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Histamine secretion from mast cells and basophils
TIPS- May 1984
!~,3
Histamine secretion from mast cells and basophils i~n the October 1983 issue of TIPS, Reuben P. Siraganian reviewed the biochemical events which accompany basophil/mast cell activationL We find ~t of importance to question two aspects of the review, i.e. the justification (1) of employing basophils and mast cells as a unifying model for a secretory system ,rod (2) of using 4-~Cauptake as evidence 'for a function of calcium in the release process. SiragavJan introduces mast cells and basophils as a model for cell secretion, with the reservation that 'it might turn out that some of the mediators produced by the cells are different and/or ~.here might be differences in the mechanism of release'. Differences between the control of histamine release from mast cells and basophils are indeed recognized 2-4, and recently even the heterogeneity of mast cells of different origin has been emphasized 5, further stressing the problem of creating unifying models. Thus, it is hardly conceivable that models based on findings with rat basophilic leukemia (RBL) cell lines (i.e. neoplastic cells) will overcome this problem. However, Siraganian apparently forgets about reservations, and throughout the review presents mast cells and basophils as an entity. The diversity of histamine-containing cells is also evident when biochemical events during histamine release are considered, e.g. phospholipid methylation and calcium influx. In RBL cells the 45Ca influx appeared to occur simultaneously with the increase in phospholipid methylation and was followed by histamine release '~. In human mast cells phospholipid methylation appeared to precede 45Ca influx, which was, in turn, followed by histamine release 7. In rat mast cells the phospholipid methylation preceded the essentially identical time courses for "~SCa influx and histamine release s . Coinciding time courses for 45Ca uptake and histamine release in rat mast cells are in accordance with findings elsewhere 9. The observed 45Ca fluxes are frequently used as evidence for a messenger function of calcium in the release process, and a positive correlation between inhibition of 45Ca uptake and histamine release is considered as further support of this
assumption t's''~. However, these findings neither indicate nor exclude a causal relation between the 45Ca uptake and the histamine release and should be interpreted with caution ~ 2 . Quantitatively, the 4"~Ca uptake observed in connection with histamine release is equivalent to influx and/or exchange of 0.5-5 mM of cellular calcium, as calculated from various studies with rat mast cells8'9'11. Fluxes of this magnitude seem incompatible with a messenger or signalling function of calcium in the release process, since such a function implies much higher sensitivity ~z. Thus, in the resting cell, the cytosolic free calcium concentration is in the range of 10-8 - 5 × 10 -7 M, and stimulus-response coupling is brought about by increases of free cytosolic calcium to the pI.M concentration range ~ 5 . The latter estimate is supported by observations with ATPtreated rat mast cells ~6. This increase can be established by an influx and/or by mobilization of calcium from intracellular sites. These perturbations of the calcium homeostasis are, however, not believed to involve the entire cell. since diffusion of calcium in the cytosol is restricted ~4"~7J8. Hence. only relevant domains within the cell may acquire the increased free calcium concentration in connection with cell stimulationm ~'~7'ms e.g. with histamine release from rat mast cells ~9. With an estimate of total cytosolic calcium of maximally 300 p.M (Ref. 15) it is very unlikely that the signal transmission exerted by calcium in rat mast cells requires membrane translocation of millimolar levels of the entire cellular calcium. The observed 45Ca uptake in connection with histamine release in rat mast cells may alternatively be a consequence rather than a cause of the release process l°-L'. Thus, the granular matrix has a high capacity for binding of cations (in-situ histamine), and by exposure to the extraceilular medium during exocytosis the histamine bound to the matrix is exchanged with cations (i.e. sodium, potassium and calcium, see Ref. 3). In addition, calcium may bind to the granular aspect of the perigranular membrane in accordance with calcium affinity for membranes in general and
