Enhanced angiogenesis promoted by human umbilical mesenchymal stem cell transplantation in stroked mouse is Notch1 signaling associated

Neuroscience. 2015 Apr 2:290:288-99. doi: 10.1016/j.neuroscience.2015.01.038. Epub 2015 Jan 28.

Abstract

Cellular therapy has provided hope for restoring neurological function post stroke through promoting endogenous neurogenesis, angiogenesis and synaptogenesis. The current study was based on the observation that transplantation of human umbilical cord mesenchymal stem cells (hUCMSCs) promoted the neurological function improvement in stroked mice and meanwhile enhanced angiogenesis in the stroked hemisphere. Grafted hUCMSCs secreted human vascular endothelial growth factor A (VEGF-A). Notch1 signaling was activated after stroke and also in the grafted hUCMSCs. To address the potential mechanism that might mediate such pro-angiogenic effect, we established a hUCMSC-neuron co-culture system. Neurons were subjected to oxygen glucose deprivation (OGD) injury before co-culturing to mimic the in vivo cell transplantation. Consistent with the in vivo data, co-culture medium claimed from hUCMSC-OGD neuron co-culture system significantly promoted the capillary-like tube formation of brain-derived endothelial cells. Moreover, coincident with our in vivo data, Notch 1 signaling activation was detected in hUCMSCs after co-cultured with OGD neurons as demonstrated by the up-regulation of key Notch1 signaling components Notch1 and Notch1 intercellular domain (NICD). In addition, OGD-neuron co-culture also increased the VEGF-A production by hUCMSCs. To verify whether Notch1 activation was involved in the pro-angiogenic effect, γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) was added into the co-culture medium before co-culture. It turned out that DAPT significantly prevented the Notch1 activation in hUCMSCs after co-culture with OGD neurons. More importantly, the pro-angiogenic effect of hUCMSCs was remarkably abolished by DAPT addition as demonstrated by inhibited capillary-like tube formation and less VEGF-A production. Regarding how Notch1 signaling was linked with VEGF-A secretion, we provided some clue that Notch1 effector Hes1 mRNA expression was significantly up-regulated by OGD-neuron co-culturing and down-regulated after additional treatment of DAPT. In summary, our data provided evidence that the VEGF-A secretion from hUCMSCs after being triggered by OGD neurons is Notch1 signaling associated. This might be a possible mechanism that contributes to the angiogenic effect of hUCMSC transplantation in stroked brain.

Keywords: Hes1; Notch1 signaling; VEGF-A; angiogenesis; human umbilical mesenchymal stem cells; stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / antagonists & inhibitors
  • Amyloid Precursor Protein Secretases / metabolism
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Hypoxia / drug effects
  • Cell Hypoxia / physiology
  • Coculture Techniques
  • Cord Blood Stem Cell Transplantation*
  • Disease Models, Animal
  • Fetal Blood / drug effects
  • Fetal Blood / physiology
  • Glucose / deficiency
  • Homeodomain Proteins / metabolism
  • Humans
  • Male
  • Mesenchymal Stem Cell Transplantation*
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / physiology
  • Mice, Inbred C57BL
  • Neovascularization, Physiologic / physiology*
  • Neurons / drug effects
  • Neurons / physiology
  • RNA, Messenger / metabolism
  • Random Allocation
  • Receptor, Notch1 / metabolism*
  • Signal Transduction / drug effects
  • Stroke / physiopathology*
  • Stroke / therapy*
  • Transcription Factor HES-1
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Homeodomain Proteins
  • NOTCH1 protein, human
  • Notch1 protein, mouse
  • RNA, Messenger
  • Receptor, Notch1
  • Transcription Factor HES-1
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • HES1 protein, human
  • Amyloid Precursor Protein Secretases
  • Glucose