ABSTRACT
The plant-specialized metabolite montbretin A (MbA) is being developed as a new treatment option for type-2 diabetes, which is among the ten leading causes of premature death and disability worldwide. MbA is a complex acylated flavonoid glycoside produced in small amounts in below-ground organs of the perennial plant Montbretia (Crocosmia × crocosmiiflora). The lack of a scalable production system limits the development and potential application of MbA as a pharmaceutical or nutraceutical. Previous efforts to reconstruct montbretin biosynthesis in Nicotiana benthamiana (Nb) resulted in low yields of MbA and higher levels of montbretin B (MbB) and montbretin C (MbC). MbA, MbB, and MbC are nearly identical metabolites differing only in their acyl moieties, derived from caffeoyl-CoA, coumaroyl-CoA, and feruloyl-CoA, respectively. In contrast to MbA, MbB and MbC are not pharmaceutically active. To utilize the montbretia caffeoyl-CoA biosynthesis for improved MbA engineering in Nb, we cloned and characterized enzymes of the shikimate shunt of the general phenylpropanoid pathway, specifically hydroxycinnamoyl-CoA: shikimate hydroxycinnamoyl transferase (CcHCT), p-coumaroylshikimate 3'-hydroxylase (CcC3'H), and caffeoylshikimate esterase (CcCSE). Gene expression patterns suggest that CcCSE enables the predominant formation of MbA, relative to MbB and MbC, in montbretia. This observation is supported by results from in vitro characterization of CcCSE and reconstruction of the shikimate shunt in yeast. Using CcHCT together with montbretin biosynthetic genes in multigene constructs resulted in a 30-fold increase of MbA in Nb. This work advances our understanding of the phenylpropanoid pathway and features a critical step towards improved MbA production in bioengineered Nb.
Subject(s)
Flavones , Hypoglycemic Agents , Nicotiana , Trisaccharides , Hypoglycemic Agents/metabolism , Nicotiana/genetics , Shikimic Acid/metabolism , Plants/metabolismABSTRACT
Histone CENP-A-containing nucleosomes play an important role in nucleating kinetochores at centromeres for chromosome segregation. However, the molecular mechanisms by which CENP-A nucleosomes engage with kinetochore proteins are not well understood. Here, we report the finding of a new function for the budding yeast Cse4/CENP-A histone-fold domain interacting with inner kinetochore protein Mif2/CENP-C. Strikingly, we also discovered that AT-rich centromere DNA has an important role for Mif2 recruitment. Mif2 contacts one side of the nucleosome dyad, engaging with both Cse4 residues and AT-rich nucleosomal DNA. Both interactions are directed by a contiguous DNA- and histone-binding domain (DHBD) harboring the conserved CENP-C motif, an AT hook, and RK clusters (clusters enriched for arginine-lysine residues). Human CENP-C has two related DHBDs that bind preferentially to DNA sequences of higher AT content. Our findings suggest that a DNA composition-based mechanism together with residues characteristic for the CENP-A histone variant contribute to the specification of centromere identity.
Subject(s)
Centromere Protein A/metabolism , Centromere/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Models, Molecular , Nucleosomes/chemistry , Nucleosomes/metabolism , Saccharomyces cerevisiae , AT Rich Sequence , Centromere/chemistry , Centromere Protein A/chemistry , Chromosomal Proteins, Non-Histone/chemistry , DNA, Satellite/metabolism , DNA-Binding Proteins/metabolism , Dimerization , Humans , Protein Binding , Protein Structure, Tertiary , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolismABSTRACT
BACKGROUND: T1 mapping of the liver is confounded by the presence of fat. Multiparametric T1 mapping combines fat-water separation with T1-weighting to enable imaging of water-specific T1 (T1Water ), proton density fat fraction (PDFF), and T2* values. However, normative T1Water values in the liver and its dependence on age/sex is unknown. PURPOSE: Determine normative values for T1Water in the liver with comparison to MOLLI and evaluate a T2*-compensation approach to reduce T1 variability. STUDY TYPE: Prospective observational; phantoms. POPULATIONS: One hundred twenty-four controls (56 male, 18-75 years), 50 patients at-risk for liver disease (18 male, 30-76 years). FIELD STRENGTH/SEQUENCE: 2.89 T; Saturation-recovery chemical-shift encoded T1 Mapping (SR-CSE); MOLLI. ASSESSMENT: SR-CSE provided T1Water measurements, PDFF and T2* values in the liver across three slices in 6 seconds. These were compared with MOLLI T1 values. A new T2*-compensation approach to reduce T1 variability was evaluated test/re-test reproducibility. STATISTICAL TESTS: Linear regression, ANCOVA, t-test, Bland and Altman, intraclass correlation coefficient (ICC). P < 0.05 was considered statistically significant. RESULTS: Liver T1 values were significantly higher in healthy females (F) than males (M) for both SR-CSE (F-973 ± 78 msec, M-930 ± 72 msec) and MOLLI (F-802 ± 55 msec, M-759 ± 69 msec). T1 values were negatively correlated with age, with similar sex- and age-dependencies observed in T2*. The T2*-compensation model reduced the variability of T1 values by half and removed sex- and age-differences (SR-CSE: F-946 ± 36 msec, M-941 ± 43 msec; MOLLI: F-775 ± 35 msec, M-770 ± 35 msec). At-risk participants had elevated PDFF and T1 values, which became more distinct from the healthy cohort after T2*-compensation. MOLLI systematically underestimated liver T1 values by ~170 msec with an additional positive T1-bias from fat content (~11 msec/1% in PDFF). Reproducibility ICC values were ≥0.96 for all parameters. DATA CONCLUSION: Liver T1Water values were lower in males and decreased with age, as observed for SR-CSE and MOLLI acquisitions. MOLLI underestimated liver T1 with an additional large positive fat-modulated T1 bias. T2*-compensation removed sex- and age-dependence in liver T1, reduced the range of healthy values and increased T1 group differences between healthy and at-risk groups. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.
