Publications de Hikari Ananda Infinity Yoshihara

Hyperpolarized (1-13C)Alaninamide Is a Multifunctional In Vivo Sensor of Aminopeptidase N Activity, pH, and CO2

Rolf Gruetter, Daniel Ortiz Trujillo, Hikari Ananda Infinity Yoshihara, Alice Radaelli

Spin hyperpolarization enables real-time metabolic imaging of carbon-13-labeled substrates. While hyperpolarized L- (1-13C)alaninamide is a probe of the cell-surface tumor marker aminopeptidase-N (APN, CD13), its activity in vivo has not been described. Sc ...

AMER CHEMICAL SOC2022

[13C]bicarbonate labelled from hyperpolarized [1-13C]pyruvate is an in vivo marker of hepatic gluconeogenesis in fasted state

Arnaud Comment, Rolf Gruetter, Josefina Adriana Maria Bastiaansen, Emine Can, Hikari Ananda Infinity Yoshihara

Hyperpolarized [1-13C]pyruvate enables direct in vivo assessment of real-time liver enzymatic activities by 13C magnetic resonance. However, the technique usually requires the injection of a highly supraphysiological dose of pyruvate. We herein demonstrate ...

2022

Dysfunction of the circadian clock in the kidney tubule leads to enhanced kidney gluconeogenesis and exacerbated hyperglycemia in diabetes

Daniel Ortiz Trujillo, Laure Menin, Hikari Ananda Infinity Yoshihara

The circadian clock is a ubiquitous molecular time-keeping mechanism which synchronizes cellular, tissue, and systemic biological functions with 24-hour environmental cycles. Local circadian clocks drive cell type- and tissuespecific rhythms and their dysr ...

2022

Performance and reproducibility of C-13 and N-15 hyperpolarization using a cryogen-free DNP polarizer

Hikari Ananda Infinity Yoshihara, Arianna Ferrari

The setup, operational procedures and performance of a cryogen-free device for producing hyperpolarized contrast agents using dissolution dynamic nuclear polarization (dDNP) in a preclinical imaging center is described. The polarization was optimized using ...

Nature Portfolio2022

Radical-free hyperpolarized MRI using endogenously occurring pyruvate analogues and UV-induced nonpersistent radicals

Rolf Gruetter, Josefina Adriana Maria Bastiaansen, Lionel Pierre Arn, Andrea Capozzi, Hikari Ananda Infinity Yoshihara, Claudia Christina Zanella, Alice Radaelli

It was recently demonstrated that nonpersistent radicals can be generated in frozen solutions of metabolites such as pyruvate by irradiation with UV light, enabling radical-free dissolution dynamic nuclear polarization. Although pyruvate is endogenous, the ...

WILEY2021

Assessment of Aspartate and Bicarbonate Produced From Hyperpolarized [1-13C]Pyruvate as Markers of Renal Gluconeogenesis

Arnaud Comment, Hikari Ananda Infinity Yoshihara

As both a consumer and producer of glucose, the kidney plays a significant role in glucose homeostasis. Measuring renal gluconeogenesis requires invasive techniques, and less invasive methods would allow renal gluconeogenesis to be measured more routinely. ...

2021

HP agents and biochemical interactions

Hikari Ananda Infinity Yoshihara

The intense but transient increase in nuclear magnetic resonance signal provided by dynamic nuclear polarization (DNP) has enabled a range of new applications, including rapid, minimally-invasive metabolic imaging at the second timescale. This chapter prov ...

Academic Press2021

C-13 Dynamic Nuclear Polarization using SA-BDPA at 6.7 T and 1.1 K: Coexistence of Pure Thermal Mixing and Well-Resolved Solid Effect

Rolf Gruetter, Andrea Capozzi, Hikari Ananda Infinity Yoshihara, Alice Radaelli

SA-BDPA is a water-soluble, narrow-line width radical previously used for dynamic nuclear polarization (DNP) signal enhancement in solid-state magic angle spinning NMR spectroscopy. Here, we report the first study using SA-BDPA under dissolution DNP condit ...

AMER CHEMICAL SOC2020

Renal tubular arginase-2 participates in the formation of the corticomedullary urea gradient and attenuates kidney damage in ischemia-reperfusion injury in mice

Dmitri Firsov, Jean-Luc Barras, Nicolas Dattner, Hikari Ananda Infinity Yoshihara

Aim Arginase 2 (ARG2) is a mitochondrial enzyme that catalyses hydrolysis ofl-arginine into urea andl-ornithine. In the kidney, ARG2 is localized to the S3 segment of the proximal tubule. It has been shown that expression and activity of this enzyme are up ...

WILEY2020

Noninvasive rapid detection of metabolic adaptation in activated human T lymphocytes by hyperpolarized 13C magnetic resonance

Arnaud Comment, Nicolas Kunz, Mor-Miri Mishkovsky, Emine Can, Hikari Ananda Infinity Yoshihara

The metabolic shift induced in human CD4+ T lymphocytes by stimulation is characterized by an upregulation of glycolysis, leading to an augmentation in lactate production. This adaptation has already been highlighted with various techniques and reported in ...

