Correction of substitution, deletion, and insertion mutations by 5'-tailed duplexes

Germline and somatic mutations cause various diseases, including cancer. Clinical applications of genome editing are keenly anticipated, since it can cure genetic diseases. Recently, we reported that a 5'-tailed duplex (TD), consisting of an approximately 80-base editor strand oligodeoxyribonucleotide and a 35-base assistant strand oligodeoxyribonucleotide, could edit a target gene on plasmid DNA and correct a single-base substitution mutation without an artificial nuclease in human cells. In this study, we assessed the ability of the TD to correct base substitution mutations located consecutively or separately, and deletion and insertion mutations. A TD with an 80-base editor strand was co-introduced into human U2OS cells with plasmid DNA bearing either a wild-type or mutated copepod green fluorescent protein (copGFP) gene. Among the mutations, three-base consecutive substitutions were efficiently repaired. The correction efficiencies of deletion mutations were similar to those of substitution mutations, and two to three times higher than those of insertion mutations. Up to three-base substitution, deletion, and insertion mutations were excellent targets for correction by TDs. These results suggested that the TDs are useful for editing disease-causing genes with small mutations.

Methylmercury Decreases AMPA Receptor Subunit GluA2 Levels in Cultured Rat Cortical Neurons

Methylmercury (MeHg) is a well-known environmental pollutant that has harmful effects on the central nervous systems of humans and animals. The molecular mechanisms of MeHg-induced neurotoxicity at low concentrations are not fully understood. Here, we investigated the effects of low-concentration MeHg on the cell viability, Ca²⁺ homeostasis, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluA2 levels, which determine Ca²⁺ permeability of AMPA receptors, in rat primary cortical neurons. Exposure of cortical neurons to 100 and 300 nM MeHg for 7 d resulted in a decrease in GluA2 levels, an increase in basal intracellular Ca²⁺ concentration, increased phosphorylation levels of extracellular signal-regulated kinase (ERK)1/2 and p38, and decreased cell viability. Moreover, glutamate stimulation exacerbated the decrease in cell viability and increased intracellular Ca²⁺ levels in MeHg-treated neurons compared to control neurons. MeHg-induced neuronal cell death was ameliorated by 1-naphthyl acetyl spermine, a specific antagonist of Ca²⁺-permeable, GluA2-lacking AMPA receptors. Our findings raise the possibility that decreased neuronal GluA2 levels and the subsequent increase in intracellular Ca²⁺ concentration may contribute to MeHg-induced neurotoxicity.

Effects of antifouling compounds on the growth of macroalgae Undaria pinnatifida

Seaweeds are some of the principal primary producers of marine environments, and they are important ecological elements of coastal ecosystems. The effects of harmful chemicals on seaweeds may adversely affect coastal ecosystems, hence we aimed to develop a new phytotoxicity test using the gametophytes of a common temperate kelp species, Undaria pinnatifida (KU-1630), for the widely used antifouling chemical substances Cybutryne, Diuron, Cu2+, and Zn2+. Toxicity to gametophytes of U. pinnatifida was assessed by comparing the relative growth rate (RGR) at the logarithmic growth phase. Fragmentation method, initial algal biomass, photon irradiance, and adhesive period were investigated for developing optimal test conditions. Cybutryne exposure tests were performed with seven replicates and control, the RGR ranging from 0.17 to 0.19, while mean 7-day EC50 and no observed effect concentration (NOEC) were 5.1 μg/L and 1.8 μg/L, respectively. The 7-day EC50 for other antifoulants was 14 μg/L for Diuron, 17 μg/L for Cu2+, and 1500 μg/L for Zn2+. This test method demonstrated high sensitivity and reproducibility, and it may be added to the routine methods used for toxicity evaluation of hazardous chemicals.

Hypertension and diabetes mellitus are associated with high FIB-4 index in a health checkup examination cohort without known liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is usually asymptomatic and lacks a specific biomarker; therefore, many individuals might remain undiagnosed even with advanced liver fibrosis. The aim of this study was to clarify the prevalence and clinical features of subjects with a high risk of advanced liver fibrosis in the general population, using the Fibrosis-4 (FIB-4) index.

METHODS

We retrospectively investigated 6,087 subjects without known liver disease who had participated in an annual health checkup examination. We analyzed the factors associated with high FIB-4 index (≥ 2.67) using a logistic regression analysis.

RESULTS

Among the 6,087 subjects, 76 (1.2%) had high FIB-4 index. Multivariate analysis identified hypertension (odds ratio [OR]; 9.040; 95% confidence interval [CI], 4.081-20.024; P < 0.001) and diabetes mellitus (OR = 4.251; 95% CI, 1.773-10.193; P = 0.001) as important risk factors for high FIB-4 index. The rates of hypertension and diabetes mellitus in subjects with high FIB-4 index were 78.9% and 23.7%, respectively. No significant association was observed between obesity or large waist circumference and high FIB-4 index. A history of cardiovascular disease was significantly more common in subjects with high FIB-4 index. These results were also observed in subjects with normal liver function test.

CONCLUSIONS

The present study revealed that approximately 1% of the general Japanese population has a high risk of advanced liver fibrosis. Many of these patients had hypertension and/or diabetes mellitus. Our findings suggest that there are many undiagnosed patients NAFLD with risk of advanced liver fibrosis in the general population.

Development of a versatile high-throughput mutagenesis assay with multiplexed short read NGS using DNA-barcoded supF shuttle vector library amplified in non-SOS E. coli

A forward mutagenesis assay using the supF gene has been widely employed for the last several decades in studies addressing mutation frequencies and mutation spectra associated with various intrinsic and environmental mutagens. In this study, by using a supF shuttle vector and non-SOS-induced Escherichia coli with short-read next-generation sequencing (NGS) technology, we present an advanced method for the study of mutations, which is simple, versatile, and cost-effective. We demonstrate the performance of our newly developed assay via pilot experiments with ultraviolet (UV) irradiation, the results from which emerge more relevant than expected. The NGS data obtained from samples of the indicator E. coli grown on titer plates provides mutation frequency and spectrum data, and uncovers obscure mutations that cannot be detected by a conventional supF assay. Furthermore, a very small amount of NGS data from selection plates reveals the almost full spectrum of mutations in each specimen and offers us a novel insight into the mechanisms of mutagenesis, despite them being considered already well known. We believe that the method presented here will contribute to future opportunities for research on mutagenesis, DNA repair, and cancer.

ACE values in the diagnosis of sarcoidosis

Background

In clinical practice, we often encounter the patients with sarcoidosis showing relatively high in the normal range of serum angiotensin-converting enzyme (ACE) value.

Purpose

We aimed to examine the serum ACE value of the patients with sarcoidosis and determine the new cut-off value for detecting the patients with sarcoidosis.