with electron microscopic evidence of lanthanum binding 2". Hence. taking the histamine content of rat mast cells as 200-300 mM (Ref. 3), exchange with an extracellular medium containing Ca:" (1 mM) can fully account fl~r 4~('a fluxes of the observed magnitude. The validity of this interpretation is evident from studies of ~Ca uptake ill rat mast cells employing a method tl where the cells were washed in order to remove extracellular calcium, including tracer superficially bound to lhe rlasm:t membrane. In this context it is important to recognize that during ex(~:~tosis the granules and granular vacuoles are accessible to the extracellular medium (including the washing medium). until the plasma membrane is restituted after the release process. With this procedure there was no time-dependent correlation between histamine release and 45Ca uptake. Furthermore. addition of the tracer at the time where the histamine release was completed resulted in a "~5Cauptake of the same magnitude as observed when the tracer was present at the time of stimulation. The~ findings are consi:~tent with a binding of calcium secondary to histamine relea~, and no calcium movement of possible relexance to stimulus-secretion coupling could be demonstrated. Hence. in rat mast cells the 45Ca uptake does not provide int\~rmation about calcium-regulated steps in the secretory process. Similar precautions regarding the interpretation of 4SCa fluxes in connection with histamine release in rat mast cells have been put forward b~, others,), t.,. T h e ~ reservations may also apply to observations in other secr~.torv cells, e.g. adrenal medullary chromaffin cells with a granular architecture l~ke that of mast cell granules, parotid e:(ocrine cells with zymogen granules of high calcium binding capacity, and neutrophils. We do not question the increasing evidence for a central role of czdcium in secretor) processes, but merely recognize the problems encountered by direct demonstration of an intracellular involvement of calcium. Evidently, measurement of ~SCa uFake is not the appropriate tool. We find it of great importance to understand the function of calcium in secretor) processes. Models of secretory. systems are useful as a summary of
TIPS- May 1984
184 current knowledge and may serve as guidelines for future research. However, models ba:;ed on misinterpreted observations may rather obscure the state of the art. NINA GROSMAN AND BERTIL DIAMANT Department of Pharmocology, Universi~ of Copenhal~en. Juliane Manes Vel 20. DK-2100 Copenhagen O. Denmark.
RemFmg fist I Silaganian. R. P. (1983) Trends Pharmacol. Y~c/,4. 432-437 2 Lichtenstein. L. M.. Foreman, J. C.. Conroy, M, C.. Marone, G, and Newball. H. H, (1979) in The Mast Cell, its Role in Health and Disease (Pepys. J. and Edwards. A. M., eds). pp. 83-96. Pitman Med. Publ, Co., Tunbridge Wells 3 Lagunoff, D. and Chi. E Y. (1980) in Hand-
book Inflammation. Vol. 2 (Weissmann, G., ed.), pp. 217--265, El~v~er, Amsterdam 4 MacGlashan, D. W., Schleimer, R. P., Peters, S. P., SchLdman, E. S., Adams, G. K., Sobotka, A. K., NewbaU. H. H. and Lichtenstein I_ M. (1983) Fed. Proc. Fed. Am. Soc. l~cp. Biol. 42, 2504--2,¢O) 5 Pearce, F. L, (1983) Trends Pharmacol. Sci. 4. 165-167 6 Crews, F. T., Mofita, Y., McGivney, A.,
Hiraha, F., Siraganian, R. P. and Axelrod, J. (1981) Arch. Biochem. Biophys. 212, 561-571 7 Ishizaka, T., Conrad, D. H., Schulman, E. S.. Sterk, A. R. and lshizaka, K. (1983) J. immunol. 130, 2357-Z'62 8 Ishizaka, T., Hirata. F., lshizaka, K. and Axelrod, J. (1980) Proc. Nail Acad. Sci. USA 77. 1903-1906 9 Foreman, J. C., Haiktt, M B. and Mongar, J. L. (1977)./. PI~vsDI. (London) 271,193-214 ll~ Gomperts. B. D. (1976) in Receptors and Recognition. Series A. Vol. 2 (Cuatrecasas, P. and Greaves. M. F., eels), pp. 43-102, Chapman and Hall, London
Dr Siraganian writes in reply A number of the points raised by Drs Gr~,nan and Diamant are not supported by experimental data. Differences have been observed in the mediators released by mast cells compared with basophils. For example. human ma~t cells, but not basophils, release PGDz and mouse mast ceil~, derived in culture secrete more LTC4 than ~-at peritoneal mast cells ~'2. This type of data is not evidence for different pathways for secretion, but could be due to cells having different enzymes involved in the processing of released metabolities like arachidonic acid. Similarly. there are differences between mucosal and peritoneal rat mast cells in their response to releasing agents 3 e.g. to compound 48/80. This could be due to differences in receptors for ~hese agomsts and not due to fundamentol differences in the pathway for cell activation. Thus, there is no evidence for different biochemical pathways for the release reaction in mast cells compared to basophils.
