Large-scale analysis of small molecule-RNA interactions using multiplexed RNA structure libraries

The large-scale analysis of small-molecule binding to diverse RNA structures is key to understanding the required interaction properties and selectivity for developing RNA-binding molecules toward RNA-targeted therapies. Here, we report a new system for performing the large-scale analysis of small molecule-RNA interactions using a multiplexed pull-down assay with RNA structure libraries. The system profiled the RNA-binding landscapes of G-clamp and thiazole orange derivatives, which recognizes an unpaired guanine base and are good probes for fluorescent indicator displacement (FID) assays, respectively. We discuss the binding preferences of these molecules based on their large-scale affinity profiles. In addition, we selected combinations of fluorescent indicators and different ranks of RNA based on the information and screened for RNA-binding molecules using FID. RNAs with high- and intermediate-rank RNA provided reliable results. Our system provides fundamental information about small molecule-RNA interactions and facilitates the discovery of novel RNA-binding molecules.

A let-7 microRNA-RALB axis links the immune properties of iPSC-derived megakaryocytes with platelet producibility

We recently achieved the first-in-human transfusion of induced pluripotent stem cell-derived platelets (iPSC-PLTs) as an alternative to standard transfusions, which are dependent on donors and therefore variable in supply. However, heterogeneity characterized by thrombopoiesis-biased or immune-biased megakaryocytes (MKs) continues to pose a bottleneck against the standardization of iPSC-PLT manufacturing. To address this problem, here we employ microRNA (miRNA) switch biotechnology to distinguish subpopulations of imMKCLs, the MK cell lines producing iPSC-PLTs. Upon miRNA switch-based screening, we find imMKCLs with lower let-7 activity exhibit an immune-skewed transcriptional signature. Notably, the low activity of let-7a-5p results in the upregulation of RAS like proto-oncogene B (RALB) expression, which is crucial for the lineage determination of immune-biased imMKCL subpopulations and leads to the activation of interferon-dependent signaling. The dysregulation of immune properties/subpopulations, along with the secretion of inflammatory cytokines, contributes to a decline in the quality of the whole imMKCL population.

Deep generative design of RNA family sequences

RNA engineering has immense potential to drive innovation in biotechnology and medicine. Despite its importance, a versatile platform for the automated design of functional RNA is still lacking. Here, we propose RNA family sequence generator (RfamGen), a deep generative model that designs RNA family sequences in a data-efficient manner by explicitly incorporating alignment and consensus secondary structure information. RfamGen can generate novel and functional RNA family sequences by sampling points from a semantically rich and continuous representation. We have experimentally demonstrated the versatility of RfamGen using diverse RNA families. Furthermore, we confirmed the high success rate of RfamGen in designing functional ribozymes through a quantitative massively parallel assay. Notably, RfamGen successfully generates artificial sequences with higher activity than natural sequences. Overall, RfamGen significantly improves our ability to design functional RNA and opens up new potential for generative RNA engineering in synthetic biology.

RNA Switches Using Cas Proteins

Expanding the number of available RNA-binding proteins (RBPs) is vital to establishing posttranscriptional circuits in mammalian cells. We focused on CRISPR-Cas systems and exploited Cas proteins for their versatility as RBPs. The translation of genes encoded in an mRNA becomes regulatable by a Cas protein by inserting a crRNA/sgRNA sequence recognizable by the specific Cas protein into its 5'UTR. These Cas protein-responsive switches vastly expand the available tools in synthetic biology because of the wide range of Cas protein orthologs that can be used as trigger proteins.Here, we describe the design principle of Cas protein-responsive switches, both plasmid and RNA versions, using Streptococcus pyogenes Cas9 (SpCas9) as an example and show an example of its use in mammalian cells, HEK293FT cells.

Target-dependent RNA polymerase as universal platform for gene expression control in response to intracellular molecules

Controlling gene expression in response to specific molecules is an essential technique for regulating cellular functions. However, current platforms with transcription and translation regulators have a limited number of detectable molecules to induce gene expression. Here to address these issues, we present a Target-dependent RNA polymerase (TdRNAP) that can induce RNA transcription in response to the intracellular target specifically recognized by single antibody. By substituting the fused antibody, we demonstrate that TdRNAPs respond to a wide variety of molecules, including peptides, proteins, RNA, and small molecules, and produce desired transcripts in human cells. Furthermore, we show that multiple TdRNAPs can construct orthogonal and multilayer genetic circuits. Finally, we apply TdRNAP to achieve cell-specific genome editing that is autonomously triggered by detecting the target gene product. TdRNAP can expand the molecular variety for controlling gene expression and provide the genetic toolbox for bioengineering and future therapeutic applications.

Programmable mammalian translational modulators by CRISPR-associated proteins

Translational modulation based on RNA-binding proteins can be used to construct artificial gene circuits, but RNA-binding proteins capable of regulating translation efficiently and orthogonally remain scarce. Here we report CARTRIDGE (Cas-Responsive Translational Regulation Integratable into Diverse Gene control) to repurpose Cas proteins as translational modulators in mammalian cells. We demonstrate that a set of Cas proteins efficiently and orthogonally repress or activate the translation of designed mRNAs that contain a Cas-binding RNA motif in the 5'-UTR. By linking multiple Cas-mediated translational modulators, we designed and built artificial circuits like logic gates, cascades, and half-subtractor circuits. Moreover, we show that various CRISPR-related technologies like anti-CRISPR and split-Cas9 platforms could be similarly repurposed to control translation. Coupling Cas-mediated translational and transcriptional regulation enhanced the complexity of synthetic circuits built by only introducing a few additional elements. Collectively, CARTRIDGE has enormous potential as a versatile molecular toolkit for mammalian synthetic biology.

