Designing the stripe-ordered cuprate phase diagram through uniaxial-stress

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], with [Formula: see text] = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO[Formula: see text] plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature [Formula: see text] and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of [Formula: see text]0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal [Formula: see text]. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism.

BRD9 determines the cell fate of hematopoietic stem cells by regulating chromatin state

ATP-dependent chromatin remodeling SWI/SNF complexes exist in three subcomplexes: canonical BAF (cBAF), polybromo BAF (PBAF), and a newly described non-canonical BAF (ncBAF). While cBAF and PBAF regulate fates of multiple cell types, roles for ncBAF in hematopoietic stem cells (HSCs) have not been investigated. Motivated by recent discovery of disrupted expression of BRD9, an essential component of ncBAF, in multiple cancers, including clonal hematopoietic disorders, we evaluate here the role of BRD9 in normal and malignant HSCs. BRD9 loss enhances chromatin accessibility, promoting myeloid lineage skewing while impairing B cell development. BRD9 significantly colocalizes with CTCF, whose chromatin recruitment is augmented by BRD9 loss, leading to altered chromatin state and expression of myeloid-related genes within intact topologically associating domains. These data uncover ncBAF as critical for cell fate specification in HSCs via three-dimensional regulation of gene expression and illuminate roles for ncBAF in normal and malignant hematopoiesis.

SETBP1 is dispensable for normal and malignant hematopoiesis

SETBP1 is a potential epigenetic regulator whose hotspot mutations preventing proteasomal degradation are recurrently detected in myeloid malignancies with poor prognosis. It is believed that the mutant SETBP1 exerts amplified effects of wild-type SETBP1 rather than neomorphic functions. This indicates that dysregulated quantitative control of SETBP1 would result in the transformation of hematopoietic cells. However, little is known about the roles of endogenous SETBP1 in malignant and normal hematopoiesis. Thus, we integrated the analyses of primary AML and healthy samples, cancer cell lines, and a newly generated murine model, Vav1-iCre;Setbp1fl/fl. Despite the expression in long-term hematopoietic stem cells, SETBP1 depletion in normal hematopoiesis minimally alters self-renewal, differentiation, or reconstitution in vivo. Indeed, its loss does not profoundly alter transcription or chromatin accessibilities. Furthermore, although AML with high SETBP1 mRNA is associated with genetic and clinical characteristics for dismal outcomes, SETBP1 is dispensable for the development or maintenance of AML. Contrary to the evidence that SETBP1 mutations are restricted to myeloid malignancies, dependency on SETBP1 mRNA expression is not observed in AML. These unexpected results shed light on the unrecognized idea that a physiologically nonessential gene can act as an oncogene when the machinery of protein degradation is damaged.

Cystic fibrosis rabbits develop spontaneous hepatobiliary lesions and CF-associated liver disease (CFLD)-like phenotypes

Cystic fibrosis (CF) is an autosomal recessive genetic disease affecting multiple organs. Approximately 30% CF patients develop CF-related liver disease (CFLD), which is the third most common cause of morbidity and mortality of CF. CFLD is progressive, and many of the severe forms eventually need liver transplantation. The mechanistic studies and therapeutic interventions to CFLD are unfortunately very limited. Utilizing the CRISPR/Cas9 technology, we recently generated CF rabbits by introducing mutations to the rabbit CF transmembrane conductance regulator (CFTR) gene. Here we report the liver phenotypes and mechanistic insights into the liver pathogenesis in these animals. CF rabbits develop spontaneous hepatobiliary lesions and abnormal biliary secretion accompanied with altered bile acid profiles. They exhibit nonalcoholic steatohepatitis (NASH)-like phenotypes, characterized by hepatic inflammation, steatosis, and fibrosis, as well as altered lipid profiles and diminished glycogen storage. Mechanistically, our data reveal that multiple stress-induced metabolic regulators involved in hepatic lipid homeostasis were up-regulated in the livers of CF-rabbits, and that endoplasmic reticulum (ER) stress response mediated through IRE1α-XBP1 axis as well as NF-κB- and JNK-mediated inflammatory responses prevail in CF rabbit livers. These findings show that CF rabbits manifest many CFLD-like phenotypes and suggest targeting hepatic ER stress and inflammatory pathways for potential CFLD treatment.

