Enzyme Induction Research Articles

The Unique BCR Inhibiting Properties of BMS-986205 in Chronic Lymphocytic Cells

B cell receptor (BCR) signaling is recognised as a central pathway in the pathogenesis of chronic lymphocytic leukaemia (CLL), the most common leukemia in the western world. In CLL, the BCR pathway is activated by antigens in the tissue microenvironment to promote the maintenance and expansion of leukemic cells. The impressive inhibition of clonal expansion of CLL cells and the disease control achieved with tyrosine kinase inhibitors that block BCR signaling provided further evidence of the role of BCR in CLL. Indoleamine 2,3-dioxygenase 1 (IDO1) is the inducible and rate-limiting enzyme involved in the catabolism of tryptophan to kynurenine. It was discovered as a modulator of the innate immune response during infection. Subsequent discoveries have implicated IDO1 as a player in acquired immune tolerance. IDO1 activity has been identified in several types of cancer cells as well as in their tumor-surrounding microenvironment. We have previously investigated and characterized the impact of IDO1 expression in CLL. Our results show that CLL microenvironmental stimuli positively modulate IDO1 expression in leukemic cells and that increased IDO1 activity leads to sustained survival of malignant lymphocytes and impaired drug sensitivity through the autocrine/paracrine activation of the aryl hydrocarbon receptor by kynurenine (Atene CG et al. 2022). To assess the functional and clinical significance of IDO1 enzymatic activity in CLL, we used several inhibitors that are currently in late-stage clinical trials. Using BMS-986205 (BMS), an irreversible inhibitor of IDO1 with the best cell-based potency, in primary patient cells, we observed not only a reduction in kynurenine production due to enzymatic inhibition of IDO1, but also lower levels of IDO1 RNA and protein following BCR stimulation with α-IgM. As we have previously shown that BCR activation can induce IDO1 expression, we treated CLL cells with increasing doses of BMS for 3 hours and then added α-IgM to the culture. BMS is able to counteract the pro-survival effect of BCR triggering, leading to significant apoptosis of CLL cells, while the viability of CLL cells in the absence of external stimuli was not significantly modulated. Focusing on the complex signaling cascade activated by BCR engagement, we observed that BMS impaired the phosphorylation of upstream kinases such as SYK and BTK, but also CD79a, CD19 and BLNK, in addition to downstream effectors such as AKT. We therefore investigated which factors that negatively regulate the BCR pathway are modulated by BMS treatment. By analyzing both mRNA and protein levels, we measured a significant induction of the phosphatases PTPN6, PTPN22 and SHIP1. Since BMS also showed a downregulation of total SYK expression, we are analyzing the expression of the proto-oncogene CBL, an E3 ubiquitin ligase known to be involved in the negative regulation of SYK. Further studies should be undertaken to determine whether, in addition to its role as an IDO1 inhibitor, BMS may also have the ability to indirectly modulate and disrupt BCR signaling. Efforts are underway to identify the proteome-wide direct target of BMS in CLL cells. In conclusion, our limited and preliminary data suggest that BMS could be considered as a potential therapeutic strategy to target CLL cells with a double hit: by blocking the pro-survival effect of BCR signaling, one of the driving forces for CLL cell survival and proliferation, and by inhibiting IDO1/kynurenine action to restore sensitivity to key leukemia treatments.

Abiotic Stress in Rice: Visiting the Physiological Response and Its Tolerance Mechanisms

Rice (Oryza sativa L.) is one of the most significant staple foods worldwide. Carbohydrates, proteins, vitamins, and minerals are just a few of the many nutrients found in domesticated rice. Ensuring high and constant rice production is vital to facilitating human food supplies, as over three billion people around the globe rely on rice as their primary source of dietary intake. However, the world’s rice production and grain quality have drastically declined in recent years due to the challenges posed by global climate change and abiotic stress-related aspects, especially drought, heat, cold, salt, submergence, and heavy metal toxicity. Rice’s reduced photosynthetic efficiency results from insufficient stomatal conductance and natural damage to thylakoids and chloroplasts brought on by abiotic stressor-induced chlorosis and leaf wilting. Abiotic stress in rice farming can also cause complications with redox homeostasis, membrane peroxidation, lower seed germination, a drop in fresh and dry weight, necrosis, and tissue damage. Frequent stomatal movements, leaf rolling, generation of reactive oxygen radicals (RORs), antioxidant enzymes, induction of stress-responsive enzymes and protein-repair mechanisms, production of osmolytes, development of ion transporters, detoxifications, etc., are recorded as potent morphological, biochemical and physiological responses of rice plants under adverse abiotic stress. To develop cultivars that can withstand multiple abiotic challenges, it is necessary to understand the molecular and physiological mechanisms that contribute to the deterioration of rice quality under multiple abiotic stresses. The present review highlights the strategic defense mechanisms rice plants adopt to combat abiotic stressors that substantially affect the fundamental morphological, biochemical, and physiological mechanisms.