Synthetic circular RNA switches and circuits that control protein expression in mammalian cells

Synthetic messenger RNA (mRNA) has been focused on as an emerging application for mRNA-based therapies and vaccinations. Recently, synthetic circular RNAs (circRNAs) have shown promise as a new class of synthetic mRNA that enables superior stability and persistent gene expression in cells. However, translational control of circRNA remained challenging. Here, we develop 'circRNA switches' capable of controlling protein expression from circRNA by sensing intracellular RNA or proteins. We designed microRNA (miRNA) and protein-responsive circRNA switches by inserting miRNA-binding or protein-binding sequences into untranslated regions (UTRs), or Coxsackievirus B3 Internal Ribosome Entry Site (CVB3 IRES), respectively. Engineered circRNAs efficiently expressed reporter proteins without inducing severe cell cytotoxicity and immunogenicity, and responded to target miRNAs or proteins, controlling translation levels from circRNA in a cell type-specific manner. Moreover, we constructed circRNA-based gene circuits that selectively activated translation by detecting endogenous miRNA, by connecting miRNA and protein-responsive circRNAs. The designed circRNA circuits performed better than the linear mRNA-based circuits in terms of persistent expression levels. Synthetic circRNA devices provide new insights into RNA engineering and have a potential for RNA synthetic biology and therapies.

Versatile strategy using vaccinia virus-capping enzyme to synthesize functional 5' cap-modified mRNAs

The potential of synthetic mRNA as a genetic carrier has increased its application in scientific fields. Because the 5' cap regulates the stability and translational activity of mRNAs, there are concerted efforts to search for and synthesize chemically-modified 5' caps that improve the functionality of mRNA. Here, we report an easy and efficient method to synthesize functional mRNAs by modifying multiple 5' cap analogs using a vaccinia virus-capping enzyme. We show that this enzyme can introduce a variety of GTP analogs to the 5' end of RNA to generate 5' cap-modified mRNAs that exhibit different translation levels. Notably, some of these modified mRNAs improve translation efficiency and can be conjugated to chemical structures, further increasing their functionality. Our versatile method to generate 5' cap-modified mRNAs will provide useful tools for RNA therapeutics and biological research.

Sensing intracellular signatures with synthetic mRNAs

The bottom-up assembly of biological components in synthetic biology has contributed to a better understanding of natural phenomena and the development of new technologies for practical applications. Over the past few decades, basic RNA research has unveiled the regulatory roles of RNAs underlying gene regulatory networks; while advances in RNA biology, in turn, have highlighted the potential of a wide variety of RNA elements as building blocks to construct artificial systems. In particular, synthetic mRNA-based translational regulators, which respond to signals in cells and regulate the production of encoded output proteins, are gaining attention with the recent rise of mRNA therapeutics. In this Review, we discuss recent progress in RNA synthetic biology, mainly focusing on emerging technologies for sensing intracellular protein and RNA molecules and controlling translation.

Efficacy and safety of pemafibrate versus bezafibrate in coronary artery disease patients receiving statin treatment: a randomized, open-label, cross-over study

Background

Fibrates activate peroxisome proliferator-activated receptor (PPAR)-α which is associated with lipid metabolism. Bezafibrate is a non-selective PPAR-α agonist, whereas pemafibrate has been developed as a higher selective PPAR-α agonist.

Objective

The efficacy and safety of pemafibrate for 24-week in patients with dyslipidemia was examined in comparison with bezafibrate.

Methods

Sixty patients with hypertriglyceridemia (fasting triglyceride (TG) level of ≥150 mg/dL) were treated with pemafibrate of 0.2 mg/day or bezafibrate of 400 mg/day for 24-week in a randomized cross-over study. Percent change from baseline in TG levels was the primary endpoint, and that in HDL-C and apolipoprotein A-I (Apo A-I) levels was the secondary endpoints.

Results

A significantly greater reduction in TG percent change was observed in pemafibrate than in bezafibrate (−46.1% vs. −34.7%, p<0.001). There was no significant difference in HDL-C percent change between pemafibrate and bezafibrate (18.4% vs. 14.0%, p=0.067), whereas Apo A-I percent change was significantly greater in pemafibrate than in bezafibrate (9.2% vs. 5.7%, p=0.018). Pemafibrate and bezafibrate significantly decreased alanine aminotransferase (ALT) and gamma-glutamyltransferase (γ-GT) levels, and pemafibrate showed a greater reduction than bezafibrate (ALT: −21.9% vs. −10.6%, p=0.048; γ-GT: −43.5% vs. −33.1%, p=0.025). Creatinine levels significantly increased in both treatments (both p<0.001), however, creatinine percent change was significantly smaller in pemafibrate than in bezafibrate (5.72% vs. 15.5%, p<0.001). There was no difference in frequency of adverse event (AE) or serious AE between two treatments, but frequency of creatinine elevation (≥0.5 mg/d and/or 25%) was significantly higher in bezafibrate than in pemafibrate (16/60 vs. 3/60, p=0.004).

Conclusion

As compared with bezafibrate, pemafibrate is more effective to reduce TG levels and to elevate Apo A-I levels, and it is safer in terms of liver and renal function.

Funding Acknowledgement

Type of funding sources: None.

Xeno-free induced pluripotent stem cell-derived neural progenitor cells for in vivo applications

BACKGROUND

Currently, there is no regenerative therapy for patients with neurological and neurodegenerative disorders. Cell-therapies have emerged as a potential treatment for numerous brain diseases. Despite recent advances in stem cell technology, major concerns have been raised regarding the feasibility and safety of cell therapies for clinical applications.

