Determining the potency of primordial germ cells by injection into early mouse embryos

Primordial germ cells (PGCs) are the earliest precursors of the gametes. During normal development, PGCs only give rise to oocytes or spermatozoa. However, PGCs can acquire pluripotency in vitro by forming embryonic germ (EG) cells and in vivo during teratocarcinogenesis. Classic embryological experiments directly assessed the potency of PGCs by injection into the pre-implantation embryo. As no contribution to embryos or adult mice was observed, PGCs have been described as unipotent. Here, we demonstrate that PGCs injected into 8-cell embryos can initially survive, divide, and contribute to the developing inner cell mass. Apoptosis-deficient PGCs exhibit improved survival in isolated epiblasts and can form naive pluripotent embryonic stem cell lines. However, contribution to the post-implantation embryo is limited, with no functional incorporation observed. In contrast, PGC-like cells show an extensive contribution to mid-gestation chimeras. We thus propose that PGC formation in vivo establishes a latent form of pluripotency that restricts chimera contribution.

Induction and in silico staging of human gastruloids with neural tube, segmented somites & advanced cell types

Embryonic organoids are emerging as powerful models for studying early mammalian development. For example, stem cell-derived 'gastruloids' form elongating structures containing all three germ layers1-4. However, although elongated, human gastruloids do not morphologically resemble post-implantation embryos. Here we show that a specific, discontinuous regimen of retinoic acid (RA) robustly induces human gastruloids with embryo-like morphological structures, including a neural tube and segmented somites. Single cell RNA-seq (sc-RNA-seq) further reveals that these human 'RA-gastruloids' contain more advanced cell types than conventional gastruloids, including neural crest cells, renal progenitor cells, skeletal muscle cells, and, rarely, neural progenitor cells. We apply a new approach to computationally stage human RA-gastruloids relative to somite-resolved mouse embryos, early human embryos and other gastruloid models, and find that the developmental stage of human RA-gastruloids is comparable to that of E9.5 mouse embryos, although some cell types show greater or lesser progression. We chemically perturb WNT and BMP signaling in human RA-gastruloids and find that these signaling pathways regulate somite patterning and neural tube length, respectively, while genetic perturbation of the transcription factors PAX3 and TBX6 markedly compromises the formation of neural crest and somites/renal cells, respectively. Human RA-gastruloids complement other embryonic organoids in serving as a simple, robust and screenable model for decoding early human embryogenesis.

A single-cell time-lapse of mouse prenatal development from gastrula to birth

The house mouse (Mus musculus) is an exceptional model system, combining genetic tractability with close evolutionary affinity to humans1,2. Mouse gestation lasts only 3 weeks, during which the genome orchestrates the astonishing transformation of a single-cell zygote into a free-living pup composed of more than 500 million cells. Here, to establish a global framework for exploring mammalian development, we applied optimized single-cell combinatorial indexing3 to profile the transcriptional states of 12.4 million nuclei from 83 embryos, precisely staged at 2- to 6-hour intervals spanning late gastrulation (embryonic day 8) to birth (postnatal day 0). From these data, we annotate hundreds of cell types and explore the ontogenesis of the posterior embryo during somitogenesis and of kidney, mesenchyme, retina and early neurons. We leverage the temporal resolution and sampling depth of these whole-embryo snapshots, together with published data4-8 from earlier timepoints, to construct a rooted tree of cell-type relationships that spans the entirety of prenatal development, from zygote to birth. Throughout this tree, we systematically nominate genes encoding transcription factors and other proteins as candidate drivers of the in vivo differentiation of hundreds of cell types. Remarkably, the most marked temporal shifts in cell states are observed within one hour of birth and presumably underlie the massive physiological adaptations that must accompany the successful transition of a mammalian fetus to life outside the womb.

Pluripotent stem cell-derived model of the post-implantation human embryo

The human embryo undergoes morphogenetic transformations following implantation into the uterus, but our knowledge of this crucial stage is limited by the inability to observe the embryo in vivo. Models of the embryo derived from stem cells are important tools for interrogating developmental events and tissue-tissue crosstalk during these stages1. Here we establish a model of the human post-implantation embryo, a human embryoid, comprising embryonic and extraembryonic tissues. We combine two types of extraembryonic-like cell generated by overexpression of transcription factors with wild-type embryonic stem cells and promote their self-organization into structures that mimic several aspects of the post-implantation human embryo. These self-organized aggregates contain a pluripotent epiblast-like domain surrounded by extraembryonic-like tissues. Our functional studies demonstrate that the epiblast-like domain robustly differentiates into amnion, extraembryonic mesenchyme and primordial germ cell-like cells in response to bone morphogenetic protein cues. In addition, we identify an inhibitory role for SOX17 in the specification of anterior hypoblast-like cells2. Modulation of the subpopulations in the hypoblast-like compartment demonstrates that extraembryonic-like cells influence epiblast-like domain differentiation, highlighting functional tissue-tissue crosstalk. In conclusion, we present a modular, tractable, integrated3 model of the human embryo that will enable us to probe key questions of human post-implantation development, a critical window during which substantial numbers of pregnancies fail.

A single-cell transcriptional timelapse of mouse embryonic development, from gastrula to pup

The house mouse, Mus musculus, is an exceptional model system, combining genetic tractability with close homology to human biology. Gestation in mouse development lasts just under three weeks, a period during which its genome orchestrates the astonishing transformation of a single cell zygote into a free-living pup composed of >500 million cells. Towards a global framework for exploring mammalian development, we applied single cell combinatorial indexing (sci-*) to profile the transcriptional states of 12.4 million nuclei from 83 precisely staged embryos spanning late gastrulation (embryonic day 8 or E8) to birth (postnatal day 0 or P0), with 2-hr temporal resolution during somitogenesis, 6-hr resolution through to birth, and 20-min resolution during the immediate postpartum period. From these data (E8 to P0), we annotate dozens of trajectories and hundreds of cell types and perform deeper analyses of the unfolding of the posterior embryo during somitogenesis as well as the ontogenesis of the kidney, mesenchyme, retina, and early neurons. Finally, we leverage the depth and temporal resolution of these whole embryo snapshots, together with other published data, to construct and curate a rooted tree of cell type relationships that spans mouse development from zygote to pup. Throughout this tree, we systematically nominate sets of transcription factors (TFs) and other genes as candidate drivers of the in vivo differentiation of hundreds of mammalian cell types. Remarkably, the most dramatic shifts in transcriptional state are observed in a restricted set of cell types in the hours immediately following birth, and presumably underlie the massive changes in physiology that must accompany the successful transition of a placental mammal to extrauterine life.

Generation of functional oocytes from male mice in vitro

Sex chromosome disorders severely compromise gametogenesis in both males and females. In oogenesis, the presence of an additional Y chromosome or the loss of an X chromosome disturbs the robust production of oocytes1-5. Here we efficiently converted the XY chromosome set to XX without an additional Y chromosome in mouse pluripotent stem (PS) cells. In addition, this chromosomal alteration successfully eradicated trisomy 16, a model of Down's syndrome, in PS cells. Artificially produced euploid XX PS cells differentiated into mature oocytes in culture with similar efficiency to native XX PS cells. Using this method, we differentiated induced pluripotent stem cells from the tail of a sexually mature male mouse into fully potent oocytes, which gave rise to offspring after fertilization. This study provides insights that could ameliorate infertility caused by sex chromosome or autosomal disorders, and opens the possibility of bipaternal reproduction.

Robust induction of primordial germ cells of white rhinoceros on the brink of extinction

In vitro gametogenesis, the process of generating gametes from pluripotent cells in culture, is a powerful tool for improving our understanding of germ cell development and an alternative source of gametes. Here, we induced primordial germ cell-like cells (PGCLCs) from pluripotent stem cells of the northern white rhinoceros (NWR), a species for which only two females remain, and southern white rhinoceros (SWR), the closest species to the NWR. PGCLC differentiation from SWR embryonic stem cells is highly reliant on bone morphogenetic protein and WNT signals. Genetic analysis revealed that SRY-box transcription factor 17 (SOX17) is essential for SWR-PGCLC induction. Under the defined condition, NWR induced pluripotent stem cells differentiated into PGCLCs. We also identified cell surface markers, CD9 and Integrin subunit alpha 6 (ITGA6), that enabled us to isolate PGCLCs without genetic alteration in pluripotent stem cells. This study provides a first step toward the production of NWR gametes in culture and understanding of the basic mechanism of primordial germ cell specification in a large animal.

