Analysis of PROKR2 gene mutation in patients with hypogonadotropic hypogonadism / 中华内科杂志

To investigate the clinical and genetic characteristics of patients with idiopathic hypogonadotropic hypogonadism (IHH), the clinical data of 23 patients with IHH were retrospectively analyzed. Gene analyses were accomplished with whole-exome sequencing (WES) and Sanger sequencing. Functional prediction of mutation sites was conducted using two bioinformatics platforms, SIFT and Polyphen. Among the 23 patients with IHH, 9 patients carried prokinin 2 (PROKR2) gene mutations including 4 missense mutations (p.W178S, p.Y113H, p.A103V, p.R164Q), and 1 frameshift mutation (p.D42delinsDED), the remaining 14 cases were found negative in gene sequencing. Functional prediction showed that the above mutations may affect protein function suggestive of a pathogenic role of PROKR2 mutation in the patients. There were no significant differences in the levels of follicle-stimulating hormone, luteinizing hormone, testosterone, and estradiol between the IHH patients with PROKR2 gene mutation and those without. PROKR2 gene mutation might associated with IHH, and the mutations reported in the present study could enrich the pathogenic spectrum of genes.

ANOS1 variants in a large cohort of Chinese patients with congenital hypogonadotropic hypogonadism / 中南大学学报(医学版)

Objective: Congenital hypogonadotropic hypogonadism (CHH) is a rare congenital gonadal dysplasia caused by defects in the synthesis, secretion or signal transduction of hypothalamic gonadotropin releasing hormone. The main manifestations of CHH are delayed or lack puberty, low levels of sex hormones and gonadotropins, and may be accompanied with other clinical phenotypes. Some patients with CHH are also accompanied with anosmia or hyposmia, which is called Kalman syndrome (KS). ANOS1, located on X chromosome, is the first gene associated with CHH in an X-linked recessive manner. This study aims to provide a basis for the genetic diagnosis of CHH by analyzing the gene variant spectrum of ANOS1 in CHH and the relationship between clinical phenotype and genotype. Methods: In this study, whole exome sequencing (WES) was used to screen rare sequencing variants (RSVs) of ANOS1 in a Chinese cohort of 165 male CHH patients. Four commonly used in silico tools were used to predict the function of the identified RSVs in coding region, including Polyphen2, Mutation Taster, SIFT, and Combined Annotation Dependent Depletion (CADD). Splice Site Prediction by Neural Network (NNSPLICE) was employed to predict possibilities of intronic RSVs to disrupt splicing. American College of Medical Genetics and Genomics (ACMG) guidelines was used to assess the pathogenicity of the detected RSVs. The ANOS1 genetic variant spectrum of CHH patients in Chinese population was established. The relationship between clinical phenotype and genotype was analyzed by collecting detailed clinical data. Results:Through WES analysis for 165 CHH patients, ANOS1 RSVs were detected in 17 of them, with the frequency of 10.3％. A total of 13 RSVs were detected in the 17 probands, including 5 nonsense variants (p. T76X, p. R191X, p. W257X, p. R262X, and p. W589X), 2 splicing site variants (c. 318+3A>C, c. 1063-1G>C), and 6 missense variants (p. N402S, p. N155D, p. P504L, p. C157R, p. Q635P, and p. V560I). In these 17 CHH probands with ANOS1 RSVs, many were accompanied with other clinical phenotypes. The most common associated phenotype was cryptorchidism (10/17), followed by unilateral renal agenesis (3/17), dental agenesis (3/17), and synkinesia (3/17). Eight RSVs, including p. T76X, p. R191X, p. W257X, p. R262X, p. W589X, c. 318+3A>C, c. 1063-1G>C, and p. C157R, were predicted to be pathogenic or likely pathogenic ANOS1 RSVs by ACMG. Eight CHH patients with pathogenic or likely pathogenic ANOS1 variants had additional features. In contrast, only one out of nine CHH patients with non-pathogenic (likely benign or uncertain of significance) ANOS1 variants according to ACMG exhibited additional features. And function of the non-pathogenic ANOS1 variants accompanied with other CHH-associated RSVs. Conclusion: The ANOS1 genetic spectrum of CHH patients in Chinese population is established. Some of the correlations between clinical phenotype and genotype are also established. Our study indicates that CHH patients with pathogenic or likely pathogenic ANOS1 RSVs tend to exhibit additional phenotypes. Although non-pathogenic ANOS1 variants only may not be sufficient to cause CHH, they may function together with other CHH-associated RSVs to cause the disease.

