👤 Hisatoyo Hiraoka

A 50-year-old man with a triglyceride (TG) level of 11,397 mg/dL was admitted to our hospital. He consumed a high-fat and high-carbohydrate diet as well as more than 100 g of alcohol per day. He had type 2 diabetes and obesity and had previously suffered from severe acute pancreatitis twice. A genetic analysis revealed compound heterozygous mutations in APOA5 (c.56C>G and c.553G>T). In addition to low-fat meals and alcohol cessation, administration of pemafibrate lowered his triglyceride levels to <150 mg/dL. Show less

Some patients with inflammatory bowel disease (IBD) who were under mesalamine treatment develop adverse reactions called "mesalamine allergy," which includes high fever and worsening diarrhea. Currently, there is no method to predict mesalamine allergy. Pharmacogenomic approaches may help identify these patients. Here we analyzed the genetic background of mesalamine intolerance in the first genome-wide association study of Japanese patients with IBD. Two independent pharmacogenetic IBD cohorts were analyzed: the MENDEL (n = 1523; as a discovery set) and the Tohoku (n = 788; as a replication set) cohorts. Genome-wide association studies were performed in each population, followed by a meta-analysis. In addition, we constructed a polygenic risk score model and combined genetic and clinical factors to model mesalamine intolerance. In the combined cohort, mesalamine-induced fever and/or diarrhea was significantly more frequent in ulcerative colitis vs Crohn's disease. The genome-wide association studies and meta-analysis identified one significant association between rs144384547 (upstream of RGS17) and mesalamine-induced fever and diarrhea (P = 7.21e-09; odds ratio = 11.2). The estimated heritability of mesalamine allergy was 25.4%, suggesting a significant correlation with the genetic background. Furthermore, a polygenic risk score model was built to predict mesalamine allergy (P = 2.95e-2). The combined genetic/clinical prediction model yielded a higher area under the curve than did the polygenic risk score or clinical model alone (area under the curve, 0.89; sensitivity, 71.4%; specificity, 90.8%). Mesalamine allergy was more common in ulcerative colitis than in Crohn's disease. We identified a novel genetic association with and developed a combined clinical/genetic model for this adverse event. Show less

The nuclear pore complex (NPC), a gateway for nucleocytoplasmic trafficking, is composed of ∼30 different proteins called nucleoporins. It remains unknown whether the NPCs within a species are homogeneous or vary depending on the cell type or physiological condition. Here, we present evidence for compositionally distinct NPCs that form within a single cell in a binucleated ciliate. In Show less

The nuclear pore complex (NPC) is an enormous proteinaceous complex composed of multiple copies of about 30 different proteins called nucleoporins. In this study, we analyzed the composition of the NPC in the model organism Schizosaccharomyces pombe using strains in which individual nucleoporins were tagged with GFP. We identified 31 proteins as nucleoporins by their localization to the nuclear periphery. Gene disruption analysis in previous studies coupled with gene disruption analysis in the present study indicates that 15 of these nucleoporins are essential for vegetative cell growth and the other 16 nucleoporins are non-essential. Among the 16 non-essential nucleoporins, 11 are required for normal progression through meiosis and their disruption caused abnormal spore formation or poor spore viability. Based on fluorescence measurements of GFP-fused nucleoporins, we estimated the composition of the NPC in S. pombe and found that the organization of the S. pombe NPC is largely similar to that of other organisms; a single NPC was estimated as being 45.8-47.8 MDa in size. We also used fluorescence measurements of single NPCs and quantitative western blotting to analyze the composition of the Nup107-Nup160 subcomplex, which plays an indispensable role in NPC organization and function. Our analysis revealed low amounts of Nup107 and Nup131 and high amounts of Nup132 in the Nup107-Nup160 subcomplex, suggesting that the composition of this complex in S. pombe may differ from that in S. cerevisiae and humans. Comparative analysis of NPCs in various organisms will lead to a comprehensive understanding of the functional architecture of the NPC. Show less