Trends and outcomes of early rehabilitation in intensive care unit for patients with cardiovascular disease – a cohort study with propensity score-matched analysis

Background

Early rehabilitation in the intensive care unit (ICU), including early mobility therapy, is known to improve the clinical outcomes in patients with critically ill. However, the effectiveness of acute-phase cardiovascular rehabilitation (CR) during ICU treatment have not been thoroughly evaluated in patients with cardiovascular disease (CVD).

Purpose

We aimed to investigate the trends and outcomes of acute-phase CR in the ICU for patients with CVD, including in-hospital and long-term clinical outcomes.

Methods

We reviewed 1948 consecutive patients with CVD admitted to tertiary academic ICU at a university hospital. Patients were arbitrarily assessed by an ICU team consisting of medical and surgical doctors, nurses and physiotherapists within 24 hours after admission to ICU to discover whether their rehabilitation could be initiated according to the specific clinical trial and statement. As clinical characteristics, disease aetiology, comorbid conditions, and ICU treatment were obtained from an electronic database. We evaluated the probability of return to walking independence and return to home as in-hospital clinical outcomes. All patients were followed for five years and investigated all-cause and cardiovascular events after hospital discharge as long-term clinical outcomes. The associations between the implementation of CR during ICU treatment (ICU-CR) and clinical outcomes were evaluated using propensity score-matched analysis with adjustment for clinical characteristics in all matched patients and various subgroups, including aged >65 years, surgical patients, emergency, and length of ICU stay ≥48 hours.

Results

Out of studied patients, 1092 patients received ICU-CR, the number of which positively correlated with year-trend (r=0.986, P<0.001). After propensity score matching with adjustment for clinical characteristics including calendar years, 758 patients were included for analysis (pairs of n=379 ICU-CR and non-ICU-CR). The ICU-CR was significantly associated with a higher probability of return to walking independence (incident rate ratio [IRR], 2.04; 95% confidence interval [CI], 1.77–2.36) and return to home (IRR, 1.22 95% CI, 1.05–1.41). These associations were consistently observed in various subgroups regarding CVD conditions (Figure 1). During the median follow-up periods of 2.6 years, all-cause clinical events and cardiovascular events occurred in 289 patients (38.1%) and 153 patients (20.2%), respectively. The ICU-CR showed significantly lower rates of five-year all-cause and cardiovascular events than non-ICU-CR (hazard ratio [95% CI] for all-cause events and cardiovascular events, 0.71 [0.56–0.89] and 0.69 [0.50–0.95], respectively, Figure 2).

Conclusions

The implementation of acute-phase CR in the ICU increased with year-trend, considered beneficial to improve in-hospital and long-term clinical outcomes in patients with CVD and various subgroups of relatively severe disease conditions.

Funding Acknowledgement

Type of funding sources: None.

Perme ICU Mobility Score as a comprehensive assessment tool of acute-phase rehabilitation is correlated with clinical outcomes in patients after cardiovascular surgery

Background

Early mobility therapy in the intensive care unit (ICU) is widely employed to improve the physical function and prognosis of patients with critically ill. On the other hand, patients who undergo cardiovascular surgery frequently suffer from disabilities after ICU care due to their cardiopulmonary conditions and treatments. However, few studies have reported the procedures and assessments of acute-phase rehabilitation in these patients. Recently, the Perme ICU Mobility Score (Perme Score) was developed as a reliable tool to assess comprehensive mobility status of patients in the ICU. We hypothesised that the Perme Score is a useful tool for assessing the mobility levels in the ICU and predicting clinical outcomes in patients undergoing acute-phase rehabilitation after cardiovascular surgery.

Purpose

To investigate the associations between the Perme Score within the second days after cardiovascular surgery and the patients' clinical outcomes, including physical function and the incidence of clinical events.

Methods

We studied 224 consecutive patients (34.4% female; aged 65±13 years) who were admitted to the ICU of a tertiary academic hospital after cardiac and/or major vascular surgery. Clinical characteristics including patient profiles, comorbidities, surgical details and APACHE II and SOFA scores were evaluated on ICU admission. The Perme Score contains categories on mental status, potential mobility barriers, muscle strength and mobility level, with higher scores indicating greater activity levels in the ICU. We assessed the Perme Score within the second days after the surgery. As a physical function at hospital discharge, we measured the six-minute walk distance (6MWD). The primary endpoint was a composite outcome of the number of all-cause mortality and/or all-cause unplanned readmission. We analysed the associations of the Perme Score with the 6MWD and the incidence of clinical events using multiple regression analysis and multivariate Poisson regression analysis, respectively.

Results

After adjusting for clinical confounding factors, a higher Perme Score was an independent factor of a higher 6MWD (Table 1). During the median follow-up period of 1.3 years, 51 cases of all-cause mortality/readmission occurred in 37 (16.5%) patients, with an incidence rate of 18.6/100 person-years. In the multivariate Poisson regression analysis, even after adjusting for the severity score in the ICU, a higher Perme Score was significantly and independently associated with lower rates of all-cause clinical events (adjusted incident rate ratio: 0.96, 95% confidence interval: 0.93–0.99, P=0.008, Figure 1).

Conclusions

The Perme Score within the second days after cardiovascular surgery is correlated with physical function at hospital discharge and the incidence of clinical events after discharge. Thus, a comprehensive assessment of acute-phase rehabilitation after cardiovascular surgery may be useful in predicting clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

Cancer as a risk factor for physical dysfunction and poor prognosis in patients with cardiovascular disease

Introduction

The emerging interdisciplinary field of cardio-oncology is of interest to clinicians because a history of cancer or cancer treatment is considered a severe risk factor for cardiovascular disease (CVD). Both cancer and CVD can reduce skeletal muscle mass; together, they can lead to a poorer prognosis. However, it is unclear whether a patient's cancer history can lower physical function and lead to a poor prognosis with the coexistence of cancer history and physical dysfunction in patients with CVD. This study aimed to identify the relationship between cancer history and physical function, as well as the prognostic value of their combination, in patients with CVD.

Methods

We reviewed 3,640 patients with CVD (mean age, 67.9±13.5 years) who underwent physical-function tests (gait speed and 6-min walking distance [6MWD]). We performed multivariate linear regression analysis to assess potential associations between cancer history and physical-function tests in patients with CVD. Additionally, we used the Kaplan–Meier curve and Cox regression analyses to assess survival and prognostic significance for patients divided into four groups according to the presence or absence of cancer history and high or low physical function.

Results

In multivariate linear regression analysis, cancer history was independently associated with lower gait speed and 6MWD (gait speed, P=0.048 and 6MWD, P=0.040). A total of 581 deaths occurred over a median follow-up period of 3.08 years (interquartile range: 1.36–5.27). For all-cause mortality, patients with a history of cancer and reduced physical function were found to have a significantly higher mortality risk even after adjusting for several covariates (gait speed, HR: 1.66, P=0.003 and 6MWD, HR: 1.71, P=0.003).

Conclusion

Cancer history was correlated with physical dysfunction in patients with CVD. Moreover, the coexistence of cancer history and physical dysfunction resulted in poorer prognosis in patients with CVD.

Funding Acknowledgement

Type of funding sources: None.

Sex differences in frequency of instrumental activities of daily living after cardiac rehabilitation and its impact on long-term mortality in patients with heart failure

Introduction

While the major outcome of cardiac rehabilitation for heart failure (HF) is the improvement of exercise tolerance, prognosis, and quality of life, instrumental activities of daily living (IADL) has also been focused on as one of the its outcomes. IADL has been reported to be associated with all-cause mortality and quality of life in community-dwelling people and in patients with stable heart disease, but no report has examined the relationship between IADL after cardiac rehabilitation for HF and prognosis. In addition, it is assumed that sex differences may affect the frequency of performing each component of IADL, but there are no reports examining the association with prognosis by sex.

Purpose

The present study aimed to investigate the sex differences in frequency of IADL and its impact on outcomes.

Methods

We retrospectively studied 490 consecutive patients who were admitted due to acute decompensated HF and participated in outpatient cardiac rehabilitation after discharge. The study was performed in accordance with the tenets of the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of our institution. IADL frequency was assessed using the questionnaire-based Frenchay Activities Index (FAI). The primary endpoint was all-cause death and secondary endpoint was combined events (all-cause death and/or readmission due to HF). We performed the Kaplan–Meier and log-rank tests and multivariable Cox regression analysis to evaluate the prognostic predictive capability of the FAI.

