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1,468 result(s) for "Metabolic Networks and Pathways - drug effects"
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Targeting the Intestinal Microbiota to Prevent Type 2 Diabetes and Enhance the Effect of Metformin on Glycaemia: A Randomised Controlled Pilot Study
Early treatment may prevent or delay the onset of type 2 diabetes mellitus (T2DM) in individuals who are at high risk. Lifestyle interventions and the hypoglycemic drug metformin have been shown to reduce T2DM incidence. The effectiveness of such interventions may be enhanced by targeting environmental factors such as the intestinal microbiota, which has been proven to predict the response to lifestyle interventions and play a part in mediating the glucose-lowering effects of metformin. Shifts in the intestinal microbiota “towards a more balanced state” may promote glucose homeostasis by regulating short-chain fatty acids’ production. This study aimed to investigate the safety and effect of a multi-strain probiotic on glycemic, inflammatory, and permeability markers in adults with prediabetes and early T2DM and to assess whether the probiotic can enhance metformin’s effect on glycaemia. A randomised controlled pilot study was conducted in 60 adults with a BMI ≥ 25 kg/m2 and with prediabetes or T2DM (within the previous 12 months). The participants were randomised to a multi-strain probiotic (L. plantarum, L. bulgaricus, L. gasseri, B. breve, B. animalis sbsp. lactis, B. bifidum, S. thermophilus, and S. boulardii) or placebo for 12 weeks. Analyses of the primary outcome (fasting plasma glucose) and secondary outcomes, including, but not limited to, circulating lipopolysaccharide, zonulin, and short chain fatty acids and a metagenomic analysis of the fecal microbiome were performed at baseline and 12 weeks post-intervention. The results showed no significant differences in the primary and secondary outcome measures between the probiotic and placebo group. An analysis of a subgroup of participants taking metformin showed a decrease in fasting plasma glucose, HbA1c, insulin resistance, and zonulin; an increase in plasma butyrate concentrations; and an enrichment of microbial butyrate-producing pathways in the probiotic group but not in the placebo group. Probiotics may act as an adjunctive to metformin by increasing the production of butyrate, which may consequently enhance glucose management.
Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men
Background The andropause is associated with declines in serum testosterone (T), loss of muscle mass (sarcopenia), and frailty. Two major interventions purported to offset sarcopenia are anabolic steroid therapies and resistance exercise training (RET). Nonetheless, the efficacy and physiological and molecular impacts of T therapy adjuvant to short‐term RET remain poorly defined. Methods Eighteen non‐hypogonadal healthy older men, 65–75 years, were assigned in a random double‐blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole‐body RET (three sets of 8–10 repetitions at 80% one‐repetition maximum). Subjects underwent dual‐energy X‐ray absorptiometry, ultrasound of vastus lateralis (VL) muscle architecture, and knee extensor isometric muscle force tests; VL muscle biopsies were taken to quantify myogenic/anabolic gene expression, anabolic signalling, muscle protein synthesis (D2O), and breakdown (extrapolated). Results Testosterone adjuvant to RET augmented total fat‐free mass (P=0.007), legs fat‐free mass (P=0.02), and appendicular fat‐free mass (P=0.001) gains while decreasing total fat mass (P=0.02). Augmentations in VL muscle thickness, fascicle length, and quadriceps cross‐section area with RET occured to a greater extent in T (P < 0.05). Sum strength (P=0.0009) and maximal voluntary contract (e.g. knee extension at 70°) (P=0.002) increased significantly more in the T group. Mechanistically, both muscle protein synthesis rates (T: 2.13 ± 0.21%·day−1 vs. P: 1.34 ± 0.13%·day−1, P=0.0009) and absolute breakdown rates (T: 140.2 ± 15.8 g·day−1 vs. P: 90.2 ± 11.7 g·day−1, P=0.02) were elevated with T therapy, which led to higher net turnover and protein accretion in the T group (T: 8.3 ± 1.4 g·day−1 vs. P: 1.9 ± 1.2 g·day−1, P=0.004). Increases in ribosomal biogenesis (RNA:DNA ratio); mRNA expression relating to T metabolism (androgen receptor: 1.4‐fold; Srd5a1: 1.6‐fold; AKR1C3: 2.1‐fold; and HSD17β3: two‐fold); insulin‐like growth factor (IGF)‐1 signalling [IGF‐1Ea (3.5‐fold) and IGF‐1Ec (three‐fold)] and myogenic regulatory factors; and the activity of anabolic signalling (e.g. mTOR, AKT, and RPS6; P < 0.05) were all up‐regulated with T therapy. Only T up‐regulated mitochondrial citrate synthase activity (P=0.03) and transcription factor A (1.41 ± 0.2‐fold, P=0.0002), in addition to peroxisome proliferator‐activated receptor‐γ co‐activator 1‐α mRNA (1.19 ± 0.21‐fold, P=0.037). Conclusions Administration of T adjuvant to RET enhanced skeletal muscle mass and performance, while up‐regulating myogenic gene programming, myocellular translational efficiency and capacity, collectively resulting in higher protein turnover, and net protein accretion. T coupled with RET is an effective short‐term intervention to improve muscle mass/function in older non‐hypogonadal men.
