Epidermal growth factor activates store-operated calcium channels in human glomerular mesangial cells

Rong Ma, S. C. Sansom

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

A cellular influx of Ca2+is critical for initiating and maintaining growth in a variety of cell types. Experiments were performed to determine whether epidermal growth factor (EGF), which is known to initiate a proliferative response in mesangial cells, could regulate by intracellular signal transduction the store-operated Ca2+ channels (SOC) of human mesangial cells (HMC) in culture. The cell-attached patch configuration was used to monitor the activity of SOC, with 90 mM Ba2+ in the pipette and physiologic saline solution in the bath. Under control conditions, the mean NPo value was 1.06 at a holding potential of -80 mV. When 100 nM EGF was added to the bath, SOC were activated by 53%. The EGF-evoked response was dose-dependent, with a half-maximal activation concentration of 4.8 nM. An inhibitor of tyrosine kinase, i.e., tyrphostin A23 (100 μM), completely abolished EGF-evoked channel activation. EGF combined with the inactive control compound tyrphostin A1 (100 μM) elicited significant (85%) activation of SOC. Calphostin C, an inhibitor of protein kinase C (PKC), did not affect the baseline activity of SOC but abolished the EGF-evoked enhancement of SOC activity. The PKC activator phorbol-12-myristate-13-acetate (PMA) significantly activated SOC. However, the effects of PMA were duplicative rather than additive or potentiating with maximal concentrations (100 nM) of EGF, suggesting that PMA and EGF activate SOC through a common PKC pathway. In addition, downregulation of PKC via incubation of HMC with PMA for 1 to 20 h depressed both basal activity and EGF-induced activation of SOC. It is concluded that EGF stimulates SOC in HMC through an intracellular signaling mechanism involving tyrosine kinase and PKC.

Original languageEnglish
Pages (from-to)47-53
Number of pages7
JournalJournal of the American Society of Nephrology
Volume12
Issue number1
StatePublished - 30 Jan 2001

Fingerprint

Mesangial Cells
Calcium Channels
Epidermal Growth Factor
Protein Kinase C
Acetates
Baths
Protein-Tyrosine Kinases
Sodium Chloride
Signal Transduction
Down-Regulation
Cell Culture Techniques

Cite this

@article{946436c741174644bc41fef52a66268e,
title = "Epidermal growth factor activates store-operated calcium channels in human glomerular mesangial cells",
abstract = "A cellular influx of Ca2+is critical for initiating and maintaining growth in a variety of cell types. Experiments were performed to determine whether epidermal growth factor (EGF), which is known to initiate a proliferative response in mesangial cells, could regulate by intracellular signal transduction the store-operated Ca2+ channels (SOC) of human mesangial cells (HMC) in culture. The cell-attached patch configuration was used to monitor the activity of SOC, with 90 mM Ba2+ in the pipette and physiologic saline solution in the bath. Under control conditions, the mean NPo value was 1.06 at a holding potential of -80 mV. When 100 nM EGF was added to the bath, SOC were activated by 53{\%}. The EGF-evoked response was dose-dependent, with a half-maximal activation concentration of 4.8 nM. An inhibitor of tyrosine kinase, i.e., tyrphostin A23 (100 μM), completely abolished EGF-evoked channel activation. EGF combined with the inactive control compound tyrphostin A1 (100 μM) elicited significant (85{\%}) activation of SOC. Calphostin C, an inhibitor of protein kinase C (PKC), did not affect the baseline activity of SOC but abolished the EGF-evoked enhancement of SOC activity. The PKC activator phorbol-12-myristate-13-acetate (PMA) significantly activated SOC. However, the effects of PMA were duplicative rather than additive or potentiating with maximal concentrations (100 nM) of EGF, suggesting that PMA and EGF activate SOC through a common PKC pathway. In addition, downregulation of PKC via incubation of HMC with PMA for 1 to 20 h depressed both basal activity and EGF-induced activation of SOC. It is concluded that EGF stimulates SOC in HMC through an intracellular signaling mechanism involving tyrosine kinase and PKC.",
author = "Rong Ma and Sansom, {S. C.}",
year = "2001",
month = "1",
day = "30",
language = "English",
volume = "12",
pages = "47--53",
journal = "Journal of the American Society of Nephrology",
issn = "1046-6673",
publisher = "American Society of Nephrology",
number = "1",

}

Epidermal growth factor activates store-operated calcium channels in human glomerular mesangial cells. / Ma, Rong; Sansom, S. C.

