Inherited metabolic diseases, as a first presentation in adults, are an under-recognised condition associated with significant morbidity and mortality. Diagnosis is challenging because of non-specific clinical and biochemical findings, resemblance to common conditions such as neuropsychiatric disorders and the misconception that these disorders predominantly affect paediatric populations. We describe a series of patients with multiple acyl-CoA dehydrogenase deficiency (MADD)/MADD-like disorders to highlight these diagnostic challenges.

Microcystis and bacteria always live together in the mucilage of Microcystis colonies. Extracellular electrons between Microcystis and bacteria can be translated from bioenergy to electric energy. Here, photosynthetic microbial fuel cells (PMFCs) were constructed to make clear the electron transfer mechanism between Microcystis and bacteria. A remarkable enhancement of current density with 2.5-fold change was detected in the coculture of Microcystis and bacteria than pure culture of Microcystis. Transcriptome analyses showed that photosynthesis efficiency of Microcystis was upregulated and may release more electron to improve extracellular electron transfer rate. Significant increase on oxidative phosphorylation of bacterial community was observed according to meta-transcriptome. Bacterial electrons were transferred out of cell membranes by enhancing VgrG and IcmF copies though the type II bacterial secretion system. Not only Microcystis and bacteria attached with each other tightly by filamentous, but also more gene copies relating to pilin and riboflavin production were detected from Microcystis culture. A confirmatory experiment found that riboflavin can upregulate the electron transfer and current density by adding riboflavin into cocultures. Thus, the direct contact and indirect interspecies electron transfer processes between Microcystis and bacteria were observed. Results enlarge knowledge for activities of Microcystis colonies in cyanobacterial blooms, and provide a better understanding for energy transformation.

Mucosal-associated invariant T (MAIT) cells are unconventional T cells that respond to riboflavin biosynthesis and cytokines through TCR-dependent and -independent pathways, respectively. MAIT cell activation plays an immunoprotective role against several pathogens, however the functional capacity of MAIT cells following direct infection or exposure to infectious agents remains poorly defined. We investigated the impact of Varicella Zoster Virus (VZV) on blood-derived MAIT cells and report virus-mediated impairment of activation, cytokine production, and altered transcription factor expression by VZV infected (antigen+) and VZV exposed (antigen-) MAIT cells in response to TCR-dependent and -independent stimulation. Furthermore, we reveal that suppression of VZV exposed (antigen-) MAIT cells is not mediated by a soluble factor from neighbouring VZV infected (antigen+) MAIT cells. Finally, we demonstrate that VZV impairs the cytolytic potential of MAIT cells in response to riboflavin synthesising bacteria. In summary, we report a virus-mediated immune-evasion strategy that disarms MAIT cell responses.

OBJECTIVE: This study aimed to analyze variations in intraoperative corneal thickness during corneal cross-linking in patients with keratoconus and to investigate its possible correlation with presurgical maximal keratometry (Kmax) and pachymetry.
METHODS: This was a prospective case series. We used a method similar to the Dresden protocol, with the application of hydroxypropyl methylcellulose 0.1% hypo-osmolar riboflavin in corneas between 330 and 400 µm after epithelium removal. Corneal thickness was measured using portable calipers before and immediately after epithelium removal, and 30 and 60 min after the procedure.
RESULTS: The 30 patients in this study were followed up for one year. A statistically significant difference was observed in pachymetry values during the intraoperative period (p<0.0001) and an increase of 3.05 µm (95%C1: 0.56-5.54) for each diopter was seen after epithelium removal (p0.019). We found an average Kmax difference of -2.12 D between men and women (p0.013). One year after treatment, there was a statistically significant reduction in pachymetry (p<0.0001) and Kmax (p0.0170) values.
CONCLUSIONS: A significant increase in pachymetry measurements was seen during the procedure, and most patients showed a regression in Kmax and pachymetry values one year after surgery.