Aberrant EVI1 splicing contributes to EVI1-rearranged leukemia

Detailed genomic and epigenomic analyses of MECOM (the MDS1 and EVI1 complex locus) have revealed that inversion or translocation of chromosome 3 drives inv(3)/t(3;3) myeloid leukemias via structural rearrangement of an enhancer that upregulates transcription of EVI1. Here, we identify a novel, previously unannotated oncogenic RNA-splicing derived isoform of EVI1 that is frequently present in inv(3)/t(3;3) acute myeloid leukemia (AML) and directly contributes to leukemic transformation. This EVI1 isoform is generated by oncogenic mutations in the core RNA splicing factor SF3B1, which is mutated in >30% of inv(3)/t(3;3) myeloid neoplasm patients and thereby represents the single most commonly cooccurring genomic alteration in inv(3)/t(3;3) patients. SF3B1 mutations are statistically uniquely enriched in inv(3)/t(3;3) myeloid neoplasm patients and patient-derived cell lines compared with other forms of AML and promote mis-splicing of EVI1 generating an in-frame insertion of 6 amino acids at the 3' end of the second zinc finger domain of EVI1. Expression of this EVI1 splice variant enhanced the self-renewal of hematopoietic stem cells, and introduction of mutant SF3B1 in mice bearing the humanized inv(3)(q21q26) allele resulted in generation of this novel EVI1 isoform in mice and hastened leukemogenesis in vivo. The mutant SF3B1 spliceosome depends upon an exonic splicing enhancer within EVI1 exon 13 to promote usage of a cryptic branch point and aberrant 3' splice site within intron 12 resulting in the generation of this isoform. These data provide a mechanistic basis for the frequent cooccurrence of SF3B1 mutations as well as new insights into the pathogenesis of myeloid leukemias harboring inv(3)/t(3;3).

Usefulness and accuracy of segmental adrenal venous sampling on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism

AIM

To clarify the usefulness and accuracy of segmental adrenal venous sampling (sAVS) on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism.

MATERIALS AND METHODS

Consecutive patients (n=162) who underwent adrenalectomy and 138 patients indicated for medication following sAVS were analysed retrospectively. Based on immunohistopathological diagnosis, the positive predictive value (PPV) of computed tomography (CT)-detectable aldosterone-producing adenoma (APA) was calculated. Moreover, endocrinological and sAVS characteristics were analysed quantitatively and qualitatively among APA, CT-undetectable aldosterone-producing nodules (APNs), multiple aldosterone-producing micronodules (MAPM), and medication groups.

RESULTS

The PPV of APA by sAVS was 137/141 (97.1%; 95% confidence interval, 92.9-99.2%). Compared to the medication cases, the APA group showed stronger disease activity clinically and significant differences in adrenal hormones, such as a higher aldosterone level and aldosterone-to-cortisol ratio, and lower cortisol levels in the adrenal central vein and aldosterone maximum tributaries on the dominant side after cosyntropin stimulation. The APA group shows focal aldosterone hypersecretion, such as mean number of aldosterone elevated segments (1.7 ± 0.7 versus 2 ± 0.9, p=0.003) and presence of aldosterone-not-elevated segments (93% versus 41%, p<0.001). Clinically and in terms of sAVS, APN and MAPM showed similar characteristics to APA and to the medication cases, respectively.

CONCLUSION

sAVS can localise functionally active tissues of CT-detectable and CT-undetectable lesions enabling decisions on surgical or medical treatment.

OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

OUP accepted manuscript

Lipoprotein, especially high-density lipoprotein (HDL), particles are composed of multiple heterogeneous subgroups containing various proteins and lipids. The molecular distribution among these subgroups is closely related to cardiovascular disease (CVD). Here, we established high-resolution proteomics and lipidomics (HiPL) methods to depict the molecular profiles across lipoprotein (Lipo-HiPL) and HDL (HDL-HiPL) subgroups by optimizing the resolution of anion-exchange chromatography and comprehensive quantification of proteins and lipids on the omics level. Furthermore, based on the Pearson correlation coefficient analysis of molecular profiles across high-resolution subgroups, we achieved the relationship of proteome‒lipidome connectivity (PLC) for lipoprotein and HDL particles. By application of these methods to high-fat, high-cholesterol diet-fed rabbits and acute coronary syndrome (ACS) patients, we uncovered the delicate dynamics of the molecular profile and reconstruction of lipoprotein and HDL particles. Of note, the PLC features revealed by the HDL-HiPL method discriminated ACS from healthy individuals better than direct proteome and lipidome quantification or PLC features revealed by the Lipo-HiPL method, suggesting their potential in ACS diagnosis. Together, we established HiPL methods to trace the dynamics of the molecular profile and PLC of lipoprotein and even HDL during the development of CVD.

Cl-Amidine Improves Survival and Attenuates Kidney Injury in a Rabbit Model of Endotoxic Shock

Objective: Sepsis causes millions of deaths on a global scale annually. Activation of peptidylarginine deiminase (PAD) enzymes in sepsis causes citrullination of histones, which results in neutrophil extracellular trap formation and sepsis progression. This study evaluates pan-PAD inhibitor, Cl-amidine, in a model of lipopolysaccharide (LPS)-induced endotoxic shock in rabbits. We hypothesized that Cl-amidine would improve survival and attenuate kidney injury. Methods: In the survival model, rabbits were injected injected intravenously with 1 mg/kg of LPS, and then randomly assigned either to receive dimethyl sulfoxide (DMSO; 1 mcL/g) or Cl-amidine (10 mg/kg diluted in 1 mcL/g DMSO). They were then monitored for 14 days to evaluate survival. In the non-survival experiment, the same insult and treatment were administered, however; the animals were euthanized 12 hours after LPS injection for kidney harvest. Acute kidney injury (AKI) scoring was performed by a histopathologist who was blinded to the group assignment. Serial blood samples were also collected and compared. Results: Rabbits that received Cl-amidine had a higher survival (72%) compared with the rabbits that received DMSO (14%; p < 0.05). Cl-amidine-treated rabbits had lower (p < 0.05) histopathologic AKI scores, as well as plasma creatinine and blood urea nitrogen (BUN) levels 12 hours after insult. Conclusions: Pan-PAD inhibitor Cl-amidine improves survival and attenuates kidney injury in LPS-induced endotoxic shock in rabbits.

Multifaceted array-based keloidal gene expression profiling reveals specific MDFI upregulation in keloid lesions

BACKGROUND

Keloid lesions are characterized by mesenchymal cell proliferation and excessive extracellular matrix deposition. Previous microarray analyses have been performed to investigate the mechanism of keloid development. However, the molecular pathology that contributes to keloid development remains obscure.

AIM

To explore the underlying essential molecules of keloids using microarrays.

METHODS

We performed microarray analyses of keloid and nonlesional skin tissues both in vivo and in vitro. Gene expression levels were compared between tissues and cells. Quantitative reverse transcription (qRT)-PCR and immunohistochemical staining were used to determine the expression levels of molecules of interest in keloid tissues.

RESULTS

Several common molecules were upregulated in both keloid tissues and keloid-lesional fibroblasts. PTPRD and NTM were upregulated both in vivo and in vitro. The genes MDFI and ITGA4 were located at the centre of the gene coexpression network analysis using keloid tissues. qRT-PCR revealed significant expression levels of PTPRD and MDFI in keloid tissues. Immunopathological staining revealed that MDFI-positive cells, which have fibroblast characteristics, were located in the keloid-associated lymphoid tissue (KALT) portion of the keloid tissue.

