Isolated hypogonadotropic hypogonadism by GnRHR gene mutation: a pedigree report and literature review / 临床儿科杂志

Objective To explore the clinical feature, gene mutations and treatment of isolated hypogonadotropic hypogonadism (IHH). Methods The clinical data from a case of IHH and his families were retrospectively analyzed. The related literatures were reviewed. Results The propositus was a 7-year-old boy with a small penis and testes, whose younger brother was 5-year-old with a small penis and cryptorchidism. In both boys testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) levels were low. The GnRH provocation test was not reactive. Their parents denied the consanguineous marriage. Illumina sequencing revealed that both of the brothers had homozygous mutation of GnRHR gene in C.806C>T, and their parents were heterozygous mutations in C.806C>T gene. After confirmation of the diagnosis, human choronic gonadotropin (hCG) treatment was given. The levels of testosterone and dihydrotestosterone were significantly increased after 6 weeks. Conclusion The combination of clinical phenotype, biochemical analysis, and gene detection is helpful for early diagnosis of IHH.

Participation of the endoplasmic reticulum protein chaperone thio-oxidoreductase in gonadotropin-releasing hormone receptor expression at the plasma membrane

Chaperone members of the protein disulfide isomerase family can catalyze the thiol-disulfide exchange reaction with pairs of cysteines. There are 14 protein disulfide isomerase family members, but the ability to catalyze a thiol disulfide exchange reaction has not been demonstrated for all of them. Human endoplasmic reticulum protein chaperone thio-oxidoreductase (ERp18) shows partial oxidative activity as a protein disulfide isomerase. The aim of the present study was to evaluate the participation of ERp18 in gonadotropin-releasing hormone receptor (GnRHR) expression at the plasma membrane. Cos-7 cells were cultured, plated, and transfected with 25 ng (unless indicated) wild-type human GnRHR (hGnRHR) or mutant GnRHR (Cys14Ala and Cys200Ala) and pcDNA3.1 without insert (empty vector) or ERp18 cDNA (75 ng/well), pre-loaded for 18 h with 1 µCi myo-[2-3H(N)]-inositol in 0.25 mL DMEM and treated for 2 h with buserelin. We observed a decrease in maximal inositol phosphate (IP) production in response to buserelin in the cells co-transfected with hGnRHR, and a decrease from 20 to 75 ng of ERp18 compared with cells co-transfected with hGnRHR and empty vector. The decrease in maximal IP was proportional to the amount of ERp18 DNA over the range examined. Mutants (Cys14Ala and Cys200Ala) that could not form the Cys14-Cys200 bridge essential for plasma membrane routing of the hGnRHR did not modify maximal IP production when they were co-transfected with ERp18. These results suggest that ERp18 has a reduction role on disulfide bonds in wild-type hGnRHR folding.

STUDIES ON DISTRIBUTION OF FSH, LH AND COLOCALIZATION WITH GnRHR IN RAT SUBMAXILARY GRANDS / 解剖学报

Objective To investigate the distribution of folliclestimulating hormone (FSH),luteinizing hormone (LH) and colocalization with gonadotropin releasing hormone receptor (GnRHR) in rat submaxilary glands. Methods Distribution of FSH, LH and colocalization with GnRHR consecutive sections of rat submaxilary glands were investigated by immunohistochemical colocalization methods. Results FSH and LH immunoreactivity were observed in the epithelial cells of serous acinus, secretory tubes, excretory ducts and granular convoluted tubule. The immunoreactive materials were brown and distributed in the cytoplasma with negative nucleolus. The results of immunohistochemical colocalization showed not only FSH but also GnRHR immunoreactivity in the same structure of two adjacent section. The distribution of the positive substance of FSH and GnRHR were similar to each other. The most of showing GnRHR immunoreactivity cells were detected LH immunoreactivity in the same structure of two adjacene section and the others were immunonegative. The GnRNR immunoreactive materials were distributed in the cytoplasma with negative nucleolus.Conclusion The epithelial cell of serous acinus, secretory tubes, excretory ducts and granular convoluted tubule of rat submaxilary glands may be synthesized and secreted FSH and LH. These cells with FSH and LH positive immunoreaction of rat submaxilary glands may be regulated by Gonadotropin releasing hormone (GnRH) through autocrine or paracrine.;