ABSTRACT
Smoking is one of the most serious risk factors for cardiovascular diseases. Although cigarette mainstream and sidestream smoke are significant contributors to increased cardiovascular mortality and morbidity, the underlying mechanism is still unclear. Here, we report that exposure of rat neonatal cardiomyocytes to cigarette smoke extract (CSE) induces mitochondrial hyperfission-mediated myocardial senescence. CSE leads to mitochondrial fission and reactive oxygen species (ROS) production through the complex formation between mitochondrial fission factor Drp1 and actin-binding protein, filamin A. Pharmacological perturbation of interaction between Drp1 and filamin A by cilnidipine and gene knockdown of Drp1 or filamin A inhibited CSE-induced mitochondrial hyperfission and ROS production as well as myocardial senescence. We previously reported that Drp1 activity is controlled by supersulfide-induced Cys644 polysulfidation. The redox-sensitive Cys644 was critical for CSE-mediated interaction with filamin A. The administration of supersulfide donor, Na2S3 also improved mitochondrial hyperfission-mediated myocardial senescence induced by CSE. Our results suggest the important role of Drp1-filamin A complex formation on cigarette smoke-mediated cardiac risk and the contribution of supersulfide to mitochondrial fission-associated myocardial senescence.
Subject(s)
Cigarette Smoking , Myocytes, Cardiac , Animals , Rats , Filamins , Mitochondria , Reactive Oxygen SpeciesABSTRACT
PURPOSE: Aging contributes significantly to cardiovascular diseases and cardiac dysfunction, leading to the upregulation of matrix metalloproteinase-9 (MMP-9) in the heart and a significant decrease in hydrogen sulfide (H2S) content, coupled with impaired cardiac diastolic function. This study explores whether supplementing exogenous hydrogen sulfide during aging ameliorates the decline in H2S concentration in the heart, suppresses MMP-9 expression, and improves the age-associated impairment in cardiac morphology and function. METHODS: We collected plasma from healthy individuals of different ages to determine the relationship between aging and H2S and MMP-9 levels through Elisa detection and liquid chromatography-tandem mass spectrometry (LC/MC) detection of plasma H2S content. Three-month-old mice were selected as the young group, while 18-month-old mice were selected as the old group, and sodium hydrosulfide (NaHS) was injected intraperitoneally from 15 months old until 18 months old as the old + NaHS group. Plasma MMP-9 content was detected using Elisa, plasma H2S content, cardiac H2S content, and cystathionine gamma-lyase (CSE) activity were detected using LC/MC, and cardiac function was detected using echocardiography. Heart structure was assessed using hematoxylin and eosin staining, Masone staining was used to detect the degree of cardiac fibrosis, while western blot was used to detect the expression of MMP-9, CSE, and aging marker proteins. Knockdown of MMP-9 and CSE in H9c2 cells using small interfering RNA was carried out to determine the upstream-downstream relationship between MMP-9 and CSE. RESULTS: H2S content in the plasma of healthy individuals decreases with escalating age, whereas MMP-9 level rises with age progression. Aging leads to a decrease in H2S levels in the heart and plasma of mice, severe impairment of cardiac diastolic function, interstitial relaxation, and fibrosis of the heart. Supplementing with exogenous H2S can improve these phenomena. CONCLUSION: H2S maintains the structure and function of the heart by inhibiting the expression of MMP-9 during the aging process.
