acetyl-CoA Synthetase Research Articles

Acylations in cardiovascular diseases: advances and perspectives.

Acylations in cardiovascular diseases: advances and perspectives.

Improving the specificity of E. coli acetate/propionate exclusion biosensors via iterative engineering

Real-time monitoring of key performance indicator analytes such as acetate and propionate within anaerobic digestors (AD) is required for optimum biogas production. In this paper the further refinement of acetate and propionate whole cell (E. coli) exclusion biosensors is reported following an iterative process in which key metabolites that might interfere with O2-uptake measurements are identified and genes required for their catabolism are knocked out (exclusion). Analysis of biological leachate from an AD reactor treating lignocellulosic material revealed the presence of formate, which was subsequently shown to elicit a response in previously developed E. coli biosensor strains. P1 phage transduction was employed to delete two genes encoding formate dehydrogenase, fdoH and fdnH, to eliminate formate catabolism. Deletion of these genes from the propionate biosensor strain W:ldgyepak abolished interference from formate and enabled accurate determination of propionate concentrations in biological leachate. However, the acetate biosensing strain E1/pGDR11-acs, despite not having any response to formate, responded to propionate. It was likely that this was a result of the promiscuity of the wild type acetyl CoA synthetase, which was replaced with Acs2 from Saccharomyces cerevisiae, resolving the problem and enabling acetate determination with the biosensor. Acetate and propionate concentrations in authentic leachate influent were estimated to be 26.5 mM and 65.5 mM, respectively, using the biosensor, and 26.6 and 70 mM, respectively, by HPLC, demonstrating the accuracy and specificity of the refined biosensor.

Acetyl-CoA Synthetase 2 as a Therapeutic Target in Tumor Metabolism.

Simple SummaryAcetyl-CoA Synthetase 2 (ACSS2) is highly expressed in a variety of tumors, which is very important for tumor growth, proliferation, invasion, and metastasis in the nutritional stress microenvironment. Studies have proven that ACSS2 inhibitors can be effective in halting cancer growth and can be combined with other antineoplastic drugs to reduce drug resistance. This article mainly reviews the mechanism of ACSS2-promoting tumor growth from many aspects and the prospect of clinical application of targeted inhibitors.Acetyl-CoA Synthetase 2 (ACSS2) belongs to a member of the acyl-CoA short-chain synthase family, which can convert acetate in the cytoplasm and nucleus into acetyl-CoA. It has been proven that ACSS2 is highly expressed in glioblastoma, breast cancer, liver cancer, prostate cancer, bladder cancer, renal cancer, and other tumors, and is closely related to tumor stage and the overall survival rate of patients. Accumulating studies show that hypoxia and a low serum level induce ACSS2 expression to help tumor cells cope with this nutrient-poor environment. The potential mechanisms are associated with the ability of ACSS2 to promote the synthesis of lipids in the cytoplasm, induce the acetylation of histones in the nucleus, and facilitate the expression of autophagy genes. Novel-specific inhibitors of ACSS2 are developed and confirmed to the effectiveness in pre-clinical tumor models. Targeting ACSS2 may provide novel approaches for tumor treatment. This review summarizes the biological function of ACSS2, its relation to survival and prognosis in different tumors, and how ACSS2 mediates different pathways to promote tumor metastasis, invasion, and drug resistance.

Ascorbic acid prevents yellowing of fresh-cut yam by regulating pigment biosynthesis and energy metabolism

The fresh-cut yam would turn yellow under 25 ℃ for 36 h, which could reduce consumer’s acceptance. This study aimed to investigate the mechanism by which 2% ascorbic acid inhibits yellowing of fresh-cut yam by detecting enzyme activities, gene expressions and metabolites. Ascorbic acid treatment was found to decrease ATPase activities, ATP content, and energy charge. The transcriptional expression levels of citrate synthase, acetyl-CoA carboxylase, and acetyl-CoA synthetase, which are involved in the tricarboxylic acid cycle, were also decreased by ascorbic acid treatment, thus blocking the supply of precursors and energy for pigment biosynthesis. In addition, ascorbic acid effectively inhibited the formation of carotenoids, flavonoids, and bisdemethoxycurcumin, as indicated by lower metabolic levels, decreased enzyme activities, and downregulated transcriptional expressions. Thus, ascorbic acid prevents yellowing in fresh-cut yam by reducing the energy metabolism level as well as inhibiting pigment (carotenoids, flavonoids, bisdemethoxycurcumin) biosynthesis pathways. Accordingly, ascorbic acid treatment is a safe, effective, and cheap method for inhibiting fresh-cut yam yellowing.

