A new multidrug resistance protein at the blood-brain barrier.

Porcine brain capillary endothelial cells (PBCEC) cultured in serum-free and hydrocortisone supplemented medium are characterised by high transendothelial electrical resistances and low cell monolayer permeabilities for small solutes very similar to the blood-brain barrier (BBB) in vivo. Differential screening of a subtracted cDNA library disclosed a 2.1-kb mRNA that is overexpressed in hydrocortisone treated PBCEC relative to untreated cells. The mRNA encodes a 656-aa member of the ATP-binding cassette (ABC) superfamily of transporters that we named brain multidrug resistance protein (BMDP). Phylogenetic analysis and multiple sequence alignment showed that porcine BMDP is most related to the human and mouse breast cancer resistance protein (BCRP). Northern blot analysis revealed that BMDP is expressed in brain tissue in vivo and was predominantly localised within the endothelial cells isolated from brain capillaries. Thus, we identified a new transport protein at the BBB that might play an important role in the exclusion of xenobiotics from the brain.

[1]  M. J. van de Vijver,et al.  Subcellular localization and distribution of the breast cancer resistance protein transporter in normal human tissues. , 2001, Cancer research.

[2]  M. Kuo,et al.  BCRP/MXR/ABCP expression in topotecan-resistant human breast carcinoma cells. , 2000, Biochemical pharmacology.

[3]  L. Doyle,et al.  Expression of breast cancer resistance protein in blast cells from patients with acute leukemia , 2000 .

[4]  Donald W. Miller,et al.  Expression of various multidrug resistance-associated protein (MRP) homologues in brain microvessel endothelial cells , 2000, Brain Research.

[5]  M Dietel,et al.  Atypical multidrug resistance: breast cancer resistance protein messenger RNA expression in mitoxantrone-selected cell lines. , 1999, Journal of the National Cancer Institute.

[6]  F H Hausheer,et al.  Circumvention of breast cancer resistance protein (BCRP)-mediated resistance to camptothecins in vitro using non-substrate drugs or the BCRP inhibitor GF120918. , 2001, Clinical cancer research : an official journal of the American Association for Cancer Research.

[7]  C. Praul,et al.  Detection of endogenous biotin-containing proteins in bone and cartilage cells with streptavidin systems. , 1998, Biochemical and biophysical research communications.

[8]  G. Fricker,et al.  Xenobiotic efflux pumps in isolated fish brain capillaries. , 2002, American journal of physiology. Regulatory, integrative and comparative physiology.

[9]  J. Walker,et al.  Distantly related sequences in the alpha‐ and beta‐subunits of ATP synthase, myosin, kinases and other ATP‐requiring enzymes and a common nucleotide binding fold. , 1982, The EMBO journal.

[10]  H. Galla,et al.  Primary cultures of brain microvessel endothelial cells: a valid and flexible model to study drug transport through the blood-brain barrier in vitro. , 2000, Brain research. Brain research protocols.

[11]  J. Wijnholds,et al.  The mouse Bcrp1/Mxr/Abcp gene: amplification and overexpression in cell lines selected for resistance to topotecan, mitoxantrone, or doxorubicin. , 1999, Cancer research.

[12]  Vincenzo,et al.  A human placenta-specific ATP-binding cassette gene (ABCP) on chromosome 4q22 that is involved in multidrug resistance. , 1998, Cancer research.

[13]  J. Schellens,et al.  Overexpression of the BCRP/MXR/ABCP gene in a topotecan-selected ovarian tumor cell line. , 1999, Cancer research.

[14]  D. Gautheret,et al.  Patterns of variant polyadenylation signal usage in human genes. , 2000, Genome research.

[15]  L. Doyle,et al.  A multidrug resistance transporter from human MCF-7 breast cancer cells. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[16]  Y. Pommier,et al.  Camptothecin resistance: role of the ATP-binding cassette (ABC), mitoxantrone-resistance half-transporter (MXR), and potential for glucuronidation in MXR-expressing cells. , 1999, Cancer research.

[17]  T. Litman,et al.  Molecular cloning of cDNAs which are highly overexpressed in mitoxantrone-resistant cells: demonstration of homology to ABC transport genes. , 1999, Cancer research.

[18]  M. Melamed,et al.  Multidrug-resistance gene (P-glycoprotein) is expressed by endothelial cells at blood-brain barrier sites. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[19]  J. Schellens,et al.  Role of breast cancer resistance protein in the bioavailability and fetal penetration of topotecan. , 2000, Journal of the National Cancer Institute.

[20]  A. Schinkel,et al.  P-Glycoprotein, a gatekeeper in the blood-brain barrier. , 1999, Advanced drug delivery reviews.

[21]  H. Galla,et al.  Hydrocortisone reinforces the blood-brain barrier properties in a serum free cell culture system. , 1998, Biochemical and biophysical research communications.