Abstract
We previously reported that uniaxial continuous stretch in human umbilical vein endothelial cells (HUVECs) induced interleukin-6 (IL-6) secretion via IκB kinase (IKK)/nuclear factor-κB (NF-κB) activation. The aim of the present study was to clarify the upstream signaling mechanism responsible for this phenomenon. Stretch-induced IKK activation and IL-6 secretion were inhibited by application of α5β1 integrin-inhibitory peptide (GRGDNP), phosphatidylinositol 3-kinase inhibitor (LY-294002), phospholipase C-γ inhibitor (U-73122), or protein kinase C inhibitor (H7). Although depletion of intra- or extracellular Ca2+ pool using thapsigargin (TG) or EGTA, respectively, showed little effect, a TG-EGTA mixture significantly inhibited stretch-induced IKK activation and IL-6 secretion. An increase in the intracellular Ca2+ concentration ([Ca2+]i) upon continuous stretch was observed even in the presence of TG, EGTA, or GRGDNP, but not in a solution containing the TG-EGTA mixture, indicating that both integrin activation and [Ca2+]i rise are crucial factors for stretch-induced IKK activation and after IL-6 secretion in HUVECs. Furthermore, while PKC activity was inhibited by the TG-EGTA mixture, GRGDNP, LY-294002, or U-73122, PLC-γ activity was retarded by GRGDNP or LY-294002. These results indicate that continuous stretch-induced IL-6 secretion in HUVECs depends on outside-in signaling via integrins followed by a PI3-K-PLC-γ-PKC-IKK-NF-κB signaling cascade. Another crucial factor, [Ca2+]i increase, may at least be required to activate PKC needed for NF-κB activation.
| Original language | English |
|---|---|
| Journal | American Journal of Physiology - Cell Physiology |
| Volume | 288 |
| Issue number | 5 57-5 |
| DOIs | |
| Publication status | Published - May 2005 |
| Externally published | Yes |
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Keywords
- Intracellular CA concentration
- Nuclear factor-κb
- Phosphatidylinositol 3-kinase
- Phospholipase C-γ
- Protein kinase C
ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology
- Physiology
Cite this
Mechanotransduction by integrin is essential for IL-6 secretion from endothelial cells in response to uniaxial continuous stretch. / Sasamoto, Akitoshi; Nagino, Masato; Kobayashi, Satoshi; Naruse, Keiji; Nimura, Yuji; Sokabe, Masahiro.
In: American Journal of Physiology - Cell Physiology, Vol. 288, No. 5 57-5, 05.2005.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanotransduction by integrin is essential for IL-6 secretion from endothelial cells in response to uniaxial continuous stretch
AU - Sasamoto, Akitoshi
AU - Nagino, Masato
AU - Kobayashi, Satoshi
AU - Naruse, Keiji
AU - Nimura, Yuji
AU - Sokabe, Masahiro
PY - 2005/5
Y1 - 2005/5
N2 - We previously reported that uniaxial continuous stretch in human umbilical vein endothelial cells (HUVECs) induced interleukin-6 (IL-6) secretion via IκB kinase (IKK)/nuclear factor-κB (NF-κB) activation. The aim of the present study was to clarify the upstream signaling mechanism responsible for this phenomenon. Stretch-induced IKK activation and IL-6 secretion were inhibited by application of α5β1 integrin-inhibitory peptide (GRGDNP), phosphatidylinositol 3-kinase inhibitor (LY-294002), phospholipase C-γ inhibitor (U-73122), or protein kinase C inhibitor (H7). Although depletion of intra- or extracellular Ca2+ pool using thapsigargin (TG) or EGTA, respectively, showed little effect, a TG-EGTA mixture significantly inhibited stretch-induced IKK activation and IL-6 secretion. An increase in the intracellular Ca2+ concentration ([Ca2+]i) upon continuous stretch was observed even in the presence of TG, EGTA, or GRGDNP, but not in a solution containing the TG-EGTA mixture, indicating that both integrin activation and [Ca2+]i rise are crucial factors for stretch-induced IKK activation and after IL-6 secretion in HUVECs. Furthermore, while PKC activity was inhibited by the TG-EGTA mixture, GRGDNP, LY-294002, or U-73122, PLC-γ activity was retarded by GRGDNP or LY-294002. These results indicate that continuous stretch-induced IL-6 secretion in HUVECs depends on outside-in signaling via integrins followed by a PI3-K-PLC-γ-PKC-IKK-NF-κB signaling cascade. Another crucial factor, [Ca2+]i increase, may at least be required to activate PKC needed for NF-κB activation.
AB - We previously reported that uniaxial continuous stretch in human umbilical vein endothelial cells (HUVECs) induced interleukin-6 (IL-6) secretion via IκB kinase (IKK)/nuclear factor-κB (NF-κB) activation. The aim of the present study was to clarify the upstream signaling mechanism responsible for this phenomenon. Stretch-induced IKK activation and IL-6 secretion were inhibited by application of α5β1 integrin-inhibitory peptide (GRGDNP), phosphatidylinositol 3-kinase inhibitor (LY-294002), phospholipase C-γ inhibitor (U-73122), or protein kinase C inhibitor (H7). Although depletion of intra- or extracellular Ca2+ pool using thapsigargin (TG) or EGTA, respectively, showed little effect, a TG-EGTA mixture significantly inhibited stretch-induced IKK activation and IL-6 secretion. An increase in the intracellular Ca2+ concentration ([Ca2+]i) upon continuous stretch was observed even in the presence of TG, EGTA, or GRGDNP, but not in a solution containing the TG-EGTA mixture, indicating that both integrin activation and [Ca2+]i rise are crucial factors for stretch-induced IKK activation and after IL-6 secretion in HUVECs. Furthermore, while PKC activity was inhibited by the TG-EGTA mixture, GRGDNP, LY-294002, or U-73122, PLC-γ activity was retarded by GRGDNP or LY-294002. These results indicate that continuous stretch-induced IL-6 secretion in HUVECs depends on outside-in signaling via integrins followed by a PI3-K-PLC-γ-PKC-IKK-NF-κB signaling cascade. Another crucial factor, [Ca2+]i increase, may at least be required to activate PKC needed for NF-κB activation.
KW - Intracellular CA concentration
KW - Nuclear factor-κb
KW - Phosphatidylinositol 3-kinase
KW - Phospholipase C-γ
KW - Protein kinase C
UR - http://www.scopus.com/inward/record.url?scp=17644418430&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17644418430&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.00314.2004
DO - 10.1152/ajpcell.00314.2004
M3 - Article
C2 - 15613495
AN - SCOPUS:17644418430
VL - 288
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0002-9513
IS - 5 57-5
ER -