Vitamin B6 alleviates osteoarthritis by suppressing inflammation and apoptosis.

BACKGROUND: Although various anti-inflammatory medicines are widely recommended for osteoarthritis (OA) treatment, no significantly clinical effect has been observed. This study aims to examine the effects of vitamin B6, a component that has been reported to be capable of alleviating inflammation and cell death in various diseases, on cartilage degeneration in OA. METHODS: Collagen-induced arthritis (CIA) mice model were established and the severity of OA in cartilage was determined using the Osteoarthritis Research Society International (OARSI) scoring system. The mRNA and protein levels of indicators associated with extracellular matrix (ECM) metabolism, apoptosis and inflammation were detected. The effect of vitamin B6 (VB6) on the mice were assessed using HE staining and masson staining. The apoptosis rate of cells was assessed using TdT-mediated dUTP nick end labeling. RESULTS: Our results showed a trend of improved OARSI score in mice treated with VB6, which remarkably inhibited the hyaline cartilage thickness, chondrocyte disordering, and knees hypertrophy. Moreover, the VB6 supplementation reduced the protein expression of pro-apoptosis indicators, including Bax and cleaved caspase-3 and raised the expression level of anti-apoptosis marker Bcl-2. Importantly, VB6 improved ECM metabolism in both in vivo and in vitro experiments. CONCLUSIONS: This study demonstrated that VB6 alleviates OA through regulating ECM metabolism, inflammation and apoptosis in chondrocytes and CIA mice. The findings in this study provide a theoretical basis for targeted therapy of OA, and further lay the theoretical foundation for studies of mechanisms of VB6 in treating OA.

Non-causal relationship of polycystic ovarian syndrome with homocysteine and B vitamins: evidence from a two-sample Mendelian randomization.

Objective: Previous observational studies have identified a correlation between elevated plasma homocysteine (Hcy) levels and polycystic ovary syndrome (PCOS). This study aimed to determine whether a causal relationship exists between Hcy and PCOS at the genetic level. Methods: A two-sample Mendelian Randomization (TSMR) study was implemented to assess the genetic impact of plasma levels of Hcy, folate, vitamin B12, and vitamin B6 on PCOS in individuals of European ancestry. Independent single nucleotide polymorphisms (SNPs) associated with Hcy (n=12), folate (n=2), vitamin B12 (n=10), and vitamin B6 (n=1) at genome-wide significance levels (P<5×10-8) were selected as instrumental variables (IVs). Data concerning PCOS were obtained from the Apollo database. The primary method of causal estimation was inverse variance weighting (IVW), complemented by sensitivity analyses to validate the results. Results: The study found no genetic evidence to suggest a causal association between plasma levels of Hcy, folate, vitamin B12, vitamin B6, and PCOS. The effect sizes, determined through random-effect IVW, were as follows: Hcy per standard deviation increase, OR = 1.117, 95%CI: (0.842, 1.483), P = 0.442; folate per standard deviation increase, OR = 1.008, CI: (0.546, 1.860), P = 0.981; vitamin B12 per standard deviation increase, OR = 0.978, CI: (0.808, 1.185), P = 0.823; and vitamin B6 per standard deviation increase, OR = 0.967, CI: (0.925, 1.012), P = 0.145. The fixed-effect IVW results for each nutrient exposure and PCOS were consistent with the random-effect IVW findings, with additional sensitivity analyses reinforcing these outcomes. Conclusion: Our findings indicate no causal link between Hcy, folate, vitamin B12, vitamin B6 levels, and PCOS.

Vitamin B6 deficiency cooperates with oncogenic Ras to induce malignant tumors in Drosophila.

