All cells in the body rely on a homeostatic microenvironment to survive and function. Blood, as the key provider of this internal environment for all tissues and organs, is naturally responsible for remaining stable and balanced to protect organs from exposure to disturbing factors. In contrast, as a filtrate of the blood, urine has no need or mechanism to remain stable. Any change introduced into the blood, either internally or externally, tends to be cleared by the liver, kidneys, and/or other organs via a variety of mechanisms in order to maintain the homeostasis of the blood. Urine, on the other hand, is where most of the waste products from blood are dumped, making it far more tolerant of changes. Biomarkers, which are measurable changes associated with physiological or pathophysiological processes, are therefore more likely to be magnified and detectable in urine than in blood.
Because of its potential in biomarker discovery, urinary proteins should be preserved for as long as the corresponding medical records of patients. Here, we propose a method to adsorb urinary proteins onto a membrane we have named Urimem. This simple and inexpensive method requires minimal sample handling, uses no organic solvents, and is environmentally friendly. Urine samples are filtered through the membrane, where urinary proteins are adsorbed onto its surface. The proteins on the membrane are then dried and stored in a vacuum bag, which keeps the protein pattern faithfully preserved.
The membrane allows for storage at room temperature for weeks, making it possible to preserve urine samples for extended periods without the need for refrigeration. Using this method, it is possible to begin preserving urine samples from all consenting individuals, allowing for more widespread biomarker research. This, in turn, can lead to more objective and large-scale prospective studies, helping to drive forward medical research and practice.
The theory and method outlined above have been proposed for over ten years, but they have not received the attention they deserve. Recently, we launched the “World Urine Project” and the “China Urine Project”, with the hope of bringing together the resources and capabilities of scientists from China and around the world. The goal is to collaborate on researching various components in urine and establish a shared database, laying the foundation for early, accurate, and personalized disease diagnosis in the near future.
We hope that laboratories from around the world, which recognize the importance of this field, will encourage their scientific research management and funding bodies to support efforts in this area. Urine preservation, and the research it enables, is an area of extremely high value to medicine and the future of human health. By working together, we can make significant strides toward advancing personalized medicine for the benefit of all.
References:
- Gao Y. Urine-an untapped goldmine for biomarker discovery?. Sci China Life Sci. 2013;56(12):1145-1146. doi:10.1007/s11427-013-4574-1
- Jia L, Liu X, Liu L, Li M, Gao Y. Urimem, a membrane that can store urinary proteins simply and economically, makes the large-scale storage of clinical samples possible. Sci China Life Sci. 2014;57(3):336-339. doi:10.1007/s11427-013-4582-1
- Gao Y H, Sun W, et al. China Urine Project proposal (in Chinese). Sci Sin Vitae, 2024, 54, doi: 10.1360/SSV-2024-0288
- Youhe Gao，Tatjana Crnogorac-Jurcevic and Bogdan Budnik World Urine Project Advances in Biomarker Sciences and Technology 6 (2024) 226–226
About the Author
Youhe Gao, MD/PhD, is a professor at the College of Life Sciences, Beijing Normal University. He is the inventor of Urimem, a groundbreaking method for preserving urine macromolecules. Dr. Gao has championed the idea that "urine is the next-generation biomarker source" and has been a leading advocate for urine-based research. He founded the Urine Proteome Initiative (UPI) within the Human Proteome Organization (HUPO) and served as its first chairman. Additionally, he proposed both the World Urine Project and the China Urine Project, aiming to revolutionize the field of biomarker discovery and early disease diagnosis through urine proteomics.
