Basolateral pressure challenges mammary epithelial cell monolayer integrity, in vitro
- 140 Downloads
Mammary gland epithelium is physiologically exposed to variations of hydrostatic pressure due to accumulation of milk and removal by suckling and mechanical milking. Integrity of the mammary gland epithelium primarily relies on the tight junction. To analyze pressure-induced effects on the tight junction, we established a modified Ussing chamber and tested the hypothesis if hydrostatic pressure on the basal side of the epithelium is able to affect barrier properties in a mammary epithelial cell model, in vitro. Therefore, a conventional Ussing chamber was modified by an additional tube system to apply hydrostatic pressure. Monolayers of the mammary epithelial cell line HC11 were mounted in the modified Ussing chambers and incubated with increasing basal hydrostatic pressure. Transepithelial resistance and short circuit current were recorded and compared to controls. Hydrostatic pressure was stably applied and incubation steps of 30 min were technically feasible, leading to a decrease of transepithelial resistance and an increase of short circuit current in all monolayers. In a series of experiments simulating the physiological exposure time by short intervals of 5 min, these electrophysiological findings were also observed, and monolayer integrity was not significantly perturbed as analyzed by fluorescence immunohistochemistry selectively staining tight junction proteins. Moreover, electrophysiology demonstrated reversibility of effects. In conclusion, the modified Ussing chamber is an adequate method to analyze the effects of hydrostatic pressure on epithelial cell monolayers, in vitro. Both, the reduction of transepithelial resistance and the increase of short circuit current may be interpreted as protective reactions.
KeywordsBarrier function Tight junction Ussing chamber Hydrostatic pressure Mammary gland HC11
We thank Martin Grunau, Katharina Söllig, Uwe Tietjen, and Susanne Trappe for excellent technical assistance. This work was supported by the Center for International Cooperation of the Freie Universität Berlin [Grant No. FSP2016-300], the Deutsche Forschungsgemeinschaft [Grant No. AM 141/11-1], and the Sonnenfeld-Stiftung [doctoral studies Grant to K.S. Mießler].
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Ball RK, Friis RR, Schonenberger CA, Doppler W, Groner B (1988) Prolactin regulation of ß-casein gene expression and of a cytosolic 120-kd protein in a cloned mouse mammary epithelial cell line. EMBO J 7:2089–2095Google Scholar
- Chen SK, Chung CA, Cheng YC, Huang CJ, Ruaan RC, Chen WY, Li C, Tsao CW, Hu WW, Chien CC (2014) Hydrostatic pressure enhances mitomycin C induced apoptosis in urothelial carcinoma cells. Urol Oncol 32:26.e17–24Google Scholar
- Dittmann I, Amasheh M, Krug SM, Markov AG, Fromm M, Amasheh S (2014) Laurate permeabilizes the paracellular pathway for small molecules in the intestinal epithelial cell model HT-29/B6 via opening the tight junctions by reversible relocation of claudin-5. Pharm Res 31:2539–2548CrossRefGoogle Scholar
- Furuya K, Enomoto K, Maeno T, Yamagishi S (1993) Mechanically induced calcium signal in mammary epithelial cells. Jpn J Physiol 43:105–108Google Scholar
- Sachs F (1992) Stretch-sensitive ion channels: an update. Soc Gen Physiol Ser 47:241–260Google Scholar