Insight into the function of voltage-sensing phosphatase in hindgut-derived pseudoplacenta of a viviparous teleost Xenotoca eiseni.

Nutrient absorption is essential for animal survival and development. Our previous study on zebrafish reported that nutrient absorption in lysosome-rich enterocytes (LREs) is promoted by the voltage-sensing phosphatase (VSP), which regulates phosphoinositide (PIP) homeostasis via electrical signaling in biological membranes. However, it remains unknown whether this VSP function is shared by different absorptive tissues in other species. Here, we focused on the function of VSP in a viviparous teleost Xenotoca eiseni, whose intraovarian embryos absorb nutrients from the maternal ovarian fluid through a specialized hindgut-derived pseudoplacental structure called trophotaenia. Xenotoca eiseni VSP (Xe-VSP) is expressed in trophotaenia epithelium, an absorptive tissue functionally similar to zebrafish LREs. Notably, the apical distribution of Xe-VSP in trophotaenia epithelial cells closely resembles zebrafish VSP (Dr-VSP) distribution in zebrafish LREs, suggesting a shared role for VSP in absorptive tissues between the two species. Electrophysiological analysis using a heterologous expression system revealed that Xe-VSP preserves functional voltage sensors and phosphatase activity with the leftward shifted voltage sensitivity compared with zebrafish VSP (Dr-VSP). We also identified a single amino acid variation in the S4 helix of Xe-VSP as one of the factors contributing to the leftward shifted voltage sensitivity. This study highlights the biological variation and significance of VSP in various animal species, as well as hinting at the potential role of VSP in nutrient absorption in X. eiseni trophotaenia.NEW & NOTEWORTHY We investigate the voltage-sensing phosphatase (VSP) in Xenotoca eiseni, a viviparous fish whose intraovarian embryos utilize trophotaenia for nutrient absorption. Although X. eiseni VSP (Xe-VSP) shares key features with known VSPs, its distinct voltage sensitivity arises from species-specific amino acid variation. Xe-VSP in trophotaenia epithelium suggests its involvement in nutrient absorption, similar to VSP in zebrafish enterocytes and potentially in species with similar absorptive cells. Our findings highlight the potential role of VSP across species.

(R)-ketamine restores anterior insular cortex activity and cognitive deficits in social isolation-reared mice.

Chronic social isolation increases the risk of mental health problems, including cognitive impairments and depression. While subanesthetic ketamine is considered effective for cognitive impairments in patients with depression, the neural mechanisms underlying its effects are not well understood. Here we identified unique activation of the anterior insular cortex (aIC) as a characteristic feature in brain-wide regions of mice reared in social isolation and treated with (R)-ketamine, a ketamine enantiomer. Using fiber photometry recording on freely moving mice, we found that social isolation attenuates aIC neuronal activation upon social contact and that (R)-ketamine, but not (S)-ketamine, is able to counteracts this reduction. (R)-ketamine facilitated social cognition in social isolation-reared mice during the social memory test. aIC inactivation offset the effect of (R)-ketamine on social memory. Our results suggest that (R)-ketamine has promising potential as an effective intervention for social cognitive deficits by restoring aIC function.

Glucose absorption activity and gene expression of sugar transporters in the trophotaenia of the viviparous teleost Xenotoca eiseni.

In viviparous reproductive systems, nutrient transfer from mother to embryo plays a critical role in the generation of offspring. Herein, we investigated the mother-to-embryo nutrient transfer machinery in the viviparous teleost Xenotoca eiseni, which belongs to the family Goodeidae. The intraovarian embryo absorbs maternal supplements via the hindgut-derived placental structure termed the trophotaenia. Tracer analysis indicated that the trophotaenia can take up glucose analogs in ex vivo cultured embryos. The candidate genes for absorption, sglt1, glut2, atp1a, and atp1b, were determined from published transcriptomes. These genes were expressed in the trophotaenia of X. eiseni embryos. Fluorescent immunohistochemistry of Na+/K+ ATPase indicated the polarity of epithelial cells in the trophotaenia. The presented evidence suggests that the epithelial cell layer transports monosaccharides from the apical membrane of epithelial cells in a basolateral direction. Taken together, this study provides insight into how maternal fish maintain their offspring during gestation and will aid in the development of strategies to improve offspring generation in these fish.

The characteristics and outcomes in patients with acute heart failure who used tolvaptan: from KCHF registry.

