Dataset Information
Ion transport function of SLC4A11 in corneal endothelium.
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ABSTRACT: Purpose
Mutations in SLC4A11, a member of the SLC4 superfamily of bicarbonate transporters, give rise to corneal endothelial cell dystrophies. SLC4A11 is a putative Na? borate and Na?:OH? transporter. Therefore we ask whether SLC4A11 in corneal endothelium transports borate (B[OH]??), bicarbonate (HCO3?), or hydroxyl (OH?) anions coupled to Na?.Methods
SLC4A11 expression in cultured primary bovine corneal endothelial cells (BCECs) was determined by semiquantitative PCR, SDS-PAGE/Western blotting, and immunofluorescence staining. Ion transport function was examined by measuring intracellular pH (pHi) or Na? ([Na?](i)) in response to Ringer solutions with/without B(OH)?? or HCO?? after overexpressing or small interfering RNA (siRNA) silencing of SLC4A11.Results
SLC4A11 is localized to the basolateral membrane in BCEC. B(OH)?? (2.5-10 mM) in bicarbonate-free Ringer induced a rapid small acidification (0.01 pH unit) followed by alkalinization (0.05-0.1 pH unit), consistent with diffusion of boric acid into the cell followed by B(OH)??. However, the rate of B(OH)??-induced pHi change was unaffected by overexpression of SLC4A11. B(OH)?? did not induce significant changes in resting [Na?(i)] or the amplitude and rate of acidification caused by Na? removal. siRNA-mediated knockdown of SLC4A11 (?70%) did not alter pHi responses to CO?/HCO??-rich Ringer, Na?-free induced acidification, or the rate of Na? influx in the presence of bicarbonate. However, in the absence of bicarbonate, siSLC4A11 knockdown significantly decreased the rate (43%) and amplitude (48%) of acidification due to Na? removal and recovery (53%) upon add-back. Additionally, the rate of acid recovery following NH?? prepulse was decreased significantly (27%) by SLC4A11 silencing.Conclusions
In corneal endothelium, SLC4A11 displays robust Na?-coupled OH? transport, but does not transport B(OH)?? or HCO??.
SUBMITTER: Jalimarada SS
PROVIDER: S-EPMC3691053 | biostudies-literature | 2013 Jun
REPOSITORIES: biostudies-literature
Publications
Ion transport function of SLC4A11 in corneal endothelium.
Investigative ophthalmology & visual science 20130621 6
<h4>Purpose</h4>Mutations in SLC4A11, a member of the SLC4 superfamily of bicarbonate transporters, give rise to corneal endothelial cell dystrophies. SLC4A11 is a putative Na⁺ borate and Na⁺:OH⁻ transporter. Therefore we ask whether SLC4A11 in corneal endothelium transports borate (B[OH]₄⁻), bicarbonate (HCO3⁻), or hydroxyl (OH⁻) anions coupled to Na⁺.<h4>Methods</h4>SLC4A11 expression in cultured primary bovine corneal endothelial cells (BCECs) was determined by semiquantitative PCR, SDS-PAGE/ ...[more]
