Non‐bilayer phospholipids arrangements (NPAs) are transient molecular associations different from lipid bilayers. When they become stable, they can trigger a disease in mice resembling human lupus, ...which is mainly characterized by the production of anti‐NPA IgG antibodies. NPAs are stabilized on liposomes or cell bilayers by the drugs procainamide or chlorpromazine, which produce drug‐induced lupus in humans. Here, we evaluated the participation of the TH2 response, through its hallmark cytokine IL‐4, on the development of the lupus‐like disease in mice. Wild‐type or IL‐4 knockout BALB/c mice received liposomes bearing drug‐induced NPAs, the drugs alone, or an anti‐NPA monoclonal antibody (H308) to induce the lupus‐like disease (the last two procedures stabilize NPAs on mice cells). IL‐4 KO mice showed minor disease manifestations, compared to wild‐type mice, with decreased production of anti‐NPA IgG antibodies, no anti‐cardiolipin, anti‐histones and anticoagulant antibodies, and no kidney or skin lesions. In these mice, H308 was the only inducer of anti‐NPA IgG antibodies. These findings indicate that IL‐4 has a central role in the development of the murine lupus‐like disease induced by NPA stabilization.
Helicobacter pylori (H. pylori) is a pathogen that can remain in the stomach of an infected person for their entire life. As a result, this leads to the development of severe gastric diseases such as ...gastric cancer. In addition, current therapies have several problems including antibiotics resistance. Therefore, new practical options to eliminate this bacterium, and its induced affections, are required to avoid morbidity and mortality worldwide. One strategy in the search for new drugs is to detect compounds that inhibit a limiting step in a central metabolic pathway of the pathogen of interest. In this work, we tested 55 compounds to gain insights into their possible use as new inhibitory drugs of H. pylori glucose-6-phosphate dehydrogenase (HpG6PD) activity. The compounds YGC-1; MGD-1, MGD-2; TDA-1; and JMM-3 with their respective scaffold 1,3-thiazolidine-2,4-dione; 1H-benzimidazole; 1,3-benzoxazole, morpholine, and biphenylcarbonitrile showed the best inhibitory activity (IC50 = 310, 465, 340, 204 and 304 μM, respectively). We then modeled the HpG6PD protein by homology modeling to conduct an in silico study of the chemical compounds and discovers its possible interactions with the HpG6PD enzyme. We found that compounds can be internalized at the NADP+ catalytic binding site. Hence, they probably exert a competitive inhibitory effect with NADP+ and a non-competitive or uncompetitive effect with G6P, that of the compounds binding far from the enzyme’s active site. Based on these findings, the tested compounds inhibiting HpG6PD represent promising novel drug candidates against H. pylori.
Background
Omega‐3 long chain polyunsaturated fatty acids (LCPUFA) reduce circulating cytokines produced by monocytes. Nevertheless, whether the omega‐3 LCPUFA regulate the monocytes and their ...cytokines in Duchenne muscular dystrophy (DMD) is unknown. The aim of this study was to evaluate whether circulating pro‐inflammatory monocytes are increased and whether omega‐3 LCPUFA selectively suppress these monocytes and their cytokines in patients with DMD.
Methods
This was a double‐blind, randomized, placebo‐controlled pilot study carried out in patients with DMD supplemented with omega‐3 LCPUFA (n = 6) or sunflower oils (placebo, n = 6) for 6 months. Monocytes and their cytokines were measured at baseline and after 1, 2, 3, and 6 months of supplementation.
Results
The anti‐inflammatory monocytes (median, 95% CI) are increased at month 3 (−0.46 −13.5–9.5 vs. 8.4 5.5–12.5, p = 0.05) in the omega‐3 LCPUFA group compared with the placebo group. The pro‐inflammatory monocytes (−5.7 −63.8–114.1 vs. −51.9 −91.2 to −25.4, p = 0.026 and −16.4 −50.8–50.6 vs. −57.9 −86.9 to −18.5, p = 0.045 at months 3 and 6, respectively) and their cytokine interleukin 6 (−11.9 −93.5–148.9 vs. −64.7 −77.8 to −42.6, p = 0.019 at month 6) decreased in the omega‐3 LCPUFA group compared with the placebo group. Pro‐inflammatory monocytes decreased and anti‐inflammatory monocytes were augmented (p < 0.05) during the 6 months of supplementation with omega‐3 LCPUFA.
Conclusions
This pilot study suggests that supplementation with omega‐3 LCPUFA could have a selective reductive effect on pro‐inflammatory monocytes and their cytokines in patients with DMD. These findings also support the performance of studies in a significant population to explore the role of omega‐3 LCPUFA on monocyte populations and their cytokines in patients with DMD. This research was registered at clinicaltrials.gov (NCT018264229).
