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Cited by 1,397Immune cells in cancerCancer, Hypoxia, and MetabolismImmune Response and Inflammation

Pyruvate kinase M2 regulates Hif-1α activity and IL-1β induction and is a critical determinant of the Warburg effect in LPS-activated macrophages

Open access
Palsson-McDermott, Eva M., Curtis, Anne M., Goel, Gautam, Lauterbach, Mario A.R., Sheedy, Frederick J., Gleeson, Laura E., van den Bosch, Mirjam W.M., Quinn, Susan R. +10 more·2015·Cell Metabolism
DOI 10.1016/j.cmet.2014.12.005PMC PMC5198835
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Abstract

Macrophages activated by the TLR4 agonist LPS undergo dramatic changes in their metabolic activity. We here show that LPS induces expression of the key metabolic regulator Pyruvate Kinase M2 (PKM2). Activation of PKM2 using two well-characterized small molecules, DASA-58 and TEPP-46, inhibited LPS-induced Hif-1α and IL-1β, as well as the expression of a range of other Hif-1α-dependent genes. Activation of PKM2 attenuated an LPS-induced proinflammatory M1 macrophage phenotype while promoting traits typical of an M2 macrophage. We show that LPS-induced PKM2 enters into a complex with Hif-1α, which can directly bind to the IL-1β promoter, an event that is inhibited by activation of PKM2. Both compounds inhibited LPS-induced glycolytic reprogramming and succinate production. Finally, activation of PKM2 by TEPP-46 in vivo inhibited LPS and Salmonella typhimurium-induced IL-1β production, while boosting production of IL-10. PKM2 is therefore a critical determinant of macrophage activation by LPS, promoting the inflammatory response.

AI snapshot

Written from the paper’s full text.

TL;DR

LPS induces PKM2 in macrophages, where dimeric/monomeric PKM2 complexes with Hif-1α and binds the IL-1β promoter to promote Warburg-like glycolysis and pro-inflammatory activation. Forcing PKM2 into tetramers with DASA-58 or TEPP-46 inhibits Hif-1α activity, IL-1β induction, glycolytic reprogramming, and succinate accumulation, while shifting macrophages toward an M2-like/IL-10-high phenotype and impairing bacterial killing in vivo.

Key findings

  • LPS induced PKM2 expression and tyrosine 105 phosphorylation in BMDMs; Pkm2 mRNA increased approximately 2.8-fold after 24 hours, and phospho-PKM2 showed a 10.3-fold increase in relative band intensity, consistent with inactive monomer/dimer formation.
  • PKM2 activators DASA-58 and TEPP-46 promoted tetramerization, inhibited LPS-induced nuclear translocation of PKM2, and blocked LPS-induced Hif-1α protein, pro-IL-1β, Il1b mRNA, and the Hif-1α target Ldha, without affecting IL-6 or TNF.
  • LPS increased PKM2–Hif-1α association and binding of both to the IL-1β promoter; TEPP-46/DASA-58 inhibited this binding. PKM2 deletion reduced LPS-induced Hif-1α, Il1β, and Ldha, and reduced glycolysis, while increasing oxidative phosphorylation.
  • DASA-58 blocked LPS-induced succinate and glycolytic intermediates; LPS caused up to a ten-fold increase in glycolysis that was markedly inhibited by TEPP-46 and DASA-58. In vivo, TEPP-46 reduced LPS- and Salmonella typhimurium-induced IL-1β, boosted IL-10, and increased bacterial dissemination.

Methods

  • Primary BMDMs and peritoneal cells from C57BL/6 mice, RAW 264.7 macrophages, and conditional PKM2fl/fl BMDMs were treated with LPS, TEPP-46, DASA-58, tamoxifen, Mtb, or S. typhimurium.
  • Main assays included Western blotting, DSS crosslinking, size-exclusion chromatography, nuclear/cytosolic fractionation, ELISA, qPCR, co-immunoprecipitation, oligonucleotide pulldown, sequential ChIP, Seahorse extracellular flux analysis, microarray profiling, and LC-MS metabolomics.
  • In vivo models used LPS-induced sepsis and S. typhimurium infection in mice treated with TEPP-46 or vehicle, measuring serum cytokines, peritoneal cell IL-1β, and bacterial CFU in liver/spleen.

