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Acta Tropica Jun 2024Gram-positive catalase-negative cocci (GPCNCs) are significant components of the genital microbiota in sheep and goats. However, characterizing them can be difficult due...
Gram-positive catalase-negative cocci (GPCNCs) are significant components of the genital microbiota in sheep and goats. However, characterizing them can be difficult due to overlapping culture features and the limited information on their susceptibility to antibiotics. In this study, 97 foreskin and 13 vaginal swabs were investigated using a culturomic approach. Of 110 animals, 76 (69.09 %) hosted GPCNCs, including strains from Streptococcaceae (37, 33.64 %), Aerococcaceae (30, 27.27 %), Enterococcaceae (6, 5.45 %) and other minor species. With increasing antimicrobial resistance rates in livestock, surveillance programs are globally required, so we conducted a pilot study on GPCNCs isolated from the genital mucosa surfaces of sheep and goats using the minimal inhibitory concentration assay (MIC). Due to gaps in interpretative standard breakpoints, normalized resistance interpretation was used for setting epidemiological susceptibility cut-off values (CO). Of 57 suitable strains, the majority (80.71 %) showed high CO with decrease susceptibility to at least one antimicrobial class, with 22.81 % displaying multiresistant profiles. Of interest, combined resistances to beta-lactams, macrolides, lincosamides, and tetracyclines were detected in strains of Streptococcus plurianimalium. Further combinations, including resistance to beta-lactams, pleuromutilins, aminoglycosides, and lincosamides, were also recorded in both Streptococcus uberis and Enterococcus spp. strains. Being beta-lactams, macrolides, and tetracyclines the most used antibiotics in livestock worldwide, our results highlight the need for their prudent use. Collectively, our findings highlight that small ruminant genital microbiota can serve as reservoirs for opportunistic severe pathogens, often zoonotic, carrying multidrug resistances, thus standing for high risks for both animals and humans.
PubMed: 38944406
DOI: 10.1016/j.actatropica.2024.107305 -
The Journal of Biological Chemistry Jun 2024One of seven natural CO fixation pathways, the anaerobic Wood-Ljungdahl Pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through...
One of seven natural CO fixation pathways, the anaerobic Wood-Ljungdahl Pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through organometallic intermediates, and in conserving (versus utilizing) net ATP. The key enzyme in the WLP is acetyl-CoA synthase (ACS), which uses an active site [2Ni-4Fe-4S] cluster (A-cluster), a CO tunnel, and an organometallic (Ni-CO, Ni-methyl, and Ni-acetyl) reaction sequence to generate acetyl-CoA. Here we reveal that an alcove, which interfaces the tunnel and the A-cluster, is essential for CO fixation and autotrophic growth by the WLP. In vitro spectroscopy, kinetics, binding, and in vivo growth experiments reveal that a Phe229A substitution at one wall of the alcove decreases CO affinity thirty-fold and abolishes autotrophic growth; however, a F229W substitution enhances CO binding 80-fold. Our results indicate the structure of the alcove is exquisitely tuned to concentrate CO near the A-cluster; protect ACS from CO loss during catalysis, provide a haven for inhibitory CO, and stabilize the tetrahedral coordination at the Ni site where CO binds. The directing, concentrating, and protective effects of the alcove explain the inability of F209A to grow autotrophically. The alcove also could help explain current controversies over whether ACS binds CO and methyl through a random or ordered mechanism. Our work redefines what we historically refer to as the metallocenter "active site". The alcove is so crucial for enzymatic function that we propose it is part of the active site. The community should now look for such alcoves in all "gas handling" metalloenzymes.
PubMed: 38944127
DOI: 10.1016/j.jbc.2024.107503 -
The Journal of Biological Chemistry Jun 2024The beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the predominant β-secretase, cleaving the amyloid precursor protein (APP) via the amyloidogenic...
The beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the predominant β-secretase, cleaving the amyloid precursor protein (APP) via the amyloidogenic pathway. In addition, BACE1 as an amyloid degrading enzyme (ADE), cleaves Aβ to produce the C-terminally truncated non-toxic Aβ fragment Aβ34 which is an indicator of amyloid clearance. Here, we analyzed effects of BACE1 inhibitors on its opposing enzymatic functions, i.e., amyloidogenic (Aβ producing) and amyloidolytic (Aβ degrading) activities, using cell culture models with varying BACE1/APP ratios. Under high level BACE1 expression, low-dose inhibition unexpectedly yielded a two-fold increase in Aβ42 and Aβ40 levels. The concomitant decrease in Aβ34 and secreted APPβ levels suggested that the elevated Aβ42 and Aβ40 levels were due to the attenuated Aβ degrading activity of BACE1. Notably, the amyloidolytic activity of BACE1 was impeded at lower BACE1 inhibitor concentrations compared to its amyloidogenic activity, thereby suggesting that the Aβ degrading activity of BACE1 was more sensitive to inhibition than its Aβ producing activity. Under endogenous BACE1 and APP levels, "low-dose" BACE1 inhibition affected both the Aβ producing and degrading activities of BACE1, i.e., significantly increased Aβ42/Aβ40 ratio and decreased Aβ34 levels, respectively. Further, we incubated recombinant BACE1 with synthetic Aβ peptides and found that BACE1 has higher affinity for Aβ substrates over APP. In summary, our results suggest that stimulating BACE1's ADE activity and halting Aβ production without decreasing Aβ clearance could still be a promising therapeutic approach with new, yet to be developed, BACE1 modulators.
PubMed: 38944120
DOI: 10.1016/j.jbc.2024.107510 -
EBioMedicine Jun 2024γ-aminobutyric acid (GABA), known as the main inhibitory neurotransmitter in the brain, exerts immunomodulatory functions by interaction with immune cells, including T...
BACKGROUND
γ-aminobutyric acid (GABA), known as the main inhibitory neurotransmitter in the brain, exerts immunomodulatory functions by interaction with immune cells, including T cells. Metabolic programs of T cells are closely linked to their effector functions including proliferation, differentiation, and cytokine production. The physiological molecules glucose and insulin may provide environmental cues and guidance, but whether they coordinate to regulate GABA-mediated T cell immunomodulation is still being examined.
METHODS
CD4 T cells that were isolated from blood samples from healthy individuals and from patients with type 1 diabetes (T1D) were activated in vitro. We carried out metabolic assays, multiple proximity extension assay (PEA), ELISA, qPCR, immunoblotting, immunofluorescence staining, flow cytometry analysis, MS-based proteomics, as well as electrophysiology and live-cell Ca imaging.
FINDINGS
We demonstrate that GABA-mediated reduction of metabolic activity and the release of inflammatory proteins, including IFNγ and IL-10, were abolished in human CD4 T cells from healthy individuals and patients with T1D when the glucose concentration was elevated above levels typically observed in healthy people. Insulin increased GABA receptor-subunit ρ2 expression, enhanced the GABA receptors-mediated currents and Ca influx. GABA decreased, whereas insulin sustained, hexokinase activity and glycolysis in a glucose concentration-dependent manner.
INTERPRETATION
These findings support that metabolic factors, such as glucose and insulin, influence the GABA-mediated immunomodulation of human primary T cells effector functions.
FUNDING
The Swedish Children's Diabetes Foundation, The Swedish Diabetes Foundation, The Swedish Research Council 2018-02952, EXODIAB, The Ernfors Foundation, The Thurings Foundation and the Science for Life Laboratory.
PubMed: 38943728
DOI: 10.1016/j.ebiom.2024.105217 -
Animal Microbiome Jun 2024Pinus koraiensis cone essential oil (PEO) contains functional compounds such as monoterpene hydrocarbons, and the administration of PEO reduced methane (CH) emissions...
Metataxonomic and metabolomic profiling revealed Pinus koraiensis cone essential oil reduced methane emission through affecting ruminal microbial interactions and host-microbial metabolism.
BACKGROUND
Pinus koraiensis cone essential oil (PEO) contains functional compounds such as monoterpene hydrocarbons, and the administration of PEO reduced methane (CH) emissions during growing phase of goats. However, the mode of action of PEO driven CH reduction is not known, especially how the administration of PEO can affect rumen microbiota and host metabolism in goats during the fattening phase. This study aimed to elucidate the potential microbial and host responses PEO supplementation in goats using metataxonomics (prokaryotes and protozoa) and metabolomics (rumen fluid and serum).
