Decellularization of intact tissue enables MALDI imaging mass spectrometry analysis of the extracellular matrix.
Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) is a powerful molecular mapping technology that offers unbiased visualization of the spatial arrangement of biomolecules in tissue. Although there has been a significant increase in the number of applications employing this technology, the extracellular matrix (ECM) has received little attention, likely because ECM proteins are mostly large, insoluble and heavily cross-linked. We have developed a new sample preparation approach to enable MALDI IMS analysis of ECM proteins in tissue. Prior to freezing and sectioning, intact tissues are decellularized by incubation in sodium dodecyl sulfate. Decellularization removes the highly abundant, soluble species that dominate a MALDI IMS spectrum while preserving the structural integrity of the ECM. In situ tryptic hydrolysis and imaging of tryptic peptides are then carried out to accommodate the large sizes of ECM proteins. This new approach allows the use of MALDI IMS for identification of spatially specific changes in ECM protein expression and modification in tissue.
Chemistry Department, University of Puget Sound, 1500 N Warner St., Tacoma, WA, 1015, USA.|Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Megan
M
Gessel
Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA.
Jeffrey M
JM
Spraggins
Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Paul
P
Voziyan
Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Billy G
BG
Hudson
Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA.|Departments of Medicine and Biochemistry, Vanderbilt University Medical Center, Nashville, TN, USA.
Richard M
RM
Caprioli
D000595:Amino Acid Sequence; D000818:Animals; D003094:Collagen / Q000737:chemistry; D005109:Extracellular Matrix / Q000737:chemistry*; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D005615:Freezing; D006801:Humans; D006868:Hydrolysis; D007091:Image Processing, Computer-Assisted; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
D016326:Extracellular Matrix Proteins; D010446:Peptide Fragments; D012967:Sodium Dodecyl Sulfate; D003094:Collagen
FTICR; MALDI; MALDI imaging; extracellular matrix; imaging mass spectrometry