Levetiracetam Interaction with Direct Oral Anticoagulants: A Pharmacovigilance Study.

Levetiracetam is widely used in post-stroke epilepsy. However, it is suspected to possess P-glycoprotein (P-gp) induction properties, and therefore, a potentially significant interaction with direct oral anticoagulants (DOACs). We aimed to search for ischemic stroke signals with levetiracetam and the DOACs. In this retrospective pharmacovigilance study, we used the FAERS database to identify ischemic stroke events associated with DOACs and concomitant use of levetiracetam. We evaluated disproportionate reporting by the adjusted reporting odds ratio (adjROR) and the lower bound of the shrinkage 95% confidence interval. When shrinkage is positive, an increased risk of a specific adverse event occurrence is emphasized over the sum of the individual risks when these same drugs are used separately. We identified 1841 (1.5%), 3731 (5.3%), 338 (4.9%), and 1723 (1.3%) ischemic stroke reports with apixaban, dabigatran, edoxaban, and rivaroxaban, respectively. The adjROR of the interaction effect was 3.57 (95% CI 2.81-4.58) between DOACs and levetiracetam. The shrinkage analysis detected an interaction between each of the DOACs and levetiracetam. The logistic model and shrinkage analysis failed to detect an interaction when queried for hemorrhagic stroke. A significant signal in the classical enzyme inducer, carbamazepine, strengthened our results (adjROR; 8.47, 95% CI 5.37-13.36). Our study shows a strong signal for the levetiracetam interaction with the DOACs. Our findings suggest implementation of a drug monitoring strategy.

Mango peel as a potential enzyme inducer in Trichoderma harzianum

Water-insoluble exopolysaccharides (I-EPS) are a virulence factor for dental biofilms. It has already been demonstrated that mango pulp induces the secretion of glucan-hydrolytic enzymes in the fungus Trichoderma harzianum, and that they have an effect on I-EPS from young biofilms. Aim: Evaluate the effect of mango peel as an enzyme inducer in T. harzianum, and the effect of enzymes secreted on mature biofilms. Methods: Fractions of the peel (PL) and ethanol-precipitated pulp (PP) of Tommy Atkins mangoes were sterilized and added to a culture medium containing T. harzianum for induction of hydrolytic enzymes. After 192 h, the culture medium was centrifuged and the supernatant (enzyme extract) was used as treatment on S. mutans biofilms (n=9): a) NaCl 0.9 %; b) 0.12 % chlorhexidine digluconate; and c) extract of enzymes induced by PL or PP. Acidogenicity, bacterial viability, quantification of insoluble polysaccharides, and three-dimensional analysis of the biofilm by scanning electron microscopy (SEM) was performed. Data were analyzed by ANOVA followed by the Tukey test (α=5 %). Results: The hydrolytic enzymes did not alter the metabolism or bacterial viability of the biofilm (p<0.05). Although the images obtained by SEM suggest some degree of matrix degradation, the quantification of I-EPS for the PL and PP groups did not differ from the control group (p>0.05), suggesting a slight effect on the disorganization of the mature S. mutans biofilm. Conclusion: The results suggest that mango peel fraction can induce secretion of mutanase by T. harzianum, however in an insufficient amount to generate significant degradation on cariogenic biofilm.