AIMS: The use of tolvaptan is increasing in clinical practice in Japan. However, the characteristics of patients who used tolvaptan and the timing of its use in patients with acute heart failure (AHF) are not fully elucidated. METHODS AND RESULTS: Among consecutive 4056 patients in the Kyoto Congestive Heart Failure registry, we analysed 3802 patients after excluding patients on dialysis, prior or unknown tolvaptan use at admission, and unknown timing of tolvaptan use, and we divided them into two groups: tolvaptan use (N = 773) and no tolvaptan use (N = 3029). The prevalence of tolvaptan use varied widely from 48.7% to 0% across the participating centres. Factors independently associated with tolvaptan use were diabetes, poor medical adherence, oedema, pleural effusion, hyponatraemia, estimated glomerular filtration rate < 30 mL/min/1.73 m2 , moderate/severe tricuspid regurgitation, dobutamine infusion within 24 h, and additional inotropes infusion beyond 24 h after admission. The mortality rate at 90 days after admission was significantly higher in the tolvaptan use group than in the no tolvaptan use group (14.3% vs. 8.6%, P = 0.049). However, after adjustment, the excess mortality risk of tolvaptan use relative to no tolvaptan use was no longer significant (hazard ratio = 1.53, 95% confidence interval = 0.77-3.02, P = 0.22). Patients with tolvaptan use had a longer hospital stay [median (interquartile range): 22 (15-34) days vs. 15 (11-21) days, P < 0.0001] and a higher prevalence of worsening renal failure (47.0% vs. 31.8%, P < 0.0001) and worsening heart failure (24.8% vs. 14.4%, P < 0.0001) than those without. CONCLUSIONS: AHF patients with tolvaptan use had more congestive status with poorer in-hospital outcomes and higher short-term mortality than those without tolvaptan use. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) and https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238).

Association between changes in loop diuretic dose and outcomes in acute heart failure.

AIMS: Little is known about the association between the starting of or dose changes in loop diuretics during acute heart failure (AHF) hospitalization and post-discharge outcomes. We investigated the clinical impact of starting loop diuretics and changing the loop diuretics dose during hospitalization on post-discharge outcomes. METHODS AND RESULTS: From the Kyoto Congestive Heart Failure registry, 3665 consecutive patients hospitalized for HF and discharged alive were included in this study. We analysed 1906 patients without loop diuretics on admission and were discharged alive and 1759 patients who received loop diuretics on admission and were discharged alive. The primary outcome measure was all-cause death. Of the 1906 patients without loop diuretics on admission, 1366 (71.7%) patients started loop diuretics during the index AHF hospitalization. Starting loop diuretics was not associated with lower post-discharge mortality [adjusted hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.68-1.25]. Of the 1759 patients who received loop diuretics on admission, loop diuretic dose was decreased in 23.8%, unchanged in 44.6%, and increased in 31.6% of the patients. Changes in the dose at discharge compared with no change in dose were not associated with lower risk of post-discharge mortality (decrease relative to no change: adjusted HR 0.98, 95% CI 0.76-1.28; increase relative to no change: adjusted HR 1.00, 95% CI 0.78-1.27). Compared with no loop diuretics at discharge, a loop diuretics dose of ≥80 mg at discharge was associated with higher post-discharge mortality risk. CONCLUSIONS: In patients with AHF, we found no association between the starting of loop diuretics and post-discharge outcomes and between dose changes and post-discharge outcomes.

Tricuspid regurgitation in elderly patients with acute heart failure: insights from the KCHF registry.

