PMID- 19261619
OWN - NLM
STAT- MEDLINE
DCOM- 20090608
LR  - 20211020
IS  - 0021-9258 (Print)
IS  - 1083-351X (Electronic)
IS  - 0021-9258 (Linking)
VI  - 284
IP  - 17
DP  - 2009 Apr 24
TI  - GEF-H1 mediates tumor necrosis factor-alpha-induced Rho activation and myosin 
      phosphorylation: role in the regulation of tubular paracellular permeability.
PG  - 11454-66
LID - 10.1074/jbc.M805933200 [doi]
AB  - Tumor necrosis factor-alpha (TNF-alpha), an inflammatory cytokine, has been shown 
      to activate the small GTPase Rho, but the underlying signaling mechanisms 
      remained undefined. This general problem is particularly important in the kidney, 
      because TNF-alpha, a major mediator of kidney injury, is known to increase 
      paracellular permeability in tubular epithelia. Here we aimed to determine the 
      effect of TNF-alpha on the Rho pathway in tubular cells (LLC-PK(1) and 
      Madin-Darby canine kidney), define the upstream signaling, and investigate the 
      role of the Rho pathway in the TNF-alpha-induced alterations of paracellular 
      permeability. We show that TNF-alpha induced a rapid and sustained RhoA 
      activation that led to stress fiber formation and Rho kinase-dependent myosin 
      light chain (MLC) phosphorylation. To identify new regulators connecting the TNF 
      receptor to Rho signaling, we applied an affinity precipitation assay with a Rho 
      mutant (RhoG17A), which captures activated GDP-GTP exchange factors (GEFs). Mass 
      spectrometry analysis of the RhoG17A-precipitated proteins identified GEF-H1 as a 
      TNF-alpha-activated Rho GEF. Consistent with a central role of GEF-H1, its 
      down-regulation by small interfering RNA prevented the activation of the Rho 
      pathway. Moreover GEF-H1 and Rho activation are downstream of ERK signaling as 
      the MEK1/2 inhibitor PD98059 mitigated TNF-alpha-induced activation of these 
      proteins. Importantly TNF-alpha enhanced the ERK pathway-dependent 
      phosphorylation of Thr-678 of GEF-H1 that was key for activation. Finally the 
      TNF-alpha-induced paracellular permeability increase was absent in LLC-PK(1) 
      cells stably expressing a non-phosphorylatable, dominant negative MLC. In 
      summary, we have identified the ERK/GEF-H1/Rho/Rho kinase/phospho-MLC pathway as 
      the mechanism mediating TNF-alpha-induced elevation of tubular epithelial 
      permeability, which in turn might contribute to kidney injury.
FAU - Kakiashvili, Eli
AU  - Kakiashvili E
AD  - Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's 
      Hospital and Department of Surgery, University of Toronto, Ontario M5B 1W8, 
      Canada.
FAU - Speight, Pam
AU  - Speight P
FAU - Waheed, Faiza
AU  - Waheed F
FAU - Seth, Romy
AU  - Seth R
FAU - Lodyga, Monika
AU  - Lodyga M
FAU - Tanimura, Susumu
AU  - Tanimura S
FAU - Kohno, Michiaki
AU  - Kohno M
FAU - Rotstein, Ori D
AU  - Rotstein OD
FAU - Kapus, Andras
AU  - Kapus A
FAU - Szaszi, Katalin
AU  - Szaszi K
LA  - eng
GR  - 75713/CAPMC/CIHR/Canada
GR  - 86019/CAPMC/CIHR/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20090303
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (ARHGEF2 protein, human)
RN  - 0 (Actin Depolymerizing Factors)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Guanine Nucleotide Exchange Factors)
RN  - 0 (Rho Guanine Nucleotide Exchange Factors)
RN  - 0 (Tumor Necrosis Factor-alpha)
RN  - EC 2.7.11.1 (rho-Associated Kinases)
RN  - EC 3.6.4.1 (Myosins)
SB  - IM
MH  - Actin Depolymerizing Factors/metabolism
MH  - Animals
MH  - Cell Line
MH  - Dogs
MH  - Enzyme Inhibitors/pharmacology
MH  - Guanine Nucleotide Exchange Factors/*metabolism
MH  - Kidney Tubules/injuries/*metabolism
MH  - Mass Spectrometry
MH  - Models, Biological
MH  - Myosins/*metabolism
MH  - Permeability
MH  - Phosphorylation
MH  - Rho Guanine Nucleotide Exchange Factors
MH  - Swine
MH  - Tumor Necrosis Factor-alpha/*metabolism
MH  - rho-Associated Kinases/*metabolism
PMC - PMC2670151
EDAT- 2009/03/06 09:00
MHDA- 2009/06/09 09:00
PMCR- 2010/04/24
CRDT- 2009/03/06 09:00
PHST- 2009/03/06 09:00 [entrez]
PHST- 2009/03/06 09:00 [pubmed]
PHST- 2009/06/09 09:00 [medline]
PHST- 2010/04/24 00:00 [pmc-release]
AID - S0021-9258(20)76941-3 [pii]
AID - 11454 [pii]
AID - 10.1074/jbc.M805933200 [doi]
PST - ppublish
SO  - J Biol Chem. 2009 Apr 24;284(17):11454-66. doi: 10.1074/jbc.M805933200. Epub 2009 
      Mar 3.