Vitamin B6 is a water-soluble vitamin which possesses antioxidant properties. Its catalytically active form, pyridoxal 5'-phosphate (PLP), is a crucial cofactor for DNA and amino acid metabolism. The inverse correlation between vitamin B6 and cancer risk has been observed in several studies, although dietary vitamin B6 intake sometimes failed to confirm this association. However, the molecular link between vitamin B6 and cancer remains elusive. Previous work has shown that vitamin B6 deficiency causes chromosome aberrations (CABs) in Drosophila and human cells, suggesting that genome instability may correlate the lack of this vitamin to cancer. Here we provide evidence in support of this hypothesis. Firstly, we show that PLP deficiency, induced by the PLP antagonists 4-deoxypyridoxine (4DP) or ginkgotoxin (GT), promoted tumorigenesis in eye larval discs transforming benign RasV12 tumors into aggressive forms. In contrast, PLP supplementation reduced the development of tumors. We also show that low PLP levels, induced by 4DP or by silencing the sgllPNPO gene involved in PLP biosynthesis, worsened the tumor phenotype in another Drosophila cancer model generated by concomitantly activating RasV12 and downregulating Discs-large (Dlg) gene. Moreover, we found that RasV12 eye discs from larvae reared on 4DP displayed CABs, reactive oxygen species (ROS) and low catalytic activity of serine hydroxymethyltransferase (SHMT), a PLP-dependent enzyme involved in thymidylate (dTMP) biosynthesis, in turn required for DNA replication and repair. Feeding RasV12 4DP-fed larvae with PLP or ascorbic acid (AA) plus dTMP, rescued both CABs and tumors. The same effect was produced by overexpressing catalase in RasV12 DlgRNAi 4DP-fed larvae, thus allowing to establish a relationship between PLP deficiency, CABs, and cancer. Overall, our data provide the first in vivo demonstration that PLP deficiency can impact on cancer by increasing genome instability, which is in turn mediated by ROS and reduced dTMP levels.

Vitamin B6 ameliorates acute pancreatitis by suppressing the caspase3 signaling pathway.

BACKGROUND: Acute pancreatitis (AP) is a prevalent exocrine inflammatory disorder of the pancreas characterized by pancreatic inflammation and injury to acinar cells. Vitamin B6 (VB6) is a vital nutrient that plays a significant role in preserving human health and has anti-inflammatory and anti-apoptotic effects. METHODS: This study aimed to explore the potential pancreatic protective effects of VB6 in mitigating pancreatic inflammation and apoptosis induced by taurocholate sodium (TLCS) in an AP model and to assess the underlying mechanism of action. AP was induced in Sprague‒Dawley (SD) rats through TLCS administration and lipopolysaccharide (LPS)-treated AR42J cells, followed by treatment with VB6. RESULTS: Various parameters associated with AP were assessed in both plasma and pancreatic tissues. VB6 has been shown to ameliorate the severity of AP through various mechanisms. It effectively reduces the levels of serum amylase, lipase, and inflammatory factors, thereby mitigating histological injury to the pancreas. Moreover, VB6 inhibited pancreatic apoptosis by downregulating bax expression and up-regulating Bcl2 expression in TLCS-treated rats. Additionally, VB6 suppressed the expression of caspase3. The anti-inflammatory and anti-apoptotic effects of VB6 observed in LPS-treated AR42J cells are consistent with those observed in a rat model of AP. CONCLUSIONS: These results suggest that VB6 exerts anti-inflammatory and anti-apoptotic effects through inhibition of the caspase3 signaling pathway and has a protective effect against AP.

Associations of serum vitamin B6 status with the risks of cardiovascular, cancer, and all-cause mortality in the elderly.

Background: There are few studies investigating the relationship between serum vitamin B6 and mortality risk in the elderly. This study hereby evaluated the associations between biomarkers of serum vitamin B6 status and cardiovascular, cancer, and all-cause mortality risks in the elderly. Methods: Our study included a total of 4,881 participants aged 60 years or older from the National Health and Nutrition Examination Survey (NHANES) 2005-2010. Serum vitamin B6 status was estimated based on levels of pyridoxal 5'-phosphate (PLP), 4-pyridoxic acid (4-PA), and vitamin B6 turnover rate (4-PA/PLP) detected by high-performance liquid chromatography. Survival status and corresponding causes of death were matched through the National Death Index records through December 31, 2019. Multivariate Cox regression model was adopted to assess the relationships between serum vitamin B6 status and the risk of mortality. Results: During a median follow-up period of 10.33 years, 507 cardiovascular deaths, 426 cancer deaths, and 1995 all-cause deaths were recorded, respectively. In the multivariate-adjusted Cox model, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the highest versus the lowest quartiles of PLP, 4-PA, and 4-PA/PLP were 0.70(0.54-0.90), 1.33(0.88-2.02), and 2.01(1.41-2.79) for cardiovascular mortality, 0.73(0.52-1.02), 1.05(0.71-1.57), and 1.95(1.25-3.05) for cancer mortality, and 0.62(0.53-0.74), 1.05(0.82-1.34), and 2.29(1.87-2.79) for all-cause mortality, respectively. Conclusion: Our study found that lower serum PLP levels were associated with increased risks of cardiovascular and all-cause mortality among the elderly population. And higher vitamin B6 turnover rate was associated with increased risks of cardiovascular, cancer, and all-cause mortality.

