Vanin1 (VNN1) in chronic diseases: Future directions for targeted therapy.

Vanin1 (VNN1) is an exogenous enzyme with pantetheinase activity that mainly exerts physiological functions through enzyme catalysis products, including pantothenic acid and cysteamine. In recent years, the crosstalk between VNN1 and metabolism and oxidative stress has attracted much attention. As a result of the ability of VNN1 to affect multiple metabolic pathways and oxidative stress to exacerbate or alleviate pathological processes, it has become a key component of disease progression. This review discusses the functions of VNN1 in glucolipid metabolism, cysteamine metabolism, and glutathione metabolism to provide perspectives on VNN1-targeted therapy for chronic diseases.

Dynamically Regulating Glucose Uptake to Reduce Overflow Metabolism with a Quorum-Sensing Circuit for the Efficient Synthesis of d-Pantothenic Acid in Bacillus subtilis.

In response to a high concentration of glucose, Bacillus subtilis, a microbial chassis for producing many industrial metabolites, rapidly takes up glucose using the phosphotransferase system (PTS), leading to overflow metabolism, a common phenomenon observed in many bacteria. Although overflow metabolism affects cell growth and reduces the production of many metabolites, effective strategies that reduce overflow metabolism while maintaining normal cell growth remain to be developed. Here, we used a quorum sensing (QS)-mediated circuit to tune the glucose uptake rate and thereby relieve overflow metabolism in an engineered B. subtilis for producing d-pantothenic acid (DPA). A low-efficiency non-PTS system was used for glucose uptake at the early growth stages to avoid a rapid glycolytic flux, while an efficient PTS system, which was activated by a QS circuit, was automatically activated at the late growth stages after surpassing a threshold cell density. This strategy was successfully applied as a modular metabolic engineering process for the high production of DPA. By enhancing the translation levels of key enzymes (3-methyl-2-oxobutanoate hydroxymethytransferase, pantothenate synthetase, aspartate 1-decarboxylase proenzyme, 2-dehydropantoate 2-reductase, dihydroxy-acid dehydratase, and acetolactate synthase) with engineered 5'-untranslated regions (UTRs) of mRNAs, the metabolic flux was promoted in the direction of DPA production, elevating the yield of DPA to 5.11 g/L in shake flasks. Finally, the engineered B. subtilis produced 21.52 g/L of DPA in fed-batch fermentations. Our work not only revealed a new strategy for reducing overflow metabolism by adjusting the glucose uptake rate in combination with promoting the translation of key metabolic enzymes through engineering the 5'-UTR of mRNAs but also showed its power in promoting the bioproduction of DPA in B. subtilis, exhibiting promising application prospects.

The vitamin B5/coenzyme A axis: A target for immunomodulation?

Coenzyme A (CoA) serves as a vital cofactor in numerous enzymatic reactions involved in energy production, lipid metabolism, and synthesis of essential molecules. Dysregulation of CoA-dependent metabolic pathways can contribute to chronic diseases, such as inflammatory diseases, obesity, diabetes, cancer, and cardiovascular disorders. Additionally, CoA influences immune cell activation by modulating the metabolism of these cells, thereby affecting their proliferation, differentiation, and effector functions. Targeting CoA metabolism presents a promising avenue for therapeutic intervention, as it can potentially restore metabolic balance, mitigate chronic inflammation, and enhance immune cell function. This might ultimately improve the management and outcomes for these diseases. This review will more specifically focus on the contribution of pathways regulating the availability of the CoA precursor Vitamin B5/pantothenate in vivo and modulating the development of Th17-mediated inflammation, CD8-dependent anti-tumor immunity but also tissue repair processes in chronic inflammatory or degenerative diseases.

A novel SLC5A6 homozygous variant in a family with multivitamin-dependent neurometabolic disorder: Phenotype expansion and long-term follow-up.

