Brief communication: body composition and hidden obesity in people living with HIV on antiretroviral therapy

BACKGROUND

Increased incidence of lifestyle diseases as side-effects of antiretroviral therapy (ART) have been reported in people living with HIV (PLWH). Few studies have evaluated obesity and hidden obesity in Japanese PLWH and their association with ART. In order to provide more appropriate drug selection and lifestyle guidance, we investigated the relationship between the effects of HIV infection and ART on the body composition of Japanese PLWH.

METHODS

PLWH who visited the outpatient clinic and had body composition measured using the body composition analyzer InBody 570 were included in this study. Medications, comorbidities, and blood test data were obtained. Body mass index (BMI), body fat percentage, and skeletal muscle mass index (SMI) were measured.

RESULTS

In this study, 543 patients were included. Based on body shape, patients were classified into a thin group (13), normal weight group (14), hidden obesity group (158), apparent obesity group (14), and obesity group (218). Compared with the normal weight group, the hidden obesity group had a higher prevalence of comorbidities and a lower SMI.

CONCLUSIONS

PLWH are more likely to have obesity than the general population, indicating that hidden obesity is common even among those with a normal BMI. It is important to measure body fat percentage along with body weight, as hidden obesity can be missed. Further investigation of the effects of ART on body composition is needed.

Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Efficacy of a Red-Light Controllable Nitric Oxide Releaser for Neurogenic Erectile Dysfunction: A Study Using a Rat Model of Cavernous Nerve Injury

PURPOSE

Neurogenic erectile dysfunction (ED) is a common side effect of radical prostatectomy (RP) because of cavernous nerve damage. In these patients, the production of nitric oxide (NO), which is important for erection, is decreased in the corpus cavernosum. Therefore, NO donors are useful for post-RP ED. However, short half-life and systemic side effects are problems of NO application in ED therapy. To avert these problems, we developed a red-light controllable NO releaser, NORD-1. This study aimed to investigate the effect of NORD-1 and red-light irradiation on neurogenic ED using a rat model of bilateral cavernous nerve injury (BCNI).

MATERIALS AND METHODS

BCNI and sham operations were conducted on 8-week-old rats. After 4 weeks, erectile function was evaluated using changes in intracavernous pressure (ICP) during electrostimulation of the cavernous nerve. ICP was measured under three conditions; without NORD-1 and red-light irradiation, with NORD-1 and without red-light irradiation, and with NORD-1 and red-light irradiation. SiR650 which absorbs red-light but does not release NO was used for the negative control. After the experiment, localization of NORD-1 was observed using a microscope.

RESULTS

Erectile function in a BCNI rat model was significantly decreased compared to sham-operated rats (p<0.05). After injecting NORD-1 into the penis, erectile function did not change without red-light irradiation. However, the combination of NORD-1 and red-light irradiation significantly improved erectile function (p<0.05) without affecting systemic arterial pressure. In contrast, when SiR650 was used, erectile function did not change in all three conditions. NORD-1 was detected only in the corpus cavernosum and not in the urethra and dorsal vein.

CONCLUSIONS

NORD-1 combined with red-light irradiation is effective for ED induced by cavernous nerve injury. This treatment may have low risks of hypotension and urinary incontinence, and it can replace the current treatment for post-RP ED.

A BODIPY-picolinium-cation conjugate as a blue-light-responsive caged group

Caged compounds protected with photolabile protecting groups (PPGs) are useful for controlling various biological events with high spatiotemporal resolution. Most of the commonly used PPGs are controlled by ultraviolet light irradiation, but it is desirable to have PPGs controlled by visible light irradiation in order to minimize tissue damage. Here, we describe a boron-dipyrromethene (BODIPY)-picolinium conjugate (BPc group) that functions as a blue-light-controllable PPG. ESR experiments indicate that the photolysis mechanism is based on intramolecular photoinduced electron transfer. We illustrate the applicability of the BPc group to biologically active compounds by employing it firstly to photocontrol release of histamine, and secondly to photocontrol release of a soluble guanylyl cyclase (sGC) activator, GSK2181236A, which induces photovasodilation. The BPc group is expected to be a useful PPG for controlling various biological events with blue light irradiation.

Photoinduced NO-release from polymer dots doped with an Ir(III) complex and N-methyl-N-nitroso-4-aminophenol

Nitric oxide (NO) is a signaling molecule that plays a variety of functions in the human body, but it is difficult to use it in biological experiments or for therapeutic purposes because of its high reactivity and instability in the biological milieu. Consequently, photocontrollable NO releasers, which enable spatiotemporal control of NO release, have an important role in elucidating the functions of NO. Our group has developed visible-light-controllable NO-releasing molecules that contain a fluorescent dye structure as a light-harvesting antenna moiety and an N-nitrosoaminophenol structure as an NO-releasing moiety. Here, we aimed to construct an NO-generating system employing an intermolecular photoredox reaction between the two separate components, since this would simplify chemical synthesis and make it easier to examine various dyes as antennae. For this purpose, we constructed polymer nanoparticles doped with both N-methyl-N-nitroso-4-aminophenol (NAP, 1) and an Ir(III) antenna complex (2, 3 or 4) in order to dissolve in aqueous solution without a co-solvent. These polymer nanoparticles released NO upon photoirradiation in vitro in the purple (400-430 nm) or blue (400-460 nm) wavelength region to activate the doped Ir(III) complex.

