Non-Invasive Differentiation of M1 and M2 Activation in Macrophages Using Hyperpolarized 13C MRS of Pyruvate and DHA at 1.47 Tesla

Macrophage activation, first generalized to the M1/M2 dichotomy, is a complex and central process of the innate immune response. Simply, M1 describes the classical proinflammatory activation, leading to tissue damage, and M2 the alternative activation promoting tissue repair. Given the central role of macrophages in multiple diseases, the ability to noninvasively differentiate between M1 and M2 activation states would be highly valuable for monitoring disease progression and therapeutic responses. Since M1/M2 activation patterns are associated with differential metabolic reprogramming, we hypothesized that hyperpolarized 13C magnetic resonance spectroscopy (HP 13C MRS), an innovative metabolic imaging approach, could distinguish between macrophage activation states noninvasively. The metabolic conversions of HP [1-13C]pyruvate to HP [1-13C]lactate, and HP [1-13C]dehydroascorbic acid to HP [1-13C]ascorbic acid were monitored in live M1 and M2 activated J774a.1 macrophages noninvasively by HP 13C MRS on a 1.47 Tesla NMR system. Our results show that both metabolic conversions were significantly increased in M1 macrophages compared to M2 and nonactivated cells. Biochemical assays and high resolution 1H MRS were also performed to investigate the underlying changes in enzymatic activities and metabolite levels linked to M1/M2 activation. Altogether, our results demonstrate the potential of HP 13C MRS for monitoring macrophage activation states noninvasively.

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Non-invasive Differentiation of M1 and M2 Activation in Macrophages using Hyperpolarized 13C MRS of Pyruvate and DHA at 1.47 Tesla

10.1101/2020.12.02.405845 ◽

2020 ◽

Author(s):

Kai Qiao ◽

Lydia M. Le Page ◽

Myriam M. Chaumeil

Keyword(s):

Macrophage Activation ◽

Dehydroascorbic Acid ◽

Metabolic Reprogramming ◽

Metabolic Imaging ◽

Alternative Activation ◽

Resonance Spectroscopy ◽

Central Process ◽

Activation Patterns ◽

Non Invasive ◽

Biochemical Assays

AbstractMacrophage activation, first generalized to the M1/M2 dichotomy, is a complex and central process of the innate immune response. Simply, M1 describes the classical pro-inflammatory activation, leading to tissue damage, and M2 the alternative activation promoting tissue repair. Given the central role of macrophages in multiple diseases, the ability to non-invasively differentiate between M1 and M2 activation states would be highly valuable for monitoring disease progression and therapeutic responses. Since M1/M2 activation patterns are associated with differential metabolic reprogramming, we hypothesized that hyperpolarized 13C magnetic resonance spectroscopy (HP 13C MRS), an innovative metabolic imaging approach, could distinguish between macrophage activation states noninvasively. The metabolic conversions of HP [1-13C]pyruvate to HP [1-13C]lactate and HP [1-13C]dehydroascorbic acid to HP [1-13C]ascorbic acid were monitored in live M1 and M2 activated J774a.1 macrophages non-invasively by HP 13C MRS on a 1.47 Tesla NMR system. Our results show that both metabolic conversions were significantly increased in M1 macrophages compared to M2 and non-activated cells. Biochemical assays and high resolution 1H MRS were also performed to investigate the underlying changes in enzymatic activities and metabolite levels linked to M1/M2 activation. Altogether, our results demonstrate the potential of HP 13C MRS for monitoring macrophage activation states non-invasively.

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TAMI-40. PEDIATRIC H3K27M MUTANT GLIOMAS UNDERGO METABOLIC REPROGRAMMING THAT CAN BE LEVERAGED FOR NON-INVASIVE METABOLIC IMAGING

Neuro-Oncology ◽

10.1093/neuonc/noab196.824 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi206-vi207

Author(s):

Meryssa Tran ◽

Georgios Batsios ◽

Céline Taglang ◽

Anne Marie Gillespie ◽

Javad Nazarian ◽

...