A Novel Strategy for Whole-Cell Biotransformation Enabling Simultaneous l-Phenyllactic Acid Production and Coenzyme Regeneration.

l-Phenyllactic acid (l-PLA) is a small molecular organic acid that exhibits a powerful capacity for inhibition against foodborne pathogens. In this work, we developed a new cost-effective and environmentally friendly process for the biosynthesis of l-PLA. This strategy designed a novel whole-cell biotransformation system employing two heterologous enzymes, namely, phenylalanine dehydrogenase (PheDH) and l-hydroxyisocaproate dehydrogenase (l-HicDH). The novelty of this strategy lies in the first-time utilization of these two enzymes, which not only enables cascade catalysis for the production of l-PLA but also facilitates the regeneration of the coenzymes (NAD+/NADH) using only two enzymes rather than introducing more heterologous enzymes to the system. Consequently, this strategy can effectively simplify the biosynthesis process of l-PLA and minimize production costs. The initial l-PLA yield using this process achieved 2.53 ± 0.07 g/L. Furthermore, through meticulous optimization of the parameters for inducible enzyme expression and l-PLA biosynthesis, the l-PLA yield was successfully increased to 4.68 ± 0.04 g/L with a yield rate of 64.54 ± 0.29%. Moreover, this novel strategy is versatile in the biosynthesis of other organic acids, which can be achieved by easily modulating the combinations of substrates and enzymes.

Plant protein and animal protein‐based Pickering emulsion: A review of preparation and modification methods

AbstractProtein‐based Pickering emulsions are gaining popularity due to their biocompatibility and alignment with people's pursuit of health. This review focuses on recent advances in the preparation of Pickering emulsions using various plant and animal proteins from different sources. For sustainability and cost reasons, plant proteins are preferred, while animal proteins provide better nutritional quality. According to the type of plant or animal protein, the suitable modification and preparation methods of stable Pickering emulsion are summarized, including heating, enzyme induction, anti‐solvent precipitation, pH‐cycling, glycosylation, microwave heating, spray drying, and high hydrostatic pressure. Different methods were employed to modify the properties of Pickering emulsion particles at the oil–water interface. To overcome the amphiphilicity limitations of some proteins, substances such as polysaccharides or polyphenols were combined to improve the physical and chemical properties of the particles. Additionally, this review analyzes the effect of different protein particle sources on the properties of Pickering emulsions.

Induction of defensive enzymes in sunflower plants treated with agrochemicals against Macrophomina phaseolina

Induction of defensive enzymes in sunflower plants treated with agrochemicals against Macrophomina phaseolina

Effect of Ivospemin and Difluoromethylornithine Polyamine Inhibitors on Viability of Myeloma Cell Lines

Abstract Introduction: Multiple myeloma (MM) is caused by heterogeneous genomic alterations that lead to activation of the MYC oncogenic pathway (Larrayoz et al., 2023). Moreover, MYC activity plays a role in immune escape by MM cells and alteration of the bone marrow microenvironment as the disease progresses, which in turn affects response to immunotherapy. Downstream targets and pathways of MYC, such as polyamine (PA) pathway, are an important avenue for therapeutic anticancer interventions for targeting MYC that is generally considered to be “undruggable”. In the present study, we therefore evaluated the effect of two polyamine inhibitors, ivospemin and difluoromethylornithine (DFMO), on growth and viability of myeloma cell lines. SBP-101, an analogue of the naturally occurring PA, spermine, is a polyamine metabolic inhibitor (PMI) that reduces native PA pools by inhibiting key synthetic enzymes and induction of catabolic enzymes. DFMO is an irreversible inhibitor of the ornithine decarboxylase and polyamine synthesis. Methods: Four myeloma cell lines: NCI-H929, RPMI-8226, ARP-1, and MM.1S, were exposed to varying concentrations of two PA inhibitors, SBP-101 and DFMO, based on the data available from clinical trials conducted for other malignancies. We analyzed the effects of these treatments on cell proliferation, cell viability, and the induction of apoptosis. The analyses were done separately for each compound as well as their combination. To assess cytotoxicity and cell proliferation, we used the Incucyte® SX5 Live-Cell Analysis System. Additionally, the detection of apoptosis was performed using Annexin V and propidium iodide flow cytometric assay. Results: Exposure of the MM cell lines to Ivospemin at increasing concentrations ranging from 1µM to 10 µM showed a significant decrease in cellular proliferation in all four MM cell lines. The mean percentage of cytotoxicity observed at 10 µM concentrations of Ivospemin in NCI-H929, RPMI-8226, ARP-1, and MM.1S cell lines were 69.17, 20.75, 83.92, and 48.71 respectively (Fig. 1a). Similarly, when we exposed the MM cell lines to DFMO at increasing concentrations ranging from 1 µM to 100 µM, we also saw a significant decrease in cellular proliferation in all four cell lines, with the most pronounced effect observed in RPMI-8226. The percentage of cells killed at DFMO 10 µM in NCI-H929, RPMI-8226, ARP-1, and MM.1S cell lines were 32.67, 63.61, 28.24, and 16.06 respectively. Moreover, when we combined Ivospemin at 10 µM and DFMO at 100 µM, we observed a complete abolition of cell growth in all the cell lines (Fig. 1b). Additionally, the treatment of the myeloma cell lines with either Ivospemin, DFMO alone, or in combination, showed an induction of apoptosis, as revealed by flow cytometric analysis (data not shown). These findings indicate that both Ivospemin and DFMO have significant anti-proliferative effects on MM cell lines, and their combination leads to even more potent growth inhibition and induction of apoptosis. Conclusion: The polyamine inhibitors,Ivospemin and DFMO, exhibited a marked anti-proliferative effect in the four human MM cell lines studied when used alone or in combination. These results confirm the anti-neoplastic potential of SBP-101 and DFMO and offer a compelling rationale for its clinical development as a potentially promising treatment option for multiple myeloma. Fig. 1. Effect of varying concentration of Ivospemin (SBP-101) treatment on myeloma cell lines (a). The data is represented as mean ± SEM of three replicates. A combination of both Ivospemin (SBP-101) and DFMO improved the cytotoxicity as compared to when used alone (b).