An Optochemical Oxygen Scavenger Enabling Spatiotemporal Control of Hypoxia

We present an optochemical O2 scavenging system that enables precise spatiotemporal control of the level of hypoxia in living cells simply by adjusting the light intensity in the illuminated region. The system employs rhodamine containing a selenium or tellurium atom as an optochemical oxygen scavenger that rapidly consumes O2 by photochemical reaction with glutathione as a coreductant upon visible light irradiation (560-590 nm) and has a rapid response time, within a few minutes. The glutathione-consuming quantum yields of the system were calculated as about 5%. The spatiotemporal O2 consuming in cultured cells was visualized with a hypoxia-responsive fluorescence probe, MAR. Phosphorescence lifetime imaging was applied to confirmed that different light intensities could generate different levels of hypoxia. To illustrate the potential utility of this system for hypoxia research, we show that it can spatiotemporally control calcium ion (Ca2+) influx into HEK293T cells expressing the hypoxia-responsive Ca2+ channel TRPA1.

Substituent Effects at the N-Nitrosoaminophenol Moiety of a Photoinduced-Electron-Transfer-Driven Nitric Oxide Releaser

Nitric oxide (NO) has multiple physiological activities, including roles in vasorelaxation, neurotransmission, and immune response. Indeed, NO-releasing compounds are utilized as therapeutic agents for cardiovascular diseases based on the potent and rapid vasorelaxation induced by NO. We have developed a series of photoinduced-electron-transfer-driven (PeT-driven) NO releasers composed of a light-harvesting antenna moiety and an NO-releasing N-nitrosoaminophenol moiety, which efficiently release NO upon irradiation with blue (500 nm), green (560 nm), or red (650 nm) light. In this paper, we investigated substituent effects at the 2-position of the N-nitrosoaminophenol moiety by means of spectroscopic, fluorescence, and NO-release measurements. Interestingly, a methyl substituent at this position had no significant effect on the NO-releasing ability, while a nitro group or a methoxy group reduced it. The nitro group may suppress electron transfer to the antenna moiety, while the methoxy group may accelerate electron transfer but suppress deprotonation to afford the phenoxyl radical, which is the key reaction for release of NO. These structure-activity relationships should be helpful for further functionalizing PeT-driven NO releasers.

Development of Nucleoside Diphosphate-Bearing Fragile Histidine Triad-Imaging Fluorescence Probes with Well-Tuned Hydrophobicity for Intracellular Delivery

Fluorescence-guided cancer surgery can dramatically improve recurrence rates and postoperative quality of life of patients by accurately distinguishing the boundary between normal and cancer tissues during surgery, thereby minimizing excision of normal tissue. One promising target in early stage cancer is fragile histidine triad (FHIT), a cancer suppressor protein with dinucleoside triphosphate hydrolase activity. In this study, we have developed fluorescence probes containing a nucleoside diphosphate moiety, which dramatically improves the reactivity and specificity for FHIT, and a moderately lipophilic ester moiety to increase the membrane permeability. The ester moiety is cleaved by ubiquitous intracellular esterases, and then, FHIT in the cells specifically cleaves nucleoside monophosphate. The remaining phosphate moiety is rapidly cleaved by ubiquitous intracellular phosphatases to release the fluorescent dye. We confirmed that this probe can detect FHIT activity in living cells. A comprehensive evaluation of the effects of various ester moieties revealed that probes with CLogP = 5-7 showed good membrane permeability and were good substrates of the target enzyme; these findings may be helpful in the rational design of other multiple phosphate-containing probes targeting intracellular enzymes.

Effects of Material Thickness and Pretreatment on the Interfacial Gap of Translucent Zirconia Restorations with Self-adhesive Resin Cement

Purpose

The first objective was to determine if the dual-curing of self-adhesive resin cement (SAC) with reduced light penetrating through zirconia had an effect on interfacial gap of zirconia restorations. The second purpose was to examine whether pretreatment methods for universal adhesive affected interfacial gap. The last aim was to compare the microhardness of SAC polymerized under different zirconia thicknesses.

Methods and Materials

This study evaluated self-adhesive resin cement (RelyX U200, 3M ESPE) after different pretreatment with universal adhesive (Single Bond Universal, 3M ESPE) under different polymerization conditions. CAD/CAM inlay cavities were prepared on extracted third molars. Translucent zirconia restorations were milled using Katana UTML (Kuraray). The teeth were divided into three groups: Groups I, II, and III in which the restoration thicknesses were 1, 2, and 3 mm. Each Group had three subgroups according to different pretreatment methods. For subgroup-1, no pretreatment was done on the prepared cavity. For subgroup-2, universal adhesive was applied and light-cured before cement placement (precure method). For subgroup-3, universal adhesive was applied; however, light-curing was done after cement placement (cocure method). After thermo-cycling, the interfacial gap at the restoration-tooth interface was investigated using swept-source optical coherence tomography imaging. Finally, microhardness was measured for SAC under different zirconia thicknesses. For statistical analysis, the interfacial gap was analyzed using two-way analysis of variance (ANOVA) to test the effect of cavity depth and pretreatment. In terms of each cavity depth and pretreatment, the interfacial gap was compared using one-way ANOVA and Scheffe’s test. One-way ANOVA was also performed for comparison of the Vickers hardness results.

