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Updated: Jul 13, 2026
09:12
In Vitro Model of Fetal Human Vessel On-chip to Study Developmental Mechanobiology
Published on: July 28, 2023
The embryonic human choriocapillaris develops by hemo-vasculogenesis
Takuya Hasegawa1, D Scott McLeod, Imran A Bhutto
1Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Summary
Human choroidal vascular development begins with hemo-vasculogenesis, where blood cells and vessels form together. Later fetal stages show angiogenesis, forming larger choroidal vessels.
Area of Science:
- Ophthalmology
- Developmental Biology
- Vascular Biology
Background:
- The development of the choroidal vasculature is crucial for ocular health.
- Understanding early vascular formation provides insights into congenital eye anomalies.
Purpose of the Study:
- To characterize the developmental process of human choroidal vasculature between 6 and 23 weeks gestation.
- To identify the cellular and molecular mechanisms driving choroidal vascularization.
Main Methods:
- Immunohistochemical analysis using markers for endothelial cells (CD34, CD31, vWf), angioblasts (CD39), leukocytes (CD45), erythroblasts (Hb-epsilon), proliferating cells (Ki67), and VEGFR-2.
- Microscopic examination of choroidal tissue from 6-23 weeks gestation.
Main Results:
- Early stages (6-7 WG) showed erythroblasts within precursor cell islands and expressing endothelial markers and VEGFR-2, suggesting hemo-vasculogenesis.
- By 8-12 WG, erythroblast presence decreased, and vascular lumens became evident.
- Later stages (14-23 WG) demonstrated endothelial cell proliferation on the scleral side, indicating angiogenesis in deeper vessel formation.
Conclusions:
- The human embryonic choriocapillaris likely forms via hemo-vasculogenesis.
- Angiogenesis is the primary mechanism for the development of intermediate and large choroidal vessels in the fetus.
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