Functional induction of P-glycoprotein in the blood-brain barrier of streptozotocin-induced diabetic rats: evidence for the involvement of nuclear factor-kappaB, a nitrosative stress-sensitive transcription factor, in the regulation.
The objective of this study was to investigate the transport kinetics of cyclosporin A, a well known substrate for P-glycoprotein (P-gp), across the blood-brain barrier (BBB), and the expression of the transporter in the brain of streptozotocin-induced diabetic rats. The in vivo transport clearance of cyclosporin A was significantly reduced in diabetic rats compared with that in the control. The decreased transport was associated with the increased level of mRNA and the protein for P-glycoprotein in the rat brain. The functional activity of the efflux transporter in mouse brain capillary endothelial (MBEC4) cells, an in vitro model of the BBB, was also stimulated when slow nitric oxide (NO)-releasing donors were present, whereas the stimulation was absent in the case of rapid NO-releasing donors (e.g., S-nitroso-N-acetyl-dl-penicillamine and diethylenetriamine). The stimulatory effect was highest for sodium nitroprusside (SNP) and the functional induction associated with the increased mRNA and protein level of the transporter. The pretreatment of the cell with SNP along with ascorbate, methylene blue, or superoxide dismutase attenuated the induction of function and expression for P-glycoprotein, suggesting that the reaction product between superoxide and NO is involved in the induction of function and expression. The level of nuclear translocation of nuclear factor-kappaB (NF-kappaB) and DNA binding activity of nuclear extracts to the NF-kappaB consensus oligonucleotide was increased in MBEC4 cells pretreated with SNP. Taken together, these observations suggest that nitrosative stress leads to the up-regulation of the message for the efflux transporter and, ultimately, to the enhanced function, probably via a NF-kappaB-dependent mechanism.
Department of Pharmaceutics, College of Pharmacy, Seoul National University, Kwanak-gu, Seoul, Korea.
Han-Joo
HJ
Maeng
Mi-Hwa
MH
Kim
Hyo-Eon
HE
Jin
Sang Mi
SM
Shin
Takasi
T
Tsuruo
Sang Geon
SG
Kim
Dae-Duk
DD
Kim
Chang-Koo
CK
Shim
Suk-Jae
SJ
Chung
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics / Q000378:metabolism; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000378:metabolism*; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009573:Nitrites / Q000097:blood / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism; D000097202:ATP-Binding Cassette Sub-Family B Member 4
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000975:Antioxidants; D001786:Blood Glucose; D016166:Free Radical Scavengers; D016328:NF-kappa B; D020030:Nitric Oxide Donors; D009573:Nitrites; D013481:Superoxides; D000097202:ATP-Binding Cassette Sub-Family B Member 4; C423013:Abcc2 protein, rat; C095122:multidrug resistance protein 3