Limitations

  • The paper does not include a dedicated limitations section.
  • Limitations evident from the text: most mechanistic work uses mouse BMDMs/PECs and RAW cells; in vivo infection experiments use TEPP-46 only because DASA-58 is not pharmacokinetically validated in vivo; some data are not shown; and the mechanism by which PKM2 promotes IL-10 production is stated to require further analysis.
  • The Mtb ELISA results are described as means ± SEMs for one representative experiment with n=2, limiting statistical robustness.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.cmet.2014.12.005

Cites

38 of 38 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 26 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Genes upregulated in M1 cells were significantly upregulated by LPS treatment compared to LPS+DASA-58 treatment.

    “We found that genes upregulated in M1 cells were significantly upregulated by LPS treatment compared to LPS+DASA-58 (Figure 2E).”
    Quote in the paperSubstantial claim
  • Findingown data

    Neither TEPP-46 nor DASA-58 had a significant effect on oxidative phosphorylation as measured by oxygen consumption rate.

    “Neither TEPP-46 nor DASA-58 had a significant effect on oxidative phosphorylation as measured by oxygen consumption rate (data not shown).”
    Quote in the paperNot a substantial claim
  • Findingcitation

    LPS-induced IL-6 and TNF protein expression are unaffected by activation of PKM2.

    “Furthermore, LPS-induced IL-6 and TNF protein expression (Figure 1J) were unaffected by activation of PKM2 consistent with these cytokine responses not directly requiring Warburg metabolism (Tannahill et al., 2013).”
    Quote in the paperSubstantial claim
  • Findingown data

    Enrichment analysis identified IRF1, IRF8, ISGF3, NRF2, and Hif-1α among the top 10 candidate transcription factors perturbed by activation of PKM2.

    “We found enrichment for several interferon associated factors (IRF1, IRF8, ISGF3) as well as NRF2 and Hif-1α amongst the top 10 candidate TFs (Table S5).”
    Quote in the paperNot a substantial claim
  • Findingown data

    Whole genome transcriptomics identified a signature set of 100 genes for which activation of PKM2 induced a markedly distinct response from LPS treatment alone.

    “We identified a signature set of 100 genes (Figure S1, Table S1) for which the activation of PKM2 induced a markedly distinct response from that observed during LPS treatment alone.”
    Quote in the paperSubstantial claim
  • May combine two claims. 51
  • Classified as probably not a substantial claim. 9
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingown data

    LPS causes up to a ten-fold increase in glycolysis in BMDMs, which is markedly inhibited by both TEPP-46 and DASA-58.

    “LPS caused up to a ten-fold increase in glycolysis, which is markedly inhibited by both TEPP-46 and DASA-58.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Activation of PKM2 using DASA-58 inhibits LPS-induced expression of Il1b mRNA but has no effect on LPS-induced Il6 mRNA levels.

    “As shown in Figure 1I, activation of PKM2 using DASA-58 also inhibited LPS-induced expression of Il1b mRNA but importantly had no effect on LPS-induced Il6 mRNA levels.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    TEPP-46 consistently boosts expression of the M2 markers Arg-1 and Mrc-1 in M1 polarized macrophages, although this effect was not significant.

    “Similarly, although not significant we consistently observed a boost in the expression of the M2 markers Arg-1 and Mrc-1 by TEPP-46 in M1 polarized macrophages.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    PFKP is relatively down-regulated by activation of PKM2, whereas ALDOC and TPI1 are significantly up-regulated by DASA-58.

    “Phosphofructokinase (PFKP), which catalyzes the irreversible conversion of fructose-6-phosphate to FBP, is relatively down-regulated by activation of PKM2 whereas the enzymes downstream of this metabolite, namely ALDOC and TPI1, are significantly up- regulated by DASA-58.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    LPS induces expression of PKM2 in macrophages, including in BMDMs up to 48 hours and Pkm2 mRNA increasing approximately 2.8-fold after 24 hours.