Results

The study population had a median age of 69 (interquartile range [IQR]: 58–76) years, and 33.9% of patients were females. The median FAI score was 24 (IQR: 16–29) points. According to the Youden index based on the area under the curve calculated by the receiver operating characteristics curve, the cut-off values of FAI for all-cause death in all-over, females, and males were 23, 22, and 23 points, respectively. Over a median follow-up period of 4.8 years (IQR: 2.3–6.6 years), all-cause death and combined events were occurred in 95 (19.4%) and 213 (43.5%), respectively. After adjustment for several pre-existing prognostic factors, IADL assessed by the FAI was independently associated with all-cause mortality (hazard ratio [HR]: 0.961, 95% confidence interval [CI]:0.937–0.986) and combined events (HR: 0.968, 95% CI: 0.952–0.985), respectively. In addition, there was no interaction between sex in prognostic capability (P=0.664).

Conclusion

Lower IADL frequency assessed by FAI at the end of outpatient cardiac rehabilitation was shown to be associated with poorer prognosis in patients with HF, regardless of sex. The IADL level is generally higher in females than in males but seems to be a useful marker for risk stratification at the end of cardiac rehabilitation in both females and males.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid [JSPS KAKENHI Grant Number JP 19K19884]

Impact of small-airway disease on exercise intolerance and long-term outcomes in patients with heart failure and reduced or preserved ejection fraction

Introduction

Exercise intolerance in patients with heart failure (HF) is a strong indicator of a poor prognosis. As the respiratory impairment in HF patients, the small airway is reportedly more susceptible than central airways, which results in increased airway resistance and may cause poor outcomes. However, the impact of small-airway disease (SAD) on exercise intolerance and prognosis in patients with HF is still unclear.

Purpose

We investigated the associations between SAD and exercise intolerance in patients with HF, and the clinical significance of SAD for long-term clinical events with a reduced or preserved ejection fraction.

Methods

We reviewed 1015 patients with HF (mean age, 66.9±14.6 years; male, 64.5%) admitted for medical treatment. Patients with a prior history of chronic respiratory disease or an obstructive lung pattern – defined as the forced expiratory volume (%) in 1 s relative to <70% forced vital capacity using spirometry – were excluded. Characteristics including HF aetiology, comorbidities conditions, medications, blood parameters, and echocardiographic variables were obtained from clinical records. All patients underwent spirometry at hospital discharge, and SAD was defined as the maximum mid-expiratory flow (%) relative to a <60% predicted value. At hospital discharge, we measured 6-min walk distance (6MWD), and <300 m was considered as exercise intolerance. The primary endpoint was a composite clinical event of all-cause death and/or unplanned readmission for HF. Multivariate logistic regression analysis was used to assess the association between SAD and exercise intolerance. The multivariate Cox proportional hazard model was used to clarify whether SAD was an independent predictor for the incidence of clinical events. We also performed subgroup analyses in each multivariate analysis based on a left ventricular ejection fraction (LVEF) of 40%.

Result

SAD was observed in 479 (47.2%) patients. LVEF subgroups included 458 (45.1%) and 518 (51.0%) patients with LVEF <40% and ≥40%, respectively. After adjusting for clinical characteristics, SAD was independently associated with 6MWD <300 m (Figure 1). Moreover, this association was consistently observed in the LVEF <40% and ≥40% (Figure 1). During the median follow-up period of 1.5 years, all-cause death/readmission occurred in 431 patients (42.5%), and the incidence rate was 17.5/100 person-years. In the multivariate Cox proportional hazard model, SAD was independently associated with lower event-free survival rates in all patients and the LVEF <40% subgroup, but not LVEF ≥40% subgroup (Figure 2A, B, and C, respectively).

Conclusion

This study is the first to reveal that SAD is associated with exercise intolerance in patients with HF regardless of LVEF. Moreover, SAD may have a predictive significance for long-term outcomes in patients with HF and subgroups with reduced, but not preserved ejection fraction.

Funding Acknowledgement

Type of funding sources: None.

A time-resolved, multi-symbol molecular recorder via sequential genome editing

DNA is naturally well suited to serve as a digital medium for in vivo molecular recording. However, contemporary DNA-based memory devices are constrained in terms of the number of distinct 'symbols' that can be concurrently recorded and/or by a failure to capture the order in which events occur1. Here we describe DNA Typewriter, a general system for in vivo molecular recording that overcomes these and other limitations. For DNA Typewriter, the blank recording medium ('DNA Tape') consists of a tandem array of partial CRISPR-Cas9 target sites, with all but the first site truncated at their 5' ends and therefore inactive. Short insertional edits serve as symbols that record the identity of the prime editing guide RNA2 mediating the edit while also shifting the position of the 'type guide' by one unit along the DNA Tape, that is, sequential genome editing. In this proof of concept of DNA Typewriter, we demonstrate recording and decoding of thousands of symbols, complex event histories and short text messages; evaluate the performance of dozens of orthogonal tapes; and construct 'long tape' potentially capable of recording as many as 20 serial events. Finally, we leverage DNA Typewriter in conjunction with single-cell RNA-seq to reconstruct a monophyletic lineage of 3,257 cells and find that the Poisson-like accumulation of sequential edits to multicopy DNA tape can be maintained across at least 20 generations and 25 days of in vitro clonal expansion.

Relationship between the spread of coronavirus disease 2019, social frailty and depressive symptoms in patients with heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the Japan Society for the Promotion of Science (JSPS) KAKENHI

Background

Owing to the spread of coronavirus disease 2019 (COVID-19), people have refrained from going out unnecessarily and have been maintaining social distance. These new lifestyle approaches have affected people physically, psychologically, and socially. Patients with heart failure (HF) are more likely to have social frailty, physical frailty, cognitive impairment, and depressive symptoms, and an overlap of these conditions leads to adverse events. Therefore, multi-domain assessment and understanding of the condition of patients with HF are important for disease management. The spread of COVID-19 is a predicted risk factor for these events, but its impact in patients with HF has not been investigated.

Purpose

We investigated whether the spread of COVID-19 is associated with the development of the multi-domain of frailty in patients with HF.

Methods

Patients who were independent in their daily activities before admission were included in the study. The presence of social frailty (Makizako’s five items), physical frailty (Fried phenotype model), cognitive impairment (Mini-Cog), and depressive symptoms (the Patient Health Questionnaire-2) in patients with HF were assessed at hospital discharge. Logistic regression analyses were used to examine the impact of the spread of COVID-19 on the development of the multi-domain of frailty in patients with HF.

Results

We included 482 patients in this study. Median patient age was 74 years, and 64.5% were male. In multivariate logistic regression analyses, the spread of COVID-19 was significantly associated with the development of social frailty (odds ratio [OR]: 1.15, 95% confidence interval [CI]: 1.02–1.30) and depressive symptoms (OR: 1.14, 95% CI: 1.02–1.27) but not with the development of physical frailty (OR: 1.24, 95% CI: 0.51–3.02) and cognitive impairment (OR: 1.72, 95% CI: 0.80–3.73).

Conclusion

The spread of COVID-19 was associated with the development of social frailty and depressive symptoms in patients with HF. Evaluation of social frailty and depressive symptoms during hospitalization would support disease management and understand their social and psychological conditions specific to the spread of COVID-19.

Prevalence of metabolic dysfunction-associated fatty liver disease and its association with physical function in patients with acute coronary syndrome

Funding Acknowledgements

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

Background

It is widely known that patients with acute coronary syndrome (ACS) are at increased risk of nonalcoholic fatty liver disease (NAFLD), which is linked to sarcopenia and physical dysfunction. However, the relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and physical dysfunction remains unclear.

Purpose

The purpose of this study was to investigate the prevalence of MAFLD in patients with ACS to assess the relationship between MAFLD and muscle strength, walking speed, and 6-minute walking distance (6 MWD).

Methods

We reviewed patients with ACS who were assessed for hepatic steatosis using the fatty liver index, and the results were further assessed to determine the presence of MAFLD. Multiple regression analysis was used to examine the association between MAFLD and physical function.

Results

Among 479 enrolled hospitalized patients, MAFLD was identified in 234 (48.9%) patients. We conducted a multiple regression analysis in which MAFLD was independently associated with lower leg strength, gait speed, and 6 MWD (leg strength, P = 0.023; gait speed, P = 0.002 and 6 MWD, P = 0.017). Furthermore, having more metabolic impairment was still associated with lower physical function decline (leg strength, P for trend = 0.002; gait speed, P for trend = 0.019 and 6 MWD, P for trend = 0.003).

Conclusions

MAFLD is common in hospitalized patients with ACS, and most patients with MAFLD have many overlapping metabolic abnormalities. MAFLD is associated with impaired physical function, and the greater the number of overlapping metabolic abnormalities, the worse the motor function.

Skeletal muscle mass metrics as factors in the prognosis of heart failure patients

Funding Acknowledgements

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

Background

Sarcopenia is a chronic condition that is characterized by the loss of skeletal muscle mass with declining muscle strength and/or performance that occurs gradually with aging. It has been reported that sarcopenia is highly prevalent in patients with heart failure (HF) and is a poor prognostic factor. Therefore, it is important to accurately assess skeletal muscle mass in patients with HF. However, there are no reports that have simultaneously examined different skeletal muscle mass metrics as factors in the prognosis of HF patients.