ABSTRACT
Vitamin D is known to have a positive effect on bone health. Despite the greater frequency of vitamin D deficiency in African Americans (AA), they have a higher bone mineral density (BMD) compared to whites, demonstrating a disconnect between BMD and vitamin D levels in AA. Another intriguing relationship seen in AA is the triglyceride (TG) paradox, an unusual phenomenon in which a normal TG status is observed even when patients house conditions known to be characterized by high TG levels, such as Type II diabetes. To the best of our knowledge, no study has examined whether these two paradoxical relationships exist simultaneously in AA subjects with Type II diabetes. In this study, we compared levels of blood markers, including HbA1c, TG, and vitamin D, measured as serum 25-hydroxyvitamin D [25(OH)VD] µM/mL, [25(OH)VD]/TG, calcium, and BMD in AA (n = 56) and white (n = 26) subjects with Type II diabetes to see whether these relationships exist concurrently. We found that AA subjects had significantly lower TG and [25(OH)VD] levels and a significantly higher BMD status compared to white subjects, even when the ages, BMI, duration of diabetes, HbA1c, and calcium levels were similar between the two groups. This demonstrates that these two paradoxical relationships exist simultaneously in Type II diabetic AA subjects. In addition to these findings, we discuss the current hypotheses in the literature that attempt to explain why these two intriguing relationships exist. This review also discusses four novel hypotheses, such as altered circulating levels and the potential role of estrogen and hydrogen sulfide on BMD and HMG-CoA reductase as a possible contributor to the TG paradox in AA subjects. This manuscript demonstrates that there are still many unanswered questions regarding these two paradoxical relationships and further research is needed to determine why they exist and how they can be implemented to improve healthcare.
Subject(s)
Diabetes Mellitus, Type 2 , Vitamin D Deficiency , Humans , Bone Density , Cross-Sectional Studies , Calcium , Black or African American , Glycated Hemoglobin , Vitamin D , Vitamins , Parathyroid HormoneABSTRACT
BACKGROUND: The floral volatile profile of Petunia x hybrida 'Mitchell diploid' (MD) is dominated by phenylpropanoids, many of which are derived from p-coumaric acid. However, the downstream processes involved in the production of caffeoyl-CoA and feruloyl-CoA from p-coumaric acid are complex, as the genes and biosynthesis steps are associated with flavonoids and lignin synthesis as well as floral volatiles benzenoid/phenylpropanoid (FVBP). Caffeoyl shikimate esterase (CSE) converts caffeoyl shikimate to caffeic acid and is considered one of the essential regulators in lignin production. Moreover, CSE in involved in phenylpropanoid production. To investigate the roles of CSE in FVBP biosynthesis, we used RNAi-mediated CSE down-regulated (ir-PhCSE) petunias. RESULTS: Lowered CSE transcript accumulation in ir-PhCSE plants resulted in reduced lignin layers in the stems and stunted growth, suggesting a positive correlation between lignin layers and lignin content. The altered CSE level influenced the expression of many FVBP genes, including elevated transcripts of p-coumarate-3-hydroxylase (C3H), hydroxycinnamoyl transferase (HCT), and 4-coumaric acid: CoA ligase (4CL). In particular, the expression of C4H in ir-PhCSE plants was more than twice the expression in MD plants. Moreover, the production of volatile compounds was alterend in ir-PhCSE plants. Most floral volatiles decreased, and the amounts of phenylalanine and caffeic acid were significantly lower. CONCLUSIONS: Reduced lignin layers in the stems and stunted growth in ir-PhCSE plants suggest that PhCSE is essential for lignin production and plant growth in petunia. The decreased CSE level influenced the expression of many FVBP genes, and interference of shikimate derivates altered volatile compound production. Significantly decreased caffeic acid, but not ferulic acid, in ir-PhCSE plants suggest that CSE is primarily involved in the reaction of caffeoyl shikimate. Higher C3H and C4H transcripts seem to alleviate accumulated p-coumaric acid resulting from altered CSE. Finally, alteration in C3H, HCT, and 4CL in CSE down-regulated plants suggests an interaction of the FVBP genes, leading to the regulation of floral volatiles of petunia.