CONCLUSION

Our gene expression profiles of keloids could distinguish the difference between lesional tissue and cultured lesional fibroblasts, and MDFI was found to be commonly expressed in both tissues and cells. Thus, MDFI-positive cells, which were located in the KALT, may play an important role in keloid pathogenesis and thus might be useful for in vitro keloid studies.

Development of the Nude Rabbit Model

Loss-of-function mutations in the forkhead box N1 (FOXN1) gene lead to nude severe combined immunodeficiency, a rare inherited syndrome characterized by athymia, severe T cell immunodeficiency, congenital alopecia, and nail dystrophy. We recently produced FOXN1 mutant nude rabbits (NuRabbits) by using CRISPR-Cas9. Here we report the establishment and maintenance of the NuRabbit colony. NuRabbits, like nude mice, are hairless, lack thymic development, and are immunodeficient. To demonstrate the functional applications of NuRabbits in biomedical research, we show that they can successfully serve as the recipient animals in xenotransplantation experiments using human induced pluripotent stem cells or tissue-engineered blood vessels. Our work presents the NuRabbit as a new member of the immunodeficient animal model family. The relatively large size and long lifespan of NuRabbits offer unique applications in regenerative medicine, cancer research, and the study of a variety of other human conditions, including immunodeficiency.

•

NuRabbit colony is established and available for the research community

•

NuRabbits are nude and immunodeficient due to a mutation(s) in the FOXN1 gene

•

NuRabbits support iPSC teratoma assay

•

NuRabbits support xenotransplant of tissue-engineered blood vessels

Human apolipoprotein A-II reduces atherosclerosis in knock-in rabbits

BACKGROUND AND AIMS

Apolipoprotein A-II (apoAII) is the second major apolipoprotein of the high-density lipoprotein (HDL) particle, after apoAI. Unlike apoAI, the biological and physiological functions of apoAII are unclear. We aimed to gain insight into the specific roles of apoAII in lipoprotein metabolism and atherosclerosis using a novel rabbit model.

METHODS

Wild-type (WT) rabbits are naturally deficient in apoAII, thus their HDL contains only apoAI. Using TALEN technology, we replaced the endogenous apoAI in rabbits through knock-in (KI) of human apoAII. The newly generated apoAII KI rabbits were used to study the specific function of apoAII, independent of apoAI.

RESULTS

ApoAII KI rabbits expressed exclusively apoAII without apoAI, as confirmed by RT-PCR and Western blotting. On a standard diet, the KI rabbits exhibited lower plasma triglycerides (TG, 52%, p < 0.01) due to accelerated clearance of TG-rich particles and higher lipoprotein lipase activity than the WT littermates. ApoAII KI rabbits also had higher plasma HDL-C (28%, p < 0.05) and their HDL was rich in apoE, apoAIV, and apoAV. When fed a cholesterol-rich diet for 16 weeks, apoAII KI rabbits were resistant to diet-induced hypertriglyceridemia and developed significantly less aortic atherosclerosis compared to WT rabbits. HDL isolated from rabbits with apoAII KI had similar cholesterol efflux capacity and anti-inflammatory effects as HDL isolated from the WT rabbits.

CONCLUSIONS

ApoAII KI rabbits developed less atherosclerosis than WT rabbits, possibly through increased plasma HDL-C, reduced TG and atherogenic lipoproteins. These results suggest that apoAII may serve as a potential target for the treatment of atherosclerosis.

Glycine-based treatment ameliorates NAFLD by modulating fatty acid oxidation, glutathione synthesis, and the gut microbiome

Nonalcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) has reached epidemic proportions with no pharmacological therapy approved. Lower circulating glycine is consistently reported in patients with NAFLD, but the causes for reduced glycine, its role as a causative factor, and its therapeutic potential remain unclear. We performed transcriptomics in livers from humans and mice with NAFLD and found suppression of glycine biosynthetic genes, primarily alanine-glyoxylate aminotransferase 1 (AGXT1). Genetic (Agxt1 -/- mice) and dietary approaches to limit glycine availability resulted in exacerbated diet-induced hyperlipidemia and steatohepatitis, with suppressed mitochondrial/peroxisomal fatty acid β-oxidation (FAO) and enhanced inflammation as the underlying pathways. We explored glycine-based compounds with dual lipid/glucose-lowering properties as potential therapies for NAFLD and identified a tripeptide (Gly-Gly-L-Leu, DT-109) that improved body composition and lowered circulating glucose, lipids, transaminases, proinflammatory cytokines, and steatohepatitis in mice with established NASH induced by a high-fat, cholesterol, and fructose diet. We applied metagenomics, transcriptomics, and metabolomics to explore the underlying mechanisms. The bacterial genus Clostridium sensu stricto was markedly increased in mice with NASH and decreased after DT-109 treatment. DT-109 induced hepatic FAO pathways, lowered lipotoxicity, and stimulated de novo glutathione synthesis. In turn, inflammatory infiltration and hepatic fibrosis were attenuated via suppression of NF-κB target genes and TGFβ/SMAD signaling. Unlike its effects on the gut microbiome, DT-109 stimulated FAO and glutathione synthesis independent of NASH. In conclusion, impaired glycine metabolism may play a causative role in NAFLD. Glycine-based treatment attenuates experimental NAFLD by stimulating hepatic FAO and glutathione synthesis, thus warranting clinical evaluation.

Using Uniaxial Stress to Probe the Relationship between Competing Superconducting States in a Cuprate with Spin-stripe Order

We report muon spin rotation and magnetic susceptibility experiments on in-plane stress effects on the static spin-stripe order and superconductivity in the cuprate system La_{2-x}Ba_{x}CuO_{4} with x=0.115. An extremely low uniaxial stress of ∼0.1  GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity, from ∼10 to 32 K; however, the onset of at-least-2D superconductivity is much less sensitive to stress. These results show not only that large-volume-fraction spin-stripe order is anticorrelated with 3D superconducting coherence but also that these states are energetically very finely balanced. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. These results strongly suggest a similar pairing mechanism for spin-stripe order and the spatially modulated 2D and uniform 3D superconducting orders, imposing an important constraint on theoretical models.

High-Temperature Charge-Stripe Correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}

We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

Lipid Profiling of Serum and Lipoprotein Fractions in Response to Pitavastatin Using an Animal Model of Familial Hypercholesterolemia

Statins are widely used for the treatment of atherosclerotic cardiovascular diseases. They inhibit cholesterol biosynthesis in the liver and cause pleiotropic effects, including anti-inflammatory and antioxidant effects. To develop novel therapeutic drugs, the effect of blood-borne lipid molecules on the pleiotropic effects of statins must be elucidated. Myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for hypercholesterolemia, are suitable for the determination of lipid molecules in the blood in response to statins because their lipoprotein metabolism is similar to that of humans. Herein, lipid molecules were investigated by lipidome analysis in response to pitavastatin using WHHLMI rabbits. Various lipid molecules in the blood were measured using a supercritical fluid chromatography triple quadrupole mass spectrometry. Cholesterol and cholesterol ester blood concentrations decreased by reducing the secretion of very low density lipoproteins from the liver. Independent of the inhibition effects of cholesterol biosynthesis, the concentrations of some lipids with anti-inflammation and antioxidant effects (phospholipid molecules with n-6 fatty acid side chains, lysophosphatidylcholines, phosphatidylethanolamine plasmalogens, and ceramide molecules) were significantly altered. These findings may lead to further investigation of the mechanism of statin action.

Development and application of 2.5 GPa-25 T high-pressure high-field electron spin resonance system using a cryogen-free superconducting magnet

We have developed a high-pressure electron spin resonance probe and successfully installed into the world's highest-field cryogen-free superconducting magnet having a maximum central field of 24.6 T. The high pressure of 2.5 GPa is achieved by the specially designed piston-cylinder pressure cell using THz-wave-transparent components. In the first application of this high-pressure high-field ESR system, we observed that the orthogonal dimer spin system SrCu₂(BO₃)₂ undergoes a quantum phase transition from the dimer singlet ground to the plaquette singlet ground states.

