👤 Akihiko Hirose

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade sarcoma affecting with predilection the acral soft tissues of middle-aged adults. Clinically, MIFS is associated with a high rate of local recurrence but infrequent distant metastases. The diagnosis remains challenging due to their wide histologic spectrum and overlap with reactive, benign, and low-grade malignant lesions. Moreover, a significant limitation is that molecular confirmation is achieved in only a subset of cases, due to its broad range of genetic alterations which requires a multiplatform approach. Thus, a definitive diagnosis, especially at nonacral sites and in molecularly negative cases, remains uncertain. Our goal was to perform a detailed clinicopathologic and molecular reappraisal of MIFS managed at a single tertiary cancer center with dedicated orthopedic oncology expertise. Additionally, we examined potential outcomes correlating with specific genetic alterations. A cohort of 33 patients (12 males, 21 females, median age 52 years) was selected. Tumors were tested by FISH, Archer, and/or targeted NGS. VGLL3 amplification was detected in 84%, BRAF fusions in 33% and combined TGFBR3/MGEA5 rearrangements in 32% of cases. Two novel fusions were detected, RRAGB::CCNB3 and FGFR1::ZBTB47. Other events included a YAP1::MAML2 fusion in two cases, one co-existing with a BRAF fusion. Overall, 8 (24%) patients recurred, 4 more than once, while 4 (12%) patients developed metastasis (3 locoregional, 1 pulmonary), all associated with VGLL3 gene amplification. Positive margin status was associated with increased recurrence and reduced disease-free survival (DFS, p = 0.02). Moreover, it emphasizes the impact of multiplatform molecular testing in confirming the diagnosis. The lack of both local recurrence and metastatic potential outside VGLL3 amplifications requires further investigation. Show less

Regulation of myosin motor extension and conformation is central to cardiac muscle contraction-relaxation, with myosin playing a critical role in mechanosensing during the cardiac cycle. Direct assessment of in vivo dynamic interplay between myosin head position, cross-bridge cycling, sarcomere shortening (filament sliding), muscle stress-strain rates and pressure-volume (PV) relationships is key to understanding both normal cardiac function and ventricle pathological states. This work aims to demonstrate that in vivo temporal regulation of myosin head transfer to actin filaments in systole and diastole has important points of difference from current models based on in vitro and ex vivo muscle studies, particularly in settings of diastolic dysfunction. The first study investigated myosin activation-deactivation in a mouse model of diet-induced obesity (high-fat high-sugar diet) with moderate contraction-relaxation impairment. In a second study myosin regulation was investigated in a novel hypertrophic cardiomyopathy mouse model due to a truncation mutation in the sarcomeric gene encoding cardiac myosin binging protein-C, Mybpc3 (Exon 33 deletion). We demonstrate with in vivo small-angle X-ray scattering (SAXS) simultaneous with PV loop analysis in the beating heart that dynamic regulation of myosin is often non-uniform across the left ventricle from the epicardium to subendocardium, with large differences in myosin head behaviour in both systole and diastole, at least in rodents. Our findings underscore that myosin activation-deactivation is intricately tuned to the mechanical demands of the heart and the work of each myocardial layer. Regional myosin filament dysregulation underpins muscle relaxation impairment, offering new insights into potential therapeutic targets. KEY POINTS: This small-angle X-ray scattering (SAXS) study demonstrates that in vivo myosin activation-deactivation and myosin interfilament spacing vary across myocardial layers and are influenced by diet, exercise and pathological conditions in vivo in the murine heart. During the isovolumetric contraction phase, myosin heads exhibit strong cross-bridge binding in response to mechanical load, which increases in the ejection phase, highlighting the critical role of mechanosensing in early force development. In the absence of myosin binding protein-C within the thick filament complex this strong cross-bridge formation is not sustained during ejection. Impaired myosin cross-bridge detachment likely contributes to sustained cross-bridge activation in the isovolumetric relaxation phase and prolongation of relaxation in hypertrophic cardiomyopathy. This study highlights how disturbed myosin mechanosensing evoked by metabolic stress and genetic mutations can impair myosin motor function and correlates with global cardiac dysfunction. Show less

Melanin is a pigment produced from the amino acid L-tyrosine in melanosomes. The CNC-family transcription factor Nrf3 is expressed in the basal layer of the epidermis, where melanocytes reside, but its melanogenic function is unclear. Here, we show that Nrf3 regulates macropinocytosis and autophagy to coordinate melanogenesis cascade. In response to an exogenous inducer of melanin production, forskolin, Nrf3 upregulates the core melanogenic gene circuit, which includes Mitf, Tyr, Tyrp1, Pmel, and Oca2. Furthermore, Nrf3 induces the gene expression of Cln3, an autophagosome-related factor, for melanin precursor uptake by macropinocytosis. Ulk2 and Gabarapl2 are also identified as Nrf3-target autophagosome-related genes for melanosome formation. In parallel, Nrf3 prompts autolysosomal melanosome degradation for melanocyte survival. An endogenous melanogenic inducer αMSH also activates Nrf3-mediated melanin production, whereas it is suppressed by an HIV-1 protease inhibitor, nelfinavir. These findings indicate the significant role of Nrf3 in the melanogenesis and the anti-melanogenic potential of nelfinavir. Show less