Subject(s)
Esterases , Petunia , Esterases/genetics , Lignin/metabolism , Petunia/genetics , Petunia/metabolism , Down-Regulation , Plant Proteins/genetics , Plant Proteins/metabolism , Mixed Function Oxygenases/genetics , Gene Expression Regulation, PlantABSTRACT
Molecule sieve effect (MSE) can enable direct separation of target, thus overcoming two major scientific and industrial separation problems in traditional separation, coadsorption, and desorption. Inspired by this, herein, the concept of coordination sieve effect (CSE) for direct separation of UO2 2+ , different from the previously established two-step separation method, adsorption plus desorption is reported. The used adsorbent, polyhedron-based hydrogen-bond framework (P-HOF-1), made from a metal-organic framework (MOF) precursor through a two-step postmodification approach, afforded high uptake capacity (close to theoretical value) towards monovalent Cs+ , divalent Sr2+ , trivalent Eu3+ , and tetravalent Th4+ ions, but completely excluded UO2 2+ ion, suggesting excellent CSE. Direct separation of UO2 2+ can be achieved from a mixed solution containing Cs+ , Sr2+ , Eu3+ , Th4+ , and UO2 2+ ions, giving >99.9% removal efficiency for Cs+ , Sr2+ , Eu3+ , and Th4+ ions, but <1.2% removal efficiency for UO2 2+ , affording benchmark reverse selectivity (SM/U ) of >83 and direct generation of high purity UO2 2+ (>99.9%). The mechanism for such direct separation via CSE, as unveiled by both single crystal X-ray diffraction and density-functional theory (DFT) calculation, is due to the spherical coordination trap in P-HOF-1 that can exactly accommodate the spherical coordination ions of Cs+ , Sr2+ , Eu3+ , and Th4+ , but excludes the planar coordination UO2 2+ ion.
ABSTRACT
The corpus cavernosum (CC) is a highly vascularized tissue and represents an excellent example of microcirculation. Indeed, erectile dysfunction is considered an early index of cardiovascular disease. Hydrogen sulfide (H2S) at the vascular level is endogenously produced from L-cysteine mainly by the action of cystathionine-γ-lyase (CSE) and plays a role in CC vascular homeostasis. Here we have evaluated the involvement of the endogenous H2S in the regulation of the soluble guanylate cyclase (sCG) redox state. The lack of CSE-derived endogenous H2S, in CSE-/- mice, disrupted the eNOS/NO/sGC/PDE pathway. Indeed, the absence of CSE-derived endogenous H2S caused a significant reduction of the relaxant response to riociguat, an sGC redox-dependent stimulator. Conversely, the response to cinaciguat, an sGC redox-independent activator, was not modified. The relevance of the role played at the redox level of the endogenous H2S was confirmed by the findings that in CC harvested from CSE-/- mice there was a significant reduction of GCß1 expression coupled with a decrease in CYP5R3, a reductase involved in the regulation of the redox state of sGC. These molecular changes driven by the lack of endogenous H2S translate into a significant reduction in cGMP levels. The replenishment of the lack of H2S with an H2S donor rescued the relaxant response to riociguat in CC of CSE-/- mice. In conclusion, the endogenous CSE-derived H2S plays a physiological key role in the regulation of the redox state of sGC in CC microcirculation.
Subject(s)
Hydrogen Sulfide , Microcirculation , Soluble Guanylyl Cyclase , Animals , Male , Mice , Cystathionine gamma-Lyase/metabolism , Hydrogen Sulfide/metabolism , Oxidation-Reduction , Penis/blood supply , Soluble Guanylyl Cyclase/metabolismABSTRACT
KEY MESSAGE: CsCSE genes might be involved in the tolerance of cucumber to pathogens. Silencing of the CsCSE5 gene resulted in attenuated resistance of cucumber to Podosphaera xanthii and Corynespora cassiicola. Caffeoyl shikimate esterase (CSE), a key enzyme in the lignin biosynthetic pathway, has recently been characterized to play a key role in defense against pathogenic infection in plants. However, a systematic analysis of the CSE gene family in cucumber (Cucumis sativus) has not yet been conducted. Here, we identified eight CsCSE genes from the cucumber genome via bioinformatic analyses, and these genes were unevenly distributed on chromosomes 1, 3, 4, and 5. Results from multiple sequence alignment indicated that the CsCSE proteins had domains required for CSE activity. Phylogenetic analysis of gene structure and protein motifs revealed the conservation and diversity of the CsCSE gene family. Collinearity analysis showed that CsCSE genes had high homology with CSE genes in wax gourd (Benincasa hispida). Cis-acting element analysis of the promoters suggested that CsCSE genes might play important roles in growth, development, and stress tolerance. Expression pattern analysis indicated that CsCSE5 might be involved in regulating the resistance of cucumber to pathogens. Functional verification data confirmed that CsCSE5 positively regulates the resistance of cucumber to powdery mildew pathogen Podosphaera xanthii and target leaf spot pathogen Corynespora cassiicola. The results of our study provide information that will aid the genetic improvement of resistant cucumber varieties.
