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Poultry Science May 2024This investigation aimed to evaluate the impact of immersion (IM) riboflavin treatment on the hatchability, production efficiency, and carcass characteristics of...
This investigation aimed to evaluate the impact of immersion (IM) riboflavin treatment on the hatchability, production efficiency, and carcass characteristics of Japanese quail eggs. A total of 260 eggs of Japanese quail birds were used for hatching and were randomly divided into 4 treatments with 5 replicates (13 eggs/replicate) in a fully randomized design. Hatching eggs were immersed in riboflavin for 2 min before incubation. The experiment treatments were designed as follows: G1 control group with no treatment, G2 treated with 3 g/L vit. B2 (IM), G3 treated with 4 g/L vit. B2 (IM) and G4 were treated with 5 g/L vit. B2 (IM). After hatching, 128 Japanese quail chicks, aged 7 d, were randomly grouped into 4 treatment groups, with 32 birds in each group. When quails were given vitamin B2 via immersion, they demonstrated significant enhancements in live body weight, body weight gain, feed consumption, and feed conversion ratio at different stages compared to the control group. Compared to control and other groups, the carcass parameters of Japanese quails given a 4 g/L immersion solution showed a significant improvement (P < 0.05). Hatchability and fertility (%) were considerably raised by Vit.B2 treatments of 3, 4, and 5g; the group immersed in 5 g/L had the highest percentages compared to the other groups. Furthermore, treated chickens with all concentrations of vitamin B2 had significantly higher blood indices than the controls. During the exploratory phase (1-6 wk) of age, the highest returns were reported in G4 treated with 5g/L vit. B2 (IM). Treating Japanese quail eggs with different dosages of vitamin B2 by immersion may be recommended to improve their productive and reproductive performance, blood indices, carcass traits, and economic efficiency.
PubMed: 38838591
DOI: 10.1016/j.psj.2024.103858 -
Current Opinion in Virology Jun 2024Mucosal-associated invariant T (MAIT) cells are an unconventional T cell population that are highly abundant in humans. They possess a semi-invariant T cell receptor... (Review)
Review
Mucosal-associated invariant T (MAIT) cells are an unconventional T cell population that are highly abundant in humans. They possess a semi-invariant T cell receptor (TCR) that recognises microbial metabolites formed during riboflavin biosynthesis, presented on a nonpolymorphic MHC-like molecule MR1. MAIT cells possess an array of effector functions, including type 1, type 17, and tissue repair activity. Deployment of these functions depends on the stimuli they receive through their TCR and/or cytokine receptors. Strong cytokine signalling, such as in response to vaccination, can bypass TCR triggering and provokes a strong proinflammatory response. Although data are still emerging, multiple aspects of MAIT cell biology are associated with modulation of immunity induced by the coronavirus disease 2019 mRNA and adenovirus vector vaccines. In this review, we will address how MAIT cells may play a role in immunogenicity of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and how these cells can be harnessed as cellular adjuvants.
PubMed: 38838550
DOI: 10.1016/j.coviro.2024.101412 -
Frontiers in Veterinary Science 2024Locoweed is a poisonous plant widely present in grasslands around the world. Swainsonine (SW), an indole alkaloid that, is the main toxic component of the locoweed. To...
Locoweed is a poisonous plant widely present in grasslands around the world. Swainsonine (SW), an indole alkaloid that, is the main toxic component of the locoweed. To understand the mechanism of SW-induced toxicity and to delineate the metabolic profile of locoweed poisoning we performed the LC-MS/MS untargeted metabolomic study to analyze metabolites in SW-treated renal tubular epithelial cells (0.8 mg/mL, 12 h) and in order to identify the SW-induced metabolomic changes. The analysis identified 2,563 metabolites in positive ion mode and 1,990 metabolites in negative ion mode. Our results showed that the metabolites were mainly benzenoids, lipids and lipid-like molecules, nucleosides, nucleotides, and analogs, organic acids, and derivatives. The differential metabolites were primarily enriched in pathways involving bile secretion, primary bile acid biosynthesis, riboflavin metabolism, ferroptosis, drug metabolism-cytochrome P450, and primidine metabolism. We have screened out substances such as swainsonine, 3alpha,7alpha-Dihydroxy-5beta-cholestanate, 2-Hydroxyiminostilbene, and glycochenodeoxycholate, which may have the potential to serve as biomarkers for swainsonine poisoning. This study provides insights into the types of metabolomic alteration in renal tubular epithelial cells induced by swainsonine.
