Glucose-6-phosphate dehydrogenase (G6PD) activity can modulate macrophage response to Leishmania major infection

Plant mediated biosynthesis of Mn3O4 nanostructures and their biomedical applications

Nanomaterials have drawn significant attention for their biomedical and pharmaceutical applications. In the present study, manganese tetra oxide (Mn3O4) nanoparticles were prepared greenly, and their physicochemical properties were studied. Taxus baccata acetone extract was used as a safely novel precursor for reducing and stabilizing nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) and X-ray diffraction (XRD). The cytotoxicity of Mn3O4 (hausmannite) nanostructures was evaluated against murine macrophage cell line J774-A1 and U87 glioblastoma cancer cells for approximately 72 h. Spherical Mn3O4 nanoparticles with tetragonal spinel structures demonstrated minimal toxicity against normal body cells with CC50 around 876.38 μg mL-1. Moreover, Mn3O4 nanoparticles as well as the combination of antimoniate meglumine and Mn3O4 nanoparticles exhibited maximum mortality in Leishmania major. The synthesized nanominerals displayed a significant inhibitory effect against glioblastoma cancer cells at 100 μg mL-1. The selective cytotoxicity of Mn3O4 nanoparticles indicates that these biogenic agents can be employed simultaneously for diagnostic and therapeutic applications in medical applications.

The role of bone marrow microenvironment (BMM) cells in acute myeloid leukemia (AML) progression: immune checkpoints, metabolic checkpoints, and signaling pathways

Acute myeloid leukemia (AML) comprises a multifarious and heterogeneous array of illnesses characterized by the anomalous proliferation of myeloid cells in the bone marrow microenvironment (BMM). The BMM plays a pivotal role in promoting AML progression, angiogenesis, and metastasis. The immune checkpoints (ICs) and metabolic processes are the key players in this process. In this review, we delineate the metabolic and immune checkpoint characteristics of the AML BMM, with a focus on the roles of BMM cells e.g. tumor-associated macrophages, natural killer cells, dendritic cells, metabolic profiles and related signaling pathways. We also discuss the signaling pathways stimulated in AML cells by BMM factors that lead to AML progression. We then delve into the roles of immune checkpoints in AML angiogenesis, metastasis, and cell proliferation, including co-stimulatory and inhibitory ICs. Lastly, we discuss the potential therapeutic approaches and future directions for AML treatment, emphasizing the potential of targeting metabolic and immune checkpoints in AML BMM as prognostic and therapeutic targets. In conclusion, the modulation of these processes through the use of directed drugs opens up new promising avenues in combating AML. Thereby, a comprehensive elucidation of the significance of these AML BMM cells' metabolic and immune checkpoints and signaling pathways on leukemic cells can be undertaken in the future investigations. Additionally, these checkpoints and cells should be considered plausible multi-targeted therapies for AML in combination with other conventional treatments in AML. Video Abstract.

Boosting the Discovery of Small Molecule Inhibitors of Glucose-6-Phosphate Dehydrogenase for the Treatment of Cancer, Infectious Diseases, and Inflammation

We present an overview of small molecule glucose-6-phosphate dehydrogenase (G6PD) inhibitors that have potential for use in the treatment of cancer, infectious diseases, and inflammation. Both steroidal and nonsteroidal inhibitors have been identified with steroidal inhibitors lacking target selectivity. The main scaffolds encountered in nonsteroidal inhibitors are quinazolinones and benzothiazinones/benzothiazepinones. Three molecules show promise for development as antiparasitic (25 and 29) and anti-inflammatory (32) agents. Regarding modality of inhibition (MOI), steroidal inhibitors have been shown to be uncompetitive and reversible. Nonsteroidal small molecules have exhibited all types of MOI. Strategies to boost the discovery of small molecule G6PD inhibitors include exploration of structure-activity relationships (SARs) for established inhibitors, employment of high-throughput screening (HTS), and fragment-based drug discovery (FBDD) for the identification of new hits. We discuss the challenges and gaps associated with drug discovery efforts of G6PD inhibitors from in silico, in vitro, and in cellulo to in vivo studies.

Leishmanicidal activities of biosynthesized BaCO3 (witherite) nanoparticles and their biocompatibility with macrophages

The aim of this study was cost-effective and greener synthesis of barium carbonate (BaCO₃ or witherite) nanoparticles with economic importance, and to evaluate their therapeutic potentials and biocompatibility with immune cells. Barium carbonate nanoparticles were biosynthesized using black elderberry extract in one step with non-toxic precursors and simple laboratory conditions; their morphologies and specific structures were analyzed using field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The therapeutic capabilities of these nanoparticles on the immune cells of murine macrophages J774 and promastigotes Leishmania tropica were evaluated. BaCO₃ nanoparticles with IC₅₀ = 46.6 µg/mL were more effective than negative control and glucantium (positive control) in reducing promastigotes (P < 0.01). Additionally, these nanoparticles with a high value of cytotoxicity concentration 50% (CC₅₀) were less toxic to macrophage cells than glucantime; however, they were significantly different at high concentrations compared to the negative control.