Inducible Expression ofthe Restriction Enzyme Uncovered Genome-Wide Distribution andDynamic Behavior ofHistones H4K16ac andH2A.Z at DNA Double-Strand Breaks inArabidopsis.

DNA double-strand breaks (DSBs) are among the most serious types of DNA damage, causing mutations and chromosomal rearrangements. In eukaryotes, DSBs are immediately repaired in coordination with chromatin remodeling for the deposition of DSB-related histone modifications and variants. To elucidate the details of DSB-dependent chromatin remodeling throughout the genome, artificial DSBs need to be reproducibly induced at various genomic loci. Recently, a comprehensive method for elucidating chromatin remodeling at multiple DSB loci via chemically induced expression of a restriction enzyme was developed in mammals. However, this DSB induction system is unsuitable for investigating chromatin remodeling during and after DSB repair, and such an approach has not been performed in plants. Here, we established a transgenic Arabidopsis plant harboring a restriction enzyme gene Sbf I driven by a heat-inducible promoter. Using this transgenic line, we performed chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) of histones H4K16ac and H2A.Z and investigated the dynamics of these histone marks around the endogenous 623 Sbf I recognition sites. We also precisely quantified DSB efficiency at all cleavage sites using the DNA resequencing data obtained by the ChIP-seq procedure. From the results, Sbf I-induced DSBs were detected at 360 loci, which induced the transient deposition of H4K16ac and H2A.Z around these regions. Interestingly, we also observed the co-localization of H4K16ac and H2A.Z at some DSB loci. Overall, DSB-dependent chromatin remodeling was found to be highly conserved between plants and animals. These findings provide new insights into chromatin remodeling that occurs in response to DSBs in Arabidopsis.

Differentiated and non-differentiated HepaRG™ cells: A possible in-vitro model system for early hepatocarcinogenesis and non-genotoxic carcinogens

Many xenobiotics are non-genotoxic carcinogens (NGC) in rodent liver. Their mode of action (MoA) and health risks for humans are unclear and no in-vitro tests are available to predict NGC. Human HepaRG™ cells in the differentiated (d-HepaRG) and non-differentiated state (nd-HepaRG) were studied as new approach methodology (NAM) for NGC. Cell-biological assays were performed with d-/nd-HepaRG and human hepatoma/hepatocarcinoma cell lines to characterize the benign/malignant phenotype. Reaction of d-/nd-HepaRG to several liver growth factors and NGC (phenobarbital, PB; cyproterone acetate, CPA; WY-14643) was compared to unaltered and premalignant rat hepatocytes in ex-vivo culture. Enzyme induction by NGC was checked by RT-qPCR/oligo-arrays. Growth, anchorage-independency, migration, clonogenicity, and in-vivo tumorigenicity of nd-HepaRG ranged between benign d-HepaRG and malignant hepatoma/hepatocarcinoma cells. All growth factors elevated DNA replication of d-/nd-HepaRG cells, similarly to unaltered/premalignant rat hepatocytes. NGC induced their prototypical enzymes in the rat and human cells, but elicited a growth response only in the unaltered/premalignant rat hepatocytes and not in human d-/nd-HepaRG cells. To conclude, a benign/premalignant phenotype of d-/nd-HepaRG cells and a reactivity towards several hepatic growth factors and NGC, as known from human hepatocytes, are essential components for an in-vitro model for early stage human hepatocarcinogenesis.The potential value as new approach methodology (NAM) for NGC is discussed.