Three subtypes of HP1, a conserved non-histone chromosomal protein enriched in heterochromatin, have been identified in humans, HP1alpha, beta and gamma. In the present study, we utilized a Drosophila system to characterize human HP1 functions. Over-expression of HP1beta in eye imaginal discs caused abnormally patterned eyes, with reduced numbers of ommatidia, and over-expression of HP1gamma in wing imaginal discs caused abnormal wings, in which L4 veins were gapped. These phenotypes were specific to the HP1 subtypes and appear to reflect suppressed gene expression. To determine the molecular domains of HP1 required for each specific phenotype, we constructed a series of chimeric molecules with HP1beta and HP1gamma. Our data show that the C-terminal chromo shadow domain (CSD) of HP1gamma is necessary for HP1gamma-type phenotype, whereas for the HP1beta-type phenotype both the chromo domain and the CSD are required. These results suggest human HP1 subtypes use different domains to suppress gene expression in Drosophila cells. Show less

Heterochromatin protein 1 (HP1) plays an important role in heterochromatin formation. Three subtypes of HP1, namely HP1alpha, beta, and gamma, have been identified in humans. In this study, using yellow fluorescent protein (YFP) fusion constructs, we examined the intracellular localization of human HP1 subtypes during the cell cycle. During interphase, all three HP1 subtypes were localized to centromeric heterochromatin and to promyelocytic leukemia (PML) nuclear bodies. Different preferences, however, were observed among the subtypes: during interphase HP1beta localized most preferentially to centromeric heterochromatin, whereas HP1alpha and gamma were more preferentially localized to PML nuclear bodies. During metaphase, only HP1alpha, was localized to the centromere. We thus determined which molecular domains of HP1 were necessary for their intracellular localization. Our results showed that the C-terminal fragment (amino acid residues 101-180) of HP1alpha was necessary for localization to the metaphase centromere and the N-terminal fragment (amino acid residues 1-76) of HP1beta was necessary for localization to the interphase centromere. Interestingly, simultaneous observations of residues 101-180 of HP1alpha and residues 1-76 of HP1beta in living HeLa cells revealed that during late prophase, the HP1beta fragment dissociated from centromeric regions and the HP1alpha fragment accumulated in centromeric regions. These results indicate that different specific regions of human HP1alpha and HP1beta mediate localization to metaphase and interphase centromeric regions resulting in association of different subtypes of HP1 with the centromere at different times during the cell cycle. Show less

The established cell lines from human prostatic cancer, such as Duke 145, 8PC93, and 19PC93, were examined in terms of their producing activity of acid phosphatase (ACP) and sensitivity to sex hormones. The results obtained are summarized. 1. ACP producing activity ACP was estimated with phenyl phosphate as a substrate. Values of the materials from each of the cells extracted with 5% Triton X-100 were Duke 145 (6.1 u/mg), 8PC93 (40.6 u/mg), and 19PC93 (40.4 u/mg), respectively. Activities of ACP were prohibited by the presence of L-tartrate. Histochemistry of ACP was demonstrated by azo-dye staining procedure, revealing the positive reactions in the cytoplasms of 8PC93 and 19PC93 cells, but weak reaction in duke 145 cells. Disk polyacrylamide gel electrophoresis (D-PAGE) was employed for ACP analysis of the cell extracts with 5% Tryton X-100 treatment. Two main bands were observed near original point and at another point proposed as ACP-2. These ACP positive reactions on the gels were also inhibited by the presence of L-tartrate in staining solution. In the case of Duke 145 cell material, the intensity of the reaction was observed weak in those specific two bands. 2. Hormone effects to the cells The prostatic cancer cells were examined in terms of sensitivity to sex steroid hormones such as androsterone, progesterone, estrone, estradiol, and estriol, by a colony formation method. Fifty percent reduction in colony formation of the 8PC93 and 19PC93 cells was found at the concentration of ca. 1.5 micrograms/ml in the case using progesterone or estrone, or estradiol, while 50% reduction of the Duke 145 cells was observed at 5 micrograms/ml only in a case using progesterone. Show less