bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2022.03.09.483667

Phospholipase Cβ2 Promotes Vascular Endothelial Growth Factor Induced Vascular Permeability

Phoenix, K. N.·Yue, Z.·Yue, L.·Cronin, C. G.·Liang, B. T.·Hoeppner, L. H.·Claffey, K. P.
View original source ↗Export metadata ↓

Abstract

BackgroundRegulation of vascular permeability (VP) is critical to maintaining tissue metabolic homeostasis. Vascular endothelial growth factor (VEGF) is a key stimulus of VP in acute and chronic diseases including ischemia reperfusion injury, sepsis and cancer. Identification of novel regulators of VP would allow for the development of effective targeted therapeutics for patients with unmet medical need. MethodsIn vitro and in vivo models of VEGFA-induced vascular permeability, pathological permeability, quantitation of intracellular calcium release and cell entry, and PIP2 levels were evaluated with and without modulation of PLC{beta}2. ResultsGlobal knock-out of PLC{beta}2 in mice resulted in blockade of VEGFA-induced vascular permeability in vivo and trans-endothelial permeability in primary lung endothelial cells. Further work in an immortalized human microvascular cell line modulated with stable knock-down of PLC{beta}2 recapitulated the observations in the mouse model and primary cell assays. Additionally, loss of PLC{beta}2 limited both intracellular release and extracellular entry of calcium following VEGF stimulation as well as reduced basal and VEGFA-stimulated levels of PIP2 compared to control cells. Finally, loss of PLC{beta}2 in both a hyperoxia induced lung permeability model and a cardiac ischemia:reperfusion model resulted in improved animal outcomes when compared to WT controls. ConclusionsThe results implicate PLC{beta}2 as a key positive regulator of VEGF-induced VP through regulation of both calcium flux and PIP2 levels at the cellular level. Targeting of PLC{beta}2 in a therapeutic setting may provide a novel approach to regulating vascular permeability in patients. Graphic Abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY HighlightsO_LIPLC{beta}2 promotes VEGFA induced vascular permeability. C_LIO_LILoss of PLC{beta}2 prevents VEGFA vascular permeability via repression of cellular calcium flux and membrane PIP2 levels. C_LIO_LILoss of PLC{beta}2 reduces vascular permeability and improves outcomes in a hyperoxic lung damage model and a cardiac ischemia:reperfusion model in vivo. C_LIO_LITargeting PLC{beta}2 inhibition may lead to a novel therapeutic for diseases such as stroke and myocardial infarction. C_LI

Source connections

Explore related subjects

cell biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Phoenix, K. N., Yue, Z., Yue, L., Cronin, C. G., Liang, B. T., Hoeppner, L. H., Claffey, K. P.. 2022-03-10. Phospholipase Cβ2 Promotes Vascular Endothelial Growth Factor Induced Vascular Permeability. https://doi.org/10.1101/2022.03.09.483667

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Sequence context and partner availability specify divergent cell fates from a single transcription factor

Transcription factors drive the gene regulatory networks that control developmental transitions, yet which of their many targets a cell uses remains unresolved. Expressing Cebp, Cebp{beta} or Cebp{delta} identically, alone or with Oct4, Sox2, Klf4 and cMyc, gave four outcomes: adipocyte from fibroblasts and neural stem cells, trophectoderm from embryonic stem cells, and myeloid from B cells. Raising Cebp levels changed how many sites it reached, not which sequence it read: clustered motifs maintained somatic enhancers, while spillover onto low-copy sites created de novo enhancers carrying composites of Cebp and cell-type-restricted partners. In fibroblasts, Cebp also redistributed Oct4, Sox2 and Klf4 from early targets, blocking iPSC formation. Supplying the predicted partners rewrote the output: Spi1 redirected Cebp into parallel adipogenic and myeloid programs, via a transient PpargCD45 state using separate enhancers for each; TFAP2C abolished adipogenic conversion. Motif density and partner composites therefore assemble a factor's instructive output in the receiving cell.

cell biology↗
bioRxiv2026

High-content screening identifies FDA-approved activators of mitophagy

Mitochondrial diseases are highly heterogeneous disorders caused by defects in oxidative phosphorylation, for which only limited therapeutic options are available. The elimination of dysfunctional mitochondria via mitophagy activation is an attractive strategy to treat several mitochondrial diseases, irrespective of the underlying genetic defect. To identify pharmacological activators of this pathway, we performed a high-content screening of 1,971 FDA-approved compounds using cellular reporters of TFEB nuclear translocation and mitophagy. This screening identified 294 compounds that promoted TFEB translocation, nine of which increased the number of mitolysosomes without compromising cell viability or damaging mitochondria. Among the selected compounds, Meptazinol and Ponatinib emerged as the top-ranked mitophagy inducers in fibroblasts from patients with complex I and IV deficiency, respectively, and were prioritised for further characterisation. However, they did not rescue the bioenergetic defect, suggesting that the stimulation of mitophagy per se is not sufficient to ameliorate the OXPHOS defect in mitochondrial diseases. Overall, our findings establish a scalable platform for the identification of pharmacological activators of TFEB and identify candidate compounds for therapeutic modulation of mitophagy.

cell biology↗
bioRxiv2026

Matrix Gla Protein deficiency reveals a previously unrecognized mucosal calcification in the mouse airways

Tracheal calcification is a common finding that is considered to have limited clinical significance when detected most often in elderly individuals. Despite its frequent occurrence, the cellular and molecular mechanisms at the origin of tracheal calcification remain largely unexplored. In this context, we aimed to characterize the development of tracheal calcification, and to determine the role of matrix Gla protein (MGP), a major inhibitor of ectopic calcification whose genetic or pharmacologic deficiency is associated with premature tracheal calcification in humans. We found that wild-type mice undergo an unexpected early physiologic calcification of the tracheal cartilage rings beginning around one month after birth. This calcification progresses in a dynamic rostro-caudal sequence through a process involving terminal differentiation of tracheal chondrocytes. These findings challenge the prevailing view that tracheal cartilage is a permanent hyaline cartilage and instead reveals an early and highly organized physiologic calcification process. Furthermore, our findings further identify MGP as a key regulator of calcification within the respiratory tract. Indeed, MGP deficiency not only markedly accelerates tracheal cartilage calcification through a similar pattern and mechanism but also induces a previously unrecognized calcification of the tracheal mucosa, a lesion absent in wild-type mice. These alterations could partly explain the respiratory manifestations observed in MGP-deficient patients having Keutel syndrome, which include dyspnea, cough, stridor, and recurrent infections, symptoms previously being mainly attributed to calcification of the tracheal cartilage rings.

cell biology↗