METHODS

We generated good manufacturing practice (GMP)-compatible neural progenitor cells (NPCs) from transgene- and xeno-free induced pluripotent stem cells (iPSCs) that can be smoothly adapted for clinical applications. NPCs were characterized in vitro for their differentiation potential and in vivo after transplantation into wild type as well as genetically immunosuppressed mice.

RESULTS

Generated NPCs had a stable gene-expression over at least 15 passages and could be scaled for up to 1018 cells per initially seeded 106 cells. After withdrawal of growth factors in vitro, cells adapted a neural fate and mainly differentiated into active neurons. To ensure a pure NPC population for in vivo applications, we reduced the risk of iPSC contamination by applying micro RNA-switch technology as a safety checkpoint. Using lentiviral transduction with a fluorescent and bioluminescent dual-reporter construct, combined with non-invasive in vivo bioluminescent imaging, we longitudinally tracked the grafted cells in healthy wild-type and genetically immunosuppressed mice as well as in a mouse model of ischemic stroke. Long term in-depth characterization revealed that transplanted NPCs have the capability to survive and spontaneously differentiate into functional and mature neurons throughout a time course of a month, while no residual pluripotent cells were detectable.

CONCLUSION

We describe the generation of transgene- and xeno-free NPCs. This simple differentiation protocol combined with the ability of in vivo cell tracking presents a valuable tool to develop safe and effective cell therapies for various brain injuries.

O-080 Impact of age-limit policy change for assisted reproductive technology (ART) subsidy in Japan

Study question

What was the impact on treatment age in Japan after a subsidy policy change that set age limits for assisted reproductive technology (ART) treatment?

Summary answer

The national policy introducing age limits in the subsidy may have promoted ART treatment among younger women.

What is known already

Japan has provided partial subsidies for ART treatment since 2004. To promote treatment at a younger age, the government introduced a subsidy policy in 2016 that set age limits: up to six treatment cycles for women younger than 40 years of age; and up to three cycles for women between 40 and 42 years old. However, two out of 47 prefectures continued to provide subsidies to women aged 43 and older.

Study design, size, duration

We conducted a time series analysis of the utilisation of ART before and after the introduction of age limits, using data from the Japanese national ART registry from 2012 to 2016.

Participants/materials, setting, methods

We described the number of fresh and frozen treatment cycles, comparing the number between 45 prefectures that followed the national policy change (hereafter, prefectures with age limits) and two prefectures that did not (hereafter, prefectures without age limits). Ordinary least squares regression models were used to assess the impact of the policy change by prefecture on the number of ART cycles by women of different ages.

Main results and the role of chance

The overall number of fresh and frozen ART cycles continuously increased in all age groups from 2012 to 2016. Meanwhile, the number of fresh ART cycles among women aged ≤ 36 and 37-39 years in 2016 increased from the previous year by + 4.0% and +1.8% in prefectures with age limits, whereas it decreased in prefectures without age limits: -3.1% and -2.3%, respectively. The number of fresh ART cycles among women aged 40-42 and 43-45 years in prefectures with age limits in 2016 changed by + 1.5% and -0.1%, respectively, whereas it increased considerably in prefectures without age limits by + 9.6% and +65.4%, respectively. Similar changes were shown for the frozen cycles. After controlling for underlying time trends and prefectural characteristics, the policy change significantly increased the number of fresh and frozen ART treatment cycles among women aged ≤ 36 years and decreased the treatment cycles of women aged 40-42 years.

Limitations, reasons for caution

We evaluated the change observed in the year of the policy change and could not assess longer-term trends. Additionally, unobserved factors might have contributed to the change in treatment numbers.

Wider implications of the findings

The introduction of a policy to set an age limit for the partial ART subsidy resulted in a significant increase in treatment even among age groups younger than the boundary groups. The policy change might have conveyed educational messages regarding the benefits of early treatment.

Trial registration number

not applicable

Purification of human iPSC-derived cells at large scale using microRNA switch and magnetic-activated cell sorting

For regenerative cell therapies using pluripotent stem cell (PSC)-derived cells, large quantities of purified cells are required. Magnetic-activated cell sorting (MACS) is a powerful approach to collect target antigen-positive cells; however, it remains a challenge to purify various cell types efficiently at large scale without using antibodies specific to the desired cell type. Here we develop a technology that combines microRNA (miRNA)-responsive mRNA switch (miR-switch) with MACS (miR-switch-MACS) to purify large amounts of PSC-derived cells rapidly and effectively. We designed miR-switches that detect specific miRNAs expressed in target cells and controlled the translation of a CD4-coding transgene as a selection marker for MACS. For the large-scale purification of induced PSC-derived cardiomyocytes (iPSC-CMs), we transferred miR-208a-CD4 switch-MACS and obtained purified iPSC-CMs efficiently. Moreover, miR-375-CD4 switch-MACS highly purified pancreatic insulin-producing cells and their progenitors expressing Chromogranin A. Overall, the miR-switch-MACS method can efficiently purify target PSC-derived cells for cell replacement therapy.

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MiR-208a-CD4 switch-MACS can purify a large amount of iPSC-CMs in a short time

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MiR-208a switch can purify iPSC-CMs in each subtype-specific protocol

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MiR-375-CD4 switch-MACS can be applied to pancreatic endocrine precursor cells

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MiR-switch-MACS method can be efficient for large-scale target cell purification

The orthostatic hypotension in patients with Stanford type A aortic dissection after surgery

Funding Acknowledgements

Type of funding sources: None.

Background

Orthostatic hypotension (OH) is sometimes observed during cardiac rehabilitation in patients with surgery for aortic dissection. However, little is known about the primary determinant of OH and influence of surgical range on incidence of OH.

