Rho A/Rho kinase mRNA and protein levels in human myometrium during pregnancy and labor.
OBJECTIVE
To quantify mRNA levels of Rho A, and rho-associated coil-forming kinases I and II (ROCK I and ROCK II) in human pregnant (before and after labor onset) and nonpregnant myometrium, and to investigate protein expression of Rho A, ROCK I, and ROCK II in these three tissue types.


METHODS
Real-time fluorescence reverse transcriptase-polymerase chain reaction (RT-PCR) using primers for Rho A, ROCK I, and ROCK II was performed on total RNA isolated from the three tissue types under investigation. Western blot analysis using antibodies specific to Rho A, ROCK I, and ROCK II was performed on protein isolated from the three tissue types.


RESULTS
Real-time fluorescence RT-PCR, using primers for Rho A, ROCK I, and ROCK II, revealed Rho A mRNA expression was significantly greater in human pregnant myometrium after labor onset, in comparison to pregnant myometrium before labor onset (P < .05), or nonpregnant myometrium (P < .01). ROCK I and ROCK II mRNA expression levels were similar in the three tissue types (P > .05). With Western blot analysis, using antibodies specific to Rho A, ROCK I, and ROCK II, Rho A protein levels were significantly lower in pregnant (before and after labor onset) in comparison to nonpregnant myometrium (P < .01). ROCK I protein levels were similar in the three tissue types (P > .05). No signal for ROCK II was detected in myometrial tissue.


CONCLUSIONS
These results outline the presence of the Rho A/Rho kinase system in modulating contractility of human myometrium. Total Rho A protein expression is down-regulated in the third trimester of pregnancy while up-regulation of Rho A mRNA occurs with labor onset.
Friel
Anne M
AM
Department of Obstetrics and Gynaecology, National University of Ireland, Galway, Ireland. anne.friel@nuigalway.ie
Curley
Michael
M
Ravikumar
Nandini
N
Smith
Terry J
TJ
Morrison
John J
JJ
D000328:Adult; D001706:Biopsy; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009215:Myometrium / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D011263:Pregnancy Trimester, Third; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054460:rho-Associated Kinases
D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases