-
International Journal of Molecular... Jun 2024Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell...
Bacterial nitroreductase enzymes capable of activating imaging probes and prodrugs are valuable tools for gene-directed enzyme prodrug therapies and targeted cell ablation models. We recently engineered a nitroreductase ( NfsB F70A/F108Y) for the substantially enhanced reduction of the 5-nitroimidazole PET-capable probe, SN33623, which permits the theranostic imaging of vectors labeled with oxygen-insensitive bacterial nitroreductases. This mutant enzyme also shows improved activation of the DNA-alkylation prodrugs CB1954 and metronidazole. To elucidate the mechanism behind these enhancements, we resolved the crystal structure of the mutant enzyme to 1.98 Å and compared it to the wild-type enzyme. Structural analysis revealed an expanded substrate access channel and new hydrogen bonding interactions. Additionally, computational modeling of SN33623, CB1954, and metronidazole binding in the active sites of both the mutant and wild-type enzymes revealed key differences in substrate orientations and interactions, with improvements in activity being mirrored by reduced distances between the N5-H of isoalloxazine and the substrate nitro group oxygen in the mutant models. These findings deepen our understanding of nitroreductase substrate specificity and catalytic mechanisms and have potential implications for developing more effective theranostic imaging strategies in cancer treatment.
Topics: Nitroreductases; Nitroimidazoles; Metronidazole; Prodrugs; Escherichia coli Proteins; Positron-Emission Tomography; Escherichia coli; Catalytic Domain; Protein Engineering; Models, Molecular; Aziridines
PubMed: 38928299
DOI: 10.3390/ijms25126593 -
International Journal of Molecular... Jun 2024It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid...
It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid arthritis. The molecular chaperone HSP60 alone induces inflammatory cytokine IL-6 and the co-chaperone HSP10 alone inhibits IL-6 induction. HSP60 and HSP10 form a complex in the presence of ATP. We analyzed the effects of Mizoribine, which is structurally similar to ATP, on the structure and physiological functions of HSP60-HSP10 using Native/PAGE and transmission electron microscopy. At low concentrations of Mizoribine, no complex formation of HSP60-HSP10 was observed, nor was the expression of IL-6 affected. On the other hand, high concentrations of Mizoribine promoted HSP60-HSP10 complex formation and consequently suppressed IL-6 expression. Here, we propose a novel mechanism of immunosuppressive action of Mizoribine.
Topics: Ribonucleosides; Interleukin-6; Chaperonin 60; Humans; Immunosuppressive Agents; Animals; Mice
PubMed: 38928158
DOI: 10.3390/ijms25126452 -
International Journal of Molecular... Jun 2024Chloroquine (CQ) is a 4-aminoquinoline derivative largely employed in the management of malaria. CQ treatment exploits the drug's ability to cross the erythrocyte...
Chloroquine (CQ) is a 4-aminoquinoline derivative largely employed in the management of malaria. CQ treatment exploits the drug's ability to cross the erythrocyte membrane, inhibiting heme polymerase in malarial trophozoites. Accumulation of CQ prevents the conversion of heme to hemozoin, causing its toxic buildup, thus blocking the survival of Plasmodium parasites. Recently, it has been reported that CQ is able to exert antiviral properties, mainly against HIV and SARS-CoV-2. This renewed interest in CQ treatment has led to the development of new studies which aim to explore its side effects and long-term outcome. Our study focuses on the effects of CQ in non-parasitized red blood cells (RBCs), investigating hemoglobin (Hb) functionality, the anion exchanger 1 (AE1) or band 3 protein, caspase 3 and protein tyrosine phosphatase 1B (PTP-1B) activity, intra and extracellular ATP levels, and the oxidative state of RBCs. Interestingly, CQ influences the functionality of both Hb and AE1, the main RBC proteins, affecting the properties of Hb oxygen affinity by shifting the conformational structure of the molecule towards the R state. The influence of CQ on AE1 flux leads to a rate variation of anion exchange, which begins at a concentration of 2.5 μM and reaches its maximum effect at 20 µM. Moreover, a significant decrease in intra and extracellular ATP levels was observed in RBCs pre-treated with 10 µM CQ vs. erythrocytes under normal conditions. This effect is related to the PTP-1B activity which is reduced in RBCs incubated with CQ. Despite these metabolic alterations to RBCs caused by exposure to CQ, no signs of variations in oxidative state or caspase 3 activation were recorded. Our results highlight the antithetical effects of CQ on the functionality and metabolism of RBCs, and encourage the development of new research to better understand the multiple potentiality of the drug.