Subject(s)
Cucumis sativus , Cucumis sativus/genetics , Esterases/genetics , Esterases/metabolism , PhylogenyABSTRACT
The AAA+ ATPase and bromodomain factor ATAD2/ANCCA is overexpressed in many types of cancer, but how it contributes to tumorigenesis is not understood. Here, we report that the Saccharomyces cerevisiae homolog Yta7ATAD2 is a deposition factor for the centromeric histone H3 variant Cse4CENP-A at the centromere in yeast. Yta7ATAD2 regulates the levels of centromeric Cse4CENP-A in that yta7∆ causes reduced Cse4CENP-A deposition, whereas YTA7 overexpression causes increased Cse4CENP-A deposition. Yta7ATAD2 coimmunoprecipitates with Cse4CENP-A and is associated with the centromere, arguing for a direct role of Yta7ATAD2 in Cse4CENP-A deposition. Furthermore, increasing centromeric Cse4CENP-A levels by YTA7 overexpression requires the activity of Scm3HJURP, the centromeric nucleosome assembly factor. Importantly, Yta7ATAD2 interacts in vivo with Scm3HJURP, indicating that Yta7ATAD2 is a cochaperone for Scm3HJURP The absence of Yta7 causes defects in growth and chromosome segregation with mutations in components of the inner kinetochore (CTF19/CCAN, Mif2CENP-C, Cbf1). Since Yta7ATAD2 is an AAA+ ATPase and potential hexameric unfoldase, our results suggest that it may unfold the Cse4CENP-A histone and hand it over to Scm3HJURP for subsequent deposition in the centromeric nucleosome. Furthermore, our findings suggest that ATAD2 overexpression may enhance malignant transformation in humans by misregulating centromeric CENP-A levels, thus leading to defects in kinetochore assembly and chromosome segregation.
Subject(s)
Centromere/metabolism , Chromosomal Proteins, Non-Histone/metabolism , DNA-Binding Proteins/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , ATPases Associated with Diverse Cellular Activities/genetics , Centromere Protein A/genetics , Chromosomal Proteins, Non-Histone/genetics , DNA-Binding Proteins/genetics , Immunoprecipitation , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae Proteins/geneticsABSTRACT
Recently proposed methods in intrusion detection are iterating on machine learning methods as a potential solution. These novel methods are validated on one or more datasets from a sparse collection of academic intrusion detection datasets. Their recognition as improvements to the state-of-the-art is largely dependent on whether they can demonstrate a reliable increase in classification metrics compared to similar works validated on the same datasets. Whether these increases are meaningful outside of the training/testing datasets is rarely asked and never investigated. This work aims to demonstrate that strong general performance does not typically follow from strong classification on the current intrusion detection datasets. Binary classification models from a range of algorithmic families are trained on the attack classes of CSE-CIC-IDS2018, a state-of-the-art intrusion detection dataset. After establishing baselines for each class at various points of data access, the same trained models are tasked with classifying samples from the corresponding attack classes in CIC-IDS2017, CIC-DoS2017 and CIC-DDoS2019. Contrary to what the baseline results would suggest, the models have rarely learned a generally applicable representation of their attack class. Stability and predictability of generalized model performance are central issues for all methods on all attack classes. Focusing only on the three best-in-class models in terms of interdataset generalization, reveals that for network-centric attack classes (brute force, denial of service and distributed denial of service), general representations can be learned with flat losses in classification performance (precision and recall) below 5%. Other attack classes vary in generalized performance from stark losses in recall (-35%) with intact precision (98+%) for botnets to total degradation of precision and moderate recall loss for Web attack and infiltration models. The core conclusion of this article is a warning to researchers in the field. Expecting results of proposed methods on the test sets of state-of-the-art intrusion detection datasets to translate to generalized performance is likely a serious overestimation. Four proposals to reduce this overestimation are set out as future work directions.
ABSTRACT
Cystathionine γ-lyase (CSE) is an enzyme responsible for the biosynthesis of cysteine from cystathionine in the final step of the transsulfuration pathway. It also has ß-lyase activity toward cystine, generating cysteine persulfide (Cys-SSH). The chemical reactivity of Cys-SSH is thought to be involved in the catalytic activity of particular proteins via protein polysulfidation, the formation of -S-(S)n-H on their reactive cysteine residues. The Cys136/171 residues of CSE have been proposed to be redox-sensitive residues. Herein, we investigated whether CSE polysulfidation occurs at Cys136/171 during cystine metabolism. Transfection of wild-type CSE into COS-7 cells resulted in increased intracellular Cys-SSH production, which was significantly increased when Cys136Val or Cys136/171Val CSE mutants were transfected, instead of the wild-type enzyme. A biotin-polyethylene glycol-conjugated maleimide capture assay revealed that CSE polysulfidation occurs at Cys136 during cystine metabolism. In vitro incubation of CSE with CSE-enzymatically synthesized Cys-SSH resulted in the inhibition of Cys-SSH production. In contrast, the mutant CSEs (Cys136Val and Cys136/171Val) proved resistant to inhibition. The Cys-SSH-producing CSE activity of Cys136/171Val CSE was higher than that of the wild-type enzyme. Meanwhile, the cysteine-producing CSE activity of this mutant was equivalent to that of the wild-type enzyme. It is assumed that Cys-SSH-producing CSE activity could be auto-inactivated via the polysulfidation of the enzyme during cystine metabolism. Thus, the polysulfidation of CSE at the Cys136 residue may be an integral feature of cystine metabolism, which functions to down-regulate Cys-SSH synthesis by the enzyme.