The letter suggests that there are differences in the sequence in which 45Ca-uptake and methylation is observed in different cell types. The data does not support that statement. Studies with human or ra't mast cells and with rat basophilic leukemia cells all have observed methylafion which precedes 45Ca uptake by the cell. The study of variants of the rat basophilic leukemia cells has found lines which have methvlation enzymes and do not take up 45Ca following, IgE-receptor activation 4-5. The essential role for C a 2+ in histamine release has b e e n r e c o g n i z e d for s o m e time. There is also e x p e r i m e n t a l e v i d e n c e that a n u m b e r o f e n z y m a t i c ~,:teps have t o ocx,ur b e t w e e n l g E r e c e p t o r bridging before Ca 2+ uptake by the cell. T h e r e f o r e , C a 2+ uptake is not the very first step a n d is n o t due to simple I g E - r e c e p t o r a g g r e g a t i o n . H o w e v e r , 45Ca u p t a k e in cells is n o t a c o n s e q u e n c e o f histamine release. There are variant rat I~asophilic leukemia cell
II Grosman, N. and Diamant, B, (1978) Agents Actions" 8, 338-346 12 Bemdge, M. J. (1982) i:: Calcimn and ('ell Function, Vol. !!1 (Cheung, W. Y., ed.). pp. 1-36, Academic Press, New York 13 Baker, P. F. and Knight, D. E. (1981) Philos. Trans. R. Soc. London Set. B 296, &~i03 14 KmLsinger, R. H. (1981) Neurosci. Res. Program Bull. 19, 213-328 15 Rasmussen, H. and Waisman. D. (1981) in Biochemical Actions of Hormones, Vol. VIII (Lietwack, G., ed.), pp. I-IIS, Academic Press, New York 16 Bennett, J. P., Cockcroft, S. and Gompens, B. D. (1981) J. Physiol. (London) 317, 335-M5 17 Baker, P. F. (1977) Sci. Prog. (Oaford) 64, 95-115 18 Matthews, E. K. (1979) Syrup. Soc. Exp. Biol. 33.223-249 19 Lawson, D., Fewtrell, C. and Raft, M. C. (1978) J. Cell Biol. 79, 394--~1) 20 Anderson, P.. SIorach, S. A. and Uvn~is. B. (1973) Acta Physiol. Scand. 88. 359-372
lines in which lgE-receptor activation results in 45Ca uptake but no histamine release 5. Some of the experime.ats that Grosman and Diamant refer to at," with rat mast cells where the histamine rc!c a_se is very rapid and kinetically it ib di~ficult to clearly separate the time course of 45Ca uptake from the release of histamine. R. SIRAGANIAN National Instffute of Dental Research, Bethesda. Maryland 20205, USA.