Methods and results

We retrospectively examined all 3781 subjects (51.1% men, 60.1±17.0 y.o.) in whom ACE was measured for any reasons including suspected sarcoidosis between 2009 and 2020 in our hospital. Of 293 patients with sarcoidosis, 101, 212, 84, and 88 were diagnosed as sarcoidosis in heart, lung, skin, and eyes, respectively. After excluding 477 patients taking ACE inhibitor and/or immunosuppression agent or those with any diseases affecting serum ACE levels, we analyzed 3304 subjects including 215 with sarcoidosis. Serum ACEs were 19.6 IU/L [IQR, 15.1–31.5] in the subjects with sarcoidosis and 10.7 [8.4–16.5] in those without (P&lt;0.01). In ROC curve analysis of ACE for diagnosis of sarcoidosis, the cut-off point was 14.7 IU/L and the AUC was 0.865. When we used the current cut-off of 21.4 or new cut-off value of 14.7, sensitivity, specificity, PPV, NPV, and accuracy were shown in Table. Finally, they were divided into four groups based on the presence of cardiac and/or extra cardiac sarcoidosis, ACE values in Group A, B, C, and D were 17.9, 20.9, 18.6, and 10.7, respectively (Figure 1).

Conclusion(s)

In the current cut-off value of serum ACE, sensitivity for detecting sarcoidosis was comparatively low, though positive predictive value was low when the new-cut-off value was used in our study. Further examinations may be needed for the patients suspected sarcoidosis with relatively high ACE in the normal range.

Funding Acknowledgement

Type of funding sources: None.

ACTIVATION OF HUMAN FIBROBLASTS BY CHRONIC RADIATION RATHER THAN ACUTE RADIATION

Cancer-associated fibroblast (CAF), an activated type of fibroblast, is a major stromal cell that contributes to tumor initiation and development in the tumor microenvironment (TME). We previously reported that fractionated radiation rather than acute radiation causes progressive damage to mitochondria and increases the generation of reactive oxygen species, playing an important role in the fibroblast activation in normal tissue injury. Activated fibroblasts then become CAF by interacting with tumor cells, promoting tumor growth in vivo. We here examined the chronic radiation effect on fibroblast activation. Acute radiation (<2.5 Gy) did not increase alpha-Smooth muscle actin, a CAF marker expression in healthy human cells, whereas chronic radiation (2.5 Gy) did. It can be concluded that the induction of fibroblast activation changes across acute radiation, fractionated radiation, and chronic radiation depending on the irradiation technique. This study highlights that radiation activates fibroblasts, playing a role in radiation-related tumor development via TME formation.

RFWD3 and translesion DNA polymerases contribute to PCNA modification-dependent DNA damage tolerance

DNA damage tolerance pathways are regulated by proliferating cell nuclear antigen (PCNA) modifications at lysine 164. Translesion DNA synthesis by DNA polymerase η (Polη) is well studied, but less is known about Polη-independent mechanisms. Illudin S and its derivatives induce alkyl DNA adducts, which are repaired by transcription-coupled nucleotide excision repair (TC-NER). We demonstrate that in addition to TC-NER, PCNA modification at K164 plays an essential role in cellular resistance to these compounds by overcoming replication blockages, with no requirement for Polη. Polκ and RING finger and WD repeat domain 3 (RFWD3) contribute to tolerance, and are both dependent on PCNA modifications. Although RFWD3 is a FANC protein, we demonstrate that it plays a role in DNA damage tolerance independent of the FANC pathway. Finally, we demonstrate that RFWD3-mediated cellular survival after UV irradiation is dependent on PCNA modifications but is independent of Polη. Thus, RFWD3 contributes to PCNA modification-dependent DNA damage tolerance in addition to translesion DNA polymerases.

Correction of monomeric enhanced green fluorescent protein (mEGFP) gene by short 5'-tailed duplexes

Mutations of important genes elicit various disorders, including cancer. Recently, a new version of a 5'-tailed duplex (short TD), consisting of a ∼100-base editor strand containing the wild-type sequence and a ∼35-base assistant strand, was shown to correct a base substitution mutation in a target gene in human cells. In that previous study, the target was the copepod green fluorescent protein (copGFP) gene. To examine the usefulness of the short TD, we performed gene correction experiments using a mutant form of the monomeric enhanced Aequorea victoria green fluorescent protein (mEGFP) gene containing a TAC to CAC mutation in codon 75 (corresponding to the tyrosine to histidine substitution in the chromophore). The short TDs with the wild-type sequence efficiently corrected the inactivated gene in human U2OS cells. These results indicated that the short TDs are effective for gene editing.

Precise Measurement of Differential Cross Sections of the Σ^{-}p→Λn Reaction in Momentum Range 470-650 MeV/c

The differential cross sections of the Σ^{-}p→Λn reaction were measured accurately for the Σ^{-} momentum (p_{Σ}) ranging from 470 to 650  MeV/c at the J-PARC Hadron Experimental Facility. Precise angular information about the Σ^{-}p→Λn reaction was obtained for the first time by detecting approximately 100 reaction events at each angular step of Δcosθ=0.1. The obtained differential cross sections show a slightly forward-peaking structure in the measured momentum regions. The cross sections integrated for -0.7≤cosθ≤1.0 were obtained as 22.5±0.68 [statistical error(stat.)] ±0.65 [systematic error(syst.)] mb and 15.8±0.83(stat)±0.52(syst)  mb for 470<p_{Σ}(MeV/c)<550 and 550<p_{Σ}(MeV/c)<650, respectively. These results show a drastic improvement compared with past measurements of the hyperon-proton scattering experiments. They will play essential roles in updating the theoretical models of the baryon-baryon interactions.

DDX41 coordinates RNA splicing and transcriptional elongation to prevent DNA replication stress in hematopoietic cells

Myeloid malignancies with DDX41 mutations are often associated with bone marrow failure and cytopenia before overt disease manifestation. However, the mechanisms underlying these specific conditions remain elusive. Here, we demonstrate that loss of DDX41 function impairs efficient RNA splicing, resulting in DNA replication stress with excess R-loop formation. Mechanistically, DDX41 binds to the 5' splice site (5'SS) of coding RNA and coordinates RNA splicing and transcriptional elongation; loss of DDX41 prevents splicing-coupled transient pausing of RNA polymerase II at 5'SS, causing aberrant R-loop formation and transcription-replication collisions. Although the degree of DNA replication stress acquired in S phase is small, cells undergo mitosis with under-replicated DNA being remained, resulting in micronuclei formation and significant DNA damage, thus leading to impaired cell proliferation and genomic instability. These processes may be responsible for disease phenotypes associated with DDX41 mutations.

Recent progress and future prospects of hyperon nucleon scattering experiment

A new hyperon-proton scattering experiment, dubbed J-PARC E40, was performed to measure differential cross sections of the Σ+p, Σ−p elastic scatterings and the Σ−p → Λn scattering by identifying a lot of Σ particles in the momentum ranging from 0.4 to 0.8 GeV/c produced by the π±p → K+Σ± reactions. We successfully measured the differential cross sections of these three channels with a drastically improved accuracy with a fine angular step. These new data will become important experimental constraints to improve the theories of the two-body baryon-baryon interactions. Following this success, we proposed a new experiment to measure the differential cross sections and spin observables by using a highly polarized Λ beam for providing quantitative information on the ΛN interaction. The results of three Σp channels and future prospects of the Λp scattering experiment are described.

