Genes provide instructions for creating proteins that carry out various functions. The VEGF gene is crucial for a biological process related to blood vessels. Understanding this gene and its product offers insights into how our bodies grow, heal, and sometimes develop diseases.
Understanding the VEGF Gene
The VEGF gene provides instructions for making a protein called Vascular Endothelial Growth Factor. This protein is a signaling molecule that stimulates the formation of blood vessels. The VEGF protein is part of the platelet-derived growth factor family of cystine-knot growth factors.
In humans, the VEGFA gene, which encodes the most studied form of VEGF, is located on chromosome 6. The VEGF protein is a glycosylated mitogen, meaning it has attached sugar molecules that encourages cell division. Multiple forms of VEGF, known as isoforms, result from alternative splicing of the VEGFA gene’s mRNA.
How VEGF Drives Blood Vessel Growth
VEGF is a primary driver of angiogenesis, the process by which new blood vessels grow from existing ones. This process is important for delivering oxygen and nutrients throughout the body. VEGF accomplishes this by binding to specific receptors, primarily VEGFR1 and VEGFR2, found on the surface of endothelial cells, which are the cells lining blood vessels.
This binding triggers events within the endothelial cells, promoting their proliferation and migration to form new vessel structures. Angiogenesis is a normal and beneficial process in several physiological contexts.
During embryonic development, VEGF is essential for the formation and patterning of the vascular system. In adults, it contributes to wound healing and tissue repair by forming new blood vessels at injury sites. VEGF also plays a role in reproductive processes, such as the menstrual cycle and pregnancy, where new blood vessel formation is required.
VEGF’s Impact on Health and Disease
While VEGF’s role in normal physiological processes is beneficial, its dysregulation can contribute to various health issues. An excess of VEGF can lead to abnormal blood vessel growth and certain diseases. For example, tumors often produce high levels of VEGF to stimulate their own blood supply, a process known as tumor angiogenesis.
This increased blood supply provides tumors with the nutrients and oxygen they need to grow and spread. In eye diseases like Age-related Macular Degeneration (AMD) and Diabetic Retinopathy, excessive VEGF leads to the formation of abnormal, leaky blood vessels in the retina. This abnormal growth and leakage can cause fluid accumulation and damage, resulting in significant vision loss.
Conversely, insufficient VEGF can be associated with conditions where blood supply is inadequate. Low levels can contribute to issues like ischemic heart disease or peripheral artery disease, where tissues do not receive enough oxygen due to poor blood flow.
Medical Applications and Therapies
Understanding VEGF’s role in disease has led to the development of targeted medical therapies. Anti-VEGF therapies block VEGF activity, inhibiting abnormal blood vessel growth. These treatments have transformed the management of several conditions.
In cancer treatment, anti-VEGF drugs like bevacizumab “starve” tumors by preventing new blood vessel formation. This approach limits tumor growth and metastasis by cutting off their nutrient supply. For eye diseases, anti-VEGF medications such as ranibizumab and aflibercept are administered as injections into the eye. These injections reduce abnormal blood vessel growth and decrease leakage, helping preserve vision in patients with AMD and diabetic retinopathy.