Results

Different thicknesses of the restoration resulted in differences in interfacial gaps except between the precure method of Groups I and II (p&lt;0.05). The effect of universal adhesive pretreatment was different depending on the restoration thickness with exceptions in Groups I and III (p&lt;0.05). Vickers hardness number decreased as the low radiant exposure of light was applied (p&lt;0.05).

Conclusion

Interfacial gap of zirconia restorations can differ depending on the material thickness, pretreatment, and activation mode. Reduced light intensity penetrating through zirconia may lead to higher interfacial gap percentage and lower microhardness of the self-adhesive resin cement. Application of a universal adhesive showed similar or reduced interfacial gaps in the cement space.

Ascorbate-assisted nitric oxide release from photocontrollable nitrosonium ion releasers for potent ex vivo photovasodilation

We found that N-nitrosoaminoanisole derivatives tethered to dyes work as photocontrollable nitrosonium cation releasers and are converted to potent nitric oxide releasers in the presence of sodium ascorbate. The N-nitrosoaminoanisole derivative 2 worked as a more potent photovasodilating reagent ex vivo than previously reported nitric oxide releasers.

A visible light-controllable Rho kinase inhibitor based on a photochromic phenylazothiazole

Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine-threonine kinase whose inhibitors are useful for the regulation of the actomyosin system. Here, we developed a photoswitchable ROCK inhibitor based on a phenylazothiazole scaffold. The reversible trans-cis isomerization by visible light stimuli enabled us to manipulate ROCK activities in vitro and in cells.

Estimation of possible candidates for ivabradine in rural Japan and investigation of their clinical characteristics

Background

In Japan, ivabradine is indicated in patients with heart failure (HF) with sinus rhythm and a resting heart rate (HR) ≥75/min under standard treatment. Particularly, it is effective for HF with reduced left ventricular ejection fraction (LVEF). However, elderly people have a higher incidence of atrial fibrillation than young people, and their sinus node function is further deteriorated, resulting in a lower intrinsic HR. In addition, Japan is an ultra-aging society, especially in the countryside; therefore, the target patients for ivabradine may be limited in these regions.

Purpose

We sought to estimate the possible candidates for ivabradine and investigate their clinical characteristics in our hospital located in rural Japan.

Method and results

We retrospectively studied 14733 consecutive patients who were suspected heart disease who underwent echocardiography between January 2006 and October 2018 in Kitaishikai Hospital located in Ozu city (Proportion of the population aged ≥65 years: 34%, in 2015) and did not take ivabradine treatment. Of these, 187 patients with hemodynamically stable condition whose E/A ratio was measured and met the criteria of LVEF &lt;40% and HR ≥75 /min were confirmed. Of these, 153 patients reached HR &lt;75 /min with additional intensive medication within one year after the index echocardiography (Controlled group; mean HR: 82 to 62/min). The remaining 34 patients with uncontrolled HR (Uncontrolled group; mean HR: 84 to 82/min) were considered possible candidates for ivabradine (34/14733: 0.23%, 2.6 patients per year; median age, 74 years; male, 56%; median LVEF, 32%; ischemic cardiomyopathy, 53%). In the comparison of clinical and echocardiographic parameters in these two groups, Uncontrolled group had a significantly smaller left ventricular diastolic volume index (71 [59–85] vs 82 [66–109] /ml/m2, p=0.02), left ventricular systolic volume index (50 [39–59] vs 59 [42–80] / ml/m2, p=0.04), stroke volume index (22 [18–26] vs 26 [20–32] /ml/m2, p=0.02), left atrial volume index (47 [40–64] vs 59 [45–71] /ml/m2, p=0.02), and more hemodialysis (12 vs 3%, p=0.04) than Controlled group. However, the discrimination ability of these parameters for identifying Uncontrolled group was modest (Figure).

Conclusion

In rural Japan, possible candidates for ivabradine may be rare, so daily attention should be paid. Patients with reduced ejection fraction, small left ventricle, and hemodialysis may be the possible targets for this therapy.

Funding Acknowledgement

Type of funding sources: None.