AIMS: Several studies demonstrated that tricuspid regurgitation (TR) is associated with poor clinical outcomes. However, data on patients with TR who experienced acute heart failure (AHF) remains scarce. The purpose of this study is to evaluate the association between TR and clinical outcomes in patients admitted with AHF, using a large-scale Japanese AHF registry. METHODS AND RESULTS: The current study population consisted of 3735 hospitalized patients due to AHF in the Kyoto Congestive Heart Failure (KCHF) registry. TR grades were assessed according to the routine clinical practice at each participating centre. We compared the baseline characteristics and outcomes according to the severity of TR. The primary outcome was all-cause death. The secondary outcome was hospitalization for heart failure (HF). The median age of the entire study population was 80 (interquartile range: 72-86) years. One thousand two hundred five patients (32.3%) had no TR, while mild, moderate, and severe TR was found in 1537 patients (41.2%), 776 patients (20.8%), and 217 patients (5.8%), respectively. Pulmonary hypertension, significant mitral regurgitation, and atrial fibrillation/flutter were strongly associated with the development of moderate/severe of TR, while left ventricular ejection fraction <50% was inversely associated with it. Among 993 patients with moderate/severe TR, the number of patients who underwent surgical intervention for TR within 1 year was only 13 (1.3%). The median follow-up duration was 475 (interquartile range: 365-653) days with 94.0% follow-up at 1 year. As the TR severity increased, the cumulative 1 year incidence of all-cause death and HF admission proportionally increased ([14.8%, 20.3%, 23.4%, 27.0%] and [18.9%, 23.0%, 28.5%, 28.4%] in no, mild, moderate, and severe TR, respectively). Compared with no TR, the adjusted risks of patients with mild, moderate, and severe TR were significant for all-cause death (hazard ratio [95% confidence interval]: 1.20 [1.00-1.43], P = 0.0498, 1.32 [1.07-1.62], P = 0.009, and 1.35 [1.00-1.83], P = 0.049, respectively), while those were not significant for hospitalization for HF (hazard ratio [95% confidence interval]: 1.16 [0.97-1.38], P = 0.10, 1.19 [0.96-1.46], P = 0.11, and 1.20 [0.87-1.65], P = 0.27, respectively). The higher adjusted HRs of all the TR grades relative to no TR were significant for all-cause death in patients aged <80 years, but not in patients aged ≥80 years with significant interaction. CONCLUSIONS: In a large Japanese AHF population, the grades of TR could successfully stratify the risk of all-cause death. However, the association of TR with mortality was only modest and attenuated in patients aged 80 or more. Further research is warranted to evaluate how to follow up and manage TR in this elderly population.

Prognostic Value of the Severity of Clinical Congestion in Patients Hospitalized for Decompensated Heart Failure: Findings From the Japanese KCHF Registry.

BACKGROUND: Congestion is a leading cause of hospitalization and a major therapeutic target in patients with heart failure (HF). Clinical practice in Japan is characterized by a long hospital stay, which facilitates more extensive decongestion during hospitalization. We herein examined the time course and prognostic impact of clinical congestion in a large contemporary Japanese cohort of HF. METHODS AND RESULTS: Peripheral edema, jugular venous pressure, and orthopnea were graded on a standardized 4-point scale (0-3) in 3787 hospitalized patients in a Japanese cohort of HF. Composite Congestion Scores (CCS) on admission and at discharge were calculated by summing individual scores. The primary outcome was a composite of all-cause death or HF hospitalization. The median admission CCS was 4 (interquartile range, 3-6). Overall, 255 patients died during the median hospitalization length of 16 days, and 1395 died or were hospitalized for HF over a median postdischarge follow-up of 396 days. The cumulative 1-year incidence of the primary outcome increased at higher tertiles of congestion on admission (32.5%, 39.3%, and 41.0% in the mild [CCS ≤3], moderate [CCS = 4 or 5], and severe [CCS ≥6] congestion groups, respectively, log-rank P < .001). The adjusted hazard ratios of moderate and severe congestion relative to mild congestion were 1.205 (95% confidence interval [CI], 1.065-1.365; P = .003) and 1.247 (95% CI, 1.103-1.410; P < .001), respectively. Among 3445 patients discharged alive, 85% had CCS of 0 (complete decongestion) and 15% had a CCS of 1 or more (residual congestion) at discharge. Although residual congestion predicted a risk of postdischarge death or HF hospitalization (adjusted hazard ratio, 1.314 [1.145-1.509]; P < .001), the admission CCS correlated with the risk of postdischarge death or HF hospitalization, even in the complete decongestion group. No correlation was observed for postdischarge death or HF hospitalization between residual congestion at discharge and admission CCS (P for the interaction = .316). CONCLUSIONS: In total, 85% of patients were discharged with complete decongestion in Japanese clinical practice. Clinical congestion, on admission and at discharge, was of prognostic value. The severity of congestion on admission was predictive of adverse outcomes, even in the absence of residual congestion. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238).

Role of K364 next to the active site cysteine in voltage-dependent phosphatase activity of Ci-VSP.

