Regulation of coenzyme A levels by degradation: the 'Ins and Outs'

Metabolic Activation versus Masked Prodrugs: Bisubstrate Mimic Inhibitors of CoaBC's PPCS Activity in Mycobacterium tuberculosis and Staphylococcus aureus

The bifunctional bacterial CoaBC is a coenzyme A (CoA) biosynthetic protein that serves as a validated bactericidal target in Mycobacterium tuberculosis (Mtb). In Staphylococcus aureus, it is the target of the natural product antibiotic CJ-15,801, which inhibits its phosphopantothenoylcysteine synthetase (PPCS) activity by forming a bisubstrate mimic of its reactive reaction intermediate in situ after metabolic activation by pantothenate kinase, the first CoA biosynthetic enzyme. We prepared PPCS bisubstrate mimics with various stable linkers that would also require metabolic activation and used purified Mtb and S. aureus enzymes to evaluate their inhibition. Additionally, we prepared masked prodrug versions of the phosphorylated (activated) form of CJ-15,801 and tested these and the bisubstrate mimics, as whole-cell inhibitors of Mtb and S. aureus. We demonstrate that such inhibitors hold promise for the development of antimicrobials targeting these organisms, although further structure-activity relationship studies are necessary to address current challenges and improve their potency.

The two faces of coenzyme A in cellular biology

Coenzyme A (CoA) is an essential cofactor present in all living cells, which plays critical roles in diverse biochemical processes, including cellular metabolism, signal transduction, regulation of gene expression, and the antioxidant response. This review summarizes current knowledge on the role of CoA and its metabolically active thioesters in promoting cellular growth and proliferation (pro-growth) and discusses emerging research on CoA's antioxidant properties that enhance cell survival (pro-survival).

Unravelling cysteine-deficiency-associated rapid weight loss

Around 40% of the US population and 1 in 6 individuals worldwide have obesity, with the incidence surging globally1,2. Various dietary interventions, including carbohydrate, fat and, more recently, amino acid restriction, have been explored to combat this epidemic3-6. Here we investigated the impact of removing individual amino acids on the weight profiles of mice. We show that conditional cysteine restriction resulted in the most substantial weight loss when compared to essential amino acid restriction, amounting to 30% within 1 week, which was readily reversed. We found that cysteine deficiency activated the integrated stress response and oxidative stress response, which amplify each other, leading to the induction of GDF15 and FGF21, partly explaining the phenotype7-9. Notably, we observed lower levels of tissue coenzyme A (CoA), which has been considered to be extremely stable10, resulting in reduced mitochondrial functionality and metabolic rewiring. This results in energetically inefficient anaerobic glycolysis and defective tricarboxylic acid cycle, with sustained urinary excretion of pyruvate, orotate, citrate, α-ketoglutarate, nitrogen-rich compounds and amino acids. In summary, our investigation reveals that cysteine restriction, by depleting GSH and CoA, exerts a maximal impact on weight loss, metabolism and stress signalling compared with other amino acid restrictions. These findings suggest strategies for addressing a range of metabolic diseases and the growing obesity crisis.

iPSC-Derived Liver Organoids as a Tool to Study Medium Chain Acyl-CoA Dehydrogenase Deficiency

Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is an inherited metabolic disease, characterized by biallelic variants in the ACADM gene. Interestingly, even with the same genotype, patients often present with very heterogeneous symptoms, ranging from fully asymptomatic to life-threatening hypoketotic hypoglycemia. The mechanisms underlying this heterogeneity remain unclear. Therefore, there is a need for in vitro models of MCADD that recapitulate the clinical phenotype as a tool to study the pathophysiology of the disease. Fibroblasts of control and symptomatic MCADD patients with the c.985A>G (p.K329E) were reprogrammed into induced pluripotent stem cells (iPSCs). iPSCs were then differentiated into hepatic expandable organoids (EHOs), further matured to Mat-EHOs, and functionally characterized. EHOs and Mat-EHOs performed typical hepatic metabolic functions, such as albumin and urea production. The organoids metabolized fatty acids, as confirmed by acyl-carnitine profiling and high-resolution respirometry. MCAD protein was fully ablated in MCADD organoids, in agreement with the instability of the mutated MCAD protein. MCADD organoids accumulated medium-chain acyl-carnitines, with a strongly elevated C8/C10 ratio, characteristic of the biochemical phenotype of the disease. Notably, C2 and C14 acyl-carnitines were found decreased in MCADD Mat-EHOs. Finally, MCADD organoids exhibited differential expression of genes involved in ω-oxidation, mitochondrial β-oxidation, TCA cycle, and peroxisomal coenzyme A metabolism, particularly upregulation of NUDT7. iPSC-derived organoids of MCADD patients recapitulated the major biochemical phenotype of the disease. Mat-EHOs expressed relevant pathways involved in putative compensatory mechanisms, notably CoA metabolism and the TCA cycle. The upregulation of NUDT7 expression may play a role in preventing excessive accumulation of dicarboxylic acids in MCADD. This patient-specific hepatic organoid system is a promising platform to study the phenotypic heterogeneity between MCADD patients.

Study of Serum Metabolic Biomarkers and Prediction Models of Cantharidin-Induced Nephrotoxicity in Rats Based on Dynamic Metabolomics

The clinical application of cantharidin (CTD) is seriously limited due to its nephrotoxicity. Therefore, this study aims to investigate sensitive biomarkers for the evaluation and prediction of nephrotoxicity induced by CTD in rat. A total of 80 rats were randomly divided into four groups: control group and three doses of CTD groups. After 0, 1, 5, 15, and 28 days of intragastric administration, rat serum and urine were collected for biochemical indexes, then serum was used for metabolomic analyses, and rat kidney was collected for pathological and ultrastructural observation. The levels of serum crea (Scr), blood urea nitrogen (BUN), urea, urine crea (Ucrea), and urinary microalbumin (UmALB) were significantly increased after administration of different doses of CTD (p < 0.05). Additionally, histopathology and cell ultrastructure observation of kidney showed significant cell inflammatory infiltration and glomerular edema. Seven metabolic biomarkers including 6-hydroxymelatonin were significantly disturbed by CTD. The CatBoost Classifier prediction model was used to establish the CTD nephrotoxicity prediction model, and the prediction accuracy and precision were 0.645 and 0.640, respectively. Moreover, 6-hydroxymelatonin was found to be most useful biomarkers for evaluating the CTD nephrotoxicity. Finally, the seven metabolic biomarkers were found mainly involved in pyruvate metabolism, pantothenate and CoA biosynthesis.

Mitochondrial Dysfunction and Reduced TCA Cycle Metabolite Levels in Inflammatory Bowel Disease Patients

Introduction

Inflammatory bowel disease (IBD) mainly includes ulcerative colitis (UC) and Crohn's disease (CD). These diseases are classified as chronic and recurrent inflammatory diseases affecting the digestive tract. An energy deficiency in intestinal cells is believed to be associated with IBD pathology.

Methods

Our study investigated the bioenergetic functionality of mitochondria using the plasma of patients with CD and UC by determining the concentration of intermediates of the tricarboxylic acid cycle (TCA), such as acetyl coenzyme A, succinate, fumarate, α-ketoglutarate, NADH2, IDH2, Cytochrome C Oxidase, Cytochrome C Reductase, and ATP.

Results

Our results show an imbalance in mitochondrial homeostasis and bioenergetics, demonstrated by reduced activity of respiratory complexes and reduced production of TCA intermediates in the plasma of patients with CD and UC. In the group of patients with CD, treatment with corticosteroids had a significant positive effect, as significantly higher IDH2 and succinate levels were found. Correlation analyses of mitochondrial functionality biomarkers with other blood markers revealed a significant relationship between CRP and ATP levels, with higher CRP significantly linked to lower ATP and a similar trend for succinate levels. Using the disease activity scale, we show that biomarkers such as IDH2, α-ketoglutarate, and succinate levels are significantly lower in patients with higher disease activity.

Conclusion

We conclude that reduced metabolites and respiratory complexes associated with the TCA indicate mitochondrial bioenergetic failure in IBD patients. Besides, Krebs cycle metabolites can be a good marker of predisposition to the disease and the course of IBD. They can be easily determined in a blood sample taken from the patient. Pharmacological protection of mitochondria in individuals predisposed to IBD development and compensation for the changed function of mitochondria in persons with the developed disease may become a new approach to personalized therapies focused on restoring the proper activity of mitochondrial enzymes.