Phase-separated membraneless organelles often contain RNAs that exhibit unusual semi-extractability using the conventional RNA extraction method, and can be efficiently retrieved by needle shearing or heating during RNA extraction. Semi-extractable RNAs are promising resources for understanding RNA-centric phase separation. However, limited assessments have been performed to systematically identify and characterize semi-extractable RNAs. In this study, 1074 semi-extractable RNAs, including ASAP1, DANT2, EXT1, FTX, IGF1R, LIMS1, NEAT1, PHF21A, PVT1, SCMH1, STRG.3024.1, TBL1X, TCF7L2, TVP23C-CDRT4, UBE2E2, ZCCHC7, ZFAND3 and ZSWIM6, which exhibited consistent semi-extractability were identified across five human cell lines. By integrating publicly available datasets, we found that semi-extractable RNAs tend to be distributed in the nuclear compartments but are dissociated from the chromatin. Long and repeat-containing semi-extractable RNAs act as hubs to provide global RNA-RNA interactions. Semi-extractable RNAs were divided into four groups based on their k-mer content. The NEAT1 group preferred to interact with paraspeckle proteins, such as FUS and NONO, implying that RNAs in this group are potential candidates of architectural RNAs that constitute nuclear bodies. Show less

Carbohydrate response element-binding protein (ChREBP) is critical in the regulation of fatty acid and triglyceride synthesis in the liver. Interestingly, Chrebp-/- mice show reduced levels of plasma cholesterol, which is critical for steroid hormone synthesis in adrenal glands. Furthermore, Chrebp mRNA expression was previously reported in human adrenal glands. Thus, it remains to be investigated whether ChREBP plays a role directly or indirectly in steroid hormone synthesis and release in adrenal glands. In the present study, we find that Chrebp mRNA is expressed in mouse adrenal glands and that ChREBP binds to carbohydrate response elements. Histological analysis of Chrebp-/- mice shows no adrenal hyperplasia and less oil red O staining compared with that in WT mice. In adrenal glands of Chrebp-/- mice, expression of Fasn and Scd1, two enzymes critical for fatty acid synthesis, was substantially lower and triglyceride content was reduced. Expression of Srebf2, a key transcription factor controlling synthesis and uptake of cholesterol and the target genes, was upregulated, while cholesterol content was not significantly altered in the adrenal glands of Chrebp-/- mice. Adrenal corticosterone content and plasma adrenocorticotropic hormone and corticosterone levels were not significantly altered in Chrebp-/- mice. Consistently, expression of genes related to steroid hormone synthesis was not altered. Corticosterone secretion in response to two different stimuli, namely 24-h starvation and cosyntropin administration, was also not altered in Chrebp-/- mice. Taking these results together, corticosterone synthesis and release were not affected in Chrebp-/- mice despite reduced plasma cholesterol levels. Show less

We performed a replication study in a Japanese population to evaluate the association between type 2 diabetes and 7 susceptibility loci originally identified by European genome-wide association study (GWAS) in 2012: ZMIZ1, KLHDC5, TLE1, ANKRD55, CILP2, MC4R, and BCAR1. We also examined the association of 3 additional loci: CCND2 and GIPR, identified in sex-differentiated analyses, and LAMA1, which was shown to be associated with non-obese European type 2 diabetes. We genotyped 6,972 Japanese participants (4,280 type 2 diabetes patients and 2,692 controls) for each of the 10 single nucleotide polymorphisms (SNPs): rs12571751 in ZMIZ1, rs10842994 near KLHDC5, rs2796441 near TLE1, rs459193 near ANKRD55, rs10401969 in CILP2, rs12970134 near MC4R, rs7202877 near BCAR1, rs11063069 near CCND2, rs8108269 near GIPR, and rs8090011 in LAMA1 using a multiplex polymerase chain reaction invader assay. The association of each SNP locus with the disease was evaluated using a logistic regression analysis. All SNPs examined in this study had the same direction of effect (odds ratio > 1.0, p = 9.77 × 10(-4), binomial test), as in the original reports. Among them, rs12571751 in ZMIZ1 was significantly associated with type 2 diabetes [p = 0.0041, odds ratio = 1.123, 95% confidence interval 1.037-1.215, adjusted for sex, age and body mass index (BMI)], but we did not observe significant association of the remaining 9 SNP loci with type 2 diabetes in the present Japanese population (p ≥ 0.005). A genetic risk score, constructed from the sum of risk alleles for the 7 SNP loci identified by un-stratified analyses in the European GWAS meta-analysis were associated with type 2 diabetes in the present Japanese population (p = 2.3 × 10(-4), adjusted for sex, age and BMI). ZMIZ1 locus has a significant effect on conferring susceptibility to type 2 diabetes also in the Japanese population. Show less