Induction of defense-related enzymes and enhanced disease resistance in rice against Sarocladium oryzae by Bacillus cereus RBS-57

Bacillus species have been identified as effective bioagents and plant growth boosters in rice. Currently, there is limited research on the effectiveness of Bacillus strains in managing the sheath rot disease of rice caused by Sarocladium oryzae, a significant threat to rice-cultivating areas in India. The aim of this study was to evaluate the efficacy of Bacillus spp. to control the sheath rot disease and promote growth in rice plants. We investigated the in vitro antagonistic activity and growth-promoting potential of eighty-four Bacillus spp. against S. oryzae. Ten efficient strains were carefully selected and analyzed at the molecular level based on their capacity for antagonism and growth promotion. A PCR study of the potential strains has revealed the presence of lipopeptide genes that produce bacilysin, bacillomycin, iturin, surfactin, subtilin, subtilosin and fengycin. Among the strains, RBS-57 had the highest mycelial growth inhibition (74.44 %) of the pathogen as well as the highest number of antibiotic genes (6). The efficacy of talc and liquid formulations of Bacillus strains BS-5, RBS-57, and RBS-3 was further tested against sheath rot disease. Results indicated that a combined application of seed treatment + seedling dip + foliar spray of RBS-57 liquid formulation under pot culture conditions, showed a considerable reduction in the incidence of sheath rot disease, followed by BS-5 and RBS-3. Similarly, a significant increase in the plant growth attributes and yield was observed with RBS-57, when compared to the other treatments. Enzymatic activities such as PO, PPO, PAL, CAT and SOD were induced in the rice sheath by B. cereus (RBS-57) treatment. Real-time expression analysis was performed to validate the fold changes in defense enzymes and reactive oxygen species. The effectiveness of RBS-57 liquid formulation in reducing disease incidence was demonstrated when applied as a combination of seed treatment @ 10 ml/l + seedling dip @ 10 ml/l + foliar spray @ 10 ml/l. Moreover, higher defense enzyme activities, maximum plant growth promotion and higher yield were reported with RBS-57 treatment. This study has the potential to be exploited to manage sheath rot disease in an eco-friendly and sustainable manner.

Environmental selenium volatilization is possibly conferred by promiscuous reactions of the sulfur metabolism

Selenium deficiency affects many million people worldwide and volatilization of biogenically methylated selenium species to the atmosphere may limit Se entering the food chain. However, there is very little systematic data on volatilization at nanomolar concentrations prevalent in pristine natural environments. Pseudomonas tolaasii cultures efficiently methylated Se at these concentrations. Nearly perfect linear correlations between the spiked Se concentrations and Dimethylselenide, Dimethyldiselenide, Dimethylselenylsulfide and 2-hydroxy-3-(methylselanyl)propanoic acid were observed up to 80 nM. The efficiency of methylation increased linearly with increasing initial Se concentration, arguing that the enzymes involved are not constitutive, but methylation proceeds promiscuously via pathways of S methylation. From the ratio of all methylated Se and S species, one can conclude that between 0.30% and 3.48% of atoms were Se promiscuously methylated at such low concentrations. At concentrations higher than 640 nM (∼50 μg/L) a steep increase in methylation and volatilization was observed, which suggested the induction of specific enzymes. Promiscuous methylation at low environmental concentrations calls into question that view that methylated Se in the atmosphere is a result of a purposeful Se metabolism serving detoxification. Rather, the concentrations of methylated Se in the atmosphere may be “coincidental” i.e., determined by the activity of S cycling microorganisms. Further, a steep increase in methylation efficiency when surpassing a certain threshold concentration (here ∼50 μg/L) calls into question that natural methylation can be estimated from high Se spikes in laboratory systems, yet highlights the possibility of using bacterial methylation as an effective remediation strategy for media higher concentrated in Se.