    “We here show that LPS induces expression of the key metabolic regulator Pyruvate Kinase M2 (PKM2).”
    • Also stated in: § Tetramerization of PKM2 using small molecule activators inhibits LPS-induced activation of primary bone marrow derived macrophages (BMDMs) · plain
      “LPS induced high levels of PKM2 in BMDMs up to 48 hours (Figure 1A).”
    • Also stated in: § Tetramerization of PKM2 using small molecule activators inhibits LPS-induced activation of primary bone marrow derived macrophages (BMDMs) · boosted
      “LPS strongly induced Pkm2 mRNA expression (Figure 1C), with expression levels increasing approximately 2.8 fold after 24 hours of LPS.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    LPS causes increased expression of PKM2 in both the cytosol and the nucleus of BMDMs.

    “As depicted in Figure 1E, LPS caused an increased expression level of PKM2 in the cytosol (compare lane 7 to lane 8) as well as in the nucleus (compare lane 1 to lane 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Metabolic network enrichment found 48 pathways significantly enriched (FDR < 0.05), with Glycolysis as the top ranking metabolic pathway.

    “we analyzed enrichment of metabolic networks and found 48 pathways to be significantly enriched (FDR < 0.05) with Glycolysis being the top ranking metabolic pathway (Table S4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    LPS-induced expression of PKM2 causes concurrent phosphorylation of PKM2 on Tyrosine 105, evident after one hour and strongest after 48 hours.

    “LPS- induced expression of PKM2 causes concurrent phosphorylation of Tyrosine 105 to an extent comparable or greater to the increased expression levels.”
    • Also stated in: § Tetramerization of PKM2 using small molecule activators inhibits LPS-induced activation of primary bone marrow derived macrophages (BMDMs) · plain
      “This phosphorylation is evident after just one hour, with the strongest induction after 48 hours (Figure 1A middle panel, 10.3 fold increase in relative band intensity).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    PKM1 protein expression levels did not increase substantially in response to LPS in BMDMs, but instead showed a slight decrease after 24 hours.

    “As shown in Figure 1D, PKM1 expression levels did not increase substantially in response to LPS but instead a slight decrease in PKM1 protein was observed after 24 hours of LPS, confirming that in relation to the Pkm gene, the effect of LPS is specific to PKM2.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    DASA-58 and TEPP-46 inhibit the induction of pro-IL-1β in LPS-activated BMDMs and peritoneal cells (PECs).

    “As shown in Figure 1H, DASA-58 and TEPP-46 inhibited the induction of pro-IL-1β in LPS-activated BMDMs. Both compounds also inhibited LPS-induced pro-IL-1β in PECs (Figure 1H).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    LPS-induced PKM2 enters into a complex with Hif-1α, which can directly bind to the IL-1β promoter, an event that is inhibited by activation of PKM2.

    “We show that LPS-induced PKM2 enters into a complex with Hif-1α, which can directly bind to the IL-1β promoter, an event that is inhibited by activation of PKM2.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In live Mtb infection, TEPP-46 inhibits Mtb-induced IL-1β and TNFα protein levels, whereas IL-10 protein is significantly increased by activation of PKM2.

    “In addition, Mtb-induced IL-1β but also TNFα protein levels were inhibited by TEPP-46, whereas IL-10 protein was significantly increased by activation of PKM2 (Figure 6I).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Activation of PKM2 using DASA-58 and TEPP-46 inhibits LPS-induced Hif-1α and IL-1β, as well as the expression of a range of other Hif-1α-dependent genes.

    “Activation of PKM2 using two well-characterized small molecules, DASA-58 and TEPP-46, inhibited LPS-induced Hif-1α and IL-1β, as well as the expression of a range of other Hif-1α-dependent genes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Treatment of BMDMs with Mtb for 24 hours upregulates PKM2 protein and mRNA.

