Regulation of blood-brain barrier Na,K,2Cl-cotransporter through phosphorylation during in vitro stroke conditions and nicotine exposure

被引:60
作者
Abbruscato, TJ [1 ]
Lopez, SP [1 ]
Roder, K [1 ]
Paulson, JR [1 ]
机构
[1] Texas Tech Univ, Hlth Sci Ctr, Sch Pharm, Dept Pharmaceut Sci, Amarillo, TX 79106 USA
关键词
D O I
10.1124/jpet.104.066274
中图分类号
R9 [药学];
学科分类号
1007 ;
摘要
Nicotine, a major constituent of tobacco smoke, has important effects on brain recovery after focal ischemia ( Wang et al., 1997). The purpose of this work is to systematically test the effects of nicotine during stroke conditions on blood-brain barrier (BBB) potassium transport, protein expression of the Na, K, 2Cl-cotransporter (NKCC), and cell signaling pathways that control NKCC activity at the BBB. Confluent bovine brain microvessel endothelial cells (BBMECs) were exposed to both a hypoxic/aglycemic (H/A) environment to model BBB function during stroke conditions and nicotine and cotinine (N/C) to model plasma levels seen in smokers. BBMECs exhibit both Na, K-ATPase and NKCC activity ( 60 and 34 nmol/min/g, respectively) that contribute to 98% of the K+ uptake in cultured endothelial cells. An adaptive up-regulation of NKCC activity was identified to occur on the basolateral surface of the BBB after in vitro stroke conditions. Twenty-four hours of N/C exposure, at doses equivalent to plasma levels of smokers, combined with 6 h of H/A, reduced NKCC protein expression and total NKCC activity ( shown by bumetanide-sensitive (RB)-R-86 uptake) compared with 6 h of H/A alone ( P < 0.01). Basolateral K+ transport was found to be modulated by nicotinic acetylcholine receptors expressed at the BBB. NKCC activity on the basolateral surface of the BBB is controlled by an ongoing phosphorylation/ dephosphorylation processes. We have identified a potential mechanism in altered BBB response to stroke conditions with prior N/C exposure directly implicating damage to brain-to-blood K+ transport mediated at the BBB and perhaps neuronal recovery after stroke.
引用
收藏
页码:459 / 468
页数:10
相关论文
共 36 条
[1]  
Abbruscato TJ, 1999, J PHARMACOL EXP THER, V289, P668
[2]   Protein expression of brain endothelial cell E-cadherin after hypoxia/aglycemia: influence of astrocyte contact [J].
Abbruscato, TJ ;
Davis, TP .
BRAIN RESEARCH, 1999, 842 (02) :277-286
[3]   Nicotine and cotinine modulate cerebral microvascular permeability and protein expression of ZO-1 through nicotinic acetylcholine receptors expressed on brain endothelial cells [J].
Abbruscato, TJ ;
Lopez, SP ;
Mark, KS ;
Hawkins, BT ;
Davis, TP .
JOURNAL OF PHARMACEUTICAL SCIENCES, 2002, 91 (12) :2525-2538
[4]  
[Anonymous], 2000, HANDB EXP PHARM
[5]   BOVINE BRAIN MICROVESSEL ENDOTHELIAL-CELL MONOLAYERS AS A MODEL SYSTEM FOR THE BLOOD-BRAIN-BARRIER [J].
AUDUS, KL ;
BORCHARDT, RT .
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES, 1987, 507 :9-18
[6]   CHARACTERIZATION OF AN INVITRO BLOOD-BRAIN-BARRIER MODEL SYSTEM FOR STUDYING DRUG TRANSPORT AND METABOLISM [J].
AUDUS, KL ;
BORCHARDT, RT .
PHARMACEUTICAL RESEARCH, 1986, 3 (02) :81-87
[7]   POLARITY OF THE BLOOD-BRAIN-BARRIER - DISTRIBUTION OF ENZYMES BETWEEN THE LUMINAL AND ANTILUMINAL MEMBRANES OF BRAIN CAPILLARY ENDOTHELIAL-CELLS [J].
BETZ, AL ;
FIRTH, JA ;
GOLDSTEIN, GW .
BRAIN RESEARCH, 1980, 192 (01) :17-28
[8]   EFFLUX MECHANISM CONTRIBUTING TO STABILITY OF POTASSIUM CONCENTRATION IN CEREBROSPINAL FLUID [J].
BRADBURY, MW ;
STULCOVA, B .
JOURNAL OF PHYSIOLOGY-LONDON, 1970, 208 (02) :415-+
[9]   JUNCTIONS BETWEEN INTIMATELY APPOSED CELL MEMBRANES IN VERTEBRATE BRAIN [J].
BRIGHTMA.MW ;
REESE, TS .
JOURNAL OF CELL BIOLOGY, 1969, 40 (03) :648-+
[10]  
BRUNING JL, 1977, COMPUTATIONAL HDB ST, P112