Whole cell potassium currents in fetal rat alveolar type II cells cultured on Matrigel matrix

1996 ◽  
Vol 270 (4) ◽  
pp. L577-L586 ◽  
Author(s):  
S. Liu ◽  
A. J. Mautone
Keyword(s):  
Patch Clamp ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Whole Cell ◽  
Fetal Rat ◽  
Matrigel Matrix ◽  
Cells Cultured ◽  
In Cells

Patch-clamp studies were performed on fetal rat alveolar type II cells isolated at 19 days of gestation and cultured on either plastic for 7 days or Matrigel matrix (40-50 microliters/cm2) for 10 days. Before study, cells cultured on Matrigel matrix were dissociated from alveolar-like structures with enzymes, replated, and washed with cold buffer at a constant flow rate to remove residual gel. This wash significantly improved obtaining of successful seals. Potassium current-voltage relationships and maximum whole cell K+ conductance (normalized to membrane capacitance) were significantly changed with time in cells cultured on plastic, but no significant change occurred in cells cultured on Matrigel matrix. Application of 20 mM tetraet hyl ammonium, 2mM 4-aminopyridine, and 5mM BaCl2 significantly inhibited K+ currents, showing differences in channel sensitivity to these agents and a voltage-dependent blockage between culture groups or with time in culture. To conclude, we have developed a new method by which epithelial cells cultured on Matrigel matrix can be successfully studied with the use of patch-clamp techniques. Furthermore, these studies show that fetal type II cells have voltage-activated K+ channels and that channel density and their sensitivity to channel blockers are modulated by the substratum on which the cells are cultured.

scholarly journals Patch-clamp study of primarily cultured alveolar type II cells: Property of outward current.

1991 ◽  
Vol 55 ◽  
pp. 118
Author(s):  
Kazuo Takahama ◽  
Hiroshi Watajima ◽  
Hirofumi Kai ◽  
Takeshi Miyata
Keyword(s):  
Patch Clamp ◽  
Outward Current ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Clamp Study

Isolation of alveolar type II cells from fetal rat lung by differential adherence in monolayer culture

1988 ◽  
Vol 960 (3) ◽  
pp. 441-453 ◽  
Author(s):  
Joseph J. Batenburg ◽  
Caroline J.M. Otto-Verberne ◽  
Ank A.W. Ten Have-Opbroek ◽  
Wies Klazinga
Keyword(s):  
Monolayer Culture ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Rat Lung ◽  
Alveolar Type Ii Cells ◽  
Fetal Rat ◽  
Fetal Rat Lung

Modulation of bioelectric properties across alveolar type II cells by substratum

1989 ◽  
Vol 257 (4) ◽  
pp. C678-C688 ◽  
Author(s):  
G. R. Cott
Keyword(s):  
Cell Morphology ◽  
Short Circuit ◽  
Alveolar Type ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Capacitance Effects ◽  
Short Circuit Currents ◽  
Cells Cultured

Rat alveolar type II cells were cultured on collagen-coated filters (CCF) and human amnionic basement membrane (ABM) to determine the effect of culture substratum on the development of monolayer bioelectric properties. Monolayers cultured on both substrata rapidly developed bioelectric properties with similar time courses, monolayer capacitance values (approximately 1 muF/cm2), current-voltage relationships, and responses to stimulants and inhibitors of active ion transport. Increasing seeding densities tended to increase monolayer bioelectric properties regardless of culture substratum. Monolayers cultured on ABM had higher resistance values (491 vs. 291 omega.cm2) and lower short-circuit currents (2.85 vs. 4.51 muA/cm2) than monolayers with similar cell densities cultured on CCF. These differences in monolayer bioelectric properties were not due to differences in substratum resistance or capacitance effects. The relationships between monolayer bioelectric properties were also affected by the culture substratum. In additional experiments, cells cultured on contracted gels formed monolayers with high short-circuit currents (9.25 muA/cm2). Cell morphology varied depending on the culture substratum, with cells cultured on contracted gels appearing the most cuboidal, whereas the flattest and most attenuated cells were those cultured on ABM. On the basis of these observations, we conclude that culture substratum significantly affects the development of bioelectric properties across alveolar type II cell monolayers. In vivo the bioelectric properties across the alveolar epithelium may also vary with changes in cellular substratum or cell density (e.g., after acute lung injury) and possibly with cell morphology (e.g., alveolar type I vs. alveolar type II cells).

scholarly journals Mechanical strain of alveolar type II cells in culture: changes in the transcellular cytokeratin network and adaptations

2008 ◽  
Vol 295 (5) ◽  
pp. L849-L857 ◽  
Author(s):  
Edward Felder ◽  
Marcus Siebenbrunner ◽  
Tobias Busch ◽  
Giorgio Fois ◽  
Pika Miklavc ◽  
...  
Keyword(s):  
Structural Changes ◽  
Cell Damage ◽  
Tensile Force ◽  
Expression Patterns ◽  
Mechanical Strain ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
In Cells

Mechanical forces exert multiple effects in cells, ranging from altered protein expression patterns to cell damage and death. Despite undisputable biological importance, little is known about structural changes in cells subjected to strain ex vivo. Here, we undertake the first transmission electron microscopy investigation combined with fluorescence imaging on pulmonary alveolar type II cells that are subjected to equibiaxial strain. When cells are investigated immediately after stretch, we demonstrate that curved cytokeratin (CK) fibers are straightened out at 10% increase in cell surface area (CSA) and that this is accompanied by a widened extracellular gap of desmosomes–the insertion points of CK fibers. Surprisingly, a CSA increase by 20% led to higher fiber curvatures of CK fibers and a concurrent return of the desmosomal gap to normal values. Since 20% CSA increase also induced a significant phosphorylation of CK8-ser431, we suggest CK phosphorylation might lower the tensile force of the transcellular CK network, which could explain the morphological observations. Stretch durations of 5 min caused membrane injury in up to 24% of the cells stretched by 30%, but the CK network remained surprisingly intact even in dead cells. We conclude that CK and desmosomes constitute a strong transcellular scaffold that survives cell death and hypothesize that phosphorylation of CK fibers is a mechano-induced adaptive mechanism to maintain epithelial overall integrity.

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