Purpose

The purpose of this study is to examine if the different skeletal muscle mass metrics are associated with the prognosis of HF patients.

Methods

We examined a total of 869 patients with HF, aged ≥20 years (73 [63, 80] years; 537 males), who were admitted to our hospital and participated in an inpatient cardiac rehabilitation program. We used skeletal muscle mass index (SMI) as measured by bioelectrical impedance analysis (BIA), mid-upper arm circumference (MUAC), arm muscle circumference (AMC), and calf circumference (CC) as metrics of skeletal muscle mass. The primary outcome was all-cause deaths, and secondary outcome was HF readmission. To investigate the association between each skeletal muscle mass metric and prognosis, patients were divided into three groups according to the tertiles of SMI, MUAC, AMC, and CC. In addition, cumulative event rates of survival curves, Gray test, and Fine & Gray test were performed to evaluate the prognostic predictive capability.

Results

Over a median follow-up period of 0.9 years (interquartile 0.4–1.9) years, a total of 80 deaths and 195 HF readmissions occurred in the patients. Cumulative event rates of survival curves and Gray test showed that there was a significant decrease in all-cause mortality and HF readmission in the high MUAC group and high AMC group compared to their respective low groups (P < 0.05). Fine & Gray test after multivariate adjustment showed significantly better prognosis in the high MUAC group and high AMC group compared to their respective low groups (All-cause mortality: high MUAC group, subdistribution hazard ratio [sHR] = 0.42, 95% confidence interval [CI] = 0.20-0.88, P < 0.05; high AMC group, sHR = 0.34, 95%CI = 0.16-0.72 P < 0.05, HF readmission: high MUAC group, sHR = 0.69, 95%CI = 0.47-1.00, P < 0.05; high AMC group, sHR = 0.63, 95%CI = 0.43-0.93, P < 0.05).

Conclusion

Patients with HF who maintained high MUAC and high AMC had a good prognosis. CC and SMI were not associated with the prognosis of HF patients. This suggests the importance of evaluating MUAC and AMC in HF patients.

Dual role of Ovol2 on the germ cell lineage segregation during gastrulation in mouse embryogenesis

In mammals, primordial germ cells (PGCs), the origin of the germ line, are specified from the epiblast at the posterior region where gastrulation simultaneously occurs, yet the functional relationship between PGC specification and gastrulation remains unclear. Here, we show that OVOL2, a transcription factor conserved across the animal kingdom, balances these major developmental processes by repressing the epithelial-to-mesenchymal transition (EMT) that drives gastrulation and the upregulation of genes associated with PGC specification. Ovol2a, a splice variant encoding a repressor domain, directly regulates EMT-related genes and, consequently, induces re-acquisition of potential pluripotency during PGC specification, whereas Ovol2b, another splice variant missing the repressor domain, directly upregulates genes associated with PGC specification. Taken together, these results elucidate the molecular mechanism underlying allocation of the germ line among epiblast cells differentiating into somatic cells through gastrulation.

This article has an associated ‘The people behind the papers’ interview.

Associations between kidney function and outcomes following cardiac rehabilitation in patients with heart failure

Background

Kidney dysfunction is considered one of the most prevalent comorbidities in patients with heart failure (HF). A combination of HF and kidney dysfunction is associated with peripheral muscle impairment, exercise intolerance, and poor prognosis. Conversely, cardiac rehabilitation (CR) for HF patients has been recognized to improve their clinical outcomes. However, the impact of kidney function on responses to CR in patients with HF is still unclear.

Purpose

This study aimed to investigate the associations between baseline kidney function and outcomes following CR including changes in physical function and prognosis in HF patients.

Methods

We reviewed a total of 3,727 patients who were admitted for HF treatment and underwent comprehensive CR during hospitalization. In addition to clinical characteristics, we assessed the kidney function using estimated glomerular filtration rate (eGFR) based on serum creatinine level at hospital discharge as baseline. The quadriceps strength (QS) and 6-minute walk distance (6MWD) were measured as muscle strength and functional capacity, respectively, at baseline. We also remeasured these parameter 5 months after hospital discharge in patients who participated in outpatient CR. The association between participation in outpatient CR and composite outcome of all-cause death and/or unplanned readmission were assessed using the multivariate Cox proportional hazard models in a subgroup of baseline eGFR. We also compared the changes in QS and 6MWD (ΔQS and Δ6MWD) between the eGFR stages.

Results

During the median follow-up period of 1.9 years, all-cause death/readmission occurred in 1604 (43.0%) patients, and their rate of incidence was 20.9/100 person-years. Out of studied patients, 1,585 (42.5%) patients participated in outpatient CR that was significantly associated with lower incidences of all-cause clinical events in patients with both eGFR ≥60 (adjusted hazard ratio [HR]: 0.73, 95% confidence interval [CI]: 0.60–0.89, P=0.002) and eGFR <60 (adjusted HR: 0.88, 95% CI: 0.78–0.99, P=0.045), but those with an eGFR <60 showed significant interaction between CR participation and adverse clinical events (interaction P<0.035, Figure 1). Among the outpatient CR participants, QS and 6MWD were significantly higher after 5-month CR than those at baseline (P<0.001, respectively), but the low baseline eGFR correlated with low ΔQS and Δ6MWD (trend P<0.001, respectively) even after adjustment for clinical confounding factors (Figure 2).

Conclusions

Although the outcomes following CR is affected by baseline kidney function, outpatient CR is significantly associated with the positive change in physical function and better prognosis in HF patients with low kidney function.

Funding Acknowledgement

Type of funding sources: None.

Associations of severity of liver damages with physical function and prognosis in patients with heart failure

Funding Acknowledgements

Type of funding sources: None.

Introduction

Heart failure (HF) and liver dysfunction often coexist because of complex cardiohepatic interactions, which adversely affects prognosis. However, the association between liver dysfunction and physical dysfunction, and between coexistence of both and prognosis in HF patients remains unclear.

Purpose

We evaluated the associations of severity of liver damage and physical function and prognosis in patients with HF.

Methods

The study population consisted of 895 patients with HF (mean age, 69.4 ± 14.2 years) who underwent liver function test using model for end-stage liver disease excluding international normalized ratio (MELD-XI) score and physical function test (grip strength, leg strength, gait speed, and 6-minute walking distance [6MWD]). The associations between MELD-XI score and physical function were assessed by multivariate linear regression model analysis. Moreover, we investigated the prognostic value of coexistence of liver dysfunction and physical dysfunction. The endpoint was all-cause mortality.

Results

After adjusting for covariates, MELD-XI score was independently associated with lower grip strength, leg strength, gait speed, and 6MWD (P < 0.001). In addition, hierarchical multivariate linear regression analysis revealed that adding MELD-XI scores or BNP explained additional variance in the physical function measures. The MELD-XI score added to the clinical model was significantly more predictive of physical function (grip strength, change in F: 27.105, P < 0.001; leg strength, change in F: 33.980, P < 0.001; gait speed, change in F: 22.826, P < 0.001; 6MWD, change in F: 59.193, P < 0.001) than BNP added to the clinical model. Eighty-six deaths occurred over a median follow-up period of 1.67 years (interquartile range: 0.62 – 3.04). Patients with high MELD-XI score and reduced physical function were found to have significantly higher mortality risk even after adjusting for several covariates (grip strength, hazard ratio [HR] = 3.80 [95% confidence interval (CI) = 2.04 – 7.08], P < 0.001; leg strength, HR = 4.65 [95% CI = 2.47 - 8.75], P < 0.001 and gait speed, HR = 2.49 [95% CI = 1.43 - 4.33], P = 0.001; 6MWD, HR = 5.48 [95% CI = 2.88 - 10.41], P < 0.001).

Conclusions

Liver dysfunction was correlated with reduced physical function. Moreover, the coexistence of lower physical function and liver dysfunction considerably affected prognosis in patients with HF.

Abstract Figure. Kaplan–Meier survival curves

Low skeletal muscle density combined with muscle dysfunction predicts adverse events after adult cardiovascular surgery

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): This study was supported by the Grant for Japan Society for the Promotion of Science (JSPS) KAKENHI.

Introduction

Although muscle dysfunction is widely known as a poor prognostic factor in patients with cardiovascular disease, no study has examined whether the addition of low skeletal muscle density (SMD) assessed by computed tomography (CT) to muscle dysfunction is useful.

