Increased ATP production and P-glycoprotein activity underlie the marked changes in blood-brain barrier transport of drugs in a mouse model of amyotrophic lateral sclerosis.

Background And Purpose: Patients with amyotrophic lateral sclerosis (ALS) are prescribed many medications for symptomatic relief. However, how potential alterations to the blood-brain barrier (BBB) affect the brain exposure of drugs in ALS remains under-investigated.

Experimental Approach: We used high-dimensional proteomic analysis, cellular metabolism, and mitochondrial functional assays to characterise isolated brain microvascular endothelial cells (BMECs) from wildtype and SOD1 transgenic mice, a mouse model of familial ALS, at a late-symptomatic age (P115-120), together with a transcardiac brain perfusion technique to assess BBB function in situ.

Ferric Ammonium Citrate Reduces Claudin-5 Abundance and Function in Primary Mouse Brain Endothelial Cells.

Background: Iron overload is implicated in many neurodegenerative diseases, where there is also blood-brain barrier (BBB) dysfunction. As there is a growing interest in the role of iron in modulating key BBB proteins, this study assessed the effect of iron on the expression and function of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and claudin-5 in primary mouse brain endothelial cells (MBECs) and their abundance in mouse brain microvessel-enriched membrane fractions (MVEFs).

Methods: Following a 48 h treatment with ferric ammonium citrate (FAC, 250 µM), MBEC protein abundance (P-gp, BCRP and claudin-5) and mRNA (abcb1a, abcg2, and cldn5) were assessed by western blotting and RT-qPCR, respectively.

Cu(ATSM) Increases P-Glycoprotein Expression and Function at the Blood-Brain Barrier in C57BL6/J Mice.

P-glycoprotein (P-gp), expressed at the blood-brain barrier (BBB), is critical in preventing brain access to substrate drugs and effluxing amyloid beta (Aβ), a contributor to Alzheimer's disease (AD). Strategies to regulate P-gp expression therefore may impact central nervous system (CNS) drug delivery and brain Aβ levels. As we have demonstrated that the copper complex copper diacetyl bis(4-methyl-3-thiosemicarbazone) (Cu(ATSM)) increases P-gp expression and function in human brain endothelial cells, the present study assessed the impact of Cu(ATSM) on expression and function of P-gp in mouse brain endothelial cells (mBECs) and capillaries in vivo, as well as in peripheral organs.