Proteomics of transformed lymphocytes from a family with familial pulmonary arterial hypertension.
BACKGROUND
Not all family members with BMPR2 mutations develop pulmonary arterial hypertension (PAH), implying that additional modifier genes or proteins are necessary for full expression of the disease.


OBJECTIVE
To determine whether protein expression is altered in patients with familial PAH (FPAH) compared with obligate carriers and nondiseased control subjects.


METHODS
Protein extracts from transformed blood lymphocytes from four patients with FPAH, three obligate carriers, and three married-in control subjects from one family with a known BMPR2 mutation (exon 3 T354G) were labeled with either Cy3 or Cy5. Cy3/5 pairs were separated by standard two-dimensional differential gel electrophoresis using a Cy2-labeled internal standard of all patient samples. Log volume ratios were analyzed using a linear mixed-effects model. Proteins were identified by matrix-assisted laser desorption ionization, time-of-flight mass spectrometry (MALDI-TOF MS) and tandem TOF/TOF MS/MS.


RESULTS
Hierarchical clustering, heat-map, and principal components analysis revealed marked changes in protein expression in patients with FPAH when compared with obligate carriers. Significant changes were apparent in expression of 16 proteins (P < 0.05) when affected patients were compared with obligates: nine showed a significant increase and seven showed a significant reduction.


CONCLUSIONS
A series of novel proteins with altered expression were found that could distinguish affected patients from obligate carriers and married-in controls in a single family with a BMPR2 mutation. These differences provide new information highlighting proteins that may be involved in the mechanism(s) that differentiates those individuals with a BMPR2 mutation who develop FPAH from those who do not.
Meyrick
Barbara O
BO
Department of Pathology, Vanderbilt University Medical Center, MCN T-1218, Nashville, TN 37232-2650, USA. barbara.meyrick@vanderbilt.edu
Friedman
David B
DB
Billheimer
D Dean
DD
Cogan
Joy D
JD
Prince
Melissa A
MA
Phillips
John A
JA
Loyd
James E
JE
D000328:Adult; D000368:Aged; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics*; D015180:Electrophoresis, Gel, Two-Dimensional; D005091:Exons / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000502:physiology; D006580:Genetic Carrier Screening; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000235:genetics*; D008213:Lymphocyte Activation / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D040901:Proteomics; D012016:Reference Values; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry
C498218:BMPR2 protein, human; D052006:Bone Morphogenetic Protein Receptors, Type II