Purpose

The present study aimed to examine whether SMDs can strengthen the predictive ability of muscle dysfunction for adverse events in patients who underwent cardiovascular surgery.

Methods

We retrospectively reviewed 853 patients (median age: 69 years, 65.1% male) aged ≥40 years who had preoperative CT for risk management purposes and muscle dysfunctions measured during postoperative cardiac rehabilitation. Muscle dysfunctions were determined from weakness (low grip strength) and slowness (slow gait speed) based on the Asia Working Group for Sarcopenia. Low SMD based on transverse abdominal CT images was defined as a mean Hounsfield unit of the psoas muscle <45. To examine the complementary prognostic value for all-cause deaths, all-cause events, and cardiovascular-related events when low SMDs were added to four patterns of muscle dysfunction (weakness only, slowness only, weakness or slowness, and weakness and slowness), the continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) index were calculated.

Results

For all definitions of muscle dysfunction, the addition of SMDs was shown to significantly improve the cNRI (estimates: 0.377 to 0.468 for all-cause death, 0.220 to 0.248 for all-cause events, 0.308 to 0.322 for cardiovascular-related events) and IDI (estimates: 0.005 to 0.011 for all-cause death, 0.005 to 0.010 for all-cause events, 0.009 to 0.012 for cardiovascular-related events) in all analyses. Low SMDs combined with muscle dysfunctions were associated with the highest risk of all-cause death (Figure 1: A-D). Patients with neither low SMDs nor muscle dysfunction had the lowest risk of all-cause events and cardiovascular-related events (Figure1: E-L).

Conclusion

The predictive ability of muscle dysfunction for adverse events was consistently increased by addition of SMDs in patients who underwent cardiovascular surgery. Our results suggest that when CT is performed for any clinical investigation, the addition of the organic assessment of skeletal muscle can strengthen the diagnostic accuracy of muscle wasting.

Abstract Figure 1

Correlation between respiratory muscle weakness and frailty status as risk markers for prognosis in patients with cardiovascular disease

Background

Respiratory muscle weakness (RMW), frequently observed in patients with cardiovascular disease (CVD), is documented as a predictor for exercise intolerance and poor prognosis. On the other hand, frailty is commonly associated with disease condition, leading to increased risk of morbidity and mortality. Although the developmental mechanism of RMW and frailty is partly similar, the relationship between these statuses remains unclear.

Purpose

We aimed to investigate the correlation between RMW and frailty and its impact on prognosis in patients with CVD.

Methods

We studied 771 consecutive patients (68.5±13.1 years, 256 females) who were hospitalized for CVD treatment and underwent cardiac rehabilitation during hospitalization. Patients who received thoracic surgery within the last 3 months or could not perform respiratory function test were excluded from this study. As patient characteristics, we obtained body mass index, comorbidity conditions, smoking history, blood examinations, echocardiographical variables, and lung function from medical database. The frailty status on admission was assessed using frailty score consisting of 5 items including gait speed, nutrition/shrinking, physical activity, forgetfulness, and emotions/exhaustion, and patients who had 3 items were defined as frailty. We also measured maximal inspiratory pressure (PImax) as respiratory muscle strength at hospital discharge, and RMW was defined with PImax <70% of predicted value. Primary end-point was all-cause clinical events including all-cause death and/or unplanned readmission after hospital discharge. We examined the prevalence of RMW and frailty and the correlation between these statuses. The relationships of RMW with the clinical events for each presence or absence of frailty were also investigated using multivariate Cox proportional hazard models.

Results

RMW and frailty were defined in 163 (33.5%) and 126 (28.7%) patients, respectively, and 95 patients (12.4%) among them showed an overlap of both statuses (Figure 1). Frailty was detected as a significant indicator of RMW after adjusting for confounding factors (adjusted odds ratio: 1.57, 95% CI: 1.12–2.19, P=0.009). Over the median follow-up periods of 1.2 years, all-cause clinical events occurred in 154 patients (20.0%). RMW was significantly and independently associated with increased incidence of all-cause clinical events in patients with both non-frailty (adjusted hazard ratio [HR]: 1.64, 95% CI: 1.09–2.46, P=0.017) and frailty (adjusted HR: 1.97, 95% CI: 1.14–3.42, P=0.015) even after adjusting for clinical confounding factors (Figure 2).

Conclusions

This study is the first to demonstrate that RMW correlated to frailty in patients with CVD, and 12.4% of patients had overlap status. Moreover, RMW was significantly associated with an increased risk of all-cause clinical events in patients with CVD and frailty.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science Grant-in-Aid

Transcriptional activation of the mouse Scd2 gene by interdependent enhancers and long noncoding RNAs in ovarian granulosa cells

Specific gene expression in granulosa cells is key for the function of ovary, but the molecular mechanism of transcriptional activation is not well studied. Here we investigated the regulatory mechanism of the mouse stearoyl-CoA desaturase 2 (Scd2) gene encoding an enzyme for lipid metabolism. Northern blot and in situ hybridization indicated that the mouse Scd2 mRNA was highly expressed in ovarian granulosa cells. We found four conserved noncoding sequences (CNSs) and two long noncoding RNAs (lncRNAs) transcribed from regions upstream of the Scd2 gene as candidates of regulatory elements/factors. These lncRNAs were predominantly transcribed in the opposite direction to Scd2 and localized in nuclei and showed the correlation with Scd2 expression, raising the possibility of their transcriptional regulatory roles. Indeed, knockdown of both lncRNAs, lncRNA-sc1 and lncRNA-sc2, significantly decreased the Scd2 mRNA level in primary granulosa cells. Then, we investigated the histone modification pattern at this locus by a chromatin immunoprecipitation assay, and two CNSs, CNS1 and CNS2, were found to be marked with high levels of histone H3K9/K27 acetylation in primary granulosa cells. By a reporter gene assay, both CNS1 and CNS2 interdependently exhibited enhancer activity for the Scd2 promoter in primary granulosa cells. These data suggest that the mouse Scd2 gene is activated by two lncRNAs and interdependent enhancers in ovarian granulosa cells, which provides a new insight into transcriptional activation in granulosa cells.

Germ cell-intrinsic effects of sex chromosomes on early oocyte differentiation in mice

A set of sex chromosomes is required for gametogenesis in both males and females, as represented by sex chromosome disorders causing agametic phenotypes. Although studies using model animals have investigated the functional requirement of sex chromosomes, involvement of these chromosomes in gametogenesis remains elusive. Here, we elicit a germ cell-intrinsic effect of sex chromosomes on oogenesis, using a novel culture system in which oocytes were induced from embryonic stem cells (ESCs) harboring XX, XO or XY. In the culture system, oogenesis using XO and XY ESCs was severely disturbed, with XY ESCs being more strongly affected. The culture system revealed multiple defects in the oogenesis of XO and XY ESCs, such as delayed meiotic entry and progression, and mispairing of the homologous chromosomes. Interestingly, Eif2s3y, a Y-linked gene that promotes proliferation of spermatogonia, had an inhibitory effect on oogenesis. This led us to the concept that male and female gametogenesis appear to be in mutual conflict at an early stage. This study provides a deeper understanding of oogenesis under a sex-reversal condition.

P6331Influence of dynapenia and obesity on prognoses of elderly heart failure patients

Background

In elderly people, a decline in activities of daily living is more closely associated with low muscle strength (dynapenia) than with low muscle mass. Moreover, the combination of low muscle strength and obesity (dynapenic obesity) is associated with a higher risk of mortality than dynapenia or obesity alone, but its influence on prognosis is still unknown in elderly heart failure (HF) patients. To clarify these relationships may contribute to the development of rehabilitation programs for elderly HF patients and the improvement their prognoses in the future.

Purpose

We aimed to investigate the influence of dynapenia and obesity on prognoses of elderly HF patients.

Methods

We evaluated 1006 elderly HF patients aged ≥65 years (76.5±6.9 years, 579 males) who were admitted to our hospital and participated in an inpatient cardiac rehabilitation program. We assessed patients' characteristics, including body mass index (BMI) and handgrip strength during hospitalization. Patients with low handgrip strength (<26 kg and <18 kg in males and females, respectively) and high BMI (≥25 kg/m2) were considered to have dynapenia and obesity, respectively. Moreover, patients fulfilling the above two criteria (dynapenia, obesity) were considered to have dynapenic obesity. Patients were divided into four groups: normal, dynapenia only, obesity only, and dynapenic obesity. We compared survival rates among the four groups using the Kaplan-Meier method and log-rank test. To identify predictors for all-cause mortality, we performed Cox regression analysis.

