Increased vesicle recycling in response to osmotic cell swelling. Cause and consequence of hypotonicity-provoked ATP release.
Osmotic swelling of Intestine 407 cells leads to an immediate increase in cell surface membrane area as determined using the fluorescent membrane dye FM 1-43. In addition, as measured by tetramethylrhodamine isothiocyanate (TRITC)-dextran uptake, a robust (>100-fold) increase in the rate of endocytosis was observed, starting after a discrete lag time of 2-3 min and lasting for approximately 10-15 min. The hypotonicity-induced increase in membrane surface area, like the cell swelling-induced release of ATP (Van der Wijk, T., De Jonge, H. R., and Tilly, B. C. (1999) Biochem. J. 343, 579-586), was diminished after 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester loading or cytochalasin B treatment. Uptake of TRITC-dextrans, however, was not affected. Treatment of the cells with the vesicle-soluble N-ethylmaleimide-sensitive factor attachment protein receptor-specific protease Clostridium botulinum toxin F not only nearly eliminated the hypotonicity-induced increase in membrane surface area but also strongly diminished the release of ATP, indicating the involvement of regulated exocytosis. Both the ATP hydrolase apyrase and the MEK inhibitor PD098059 diminished the osmotic swelling-induced increase in membrane surface area as well as the subsequent uptake of TRITC-dextrans. Taken together, the results indicate that extracellular ATP is required for the hypotonicity-induced vesicle recycling and suggest that a positive feedback loop, involving purinergic activation of the Erk-1/2 pathway, may contribute to the release of ATP from hypo-osmotically stimulated cells.
van der Wijk
Thea
T
Department of Biochemistry, Erasmus University Medical Center, 3000DR Rotterdam, The Netherlands.
Tomassen
Sebastian F B
SF
Houtsmuller
Adriaan B
AB
de Jonge
Hugo R
HR
Tilly
Ben C
BC
D000255:Adenosine Triphosphate / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D048429:Cell Size / Q000502:physiology*; D003911:Dextrans; D004705:Endocytosis; D005089:Exocytosis; D005246:Feedback; D005456:Fluorescent Dyes; D006801:Humans; D007038:Hypotonic Solutions; D020935:MAP Kinase Signaling System; D009997:Osmotic Pressure; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D012235:Rhodamines
D003911:Dextrans; C073804:FM1 43; D005456:Fluorescent Dyes; D007038:Hypotonic Solutions; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D012235:Rhodamines; C009434:tetramethylrhodamine isothiocyanate; D000255:Adenosine Triphosphate