Regulation of human luteinizing hormone receptor in the ovary

Abstract

The luteinizing hormone receptor (LHR) is essential for elevated levels of progesterone to maintain pregnancy during the first trimester; the maintenance of the expression of LHR is a key factor controlling the duration of luteal function. Therefore, as the expression of LHR is most likely to be regulated by the stability of the receptor mRNA at the luteal phase of the human menstrual cycle, we focused on studies examining the stability of mRNA rather than the production of mRNA. In addition, LHR (exon 9), one of the splice variants of human LHR (hLHR), was cloned in the corpus luteum of a patient with a regular menstrual cycle. The results of Western blots using Percoll gradient fractionation indicated that hLHR formed complexes with hLHR (exon 9), which are transferred to the lysosome, where they are eventually degraded, instead of being translocated from the endoplasmic reticulum to the transducing organelle. These results showed that hLHR (exon 9) caused a reduction in the expression of functional receptor number and affected the signaling condition of wild-type hLHR. As the luteal phase progressed hLHR (exon 9) increased relative to hLHR, demonstrating that hLHR (exon 9) was expressed more than hLHR in the late luteal phase. This work reveals the essential function of the regulatory and structural elements involved in human LH receptor splicing, and that hLHR (exon 9) can negatively control the function of wild-type receptors. Moreover, this finding presented a novel mechanism of regulation of LHR in the human corpus luteum. (Reprod Med Biol 2008; 7: 11-16)

Anti-Infertility Effects Test of Date Palm Fruit Extract (Phoenix Dactylifera L.) in Female Mice (Mus Musculus) Compared With Propolis

“…Estrogen plays an important role in the regulation of growth, development, homeostasis, and cell death (apoptosis) in the ovaries. Estrogens prevent apoptosis in granulosa cells by inhibiting endonuclease activity in granulosa cells [9]. The average number of follicular atresia of the treatment group did not differ significantly with the control group (sig>0.05) also showed that elevated estrogen levels were not so high that they did not cause negative feedback and inhibited the secretion of follicle-stimulating hormone and luteinizing hormone in the hypothalamus resulting in follicular atresia.…”

“…Estrogen consists of three types of estriol, estrone, and estradiol. Estradiol increases the proliferation of granulosa cells and promotes the growth of preantral follicles and antrum formation [9]. The result showed that the average number of treatment group atresia follicles did not differ significantly with the control group (sig>0.05).…”

Antiestrogenic Potential of Turmeric Rhizomes Extract to Decrease Weight and Uterine Diameters on Rats

“…Curcumin has the potential to be anti-fertility because curcumin can reduce the expression of the ERβ (Estrogen Receptor β) gene and estrogen in granulosa cells induced by FSH and LH hormones, decreased Erβ (Estrogen Receptor β) and estrogen result in interference with estrogen action. Disruption in the work of estrogen inhibited the steroidogenesis and folliculogenesis processes which resulted in the disruption of cell differentiation, FSH (Follicle Stimulating Hormone) mechanism, estrogen synthesis, LHR (Luteinizing Hormone Receptor), and FSHR (Follicle Stimulating Hormone Receptor) expression [22].…”

In Vitro Anti-Inflammatory Activity Test of Tinocrisposide and Freeze-Dried Aqueous Extract of Tinospora Crispa Stems on Human Red Blood Cell by Increasing Membrane Stability Experiment

“…As a positive control, 5% SDS was employed and an isotonic NaCl solution was used as a negative control. Measurements were replicated 3 times for each concentration [19]. The hemolytic activity was calculated with the following equation:…”