Results

During the 8-year follow-up period, 228 patients (21.2%) died. Eight-year cumulative incidences of mortality were 35.4%, 26.0%, 62.6%, and 33.1% in the normal, obesity only, dynapenia only, and dynapenic obesity groups, respectively. Significantly lower survival rates were observed in the dynapenia only group than in the other 3 groups (log-rank: 28.893, P<0.001). Cox regression analysis, after adjusting for age and sex, showed significantly poor prognosis in the dyanapenia only group than in the other 3 groups (normal group, hazard ratio [HR] = 0.684, 95% confidence interval [CI] = 0.488–0.959, P=0.028; obesity only group, HR = 0.330, 95% CI = 0.182–0.598, P<0.001; dynapenic obesity group, HR = 0.390, 95% CI = 0.206–0.739, P=0.004).

Conclusion

Elderly HF patients with dynapenia alone had poor prognoses. Obesity may have protective effects on the survival of dynapenia patients with HF.

P2514Pupillary area predicts all-cause mortality in patients with cardiovascular disease

Background

Autonomic dysfunction is among the most important pathophysiological factors involved in the high mortality rate associated with cardiovascular disease (CVD). Autonomic function is generally evaluated by heart rate variability, which is obtained by Holter electrocardiography. However, the measurement of heart rate variability requires continuous electrocardiographic monitoring for 24 h, which is time consuming and not always feasible. The pupillary area is controlled by the autonomic nervous system; however, limited data are available regarding the utility of the pupillary area for predicting prognosis in patients with CVD.

Purpose

We aimed to investigate whether pupillary area can be used as a novel prognostic marker in patients with CVD.

Methods

We retrospectively reviewed 1342 consecutive Japanese patients hospitalized for CVD. The study was performed in accordance with the tenets of the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of our University Hospital. The pupillary area measurement was performed on both eyes at least 7 days after hospitalization for CVD using a portable videopupillography system (Iriscorder Dual C10641; Hamamatsu Photonics, Hamamatsu, Japan) consisting of a goggle-shaped measurement portion with a charge-coupled device camera and a control portion with a video monitor and microcomputer with software for data analysis. After securing the goggles on the patient's face and fully covering the patient's eyes, a 5-minute period was allowed for dark adaptation. All patients were tested once between 09:00 and 12:00 h. The primary outcome of this study was all-cause mortality, and the endpoint time was calculated as the number of days from the date of pupillary area measurement up to three years. We performed the Kaplan–Meier and log-rank tests and multivariable Cox regression analysis to evaluate the prognostic predictive capability of the pupillary area.

Results

The study population had a mean age of 65±13 years, and 69.4% of the patients were male. The median of the pupillary area was 18.5 mm2 (interquartile range: 13.3–23.4 mm2). Over a median follow-up period of 1.9 years (interquartile range: 1.0–3.0 years), a total of 114 deaths occurred in the patient population. The Kaplan–Meier and log-rank tests revealed that all-cause mortality was significantly higher in the small pupillary area group than in the large pupillary area group (P<0.0001, Figure). Furthermore, Cox regression analysis indicated that the pupillary area was an independent predictor of mortality (Hazard ratio: 0.96; 95% confidence interval: 0.93–0.98; P=0.006) even after adjusting for several preexisting prognostic factors.

Kaplan-Meire Curve

Conclusion

The pupillary area can be an independent predictor of prognosis in patients with CVD, and our observations suggest that the assessment of the pupillary area can be useful as a new noninvasive prognostic predictor in patients with CVD.

P2610Increase in comfortable walking speed during hospitalization predicts the readmission due to decompensated heart failure in heart failure patients with preserved ejection fraction

Background

Heart failure patients with preserved ejection fraction (HFpEF) have reduced exercise capacity and poor prognosis as well as those with reduced ejection fraction (HFrEF). Both cardiac function and exercise capacity have been known as prognostic factors for patients with HFrEF. However, few reports documented the relations of comfortable walking speed (CWS) during hospitalization to exercise capacity and prognosis. is used as a clinical measure to assess their exercise capacity and prognosis. However, few reports documented the correlations of CWS with exercise capacity and prognosis in patients with HFpEF.

Purpose

This study aimed to investigate whether CWS at hospital discharge and the increase in CWS during hospitalization predicted the readmission due to decompensated heart failure in patients with HFpEF and HFrEF.

Methods

Patients who were hospitalized due to heart failure with New York Heart Association (NYHA) Functional Classification III or IV were prospectively followed up for 3 years after hospital discharge. Consequently, 264 patients, 173 males and 92 females, aged 73.2±6.8 years were studied. Patients were divided into 3 groups based on their ejection fraction (EF): HFpEF group (EF≥50%; n=98), HFrEF group (EF<40%; n=138) and heart failure with mid-range ejection fraction (HFmrEF) group (40%≤EF≤49%; n=28). We assessed clinical characteristics including age, gender, height, NYHA functional classification, etiology of CHF, plasma brain natriuretic peptide and left ventricular ejection fraction (LVEF) on admission, and measured CWS several days after admission and at discharge. We determined significant factors affecting the readmission and their cut-off values using univariate and multivariate logistic regression analyses and the area under the receiver operating characteristics curves in the three groups.

Results

Forty patients (40.8%), 54 (39.1%) and 6 (21.4%) were readmitted in the HFpEF, HFrEF and HFmrEF groups, respectively, within 3 years after the discharge. Univariate logistic regression analysis detected the age, LVEF, CWS at discharge and the CWS increase during hospitalization as significant limiting factors for readmission in the HFpEF and HFrEF groups (P<0.05, respectively). The multivariate logistic regression analysis detected the CWS increase during hospitalization as significant limiting factor for readmission in the HFpEF and HFrEF groups (P<0.001 and P<0.05, respectively). The odds ratios of readmission were 1.86 (P<0.01) and 1.44 (P<0.001) with each 5-meter decrease of CWS increase during hospitalization and predictive cut-off values of the CWS increase were 7.5 and 8.5 meters/min in the HFpEF and HFrEF groups, respectively.

Conclusion

This study demonstrated that the CWS increase during hospitalization was a strong predictor for readmission due to decompensated heart failure in patients not only with HFrEF but also with HFpEF and each predictive the cut-off value was 7.5 and 8.5 meters/min.

298Change in respiratory muscle strength predicts clinical events in patients with chronic heart failure

Background

Respiratory muscle weakness, frequently observed in patients with chronic heart failure (CHF), has been documented as a predictor for poor prognosis. Several studies have reported that respiratory muscle training increases respiratory muscle strength and consequently improves exercise tolerance and quality of life in these patients. However, the relationship between the change in respiratory muscle strength and prognosis is still unclear.

Purpose

We aimed to investigate whether the change in respiratory muscle strength following cardiac rehabilitation predicts the incidence of clinical events in CHF patients.

Methods

We studied 348 patients with CHF who were hospitalized because of decompensated heart failure and received 5-month cardiac rehabilitation during hospitalization and after hospital discharge. Clinical characteristics including aetiology of heart failure, comorbidity conditions, medications, blood examination and echocardiographic variables were obtained from clinical records. We also measured maximal inspiratory pressure (PImax) as respiratory muscle strength at hospital discharge and 5 months later. The change of PImax (ΔPImax) between the 5-month observation period was examined. We followed up the patients after the observation period and investigated the incidence of all-cause mortality or all-cause unplanned readmission. In statistical analysis, patients were divided into two groups based on the median value of ΔPImax. We compared the event-free survival rate between the two groups using the Kaplan-Meier method with a log-rank test. We also performed the Cox proportional hazard model to clarify whether the ΔPImax was an independent predictor for the incidence of clinical events.

Results

Over a median follow-up of 1.6 years, 121 patients (34.8%) died or readmitted, and their rate of incidence was 21.7/100 person-years. The higher ΔPImax was associated significantly with a higher rate of event-free survival (Log-rank: 8.085, P=0.004, Figure 1). In univariate Cox proportional hazard model, ΔPImax was a significant predictor for the all-cause mortality/readmission (unadjusted hazard ratio for PImax increase of 10 cmH2O: 0.842, 95% CI: 0.763 - 0.931, P=0.001). Even after adjustment for clinical confounding factors including baseline PImax, ΔPImax remained significant and independent predictor for the all-cause mortality/readmission (adjusted hazard ratio for PImax increase of 10 cmH2O: 0.862, 95% CI: 0.763 - 0.974, P=0.017, Figure 2).

Conclusion

This study is the first to demonstrate that the change in respiratory muscle strength following cardiac rehabilitation independently predicts the incidence of clinical events in patients with CHF. The increase in PImax of 10 cmH2O was associated significantly with a 14% decrease in the rate of all-cause mortality or readmission.