Improvement of acetyl-CoA supply and glucose utilization increases l-leucine production in Corynebacterium glutamicum.

l-Leucine is an important essential amino acid with multiple industrial applications, whose market requirements cannot be met because of the low productivity. In this study, a strain of Corynebacterium glutamicum with high l-leucine yield was constructed to enhance its acetyl-CoA supply and glucose utilization. One copy of leuA under the control of a strong promoter was incorporated into the C. glutamicum genome. Then, acetyl-CoA supply was increased by the integration of a terminator in front of gltA and by the heterogeneous overexpression of acetyl-CoA synthetase (ACS) and deacetylase (CobB) derived from Escherichia coli. Next, the transcriptional regulator sugR was deleted to enhance glucose uptake via a phosphotransferase-mediated route. In fed-batch fermentation performed in a 5-L reactor, l-leucine production of 40.11 ± 0.73g L-1 was achieved under the optimized conditions, with an l-leucine yield and productivity of 0.25g g-1 glucose and 0.59g L-1 h-1 , respectively. These results represent a significant improvement in the l-leucine production of C. glutamicum, indicating that the process possesses high potential for industrial application. These strategies can be also expanded to enable the production of other value-added biochemicals derived from the intermediates of central carbon metabolism.

Adaptive Laboratory Evolution of Halomonas bluephagenesis Enhances Acetate Tolerance and Utilization to Produce Poly(3-hydroxybutyrate).

Acetate is a promising economical and sustainable carbon source for bioproduction, but it is also a known cell-growth inhibitor. In this study, adaptive laboratory evolution (ALE) with acetate as selective pressure was applied to Halomonas bluephagenesis TD1.0, a fast-growing and contamination-resistant halophilic bacterium that naturally accumulates poly(3-hydroxybutyrate) (PHB). After 71 transfers, the evolved strain, B71, was isolated, which not only showed better fitness (in terms of tolerance and utilization rate) to high concentrations of acetate but also produced a higher PHB titer compared with the parental strain TD1.0. Subsequently, overexpression of acetyl-CoA synthetase (ACS) in B71 resulted in a further increase in acetate utilization but a decrease in PHB production. Through whole-genome resequencing, it was speculated that genetic mutations (single-nucleotide variation (SNV) in phaB, mdh, and the upstream of OmpA, and insertion of TolA) in B71 might contribute to its improved acetate adaptability and PHB production. Finally, in a 5 L bioreactor with intermittent feeding of acetic acid, B71 was able to produce 49.79 g/L PHB and 70.01 g/L dry cell mass, which were 147.2% and 82.32% higher than those of TD1.0, respectively. These results highlight that ALE provides a reliable method to harness H. bluephagenesis to metabolize acetate for the production of PHB or other high-value chemicals more efficiently.

OGT/CDK5/ACSS2 Axis Regulates Breast Cancer Brain Metastasis Growth

Onset of brain metastases (BMs) in breast cancer patients is considered an end‐stage event, with no effective drug treatment and a median survival after diagnosis measured in months. Thus, there is an urgent need to develop novel treatment strategies. Metastatic breast cancer cells colonizing the brain encounter adverse ‘nutritional environment’, as the levels of key metabolic fuels such as glucose are much lower, in part because they are avidly consumed by neurons. To overcome this challenge, brain‐metastatic cancer cells rely on acetate as a fuel source and convert it into acetyl‐CoA via upregulation of acetyl‐CoA synthetase 2 (ACSS2) enzyme. We have previously shown that brain tumors increase the nutrient sensing post‐translational modification O‐GlcNAcylation and O‐GlcNAc transferase (OGT) levels to regulate acetate metabolism into acetyl‐CoA via increased phosphorylation of ACSS2 on Ser‐267 in a cyclin dependent kinase 5 (CDK5)‐dependent manner, increasing brain tumor growth. Here, we show that human breast cancer cells selected to metastasize to the brain contain increased levels of O‐GlcNAc, OGT and ACSS2‐Ser267 phosphorylation compared to parental cells and show that human breast cancer brain metastatic patient samples contain elevated ACSS2‐Ser‐267 levels. Moreover, overexpression of OGT or ACSS2‐S267D phospho‐mimetic mutant confer a growth advantage on brain metastatic breast cancer cells in an in vivo intracranial xenograft model, may be due to an increase in lipogenic proteins. Additionally, we show that pharmacologically targeting CDK5 and ACSS2 with small molecule inhibitors reduces tumor growth in a novel orthotopic ex vivo brain slice model. These results suggest a crucial role for OGT/CDK5/ACSS2 signaling in transducing nutritional state to regulate acetate metabolism in breast cancer BM cells and identify CDK5 and ACSS2 as novel therapeutic targets for treatment of breast cancer brain metastasis.