The sodium-dependent multivitamin transporter (hSMVT) encoded by the SLC5A6 gene is required for the intestinal absorption of biotin, pantothenic acid and lipoate, three micronutrients essential for normal growth and development. Systemic deficiency of these elements, either occurring from nutritional causes or genetic defects, is associated with neurological disorders, growth delay, skin and hair changes, metabolic and immunological abnormalities. A few patients with biallelic variants of SLC5A6 have been reported, exhibiting a spectrum of neurological and systemic clinical features with variable severity. We describe three patients from a single family carrying a homozygous p.(Leu566Valfs*33) variant of SLC5A6 disrupting the frame of the C-terminal portion of the hSMVT. In these patients, we documented a severe disorder featuring developmental delay, sensory polyneuropathy, optic atrophy, recurrent infections, and repeated episodes of intestinal pseudo-obstruction. Two patients who did not receive multivitamin supplementation therapy died in early infancy. In a third patient, early supplementation of biotin and pantothenic acid stabilized the clinical picture changing the course of the disease. These findings extend genotype-phenotype correlations and show how a timely and lifelong multivitamin treatment may be crucial to reduce the risk of life-threatening events in patients with pathogenic variants of the SLC5A6 gene.

Metabolomic differentiation of tumor core versus edge in glioma.

OBJECTIVE: Gliomas exhibit high intratumor and interpatient heterogeneity. Recently, it has been shown that the microenvironment and phenotype differ significantly between the glioma core (inner) and edge (infiltrating) regions. This proof-of-concept study differentiates metabolic signatures associated with these regions, with the potential for prognosis and targeted therapy that could improve surgical outcomes. METHODS: Paired glioma core and infiltrating edge samples were obtained from 27 patients after craniotomy. Liquid-liquid metabolite extraction was performed on the samples and metabolomic data were obtained via 2D liquid chromatography-mass spectrometry/mass spectrometry. To gauge the potential of metabolomics to identify clinically relevant predictors of survival from tumor core versus edge tissues, a boosted generalized linear machine learning model was used to predict metabolomic profiles associated with O6-methylguanine DNA methyltransferase (MGMT) promoter methylation. RESULTS: A panel of 66 (of 168) metabolites was found to significantly differ between glioma core and edge regions (p ≤ 0.05). Top metabolites with significantly different relative abundances included DL-alanine, creatine, cystathionine, nicotinamide, and D-pantothenic acid. Significant metabolic pathways identified by quantitative enrichment analysis included glycerophospholipid metabolism; butanoate metabolism; cysteine and methionine metabolism; glycine, serine, alanine, and threonine metabolism; purine metabolism; nicotinate and nicotinamide metabolism; and pantothenate and coenzyme A biosynthesis. The machine learning model using 4 key metabolites each within core and edge tissue specimens predicted MGMT promoter methylation status, with AUROCEdge = 0.960 and AUROCCore = 0.941. Top metabolites associated with MGMT status in the core samples included hydroxyhexanoycarnitine, spermine, succinic anhydride, and pantothenic acid, and in the edge samples metabolites included 5-cytidine monophosphate, pantothenic acid, itaconic acid, and uridine. CONCLUSIONS: Key metabolic differences are identified between core and edge tissue in glioma and, furthermore, demonstrate the potential for machine learning to provide insight into potential prognostic and therapeutic targets.

Metabolic Engineering of Saccharomyces cerevisiae for Vitamin B5 Production.

Vitamin B5, also called d-pantothenic acid, is an essential vitamin in the human body and is widely used in pharmaceuticals, nutritional supplements, food, and cosmetics. However, few studies have investigated the microbial production of d-pantothenic acid, especially in Saccharomyces cerevisiae. By employing a systematic optimization strategy, we screened seven key genes in d-pantothenic acid biosynthesis from diverse species, including bacteria, yeast, fungi, algae, plants, animals, etc., and constructed an efficient heterologous d-pantothenic acid pathway in S. cerevisiae. By adjusting the copy number of the pathway modules, knocking out the endogenous bypass gene, balancing NADPH utilization, and regulating the GAL inducible system, a high-yield d-pantothenic acid-producing strain, DPA171, which can regulate gene expression using glucose, was constructed. By optimizing fed-batch fermentation, DPA171 produced 4.1 g/L d-pantothenic acid, which is the highest titer in S. cerevisiae to date. This study provides guidance for the development of vitamin B5 microbial cell factories.

