Human Umbilical Vein Endothelial Cells (HUVEC)

HUVEC are primary endothelial cells that serve as a crucial tool in biomedical research. They help researchers study angiogenesis, vascular biology, and diseases like atherosclerosis and cancer. HUVECs are used to explore endothelial cell behaviour, cellular signalling mechanisms, and drug testing, offering valuable insights into potential therapies or treatments for cardiovascular diseases and cancer. It also serves as a model system for vascular biology studies.

This article incorporates all the fundamental information you need before working with HUVEC cells. It will cover:

Origin and general attributes of HUVEC cells
Culturing information about the HUVEC cell line
HUVEC cell line: Advantages & Limitations
Applications of HUVEC cells in research
Publications featuring HUVEC cells
Resources for HUVEC cell line: Protocols, Videos, and More

1. Origin and general attributes of HUVEC cells

Knowledge about a cell line's origin and general attributes is pivotal in deciding its appropriateness for your study. This section will help you learn this essential information about HUVEC endothelial cells: What are HUVEC cells used for? What is the full form of HUVEC cells? What are the distinguishing characteristics of HUVEC? What is Huvec morphology? What is the diameter of HUVECs? What is Huvec cell size?

HUVEC cells are extracted from the endothelium of the human umbilical cord vein.
HUVEC morphology is endothelial-like. They are usually polygonal in shape and have a round nucleus in the centre.
The HUVEC cell size is 17 μm in diameter.
These endothelial cells are diploid. They possess a modal chromosome number of 46.

HUVEC TERT2

HUVEC TERT2 is an immortalized cell line derived from primary human umbilical vein endothelial cells (HUVECs). It was developed by introducing the human telomerase reverse transcriptase (TERT) gene in the HUVEC cells genome. This modification helped in extending their lifespan in culture, allowing longer-term experiments without the limitations associated with the primary HUVECs.

What is the difference between HUVEC and HMEC-1?

The structure and complexity of HUVEC and HMEC-1 endothelial cell lines are comparable. However, HMEC-1 cells exhibit a more homogeneous population than HUVECs in the context of cell size and granularity. This may reduce variations in experimental data.

A high quality microscopic journey at multiple magnifications - smooth movement and focused examination of a real human vein sample.

2. Culturing information about the HUVEC cell line

This section of the article is focused on equipping you with crucial knowledge about HUVEC cell culture. This will greatly help your work with them. Herein, you'll find answers to the following frequently asked questions: What is the HUVEC doubling time? What is the seeding density of HUVEC? How many passages are there in HUVECs? What is HUVEC cell media? How do you culture HUVECs?

Key Points for Culturing HUVEC Cells

Doubling Time:	The HUVEC doubling time is roughly 23.5 hours. Nonetheless, it may vary according to cell culture conditions and passage number.
Adherent or in Suspension:	The HUVEC is an adherent cell line. Cells grow and make monolayers.
Split Ratio:	The subcultivation ratio for HUVECs is 1:2 to 1:4. For seeding; cells are washed with 1x phosphate buffer saline and added with a dissociation solution (Accutase) for 8 to 10 minutes at ambient temperature. Afterwards, culture media is added, and detached cells are centrifuged. The supernatant is discarded, and the cell pellet is carefully resuspended. Cells are dispensed into a new culture flask for growth.
Growth Medium:	Endothelial Cell Growth Medium is used to culture HUVEC cells. Media is replaced every 2-3 days. HUVECs are good to use for up to 8-10 passages.
Growth Conditions:	The human endothelial cell line (HUVEC) is maintained in a humidified incubator with 5% CO2 at 37°C.
Storage:	HUVEC cells are usually stored at below -150 °C temperature in an ultra-low temperature freezer or the vapour phase of liquid nitrogen. This protects the cell viability for longer terms.
Freezing Process and Medium:	For preserving HUVEC cells, CM-1 or CM-ACF freezing media is advised. Generally, a slow freezing process is recommended as it allows only a 1 °C decrease in temperature per minute, preventing cells from shock and maintaining viability.
Thawing Process:	To thaw frozen cells, place them in a pre-warmed water bath at 37°C for 40 to 60 seconds until only a small clump of ice is left. Next, add fresh medium into the cells and centrifuge. This step is necessary to remove cells to remove any remnants of freezing media. Resuspend the cell pellet and transfer cells into a new flask with the culture medium.
Biosafety Level:	A Biosafety Level 1 laboratory is required to properly handle HUVEC cell cultures.

A detailed microscopic view of human umbilical vein endothelial cells at different densities and magnifications.

3. Advantages & Limitations

Like other human cell lines, HUVEC cells have their own advantages and limitations. In this section, we will delve into some notable ones that significantly impact their use in research.

Advantages

The key advantages of the HUVEC cells are:

Endothelial Cell Model
Highly relevant models for studying angiogenesis, vascular biology, and diseases related to endothelial function.
Easy to Culture
Relatively easy to isolate from human umbilical cords. Do not have fussy cell culture requirements and are easily maintainable in research laboratories.