Purpose

The aim of this study was to elucidate the incidence of OH in patients with surgery for aortic dissection, and compare it between the patients with ascending aortic replacement surgery (ascending group) and those with ascending aorta and hemiarch or total arch replacement surgery (arch group).

Methods

We analyzed 59 patients who underwent emergent surgery due to Stanford type A aortic dissection from January 2014 to March 2018, and compared the incidence of OH between ascending group (n = 28, age 69.8 ± 11.3 years) and arch group (n = 31, age 64.1 ± 13.0 years).

Results

The incidence of OH in total patients was 30.5%. There were no significant differences in patient characteristics including body tall, body weight, antihypertensive use and progress of rehabilitation between 2 groups. The arch group showed a significant higher incidence of OH as compared with ascending group (arch group: 46.4% vs. ascending group: 16.1%, p = 0.03). Moreover, the patients who occurred OH were significantly taller than those who did not occur OH.

Conclusions

OH was observed in about one third of patients with surgery for aortic dissection and it showed a close relationship with patient’s height and the range repaired by surgical operation. More careful cardiac rehabilitation is needed for tall patients with large area replacement of aorta.

Translational recoding by chemical modification of non-AUG start codon ribonucleotide bases

In contrast to prokaryotes wherein GUG and UUG are permissive start codons, initiation frequencies from non-AUG codons are generally low in eukaryotes, with CUG being considered as strongest. Here, we report that combined 5-cytosine methylation (5mC) and pseudouridylation (Ψ) of near-cognate non-AUG start codons convert GUG and UUG initiation strongly favored over CUG initiation in eukaryotic translation under a certain context. This prokaryotic-like preference is attributed to enhanced NUG initiation by Ψ in the second base and reduced CUG initiation by 5mC in the first base. Molecular dynamics simulation analysis of tRNA_i^Met anticodon base pairing to the modified codons demonstrates that Ψ universally raises the affinity of codon:anticodon pairing within the ribosomal preinitiation complex through partially mitigating discrimination against non-AUG codons imposed by eukaryotic initiation factor 1. We propose that translational control by chemical modifications of start codon bases can offer a new layer of proteome diversity regulation and therapeutic mRNA technology.

Versatile Design of Intracellular Protein-Responsive Translational Regulation System for Synthetic mRNA

Synthetic mRNA (mRNA) enables transgene expression without the necessity of nuclear import and the risk of insertional mutagenesis, which makes it an attractive tool for medical applications such as vaccination and protein replacement therapy. For further improvement of mRNA therapeutics, cell-selective translation is desirable, because transgene expression in nontarget cells sometimes causes adverse effects. In this study, we developed an intracellular protein-responsive translational regulation system based on Caliciviral VPg-based translational activator (CaVT) combined with inteins and target protein-binding nanobodies. This system enabled both translational activation and repression in a target protein-dependent manner. Importantly, the target protein can be altered by simply exchanging the nanobodies. The versatile design for target protein-responsive translational regulation holds promise for producing mRNA therapeutics with high safety.

Meta-regression Analysis of Study Heterogeneity for Systemic Outcomes after Periodontal Therapy

INTRODUCTION

The contribution of periodontal disease to adverse systemic consequences remains controversial. This analysis examined 2 well-investigated conditions independently and combined-adverse pregnancy outcomes and glycemic control for patients with diabetes-based on shared pathogenic mechanisms of periodontal infection and inflammation. It was proposed that inconsistencies in study design significantly contribute to outcome discrepancies found between periodontal intervention studies undergoing meta-analysis.

METHODS

Meta-analyses evaluating periodontal interventions on the rate of preterm birth and changes in glycated hemoglobin A1c in type 2 diabetes populations were conducted based on a systematic review of randomized controlled trials. Meta-regression covariates for exploring heterogeneity included sample size, level of medical management, and bias risk as moderator variables in a random-effects meta-regression.

RESULTS

Systematic review identified 17 studies of diabetes and 13 of pregnancy outcomes. Analyses of these studies identified 0.50% reduction in HbA1c and 0.78 odds ratio for preterm births. The heterogeneity associated with the models was high (I2 = 92.4 and I2 = 62.7%, respectively). The adjusted models evaluating each systemic condition separately accounted for 52.2% of the effect for diabetes and 81.4% for pregnancy outcome effects independently, and 63.5% collectively, across interventional studies.

CONCLUSION

This systematic review with meta-regression analysis of heterogeneity demonstrates that disparate results seen in randomized controlled trials of periodontal therapy affecting systemic outcomes may be explained in large part by study design, specifically stringency in consideration of medical management and sample size. The potential for confounding factors to influence outcomes remains a concern in understanding the implications of oral health on systemic conditions.

KNOWLEDGE TRANSFER STATEMENT

The findings of this study demonstrate that much of the benefits seen from periodontal therapy on adverse systemic outcomes for diabetes and pregnancy are due to limitations in study design.

A versatile and robust cell purification system with an RNA-only circuit composed of microRNA-responsive ON and OFF switches

Human induced pluripotent stem cells (iPSCs) are promising cell resources for cell therapy and drug discovery. However, iPSC-derived differentiated cells are often heterogenous and need purification using a flow cytometer, which has high cost and time consumption for large-scale purification. MicroRNAs (miRNAs) can be used as cell selection markers, because their activity differs between cell types. Here, we show miRNA-responsive ON and OFF switch mRNAs for robust cell purification. The ON switch contains a miRNA-target sequence after the polyadenylate tail, triggering translational activation by sensing the target miRNA. By designing RNA-only circuits with miRNA-ON and -OFF switch mRNAs that encode a lethal ribonuclease, Barnase, and its inhibitor, Barstar, we efficiently purified specific cell types, including human iPSCs and differentiated cardiomyocytes, without flow cytometry. Synthetic mRNA circuits composed of ON and OFF switches provide a safe, versatile, and time-saving method to purify various cell types for biological and clinical applications.