RESULTS
Ten fattening Korean native goats were divided into two dietary groups: control (CON; basal diet without additives) and PEO (basal diet + 1.5 g/d of PEO) with a 2 × 2 crossover design and the treatment lasted for 11 weeks. Administration of PEO reduced CH concentrations in the exhaled gas from eructation by 12.0-13.6% (P < 0.05). Although the microbial composition of prokaryotes (bacteria and archaea) and protozoa in the rumen was not altered after PEO administration. MaAsLin2 analysis revealed that the abundance of Selenomonas, Christensenellaceae R-7 group, and Anaerovibrio were enriched in the rumen of PEO supplemented goats (Q < 0.1). Co-occurrence network analysis revealed that Lachnospiraceae AC2044 group and Anaerovibrio were the keystone taxa in the CON and PEO groups, respectively. Methane metabolism (P < 0.05) was enriched in the CON group, whereas metabolism of sulfur (P < 0.001) and propionate (P < 0.1) were enriched in the PEO group based on microbial predicted functions. After PEO administration, the abundance of 11 rumen and 4 serum metabolites increased, whereas that of 25 rumen and 14 serum metabolites decreased (P < 0.1). Random forest analysis identified eight ruminal metabolites that were altered after PEO administration, among which four were associated with propionate production, with predictive accuracy ranging from 0.75 to 0.88. Additionally, we found that serum sarcosine (serum metabolite) was positively correlated with CH emission parameters and abundance of Methanobrevibacter in the rumen (|r|≥ 0.5, P < 0.05).
CONCLUSIONS
This study revealed that PEO administration reduced CH emission from of fattening goats with altered microbial interactions and metabolites in the rumen and host. Importantly, PEO administration affected utilizes various mechanisms such as formate, sulfur, methylated amines metabolism, and propionate production, collectively leading to CH reduction. The knowledge is important for future management strategies to maintain animal production and health while mitigate CH emission.
PubMed: 38943213
DOI: 10.1186/s42523-024-00325-4 -
Cancer Cell International Jun 2024Despite effective strategies, resistance in EGFR mutated lung cancer remains a challenge. Metabolic reprogramming is one of the main mechanisms of tumor drug resistance....
BACKGROUND
Despite effective strategies, resistance in EGFR mutated lung cancer remains a challenge. Metabolic reprogramming is one of the main mechanisms of tumor drug resistance. A class of drugs known as "statins" inhibit lipid cholesterol metabolism and are widely used in patients with cardiovascular diseases. Previous studies have also documented its ability to improve the therapeutic impact in lung cancer patients who receive EGFR-TKI therapy. Therefore, the effect of statins on targeted drug resistance to lung cancer remains to be investigated.
METHODS
Prolonged exposure to gefitinib resulted in the emergence of a resistant lung cancer cell line (PC9GR) from the parental sensitive cell line (PC9), which exhibited a traditional EGFR mutation. The CCK-8 assay was employed to assess the impact of various concentrations of pitavastatin on cellular proliferation. RNA sequencing was conducted to detect differentially expressed genes and their correlated pathways. For the detection of protein expression, Western blot was performed. The antitumor activity of pitavastatin was evaluated in vivo via a xenograft mouse model.
RESULTS
PC9 gefitinib resistant strains were induced by low-dose maintenance. Cell culture and animal-related studies validated that the application of pitavastatin inhibited the proliferation of lung cancer cells, promoted cell apoptosis, and restrained the acquired resistance to EGFR-TKIs. KEGG pathway analysis showed that the hippo/YAP signaling pathway was activated in PC9GR cells relative to PC9 cells, and the YAP expression was inhibited by pitavastatin administration. With YAP RNA interference, pAKT, pBAD and BCL-2 expression was decreased, while BAX expression as increased. Accordingly, YAP down-regulated significantly increased apoptosis and decreased the survival rate of gefitinib-resistant lung cancer cells. After pAKT was increased by SC79, apoptosis of YAP down-regulated cells induced by gefitinib was decreased, and the cell survival rate was increased. Mechanistically, these effects of pitavastatin are associated with the YAP pathway, thereby inhibiting the downstream AKT/BAD-BCL-2 signaling pathway.
CONCLUSION
Our study provides a molecular basis for the clinical application of the lipid-lowering drug pitavastatin enhances the susceptibility of lung cancer to EGFR-TKI drugs and alleviates drug resistance.
PubMed: 38943199
DOI: 10.1186/s12935-024-03416-z -
Respiratory Research Jun 2024To detect the expression of autophagy components, p38 MAPK (p38) and phosphorylated forkhead box transcription factor O-1 (pFoxO1) in pulmonary vascular endothelial...