Limitations

The limitations associated with the HUVEC endothelial cell line are:

Finite Lifespan
HUVECs have a finite lifespan, typically good for 8 to 10 passages, which is a limitation for long-term experiments. They may undergo senescence as the passage number increases.

4. Applications of HUVEC cells in research

HUVEC cells hold significant potential for various applications in the biomedical field. Herein, we'll highlight some important research uses of HUVEC cells.

Cardiovascular Disease Studies: HUVEC cell line is a valuable endothelial cell model, thus providing insights into the mechanisms underlying cardiovascular diseases such as atherosclerosis, thrombosis, and hypertension. Researchers employ these cells to investigate mechanisms underlying endothelial dysfunction, oxidative stress, and inflammation. Such as a study conducted in 2020 used HUVECs and explored that long non-coding RNA TTTY15 plays a pivotal role in ameliorating hypoxia-mediated vascular endothelial cell injury by targeting miRNA-186-5p axis [1].
Cancer Research: HUVECs are ideal for studying vascular biology. Therefore, they are used to explore tumour angiogenesis and endothelial cell interactions. This aids researchers in understanding how tumours obtain surplus blood supply and proliferate. Such as Hui Wang and colleagues found out that exosomes released by oral squamous cell carcinoma (OSCC) cells upsurge miRNA-210-3p levels and decrease ephrin A3 expression in HUVEC cells and promote tube formation via regulating PI3K/AKT cascade as confirmed through HUVEC tube formation assay [2].
Drug Testing: HUVEC endothelial cells are widely used for drug testing. Researchers can assess drug efficacy, toxicity, and potential side effects of natural compounds, nanoparticles, and other therapeutic agents in vitro using HUVECs. For instance, a study evaluated the toxicity of Rheum ribes extract synthesized silver nanoparticles using HUVEC cells [3].

5. Publications featuring HUVEC cells

This section of the article will enlist a few frequently cited and interesting research publications featuring HUVEC cells.

A novel mechanism of Gamma-aminobutyric acid (GABA) protecting human umbilical vein endothelial cells (HUVECs) against H2O2-induced oxidative injury

This study was published in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology (2019). It stated that Gamma-aminobutyric acid (GABA), a neurotransmitter, inhibits H₂O₂-induced oxidative stress in HUVEC cells; thus, it could be an effective pharmacological agent against oxidative damage-related cardiovascular diseases.

Estrogen downregulates gp130 expression in HUVECs by regulating ADAM10 and ADAM17 via the estrogen receptor

This study in Biochemical and Biophysical Research Communications (2020) explored how estrogen regulates a signal transducer, glycoprotein130 (gp130) in HUVEC cells.

Substrate stiffness regulated migration and angiogenesis potential of A549 cells and HUVECs

This research article in the Journal of Cellular Physiology (2017) investigated the effects of varying substrate stiffness on migration and angiogenesis of endothelial cells (A549 and HUVECs). They performed the HUVEC migration and HUVEC angiogenesis assays to evaluate these effects.

Lysosomal deposition of copper oxide nanoparticles triggers HUVEC cells death

This research in Biomaterials (2018) investigates the potential mechanisms responsible for the toxicity of copper oxide nanoparticles in vascular endothelial cells.

Quercetin inhibits TNF-α induced HUVECs apoptosis and inflammation via downregulating NF-kB and AP-1 signaling pathway in vitro

This study in Medicine (2020) proposed that a natural compound, quercetin, suppresses TNF-alpha-mediated HUVEC apoptosis and inflammation by regulating AP-1 and NF-kB signalling pathways.

6. Resources for HUVEC cell line: Protocols, Videos, and More

The following are a few online resources available on HUVEC cells.

HUVEC transfection: This website link will provide comprehensive knowledge regarding HUVEC transfection. For example, it includes transfection reagent information and a protocol for in vitro HUVEC transfection.

The following link contains the HUVEC cell culture protocol.

HUVEC cell culture: This document will help you learn HUVEC cell culture protocols for subculturing and handling cryopreserved cultures.

References

Zheng, J., et al., LncRNA TTTY15 regulates hypoxia-induced vascular endothelial cell injury via targeting miR-186-5p in cardiovascular disease. European Review for Medical & Pharmacological Sciences, 2020. 24(6).
Wang, H., et al., OSCC exosomes regulate miR-210-3p targeting EFNA3 to promote oral cancer angiogenesis through the PI3K/AKT pathway. BioMed research international, 2020. 2020.
Unal, İ. and S. Egri, Biosynthesis of silver nanoparticles using the aqueous extract of Rheum ribes, characterization and the evaluation of its toxicity on HUVECs and Artemia salina. Inorganic and Nano-Metal Chemistry, 2022: p. 1-14.