Keyword(s):

Magnetic Resonance ◽

Phospholipid Metabolism ◽

Metabolic Reprogramming ◽

Metabolic Imaging ◽

Resonance Spectroscopy ◽

1H Mrs ◽

Hyperpolarized 13C ◽

Non Invasive ◽

13C Mrs

Abstract Diffuse midline gliomas (DMGs) are a universally lethal form of childhood cancer. The infiltrative nature of DMGs makes them difficult to visualize by conventional magnetic resonance imaging. Genomics studies indicate that DMGs are driven by unique histone H3K27M mutations that result in broad epigenetic dysregulation. Many of the resulting changes in gene expression have the potential to induce metabolic reprogramming, which has been identified as a hallmark of cancer. The goal of this study was to dissect metabolic reprogramming in preclinical DMG models in order to identify novel magnetic resonance spectroscopy (MRS)-detectable metabolic biomarkers that can be exploited for non-invasive imaging. First, we used 1H-MRS, which reports on steady-state metabolism, to examine H3K27M mutant SF7761 cells and H3 wild-type normal human astrocytes (NHA). Lactate, glutathione and phosphocholine, which are involved in glycolysis, redox and phospholipid metabolism respectively, were elevated in SF7761 cells relative to NHAs. Mechanistically, these metabolic alterations were associated with upregulation of key enzymes including hexokinase 2, glutamate cysteine ligase and choline kinase a. Importantly, in vivo 1H-MRS showed elevated lactate, glutathione and total choline (combined signal from choline, phosphocholine and glycerophosphocholine) in mice bearing orthotopic SF7761 tumors relative to tumor-free controls. We then examined alterations in dynamic metabolic pathways in our models. Using thermally-polarized 13C-MRS, we identified elevated production of [2-13C]-lactate from [2-13C]-glucose in SF7761 cells relative to NHAs. Hyperpolarized 13C-MRS is a method of enhancing the 13C-MR signal such that metabolic fluxes can be interrogated with high sensitivity. Hyperpolarized [1-13C]-pyruvate flux to [1-13C]-lactate non-invasively monitors glycolysis and is in clinical trials in adult glioma patients. Importantly, hyperpolarized [1-13C]-pyruvate metabolism to lactate was elevated in SF7761 cells relative to NHAs. Collectively, our studies suggest that H3K27M mutant DMGs undergo reprogramming of glucose, redox and phospholipid metabolism that can be leveraged for non-invasive 1H- and hyperpolarized 13C-MRS-based imaging.

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EXTH-20. HYPERPOLARIZED [2-13C] PYRUVATE TO [5-13C] GLUTAMATE AS BIOMARKERS OF IDH1 MUTANT GLIOMA RESPONSE TO TEMOZOLOMIDE THERAPY

Neuro-Oncology ◽

10.1093/neuonc/noz175.354 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi86-vi86 ◽

Cited By ~ 1

Author(s):

Elavarasan Subramani ◽

Chloe Najac ◽

Georgios Batsios ◽

Pavithra Viswanath ◽

Marina Radoul ◽

...

Keyword(s):

