Expression of FSHR mRNA in female genital organs

Yoo, Jin Hee; Yoo, Sun Won; Jeong, Mi Young; Son, Haw Jeong; Cha, Jung Ho; Kim, Jang Heub; Kim, Eun Jung; Kim, Jin Hong; Ryu, Ki Sung

Abstract

FSH is the pivotal hormone in the regulation of ovarian function and acts by binding to specific receptor, FSH receptor (FSHR), which is belong to the family of G-protein coupled receptor. It have been considered that ovary is the only target organ of FSH because FSHR mRNA was first detected in ovarian follicles. However expression of FSHR mRNA was also detected on fallopian tube in experimental animal study and it is related wih tumorigenesis in postmenopausal women.In this study, in order to understand the FSH function in female genital organs, the ontogeny of the production profile of FSHR and the pattern of its localization in female genital organs were studied. We obtained the fresh tissues of ovary, fallopian tube, uterine body and uterine cervix with blood samples during proliferative phase in women with regular menstrual cycle. To establish FSHR mRNA expression of human internal genital organ, we studied by using in situ hybridization and quantitative competitive reverse transcription polymerase chain reaction (QC RT-PCR). To localize FSHR transcripts by in situ hybridization, we synthesized digoxigenin-labelled ssRNA probe (about 800 bp) from the cloned FSHR cDNA. For QC RT-PCR, we designed oligonucleotide primers (antisense: 5'-GGCCCTGCTCCTGGTCTCTTTG-3', sense: 3'-AACAGCGGGAGTACCTTCGG-5') which produced 799 bp sized PCR products. Simultaneously we synthesized 149 bp deleted DNA competitor by site-directed mutagenesis to quantify target FSHR mRNA expression comparing as internal control.In situ hybridization with digoxigenin-labelled ssRNA probe showed no signal above the background in primordial follicles. FSHR mRNA was first detected in the single layer of cuboidal granulosa cells surrounding primary follicles. As follicular growth progressed, FSHR mRNA expression increased gradually in antral and graafian follicles. Similary, in fallopian tube, the epithelium stained intensly. But FSHR mRNA expression was absent in uterine body including endometrium and myometrium and uterine cervix. Total RNA was extracted and quantitated by QC RT-PCR. The amounts of FSHR transcript measured were 840.00+/-516.29 in the ovarian tissue, 240.00+/-154.91 in the fallopian tube, 6.06+/-4.13 in the uterine body, 5.48+/-5.00 fg in the uterine cervix. These experiments demonstrated that FSHR mRNA is expressed in the ovary and fallopian tube, albeit only small amount was expressed in uterine body and cervix.In conclusion, the presence of FSHR mRNA in female internal genital organ with site specific pattern suggested that FSH may have some role in female genital organs during the adult reproductive cycle and may act as an factor in the tumorigenesis. Further study about the functional role and tumorigenesis of FSH should be performed in human internal genital organ.