Reading List I MacGlashan, D. W., Jr, Schleimer, R. P.. Peters, S. P., Schulman, E. S., Adams, G K., Sobotka, A. K., Newball, H. H. and Lichtenstein, L. M. (1983) Fed. Proc. Fed. Am. Soc. Exp. Biol. 42, 2504-2~J9 2 Razin, E., Menda-Huerta, J. M., Lewis, R A.. Corey, E. J. and Austen, K. F. (1982) Proc. Nail Acad. Sci. USA 79, 4665-4667 3 Pearce, F. L. (1983) Trends in Phar,n~co;. ;ici. 4, 165-168 4 McGivney, A. Crews, F. T., Hirata, F., Axelrod, J. and Siraganian, R. P. (1981) Proc. Nail Acad. Sci. USA 78, 6176-6180 5 Siraganian, R. P., McGivncy, A., Barsumian, E. L., Crews, F. T., Hirata, F. and Axelrod, J. (1982) Fed. Proc. Fed. Am. Soc. Exp. Biol. 41, 3tb-34
!~,3
Histamine secretion from mast cells and basophils i~n the October 1983 issue of TIPS, Reuben P. Siraganian reviewed the biochemical events which accompany basophil/mast cell activationL We find ~t of importance to question two aspects of the review, i.e. the justification (1) of employing basophils and mast cells as a unifying model for a secretory system ,rod (2) of using 4-~Cauptake as evidence 'for a function of calcium in the release process. SiragavJan introduces mast cells and basophils as a model for cell secretion, with the reservation that 'it might turn out that some of the mediators produced by the cells are different and/or ~.here might be differences in the mechanism of release'. Differences between the control of histamine release from mast cells and basophils are indeed recognized 2-4, and recently even the heterogeneity of mast cells of different origin has been emphasized 5, further stressing the problem of creating unifying models. Thus, it is hardly conceivable that models based on findings with rat basophilic leukemia (RBL) cell lines (i.e. neoplastic cells) will overcome this problem. However, Siraganian apparently forgets about reservations, and throughout the review presents mast cells and basophils as an entity. The diversity of histamine-containing cells is also evident when biochemical events during histamine release are considered, e.g. phospholipid methylation and calcium influx. In RBL cells the 45Ca influx appeared to occur simultaneously with the increase in phospholipid methylation and was followed by histamine release '~. In human mast cells phospholipid methylation appeared to precede 45Ca influx, which was, in turn, followed by histamine release 7. In rat mast cells the phospholipid methylation preceded the essentially identical time courses for "~SCa influx and histamine release s . Coinciding time courses for 45Ca uptake and histamine release in rat mast cells are in accordance with findings elsewhere 9. The observed 45Ca fluxes are frequently used as evidence for a messenger function of calcium in the release process, and a positive correlation between inhibition of 45Ca uptake and histamine release is considered as further support of this
assumption t's''~. However, these findings neither indicate nor exclude a causal relation between the 45Ca uptake and the histamine release and should be interpreted with caution ~ 2 . Quantitatively, the 4"~Ca uptake observed in connection with histamine release is equivalent to influx and/or exchange of 0.5-5 mM of cellular calcium, as calculated from various studies with rat mast cells8'9'11. Fluxes of this magnitude seem incompatible with a messenger or signalling function of calcium in the release process, since such a function implies much higher sensitivity ~z. Thus, in the resting cell, the cytosolic free calcium concentration is in the range of 10-8 - 5 × 10 -7 M, and stimulus-response coupling is brought about by increases of free cytosolic calcium to the pI.M concentration range ~ 5 . The latter estimate is supported by observations with ATPtreated rat mast cells ~6. This increase can be established by an influx and/or by mobilization of calcium from intracellular sites. These perturbations of the calcium homeostasis are, however, not believed to involve the entire cell. since diffusion of calcium in the cytosol is restricted ~4"~7J8. Hence. only relevant domains within the cell may acquire the increased free calcium concentration in connection with cell stimulationm ~'~7'ms e.g. with histamine release from rat mast cells ~9. With an estimate of total cytosolic calcium of maximally 300 p.M (Ref. 15) it is very unlikely that the signal transmission exerted by calcium in rat mast cells requires membrane translocation of millimolar levels of the entire cellular calcium. The observed 45Ca uptake in connection with histamine release in rat mast cells may alternatively be a consequence rather than a cause of the release process l°-L'. Thus, the granular matrix has a high capacity for binding of cations (in-situ histamine), and by exposure to the extraceilular medium during exocytosis the histamine bound to the matrix is exchanged with cations (i.e. sodium, potassium and calcium, see Ref. 3). In addition, calcium may bind to the granular aspect of the perigranular membrane in accordance with calcium affinity for membranes in general and
