TY - JOUR
T1 - Transepithelial bioelectrical properties of rabbit acinar cell monolayers on polyester membrane scaffolds
AU - Selvam, Shivaram
AU - Thomas, Padmaja B.
AU - Gukasyan, Hovhannes J.
AU - Yu, Alan S.
AU - Stevenson, Douglas
AU - Trousdale, Melvin D.
AU - Mircheff, Austin K.
AU - Schechter, Joel E.
AU - Smith, Ronald E.
AU - Yiu, Samuel C.
PY - 2007/10
Y1 - 2007/10
N2 - In our quest to develop a tissue-engineered tear secretory system, we have tried to demonstrate active transepithelial ion fluxes across rabbit lacrimal acinar cell monolayers on polyester membrane scaffolds to evaluate the bioelectrical properties of the cultured cells. Purified lacrimal gland acinar cells were seeded onto polyester membrane inserts and cultured to confluency. Morphological properties of the cell monolayers were evaluated by transmission electron microscopy and immunofluorescence staining for Na+,K +-ATPase and the tight junction-associated protein occludin. Sections revealed cell monolayers with well-maintained epithelial cell polarity, i.e., presence of apical (AP) secretory granules, microvilli, and junctional complexes. Na+,K+-ATPase was localized on both the basal-lateral and apical plasma membranes. The presence of tight cell junctions was demonstrated by a positive circumferential stain for occludin. Bioelectrical properties of the cell monolayers were studied in Ussing chambers under short-circuit conditions. Active ion fluxes were evaluated by inhibiting the short-circuit current (Isc) with a Na+,K +-ATPase inhibitor, ouabain (100 μM; basal-lateral, BL), and under Cl--free buffer conditions after carbachol stimulation (CCh; 100 μM). The directional apical secretion of Cl- was demonstrated through pharmacological analysis, using amiloride (1 mM; BL) and bumetanide (0.1 mM; BL), respectively. Regulated protein secretion was evaluated by measuring the β-hexosaminidase catalytic activity in the AP culture medium in response to 100 μM basal CCh. In summary, rabbit lacrimal acinar cell monolayers generate a Cl--dependent, ouabain-sensitive AP → BL Isc in response to CCh, consistent with current models for Na +-dependent Cl- secretion.
AB - In our quest to develop a tissue-engineered tear secretory system, we have tried to demonstrate active transepithelial ion fluxes across rabbit lacrimal acinar cell monolayers on polyester membrane scaffolds to evaluate the bioelectrical properties of the cultured cells. Purified lacrimal gland acinar cells were seeded onto polyester membrane inserts and cultured to confluency. Morphological properties of the cell monolayers were evaluated by transmission electron microscopy and immunofluorescence staining for Na+,K +-ATPase and the tight junction-associated protein occludin. Sections revealed cell monolayers with well-maintained epithelial cell polarity, i.e., presence of apical (AP) secretory granules, microvilli, and junctional complexes. Na+,K+-ATPase was localized on both the basal-lateral and apical plasma membranes. The presence of tight cell junctions was demonstrated by a positive circumferential stain for occludin. Bioelectrical properties of the cell monolayers were studied in Ussing chambers under short-circuit conditions. Active ion fluxes were evaluated by inhibiting the short-circuit current (Isc) with a Na+,K +-ATPase inhibitor, ouabain (100 μM; basal-lateral, BL), and under Cl--free buffer conditions after carbachol stimulation (CCh; 100 μM). The directional apical secretion of Cl- was demonstrated through pharmacological analysis, using amiloride (1 mM; BL) and bumetanide (0.1 mM; BL), respectively. Regulated protein secretion was evaluated by measuring the β-hexosaminidase catalytic activity in the AP culture medium in response to 100 μM basal CCh. In summary, rabbit lacrimal acinar cell monolayers generate a Cl--dependent, ouabain-sensitive AP → BL Isc in response to CCh, consistent with current models for Na +-dependent Cl- secretion.
KW - Epithelial ion channels
KW - Lacrimal gland
KW - Na /H exchangers
KW - Na-K-2Cl symporters
KW - Short-circuit current
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UR - http://www.scopus.com/inward/citedby.url?scp=35048886470&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.00200.2007
DO - 10.1152/ajpcell.00200.2007
M3 - Article
C2 - 17699637
AN - SCOPUS:35048886470
SN - 0363-6143
VL - 293
SP - C1412-C1419
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
IS - 4
ER -