Methotrexate Normalizes Up‐Regulated Folate Pathway Genes in Rheumatoid Arthritis

Abstract

Objective. The folate antagonist methotrexate (MTX) is an anchor drug in the treatment of rheumatoid arthritis (RA), but its mechanism of action with regard to the impact on folate metabolism remains elusive. The aim of the present study was to investigate the cellular pharmacologic impact of MTX on peripheral blood cells, by comparing MTX-treated RA patients to MTX-naive RA patients and healthy controls.Methods. Gene expression microarray data were used to investigate the expression of 17 folate pathway genes by peripheral blood cells from a cohort of 25 RA patients treated with MTX, 10 MTX-naive RA patients starting treatment with MTX, and 15 healthy controls (test cohort). Multiplex real-time polymerase chain reaction was used to validate the results in an independent cohort, consisting of 151 RA patients treated with MTX, 28 MTX-naive RA patients starting treatment with MTX, and 24 healthy controls (validation cohort).Results. Multiple folate metabolism-related genes were consistently and significantly altered between the 3 groups in both cohorts. Concurrent with evidence of an immune-activation gene signature in MTX-naive RA patients, significant up-regulation of the folate-metabolizing enzymes ␥-glutamyl hydrolase and dihydrofolate reductase, as well as the MTX/folate efflux transporters ABCC2 and ABCC5, was observed in the MTX-naive RA group compared to healthy controls. Strikingly, MTX treatment of RA patients normalized these differential gene expression levels to the levels observed in healthy controls.Conclusion. These results suggest that under inflammatory conditions, basal folate metabolism in the peripheral blood cells of RA patients is markedly upregulated, and treatment with MTX restores folate metabolism to normal levels. Identification of this novel gene signature provides insight into the mechanism of action of MTX, thus paving the way for development of novel folate metabolism-targeted therapies.

Developing Peripheral Blood Gene Expression-Based Diagnostic Tests for Coronary Artery Disease: a Review

“…Disease definitions varied between studies, as did patient populations. Different exclusions were applied to patients with a previous history of MI or CAD, as well as other conditions whose presence might confound CAD signals; diabetes and rheumatoid arthritis have each been shown to influence the expression of genes associated with CAD [18,19] as has the use of steroids or immunosuppressive drugs [20][21][22][23]. A variety of gene expression profiling technologies exist (summarized in Table 2) including multiple microarray platforms, which differed between the above studies.…”

Association of Blood Gene Expressions in Rheumatoid Arthritis Patients With Clinical and Laboratory Parameters Before and After Methotrexate Therapy

“…Поскольку МТ является антагонистом фолата, в одномоментном исследо-вании было проведено сравнение экспрессии генов мета-болизма фолата у больных РА (получавших и не получав-ших МТ) и у здоровых лиц. При этом оказалось, что на-чальные уровни экспрессии генов метаболизма фолата по-вышены у больных, которые не получали МТ, а на фоне те-рапии МТ их экспрессия снижалась и была сопоставима с таковой у здоровых лиц [11]. Однако, несмотря на сниже-ние экспрессии генов метаболизма фолата у больных, по-лучавших МТ, активность заболевания оставалась высо-кой.…”

Methotrexate in Rheumatoid Arthritis – 2015: New Facts and Ideas

“…[18], по данным которых, у пациен-тов с РА, не получавших МТ, наблюдается увеличение экс-прессии широкого спектра генов фолат-зависимых белков в клетках периферической крови (гамма-глютамилгидро-лаза, ДГФ, транспортеры ABCC2, ABCC5 и др.). Лечение МТ приводило к нормализации экспрессии этих генов до нормального уровня.…”