Inhibiting glutamine metabolism has been proposed as a potential treatment strategy for improving non-alcoholic steatohepatitis (NASH). However, effective methods for assessing dynamic metabolic responses during interventions targeting glutaminolysis have not yet emerged. Here, we developed a positron emission tomography (PET) imaging platform using l-[5-¹¹C]glutamine ([¹¹C]Gln) and evaluated its efficacy in NASH mice undergoing metabolic therapy with bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES), a glutaminase 1 (GLS1) inhibitor that intervenes in the first and rate-limiting step of glutaminolysis. PET imaging with [¹¹C]Gln effectively delineated the pharmacokinetics of l-glutamine, capturing its temporal-spatial pattern of action within the body. Furthermore, [¹¹C]Gln PET imaging revealed a significant increase in hepatic uptake in methionine and choline deficient (MCD)-fed NASH mice, whereas systemic therapeutic interventions with BPTES reduced the hepatic avidity of [¹¹C]Gln in MCD-fed mice. This reduction in [¹¹C]Gln uptake correlated with a decrease in GLS1 burden and improvements in liver damage, indicating the efficacy of BPTES in mitigating NASH-related metabolic abnormalities. These results suggest that [¹¹C]Gln PET imaging can serve as a noninvasive diagnostic platform for whole-body, real-time tracking of responses of glutaminolysis to GLS1 manipulation in NASH, and it may be a valuable tool for the clinical management of patients with NASH undergoing glutaminolysis-based metabolic therapy.

1) A total of 60 medical and nursing student volunteers operated summer camps for 37 childhood cancer survivors treated at Mie University Hospital and for 51 members of their families in August, 2007 and 2008.2) A questionnaire survey (response rate, 81%; N=47) revealed that the students were seeking to make valuable contributions and to gain benefits for their future careers.3)The students were able to deepen their understanding of childhood cancer survivors and their families.