    “Results from BMDMs treated with Mtb for 24 hours revealed an upregulation of PKM2 protein (Figure 6D, third panel, compare lanes 1 and 2) as well as PKM2 mRNA (Figure 6E).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Pkm1 expression is compensatorily increased in PKM2-ablated BMDMs, including PKM1 protein upregulation following Tamoxifen and LPS treatment compared to control.

    “however as expected Pkm1 expression was compensatorily increased (Figure 5B).”
    • Also stated in: § Isoform-specific deletion of PKM2 inhibits LPS-mediated activation of Hif-1α and expression of Hif-1α target genes in macrophages · plain
      “whereas PKM1 protein was upregulated following Tamoxifen and LPS-treatment compared to control (Figure 5C second panel).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Activation of PKM2 attenuates an LPS-induced pro-inflammatory M1 macrophage phenotype while promoting traits typical of an M2 macrophage.

    “Activation of PKM2 attenuated an LPS-induced pro-inflammatory M1 macrophage phenotype while promoting traits typical of an M2 macrophage.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    LPS causes a reduction in OCR in PKM2+/+ cells, and the same inhibitory effect is still observed in BMDMs derived from PKM2−/− cells.

    “However, although as expected LPS causes a reduction on OCR in PKM2+/+ cells (Tannahill et al., 2013), the same inhibitory effect was still observed in BMDMs derived from PKM2−/− cells (data not shown).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Tannahill et al., 2013 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Activation of PKM2 by TEPP-46 in vivo inhibits LPS and Salmonella typhimurium-induced IL-1β production, whilst boosting production of IL-10.

    “Finally, activation of PKM2 by TEPP-46 in vivo inhibited LPS and Salmonella typhimurium-induced IL-1β production, whilst boosting production of IL-10.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    LPS-activated macrophages demonstrate PKM2 up-regulation and phosphorylation, with only a minor change in PKM1 protein expression.

    “We demonstrate PKM2 up-regulation and phosphorylation in an activated macrophage, with only a minor change in PKM1 protein expression.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In PKM2-ablated BMDMs, LPS-induced Il1b expression is attenuated, with no further inhibitory effect observed following pre-treatment with TEPP-46 or DASA-58.

    “LPS-induced Il1b expression was attenuated in PKM2 ablated cells, with no further inhibitory effect observed following pre-treatment with TEPP-46 or DASA-58.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In a model of macrophage infection using live Mtb strain H37Ra, TEPP-46 inhibits Mtb-induced Il1b mRNA levels, boosts Mtb-induced Il10 mRNA levels, and has no effect on Tnf levels.

    “In a model of macrophage infection using live Mtb (strain H37Ra), TEPP-46 inhibited Mtb-induced Il1b mRNA levels, boosted Mtb-induced levels of Il10 mRNA and had no effect on levels of Tnf (Figure 6H).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    FSL-1 and CpG induce pro-IL-1β and Hif-1α protein expression.

    “In addition, both FSL-1 and CpG induced pro-IL-1β and Hif-1α protein expression (Figure 6A).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Both DASA-58 and TEPP-46 inhibit LPS-induced glycolytic reprogramming and succinate production.

    “Both compounds inhibited LPS- induced glycolytic reprogramming and succinate production.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The pentose phosphate pathway intermediate R5P significantly accumulates in response to LPS, and this accumulation is alleviated by activation of PKM2.

    “Additionally, the pentose phosphate pathway intermediate Ribose 5-phosphate (R5P), was significantly accumulated in response to LPS (Figure 4C; left panel), however this was alleviated by activation of PKM2 (right panel).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    BMDMs derived from IL-1 Type I Receptor knockout mice infected with Mtb display an increased bacterial load compared to wild type cells, with no effect of TEPP-46.

    “As illustrated in Figure 6K BMDMs derived from IL-1 Type I Receptor knock out mice when infected with Mtb display an increased bacterial load compared to wild type cells, with no effect of TEPP-46”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    TEPP-46 inhibits Mtb-induced pro-IL-1β and Hif-1α protein, as well as TNFα and IL-6, whilst significantly boosting Mtb-induced IL-10.