Control of rat bladder neck relaxation with NORD-1, a red light-reactive nitric oxide releaser: In vitro study

We aimed to control the relaxation of rat bladder neck specimens by using NORD-1, a red light-reactive nitric oxide (NO) releaser. Female and male 10-11-week-old Wistar/ST rats were divided into three groups: NORD-1, vehicle, and NORD-1+[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; a soluble guanylyl cyclase inhibitor). We infused 10-4 M NORD-1 into the bladders of NORD-1 and NORD-1+ODQ group rats and the vehicle into those of vehicle group rats. Isometric tension was analyzed using circular bladder neck specimens with 10-5 M NG-nitro-l-arginine methyl ester, an NO synthase inhibitor. Moreover, 10-5 M ODQ was added into the NORD-1+ODQ group bath. After precontraction with 10-5 M carbachol, the specimens were irradiated with red light and their relaxation responses were measured. We evaluated NORD-1 tissue permeability by observing the sliced bladder neck specimens. The NORD-1 group specimens relaxed during red light irradiation; the relaxation response increased with the increase in light intensity. The vehicle and NORD-1+ODQ group specimens did not respond to irradiation. Sex-related differences in responsiveness were not noted. NORD-1 permeated into the urothelium of NORD-1 group specimens. Rat bladder neck relaxation was controlled by NORD-1 and light irradiation in vitro. NORD-1 might be a novel therapeutic agent for voiding dysfunction.

Synthesis of Fluorescent Probes Targeting Tumor-Suppressor Protein FHIT and Identification of Apoptosis-Inducing FHIT Inhibitors

For the early diagnosis of cancer, leading to a better chance of full recovery, marker genes whose expression is already altered in precancerous lesions are desirable, and the tumor-suppressor gene FHIT is one candidate. The gene product, FHIT protein, has a unique dinucleoside triphosphate hydrolase (AP₃Aase) activity, and in this study, we designed and synthesized a series of FHIT fluorescent probes utilizing this activity. We optimized the probe structure for high and specific reactivity with FHIT and applied the optimized probe in a screening assay for FHIT inhibitors. Screening of a compound library with this assay identified several hits. Structural development of a hit compound afforded potent FHIT inhibitors. These inhibitors induce apoptosis in FHIT-expressing cancers via caspase activation. Our results support the idea that FHIT binders, no matter whether inhibitors or agonists of AP₃Aase activity, might be promising anticancer agents.

FKBP51 and FKBP52 regulate androgen receptor dimerization and proliferation in prostate cancer cells

The growth of prostate cancer is dependent on the androgen receptor (AR), which serves as a ligand-specific transcription factor. Although two immunophilins, FKBP51 and FKBP52, are known to regulate AR activity, the precise mechanism remains unclear. We found that depletion of either FKBP51 or FKBP52 reduced AR dimer formation, chromatin binding, and phosphorylation, suggesting defective AR signaling. Furthermore, the peptidyl-prolyl cis/trans isomerase activity of FKBP51 was found to be required for AR dimer formation and cancer cell growth. Treatment of prostate cancer cells with FK506, which binds to the FK1 domain of FKBPs, or with MJC13, an inhibitor of FKBP52-AR signaling, also inhibited AR dimer formation. Finally, elevated expression of FKBP52 was associated with a higher rate of prostate-specific antigen recurrence in patients with prostate cancer. Collectively, these results suggest that FKBP51 and FKBP52 might be promising targets for prostate cancer treatment through the inhibition of AR dimer formation.

Effects of pulse field and radiofrequency pulmonary vein isolation on parasympathetic cardiac innervation

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): IKEM

Background

Pulmonary vein isolation (PVI) is an established treatment modality for patients with atrial fibrillation (AF). PVI performed by radiofrequency (RF) energy results in parasympathetic denervation of the heart by collateral ganglionic plexi ablation. Pulse field (PF) is a novel nonthermal energy source for PVI that selectively ablates atrial myocardium while preserving cardiac autonomic nerves, which may affect the outcome after PVI.

Purpose

The study compared the effect of PVI between RF and PF ablation on cardiac autonomic function and a short-term AF recurrence rate. The resting heart rate (HR) was evaluated as a simple index of sinus nodal parasympathetic innervation.

Methods

We investigated 45 patients (aged 64 ± 7 years, 4 women) who underwent PVI by novel three-dimensional electroanatomical mapping/ablation system (lattice electrode ablation system). PVI was performed by either high-energy RF (n = 21) or PF (n = 24) energy using the identical ablation catheter. Resting HR assessed by standard ECG was recorded the day before the procedure and at the 3-month visit. Arrhythmia recurrences were analysed by 24-Holter at the 3-month visit.

Results

All PVs were acutely isolated in all patients. The HR data are shown in the Table. The baseline HR did not differ between both groups. A significant increase in HR was observed only in the RF ablation subgroup. The between-group difference remained significant even after adjustment for age, gender, and baseline HR. There was no difference in arrhythmia recurrences at the 3-month visit between study groups.

Conclusions

  Parasympathetic denervation effects on HR after the PF ablation are virtually absent. Comparable AF recurrence rate at 3-month visit after RF and PF ablation suggests that preservation of autonomic innervation has no impact on AF recurrence during short-term follow-up. Table RF PVI (n = 21) PF PVI (n = 24) P Baseline HR (bpm) 60.0 ± 7.1 63.8 ± 9.4 n.s. HR change - 3-month visit (bpm) 14.4 ± 6.9 0.3 ± 8.6 P &lt;0.001 Arrhythmia recurrences 3/21 (14%) 2/24 (8%) n.s.