Gene correction by 5'-tailed duplexes with short editor oligodeoxyribonucleotides

Various diseases, including cancer, are caused by genetic mutations. A 5'-tailed duplex (TD) DNA, consisting of a long single-stranded (ss) editor DNA and a short (∼35-base) ss assistant oligodeoxyribonucleotide, can introduce a base-substitution in living cells and thus correct mutated genes. Previously, several hundred-base DNAs were employed as the editor DNAs. In this study, 5'-TDs were prepared from various editor DNAs with different lengths and examined for their gene correction abilities, using plasmid DNA bearing a mutated copepod green fluorescent protein (copGFP) gene, in human cells. High-throughput analysis was performed by the reactivated fluorescence of the wild-type protein encoded by the corrected gene as the indicator. The analysis revealed that 5'-TDs with ∼100-base ss editor DNAs enabled gene editing at least as efficiently as those with longer editor DNAs. Moreover, the antisense strand was more effective as the editor than the sense strand, in contrast to the 5'-TDs with longer editor strands. These results indicated that the 5'-TD fragments with shorter editor strands than those used in previous studies are useful nucleic acids for gene correction.

Conduction gaps after pulmonary vein isolation due to high contact force ablation in patients with atrial fibrillation

Background

Catheter ablation for atrial fibrillation (AF) with high contact force (CF) has been reported to lead to the gaps after pulmonary vein isolation (PVI), and the appearance of the gaps depends on the site in the left atrium (LA).

Purpose

The aim of this study is to clarify the relationship between the gaps appearance and high CF.

Methods

In the clinical study, 74 consecutive patients (39 males, age 71±9, 46 with paroxysmal AF) underwent conventional PVI with a point-by-point radiofrequency (RF) ablation using a CF sensing catheter (TactiCath SETM). RF energy (J), number of RF point, Lesion index (LSI), force-time integral (FTI), average CF (g), and the degree of LA depression with high CF were evaluated. In the experimental study (figure), the relationship between the ablation area and the degree of depression with high CF using bovine left ventricular wall.

Results

In the clinical study, the gaps were found in 175 of 1182 sites after first path PVI ablation. The CF in the gap sites was higher than without the gap sites in RPV roof, anterior RSPV and anterior RPV carina (18.9±6.8 vs 15.0±5.7g p=0.0262, 26.4±11.6 vs 19.5±6.0g p=0.0029, 22.7±6.4 vs 19.1±5.5g, p=0.0161). Meanwhile, there were no differences in RF energy, number of RF point, LSI, FTI. High CF (≥30g) showed a depression of 3 mm or more in only RPV roof and anterior RPV (figure). In the experimental study, the ablation range narrowed as the indentation deepened with more than 30g CF (r=0.6417, p=0.0625).

Conclusion

Catheter ablation for AF with high contact force might lead to the gaps in RPV roof and anterior RPV site by the reduction of the ablation area due to depression caused by the pressure.

Extension of each contact force

Funding Acknowledgement

Type of funding source: None

Clinical retrospective study of dental implant removal: do patients who require implant removal desire implant prosthesis again?

Background

This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments.

Material and Methods

A retrospective case–control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prostheses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal.

Results

A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%). Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal.

Conclusions

Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications.

Key words:Dental implant removal, complications, implant prosthesis, retrospective study, re-implantation.

Prospective validation of 0-hour/1-hour algorithm using high-sensitivity cardiac troponin I in Japanese patients presenting to emergency department

Background

The diagnostic performance of 0-hour/1-hour algorithm using high-sensitivity cardiac troponin I (hsTnI) for non-ST-segment elevation myocardial infarction (NSTEMI) has not been evaluated in an Asian population.

Purpose

We aimed to prospectively validate the 0-hour/1-hour algorithm using hsTnI in a Japanese population.

Method

We enrolled 754 Japanese patients (mean age of 70 years, 395 men) presenting to our emergency department with symptoms suggestive of NSTEMI. The hsTnI concentration was measured using the Siemens ADVIA Centaur hsTnI assay at presentation and after 1 hour. Patients were divided into three groups according to the algorithm: hsTnI below 3 ng/L (only applicable if chest pain onset &gt;3 hours) or below 6 ng/L and delta 1 hour below 3 ng/L were the “rule-out” group; hsTnI at least 120 ng/L or delta 1 hour at least 12 ng/L were in the “rule-in” group; the remaining patients were classified as the “observe” group. Based on the Fourth Universal Definition of Myocardial Infarction, the final diagnosis was adjudicated by 2 independent cardiologists using all available information, including coronary angiography, coronary computed tomography, and follow-up data. Safety of rule-out was quantified by the negative predictive value (NPV) for NSTEMI, accuracy of rule-in by the positive predictive value (PPV), and overall efficacy by the proportion of patients triaged towards rule-out or rule-in within 1 hour.

Results

Prevalence of NSTEMI was 6.5%. The safety of rule-out (NPV 100%), accuracy of rule-in (PPV 26%), and overall efficacy (54%) were shown in Figure.

Conclusion

The 0-hour/1-hour algorithm using hsTnI is very safe and effective in triaging Japanese patients with suspected NSTEMI.

Funding Acknowledgement

Type of funding source: None

Five-year major adverse cardiac and cerebrovascular events of patients with lipid core abutting lumen (LCAL) on integrated-backscatter intravascular ultrasound undergoing PCI with current DES

Background

Percutaneous Coronary Intervention (PCI) using the new generation drug-eluting stent (DES) has been extremely reduced target lesion revascularization (TLR) in recent years. However, a high incidence of non-target lesion-related cardiovascular events in patients undergoing PCI is an important problem to be solved. According to the previous findings, patients with vulnerable plaques particularly have a high recurrence of cardiovascular events. Little studies, however, has been done to examine the relationship between plaque characteristics on intravascular imaging in a target lesion and non-target lesion-related cardiovascular events.

Purpose

The main objective of this study is to investigate the five-year major adverse cardiac and cerebrovascular events (MACCE) of patients with lipid core abutting lumen (LCAL) on integrated backscatter intravascular ultrasound (IB-IVUS) in a target lesion undergoing PCI with current DES.

Methods and results

Between February 2010 and September 2013, in total 780 patients with ischemic heart disease undergoing PCI, 166 target lesions in 166 consecutive patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS) and stable angina pectoris (SAP) undergoing IVUS-guided PCI were studied.

Plaque characteristics in all target lesions were analyzed by three-dimensional IB-IVUS system using the mechanical IVUS catheter. Our previous study has found that LCAL which is defined as a lipid pool directly in contact with the lumen visualizes the thin fibrous cap of less than 75μm on optical coherence tomography (OCT). On the basis of this data, LCAL at minimal lumen area (MLA) site was identified.

In total, 39 patients had lesions with LCAL at MLA site (LCAL(+)), and 127 patients had those without LCAL (LCAL(−)).

