👤 R Kageyama

Congenital hypogonadotropic hypogonadism (CHH) is a rare endocrine disorder characterized by gonadal dysfunction attributed to impaired gonadotropin secretion. CHH is associated with approximately 60 genes including Show less

High-grade astrocytoma with piloid features (HGAP) is a novel condition introduced in the 2021 World Health Organization classification. Given that it has been recently classified, reports clarifying its clinical features or diagnostic criteria are lacking, especially in cases of atypical presentation. Herein, the authors present a rare case of HGAP with repeated symptomatic hemorrhages. A woman in her 20s presented with an acute headache and vertigo. Computed tomography and magnetic resonance imaging revealed a 2.5 × 2.8 × 2.3-cm hemorrhagic cerebellar mass with calcifications. After moderate improvement of her symptoms, she developed recurrent hemorrhage, and the tumor size increased (3.0 × 3.6 × 4.0 cm) 18 days later, necessitating resection. Pathological and molecular analyses confirmed the diagnosis of HGAP with an FGFR1-TACC1 fusion, MTAP/CDKN2A/B deletion, and SETD2 rearrangement. Radiologically, the presence of calcification and cystic components and the absence of perilesional edema were atypical features of previously reported HGAP. Although recurrent symptomatic intracranial hemorrhages are rare in HGAP, enhancing lesions on magnetic resonance imaging suggest the need for resection to obtain tissue for molecular diagnosis and guide adjuvant treatment strategies. https://thejns.org/doi/10.3171/CASE24395. Show less

To assess the use of plasma free amino acids (PFAAs) as biomarkers for metabolic disorders, it is essential to identify genetic factors that influence PFAA concentrations. PFAA concentrations were absolutely quantified by liquid chromatography-mass spectrometry using plasma samples from 1338 Japanese individuals, and genome-wide quantitative trait locus (QTL) analysis was performed for the concentrations of 21 PFAAs. We next conducted a conditional QTL analysis using the concentration of each PFAA adjusted by the other 20 PFAAs as covariates to elucidate genetic determinants that influence PFAA concentrations. We identified eight genes that showed a significant association with PFAA concentrations, of which two, SLC7A2 and PKD1L2, were identified. SLC7A2 was associated with the plasma levels of arginine and ornithine, and PKD1L2 with the level of glycine. The significant associations of these two genes were revealed in the conditional QTL analysis, but a significant association between serine and the CPS1 gene disappeared when glycine was used as a covariate. We demonstrated that conditional QTL analysis is useful for determining the metabolic pathways predominantly used for PFAA metabolism. Our findings will help elucidate the physiological roles of genetic components that control the metabolism of amino acids. Show less

Neural precursor cells proliferate in the ventricular zone while giving rise to neurons of deep layers first, then those of the superficial layers, and lastly, glial cells in the brain. Thus, it is essential to maintain neural precursor cells until late stages of neural development for generation of a wide variety of cell types. Here, we found that the Hes-related basic helix-loop-helix (bHLH) genes Hesr1/Hey1 and Hesr2/Hey2 are expressed in the ventricular zone, which contains neural precursor cells. Misexpression of Hesr1 and Hesr2 by electroporation in mouse brain at embryonic day 13.5 transiently maintains neural precursor cells and thereby increases late-born neurons, which are located in the superficial layers. In contrast, misexpression of the genes at later stages inhibits neurogenesis and promotes generation of astroglial cells. In transient transfection assay with cultured cells, both Hesr1 and Hesr2 inhibit transcription induced by the neuronal bHLH genes Mash1 and Math3. These results indicate that Hesr1 and Hesr2 negatively regulate neuronal bHLH genes, promote maintenance of neural precursor cells, and increase late-born cell types in the developing brain. Show less

Members of a subclass of hairy/Enhancer of split [E(spl)] homologs, called hesr genes, are structurally related to another subclass of hairy/E(spl) homologs, Hes genes, which play an important role in neural development. To characterize the roles of hesr genes in neural development, we used the retina as a model system. In situ hybridization analysis indicated that all hesr genes are expressed in the developing retina, but only hesr2 expression is associated spatially with gliogenesis. Each member was then misexpressed with retrovirus in the retinal explant cultures prepared from mouse embryos or neonates, which well mimic in vivo retinal development. Interestingly, hesr2 but not hesr1 or hesr3 promoted gliogenesis while inhibiting rod genesis without affecting cell proliferation or death, suggesting that the cells that normally differentiate into rods adopted the glial fate by misexpression of hesr2. The gliogenic activity of hesr2 was more profound when it was misexpressed postnatally than prenatally. In addition, double mutation of the neuronal determination genes Mash1 and Math3, which increases Müller glia at the expense of bipolar cells, upregulated hesr2 expression. These results indicate that, among structurally related hesr genes, only hesr2 promotes glial versus neuronal cell fate specification in the retina and that antagonistic regulation between hesr2 and Mash1-Math3 may determine the ratios of neurons and glia. Show less