Preclinical characterization and target validation of the antimalarial pantothenamide MMV693183

Drug resistance and a dire lack of transmission-blocking antimalarials hamper malaria elimination. Here, we present the pantothenamide MMV693183 as a first-in-class acetyl-CoA synthetase (AcAS) inhibitor to enter preclinical development. Our studies demonstrate attractive drug-like properties and in vivo efficacy in a humanized mouse model of Plasmodium falciparum infection. The compound shows single digit nanomolar in vitro activity against P. falciparum and P. vivax clinical isolates, and potently blocks P. falciparum transmission to Anopheles mosquitoes. Genetic and biochemical studies identify AcAS as the target of the MMV693183-derived antimetabolite, CoA-MMV693183. Pharmacokinetic-pharmacodynamic modelling predict that a single 30 mg oral dose is sufficient to cure a malaria infection in humans. Toxicology studies in rats indicate a > 30-fold safety margin in relation to the predicted human efficacious exposure. In conclusion, MMV693183 represents a promising candidate for further (pre)clinical development with a novel mode of action for treatment of malaria and blocking transmission.

Regulation of Peroxisome Homeostasis by Post-Translational Modification in the Methylotrophic Yeast Komagataella phaffii.

The methylotrophic yeast Komagataella phaffii (synoym Pichia pastoris) can grow on methanol with an associated proliferation of peroxisomes, which are subsequently degraded by pexophagy upon depletion of methanol. Two cell wall integrity and stress response component (WSC) family proteins (Wsc1 and Wsc3) sense the extracellular methanol concentration and transmit the methanol signal to Rom2. This stimulates the activation of transcription factors (Mxr1, Trm1, and Mit1 etc.), leading to the induction of methanol-metabolizing enzymes (methanol-induced gene expression) and synthesis of huge peroxisomes. Methanol-induced gene expression is repressed by the addition of ethanol (ethanol repression). This repression is not conducted directly by ethanol but rather by acetyl-CoA synthesized from ethanol by sequential reactions, including alcohol and aldehyde dehydrogenases, and acetyl-CoA synthetase. During ethanol repression, Mxr1 is inactivated by phosphorylation. Peroxisomes are degraded by pexophagy on depletion of methanol and this event is triggered by phosphorylation of Atg30 located at the peroxisome membrane. In the presence of methanol, Wsc1 and Wsc3 repress pexophagy by transmitting the methanol signal via the MAPK cascade to the transcription factor Rlm1, which induces phosphatases involved in dephosphorylation of Atg30. Upon methanol consumption, repression of Atg30 phosphorylation is released, resulting in initiation of pexophagy. Physiological significance of these machineries involved in peroxisome homeostasis and their post-translational modification is also discussed in association with the lifestyle of methylotrophic yeast in the phyllosphere.

Efectos del alcohol sobre el metabolismo a través de la acetil-Coenzima A sintetasa: revisión sistemática y metanálisis

Objective: To evaluate the effects of alcohol on the metabolism of the acetyl-Coenzyme A synthetase pathway. Methods: For this meta-analysis, articles published up to December 2019 were searched and the levels of phosphorylated adenosine, acetate, acetyl-CoA, acetoacetate and acetyl-CoA activity were evaluated. The standardized mean difference and the weighted mean from the meta-analysis were compared using the random model. Results: Alcohol promoted an increase in the levels of adenosine triphosphate, adenosine diphosphate, adenosine monophosphate and inorganic phosphate (odds ratio [OR] = 1.16; 95% confidence interval [CI], 0.42, 2 .10; p = 0.003). In addition, the levels of acetate, acetoacetate and acetyl-CoA increased due to alcohol (OR = 2.05; 95% CI, 1.07, 3.04; p < 0.0001), however, with high heterogeneity (I² = 77%). Acetyl-CoA synthetase (ACSS2) activity increased after alcohol administration (OR = 2.07; 95% CI, 0.16, 3.97; p = 0.03), with high heterogeneity (I² = 88%). Final considerations: Alcohol has a supplementary effect on this metabolic pathway, but in a restricted way. Furthermore, ACSS2 activity increased after exposure to alcohol. However, these effects of alcohol were time dependent.

