyl carbamate (VC), a carcinogenic metabolite. EC, as a Group 2A probable human carcinogen, and the more potent VC, are known to cause tumors in rodents. However, their effects on the kidney are unknown and were explored here. Female A/J inbred mice received an intraperitoneal injection of vehicle or VC. Beginning 5 weeks after VC injection, mice showed signs of moribund state. Mouse necropsies revealed renal glomerular injury that histopathologically recapitulated human membranoproliferative glomerulonephritis (MPGN), as evidenced by light microscopy, immunostaining for immunoglobulins and complements, and electron microscopy. To determine the molecular pathomechanisms, a post-hoc analysis was performed on a publicly available RNA-Seq transcriptome of kidneys from control rats and rats treated with fermented wine containing high concentrations of EC. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the differentially expressed genes revealed that the complement and coagulation cascades were a top predicted biological process involved. Furthermore, pathway-based data integration and visualization revealed that key regulators of complement activation were altered by high EC treatment. Among these, complement factors (CF) D and H, critical positive and negative regulators of the alternative pathway, respectively, were most affected, with CFD induced by 3.49-fold and CFH repressed by 5.9-fold, underscoring a hyperactive alternative pathway. Consistently, exposure of primary glomerular endothelial cells to EC or VC resulted in induction of CFD and repression of CFH, accompanied by increased fixation of C3 and C5b9. This effect seems to be mediated by Ras, one of the top genes that interact with both EC and VC, as identified by analyzing the chemical-gene/protein interactions database. Indeed, EC or VC-elicited complement activation was associated with activation of Ras signaling, but was abolished by the Ras inhibitor farnesyl thiosalicylic acid. Collectively, our findings suggest that VC, a metabolite of EC, induces glomerular injury in mice akin to human MPGN, possibly via perturbing the expression of complement regulators, resulting in an effect that favors activation of the alternative complement pathway.

Rheumatoid arthritis-recent advances in pathogenesis and the anti-inflammatory effect of plant-derived COX inhibitors

The majority of people with autoimmune disorders, including those with rheumatoid arthritis, osteoarthritis, and tendonitis report pain, stiffness, and inflammation as major contributors to their worse quality of life in terms of overall health. Of all the available treatment options, COX inhibitors are the ones that are utilized most frequently to ease the symptoms. Various signaling cascades have been reported to be involved in the pathogenesis of rheumatoid arthritis which includes JAK/STAT, MAPK, and NF-kB signaling pathways, and several allopathic inhibitors (tofacitinib and baricitinib) have been reported to target the components of these cascades and have received approval for RA treatment. However, the prolonged use of these COX inhibitors and other allopathic drugs can pose serious health challenges due to their significant side effects. Therefore, searching for a more effective and side effect-free treatment for rheumatoid arthritis has unveiled phytochemicals as both productive and promising. Their therapeutic ability helps develop potent and safe drugs targeting immune-inflammatory diseases including RA. Various scientific databases were used for searching articles such as NCBI, SpringerLink, BioMed Central, ResearchGate, Google Scholar, Scopus, Nature, Wiley Online Library, and ScienceDirect. This review lists various phytochemicals and discusses their potential molecular targets in RA treatment, as demonstrated by various in vitro, in vivo (pre-clinical), and clinical studies. Several pre-clinical and clinical studies suggest that various phytochemicals can be an alternative promising intervention for attenuating and managing inflammation-associated pathogenesis of rheumatoid arthritis.

Vegetative forms of Clostridium chauvoei trigger apoptotic and inflammatory responses on macrophages

BACKGROUND

Clostridium chauvoei is a gram-positive, spore-forming, strictly anaerobic bacterium that causes blackleg, a disease that affects cattle by inducing fulminant myonecrosis, thereby leading to high and constant losses of cattle. Macrophages (Mɸs) are depleted in tissues infected with the vegetative form of C. chauvoei, but the mechanism remains partially known. Consequently, Mɸs may be a critical target in the pathogenicity of C. chauvoei.

AIM

The objective of this work was to study the mechanism of death of mouse-primary Mɸs infected in vitro for 24 h with the vegetative form of C. chauvoei.

METHODS

Mouse peritoneal Mɸs were infected in vitro with different multiplicities of infection (MOIs) of C. chauvoei (i.e., 5:1, 20:1, and 100:1). After 24 h post-infection, cell viability (MTT reduction assay), apoptosis (apoptotic bodies, DNA ladder, and Annexin V assays), and inflammatory cell response (iNOS and TNF-α expression) were assessed.

RESULTS

All the MOIs investigated decreased cell viability. An MOI of 20:1 caused the highest production of apoptotic bodies and an electrophoretic DNA-ladder pattern typical of an apoptosis cell death process. These results were corroborated using the Annexin V-flow cytometry assay. Concurrently with apoptotic cell death, Mϕs expressed iNOS and TNF-α.

CONCLUSION

Inflammation-mediated apoptosis of Mϕs can be a potential mechanism of evasion of the immune response used by C. chauvoei in tissues for depleting phagocytic cells at the site of infection.