Impact of Proteinuria and Low eGFR on Lifetime Risk of Cardiovascular Disease Death: A Pooled Analysis of Data From the Evidence for Cardiovascular Prevention From Observational Cohorts in Japan Study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): H20–Junkankitou [Seishuu]–Ippan–013; H23–Junkankitou [Seishuu]–Ippan–005; H26-Junkankitou [Seisaku]-Ippan-001; H29–Junkankitou–Ippan–003 and 20FA1002

OnBehalf

EPOCH-JAPAN

Introduction

Absolute risk of Lifetime risk (LTR) is useful estimate for risk communication compared with short term risk or relative risk especially for young people. Proteinuria is leading cause of end-stage kidney disease (ESKD) and independent risk factor for cardiovascular disease (CVD). Although nonproteinuric renal disease is global burden of ESKD, it has been poorly focused. To date, there have been no reports of impact of proteinuria and low eGFR on LTR with the outcome of CVD death in Asian population.

Purpose

We aimed to estimate LTR of CVD death stratified by the status of proteinuria and low eGFR.

Methods

We used modified Kaplan-Meier approach to estimate the remaining lifetime risk of cardiovascular death based on EPOCH-JAPAN(Evidence for Cardiovascular Prevention From Observational Cohorts in Japan) database. LTR was estimated at each index age starting from 40 years for those with proteinuria and without proteinuria stratified by low eGFR, which is defined as eGFR &lt;60 ml/min/1.73 m². Participants were classified into three groups, which were those with proteinuria (Proteinuria (+)), those without proteinuria with low eGFR (Proteinuria (-)/Low eGFR (+)), those without proteinuria without low eGFR (Proteinuria (-)/Low eGFR (-)).

Results

A total of 47,292 participants from 9 cohorts was included in the analysis. Mean follow-up period was 14.6 years with 690,463 person years and total CVD death was 1,075 in men and 1,193 in women. The LTRs at the index age of 40 years were as follows: 17.7% (95% confidence interval: 15.4 – 19.0%) in Proteinuria (-)/Low eGFR (-) group, 26.2% (20.2 – 31.1%) in Proteinuria (-)/low eGFR (+) group, 24.5% (15.1 – 29.3%) in Proteinuria (+) group for men; 15.3%(13.7 – 16.5%), 29.9%(14.7 – 46.8%) , 28.3%(19.4 – 34.7%) for women.

Conclusions

We observed that those without proteinuria with low eGFR have equivalently high LTR with those with proteinuria. These results indicate that even in the absence of proteinuria, low eGFR has high impact on LTR. Lifestyle modification from young age is necessary to prevent from renal dysfunction.

A Set of Highly Sensitive Sirtuin Fluorescence Probes for Screening Small-Molecular Sirtuin Defatty-Acylase Inhibitors

Human sirtuins (SIRT1-7) regulate not only deacetylation but also deacylation of fatty acid-derived acyl moieties (defatty-acylation) at the ε-amino group of lysine residues. SIRT-subtype-specific defatty-acylase activity modulators are needed for detailed investigation of the biological roles of these enzymes, and to find suitable small molecules, we require appropriate screening systems. Here, we designed and synthesized a set of SIRT defatty-acylase activity probes with various quencher moieties and peptide sequences based on our previously developed one-step FRET-based SIRT probe SFP3, using improved methodology. Scanning of this set of probes with SIRT isozymes revealed that certain probe/isozyme combinations showed especially high responses. To illustrate the utility of the combinations thus identified, we applied compound 18/SIRT2 for inhibitor screening of a large chemical library. This enabled us to discover a new small molecule SIRT2-specific defatty-acylase inhibitor.

Development of a Red-Light-Controllable Nitric Oxide Releaser to Control Smooth Muscle Relaxation in Vivo

We designed and synthesized a novel Si-rhodamine derivative, NORD-1, as a red-light-controllable nitric oxide (NO) releaser, on the basis of photoredox parameter analysis. Red-light-responsive NO release from NORD-1 was confirmed by ESR spin trapping and quantified with an NO electrode and by means of Griess assay. The NO release cross section (ε_656 nm·Φ_NO) of NORD-1 was calculated to be 3.65 × 10², which is larger than that of a previously reported yellowish-green-light-controllable NO releaser, NO-Rosa5. The photoresponsiveness of NO release from NORD-1 was precise and efficient enough to induce vasodilation ex vivo under Magnus test conditions. Finally, we showed that intracavernous pressure (ICP) could be controlled in rats in vivo with the combination of NORD-1 and a red-light source without increasing systemic blood pressure, which is a serious side effect of usual NO releasers, such as nitroglycerin and isopentyl nitrite. NORD-1 is expected to be a useful chemical tool for NO research, as well as a candidate agent to control the circulatory system.