Impact of Serum Vitamin D, B6, and B12 and Cognitive Functions on Quality of Life in Peri- and Postmenopausal Polish Women.

BACKGROUND Menopause initiates or accelerates health problems in a woman’s life, and affects cognitive processes and quality of life. We aimed to assess the quality of life, cognitive functions, and serum vitamin D, B6, and B12 concentrations in perimenopausal and postmenopausal Polish women. Also, we correlated the assessment of the quality of life with these vitamin concentrations and cognitive functions. MATERIAL AND METHODS The study was conducted in 287 perimenopausal and postmenopausal women. Serum levels of vitamin D, B6, and B12, cognitive functions using CNS Vital Signs software, and quality of life using WHO Quality of Life Brief were tested. RESULTS Almost all of the perimenopausal and postmenopausal women had normal concentrations of serum vitamin B12 (96%), 80% of them had normal B6 concentration, while only 9% had optimal serum vitamin D concentration. Postmenopausal women had lower Neurocognitive Index, psychomotor speed, motor speed, reaction time, and lower assessment of overall quality of life, physical health, and social relationships compared to perimenopausal women. In comparison to postmenopausal women, perimenopausal women had a lower serum vitamin B6 concentration, and the lower the concentration of this vitamin in serum they had, the lower they assessed their environment. Perimenopausal women assessed their social relationships the better, the better the visual memory, and the lower the processing speed they had. Postmenopausal women assessed the environment the better, the higher their Neurocognition Index was, and the better the reaction time they had. CONCLUSIONS Assessment of quality of life was associated with some cognitive functions in both perimenopausal and postmenopausal women.

RENAL PROTECTIVE EFFECT AND CLINICAL ANALYSIS OF VITAMIN B 6 IN PATIENTS WITH SEPSIS.

ABSTRACT: Objective: To investigate the protective effect and possible mechanisms of vitamin B 6 against renal injury in patients with sepsis. Methods: A total of 128 patients with sepsis who met the entry criteria in multiple centers were randomly divided into experimental (intravenous vitamin B 6 therapy) and control (intravenous 0.9% sodium chloride therapy) groups based on usual care. Clinical data, the inflammatory response indicators interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor (TNF-α), and endothelin-1 (ET-1), the oxidative stress response indicators superoxide dismutase, glutathione and malondialdehyde, and renal function (assessed by blood urea nitrogen, serum creatinine, and renal resistance index monitored by ultrasound) were compared between the two groups. Results: After 7 d of treatment, the IL-6, IL-8, TNF-α, and ET-1 levels in the experimental group were significantly lower than those in the control group, the oxidative stress response indicators were significantly improved in the experimental group and the blood urea nitrogen, serum creatinine, and renal resistance index values in the experimental group were significantly lower than those in the control group ( P < 0.05). There was no statistical difference between the two groups in the rate of renal replacement therapy and 28 d mortality ( P > 0.05). However, the intensive care unit length of stay and the total hospitalization expenses in the experimental group were significantly lower than those in the control group ( P < 0.05). Conclusion: The administration of vitamin B 6 in the treatment of patients with sepsis attenuates renal injury, and the mechanism may be related to pyridoxine decreasing the levels of inflammatory mediators and their regulation by redox stress.

Immunotoxicity of 2-Acetyl-4-tetrahydroxybutylimidazole in BALB/c mice with different vitamin B6 nutritional statuses.