In: Journal of the American Society of Nephrology, Vol. 12, No. 1, 30.01.2001, p. 47-53.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Epidermal growth factor activates store-operated calcium channels in human glomerular mesangial cells

AU - Ma, Rong

AU - Sansom, S. C.

PY - 2001/1/30

Y1 - 2001/1/30

N2 - A cellular influx of Ca2+is critical for initiating and maintaining growth in a variety of cell types. Experiments were performed to determine whether epidermal growth factor (EGF), which is known to initiate a proliferative response in mesangial cells, could regulate by intracellular signal transduction the store-operated Ca2+ channels (SOC) of human mesangial cells (HMC) in culture. The cell-attached patch configuration was used to monitor the activity of SOC, with 90 mM Ba2+ in the pipette and physiologic saline solution in the bath. Under control conditions, the mean NPo value was 1.06 at a holding potential of -80 mV. When 100 nM EGF was added to the bath, SOC were activated by 53%. The EGF-evoked response was dose-dependent, with a half-maximal activation concentration of 4.8 nM. An inhibitor of tyrosine kinase, i.e., tyrphostin A23 (100 μM), completely abolished EGF-evoked channel activation. EGF combined with the inactive control compound tyrphostin A1 (100 μM) elicited significant (85%) activation of SOC. Calphostin C, an inhibitor of protein kinase C (PKC), did not affect the baseline activity of SOC but abolished the EGF-evoked enhancement of SOC activity. The PKC activator phorbol-12-myristate-13-acetate (PMA) significantly activated SOC. However, the effects of PMA were duplicative rather than additive or potentiating with maximal concentrations (100 nM) of EGF, suggesting that PMA and EGF activate SOC through a common PKC pathway. In addition, downregulation of PKC via incubation of HMC with PMA for 1 to 20 h depressed both basal activity and EGF-induced activation of SOC. It is concluded that EGF stimulates SOC in HMC through an intracellular signaling mechanism involving tyrosine kinase and PKC.

AB - A cellular influx of Ca2+is critical for initiating and maintaining growth in a variety of cell types. Experiments were performed to determine whether epidermal growth factor (EGF), which is known to initiate a proliferative response in mesangial cells, could regulate by intracellular signal transduction the store-operated Ca2+ channels (SOC) of human mesangial cells (HMC) in culture. The cell-attached patch configuration was used to monitor the activity of SOC, with 90 mM Ba2+ in the pipette and physiologic saline solution in the bath. Under control conditions, the mean NPo value was 1.06 at a holding potential of -80 mV. When 100 nM EGF was added to the bath, SOC were activated by 53%. The EGF-evoked response was dose-dependent, with a half-maximal activation concentration of 4.8 nM. An inhibitor of tyrosine kinase, i.e., tyrphostin A23 (100 μM), completely abolished EGF-evoked channel activation. EGF combined with the inactive control compound tyrphostin A1 (100 μM) elicited significant (85%) activation of SOC. Calphostin C, an inhibitor of protein kinase C (PKC), did not affect the baseline activity of SOC but abolished the EGF-evoked enhancement of SOC activity. The PKC activator phorbol-12-myristate-13-acetate (PMA) significantly activated SOC. However, the effects of PMA were duplicative rather than additive or potentiating with maximal concentrations (100 nM) of EGF, suggesting that PMA and EGF activate SOC through a common PKC pathway. In addition, downregulation of PKC via incubation of HMC with PMA for 1 to 20 h depressed both basal activity and EGF-induced activation of SOC. It is concluded that EGF stimulates SOC in HMC through an intracellular signaling mechanism involving tyrosine kinase and PKC.

UR - http://www.scopus.com/inward/record.url?scp=0035169382&partnerID=8YFLogxK

M3 - Article

C2 - 11134249

AN - SCOPUS:0035169382

VL - 12

SP - 47

EP - 53

JO - Journal of the American Society of Nephrology

JF - Journal of the American Society of Nephrology

SN - 1046-6673

IS - 1

ER -