PubMed: 38835895
DOI: 10.3389/fvets.2024.1387853 -
Progress in Retinal and Eye Research Jun 2024Changes in the biomechanical and biochemical properties of the human cornea play an important role in the pathogenesis of ectatic diseases. A number of conditions in... (Review)
Review
Changes in the biomechanical and biochemical properties of the human cornea play an important role in the pathogenesis of ectatic diseases. A number of conditions in primarily acquired (keratoconus or pellucid marginal degeneration) or secondarily induced (iatrogenic keratectasia after refractive laser surgeries) ectatic disorders lead to decreased biomechanical stability. Corneal collagen cross-linking (CXL) represents a technique to slow or even halt the progression of ectatic pathologies. In this procedure, riboflavin is applied in combination with ultraviolet A radiation. This interaction induces the production of reactive oxygen species, which leads to the formation of additional covalent bonds between collagen molecules and subsequent biomechanical corneal strengthening. This procedure is so far the only method that partially interferes etiopathogenetically in the treatment of ectatic diseases that slows or stops the process of corneal destabilization, otherwise leading to the need for corneal transplantation. Besides, CXL process increases markedly resistance of collagenous matrix against digesting enzymes supporting its use in the treatment of corneal ulcers. Since the discovery of this therapeutic procedure and the first laboratory experiments, which confirmed the validity of this method, and the first clinical studies that proved the effectiveness and safety of the technique, it has been spread and adopted worldwide, even with further modifications. Making use of the Bunsen-Roscoe photochemical law it was possible to shorten the duration of this procedure in accelerated CXL and thus improve the clinical workflow and patient compliance while maintaining the efficacy and safety of the procedure. The indication spectrum of CXL can be further expanded by combining it with other vision-enhancing procedures such as individualized topographically-guided excimer ablation. Complementing both techniques will allow a patient with a biomechanically stable cornea to regularize it and improve visual acuity without the need for tissue transplantation, leading to a long-term improvement in quality of life.
PubMed: 38830532
DOI: 10.1016/j.preteyeres.2024.101276 -
BJPsych Open Jun 2024Broad-spectrum micronutrients (minerals and vitamins) have shown benefit for treatment of depressive symptoms.
BACKGROUND
Broad-spectrum micronutrients (minerals and vitamins) have shown benefit for treatment of depressive symptoms.
AIMS
To determine whether additional micronutrients reduce symptoms of antenatal depression.
METHOD
Eighty-eight medication-free pregnant women at 12-24 weeks gestation, who scored ≥13 on the Edinburgh Postnatal Depression Scale (EPDS), were randomised 1:1 to micronutrients or active placebo (containing iodine and riboflavin), for 12 weeks. Micronutrient doses were generally between recommended dietary allowance and tolerable upper level. Primary outcomes (EPDS and Clinical Global Impression - Improvement Scale (CGI-I)) were analysed with constrained longitudinal data analysis.
RESULTS
Seventeen (19%) women dropped out, with no group differences, and four (4.5%) gave birth before trial completion. Both groups improved on the EPDS, with no group differences ( = 0.1018); 77.3% taking micronutrients and 72.7% taking placebos were considered recovered. However, the micronutrient group demonstrated significantly greater improvement, based on CGI-I clinician ratings, over time ( = 0.0196). The micronutrient group had significantly greater improvement on sleep and global assessment of functioning, and were more likely to identify themselves as 'much' to 'very much' improved (68.8%) compared with placebo (38.5%) (odds ratio 3.52, = 0.011; number needed to treat: 3). There were no significant group differences on treatment-emergent adverse events, including suicidal ideation. Homocysteine decreased significantly more in the micronutrient group. Presence of personality difficulties, history of psychiatric medication use and higher social support tended to increase micronutrient response compared with placebo.
CONCLUSIONS
This study highlights the benefits of active monitoring on antenatal depression, with added efficacy for overall functioning when taking micronutrients, with no evidence of harm. Trial replication with larger samples and clinically diagnosed depression are needed.
PubMed: 38828982
DOI: 10.1192/bjo.2024.706 -
Carbohydrate Polymers Sep 2024This paper reports on biofunctionalisation of a poly(lactic acid) (PLA) film by surface activation through cold plasma treatment followed by coating with a...