Role of Vanin-1 Gene Methylation in Fat Synthesis in Goose Liver: Effects of Betaine and 5-Azacytidine Treatments

This study aimed to investigate the mediating effect of vanin-1 (VNN1) and its DNA methylation on the reduction in liver fat synthesis due to the role of betaine and 5-Azacytidine (5-AZA) in geese. Twenty-eight 35-day-old male Jiangnan white geese with similar body weight (BW) and good health conditions were randomized into four groups (seven birds per group). All the birds were housed with the same type of basal diet. The control group was treated with normal saline intraperitoneally (I.P.); the AZA group was treated I.P. with AZA (2 mg/kg); the betaine group was fed with betaine through the diet and treated I.P. with normal saline (1.2 g/kg); the AZA+betaine group was fed with betaine through the diet and treated I.P. with AZA. The results showed that the administration of AZA significantly increased serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and VNN1 enzyme activity (p < 0.05); additionally, the expression levels of the molecules in various tissues were up-regulated to different extents, such as VNN1, fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl-CoA dehydrogenase (SCD), and sterol regulatory element binding protein (SREBP); in contrast, the treatment of betaine reduced serum TC levels and the S-adenosylmethionine/S-adenosylhomocysteine (SAM/SAH) ratio; furthermore, hepatic DNA methylation in the AZA group was decreased in terms of the VNN1 promoter region. The results demonstrated that the expression of the VNN1 gene was negatively correlated with DNA methylation. This finding verified the key role of VNN1 and its methylation in the inhibition of liver lipid synthesis by betaine and provided a novel molecular mechanism for the regulation of liver lipid metabolism.

Modulation of hepatic transcription factor EB activity during cold exposure uncovers direct regulation of bis(monoacylglycero)phosphate lipids by Pla2g15

Cold exposure is a selective environmental stress that elicits a rapid metabolic shift to maintain energy homeostasis. In response to cold exposure, the liver rewires the metabolic state shifting from glucose to lipid catabolism. By probing the liver lipids in cold exposure, we observed that the lysosomal bis(monoacylglycero)phosphate (BMP) lipids were rapidly increased during cold exposure. BMP lipid changes occurred independently of lysosomal abundance but were dependent on the lysosomal transcriptional regulator transcription factor EB (TFEB). Knockdown of TFEB in hepatocytes decreased BMP lipid levels and led to cold intolerance in mice. We assessed TFEB binding sites of lysosomal genes and determined that the phospholipase Pla2g15 regulates BMP lipid catabolism. Knockdown of Pla2g15 in mice increased BMP lipid levels, ablated the cold-induced rise, and improved cold tolerance. Knockout of Pla2g15 in mice and hepatocytes led to increased BMP lipid levels, that were decreased with re-expression of Pla2g15. Mutation of the catalytic site of Pla2g15 ablated the BMP lipid breakdown. Together, our studies uncover TFEB regulation of BMP lipids through Pla2g15 catabolism.

Host metabolism balances microbial regulation of bile acid signalling

Metabolites derived from the intestinal microbiota, including bile acids (BA), extensively modulate vertebrate physiology, including development1, metabolism2-4, immune responses5-7 and cognitive function8. However, to what extent host responses balance the physiological effects of microbiota-derived metabolites remains unclear9,10. Here, using untargeted metabolomics of mouse tissues, we identified a family of BA-methylcysteamine (BA-MCY) conjugates that are abundant in the intestine and dependent on vanin 1 (VNN1), a pantetheinase highly expressed in intestinal tissues. This host-dependent MCY conjugation inverts BA function in the hepatobiliary system. Whereas microbiota-derived free BAs function as agonists of the farnesoid X receptor (FXR) and negatively regulate BA production, BA-MCYs act as potent antagonists of FXR and promote expression of BA biosynthesis genes in vivo. Supplementation with stable-isotope-labelled BA-MCY increased BA production in an FXR-dependent manner, and BA-MCY supplementation in a mouse model of hypercholesteraemia decreased lipid accumulation in the liver, consistent with BA-MCYs acting as intestinal FXR antagonists. The levels of BA-MCY were reduced in microbiota-deficient mice and restored by transplantation of human faecal microbiota. Dietary intervention with inulin fibre further increased levels of both free BAs and BA-MCY levels, indicating that BA-MCY production by the host is regulated by levels of microbiota-derived free BAs. We further show that diverse BA-MCYs are also present in human serum. Together, our results indicate that BA-MCY conjugation by the host balances host-dependent and microbiota-dependent metabolic pathways that regulate FXR-dependent physiology.

Inorganic pyrophosphatase 1: a key player in immune and metabolic reprogramming in ankylosing spondylitis

The relationships among immune cells, metabolites, and AS events were analyzed via Mendelian randomization (MR), and potential immune cells and metabolites were identified as risk factors for AS. Their relationships were subjected to intermediary MR analysis to identify the final immune cells and metabolites. The vertebral bone marrow blood samples from three patients with and without AS were subjected to 10× single-cell sequencing to further elucidate the role of immune cells in AS. The key genes were screened via expression quantitative trait loci (eQTLs) and MR analyses. The metabolic differences between the two groups were compared through single-cell metabolism analysis. Two subgroups of differentiated (CD)8+ memory T cells and naive B cells were obtained from the combined results of intermediary MR analysis and AS single-cell analysis. After the verification of key genes, inorganic pyrophosphatase 1 (PPA1) was identified as the hub gene, as it is differentially expressed in CD8+ memory T cells and can affect the metabolism of T cells in AS by affecting the expression of ferulic acid (FA)4 sulfate, which participates in the cellular immunity in AS.

CCKR signaling map, G-Protein bindings, hormonal regulation, and neural mechanisms may influence the osteogenic/cementogenic differentiation potential of hPDLSCs

OBJECTIVE

Periodontal regeneration poses challenges due to the periodontium's complexity, relying on mesenchymal cells from the periodontal ligament (hPDLSCs) to regenerate hard tissues like bone and cementum. While some hPDLSCs have high regeneration potential (HOP-hPDLSCs), most are low potential (LOP-hPDLSCs). This study analyzed hPDLSCs from a single donor to minimize inter-individual variability and focus on key differences in differentiation potentials.

DESIGN

This study used RNA-seq, genomic databases, and bioinformatics tools to explore signaling pathways (SPs), biological processes (BPs), and molecular functions (MFs) guiding HOP cells to mineralized matrix production. It also investigated limitations of LOP cells and strategies for enhancing their osteo/cementogenesis.

RESULTS

In basal conditions, HOP exhibited a multifunctional gene network with higher expression of genes related to osteo/cementogenesis, cell differentiation, immune modulation, stress response, and hormonal regulation. In contrast, LOP focused on steroid hormone biosynthesis and nucleic acid maintenance. During osteo/cementogenic induction, HOP showed strong modulation of genes related to angiogenesis, cell division, mesenchymal differentiation, and extracellular matrix production. LOP demonstrated neural synaptic-related processes and preserved cellular cytoskeleton integrity. CCKR map signaling and G-protein receptor bindings gained significance during osteo/cementogenesis in HOP-hPDLSCs. Both HOP and LOP shared common BPs related to gastrointestinal and reproductive system development.

CONCLUSION

The osteo/cementogenic differentiation of HOP cells may be regulated by CCKR signaling, G-protein bindings, and specific hormonal regulation. LOP cells seem committed to neural mechanisms. This study sheds light on hPDLSCs' complex characteristics, offering a deeper understanding of their differentiation potential for future periodontal regeneration research and therapies.

Assessment of the dietary amino acid profiles and the relative biomarkers for amino acid balance in the low-protein diets for broiler chickens

BACKGROUND

Research on low-protein-level diets has indicated that even though the profiles of essential amino acids (EAAs) follow the recommendation for a normal-protein-level diet, broilers fed low-protein diets failed to achieve productive performance compared to those fed normal diets. Therefore, it is imperative to reassess the optimum profile of EAAs in low-protein diets and establish a new ideal pattern for amino acid balance. Furthermore, identifying novel sensitive biomarkers for assessing amino acid balance will greatly facilitate the development of amino acid nutrition and application technology. In this study, 12 dietary treatments [Con(+), Con(-), L&A(-), L&A(+), M&C(-), M&C(+), BCAA (-), BCAA(+), Thr(-), Thr(+), Trp(-) and Trp(+)] were established by combining different EAAs including lysine and arginine, methionine and cysteine, branched-chain amino acid (BCAA), threonine, and tryptophan to observe the growth and development of the broiler chickens fed with low-protein-level diets. Based on the biochemical parameters and untargeted metabolomic analysis of animals subjected to different treatments, biomarkers associated with optimal and suboptimal amino acid balance were identified.