Brain CoA and Acetyl CoA Metabolism in Mechanisms of Neurodegeneration.

The processes of biotransformation of pantothenic acid (Pan) in the biosynthesis and hydrolysis of CoA, key role of pantothenate kinase (PANK) and CoA synthetase (CoASY) in the formation of the priority mitochondrial pool of CoA, with a high metabolic turnover of the coenzyme and limited transport of Pan across the blood-brain barrier are considered. The system of acetyl-CoA, a secondary messenger, which is the main substrate of acetylation processes including formation of N-acetyl aspartate and acetylcholine, post-translational modification of histones, predetermines protection of the neurons against degenerative signals and cholinergic neurotransmission. Biochemical mechanisms of neurodegenerative syndromes in the cases of PANK and CoASY defects, and the possibility of correcting of CoA biosynthesis in the models with knockouts of these enzymes have been described. The data of a post-mortem study of the brains from the patients with Huntington's and Alzheimer's diseases are presented, proving Pan deficiency in the CNS, which is especially pronounced in the pathognomonic neurostructures. In the frontal cortex of the patients with Parkinson's disease, combined immunofluorescence of anti-CoA- and anti-tau protein was detected, reflecting CoAlation during dimerization of the tau protein and its redox sensitivity. Redox activity and antioxidant properties of the precursors of CoA biosynthesis were confirmed in vitro with synaptosomal membranes and mitochondria during modeling of aluminum neurotoxicity accompanied by the decrease in the level of CoA in CNS. The ability of CoA biosynthesis precursors to stabilize glutathione pool in neurostructures, in particular, in the hippocampus, is considered as a pathogenetic protection mechanism during exposure to neurotoxins, development of neuroinflammation and neurodegeneration, and justifies the combined use of Pan derivatives (for example, D-panthenol) and glutathione precursors (N-acetylcysteine). Taking into account the discovery of new functions of CoA (redox-dependent processes of CoAlation of proteins, possible association of oxidative stress and deficiency of Pan (CoA) in neurodegenerative pathology), it seems promising to study bioavailability and biotransformation of Pan derivatives, in particular of D-panthenol, 4'-phospho-pantetheine, its acylated derivatives, and compositions with redox pharmacological compounds, are promising for their potential use as etiopathogenetic agents.

Enhanced supply of acetyl-CoA by exogenous pantothenate kinase promotes synthesis of poly(3-hydroxybutyrate).

BACKGROUND: Coenzyme A (CoA) is a carrier of acyl groups. This cofactor is synthesized from pantothenic acid in five steps. The phosphorylation of pantothenate is catalyzed by pantothenate kinase (CoaA), which is a key step in the CoA biosynthetic pathway. To determine whether the enhancement of the CoA biosynthetic pathway is effective for producing useful substances, the effect of elevated acetyl-CoA levels resulting from the introduction of the exogenous coaA gene on poly(3-hydroxybutyrate) [P(3HB)] synthesis was determined in Escherichia coli, which express the genes necessary for cyanobacterial polyhydroxyalkanoate synthesis (phaABEC). RESULTS: E. coli containing the coaA gene in addition to the pha genes accumulated more P(3HB) compared with the transformant containing the pha genes alone. P(3HB) production was enhanced by precursor addition, with P(3HB) content increasing from 18.4% (w/w) to 29.0% in the presence of 0.5 mM pantothenate and 16.3%-28.2% by adding 0.5 mM ß-alanine. Strains expressing the exogenous coaA in the presence of precursors contained acetyl-CoA in excess of 1 nmol/mg of dry cell wt, which promoted the reaction toward P(3HB) formation. The amount of acetate exported into the medium was three times lower in the cells carrying exogenous coaA and pha genes than in the cells carrying pha genes alone. This was attributed to significantly enlarging the intracellular pool size of CoA, which is the recipient of acetic acid and is advantageous for microbial production of value-added materials. CONCLUSIONS: Enhancing the CoA biosynthetic pathway with exogenous CoaA was effective at increasing P(3HB) production. Supplementing the medium with pantothenate facilitated the accumulation of P(3HB). ß-Alanine was able to replace the efficacy of adding pantothenate.

