👤 Mayumi Ishizuka

Hospitalization-associated disability (HAD) is linked to poor post-discharge outcomes in older individuals with heart failure (HF). We investigated whether HAD could be predicted by physical activity measured using a wearable device. We retrospectively analyzed data from 104 older individuals with HF whose physical activity was recorded for 3 consecutive days after initiating cardiac rehabilitation. Physical activity was categorized as sedentary behavior (≤1.5 metabolic equivalents [METs]), light-intensity physical activity (LPA; 1.6-2.9 METs), and moderate-to-vigorous physical activity (≥3.0 METs). HAD was observed in 31 (29.8%) individuals. LPA duration was significantly shorter in the HAD than non-HAD group (mean [±SD] 45.7±24.9 vs. 121.2±67.4 min/day; P<0.0001). In receiver operating characteristic curve analysis, the optimal LPA cut-off was 68 min/day, with 87.1% sensitivity and 80.8% specificity (area under the curve=0.888; P<0.0001). Physical activity measured using a wearable device may be useful in predicting HAD in older individuals with HF. Show less

Lysophosphatidic acid (LPA) is a crucial bioactive lipid mediator involved in various physiological processes; however, its role in macrophage polarization remains poorly understood; therefore, this study aimed to elucidate the modulatory effect of LPA on macrophage polarization, particularly its ability to shift M1 macrophages towards an M2-like phenotype, using murine macrophage RAW264.7 cells to confirm the expression of LPA receptor 1 (LPAR1) through immunofluorescence staining, which revealed that treatment of resting MO macrophages with LPA decreased inflammatory cytokines (IL-6, TNF-α) and increased TGF-β, with similar effects observed in LPS-stimulated cells and reversed by the LPAR1 inhibitor AM095, and immunostaining demonstrated a notable shift from an M1- to M2-like phenotype, as evidenced by an increase in the arginase-1/CD68 ratio; furthermore, LPA significantly decreased lactate production and increased ATP production in M1 macrophages, promoting a shift towards oxidative phosphorylation and suggesting metabolic reprogramming towards an M2-like phenotype, significantly influencing macrophage polarization and promoting a shift from a pro-inflammatory M1-like phenotype to an anti-inflammatory M2-like phenotype; these results suggest that treatment with LPA may help ameliorate diseases characterized by aberrant macrophage polarization, providing insights for the development of potential therapeutic strategies for inflammatory and autoimmune diseases. Show less

AA amyloidosis is a rare renal complication of Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL). A 66-year-old man with WM/LPL presented with nephrotic syndrome. A renal biopsy showed AA amyloidosis. Chemotherapy resulted in the remission of hematologic and nephrotic syndromes. Two years into follow-up, he became infected with coronavirus disease 2019 and had massive proteinuria, despite no relapse of WM/LPL. A second renal biopsy confirmed a diagnosis of AA amyloidosis. However, increased prednisolone did not improve proteinuria. The patient ultimately died of cryptococcal meningitis. This case highlights the diverse spectrum of renal involvement in monoclonal IgM-secreting diseases and difficulty in managing fatal complications. Show less

We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. In genic CNVs, we found an increased burden of smaller (<100 kb) exonic deletions in BD, which contrasted with the highest burden of larger (>500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25-0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD. Show less

Here we re-analyze RNA-sequencing data from the anterior cingulate cortex (ACC) of SZ patients using recent methods to improve accuracy and sensitivity of results, such as the quality surrogate variable analysis (qSVA) method and the derfinder R package. We found that genes significantly down-regulated in SZ demonstrated an enrichment for parvalbumin-positive interneurons (FDR < 0.0001). Down-regulated genes were also enriched in oxidative phosphorylation functions (FDR < 0.05). We also addressed whether lifetime exposure to antipsychotics might influence gene expression, highlighting DUSP6, LBH, and NR1D1. Our results support the role of redox imbalance/mitochondrial dysfunction and implicate interneuron subtypes in SZ pathophysiology. Show less