The primary endpoint was defined as MACCE, including cardiovascular death, non-fatal myocardial infarction, non-fatal stroke and non-TLR for the new lesion during a median follow up of five years. The MACCE occurred significantly higher in the LCAL(+) than in the LCAL(−) (38.5% vs. 17.3%; p&lt;0.005). And the Kaplan-Meier estimates have shown that the cumulative incidence of MACCE was significantly higher in the LCAL(+) than in the LCAL(−) (log rank test, p=0.041). Additionally, after adjustment for confounders, gender, prior PCI and LCAL was the independent predictors for the MACCE of patients undergoing PCI with current DES.

Furthermore, after adding LCAL to a baseline model with established factors consisting of age, gender, diabetes mellitus, prior PCI and percentage lipid volume on IB-IVUS, the net reclassification (p&lt;0.002) and integrated discrimination improvement (p&lt;0.004) significantly improved compared to baseline model alone.

Conclusions

In this study, it has become clear that LCAL on IB-IVUS is likely to be a surrogate marker of MACCE in patients undergoing PCI with current DES.

Funding Acknowledgement

Type of funding source: None

Circulating presepsin (soluble CD14 subtype) as a novel marker of mortality in patients treated at medical cardiac intensive care units

Background

Presepsin, a subtype of soluble CD14, is an inflammatory marker, which largely reflects monocyte activation. The association between presepsin levels and mortality in patients treated at medical cardiac intensive care units (CICUs) remains poorly known.

Objective

We aimed to understand the prognostic value of presepsin levels on admission to medical CICUs for mortality.

Methods

We prospectively studied 1636 heterogeneous patients (median age; 71 years) treated at medical (non-surgical) CICUs. Patients with stage 5 chronic kidney disease (estimated glomerular filtration rate [eGFR] &lt;15 mL/min/1.73 m2) were excluded. Acute coronary syndrome was present in 46% of the patients, and acute decompensated heart failure in 36%. Upon admission, baseline plasma presepsin levels were measured. The primary endpoint was all-cause death.

Results

During a mean follow-up period of 44.6 months after admission, there were 323 (19.7%) deaths. Patients who died were older (median: 75 vs. 71 years, P&lt;0.0001); had higher levels of presepsin (194 vs. 110 pg/mL, P&lt;0.0001), B-type natriuretic peptide (BNP: 520 vs. 144 pg/mL, P&lt;0.0001), high-sensitivity C-reactive protein (hsCRP: 4.7 vs. 2.0 mg/L, P&lt;0.0001), and sequential organ failure assessment (SOFA) score (3 vs. 2, P&lt;0.0001); and had lower levels of eGFR (55 vs. 69 mL/min/1.73m2, P&lt;0.0001) and left ventricular ejection fraction (46% vs. 52%, P&lt;0.0001) than those of the survivors. Multivariate Cox regression analyses revealed presepsin levels as independent predictors of all-cause deaths when assessed as either continuous variables (relative risk [RR] 3.33 per 10-fold increment; P&lt;0.0001) or variables categorized according to quartiles (RR quartile 4 vs. 1, 3.60; P&lt;0.0001). Quartiles of presepsin levels were significantly (P&lt;0.0001) associated with increased risk of mortality (Figure). Adding presepsin levels to a baseline model that included established risk factors, BNP, and hsCRP further enhanced reclassification (P=0.009) and discrimination (P=0.0008) beyond that of the baseline model alone.

Conclusions

Circulating concentration of presepsin on admission may be a potent and independent predictor of mortality, and it may improve the risk stratification of patients admitted at medical CICUs.

Presepsin quartiles and mortality

Funding Acknowledgement

Type of funding source: None

APC/CCdh1 is required for the termination of chromosomal passenger complex activity upon mitotic exit

During mitosis, the chromosomal passenger complex (CPC) ensures the faithful transmission of the genome. The CPC is composed of the enzymatic component Aurora B (AURKB) and the three regulatory and targeting components borealin, INCENP, and survivin (also known as BIRC5). Although the CPC is known to be involved in diverse mitotic events, it is still unclear how CPC function terminates after mitosis. Here we show that borealin is ubiquitylated by the anaphase promoting complex/cyclosome (APC/C) and its cofactor Cdh1 (also known as FZR1) and is subsequently degraded in G1 phase. Cdh1 binds to regions within the N terminus of borealin that act as a non-canonical degron. Aurora B has also been shown previously to be degraded by the APC/C^Cdh1 from late mitosis to G1. Indeed, Cdh1 depletion sustains an Aurora B activity with stable levels of borealin and Aurora B throughout the cell cycle, and causes reduced efficiency of DNA replication after release from serum starvation. Notably, inhibition of Aurora B kinase activity improves the efficiency of DNA replication in Cdh1-depleted cells. We thus propose that APC/C^Cdh1 terminates CPC activity upon mitotic exit and thereby contributes to proper control of DNA replication.

Summary: APC/C^Cdh1 ubiquitylates both borealin, via a non-canonical degron motif, and Aurora B to terminate activity of the CPC in G1 phase. Disruption of this ubiquitylation reduces the efficiency of DNA replication.

Single-stranded DNA versus tailed duplex in sequence conversion of lacZα DNA

Targeted DNA editing has great potential to cure some genetic diseases; however, the use of artificial nucleases such as CRISPR-Cas9 and TALEN in gene therapy can potentially cause severe side effects due to off-target DNA cleavages. Single-stranded (ss) DNAs and 5'-tailed duplexes (TDs) can achieve target base substitutions when introduced without artificial nucleases into cultured cells and mouse liver. In this study, ss DNA and TD were separately co-introduced into human U2OS cells, together with a target plasmid DNA bearing an inactivated lacZα gene, and the gene correction efficiencies were compared. Unlike the genes examined in previous studies, ss DNA and TD showed similar efficiencies. Therefore, ss DNAs might be as useful as TD for gene correction, depending on the target sequence.

P7 The impact of coronary calcification on diagnostic performance of workstation CT derived fractional flow reserve - a multicentre experience

Background

On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess the vessel specific ischaemia in coronary artery disease (CAD). The impact of coronary calcification on its diagnostic performance is unknown.

Purpose

To evaluate the impact of coronary calcification on the diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia.

Methods

This is a retrospective pooled analysis of 141 patients with suspected CAD enrolled from 3 global centres who underwent CT-coronary angiography (CTA), onsite CT-FFR and invasive FFR.  Coronary calcification was assessed by Agatston score (AS). The diagnostic performance of CT-FFR (≤0.8) and CTA (≥50%) in evaluation of vessel specific ischaemia (FFR ≤ 0.8) was assessed across AS quartiles (Q1-4). A comparison of diagnostic performance of the low to mid AS (Q1 to Q3) versus high AS (Q4) was performed.