Enhanced production of D-pantothenic acid in Corynebacterium glutamicum using an efficient CRISPR-Cpf1 genome editing method.

BACKGROUND: Corynebacterium glutamicum has industrial track records for producing a variety of valuable products such as amino acids. Although CRISPR-based genome editing technologies have undergone immense developments in recent years, the suicide-plasmid-based approaches are still predominant for C. glutamicum genome manipulation. It is crucial to develop a simple and efficient CRISPR genome editing method for C. glutamicum. RESULTS: In this study, we developed a RecombinAtion Prior to Induced Double-strand-break (RAPID) genome editing technology for C. glutamicum, as Cpf1 cleavage was found to disrupt RecET-mediated homologous recombination (HR) of the donor template into the genome. The RAPID toolbox enabled highly efficient gene deletion and insertion, and notably, a linear DNA template was sufficient for gene deletion. Due to the simplified procedure and iterative operation ability, this methodology could be widely applied in C. glutamicum genetic manipulations. As a proof of concept, a high-yield D-pantothenic acid (vitamin B5)-producing strain was constructed, which, to the best of our knowledge, achieved the highest reported titer of 18.62 g/L from glucose only. CONCLUSIONS: We developed a RecET-assisted CRISPR-Cpf1 genome editing technology for C. glutamicum that harnessed CRISPR-induced DSBs as a counterselection. This method is of great importance to C. glutamicum genome editing in terms of its practical applications, which also guides the development of CRISPR genome editing tools for other microorganisms.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Vitamin B5, a coenzyme A precursor, rescues TANGO2 deficiency disease-associated defects in Drosophila and human cells.

Mutations in the Transport and Golgi Organization 2 (TANGO2) gene are associated with intellectual deficit, neurodevelopmental delay and regression. Individuals can also present with an acute metabolic crisis that includes rhabdomyolysis, cardiomyopathy, and cardiac arrhythmias, the latter of which are potentially lethal. While preventing metabolic crises has the potential to reduce mortality, no treatments currently exist for this condition. The function of TANGO2 remains unknown but is suspected to be involved in some aspect of lipid metabolism. Here, we describe a model of TANGO2-related disease in the fruit fly Drosophila melanogaster that recapitulates crucial disease traits. Pairing a new fly model with human cells, we examined the effects of vitamin B5, a coenzyme A (CoA) precursor, on alleviating the cellular and organismal defects associated with TANGO2 deficiency. We demonstrate that vitamin B5 specifically improves multiple defects associated with TANGO2 loss-of-function in Drosophila and rescues membrane trafficking defects in human cells. We also observed a partial rescue of one of the fly defects by vitamin B3, though to a lesser extent than vitamin B5. Our data suggest that a B complex supplement containing vitamin B5/pantothenate may have therapeutic benefits in individuals with TANGO2-deficiency disease. Possible mechanisms for the rescue are discussed that may include restoration of lipid homeostasis.

High-resolution crystal structure and chemical screening reveal pantothenate kinase as a new target for antifungal development.

Fungal infections are the leading cause of mortality by eukaryotic pathogens, with an estimated 150 million severe life-threatening cases and 1.7 million deaths reported annually. The rapid emergence of multidrug-resistant fungal isolates highlights the urgent need for new drugs with new mechanisms of action. In fungi, pantothenate phosphorylation, catalyzed by PanK enzyme, is the first step in the utilization of pantothenic acid and coenzyme A biosynthesis. In all fungi sequenced so far, this enzyme is encoded by a single PanK gene. Here, we report the crystal structure of a fungal PanK alone as well as with high-affinity inhibitors from a single chemotype identified through a high-throughput chemical screen. Structural, biochemical, and functional analyses revealed mechanisms governing substrate and ligand binding, dimerization, and catalysis and helped identify new compounds that inhibit the growth of several Candida species. The data validate PanK as a promising target for antifungal drug development.