Caramel color is a widely used food pigment, and 2-Acetyl-4-tetrahydroxybutylimidazole (THI) is a by-products of Class III caramel color. Some studies have shown that THI can reduce the number of peripheral blood lymphocytes. However, the comprehensive mechanism of THI immunotoxicity requires further study. In this study, the effects of THI on lymphocyte count, humoral immunity, cellular immunity and nonspecific immunity were determined and the effect of the nutritional status of VB6 on THI immunotoxicity was evaluated. Female BALB/c mice were divided into 3 groups and fed chow containing different doses of VB6: VB6-normal (6 mg/kg VB6), VB6-deprived (0.5 mg/kg VB6) or VB6-enhanced (12 mg/kg VB6) feed. Each group was further divided into 4 subgroups and treated with THI (0.5, 2.5 or 12.5 mg/kg bw) or the solvent control by gavage for 30 days. The thymic cortical thickness was measured with ViewPoint; the proportions of major immune cells and T cells in peripheral blood and tissues were detected via flow cytometry; the transformation and proliferation abilities of T and B cells were detected via T and B lymphocyte proliferation assays; NK cell activity was assessed via lactate dehydrogenase assays; humoral immune function was assessed via plaque-forming cell assays; and the immune function of T lymphocytes was assessed via delayed type hypersensitivity assays. The results showed that compared with those in the corresponding control group, the white blood cell count and lymphocyte count decreased significantly in all the VB6-deprived groups, in the 2.5 and 12.5 mg/kg VB6 groups, and in the 12.5 mg/kg VB6-enhanced group. With increasing THI dose, the thymic cortical layer became thinner. In the thymus, THI increased the proportions of CD3+ T cells and mature CD8+ T cells and decreased the proportions of immature double-positive, double-negative T cells and CD69-expressing lymphocytes. The proportions of naïve T cells and Tcm (central memory T) cells related to homing decreased. The proportion of mature T cells in the spleen decreased significantly. The proliferation of T cells stimulated by ConA decreased after THI exposure. VB6-deficient mice were more sensitive to THI immunotoxicity, and supplementation with VB6 had a certain protective effect on these mice. The results of the PFC and NK cell activity assays indicated that THI exposure might not affect humoral immune or innate immune function.

Enhancement of vitamin B6 production driven by omics analysis combined with fermentation optimization.

BACKGROUND: Microbial engineering aims to enhance the ability of bacteria to produce valuable products, including vitamin B6 for various applications. Numerous microorganisms naturally produce vitamin B6, yet the metabolic pathways involved are rigorously controlled. This regulation by the accumulation of vitamin B6 poses a challenge in constructing an efficient cell factory. RESULTS: In this study, we conducted transcriptome and metabolome analyses to investigate the effects of the accumulation of pyridoxine, which is the major commercial form of vitamin B6, on cellular processes in Escherichia coli. Our omics analysis revealed associations between pyridoxine and amino acids, as well as the tricarboxylic acid (TCA) cycle. Based on these findings, we identified potential targets for fermentation optimization, including succinate, amino acids, and the carbon-to-nitrogen (C/N) ratio. Through targeted modifications, we achieved pyridoxine titers of approximately 514 mg/L in shake flasks and 1.95 g/L in fed-batch fermentation. CONCLUSION: Our results provide insights into pyridoxine biosynthesis within the cellular metabolic network for the first time. Our comprehensive analysis revealed that the fermentation process resulted in a remarkable final yield of 1.95 g/L pyridoxine, the highest reported yield to date. This work lays a foundation for the green industrial production of vitamin B6 in the future.

Vitamin B6 alleviates chronic sleep deprivation-induced hippocampal ferroptosis through CBS/GSH/GPX4 pathway.

Several studies have found that sleep deprivation (SD) can lead to neuronal ferroptosis and affect hippocampal function. However, there are currently no effective interventions. Vitamin B6 is a co-factor for key enzymes in the transsulfuration pathway which is critical for maintaining cell growth in the presence of cysteine deprivation. The results showed that SD inhibited cystine-glutamate antiporter light chain subunit xCT protein expression and caused cysteine deficiency, which reduced the synthesis of the glutathione (GSH) to trigger neuronal ferroptosis. Nissl staining further revealed significant neuronal loss and shrinkage in the CA1 and CA3 regions of the hippocampus in SD mice. Typical ferroptotic indicators characterized by lipid peroxidation and iron accumulation were showed in the hippocampus after sleep deprivation. As expected, vitamin B6 could alleviate hippocampal ferroptosis by upregulating the expression of cystathionine beta-synthase (CBS) in the transsulfuration pathway, thereby replenishing the intracellular deficient GSH and restoring the expression of GPX4. Similar anti-ferroptotic effects of vitamin B6 were demonstrated in HT-22 cells treated with ferroptosis activator erastin. Furthermore, vitamin B6 had no inhibitory effect on erastin-induced ferroptosis in CBS-knockout HT22 cells. Our findings suggested chronic sleep deprivation caused hippocampal ferroptosis by disrupting the cyst(e)ine/GSH/GPX4 axis. Vitamin B6 alleviated sleep deprivation-induced ferroptosis by enhancing CBS expression in the transsulfuration pathway.