RESULTS

Growth performance, carcass characteristics, hepatic enzyme activity, serum biochemical parameters, and breast muscle mRNA expression differed significantly between male and female broilers under different dietary amino acid patterns. Male broilers exhibited higher sensitivity to the adjustment of amino acid patterns than female broilers. For the low-protein diet, the dietary concentrations of lysine, arginine, and tryptophan, but not of methionine, cystine, or threonine, needed to be increased. Therefore, further research on individual BCAA is required. For untargeted metabolomic analysis, Con(+) was selected as a normal diet (NP) while Con(-) represented a low-protein diet (LP). L&A(+) denotes a low-protein amino acid balanced diet (LPAB) and Thr(+) represents a low-protein amino acid imbalance diet (LPAI). The metabolites oxypurinol, pantothenic acid, and D-octopine in birds were significantly influenced by different dietary amino acid patterns.

CONCLUSION

Adjusting the amino acid profile of low-protein diets is required to achieve normal growth performance in broiler chickens fed normal-protein diets. Oxypurinol, pantothenic acid, and D-octopine have been identified as potentially sensitive biomarkers for assessing amino acid balance.

Association analysis of gut microbiota with LDL-C metabolism and microbial pathogenicity in colorectal cancer patients

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal malignancy worldwide, with obesity-induced lipid metabolism disorders playing a crucial role in its progression. A complex connection exists between gut microbiota and the development of intestinal tumors through the microbiota metabolite pathway. Metabolic disorders frequently alter the gut microbiome, impairing immune and cellular functions and hastening cancer progression.

METHODS

This study thoroughly examined the gut microbiota through 16S rRNA sequencing of fecal samples from 181 CRC patients, integrating preoperative Low-density lipoprotein cholesterol (LDL-C) levels and RNA sequencing data. The study includes a comparison of microbial diversity, differential microbiological analysis, exploration of the associations between microbiota, tumor microenvironment immune cells, and immune genes, enrichment analysis of potential biological functions of microbe-related host genes, and the prediction of LDL-C status through microorganisms.

RESULTS

The analysis revealed that differences in α and β diversity indices of intestinal microbiota in CRC patients were not statistically significant across different LDL-C metabolic states. Patients exhibited varying LDL-C metabolic conditions, leading to a bifurcation of their gut microbiota into two distinct clusters. Patients with LDL-C metabolic irregularities had higher concentrations of twelve gut microbiota, which were linked to various immune cells and immune-related genes, influencing tumor immunity. Under normal LDL-C metabolic conditions, the protective microorganism Anaerostipes_caccae was significantly negatively correlated with the GO Biological Process pathway involved in the negative regulation of the unfolded protein response in the endoplasmic reticulum. Both XGBoost and MLP models, developed using differential gut microbiota, could forecast LDL-C levels in CRC patients biologically.

CONCLUSIONS

The intestinal microbiota in CRC patients influences the LDL-C metabolic status. With elevated LDL-C levels, gut microbiota can regulate the function of immune cells and gene expression within the tumor microenvironment, affecting cancer-related pathways and promoting CRC progression. LDL-C and its associated gut microbiota could provide non-invasive markers for clinical evaluation and treatment of CRC patients.

Mitochondrial Phosphopantetheinylation is Required for Oxidative Function

4'-phosphopantetheinyl (4'PP) groups are essential co-factors added to target proteins by p hospho p antetheinyl transferase (PPTase) enzymes. Although mitochondrial 4'PP-modified proteins have been described for decades, a mitochondrially-localized PPTase has never been found in mammals. We discovered that the cytoplasmic PPTase a mino a dipate s emialdehyde d ehydrogenase p hospho p antetheinyl t ransferase (AASDHPPT) is required for mitochondrial respiration and oxidative metabolism. Loss of AASDHPPT results in failed 4'-PP modification of the mitochondrial acyl carrier protein and blunted activity of the mitochondrial fatty acid synthesis (mtFAS) pathway. We found that in addition to its cytoplasmic localization, AASDHPPT localizes to the mitochondrial matrix via an N-terminal mitochondrial targeting sequence contained within the first 13 amino acids of the protein. Our data show that this novel mitochondrial localization of AASDHPPT is required to support mtFAS activity and oxidative function. We further identify two variants of uncertain significance in AASDHPPT that are likely pathogenic in humans due to loss of mtFAS activity.

Identification of the Regulatory Elements and Protein Substrates of Lysine Acetoacetylation

Short chain fatty acylations establish connections between cell metabolism and regulatory pathways. Lysine acetoacetylation (Kacac) was recently identified as a new histone mark. However, regulatory elements, substrate proteins, and epigenetic functions of Kacac remain unknown, hindering further in-depth understanding of acetoacetate modulated (patho)physiological processes. Here, we created a chemo-immunological approach for reliable detection of Kacac, and demonstrated that acetoacetate serves as the primary precursor for histone Kacac. We report the enzymatic addition of the Kacac mark by the acyltransferases GCN5, p300, and PCAF, and its removal by deacetylase HDAC3. Furthermore, we establish acetoacetyl-CoA synthetase (AACS) as a key regulator of cellular Kacac levels. A comprehensive proteomic analysis has identified 139 Kacac sites on 85 human proteins. Bioinformatics analysis of Kacac substrates and RNA-seq data reveal the broad impacts of Kacac on multifaceted cellular processes. These findings unveil pivotal regulatory mechanisms for the acetoacetate-mediated Kacac pathway, opening a new avenue for further investigation into ketone body functions in various pathophysiological states.

Associations between blood nickel and lung function in young Chinese: An observational study combining epidemiology and metabolomics

Prior research has explored the relationship between occupational exposure to nickel and lung function. Nonetheless, there is limited research examining the correlation between blood nickel levels and lung function among young adults in the general population. The metabolomic changes associated with nickel exposure have not been well elucidated. On August 23, 2019, we enrolled 257 undergraduate participants from the Chinese Undergraduates Cohort to undergo measurements of blood nickel levels and lung function. The follow-up study was conducted in May 2021. A linear mixed-effects model was employed to assess the relationship between blood nickel levels and lung function. We also conducted stratified analyses by home address. In addition, in order to explore the biological mechanism of lung function damage caused by nickel exposure, we performed metabolomic analyses of baseline serum samples (N = 251). Both analysis of variance and mixed linear effect models were utilized to assess the impact of blood nickel exposure on metabolism. Our findings from cross-sectional and cohort analyses revealed a significant association between blood nickel levels and decreased forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) among young adults in the general population. Furthermore, we found stronger associations in urban areas. In metabolomics analysis, a total of nine metabolites were significantly changed under blood nickel exposure. The changed metabolites were mainly enriched in six pathways including carbohydrate, amino acid, and cofactor vitamin metabolism. These metabolic pathways involve inflammation and oxidative stress, indicating that high concentrations of nickel exposure can cause inflammation and oxidative stress by disrupting the above metabolism of the body.

Electroacupuncture at different frequencies improves visceral pain in IBS rats through different pathways

BACKGROUND

The aim of this study was to investigate the frequency dependence of electroacupuncture (EA) in alleviating chronic visceral pain in patients with irritable bowel syndrome (IBS) and the differences in the gut microbiota and metabolites as potential mechanisms to explain frequency dependence.

METHODS

A visceral hyperalgesia model was established by colorectal instillation of 2,4,6-trinitrobenzene sulfonic acid in rats, and EA treatment at 2/10 Hz, 2/50 Hz and 2/100 Hz was applied at ST25. Visceral sensation was quantified by the abdominal withdrawal reflex score and the area under the curve of the rectus abdominis electromyogram in response to colorectal distension. Ultrastructural morphological damage of colonic tissue of the rats was examined by transmission electron microscopy. 16S rRNA gene sequencing and 1H-nuclear magnetic resonance spectroscopy were applied to study the differences in the gut microbiota and to perform metabonomic profiling of the colonic tissue.