AIMS
To detect the expression of autophagy components, p38 MAPK (p38) and phosphorylated forkhead box transcription factor O-1 (pFoxO1) in pulmonary vascular endothelial cells of chronic thromboembolic pulmonary hypertension (CTEPH) rats and to investigate the possible mechanism through which tissue factor (TF) regulates autophagy.
METHODS
Pulmonary artery endothelial cells (PAECs) were isolated from CTEPH (CTEPH group) and healthy rats (control group (ctrl group)) which were cocultured with TF at different time points including 12 h, 24 h, 48 h and doses including 0 nM,10 nM, 100 nM, 1µM, 10µM, 100µM and cocultured with TFPI at 48 h including 0 nM, 2.5 nM, 5 nM. The expression of forkhead box transcription factor O-1 (FoxO1), pFoxO1, p38, Beclin-1 and LC3B in PAECs was measured. Coimmunoprecipitation (co-IP) assays were used to detect the interaction between FoxO1 and LC3.
RESULTS
The protein expression of p-FoxO1/FoxO1 was significantly lower in the CTEPH groups (cocultured with TF from 0 nM to 100 µM) than in the ctrl group at 12 h, 24 h, and 48 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of p38 in the CTEPH groups treated with 0 nM, 10 nM, 100 nM or 1 µM TF for 48 h significantly increased than ctrl groups (P < 0.05) and was significantly increased in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of Beclin1 at the same concentration (cocultured with TF from 0 nM to 100 µM) was significantly lower in the CTEPH groups than ctrl groups after 24 h and 48 h (P < 0.05) and was significantly decreased in the CTEPH groups (cocultured with TFPI concentration from 2.5 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of LC3-II/LC3-I at the same concentration (cocultured with TF 0 nM, 1 µM, 10 µM, and 100 µM) was significantly lower in the CTEPH than in the ctrl groups after 12 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). There were close interactions between FoxO1 and LC3 in the control and CTEPH groups at different doses and time points.
CONCLUSION
The autophagic activity of PAECs from CTEPH rats was disrupted. TF, FoxO1 and p38 MAPK play key roles in the autophagic activity of PAECs. TF may regulate autophagic activity through the p38 MAPK-FoxO1 pathway.
Topics: Animals; Autophagy; p38 Mitogen-Activated Protein Kinases; Pulmonary Artery; Rats; Male; Endothelial Cells; Rats, Sprague-Dawley; Cells, Cultured; Thromboplastin; Hypertension, Pulmonary; Pulmonary Embolism; Chronic Disease; Signal Transduction; Forkhead Box Protein O1
PubMed: 38943142
DOI: 10.1186/s12931-024-02886-z -
Scientific Reports Jun 2024Systemic Immune Inflammatory Index (SII) is a novel indicator of inflammation. However, no studies have reported the effect of SII on the association between metals and...
Systemic Immune Inflammatory Index (SII) is a novel indicator of inflammation. However, no studies have reported the effect of SII on the association between metals and total fat (TOFAT). We aim to investigate the mediated effect of SII on the relationship between urinary metals and TOFAT in a US adult population. This cross-sectional study was conducted among adults with complete information on SII, urine metal concentrations, and TOFAT from the 2011-2018 National Health and Nutrition Examination Survey (NHANES). Multifactorial logistic regression and restricted cubic splines were used to explore the association between urine metal levels and TOFAT. Furthermore, serial mediation analyses were used to investigate the mediating effect of SII on metals and TOFAT. A total of 3324 subjects were included in this study. After adjusting for confounders, arsenic (As), cadmium (Cd), cobalt (Co), cesium (Cs), inorganic mercury (Hg), molybdenum (Mo), manganese (Mn), lead (Pb), antimony (Sb), and thallium(Tl) had negative decreased trends of odds ratios for TOFAT (all P for trend < 0.05). In the total population, we found that Cd, Co, and Tu were positively associated with SII (β = 29.70, 79.37, and 31.08), whereas As and Hg had a negative association with SII. The mediation analysis showed that SII mediated the association of Co with TOFAT, with the β of the mediating effect being 0.9% (95%CI: 0.3%, 1.6%). Our findings suggested that exposure to As, Cd, and Hg would directly decrease the level of TOFAT. However, Co would increase TOFAT, completely mediated by SII, mainly exerted in females rather than males.