Brown fat is a therapeutic target for the treatment of obesity-associated metabolic diseases. However, nutritional intervention strategies for increasing the mass and activity of human brown adipocytes have not yet been established. To identify vitamins required for brown adipogenesis and adipocyte browning, chemical compound-induced brown adipocytes (ciBAs) were converted from human dermal fibroblasts under serum-free and vitamin-free conditions. Choline was found to be essential for adipogenesis. Additional treatment with pantothenic acid (PA) provided choline-induced immature adipocytes with browning properties and metabolic maturation, including uncoupling protein 1 (UCP1) expression, lipolysis, and mitochondrial respiration. However, treatment with high PA concentrations attenuated these effects along with decreased glycolysis. Transcriptome analysis showed that a low PA concentration activated metabolic genes, including the futile creatine cycle-related thermogenic genes, which was reversed by a high PA concentration. Riboflavin treatment suppressed thermogenic gene expression and increased lipolysis, implying a metabolic pathway different from that of PA. Thiamine treatment slightly activated thermogenic genes along with decreased glycolysis. In summary, our results suggest that specific B vitamins and choline are uniquely involved in the regulation of adipocyte browning via cellular energy metabolism in a concentration-dependent manner.

Leishmania donovani relies on specific vitamins and cofactors crucial for its survival and pathogenesis. Tailoring therapies to disrupt these pathways offers a promising strategy for the treatment of Visceral Leishmaniasis. Current treatment regimens are limited due to drug resistance and high costs. The dependency of Leishmania parasites on Vitamin B2 and its metabolic products is not known. In this study, we have biochemically and biophysically characterized a Vitamin B2 metabolism enzyme, riboflavin kinase from L. donovani (LdRFK) which converts riboflavin (vitamin B2) into flavin mononucleotide (FMN). Sequence comparison with human counterpart reflects 31.58 % identity only, thus opening up the possibility of exploring it as drug target. The rfk gene was cloned, expressed and the recombinant protein was purified. Kinetic parameters of LdRFK were evaluated with riboflavin and ATP as substrates which showed differential binding affinity when compared with the human RFK enzyme. Thermal and denaturant stability of the enzyme was evaluated. The rfk gene was overexpressed in the parasites and its role in growth and cell cycle was evaluated. In the absence of crystal structure, homology modelling and molecular dynamic simulation studies were performed to predict LdRFK structure. The data shows differences in substrate binding between human and parasite enzyme. This raises the possibility of exploring LdRFK for specific designing of antileishmanial molecules. Gene disruption studies can further validate its candidature as antileishmanial target.

The antibiotic roseoflavin is a riboflavin (vitamin B2) analog. One step of the roseoflavin biosynthetic pathway is catalyzed by the phosphatase RosC, which dephosphorylates 8-demethyl-8-amino-riboflavin-5\'-phosphate (AFP) to 8-demethyl-8-amino-riboflavin (AF). RosC also catalyzes the potentially cell-damaging dephosphorylation of the AFP analog riboflavin-5\'-phosphate also called \"flavin mononucleotide\" (FMN), however, with a lower efficiency. We performed X-ray structural analyses and mutagenesis studies on RosC from Streptomyces davaonensis to understand binding of the flavin substrates, the distinction between AFP and FMN and the catalytic mechanism of this enzyme. This work is the first structural analysis of an AFP phosphatase. Each monomer of the RosC dimer consists of an α/β-fold core, which is extended by three specific elongated strand-to-helix sections and a specific N-terminal helix. Altogether these segments envelope the flavin thereby forming a novel flavin-binding site. We propose that distinction between AFP and FMN is provided by substrate-induced rigidification of the four RosC specific supplementary segments mentioned above and by an interaction between the amino group at C8 of AFP and the β -carboxylate of D166. This key amino acid is involved in binding the ring system of AFP and positioning its ribitol phosphate part. Accordingly, site-specific exchanges at D166 disturbed the active site geometry of the enzyme and drastically reduced the catalytic activity. Based on the structure of the catalytic core we constructed a whole series of RosC variants but a disturbing, FMN dephosphorylating \"killer enzyme\", was not generated.

