Localization and variable expression of G alpha(i2) in human endometrium and Fallopian tubes.
BACKGROUND
Heterotrimeric G proteins take part in membrane-mediated cell signalling and have a role in hormonal regulation. This study clarifies the expression and localization of the G protein subunit G alpha(i2) in the human endometrium and Fallopian tube and changes in G alpha(i2) expression in human endometrium during the menstrual cycle.


METHODS
The expression of G alpha(i2) was identified by Polymerase chain reaction (PCR), and localization confirmed by immunostaining. Cyclic changes in G alpha(i2) expression during the menstrual cycle were evaluated by quantitative real-time PCR.


RESULTS
We found G alpha(i2) to be expressed in human endometrium, Fallopian tube tissue and in primary cultures of Fallopian tube epithelial cells. Our studies revealed enriched localization of G alpha(i2) in Fallopian tube cilia and in endometrial glands. We showed that G alpha(i2) expression in human endometrium changes significantly during the menstrual cycle, with a higher level in the secretory versus proliferative and menstrual phases (P < 0.05).


CONCLUSIONS
G alpha(i2) is specifically localized in human Fallopian tube epithelial cells, particularly in the cilia, and is likely to have a cilia-specific role in reproduction. Significantly variable expression of G alpha(i2) during the menstrual cycle suggests G alpha(i2) might be under hormonal regulation in the female reproductive tract in vivo.
Mönkkönen
Kati S
KS
Department of Pharmacology and Toxicology, University of Kuopio, Kuopio, Finland.
Aflatoonian
Reza
R
Lee
Kai-Fai
KF
Yeung
William S B
WS
Tsao
Sai-Wah
SW
Laitinen
Jarmo T
JT
Tuckerman
Elizabeth M
EM
Li
T C
TC
Fazeli
Alireza
A
D000328:Adult; D004717:Endometrium / Q000378:metabolism*; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D051960:GTP-Binding Protein alpha Subunit, Gi2 / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000378:metabolism; D016133:Polymerase Chain Reaction
D051960:GTP-Binding Protein alpha Subunit, Gi2