Neo-CheckRay: radiation therapy and adenosine pathway blockade to increase benefit of immuno-chemotherapy in early stage luminal B breast cancer, a randomized phase II trial
Background Residual breast cancer after neo-adjuvant chemotherapy (NACT) predicts disease outcome and is a surrogate for survival in aggressive breast cancer (BC) subtypes. Pathological complete response (pCR) rate, however, is lower for luminal B BC in comparison to the triple negative (TNBC) and HER2+ subtypes. The addition of immune checkpoint blockade (ICB) to NACT has the potential to increase pCR rate but is hampered by the lower immunogenicity of luminal B BC. Novel strategies are needed to stimulate the immune response and increase the response rate to ICB in luminal B BC. Methods The Neo-CheckRay trial is a randomized phase II trial investigating the impact of stereotactic body radiation therapy (SBRT) to the primary breast tumor in combination with an anti-CD73 (oleclumab) to increase response to anti PD-L1 (durvalumab) and NACT. The trial is designed as a three-arm study: NACT + SBRT +/− durvalumab +/− oleclumab. The result at surgery will be evaluated using the residual cancer burden (RCB) index as the primary endpoint. Six patients will be included in a safety run-in, followed by a randomized phase II trial that will include 136 evaluable patients in 3 arms. Inclusion is limited to luminal B breast cancers that are MammaPrint genomic high risk. Discussion combination of ICB with chemotherapy in luminal B BC might benefit from immune priming agents to increase the response rate. As none have been identified so far, this phase II trial will evaluate SBRT and oleclumab as potential immune priming candidates. Trial registration trial registered on ClinicalTrials.gov ( NCT03875573 ) on March 14th, 2019.
Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial
Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B6 metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.
Procalcitonin metabolomics in the critically ill reveal relationships between inflammation intensity and energy utilization pathways
Procalcitonin is a biomarker of systemic inflammation and may have importance in the immune response. The metabolic response to elevated procalcitonin in critical illness is not known. The response to inflammation is vitally important to understanding metabolism alterations during extreme stress. Our aim was to determine if patients with elevated procalcitonin have differences in the metabolomic response to early critical illness. We performed a metabolomics study of the VITdAL-ICU trial where subjects received high dose vitamin D 3 or placebo. Mixed-effects modeling was used to study changes in metabolites over time relative to procalcitonin levels adjusted for age, Simplified Acute Physiology Score II, admission diagnosis, day 0 25-hydroxyvitamin D level, and the 25-hydroxyvitamin D response to intervention. With elevated procalcitonin, multiple members of the short and medium chain acylcarnitine, dicarboxylate fatty acid, branched-chain amino acid, and pentose phosphate pathway metabolite classes had significantly positive false discovery rate corrected associations. Further, multiple long chain acylcarnitines and lysophosphatidylcholines had significantly negative false discovery rate corrected associations with elevated procalcitonin. Gaussian graphical model analysis revealed functional modules specific to elevated procalcitonin. Our findings show that metabolite differences exist with increased procalcitonin indicating activation of branched chain amino acid dehydrogenase and a metabolic shift.