In Duchenne muscular dystrophy, muscle fiber is damaged, (1) resulting in a chronic inflammatory process (2), (3), (4), and (5). We propose that omega‐3 long chain polyunsaturated fatty acids (LCPUFA) are incorporated into muscle fiber (A). These fatty acids are precursors of anti‐inflammatory molecules (B) and also block the synthesis of pro‐inflammatory cytokines (C). The downregulation of these cytokines could modulate monocyte subpopulations by increasing the anti‐inflammatory monocytes, decreasing the intermediate and pro‐inflammatory monocytes (D), and regulating the cytokines produced by those cells. The modulation of monocyte subpopulations can influence the differentiation of anti‐inflammatory monocytes and favor the activation of the anti‐inflammatory cascade (E).
ABSTRACT
Introduction: Patients with Duchenne muscular dystrophy (DMD) demonstrate decreased bone mineral density (BD). It is not clear which factors exert the greatest impact on BD loss in these ...patients.
Methods: In 63 patients with DMD, serum cytokines (interleukin IL‐1, IL‐6, and tumor necrosis factor‐beta TNF‐β), C‐reactive protein (CRP), creatine kinase (CK), muscle function (by Vignos scale), body composition, and total BD (the latter 2 measured by dual‐energy X‐ray absorptiometry, or DEXA) were determined.
Results: The main factors associated with BD loss were muscle function (34.0%; β = −0.139; P < 0.023) and age (36.7%; β = −0.151; P = 0.004). Cytokines, CRP, body fat mass, and CK did not contribute to BD loss.
Discussion: Muscle function and age contribute to BD loss in DMD. We propose that a cut‐off of at least 6 points for the Vignos scale and at least 10.5 years of age predict a Z‐score of less than or equal to −2.0. Muscle Nerve 59:417–421, 2019
Pathogenic bacteria have several mechanisms to evade the host’s immune response and achieve an efficient infection. Bacterial extracellular vesicles (EVs) are a relevant cellular communication ...mechanism, since they can interact with other bacterial cells and with host cells. In this review, we focus on the EVs produced by some World Health Organization (WHO) priority Gram-negative and Gram-positive pathogenic bacteria; by spore-producing bacteria; by Mycobacterium tuberculosis (a bacteria with a complex cell wall); and by Treponema pallidum (a bacteria without lipopolysaccharide). We describe the classification and the general properties of bacterial EVs, their role during bacterial infections and their effects on the host immune response. Bacterial EVs contain pathogen-associated molecular patterns that activate innate immune receptors, which leads to cytokine production and inflammation, but they also contain antigens that induce the activation of B and T cell responses. Understanding the many effects of bacterial EVs on the host’s immune response can yield new insights on the pathogenesis of clinically important infections, but it can also lead to the development of EV-based diagnostic and therapeutic strategies. In addition, since EVs are efficient activators of both the innate and the adaptive immune responses, they constitute a promising platform for vaccine development.
Chagas disease is caused by
and represents a major public health problem, which is endemic in Latin America and emerging in the rest of the world. The two drugs that are currently available for its ...treatment, Benznidazole and Nifurtimox, are partially effective in the chronic phase of the disease. In this study, we designed and synthesized the benzyl ester of N-isopropyl oxamic acid (B-NIPOx), which is a non-polar molecule that crosses cell membranes. B-NIPOx is cleaved inside the parasite by carboxylesterases, releasing benzyl alcohol (a molecule with antimicrobial activity), and NIPOx, which is an inhibitor of α-hydroxy acid dehydrogenase isozyme II (HADH-II), a key enzyme in
metabolism. We evaluated B-NIPOx cytotoxicity, its toxicity in mice, and its inhibitory activity on purified HADH-II and on
homogenates. We then evaluated the trypanocidal activity of B-NIPOx in vitro and in vivo and its effect in the intestine of
-infected mice. We found that B-NIPOx had higher trypanocidal activity on epimastigotes and trypomastigotes than Benznidazole and Nifurtimox, that it was more effective to reduce blood parasitemia and amastigote nests in infected mice, and that, in contrast to the reference drugs, it prevented the development of Chagasic enteropathy.
Tuberculosis is an infectious disease caused by
(Mtb). In the lungs, macrophages and neutrophils are the first immune cells that have contact with the infecting mycobacteria. Neutrophils are ...phagocytic cells that kill microorganisms through several mechanisms, which include the lytic enzymes and antimicrobial peptides that are found in their lysosomes, and the production of reactive oxygen species. Neutrophils also release extracellular vesicles (EVs) (100-1,000 nm in diameter) to the extracellular milieu; these EVs consist of a lipid bilayer surrounding a hydrophilic core and participate in intercellular communication. We previously demonstrated that human neutrophils infected
with Mtb H37Rv release EVs (EV-TB), but the effect of these EVs on other cells relevant for the control of Mtb infection, such as macrophages, has not been completely analyzed. In this study, we characterized the EVs produced by non-stimulated human neutrophils (EV-NS), and the EVs produced by neutrophils stimulated with an activator (PMA), a peptide derived from bacterial proteins (fMLF) or Mtb, and observed that the four EVs differed in their size. Ligands for toll-like receptor (TLR) 2/6 were detected in EV-TB, and these EVs favored a modest increase in the expression of the co-stimulatory molecules CD80, a higher expression of CD86, and the production of higher amounts of TNF-α and IL-6, and of lower amounts of TGF-β, in autologous human macrophages, compared with the other EVs. EV-TB reduced the amount of intracellular Mtb in macrophages, and increased superoxide anion production in these cells. TLR2/6 ligation and superoxide anion production are known inducers of autophagy; accordingly, we found that EV-TB induced higher expression of the autophagy-related marker LC3-II in macrophages, and the co-localization of LC3-II with Mtb inside infected macrophages. The intracellular mycobacterial load increased when autophagy was inhibited with wortmannin in these cells. In conclusion, our results demonstrate that neutrophils produce different EVs in response to diverse activators, and that EV-TB activate macrophages and promote the clearance of intracellular Mtb through early superoxide anion production and autophagy induction, which is a novel role for neutrophil-derived EVs in the immune response to Mtb.
