Proteomics Clin. Appl. 2015, 9, 445–446
445
DOI 10.1002/prca.201500034
Using fibers for rapid extraction of proteins from urine Youhe Gao Beijing Normal University, Beijing, P. R. China The method for rapid extraction of proteins from urine published in this special issue (Manard, B. T. et al., Proteomics Clin. Appl. 2015, 9, 522–530) may have more profound implications than the authors have claimed, simply because urine is more important than most biomarker researchers realized. Unlike blood that is tightly controlled by homeostatic mechanisms of the body, urine tolerates, and accumulates a much larger degree of changes in its components, making it a more important biomarker source than blood.
Received: April 2, 2015 Accepted: April 23, 2015
Keywords: Fiber / Solid phase extraction / Storage / Urinary proteins
In this special issue on urine proteomics, Marcus’s group demonstrated a capillary-channeled polymer (C-CP) fibers for the rapid extraction of proteins from urine [1]. As the authors stated urine specimens are the most easily obtained body fluid. It is also considered as a completely noninvasively accessible, informative, and clean biofluid. Sweat can be obtained noninvasively, but it may not be as informative and free of contaminants as urine. However, the significance of urine as biomarker source is still being underestimated by the field. There are still well over 90% of biomarker research done in blood. If we can define biomarkers as changes associated with certain diseases, urine should contain more changes than blood, because blood is kept within a narrow range around the homeostasis point by various homeostatic mechanisms of the body. In contrary urine accumulates all kinds of changes and should be better biomarker source than blood [2]. With that potential of urine in mind, the method that can extract proteins from urine directly, rapidly, and economically before the MS analysis is very important for the potential application of urine in the biomarker field. Urine is very diluted. The most valuable information in urine exists in the substances dissolved in urine instead of the water itself. The volume of water is an important piece of information. But after measuring the volume, the water needs to be removed for better storage and easy analysis. For removing water, SPE that the authors used is much more effective than ultracentrifugation and ultrafiltration, and less compli-
cated and more direct than gel electrophoresis even though SPE does not offer much molecular weight information. The solid phase can be resin or membrane, and in this case, an eight colinear channel fiber. Resin and membrane are easier to scale up while this type of fiber aims at miniaturization. The miniature offers the advantages including economy and convenience for automation, especially when a high abundant substance is about to be analyzed. Fiber-based SPE can be connected with MS easily for downstream analysis. On the other hand if the fiber is cheap enough, it can also be used for massive clinical sample storage. The dry substances in urine can be concentrated and stored in the fiber without immediate analysis. Massive storage of samples economically is the foundation for future prospective studies, and this fiber-based SPE may become one of the options, along with the currently available membrane and resin-based methods, for urine sample processing and storage. Fibers with different properties may selectively retain different substances from urine just like membranes with different properties [3,4]. Fibers can be dried to keep the substances from degradation just like membranes too. We can speculate that in the future the substances in urine such as proteins, nucleic acids (including microRNA), and small molecule metabolites can all be extracted separately based on their binding properties, and stored for later analysis. The author has declared no conflict of interest.
References Correspondence: Professor Youhe Gao, Beijing Normal University, Beijing 100875, P. R. China E-mail: [email protected] C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
[1] Manard, B. T., Jones, S. M. H., Marcus, R. K., Capillarychanneled polymer (C-CP) fibers for the rapid extraction of www.clinical.proteomics-journal.com
446
Y. Gao
proteins from urine matrices prior to detection with MALDIMS proteomics clinical applications. Proteomics Clin. Appl. 2015, 9, 522–530. [2] Gao, Y., Urine—an untapped goldmine for biomarker discovery? Sci. China Life Sci. 2013, 56, 1145–1146. [3] Jia, L., Liu, X., Liu, L., Li, M., Gao, Y., Urimem, a membrane that can store urinary proteins simply and economically, makes
C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Proteomics Clin. Appl. 2015, 9, 445–446
the large-scale storage of clinical samples possible. Sci. China Life Sci. 2014, 57, 336–339. [4] Zhang, F., Yuan, Y., Wu, J., Gao, Y., Urinary nucleic acids can be concentrated, dried on membranes and stored at room temperature in vacuum bags. PeerJ PrePrints 2014, 2, e566v1.
www.clinical.proteomics-journal.com
445
DOI 10.1002/prca.201500034
Using fibers for rapid extraction of proteins from urine Youhe Gao Beijing Normal University, Beijing, P. R. China The method for rapid extraction of proteins from urine published in this special issue (Manard, B. T. et al., Proteomics Clin. Appl. 2015, 9, 522–530) may have more profound implications than the authors have claimed, simply because urine is more important than most biomarker researchers realized. Unlike blood that is tightly controlled by homeostatic mechanisms of the body, urine tolerates, and accumulates a much larger degree of changes in its components, making it a more important biomarker source than blood.