Topics: Erythrocytes; Humans; Chloroquine; Hemoglobins; Anion Exchange Protein 1, Erythrocyte; Adenosine Triphosphate; Antimalarials; Caspase 3
PubMed: 38928131
DOI: 10.3390/ijms25126424 -
Antibiotics (Basel, Switzerland) Jun 2024() is a multidrug-resistant nontuberculous mycobacterium (NTM) that is responsible for a wide spectrum of infections in humans. The lack of effective bactericidal drugs...
() is a multidrug-resistant nontuberculous mycobacterium (NTM) that is responsible for a wide spectrum of infections in humans. The lack of effective bactericidal drugs and the formation of biofilm make its clinical treatment very difficult. The FDA-approved drug library containing 3048 marketed and pharmacopeial drugs or compounds was screened at 20 μM against type strain 19977 in 7H9 medium, and 62 hits with potential antimicrobial activity against were identified. Among them, bithionol, a clinically approved antiparasitic agent, showed excellent antibacterial activity and inhibited the growth of three different subtypes of from 0.625 μM to 2.5 μM. We confirmed the bactericidal activity of bithionol by the MBC/MIC ratio being ≤4 and the time-kill curve study and also electron microscopy study. Interestingly, it was found that at 128 μg/mL, bithionol could completely eliminate biofilms after 48h, demonstrating an outstanding antibiofilm capability compared to commonly used antibiotics. Additionally, bithionol could eliminate 99.9% of biofilm bacteria at 64 μg/mL, 99% at 32 μg/mL, and 90% at 16 μg/mL. Therefore, bithionol may be a potential candidate for the treatment of infections due to its significant antimicrobial and antibiofilm activities.
PubMed: 38927195
DOI: 10.3390/antibiotics13060529 -
Biomolecules Jun 2024Alterations in mitochondrial function have been linked to a variety of cellular and organismal stress responses including apoptosis, aging, neurodegeneration and...
Alterations in mitochondrial function have been linked to a variety of cellular and organismal stress responses including apoptosis, aging, neurodegeneration and tumorigenesis. However, adaptation to mitochondrial dysfunction can occur through the activation of survival pathways, whose mechanisms are still poorly understood. The yeast is an invaluable model organism for studying how mitochondrial dysfunction can affect stress response and adaptation processes. In this study, we analyzed and compared in the absence and in the presence of osmostress wild-type cells with two models of cells lacking mitochondrial DNA: ethidium bromide-treated cells (ρ) and cells lacking the mitochondrial pyrimidine nucleotide transporter (Δ). Our results revealed that the lack of mitochondrial DNA provides an advantage in the kinetics of stress response. Additionally, wild-type cells exhibited higher osmosensitivity in the presence of respiratory metabolism. Mitochondrial mutants showed increased glycerol levels, required in the short-term response of yeast osmoadaptation, and prolonged oxidative stress. The involvement of the mitochondrial retrograde signaling in osmoadaptation has been previously demonstrated. The expression of , encoding the peroxisomal isoform of citrate synthase and whose up-regulation is prototypical of RTG pathway activation, appeared to be increased in the mutants. Interestingly, selected TCA cycle genes, and , whose expression depends on RTG signaling upon stress, showed a different regulation in ρ and Δ cells. These data suggest that osmoadaptation can occur through different mechanisms in the presence of mitochondrial defects and will allow us to gain insight into the relationships among metabolism, mitochondria-mediated stress response, and cell adaptation.
Topics: Saccharomyces cerevisiae; DNA, Mitochondrial; Saccharomyces cerevisiae Proteins; Mitochondria; Adaptation, Physiological; Oxidative Stress; Glycerol; Ethidium
PubMed: 38927107
DOI: 10.3390/biom14060704 -
Malaria Journal Jun 2024Although Tanzania adopted and has been implementing effective interventions to control and eventually eliminate malaria, the disease is still a leading public health...
High prevalence and risk of malaria among asymptomatic individuals from villages with high prevalence of artemisinin partial resistance in Kyerwa district of Kagera region, north-western Tanzania.
BACKGROUND
Although Tanzania adopted and has been implementing effective interventions to control and eventually eliminate malaria, the disease is still a leading public health problem, and the country experiences heterogeneous transmission. Recent studies reported the emergence of parasites with artemisinin partial resistance (ART-R) in Kagera region with high prevalence (> 10.0%) in two districts of Karagwe and Kyerwa. This study assessed the prevalence and predictors/risk of malaria infections among asymptomatic individuals living in a hyperendemic area where ART-R has emerged in Kyerwa District of Kagera region, north-western Tanzania.
METHODS
This was a community-based cross-sectional survey which was conducted in July and August 2023 and involved individuals aged ≥ 6 months from five villages in Kyerwa district. Demographic, anthropometric, clinical, parasitological, type of house inhabited and socio-economic status (SES) data were collected using electronic capture tools run on Open Data Kit (ODK) software. Predictors/risks of malaria infections were determined by univariate and multivariate logistic regression, and the results were presented as crude (cORs) and adjusted odds ratios (aORs), with 95% confidence intervals (CIs).