Abstract 189: Improved Triglyceride-Rich Lipoprotein Clearance In Human Apolipoprotein A-Ii Knockin Rabbits

Apolipoprotein A-II (apoA-II) is a second major apolipoprotein in HDL particles, which account for 15-20 % of total HDL protein in human. Compared with apolipoprotein A-I (apoA-I) which is a most major apolipoproteins in HDL, physiological role of apoA-II is not fully understood. We previously reported that overexpression of apoA-II in rabbits significantly suppressed cholesterol-rich diet induced atherosclerosis. Because rabbits are the animal of naturally deficient in apoA-II, so it becomes a good animal model to study the functions of apoA-II. To elucidate the role of apoA-II independent from apoA-I in HDL on lipid metabolism and atherogenesis, we generated a rabbit model in which the human apoA-II was knocked in to rabbit apoA-I locus by TALEN technology. The model was confirmed by genomic PCR, sequencing, RT-PCR and proteomics. With this model, we found that the triglyceride (TG) levels are significantly lower in homozygote than that in wild type control. The results of lipoprotein analysis using ultracentrifugation and FPLC also show that TG-rich lipoproteins were lower in homozygote than that of wild type. TGs were not increased in homozygote even after feeding of food. Small LDL and HDL2 particles were increased in homozygote rabbits. In addition, increased apoE was shown in HDL3 particle from homozygote. These results suggest that apoA-II knock-in has critical roles in the metabolism of TG-rich lipoproteins. Roles of apoA-II only HDLs from homozygote on cholesterol efflux and atherogenesis are under investigation.

Deficiency of Cholesteryl Ester Transfer Protein Protects Against Atherosclerosis in Rabbits

OBJECTIVE

CETP (cholesteryl ester transfer protein) plays an important role in lipoprotein metabolism; however, whether inhibition of CETP activity can prevent cardiovascular disease remains controversial.

APPROACH AND RESULTS

We generated CETP knockout (KO) rabbits by zinc finger nuclease gene editing and compared their susceptibility to cholesterol diet-induced atherosclerosis to that of wild-type (WT) rabbits. On a chow diet, KO rabbits showed higher plasma levels of high-density lipoprotein (HDL) cholesterol than WT controls, and HDL particles of KO rabbits were essentially rich in apolipoprotein AI and apolipoprotein E contents. When challenged with a cholesterol-rich diet for 18 weeks, KO rabbits not only had higher HDL cholesterol levels but also lower total cholesterol levels than WT rabbits. Analysis of plasma lipoproteins revealed that reduced plasma total cholesterol in KO rabbits was attributable to decreased apolipoprotein B-containing particles, while HDLs remained higher than that in WT rabbits. Both aortic and coronary atherosclerosis was significantly reduced in KO rabbits compared with WT rabbits. Apolipoprotein B-depleted plasma isolated from CETP KO rabbits showed significantly higher capacity for cholesterol efflux from macrophages than that from WT rabbits. Furthermore, HDLs isolated from CETP KO rabbits suppressed tumor necrosis factor-α-induced vascular cell adhesion molecule 1 and E-selectin expression in cultured endothelial cells.

CONCLUSIONS

These results provide evidence that genetic ablation of CETP activity protects against cholesterol diet-induced atherosclerosis in rabbits.

Formula feeding and systemic hypoxia synergistically induce intestinal hypoxia in experimental necrotizing enterocolitis

PURPOSE

Feeding and systemic hypoxia are major stresses inducing necrotizing enterocolitis (NEC). This study aims to investigate the role of systemic hypoxia in NEC and its effect before and after feeding.

METHODS

Neonatal mice were studied in three groups. Control (N = 9): breast feeding; NEC A (N = 8), gavage feeding + lipopolysaccharide (LPS) + preprandial hypoxia; and NEC B (N = 9), feeding + LPS + postprandial hypoxia. Pimonidazole, a hypoxia marker, was injected intraperitoneally before ileum was harvested for histology and quantitative RT-PCR studies. Statistical analysis was done using the ANOVA and Chi-square test.