KEY RESULTS

EA at ST25 at different frequencies attenuated chronic visceral pain, ultrastructural morphological damage to colonic tissue and disruption of the gut microbiota in IBS rats. The frequency of 2/100 Hz has more regulatory pathways than 2/10 Hz and 2/50 Hz. In addition, IBS rats exhibited colonic metabolic disorders, and pantothenate was significantly upregulated after EA treatment at different frequencies. Very low-density lipoprotein and 2-hydroxybutyrate were significantly increased in the 2/10 Hz group, while low density lipoprotein, very low-density lipoprotein, 2-hydroxybutyrate, methylmalonate and alpha-hydroxyisobutyric acid were significantly increased in the 2/100 Hz group.

CONCLUSIONS AND INFERENCES

EA at ST25 at different frequencies attenuated chronic visceral pain through different gut microbiota and metabolic pathways.

Multi-omics analysis of gut microbiota and metabolites reveals contrasting profiles in domestic pigs and wild boars across urban environments

The gut microbiota plays a crucial role in host health and metabolism. This study explores the differences in gut microbiota and metabolites between domestic pigs (DP) and wild boars (WB) in urban environments. We analyzed gut microbial composition, metabolic profiles, virome composition, antibiotic resistance genes (ARGs), and human pathogenic bacteria (HPB) in both DP and WB. Our results revealed that DP exhibited a higher Firmicutes/Bacteroidetes ratio and were enriched in bacterial genera associated with domestication and modern feeding practices. Metabolomic analysis showed distinct profiles, with WB significantly enriched in the Pantothenate and CoA biosynthesis pathway, highlighting dietary and environmental influences on host metabolism. Additionally, DP had a distinct gut virome composition, particularly enriched in lytic phages of the Chaseviridae family. ARG analysis indicated a higher abundance of tetracycline resistance genes in DP, likely due to antibiotic use in pig farms. Furthermore, variations in HPB composition underscored potential health risks associated with contact with pig feces. These findings provide valuable insights into the microbial ecology of domestic pigs and wild boars, emphasizing the importance of these comparisons in identifying zoonotic pathogen transmission pathways and managing antibiotic resistance. Continued research in this area is essential for developing effective strategies to mitigate public health risks and promote sustainable livestock management practices.

Unraveling cysteine deficiency-associated rapid weight loss

Forty percent of the US population and 1 in 6 individuals worldwide are obese, and the incidence of this disease is surging globally1,2. Various dietary interventions, including carbohydrate and fat restriction, and more recently amino acid restriction, have been explored to combat this epidemic3-6. We sought to investigate the impact of removing individual amino acids on the weight profiles of mice. Compared to essential amino acid restriction, induction of conditional cysteine restriction resulted in the most dramatic weight loss, amounting to 20% within 3 days and 30% within one week, which was readily reversed. This weight loss occurred despite the presence of substantial cysteine reserves stored in glutathione (GSH) across various tissues7. Further analysis demonstrated that the weight reduction primarily stemmed from an increase in the utilization of fat mass, while locomotion, circadian rhythm and histological appearance of multiple other tissues remained largely unaffected. Cysteine deficiency activated the integrated stress response (ISR) and NRF2-mediated oxidative stress response (OSR), which amplify each other, leading to the induction of GDF15 and FGF21, hormones associated with increased lipolysis, energy homeostasis and food aversion8-10. We additionally observed rapid tissue coenzyme A (CoA) depletion, resulting in energetically inefficient anaerobic glycolysis and TCA cycle, with sustained urinary excretion of pyruvate, orotate, citrate, α-ketoglutarate, nitrogen rich compounds and amino acids. In summary, our investigation highlights that cysteine restriction, by depleting GSH and CoA, exerts a maximal impact on weight loss, metabolism, and stress signaling compared to other amino acid restrictions. These findings may pave the way for innovative strategies for addressing a range of metabolic diseases and the growing obesity crisis.

Lipidomic analysis of human TANGO2-deficient cells suggests a lipid imbalance as a cause of TANGO2 deficiency disease

TANGO2 deficiency disease (TDD) is a multisystem disease caused by variants in the TANGO2 gene. Symptoms include neurodevelopmental delays, seizures and potentially lethal metabolic crises and cardiac arrhythmias. While the function of TANGO2 remains elusive, vitamin B5/pantothenic acid supplementation has been shown to alleviate symptoms in a fruit fly model and has also been used with success to treat individuals suffering from TDD. Since vitamin B5 is the precursor to the lipid activator coenzyme A (CoA), we hypothesized that TANGO2-deficient cells would display changes in the lipid profile compared to control and that these changes would be rescued by vitamin B5 supplementation. In addition, the specific changes seen might point to a pathway in which TANGO2 functions. Indeed, we found profound changes in the lipid profile of human TANGO2-deficient cells as well as an increased pool of free fatty acids in both human cells devoid of TANGO2 and Drosophila harboring a previously described TANGO2 loss of function allele. All these changes were reversed upon vitamin B5 supplementation. Pathway analysis showed significant increases in triglyceride as well as in lysophospholipid levels as the top enriched pathways in the absence of TANGO2. Consistent with a defect in triglyceride metabolism, we found changes in lipid droplet numbers and sizes in the absence of TANGO2 compared to control. Our data will allow for comparison between other model systems of TDD and the homing in on critical lipid imbalances that lead to the disease state.

Coenzyme A biosynthesis: mechanisms of regulation, function and disease

The tricarboxylic acid cycle, nutrient oxidation, histone acetylation and synthesis of lipids, glycans and haem all require the cofactor coenzyme A (CoA). Although the sources and regulation of the acyl groups carried by CoA for these processes are heavily studied, a key underlying question is less often considered: how is production of CoA itself controlled? Here, we discuss the many cellular roles of CoA and the regulatory mechanisms that govern its biosynthesis from cysteine, ATP and the essential nutrient pantothenate (vitamin B5), or from salvaged precursors in mammals. Metabolite feedback and signalling mechanisms involving acetyl-CoA, other acyl-CoAs, acyl-carnitines, MYC, p53, PPARα, PINK1 and insulin- and growth factor-stimulated PI3K-AKT signalling regulate the vitamin B5 transporter SLC5A6/SMVT and CoA biosynthesis enzymes PANK1, PANK2, PANK3, PANK4 and COASY. We also discuss methods for measuring CoA-related metabolites, compounds that target CoA biosynthesis and diseases caused by mutations in pathway enzymes including types of cataracts, cardiomyopathy and neurodegeneration (PKAN and COPAN).

Gehua Jiejiu Dizhi decoction ameliorates alcoholic fatty liver in mice by regulating lipid and bile acid metabolism and with exertion of antioxidant stress based on 4DLabel-free quantitative proteomic study

OBJECTIVE

To analyze the effect and molecular mechanism of Gehua Jiejiu Dizhi decoction (, GJDD) on alcoholic fatty live disease (AFLD) by using proteomic methods.

METHODS

The male C57BL/6J mouse were randomly divided into four groups: control group, model group, GJDD group and resveratrol group. After the AFLD model was successfully prepared by intragastric administration of alcohol once on the basis of the Lieber-DeCarli classical method, the GJDD group and resveratrol group were intragastrically administered with GJDD (4900 mg/kg) and resveratrol (400 mg/kg) respectively, once a day for 9 d. The fat deposition of liver tissue was observed and evaluated by oil red O (ORO) staining. 4DLabel-free quantitative proteome method was used to determine and quantify the protein expression in liver tissue of each experimental group. The differentially expressed proteins were screened according to protein expression differential multiples, and then analyzed by Gene ontology classification and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. Finally, expression validation of the differentially co-expressed proteins from control group, model group and GJDD group were verified by targeted proteomics quantification techniques.

RESULTS

In semiquantitative analyses of ORO, all kinds of steatosis (ToS, MaS, and MiS) were evaluated higher in AFLD mice compared to those in GJDD or resveratrol-treated mice. 4DLabel-free proteomics analysis results showed that a total of 4513 proteins were identified, of which 3763 proteins were quantified and 946 differentially expressed proteins were screened. Compared with the control group, 145 proteins were up-regulated and 148 proteins were down-regulated in the liver tissue of model group. In addition, compared with the model group, 92 proteins were up-regulated and 135 proteins were down-regulated in the liver tissue of the GJDD group. 15 differentially co-expressed proteins were found between every two groups (model group vs control group, GJDD group vs model group and GJDD group vs control group), which were involved in many biological processes. Among them, 11 differentially co-expressed key proteins (Aox3, H1-5, Fabp5, Ces3a, Nudt7, Serpinb1a, Fkbp11, Rpl22l1, Keg1, Acss2 and Slco1a1) were further identified by targeted proteomic quantitative technology and their expression patterns were consistent with the results of 4D label-free proteomic analysis.