Impact of right ventricular contractile reserve on exercise capacity in patients with heart failure: clinical application of low-load exercise stress echocardiography

Background

The peak oxygen uptake (VO2) evaluated by the cardiopulmonary exercise test (CPX) is an established marker of exercise capacity in patients with heart failure (HF). In particular, peak VO2 &lt;14 ml/kg/min is used to be one of the criteria for heart transplantation. However, given exercise intolerance in patients with HF, it is difficult for refractory HF patients to reach sufficient exercise load. A recent report has highlighted significant impact of right ventricular (RV) function on mortality and urgent heart transplantation. Taken together, we hypothesized that the assessment of RV function was helpful to predict exercise capacity by using low-load exercise stress echocardiography (low-load ESE) in patients with HF.

Purpose

We evaluated whether RV dysfunction assessed by the low-load ESE determined a low peak VO2 &lt;14 ml/kg/min in patients with HF.

Methods

We studied 67 consecutive hospitalized patients with HF (mean age, 65 years; 75% male; mean LV ejection fraction, 36%) who underwent ESE and CPX after stabilized HF condition, and the time interval of CPX and ESE tests was within 48 hours. CPX was performed using an upright cycle ergometer by a ramp protocol, while ESE was performed using ergometer in semi-supine position and the workload was generally increased by 25 watts every 3 minutes. The low-load ESE was defined as the 25 watts exercise. The increments of RV s' velocity at tricuspid annulus and RV strain in the free wall were considered as a preservation of RV contractile reserve. Among the study population, 26 patients were performed right heart catheterization and RV dP/dt/Pmax was estimated as an invasive marker of RV contractility.

Results

The achieved intensity of exercise was 50.4±21.0 watts, and all patients completed the low-load ESE. The invasive study showed that the change of RV s' velocity during the low-load ESE significantly correlated with RV dP/dt/Pmax (r=0.706, p&lt;0.001). As shown in Figure, the non-invasive parameters of RV contractile reserve during the low-load ESE were significantly correlated with peak VO2 (RV s' velocity: r=0.787, p&lt;0.001; RV strain: r=0.244, p=0.047). ROC analysis showed that the change of RV s' velocity during the low-load ESE correctly identified patients with peak VO2 &lt;14 ml/kg/min (AUC=0.95, sensitivity 92.3%, specificity 85.2%). In terms of inter- and intra-observer variabilities, ICCs of the change of RV s' velocity were 0.86 and 0.96, and ICCs of the changes of RV strain were 0.63 and 0.70, respectively.

Conclusion

The change of RV s' velocity during the low-load ESE could determine exercise tolerance in patients with HF. The assessment of RV contractile reserve might be clinically useful to discriminate high risk HF patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

Synthesis of artificial substrate based on inhibitor for detecting LSD1 activity

Lysine methylation is one of the most important modification, which is regulated by histone lysine methyltransferases and histone lysine demethylases. Lysine-specific demethylase 1 (LSD1) specifically demethylates mono- and dimethyl-lysine on histone H3 (H3K4Me/Me₂, H3K9Me/Me₂) to control chromatin structure, resulting in transcriptional repression or activation of target genes. Furthermore, LSD1 is overexpressed in various cancers. Therefore, LSD1 inhibitors would be not only potential therapeutic agents for cancers but also chemical tools to research biological significance of LSD1 in physiological and pathological events. However, known assay methods to date have some inherent drawbacks. The development of simple method in detecting LSD1 activity has been indispensable to identify useful inhibitors. In this study, we designed and synthesized artificial substrates based on inhibitors of LSD1 to examine LSD1 activity by an absorption increment.

Identification of Potent In Vivo Autotaxin Inhibitors that Bind to Both Hydrophobic Pockets and Channels in the Catalytic Domain

Autotaxin (ATX, also known as ENPP2) is a predominant lysophosphatidic acid (LPA)-producing enzyme in the body, and LPA regulates various physiological functions, such as angiogenesis and wound healing, as well as pathological functions, including proliferation, metastasis, and fibrosis, via specific LPA receptors. Therefore, the ATX-LPA axis is a promising therapeutic target for dozens of diseases, including cancers, pulmonary and liver fibroses, and neuropathic pain. Previous structural studies revealed that the catalytic domain of ATX has a hydrophobic pocket and a hydrophobic channel; these serve to recognize the substrate, lysophosphatidylcholine (LPC), and deliver generated LPA to LPA receptors on the plasma membrane. Most reported ATX inhibitors bind to either the hydrophobic pocket or the hydrophobic channel. Herein, we present a unique ATX inhibitor that binds mainly to the hydrophobic pocket and also partly to the hydrophobic channel, inhibiting ATX activity with high potency and selectivity in vitro and in vivo. Notably, our inhibitor can rescue the cardia bifida (two hearts) phenotype in ATX-overexpressing zebrafish embryos.

Multiplexed single-molecule enzyme activity analysis for counting disease-related proteins in biological samples

We established an ultrasensitive method for identifying multiple enzymes in biological samples by using a multiplexed microdevice-based single-molecule enzymatic assay. We used a paradigm in which we "count" the number of enzyme molecules by profiling their single enzyme activity characteristics toward multiple substrates. In this proof-of-concept study of the single enzyme activity-based protein profiling (SEAP), we were able to detect the activities of various phosphoric ester-hydrolyzing enzymes such as alkaline phosphatases, tyrosine phosphatases, and ectonucleotide pyrophosphatases in blood samples at the single-molecule level and in a subtype-discriminating manner, demonstrating its potential usefulness for the diagnosis of diseases based on ultrasensitive detection of enzymes.

