Name: Video: Fixing and Blocking 2D Human Umbilical Vein Endothelial Cell (HUVEC) Cultures for Immunohistochemical Analysis
Uploaded: 2024-05-31T14:50:00
Description: 25 Views. Fixing and Blocking 2D Human Umbilical Vein Endothelial Cell (HUVEC) Cultures for Immunohistochemical Analysis

fixing and blocking 2d human umbilical vein endothelial cell (huvec) cultures for immunohistochemical analysis

Study of Angiogenesis Using Scratch Wound Migration and Spheroid Sprouting Assays

Angiogenesis, which refers to the formation of new blood vessels from pre-existing ones1, is a crucial process during physiological development and pathologic conditions. It is indispensable for providing energy to highly metabolically active tissues such as the retina2 or the developing central nervous system3 and during the healing of damaged tissue4. Abnormal angiogenesis, on the other hand, is the basis for numerous diseases. Solid tumors, such as colorectal cancer or non-small cell lung cancer, facilitate their growth and the necessary energy supply by promoting angiogenesis5. Apart from cancer, neovascular diseases of the eye like diabetic retinopathy or age-related macular degeneration, which represent leading causes of blindness in the developed world, result from aberrant vessel growth6,7. A detailed understanding of the underlying pathomechanism is crucial to comprehend how physiological angiogenesis can be enhanced, for instance, in wound healing while better controlling pathological conditions such as vasoproliferative eye diseases.
On a cellular level, vascular endothelial cells are activated by various signaling molecules in angiogenesis, initiating cell proliferation and migration8. The cells subsequently organize into a hierarchy, with non-proliferating tip cells forming filopodia at the leading edge of the developing vessel branch8. Alongside, fast-proliferating stalk cells trail the tip cells, contributing to the formation of the emerging vessel. Subsequently, other cell types, such as pericytes or smooth muscle cells, are recruited to further stabilize the nascent branch9.
To explore molecular processes at the vascular endothelial cell level, numerous in vitro protocols have been developed and recently reviewed10. These assays typically fall into two categories: more simplistic but scalable 2D approaches and more elaborate 3D protocols. In a recent project, we conducted a comprehensive comparative analysis between the 2D scratch wound migration assay and the 3D spheroid sprouting assay11 to assess the extent of their differences and their ability to model various aspects of angiogenesis12. 
While both offer the advantages of being reliable and easily implementable, on a molecular level, the 3D spheroid sprouting assay was favorable in addressing key aspects of angiogenesis compared to in vivo data, such as metabolic switches or cell-matrix interactions. Since in vitro angiogenesis assays are used to evaluate the angiomodulatory potential of signaling pathways13 and to screen for therapeutic agents, transferability of in vitro results to in vivo settings is essential. Furthermore, the opportunity for omics-based analyses on the RNA and protein levels to characterize the molecular changes in response to targeted modulation of angiogenic processes under controlled conditions remains an important benefit compared to in vivo settings14,15.
In this publication, we present key assays for exploring angiogenesis-related questions through the utilization of a live-cell imaging migration assay and a spheroid sprouting assay, including subsequent molecular analyses like RNA sequencing for transcriptomic analysis and immunohistochemistry on the protein level.

Author Spotlight: Investigating Angiogenesis Through Challenges and Innovations in Assay Development

Investigating Angiogenesis on a Functional and Molecular Level by Leveraging the Scratch Wound Migration Assay and the Spheroid Sprouting Assay

Fixing and Blocking 2D Human Umbilical Vein Endothelial Cell (HUVEC) Cultures for Immunohistochemical Analysis

fixing-blocking-2d-human-umbilical-vein-endothelial-cell-huvec

Research

JoVE Journal

Medicine

25 Views. Fixing and Blocking 2D Human Umbilical Vein Endothelial Cell (HUVEC) Cultures for Immunohistochemical Analysis

Video: Fixing and Blocking 2D Human Umbilical Vein Endothelial Cell (HUVEC) Cultures for Immunohistochemical Analysis

Angiogenesis plays a crucial role in both physiological and pathological processes within the body including tumor growth or neovascular eye disease. A detailed understanding of the underlying molecular mechanisms and reliable screening models are essential for targeting diseases effectively and developing new therapeutic options. Several in vitro assays have been developed to model angiogenesis, capitalizing on the opportunities a controlled environment provides to elucidate angiogenic drivers at a molecular level and screen for therapeutic targets.
This study presents workflows for investigating angiogenesis in vitro using human umbilical vein endothelial cells (HUVECs). We detail a scratch wound migration assay utilizing a live cell imaging system measuring endothelial cell migration in a 2D setting and the spheroid sprouting assay assessing endothelial cell sprouting in a 3D setting provided by a collagen matrix. Additionally, we outline strategies for sample preparation to enable further molecular analyses such as transcriptomics, particularly in the 3D setting, including RNA extraction as well as immunocytochemistry. Altogether, this framework offers scientists a reliable and versatile toolset to pursue their scientific inquiries in in vitro angiogenesis assays.

This study presents the two-dimensional (2D) scratch wound migration assay and the three-dimensional (3D) spheroid sprouting assay, along with their respective downstream analysis methods, including RNA extraction and immunocytochemistry, as suitable assays to study angiogenesis in vitro.

Angiogenesis plays a crucial role in both physiological and pathological processes within the body including tumor growth or neovascular eye disease. A ...