CONCLUSIONS

Our study provided proteomics-based evidence that GJDD alleviated AFLD by modulating liver protein expression, likely through the modulation of lipid metabolism, bile acid metabolism and with exertion of antioxidant stress.

Lysine acetylation of histone acetyltransferase adaptor protein ADA2 is a mechanism of metabolic control of chromatin modification in plants

Histone acetylation is a predominant active chromatin mark deposited by histone acetyltransferases (HATs) that transfer the acetyl group from acetyl coenzyme A (acetyl-CoA) to lysine ε-amino groups in histones. GENERAL CONTROL NON-REPRESSED PROTEIN 5 (GCN5) is one of the best-characterized HATs and functions in association with several adaptor proteins such as ADA2 within multiprotein HAT complexes. ADA2-GCN5 interaction increases GCN5 binding to acetyl-CoA and stimulates its HAT activity. It remains unclear whether the HAT activity of GCN5 (which acetylates not only histones but also cellular proteins) is regulated by acetyl-CoA levels, which vary greatly in cells under different metabolic and nutrition conditions. Here we show that the ADA2 protein itself is acetylated by GCN5 in rice cells. Lysine acetylation exposes ADA2 to a specific E3 ubiquitin ligase and reduces its protein stability. In rice plants, ADA2 protein accumulation reversely parallels its lysine acetylation and acetyl-CoA levels, both of which are dynamically regulated under varying growth conditions. Stress-induced ADA2 accumulation could stimulate GCN5 HAT activity to compensate for the reduced acetyl-CoA levels for histone acetylation. These results indicate that ADA2 lysine acetylation that senses cellular acetyl-CoA variations is a mechanism to regulate HAT activity and histone acetylation homeostasis in plants under changing environments.

Tracer-based lipidomics enables the discovery of disease-specific candidate biomarkers in mitochondrial β-oxidation disorders

Carnitine derivatives of disease-specific acyl-CoAs are the diagnostic hallmark for long-chain fatty acid β-oxidation disorders (lcFAOD), including carnitine shuttle deficiencies, very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD), long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) and mitochondrial trifunctional protein deficiency (MPTD). The exact consequence of accumulating lcFAO-intermediates and their influence on cellular lipid homeostasis is, however, still unknown. To investigate the fate and cellular effects of the accumulating lcFAO-intermediates and to explore the presence of disease-specific markers, we used tracer-based lipidomics with deuterium-labeled oleic acid (D9-C18:1) in lcFAOD patient-derived fibroblasts. In line with previous studies, we observed a trend towards neutral lipid accumulation in lcFAOD. In addition, we detected a direct connection between the chain length and patterns of (un)saturation of accumulating acylcarnitines and the various enzyme deficiencies. Our results also identified two disease-specific candidate biomarkers. Lysophosphatidylcholine(14:1) (LPC(14:1)) was specifically increased in severe VLCADD compared to mild VLCADD and control samples. This was confirmed in plasma samples showing an inverse correlation with enzyme activity, which was better than the classic diagnostic marker C14:1-carnitine. The second candidate biomarker was an unknown lipid class, which we identified as S-(3-hydroxyacyl)cysteamines. We hypothesized that these were degradation products of the CoA moiety of accumulating 3-hydroxyacyl-CoAs. S-(3-hydroxyacyl)cysteamines were significantly increased in LCHADD compared to controls and other lcFAOD, including MTPD. Our findings suggest extensive alternative lipid metabolism in lcFAOD and confirm that lcFAOD accumulate neutral lipid species. In addition, we present two disease-specific candidate biomarkers for VLCADD and LCHADD, that may have significant relevance for disease diagnosis, prognosis, and monitoring.

Relationship between circulating metabolites and diabetic retinopathy: a two-sample Mendelian randomization analysis

Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes mellitus, however, its underlying biological mechanisms remain poorly understood. We examined single nucleotide polymorphisms linked to 486 blood metabolites through extensive genome-wide association studies conducted on individuals of European ancestry. The FinnGen Biobank database served as a reference to define DR. Two-sample MR analysis was conducted to reveal the association between the levels of genetically predicted circulating metabolites and the susceptibility to DR. To validate the robustness of the obtained findings, sensitivity analyses with weighted median, weighted mode, and MR-Egger were conducted. 1-oleoylglycerophosphoethanolamine (odds ratio [OR] (OR per one standard deviation [SD] increase) = 0.414; 95% confidence interval [CI] 0.292-0.587; P = 7.613E-07, PFDR = 6.849E-06), pyroglutamine (OR per one SD increase = 0.414; 95% confidence interval [CI] 0.292-0.587; P = 8.31E-04, PFDR = 0.007), phenyllactate (PLA) (OR per one SD increase = 0.591; 95% confidence interval [CI] 0.418-0.836; P = 0.003, PFDR = 0.026), metoprolol acid metabolite (OR per one SD increase = 0.978; 95% confidence interval [CI] 0.962-0.993; P = 0.005, PFDR = 0.042), 10-undecenoate (OR per one SD increase = 0.788; 95% confidence interval [CI] 0.667-0.932; P = 0.005, PFDR = 0.049), erythritol (OR per one SD increase = 0.691; 95% confidence interval [CI] 0.513-0.932; P = 0.015, PFDR = 0.034), 1-stearoylglycerophosphoethanolamine (OR per one SD increase = 0.636; 95% confidence interval [CI] 0.431-0.937; P = 0.022, PFDR = 0.099), 1-arachidonoylglycerophosphoethanolamine (OR per one SD increase = 0.636; 95% confidence interval [CI] 0.431-0.937; P = 0.030, PFDR = 0.099) showed a significant causal relationship with DR and could have protective effects. stachydrine (OR per one SD increase = 1.146; 95% confidence interval [CI] 1.066-1.233; P = 2.270E-04, PFDR = 0.002), butyrylcarnitine (OR per one SD increase = 1.117; 95% confidence interval [CI] 1.023-1.219; P = 0.014, PFDR = 0.062), 5-oxoproline (OR per one SD increase = 1.569; 95% confidence interval [CI] 1.056-2.335; P = 0.026, PFDR = 0.082), and kynurenine (OR = 1.623; 95% CI 1.042-2.526; P = 0.041, PFDR = 0.097) were significantly associated with an increased risk of DR. This study identified metabolites have the potential to be considered prospective compounds for investigating the underlying mechanisms of DR and for selecting appropriate drug targets.

Transcriptomic and metabolomic analysis of peri-tumoral hepatic tissue in hepatocellular carcinoma: unveiling the molecular landscape of immune checkpoint therapy resistance

Background: Hepatocellular carcinoma (HCC) often resists traditional treatments, necessitating new therapeutic approaches. With immune checkpoint therapy emerging as a promising alternative, understanding its resistance mechanisms becomes crucial. Methods: Using 22 samples from 11 HCC patients, we conducted a comprehensive transcriptomic and metabolomic analysis of peri-tumoral hepatic tissues from those treated with Atezolizumab. Results: We identified significant metabolic alterations and a correlation between the COMMD3-BMI1 gene and Dephospho-CoA metabolite. Findings suggest these as potential markers for therapeutic resistance, as evidenced by upregulated COMMD3-BMI1 and downregulated Dephospho-CoA in non-responsive patients, with animal models further supporting these observations. Discussion: The study highlights COMMD3-BMI1 and Dephospho-CoA as critical actors in immune checkpoint therapy resistance in HCC, providing insights and potential pathways for more effective therapeutic strategies.

Pantothenic acid - a scoping review for Nordic Nutrition Recommendations 2023

Pantothenic acid, also referred to as vitamin B5, is a water-soluble vitamin that has essential functions in the body as a component of coenzyme A (CoA) and acyl carrier protein (ACP). It is widely distributed in animal and plant-source foods. Nutritional deficiency of pantothenic acid is rare and toxicity negligible. Information on pantothenic acid intakes in the Nordic countries is limited and biomarker data from Nordic and Baltic populations is missing. Due to a lack of data, no dietary reference values (DRVs) were given for pantothenic acid in the Nordic Nutrition Recommendations (NNR) since 2012. The aim of this scoping review was to examine recent evidence relevant for updating the DRVs for NNR2023. Scientific literature since 2012 on associations of pantothenic acid with health-related issues in Nordic and Baltic countries was searched. No health concerns related to pantothenic acid were identified.