RESULTS
Overall, 4454 individuals were tested using rapid diagnostic tests (RDTs), and 1979 (44.4%) had positive results. The prevalence of malaria infections ranged from 14.4% to 68.5% and varied significantly among the villages (p < 0.001). The prevalence and odds of infections were significantly higher in males (aOR = 1.28, 95% CI 1.08 -1.51, p = 0.003), school children (aged 5-≤10 years (aOR = 3.88, 95% CI 3.07-4.91, p < 0.001) and 10-≤15 years (aOR = 4.06, 95% CI 3.22-5.13, p < 0.001)) and among individuals who were not using bed nets (aOR = 1.22, 95% CI 1.03-1.46, p = 0.024). The odds of malaria infections were also higher in individuals with lower SES (aOR = 1.42, 95% CI 1.17-1.72, p < 0.001), and living in houses without windows (aOR = 2.08, 95% CI 1.46-2.96, p < 0.001), partially open (aOR = 1.33, 95% CI 1.11-1.58, p = 0.002) or fully open windows (aOR = 1.30, 95%CI 1.05-1.61, p = 0.015).
CONCLUSION
The five villages had a high prevalence of malaria infections and heterogeneity at micro-geographic levels. Groups with higher odds of malaria infections included school children, males, and individuals with low SES, living in poorly constructed houses or non-bed net users. These are important baseline data from an area with high prevalence of parasites with ART-R and will be useful in planning interventions for these groups, and in future studies to monitor the trends and potential spread of such parasites, and in designing a response to ART-R.
Topics: Tanzania; Male; Prevalence; Female; Humans; Artemisinins; Cross-Sectional Studies; Child; Child, Preschool; Adolescent; Adult; Young Adult; Antimalarials; Middle Aged; Infant; Drug Resistance; Malaria; Aged; Malaria, Falciparum; Risk Factors; Plasmodium falciparum
PubMed: 38926854
DOI: 10.1186/s12936-024-05019-5 -
BMC Pediatrics Jun 2024Despite the highest (88%) Prevention of Mother-To-Child Transmission (PMTCT) of HIV coverage in Eastern Africa, 50% of new HIV infections in children aged 0-14 years...
Feeding modalities, HIV transmission and its predictors among HIV-exposed infants visited Gamo and Gofa zones public health facilities, Southern Ethiopia: a retrospective follow up study.
BACKGROUND
Despite the highest (88%) Prevention of Mother-To-Child Transmission (PMTCT) of HIV coverage in Eastern Africa, 50% of new HIV infections in children aged 0-14 years occur in the region.
OBJECTIVE
The aim of this study was to assess the feeding modalities, the rate of HIV transmission and its predictors among HIV exposed infants (HIV-EIs) visited Gamo and Gofa Zones public health facilities, Southern Ethiopia from January 2013 to February 2019.
METHOD AND MATERIALS
Institution-based retrospective follow up study was employed among 450 HIV-EIs having DNA/PCR test results. All infant-mother pair records in selected health facilities were reviewed using a standard data extraction tool from March to July 2019. HIV transmission probabilities were assessed by Kaplan-Meier time-to-event analysis method and log-rank tests were used to compare the risk among different groups. The Cox-proportional hazards model, adjusted on infant feeding modalities and other co-variants was used to identify predictors of HIV transmission, and statistical significance was declared at a p-value of < 0.05.
RESULTS
In total, 383 complete records were analyzed. In the study, 85.6% (95%CI: 81.6%, 89.1%) of HIV-EIs were exclusively breastfed in the first six months. The 18 months probability of infant HIV transmission was 64 (16.7%) (95%CI: 13.1%-20.8%). The risk of HIV-transmission was higher among infants who were delivered at the hospital than health centers/health posts (AHR = 3.07; 95%CI: 1.19, 7.95); discontinued Cotrimoxazole prophylaxis in at least one visit (AHR = 6.32; 95%CI: 3.35, 11.94); did not exclusively breastfeed (AHR = 3.07; 95%CI: 1.72, 5.47) and came from urban areas (AHR = 5.90; 95%CI: 1.40, 24.85).
CONCLUSIONS
The study showed that HIV-EIs had a greater rate of 18 months HIV transmission than the national pooled prevalence. The risk of transmission is higher among infants who do not breastfeed exclusively for the first 6 months, and the risk increases with the number of months spent by breastfeeding. Therefore, strengthening counselling on safer feeding options and Cotrimoxazole prophylaxis use; provision of quality PMTCT service with special focus in hospitals and urban residents were recommended.
