Selective increase of two ABC drug efflux transporters at the blood-spinal cord barrier suggests induced pharmacoresistance in ALS

NEUROBIOLOGY OF DISEASE

卷:47

Article

Jablonski, Michael R.¹  Jacob, Dena A.¹  Campos, Christopher²  Miller, David S.²  Maragakis, Nicholas J.³  Pasinelli, Piera¹  Trotti, Davide¹ 

[1] Thomas Jefferson Univ, Dept Neurosci, Farber Inst Neurosci, Weinberg Unit ALS Res, Philadelphia, PA 19107 USA

[2] NIEHS, Lab Toxicol & Pharmacol, NIH, Res Triangle Pk, NC 27709 USA

[3] Johns Hopkins Univ, Dept Neurol, Sch Med, Baltimore, MD 21287 USA

关键词: Amyotrophic Lateral Sclerosis;    ABC transporters;    P-glycoprotein;    Breast cancer resistance protein;    Blood-brain barrier;    Blood-spinal cord barrier;    Pharmacoresistance;   

DOI  :  10.1016/j.nbd.2012.03.040

来源: Elsevier

【 摘 要 】

ATP-binding cassette (ABC) drug efflux transporters in the CNS are predominantly localized to the luminal surface of endothelial cells in capillaries to impede CNS accumulation of xenobiotics. Inflammatory mediators and cellular stressors regulate their activity. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of upper and lower motor neurons characterized by extensive neuroinflammation. Here we tested the hypothesis that disease-driven changes in ABC transporter expression and function occur in ALS. Given the multitude of ABC transporters with their widespread substrate recognition, we began by examining expression levels of several ABC transporters. We found a selective increase in only two transporters: P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) both at mRNA and protein levels, in the SOD1-G93A mouse model of ALS, specifically in disease-affected CNS regions. Detailed analysis revealed a similar disease-driven increase in P-gp and BCRP levels in spinal cord microvessels, indicating that their altered expression occurs at the blood spinal cord barrier. Transport activity of P-gp and BCRP increased with disease progression in spinal cord and cerebral cortex capillaries. Finally, P-gp and BCRP protein expression also increased in spinal cords of ALS patients. Preclinical drug trials in the mouse model of ALS have failed to decisively slow or arrest disease progression; pharmacoresistance imparted by ABC transporters is one possible explanation for these failures. Our observations have large implications for ALS therapeutics in humans and suggest that the obstacle provided by these transporters to drug treatments must be overcome to develop effective ALS pharmacotherapies. (C) 2012 Elsevier Inc. All rights reserved.

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