Tca Cycle ◽

Response To Therapy ◽

Response To Treatment ◽

Metabolic Imaging ◽

Imaging Biomarkers ◽

Resonance Spectroscopy ◽

Low Grade ◽

1H Mrs ◽

Hyperpolarized 13C ◽

13C Mrs

Abstract Low-grade gliomas, driven by mutations in the cytosolic isocitrate dehydrogenase 1 (IDH1) gene, are less aggressive than primary glioblastoma, but nonetheless always recur and ultimately lead to patient death. The treatment of IDH1 mutant patients with Temozolomide (TMZ) improves survival, but there remains a need for complementary imaging methods to assess response to therapy at an early time point. The goal of this study was, therefore, to determine the value of magnetic resonance spectroscopy (MRS)-based metabolic imaging biomarkers for detection of response to treatment. To this end we investigated NHA and U87 cells expressing IDH1 R132H mutant gene (NHAIDHmut and U87IDHmut) and first used 1H MRS combined with chemometrics to examined the metabolic alterations that occurred following treatment with the IC50 value of TMZ. We observed a significant increase in 2-hydroxyglutarate (2-HG), glutamate, and glutamine, and metabolic pathway analysis showed tricarboxylic acid (TCA) cycle and pyruvate metabolism to be significantly altered pathways following TMZ treatment compared to DMSO control. To confirm changes in TCA cycle flux and to assess the metabolic pathways contributing to the increase in 2-HG and glutamate/glutamine, cells were then labelled with [1-13C] glucose and [3-13C] glutamine. Our data indicated that both glucose flux via the TCA to glutamate and 2HG, and the contribution of glutamine to glutamate and 2HG were increased following TMZ treatment. Finally, we used hyperpolarized 13C-MRS to dynamically probe the metabolism of hyperpolarized [2-13C] pyruvate and its conversion to hyperpolarized [5-13C] glutamate via the TCA cycle. Consistent with our previous findings, we observed that hyperpolarized [5-13C] glutamate synthesis was significantly higher in TMZ-treated cells compared to controls. Collectively, our findings identify 1H MRS-detectable elevation of 2-HG and glutamate/glutamine as well as hyperpolarized 13C-MRS-detectable [5-13C] glutamate production from [2-13C] pyruvate as potentially translatable metabolic biomarkers of response to TMZ therapy in mutant IDH1 glioma.

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EXTH-46. MRS BASED BIOMARKERS OF IDH1 MUTANT GLIOMA RESPONSE TO THE IDH INHIBITOR BAY-1436032

Neuro-Oncology ◽

10.1093/neuonc/noab196.685 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi173-vi173

Author(s):

Donghyun Hong ◽

Noriaki Minami ◽

Céline Taglang ◽

Georgios Batsios ◽

Anne Marie Gillespie ◽

...

Keyword(s):

Animal Models ◽

Animal Studies ◽

Response To Treatment ◽

Resonance Spectroscopy ◽

Low Grade ◽

Isocitrate Dehydrogenase 1 ◽

1H Mrs ◽

Hyperpolarized 13C ◽

13C Mrs ◽

Mutant Idh1

Abstract Gliomas are the most prevalent type of brain tumor in the central nervous system. Mutations in the cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) are a common feature of primary low-grade gliomas, catalyzing the conversion of α-ketoglutarate (αKG) to the oncometabolite 2-hydroxyglutarate (2HG), and mutant IDH1 is a therapeutic target for these tumors. Several mutant IDH inhibitors are currently in clinical trials, nonetheless, complementary non-invasive early biomarkers to assess drug delivery and potential therapeutic response are still needed. The goal of this study was therefore to determine the potential of 1H and hyperpolarized 13C magnetic resonance spectroscopy (MRS)-based biomarkers as indicators of mutant IDH1 low-grade glioma response to treatment with the clinically-relevant IDH1 inhibitor BAY-1436032 in cells and animal models. Immortalized human astrocytes engineered to express mutant IDH1 were treated with 500nM (IC50 value) of BAY-1436032 and BT257 tumors implanted in rats were treated with 150mg/kg of BAY-1436032. To assess steady-state metabolite levels, 1H MRS spectra were acquired on a 500 MHz MRS cancer for cells and a 3 T scanner for animal studies. To assess metabolic fluxes, we used hyperpolarized 13C MRS and probed the fate of hyperpolarized [1-13C]αKG. 1H MRS showed a significant decrease in 2HG as well as a significant increase in glutamate (Glu) and phosphocholine (PCh) following BAY-1436032 treatment in both cell and animal models compared to controls. Furthermore, hyperpolarized 13C MRS showed that hyperpolarized 2HG production from hyperpolarized [1-13C]αKG was decreased and hyperpolarized glutamate production from hyperpolarized [1-13C]αKG was increased in the BAY-1436032 treated groups compared to controls. These findings are consistent with our previous study, which investigated the MRS-detectable consequences of two other mutant IDH inhibitors: AG120 and AG881. Collectively, our work identifies translatable MRS-based metabolic biomarkers of mutant IDH1 inhibition.