Dietary intake with supplementation of vitamin D, vitamin B6, and magnesium on depressive symptoms: a public health perspective.

Objective: This study aims to understand the impact of dietary intake through supplementation of vitamins D, B6, and magnesium on elevated depressive symptoms, a mental health illness that is a leading contributor to global disability and a public health concern. Methods: Multiple datasets from the National Health and Nutrition Examination Survey 2017-March 2020 investigated the associations between vitamin D, B6, and magnesium on depression screening scores. A cross-sectional sample of adults over 20 was extracted (n = 9,232). Chi-square tests and logistic regression analyses were used to investigate the associations. Results: Individuals with low amounts of vitamin D (p = 0.0481) were more likely to report elevated depressive symptoms relative to those with low amounts of vitamin B6 (p = 0.0225). These results remained significant among those with high magnesium (p = 0.0133) proportionate to high vitamin B6 (p = 0.0225). In the age-adjusted model, a lower intake of vitamin D, vitamin B6, and magnesium showed a relationship with elevated depressive symptoms (Vitamin D: OR = 0.611, 95% CI 0.382-0.980 Vitamin B6: OR = 0.503, 95% CI 0.291-0.867 Magnesium: OR = 0.458, 95% CI 0.277-0.759). The fully adjusted regression model (gender, race/ethnicity, and household food security) showed that a lower intake of vitamin B6 and magnesium correlated with elevated depressive symptoms (Vitamin B6: OR = 0.439, 95% CI 0.260-0.738 Magnesium: OR = 0.465, 95% CI 0.303-0.714). Conclusion: Preventive measures could be addressed by identifying the risks of vitamin deficiencies. Further epidemiological research is needed for the individual effects of vitamin supplementation and depression screening scores. Future prospective cohort studies exploring these associations, focusing on daily dietary intake, are needed to validate the direction of causation further and understand the underlying mechanisms.

Contribution of Beef to Key Nutrient Intakes and Nutrient Adequacy in Pregnant and Lactating Women: NHANES 2011-2018 Analysis.

Beef is an important source of high-quality protein and several micronutrients, including iron, zinc, and B-vitamins. The objective was to assess the association of beef intake with nutrient intake and adequacy among pregnant and lactating women using 24-h dietary recall data. Usual intakes from foods were determined with the National Cancer Institute (NCI) method and % population below Estimated Average Requirement (EAR) or above Adequate Intake (AI) were estimated. A high proportion of pregnant and lactating women had inadequate intakes for vitamin D (94%), vitamin E (82%), vitamin C (52%), and vitamin A (50%), magnesium (35%), folate (31%), zinc (25%), and vitamin B6 (22%); only 4% and 35% met AI for choline and potassium, respectively. About 67% of pregnant and lactating women were beef consumers, consuming 49 g beef/day. Beef consumers had higher intakes (p < 0.05) of energy, protein, calcium, iron, phosphorus, selenium, sodium, zinc, thiamin, riboflavin, and niacin, and a higher proportion (p < 0.05) met nutrient recommendations for protein, calcium, iron, zinc, thiamin, riboflavin, niacin, vitamin B6, and vitamin B12 compared to non-consumers. In conclusion, pregnant and lactating women generally have inadequate nutrient intakes from their diets. Beef consumers have higher intakes and adequacy for certain nutrients, many of which are inherently available in beef or in foods eaten with beef.

Does an antihypertensive diet cost more? Analysis from the Chinese Heart-Healthy diet trial.