The coenzyme A precursor pantethine enhances antitumor immunity in sarcoma

The tumor microenvironment is a dynamic network of stromal, cancer, and immune cells that interact and compete for resources. We have previously identified the Vanin1 pathway as a tumor suppressor of sarcoma development via vitamin B5 and coenzyme A regeneration. Using an aggressive sarcoma cell line that lacks Vnn1 expression, we showed that the administration of pantethine, a vitamin B5 precursor, attenuates tumor growth in immunocompetent but not nude mice. Pantethine boosts antitumor immunity, including the polarization of myeloid and dendritic cells towards enhanced IFNγ-driven antigen presentation pathways and improved the development of hypermetabolic effector CD8+ T cells endowed with potential antitumor activity. At later stages of treatment, the effect of pantethine was limited by the development of immune cell exhaustion. Nevertheless, its activity was comparable with that of anti-PD1 treatment in sensitive tumors. In humans, VNN1 expression correlates with improved survival and immune cell infiltration in soft-tissue sarcomas, but not in osteosarcomas. Pantethine could be a potential therapeutic immunoadjuvant for the development of antitumor immunity.

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.

Starving the Beast: Limiting Coenzyme A Biosynthesis to Prevent Disease and Transmission in Malaria

Malaria parasites must acquire all necessary nutrients from the vertebrate and mosquito hosts to successfully complete their life cycle. Failure to acquire these nutrients can limit or even block parasite development and presents a novel target for malaria control. One such essential nutrient is pantothenate, also known as vitamin B5, which the parasite cannot synthesize de novo and is required for the synthesis of coenzyme A (CoA) in the parasite. This review examines pantothenate and the CoA biosynthesis pathway in the human-mosquito-malaria parasite triad and explores possible approaches to leverage the CoA biosynthesis pathway to limit malaria parasite development in both human and mosquito hosts. This includes a discussion of sources for pantothenate for the mosquito, human, and parasite, examining the diverse strategies used by the parasite to acquire substrates for CoA synthesis across life stages and host resource pools and a discussion of drugs and alternative approaches being studied to disrupt CoA biosynthesis in the parasite. The latter includes antimalarial pantothenate analogs, known as pantothenamides, that have been developed to target this pathway during the human erythrocytic stages. In addition to these parasite-targeted drugs, we review studies of mosquito-targeted allosteric enzymatic regulators known as pantazines as an approach to limit pantothenate availability in the mosquito and subsequently deprive the parasite of this essential nutrient.

LC-MS-based serum metabolomics analysis for the screening and monitoring of colorectal cancer

Background

Colorectal Cancer (CRC) is a prevalent digestive system tumour with significant mortality and recurrence rates. Serum metabolomics, with its high sensitivity and high throughput, has shown potential as a tool to discover biomarkers for clinical screening and monitoring of the CRC patients.

Methods

Serum metabolites of 61 sex and age-matched healthy controls and 62 CRC patients (before and after surgical intervention) were analyzed using a ultra-performance liquid chromatography-high resolution mass spectrometer (UPLC-MS). Statistical methods and pathway enrichment analysis were used to identify potential biomarkers and altered metabolic pathways.

Results

Our analysis revealed a clear distinction in the serum metabolic profile between CRC patients and healthy controls (HCs). Pathway analysis indicated a significant association with arginine biosynthesis, pyrimidine metabolism, pantothenate, and CoA biosynthesis. Univariate and multivariate statistical analysis showed that 9 metabolites had significant diagnostic value for CRC, among them, Guanosine with Area Under the Curve (AUC) values of 0.951 for the training group and0.998 for the validation group. Furthermore, analysis of four specific metabolites (N-Phenylacetylasparticacid, Tyrosyl-Gamma-glutamate, Tyr-Ser and Sphingosine) in serum samples of CRC patients before and after surgery indicated a return to healthy levels after an intervention.

Conclusion

Our results suggest that serum metabolomics may be a valuable tool for the screening and monitoring of CRC patients.

Acyl-CoA thioesterase-2 facilitates β-oxidation in glycolytic skeletal muscle in a lipid supply dependent manner

Acyl-Coenzyme A (acyl-CoA) thioesters are compartmentalized intermediates that participate in in multiple metabolic reactions within the mitochondrial matrix. The limited availability of free CoA (CoASH) in the matrix raises the question of how the local acyl-CoA concentration is regulated to prevent trapping of CoASH from overload of any specific substrate. Acyl-CoA thioesterase-2 (ACOT2) hydrolyzes long-chain acyl-CoAs to their constituent fatty acids and CoASH, and is the only mitochondrial matrix ACOT refractory to inhibition by CoASH. Thus, we reasoned that ACOT2 may constitutively regulate matrix acyl-CoA levels. Acot2 deletion in murine skeletal muscle (SM) resulted in acyl-CoA build-up when lipid supply and energy demands were modest. When energy demand and pyruvate availability were elevated, lack of ACOT2 activity promoted glucose oxidation. This preference for glucose over fatty acid oxidation was recapitulated in C2C12 myotubes with acute depletion of Acot2 , and overt inhibition of β-oxidation was demonstrated in isolated mitochondria from Acot2 -depleted glycolytic SM. In mice fed a high fat diet, ACOT2 enabled the accretion of acyl-CoAs and ceramide derivatives in glycolytic SM, and this was associated with worse glucose homeostasis compared to when ACOT2 was absent. These observations suggest that ACOT2 supports CoASH availability to facilitate β-oxidation in glycolytic SM when lipid supply is modest. However, when lipid supply is high, ACOT2 enables acyl-CoA and lipid accumulation, CoASH sequestration, and poor glucose homeostasis. Thus, ACOT2 regulates matrix acyl-CoA concentration in glycolytic muscle, and its impact depends on lipid supply.

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.

Metabolomic analysis of bone-derived exosomes in osteonecrosis of the femoral head based on UPLC-MS/MS

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a disorder that causes a collapse of the femoral head, requiring subsequent total hip replacement. However, the pathogenesis of ONFH remains largely unclear. Herein, exosome metabolomics analyses were conducted to explore the pathophysiology of ONFH.

OBJECTIVES

This study aimed to conduct metabolic profiling of bone-derived exosomes of ONFH.

METHODS

30 ONFH patients and 30 femoral neck fracture (FNF) patients were included in this study. Exosomes were harvested from the femoral head by using ultracentrifugation. Ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was performed in combination with multivariate statistical analysis to reveal and provided new insight into identify the global metabolic profile of ONFH.

RESULTS

The results of transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blots indicated that the microvesicles isolated from the femoral head were exosomes. Several compounds were identified, including lipids and lipid-like molecules, amino acids, peptides, organooxygen compounds. 44 differential metabolites were screened between ONFH and FNF patients. The up-and down-regulation of Riboflavin metabolism, Pantothenate and CoA biosynthesis, Glycerophospholipid metabolism, and Sphingolipid metabolism were associated with ONFH pathophysiology.

CONCLUSION

Our results suggest that metabolomics has huge prospects for elucidating pathophysiology of ONFH.

Inherited Disorders of Coenzyme A Biosynthesis: Models, Mechanisms, and Treatments

Coenzyme A (CoA) is a vital and ubiquitous cofactor required in a vast number of enzymatic reactions and cellular processes. To date, four rare human inborn errors of CoA biosynthesis have been described. These disorders have distinct symptoms, although all stem from variants in genes that encode enzymes involved in the same metabolic process. The first and last enzymes catalyzing the CoA biosynthetic pathway are associated with two neurological conditions, namely pantothenate kinase-associated neurodegeneration (PKAN) and COASY protein-associated neurodegeneration (CoPAN), which belong to the heterogeneous group of neurodegenerations with brain iron accumulation (NBIA), while the second and third enzymes are linked to a rapidly fatal dilated cardiomyopathy. There is still limited information about the pathogenesis of these diseases, and the knowledge gaps need to be resolved in order to develop potential therapeutic approaches. This review aims to provide a summary of CoA metabolism and functions, and a comprehensive overview of what is currently known about disorders associated with its biosynthesis, including available preclinical models, proposed pathomechanisms, and potential therapeutic approaches.