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A Noninvasive Comparison Study between Human Gliomas with IDH1 and IDH2 Mutations by MR Spectroscopy

Metabolites ◽

10.3390/metabo9020035 ◽

2019 ◽

Vol 9 (2) ◽

pp. 35 ◽

Cited By ~ 8

Author(s):

Xin Shen ◽

Natalie Voets ◽

Sarah Larkin ◽

Nick de Pennington ◽

Puneet Plaha ◽

...

Keyword(s):

Pulse Sequence ◽

Pearson Correlation ◽

Correlation Coefficients ◽

Idh1 Mutation ◽

Metabolic Reprogramming ◽

Resonance Spectroscopy ◽

1H Mrs ◽

Diffuse Gliomas ◽

Metabolite Quantification ◽

Idh1 And Idh2 Mutations

The oncogenes that are expressed in gliomas reprogram particular pathways of glucose, amino acids, and fatty acid metabolism. Mutations in isocitrate dehydrogenase genes (IDH1/2) in diffuse gliomas are associated with abnormally high levels of 2-hydroxyglutarate (2-HG) levels. The aim of this study was to determine whether metabolic reprogramming associated with IDH mutant gliomas leads to additional 1H MRS-detectable differences between IDH1 and IDH2 mutations, and to identify metabolites correlated with 2-HG. A total of 21 glioma patients (age= 37 ± 11, 13 males) were recruited for magnetic resonance spectroscopy (MRS) using semi-localization by adiabatic selective refocusing pulse sequence at an ultra-high-field (7T). For 20 patients, the tumor mutation subtype was confirmed by immunohistochemistry and DNA sequencing. LCModel analysis was applied for metabolite quantification. A two-sample t-test was used for metabolite comparisons between IDH1 (n = 15) and IDH2 (n = 5) mutant gliomas. The Pearson correlation coefficients between 2-HG and associated metabolites were calculated. A Bonferroni correction was applied for multiple comparison. IDH2 mutant gliomas have a higher level of 2-HG/tCho (total choline=phosphocholine+glycerylphosphorylcholine) (2.48 ± 1.01vs.0.72 ± 0.38, Pc < 0.001) and myo-Inositol/tCho (2.70 ± 0.90 vs. 1.46 ± 0.51, Pc = 0.011) compared to IDH1 mutation gliomas. Associated metabolites, myo-Inositol and glucose+taurine were correlated with 2-HG levels. These results show the improved characterization of the metabolic pathways in IDH1 and IDH2 gliomas for precision medicine.

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Assessing Cerebral Metabolism in the Immature Rodent: From Extracts to Real-Time Assessments

Developmental Neuroscience ◽

10.1159/000496921 ◽

2018 ◽

Vol 40 (5-6) ◽

pp. 463-474

Author(s):

Alkisti Mikrogeorgiou ◽

Duan Xu ◽

Donna M. Ferriero ◽

Susan J. Vannucci

Keyword(s):

