Galectin-3 (LGALS3) is a protein naturally present throughout the human body, playing a fundamental role in various biological processes. Its widespread presence and diverse functions have led to growing scientific interest, with researchers actively investigating its contributions to both healthy bodily functions and disease development.
Understanding Galectin-3
Galectin-3 is classified as a “lectin,” a type of protein that specifically binds to certain sugar structures found on the surface of cells and within the extracellular matrix, the network of molecules surrounding cells. This binding ability is due to its carbohydrate-recognition-binding domain (CRD). The protein is relatively small, weighing around 30 kilodaltons (kDa).
The LGALS3 gene encodes Galectin-3. It is structurally unique among galectins. This protein can be found in various cellular locations, including the cytoplasm, nucleus, cell surface, and secreted into the extracellular environment.
Galectin-3’s Healthy Functions
Galectin-3 contributes to various normal physiological processes. It plays a role in cell-to-cell communication, influences cell growth and division, and aids cell adhesion, helping cells stick together.
A significant aspect of Galectin-3’s healthy function involves its participation in the body’s immune response. It helps regulate inflammation, acting as a component of host defense against microbial infections. Furthermore, Galectin-3 is involved in tissue repair mechanisms, assisting in the resolution of inflammatory responses.
Galectin-3 and Disease
Dysregulation or overexpression of Galectin-3 is implicated in numerous health conditions, often contributing to disease progression. Its involvement in chronic inflammation is well-documented, promoting the infiltration of immune cells to inflamed sites. This sustained inflammation can lead to fibrosis, the scarring and hardening of tissues, notably in organs like the heart, kidneys, and liver.
In the context of cancer, Galectin-3 influences tumor growth, metastasis (the spread of cancer cells), and the ability of tumor cells to evade the immune system. It can promote neoplastic transformation and enhance the adhesion of tumor cells to the extracellular matrix. While overexpression is common in many cancers, its expression levels can vary depending on the tumor type and its invasiveness.
Galectin-3 is also connected to cardiovascular diseases, including heart failure. Its expression in the heart is typically low but increases significantly during heart failure, contributing to cardiac fibrosis and adverse remodeling of damaged heart tissue. This protein’s pro-inflammatory role also contributes to atherosclerosis, a condition where plaque builds up inside arteries.
Measuring and Targeting Galectin-3
Galectin-3 levels can be measured, typically through a blood test, providing insights into various health states. Elevated levels can indicate ongoing inflammation, fibrosis, or disease progression in conditions such as heart, kidney, and liver diseases, as well as certain cancers. The stability of Galectin-3 as a biomarker, without significant association with age, body mass index, or sex, makes it a reliable indicator.
Given its involvement in numerous diseases, Galectin-3 is being explored as a potential therapeutic target. Scientists are investigating ways to modulate its activity, for instance, through the development of inhibitors that block its detrimental roles. This research aims to develop new treatments for diseases where Galectin-3 plays a contributing role.