    “In addition, TEPP-46 inhibited Mtb-induced pro-IL-1β and Hif-1α protein, (Figure 6D), as well as TNFα and IL-6 (Figure 6G), whilst significantly boosting Mtb induced IL-10 (Figure 6F).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    LPS stimulation leads to accumulation of upstream glycolytic intermediates, such as G6P, FBP, DHAP and 2-PG, and TCA cycle intermediates including succinate.

    “We confirmed that LPS stimulation leads to accumulation of upstream glycolytic intermediates, such as G6P, FBP, DHAP and 2-PG, and TCA cycle intermediates including succinate (Tannahill et al., 2013).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Tannahill et al., 2013 source

      Not checked in the free run.

  • May combine two claims.

    Findingreasoning

    These events are all prevented by PKM2 activation by DASA-58 and TEPP-46, which thereby prevent macrophage activation by LPS.

    “These events are all prevented by PKM2 activation by DASA-58 and TEPP-46, which thereby prevent macrophage activation by LPS.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Activation of PKM2 impairs the ability of the PKM2 and Hif-1α complex to bind to the Hif-1α motif in the promoter of IL-1β, thereby inhibiting the transcriptional activity of Hif-1α and induction of IL-1β in response to LPS.

    “This impairs the ability of the PKM2 and Hif-1α complex to bind to the Hif-1α motif in the promoter of the known Hif-1α target gene IL-1β (Peyssonnaux et al., 2007; Zhang et al., 2006), thereby inhibiting the transcriptional activity of Hif-1α and induction of IL-1β”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Peyssonnaux et al., 2007 source

      Not checked in the free run.

    • cites Zhang et al., 2006 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Activation of PKM2 inhibited induction of IL-1β and boosted IL-10 production in Mtb-infected macrophages, promoting bacterial growth.

    “Activation of PKM2 also inhibited induction of IL-1β and boosted IL-10 production in Mtb-infected macrophages promoting bacterial growth.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    TEPP-46 and DASA-58 are highly specific small-molecule PKM2 activators that promote active PKM2 tetramers, boost PKM2 enzymatic activity, and limit tumor growth in vivo.

    “In order to examine the functional relevance of PKM2 for LPS action we next examined the effect of two highly specific small-molecule PKM2 activators, TEPP-46 and DASA-58.”
    • Also stated in: § Tetramerization of PKM2 using small molecule activators inhibits LPS-induced activation of primary bone marrow derived macrophages (BMDMs) · plain
      “They promote the formation of active PKM2 tetramers thereby boosting PKM2 enzymatic activity and limiting tumor growth in vivo (Anastasiou et al., 2012).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Anastasiou et al., 2012 source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    The polarizing conditions were validated by upregulation of Il12p40 and Cxcl-10 in M1 macrophages and increased expression of Arg-1 and Mrc-1 during M2 polarizing conditions.

    “Figure 2A validates the polarizing conditions showing an upregulation of the markers Interleukin-12 p40 (Il12p40) and C-X-C chemokine 10 (Cxcl-10) in M1 macrophages and an increased expression of Arginase-1 (Arg-1) and Manose Receptor C, type 1 (Mrc-1) during M2 polarizing conditions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Phosphorylation of PKM2 on Tyrosine 105 is indicative of monomer/dimer formation, prevents PKM2 tetramer configuration, and further promotes the Warburg effect.

    “Phosphorylation of PKM2 on Tyrosine 105 is indicative of monomer/dimer formation, as it prevents PKM2 tetramer configuration, further promoting the Warburg effect (Hitosugi et al., 2009).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Hitosugi et al., 2009 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    PKM2 interacts with Hif-1α and stimulates Hif-1α transactivation domain function and recruitment of p300 to the Hif Response Element (HRE) of Hif-1α target genes.

    “PKM2 has been shown to interact with Hif-1α and stimulate Hif-1α transactivation domain function and recruitment of p300 to the Hif Response Element (HRE) of Hif-1α target genes (Luo et al., 2011).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Luo et al., 2011 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Activation of PKM2 in vivo counteracts the inflammatory effects of LPS, most likely through inhibiting Warburg metabolism.