Pantothenate biosynthesis in Toxoplasma gondii tachyzoites is not a drug target

Toxoplasma gondii is a pervasive apicomplexan parasite that can cause severe disease and death in immunocompromised individuals and the developing foetus. The treatment of toxoplasmosis often leads to serious side effects and novel drugs and drug targets are therefore actively sought. In 2014, Mageed and colleagues suggested that the T. gondii pantothenate synthetase, the enzyme responsible for the synthesis of the vitamin B₅ (pantothenate), the precursor of the important cofactor, coenzyme A, is a good drug target. Their conclusion was based on the ability of potent inhibitors of the M. tuberculosis pantothenate synthetase to inhibit the proliferation of T. gondii tachyzoites. They also reported that the inhibitory effect of the compounds could be antagonised by supplementing the medium with pantothenate, supporting their conclusion that the compounds were acting on the intended target. Contrary to these observations, we find that compound SW314, one of the compounds used in the Mageed et al. study and previously shown to be active against M. tuberculosis pantothenate synthetase in vitro, is inactive against the T. gondii pantothenate synthetase and does not inhibit tachyzoite proliferation, despite gaining access into the parasite in situ. Furthermore, we validate the recent observation that the pantothenate synthetase gene in T. gondii can be disrupted without detrimental effect to the survival of the tachyzoite-stage parasite in the presence or absence of extracellular pantothenate. We conclude that the T. gondii pantothenate synthetase is not essential during the tachyzoite stage of the parasite and it is therefore not a target for drug discovery against T. gondii tachyzoites.

Probing coenzyme A homeostasis with semisynthetic biosensors

Coenzyme A (CoA) is one of the central cofactors of metabolism, yet a method for measuring its concentration in living cells is missing. Here we introduce the first biosensor for measuring CoA levels in different organelles of mammalian cells. The semisynthetic biosensor is generated through the specific labeling of an engineered GFP-HaloTag fusion protein with a fluorescent ligand. Its readout is based on CoA-dependent changes in Förster resonance energy transfer efficiency between GFP and the fluorescent ligand. Using this biosensor, we probe the role of numerous proteins involved in CoA biosynthesis and transport in mammalian cells. On the basis of these studies, we propose a cellular map of CoA biosynthesis that suggests how pools of cytosolic and mitochondrial CoA are maintained.

Rats with Long-Term Cholestasis Have a Decreased Cytosolic but Maintained Mitochondrial Hepatic CoA Pool

Previous studies showed that rats with long-term bile duct ligation have reduced coenzyme A stores per g of liver but maintained mitochondrial CoA stores. Based on these observations, we determined the CoA pool in the liver homogenate, liver mitochondria, and liver cytosol of rats with bile duct ligation for 4 weeks (BDL rats, n = 9) and sham-operated control rats (CON rats, n = 5). In addition, we tested the cytosolic and mitochondrial CoA pools by assessing the metabolism of sulfamethoxazole and benzoate in vivo and of palmitate in vitro. The hepatic total CoA content was lower in BDL than CON rats (mean ± SEM; 128 ± 5 vs. 210 ± 9 nmol/g), affecting all subfractions equally (free CoA (CoASH), short- and long-chain acyl-CoA). In BDL rats, the hepatic mitochondrial CoA pool was maintained, and the cytosolic pool was reduced (23.0 ± 0.9 vs. 84.6 ± 3.7 nmol/g liver; CoA subfractions were affected equally). The urinary excretion of hippurate after i.p. benzoate administration (measuring mitochondrial benzoate activation) was reduced in BDL rats (23.0 ± 0.9 vs. 48.6 ± 3.7% of dose/24 h), whereas the urinary elimination of N-acetylsulfamethoxazole after i.p. sulfamethoxazole administration (measuring the cytosolic acetyl-CoA pool) was maintained (36.6 ± 3.0 vs. 35.1 ± 2.5% of dose/24 h BDL vs. CON rats). Palmitate activation was impaired in the liver homogenate of BDL rats but the cytosolic CoASH concentration was not limiting. In conclusion, BDL rats have reduced hepatocellular cytosolic CoA stores, but this reduction does not limit sulfamethoxazole N-acetylation or palmitate activation. The hepatocellular mitochondrial CoA pool is maintained in BDL rats. Impaired hippurate formation in BDL rats is explained best by mitochondrial dysfunction.

Construction and validation of a fatty acid metabolism-related gene signature for predicting prognosis and therapeutic response in patients with prostate cancer

Background

Reprogramming of fatty acid metabolism is a newly-identified hallmark of malignancy. However, no studies have systematically investigated the fatty acid metabolism related-gene set in prostate cancer (PCa).

Methods

A cohort of 381 patients with gene expression and clinical data from The Cancer Genome Atlas was used as the training set, while another cohort of 90 patients with PCa from GEO (GSE70769) was used as the validation set. Differentially expressed fatty acid metabolism-related genes were subjected to least absolute shrinkage and selection operator (LASSO)-Cox regression to establish a fatty acid metabolism-related risk score. Associations between the risk score and clinical characteristics, immune cell infiltration, tumor mutation burden (TMB), tumor immune dysfunction and exclusion (TIDE) score, and response to chemotherapy were analyzed. Finally, the expression level of genes included in the model was validated using real-time PCR.

Results

A prognostic risk model based on five fatty acid metabolism related genes (ALDH1A1, CPT1B, CA2, CROT, and NUDT19) were constructed. Tumors with higher risk score were associated with larger tumor size, lymph node involvement, higher Gleason score, and poorer biochemical recurrence (BCR)-free survival. Furthermore, the high- and low-risk tumors exhibited distinct immune cell infiltration features and immune-related pathway activation. High-risk tumors were associated with favorable response to immunotherapy as indicated by high TMB and low TIDE score, but poor response to bicalutamide and docetaxel chemotherapy.

Conclusion

This study established a fatty acid metabolism-related gene signature which was predictive of BCR and response to chemotherapy and immunotherapy, providing a novel therapeutic biomarker for PCa.

Transcriptome and DNA Methylation Responses in the Liver of Yellowfin Seabream Under Starvation Stress

Fish suffer from starvation due to environmental risks such as extreme weather in the wild and due to insufficient feedings in farms. Nutrient problems from short-term or long-term starvation conditions can result in stress-related health problems for fish. Yellowfin seabream (Acanthopagrus latus) is an important marine economic fish in China. Understanding the molecular responses to starvation stress is vital for propagation and culturing yellowfin seabream. In this study, the transcriptome and genome-wide DNA methylation levels in the livers of yellowfin seabream under 14-days starvation stress were analyzed. One hundred sixty differentially expressed genes (DEGs) by RNA-Seq analysis and 737 differentially methylated-related genes by whole genome bisulfite sequencing analysis were identified. GO and KEGG pathway enrichment analysis found that energy metabolism-related pathways such as glucose metabolism and lipid metabolism were in response to starvation. Using bisulfite sequencing PCR, we confirmed the presence of CpG methylation differences within the regulatory region of a DEG ppargc1a in response to 14-days starvation stress. This study revealed the molecular responses of livers in response to starvation stress at the transcriptomic and whole genome DNA methylation levels in yellowfin seabream.

The multiple facets of acetyl-CoA metabolism: Energetics, biosynthesis, regulation, acylation and inborn errors

Acetyl-coenzyme A (Ac-CoA) is a core metabolite with essential roles throughout cell physiology. These functions can be classified into energetics, biosynthesis, regulation and acetylation of large and small molecules. Ac-CoA is essential for oxidative metabolism of glucose, fatty acids, most amino acids, ethanol, and of free acetate generated by endogenous metabolism or by gut bacteria. Ac-CoA cannot cross lipid bilayers, but acetyl groups from Ac-CoA can shuttle across membranes as part of carrier molecules like citrate or acetylcarnitine, or as free acetate or ketone bodies. Ac-CoA is the basic unit of lipid biosynthesis, providing essentially all of the carbon for the synthesis of fatty acids and of isoprenoid-derived compounds including cholesterol, coenzyme Q and dolichols. High levels of Ac-CoA in hepatocytes stimulate lipid biosynthesis, ketone body production and the diversion of pyruvate metabolism towards gluconeogenesis and away from oxidation; low levels exert opposite effects. Acetylation changes the properties of molecules. Acetylation is necessary for the synthesis of acetylcholine, acetylglutamate, acetylaspartate and N-acetyl amino sugars, and to metabolize/eliminate some xenobiotics. Acetylation is a major post-translational modification of proteins. Different types of protein acetylation occur. The most-studied form occurs at the epsilon nitrogen of lysine residues. In histones, lysine acetylation can alter gene transcription. Acetylation of other proteins has diverse, often incompletely-documented effects. Inborn errors related to Ac-CoA feature a broad spectrum of metabolic, neurological and other features. To date, a small number of studies of animals with inborn errors of CoA thioesters has included direct measurement of acyl-CoAs. These studies have shown that low levels of tissue Ac-CoA correlate with the development of clinical signs, hinting that shortage of Ac-CoA may be a recurrent theme in these conditions. Low levels of Ac-CoA could potentially disrupt any of its roles.