Results

Mean age and median AS was 65.8 ± 9.9 and 327.3 (interquartile range = 78.5 – 798.1). Diagnostic accuracy, sensitivity and specificity of CT-FFR for low-mid AS (0-798) and high AS (799-4019) were 77.4% vs 82.9%; 78.9% vs 94.7%; 68.8% vs 76.5% respectively with no statistical difference between the two groups.  The AUC for ischaemia of CT-FFR in low to mid AS was comparable with AUC in the high AS (0.76 [95% CI: 0.66-0.86] vs 0.84 [0.69-0.99]; P = 0.397).  The AUC for ischemia for CT-FFR in both low to mid AS and high AS was significantly higher than for CTA (0.76 [0.66-0.86] vs 0.57 [0.50-0.64]; P = 0.003 and 0.84 [0.69-0.99] vs 0.48 [0.38-0.57]; P &lt; 0.001 respectively).

Conclusion

On-site workstation CT-FFR demonstrated consistently high diagnostic performance in patients with high AS. Its diagnostic performance was superior when compared with significant stenosis assessment on CTA across all spectrum of Agatston scores.

P6178The optimal point of CT-FFR measurement in comparison with invasive FFR

Background

Currently, invasive fractional flow reserve (FFR), has become a gold standard to select patients requiring revascularization. Coronary computed tomography angiography (CTA) -derived FFR (FFRCT/CT-FFR) can be used for the management of coronary artery disease, which would be a gatekeeper of invasive coronary angiography. In most of the previous report to evaluate the diagnostic performance of FFRCT/CT-FFR, FFRCT/CT-FFR value was measured at the same point as the invasive FFR. Clinically, FFRCT/CT-FFR should be measured without the information of invasive FFR. However, optimal measurement point for CT-FFR has not been established yet.

Purpose

To assess the optimal measurement point of CT-FFR in comparison with invasive FFR as a gold standard.

Methods

CTA images scanned at 70–99% of R-R interval with 320 slice CT were screened. In the de-novo lesions with invasive FFR data were included in this study. Since calcified lesions could affect CT-FFR value, severe calcified lesions on CTA were excluded from the analysis. The CT-FFR analysis was performed by 2 cardiologists blinded to the results of the invasive FFR using a standard desktop computer and dedicated software. CT-FFR values could be provided at any point from ostium of coronary artery to the distal with vessel diameter of 1.8mm. To determine the optimal point for measurement of CT-FFR, CT-FFR values were obtained at 3 points in each coronary artery; 1) at the same point as invasive FFR; 2) lowest CT-FFR at distal point of coronary artery; 3) at 2.0 cm distal to the lesion. The diagnostic performance at each point was compared with invasive FFR.

Results

Fifty vessels of 44 patients (average age 68 years, male were 32) were included. Average Agatston score was 279.4. There was significant correlation between CT-FFR at each point and invasive FFR. CT-FFR at the same point as invasive FFR showed the good correlation with invasive FFR (R=0.641, 95% CI= 0.041–0.127, p<0.0001). Compared to the lowest CT-FFR at distal (R=0.608, 95% CI= 0.069–0.160, p<0.0001), CT-FFR at 2.0 cm distal to the lesion (R=0.604, 95% CI= 0.007–0.061, p<0.0001) revealed better correlation with invasive FFR. Sensitivity, specificity, positive and negative predictive value at each point were 92.8 / 93.3 / 81.8; 75.0 / 57.1 / 94.2; 61.9 / 48.2 / 60.0; and 96.0 / 95.2 / 84.6, respectively. Diagnostic accuracy showed that CT-FFR at 2cm distal to the lesion (0.84) was similar to CT-FFR at the same point as invasive FFR (0.80), and it was better than far distal (0.68) to detect invasive FFR derived ischemia.

Conclusions

CT-FFR was feasible to detect invasive FFR derived ischemia at the same point.

CT-FFR at 2.0 cm distal to the lesion showed higher diagnostic performance compared with CT-FFR measured at the far distal. CT-FFR measurement at 2.0 cm distal to the lesion would be a optimal position clinically.

P6187Multicentre diagnostic performance of on-site workstation CT derived fractional flow reserve

Background

On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess vessel specific ischaemia in coronary artery disease (CAD). Global data on its diagnostic performance when compared with CT coronary angiography (CTA) is limited.

Purpose

To evaluate the on-site multicentre diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia.

Method

This is a retrospective pooled analysis of 141 patients (204 vessels) with suspected CAD enrolled from 3 global centres who underwent CTA, onsite CT-FFR and invasive FFR. On-site CT-FFR was performed using a reduced order model on a standard desktop computer with dedicated software. The per vessel diagnostic performance of CT-FFR (≤0.8) for vessel specific ischemia (FFR≤0.8) was compared with CTA (≥50% stenosis).

Results

Mean age was 65.8±9.9, 70.7% were male. FFR significant stenosis was present in 34.3% (70/204) of vessels. Pearson correlation of CT-FFR for invasive FFR was 0.52, P<0.001. Bland Altman analysis demonstrated a mean difference of 0.06±0.15 (95% limits of agreement −0.22 to 0.35). Per vessel diagnostic accuracy, sensitivity and specificity of CT-FFR and CTA were 79.9% vs 53.5%; 78.6% vs 85.7%; 80.6% vs 35.9% respectively. Diagnostic performance as assessed by area under the receiver operator curve (AUC) for CT FFR was superior to CTA (0.82 [95% CI 0.76–0.88] vs 0.61 [0.55–0.67]; P<0.001).

Conclusion

On-site workstation CT-FFR demonstrated high per vessel diagnostic performance and was superior when compared with CTA in assessment of vessel specific ischaemia as assessed by invasive FFR in a multicentre setting.

P6171Role of myocardial mass for identifying FFR-verified ischemia and determining therapeutic strategy

Background

Conventional noninvasive approach using coronary CT angiography (CTA) focusing on only coronary artery lesions remains mismatch in identifying functional ischemia and determining indication for coronary revascularization.

Purpose

We aimed to assess the usefulness of CT-verified myocardial mass for identifying FFR-verified myocardial ischemia and determining the indication of coronary revascularization after FFR examination.

Methods

We examined 244 vessels with intermediate stenoses (50 to 90% stenosis visually on CTA) in 216 patients (mean age 69.2±9.2, 166 men) who underwent both coronary CTA and invasive FFR. In addition to coronary stenosis severity and plaque characteristics on visual, minimal lumen diameter (MLD), minimal lumen area (MLA), plaque volume, the entire myocardial volume of the target vessel (MTV) and that exposed to ischemia (FFR ≤0.80) (myocardial volume of ischemia: MVI) were evaluated. Additionally, therapeutic strategy after FFR was recorded.

Results

Of 244 vessels, myocardial ischemia (FFR ≤0.80) was shown in 99 (40.6%). MTV was larger in the patients with FFR-verified ischemia than those without (53.3±19.2 vs. 41.5±21.6, P<0.001); MLA, plaque burden (PB) and percentage of aggregated plaque volume (%APV) were also associated with ischemia. The area under the curves (AUCs) of MLA, PB, %APV, and MTV were 0.69, 0.67, 0.64, and 0.71, respectively. Addition of MTV to a model with coronary stenosis on visual, MLA, PB, and %APV improved C-index (from 0.72 to 0.79, P<0.01), net reclassification improvement (NRI) (0.71, P<0.01), and integrated discrimination improvement (IDI) (0.10, P<0.01). Of 99 vessels with FFR ≤0.80, MVI was larger in the vessels with early revascularization after FFR than those without (38.8 vs. 29.1, P=0.01).