PI3K drives the de novo synthesis of coenzyme A from vitamin B5.

In response to hormones and growth factors, the class I phosphoinositide-3-kinase (PI3K) signalling network functions as a major regulator of metabolism and growth, governing cellular nutrient uptake, energy generation, reducing cofactor production and macromolecule biosynthesis1. Many of the driver mutations in cancer with the highest recurrence, including in receptor tyrosine kinases, Ras, PTEN and PI3K, pathologically activate PI3K signalling2,3. However, our understanding of the core metabolic program controlled by PI3K is almost certainly incomplete. Here, using mass-spectrometry-based metabolomics and isotope tracing, we show that PI3K signalling stimulates the de novo synthesis of one of the most pivotal metabolic cofactors: coenzyme A (CoA). CoA is the major carrier of activated acyl groups in cells4,5 and is synthesized from cysteine, ATP and the essential nutrient vitamin B5 (also known as pantothenate)6,7. We identify pantothenate kinase 2 (PANK2) and PANK4 as substrates of the PI3K effector kinase AKT8. Although PANK2 is known to catalyse the rate-determining first step of CoA synthesis, we find that the minimally characterized but highly conserved PANK49 is a rate-limiting suppressor of CoA synthesis through its metabolite phosphatase activity. Phosphorylation of PANK4 by AKT relieves this suppression. Ultimately, the PI3K-PANK4 axis regulates the abundance of acetyl-CoA and other acyl-CoAs, CoA-dependent processes such as lipid metabolism and proliferation. We propose that these regulatory mechanisms coordinate cellular CoA supplies with the demands of hormone/growth-factor-driven or oncogene-driven metabolism and growth.

Engineering precursor and co-factor supply to enhance D-pantothenic acid production in Bacillus megaterium.

High-yielding chemical and chemo-enzymatic methods of D-pantothenic acid (DPA) synthesis are limited by using poisonous chemicals and DL-pantolactone racemic mixture formation. Alternatively, the safe microbial fermentative route of DPA production was found promising but suffered from low productivity and precursor supplementation. In this study, Bacillus megaterium was metabolically engineered to produce DPA without precursor supplementation. In order to provide a higher supply of precursor D-pantoic acid, key genes involved in its synthesis are overexpressed, resulting strain was produced 0.53 ± 0.08 g/L DPA was attained in shake flasks. Cofactor CH2-THF was found to be vital for DPA biosynthesis and was regenerated through the serine-glycine degradation pathway. Enhanced supply of another precursor, ß-alanine was achieved by codon optimization and dosing of the limiting L-asparate-1-decarboxylase (ADC). Co-expression of Pantoate-ß-alanine ligase, ADC, phosphoenolpyruvate carboxylase, aspartate aminotransferase and aspartate ammonia-lyase enhanced DPA concentration to 2.56 ± 0.05 g/L at shake flasks level. Fed-batch fermentation in a bioreactor with and without the supplementation of ß-alanine increased DPA concentration to 19.52 ± 0.26 and 4.78 ± 0.53 g/L, respectively. This present study successfully demonstrated a rational approach combining precursor supply engineering with cofactor regeneration for the enhancement of DPA titer in recombinant B. megaterium.

A mild case of sodium-dependent multivitamin transporter (SMVT) deficiency illustrating the importance of treatment response in variant classification.

Sodium-dependent multivitamin transporter (SMVT) deficiency is a recently described multivitamin-responsive inherited metabolic disorder (IMD) of which the phenotypic spectrum and response to treatment remains to be elucidated. So far, four pediatric patients have been described in three case reports with symptoms ranging from severe neurodevelopmental delay to feeding problems and failure to thrive, who demonstrated significant improvement after initiation of enhancement of targeted multivitamin treatment (biotin, pantothenic acid, and lipoic acid). We describe a fifth case of a patient presenting at the relatively mild end of the phenotypic spectrum with failure to thrive, frequent vomiting and metabolic acidosis with hypoglycemia, and mild osteopenia, who was diagnosed with SMVT deficiency due to compound heterozygous variants in SLC5A6 Additional genetic testing of variants of unknown significance (VUSs) as well as the clinical improvement in all aspects of the patient's disease upon initiation of treatment with biotin and pantothenic acid (plus lipoate as antioxidant) aided in the confirmation of this diagnosis. This case report aims to enhance recognition of the broad phenotypic spectrum of SMVT deficiency due to SLC5A6 mutations and discusses the different treatment strategies. It demonstrates how combining biochemical and genetic testing with the evaluation of (early) treatment response (i.e., using a "diagnostic therapeuticum") can influence confirmation of pathogenicity of genomic variants.