UNASSIGNED: To comparatively evaluate the influence of different riboflavin formulations and soaking durations on the anterior segment optical coherence tomography (AS-OCT) findings following accelerated corneal crosslinking (ACXL) at 9 mW/cm2 for in progressive keratoconus.
UNASSIGNED: In this prospective study, consecutive patients with progressive keratoconus were randomized into 4 groups. Group 1: hydroxypropyl methylcellulose (HPMC)-based riboflavin for 10 min; Group 2: HPMC-based riboflavin for 20 min; Group 3: dextran-based riboflavin (0.1%) for 30 min. Riboflavin soaking was followed by ultraviolet-A irradiation at 9 mW/cm2 for 10 min in all three groups. Group 4 underwent conventional CXL (CCXL) using Dresden protocol. The AS-OCT features of the crosslinked cornea were evaluated at postoperative month 1 and correlated to the clinical outcomes at postoperative month 12.
UNASSIGNED: The study enrolled 26 eyes of 26 patients in each group. In groups 1 and 2, the AS-OCT findings were similar (p > .05) and the demarcation lines depth (DLD) were deep as obtained following CCXL. The DLD was significantly shallower in group 3 compared to the other groups (p < .01). There were no between-group differences in regards to the visual, refractive, keratometric, and tomographic outcomes at postoperative month 12. No significant endothelial cell loss or any other clinically significant adverse event was encountered in any patient\'s eye at 12 months follow-up.
UNASSIGNED: Although structural variations were noted in the crosslinked cornea, DLDs observed following ACXL (9 mW/cm2) using HPMC-based solution for 10 or 20 min were similar to those observed following CCXL. Whereas, ACXL (9 mW/cm2) using dextran-based solution for 30 min resulted in the shallowest DLD. Despite these remodeling differences, the visual, refractive and tomographic outcomes of all groups were comparable at postoperative 1-year follow-up. Studies with a greater number of patients and longer follow-ups are required to establish any relation between AS-OCT characteristics of crosslinked cornea and ACXL efficacy.

2-Aminoacetophenone is an off-flavor that can result from tryptophan degradation via riboflavin-photosensitized reaction. This study investigates the impact of light exposure, provided by a UV-C source, oxygen concentrations and transition metals on the formation of 2-aminoacetophenone in model wine containing tryptophan and riboflavin. Irrespective of oxygen and transition metals, >85% of tryptophan were degraded via first-order kinetics to unknown product(s). However, longer light exposure and more oxygen caused 2-aminoacetophenone concentrations to increase. Transition metals decelerated the 2-aminoacetophenone formation and acetaldehyde was formed suggesting photo-Fenton reaction occurred as a competitive reaction. The degradation rate of riboflavin inclined with less oxygen and in the presence of transition metals due to the depletion of oxygen by photo-Fenton reaction. Oxygen plays an important role in the regeneration of riboflavin and therefore must be seen as an intensifier for light-induced 2-aminoacetophenone formation. This paper provides new insights into riboflavin-photosensitized reactions.

The environmental fate and risks of mononitrophenols (mono-NPs), the simplest nitrophenols (NPs) often found in aquatic environments, are profoundly influenced by anaerobic bioreduction and co-existing electron shuttles (ESs), but little is known about the underlying mechanisms. Here, we elucidate the pathways of anaerobic mono-NPs bioreduction by Shewanella oneidensis MR-1 and assess the effect of model ESs on these processes. We found that all three mono-NPs isomers could be readily reduced to their corresponding aminophenols by S. oneidensis MR-1 under anaerobic conditions. CymA, a core component of the Mtr respiratory pathway, performs a dynamic role in these bioreduction, which is highly dependent on the bioreduction kinetics. The exogenous addition of quinones was found to accelerate the mono-NPs bioreduction through interactions with key outer-membrane proteins (e.g., OmcA and MtrC), and all these processes matched well to linear free energy relationships (LFERs). Surprisingly, adding riboflavin did not influence the bioreduction of all three mono-NPs isomers, which may be due to the contribution of OmcA and MtrC to these bioreduction processes and their downregulated expression. This study enhances our understanding of the environmental fate of mono-NPs and their bioconversion processes, providing valuable insights for the bioremediation of nitrophenol-contaminated sites.