Analysis of CYP17A1 gene variants in 5 patients with 17-hydroxylase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To identify pathogenic variants in 5 sporadic patients and two Chinese pedigrees affected with 17-hydroxylase deficiency (17-OHD).@*METHODS@#Peripheral blood samples were collected with informed consent. Variants of CYP17A1 gene were screened by PCR and Sanger sequencing. Suspected mutations were validated in other members of the pedigrees.@*RESULTS@#Gene sequencing has identified a homozygous c.985_987delTACinsAA (Y329Kfs) mutation in exon 6 of the CYP17A1 gene in 4 patients and the sister of case 3. Case 1 was found to harbor compound heterozygous mutations c.1459_1467del9 (p.D487_F489del) and c.1244-3C>A. The parents and brother of cases 2 and 5 were heterozygous carriers of a c.985_987delTACinsAA(Y329Kfs) mutation.@*CONCLUSION@#Mutations of the CYP17A1 gene probably underlie the pathogenesis of 17-OHD, for which c.985_987delTACinsAA(Y329Kfs) is the most common. The c.1244-3C>A is a novel mutation. Above results have facilitated genetic counseling for the affected families.

Analysis of CYP17A1 gene variants in 5 patients with 17-hydroxylase deficiency / 中华医学遗传学杂志

Objective@#To identify pathogenic variants in 5 sporadic patients and two Chinese pedigrees affected with 17-hydroxylase deficiency (17-OHD).@*Methods@#Peripheral blood samples were collected with informed consent. Variants of CYP17A1 gene were screened by PCR and Sanger sequencing. Suspected mutations were validated in other members of the pedigrees.@*Results@#Gene sequencing has identified a homozygous c. 985_987delTACinsAA (Y329Kfs) mutation in exon 6 of the CYP17A1 gene in 4 patients and the sister of case 3. Case 1 was found to harbor compound heterozygous mutations c. 1459_1467del9 (p.D487_F489del) and c. 1244-3C>A. The parents and brother of cases 2 and 5 were heterozygous carriers of a c. 985_987delTACinsAA(Y329Kfs) mutation.@*Conclusion@#Mutations of the CYP17A1 gene probably underlie the pathogenesis of 17-OHD, for which c. 985_987delTACinsAA(Y329Kfs) is the most common. The c. 1244-3C>A is a novel mutation. Above results have facilitated genetic counseling for the affected families.

Mechanism for synergistic effect of IRF4 and MITF on tyrosinase promoter / 中南大学学报(医学版)

Objective:To investigate the mechanism for the synergistic effect of interferon regulatory factor 4 (IRF4) and microphthalmia-associated transcription factor (MITF) on tyrosinase (TYR)promoter.Methods:The synergistic transcriptional effect,subcellular localization,and protein-protein interaction for IRF4 and MITF were observed by luciferase assay,immunofluorescence,GST-pull down,and co-immunoprecipitation,respectively.Results:IRF4 and MITF proteins were co-expressed in the cell nucleus.IRF4 augmented the transcriptional function of MITF (but not the mutant MITF) to activate the expression of the TYR promoter,but with no effect on other MITF-specific target promoters.IRF4 alone did not affect TYR promoter significantly.No direct interaction between the two proteins was noted.Conclusion:IRF4 and MITF exert a specifically synergistic effect on activation of TYR promoter through IRF4-mediated upregulation of transcriptional function of MITF.This synergistic effect is mainly regulated by MITF;DNA might be involved in the interaction between the two proteins.

Analysis of nuclear localization and signal function of MITF protein predisposing to Warrdenburg syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the role of dysfunction of nuclear localization signals (NLS) of MITF protein in the pathogenesis of Waardenburg syndrome.</p><p><b>METHODS</b>Eukaryotic expression plasmid pCMV-MITF-Flag was used as a template to generate mutant plasmid pCMV-MITF△NLS-Flag by molecular cloning technique in order to design the mutagenic primers. The UACC903 cells were transfected transiently with MITF and MITF△NLS plasmids, and the luciferase activity assays were performed to determine their impact on the transcriptional activities of target gene tyrosinase (TYR). The oligonucleotide 5'-GAACGAAGAAGAAGATTT-3' was subcloned into pEGFP-N1 to generate recombinant eukaryotic expression plasmid pEGFP-N1-MITF-NLS. The NIH3T3 cells were transfected separately with MITF, MITF△NLS, pEGFP-N1 and pEGFP-N1-NLS plasmids, and their subcellular distribution was observed by immunoflorescence assays.</p><p><b>RESULTS</b>Expression plasmids for the mutant MITF△NLS with loss of core NLS sequence and pEGFP-N1-NLS coupled with MITF△NLS were successfully generated. Compared with the wild-type MITF, MITF△NLS was not able to transactivate the transcriptional activities of promoter TYR and did not affect the normal function of MITF. MITF△NLS was only localized in the cytoplasm and pEGFP-N1 was found in both the cytoplasm and nucleus, whereas pEGFP-N1-NLS was mainly located in the nucleus.</p><p><b>CONCLUSION</b>This study has confirmed the localization function of NLS sequence 213ERRRRF218 within the MITF protein. Mutant MITF with loss of NLS has failed to transactivate the transcriptional activities of target gene TYR, which can result in melanocyte defects and cause WS.</p>