Acknowledgement/Funding

JSPS KAKENHI JP16K16442

P3106Atrial fibrillation is not associated with the responses to exercise training in heart failure patients with preserved ejection fraction

Background

Atrial fibrillation (AF) is known as a common arrhythmia in heart failure patients with preserved left ventricular ejection fraction (HFpEF). Several studies have reported that HFpEF patients with AF show lower exercise tolerance and poorer prognosis as compared with those with sinus rhythm (SR). On the other hand, exercise training is documented to improve peripheral muscle function and exercise tolerance in HFpEF patients. However, the relationship between AF status and outcomes due to exercise training is still unclear in these patients.

Purpose

We aimed to investigate the influence of AF on the responses to outcomes with exercise training in HFpEF patients.

Methods

We studied 426 patients with HFpEF who received 5-month cardiac rehabilitation including exercise training during hospitalization and after hospital discharge. As clinical characteristics, we obtained body mass index, disease aetiology, comorbidity conditions, blood examination and echocardiographic variables from medical records. We also measured isometric quadriceps strength (QS) and 6-minute walk distance (6MWD) as peripheral muscle strength and exercise tolerance, respectively. The QS and 6MWD were assessed at hospital discharge as the baseline and 5 months later. AF status was determined by the presence on electrocardiogram at baseline 6MWD or medical history of AF during hospitalization. In statistical analysis, we compared baseline clinical characteristics, QS and 6MWD between the rhythm status (SR group or AF group). We also examined the changes in QS and 6MWD from baseline to the 5-month observation period (ΔQS and Δ6MWD) and compared them between the 2 groups using analysis of covariance with adjustment for baseline clinical confounding factors.

Results

At baseline, 289 patients (68%) were in SR, and 111 patients (26%) had AF. The AF was associated significantly with older age (P<0.001) and lower levels of estimated glomerular filtration rate (P=0.013), QS (P<0.001) and 6MWD (P<0.001) at baseline. The QS increased significantly from 25.2±11.0 kg at baseline to 30.8±13.0 kg after 5-month cardiac rehabilitation in the SR group, and from 21.1±8.3 kg to 26.0±9.4 kg in the AF group (P<0.001, respectively). The 6MWD also increased significantly from 394.8±129.2 to 463.5±133.5 meters in the SR, and from 343.7±107.9 to 403.0±114.5 meters in the AF (P<0.001, respectively). There were no significant differences in ΔQS and Δ6MWD between the SR and AF groups even after adjustment for clinical confounding factors including baseline QS or 6MWD (Figure).

Conclusions

The AF status in HFpEF patients was associated with older age, lower peripheral muscle function and also lower exercise tolerance at baseline, but not associated with the responses to exercise training.

Acknowledgement/Funding

JSPS KAKENHI JP16K16442

Mechanical stress accompanied with nuclear rotation is involved in the dormant state of mouse oocytes

The most immature oocytes remain dormant in primordial follicles in the ovary, ensuring the longevity of female reproductive life. Despite its biological and clinical importance, knowledge of mechanisms regulating the dormant state remains limited. Here, we show that mechanical stress plays a key role in maintaining the dormant state of the oocytes in primordial follicles in mice. Transcriptional and histological analyses revealed that oocytes were compressed by surrounding granulosa cells with extracellular matrix. This environmental state is functionally crucial, as oocytes became activated upon loosening the structure and the dormancy was restored by additional compression with exogenous pressure. The nuclei of oocytes in primordial follicles rotated in response to the mechanical stress. Pausing the rotation triggered activation of oocytes through nuclear export of forkhead box O3 (FOXO3). These results provide insights into the mechanisms by which oocytes are kept dormant to sustain female reproductive life.

Pioneer Factor NeuroD1 Rearranges Transcriptional and Epigenetic Profiles to Execute Microglia-Neuron Conversion

Minimal sets of transcription factors can directly reprogram somatic cells into neurons. However, epigenetic remodeling during neuronal reprogramming has not been well reconciled with transcriptional regulation. Here we show that NeuroD1 achieves direct neuronal conversion from mouse microglia both in vitro and in vivo. Exogenous NeuroD1 initially occupies closed chromatin regions associated with bivalent trimethylation of histone H3 at lysine 4 (H3K4me3) and H3K27me3 marks in microglia to induce neuronal gene expression. These regions are resolved to a monovalent H3K4me3 mark at later stages of reprogramming to establish the neuronal identity. Furthermore, the transcriptional repressors Scrt1 and Meis2 are induced as NeuroD1 target genes, resulting in a decrease in the expression of microglial genes. In parallel, the microglial epigenetic signature in promoter and enhancer regions is erased. These findings reveal NeuroD1 pioneering activity accompanied by global epigenetic remodeling for two sequential events: onset of neuronal property acquisition and loss of the microglial identity during reprogramming.

Prognostic usefulness of arm circumference and nutritional screening tools in older patients with cardiovascular disease

BACKGROUND AND AIM

Arm circumference (AC) and nutritional screening tools have been shown to have prognostic capability in patients with cardiovascular disease (CVD). This study aimed to compare the prognostic predictive capabilities of AC and nutritional screening tools in older patients with CVD.

METHODS AND RESULTS

The study population consisted of 949 admitted patients ≥60 years old with CVD. Patients underwent AC measurement and nutritional screening before hospital discharge. We used the controlling nutritional status index (CONUT), the geriatric nutritional risk index (GNRI), and the prognostic nutritional index (PNI) as nutritional screening tools. The end point of the study was all-cause mortality. The mean age of the study population was 72.3 ± 7.2 years, and 68.2% of the patients were male. A total of 130 deaths occurred over a median follow-up period of 2.2 years (interquartile range, 1.1-3.8 years). After adjusting for other prognostic factors, AC (hazard ratio [HR]: 0.59; p < 0.001), CONUT (HR: 0.82; p = 0.016), GNRI (HR: 0.77; p = 0.040), and PNI (HR: 0.80; p = 0.014) were significant predictors of mortality. However, adding AC to the multivariate-adjusted model (0.739 vs. 0.714, respectively; p = 0.037), but not CONUT, GNRI, or PNI (0.724, 0.717, and 0.723 vs. 0.714; p = 0.072, p = 0.306, and p = 0.127, respectively), significantly increased the area under the curve on receiver operating characteristic curve.

CONCLUSIONS

AC, but not nutritional screening tools, plays a complementary role to preexisting prognostic factors for predicting prognosis in older patients with CVD.

DNA Methylome Analysis Identifies Transcription Factor-Based Epigenomic Signatures of Multilineage Competence in Neural Stem/Progenitor Cells

Regulation of the epigenome during in vivo specification of brain stem cells is still poorly understood. Here, we report DNA methylome analyses of directly sampled cortical neural stem and progenitor cells (NS/PCs) at different development stages, as well as those of terminally differentiated cortical neurons, astrocytes, and oligodendrocytes. We found that sequential specification of cortical NS/PCs is regulated by two successive waves of demethylation at early and late development stages, which are responsible for the establishment of neuron- and glia-specific low-methylated regions (LMRs), respectively. The regulatory role of demethylation of the gliogenic genes was substantiated by the enrichment of nuclear factor I (NFI)-binding sites. We provide evidence that de novo DNA methylation of neuron-specific LMRs establishes glia-specific epigenotypes, essentially by silencing neuronal genes. Our data highlight the in vivo implications of DNA methylation dynamics in shaping epigenomic features that confer the differentiation potential of NS/PCs sequentially during development.

Detection of Bidirectional Promoter-Derived lncRNAs from Small-Scale Samples Using Pre-Amplification-Free Directional RNA-seq Method

Development of high-throughput sequencing technologies has uncovered the immensity of the long noncoding RNA (lncRNA) world. Divergently transcribed lncRNAs from bidirectional gene promoters, called promoter-associated noncoding RNAs (pancRNAs), account for ~20% of the total number of lncRNAs, and this major fraction is involved in many biological processes, such as development and cancer formation. Recently, we have found that the pancRNAs activate their partner genes, as represented by the fact that pancIl17d, a pancRNA that is transcribed from the antisense strand of the promoter region of Interleukin 17d (Il17d) at the onset of zygotic gene activation (ZGA), is essential for mouse preimplantation development through Il17d upregulation. The discovery of the expression of a specific set of pancRNAs during ZGA was achieved by using a method that generates directional RNA-seq libraries from small-scale samples. Although there are several methods available for small-scale samples, most of them require a pre-amplification procedure that frequently generates some amplification biases toward a subset of transcripts. We provide here a highly sensitive and reproducible method based on the preparation of directional RNA-seq libraries from as little as 100 mouse oocytes or embryos without pre-amplification for the quantification of lncRNAs as well as mRNAs.