Subject(s)
Cystathionine gamma-Lyase , Hydrogen Sulfide , Cystathionine gamma-Lyase/genetics , Cystathionine gamma-Lyase/metabolism , Cystine/metabolism , Cysteine/metabolism , Proteins/metabolism , Oxidation-Reduction , Hydrogen Sulfide/metabolismABSTRACT
Over the past decades, the problem of bacterial resistance to most antibiotics has become a serious threat to patients' survival. Nevertheless, antibiotics of a novel class have not been approved since the 1980s. The development of antibiotic potentiators is an appealing alternative to the challenging process of searching for new antimicrobials. Production of H2S-one of the leading defense mechanisms crucial for bacterial survival-can be influenced by the inhibition of relevant enzymes: bacterial cystathionine γ-lyase (bCSE), bacterial cystathionine ß-synthase (bCBS), or 3-mercaptopyruvate sulfurtransferase (MST). The first one makes the main contribution to H2S generation. Herein, we present data on the synthesis, in silico analyses, and enzymatic and microbiological assays of novel bCSE inhibitors. Combined molecular docking and molecular dynamics analyses revealed a novel binding mode of these ligands to bCSE. Lead compound 2a manifested strong potentiating activity when applied in combination with some commonly used antibiotics against multidrug-resistant Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. The compound was found to have favorable in vitro absorption, distribution, metabolism, excretion, and toxicity parameters. The high effectiveness and safety of compound 2a makes it a promising candidate for enhancing the activity of antibiotics against high-priority pathogens.
Subject(s)
Hydrogen Sulfide , Methicillin-Resistant Staphylococcus aureus , Humans , Anti-Bacterial Agents/pharmacology , Hydrogen Sulfide/metabolism , Cystathionine gamma-Lyase/metabolism , Methicillin-Resistant Staphylococcus aureus/metabolism , Pyrroles/pharmacology , Molecular Docking Simulation , Bacteria/metabolism , Indoles/pharmacology , Cystathionine beta-Synthase/metabolismABSTRACT
Cigarette smoke (CS) induced emphysema and chronic pulmonary inflammation are major comorbidities of chronic obstructive pulmonary disease (COPD), a major cause of morbidity and mortality worldwide. CS exposure exacerbates pulmonary inflammation and compromises immunity to various infections. Aurintricarboxylic acid (ATA) is a polyanionic aromatic compound especially recognized for its anti-inflammatory, nucleic acid, and protein interaction inhibition properties. The study was designed to investigate the anti-inflammatory role of ATA against cigarette smoke extract (CSE) induced pulmonary inflammation. Nicotine concentration was quantified in CSE by UPLC/MS technique. In vitro, fluorescence microscopy, and flow cytometry was performed in CSE stimulated alveolar epithelial cells to determine the effect of ATA on oxidative stress-mediated cellular apoptosis. In vivo, pulmonary inflammation was induced in male Wistar rats via a modified non-invasive intratracheal instillation of cigarette smoke extract (100 µl/animal) twice a week for 8 weeks and post-treated with ATA (10 mg/kg) intraperitoneally for 15 days. Lung homogenates were assessed for MDA and GSH. Lung tissues were subjected to western blotting and histopathological analysis. As result, ATA reduced CSE-induced chromatin condensation, fragmentation, cellular apoptosis in alveolar epithelial cells, and apoptotic biomarkers expression including BAX and Caspase-3 in the lungs. ATA reduced inflammation by normalizing redox balance reflected by MDA/GSH levels. ATA obviated airspace enlargement, fiber deposition, and immune cell infiltration. Reduced inflammation was accompanied by inhibition of inflammatory biomarkers TNF-α, TNFR1, TWEAK, and NF-Ò¡B/p65 activation and nuclear translocation. ATA efficaciously diminished the oxidative stress and pulmonary inflammation associated with lung pathogenesis through TNF-α/TNFR1/NF-Ò¡B/p65 signaling pathway. HIGHLIGHTSATA treatment attenuates CSE-stimulated chromatin condensation, fragmentation, and cellular apoptosis in alveolar epithelial cells.ATA treatment inhibits CSE stimulated activation and nuclear translocation of NF-Ò¡B/p65.ATA treatment diminishes CSE-induced oxidant injury, apoptosis, and emphysema-like phenotypic changes in the lungs.ATA inhibits lung inflammation via suppression of the NF-Ò¡B/p65 signaling pathway.