Construction and analysis of recombinant eukaryotic expression plasmids for SOX10, the causative gene of Warrdenburg syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the exogenous expression and subcellular localization of wild type (WT) and mutant SOX10 proteins in vitro through generation of expression plasmids in order to reveal the pathogenesis of Waardenburg syndrome (WS).</p><p><b>METHODS</b>The plasmids pECE-SOX10 and pCMV-Flag were ligated after they were subjected to double enzyme digestion using molecular cloning technique to generate recombinant eukaryotic expression plasmid pCMV-SOX10-Flag, which was as a template to generate expression plasmids for novel mutations G37fs, G38fs and E248fs of the SOX10 gene. The constructs were verified by direct sequencing. NIH3T3 cells were transiently transfected with the expression plasmids of wide type SOX10, G37fs, G38fs and E248fs, respectively. The exogenous expression of WT SOX10 protein and mutant G37fs, G38fs and E248fs proteins were analyzed using Western blot assay, while their subcellular distribution were observed with an immunofluorescence assay.</p><p><b>RESULTS</b>The DNA sequences of expression plasmids for SOX10 and its mutant G37fs, G38fs and E248f were all correct. Both WT and mutant SOX10 proteins were detected at the expected site. WT SOX10 and E248fs proteins have only localized in the nucleus, whereas G37fs and G38fs proteins showed aberrant localization in both cytoplasm and nucleus.</p><p><b>CONCLUSION</b>Recombinant eukaryotic expression plasmids for the SOX10 gene and its mutants were successfully constructed. Preliminary analysis showed that the mutations have affected the subcellular distribution of WT SOX10 proteins, which has laid a basis for further study of the molecular mechanism of WS caused by SOX10 gene mutations.</p>

Generation and Expression of Recombinant Eukaryotic Expression Plasmids of PAX3 Gene and Its Significance / 听力学及言语疾病杂志

Objective To study exogenous expression and subcellular localization of wild type (WT ) and mu-tant PAX3 proteins in vitro by generating their expression plasmids for further study of pathogenesis of Waarden-burg syndrome (WS) .Methods The plasmids pECE-PAX3 and pcDNA3 .0-HA were ligased after they were cut by double enzyme digestion using molecular cloning technique to generate recombinant eukaryotic expression plasmid pcDNA3 .0-PAX3-HA ,which was as a template to generate expression plasmids pcDNA 3 .0 -H80D -HA and pcDNA3 .0-H186fs-HA of novel mutations H80D and H186fs of PAX3 gene .All constructs were verified by di-rect nucleotide sequencing .NIH3T3 cells were transfected transiently with the expression plasmids of PAX3 ,H80D and H186fs respectively .The exogenous expression of WT PAX3 protein and mutant H80D ,H186fs proteins were analysed using Western blot assay ,while their subcellular distribution were observed using immunofluorescence as-say .Results The DNA sequences of expression plasmids of PAX3 and its mutant H80D ,H186fs were correct . Both WT and mutant PAX3 proteins were detected at the expected size .WT PAX3 and H80D proteins were only lo-calized in the nucleus ,whereas H186fs protein showed aberrant localization in both cytoplasm and nucleus .Conclu-sion We successfully generated the recombinant eukaryotic expression plasmids of PAX 3 gene and its mutants and drew preliminary conlusion of gene mutation having effect on subcellular distribution of WT PAX 3 proteins in vitro , which lays experimental basis for further study of the moceluar mechanism of WS caused by PAX3 gene mutations in China .

Selecting EGF-binding Clones From a pⅧ-based Phage Display Library / 生物化学与生物物理进展

Angiogenesis-related diseases involving EGF include acherosclerotic plaques, haemangioma, angiofibroma, tumor growth and arthritis. EGF may serve as a drug target and its antagonists may have important clinical applications.Peptide phage display libraries have been successfully applied in areas of finding ligands for enzymes, receptors, and many other molecules. A pⅧ-based peptide phage display library was panned with the cytokine EGF and several EGF-binding clones were selected based on ELISA and micropanning assays. The selected EGF-binders from peptide phage display library may be utilized in affinity chromatography in EGF downstream processing and even act as potential antagonists of EGF if their affinity is further improved through secondary library strategy.