Phospholipase Cε Modulates Rap1 Activity and the Endothelial Barrier

DiStefano, Peter V.; Smrcka, Alan V.; Glading, Angela

doi:10.1371/journal.pone.0162338

Cited by 4 publications

(2 citation statements)

References 53 publications

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“…These results suggest that increased cAMP might lead to increased Rap1/Rac1 activation in an Epac1-independent manner. One candidate is the phosphoinositide-specific phospholipase C (PLCε), which was shown to stimulate Rap1/Rac1 activity after cAMP increase via KRIT1 [ 51 ]. Altogether, Epac1 appeared to be required for proper baseline and cAMP-mediated activation of Rap1 but might be less important for Rac1 activation.…”

Section: Discussionmentioning

confidence: 99%

Epac1 Is Crucial for Maintenance of Endothelial Barrier Function through A Mechanism Partly Independent of Rac1

García‐Ponce

Schuster

Døskeland

et al. 2020

Cells

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Epac1 (exchange protein activated by cAMP) stabilizes the endothelial barrier, but detailed studies are limited by the side effects of pharmacological Epac1 modulators and transient transfections. Here, we compare the key properties of barriers between endothelial cells derived from wild-type (WT) and Epac1-knockout (KO) mice myocardium. We found that KO cell layers, unlike WT layers, had low and cAMP-insensitive trans-endothelial resistance (TER). They also had fragmented VE-cadherin staining despite having augmented cAMP levels and increased protein expression of Rap1, Rac1, RhoA, and VE-cadherin. The simultaneous direct activation of Rac1 and RhoA by CN04 compensated Epac1 loss, since TER was increased. In KO-cells, inhibition of Rac1 activity had no additional effect on TER, suggesting that other mechanisms compensate the inhibition of the Rac1 function to preserve barrier properties. In summary, Epac1 is crucial for baseline and cAMP-mediated barrier stabilization through mechanisms that are at least partially independent of Rac1.

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Section: Discussionmentioning

confidence: 99%

Epac1 Is Crucial for Maintenance of Endothelial Barrier Function through A Mechanism Partly Independent of Rac1

García‐Ponce

Schuster

Døskeland

et al. 2020

Cells

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“…Treatment with I942 alone provoked significant changes in the RNA expression of 1413 genes, which were largely associated with microtubule stability and cell cycle progression (Figure 2). While it can be argued that many of the gene expression changes evoked by I942 could represent “off-target” effects, it should be pointed out that EPAC1 activation has already been linked to microtubule stability [37,38,39,40], cell cycle progression [41,42,43,44,45,46,47,48] and physical interaction with microtubule cytoskeleton components [49,50,51,52,53], so these results are consistent with “on-target” EPAC1-dependent actions of I942. Moreover, it has been shown that EPAC1 and PKA signalling responses are often mutually dependent [48,54].…”

Section: Discussionmentioning

confidence: 99%

Genome-Wide Mapping Defines a Role for C/EBPβ and c-Jun in Non-Canonical Cyclic AMP Signalling

Wiejak

Basten

Hamilton

et al. 2019

Cells

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The novel exchange protein activated by cyclic AMP (EPAC1) activator, I942, induces expression of the suppressor of cytokine signalling 3 (SOCS3) gene, thereby inhibiting interleukin 6 (IL6) inflammatory processes in human umbilical vein endothelial cells (HUVECs). Here we use RNA-SEQ and ChIP-SEQ to determine global gene responses to I942, in comparison with cyclic AMP production promoted by forskolin and rolipram (F/R). We found that I942 promoted significant changes in the RNA expression of 1413 genes, largely associated with microtubule stability and cell cycle progression, whereas F/R regulated 197 genes linked to endothelial cell function, including chemokine production and platelet aggregation. A further 108 genes were regulated by both treatments, including endothelial regulatory genes involved in purinergic signalling and cell junction organization. ChIP-SEQ demonstrated that F/R induced genome-wide recruitment of C/EBPβ and c-Jun transcription factors, whereas I942 promoted recruitment of c-Jun to genes associated with IL6 signalling, with little effect on C/EBPβ activation. Despite this, certain key inflammatory genes, including IL6, VEGF, CCL2/MCP1, VCAM1, SELE and ICAM1 were regulated by I942 without significant c-Jun recruitment, suggesting an additional, indirect mode of action for I942. In this regard, SOCS3 induction by I942 was found to require c-Jun and was associated with suppression of IL6-promoted ERK MAP kinase and AKT activity and induction of ICAM1. Pharmacological inhibition of ERK and AKT also potentiated ICAM1 induction by I942. We therefore propose that c-Jun activation by I942 regulates endothelial gene expression in HUVECs through direct mechanisms, involving recruitment of c-Jun or, as for ICAM1, through indirect regulation of tertiary regulators, including SOCS3.

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Establishment of the deuterium oxide dilution method as a new possibility for determining the transendothelial water permeability

Müller,

Hahn,

Gierke

et al. 2024

Pflugers Arch - Eur J Physiol

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Increase in transendothelial water permeability is an essential etiological factor in a variety of diseases like edema and shock. Despite the high clinical relevance, there has been no precise method to detect transendothelial water flow until now. The deuterium oxide (D2O) dilution method, already established for measuring transepithelial water transport, was used to precisely determine the transendothelial water permeability. It detected appropriate transendothelial water flow induced by different hydrostatic forces. This was shown in four different endothelial cell types. The general experimental setup was verified by gravimetry and absorbance spectroscopy. Determination of transendothelial electrical resistance (TEER) and immunocytochemical staining for proteins of the cell-cell contacts were performed to ensure that no damage to the endothelium occurred because of the measurements. Furthermore, endothelial barrier function was modulated. Measurement of transendothelial water flux was verified by measuring the TEER, the apparent permeability coefficient and the electrical capacity. The barrier-promoting substances cyclic adenosine monophosphate and iloprost reduced TEER and electrical capacity and increased permeability. This was accompanied by a reduced transendothelial water flux. In contrast, the barrier-damaging substances thrombin, histamine and bradykinin reduced TEER and electrical capacity, but increased permeability. Here, an increased water flow was shown. This newly established in vitro method for direct measurement of transendothelial water permeability was verified as a highly precise technique in various assays. The use of patient-specific endothelial cells enables individualized precision medicine in the context of basic edema research, for example regarding the development of barrier-protective pharmaceuticals.

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Phospholipase Cε Modulates Rap1 Activity and the Endothelial Barrier

Cited by 4 publications

References 53 publications

Epac1 Is Crucial for Maintenance of Endothelial Barrier Function through A Mechanism Partly Independent of Rac1

Epac1 Is Crucial for Maintenance of Endothelial Barrier Function through A Mechanism Partly Independent of Rac1

Genome-Wide Mapping Defines a Role for C/EBPβ and c-Jun in Non-Canonical Cyclic AMP Signalling

Establishment of the deuterium oxide dilution method as a new possibility for determining the transendothelial water permeability

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