p230/golgin-245 is a trans-Golgi coiled-coil protein that is known to participate in regulatory transport from the trans-Golgi network (TGN) to the cell surface. We investigated the role of p230 and its interacting protein, microtubule actin crosslinking protein 1 (MACF1), in amino acid starvation-induced membrane transport. p230 or MACF1 knock-down (KD) cells failed to increase the autophagic flow rate and the number of microtubule-associated protein 1 light chain 3 (LC3)-positive puncta under starvation conditions. Loss of p230 or MACF1 impaired mAtg9 recruitment to peripheral phagophores from the TGN, which was observed in the early step of autophagosome formation. Overexpression of the p230-binding domain of MACF1 resulted in the inhibition of mAtg9 trafficking in starvation conditions as in p230-KD or MACF1-KD cells. These results indicate that p230 and MACF1 cooperatively play an important role in the formation of phagophore through starvation-induced transport of mAtg9-containing membranes from the TGN. In addition, p230 itself was detected in autophagosomes/autolysosome with p62 or LC3 during autophagosome biogenesis. Thus, p230 is an important molecule in phagophore formation, although it remains unclear whether p230 has any role in late steps of autophagy. Show less

We evaluated multiple effects of genetic variations of five candidate loci (LEP, LEPR, MC4R, PIK3C3 and VRTN) on four production traits (average daily weight gain (ADG); backfat thickness (BFT); loin eye muscle area (EMA); and intramuscular fat content (IMF)) in a closed nucleus herd of pure Duroc pigs. Polymorphisms in LEPR, MC4R and PIK3C3 had significant single gene effects on ADG and BFT. The additive genetic variance in ADG and BFT (16.99% and 22.51%, respectively) was explained by genetic effects of these three loci. No correlations were observed between the LEP genotype and production traits in this study. Although we detected marginally epistatic interactions between LEPR and PIK3C3 on the eye muscle area, there were no significant epistatic effects on any traits among all loci pairs. These results suggest that LEPR, MC4R, PIK3C3 and VRTN may independently influence growth rate and fat deposition. Furthermore, the statistical models for predicting the breeding values of each trait had the lowest Akaike's information criterion values when considering the effect of the MC4R, LEPR, PIK3C3 and VRTN genotype simultaneously. These results suggest that LEPR, MC4R, PIK3C3 and VRTN are useful markers for accurately predicting breeding values in Duroc pigs. Show less

Organotins, including tri-butyltin chloride (TBTC), are widely used in agricultural and chemical industries and cause persistent and widespread pollution. TBTC has been shown to activate nuclear receptor retinoid X receptor (RXR)/PPARγ signaling by interacting with RXR to modulate adipogenesis. However, whether TBTC affects liver X receptor (LXR)/RXR activity and subsequently the expression of cholesterol mobilizing genes is not known. In this study, we evaluated the ability of TBTC to activate LXR/RXR and ABC transporter A1 (ABCA1) expression. ABCA1 plays a critical role in HDL generation, maintaining cholesterol homeostasis, and cholesterol accumulation-induced diseases, such as atherosclerosis and pancreatic islet dysfunction. In a reporter gene assay, TBTC activated LXRα/RXR but not LXRβ/RXR. In mouse macrophage RAW264 cells, TBTC activated the ABCA1 promoter in an LXR-responsive element dependent manner and increased ABCA1 mRNA expression. TBTC augmented ABCA1 protein levels and apolipoprotein A-I-dependent cellular cholesterol efflux (HDL generation). The LXR-target fatty acid synthase and Spα mRNA levels were also increased by TBTC exposure. We conclude that TBTC has the ability to activate permissive LXRα/RXR signaling and thereby modulate cellular cholesterol efflux. Show less

A C↔T single nucleotide polymorphism (SNP) on exon 24 of the porcine class 3 phosphoinositide-3-kinase (PIK3C3) gene is considered a possible genetic marker for selecting backfat (BF) thickness and carcass fat, although only one study has published results on its effects by performing experiments on a single resource family. We analyzed the association of this PIK3C3 polymorphism with production traits in 739 Duroc pigs. The C allele frequency was 67.9% in our study population. PIK3C3 polymorphism showed significant effects on average daily weight gain (ADG), BF thickness, intermuscular fat content (IMF), and the size of the loin eye muscle area (EMA). The C alleles increased ADG, BF and IMF, and decreased EMA. The predicted differences in traits between the homozygous pigs of the C and T alleles were 40 g/day for DG, 1.2 mm for BF, 0.44% for IMF, and 1.6 cm(2) for EMA. Furthermore, the statistical models for estimating the breeding values of each trait had lower Akaike's information criterion values when adding PIK3C3 genotype information. We therefore confirmed that the polymorphism in PIK3C3 (C2604T) has the potential to be a genetic marker for production traits in Duroc pigs. Show less