    “This suggests that activation of PKM2 in vivo counteracts the inflammatory effects of LPS, most likely through inhibiting Warburg metabolism.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    PKM2 is a critical determinant of macrophage activation by LPS, promoting the inflammatory response.

    “PKM2 is therefore a critical determinant of macrophage activation by LPS, promoting the inflammatory response.”
    • Also stated in: § INTRODUCTION · boosted
      “This event is required for macrophage activation by LPS and we identify PKM2 as a critical modulator of IL-1β production, macrophage polarization, glycolytic reprogramming and Warburg metabolism in LPS-activated macrophages.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    Tamoxifen treatment of PKM2fl/fl BMDMs successfully ablates Pkm2 expression and reduces PKM2 protein levels.

    “Pkm2 expression was successfully ablated (Figure 5A), however as expected Pkm1 expression was compensatorily increased (Figure 5B). In addition, PKM2 protein levels were successfully reduced following treatment with Tamoxifen (Figure 5C top panel, compare lanes 5 and 6 to lanes 7 and 8)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    PKM2, when highly expressed, exists in an equilibrium of enzymatically inactive pyruvate kinase dimers (or monomers) which can translocate into the nucleus, and enzymatically active tetramers which are retained in the cytosol.

    “Current data indicates that PKM2, when highly expressed, exists in an equilibrium of enzymatically inactive pyruvate kinase dimers (or monomers) which can translocate into the nucleus(Christofk et al., 2008; Hitosugi et al., 2009), and enzymatically active tetramers which are retained in the cytosol(Mazurek et al., 2005).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Christofk et al., 2008 source

      Not checked in the free run.

    • cites Hitosugi et al., 2009 source

      Not checked in the free run.

    • cites Mazurek et al., 2005 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    The pyruvate kinase activity of PKM2 tetramers can be regulated by the concentration of FBP, serine, and by post-translational modifications including tyrosine phosphorylation.

    “The pyruvate kinase activity of the tetramers can be regulated by the concentration of the naturally occurring upstream glycolytic intermediate FBP (Ashizawa et al., 1991; Jurica et al., 1998), serine (Chaneton et al., 2012), as well as by a multitude of post-translational modifications (Wu and Le, 2013) including tyrosine phosphorylation.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Ashizawa et al., 1991 source

      Not checked in the free run.

    • cites Jurica et al., 1998 source

      Not checked in the free run.

    • cites Chaneton et al., 2012 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The metabolomic changes are consistent with DASA-58 activating PKM2, which would lead to a decrease in glycolytic and pentose phosphate pathway intermediates.

    “These metabolomic changes are consistent with DASA-58 activating PKM2, which would lead to a decrease in glycolytic and pentose phosphate pathway intermediates.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Mycobacterium tuberculosis signals mainly through TLR 2, 6, and 9.

    “As the main causative agent of tuberculosis, Mtb signals mainly through TLR 2, 6 and 9 (Bafica et al., 2005; Means et al., 1999).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Bafica et al., 2005 source

      Not checked in the free run.

    • cites Means et al., 1999 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    TEPP-46, but not DASA-58, is pharmacokinetically validated in vivo.

    “TEPP-46, but not DASA-58, is pharmacokinetically validated in vivo (Anastasiou et al., 2012).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Anastasiou et al., 2012 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Tyrosine phosphorylation of PKM2 at residue 105 is important for the Warburg effect in hypoxia and cancer.

    “This event has been shown to be important for the Warburg effect in hypoxia and cancer(Hitosugi et al., 2009).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hitosugi et al., 2009 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Activation of PKM2 limits the succinate increase and this will lead to Hif-1α destabilization.

    “Activation of PKM2 also limits this response and this will lead to Hif-1α destabilization.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Hif-1α is stabilized by succinate inhibiting PHDs.

  • May combine two claims.

    Interpretationreasoning

    Activation of PKM2 limits the nuclear function of PKM2 and decreases Hif-1α-dependent gene expression in LPS-activated macrophages.

    “Firstly, it will limit the nuclear function of PKM2 and decrease Hif-1α-dependent gene expression.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Activation of PKM2 is a potential therapeutic target in inflammatory disease.