Large-Scale Analysis of RNA-Protein Interactions for Functional RNA Motif Discovery Using FOREST

RNA transcripts can form a variety of higher-order structures. We developed a large-scale affinity analysis system, FOREST (Folded RNA Element Profiling with Structure Library), to investigate the function of these RNA structures on transcriptome-wide scale. Here we describe a protocol to analyze RNA-protein interactions using FOREST . Users of the protocol prepare an RNA structure library comprised of diverse species of transcripts and perform high-throughput characterization of the RNA-protein interactions to obtain quantitative and comprehensive information on the binding affinities and specificities. Moreover, we demonstrate how FOREST can be used to analyze a non-canonical structure, the RNA G-quadruplex, without sequencing bias, because the quantification is performed directly on a microarray without sequence amplification. FOREST will contribute to the discovery of RNA structure motifs that determine RNA-protein interactions.

P–721 Probability of receiving assisted reproductive technology treatment through out-of-pocket payment and household income: A discrete choice experiment in Japan

Study question

What is the probability that patients will receive assisted reproductive technology (ART) treatment based on their out-of-pocket payment and income class?

Summary answer

Higher-income patients opted for ART even at a higher cost, whereas an out-of-pocket payment was the most influential determinant in all income groups.

What is known already

Economic disparities affect access to ART treatment in many countries. At the time of this survey, Japan provided partial reimbursement for ART treatment exclusively for those in low- or middle-income classes due to limited governmental budgets. However, the optimal financial support by income class is unknown.

Study design, size, duration

We conducted a discrete choice experiment (DCE) in Japan in January 2020 including 824 women with fertility problems who were recruited via an online social research panel.

Participants/materials, setting, methods

Participants included women aged 25–44 years undergoing fertility diagnosis or treatment. They completed a DCE questionnaire including 16 hypothetical scenarios, created by orthogonal design, to measure six relevant ART attributes (pregnancy rate, risk of adverse effects, number of visits to outpatient clinics, consultation hours, kindness of staff, and out-of-pocket expense) and their relation to treatment choice. We used mixed-effect logistic regression models to estimate the probability of receiving ART treatment for each attribute.

Main results and the role of chance

Of the 1,247 eligible women recruited, 824 completed the survey (66% participation rate). All six attributes significantly influenced treatment preference, with participants valuing out-of-pocket payment the most, followed by pregnancy rates and kindness of staff. The odds ratios of each attribute to receiving ART treatment were 0.58 (95% confidence interval [CI]: 0.57 − 0.59) for out-of-pocket payments per additional 100,000 Japanese yen (JPY; i.e., 800 euros), 1.47 (95% CI: 1.43 − 1.53) for pregnancy rates per additional 5%, and 4.16 (95% CI: 3.73 − 4.64) for kindness of staff, after adjusting for clinical and socioeconomic factors. Significant interactions occurred between high household income (≥8 million JPY) and high out-of-pocket payment (≥500,000 JPY). However, the mean predicted probability of the highest-income patients (i.e., ≥10 million JPY) to receive ART treatment at the average cost without public funding (i.e., 400,000 JPY) was 47% (interquartile range: 18%−76%), whereas that of middle-income patients (i.e., 6–8 million JPY) to receive ART at the average subsidized cost (i.e., 100,000 JPY) was 60% (interquartile range: 33%–88%).

Limitations, reasons for caution

Other attributes not included in our DCE scenarios might be relevant in real-life settings. Choices made in a DCE would not wholly match the actual treatment choices.

Wider implications of the findings: The present DCE suggested that out-of-pocket payment was the primary determinant in patients’ ART decisions. High-income patients were more likely to receive ART treatment even at a high cost, but their ineligibility for government financial support due to their high income might discourage them from receiving treatment.

Trial registration number

NA

Radiomics analysis of myocardial perfusion SPECT images in patients with cardiomyopathy and heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grants

Background

Although myocardial perfusion heterogeneity due to focally damaged cardiomyocytes is observed in single−photon emission computed tomography (SPECT) imaging, a current perfusion defect scoring system does not allow us to provide sufficient diagnostic information for heterogeneity.

Purpose

The aim of this study was to perform radiomics analysis of myocardial perfusion SPECT (MPS) images to investigate the potential to detect myocardial perfusion heterogeneity.

Methods

Patients with hypertrophic cardiomyopathy (n = 3), heart failure (n = 9), and with a low likelihood of coronary artery disease (n =15) (Figure 1), who underwent a rest 99mTc-MIBI myocardial perfusion SPECT, were assessed using a LIFEx software. Four shape−based features, 6 histogram−based features, and 32 textural features were computed. The relevant features for the classification of the patients were selected using the Boruta algorithm, and hierarchical clustering of the selected features using the Spearman correlation coefficient was also performed for the feature reduction. The receiver operating characteristics (ROC) analysis was performed by the support vector machine to calculate the area under the ROC curve (AUC) for the selected features.

Results

Of 40 features, 17 were selected by the classification analysis, and these features were classified into 7 classes by the correlation analysis (Figure 2). The ROC AUCs for 7 features extracted from each class were 0.99, 0.97, 0.96, 0.92, 0.90, 0.86, and 0.83 for the contrast of NDGLDM, the entropy of histogram, ZLNU of GLZLM, the energy of GLCM, the energy of histogram, SZLGE of GLZLM, and the correlation of GLCM, respectively, as compared to 0.39 for a summed rest score.