Subject(s)
Cigarette Smoking , Emphysema , Pneumonia , Pulmonary Emphysema , Male , Rats , Animals , Receptors, Tumor Necrosis Factor, Type I/toxicity , Receptors, Tumor Necrosis Factor, Type I/metabolism , Aurintricarboxylic Acid/toxicity , Aurintricarboxylic Acid/metabolism , Tumor Necrosis Factor-alpha/metabolism , Cigarette Smoking/adverse effects , NF-kappa B/metabolism , Rats, Wistar , Lung , Pneumonia/chemically induced , Pneumonia/prevention & control , Pulmonary Emphysema/chemically induced , Pulmonary Emphysema/prevention & control , Pulmonary Emphysema/metabolism , Oxidative Stress , Signal Transduction , Nicotiana/toxicity , Inflammation/chemically induced , Inflammation/prevention & control , Inflammation/metabolism , Anti-Inflammatory Agents/pharmacology , Emphysema/metabolism , Emphysema/pathology , ChromatinABSTRACT
The present study investigates the direct impact of learning organizations on organizational innovations and investigates the mediating mechanism of change self-efficacy between learning organizations and organizational innovations. Furthermore, this study proposes adaptive leadership as a moderator between learning organizations, change self-efficacy, and organizational innovations. Three hundred seventy-three permanent employees from the pharmaceutical industry voluntarily participated. Data was collected using a simple random sampling technique through the temporal separation method (One-month interval between two temporal separations). SPSS v.25, AMOS v.22, and Smart-PLS were utilized to analyze reliability, validity, descriptive statistics, and correlations, and PROCESS-macro v3.4 was used for direct, indirect (mediation), and interaction (moderation) effects analysis. The study supports the hypothesized link between learning organizations and organizational innovations. In addition, change self-efficacy partially mediates the learning organizations - organizational innovations relationship. Moreover, adaptive leadership moderates the association between learning organization and organizational innovation, learning organizations and change self-efficacy, and change self-efficacy and organizational innovations relationship. The study's findings suggest that adaptive leadership is imperative not only for higher change self-efficacy of the individuals but also helps the organizations for organizational innovations with the utilization of learning organizations phenomenon. Additionally, this study highlights the importance of change self-efficacy, which plays a vital role in learning organizations for organizational innovations. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-023-04669-z.
ABSTRACT
The importin α/ß transport machinery mediates the nuclear import of cargo proteins that bear a classical nuclear localization sequence (cNLS). These cargo proteins are linked to the major nuclear protein import factor, importin-ß, by the importin-α adapter, after which cargo/carrier complexes enter the nucleus through nuclear pores. In the nucleus, cargo is released by the action of RanGTP and the nuclear pore protein Nup2, after which the importins are recycled to the cytoplasm for further transport cycles. The nuclear export of importin-α is mediated by Cse1/CAS. Here, we exploit structures of functionally important complexes to identify residues that are critical for these interactions and provide insight into how cycles of protein import and recycling of importin-α occur in vivo using a Saccharomyces cerevisiae model. We examine how these molecular interactions impact protein localization, cargo import, function and complex formation. We show that reversing the charge of key residues in importin-α (Arg44) or Cse1 (Asp220) results in loss of function of the respective proteins and impairs complex formation both in vitro and in vivo. To extend these results, we show that basic residues in the Nup2 N-terminus are required for both Nup2 interaction with importin-α and Nup2 function. These results provide a more comprehensive mechanistic model of how Cse1, RanGTP and Nup2 function in concert to mediate cNLS-cargo release in the nucleus.