Novel biallelic variants expand the SLC5A6-related phenotypic spectrum.

The sodium (Na+):multivitamin transporter (SMVT), encoded by SLC5A6, belongs to the sodium:solute symporter family and is required for the Na+-dependent uptake of biotin (vitamin B7), pantothenic acid (vitamin B5), the vitamin-like substance α-lipoic acid, and iodide. Compound heterozygous SLC5A6 variants have been reported in individuals with variable multisystemic disorder, including failure to thrive, developmental delay, seizures, cerebral palsy, brain atrophy, gastrointestinal problems, immunodeficiency, and/or osteopenia. We expand the phenotypic spectrum associated with biallelic SLC5A6 variants affecting function by reporting five individuals from three families with motor neuropathies. We identified the homozygous variant c.1285 A > G [p.(Ser429Gly)] in three affected siblings and a simplex patient and the maternally inherited c.280 C > T [p.(Arg94*)] variant and the paternally inherited c.485 A > G [p.(Tyr162Cys)] variant in the simplex patient of the third family. Both missense variants were predicted to affect function by in silico tools. 3D homology modeling of the human SMVT revealed 13 transmembrane helices (TMs) and Tyr162 and Ser429 to be located at the cytoplasmic facing region of TM4 and within TM11, respectively. The SLC5A6 missense variants p.(Tyr162Cys) and p.(Ser429Gly) did not affect plasma membrane localization of the ectopically expressed multivitamin transporter suggesting reduced but not abolished function, such as lower catalytic activity. Targeted therapeutic intervention yielded clinical improvement in four of the five patients. Early molecular diagnosis by exome sequencing is essential for timely replacement therapy in affected individuals.

MMP-3 plays a major role in calcium pantothenate-promoted wound healing after fractional ablative laser treatment.

Ablative fractional laser treatment leads to a loss of matrix metalloproteinase-3 (MMP-3) expression; therefore, in the present in vitro study, we addressed the role of MMP-3 and its regulation by calcium pantothenate in wound healing processes at the molecular level. Utilizing confocal laser microscopy, we investigated MMP-3 protein expression in fractional ablative CO2 laser-irradiated skin models. In addition, we established full-thickness 3D skin models using fibroblasts and keratinocytes with a MMP-3 knockdown that were irradiated with a fractional ablative Er:YAG laser to set superficial injuries with standardized dimensions and minimal thermal damage to the surrounding tissue. We revealed an upregulation of MMP-3 protein expression in laser-irradiated skin models receiving aftercare treatment with calcium pantothenate. Skin models with MMP-3 knockdown exhibited a slower wound closure after laser treatment compared to controls. Gene expression profiling detected an MMP-3 knockdown-dependent upregulation of cytokines and chemokines (e.g. IL-36B, CXCL17, IL-37, CXCL5), antimicrobial peptides (e.g., S100A7, S100A12), epidermal crosslinking enzymes (TGM5), and differentiation markers (e.g., LOR, KRT1, FLG2). We also detected a downregulation of cathepsin V and MMP-10, both of which play a prominent role in wound healing processes. After fractional ablative laser injury, an aftercare treatment with calcium pantothenate accelerated wound closure in MMP-3 expressing models faster than in MMP-3 knockdown models. Our data substantiate a major role of MMP-3 in wound healing processes after ablative laser treatments. For the first time, we could show that calcium pantothenate exerts its wound healing-promoting effects at least partly via MMP-3.