A clinical case of X-linked adrenoleukodystrophy in a 9-year-old boy

X-linked adrenoleukodystrophy belongs to peroxisomal disorders characterized by combined damage to the nervous system and adrenal glands and often leading to death. This hereditary disease results in mutations in the ABCD1 gene, leading to ineffective β-oxidation of fatty acids following a decrease in the activity of acetyl-CoA synthetase of their long chains. Accumulation of acyl-CoA derivatives of fatty acids takes place, which affect the physicochemical properties of cell membranes.We have described a clinical case of X-linked adrenoleukodystrophy in a 9-year-old boy with the primary manifestation of the disease at the age of 7 years and 10 months in form of enterovirus encephalitis.Early diagnosis, prenatal screening of adrenoleukodystrophy for performing gene-specific therapy, slowing the progression of the disease, and prolonging the life of the patient with the diagnosis of a rare hereditary disease are required.

Poly-3-hydroxybutyrate production in acetate minimal medium using engineered Methylorubrum extorquens AM1

Acetate is regarded as a sustainable microbial feedstock that is synthesized from biowastes such as synthesis gas (syngas), carbon dioxide, lignocellulose, or organic waste. In this study, Methylorubrum extorquens AM1 was engineered to improve the production of bioplastic poly-3-hydroxybutyrate (PHB) using acetate as the sole carbon source. To utilize acetate as a carbon source and methanol as an energy source, acs encoding acetyl-CoA synthetase and fdh from Burkholderia stabilis were overexpressed, while ftfL involved in the assimilation of methanol into formyl-tetrahydrofolate was deleted. The yields of biomass and PHB from acetate significantly improved, and the growth rate and PHB content of the bacteria increased. In addition, sustainability of the PHB production was demonstrated using acetate derived from carbon dioxide and syngas. This study shows that biopolymers could be synthesized efficiently using acetate as the sole carbon source through metabolic engineering and the supply of energy cofactors.

Dynamics of the bacterial communities and predicted functional profiles in wilted alfalfa silage.

To investigate the fermentation characteristics, bacterial community and predicted functional profiles during the ensiling of wilted alfalfa (Medicago sativa L.). First-cutting alfalfa was harvested at the early bloom stage, wilted for 6h, and ensiled in laboratory-scale silos (1L capacity). Triplicate silos were sampled after 1, 3, 7, 15, 30 and 60days of ensiling, respectively. The bacterial communities of wilted alfalfa and silages on day3 and 60 were assessed through high throughput sequencing technology, and their functional characteristics were evaluated according to the Kyoto Encyclopedia of Genes and Genomes using Tax4Fun. After 60days of ensiling, alfalfa silage showed a moderate fermentation quality, indicated by high lactic acid (56.7gkg-1 dry matter [DM]) and acetic acid (39.4gkg-1 DM) contents, and low concentrations of butyric acid (2.12gkg-1 DM) and ammonia nitrogen (128gkg-1 total nitrogen). Lactobacillus rapidly became predominant on day3 and increased to 60.4% on day60. Results of functional prediction analyses showed that the metabolism of amino acid, energy, cofactors and vitamins were reduced, while metabolism of nucleotide and carbohydrate were increased during ensiling. Fructokinase, 1-phosphofructokinase and pyruvate kinase played important roles in producing lactic acid. The production of acetic acid may be correlated with the enhancement of 6-phosphogluconate dehydrogenase and acetyl-CoA synthetase. Knowledge regarding bacterial dynamics and their metabolic pathways during alfalfa ensiling is important for understanding the fermentation process and may contribute to the production of nutritious and stable alfalfa silage. High throughput sequencing technology combined with 16S rRNA gene-predicted functional analyses could provide a new and comprehensive insight into bacterial community dynamics and functional profiles to further improve the silage quality.

Physiological and Molecular Aspects of Two Thymus Species Differently Sensitive to Drought Stress.

