Functional relevance of the multi-drug transporter abcg2 on teriflunomide therapy in an animal model of multiple sclerosis

Abstract

Background: The multi-drug resistance transporter ABCG2, a member of the ATP-binding cassette (ABC) transporter family, mediates the efflux of different immunotherapeutics used in multiple sclerosis (MS), e.g., teriflunomide (teri), cladribine, and mitoxantrone, across cell membranes and organelles. Hence, the modulation of ABCG2 activity could have potential therapeutic implications in MS. In this study, we aimed at investigating the functional impact of abcg2 modulation on teri-induced effects in vitro and in vivo. Methods: T cells from C57BL/6 J wild-type (wt) and abcg2-knockout (KO) mice were treated with teri at different concentrations with/without specific abcg2-inhibitors (Ko143; Fumitremorgin C) and analyzed for intracellular teri concentration (HPLC; LS-MS/MS), T cell apoptosis (annexin V/PI), and proliferation (CSFE). Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6J by active immunization with MOG 35-55 /CFA. Teri (10 mg/kg body weight) was given orally once daily after individual disease onset. abcg2-mRNA expression (spinal cord, splenic T cells) was analyzed using qRT-PCR. Results: In vitro, intracellular teri concentration in T cells was 2.5-fold higher in abcg2-KO mice than in wt mice. Teri-induced inhibition of T cell proliferation was two fold increased in abcg2-KO cells compared to wt cells. T cell apoptosis demonstrated analogous results with 3.1-fold increased apoptosis after pharmacological abcg2-inhibition in wt cells. abcg2-mRNA was differentially regulated during different phases of EAE within the central nervous system and peripheral organs. In vivo, at a dosage not efficacious in wt animals, teri treatment ameliorated clinical EAE in abcg2-KO mice which was accompanied by higher spinal cord tissue concentrations of teri. Conclusion: Functional relevance of abcg2 modulation on teri effects in vitro and in vivo warrants further investigation as a potential determinant of interindividual treatment response in MS, with potential implications for other immunotherapies.

Targeting deoxycytidine kinase improves symptoms in mouse models of multiple sclerosis

“…When treatments are started at disease induction, TRE-515 has a median efficacy of 45% compared to leflunomide (a metabolic precursor of teriflunomide) with a median efficacy of $25%, Interferon β with a median efficacy of $40%, dimethyl fumarate with a median efficacy of $40%, glatiramer acetate with a median efficacy of $65%, and fingolimod with a median efficacy of $70% [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64]. When treatments are started at symptom onset, TRE-515 has a median efficacy of 39% compared to Interferon β with a median efficacy of 0%, teriflunomide with a median efficacy of 0%, dimethyl fumarate with a median efficacy of $35%, fingolimod with a median efficacy of $35%, and glatiramer acetate with a median efficacy of $65% [46][47][48][49][50][65][66][67][68][69]. The efficacy of a therapy in patients with MS will be surely different than the efficacy of that therapy in the MOG 35-55 EAE model for many reasons including differences in underlying biology and the achievable dose of a therapy in patients.…”

CNS Antigen-Specific Neuroinflammation Attenuates Ischemic Stroke With Involvement of Polarized Myeloid Cells

“…Active EAE was induced in 8–10-week-old mice as described previously. 14 , 15 Briefly, myelin oligodendrocyte peptide 35–55 (MOG 35-55 ) (Institute of Medical Immunology, Charité, Berlin, Germany) emulsified in complete Freund adjuvant (CFA) was injected subcutaneously, followed by the intraperitoneal injection of pertussis toxin at days 0 and 2. Sham-immunized control mice received CFA alone without MOG peptide (subsequently referred to as CFA mice).…”

“…Neurologic deficits were assessed daily using a 10-point EAE score: 0 = no clinical signs; 1 = reduced tone of tail; 2 = limp tail, impaired righting; 3 = absent righting; 4 = gait ataxia; 5 = mild hind limb paraparesis; 6 = moderate paraparesis; 7 = severe paraparesis or paraplegia; 8 = tetraparesis; 9 = moribund; and 10 = death. 14 , 15 The acute phase of EAE was defined as 1–4 days after first clinical symptoms and the chronic phase of EAE as remission of symptoms with a stable score for at least 2–3 days. The scores given in the figures are maximum disease scores detected in the acute EAE phase.…”

Multiple sclerosis: Immunopathological heterogeneity and its implications

“…At the same time, the BBB establishes a metabolic barrier, in which polarized expression of specific transporters and enzymes ensures that toxic metabolites are rapidly removed from the CNS. These transporters may also be relevant for (heterogenous) distribution of therapeutic agents [21]. Importantly, the biochemically unique BBB characteristics are not intrinsic to brain microvascular endothelial cells but rather rely on the continuous cross-talk involving wnt/β-catenin and hedgehog signaling pathways with pericytes and astrocytes surrounding the CNS microvessels [20,22].…”