This paper reports on biofunctionalisation of a poly(lactic acid) (PLA) film by surface activation through cold plasma treatment followed by coating with a chitosan-gelatin xerogel. The UV cross-linking of the xerogel precursor was simultaneously performed with the fixation onto the PLA support. This has a strong effect on surface properties, in terms of wettability, surface free energy, morphology and micromechanical features. The hydrophilic - hydrophobic character of the surface, determined by contact angle measurements, was tuned along the process, passing from moderate hydrophobic PLA to enhanced hydrophilic plasma activated surface, which favors coating adhesion, then to moderate hydrophobic chitosan-gelatin coating. The coating has a Lewis amphoteric surface, with a porous xerogel-like morphology, as revealed by scanning electron microscopy images. By riboflavin mediated UV cross-linking the chitosan-gelatin coating becomes high adhesive and with a more pronounced plasticity, as shown by AFM force-distance spectroscopy. Thus prepared surface-coated PLA supports were successfully tested for growth of dermal fibroblasts, which are known for their induction potential of chondrogenic cells, which is very important in cartilage tissue engineering.
Topics: Chitosan; Gelatin; Polyesters; Fibroblasts; Humans; Surface Properties; Gels; Ultraviolet Rays; Plasma Gases; Hydrophobic and Hydrophilic Interactions; Coated Materials, Biocompatible; Cross-Linking Reagents; Wettability
PubMed: 38823936
DOI: 10.1016/j.carbpol.2024.122288 -
Microbial Cell Factories May 2024Bacillus subtilis is widely used in industrial-scale riboflavin production. Previous studies have shown that targeted mutagenesis of the ribulose 5-phosphate 3-epimerase...
BACKGROUND
Bacillus subtilis is widely used in industrial-scale riboflavin production. Previous studies have shown that targeted mutagenesis of the ribulose 5-phosphate 3-epimerase in B. subtilis can significantly enhance riboflavin production. This modification also leads to an increase in purine intermediate concentrations in the medium. Interestingly, B. subtilis exhibits remarkable efficiency in purine nucleoside synthesis, often exceeding riboflavin yields. These observations highlight the importance of the conversion steps from inosine-5'-monophosphate (IMP) to 2,5-diamino-6-ribosylamino-4(3 H)-pyrimidinone-5'-phosphate (DARPP) in riboflavin production by B. subtilis. However, research elucidating the specific impact of these reactions on riboflavin production remains limited.
RESULT
We expressed the genes encoding enzymes involved in these reactions (guaB, guaA, gmk, ndk, ribA) using a synthetic operon. Introduction of the plasmid carrying this synthetic operon led to a 3.09-fold increase in riboflavin production compared to the control strain. Exclusion of gmk from the synthetic operon resulted in a 36% decrease in riboflavin production, which was further reduced when guaB and guaA were not co-expressed. By integrating the synthetic operon into the genome and employing additional engineering strategies, we achieved riboflavin production levels of 2702 mg/L. Medium optimization further increased production to 3477 mg/L, with a yield of 0.0869 g riboflavin per g of sucrose.
CONCLUSION
The conversion steps from IMP to DARPP play a critical role in riboflavin production by B. subtilis. Our overexpression strategies have demonstrated their effectiveness in overcoming these limiting factors and enhancing riboflavin production.
Topics: Riboflavin; Bacillus subtilis; Purines; Metabolic Engineering; Biosynthetic Pathways; Operon; Bacterial Proteins
PubMed: 38822377
DOI: 10.1186/s12934-024-02426-w -
Blood Transfusion = Trasfusione Del... May 2024Quality assessment of modified or processed red blood cell (RBC) components, such as pathogen-reduced RBCs, using only in vitro testing may not always be predictive of...
BACKGROUND
Quality assessment of modified or processed red blood cell (RBC) components, such as pathogen-reduced RBCs, using only in vitro testing may not always be predictive of in vivo performance. Mouse or rat in vivo models are limited by a lack of applicability to certain aspects of human RBC biology. Here, we used a guinea pig model to study the effects of riboflavin combined with UV light on the integrity of RBCs in vitro and following transfusion in vivo.
MATERIALS AND METHODS
Guinea pig RBCs were collected from whole blood (WB) treated with varying UV doses (10, 20, 40 or 80 J/mL) in the presence of riboflavin (UVR-RBCs). In vitro tests for UVR-RBCs included hemolysis, osmotic fragility, and cellular morphology by scanning electron microscopy. Guinea pigs transfused with one-day post-treatment UVR-RBCs were evaluated for plasma hemoglobin (Hb), non-transferrin bound iron (NTBI), total iron and Perls-detectable hemosiderin deposition in the spleen and kidney, and renal uptake of Hb.
