Stromal Cell-Derived Factor-1α Promotes Endothelial Colony-Forming Cell Migration Through the Ca²⁺-Dependent Activation of the Extracellular Signal-Regulated Kinase 1/2 and Phosphoinositide 3-Kinase/AKT Pathways

Abstract

Stromal cell-derived factor-1α (SDF-1α) drives endothelial colony-forming cell (ECFC) homing and incorporation within neovessels, thereby restoring tissue perfusion in ischemic tissues and favoring tumor vascularization and metastasis. SDF-1α stimulates ECFC migration by activating the G-protein-coupled receptor, CXCR4, and then engaging the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway. Sporadic evidence showed that SDF-1α may also act through an increase in intracellular Ca concentration ([Ca]) in bone marrow-derived hematopoietic progenitor cells and fully differentiated endothelial cells. Of note, recent evidence demonstrated that intracellular Ca signals play a key role in controlling the proangiogenic activity of ECFCs. The present investigation was, therefore, undertaken to assess whether and how SDF-1α induces ECFC motility by triggering intracellular Ca signals. We found that SDF-1α caused a dose-dependent increase in [Ca] that was inhibited by ADM3100, a selective CXCR4 antagonist. Pharmacological manipulation revealed that the Ca response to [Ca] was shaped by an initial intracellular Ca release through inositol-1,4,5-trisphosphate receptors (InsPRs), followed by a sustained phase of extracellular Ca entry through store-operated Ca channels. InsP-dependent Ca release and store-operated Ca entry (SOCE) were both necessary for SDF-1α-induced extracellular signal-regulated kinases 1/2 (ERK 1/2) and AKT phosphorylation. Finally, SDF-1α employed intracellular Ca signals, ERK 1/2, and PI3K/AKT to promote ECFC migration in vitro and neovessel formation in vivo. These data, therefore, provide the first evidence that SDF-1α induces ECFC migration through the Ca-dependent activation of the ERK 1/2 and PI3K/AKT pathways.

Phosphatidylethanolamine Induces an Antifibrotic Phenotype in Normal Human Lung Fibroblasts and Ameliorates Bleomycin-Induced Lung Fibrosis in Mice

“…Moreover, PE has been shown to activate the extracellular signal-regulated kinases (Erk) and Stat signaling pathways [ 28 ], which may inhibit type 1 collagen expression in human dermal fibroblasts [ 29 , 30 ]. Of note, intracellular Ca 2+ signaling may recruit both Erk [ 31 ] and Stat signaling [ 32 ].…”

Therapeutic Potential of Endothelial Colony-Forming Cells in Ischemic Disease: Strategies to Improve their Regenerative Efficacy

“…Similarly, SDF-1α stimulated E-selectin mediated ECFC adhesion and migration following endotoxic endothelial injury in a CXCR4-dependent manner [ 146 ]. Additionally, SDF-1α promoted the Ca 2+ -dependent recruitment of the phosphatidylinositol 3-kinase (PI3K)/Akt and ERK signaling cascades, thereby further contributing to induce ECFC migration in vitro and neovessel formation in vivo [ 186 ].…”

Endothelial Transient Receptor Potential Channels and Vascular Remodeling: Extracellular Ca2 + Entry for Angiogenesis, Arteriogenesis and Vasculogenesis

“…Nevertheless, depletion of the ER Ca 2+ pool failed to induce a detectable store-operated Ca 2+ current in ECFCs Moccia et al, 2019b), which suggests that Orai1 and TRPC1 tightly interact to mediate an I CRAC -like conductance, as described in mouse PAECs (Cioffi et al, 2012). SOCE may be recruited, respectively, by stromal derived factor-1α (SDF-1α) to promote ECFC migration in vitro and neovessel formation in vivo (Zuccolo et al, 2018) and by VEGF to stimulate ECFC proliferation and tube formation (Dragoni et al, 2011(Dragoni et al, , 2015b. Of note, SOCE engages the ERK 1/2 and PI3K/Akt signaling pathways to drive SDF-1α-induced ECFC motility (Zuccolo et al, 2018), whereas the pro-angiogenic response to VEGF involves the Ca 2+ -sensitive transcription factor, NF-κB (Dragoni et al, 2011).…”

“…SOCE may be recruited, respectively, by stromal derived factor-1α (SDF-1α) to promote ECFC migration in vitro and neovessel formation in vivo (Zuccolo et al, 2018) and by VEGF to stimulate ECFC proliferation and tube formation (Dragoni et al, 2011(Dragoni et al, , 2015b. Of note, SOCE engages the ERK 1/2 and PI3K/Akt signaling pathways to drive SDF-1α-induced ECFC motility (Zuccolo et al, 2018), whereas the pro-angiogenic response to VEGF involves the Ca 2+ -sensitive transcription factor, NF-κB (Dragoni et al, 2011). Similar to human ECFCs, STIM1, TRPC1 and Orai1 interact to mediate SOCE and support in vitro angiogenesis (proliferation, motility and the formation) in rodent MACs (Kuang et al, 2010(Kuang et al, , 2012Wang et al, 2015).…”

“…Multiple pro-angiogenic cues, such as VEGF, bFGF, PDGF, epidermal growth factor (EGF), stromal derived factor-1α (SDF-1α), and angiopoietins regulate endothelial cell behavior and fate through an increase in intracellular Ca 2+ concentration ([Ca 2+ ] i ) (Moccia et al, 2003;Yokota et al, 2015;Noren et al, 2016;Savage et al, 2019). Likewise, VEGF and SDF-1α induce pro-angiogenic Ca 2+ signals in endothelial colony forming cells (ECFCs) (Dragoni et al, 2011(Dragoni et al, , 2013Zuccolo et al, 2018;Moccia, 2020), which represent the only EPC subtype truly belonging to the vascular endothelial lineage (Medina et al, 2017;Poletto et al, 2018). Transient Receptor Potential (TRP) channels regulate numerous endothelial cell functions by mediating extracellular Ca 2+ entry in response to chemical, mechanical and thermal stimuli (Moccia et al, 2012a;Earley and Brayden, 2015;Guerra et al, 2018;Smani et al, 2018;Thakore and Earley, 2019).…”