High-throughput virtual screening of novel potent inhibitor(s) for Human Vanin-1 enzyme.

Vanin-1 (VNN1) is a glycosylphosphatidylinositol (GPI)-anchored ectoenzyme which hydrolyzes pantetheine to pantothenic acid and cysteamine. It has emerged as a promising drug target for many human diseases associated with oxidative stress and inflammatory pathways. In the present study we used structure-based virtual screening approach for the identification of small molecule inhibitors of vanin-1. A chemical library consisting of natural compounds, synthetic compounds and RRV analogs were screened for drug-like molecules. The filtered molecules were subjected to molecular docking studies. Three potential hits-ZINC04073864 (Natural compound), CID227017 (synthetic compound) and CID129558381 (RRV analog)-were identified for the target enzyme. The molecules form good number of hydrogen bonds with the catalytic residues such as Glu79, Lys178 and Cys211. The apo-VNN1 and VNN1-ligand complexes were subjected to molecular dynamics (MD) simulation for 30 ns. The geometric properties such as root mean square deviation, radius of gyration, solvent accessible surface area, number of hydrogen bonds and the distance between the catalytic triad residues-Glu79, Lys178 and Cys211 were altered upon binding of the compounds. Essential dynamics and entropic studies further confirmed that the fluctuations in VNN1 decrease upon binding of the compounds. The lead molecules were stable throughout the simulation time period. Molecular Mechanics Poisson-Boltzmann Surface Area (MM/PBSA) studies showed that Van der Waals interaction energy contributes significantly to the total binding free energy. Thus, our study reveals three lead molecules-ZINC04073864, CID227017 and CID129558381 as potential inhibitors of Vanin-1 which can be validated through further studies. Communicated by Ramaswamy H. Sarma.

Comparative metabolic profiling of posterior parietal cortex, amygdala, and hippocampus in conditioned fear memory.

Fear conditioning and retrieval are suitable models to investigate the biological basis of various mental disorders. Hippocampus and amygdala neurons consolidate conditioned stimulus (CS)-dependent fear memory. Posterior parietal cortex is considered important for the CS-dependent conditioning and retrieval of fear memory. Metabolomic screening among functionally related brain areas provides molecular signatures and biomarkers to improve the treatment of psychopathologies. Herein, we analyzed and compared changes of metabolites in the hippocampus, amygdala, and posterior parietal cortex under the fear retrieval condition. Metabolite profiles of posterior parietal cortex and amygdala were similarly changed after fear memory retrieval. While the retrieval of fear memory perturbed various metabolic pathways, most metabolic pathways that overlapped among the three brain regions had high ranks in the enrichment analysis of posterior parietal cortex. In posterior parietal cortex, the most perturbed pathways were pantothenate and CoA biosynthesis, purine metabolism, glutathione metabolism, and NAD+ dependent signaling. Metabolites of posterior parietal cortex including 4'-phosphopantetheine, xanthine, glutathione, ADP-ribose, ADP-ribose 2'-phosphate, and cyclic ADP-ribose were significantly regulated in these metabolic pathways. These results point to the importance of metabolites of posterior parietal cortex in conditioned fear memory retrieval and may provide potential biomarker candidates for traumatic memory-related mental disorders.

In Vitro Reconstitution of the Pantothenic Acid Degradation Pathway in Ochrobactrum anthropi.

Pantothenic acid is an essential metabolite found throughout all branches of life. Although the enzymes responsible for pantothenic biosynthesis have been characterized, those leading to its biodegradation remain poorly understood. In the study described herein, we showed that use of a "genomic enzymology" strategy enabled identification of four biodegradation pathway genes, which were then confirmed by using kinetic analysis of the purified recombinant enzymes encoded in Ochrobactrum anthropi. The reconstituted pathway converts pantothenic acid to ß-alanine and (R)-pantoate, and then (R)-pantoate to aldopentoate, which is transformed to (R)-3,3-dimethylmalate and hence to α-ketoisovalerate. The pathway genes are common to Proteobacterial genomes in which they are not colocated.