Optimization of a Microencapsulation Process Using Oil-in-Water (O/W) Emulsion to Increase Thermal Stability of Sulforaphane.

Sulforaphane (SFN) is a bioactive compound widely studied for its potential applications in pharmaceutical, nutraceutical, and food industries since it offers health benefits due to its nature as a Phase 2 enzyme inducer. Its application in the food industry has been limited because SFN is unstable at high temperatures in an aqueous milieu. An option to increase SFN stability and protect it from thermal degradation is microencapsulation. The aim of this work was to optimize a microencapsulation process using oil-in-water emulsion to increase the thermal stability of SFN. The operation conditions that gave the highest entrapment efficiency were determined via experimental design and response surface methodology. Thermal degradation of microencapsulated SFN was studied at 37, 50, 60, and 70 °C. The optimum microencapsulation conditions were 8 min stirring, SFN/Gum Arabic ratio of 0.82, and surfactant/oil ratio of 1.0, resulting in an entrapment efficiency of 65%, which is the highest reported so far. The thermal stability of microencapsulated SFN was greatly enhanced compared with free SFN, with a 6-fold decrease in the degradation kinetic constant and a 41% increase in the activation energy. These results will contribute to a more efficient incorporation of SFN in various food matrices and explore new microencapsulation technologies to maximize the efficiency and stability of SFN.

Induction of Tolerance in Groundnut Plants Against Drought Stress and Cercospora Leaf Spot Disease with Exogenous Application of Arginine and Sodium Nitroprusside Under Field Conditions

Naturally, under field conditions, plants are regularly experienced by a mixture of two or more stress factors. Drought is a major abiotic stress, and fungal pathogens characterize a main biotic stress challenge faced by plants and impact negatively on plant development and productivity. We propose that foliar application of nitric oxide (NO) donors can have positive effects on the induction of tolerance to biotic and abiotic stress on groundnut plants. This investigation was carried out to study the changes in growth, some biochemical aspects, and yield and quality of groundnut plants as well as induction of resistance to Cercospora leaf spot disease in response to nitric oxide (NO) donors, sodium nitroprusside (SNP), and arginine (Arg) (2.5, 5.0, and 7.5 mM) under two water irrigation levels 100% and 75% of water irrigation requirements (WIR), in two field experiments through two successive growing seasons of 2021 and 2022. Decreasing irrigation water significantly reduced shoot length, branches numberplant-1, shoot fresh and dry weight, photosynthetic pigments components, endogenous indole acetic acid (IAA) contents, and yield components. Furthermore, root fresh and dry weight, phenols, total soluble sugars (TSS), proline contents, and the accumulation of hydrogen peroxide (H2O2) and lipid peroxidation of groundnut leaves increased significantly. Contrarily, foliar application with Arg and SNP alleviated the negative influences of drought on growth and productivity of groundnut plants via enhancing photosynthetic pigments, IAA, phenolic compounds, TSS, and proline contents. Additionally, SNP and Arg significantly decreased oxidative damage through decreasing H2O2 and lipid peroxidation by the induction of antioxidant enzymes. Remarkably, the increase of drought level led to a reduction in Cercospora leaf spot (CLS) disease with the use of high concentrations of both Arg and SNP. Interestingly, in both stressed and unstressed plants, SNP treatment at 7.5 mM was the most effective in reducing the incidence and severity of disease, while Arg at 2.5 mM recorded the lowest reduction compared to other treatments. In conclusion, foliar treatment of either SNP or Arg is a profound effect on modulating the drought stress and induction of resistance to Cercospora leaf spot disease of groundnut plants throughout regulating physiological and biochemical processes associated with photosynthesis and oxidative responses.

