Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA.
Department of Pediatric Otolaryngology, Emory University, Atlanta, GA 30322, USA.
Int J Mol Sci. 2024 Oct 17;25(20):11182. doi: 10.3390/ijms252011182.
Notch signaling, an important signaling pathway in cardiac development, has been shown to mediate the reparative functions of c-kit+ progenitor cells (CPCs). However, it is unclear how each of the four canonical Notch-activating ligands affects intracellular processes in c-kit+ cells when used as an external stimulus. Neonatal c-kit+ CPCs were stimulated using four different chimeric Notch-activating ligands tethered to Dynabeads, and the resulting changes were assessed using TaqMan gene expression arrays, with subsequent analysis by principal component analysis (PCA). Additionally, functional outcomes were measured using an endothelial cell tube formation assay and MSC migration assay to assess the paracrine capacity to stimulate new vessel formation and recruit other reparative cell types to the site of injury. Gene expression data showed that stimulation with Jagged-1 is associated with the greatest pro-angiogenic gene response, including the expression of VEGF and basement membrane proteins, while the other canonical ligands, Jagged-2, Dll-1, and Dll-4, are more associated with regulatory and epigenetic changes. The functional assay showed differential responses to the four ligands in terms of angiogenesis, while none of the ligands produced a robust change in migration. These data demonstrate how the four Notch-activating ligands differentially regulate CPC gene expression and function.
Notch 信号通路是心脏发育过程中的一个重要信号通路，已被证明介导 c-kit+祖细胞（CPCs）的修复功能。然而，当用作外部刺激时，四种经典的 Notch 激活配体中的每一种如何影响 c-kit+细胞内的过程尚不清楚。使用与 Dynabeads 连接的四种不同嵌合 Notch 激活配体刺激新生 c-kit+CPCs，并使用 TaqMan 基因表达谱评估由此产生的变化，随后通过主成分分析（PCA）进行分析。此外，还通过内皮细胞管形成测定和 MSC 迁移测定来测量功能结果，以评估刺激新血管形成和招募其他修复细胞类型到损伤部位的旁分泌能力。基因表达数据表明，Jagged-1 的刺激与最大的促血管生成基因反应相关，包括 VEGF 和基底膜蛋白的表达，而其他经典配体 Jagged-2、Dll-1 和 Dll-4 则与调节和表观遗传变化更相关。功能测定表明，四种配体在血管生成方面的反应不同，而四种配体均未产生迁移的显著变化。这些数据表明四种 Notch 激活配体如何差异调节 CPC 的基因表达和功能。