Received: April 2, 2015 Accepted: April 23, 2015
Keywords: Fiber / Solid phase extraction / Storage / Urinary proteins
In this special issue on urine proteomics, Marcus’s group demonstrated a capillary-channeled polymer (C-CP) fibers for the rapid extraction of proteins from urine [1]. As the authors stated urine specimens are the most easily obtained body fluid. It is also considered as a completely noninvasively accessible, informative, and clean biofluid. Sweat can be obtained noninvasively, but it may not be as informative and free of contaminants as urine. However, the significance of urine as biomarker source is still being underestimated by the field. There are still well over 90% of biomarker research done in blood. If we can define biomarkers as changes associated with certain diseases, urine should contain more changes than blood, because blood is kept within a narrow range around the homeostasis point by various homeostatic mechanisms of the body. In contrary urine accumulates all kinds of changes and should be better biomarker source than blood [2]. With that potential of urine in mind, the method that can extract proteins from urine directly, rapidly, and economically before the MS analysis is very important for the potential application of urine in the biomarker field. Urine is very diluted. The most valuable information in urine exists in the substances dissolved in urine instead of the water itself. The volume of water is an important piece of information. But after measuring the volume, the water needs to be removed for better storage and easy analysis. For removing water, SPE that the authors used is much more effective than ultracentrifugation and ultrafiltration, and less compli-
cated and more direct than gel electrophoresis even though SPE does not offer much molecular weight information. The solid phase can be resin or membrane, and in this case, an eight colinear channel fiber. Resin and membrane are easier to scale up while this type of fiber aims at miniaturization. The miniature offers the advantages including economy and convenience for automation, especially when a high abundant substance is about to be analyzed. Fiber-based SPE can be connected with MS easily for downstream analysis. On the other hand if the fiber is cheap enough, it can also be used for massive clinical sample storage. The dry substances in urine can be concentrated and stored in the fiber without immediate analysis. Massive storage of samples economically is the foundation for future prospective studies, and this fiber-based SPE may become one of the options, along with the currently available membrane and resin-based methods, for urine sample processing and storage. Fibers with different properties may selectively retain different substances from urine just like membranes with different properties [3,4]. Fibers can be dried to keep the substances from degradation just like membranes too. We can speculate that in the future the substances in urine such as proteins, nucleic acids (including microRNA), and small molecule metabolites can all be extracted separately based on their binding properties, and stored for later analysis. The author has declared no conflict of interest.
References Correspondence: Professor Youhe Gao, Beijing Normal University, Beijing 100875, P. R. China E-mail: [email protected] C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
[1] Manard, B. T., Jones, S. M. H., Marcus, R. K., Capillarychanneled polymer (C-CP) fibers for the rapid extraction of www.clinical.proteomics-journal.com
446
Y. Gao
proteins from urine matrices prior to detection with MALDIMS proteomics clinical applications. Proteomics Clin. Appl. 2015, 9, 522–530. [2] Gao, Y., Urine—an untapped goldmine for biomarker discovery? Sci. China Life Sci. 2013, 56, 1145–1146. [3] Jia, L., Liu, X., Liu, L., Li, M., Gao, Y., Urimem, a membrane that can store urinary proteins simply and economically, makes
C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Proteomics Clin. Appl. 2015, 9, 445–446
the large-scale storage of clinical samples possible. Sci. China Life Sci. 2014, 57, 336–339. [4] Zhang, F., Yuan, Y., Wu, J., Gao, Y., Urinary nucleic acids can be concentrated, dried on membranes and stored at room temperature in vacuum bags. PeerJ PrePrints 2014, 2, e566v1.
www.clinical.proteomics-journal.com