Drought is one of the most important threats to plants and agriculture. Here, the effects of four drought levels (90%, 55%, 40%, and 25% field capacity) on the relative water content (RWC), chlorophyll and carotenoids levels, and mRNA gene expression of metabolic enzymes in Thymus vulgaris (as sensitive to drought) and Thymus kotschyanus (as a drought-tolerant species) were evaluated. The physiological results showed that the treatment predominantly affected the RWC, chlorophyll, and carotenoids content. The gene expression analysis demonstrated that moderate and severe drought stress had greater effects on the expression of histone deacetylase-6 (HDA-6) and acetyl-CoA synthetase in both Thymus species. Pyruvate decarboxylase-1 (PDC-1) was upregulated in Thymus vulgaris at high drought levels. Finally, succinyl CoA ligase was not affected by drought stress in either species. Data confirmed water stress is able to alter the gene expression of specific enzymes. Furthermore, our results suggest that PDC-1 expression is independent from HDA-6 and the increased expression of ACS can be due to the activation of new pathways involved in carbohydrate production.

Acetyl-CoA synthetases ACSS1 and ACSS2 are 4-hydroxytamoxifen responsive factors that promote survival in tamoxifen treated and estrogen deprived cells

Acetyl-CoA synthetases ACSS1 and ACSS2 promote conversion of acetate to acetyl-CoA for use in lipid synthesis, protein acetylation, and energy production. These enzymes are elevated in some cancers and important for cell survival under hypoxia and nutrient stress. 4-hydroxytamoxifen (4-OHT) can induce metabolic changes that increase cancer cell survival. An effect of 4-OHT on expression of ACSS1 or ACSS2 has not been reported. We found ACSS1 and ACSS2 are increased by 4-OHT in estrogen receptor-α positive (ER+) breast cancer cells and 4-OHT resistant derivative cells. ERα knockdown blocked ACSS1 induction by 4-OHT but not ACSS2. 4-OHT also induced ACSS2 but not ACSS1 expression in triple negative breast cancer cells. Long-term estrogen deprivation (LTED) is a model for acquired resistance to aromatase inhibitors. We found LTED cells and tumors express elevated levels of ACSS1 and/or ACSS2 and are especially sensitive to viability loss caused by depletion of ACSS1 and ACSS2 or treatment with an ACSS2-specific inhibitor. ACSS2 inhibitor also increased toxicity in cells treated with 4-OHT. We conclude ACSS1 and ACSS2 are 4-OHT regulated factors important for breast cancer cell survival in 4-OHT-treated and long-term estrogen deprived cells.

O-GlcNAc transferase regulates glioblastoma acetate metabolism via regulation of CDK5-dependent ACSS2 phosphorylation.

Glioblastomas (GBMs) preferentially generate acetyl-CoA from acetate as a fuel source to promote tumor growth. O-GlcNAcylation has been shown to be elevated by increasing O-GlcNAc transferase (OGT) in many cancers and reduced O-GlcNAcylation can block cancer growth. Here, we identify a novel mechanism whereby OGT regulates acetate-dependent acetyl-CoA and lipid production by regulating phosphorylation of acetyl-CoA synthetase 2 (ACSS2) by cyclin-dependent kinase 5 (CDK5). OGT is required and sufficient for GBM cell growth and regulates acetate conversion to acetyl-CoA and lipids. Elevating O-GlcNAcylation in GBM cells increases phosphorylation of ACSS2 on Ser-267 in a CDK5-dependent manner. Importantly, we show that ACSS2 Ser-267 phosphorylation regulates its stability by reducing polyubiquitination and degradation. ACSS2 Ser-267 is critical for OGT-mediated GBM growth as overexpression of ACSS2 Ser-267 phospho-mimetic rescues growth in vitro and in vivo. Importantly, we show that pharmacologically targeting OGT and CDK5 reduces GBM growth ex vivo. Thus, the OGT/CDK5/ACSS2 pathway may be a way to target altered metabolic dependencies in brain tumors.

Denitrification performance and mechanism of denitrification biofilm reactor based on carbon-nitrate counter-diffusional

This study researched denitrification performance and mechanism of denitrification biofilm reactor with different HRTs and carbon sources dosages. Experimental group (EG) had better nitrate and COD removal performance than control group (CG) with different HRTs or carbon doses, and the maximum nitrate-to-nitrite transformation ratio (NTR) of them reached 7.91 ± 1.60% and 17.50 ± 1.92%, respectively. Because organic carbon sources were added to the carrier's interior in EG, forming high local concentrations in biofilms and counter-diffusional with nitrate. By contrast, carbon sources and nitrate were provided from the aqueous phase in CG. Thus, the EG system has more active regions of the biofilm than CG. In addition, EG had higher proportions of microorganisms and enzymes related to denitrification and carbon metabolism. The most dominant phylum, genus, and species were Proteobacteria, Thaurea, and Thauera_sp._27, respectively. The transcript of acetyl-CoA synthetase (K01895) and denitrification (M00529) was mainly originated from unclassified_g__Pseudomonas and unclassified_g__Thauera, respectively.

