Canonical Transient Receptor Potential 3 Channel Triggers Vascular Endothelial Growth Factor-Induced Intracellular Ca²⁺Oscillations in Endothelial Progenitor Cells Isolated from Umbilical Cord Blood

Abstract

Endothelial colony-forming cells (ECFCs) are the only endothelial progenitor cells (EPCs) that are capable of acquiring a mature endothelial phenotype. ECFCs are mainly mobilized from bone marrow to promote vascularization and represent a promising tool for cell-based therapy of severe ischemic diseases. Vascular endothelial growth factor (VEGF) stimulates the proliferation of peripheral blood-derived ECFCs (PB-ECFCs) through oscillations in intracellular Ca(2+) concentration ([Ca(2+)]i). VEGF-induced Ca(2+) spikes are driven by the interplay between inositol-1,4,5-trisphosphate (InsP3)-dependent Ca(2+) release and store-operated Ca(2+) entry (SOCE). The therapeutic potential of umbilical cord blood-derived ECFCs (UCB-ECFCs) has also been shown in recent studies. However, VEGF-induced proliferation of UCB-ECFCs is faster compared with their peripheral counterpart. Unlike PB-ECFCs, UCB-ECFCs express canonical transient receptor potential channel 3 (TRPC3) that mediates diacylglycerol-dependent Ca(2+) entry. The present study aimed at investigating whether the higher proliferative potential of UCB-ECFCs was associated to any difference in the molecular underpinnings of their Ca(2+) response to VEGF. We found that VEGF induces oscillations in [Ca(2+)]i that are patterned by the interaction between InsP3-dependent Ca(2+) release and SOCE. Unlike PB-ECFCs, VEGF-evoked Ca(2+) oscillations do not arise in the absence of extracellular Ca(2+) entry and after pharmacological (with Pyr3 and flufenamic acid) and genetic (by employing selective small interference RNA) suppression of TRPC3. VEGF-induced UCB-ECFC proliferation is abrogated on inhibition of the intracellular Ca(2+) spikes. Therefore, the Ca(2+) response to VEGF in UCB-ECFCs is shaped by a different Ca(2+) machinery as compared with PB-ECFCs, and TRPC3 stands out as a promising target in EPC-based treatment of ischemic pathologies.

Dysregulation of VEGF-induced proangiogenic Ca2+ oscillations in primary myelofibrosis-derived endothelial colony-forming cells

“…As illustrated in Figure 1A, neighboring PMF-ECFCs recorded from the same microscopic field displayed asynchronous Ca 2þ spikes in response to VEGF. Such heterogeneity had already been observed in both N-ECFCs and UCB-derived ECFCs [13,18] and represents the hallmark of growth factorinduced Ca 2þ signals in ECs [27], as well other nonexcitable cell types [28]. Each baseline Ca 2þ transient was preceded by a gradual increase in [Ca 2þ ] i (dashed box in Fig.…”

“…VEGF-induced Ca 2þ oscillations are weaker in PMF-ECFCs than in control cells The most suitable concentration of VEGF for triggering intracellular Ca 2þ oscillations in ECFCs is 10 ng/mL [13,18]. Therefore, we used this dose to compare VEGFinduced Ca 2þ spikes between N-and PMF-ECFCs.…”

“…These cells exhibited a reduction in InsP 3 -depedent Ca 2þ release and two pharmacologically distinguishable types of SOCCs: one is stimulated by passive ER depletion, is inhibited by BTP-2 and La 3þ , and is resistant to Gd 3þ , whereas the other is tuned by the InsP 3 -sensitive Ca 2þ pool and inhibited by BTP-2, La 3þ , and Gd 3þ [17]. Unlike EPCs derived from peripheral blood of healthy donors and from umbilical cord blood (UCB) [15,18], the pharmacologic blockade of store-operated Ca 2þ entry (SOCE) did not block PMF-derived EPC proliferation when the cells were grown in an endothelial growth medium enriched with growth factors, including VEGF [17]. These findings lead to two important questions: (i) Is VEGF capable of triggering Ca 2þ oscillations in EPCs harvested from PMF patients?…”

Modulation de la sensibilité aux glucocorticoïdes dans les leucémies aiguës lymphoblastiques

“…Il permet d'inhiber les influx de calcium ainsi que la signalisation cellulaire liée à ce canal, la croissance et la mort cellulaire [4]. Dans les cellules non-excitables telles que les cellules sanguines, l'épuise-ment des pools calciques intracellulaires active les canaux calciques membranaires à l'origine d'un influx calcique appelé SOCE (store-operated Ca 2 + entry) [5].…”

Akt/eNOS signaling pathway mediates inhibition of endothelial progenitor cells by palmitate-induced ceramide

“…EPCs have been found in the bone marrow, spleen, umbilical cord blood, and peripheral blood and can contribute to the formation of new blood vessels in postnatal life and incorporate into injured vessels to form mature endothelial cells (ECs) in response to tissue ischemia (9,28). Increasing evidence indicates that incorporation of EPCs plays an important role in postnatal neovascularization (1,12).…”