RESULTS

NEC incidence was 62.5% in NEC A and 88.9% in NEC B. The mortality in NEC B (55.6%) but not A (25%) is significantly higher than control (0%, p < 0.05). Pimonidazole staining elevated in both NEC A and B with higher pimonidazole grade in NEC B (p < 0.01). Both NEC groups had increased the expression of hypoxia-related genes: HIF-1α, GLUT-1, and PHD-3 with GLUT-1 expressed more in NEC B compared with NEC A (p < 0.01). The inflammation marker, IL6, was similarly raised in both NEC A and B.

CONCLUSION

Feeding and postprandial hypoxia synergistically induce intestinal hypoxia in NEC. As feeding increases intestinal oxygen demand, maintaining a balance between intestinal oxygen supply and demand is important to prevent NEC.

Glycosaminoglycan and versican deposits in taxane-induced sclerosis

Docetaxel and paclitaxel are widely used in the treatment of various malignant neoplasms. Taxane-induced sclerosis is dose-dependent and usually not generalized. Little information on the pathogenesis of scleroderma is currently available. Here, we report a case of generalized scleroderma and a case of early-stage oedematous sclerosis, both of which presented with intense versican deposits after administration of taxane for angiosarcoma.

Real space imaging of spin polarons in Zn-doped SrCu(2)(BO(3))(2)

We report on the real space profile of spin polarons in the quasi-two-dimensional frustrated dimer spin system SrCu(2)(BO(3))(2) doped with 0.16% of Zn. The (11)B nuclear magnetic resonance spectrum exhibits 15 additional boron sites near nonmagnetic Zn impurities. With the help of exact diagonalizations of finite clusters, we have deduced from the boron spectrum, the distribution of local magnetizations at the Cu sites with fine spatial resolution, providing direct evidence for an extended spin polaron. The results are confronted with those of other experiments performed on doped and undoped samples of SrCu(2)(BO(3))(2).

Late enhancement of brain-behavior correlations during response inhibition

Previous neuroimaging studies of response inhibition have examined correlations between behavioral efficiency and brain activity, but the temporal stability of the correlations has largely been ignored. The present functional magnetic resonance imaging (fMRI) study demonstrates the temporal changes of the brain activity associated with performance efficiency that led to more robust brain-behavior correlations in a later part of the experimental sessions. Participants performed a stop-signal task requiring inhibition of inappropriate responses, where more efficient behavioral performance is reflected in a shorter stop-signal reaction time (SSRT). Among across-subject negative correlations between the brain activity and the SSRT, the majority of the negative correlations were observed in the second half of experimental sessions. In the cerebellar region that showed the greatest difference in correlations between the second and the first halves, the brain activity increased in efficient performers, whereas the brain activity decreased in poor performers. These results suggest the existence of multiple brain mechanisms that increase and decrease the brain activity depending on the behavioral efficiency of the performers. More practically, these results indicate that robust brain-behavior correlations can more effectively be detected in a later part of the experimental sessions.

A prospective, randomized, double-blind, controlled trial on the efficacy of carbon dioxide insufflation in gastric endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Carbon dioxide (CO2) insufflation is expected to be safe and effective in endoscopic submucosal dissection (ESD) as well as in other endoscopic procedures. The present study aimed to clarify the usefulness and safety of CO2 insufflation in gastric ESD.

PATIENTS AND METHODS

A total of 102 consecutive patients were randomly assigned to CO2 insufflation (CO2 group, n = 54) or air insufflation (Air group, n = 48). Abdominal pain and distension were chronologically recorded on a 100-mm visual analog scale (VAS). The volume of residual gas in the digestive tract was measured by computed tomography performed immediately after ESD.