RESULTS
Acute RBC injury was dose dependently accelerated after treatment with UV light in the presence of riboflavin. Aberrant RBC morphology was evident at 20, 40, and 80 J/mL, and membrane lysis with Hb release was prominent at 80 J/mL. Guinea pigs transfused with 40 and 80 J/mL UVR-RBCs showed increased plasma Hb levels, and plasma NTBI was elevated in all UVR-RBC groups (10-80 J/mL). Total iron levels and Perls-hemosiderin staining in spleen and kidney as well as Hb uptake in renal proximal tubules were increased 8 hours post-transfusion with 40 and 80 J/mL UVR-RBCs.
DISCUSSION
UVR-RBCs administered to guinea pigs increased markers of intravascular and extravascular hemolysis in a UV dose-dependent manner. This model may allow for the discrimination of RBC injury during testing of extensively processed RBCs intended for transfusion.
PubMed: 38814883
DOI: 10.2450/BloodTransfus.718 -
Scientific Reports May 2024Tuberculosis (TB) continues to be a global health crisis, necessitating urgent interventions to address drug resistance and improve treatment efficacy. In this study, we...
Tuberculosis (TB) continues to be a global health crisis, necessitating urgent interventions to address drug resistance and improve treatment efficacy. In this study, we validate lumazine synthase (RibH), a vital enzyme in the riboflavin biosynthetic pathway, as a potential drug target against Mycobacterium tuberculosis (M. tb) using a CRISPRi-based conditional gene knockdown strategy. We employ a high-throughput molecular docking approach to screen ~ 600,000 compounds targeting RibH. Through in vitro screening of 55 shortlisted compounds, we discover 3 compounds that exhibit potent antimycobacterial activity. These compounds also reduce intracellular burden of M. tb during macrophage infection and prevent the resuscitation of the nutrient-starved persister bacteria. Moreover, these three compounds enhance the bactericidal effect of first-line anti-TB drugs, isoniazid and rifampicin. Corroborating with the in silico predicted high docking scores along with favourable ADME and toxicity profiles, all three compounds demonstrate binding affinity towards purified lumazine synthase enzyme in vitro, in addition these compounds exhibit riboflavin displacement in an in vitro assay with purified lumazine synthase indicative of specificity of these compounds to the active site. Further, treatment of M. tb with these compounds indicate reduced production of flavin adenine dinucleotide (FAD), the ultimate end product of the riboflavin biosynthetic pathway suggesting the action of these drugs on riboflavin biosynthesis. These compounds also show acceptable safety profile in mammalian cells, with a high selective index. Hence, our study validates RibH as an important drug target against M. tb and identifies potent antimycobacterial agents.
Topics: Mycobacterium tuberculosis; Antitubercular Agents; Molecular Docking Simulation; Multienzyme Complexes; Drug Discovery; Bacterial Proteins; Humans; Tuberculosis; Microbial Sensitivity Tests; Animals
PubMed: 38806590
DOI: 10.1038/s41598-024-63051-6 -
The Journal of Physical Chemistry. B Jun 2024It is still a puzzle that has not been entirely solved how migratory birds utilize the Earth's magnetic field for biannual migration. The most consistent explanation...
It is still a puzzle that has not been entirely solved how migratory birds utilize the Earth's magnetic field for biannual migration. The most consistent explanation thus far is rooted in the modulation of the biological function of the cryptochrome 4 (Cry4) protein by an external magnetic field. This phenomenon is closely linked with the flavin adenine dinucleotide (FAD) cofactor that is noncovalently bound in the protein. Cry4 is activated by blue light, which is absorbed by the FAD cofactor. Subsequent electron and proton transfers trigger radical pair formation in the protein, which is sensitive to the external magnetic field. An important long-lasting redox state of the FAD cofactor is the signaling (FADH) state, which is present after the transient electron transfer steps have been completed. Recent experimental efforts succeeded in crystallizing the Cry4 protein from (ClCry4) with all of the important residues needed for protein photoreduction. This specific crystallization of Cry4 protein so far is the only avian cryptochrome crystal structure available, which, however, has great similarity to the Cry4 proteins of night migratory birds. The previous experimental studies of the ClCry4 protein included the absorption properties of the protein in its different redox states. The absorption spectrum of the FADH state demonstrated a peculiar red shift compared to the photoabsorption properties of the FAD cofactor in its FADH state in other Cry proteins from other species. The aim of this study is to understand this red shift by employing the tools of computational microscopy and, in particular, a QM/MM approach that relies on the polarizable embedding approximation.
Topics: Cryptochromes; Flavin-Adenine Dinucleotide; Animals; Avian Proteins; Oxidation-Reduction
PubMed: 38805723
DOI: 10.1021/acs.jpcb.4c00710