Subject(s)
Nuclear Localization Signals , Saccharomyces cerevisiae Proteins , Active Transport, Cell Nucleus , Cell Nucleus/metabolism , Karyopherins/metabolism , Nuclear Localization Signals/metabolism , Nuclear Pore Complex Proteins/genetics , Nuclear Pore Complex Proteins/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , alpha Karyopherins/genetics , alpha Karyopherins/metabolismABSTRACT
The transcriptional coactivator with PDZ-binding motif (TAZ) (WWTR1) induces epithelial-mesenchymal transition and enhances drug resistance in multiple cancers. TAZ has been shown to interact with transcription factors in the nucleus, but when phosphorylated, translocates to the cytoplasm and is degraded through proteasomes. Here, we identified a compound TAZ inhibitor 4 (TI-4) that shifted TAZ localization to the cytoplasm independently of its phosphorylation. We used affinity beads to ascertain a putative target of TI-4, chromosomal segregation 1 like (CSE1L), which is known to be involved in the recycling of importin α and as a biomarker of cancer malignancy. We found that TI-4 suppressed TAZ-mediated transcription in a CSE1L-dependent manner. CSE1L overexpression increased nuclear levels of TAZ, whereas CSE1L silencing delayed its nuclear import. We also found via the in vitro coimmunoprecipitation experiments that TI-4 strengthened the interaction between CSE1L and importin α5 and blocked the binding of importin α5 to TAZ. WWTR1 silencing attenuated CSE1L-promoted colony formation, motility, and invasiveness of human lung cancer and glioblastoma cells. Conversely, CSE1L silencing blocked TAZ-promoted colony formation, motility, and invasiveness in human lung cancer and glioblastoma cells. In human cancer tissues, the expression level of CSE1L was found to correlate with nuclear levels of TAZ. These findings support that CSE1L promotes the nuclear accumulation of TAZ and enhances malignancy in cancer cells.
Subject(s)
Cell Nucleus/metabolism , Cellular Apoptosis Susceptibility Protein/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Neoplasms/metabolism , Neoplasms/pathology , Trans-Activators/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Gene Expression Regulation, Neoplastic , Gene Silencing , Green Fluorescent Proteins/metabolism , Humans , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Models, Biological , Neoplasm Invasiveness , Neoplasms/genetics , Phosphorylation , Photobleaching , Protein Binding , Protein Transport , Subcellular Fractions/metabolism , Transcriptional Coactivator with PDZ-Binding Motif Proteins , Tumor Stem Cell Assay , alpha Karyopherins/metabolismABSTRACT
Left ventricular hypertrophy (LVH) is characterized by increased myocardium thickness due to increased oxidative stress and downregulation of cystathione γ lyase (CSE) endothelial nitric oxide synthase (eNOS). Upregulation of CSE by hydrogen sulphide (H2S) and ENOS by L-arginine can arrest the progression of LVH individually. The present study explored the combined treatment of H2S and NO in the progression of LVH, and demonstrated that the response is due to H2S, NO or formation of either new molecule in physiological, pathological, and pharmacological in vivo settings of LVH. Exogenous administration H2S+NO in LVH significantly reduced (all p < 0.05) systolic blood pressure (SBP) and mean arterial pressure (MAP), LV index, heart index and oxidative stress when compared to the LVH group. There was downregulation of CSE mRNA and eNOS in the heart, and exogenous administration of H2S+NO groups upregulated eNOS MRNA while CSE MRNA remained downregulated in the hearts of the LVH group. Similar trends were observed with concentrations of H2S and NO in the plasma and tissue. It can be concluded that combined treatment of LVH with H2S and NO significantly ameliorate the progression of LVH by attenuating systemic hemodynamic and physical indices, and by decreasing oxidative stress. Molecular expression data in the myocardium of LVH depicts that combined treatment upregulated eNOS/NO while it downregulated CSE/H2S pathways in in vivo settings, and it is always eNOS/NO pathways which play a major role.
ABSTRACT
PURPOSE: To study the effect of field inhomogeneity distributions in trabecularized bone regions on the gradient echo (GRE) signal with short TEs and to characterize quantification errors on R2*$$ {R}_2^{\ast } $$ and proton density fat fraction (PDFF) maps when using a water-fat model with an exponential R2*$$ {R}_2^{\ast } $$ decay model at short TEs. METHODS: Field distortions were simulated based on a trabecular bone micro CT dataset. Simulations were performed for different bone volume fractions (BV/TV) and for different bone-fat composition values. A multi-TE UTE acquisition was developed to acquire multiple UTEs with random order to minimize eddy currents. The acquisition was validated in phantoms and applied in vivo in a volunteer's ankle and knee. Chemical shift encoded MRI (CSE-MRI) based on a Cartesian multi-TE GRE scan was acquired in the spine of patients with metastatic bone disease. RESULTS: Simulations showed that signal deviations from the exponential signal decay at short TEs were more prominent for a higher BV/TV. UTE multi-TE measurements reproduced in vivo the simulation-based predicted behavior. In regions with high BV/TV, the presence of field inhomogeneities induced an R2*$$ {R}_2^{\ast } $$ underestimation in trabecularized bone marrow when using CSE-MRI at 3T with a short TE. CONCLUSION: R2*$$ {R}_2^{\ast } $$ can be underestimated when using short TEs (<2 ms at 3 T) and a water-fat model with an exponential R2*$$ {R}_2^{\ast } $$ decay model in multi-echo GRE acquisitions of trabecularized bone marrow.