Conclusions

Radiomics analysis successfully determined the myocardial perfusion heterogeneity in patients with cardiomyopathy and heart failure. It might be promising for the evaluation of myocardial damages that cannot be analyzed by the conventional scoring method.

Fluid flow-induced left-right asymmetric decay of Dand5 mRNA in the mouse embryo requires a Bicc1-Ccr4 RNA degradation complex

Molecular left-right (L-R) asymmetry is established at the node of the mouse embryo as a result of the sensing of a leftward fluid flow by immotile cilia of perinodal crown cells and the consequent degradation of Dand5 mRNA on the left side. We here examined how the fluid flow induces Dand5 mRNA decay. We found that the first 200 nucleotides in the 3' untranslated region (3'-UTR) of Dand5 mRNA are necessary and sufficient for the left-sided decay and to mediate the response of a 3'-UTR reporter transgene to Ca2+, the cation channel Pkd2, the RNA-binding protein Bicc1 and their regulation by the flow direction. We show that Bicc1 preferentially recognizes GACR and YGAC sequences, which can explain the specific binding to a conserved GACGUGAC motif located in the proximal Dand5 3'-UTR. The Cnot3 component of the Ccr4-Not deadenylase complex interacts with Bicc1 and is also required for Dand5 mRNA decay at the node. These results suggest that Ca2+ currents induced by leftward fluid flow stimulate Bicc1 and Ccr4-Not to mediate Dand5 mRNA degradation specifically on the left side of the node.

Electric Quadrupolar Contributions in the Magnetic Phases of UNi_{4}B

We present acoustic signatures of the electric quadrupolar degrees of freedom in the honeycomb-layer compound UNi_{4}B. The transverse ultrasonic mode C_{66} shows softening below 30 K both in the paramagnetic phase and antiferromagnetic phases down to ∼0.33  K. Furthermore, we traced magnetic field-temperature phase diagrams up to 30 T and observed a highly anisotropic elastic response within the honeycomb layer. These observations strongly suggest that Γ_{6}(E_{2g}) electric quadrupolar degrees of freedom in localized 5f^{2} (J=4) states are playing an important role in the magnetic toroidal dipole order and magnetic-field-induced phases of UNi_{4}B, and evidence some of the U ions remain in the paramagnetic state even if the system undergoes magnetic toroidal ordering.

Immunohistochemical expression levels of cyclin D1 and CREPT reflect the course and prognosis in oral precancerous lesions and squamous cell carcinoma

Cyclin D1 is the most essential progressive regulator of the cell cycle, and its transcription is enhanced by CREPT (cell cycle-related and expression-elevated protein in tumour). These molecules regulate cell growth, and their aberrant expression can cause malignant transformation. In this study, the expression of these molecules was explored to investigate the molecular alterations in oral precancerous lesions and squamous cell carcinoma. Cyclin D1 and CREPT expression was examined immunohistochemically in tissue specimens from 55 patients with oral epithelial precursor lesions (OEPLs) and 84 patients with oral squamous cell carcinoma (OSCC). Associations between the results and clinicopathological variables were examined. Cyclin D1 and CREPT expression levels were higher in OSCC than in OEPLs. Furthermore, there were statistically significant differences in cyclin D1 expression among the different grades of OEPLs and OSCC lesions. In OSCC, there were statistically significant differences in CREPT expression according to sex, T stage, and degree of differentiation. In addition, the expression of both molecules was significantly correlated with postoperative metastasis and modes of invasion. The expression of cyclin D1 and CREPT was found to depend upon the state of development and progression of the oral epithelial lesions, and clinicopathological behaviours might be affected by these molecules in OSCC.

Light-controllable RNA-protein devices for translational regulation of synthetic mRNAs in mammalian cells

The photo-regulation of transgene expression is one effective approach in mammalian synthetic biology due to its high spatial and temporal resolution. While DNAs are mainly used as vectors, modified RNAs (modRNAs) are also useful for medical applications of synthetic biology, because they can avoid insertional mutagenesis and immunogenicity. However, the optogenetic control of modRNA-delivered transgenes is much more difficult than that of DNA-delivered transgenes. Here, we develop two types of photo-controllable translational activation systems that are compatible with modRNAs. One is composed of a heterodimerization domain-fused split translational activator protein and a photocaged heterodimerizer. The other is composed of a destabilizing domain-fused translational activator protein and a photocaged stabilizer. The destabilized type can be used for not only translational activation but also translational repression of the modRNAs. These photo-controllable translation systems will expand the application of mammalian synthetic biology research.

Prognostic significance of 2019 Asian Working Group for Sarcopenia update on definition of sarcopenia

Background/Introduction

Sarcopenia plays a major role in the pathophysiology of frailty and is associated with worse outcome in the elderly population including patients with heart failure. A recent update of the most common definition of sarcopenia in Asia, Asian Working Group for Sarcopenia (AWGS2019), included significant changes in the diagnostic algorithm with newly dividing sarcopenia into severe and “non-severe” sarcopenia.

Purpose

The objective of this study was to evaluate the differences between AWGS2014 and AWGS2019 in patients with heart failure.

Methods

In the multicenter prospective FRAGILE-HF registry, which included elderly (≥65 years old) patients who were hospitalized with heart failure, we studied 865 patients (80±8 years old, 42% female). All-cause death in 1-year follow-up was tracked.

