{"doi":"10.1101/2020.12.02.405845","title":"Non-invasive Differentiation of M1 and M2 Activation in Macrophages using Hyperpolarized <sup>13</sup> C MRS of Pyruvate and DHA at 1.47 Tesla","abstract":"Abstract 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 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 13 C magnetic resonance spectroscopy (HP 13 C MRS), an innovative metabolic imaging approach, could distinguish between macrophage activation states noninvasively. The metabolic conversions of HP [1- 13 C]pyruvate to HP [1- 13 C]lactate and HP [1- 13 C]dehydroascorbic acid to HP [1- 13 C]ascorbic acid were monitored in live M1 and M2 activated J774a.1 macrophages non-invasively by HP 13 C 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 1 H 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 13 C MRS for monitoring macrophage activation states non-invasively.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":127730,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9588,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":577191,"name":"Lydia M. Le Page","orcid":"0000-0002-3807-4772","position":1,"is_corresponding":false},{"id":577192,"name":"Myriam M. Chaumeil","orcid":"0000-0002-2110-4613","position":2,"is_corresponding":false},{"id":577985,"name":"Kai Qiao","orcid":null,"position":0,"is_corresponding":true}],"reference_count":53,"raw_metadata":null,"created_at":"2026-07-18T23:15:34.966380Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}