Role of B vitamins in modulating homocysteine and metabolic pathways linked to brain atrophy: Metabolomics insights from the VITACOG trial
INTRODUCTION Elevated total homocysteine (tHcy) is a major predictor of brain atrophy, cognitive decline, and Alzheimer's disease (AD) progression. The VITACOG trial, a randomized, placebo‐controlled study in mild cognitive impairment (MCI), previously showed that B vitamin supplementation lowered tHcy, slowing brain atrophy and cognitive decline; however, the underlying mechanisms remained unclear. METHODS We used untargeted, multi‐platform metabolomics, with nuclear magnetic resonance and liquid chromatography‐mass spectrometry to analyze serum samples from 89 B vitamin–treated and 84 placebo‐treated MCI participants over a 2 year follow‐up period. RESULTS Multivariate modeling distinguished treated from placebo groups with 91.2 ± 1.8% accuracy. B vitamin supplementation induced significant metabolic reprogramming, lowering quinolinic acid, α‐ketoglutarate, α‐ketobutyrate, glucose, and glutamate. DISCUSSION These findings reveal that B vitamins influence metabolic pathways beyond tHcy reduction, particularly the tricarboxylic acid cycle and glutamine–glutamate cycling, critical for brain energy homeostasis and neurotransmission. This metabolic signature supports B vitamin supplementation as a strategy for slowing MCI progression. Highlights Nuclear magnetic resonance and multi‐platform liquid chromatography tandem mass spectrometry metabolomics were performed on serum samples from 89 B vitamin–treated and 84 placebo participants in the VITACOG trial. Multi‐platform metabolomics revealed B vitamin–driven metabolic reprogramming, achieving 91% classification accuracy. B vitamin supplementation modulates key neuroprotective metabolic pathways. Regulation of energy metabolism and neurotransmission by B vitamins contributes to brain health in elderly individuals. B vitamins demonstrate potential as an adjunct therapy in mild cognitive impairment, potentially mitigating progression to Alzheimer's disease.
Baseline metabolic profiles of early rheumatoid arthritis patients achieving sustained drug-free remission after initiating treat-to-target tocilizumab, methotrexate, or the combination: insights from systems biology
Background We previously identified, in newly diagnosed rheumatoid arthritis (RA) patients, networks of co-expressed genes and proteomic biomarkers associated with achieving sustained drug-free remission (sDFR) after treatment with tocilizumab- or methotrexate-based strategies. The aim of this study was to identify, within the same patients, metabolic pathways important for achieving sDFR and to subsequently study the complex interactions between different components of the biological system and how these interactions might affect the therapeutic response in early RA. Methods Serum samples were analyzed of 60 patients who participated in the U-Act-Early trial (ClinicalTrials.gov number NCT01034137) and initiated treatment with methotrexate, tocilizumab, or the combination and who were thereafter able to achieve sDFR ( n  = 37); as controls, patients were selected who never achieved a drug-free status ( n  = 23). Metabolomic measurements were performed using mass spectrometry on oxidative stress, amine, and oxylipin platforms covering various compounds. Partial least square discriminant analyses (PLSDA) were performed to identify, per strategy arm, relevant metabolites of which the biological pathways were studied. In addition, integrative analyses were performed correlating the previously identified transcripts and proteins with the relevant metabolites. Results In the tocilizumab plus methotrexate, tocilizumab, and methotrexate strategy, respectively, 19, 13, and 12 relevant metabolites were found, which were subsequently used for pathway analyses. The most significant pathway in the tocilizumab plus methotrexate strategy was “histidine metabolism” ( p  < 0.001); in the tocilizumab strategy it was “arachidonic acid metabolism” ( p  = 0.018); and in the methotrexate strategy it was “arginine and proline metabolism” ( p  = 0.022). These pathways have treatment-specific drug interactions with metabolites affecting either the signaling of interleukin-6, which is inhibited by tocilizumab, or affecting protein synthesis from amino acids, which is inhibited by methotrexate. Conclusion In early RA patients treated-to-target with a tocilizumab- or methotrexate-based strategy, several metabolites were found to be associated with achieving sDFR. In line with our previous observations, by analyzing relevant transcripts and proteins within the same patients, the metabolic profiles were found to be different between the strategy arms. Our metabolic analysis further supports the hypothesis that achieving sDFR is not only dependent on predisposing biomarkers, but also on the specific treatment that has been initiated. Trial registration ClinicalTrials.gov, NCT01034137 . Registered on January 2010
Navigating metabolic pathways to enhance antitumour immunity and immunotherapy
The development of immunotherapies over the past decade has resulted in a paradigm shift in the treatment of cancer. However, the majority of patients do not benefit from immunotherapy, presumably owing to insufficient reprogramming of the immunosuppressive tumour microenvironment (TME) and thus limited reinvigoration of antitumour immunity. Various metabolic machineries and nutrient-sensing mechanisms orchestrate the behaviour of immune cells in response to nutrient availability in the TME. Notably, tumour-infiltrating immune cells typically experience metabolic stress as a result of the dysregulated metabolic activity of tumour cells, leading to impaired antitumour immune responses. Moreover, the immune checkpoints that are often exploited by tumour cells to evade immunosurveillance have emerging roles in modulating the metabolic and functional activity of T cells. Thus, repurposing of drugs targeting cancer metabolism might synergistically enhance immunotherapy via metabolic reprogramming of the TME. In addition, interventions targeting the metabolic circuits that impede antitumour immunity have been developed, with several clinical trials underway. Herein, we discuss how these metabolic circuits regulate antitumour immunity and the possible approaches to targeting these pathways in the context of anticancer immunotherapy. We also describe hypothetical combination treatments that could be used to better unleash the potential of adoptive cell therapies by enhancing T cell metabolism.The metabolic conditions in tumours can result in phenotypic reprogramming of non-tumour cells, including immune cells, in the tumour microenvironment. This Review provides an overview of the pathways of cancer metabolism that intersect with immunometabolism, typically resulting in immunosuppression, with a focus on how these metabolic pathways could be targeted in order to enhance anticancer immunity and immunotherapy.