Conclusions

The measurement of myocardial mass improves the diagnostic performance of coronary CTA for the identification of coronary arteries with FFR-verified ischemia. Furthermore, it is associated with therapeutic strategy for the diseased vessels after FFR examination.

P2240CTA derived plaque characteristics and cardiac events in deferred lesions by invasive FFR

Background

Fractional flow reserve (FFR) based strategy for coronary artery disease (CAD) is widely accepted. However, cardiac events could occur at deferred lesions after FFR. We previous reported that CT derived high risk plaque (HRP) and residual stenosis were the independent predictors of cardiac events.

Purpose

The purpose of this study was to investigate if plaque characteristics on CTA could predict cardiac events in deferred lesions after FFR.

Methods

We included 211 vessels of 193 patients who were deferred revascularization after CTA and invasive FFR. The presence of HRP and the stenosis grading on CTA were analyzed.

Results

Median follow-up period after CTA was 623 days (IQR 302–945). HRP and obstructive stenosis were detected in 58 (27.5%) and 87 (41.2%) lesions, respectively. Cardiac events were occurred in 10 lesions at 440±167 days in average (range: 150–770 days). Multivaliate cox hazard regression analysis revealed that HRP (HR8.01, p=0.0032) and obstructive stenosis with ≥70% (HR 34.93, p<0.0001) were the independent predictors of cardiac events after adjusted for age, sex, and FFR≤0.8. Of 21 lesions with both HRP and obstructive stenosis, 29% lesions resulted in cardiac events in 2 years.

Conclusions

Even in the deferred lesions by invasive FFR, lesions with HRP and obstructive stenosis showed high rate of cardiac events. These lesions should be treated with intensive medical therapy to prevent cardiac events.

P1806Diagnosis of isolated cardiac sarcoidosis using FDG-PET/CT on the basis of new guidelines

Introduction

Sarcoidosis is a systemic inflammatory disease which can involve any organs. The reported prevalence of isolated cardiac sarcoidosis (CS) varies widely because of the lack of an agreed definition of isolated CS (iCS). ICS was newly defined in the new guidelines for CS by Japanese Circulation Society.

Purpose

We aimed to examine the diagnostic accuracy of 18F-FDG PET/CT and the ratio of iCS in the whole CS by reviewing the patients with suspected CS undergoing the whole-body and cardiac FDG PET/CT scans.

Methods

We retrospectively reviewed 74 consecutive patients undergoing 18F-FDG PET/CT from 2013 to 2018 (mean age 60±14 years, 37 male) without the initiation of corticosteroid. Myocardial FDG uptake in CS was defined as a “focal” or “focal on diffuse” pattern. Systemic sarcoidosis (sCS) and iCS were diagnosed according to guidelines for the diagnosis and treatment of CS by Japanese Circulation Society. In short, iCS was diagnosed clinically when no clinical findings of sarcoidosis in any other organs and FDG uptake in heart were shown in addition to the following three of four criteria: high-grade atrioventricular block or fatal ventricular arrhythmia, structural abnormality, left ventricular contractile dysfunction, and delayed Gadolinium enhancement of myocardium on MRI.

Results

Of 31 patients with extra-cardiac sarcoidosis, 10 already met the diagnostic criteria of sCS before undergoing 18F-FDG PET/CT and 11 was newly diagnosed as sCS after FDG PET/CT. Of the remaining 43 without extra-cardiac sarcoidosis, 18 had FDG uptake in heart. Of 18 with FDG uptake in heart, iCS was diagnosed in 7, and sCS in 3 with extra-cardiac uptake of FDG as well as myocardium. Finally, 24 and 7 patients met the criteria of sCS and iCS based on the guideline, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG PET/CT for CS including sCS and iCS were 90, 87, 88, 85, and 92%, respectively.

Conclusion

The ratio of iCS on the basis of new guidelines for diagnosis and treatment of CS was 22% of the whole CS.

P4620Circulating concentration of presepsin improves early prediction of short-term mortality in patients treated at medical cardiac intensive care units

Background

Presepsin, a subtype of soluble CD14, is an inflammatory marker, which largely reflects monocytic activation. Presepsin appears to be an accurate diagnostic marker of sepsis, but its clinical significance remains unclear in cardiovascular disease.

Purpose

This prospective study aimed to investigate the predictive value of plasma presepsin levels on admission to medical (non-surgical) cardiac intensive care units (MCICUs) for short-term mortality.

Methods

We examined 1560 patients hospitalized in MCICUs and measured the baseline plasma presepsin levels at admission.

Results

Acute coronary syndrome was present in 46% of the patients, and acute decompensated heart failure in 36%. Before MCICUs admission, emergent coronary angiography or percutaneous coronary intervention was performed in 36%, mechanical ventilation was required for respiratory insufficiency in 2.1%, and intraaortic balloon pumps were needed for hemodynamic instability in 8.9%. During 6 months after admission, there were 113 (7.2%) deaths. Patients who died were older (median: 77 vs. 71 years, P<0.0001); had higher levels of presepsin (263 vs. 119 pg/mL, P<0.0001), B-type natriuretic peptide (BNP: 696 vs. 186 pg/mL, P<0.0001), high-sensitivity troponin T (hsTnT: 81 vs. 47 pg/mL, P=0.004), and high-sensitivity C-reactive protein (13.8 vs. 2.2 mg/L, P<0.0001); and had lower levels of estimated glomerular filtration rate (50 vs. 65 mL/min/1.73m2, P<0.0001) and left ventricular ejection fraction (43% vs. 51%, P<0.0001) than those of the survivors. In the multivariate Cox regression analysis, higher levels of presepsin (P=0.0002), BNP (P=0.04), and hsTnT (P=0.009) were all independent predictors of 6-month deaths. Quartiles of presepsin levels were associated with higher mortality rates within 6 months after admission (Table). Adding presepsin levels to a baseline model that included established risk factors, BNP, and hsTnT further enhanced reclassification (P=0.004) and discrimination (P=0.003) beyond that of the baseline model.

Mortality rates according to presepsin Presepsin quartile 1st 2nd 3rd 4th P value ≤80 pg/mL 81–124 pg/mL 125–232 pg/mL >232 pg/mL 1-month mortality 0.8% 2.0% 3.3% 8.0% <0.0001 6-month mortality 0.8% 3.8% 8.2% 16.3% <0.0001

Conclusions

Presepsin levels at admission could improve the prediction of short-term mortality in patients hospitalized at MCICUs.