PSD-95 associated PSD proteins play a critical role in regulating the density and activity of glutamate receptors. Numerous previous studies have shown an association between the genes that encode these proteins and schizophrenia (SZ) and autism spectrum disorders (ASD), which share a substantial portion of genetic risks. We sequenced the protein-encoding regions of DLG1, DLG2, DLG4, DLGAP1, DLGAP2, and SynGAP in 562 cases (370 SZ and 192 ASD patients) on the Ion PGM platform. We detected 26 rare (minor allele frequency <1%), non-synonymous mutations, and conducted silico functional analysis and pedigree analysis when possible. Three variants, G344R in DLG1, G241S in DLG4, and R604C in DLGAP2, were selected for association analysis in an independent sample set of 1315 SZ patients, 382 ASD patients, and 1793 healthy controls. Neither DLG4-G241S nor DLGAP2-R604C was detected in any samples in case or control sets, whereas one additional SZ patient was found that carried DLG1-G344R. Our results suggest that rare missense mutations in the candidate PSD genes may increase susceptibility to SZ and/or ASD. These findings may strengthen the theory that rare, non-synonymous variants confer substantial genetic risks for these disorders. Show less

Mammalian tribbles homolog 1 (TRIB1) regulates hepatic lipogenesis and is genetically associated with plasma triglyceride (TG) levels and cholesterol, but the molecular mechanisms remain obscure. We explored these mechanisms in mouse livers transfected with a TRIB1 overexpression, a shRNA template or a control (LacZ) adenovirus vector. The overexpression of TRIB1 reduced, whereas induction of the shRNA template increased, plasma glucose, TG, and cholesterol and simultaneously hepatic TG and glycogen levels. The involvement of TRIB1 in hepatic lipid accumulation was supported by the findings of a human SNP association study. A TRIB1 SNP, rs6982502, was identified in an enhancer sequence, modulated enhancer activity in reporter gene assays, and was significantly (P=9.39 × 10(-7)) associated with ultrasonographically diagnosed non-alcoholic fatty liver disease in a population of 5570 individuals. Transcriptome analyses of mouse livers revealed significant modulation of the gene sets involved in glycogenolysis and lipogenesis. Enforced TRIB1 expression abolished CCAAT/enhancer binding protein A (CEBPA), CEBPB, and MLXIPL proteins, whereas knockdown increased the protein level. Levels of TRIB1 expression simultaneously affected MKK4 (MAP2K4), MEK1 (MAP2K1), and ERK1/2 (MAPK1/3) protein levels and the phosphorylation of JNK, but not of ERK1/2. Pull-down and mammalian two-hybrid analyses revealed novel molecular interaction between TRIB1 and a hepatic lipogenic master regulator, MLXIPL. Co-expression of TRIB1 and CEBPA or MLXIPL reduced their protein levels and proteasome inhibitors attenuated the reduction. These data suggested that the modulation of TRIB1 expression affects hepatic lipogenesis and glycogenesis through multiple molecular interactions. Show less

MLXIPL is a transcription factor integral to the regulation of glycolysis and lipogenesis in the liver. Common variants of the MLXIPL gene (MLXIPL) are known to influence plasma triglyceride levels in people of European descent. As MLXIPL has a key role in energy storage, genetic variations of the MLXIPL may be relevant to physiological adaptations to nutritional stresses that have occurred during the evolution of modern humans. In the present study, we assessed the phenotypic consequences of the Q241H variant of MLXIPL in populations of Asian and Oceanian origin and also surveyed the prevalence of Q241H variant in populations worldwide. Multiple linear regression models based on 2373 individuals of Asian origin showed that the H allele was significantly associated with decreased concentrations of plasma triglycerides (P=0.0003). Direct genotyping of 1455 individuals from Africa, Asia and Oceania showed that the triglyceride-lowering H allele was found at quite low frequencies (0.00-0.16) in most of the populations examined. The exceptions were some Central Asian populations, including Mongolians, Tibetans and Uyghurs, which exhibited much higher frequencies of the H allele (0.21-0.26). The high prevalence of the H allele in Central Asia implies that the Q241H variant of MLXIPL might have been significant for utilization of carbohydrates and fats in the common ancestors of these populations, who successfully adapted to the environment of Central Asia by relying on nomadic livestock herding. Show less

