Evidence for a role of TGF-beta1 in the expression and regulation of alpha-SMA in fetal growth restricted placentae.
There is evidence that alpha-smooth muscle actin (alpha-SMA) is a protein that plays a pivotal role in the production of contractile forces and it is induced by transforming growth factor-beta1 (TGF-beta1). We have analysed the expression of alpha-SMA, TGF-beta1, its receptor RI and the activator phospho-Smad2 in (a) fetal growth restriction pre-eclamptic placentae characterised by early onset and absence of end diastolic velocities in the umbilical arteries (FGR-AED) and (b) control placentae accurately matched for gestational age. The study was performed by immunohistochemical, quantitative Western blotting, ELISA, RT-PCR and in vitro analyses. We found that TGF-beta1 stimulates alpha-SMA production in chorionic villi cultured in vitro. In addition, we observed that in vivo TGF-beta1 concentration is significantly higher in FGR-AED placental samples than in control placentae and that this growth factor could have a paracrine action on villous stroma myofibroblasts expressing TGF-beta1 receptors and phospho-Smad2. Indeed, we report that alpha-SMA undergoes a redistribution in FGR-AED placental villous tree, i.e. we show that alpha-SMA is enhanced in medium and small stem villi and significantly decreased in the peripheral villi. Our data allow us to consider TGF-beta1 and alpha-SMA as key molecules related to FGR-AED placental villous tree phenotypic changes responsible for increased impedance to blood flow observable in this pathology.
Todros
T
T
Department of Obstetrics and Gynecology, University of Turin, 10126 Turin, Italy.
Marzioni
D
D
Lorenzi
T
T
Piccoli
E
E
Capparuccia
L
L
Perugini
V
V
Cardaropoli
S
S
Romagnoli
R
R
Gesuita
R
R
Rolfo
A
A
Paulesu
L
L
Castellucci
M
M
D000199:Actins / Q000378:metabolism*; D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005333:Fetus; D005786:Gene Expression Regulation; D006801:Humans; D010920:Placenta / Q000098:blood supply / Q000503:physiopathology*; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D011248:Pregnancy Complications; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism*
C541116:ACTA2 protein, human; D000199:Actins; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I