Reconstitution in vitro of the entire cycle of the mouse female germ line

The female germ line undergoes a unique sequence of differentiation processes that confers totipotency to the egg. The reconstitution of these events in vitro using pluripotent stem cells is a key achievement in reproductive biology and regenerative medicine. Here we report successful reconstitution in vitro of the entire process of oogenesis from mouse pluripotent stem cells. Fully potent mature oocytes were generated in culture from embryonic stem cells and from induced pluripotent stem cells derived from both embryonic fibroblasts and adult tail tip fibroblasts. Moreover, pluripotent stem cell lines were re-derived from the eggs that were generated in vitro, thereby reconstituting the full female germline cycle in a dish. This culture system will provide a platform for elucidating the molecular mechanisms underlying totipotency and the production of oocytes of other mammalian species in culture.

Gene activation-associated long noncoding RNAs function in mouse preimplantation development

In mice, zygotic activation occurs for a wide variety of genes, mainly at the 2-cell stage. Long noncoding RNAs (lncRNAs) are increasingly being recognized as modulators of gene expression. In this study, directional RNA-seq of MII oocytes and 2-cell embryos identified more than 1000 divergently transcribed lncRNA/mRNA gene pairs. Expression of these bidirectional promoter-associated noncoding RNAs (pancRNAs) was strongly associated with the upregulation of their cognate genes. Conversely, knockdown of three abundant pancRNAs led to reduced mRNA expression, accompanied by sustained DNA methylation even in the presence of enzymes responsible for DNA demethylation. In particular, microinjection of siRNA against the abundant pancRNA partner of interleukin 17d (Il17d) mRNA at the 1-cell stage caused embryonic lethality, which was rescued by supplying IL17D protein in vitro at the 4-cell stage. Thus, this novel class of lncRNAs can modulate the transcription machinery in cis to activate zygotic genes and is important for preimplantation development.

Structure-activity studies on nociceptin analogues: ORL1 receptor binding and biological activity of cyclic disulfide-containing analogues of nociceptin peptides

Nociceptin/Orphanin FQ is an endogenous peptide ligand for the opioid receptor-like 1 (ORL1) receptor. To investigate the structural and conformational requirements of the nociceptin (NC)-receptor interaction, six cyclic analogues containing Cys disulfide linkages were designed and synthesized. Analogues cyclized at the N-terminal part, cyclo[Cys(0), Cys(7)]NC(1-13)-NH(2) (2) and cyclo[Cys(0), Cys(11)]NC(1-13)-NH(2) (4), and their corresponding linear peptides had very low activities in both the receptor binding and the GTP gamma S functional assays using human ORL1 transfected cell membranes. On the contrary, analogues cyclized at the C-terminal parts by the disulfide linkages at positions 6-10, 7-11, 7-14, and 10-14 sustained relatively high potencies in both assays. Notably, cyclo[Cys(10), Cys(14)]NC(1-14)-NH(2) (12) was found to be a potent NC agonist nearly as active as the parent peptide or NC. The maximum efficacy (Emax) of the C-terminally cyclized analogues and their linear counterparts in the GTP gamma S functional assay showed more than 94% (vs NC as 100%), suggesting that these analogues are full agonists. Analogue 12 is the first conformationally constrained NC analogue with almost full activity, and thus may serve to analyze the bioactive conformations of NC at the receptor site as well as serving as a template for more potent NC agonists.

[Usefulness of three-dimensional color Doppler sonography for the differential diagnosis of subpleural lesions]

The purpose of our investigation was to assess the usefulness of three-dimensional color Doppler sonography (velocity mode and power mode) for the differential diagnosis of subpleural lesions. Thirty lesions (11 pneumonias, 5 lung abscesses, 11 primary lung cancers, 3 metastatic lung cancers) were examined. Three-dimensional images were reconstructed by a maximum intensity projection method. Three-dimensional representations of intralesional blood flow became available for all lesions approximately 11 seconds after scanning. In every case, the entire vasculature of the tumor, the pneumonia, the abscess, or the inflamed region of the lung was appreciated more easily from three-dimensional images than from two-dimensional images. We classified the color flow pattern of subpleural lesions depicted by color flow imaging into seven groups. Color flow was depicted better by the three-dimensional color Doppler power mode than the velocity mode. Three-dimensional color flow patterns observed in power mode, patterns of the pneumonias and the lung cancers differed significantly. Our results suggest that the three-dimensional color Doppler power mode is useful for the differential diagnosis of subpleural lesions.

Dual-viral vector approach induced strong and long-lasting protective immunity against very virulent infectious bursal disease virus

To induce strong protective immunity against very virulent infectious bursal disease virus (vvIBDV) in chickens, two viral vector systems, Marek's disease and Fowlpox viruses expressing the vvIBDV host-protective antigen VP2 (rMDV, rFPV), were used. Most of chickens vaccinated with the rFPV or rMDV alone, or vaccinated simultaneously with both at their hatch (rMDV-rFPV(1d)), were protected against developing clinical signs and mortality; however, only zero to 14% of the chickens were protected against gross lesions. In contrast, gross lesions were protected in 67% of chickens vaccinated primarily with the rMDV followed by boosting with the rFPV 2 weeks later (rMDV-rFPV(14d)). Protection against the severe histopathological lesions of rFPV, rMDV, rMDV-rFPV(1d), and rMDV-rFPV(14d) vaccine groups were 33, 42, 53, and 73%, respectively. Geometric mean antibody titers to VP2 of chickens vaccinated with the rFPV, rMDV, rMDV-rFPV(1d), and rMDV-rFPV(14d) before the challenge were 110, 202, 254, and 611, respectively. Persistent infection of the rMDV in chickens after the booster vaccination with rFPV was suggested by detection of the rMDV genes from peripheral blood lymphocyte DNA at 28 weeks of age. These results indicate that the dual-viral vector approach is useful for quickly and safely inducing strong and long-lasting protective immunity against vvIBDV in chickens.

Lesions of bone and bone marrow in myeloid leukosis occurring naturally in adult broiler breeders

Lesions of bone and bone marrow in myeloid leukosis (ML) occurring naturally in adult broiler breeders were investigated pathologically. During gross examination, nodules and protrusions were commonly observed on the surface of the sternum, ribs, vertebrae, and synsacrum. The bone marrow of all the bones of the body was pale in color. Histologically, granulated myelocytes proliferated in the bone marrow of various bones and in the periosteum of the sternum, ribs, vertebrae, and synsacrum. The first proliferation of tumor cells occurred in the bone marrow of epiphysis. The myelocytes invaded through haversian and Volkmann's canals from the bone marrow to periosteal areas. Hematopoiesis was suppressed by marked proliferation of tumor cells in the bone marrow of the whole bone. Atrophy was also seen in the bones, including medullary bones of the chickens suffering from ML. Proliferation of myelocytes was seen in the bone marrow and periosteum of ossified cartilaginous rings of the trachea and larynx. Marked proliferation of myelocytes was seen in the dura mater of spinal cords, and it subsequently depressed the spinal cords. Bone formation with cartilage was seen in the periosteum of the sternum having marked proliferation of myelocytes in the bone marrow and periosteum. Ultrastructurally, tumor cells showed large nuclei and cytoplasm with large round electron-dense lysosomes. The virus particles were rarely detected in the cytoplasm of tumor cells. The polymerase chain reaction test of tumor samples showed positive for subgroup J avian leukosis virus. This study indicates that the myelocytes can invade through the compact bones to the periosteum in the sternum, ribs, vertebrae, synsarcum, and ossified cartilage of trachea and larynx having thinner compact bones. In addition, the periosteal osteogenesis with cartilage in the sternum may be reactive change against the bone atrophy because of the marked proliferation of myelocytes.

[Usefulness of power Doppler sonography for the assessment of subpleural lesions]

We investigated the usefulness of color Doppler power mode imaging for the assessment of subpleural lesions in 48 patients (27 with pneumonia, 4 with pulmonary abscesses, 12 with primary lung cancer, and 5 with metastatic lung cancer). We classified the patterns obtained by color flow imaging of subpleural lesions into six groups: type 0, no color flow; type I, spotty color flow; type II, linear color flow; type III, branchy color flow; and type IV, tortuous color flow, with type IV-A, for partial tortuous flow and type IV-B, for general tortuous flow. The color Doppler power mode proved better than velocity mode in terms of ability to generate clear color flow patterns. Color flow patterns obtained in power mode on the patients with pneumonia differed significantly from the patterns obtained on the lung cancer patients. Although the color flow patterns observed in power mode differed significantly for the benign and malignant groups, no statistically significant differences were observed in velocity mode. These findings illustrated the usefulness of color Doppler power mode imaging as a means of diagnosing benign and malignant subpleural lesions.