Ratiometric assay of CARM1 activity using a FRET-based fluorescent probe

One of the regulatory mechanisms of epigenetic gene expression is the post-translational methylation of arginine residues, which is catalyzed by protein arginine methyltransferases (PRMTs). Abnormal expression of PRMT4/CARM1, one of the PRMTs, is associated with various diseases, including cancers. Here, we designed and synthesized a Förster resonance energy transfer (FRET)-based probe, FRC, which contains coumarin and fluorescein fluorophores at the N-terminus and C-terminus of a peptide containing an arginine residue within an appropriate amino acid sequence to serve as a substrate of CARM1; the two fluorophores act as a FRET donor and a FRET acceptor, respectively. Since trypsin specifically hydrolyzes the arginine residue, but not a monomethylarginine or dimethylarginine residue, CARM1 activity can be evaluated from the change of the coumarin/fluorescein fluorescence ratio of FRC in the presence of trypsin.

P6234The relationship of alcohol consumption with risk factors of coronary heart disease and the intake of macro- and micro-nutrients in Japanese: the INTERLIPID study

Background

Many studies have reported the J-shaped relationship between alcohol consumption and coronary heart disease (CHD) risk; therefore, light-drinkers is generally recognized to be associated with the lower risk of CHD. However, the mechanisms of lower risk for CHD in light-drinkers are still unclear. Alcohol drinking status is likely to be associated with not only CHD risk factors but also dietary intake. Nevertheless, few studies report these relationships in detail.

Purpose

The purpose of this study is to evaluate the relationships of alcohol drinking status with CHD classical risk factors and the intake of macro- and micro- nutrients in Japanese.

Methods

Study participants were 1,090 Japanese men and women aged 40–59 years from The INTERLIPID study excepted for 55 individuals who had missing data (n=26) and were past-drinkers (n=29). Alcohol consumption was assessed with two 7-day alcohol records, and average ethanol intake (per week) was calculated. Participants were classified into following 4 groups: non-drinkers (0g/week), light-drinkers (<100 g/week), moderate-drinkers (100–299 g/week), and heavy-drinkers (≥300 g/week). Serum LDL and HDL cholesterol, blood pressure (BP), the prevalence of hypertension and dyslipidemia, and smoking status were assessed as CHD risk factors. The intake of energy and macro- and micro-nutrients were evaluated from the four-timed in-depth 24-hr dietary recalls. Nutrient intake densities were calculated per total energy intake without alcohol. The analysis of variance and chi-squared test were used to evaluate the relations of alcohol status with CHD risk factors and nutrient intake.

Results

Serum HDL cholesterol levels increased and LDL cholesterol levels decreased with increasing alcohol consumption. Systolic and diastolic BP increased with increasing alcohol consumption. J-shaped relationships with alcohol consumption were observed for the proportion of current smoker, number of cigarettes, and the prevalence of hypertension; that is, light-drinkers was lowest among all groups. The prevalence of dyslipidemia was the highest in non-drinkers, and decreased with increasing alcohol consumption. In heavy-drinkers, total energy (kcal/day) was the highest, but energy intake without alcohol (kcal/day) was the lowest. For macronutrients, the intake of carbohydrate (%kcal) decreased, and the intakes of total and animal protein (%kcal) increased with increasing alcohol consumption. The intakes of total cholesterol (mg/1000kcal) and sodium (mg/1000kcal) increased, and total fiber (g/1000kcal) decreased with increasing alcohol consumption. These associations were similar in men and women.

Conclusions

Alcohol consumption was related with not only CHD classical risk factors but also the intake of macro- and micro-nutrients. Non-drinkers had a higher proportion of some CHD risk factors than light-drinkers. These results might influence on J-shaped relationship between alcohol consumption and CHD risk.

Acknowledgement/Funding

1: Ministry of Education, Science, Sports, and Culture of Japan, 2: National Institutes of Health, Bethesda, MD, USA

Development of a highly sensitive fluorescence probe for peptidyl arginine deiminase (PAD) activity

Peptidyl arginine deiminases (PADs) catalyze the post-translational deimination of arginine residues to citrulline residues. Aberrant levels of PAD activity are associated with various diseases, such as rheumatoid arthritis, Alzheimer's disease, and multiple sclerosis, so there is a need for simple and convenient high-throughput screening systems to discover PAD inhibitors as candidate therapeutic agents. Here, we report a highly sensitive off/on-type fluorescence probe for PAD activity based on the donor-excited photoinduced electron transfer (d-PeT) mechanism, utilizing the specific cycloaddition reaction between the benzil group of the probe and the ureido group of the PAD product, citrulline, under acidic conditions. We synthesized and functionally evaluated a series of probes bearing substituents on the benzil phenyl group, and found that 4MEBz-FluME could successfully detect citrulline with higher sensitivity and broader dynamic range than our previously reported fluorescence probe, FGME. Moreover, we succeeded in establishing multiple assay systems for PAD subtypes activities, including PAD2 and PAD4, with 4MeBz-FluME thanks to its high sensitivity. We expect that our fluorescence probes will become a powerful tool for discovering PAD inhibitors of several subtypes. Thus, it should be suitable for high-throughput screening of chemical libraries for inhibitors of PADs.

