Expression and distribution of Na, K-ATPase isoforms in the human uterus.
Na, K-ATPase activity relies on the composition of its catalytic alpha, beta, and FXYD constituents, all of which are expressed as multiple isoforms (4alpha, 4beta, and 7 FXYD). We used reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry to study Na, K-ATPase expression in uterine samples from nonlaboring elective and laboring emergency caesarean sections (CSs). Transcripts of alpha1 to 3, beta1 to 3, and FXYD1 isoforms were detected in all samples, but FXYD2 was only present in hysterectomy samples. Abundant immunoreactivity of alpha1 and moderate alpha2 was localized in myometrial smooth muscle and secretory glands of all groups. Smooth muscle and gland epithelia showed diffuse cytoplasmic alpha3 immunoreactivity. beta isoforms were detected in all groups but beta3 showed much denser immunoreactivity in myometrial samples taken from women in labor. In pregnancy, there was a switch in isoform expression, resulting in increased beta3 and decreased FXYD2 at the protein and messenger RNA (mRNA) levels. Na, K-ATPase isoform alterations may modulate uterine contractility during labor.
Floyd
Rachel V
RV
Department of Physiology, School of Biomedical Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom.
Wray
Susan
S
Quenby
Siobhan
S
Martín-Vasallo
Pablo
P
Mobasheri
Ali
A
D000328:Adult; D002585:Cesarean Section; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009215:Myometrium / Q000201:enzymology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014590:Uterine Contraction / Q000378:metabolism; D014599:Uterus / Q000201:enzymology*
D008565:Membrane Proteins; D010750:Phosphoproteins; D020033:Protein Isoforms; C069141:phospholemman; C416502:FXYD2 protein, human; D000254:Sodium-Potassium-Exchanging ATPase