Stepwise multipolyubiquitination of p53 by the E6AP-E6 ubiquitin ligase complex

The human papillomavirus (HPV) oncoprotein E6 specifically binds to E6AP (E6-associated protein), a HECT (homologous to the E6AP C terminus)-type ubiquitin ligase, and directs its ligase activity toward the tumor suppressor p53. To examine the biochemical reaction in vitro, we established an efficient reconstitution system for the polyubiquitination of p53 by the E6AP-E6 complex. We demonstrate that E6AP-E6 formed a stable ternary complex with p53, which underwent extensive polyubiquitination when the isolated ternary complex was incubated with E1, E2, and ubiquitin. Mass spectrometry and biochemical analysis of the reaction products identified lysine residues as p53 ubiquitination sites. A p53 mutant with arginine substitutions of its 18 lysine residues was not ubiquitinated. Analysis of additional p53 mutants retaining only one or two intact ubiquitination sites revealed that chain elongation at each of these sites was limited to 5-6-mers. We also determined the size distribution of ubiquitin chains released by en bloc cleavage from polyubiquitinated p53 to be 2-6-mers. Taken together, these results strongly suggest that p53 is multipolyubiquitinated with short chains by E6AP-E6. In addition, analysis of growing chains provided strong evidence for step-by-step chain elongation. Thus, we hypothesize that p53 is polyubiquitinated in a stepwise manner through the back-and-forth movement of the C-lobe, and the permissive distance for the movement of the C-lobe restricts the length of the chains in the E6AP-E6-p53 ternary complex. Finally, we show that multipolyubiquitination at different sites provides a signal for proteasomal degradation.

Replication stress induces accumulation of FANCD2 at central region of large fragile genes

During mild replication stress provoked by low dose aphidicolin (APH) treatment, the key Fanconi anemia protein FANCD2 accumulates on common fragile sites, observed as sister foci, and protects genome stability. To gain further insights into FANCD2 function and its regulatory mechanisms, we examined the genome-wide chromatin localization of FANCD2 in this setting by ChIP-seq analysis. We found that FANCD2 mostly accumulates in the central regions of a set of large transcribed genes that were extensively overlapped with known CFS. Consistent with previous studies, we found that this FANCD2 retention is R-loop-dependent. However, FANCD2 monoubiquitination and RPA foci formation were still induced in cells depleted of R-loops. Interestingly, we detected increased Proximal Ligation Assay dots between FANCD2 and R-loops following APH treatment, which was suppressed by transcriptional inhibition. Collectively, our data suggested that R-loops are required to retain FANCD2 in chromatin at the middle intronic region of large genes, while the replication stress-induced upstream events leading to the FA pathway activation are not triggered by R-loops.

Spironolactone-induced XPB degradation depends on CDK7 kinase and SCFFBXL18 E3 ligase

The multisubunit complex transcription factor IIH (TFIIH) has dual functions in transcriptional initiation and nucleotide excision repair (NER). TFIIH is comprised of two subcomplexes, the core subcomplex (seven subunits) including XPB and XPD helicases and the cyclin-dependent kinase (CDK)-activating kinase (CAK) subcomplex (three subunits) containing CDK7 kinase. Recently, it has been reported that spironolactone, an anti-aldosterone drug, inhibits cellular NER by inducing proteasomal degradation of XPB and potentiates the cytotoxicity of platinum-based drugs in cancer cells, suggesting possible drug repositioning. In this study, we have tried to uncover the mechanism underlying the chemical-induced XPB destabilization. Based on siRNA library screening and subsequent analyses, we identified SCF^FBXL18 E3 ligase consisting of Skp1, Cul1, F-box protein FBXL18 and Rbx1 responsible for spironolactone-induced XPB polyubiquitination and degradation. In addition, we showed that CDK7 kinase activity is required for this process. Finally, we found that the Ser90 residue of XPB is essential for the chemical-induced destabilization. These results led us to propose a model that spironolactone may trigger the phosphorylation of XPB at Ser90 by CDK7, which promotes the recognition and polyubiquitination of XPB by SCF^FBXL18 for proteasomal degradation.

Preferential digestion of PCNA-ubiquitin and p53-ubiquitin linkages by USP7 to remove polyubiquitin chains from substrates

Ubiquitin-specific protease 7 (USP7) regulates various cellular pathways through its deubiquitination activity. Despite the identification of a growing number of substrates of USP7, the molecular mechanism by which USP7 removes ubiquitin chains from polyubiquitinated substrates remains unexplored. The present study investigated the mechanism underlying the deubiquitination of Lys⁶³-linked polyubiquitinated proliferating cell nuclear antigen (PCNA). Biochemical analyses demonstrated that USP7 efficiently removes polyubiquitin chains from polyubiquitinated PCNA by preferential cleavage of the PCNA-ubiquitin linkage. This property was largely attributed to the poor activity toward Lys⁶³-linked ubiquitin chains. The preferential cleavage of substrate-ubiquitin linkages was also observed for Lys⁴⁸-linked polyubiquitinated p53 because of the inefficient cleavage of the Lys⁴⁸-linked ubiquitin chains. The present findings suggest a mechanism underlying the removal of polyubiquitin signals by USP7.

Longitudinal Findings of MRI and PET in West Syndrome with Subtle Focal Cortical Dysplasia

BACKGROUND AND PURPOSE

Despite the development of neuroimaging, identification of focal cortical dysplasia remains challenging. The purpose of this study was to show the longitudinal changes of MR imaging and FDG-PET in patients with West syndrome and subtle focal cortical dysplasia.

MATERIALS AND METHODS

Among 52 consecutive patients with West syndrome, 4 were diagnosed with subtle focal cortical dysplasia on 3T MR imaging. MR imaging and PET findings were evaluated longitudinally at onset and at 12 and 24 months of age.

RESULTS

At the onset of West syndrome, MR imaging demonstrated focal signal abnormalities of the subcortical white matter in 2 patients. In the other 2 patients, focal subcortical high-intensity signals became visible on follow-up T2WI as myelination progressed. PET at onset showed focal cortical hypometabolism in 3 patients, with 1 of these patients also having focal hypermetabolism and 1 having normal findings. On PET at 24 months, hypometabolism persisted in 2 patients and disappeared in 1, and hypermetabolism disappeared in 1. In 1 patient with normal MR imaging and PET findings at onset, focal hyperintensity and hypometabolism first appeared at 24 months of age. The findings on MR imaging and PET in these patients evolved differently with brain maturation and the clinical course.

CONCLUSIONS

Subtle focal cortical dysplasia can be undetectable on MR imaging at the onset of West syndrome and is not always accompanied by hypometabolism or hypermetabolism on PET. Longitudinal MR imaging and PET studies may be useful for detecting such lesions. Even in West syndrome with a congenital structural abnormality, PET findings evolve differently with brain maturation and the clinical condition.