Results

Based on the original version of AWGS (AWGS2014), 183 patients (21%) were diagnosed with sarcopenia, which was associated with higher age, lower physical performance, less muscle mass, and greater heart failure risk (all p<0.001) as well as higher rate of all-cause death (HR 1.90, p=0.004 after adjustment by multivariable regression). Those patients with sarcopenia by AWGS2014 were reclassified mainly to severe sarcopenia (155, 84.7%) by AWGS2019, and 25 (13.7%) and 2 (1.1%) were classified into sarcopenia and non-sarcopenia. Meanwhile, 24 (3.5%) and 4 (0.6%) of patients without sarcopenia by AWGS2014 were reclassified into sarcopenia and severe sarcopenia, respectively. Although severe sarcopenia by AWGS2019 was associated with higher age, lower physical performance, less muscle mass, and greater heart failure risk (all p<0.001), patients with “non-severe” sarcopenia was rather younger (p<0.001) and had better physical performance (p=0.021) despite less muscle mass (p<0.001) than those without sarcopenia. Multivariate Cox analysis demonstrated severe sarcopenia by AWGS2019 was an independent prognostic factor (HR 1.77, p=0.014), but “non-severe” sarcopenia was not (HR 1.52, p=0.37). The prognosis of patients who were reclassified from non-sarcopenia to sarcopenia or severe sarcopenia were comparable to those remained non-sarcopenia. When added to other risk factors, the prognostic predictability of AWGS2019 was significantly lower than AWGS2014 (net reclassification improvement −0.26, p=0.025).

Conclusions

About a half of “non-severe” sarcopenia in AWGS2019 were patients without sarcopenia in AWGS2014. The prognosis of such patients who were newly diagnosed as sarcopenia was good, resulting in low overall prognostic predictability of AWGS2019. A further consideration for diagnostic algorithms of sarcopenia may be warranted in patients with heart failure.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Japan Heart Foundation

Negative impact of skeletal muscle impairment in older patients with heart failure with reduced versus preserved ejection fraction

Background/Introduction

Reduced functional capacity is an important phenotype of heart failure (HF), even though it may be considered multifactorial, especially in HF with preserved ejection fraction (HFpEF). Impairment in skeletal muscle may be one of extra-cardiac factors for reduced functional capacity and subsequent poor outcome.

Purpose

We sought to investigate the impact of the impairment in skeletal muscle, defined by the cut-offs proposed by the international consensus, on functional capacity and clinical outcome, in HF patients with preserved and reduced EF (HFrEF).

Methods

This is a multicenter prospective study including 1317 consecutive older (≥65 years) hospitalized patients with HF [HFpEF (ejection fraction ≥45%, n=675, 82±7 years, 46.4% male) and HFrEF (ejection fraction <45%, n=642, 78±8 years, 68.4% male)].

Results

HFrEF patients were more likely to have low skeletal muscle mass measured by bioelectrical impedance analysis (30.9% vs 22.1%, p=0.003) whereas less likely to have low muscle strength (handgrip strength; 62.9% vs 73.8%, p<0.001) than HFpEF, resulting in similar prevalence of sarcopenia between the two groups (21.6% vs 18.1%, p=0.19). In HFrEF, presence of sarcopenia was an independent predictor of reduced functional capacity assessed by a 6-minute walk distance (standardized beta=−0.093, p=0.039 in multivariate linear regression analysis) and 1-year mortality (adjusted hazard ratio (aHR) and 95% CI; 2.14 (1.22–3.70), p=0.009 in multivariate Cox-regression analysis). In patients with HFpEF, sarcopenia could predict mortality (aHR and 95% CI; 2.23 (1.23–3.91), p=0.009), though its association with reduced functional capacity was not significant after multivariate adjustment (standardized beta=−0.059, p=0.20). Kaplan-Meier survival curves in HFpEF and HFrEF are shown (Figure).

Conclusion(s)

In older patients with HF, sarcopenia was similarly contributed to mortality in HFpEF and HFrEF whereas its influence on functional capacity was pronounced in HFrEF.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Japan Heart Foundation Research Grant

Chronotropic incompetence and exercise capacity after mitral valve surgery: the importance of blood hemoglobin level

Background

Chronotropic incompetence (CI) is sometimes observed during exercise training of cardiac rehabilitation in patients with cardiac surgery, however, little is known concerning the differences between patients with mitral valve (MV) and aortic valve (AV) surgery.

Purpose

Because the possibility exists that cardiac sympathetic nerves might be impaired by left atrium incision, we hypothesized that the incidence of CI was higher in patients with MV surgery (Mitral Valve Replacement and Mitral Valvuloplasty) as compared with patients with AV surgery (Aortic Valve Replacement). And if so, which factor determines the exercise capacity of patients after MV surgery. We thus aimed this study to elucidate the hypothesis with cardiopulmonary exercise testing (CPX).

Methods

We performed CPX by ramp loading with ergometer exercise in total 61 patients who had undergone elective cardiac valve operation (25 patients with MV surgery, age 59.2±9.9 years; 36 patients with AV surgery, age 64.6±12.3 years). We analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), and peak oxygen pulse (peak VO2/HR) with CPX, and blood hemoglobin concentration (Hb).

Results

The value of CRI was significantly decreased in the patients with MV surgery compared with those with AV surgery (MV; 0.19±0.10 vs. AV; 0.41±0.17, p<0.001). Peak VO2, peak VO2/HR and Hb were not significantly different between patients with MV and those with AV surgery. Patients with MV surgery showed correlations between peak VO2 and Hb (r=0.45, p<0.05), AT and Hb (r=0.52, p<0.01), and a strong correlation between peak VO2 and peak VO2/HR (r=0.63, p<0.001), but not in those with AV surgery.

Conclusions

The present study demonstrated that higher incidence of CI was shown in patients with MV surgery as compared with those with AV surgery. The exercise capacity of patients with MV surgery was determined by peak VO2/HR and Hb. These results suggest that 1) left atrium incision impairs cardiac sympathetic nerves and causes CI, 2) peak VO2/HR which is consisted of arterio-venous oxygen difference and Hb is critical indicator for exercise capacity in patients with MV surgery with CI.

