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Crim1 maintains retinal vascular stability during development by regulating endothelial cell Vegfa autocrine signaling.

ABSTRACT: Angiogenesis defines the process in which new vessels grow from existing vessels. Using the mouse retina as a model system, we show that cysteine-rich motor neuron 1 (Crim1), a type I transmembrane protein, is highly expressed in angiogenic endothelial cells. Conditional deletion of the Crim1 gene in vascular endothelial cells (VECs) causes delayed vessel expansion and reduced vessel density. Based on known Vegfa binding by Crim1 and Crim1 expression in retinal vasculature, where angiogenesis is known to be Vegfa dependent, we tested the hypothesis that Crim1 is involved in the regulation of Vegfa signaling. Consistent with this hypothesis, we showed that VEC-specific conditional compound heterozygotes for Crim1 and Vegfa exhibit a phenotype that is more severe than each single heterozygote and indistinguishable from that of the conditional homozygotes. We further showed that human CRIM1 knockdown in cultured VECs results in diminished phosphorylation of VEGFR2, but only when VECs are required to rely on an autocrine source of VEGFA. The effect of CRIM1 knockdown on reducing VEGFR2 phosphorylation was enhanced when VEGFA was also knocked down. Finally, an anti-VEGFA antibody did not enhance the effect of CRIM1 knockdown in reducing VEGFR2 phosphorylation caused by autocrine signaling, but VEGFR2 phosphorylation was completely suppressed by SU5416, a small-molecule VEGFR2 kinase inhibitor. These data are consistent with a model in which Crim1 enhances the autocrine signaling activity of Vegfa in VECs at least in part via Vegfr2.

SUBMITTER: Fan J

PROVIDER: S-EPMC3879820 | biostudies-other | 2014 Jan

REPOSITORIES: biostudies-other

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Crim1 maintains retinal vascular stability during development by regulating endothelial cell Vegfa autocrine signaling.

Fan Jieqing J Ponferrada Virgilio G VG Sato Tomohito T Vemaraju Shruti S Fruttiger Marcus M Gerhardt Holger H Ferrara Napoleone N Lang Richard A RA

Development (Cambridge, England) 20131218 2

Angiogenesis defines the process in which new vessels grow from existing vessels. Using the mouse retina as a model system, we show that cysteine-rich motor neuron 1 (Crim1), a type I transmembrane protein, is highly expressed in angiogenic endothelial cells. Conditional deletion of the Crim1 gene in vascular endothelial cells (VECs) causes delayed vessel expansion and reduced vessel density. Based on known Vegfa binding by Crim1 and Crim1 expression in retinal vasculature, where angiogenesis is ...[more]

PMID: 24353059

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Project description:BackgroundInfantile hemangioma (IHA) is the most common tumor in infancy. We aimed to explore the effect of propranolol on the expression of microRNA (miR)-424 in IHA tissues and XPTS-1 cells, as well as its molecular mechanism of inhibiting XPTS-1 cell activity.MethodsTumor tissues and peritumoral tissue were collected from 13 IHA patients in Lishui Municipal Central Hospital. The level of miR-424 were detected using real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Cell counting kit-8 (CCK-8) was used to measure XPTS-1 cell viability. Flow cytometry and transwell were used to detect the apoptosis level and invasion ability of XPTS-1 cells. Western blot was used to measure the protein level of vascular endothelial growth factor-A (VEGFA). The luciferase reporter gene assay detected the targeting relationship between miR-424 and VEGFA.ResultsCompared with normal tissues and human umbilical vein endothelial cells, the expression level of miR-424 in IHA tissues and XPTS-1 cells was significantly reduced (P<0.05). As the concentration of propranolol increased, XPTS-1 cell viability gradually decreased (P<0.05), and the expression level of VEGFA decreased (P<0.05). The expression of miR-424 increased with the time of propranolol treatment (P<0.05). Compared with the control group, treatment with an miR-424 inhibitor resulted in a significant increase in XPTS-1 cell viability and invasion ability (P<0.05), and a decrease in apoptosis (P<0.05). However, both propranolol and miR-424 inhibitor treatment resulted in a partial decrease in XPTS-1 cell viability (P<0.05), and a partial increase in the level of apoptosis (P<0.05). MiR-424 directly targeted VEGFA; the overexpression of miR-424 resulted in a decrease in the VEGFA protein level (P<0.05), while inhibition of miR-424 resulted in an increase in the VEGFA protein level (P<0.05). Compared with the propranolol group, the XPTS-1 cell viability and invasion ability in the propranolol + VEGFA-si group were significantly decreased (P<0.05), while the level of apoptosis increased (P<0.05). Meanwhile, simultaneous miR-424 inhibitor treatment resulted in no difference in cell viability and apoptosis levels compared with the propranolol group, and the invasion ability was partially restored (P<0.05).ConclusionsPropranolol affects the malignant biological behavior of IHA cells by regulating the miR-424/VEGFA axis.

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Crim1 maintains retinal vascular stability during development by regulating endothelial cell Vegfa autocrine signaling.

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Crim1 maintains retinal vascular stability during development by regulating endothelial cell Vegfa autocrine signaling.

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