Newly Study in PNAS Links LDL Receptor to Abeta Brain Clearance

August 30, 2012 ST. LOUIS, MO – C2N Diagnostics today announced its participation in a newly published study, which appeared in the online, August 27 edition of the Proceedings of the National Academy of Sciences[1]. Conducted in the lab of Dr. David Holtzman at the Washington University School of Medicine in St. Louis, Dr. Holtzman and colleagues investigated the role of the low-density lipoprotein receptor (LDLR) in clearance of amyloid beta (Aβ) from the brain. The methods, in part, included use of C2N's proprietary "Stable Isotope Spike Absolute Quantitation" (SISAQ™) method to measure Ab levels in the blood.

Investigators examined whether overexpressed LDLR enhances the rate of Aβ clearance from the brains of mice. Brain Ab clearance rate was higher in mice genetically programmed to overexpress LDLR. The results suggest that LDLR plays an important role in Aβ brain metabolism and may represent a therapeutic avenue for clearing Aβ from the brain.

Dr. Joel Braunstein, CEO of C2N Diagnostics, noted "We are delighted to have been part of this study demonstrating the importance of LDLR in Aβ brain metabolism. Our proprietary SISAQ™ assay is uniquely well suited for quantifying Aβ levels from a host of biological samples, in a robust and reproducible manner. We look forward to expanding the use of our SISAQ™ platform in future theranostic and diagnostic applications, and to further elucidate mechanisms of neurodegeneration."

[1] Castellano, J.M., Deane, R., Gottesdiener, A.J., Verghese, P.B., Stewart, F.R., West, T., Paoletti, A.C., Kasper, T.R., DeMattos, R.B., Zlokovic, B.V., Holtzman, D.M. Low-density lipoprotein receptor overexpression enhances the rate of brain-to-blood Aβ clearance in a mouse model of β-amyloidosis. Proc Natl Acad Sci U S A 2012 Aug 27. [Epub ahead of print]. Link to text:

About C2N’s SISAQ™ Platform

C2N's SISAQ™ platform is a patent-pending, mass spectrometry-based protein quantitation method that measures the concentration of Aβ isoforms in biological samples. From a single sample, the SISAQ-Aβ™ assay allows users to measure the absolute concentration of Aβ and its various isoforms. The SISAQ™ method can be used as a stand-alone assay or in combination with C2N's stable isotope labeling methods to measure the kinetics (SILK™), or metabolism, of brain-derived proteins.

About C2N Diagnostics

C2N Diagnostics, LLC ( formed in late 2007 by scientific co-founders Drs. David Holtzman and Randall Bateman of Washington University School of Medicine in St. Louis, the Washington University Office of Technology Management, and LifeTech Research, a Maryland-based technology research and commercialization firm ( C2N is developing a suite of novel biomarker assays and tools to assist in pre-clinical drug discovery, clinical drug development, and the early detection and assessment of progression of debilitating neurodegenerative disorders. The company’s products include the SILK-Aβ®, SISAQ-Aβ™, and SISAQ-Tau™ Assays, which rely upon stable isotope labeling and tandem mass spectrometry for the measurement of the kinetics, or in vivo metabolism, and absolute quantitation of brain derived proteins. Beyond AD, products are in development to target Parkinson’s disease, Huntington’s disease, brain injury, schizophrenia, and amyotrophic lateral sclerosis (ALS), among others. For additional information, please contact or call 1-877-C2N-DIAG (1-877-226-3424).