Discovery and inhibition of an interspecies gut bacterial pathway for Levodopa metabolism
The efficacy of l -dopa treatment for Parkinson's disease is hugely variable between individuals, depending on the composition of their microbiota. l -Dopa is decarboxylated into active dopamine, but if the gut microbiota metabolize l -dopa before it crosses the blood-brain barrier, medication is ineffective. Maini Rekdal et al. found that different species of bacterium are involved in l -dopa metabolism (see the Perspective by O'Neill). Tyrosine decarboxylase (TDC) from Enterococcus faecalis and dopamine dehydroxylase (Dadh) from Eggerthella lenta A2 sequentially metabolized l -dopa into m -tyramine. The microbial l -dopa decarboxylase can be inactivated by ( S )-α-fluoromethyltyrosine (AFMT), which indicates possibilities for developing combinations of Parkinson's drugs to circumvent microbial inactivation. Science , this issue p. eaau6323 ; see also p. 1030 An interspecies metabolic pathway allows human gut bacteria to metabolize the Parkinson’s drug levodopa. The human gut microbiota metabolizes the Parkinson’s disease medication Levodopa ( l -dopa), potentially reducing drug availability and causing side effects. However, the organisms, genes, and enzymes responsible for this activity in patients and their susceptibility to inhibition by host-targeted drugs are unknown. Here, we describe an interspecies pathway for gut bacterial l -dopa metabolism. Conversion of l -dopa to dopamine by a pyridoxal phosphate-dependent tyrosine decarboxylase from Enterococcus faecalis is followed by transformation of dopamine to m -tyramine by a molybdenum-dependent dehydroxylase from Eggerthella lenta . These enzymes predict drug metabolism in complex human gut microbiotas. Although a drug that targets host aromatic amino acid decarboxylase does not prevent gut microbial l -dopa decarboxylation, we identified a compound that inhibits this activity in Parkinson’s patient microbiotas and increases l -dopa bioavailability in mice.
LDHA-mediated ROS generation in chondrocytes is a potential therapeutic target for osteoarthritis
The contribution of inflammation to the chronic joint disease osteoarthritis (OA) is unclear, and this lack of clarity is detrimental to efforts to identify therapeutic targets. Here we show that chondrocytes under inflammatory conditions undergo a metabolic shift that is regulated by NF-κB activation, leading to reprogramming of cell metabolism towards glycolysis and lactate dehydrogenase A (LDHA). Inflammation and metabolism can reciprocally modulate each other to regulate cartilage degradation. LDHA binds to NADH and promotes reactive oxygen species (ROS) to induce catabolic changes through stabilization of IκB-ζ, a critical pro-inflammatory mediator in chondrocytes. IκB-ζ is regulated bi-modally at the stages of transcription and protein degradation. Overall, this work highlights the function of NF-κB activity in the OA joint as well as a ROS promoting function for LDHA and identifies LDHA as a potential therapeutic target for OA treatment. Chondrocytes have altered cellular metabolism in the context of osteoarthritis, but whether and how these changes are associated with inflammation is a controversial area. Here the authors show that inflammatory NF-κB signalling drives a glycolytic shift in chondrocytes and the production of ROS, which drives cartilage catabolism.