Topics: Humans; Ethiopia; HIV Infections; Infectious Disease Transmission, Vertical; Retrospective Studies; Infant; Female; Breast Feeding; Male; Infant, Newborn; Follow-Up Studies; Bottle Feeding; Trimethoprim, Sulfamethoxazole Drug Combination; Adult; Risk Factors; Infant Formula
PubMed: 38926639
DOI: 10.1186/s12887-024-04894-w -
Scientific Reports Jun 2024The aim of this study is to introduce a dental capping agent for the treatment of pulp inflammation (pulpitis). Nanohydroxyapatite with Elaeagnus angustifolia L. extract...
The aim of this study is to introduce a dental capping agent for the treatment of pulp inflammation (pulpitis). Nanohydroxyapatite with Elaeagnus angustifolia L. extract (nHAEA) loaded with metronidazole (nHAEA@MTZ) was synthesized and evaluated using a lipopolysaccharide (LPS) in vitro model of pulpitis. nHAEA was synthesized through sol-gel method and analyzed using Scanning Electron Microscopy, Transmission Electron Microscopy, and Brunauer Emmett Teller. Inflammation in human dental pulp stem cells (HDPSCs) induced by LPS. A scratch test assessed cell migration, RT PCR measured cytokines levels, and Alizarin red staining quantified odontogenesis. The nHAEA nanorods were 17-23 nm wide and 93-146 nm length, with an average pore diameter of 27/312 nm, and a surface area of 210.89 m/g. MTZ loading content with controlled release, suggesting suitability for therapeutic applications. nHAEA@MTZ did not affect the odontogenic abilities of HDPSCs more than nHAEA. However, it was observed that nHAEA@MTZ demonstrated a more pronounced anti-inflammatory effect. HDPSCs treated with nanoparticles exhibited improved migration compared to other groups. These findings demonstrated that nHAEA@MTZ could be an effective material for pulp capping and may be more effective than nHAEA in reducing inflammation and activating HDPSCs to enhance pulp repair after pulp damage.
Topics: Plant Extracts; Humans; Pulpitis; Metronidazole; Dental Pulp; Durapatite; Nanoparticles; Green Chemistry Technology; Drug Carriers; Stem Cells; Cell Movement; Cells, Cultured
PubMed: 38926433
DOI: 10.1038/s41598-024-65582-4 -
BMJ Case Reports Jun 2024This report describes a male in his late 20s who presented with a 2-month history of recurrent haemoptysis and chest pain. A chronic infection, such as tuberculosis, was...
This report describes a male in his late 20s who presented with a 2-month history of recurrent haemoptysis and chest pain. A chronic infection, such as tuberculosis, was suspected. He had undergone surgical resection of an intrapericardial hydatid cyst in the past. His blood investigations showed peripheral eosinophilia, and his chest X-ray showed a cystic oval lesion in the left upper zone. A CT pulmonary angiogram revealed filling defects in the bilateral segmental and subsegmental arteries with a cystic lesion in the left upper lobe. Further workup, including bronchoalveolar lavage culture and MRI of the thorax, confirmed the diagnosis of a hydatid cyst of pulmonary echinococcosis. This case illustrates the presentation of multisystemic echinococcosis in a young male with no other risk factors, initially treated with surgical resection and antihelminthic therapy. The disease later recurred, which required prolonged medications, which brought the patient into remission.
Topics: Humans; Male; Echinococcosis, Pulmonary; Adult; Albendazole; Hemoptysis; Anthelmintics; Recurrence; Chest Pain; Heart Diseases; Tomography, X-Ray Computed; Magnetic Resonance Imaging; Follow-Up Studies
PubMed: 38926123
DOI: 10.1136/bcr-2023-256689 -
Journal of Medicinal Chemistry Jun 2024Several G-quadruplex nucleic acid (G4s) ligands have been developed seeking target selectivity in the past decade. Naphthalene diimide (NDI)-based compounds are...
Several G-quadruplex nucleic acid (G4s) ligands have been developed seeking target selectivity in the past decade. Naphthalene diimide (NDI)-based compounds are particularly promising due to their biological activity and red-fluorescence emission. Previously, we demonstrated the existence of G4s in the promoter region of parasite genomes, assessing the effectiveness of NDI-derivatives against them. Here, we explored the biological activity of a small library of G4-DNA ligands, exploiting the NDI pharmacophore, against both and parasites. Biophysical and biological assays were conducted. Among the various families analyzed, core-extended NDIs exhibited the most promising results concerning the selectivity and antiparasitic effects. NDI emerged as the most potent, with an IC of 0.011 nM against and remarkable selectivity vs MRC-5 cells (3454-fold). Fascinating, is 480-fold more potent than the standard drug pentamidine (IC = 5.3 nM). Cellular uptake and parasite localization were verified by exploiting core-extended NDI red-fluorescent emission.
PubMed: 38924701
DOI: 10.1021/acs.jmedchem.4c00135