with electron microscopic evidence of lanthanum binding 2". Hence. taking the histamine content of rat mast cells as 200-300 mM (Ref. 3), exchange with an extracellular medium containing Ca:" (1 mM) can fully account fl~r 4~('a fluxes of the observed magnitude. The validity of this interpretation is evident from studies of ~Ca uptake ill rat mast cells employing a method tl where the cells were washed in order to remove extracellular calcium, including tracer superficially bound to lhe rlasm:t membrane. In this context it is important to recognize that during ex(~:~tosis the granules and granular vacuoles are accessible to the extracellular medium (including the washing medium). until the plasma membrane is restituted after the release process. With this procedure there was no time-dependent correlation between histamine release and 45Ca uptake. Furthermore. addition of the tracer at the time where the histamine release was completed resulted in a "~5Cauptake of the same magnitude as observed when the tracer was present at the time of stimulation. The~ findings are consi:~tent with a binding of calcium secondary to histamine relea~, and no calcium movement of possible relexance to stimulus-secretion coupling could be demonstrated. Hence. in rat mast cells the 45Ca uptake does not provide int\~rmation about calcium-regulated steps in the secretory process. Similar precautions regarding the interpretation of 4SCa fluxes in connection with histamine release in rat mast cells have been put forward b~, others,), t.,. T h e ~ reservations may also apply to observations in other secr~.torv cells, e.g. adrenal medullary chromaffin cells with a granular architecture l~ke that of mast cell granules, parotid e:(ocrine cells with zymogen granules of high calcium binding capacity, and neutrophils. We do not question the increasing evidence for a central role of czdcium in secretor) processes, but merely recognize the problems encountered by direct demonstration of an intracellular involvement of calcium. Evidently, measurement of ~SCa uFake is not the appropriate tool. We find it of great importance to understand the function of calcium in secretor) processes. Models of secretory. systems are useful as a summary of
TIPS- May 1984
184 current knowledge and may serve as guidelines for future research. However, models ba:;ed on misinterpreted observations may rather obscure the state of the art. NINA GROSMAN AND BERTIL DIAMANT Department of Pharmocology, Universi~ of Copenhal~en. Juliane Manes Vel 20. DK-2100 Copenhagen O. Denmark.
RemFmg fist I Silaganian. R. P. (1983) Trends Pharmacol. Y~c/,4. 432-437 2 Lichtenstein. L. M.. Foreman, J. C.. Conroy, M, C.. Marone, G, and Newball. H. H, (1979) in The Mast Cell, its Role in Health and Disease (Pepys. J. and Edwards. A. M., eds). pp. 83-96. Pitman Med. Publ, Co., Tunbridge Wells 3 Lagunoff, D. and Chi. E Y. (1980) in Hand-
book Inflammation. Vol. 2 (Weissmann, G., ed.), pp. 217--265, El~v~er, Amsterdam 4 MacGlashan, D. W., Schleimer, R. P., Peters, S. P., SchLdman, E. S., Adams, G. K., Sobotka, A. K., NewbaU. H. H. and Lichtenstein I_ M. (1983) Fed. Proc. Fed. Am. Soc. l~cp. Biol. 42, 2504--2,¢O) 5 Pearce, F. L, (1983) Trends Pharmacol. Sci. 4. 165-167 6 Crews, F. T., Mofita, Y., McGivney, A.,
Hiraha, F., Siraganian, R. P. and Axelrod, J. (1981) Arch. Biochem. Biophys. 212, 561-571 7 Ishizaka, T., Conrad, D. H., Schulman, E. S.. Sterk, A. R. and lshizaka, K. (1983) J. immunol. 130, 2357-Z'62 8 Ishizaka, T., Hirata. F., lshizaka, K. and Axelrod, J. (1980) Proc. Nail Acad. Sci. USA 77. 1903-1906 9 Foreman, J. C., Haiktt, M B. and Mongar, J. L. (1977)./. PI~vsDI. (London) 271,193-214 ll~ Gomperts. B. D. (1976) in Receptors and Recognition. Series A. Vol. 2 (Cuatrecasas, P. and Greaves. M. F., eels), pp. 43-102, Chapman and Hall, London
Dr Siraganian writes in reply A number of the points raised by Drs Gr~,nan and Diamant are not supported by experimental data. Differences have been observed in the mediators released by mast cells compared with basophils. For example. human ma~t cells, but not basophils, release PGDz and mouse mast ceil~, derived in culture secrete more LTC4 than ~-at peritoneal mast cells ~'2. This type of data is not evidence for different pathways for secretion, but could be due to cells having different enzymes involved in the processing of released metabolities like arachidonic acid. Similarly. there are differences between mucosal and peritoneal rat mast cells in their response to releasing agents 3 e.g. to compound 48/80. This could be due to differences in receptors for ~hese agomsts and not due to fundamentol differences in the pathway for cell activation. Thus, there is no evidence for different biochemical pathways for the release reaction in mast cells compared to basophils.