    “This further implies the activation of PKM2 as a potential therapeutic target in inflammatory disease.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    PKM2 in its dimeric, catalytically less active form is required for glycolytic reprogramming in response to LPS, most likely because of the role dimeric PKM2 plays in Hif-1α function.

    “PKM2 in its dimeric, catalytically less active form, is therefore required for glycolytic reprogramming in response to LPS, most likely because of the role dimeric PKM2 plays in Hif-1α function.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Tetramerization of PKM2 limits the host immune response in vivo by attenuating both LPS and S. typhimurium-induced IL-1β whilst boosting IL-10, leading to impaired clearance of infection evident from increased bacterial dissemination.

    “We demonstrate the impact tetramerization of PKM2 has on limiting the host immune response in vivo, by attenuating both LPS and S. typhimurium-induced IL-1β whilst boosting IL-10, leading to impaired clearance of infection evident from increased bacterial dissemination.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The paper reveals a novel role for PKM2 in LPS-induced activation of macrophages and in macrophages infected with Mtb, as well as in an in vivo S. typhimurium model of infection.

    “In conclusion, we have revealed a novel role for PKM2 in LPS induced activation of macrophages and in macrophages infected with Mtb, as well as in an in vivo S.typhimurium model of infection”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    DASA-58 and TEPP-46 are well-characterized and highly specific compounds that bind PKM2, which then forms a tight tetramer with PKM1-like kinetic properties, an event resistant to inhibition by tyrosine phosphorylation.

    “These well-characterized and highly specific compounds bind PKM2, which then forms a tight tetramer with PKM1-like kinetic properties, an event that is resistant to inhibition by tyrosine phosphorylation.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Anastasiou et al., 2012 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Microarray data were checked for correlation between replicates (>0.96 on average within groups).

    “Data was checked for correlation between replicates, (>0.96 on average within groups).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The increase in IL-10 production may be explained by increased flux of pyruvate into the TCA cycle, because M2 macrophage activity may require mitochondrial oxidative metabolism.

    “This could explain the increase in IL-10 production, which in the case of M2 macrophage activity may require mitochondrial oxidative metabolism (Krawczyk et al., 2010).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Krawczyk et al., 2010 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The data indicate a combination of transcriptional regulation of key enzymes to increase flux into lactate, divert metabolites into the pentose phosphate pathway and thereby divert pyruvate away from the TCA cycle.

    “The data indicates a combination of transcriptional regulation of key enzymes to increase flux into lactate, divert metabolites into the pentose phosphate pathway and thereby divert pyruvate away from the TCA cycle.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Interpretationreasoning

    Activation of PKM2 decreases succinate, which further limits Hif-1α.

    “Secondly, the decrease in succinate will further limit Hif-1α through stabilization and degradation.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Hif-1α is stabilized by succinate inhibiting PHDs.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    p-values were corrected for multiple hypothesis testing by Benjamini-Hochberg's method to control false discovery rate at 25%.

    “p-values were corrected for multiple hypothesis testing by Benjamini- Hochberg’s method to control false discovery rate at 25%.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Targeting PKM2 to inhibit glycolysis or re-engage mitochondrial oxidative metabolism in an overactive macrophage may provide novel therapeutic approaches for inflammatory diseases.

    “Targeting PKM2 in order to inhibit glycolysis or re-engaging mitochondrial oxidative metabolism in an overactive macrophage may provide novel therapeutic approaches for inflammatory diseases.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    Metabolomics data were log transformed and correlation between replicates was >0.94 on average within different treatment groups.

    “Processed data was log transformed (base 2). Correlation between replicates were >0.94 on average within different treatment groups.”
    Quote in the paperNot a substantial claim
57 of 57

  • The paper relies on this without support.

    There is only limited information on the precise molecular determinants of the profound metabolic change in LPS-activated macrophages.

    “There is only limited information on the precise molecular determinants of this profound change in metabolism.”

  • The paper relies on this without support.

    LPS-activated macrophages have a high demand for biosynthetic precursors and increased energy demand, and these events are required for the cells to respond to infection or tissue injury during inflammation.