Cyanide Bioremediation by Bacillus subtilis under Alkaline Conditions

Cyanide (CN) is a toxic environmental pollutant generated by various industrial activities, necessitating the application of bioremediation techniques for its degradation. Biodegradation is a more cost-effective and environmentally friendly technique with high efficiency in CN removal. This study isolated cyanide-degrading bacteria from Tutupaca mining site soil from Tacna, Peru. Bacillus subtilis strain TT10s was selected for its exceptional capacity to rapidly and completely eliminate cyanide under alkaline conditions (pH 10.5), removing 1000 ppm cyanide within 48 h. A kinetic analysis revealed that the biodegradation follows second-order rate kinetics (k2 = 0.08649 mg/(mg·h), R2 = 0.96622), consistent with the literature attribution of the rate-limiting step to the inducible cyanide dihydratase enzyme, which converts cyanide into ammonia and formate via the Michaelis–Menten model. Fourier-transform infrared spectroscopy (FTIR) spectral analysis further corroborated this enzymatic mechanism, showing the disappearance of CN peaks coupled with the emergence of ammonia (NH) and formate (C=O) peaks. Quantitative kinetic modelling integrated with FTIR profiles and degradation curves implicates cyanide dihydratase as the key rate-controlling enzyme in alkaline cyanide biodegradation without the need for an extra carbon source, generating interest for future bioremediation applications in highly contaminated environments.

Changes in Whole Blood Polyamine Levels and Their Background in Age-Related Diseases and Healthy Longevity.

The relationship between polyamines and healthy longevity has received much attention in recent years. However, conducting research without understanding the properties of polyamines can lead to unexpected pitfalls. The most fundamental consideration in conducting polyamine studies is that bovine serum used for cell culture contains bovine serum amine oxidase. Bovine serum amine oxidase, which is not inactivated by heat treatment, breaks down spermine and spermidine to produce the highly toxic aldehyde acrolein, which causes cell damage and activates autophagy. However, no such enzyme activity has been found in humans. Polyamine catabolism does not produce toxic aldehydes under normal conditions, but inflammation and some pathogens provoke an inducible enzyme, spermine oxidase, which only breaks down spermine to produce acrolein, resulting in cytotoxicity and the activation of autophagy. Therefore, spermine oxidase activation reduces spermine concentration and the ratio of spermine to spermidine, a feature recently reported in patients with age-related diseases. Spermine, which is increased by a long-term, continuous high polyamine diet, suppresses aberrant gene methylation and the pro-inflammatory status that progress with age and are strongly associated with the development of several age-related diseases and senescence. Changes in spermine concentration and the spermine/spermidine ratio should be considered as indicators of human health status.

Inoculum size-insensitive susceptibility determination of urine sample based on in-situ measurement of inducible enzyme activity after 20 min of antibiotic exposure

BackgroundThe empirical antibiotic therapies for bacterial infections cause the emergence and propagation of multi-drug resistant bacteria, which not only impair the effectiveness of existing antibiotics but also raise healthcare costs. To reduce the empirical treatments, rapid antimicrobial susceptibility testing (AST) of causative microorganisms in clinical samples should be conducted for prescribing evidence-based antibiotics. However, most of culture-based ASTs suffer from inoculum effect and lack differentiation of target pathogen and commensals, hampering their adoption for evidence-based antibiotic prescription. Therefore, rapid ASTs which can specifically determine pathogens’ susceptibilities, regardless of the bacterial load in clinical samples, are in urgent need. ResultsWe present a pathogen-specific and inoculum size-insensitive AST to achieve the reliable susceptibility determination on Escherichia coli (E. coli) in urine samples. The developed AST is featured with an 1 h sample-to-result workflow in a filter, termed on-filter AST. The AST results can be obtained by using an inducible enzymatic assay to in-situ measure the cell response of E. coli collected from urine after 20 min of antibiotic exposure. The calculated detection limit of our AST (1.95 × 104 CFU/mL) is much lower than the diagnosis threshold of urinary tract infections. The specific expression of the inducible enzyme enables on-filter AST to correctly profile the susceptibilities of target pathogen to multi-type antibiotics without the interference from commensals. We performed the on-filter AST on 1 mL urine samples with bacterial loads varying from 105 CFU/mL to 107 CFU/mL and compared the results to that of standard method, demonstrating its insensitivity to inoculum size. SignificanceThe developed AST is demonstrated to be of high sensitivity, specificity, and insensitive to inoculum size. With further developments for additional bacteria and clinical validation, on-filter AST is promising as a rapid and reliable surrogate of culture-based AST to promote the evidence-based prescription at the first visit and minimize the emergency of new multi-drug resistant microorganisms.

Nasal Nitric Oxide in Children: A Review of Current Outreach in Pediatric Respiratory Medicine.