Ketone Bodies ◽

Current Knowledge ◽

Cerebral Metabolism ◽

High Energy ◽

Resonance Spectroscopy ◽

Neurodevelopmental Outcomes ◽

1H Mrs ◽

13C Mrs ◽

The Brain

Brain development is an energy-expensive process. Although glucose is irreplaceable, the developing brain utilizes a variety of substrates such as lactate and the ketone bodies, β-hydroxybutyrate and acetoacetate, to produce energy and synthesize the structural components necessary for cerebral maturation. When oxygen and nutrient supplies to the brain are restricted, as in neonatal hypoxia-ischemia (HI), cerebral energy metabolism undergoes alterations in substrate use to preserve the production of adenosine triphosphate. These changes have been studied by in situ biochemical methods that yielded valuable quantitative information about high-energy and glycolytic metabolites and established a temporal profile of the cerebral metabolic response to hypoxia and HI. However, these analyses relied on terminal experiments and averaging values from several animals at each time point as well as challenging requirements for accurate tissue processing.More recent methodologies have focused on in vivo longitudinal analyses in individual animals. The emerging field of metabolomics provides a new investigative tool for studying cerebral metabolism. Magnetic resonance spectroscopy (MRS) has enabled the acquisition of a snapshot of the metabolic status of the brain as quantifiable spectra of various intracellular metabolites. Proton (1H) MRS has been used extensively as an experimental and diagnostic tool of HI in the pursuit of markers of long-term neurodevelopmental outcomes. Still, the interpretation of the metabolite spectra acquired with 1H MRS has proven challenging, due to discrepancies among studies, regarding calculations and timing of measurements. As a result, the predictive utility of such studies is not clear. 13C MRS is methodologically more challenging, but it provides a unique window on living tissue metabolism via measurements of the incorporation of 13C label from substrates into brain metabolites and the localized determination of various metabolic fluxes. The newly developed hyperpolarized 13C MRS is an exciting method for assessing cerebral metabolism in vivo, that bears the advantages of conventional 13C MRS but with a huge gain in signal intensity and much shorter acquisition times. The first part of this review article provides a brief description of the findings of biochemical and imaging methods over the years as well as a discussion of their associated strengths and pitfalls. The second part summarizes the current knowledge on cerebral metabolism during development and HI brain injury.

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Pan-cancer imaging of TERT expression using deuterium magnetic resonance spectroscopy-based assessment of pyruvate metabolism

10.1101/2021.10.05.462047 ◽

2021 ◽

Author(s):

Georgios Batsios ◽

Celine Taglang ◽

Meryssa Tran ◽

Nicholas Stevers ◽

Carter Barger ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Imaging Modality ◽

Response To Therapy ◽

Metabolic Reprogramming ◽

Metabolic Imaging ◽

Resonance Spectroscopy ◽

Tert Expression ◽

Pan Cancer

Telomerase reverse transcriptase (TERT) expression is indispensable for tumor immortality. Non-invasive methods of imaging TERT can, therefore, report on tumor proliferation and response to therapy. Here, we show that TERT expression is associated with elevated levels of the redox metabolite NADH in multiple cancers, including glioblastoma, oligodendroglioma, melanoma, neuroblastoma, and hepatocellular carcinoma. Mechanistically, TERT acts via the metabolic regulator FOXO1 to upregulate nicotinamide phosphoribosyl transferase, which is the key enzyme for NADH biosynthesis. Importantly, deuterium magnetic resonance spectroscopy (2H-MRS), which is a novel, clinically translatable metabolic imaging modality, can be leveraged for imaging TERT-linked NADH in preclinical tumor models in vivo. Since NADH is essential for pyruvate flux to lactate, 2H-MRS following administration of 2H-labeled pyruvate non-invasively visualizes TERT expression and reports on early response to therapy. Collectively, our study provides insights into the mechanisms of TERT-linked metabolic reprogramming and, importantly, establishes 2H-MRS as a pan-cancer strategy for imaging tumor immortality.

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Reduced Warburg Effect in Cancer Cells Undergoing Autophagy: Steady- State 1H-MRS and Real-Time Hyperpolarized 13C-MRS Studies

PLoS ONE ◽

10.1371/journal.pone.0092645 ◽

2014 ◽

Vol 9 (3) ◽

pp. e92645 ◽

Cited By ~ 15

Author(s):

Gigin Lin ◽

Gabriela Andrejeva ◽

Anne-Christine Wong Te Fong ◽

Deborah K. Hill ◽

Matthew R. Orton ◽

...

