TY - JOUR
T1 - ORAI1 Activates Proliferation of Lymphatic Endothelial Cells in Response to Laminar Flow Through Krüppel-Like Factors 2 and 4
AU - Choi, Dongwon
AU - Park, Eunkyung
AU - Jung, Eunson
AU - Seong, Young Jin
AU - Hong, Mingu
AU - Lee, Sunju
AU - Burford, James
AU - Gyarmati, Georgina
AU - Peti-Peterdi, Janos
AU - Srikanth, Sonal
AU - Gwack, Yousang
AU - Koh, Chester J.
AU - Boriushkin, Evgenii
AU - Hamik, Anne
AU - Wong, Alex K.
AU - Hong, Young Kwon
N1 - Publisher Copyright:
© 2017 American Heart Association, Inc.
PY - 2017/4/28
Y1 - 2017/4/28
N2 - Rationale: Lymphatic vessels function to drain interstitial fluid from a variety of tissues. Although shear stress generated by fluid flow is known to trigger lymphatic expansion and remodeling, the molecular basis underlying flow-induced lymphatic growth is unknown. Objective: We aimed to gain a better understanding of the mechanism by which laminar shear stress activates lymphatic proliferation. Methods and Results: Primary endothelial cells from dermal blood and lymphatic vessels (blood vascular endothelial cells and lymphatic endothelial cells [LECs]) were exposed to low-rate steady laminar flow. Shear stress-induced molecular and cellular responses were defined and verified using various mutant mouse models. Steady laminar flow induced the classic shear stress responses commonly in blood vascular endothelial cells and LECs. Surprisingly, however, only LECs showed enhanced cell proliferation by regulating the vascular endothelial growth factor (VEGF)-A, VEGF-C, FGFR3, p57/CDKN1C genes. As an early signal mediator, ORAI1, a pore subunit of the calcium release-activated calcium channel, was identified to induce the shear stress phenotypes and cell proliferation in LECs responding to the fluid flow. Mechanistically, ORAI1 induced upregulation of Krüppel-like factor (KLF)-2 and KLF4 in the flow-activated LECs, the 2 KLF proteins cooperate to regulate VEGF-A, VEGF-C, FGFR3, p57 by binding to the regulatory regions of the genes. Consistently, freshly isolated LECs from Orai1 knockout embryos displayed reduced expression of KLF2, KLF4, VEGF-A, VEGF-C, FGFR3 and elevated expression of p57. Accordingly, mouse embryos deficient in Orai1, Klf2, or Klf4 showed a significantly reduced lymphatic density and impaired lymphatic development. Conclusions: Our study identified a molecular mechanism for laminar flow-activated LEC proliferation.
AB - Rationale: Lymphatic vessels function to drain interstitial fluid from a variety of tissues. Although shear stress generated by fluid flow is known to trigger lymphatic expansion and remodeling, the molecular basis underlying flow-induced lymphatic growth is unknown. Objective: We aimed to gain a better understanding of the mechanism by which laminar shear stress activates lymphatic proliferation. Methods and Results: Primary endothelial cells from dermal blood and lymphatic vessels (blood vascular endothelial cells and lymphatic endothelial cells [LECs]) were exposed to low-rate steady laminar flow. Shear stress-induced molecular and cellular responses were defined and verified using various mutant mouse models. Steady laminar flow induced the classic shear stress responses commonly in blood vascular endothelial cells and LECs. Surprisingly, however, only LECs showed enhanced cell proliferation by regulating the vascular endothelial growth factor (VEGF)-A, VEGF-C, FGFR3, p57/CDKN1C genes. As an early signal mediator, ORAI1, a pore subunit of the calcium release-activated calcium channel, was identified to induce the shear stress phenotypes and cell proliferation in LECs responding to the fluid flow. Mechanistically, ORAI1 induced upregulation of Krüppel-like factor (KLF)-2 and KLF4 in the flow-activated LECs, the 2 KLF proteins cooperate to regulate VEGF-A, VEGF-C, FGFR3, p57 by binding to the regulatory regions of the genes. Consistently, freshly isolated LECs from Orai1 knockout embryos displayed reduced expression of KLF2, KLF4, VEGF-A, VEGF-C, FGFR3 and elevated expression of p57. Accordingly, mouse embryos deficient in Orai1, Klf2, or Klf4 showed a significantly reduced lymphatic density and impaired lymphatic development. Conclusions: Our study identified a molecular mechanism for laminar flow-activated LEC proliferation.
KW - Calcium channel
KW - Capillary
KW - Cell proliferation
KW - lymphatic vessels
KW - vascular endothelial growth factor A
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U2 - 10.1161/CIRCRESAHA.116.309548
DO - 10.1161/CIRCRESAHA.116.309548
M3 - Article
C2 - 28167653
AN - SCOPUS:85012141583
SN - 0009-7330
VL - 120
SP - 1426
EP - 1439
JO - Circulation Research
JF - Circulation Research
IS - 9
ER -