Canine peripheral blood mononuclear cell-derived B lymphocytes pretreated with lipopolysaccharide enhance the immunomodulatory effect through macrophage polarization

BACKGROUND

Preconditioning with lipopolysaccharide (LPS) is used to improve the secretion of anti-inflammatory agents in B cells. However, there are only a few studies on canine B cells.

OBJECTIVE

This study aimed to evaluate the immune regulatory capacity of canine peripheral blood mononuclear cell-derived B cells pretreated with LPS.

METHODS

Canine B cells were isolated from canine peripheral blood mononuclear cells, which were obtained from three healthy canine donors. The B cells were preconditioned with LPS, and then cell viability and the expression of the regulatory B cell marker were assessed. Finally, RNA extraction and immunofluorescence analysis were performed.

RESULTS

LPS primed B cells expressed the interleukin (IL)-10 surface marker and immunoregulatory gene expression, such as IL-10, programmed death-ligand 1, and transforming growth factor beta. Macrophages in the inflammatory condition cocultured with primed B cells were found to have significantly down-regulated pro-inflammatory cytokine, such as tumor necrosis factor-α, and up-regulated anti-inflammatory cytokines such as IL-10. Additionally, it was revealed that co-culture with primed B cells re-polarized M1 macrophages to M2 macrophages.

CONCLUSIONS

This study revealed that LPS-primed B cells have an anti-inflammatory effect and can re-polarize macrophages, suggesting the possibility of using LPS-primed B cells as a therapeutic agent for its anti-inflammatory effects and immune modulation.

Exosomal miR-21 secreted by IL-1β-primed-mesenchymal stem cells induces macrophage M2 polarization and ameliorates sepsis

Sepsis occurs due to a damaging host response to infection and is the chief cause of death in most intensive care units. Mesenchymal stem cells (MSCs) exhibit immunomodulatory properties and can modulate key cells of the innate and adaptive immune systems through various effector mechanisms, such as exosomes. Exosomes and their microRNA (miRNA or miR) cargo including miR-21 can initiate profound phenotypic changes in the tumor microenvironment due to their intercellular communication transmitting the pleiotropic messages between different cell types, tissues, and body fluids. Here, we aimed to characterize the effect of miR-21 delivered from MSC-derived exosomes on the polarization of macrophages in a mouse sepsis model. First, we isolated exosomes from interleukin-1β (IL-1β)-pretreated murine MSCs (βMSCs) and injected them into cecal ligation and puncture (CLP) septic models. We found that βMSCs-derived exosomes could more effectively induce M2-like polarization of macrophages in vitro and in vivo. Administration of βMSCs-derived exosomes attenuated the symptoms in septic mice more effectively and increased their survival rate as compared to exosomes released by naïve MSCs. Importantly, we found that miR-21 was abundantly upregulated in MSCs upon IL-1β stimulation and packaged into exosomes. This exosomal miR-21 was transferred to macrophages, leading to M2 polarization in vitro and in vivo. The therapeutic efficacy of βMSC-derived exosomes was partially lost upon miR-21 inhibition by its specific inhibitors. More specifically, we demonstrated βMSCs-derived exosomes inhibited the effects of PDCD4, the target gene of miR-21, on macrophage polarization and sepsis. In conclusion, exosomal miR-21 emerged as a key mediator of IL-1β pretreatment induced immunomodulatory properties of MSCs. The study indicated a novel basis for therapeutic application of MSCs in sepsis.

Bioactive Exopolysaccharides Reveal Camellia oleifera Infected by the Fungus Exobasidium gracile Could Have a Functional Use

Camellia oleifera is an important Chinese commercial crop. Camellia oleifera can display abnormal leaves due to infection by the parasitic fungus Exobasidium gracile. Exobasidium gracile was isolated from infected leaves and used in fermentation, and exopolysaccharides EP0-1 and EP0.5-1 were purified from the fermentation broth. EP0-1 was an alkaline polysaccharide consisting mainly of the linkages α-d-Manp(1→, →2)-α-d-Manp(1→ and →6)-α-d-Manp(1→, →3)-α-d-Glcp(1→ and→4)-α-d-Glcp(1→, terminal β-d-Galf, (1→5)-β-d-Galf, and terminal β-D-GlcN(1→. EP0.5-1 was an acidic galactofuranose-containing polysaccharide. It contained the linkages of α-d-Manp(1→, →2)-α-d-Manp(1→, →6)-α-d-Manp(1→,→2, 6)-α-d-Manp(1→, →4)-α-d-Glcp(1→, and →4)-α-d-GlcUA(1→. Galactofuranose linkages were composed of terminal β-d-Galf, (1→6)-β-d-Galf and (1→2)-β-d-Galf. Exobasidium gracile exopolysaccharides displayed significant immunoregulatory activity by activating macrophages. This research indicates that infected leaves from Camellia oleifera including the exopolysaccharides produced by the parasitic fungus Exobasidium gracile by are worth further investigation as a functional product.