, Volume 21, Issue 2, pp 299–312 | Cite as

Soluble delta-like 1 homolog (DLK1) stimulates angiogenesis through Notch1/Akt/eNOS signaling in endothelial cells

  • Chao-Cheng Huang
  • Hsiao-Mei Kuo
  • Pei-Chang Wu
  • Shih-Hsuan Cheng
  • Tzu-Ting Chang
  • Yi-Chen Chang
  • Mei-Lang Kung
  • Deng-Chyang Wu
  • Jiin-Haur Chuang
  • Ming-Hong Tai
Original Paper



Delta-like 1 homolog (DLK1) is a non-canonical ligand of Notch signaling, which plays a pivotal role in vascular development and tumor angiogenesis. This study aimed to elucidate the function and mechanism of DLK1 in angiogenesis.

Methods and results

By using in situ hybridization and immunohistochemical studies, expression analysis revealed a unique vascular tropism of DLK1 in vasculature of neuroblastoma and vascular tumors. Thus, it was hypothesized that DLK1 may be cleaved and then bound to endothelial cells, thereby regulating the endothelial function. To test such hypothesis, soluble DLK1 encompassing DLK1 extracellular domain (DLK1-EC) was generated and validated by its inhibitory function in adipogenesis assay. Recombinant DLK1-EC exhibited the preferential binding capability toward endothelial cells and stimulated the microvessels sprouting in aorta rings. Above all, implantation of DLK1-EC dose-dependently elicited the cornea neovascularization in rats. By using various angiogenesis assays, it was delineated that DLK1-EC stimulated the angiogenesis by promoting the proliferation, motility and tube formation of endothelial cells. By immunoblot and luciferase analysis, it was elucidated that DLK1-EC enhanced the expression and activities of Notch1/Akt/eNOS/Hes-1 signaling in dose- and time-dependent manners. Pharmaceutical blockage of Notch signaling using γ-secretase inhibitor DAPT abrogated the DLK1-EC-induced endothelial migration and Hes-1-driven luciferase activities. Furthermore, Notch1 inactivation by neutralizing antibodies or RNA interference reversed the DLK1-EC-induced angiogenesis.


The present study unveils the pro-angiogenic function and mechanism of soluble DLK1 through activation of Notch1 signaling in endothelial cells.


Delta-like 1 homolog (DLK1) Notch1 Angiogenesis Endothelial cells 



We thank Chang Gung Medical Foundation and Tissue Bank of Kaohsiung Chang Gung Memorial Hospital (CLRPG8B0031 and CLRPG8B0033) for technical support.


This work was supported by Grants from the Ministry of Science and Technology, Taiwan (MOST 102-2325-B-110-001 to MHT, MOST 98-2320-B-182-023-MY3 and MOST 101-2320-B-182-009 to CCH), Chang Gung Memorial Hospital (CMRPG890303 and CMRPG891091), NSYSU-KMU Joint Research Project (NSYSUKMU104-P039) and the Center for Stem Cell Research, Kaohsiung Medical University, Taiwan (KMU-TP105G01).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

10456_2018_9596_MOESM1_ESM.doc (214 kb)
Supplementary material 1 (DOC 213 kb)


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Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  • Chao-Cheng Huang
    • 1
    • 2
  • Hsiao-Mei Kuo
    • 3
    • 4
  • Pei-Chang Wu
    • 5
  • Shih-Hsuan Cheng
    • 1
    • 11
  • Tzu-Ting Chang
    • 4
    • 6
  • Yi-Chen Chang
    • 7
    • 8
  • Mei-Lang Kung
    • 9
  • Deng-Chyang Wu
    • 10
    • 11
  • Jiin-Haur Chuang
    • 12
  • Ming-Hong Tai
    • 3
    • 4
    • 7
    • 8
    • 10
    • 11
    • 13
  1. 1.Biobank and Tissue Bank and Department of PathologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
  2. 2.Graduate Institute of Clinical Medical SciencesChang Gung University College of MedicineKaohsiungTaiwan
  3. 3.Center for NeuroscienceNational Sun Yat-Sen UniversityKaohsiungTaiwan
  4. 4.Department of Biological SciencesNational Sun Yat-Sen UniversityKaohsiungTaiwan
  5. 5.Departments of OphthalmologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
  6. 6.Institute of ChemistryAcademia SinicaTaipeiTaiwan
  7. 7.Doctoral Degree Program in Marine BiotechnologyNational Sun Yat-Sen UniversityKaohsiungTaiwan
  8. 8.Doctoral Degree Program in Marine BiotechnologyAcademia SinicaTaipeiTaiwan
  9. 9.Department of ChemistryNational Sun Yat-Sen UniversityKaohsiungTaiwan
  10. 10.Center for Stem Cell Research, Department of Internal MedicineKaohsiung Medical UniversityKaohsiungTaiwan
  11. 11.Division of Gastroenterology, Department of Internal MedicineKaohsiung Medical UniversityKaohsiungTaiwan
  12. 12.Division of Pediatric Surgery, Department of SurgeryKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
  13. 13.Institute of Biomedical SciencesNational Sun Yat-Sen UniversityKaohsiungTaiwan

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