Trichomoniasis is a sexually transmitted disease with a high incidence worldwide, affecting 270 million people. Despite the existence of a catalog of available drugs to combat this infection, their ...extensive use promotes the appearance of resistant
(
), and some side effects in treated people, which are reasons why it is necessary to find new alternatives to combat this infection. In this study, we investigated the impact of an in-house library comprising 55 compounds on the activity of the fused
G6PD::6PGL (TvG6PD::6PGL) protein, a protein mediating the first reaction step of the pentose phosphate pathway (PPP), a crucial pathway involved in the parasite's energy production. We found four compounds: JMM-3, CNZ-3, CNZ-17, and MCC-7, which inhibited the TvG6PD::6PGL protein by more than 50%. Furthermore, we determined the IC
, the inactivation constants, and the type of inhibition. Our results showed that these inhibitors induced catalytic function loss of the TvG6PD::6PGL enzyme by altering its secondary and tertiary structures. Finally, molecular docking was performed for the best inhibitors, JMM-3 and MCC-7. All our findings demonstrate the potential role of these selected hit compounds as TvG6PD::6PGL enzyme selective inhibitors.
Metronidazole (MTZ) is the most common drug used against Trichomonas vaginalis (T. vaginalis) infections; however, treatment failures and high rates of recurrence of trichomoniasis have been ...reported, suggesting the presence of resistance in T. vaginalis to MTZ. Therefore, research into new therapeutic options against T. vaginalis infections has become increasingly urgent. This study investigated the trichomonacidal activity of a series of five imidazole carbamate compounds (AGR-1, AGR-2, AGR-3, AGR-4, and AGR-5) through in vitro susceptibility assays to determine the IC50 value of each compound. All five compounds demonstrated potent trichomonacidal activity, with IC50 values in the nanomolar range and AGR-2 being the most potent (IC50 400 nM). To gain insight into molecular events related to AGR-induced cell death in T. vaginalis, we analyzed the expression profiles of some metabolic genes in the trophozoites exposed to AGR compounds and MTZ. It was found that both AGR and MTZ compounds reduced the expression of the glycolytic genes (CK, PFK, TPI, and ENOL) and genes involved in metabolism (G6PD, TKT, TALDO, NADHOX, ACT, and TUB), suggesting that disturbing these key metabolic genes alters the survival of the T. vaginalis parasite and that they probably share a similar mechanism of action. Additionally, the compounds showed low cytotoxicity in the Caco-2 and HT29 cell lines, and the results of the ADMET analysis indicated that these compounds have pharmacokinetic properties similar to those of MTZ. The findings offer significant insights that can serve as a basis for future in vivo studies of the compounds as a potential new treatment against T. vaginalis.
Protozoan parasites, such as
and
, cause the most prevalent infections in humans in developing countries and provoke significant morbidity and mortality in endemic countries. Despite its ...side-effects, metronidazole is still the drug of choice as a giardiacidal and trichomonacidal tissue-active agent. However, the emergence of metronidazole resistance and its evolved strategies of parasites to evade innate host defenses have hindered the identification and development of new therapeutic strategies against these parasites. Here, we tested five synthesized benzimidazole derivatives as possible drugs for treating giardiasis and trichomoniasis, probing the bifunctional enzyme glucose 6-phosphate dehydrogenase::6-phosphogluconolactone from
(GlG6PD::6PGL) and
(TvG6PD::6PGL) as a drug target. The investigated benzimidazole derivatives were
,
,
,
, and
. The recombinant enzymes were used in inhibition assays, and in silico computational predictions and spectroscopic studies were applied to follow the structural alteration of the enzymes and identify the possible mechanism of inhibition. We identified two potent benzimidazole compounds (
and
), which are capable of inhibiting both protozoan G6PD::6PGL enzymes and in vitro assays with these parasites, showing that these compounds also affect their viability. These results demonstrate that other therapeutic targets of the compounds are the enzymes GlG6PD::6PGL and TvG6PD::6PGL, which contribute to their antiparasitic effect and their possible use in antigiardial and trichomonacidal therapies.
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