Expression of Gonadotropin-Releasing Hormone Receptor in Human Uterine Endometrial and Ovarian Tissues / 대한암학회지

PURPOSE: Gonadotropin-releasing hormone (Gn-RH) can cause regression of hormonedependent human tumors, including uterine endometrial and ovarian carcinomas. These effects were thought to be mediated through the inhibition of gonadotropic and steroid hormone from the hypothalamus. But, in addition to its classic hypophysiotropic action, Gn-RH might play a role as a modulator of activity in the brain and many peripheral organs. It has been reported that this analog has a direct inhibitory effect on the tumor and that the specific binding sites for Gn-RH were demonstrated in certain tumors responsive to Gn-RH. In support of a possible clinical use of Gn-RH analogs in the treatment of the endometrial and ovarian carcinomas, we tried to find out whether Gn-RH receptors are present on hormone dependent tumors. MATERIALS AND METHODS: We have studied endometrial and ovarian tumor specimens and established uterine endometrial and ovarian carcinoma cell lines for the presence of Gn-RH receptor by the detection of its messenger ribonucleic acid (mRNA). We also compared the results obtained from tumor tissue specimens with the results from their corresponding normal tissues. Gn-RH receptor mRNA was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized according to the published human Gn-RH receptor sequence. RESULTS: Gn-RH receptor mRNA was detected in all normal endometrium and abnormally proliferative endometrium presenting dysfunctional bleeding, but not all in endometrial carcinomas (83%). Tumor stage and histologic grading had no relationship with receptor positivity. And, Gn-RH receptor mRNA was detected in less than 40% in normal myometrium and myomas. Gn-RH receptor expression was detected in same frequencies (86%) in normal ovarian tissues and ovarian carcinomas. Receptors were detected in a high proportion of the specimens from epithelial carcinomas (92%) and stromal tumors (100%) of the ovary. But, Gn-RH receptor was not detected in germ-cell derived tumors of the ovary. Established endometrial carcinoma (CUME-1) and epithelial ovarian carcinoma (CUMO-2) cell lines also demonstrated Gn-RH receptor mRNA, respectively. CONCLUSIONS: The expression of Gn-RH receptor raises the possibility that Gn-RH may play a direct regulatory role in the growth of hormone-dependent normal tissues and their respective tumors, and provides a possible point of attack for therapeutic approaches using Gn-RH analogs in endometrial and ovarian malignancies.

STUDIES ON LOCALIZATION OF GONADOTROPIN-RELEASING HORMONE RECEPTORS IN RAT LIVER / 解剖学报

Objective To detect the existence of gonadotropin-releasing hormone receptors(GnRH-R) in rat liver,and to supply morphological evidence for studying the functional significance of the GnRH in hepatocyte. Methods Immunohistochemical SABC method and in situ hybridization with a digoxigenin labeled probe were used to study the localization of GnRH-R in the livers of five rats. Results The rat hepatocytes were found with the GnRH-R immunoreactivity and GnRHR mRNA hybridization signals.The GnRH-R immunoreactive substance was distributed in the cytoplasm of all positive cells,with immuno-negative nuclei.The GnRHR mRNA hybridization signals were also detected in the cytoplasm of all positive cells but not in the nuclei.Hepatocytes in different parts of liver lobules showed different intensity of GnRH-R immunoreactivity and GnRH-R mRNA hybridization signals.Conclusion The rat hepatocyte may express GnRH-R.The hepatocytes in different parts in liver lobules exhibit different levels of GnRH-R expression.