The role of MDR1 gene in volume-activated chloride currents in pigmented ciliary epithelial cells.
The role of multidrug resistance (MDR1) gene in the activation of volume-activated chloride currents in bovine pigmented ciliary epithelial (PCE) cells was investigated by the patch-clamp technique, the antisense approach, the immunofluorescent technique and the confocal microscopy. PCE cells express P-glycoprotein (P-gp, the product of MDR1 gene). An MDR1 antisense oligonucleotide suppressed MDR1 expression (93% reduction of P-gp immunofluorescence), delayed the activation of a volume-activated chloride current (latency prolonged by 109%), reduced the activation rate by 62% and decreased the peak value of the current by 56%. The transfection reagent lipofectin and the mismatch control oligonucleotide did not significantly affect the current. The data indicate that the volume-activated chloride current is associated with the endogenous expression of MDR1 gene in PCE cells.
Chen
Li-Xin
LX
Laboratory of Cell Biology, Guangdong Medical College, Zhanjiang 524023, China  Cardiff School of Biosciences, Cardiff University, Cardiff, UK. CHENL1@cardiff.ac.uk
Wang
Li-Wei
LW
Jacob
Tim
T
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D018118:Chloride Channels / Q000502:physiology*; D002924:Ciliary Body / Q000166:cytology* / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression / Q000187:drug effects; D019450:Genes, MDR / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018118:Chloride Channels; D016376:Oligonucleotides, Antisense