OBJECTIVE: To determine whether the Chinese heart-healthy diet (Sichuan cuisine version) (CHH diet-SC) was more expensive than the conventional Sichuan diet and explore the food groups and nutrients that mainly affected the cost of CHH diet-SC. DESIGN: Cost analysis of 4-week intervention diets in the Sichuan center representing southwestern China in the CHH diet study. SETTING: A multicentre, parallel-group, single-blind, randomised feeding trial evaluating the efficacy of lowering blood pressure with the cuisine-based CHH diet. PARTICIPANTS: Totally, fifty-three participants with hypertension aged 25-75 years in the Sichuan center were randomised into the control group (n 26) or the CHH diet-SC group (n 27). RESULTS: The CHH diet-SC was more expensive than the control diet (¥27·87 ± 2·41 v. ¥25·18 ± 2·79 equals $3·90 ± 0·34 v. $3·52 ± 0·39, P < 0·001), and the incremental cost-effectiveness ratio for a 1-mm Hg systolic blood pressure reduction was ¥9·12 ($1·28). Intakes and the cost of seafood, dairy products, fruits, soybeans and nuts, whole grains and mixed beans were higher for the CHH diet-SC than for the control diet (P < 0·001). Intakes of vitamin B1, vitamin B6, vitamin C, Mg and phosphorus were positively correlated with the cost (P < 0·05). CONCLUSIONS: The CHH diet-SC costs more than the conventional Sichuan diet, partly due to the high cost of specific food groups. Positive correlations between the intakes of vitamin B1, vitamin B6, vitamin C, Mg, phosphorus and the dietary cost could be a direction to adjust the composition within the food groups to reduce the cost of the CHH diet-SC.

Neopterin, kynurenine metabolites, and indexes related to vitamin B6 are associated with post-stroke cognitive impairment: The Nor-COAST study.

BACKGROUND AND AIMS: We have previously shown that systemic inflammation was associated with post-stroke cognitive impairment (PSCI). Because neopterin, kynurenine pathway (KP) metabolites, and B6 vitamers are linked to inflammation, in our study we investigated whether those biomarkers were associated with PSCI. MATERIAL AND METHODS: The Norwegian Cognitive Impairment After Stroke study is a prospective multicenter cohort study of patients with acute stroke recruited from May 2015 through March 2017. Plasma samples of 422 participants (59 % male) with ischemic stroke from the index hospital stay and 3 months post-stroke were available for analyses of neopterin, KP metabolites, and B6 vitamers using liquid chromatography-tandem mass spectrometry. Mixed linear regression analyses adjusted for age, sex, and creatinine, were used to assess whether there were associations between those biomarkers and cognitive outcomes, measured by the Montreal Cognitive Assessment scale (MoCA) at 3-, 18-, and 36-month follow-up. RESULTS: Participants had a mean (SD) age of 72 (12) years, with a mean (SD) National Institutes of HealthStroke Scale score of 2.7 (3.6) at Day 1. Higher baseline values of quinolinic acid, PAr (i.e., an inflammatory marker based on vitamin B6 metabolites), and HKr (i.e., a marker of functional vitamin B6 status based on selected KP metabolites) were associated with lower MoCA score at 3, 18, and 36 months post-stroke (p < 0.01). Higher baseline concentrations of neopterin and 3-hydroxykynurenine were associated with lower MoCA scores at 18 and 36 months, and higher concentrations of xanthurenic acid were associated with higher MoCA score at 36 months (p < 0.01). At 3 months post-stroke, higher concentrations of neopterin and lower values of pyridoxal 5́-phosphate were associated with lower MoCA scores at 18- and 36-month follow-up, while lower concentrations of picolinic acid were associated with a lower MoCA score at 36 months (p < 0.01). CONCLUSION: Biomarkers and metabolites of systemic inflammation, including biomarkers of cellular immune activation, indexes of vitamin B6 homeostasis, and several neuroactive metabolites of the KP pathway, were associated with PSCI. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02650531.

Bacterial vitamin B6 is required for post-embryonic development in C. elegans.