Hypospadias is a common congenital anomaly caused by incomplete fusion of urethral folds. Development of the urethra and external genital system in the male fetus is an androgen-dependent process. In this regard, enzymes 17 β-hydroxysteroid dehydrogenase type 3 (17 β HSD3, encoded by HSD17B3) and steroid 5 α-reductase type 2 (encoded by SRD5A2) play crucial roles. To investigate the possible associations between common polymorphisms in HSD17B3 as well as well-known V89L polymorphism in SRD5A2 and risk of hypospadias. A case-control study was performed between 1999 and 2005. There were 89 Japanese boys with hypospadias and 291 newborn controls. We genotyped HSD17B3-1999T>C, +10A>G, +20A>G, +139G>A (V31I), +913G>A (G289S), and SRD5A2+336G>C (V89L) polymorphisms by allelic discrimination assay. We measured mRNA expression of the wildtype G289 allele and the mutant S289 allele of the HSD17B3 gene in the transfected human fetal kidney HEK293 cells. Assessment of hypospadias including its severity and HSD17B3 and SRD5A2 genes using DNA blood samples: allele and genotype distribution of single nucleotide polymorphisms in these two genes in cases and controls. In our study, the risk of hypospadias was significantly higher in subjects carrying homozygous HSD17B3+913A (289S) alleles (odds ratio [OR]: 3.06; 95% confidence interval [CI]: 1.38-6.76). The risk of severe hypospadias was much higher in these subjects (OR: 3.93; 95% CI: 1.34-11.49). The mRNA expression levels of HSD17B3 G289 were higher than those of HSD17B3 S289 mutant (P < 0.001). In addition, the risk of severe hypospadias increased in boys carrying the SRD5A2+336C (89L) allele (OR: 3.19; 95% CI: 1.09-9.36). These results suggest that the HSD17B3 G289S polymorphism may be a potential risk modifier for hypospadias. Our findings provide evidence that a certain genotype related to androgen production may potentiate risk of hypospadias. Show less

A role for the centrosome has been suggested in the pathology of major mental illnesses, especially schizophrenia (SZ). To show that pericentriolar material 1 protein (PCM1) forms a complex at the centrosome with disrupted-in-schizophrenia 1 (DISC1) and Bardet-Biedl syndrome 4 protein (BBS4), which provides a crucial pathway for cortical development associated with the pathology of SZ. To identify mutations in the PCM1 gene in an SZ population. Interaction of DISC1, PCM1, and BBS proteins was assessed by immunofluorescent staining and coimmunoprecipitation. Effects of PCM1, DISC1, and BBS on centrosomal functions and corticogenesis in vivo were tested by RNA interference. The PCM1 gene was examined by sequencing 39 exons and flanking splice sites. Probands and controls were from the collection of one of us (A.E.P.). Thirty-two probands with SZ from families that had excess allele sharing among affected individuals at 8p22 and 219 white controls. Protein interaction and recruitment at the centrosome in cells; neuronal migration in the cerebral cortex; and variant discovery in PCM1 in patients with SZ. PCM1 forms a complex with DISC1 and BBS4 through discrete binding domains in each protein. DISC1 and BBS4 are required for targeting PCM1 and other cargo proteins, such as ninein, to the centrosome in a synergistic manner. In the developing cerebral cortex, suppression of PCM1 leads to neuronal migration defects, which are phenocopied by the suppression of either DISC1 or BBS4 and are exacerbated by the concomitant suppression of both. Furthermore, a nonsense mutation that segregates with SZ spectrum psychosis was found in 1 family. Our data further support for the role of centrosomal proteins in cortical development and suggest that perturbation of centrosomal function contributes to the development of mental diseases, including SZ. Show less