Topics: Humans; Female; Male; Adult; Nutrition Surveys; Inflammation; Middle Aged; Cross-Sectional Studies; Metals
PubMed: 38942999
DOI: 10.1038/s41598-024-65925-1 -
Scientific Reports Jun 2024Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve...
Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve barley's adaptation to salinity stress by deeply studying the effects of salt stress and the responses of barley to this stress. In this context, our study aims to explore the variation in physiological and biochemical responses of five Tunisian spring barley genotypes to salt stress during the heading phase. Two salinity treatments were induced by using 100 mM NaCl (T1) and 250 mM NaCl (T2) in the irrigation water. Significant phenotypic variations were detected among the genotypes in response to salt stress. Plants exposed to 250 mM of NaCl showed an important decline in all studied physiological parameters namely, gas exchange, ions concentration and relative water content RWC. The observed decreases in concentrations ranged from, approximately, 6.64% to 40.76% for K, 5.91% to 43.67% for Na, 14.12% to 52.38% for Ca, and 15.22% to 38.48% for Mg across the different genotypes and salt stress levels. However, under salinity conditions, proline and soluble sugars increased for all genotypes with an average increase of 1.6 times in proline concentrations and 1.4 times in soluble sugars concentration. Furthermore, MDA levels rose also for all genotypes, with the biggest rise in Lemsi genotype (114.27% of increase compared to control). Ardhaoui and Rihane showed higher photosynthetic activity compared to the other genotypes across all treatments. The stepwise regression approach identified potassium content, K/Na ratio, relative water content, stomatal conductance and SPAD measurement as predominant traits for thousand kernel weight (R2 = 84.06), suggesting their significant role in alleviating salt stress in barley. Overall, at heading stage, salt accumulation in irrigated soils with saline water significantly influences the growth of barley by influencing gas exchange parameters, mineral composition and water content, in a genotype-dependent manner. These results will serve on elucidating the genetic mechanisms underlying these variations to facilitate targeted improvements in barley's tolerance to salt stress.
Topics: Hordeum; Salt Stress; Water; Minerals; Genotype; Salinity; Sodium Chloride
PubMed: 38942909
DOI: 10.1038/s41598-024-65967-5 -
Scientific Reports Jun 2024In honey bees, circulation of blood (hemolymph) is driven by the peristaltic contraction of the heart vessel located in the dorsal part of the abdomen....
In honey bees, circulation of blood (hemolymph) is driven by the peristaltic contraction of the heart vessel located in the dorsal part of the abdomen. Chlorantraniliprole (CHL) is an insecticide of the anthranilic diamide class which main mode of action is to alter the function of intracellular Ca release channels (known as RyRs, for ryanodine receptors). In the honey bee, it was recently found to be more toxic when applied on the dorsal part of the abdomen, suggesting a direct cardiotoxicity. In the present study, a short-term exposure of semi-isolated bee hearts to CHL (0.1-10 µM) induces alterations of cardiac contraction. These alterations range from a slow-down of systole and diastole kinetics, to bradycardia and cardiac arrest. The bees heart wall is made of a single layer of semi-circular cardiomyocytes arranged concentrically all along the long axis of tube lumen. Since the heart tube is suspended to the cuticle through long tubular muscles fibers (so-called alary muscle cells), the CHL effects in ex-vivo heart preparations could result from the modulation of RyRs present in these skeletal muscle fibers as well as cardiomyocytes RyRs themselves. In order to specifically assess effects of CHL on cardiomyocytes, for the first time, intact heart cells were enzymatically dissociated from bees. Exposure of cardiomyocytes to CHL induces an increase in cytoplasmic calcium, cell contraction at the highest concentrations and depletion of intracellular stores. Electrophysiological properties of isolated cardiomyocytes were described, with a focus on voltage-gated Ca channels responsible for the cardiac action potentials depolarization phase. Two types of Ca currents were measured under voltage-clamp. Exposure to CHL was accompanied by a decrease in voltage-activated Ca currents densities. Altogether, these results show that chlorantraniliprole can cause cardiac defects in honey bees.
Topics: Animals; Bees; ortho-Aminobenzoates; Myocytes, Cardiac; Insecticides; Cardiotoxicity; Calcium; Myocardial Contraction; Heart; Ryanodine Receptor Calcium Release Channel; Diamide
PubMed: 38942905
DOI: 10.1038/s41598-024-65007-2