Nutritional intake influences animal growth, reproductive capacity, and survival of animals. Under nutrition deficiency, animal developmental arrest occurs as an adaptive strategy to survive. However, the nutritional basis and the underlying nutrient sensing mechanism essential for animal regrowth after developmental arrest remain to be explored. In Caenorhabditis elegans, larvae undergo early developmental arrest are stress resistant, and they require certain nutrients to recover postembryonic development. Here, we investigated the developmental arrest in C. elegans feeding on Lactiplantibacillus plantarum, and the rescue of the diapause state with trace supplementation of Escherichia coli. We performed a genome-wide screen using 3983 individual gene deletion E. coli mutants and identified E. coli genes that are indispensable for C. elegans larval growth on originally not nutritionally sufficient bacteria L. plantarum. Among these crucial genes, we confirmed E. coli pdxH, and the downstream metabolite pyridoxal 5-P (PLP, Vitamin B6) as important nutritional factors for C. elegans postembryonic development. Transcriptome results suggest that bacterial pdxH affects host development by coordinating host metabolic processes and PLP binding. Additionally, the developmental arrest induced by the L. plantarum diet in worm does not depend on the activation of FoxO/DAF-16. Altogether, these results highlight the role of microbial metabolite PLP as a crucial cofactor to restore postembryonic development in C. elegans.

Higher dietary methyl donor micronutrient consumption is associated with higher muscle strength in adults: a cross-sectional study.

Methyl donor micronutrients might affect muscle strength via DNA methylation. We aimed to evaluate the combined relationship of dietary methyl donor micronutrients containing betaine, choline, methionine, vitamin B12, vitamin B6 and folate on muscle strength. This cross-sectional study was conducted on 267 subjects including 113 men and 154 women. Dietary intake of micronutrients was assessed utilising a validated 168-item semi-quantitative FFQ, and methyl donor micronutrient score (MDMS) was calculated. The muscle strength of the participants was measured using a digital handgrip dynamometer. The association was determined using linear regression analysis. The mean age of participants was 36·8 ± 13·2 years. After taking into account potential confounding variables, there was no significant association between dietary methyl donor micronutrient score (MDMS) and the mean left-hand muscle strength (ß: 0·07, se: 0·05, P = 0·07); however, the changes were significant in the mean right-hand muscle strength (ß: 0·09, se: 0·04, P = 0·03). There was also a significant positive relationship between mean muscle strength and methyl donors' intake after fully adjusting for potential confounders (ß: 0·08, se: 0·04, P = 0·04). In conclusion, our findings revealed that higher dietary methyl donor micronutrient consumption is associated with enhanced muscle strength. As a result, advice on a higher intake of methyl donor-rich foods including grains, nuts, dairy products and seafood might be recommended by dietitians as a general guideline to adhere to. Additional prospective studies are needed to confirm the findings.

PDX proteins from Arabidopsis thaliana as novel substrates of cathepsin B: implications for vitamin B6 biosynthesis regulation.

Vitamin B6 is a critical molecule for metabolism, development, and stress sensitivity in plants. It is a cofactor for numerous biochemical reactions, can serve as an antioxidant, and has the potential to increase tolerance against both biotic and abiotic stressors. Due to the importance of vitamin B6, its biosynthesis is likely tightly regulated. Plants can synthesize vitamin B6 de novo via the concerted activity of Pyridoxine Biosynthesis Protein 1 (PDX1) and PDX2. Previously, PDX proteins have been identified as targets for ubiquitination, indicating they could be marked for degradation by two highly conserved pathways: the Ubiquitin Proteasome Pathway (UPP) and the autophagy pathway. Initial experiments show that PDXs are in fact degraded, but surprisingly, in a ubiquitin-independent manner. Inhibitor studies pointed toward cathepsin B, a conserved lysosomal cysteine protease, which is implicated in both programed cell death and autophagy in humans and plants. In plants, cathepsin Bs are poorly described, and no confirmed substrates have been identified. Here, we present PDX proteins from Arabidopsis thaliana as interactors and substrates of a plant Cathepsin B. These findings not only describe a novel cathepsin B substrate in plants, but also provide new insights into how plants regulate de novo biosynthesis of vitamin B6.

Pyridoxal 5'-Phosphate Biosynthesis by Pyridox-(am)-ine 5'-Phosphate Oxidase: Species-Specific Features.

