Investigating the utility of glycans, glycomics in reversing skin aging
Q: What is glycomics?
The first frontier was genomics, which is the study of human genes made from DNA. DNA is composed of four bases, namely adenine, cytosine, guanine and thymine. Two-hundred-and-fifty four-unit structures can be formed from these bases providing the genetic code for humans, and the human genome project sequenced and identified these genes.
This led to the second frontier, which was proteomics, the study of proteins that are made from a recipe specified by human genes. These proteins are made from amino acids, which can yield 16,000 four-unit structures.
The newest and third frontier is glycomics, which is based on sugars. Glycomics is the study of 16 million four-unit structures and represents the broadest field of study yet, allowing for a greater understanding of skin physiology.
Q: What are glycans?
A: Glycans are sugars that perform a variety of functions in the body. Glycans located on the cell surface interact with proteins from bacteria, bacterial toxins, antibodies and tumor antigens as a form of cellular communication.
Glycans also play a role in the biology of healthy skin. Monosaccharides such as glucose, fructose and mannose and disaccharides such as galactose, lactose and sucrose are nutrients used for energy and skin functioning.
Oligosaccharides and polysaccharides such as glycogen, glycosaminoglycans and proteoglycans are used for energy storage in the cytoplasm, co-activators of cell membrane receptors, structural components of the extracellular matrix, and function as hydration factors.
The study of glycans has been termed glycobiology. Glycobiology is the study of glycans and their importance on the cell surface to deliver biologic messages to maintain homeostasis in the skin. Glycans are instrumental in cell synthesis, proliferation and differentiation. In addition, glycans function in the structure of the skin.
Q: What happens to glycans with aging?
A: Glycans decrease with aging. This loss reduces the ability of cells to coordinate cellular function, as glycans are exposed on the surface of the cells. Glycan loss also reduces skin architecture, creating the changes visible with skin aging. Stratum corneum free mannose, galactose, N-acetylglucosamine and N-acetylgalactosamine decrease with age, but glucose is the most affected.
It is theorized that the loss of glycans may lead to aging and a poor appearance. This understanding has encouraged cosmetic chemists to develop moisturizers designed to enhance glycan functioning, leading to a new generation of anti-aging products. The first glycan-based moisturizer was launched this past year.
Zoe Diana Draelos, M.D., is a Dermatology Times editorial adviser and consulting professor of dermatology, Duke University School of Medicine, Durham, N.C. Questions may be submitted via email to [email protected]