Main results

Funding Acknowledgement

Type of funding source: None

Social frailty provides additive prognostic impact on one-year outcome in aged patients with congestive heart failure

Background

Frailty is associated with multisystem declines in physiologic reserve and increased vulnerability to stressors, resulting in increased risks of adverse clinical outcomes in patients with heart failure (HF). Although frailty is conceptualized as an accumulation of deficits in multiple areas, most of the studies have focused mainly on physical frailty, and the social domains is one of the least investigated area.

Objectives

We prospectively evaluated the incidence and prognostic implication of social frailty (SF) in older patients with HF.

Methods

The FRAGILE-HF is a multicenter, prospective cohort study including patients hospitalized for HF and aged ≥65 years old. We defined SF by Makizako's 5 items, which are 5 questions proposed and validated to be associated with future disability. The primary endpoint of this study was a composite of death from any cause and rehospitalization due to HF. The impact of SF on all-cause mortality alone was also evaluated.

Results

Among 1,240 hospitalized HF patients, 5 simple questions revealed that 825 (66.5%) were in SF. During 1-year observation period after the discharge, the combined endpoint was observed in 399 (32.2%) patients, and 145 (11.7%) patients died. Kaplan-Meier analysis showed that SF patients had significantly higher rates of both the combined endpoint and all-cause mortality than those without SF (Log-rank test: p<0.05 for both, Figures). Moreover, SF remained independently associated with higher event rate of the combined endpoint (hazard ratio: 1.30; 95% confidence interval: 1.02 to 1.66; p=0.038) and all-cause mortality (hazard ratio: 1.53; 95% confidence interval: 1.01 to 2.30; p=0.044), even after adjusting for other covariates. Significant incremental prognostic value was shown when information on social frailty was added to known risk factors for combined endpoint (NRI: 0.189, 95% confidence interval: 0.063–0.316, p=0.003) and all-cause mortality (NRI: 0.234, 95% confidence interval: 0.073–0.395, p=0.004).

Conclusions

Among older hospitalized patients with heart failure, two-thirds of the population was with SF. Evaluating SF provides additive prognostic information in elderly patients with heart failure.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Novartis Pharma Research Grants, Japan Heart Foundation Research Grant

N 1-Methylpseudouridine substitution enhances the performance of synthetic mRNA switches in cells

Synthetic messenger RNA (mRNA) tools often use pseudouridine and 5-methyl cytidine as substitutions for uridine and cytidine to avoid the immune response and cytotoxicity induced by introducing mRNA into cells. However, the influence of base modifications on the functionality of the RNA tools is poorly understood. Here we show that synthetic mRNA switches containing N¹-methylpseudouridine (m1Ψ) as a substitution of uridine substantially out-performed all other modified bases studied, exhibiting enhanced microRNA and protein sensitivity, better cell-type separation ability, and comparably low immune stimulation. We found that the observed phenomena stem from the high protein expression from m1Ψ containing mRNA and efficient translational repression in the presence of target microRNAs or proteins. In addition, synthetic gene circuits with m1Ψ significantly improve performance in cells. These findings indicate that synthetic mRNAs with m1Ψ modification have enormous potentials in the research and application of biofunctional RNA tools.

New physician specialty training system impact on distribution of trainees in Japan

OBJECTIVES

The problem of uneven distribution of medical services and inequitable distribution of physicians is drawing much attention worldwide. Revealing how changes in the specialty training system in Japan have affected the distribution of doctors could help us understand this problem. In 2018, a new and standardized specialty training system was implemented by the Japanese Medical Specialty Board, which is recognized by the Ministry of Health, Labor and Welfare. The purpose of this study was to investigate how this new system has affected the geographical distribution of doctors commencing specialty training (trainees) and choice of specialty in Japan.

STUDY DESIGN

Retrospective observational study.

METHODS

The change in the number of trainees between the control period (2012-2014) and 2018 was investigated, taking into account the prefecture and specialty selected. Population, the proportion of residents aged 65 years or older (aging rate), and the total number of overall doctors in each prefecture were considered as the background characteristics of each prefecture. We created a Lorenz curve and calculated the Gini coefficient for the distribution of trainees.

RESULTS

In 2018, the number of trainees per 100,000 population increased to 6.6 nationwide compared with 5.5 during the control period. The number of trainees per 100,000 population in 2018 increased in prefectures with a large population of ≧ 2,000,000, a low aging rate (<27%), and a high doctor density (≧ 250 doctors per 100,000 population). The Gini coefficient showed an increase to 0.226 in 2018 compared with only 0.160 during the control period.

CONCLUSIONS

After the implementation of the new training system, there was an increase in the number of doctors enrolling in specialty programs, and the specialties other than internal medicine and surgery have attracted more trainees. Inequality in the distribution of doctors between urban and rural prefectures worsened. This indicates the need to explore new ways of balancing distribution while maintaining optimal opportunities for specialist training.

Synthetic mRNA-Based Systems in Mammalian Cells

Living organisms are programmed to perform multiple functions by sensing intra- and extra-cellular environments and by controlling gene expressions. Synthetic biologists aim to program cells by mimicking, designing, and constructing genetic circuits. Synthetic mRNA-based genetic switches and circuits have attracted attention for future therapeutic applications because of their safety and functional diversity. Here, the mRNA-based switches and circuits that detect specific microRNAs or proteins expressed in a target cell to control transgene expression and cell fate are reviewed. Future perspectives of artificial RNA systems for cell engineering will also be addressed.