Download presentation
Presentation is loading. Please wait.
Published byReginald Lambert Modified over 9 years ago
1
Mechanosensitive properties in endothelium and their roles in regulation of endothelial function Zhi-Ren Zhang M.D., Ph.D. Harbin Medical University
2
Sensors for shear stress on vascular endothelial cells Kimiko Yamamoto. Circulation Journal. 2009
3
Endothelial cells isolated from mouse express CD31 and have primary cilia. Nauli, et al. Circulation 2008 Do vascular endothelial cells isolated from mouse express primary cilia?
4
Colocalization of polycystin-1 (PC1) and polaris. Nauli, et al. Circulation 2008 Polycystin-1 is localized in aortic endothelial cilia of embryonic mouse aorta. Does polycystin-1 (TRPP1, PKD1) express and localize in endothelial cilia of embryonic mouse aorta?
5
Fluid shear–induced calcium and transient NO require polaris and polycystin-1. Nauli, et al. Circulation 2008 Does TRPP1 or cilium play a role in regulation of endothelial function?
6
Is TRPP2 localized in the cilia of vascular endothelial cells? Human MouseWissam A. et al. Cellular biology.2009
7
Normal expression level and localization of TRPP2 in cilia is required for the endothelial cilia to sense fluid shear stress. Wissam A. et al. Cellular biology.2009
8
Fluid flow (shear stress) Cilia Polycystin-1 Polycystin-2 Ca 2+ PKC eNOS CaM Akt/PKB Ca 2+ /CaM Nitric oxide Vasodilator Mechanosensory cilia as microcompartments. Surya M, et al. International Journal of Vascular Medicine 2011
9
Are there other sensors for shear stress on vascular endothelial cells beyond what have found so far?
10
Control 5 mM Chloral hydrate (3 days) Nuclei α-tubulin Merged XZ view Do human umbilical vein endothelial cells (HUVECs) have primary cilia?
11
Are cilia involved in [Ca 2+ ] i increase in response to alteration of shear stress in HUVECs? 30s 0 10 dyne/cm 2
12
Is cilium involved in [NO] i increase in response to alteration of shear stress? 0 10 dyne/cm 2 ~75s
13
The data presented thus far indicate that there is another “secondary” sensor beyond primary cilium. What is it? We have previously indentified a functional channel complex formed by TRPP2 and TRPV4 in CCD isolated from mouse and this channel complex exerts dual functions (submitted to Cell).
14
TRPV4MergeNucleiTRPP2 WB: IP:Lysate TRPV4 IgGTRPP2 WB:TRPP2 IP:LysateIgGTRPV4 A B Do TRPP2 and TRPV4 physically interact in HUVECs? IgG
15
C Does TRPP2 or TRPV4 express in cilia of HUVECs?
16
TRPP2 TRPV4 Merged cilium Are TRPP2 and TRPV4 co-localized on cilium?
17
Are TRPP2 and TRPV4 co-localized on human mesenteric vascular endothelial cells?
18
The data presented thus far strongly suggest that TRPP2/TRPV4 physically interact in HUVECs, and that this complex expresses both in cilia and plasma membrane of HUVECs Question Does this complex play a role in response to macheno-stimuli in HUVECs?
19
qtRT-PCR demonstrating gene silencing efficiency
20
TRPP2 β-actin TRPV4 β-actin CtrlScr P2-shRNA CtrlScr P2/V4-shRNA CtrlScr V4-shRNA CtrlScr P2/V4-shRNA
21
Does knock down TRPP2 and/or TRPV4 affect [Ca 2+ ] i transient in response to alteration of shear stress in HUVECs ? 0 10 dyne/cm 2 30s
22
Does knock down TRPP2 or TRPV4 affect increase in [NO] i in response to alteration of shear stress in HUVECs ? 0 10 dyne/cm 2
23
p-AMPK AMPK p-eNOS e-NOS CtrlScr Ctrl Flow 10 min
24
p-AMPKα AMPKα CtrlScrCtrlScrCtrlScr p-eNOS e-NOS V4- shRNA P2- shRNA P2/V4- shRNA Flow 10 min p-eNOS e-NOS PI3K inhibitor (+) (-) (+) (-) (+) (-) CtrlScrCtrlScrCtrlScr P2- shRNA V4- shRNA P2/V4- shRNA
26
A Do TRPP2 and TRPV4 form a functional channel complex in HUVECs? baseline 100 mV TRPP2/TRPV4 forms a non-selective calcium permeable cation channel
27
There are several different machenosensors in vascular endothelial cells, including primary cilium. TRPP2 and TRPV4 assemble to form a functional channel complex in HUVECs. TRPP2/TRPV4 channel complex exerts dual functions, i. e. acting as a mechanosensor and regulating [Ca 2+ ] i and NO production in response to alternation of shear stress in HUVECs, via AMPK-p- eNOS (?).
28
Jia-Ning Zhang, Ph.D. candidate Dan Zhao, Ph.D. Associate Prof. Ying Zhao, Bing-Kun Zhang John Y.-J. Shyy, Ph.D., Prof. Univ. of California, Riverside Funding: CNSF, NIH
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.