    “In macrophages activated with the TLR4 agonist LPS there is a high demand for biosynthetic precursors including proteins, lipids, and nucleic acids as well as increased energy demand. These events are required for the cells to respond to infection or tissue injury during inflammation.”

  • The paper relies on this without support.

    PKM2 enters the nucleus as a dimer.

    “Since previous reports have established that PKM2 enters the nucleus as a dimer, we then carried out further DSS cross-linking studies in order to support a model for nuclear exclusion of PKM2 following treatment with our small molecule activators.”

  • The paper relies on this without support.

    Hif-1α is stabilized by succinate inhibiting PHDs.

    “Hif-1α will also be stabilized by succinate inhibiting PHDs, providing further regulation of Hif-1α.”

  • The paper relies on this without support.

    Mycobacterium tuberculosis utilizes TLR2, TLR6 and TLR9.

    “This extended our observation beyond TLR4 and LPS to a bacterial pathogen that utilizes TLR2, TLR6 and TLR9.”
5 of 5

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Chromatography treatment is named TEPP-58 instead of TEPP-46

    Minor

    The methods name TEPP-58 for the size-exclusion experiment, while the results identify TEPP-46 as the treatment in that experiment.

1 of 1

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Authors
Palsson-McDermott, E. M., Curtis, A. M., Goel, G., Lauterbach, M. A. R., Sheedy, F. J., Gleeson, L. E., van den Bosch, M. W. M., Quinn, S. R., Domingo-Fernandez, R., Johnston, D. G. W., Jiang, J.-K., Israelsen, W. J., Keane, J., Thomas, C., Clish, C., Vander Heiden, M., Xavier, R. J., & O’Neill, L. A. J.
Affiliations
  • Broad Institute (US)
  • Trinity College Dublin (IE)
  • National Institutes of Health (US)
  • Koch Institute for Integrative Cancer Research At MIT (US)
ORCID
Venue
Cell Metabolism
Publisher
Elsevier BV
Published
2015-01
Volume
21
Issue
1
Pages
65-80
ISSN
1550-4131 (ISSN-L)
DOI
10.1016/j.cmet.2014.12.005
PMC
PMC5198835
OpenAlex
W2153586956
Cited by
1,397
References
38
Citations by year
2026: 154 · 2025: 177 · 2024: 186 · 2023: 133 · 2022: 132 · 2021: 161 · 2020: 140 · 2019: 81 · 2018: 85 · 2017: 77 · 2016: 51 · 2015: 19
FWCI
38.04
Type
journal article
Language
en
Update notices
erratum (2015-02-03)
Open access
Licence
Locations
  • Cell Metabolism (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Trinity's Access to Research Output (TARA) (Trinity College Dublin) (submittedVersion)
Funders
  • Health Research Board
  • Seventh Framework Programme (FP7-2007-2013, HEALTH-14-2011-281608)
  • National Institutes of Health
  • European Research Council
  • Science Foundation Ireland
  • Wellcome Trust
Topics
  • Life Sciences › Immunology and Microbiology › Immunology › Immune cells in cancer
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer, Hypoxia, and Metabolism
  • Life Sciences › Immunology and Microbiology › Immunology › Immune Response and Inflammation
Keywords
PKM2, HIF-1α, IL-1β, Warburg effect, macrophage polarization, M1/M2 macrophages, lipopolysaccharide stimulation, TLR4, glycolytic reprogramming, succinic acid, TEPP-46, IL-10, Salmonella typhimurium, inflammation, macrophage metabolism
MeSH terms
Animals, Bone Marrow Cells, Cells, Cultured, Glycolysis, Lipopolysaccharides, Macrophage Activation, Macrophages, Mice, Inbred C57BL, Promoter Regions, Genetic, Protein Binding, Pyruvate Kinase, RNA, Messenger, Salmonella typhimurium, Gene Expression, Enzyme Activators, Toll-Like Receptor 4, Mice, Hypoxia-Inducible Factor 1, alpha Subunit, Interleukin-1beta

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

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