Enzymes reliant on pyridoxal 5'-phosphate (PLP), the metabolically active form of vitamin B6, hold significant importance in both biology and medicine. They facilitate various biochemical reactions, particularly in amino acid and neurotransmitter metabolisms. Vitamin B6 is absorbed by organisms in its non-phosphorylated form and phosphorylated within cells via pyridoxal kinase (PLK) and pyridox-(am)-ine 5'-phosphate oxidase (PNPOx). The flavin mononucleotide-dependent PNPOx enzyme converts pyridoxine 5'-phosphate and pyridoxamine 5'-phosphate into PLP. PNPOx is vital for both biosynthesis and salvage pathways in organisms producing B6 vitamers. However, for those depending on vitamin B6 as a nutrient, PNPOx participates only in the salvage pathway. Transferring the PLP produced via PNPOx to client apo-enzymes is indispensable for their catalytic function, proper folding and targeting of specific organelles. PNPOx activity deficiencies due to inborn errors lead to severe neurological pathologies, particularly neonatal epileptic encephalopathy. PNPOx maintains PLP homeostasis through highly regulated mechanisms, including structural alterations throughout the catalytic cycle and allosteric PLP binding, influencing substrate transformation at the active site. Elucidation at the molecular level of the mechanisms underlying PNPOx activity deficiencies is a requirement to develop personalized approaches to treat related disorders. Finally, despite shared features, the few PNPOx enzymes molecularly and functionally studied show species-specific regulatory properties that open the possibility of targeting it in pathogenic organisms.

Drug Efficacy in the Treatment of Antipsychotic-Induced Akathisia: A Systematic Review and Network Meta-Analysis.

Importance: Antipsychotic-induced akathisia (AIA) occurs in 14% to 35% of patients treated with antipsychotics and is associated with increased suicide and decreased adherence in patients with schizophrenia. However, no comprehensive review and network meta-analysis has been conducted to compare the efficacy of treatments for AIA. Objective: To compare the efficacy associated with AIA treatments. Data Sources: Three databases (MEDLINE, Web of Science, and Google Scholar) were systematically searched by multiple researchers for double-blind randomized clinical trials (RCTs) comparing active drugs for the treatment of AIA with placebo or another treatment between May 30 and June 18, 2023. Study Selection: Selected studies were RCTs that compared adjunctive drugs for AIA vs placebo or adjunctive treatment in patients treated with antipsychotics fulfilling the criteria for akathisia, RCTs with sample size of 10 patients or more, only trials in which no additional drugs were administered during the study, and RCTs that used a validated akathisia score. Trials with missing data for the main outcome (akathisia score at the end points) were excluded. Data Extraction and Synthesis: Data extraction and synthesis were performed, estimating standardized mean differences (SMDs) through pairwise and network meta-analysis with a random-effects model. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed. Main Outcomes and Measures: The primary outcome was the severity of akathisia measured by a validated scale at the last available end point. Results: Fifteen trials involving 492 participants compared 10 treatments with placebo. Mirtazapine (15 mg/d for ≥5 days; SMD, -1.20; 95% CI, -1.83 to -0.58), biperiden (6 mg/d for ≥14 days; SMD, -1.01; 95% CI, -1.69 to -0.34), vitamin B6 (600-1200 mg/d for ≥5 days; SMD, -0.92; 95% CI, -1.57 to -0.26), trazodone (50 mg/d for ≥5 days; SMD, -0.84; 95% CI, -1.54 to -0.14), mianserin (15 mg/d for ≥5 days; SMD, -0.81; 95% CI, -1.44 to -0.19), and propranolol (20 mg/d for ≥6 days; SMD, -0.78; 95% CI, -1.35 to -0.22) were associated with greater efficacy than placebo, with low to moderate heterogeneity (I2 = 34.6%; 95% CI, 0.0%-71.1%). Cyproheptadine, clonazepam, zolmitriptan, and valproate did not yield significant effects. Eight trials were rated as having low risk of bias; 2, moderate risk; and 5, high risk. Sensitivity analyses generally confirmed the results for all drugs except for cyproheptadine and propranolol. No association between effect sizes and psychotic severity was found. Conclusions and Relevance: In this systematic review and network meta-analysis, mirtazapine, biperiden, and vitamin B6 were associated with the greatest efficacy for AIA, with vitamin B6 having the best efficacy and tolerance profile. Trazodone, mianserin, and propranolol appeared as effective alternatives with slightly less favorable efficacy and tolerance profiles. These findings should assist prescribers in selecting an appropriate medication for treating AIA.