Expression of FSHR mRNA in female genital organs / 대한산부인과학회잡지

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.

Influence of aging on expression of FSHR mRNA in human ovary / 대한산부인과학회잡지

FSH is the central hormone for the regulation of ovarian function and acts by binding with specific receptor, FSHR, which is one of the G-protein coupled receptor family. The aging of ovary decreases the number and the activity of follicle, which results in the increase of FSH by reduction of inhibin and estrogen. The study on FSH level and FSHR mRNA expression in the ovary of perimenopausal women is the crucial step for the understanding of the menopausal mechanism.We studied FSHR mRNA expression of ovarian follicle by using in situ hybridization and QC RT-PCR. The fresh ovarian tissues and blood samples were obtained from premenopausal women in mid-follicular stage and postmenopausal women. The experimental samples were grouped as below 40 years old women, 40-44 years old ones, 45-49 years old ones, 50-54 years old ones, and postmenopausal women as negative control. To localize FSHR transcripts by in situ hybridization, we synthesized digoxigenin-labelled ssRNA probe (about 800 bp) and measured the degree of staining as 0, 1+, 2+ in the primary follicles which were independent to FSH effect. To do QC RT-PCR, we synthesized oligonucleotide primers (antisense: 5-GGCCCTGCTCCTGG- TCTCTTTG-3, sense: 3-AACAGCGGGAGTACCTTCGG-5) to form the 799 bp sized PCR products. We also synthesized 149 bp deleted DNA competitor by site-directed mutagenesis and then calculated the relative amount of target FSHR mRNA by comparing with competitor after PCR.There were significant reverse relationships between follicular number and aging (r=-0.934, P=0.01), and FSH level (r=-0.713, P<0.001). The similar amount of FSHR mRNA was expressed in the group of below 40 years by in situ hybridization. In the groups of above 40 years, the FSHR mRNA expression decreased progressively according to aging (r=-0.744, P<0.001) and FSH level (r=-0.771, P<0.001). But we could not find FSHR mRNA expression in menopausal ovaries. The amount of follicular FSHR mRNA was measured as 840.00+/-516.29 for the below 40 years group, 240.00+/-154.91 for the 40-44 years group, 40.00+/-21.90 for the 45-49 years group, 6.06+/-4.13 for the 50-54 years group, and 0.48+/-0.00 fg in the postmenopausal ovary. The amount of FSHR mRNA decreased with ovarian aging (r=-0.857, P<0.001) and FSH level (r=-0.771, P<0.001).These results demonstrate that the gradual increase of FSH and the decrease of FSHR mRNA expression in older than 40 years women are related to the changes of sex hormones. However the gradual decrease of the FSHR mRNA expression in the primary follicle may be due to the follicular aging itself. Therefore the menopausal transition already starts at the beginning of 40 years and one of the major cause of the menopause may be the reduction of FSHR mRNA expression followed the decrease of ovarian response to gonadotropins. The further studies should be required to elucidate the underlying mechanism and the associated factors of menopause.