Substrate selectivity and its mechanistic insight of the photo-responsive non-nucleoside triphosphate for myosin and kinesin

Linear motor proteins including kinesin and myosin are promising biomaterials for developing nano-devices. Photoswitchable substrates of these biomotors can be used to optically regulate the motility of their associated cytoskeletal filaments in in vitro systems. Here, we describe the discovery of the myosin selective azobenzene-tethered triphosphate. It enables the specific photocontrol over myosin in a reversible mode with the composite motility assay composed of both kinesin and myosin. The mechanistic insight into this myosin selectivity is also explained with the docking simulation study.

Structure-efficiency relationship of photoinduced electron transfer-triggered nitric oxide releasers

Spatiotemporally controllable nitric oxide (NO) releasers are required for biological studies and as candidate therapeutic agents. Here, we investigate the structure-efficiency relationship of a series of photoinduced electron transfer-triggered NO releasers based on our reported yellowish-green light-controllable NO releaser, NO-Rosa. The distance between the NO-releasing N-nitrosoaminophenol moiety and the rosamine antenna moiety was critical for efficient NO release. Notably, substitution at the phenolic hydroxyl group blocked NO release. We synthesized NO-Rosa-Gal bearing D-galactose (Gal) at this location, and showed that hydrolysis by β-galactosidase restored the photoresponse. This represents proof-of-concept of a strategy for highly specific control of NO release by using a double-lock system involving both enzymatic reactivation and photo-control.

Detection of Talaromyces macrosporus and Talaromyces trachyspermus by a PCR assay targeting the hydrophobin gene

Talaromyces species are typical fungi capable of producing the heat-resistant ascospores responsible for the spoilage of processed food products. Hydrophobins, which are unique to fungi, are small secreted proteins that form amphipathic layers on the outer surface of fungal cell walls. In this study, species-specific primer sets for detecting and identifying Talaromyces macrosporus and Talaromyces trachyspermus were designed based on hydrophobin gene sequences. A conventional polymerase chain reaction (PCR) assay using these primer sets produced species-specific amplicons for T. macrosporus and T. trachyspermus. The detection limit for each primer set was 100 pg template DNA. This assay also detected fungal DNA extracted from blueberries inoculated with T. macrosporus. Other heat-resistant fungi, including Byssochlamys, Neosartorya and Talaromyces species, which cause food spoilage, were not detected in PCR amplifications with these primer sets. Furthermore, a conventional PCR assay using a crude DNA extract as the template also yielded amplicons specific to T. macrosporus and T. trachyspermus. The simple and rapid PCR assay described herein is highly species-specific and can reliably detect T. macrosporus and T. trachyspermus, suggesting it may be relevant for the food and beverage industry. SIGNIFICANCE AND IMPACT OF THE STUDY: The heat-resistant ascospores of Talaromyces macrosporus and Talaromyces trachyspermus are responsible for food spoilage after pasteurization. Traditional methods for detecting fungal contamination based on morphological characteristics are time-consuming and exhibit low sensitivity and specificity. In this study, a conventional polymerase chain reaction (PCR) assay based on hydrophobin gene sequences was developed for the specific detection of T. macrosporus and T. trachyspermus. This detection method was simple, rapid and highly specific. These results suggest that the conventional PCR assay developed in this study may be useful for detecting T. macrosporus and T. trachyspermus in raw materials and processed food products.

Cationic axial ligands on sulfur substituted silicon(iv) phthalocyanines: improved hydrophilicity and exceptionally red-shifted absorption into the NIR region

Herein, we report the exceptionally red-shifted absorption of sulfur-substituted silicon(iv) phthalocyanines upon introduction of cationic axial ligands.

An irreversible inhibitor of peptidyl-prolyl cis/trans isomerase Pin1 and evaluation of cytotoxicity

Pin1 (protein interacting with never in mitosis A-1) is a member of the peptidyl prolyl isomerase (PPIase) family, and catalyzes cis-trans isomerization of pThr/Ser-Pro amide bonds. Because Pin1 is overexpressed in various cancer cell lines and promotes cell growth, it is considered a target for anticancer agents. Here, we designed and synthesized a covalently binding Pin1 inhibitor (S)-2 to target Pin1's active site. This compound inhibited Pin1 in protease-coupled assay, and formed a covalent bond with Cys113 of Pin1, as determined by ESI-MS. The acetoxymethyl ester of (S)-2, i.e., 6, suppressed cyclin D1 expression in human prostate cancer PC-3 cells, and exhibited cytotoxicity. Pin1-knockdown experiments indicated that a target for the cytotoxicity of 6 is Pin1.