Radiation-Induced Myofibroblasts Promote Tumor Growth via Mitochondrial ROS-Activated TGFβ Signaling

Fibroblasts are a key stromal cell in the tumor microenvironment (TME) and promote tumor growth via release of various growth factors. Stromal fibroblasts in cancer, called cancer-associated fibroblasts (CAF), are related to myofibroblasts, an activated form of fibroblast. While investigating the role of stroma fibroblasts on radiation-related carcinogenesis, it was observed following long-term fractionated radiation (FR) that the morphology of human diploid fibroblasts changed from smaller spindle shapes to larger flat shapes. These cells expressed smooth muscle actin (α-SMA) and platelet-derived growth factor receptors, markers of myofibroblasts and CAFs, respectively. Long-term FR induces progressive damage to the fibroblast nucleus and mitochondria via increases in mitochondrial reactive oxygen species (ROS) levels. Here, it is demonstrated that long-term FR-induced α-SMA-positive cells have decreased mitochondrial membrane potential and activated oxidative stress responses. Antioxidant N-acetyl cysteine suppressed radiation-induced mitochondrial damage and generation of myofibroblasts. These results indicate that mitochondrial ROS are associated with the acquisition of myofibroblasts after long-term FR. Mechanistically, mitochondrial ROS activated TGFβ signaling which in turn mediated the expression of α-SMA in radiation-induced myofibroblasts. Finally, in vivo tumor growth analysis in a human tumor xenograft model system revealed that long-term FR-induced myofibroblasts promote tumor growth by enhancing angiogenesis.Implications: Radiation affects malignant cancer cells directly and indirectly via molecular alterations in stromal fibroblasts such as activation of TGFβ and angiogenic signaling pathways. Mol Cancer Res; 16(11); 1676-86. ©2018 AACR.

Factors related to dissociation between objective and subjective masticatory function in Japanese community-dwelling elderly adults

Clinicians' evaluations of older adults sometimes reveal inconsistencies between objective and subjective dental status. This study investigated which factors contribute both to good objective masticatory function (OMF) and the poor subjective masticatory function (SMF) that often becomes a clinical issue. Study participants included 635 elderly community-dwelling Japanese adults who underwent a comprehensive geriatric health examination in 2012. SMF was assessed with a question from the Kihon Checklist on eating difficulties (poor or good). OMF was assessed by a colour-changing gum (poor or good). Also investigated were age, sex, depressive symptoms, instrumental activities of daily living (I-ADLs), number of people who joined the participant at dinner, grip strength, usual walking speed, number of remaining teeth, number of functional teeth and their occlusal force. The group with good OMF and good SMF, defined as group 1, and the group with good OMF but poor SMF, group 2, were compared. Logistic regression analyses confirmed that the number of remaining and functional teeth participants had was statistically unrelated to differences between OMF and SMF. Instead, differences were related to stronger depressive symptoms (OR = 1.67, CI = 1.14-2.44), less ability to conduct I-ADL activities (OR = 0.73, CI = 0.59-0.91), slower usual walking speeds (OR = 0.18, CI = 0.06-0.58) and less occlusal force (OR = 0.99, CI = 0.99-1.00). Depressive symptoms, I-ADLs, and physical function are shown to be significantly related to divergence between objective and subjective masticatory function in elderly Japanese. This suggests that dissociations between objective and subjective dental evaluations of elderly adults indicate need for assessment of their mental and physical function.

Frailty Severity and Dietary Variety in Japanese Older Persons: A Cross-Sectional Study

Providing older person individuals with an appropriate intervention at the time of frailty onset is important to prevent the progression of the condition and the need for long-term care. However, the proper timing of starting nutritional and dietary interventions for frail older person subjects has not been fully elucidated. Therefore, in this cross-sectional study, we aimed to clarify the association between frailty and dietary variety among older persons in Japan. We surveyed sex, age, body height, body weight, body mass index, serum albumin level, dietary variety, and nutritional intake indexes in 747 community-dwelling older person individuals who underwent a comprehensive health examination in October 2014. Frailty was determined using the Kihon Checklist (25 questions). Kihon Checklist is widely used to assess frailty in Japan, and their physical, cognitive and social function was evaluated. After excluding those who did not complete the Kihon Checklist and those who required long-term care, frailty status was analyzed in 665 older person individuals. The numbers and percentages of frail, pre-frail and robust older persons were found to be 77 (11.6%), 182 (27.4%) and 406 (61.0%) respectively. Significant differences among robust, pre-frail, and frail subjects were observed in terms of age, serum albumin level, alcohol consumption, smoking, and history of diabetes. Among the nutrition-related indexes, only the dietary variety showed a significant difference. The results of ordinal logistic regression analysis showed a significant association between frailty and sex, age, smoking status, diabetes, and dietary variety score. Dietary variety was significantly associated with the progression of frailty among older persons in the community.

ATM-mediated mitochondrial damage response triggered by nuclear DNA damage in normal human lung fibroblasts

Ionizing radiation (IR) elevates mitochondrial oxidative phosphorylation (OXPHOS) in response to the energy requirement for DNA damage responses. Reactive oxygen species (ROS) released during mitochondrial OXPHOS may cause oxidative damage to mitochondria in irradiated cells. In this paper, we investigated the association between nuclear DNA damage and mitochondrial damage following IR in normal human lung fibroblasts. In contrast to low-doses of acute single radiation, continuous exposure of chronic radiation or long-term exposure of fractionated radiation (FR) induced persistent Rad51 and γ-H2AX foci at least 24 hours after IR in irradiated cells. Additionally, long-term FR increased mitochondrial ROS accompanied with enhanced mitochondrial membrane potential (ΔΨm) and mitochondrial complex IV (cytochrome c oxidase) activity. Mitochondrial ROS released from the respiratory chain complex I caused oxidative damage to mitochondria. Inhibition of ATM kinase or ATM loss eliminated nuclear DNA damage recognition and mitochondrial radiation responses. Consequently, nuclear DNA damage activates ATM which in turn increases ROS level and subsequently induces mitochondrial damage in irradiated cells. In conclusion, we demonstrated that ATM is essential in the mitochondrial radiation responses in irradiated cells. We further demonstrated that ATM is involved in signal transduction from nucleus to the mitochondria in response to IR.

Overexpression of Rev1 promotes the development of carcinogen-induced intestinal adenomas via accumulation of point mutation and suppression of apoptosis proportionally to the Rev1 expression level

Cancer development often involves mutagenic replication of damaged DNA by the error-prone translesion synthesis (TLS) pathway. Aberrant activation of this pathway plays a role in tumorigenesis by promoting genetic mutations. Rev1 controls the function of the TLS pathway, and Rev1 expression levels are associated with DNA damage induced cytotoxicity and mutagenicity. However, it remains unclear whether deregulated Rev1 expression triggers or promotes tumorigenesis in vivo. In this study, we generated a novel Rev1-overexpressing transgenic (Tg) mouse and characterized its susceptibility to tumorigenesis. Using a small intestinal tumor model induced by N-methyl-N-nitrosourea (MNU), we found that transgenic expression of Rev1 accelerated intestinal adenoma development in proportion to the Rev1 expression level; however, overexpression of Rev1 alone did not cause spontaneous development of intestinal adenomas. In Rev1 Tg mice, MNU-induced mutagenesis was elevated, whereas apoptosis was suppressed. The effects of hREV1 expression levels on the cytotoxicity and mutagenicity of MNU were confirmed in the human cancer cell line HT1080. These data indicate that dysregulation of cellular Rev1 levels leads to the accumulation of mutations and suppression of cell death, which accelerates the tumorigenic activities of DNA-damaging agents.