Keyword(s):

Steady State ◽

Cancer Cells ◽

Real Time ◽

Warburg Effect ◽

1H Mrs ◽

Hyperpolarized 13C ◽

13C Mrs

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Glutamate connectivity associations converge upon the salience network in schizophrenia and healthy controls

Translational Psychiatry ◽

10.1038/s41398-021-01455-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Robert A. McCutcheon ◽

Toby Pillinger ◽

Maria Rogdaki ◽

Juan Bustillo ◽

Oliver D. Howes

Keyword(s):

Functional Connectivity ◽

Frontal Cortex ◽

Network Connectivity ◽

Resonance Spectroscopy ◽

Salience Network ◽

Healthy Controls ◽

1H Mrs ◽

Before And After ◽

Functional Brain Networks ◽

The Relationship

AbstractAlterations in cortical inter-areal functional connectivity, and aberrant glutamatergic signalling are implicated in the pathophysiology of schizophrenia but the relationship between the two is unclear. We used multimodal imaging to identify areas of convergence between the two systems. Two separate cohorts were examined, comprising 195 participants in total. All participants received resting state functional MRI to characterise functional brain networks and proton magnetic resonance spectroscopy (1H-MRS) to measure glutamate concentrations in the frontal cortex. Study A investigated the relationship between frontal cortex glutamate concentrations and network connectivity in individuals with schizophrenia and healthy controls. Study B also used 1H-MRS, and scanned individuals with schizophrenia and healthy controls before and after a challenge with the glutamatergic modulator riluzole, to investigate the relationship between changes in glutamate concentrations and changes in network connectivity. In both studies the network based statistic was used to probe associations between glutamate and connectivity, and glutamate associated networks were then characterised in terms of their overlap with canonical functional networks. Study A involved 76 individuals with schizophrenia and 82 controls, and identified a functional network negatively associated with glutamate concentrations that was concentrated within the salience network (p < 0.05) and did not differ significantly between patients and controls (p > 0.85). Study B involved 19 individuals with schizophrenia and 17 controls and found that increases in glutamate concentrations induced by riluzole were linked to increases in connectivity localised to the salience network (p < 0.05), and the relationship did not differ between patients and controls (p > 0.4). Frontal cortex glutamate concentrations are associated with inter-areal functional connectivity of a network that localises to the salience network. Changes in network connectivity in response to glutamate modulation show an opposite effect compared to the relationship observed at baseline, which may complicate pharmacological attempts to simultaneously correct glutamatergic and connectivity aberrations.

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Characterization of Distinctive In Vivo Metabolism between Enhancing and Non-Enhancing Gliomas Using Hyperpolarized Carbon-13 MRI

Metabolites ◽

10.3390/metabo11080504 ◽

2021 ◽

Vol 11 (8) ◽

pp. 504

Author(s):

Seunggwi Park ◽

Hashizume Rintaro ◽

Seul Kee Kim ◽

Ilwoo Park

Keyword(s):

Metabolic Imaging ◽

Metabolic Profiles ◽

Rodent Models ◽

In Vivo Metabolism ◽

Hyperpolarized 13C ◽

Noninvasive Assessment ◽

Diffuse Midline Glioma ◽

Mr Spectroscopic Imaging

The development of hyperpolarized carbon-13 (13C) metabolic MRI has enabled the sensitive and noninvasive assessment of real-time in vivo metabolism in tumors. Although several studies have explored the feasibility of using hyperpolarized 13C metabolic imaging for neuro-oncology applications, most of these studies utilized high-grade enhancing tumors, and little is known about hyperpolarized 13C metabolic features of a non-enhancing tumor. In this study, 13C MR spectroscopic imaging with hyperpolarized [1-13C]pyruvate was applied for the differential characterization of metabolic profiles between enhancing and non-enhancing gliomas using rodent models of glioblastoma and a diffuse midline glioma. Distinct metabolic profiles were found between the enhancing and non-enhancing tumors, as well as their contralateral normal-appearing brain tissues. The preliminary results from this study suggest that the characterization of metabolic patterns from hyperpolarized 13C imaging between non-enhancing and enhancing tumors may be beneficial not only for understanding distinct metabolic features between the two lesions, but also for providing a basis for understanding 13C metabolic processes in ongoing clinical trials with neuro-oncology patients using this technology.

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