Functional Characteristics of Aldehyde Dehydrogenase and Its Involvement in Aromatic Volatile Biosynthesis in Postharvest Banana Ripening.

Butanol vapor feeding to ripe banana pulp slices produced abundant butyl butanoate, indicating that a portion of butanol molecules was converted to butanoate/butanoyl-CoA via butanal, and further biosynthesized to ester. A similar phenomenon was observed when feeding propanol and pentanol, but was less pronounced when feeding hexanol, 2-methylpropanol and 3-methylbutanol. Enzymes which catalyze the cascade reactions, such as alcohol dehydrogenase (ADH), acetyl-CoA synthetase, and alcohol acetyl transferase, have been well documented. Aldehyde dehydrogenase (ALDH), which is presumed to play a key role in the pathway to convert aldehydes to carboxylic acids, has not been reported yet. The conversion is an oxygen-independent metabolic pathway and is enzyme-catalyzed with nicotinamide adenine dinucleotide (NAD+) as the cofactor. Crude ALDH was extracted from ripe banana pulps, and the interference from ADH was removed by two procedures: (1) washing off elutable proteins which contain 95% of ADH, but only about 40% of ALDH activity, with the remaining ALDH extracted from the pellet residues at the crude ALDH extraction stage; (2) adding an ADH inhibitor in the reaction mixture. The optimum pH of the ALDH was 8.8, and optimum phosphate buffer concentration was higher than 100 mM. High affinity of the enzyme was a straight chain of lower aldehydes except ethanal, while poor affinity was branched chain aldehydes.

Enzymatic transfer of acetate on histones from lysine reservoir sites to lysine activating sites.

Histone acetylation is governed by nuclear acetyl-CoA pools generated, in part, from local acetate by metabolic enzyme acetyl-CoA synthetase 2 (ACSS2). We hypothesize that during gene activation, a local transfer of intact acetate occurs via sequential action of epigenetic and metabolic enzymes. Using stable isotope labeling, we detect transfer between histone acetylation sites both in vitro using purified mammalian enzymes and in vivo using quiescence exit in Saccharomyces cerevisiae as a change-of-state model. We show that Acs2, the yeast ortholog of ACSS2, is recruited to chromatin during quiescence exit and observe dynamic histone acetylation changes proximal to Acs2 peaks. We find that Acs2 is preferentially associated with the most up-regulated genes, suggesting that acetyl group transfer plays an important role in gene activation. Overall, our data reveal direct transfer of acetate between histone lysine residues to facilitate rapid transcriptional induction, an exchange that may be critical during changes in nutrient availability.

Acetate Improves the Killing of Streptococcus pneumoniae by Alveolar Macrophages via NLRP3 Inflammasome and Glycolysis-HIF-1α Axis.

Short-chain fatty acids (SCFAs) are metabolites produced mainly by the gut microbiota with a known role in immune regulation. Acetate, the major SCFA, is described to disseminate to distal organs such as lungs where it can arm sentinel cells, including alveolar macrophages, to fight against bacterial intruders. In the current study, we explored mechanisms through which acetate boosts macrophages to enhance their bactericidal activity. RNA sequencing analyses show that acetate triggers a transcriptomic program in macrophages evoking changes in metabolic process and immune effector outputs, including nitric oxide (NO) production. In addition, acetate enhances the killing activity of macrophages towards Streptococcus pneumoniae in an NO-dependent manner. Mechanistically, acetate improves IL-1β production by bacteria-conditioned macrophages and the latter acts in an autocrine manner to promote NO production. Strikingly, acetate-triggered IL-1β production was neither dependent of its cell surface receptor free-fatty acid receptor 2, nor of the enzymes responsible for its metabolism, namely acetyl-CoA synthetases 1 and 2. We found that IL-1β production by acetate relies on NLRP3 inflammasome and activation of HIF-1α, the latter being triggered by enhanced glycolysis. In conclusion, we unravel a new mechanism through which acetate reinforces the bactericidal activity of alveolar macrophages.