The letter suggests that there are differences in the sequence in which 45Ca-uptake and methylation is observed in different cell types. The data does not support that statement. Studies with human or ra't mast cells and with rat basophilic leukemia cells all have observed methylafion which precedes 45Ca uptake by the cell. The study of variants of the rat basophilic leukemia cells has found lines which have methvlation enzymes and do not take up 45Ca following, IgE-receptor activation 4-5. The essential role for C a 2+ in histamine release has b e e n r e c o g n i z e d for s o m e time. There is also e x p e r i m e n t a l e v i d e n c e that a n u m b e r o f e n z y m a t i c ~,:teps have t o ocx,ur b e t w e e n l g E r e c e p t o r bridging before Ca 2+ uptake by the cell. T h e r e f o r e , C a 2+ uptake is not the very first step a n d is n o t due to simple I g E - r e c e p t o r a g g r e g a t i o n . H o w e v e r , 45Ca u p t a k e in cells is n o t a c o n s e q u e n c e o f histamine release. There are variant rat I~asophilic leukemia cell
II Grosman, N. and Diamant, B, (1978) Agents Actions" 8, 338-346 12 Bemdge, M. J. (1982) i:: Calcimn and ('ell Function, Vol. !!1 (Cheung, W. Y., ed.). pp. 1-36, Academic Press, New York 13 Baker, P. F. and Knight, D. E. (1981) Philos. Trans. R. Soc. London Set. B 296, &~i03 14 KmLsinger, R. H. (1981) Neurosci. Res. Program Bull. 19, 213-328 15 Rasmussen, H. and Waisman. D. (1981) in Biochemical Actions of Hormones, Vol. VIII (Lietwack, G., ed.), pp. I-IIS, Academic Press, New York 16 Bennett, J. P., Cockcroft, S. and Gompens, B. D. (1981) J. Physiol. (London) 317, 335-M5 17 Baker, P. F. (1977) Sci. Prog. (Oaford) 64, 95-115 18 Matthews, E. K. (1979) Syrup. Soc. Exp. Biol. 33.223-249 19 Lawson, D., Fewtrell, C. and Raft, M. C. (1978) J. Cell Biol. 79, 394--~1) 20 Anderson, P.. SIorach, S. A. and Uvn~is. B. (1973) Acta Physiol. Scand. 88. 359-372
lines in which lgE-receptor activation results in 45Ca uptake but no histamine release 5. Some of the experime.ats that Grosman and Diamant refer to at," with rat mast cells where the histamine rc!c a_se is very rapid and kinetically it ib di~ficult to clearly separate the time course of 45Ca uptake from the release of histamine. R. SIRAGANIAN National Instffute of Dental Research, Bethesda. Maryland 20205, USA.
Reading List I MacGlashan, D. W., Jr, Schleimer, R. P.. Peters, S. P., Schulman, E. S., Adams, G K., Sobotka, A. K., Newball, H. H. and Lichtenstein, L. M. (1983) Fed. Proc. Fed. Am. Soc. Exp. Biol. 42, 2504-2~J9 2 Razin, E., Menda-Huerta, J. M., Lewis, R A.. Corey, E. J. and Austen, K. F. (1982) Proc. Nail Acad. Sci. USA 79, 4665-4667 3 Pearce, F. L. (1983) Trends in Phar,n~co;. ;ici. 4, 165-168 4 McGivney, A. Crews, F. T., Hirata, F., Axelrod, J. and Siraganian, R. P. (1981) Proc. Nail Acad. Sci. USA 78, 6176-6180 5 Siraganian, R. P., McGivncy, A., Barsumian, E. L., Crews, F. T., Hirata, F. and Axelrod, J. (1982) Fed. Proc. Fed. Am. Soc. Exp. Biol. 41, 3tb-34