Troponin T as a marker of differentiation revealed by proteomic analysis in renal arterioles.
Renovascular hypertension is characterized by stenosis of the renal artery and high plasma renin levels. The renal phenotype is characterized by high levels of renin in the hypoperfused kidney due to the recruitment of renin-producing cells along the afferent arterioles. This increase in myoepithelioïd cells is due mainly to the differentiation of existing smooth muscle cells with acquisition of a secretory phenotype. To understand the molecular mechanisms involved in this recruitment, we used the established rat model of renovascular hypertension known as the two-kidney, one-clip model in the Lewis rat. Renal arterioles were isolated using magnetized iron suspension. Differential proteomic analysis was performed using 2-D polyacrylamide gel electrophoresis followed by mass spectrometry. Comparative analysis of soluble proteins extracted from afferent arterioles of clipped and contralateral kidneys showed 14 proteins significantly differentially expressed by at least a factor of 2. These proteins were identified by mass spectrometry. The most striking protein revealed by proteomics is troponin T, which is down-regulated in the afferent arterioles of the clipped kidney. Confocal microscopy showed that troponin T is specific of the smooth muscle phenotype and absent in the myoepithelioïd phenotype. Our data suggest that troponin T is only present in renal smooth muscle cells.
Pinet
Florence
F
INSERM U508, Pasteur Institute, 1 rue du professeur Calmette, 59019 Lille cedex, France. florence.pinet@pasteur-lille.fr
Poirier
Florence
F
Fuchs
Sébastien
S
Tharaux
Pierre-Louis
PL
Caron
Michel
M
Corvol
Pierre
P
Michel
Jean-Baptiste
JB
Joubert-Caron
Raymonde
R
D000818:Animals; D001160:Arterioles / Q000378:metabolism; D002454:Cell Differentiation; D015180:Electrophoresis, Gel, Two-Dimensional; D006978:Hypertension, Renovascular / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000098:blood supply*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D040901:Proteomics; D051381:Rats; D011917:Rats, Inbred Lew; D012083:Renin / Q000096:biosynthesis / Q000235:genetics; D012084:Renin-Angiotensin System / Q000502:physiology; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016622:Silver Staining; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020107:Troponin T / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics
D020107:Troponin T; D012083:Renin