Nature Research2020

Detection of myocardial medium‐chain fatty acid oxidation and tricarboxylic acid cycle activity with hyperpolarized [1– 13 C]octanoate

Arnaud Comment, Josefina Adriana Maria Bastiaansen, Hikari Ananda Infinity Yoshihara

Under normal conditions, the heart mainly relies on fatty acid oxidation to meet its energy needs. Changes in myocardial fuel preference are noted in the diseased and failing heart. The magnetic resonance signal enhancement provided by spin hyperpolarizati ...

2020

In vivo detection of d-amino acid oxidase with hyperpolarized d-[1-C-13]alanine

Rolf Gruetter, Hikari Ananda Infinity Yoshihara, Alice Radaelli

d-amino acid oxidase (DAO) is a peroxisomal enzyme that catalyzes the oxidative deamination of several neutral and basic d-amino acids to their corresponding alpha-keto acids. In most mammalian species studied, high DAO activity is found in the kidney, liv ...

2020

In vivo detection of gamma-glutamyl-transferase up-regulation in glioma using hyperpolarized gamma-glutamyl-[1-C-13]glycine

Hikari Ananda Infinity Yoshihara

Glutathione (GSH) is often upregulated in cancer, where it serves to mitigate oxidative stress. gamma-glutamyl-transferase (GGT) is a key enzyme in GSH homeostasis, and compared to normal brain its expression is elevated in tumors, including in primary gli ...

Nature Research2020

Up-Regulation of γ-Glutamyl-Transferase Can Be Used to Image Glioblastoma Using Hyperpolarized γ-Glutamyl-[1-13C]Glycine MRS

Hikari Ananda Infinity Yoshihara

OXFORD UNIV PRESS INC2019

Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo-induced nonpersistent radicals

Arnaud Comment, Rolf Gruetter, Josefina Adriana Maria Bastiaansen, Andrea Capozzi, Hikari Ananda Infinity Yoshihara

Purpose To probe the cardiac metabolism of carbohydrates and short chain fatty acids simultaneously in vivo following the injection of a hyperpolarized 13C-labeled substrate mixture prepared using photo-induced nonpersistent radicals. Methods Droplets of m ...

Wiley2018

Hyperpolarized C-13 Magnetic Resonance Spectroscopy Reveals the Rate-Limiting Role of the Blood-Brain Barrier in the Cerebral Uptake and Metabolism of L-Lactate in Vivo

Arnaud Comment, Sylvain Eric Lengacher, Bernard Lanz, Mor-Miri Mishkovsky, Tian Cheng, Josefina Adriana Maria Bastiaansen, Yuhei Takado, Hikari Ananda Infinity Yoshihara

The dynamics of L-lactate transport across the blood-brain barrier (BBB) and its cerebral metabolism are still subject to debate. We studied lactate uptake and intracellular metabolism in the mouse brain using hyperpolarized C-13 magnetic resonance spectro ...

2018

Diffusion-weighted MRS of acetate in the rat brain

Nicolas Kunz, Bernard Lanz, Rolf Gruetter, Masoumeh Dehghani Moghadam, Hikari Ananda Infinity Yoshihara

Acetate has been proposed as an astrocyte-specific energy substrate for metabolic studies in the brain. The determination of the relative contribution of the intracellular and extracellular compartments to the acetate signal using diffusion-weighted magnet ...

Wiley-Blackwell2017

In-Vivo Detection and Tracking of T Cells in Various Organs in a Melanoma Tumor Model by F-19-Fluorine MRS/MRI

Lothar Helm, Olivier Michielin, Pascal Miéville, Hikari Ananda Infinity Yoshihara

Background F-19-MRI and F-19-MRS can identify specific cell types after in-vitro or in-vivo F-19-labeling. Knowledge on the potential to track in-vitro F-19-labeled immune cells in tumor models by F-19-MRI/MRS is scarce. Aim To study F-19-based MR techniqu ...

Public Library of Science2016

Direct Monitoring of γ-Glutamyl Transpeptidase Activity In Vivo Using a Hyperpolarized (13) C-Labeled Molecular Probe

Arnaud Comment, Josefina Adriana Maria Bastiaansen, Yuhei Takado, Emine Can, Hikari Ananda Infinity Yoshihara

The γ-glutamyl transpeptidase (GGT) enzyme plays a central role in glutathione homeostasis. Direct detection of GGT activity could provide critical information for the diagnosis of several pathologies. We propose a new molecular probe, γ-Glu-[1-(13) C]Gly, ...

Wiley-Blackwell2016

High-field dissolution dynamic nuclear polarization of [1-C-13]pyruvic acid

Arnaud Comment, Emine Can, Hikari Ananda Infinity Yoshihara

[1-C-13]pyruvate is the most widely used hyperpolarized metabolic magnetic resonance imaging agent. Using a custom-built 7.0 T polarizer operating at 1.0 K and trityl radical-doped [1-C-13] pyruvic acid, unextrapolated solution-state C-13 polarization grea ...

Royal Soc Chemistry2016