Voltage-sensing phosphatase (VSP) consists of the voltage sensor domain (VSD) similar to that of voltage-gated ion channels and the cytoplasmic phosphatase region with remarkable similarity to the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Membrane depolarization activates VSD, leading to dephosphorylation of three species of phosphoinositides (phosphatidylinositol phosphates (PIPs)), PI(3,4,5)P3, PI(4,5)P2, and PI(3,4)P2. VSP dephosphorylates 3- and 5-phosphate of PIPs, unlike PTEN, which shows rigid 3-phosphate specificity. In this study, a bioinformatics search showed that some mammals have VSP orthologs with amino acid diversity in the active center motif, Cx5R, which is highly conserved among protein tyrosine phosphatases and PTEN-related phosphatases; lysine next to the active site cysteine in the Cx5R motif was substituted for methionine in VSP orthologs of Tasmanian devil, koala, and prairie deer mouse, and leucine in opossum. Since lysine at the corresponding site in PTEN is known to be critical for enzyme activities, we attempted to address the significance of amino acid diversity among VSP orthologs at this site. K364 was changed to different amino acids in sea squirt VSP (Ci-VSP), and voltage-dependent phosphatase activity in Xenopus oocyte was studied using fluorescent probes for PI(4,5)P2 and PI(3,4)P2. All mutants retained both 5-phosphatase and 3-phosphatase activity, indicating that lysine at this site is dispensable for 3-phosphatase activity, unlike PTEN. Notably, K364M mutant showed increased activity both of 5-phosphatase and 3-phosphatase compared with the wild type (WT). It also showed slower kinetics of voltage sensor motion. Malachite green assay of K364M mutant did not show significant difference of phosphatase activity from WT, suggesting tighter interaction between substrate binding and voltage sensing. Mutation corresponding to K364M in the zebrafish VSP led to enhanced voltage-dependent dephosphorylation of PI(4,5)P2. Further studies will provide clues to understanding of substrate preference in PIPs phosphatases as well as to customization of a molecular tool.

Voltage-sensing phosphatase (Vsp) regulates endocytosis-dependent nutrient absorption in chordate enterocytes.

Voltage-sensing phosphatase (Vsp) is a unique membrane protein that translates membrane electrical activities into the changes of phosphoinositide profiles. Vsp orthologs from various species have been intensively investigated toward their biophysical properties, primarily using a heterologous expression system. In contrast, the physiological role of Vsp in native tissues remains largely unknown. Here we report that zebrafish Vsp (Dr-Vsp), encoded by tpte gene, is functionally expressed on the endomembranes of lysosome-rich enterocytes (LREs) that mediate dietary protein absorption via endocytosis in the zebrafish mid-intestine. Dr-Vsp-deficient LREs were remarkably defective in forming endosomal vacuoles after initial uptake of dextran and mCherry. Dr-Vsp-deficient zebrafish exhibited growth restriction and higher mortality during the critical period when zebrafish larvae rely primarily on exogenous feeding via intestinal absorption. Furthermore, our comparative study on marine invertebrate Ciona intestinalis Vsp (Ci-Vsp) revealed co-expression with endocytosis-associated genes in absorptive epithelial cells of the Ciona digestive tract, corresponding to zebrafish LREs. These findings signify a crucial role of Vsp in regulating endocytosis-dependent nutrient absorption in specialized enterocytes across animal species.

Insomnia in patients with acute heart failure: from the KCHF registry.

AIMS: Insomnia is a known risk factor for heart failure (HF) and a predictor of cardiac events in HF patients, but the clinical significance of insomnia in patients with acute HF (AHF) is not adequately evaluated. This study aimed to investigate the association between insomnia and subsequent clinical outcomes in patients with AHF. METHODS: From the Kyoto Congestive Heart Failure registry, consecutive 3414 patients hospitalized for HF who were discharged alive were divided into the 2 groups at discharge: insomnia group and non-insomnia group. We compared baseline characteristics and 1 year clinical outcomes according to the presence of insomnia. The primary outcome measure was all-cause death. RESULTS: There were 330 patients (9.7%) and 3084 patients (90.3%) with and without insomnia, respectively. In the multivariable logistic regression analysis, brain-type natriuretic peptide above median value at discharge (OR = 1.50, 95% CI = 1.08-2.10, P = 0.02) and the presence of oedema at discharge (OR = 4.23, 95% CI = 2.95-6.07, P < 0.001) were positively associated with insomnia at discharge, whereas diuretics at discharge (OR = 0.60, 95% CI = 0.39-0.90, P = 0.01) were negatively associated with insomnia at discharge. The cumulative 1 year incidence of all-cause death was significantly higher in the insomnia group than in the non-insomnia group (25.1% vs. 16.2%, P < 0.001). Even after adjusting the confounders, the higher mortality risk of patients with insomnia relative to those without insomnia remained significant (HR = 1.55, 95% CI = 1.24-1.94; P < 0.001). CONCLUSIONS: Patients with insomnia at discharge were associated with a higher risk of mortality than those without insomnia at discharge.