Fat storage-inducing transmembrane proteins: beyond mediating lipid droplet formation

Fat storage-inducing transmembrane proteins (FITMs) were initially identified in 2007 as members of a conserved endoplasmic reticulum (ER) resident transmembrane protein gene family, and were found to be involved in lipid droplet (LD) formation. Recently, several studies have further demonstrated that the ability of FITMs to directly bind to triglyceride and diacylglycerol, and the diphosphatase activity of hydrolyzing fatty acyl-CoA, might enable FITMs to maintain the formation of lipid droplets, engage in lipid metabolism, and protect against cellular stress. Based on the distribution of FITMs in tissues and their important roles in lipid droplet biology and lipid metabolism, it was discovered that FITMs were closely related to muscle development, adipocyte differentiation, and energy metabolism. Accordingly, the abnormal expression of FITMs was not only associated with type 2 diabetes and lipodystrophy, but also with cardiac disease and several types of cancer. This study reviews the structure, distribution, expression regulation, and functionality of FITMs and their potential relationships with various metabolic diseases, hoping to provide inspiration for fruitful research directions and applications of FITM proteins. Moreover, this review will provide an important theoretical basis for the application of FITMs in the diagnosis and treatment of related diseases.

Antiperspirant effects and mechanism investigation of Mulisan decoction in rats based on plasma metabolomics

CONTEXT

Mulisan decoction (MLS) is a classic formula of traditional Chinese medicine for treating hyperhidrosis. The mechanism remains unclear.

OBJECTIVE

To investigate the antiperspirant effect and underlying mechanisms of MLS.

MATERIALS AND METHODS

Fifty rats were divided into control, model, and three doses of MLS intervention groups (n = 10). Rats except for control group were induced diseases features of the applicable scope of MLS via i.p. reserpine (0.5 mg/kg/d) for 10 days. From day 11, MLS groups were administrated orally MLS at 0.6, 3, and 15 g/kg once a day for 14 days, respectively. After the last administration, sweating was induced in all rats via s.c. pilocarpine (25 mg/kg), the right hind foot of rats was stained, and sweat point numbers were observed. Rat serum was collected to detect IL-2, IL-6, IFN-γ, and TNF-α. Rat plasma was collected for endogenous metabolite analysis via UPLC-QE-Focus-MS.

RESULTS

Rats treated with MLS presented a significant decrease in sweat point numbers (13.5%), increase in body weight (13.2%), and promotion in the balance of Th1/Th2 cytokine ratio via increasing IL-2 (38.3%), IFN-γ (20.1%), and TNF-α (22.0%) and decreasing IL-6 (24.7%) compared with the model group (p < 0.05). Plasma metabolomics disclosed 15 potential biomarkers related to model rats, of which two could be significantly reversed by MLS (p < 0.05). The involved pathways were pantothenate and CoA biosynthesis, and porphyrin metabolism.

CONCLUSIONS

MLS demonstrated a good antiperspirant effect and metabolism improvement. These findings inspire more clinical study validation on immune improvement and antiperspirant effect.

NUDT7 regulates total hepatic CoA levels and the composition of the intestinal bile acid pool in male mice fed a Western diet

Nudix hydrolase 7 (NUDT7) is an enzyme that hydrolyzes CoA species, is highly expressed in the liver, and resides in the peroxisomes. Peroxisomes are organelles where the preferential oxidation of dicarboxylic fatty acids occurs and where the hepatic synthesis of the primary bile acids cholic acid and chenodeoxycholic acid is completed. We previously showed that liver-specific overexpression of NUDT7 affects peroxisomal lipid metabolism but does not prevent the increase in total liver CoA levels that occurs during fasting. We generated Nudt7^-/- mice to further characterize the role that peroxisomal (acyl-)CoA degradation plays in the modulation of the size and composition of the acyl-CoA pool and in the regulation of hepatic lipid metabolism. Here, we show that deletion of Nudt7 alters the composition of the hepatic acyl-CoA pool in mice fed a low-fat diet, but only in males fed a Western diet does the lack of NUDT7 activity increase total liver CoA levels. This effect is driven by the male-specific accumulation of medium-chain dicarboxylic acyl-CoAs, which are produced from the β-oxidation of dicarboxylic fatty acids. We also show that, under conditions of elevated synthesis of chenodeoxycholic acid derivatives, Nudt7 deletion promotes the production of tauromuricholic acid, decreasing the hydrophobicity index of the intestinal bile acid pool and increasing fecal cholesterol excretion in male mice. These findings reveal that NUDT7-mediated hydrolysis of acyl-CoA pathway intermediates in liver peroxisomes contributes to the regulation of dicarboxylic fatty acid metabolism and the composition of the bile acid pool.

4′-phosphopantetheine acts as a potential antioxidant to limit atherosclerotic plaque formation by inhibiting ROS generation

Coronary heart disease (CHD) is caused by coronary atherosclerosis and has a high morbidity and mortality rate worldwide. There are challenges in both early screening and treatment of CHD. The appearance and development of CHD is a complex metabolic disorder process. Therefore, to search for new biomarkers of CHD, we analyzed the peripheral blood metabolome in patients with CHD. In the study, a plasma metabolite, 4′-Phosphopantetheine (4-PPanSH), which was discovered by HPLC-MS/MS, as peripheral blood 4-PPanSH decreases, the degree of coronary blockage gradually aggravates. In addition, the 4-PPanSH supplement limited atherosclerotic plaque formation and endothelial injury in mice. Further, in vascular endothelial cells, 4-PPanSH effectively inhibited ROS generation and ox-LDL accumulation. In summary, 4-PPanSH was associated with the degree of coronary stenosis, and the 4-PPanSH supplement reduced atherosclerotic plaque generation, which could be associated with 4-PPanSH acting as a potent antioxidant that inhibits ROS generation and alleviates vascular endothelial injury.

Harnessing the Vnn1 pantetheinase pathway boosts short chain fatty acids production and mucosal protection in colitis

OBJECTIVE

In the management of patients with IBD, there is a need to identify prognostic markers and druggable biological pathways to improve mucosal repair and probe the efficacy of tumour necrosis factor alpha biologics. Vnn1 is a pantetheinase that degrades pantetheine to pantothenate (vitamin B₅, a precursor of coenzyme A (CoA) biosynthesis) and cysteamine. Vnn1 is overexpressed by inflamed colonocytes. We investigated its contribution to the tolerance of the intestinal mucosa to colitis-induced injury.

DESIGN

We performed an RNA sequencing study on colon biopsy samples from patients with IBD stratified according to clinical severity and modalities of treatment. We generated the VIVA mouse transgenic model, which specifically overexpresses Vnn1 on intestinal epithelial cells and explored its susceptibility to colitis. We developed a pharmacological mimicry of Vnn1 overexpression by administration of Vnn1 derivatives.

RESULTS

VNN1 overexpression on colonocytes correlates with IBD severity. VIVA mice are resistant to experimentally induced colitis. The pantetheinase activity of Vnn1 is cytoprotective in colon: it enhances CoA regeneration and metabolic adaptation of colonocytes; it favours microbiota-dependent production of short chain fatty acids and mostly butyrate, shown to regulate mucosal energetics and to be reduced in patients with IBD. This prohealing phenotype is recapitulated by treating control mice with the substrate (pantethine) or the products of pantetheinase activity prior to induction of colitis. In severe IBD, the protection conferred by the high induction of VNN1 might be compromised because its enzymatic activity may be limited by lack of available substrates. In addition, we identify the elevation of indoxyl sulfate in urine as a biomarker of Vnn1 overexpression, also detected in patients with IBD.

CONCLUSION

The induction of Vnn1/VNN1 during colitis in mouse and human is a compensatory mechanism to reinforce the mucosal barrier. Therefore, enhancement of vitamin B₅-driven metabolism should improve mucosal healing and might increase the efficacy of anti-inflammatory therapy.