The Controversial Role of Glucose-6-Phosphate Dehydrogenase Deficiency on Cardiovascular Disease: A Narrative Review

Cardiovascular disorders (CVD) are highly prevalent and the leading cause of death worldwide. Atherosclerosis is responsible for most cases of CVD. The plaque formation and subsequent thrombosis in atherosclerosis constitute an ongoing process that is influenced by numerous risk factors such as hypertension, diabetes, dyslipidemia, obesity, smoking, inflammation, and sedentary lifestyle. Among the various risk and protective factors, the role of glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common inborn enzyme disorder across populations, is still debated. For decades, it has been considered a protective factor against the development of CVD. However, in the recent years, growing scientific evidence has suggested that this inherited condition may act as a CVD risk factor. The role of G6PD deficiency in the atherogenic process has been investigated using in vitro or ex vivo cellular models, animal models, and epidemiological studies in human cohorts of variable size and across different ethnic groups, with conflicting results. In this review, the impact of G6PD deficiency on CVD was critically reconsidered, taking into account the most recent acquisitions on molecular and biochemical mechanisms, namely, antioxidative mechanisms, glutathione recycling, and nitric oxide production, as well as their mutual interactions, which may be impaired by the enzyme defect in the context of the pentose phosphate pathway. Overall, current evidence supports the notion that G6PD downregulation may favor the onset and evolution of atheroma in subjects at risk of CVD. Given the relatively high frequency of this enzyme deficiency in several regions of the world, this finding might be of practical importance to tailor surveillance guidelines and facilitate risk stratification.

Photodynamic activity of Photogem® in Leishmania promastigotes and infected macrophages

Objectives: This study aimed to evaluate the effect of photodynamic therapy (PDT) with Photogem^® in promastigotes of Leishmania braziliensis and Leishmania major, and in infected macrophages. Materials & methods: The following parameters were analyzed: Photogem^® internalization, mitochondrial activity, viability, tubulin marking and morphological alterations in promastigotes and viability in infected macrophages. Results: Photogem^® accumulated in the cytosol and adhered to the flagellum. Changes were observed in the mitochondrial activity in groups maintained in the dark, with no viability alteration. After PDT, viability decreased up to 80%, and morphology was affected. Conclusion: The results point out that PDT with Photogem^® can reduce parasite and macrophage viability.

Impaired inflammasome activation and bacterial clearance in G6PD deficiency due to defective NOX/p38 MAPK/AP-1 redox signaling

Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme of the pentose phosphate pathway that modulates cellular redox homeostasis via the regeneration of NADPH. G6PD-deficient cells have a reduced ability to induce the innate immune response, thus increasing host susceptibility to pathogen infections. An important part of the immune response is the activation of the inflammasome. G6PD-deficient peripheral blood mononuclear cells (PBMCs) from patients and human monocytic (THP-1) cells were used as models to investigate whether G6PD modulates inflammasome activation. A decreased expression of IL-1β was observed in both G6PD-deficient PBMCs and PMA-primed G6PD-knockdown (G6PD-kd) THP-1 cells upon lipopolysaccharide (LPS)/adenosine triphosphate (ATP) or LPS/nigericin stimulation. The pro-IL-1β expression of THP-1 cells was decreased by G6PD knockdown at the transcriptional and translational levels in an investigation of the expression of the inflammasome subunits. The phosphorylation of p38 MAPK and downstream c-Fos expression were decreased upon G6PD knockdown, accompanied by decreased AP-1 translocation into the nucleus. Impaired inflammasome activation in G6PD-kd THP-1 cells was mediated by a decrease in the production of reactive oxygen species (ROS) by NOX signaling, while treatment with hydrogen peroxide (H₂O₂) enhanced inflammasome activation in G6PD-kd THP-1 cells. G6PD knockdown decreased Staphylococcus aureus and Escherichia coli clearance in G6PD-kd THP-1 cells and G6PD-deficient PBMCs following inflammasome activation. These findings support the notion that enhanced pathogen susceptibility in G6PD deficiency is, in part, due to an altered redox signaling, which adversely affects inflammasome activation and the bactericidal response.

Effect of static magnetic field on morphology and growth metabolism of Flavobacterium sp. m1-14

Increasing evidence shows that static magnetic fields (SMFs) can affect microbial growth metabolism, but the specific mechanism is still unclear. In this study, we have investigated the effect of moderate-strength SMFs on growth and vitamin K₂ biosynthesis of Flavobacterium sp. m1-14. First, we designed a series of different moderate-strength magnetic field intensities (0, 50, 100, 150, 190 mT) and exposure times (0, 24, 48, 72, 120 h). With the optimization of static magnetic field intensity and exposure time, biomass and vitamin K₂ production significantly increased compared to control. The maximum vitamin K₂ concentration and biomass were achieved when exposed to 100 mT SMF for 48 h; compared with the control group, they increased by 71.3% and 86.8%, respectively. Interestingly, it was found that both the cell viability and morphology changed significantly after SMF treatment. Second, the adenosine triphosphate (ATP) and glucose-6-phosphate dehydrogenase (G6PDH) metabolism is more vigorous after exposed to 100 mT SMF. This change affects the cell energy metabolism and fermentation behavior, and may partially explain the changes in bacterial biomass and vitamin K₂ production. The results show that moderate-strength SMFs may be a promising method to promote bacterial growth and secondary metabolite synthesis.