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Bradykinin receptors and signal transduction pathways in human fibroblasts : Integral role for extracellular calcium

McAllister, Bradley S. ; Leeb-Lundberg, L. M.F. LU ; Javors, Martin A. and Olson, Merle S. (1993) In Archives of Biochemistry and Biophysics 304(1). p.294-301
Abstract


Bradykinin receptors have been identified in human gingival fibroblasts; the primary signal transduction pathways and their dependence on calcium have been characterized. Binding data revealed a calcium-independent binding of bradykinin to the cell membrane with a receptor density of 25,000 receptors per cell and a K
d
of 1.6 nM. The bradykinin receptor-mediated activation of phospholipase C (PLC) resulted in an extensive and rapid stimulation of phosphoinositide metabolism. Using radioreceptor assay techniques, in the absence of LiCl, the inositol 1,4,5-trisphosphate (Ins 1,4,5 P
3
... (More)


Bradykinin receptors have been identified in human gingival fibroblasts; the primary signal transduction pathways and their dependence on calcium have been characterized. Binding data revealed a calcium-independent binding of bradykinin to the cell membrane with a receptor density of 25,000 receptors per cell and a K
d
of 1.6 nM. The bradykinin receptor-mediated activation of phospholipase C (PLC) resulted in an extensive and rapid stimulation of phosphoinositide metabolism. Using radioreceptor assay techniques, in the absence of LiCl, the inositol 1,4,5-trisphosphate (Ins 1,4,5 P
3
) generation was found to be transient, with maximal levels attained within 15 s. An EC
50
of 12 nM was observed for the accumulation of total inositol polyphosphates. The activation of phospholipase A
2
(PLA
2
), and the subsequent release of arachidonic acid and the primary metabolite prostaglandin E
2
, also was found to be time- and concentration-dependent. Stimulation of tyrosine kinase activity by bradykinin was concentration-dependent and resulted in the phosphorylation of three substrates of unknown identity. Bradykinin stimulation did not activate adenylate cyclase as there occurred no increase in the generation of cyclic AMP. The mobilization of intracellular calcium stores followed closely the Ins 1,4,5 P
3
kinetics and had an EC
50
of 11 nM. Chelation of extracellular calcium reduced significantly the duration of the calcium response, while only minimally lowering the rapid, maximal increase in intracellular free calcium concentration ([Ca
2+
]
i
). A sustained elevation of [Ca
2+
]
i
was found to be essential in PLC and PLA
2
signaling, as well as in tyrosine kinase activation, suggesting a major role for membrane calcium channels in bradykinin stimulation of cellular responses in these cells. Bradykinin was found to inhibit dramatically epidermal growth factor-induced DNA synthesis in confluent cells, although to a much lesser degree in subconfluent cells. This pattern was similar to the observed maximal specific increase in bradykinin binding with confluency. Together these results demonstrate the presence of bradykinin receptors in human gingival fibroblasts; these receptors are coupled to signal transduction mechanisms involving the PLC, PLA
2
, and tyrosine kinase effector systems, all of which require extracellular calcium to achieve maximal activation.

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author
; ; and
publishing date
type
Contribution to journal
publication status
published
subject
in
Archives of Biochemistry and Biophysics
volume
304
issue
1
pages
294 - 301
publisher
Academic Press
external identifiers
  • pmid:7686736
  • scopus:0027302706
ISSN
0003-9861
DOI
10.1006/abbi.1993.1352
language
English
LU publication?
no
id
dd53e69f-c103-4111-b140-2b87809bb0a3
date added to LUP
2019-06-12 11:44:42
date last changed
2024-01-01 09:53:59
@article{dd53e69f-c103-4111-b140-2b87809bb0a3,
  abstract     = {{<p><br>
                            Bradykinin receptors have been identified in human gingival fibroblasts; the primary signal transduction pathways and their dependence on calcium have been characterized. Binding data revealed a calcium-independent binding of bradykinin to the cell membrane with a receptor density of 25,000 receptors per cell and a K<br>
                            <sub>d</sub><br>
                             of 1.6 nM. The bradykinin receptor-mediated activation of phospholipase C (PLC) resulted in an extensive and rapid stimulation of phosphoinositide metabolism. Using radioreceptor assay techniques, in the absence of LiCl, the inositol 1,4,5-trisphosphate (Ins 1,4,5 P<br>
                            <sub>3</sub><br>
                            ) generation was found to be transient, with maximal levels attained within 15 s. An EC<br>
                            <sub>50</sub><br>
                             of 12 nM was observed for the accumulation of total inositol polyphosphates. The activation of phospholipase A<br>
                            <sub>2</sub><br>
                             (PLA<br>
                            <sub>2</sub><br>
                            ), and the subsequent release of arachidonic acid and the primary metabolite prostaglandin E<br>
                            <sub>2</sub><br>
                            , also was found to be time- and concentration-dependent. Stimulation of tyrosine kinase activity by bradykinin was concentration-dependent and resulted in the phosphorylation of three substrates of unknown identity. Bradykinin stimulation did not activate adenylate cyclase as there occurred no increase in the generation of cyclic AMP. The mobilization of intracellular calcium stores followed closely the Ins 1,4,5 P<br>
                            <sub>3</sub><br>
                             kinetics and had an EC<br>
                            <sub>50</sub><br>
                             of 11 nM. Chelation of extracellular calcium reduced significantly the duration of the calcium response, while only minimally lowering the rapid, maximal increase in intracellular free calcium concentration ([Ca<br>
                            <sup>2+</sup><br>
                            ]<br>
                            <sub>i</sub><br>
                            ). A sustained elevation of [Ca<br>
                            <sup>2+</sup><br>
                            ]<br>
                            <sub>i</sub><br>
                             was found to be essential in PLC and PLA<br>
                            <sub>2</sub><br>
                             signaling, as well as in tyrosine kinase activation, suggesting a major role for membrane calcium channels in bradykinin stimulation of cellular responses in these cells. Bradykinin was found to inhibit dramatically epidermal growth factor-induced DNA synthesis in confluent cells, although to a much lesser degree in subconfluent cells. This pattern was similar to the observed maximal specific increase in bradykinin binding with confluency. Together these results demonstrate the presence of bradykinin receptors in human gingival fibroblasts; these receptors are coupled to signal transduction mechanisms involving the PLC, PLA<br>
                            <sub>2</sub><br>
                            , and tyrosine kinase effector systems, all of which require extracellular calcium to achieve maximal activation.</p>}},
  author       = {{McAllister, Bradley S. and Leeb-Lundberg, L. M.F. and Javors, Martin A. and Olson, Merle S.}},
  issn         = {{0003-9861}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{1}},
  pages        = {{294--301}},
  publisher    = {{Academic Press}},
  series       = {{Archives of Biochemistry and Biophysics}},
  title        = {{Bradykinin receptors and signal transduction pathways in human fibroblasts : Integral role for extracellular calcium}},
  url          = {{http://dx.doi.org/10.1006/abbi.1993.1352}},
  doi          = {{10.1006/abbi.1993.1352}},
  volume       = {{304}},
  year         = {{1993}},
}