Nasal nitric oxide (nNO) is a gas synthesized by the inducible and constitutive NO synthase (NOS) enzyme in the airway cells of the nasal mucosa. Like lung nitric oxide, it is thought to be associated with airway inflammation in various respiratory diseases in children. The aim of our review was to investigate the current state of use of nNO measurement in children. A comprehensive search was conducted using the Web of Science and PubMed databases specifically targeting publications in the English language, with the following keywords: nasal NO, children, allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, primary ciliary dyskinesia (PCD), and cystic fibrosis (CF). We describe the use of nNO in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF based on the latest literature. nNO is a noninvasive, clinically applicable test for use in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF. It can be used as a complementary method in the diagnosis of these respiratory diseases and as a monitoring method for the treatment of allergic rhinitis and acute and chronic rhinosinusitis.

Induction of systemic resistance in Solanum lycopersicum and Capsicum annum seedlings against Fusarium wilt by Streptomyces bioformulations.

Plant diseases induced by various phytopathogens pose a significant threat to contemporary agricultural systems around the world. In modern agriculture, the use of pesticides is still a valuable and effective method to control plant diseases. However, agrochemicals are becoming less popular because of the accretion of toxic compounds perilous and potentially hazardous to humans and the environment. Taking into consideration these aspects, the present study was conducted to explore the biocontrol potential of an endophyticStreptomyces sp. SP5 bioformulations against Fusarium wilt. Three bioformulations were prepared using cell biomass and different carriers, i.e., B1 (talc-kaolin), B2 (MgSO4/glycerol/Na-alginate/talc/Ca-lignosulfonate), and B3 (calcium carbonate/CMC/talc). Apart from antagonistic action against Fusarium wilt, the influence of bioformulations on plant growth and systemic resistance was investigated by analyzing morphological parameters (root length, shoot length, root weight, shoot weight), biochemical parameters (photosynthetic pigments, non-enzymatic antioxidants), and induction of antioxidative enzymes, e.g., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and superoxide dismutase (SOD), in S. lycopersicum and C. annum seedlings. The results revealed that Streptomyces bioformulations effectively controlled Fusarium wilt in S. lycopersicum and C. annum (82.6-83.4% and 81.8-100%, respectively). Besides reducing disease prevalence, bioformulations significantly increased all the morphological parameters and increased the activity of antioxidative enzymes, i.e., CAT, APX, GPX, and SOD, in plants. The current findings display that bioformulations can be utilized as environment-friendly biocontrol agents against Fusarium wilt and also as plant growth promoters.

Drug interaction potential of high-dose rifampicin in patients with pulmonary tuberculosis.

Accumulating evidence supports the use of higher doses of rifampicin for tuberculosis (TB) treatment. Rifampicin is a potent inducer of metabolic enzymes and drug transporters, resulting in clinically relevant drug interactions. To assess the drug interaction potential of higher doses of rifampicin, we compared the effect of high-dose rifampicin (40 mg/kg daily, RIF40) and standard-dose rifampicin (10 mg/kg daily, RIF10) on the activities of major cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp). In this open-label, single-arm, two-period, fixed-order phenotyping cocktail study, adult participants with pulmonary TB received RIF10 (days 1-15), followed by RIF40 (days 16-30). A single dose of selective substrates (probe drugs) was administered orally on days 15 and 30: caffeine (CYP1A2), tolbutamide (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and digoxin (P-gp). Intensive pharmacokinetic blood sampling was performed over 24 hours after probe drug intake. In all, 25 participants completed the study. Geometric mean ratios (90% confidence interval) of the total exposure (area under the concentration versus time curve, RIF40 versus RIF10) for each of the probe drugs were as follows: caffeine, 105% (96%-115%); tolbutamide, 80% (74%-86%); omeprazole, 55% (47%-65%); dextromethorphan, 77% (68%-86%); midazolam, 62% (49%-78%), and 117% (105%-130%) for digoxin. In summary, high-dose rifampicin resulted in no additional effect on CYP1A2, mild additional induction of CYP2C9, CYP2C19, CYP2D6, and CYP3A, and marginal inhibition of P-gp. Existing recommendations on managing drug interactions with rifampicin can remain unchanged for the majority of co-administered drugs when using high-dose rifampicin. Clinical Trials registration number NCT04525235.