Mutation profiles and clinical characteristics of Chinese males with isolated hypogonadotropic hypogonadism
FERTILITY AND STERILITY
Authors: Zhou, Chengming; Niu, Yonghua; Xu, Hao; Li, Zongzhe; Wang, Tao; Yang, Weimin; Wang, Shaogang; Wang, Dao Wen; Liu, Jihong
Abstract
Objective: To investigate the mutation profiles and clinical characteristics or Chinese males with isolated hypogonadotropic hypogonadism (IHH) and discover new pathogenic genes that cause IHH. Design: A gene panel, including 31 known IHH genes and 52 candidate genes, was used to perform semiconductor next-generation sequencing. Setting: University hospital. Patients: One hundred thirty-eight sporadic male IHH patients and 10 IHH families; 100 healthy men with normal fertility served as control subjects. Interventions(s): None. Main Outcome Measure(s): Targeted next-generation sequencing, polymerise chain reaction and sequencing, pedigree analysis, and bioinformatics analysis. Result(s): Variants were distributed uniformly throughout 52 genes (52/83, 62.65%), including 16 (16/31, 51.61%) causal genes and 36 (36/ 52, 69.23%) candidate genes. Six new pathogenic variants and 52 likely pathogenic variants were identified in 16 genes known to cause nIHH/KS (normosmic IHH/Kallmann syndrome). In the 148 probands, PROKR2 (22/148, 14.86%), CHD7, FGFR1, and KAL1 had high mutation rates, and 8.78%(13/148) of the patients carried at least two variants in known genes. In addition, variants were identified in 36 candidate genes, and EGFR, ERBB4, PAX6, IGF1, SEMA4D, and SEMA7A should be prioritized for further research and genetic testing in IHH. Conclusion(s): The mutation frequency of IHH-causal genes in Chinese HAN males was different from the data reported in white populations. Oligogenic inheritance was a common phenomenon in IHH. Our study expands the mutation profile for IHH, and the new likely pathogenic genes identified in our study warrant further research in GnRH neuronal networks. (C) 2018 by American Society for Reproductive Medicine.
Acetylated Signal Transducer and Activator of Transcription 3 Functions as Molecular Adaptor Independent of Transcriptional Activity During Human Cardiogenesis
STEM CELLS
Authors: Mehta, Ashish; Ramachandra, Chrishan J. A.; Chitre, Anuja; Singh, Pritpal; Lua, Chong Hui; Shim, Winston
Abstract
Activation of signal transducer and activator of transcription 3 (STAT3) is imperative for mammalian development, specifically cardiogenesis. STAT3 phosphorylation and acetylation are key post-translational modifications that regulate its transcriptional activity. Significance of such modifications during human cardiogenesis remains elusive. Using human pluripotent stem cells to recapitulate cardiogenesis, two independently modified STAT3 alpha (92 kDa) isoforms (phosphorylated and acetylated), which perform divergent functions were identified during cardiomyocyte (CM) formation. Phosphorylated STAT3 alpha functioned as the canonical transcriptional activator, while acetylated STAT3 alpha underwent caspase-3-mediated cleavage to generate a novel STAT3 zeta fragment (similar to 45 kDa), which acted as a molecular adaptor integral to the ErbB4-p38 gamma signaling cascade in driving CM formation. While STAT3 alpha knockdown perturbed cardiogenesis by eliminating both post-translationally modified STAT3 alpha isoforms, caspase-3 knockdown specifically abrogates the function of acetylated STAT3 alpha, resulting in limited STAT3 zeta formation thereby preventing nuclear translocation of key cardiac transcription factor Nkx2-5 that disrupted CM formation. Our findings show the coexistence of two post-translationally modified STAT3 alpha isoforms with distinct functions and define a new role for STAT3 as a molecular adaptor that functions independently of its canonical transcriptional activity during human cardiogenesis.