Characterization of in vivo 1H-NMR biomarkers for pulmonary phospholipidosis
EMSL Project ID
16109
Abstract
Pulmonary phospholipidosis is a phospholipid storage disorder that can occur in humans and is inducible in laboratory animals upon inhalation of different airborne agents, including –silica dust, common insecticides, diesel exhaust, and certain types of pharmaceuticals. The hallmark of pulmonary phospholipidosis is an excessive accumulation of both inter and intracellular phospholipids within the lung. Biomarkers for pulmonary phospholidosis are not only of potential utility for diagnostic medicine but also for toxicological risk assessment and drug development. In recognition of this previous efforts to identify a potential marker of phospholipidosis have focused on the direct measurement of phospholipids in biopsy samples or bronchoalveolar lavage fluids. These approaches, however, are highly invasive and provide no information about the disorder’s localization within the respiratory tract. Conversely, potential biomarkers identified in urine and plasma can be measured non-invasively but don’t directly reflect the disorder’s pathology. Alternatively, non-invasive 1H NMR spectroscopy is capable of measuring phospholipids in-vivo but the heterogeneous nature of lung tissues broadens the NMR metabolite lines so biochemical information is normally obscured when data is acquired with traditional techniques. At PNNL a method has been developed whereby this broadening is eliminated by a combination of special radio frequency (RF) pulse sequences and a (ultra)-slow magic angle spinning (MAS) of the object, and it has already been demonstrated that slow-MAS NMR can be applied successfully for studying biomarkers in both excised tissues and live mice. The primary goal of this project is to test the potential utility of slow MAS 1H-NMR methods for directly monitoring pulmonary phospholipid accumulation in live animals and in real-time. It is anticipated that the direct biochemical analysis of lung tissue will also eliminate the many problems associated with ex vivo sample preparation. This may vastly increase the reliability/sensitivity of detection to the development of pulmonary phospholipidosis, and in this way, greatly improve current understanding of the potential health risks associated with its induction by either inhaled materials and/or pharmacological agents. To carry out the proposed work, mice will be used as test animals, silica dust will be used as model particulate matter (PM), and standard laboratory evaluations on excised lung tissues will be carried out to validate in vivo slow-MAS results. Additionally, standard magnetic resonance imaging of the lungs of mice prior to and after silica exposure will be performed to detect any accompanying inflammation. Slow-MAS NMR will also be employed to study dense cell systems or cell aggregates where standard NMR fails. It is hypothesized that a link between the onset pulmonary phospholipidosis in animals and that in cultured cells from in vitro studies will be established by using such an integrated approach.
Project Details
Project type
Capability Research
Start Date
2005-10-01
End Date
2006-04-03
Status
Closed
Released Data Link
Team
Principal Investigator