RESULTS

Abdominal pain on a 100-mm VAS in the CO2 vs. Air group was 4 vs. 3 immediately after ESD, 4 vs. 4 one hour after the procedure, 3 vs. 3 three hours after the procedure, and 1 vs. 4 the next morning, showing no difference between the groups. In addition, there was no difference in abdominal distension on the 100-mm VAS over the time course of the study. The volume of residual gas in the digestive tract in the CO2 group was significantly smaller than that in the Air group (643 mL vs. 1037 mL, P < 0.001). The dose of sedative drugs did not differ between the groups. Neither the incidences of complications nor clinical courses differed between the groups.

CONCLUSIONS

Compared with air insufflation, CO2 insufflation during gastric ESD significantly reduced the volume of residual gas in the digestive tract but not the VAS score of abdominal pain and distension.

Role of lattice coupling in establishing electronic and magnetic properties in quasi-one-dimensional cuprates

High resolution resonant inelastic x-ray scattering has been performed to reveal the role of lattice coupling in a family of quasi-1D insulating cuprates, Ca2+5xY2-5xCu5O10. Site-dependent low-energy excitations arising from progressive emissions of a 70 meV lattice vibrational mode are resolved for the first time, providing a direct measurement of electron-lattice coupling strength. We show that such electron-lattice coupling causes doping-dependent distortions of the Cu-O-Cu bond angle, which sets the intrachain spin exchange interactions. Our results indicate that the lattice degrees of freedom are fully integrated into the electronic behavior in low-dimensional systems.

A pilot study to assess mediastinal emphysema after esophageal endoscopic submucosal dissection with carbon dioxide insufflation

BACKGROUND AND AIMS

Mediastinal emphysema sometimes develops following esophageal endoscopic submucosal dissection (ESD) without perforation because the esophagus has no serosa. Carbon dioxide (CO2) insufflation during esophageal ESD may reduce the incidence of mediastinal emphysema. The aim of the present study was to compare the incidence and severity of post-ESD mediastinal emphysema in patients receiving CO2 insufflation vs. standard air insufflation during esophageal ESD.

PATIENTS AND METHODS

A total of 27 patients who had undergone esophageal ESD with insufflation of CO2 between July 2009 and March 2010 were enrolled in this study (CO2 group). Another 105 patients who had undergone esophageal ESD with air insufflation between March 2004 and May 2009 were included as historical controls (air group). Multi-detector row computed tomography (MDCT) was carried out immediately after ESD. A conventional chest radiograph was taken the next day. Mediastinal emphysema findings on MDCT and radiography were compared between the groups.

RESULTS

Mediastinal emphysema detected by chest radiography was 0 % in the CO2 group vs. 6.6 % in the air group (n.s.). Mediastinal emphysema on MDCT was significantly less frequent in the CO2 group compared with the air group (30 % vs. 63 %; P = 0.002). The severity of mediastinal emphysema also tended to be lower in the CO2 group.

CONCLUSIONS

Whereas mediastinal emphysema detected by radiography is not so common, MDCT immediately after ESD revealed a certain prevalence of post-ESD mediastinal emphysema. Insufflation of CO2 rather than air during esophageal ESD significantly reduced postprocedural mediastinal emphysema. CO2 can be considered as insufflating gas for esophageal ESD.

Hidden itinerant-spin phase in heavily overdoped La(2-x)Sr(x)CuO4 superconductors revealed by dilute Fe doping: a combined neutron scattering and angle-resolved photoemission study

We demonstrated experimentally a direct way to probe a hidden propensity to the formation of a spin-density wave in a nonmagnetic metal with strong Fermi surface nesting. Substituting Fe for a tiny amount of Cu (1%) induced an incommensurate magnetic order below 20 K in heavily overdoped La(2-x)Sr(x)CuO(4). Elastic neutron scattering suggested that this order cannot be ascribed to the localized spins on Cu or doped Fe. Angle-resolved photoemission revealed a strong Fermi surface nesting inherent in the pristine La(2-x)Sr(x)CuO(4) that likely drives this order. Our finding presents the first example of the long-sought "itinerant-spin extreme" of cuprates, where the spins of itinerant doped holes define the magnetic ordering ground state; it complements the current picture of cuprate spin physics that highlights the predominant role of localized spins at lower dopings.