A 17-year-old male with acute myocarditis following mRNA-1273 vaccination in Japan.

Vaccinations are the main tool being used to control the COVID-19 pandemic. When the Japanese Ministry of Health approved the Moderna mRNA-1273 vaccination in May 2021, it was limited to patients over 18 years old; however, using the additional data of efficacy and safety from clinical trials, vaccination was approved for 12- to 17-year-olds in Japan in July 2021. A previous study reported that myocarditis after the mRNA-1273 vaccination was more prevalent in young men; however, no patients under 18 years old with myocarditis diagnosed by cardiovascular magnetic resonance (CMR) findings after mRNA-1273 vaccination have been reported in Japan. In the present case, a 17-year-old healthy male developed arthralgia and had fever on the day of the second mRNA-1273 vaccination for severe acute respiratory syndrome coronavirus 2. Three days after the vaccination, the patient felt severe chest pain with broad ST elevations on electrocardiography and troponin T elevations. Symptoms and findings rapidly improved; however, on CMR, myocarditis remained. Thus, it is necessary to be vigilant of potential acute myocarditis in young men following mRNA-1273 vaccination. Learning objective: Although it is very rare, acute myocarditis after mRNA-1273 (Moderna) vaccination developed within 3-5 days following the second dose of the vaccine.Most reported cases were mild or moderate in severity, but there were cases of cardiogenic shock. We need to be vigilant of acute myocarditis in young men following mRNA-1273 vaccination.

Insight into the function of a unique voltage-sensor protein (TMEM266) and its short form in mouse cerebellum.

Voltage-sensing proteins generally consist of voltage-sensor domains and pore-gate domains, forming the voltage-gated ion channels. However, there are several unconventional voltage-sensor proteins that lack pore-gate domains, conferring them unique voltage-sensing machinery. TMEM266, which is expressed in cerebellum granule cells, is one of the interesting voltage-sensing proteins that has a putative intracellular coiled-coil and a functionally unidentified cytosolic region instead of a pore-gate domain. Here, we approached the molecular function of TMEM266 by performing co-immunoprecipitation experiments. We unexpectedly discovered that TMEM266 proteins natively interact with the novel short form splice variants that only have voltage-sensor domains and putative cytosolic coiled-coil region in cerebellum. The crystal structure of coiled-coil region of TMEM266 suggested that these coiled-coil regions play significant roles in forming homodimers. In vitro expression experiments supported the idea that short form TMEM266 (sTMEM266) or full length TMEM266 (fTMEM266) form homodimers. We also performed proximity labeling mass spectrometry analysis for fTMEM266 and sTMEM266 using Neuro-2A, neuroblastoma cells, and fTMEM266 showed more interacting molecules than sTMEM266, suggesting that the C-terminal cytosolic region in fTMEM266 binds to various targets. Finally, TMEM266-deficient animals showed the moderate abnormality in open-field test. The present study provides clues about the novel voltage-sensing mechanism mediated by TMEM266.

Appetite loss at discharge from acute decompensated heart failure: Observation from KCHF registry.

OBJECTIVE: The complex link between nutritional status, protein and lipid synthesis, and immunity plays an important prognostic role in patients with heart failure. However, the association between appetite loss at discharge and long-term outcome remains unclear. METHODS: The Kyoto Congestive Heart Failure registry is a prospective cohort study that enrolled consecutive patients hospitalized for acute decompensated heart failure (ADHF) in Japan. We assessed 3528 patients alive at discharge, and for whom appetite and follow-up data were available. We compared one-year clinical outcomes in patients with and without appetite loss at discharge. RESULTS: In the multivariable logistic regression analysis using 19 clinical and laboratory factors with P value < 0.1 by univariate analysis, BMI < 22 kg/m2 (odds ratio (OR): 1.57, 95% confidence interval (CI): 1.11-2.24, P = 0.01), CRP >1.0mg/dL (OR: 1.49, 95%CI: 1.04-2.14, P = 0.03), and presence of edema at discharge (OR: 4.30, 95%CI: 2.99-6.22, P<0.001) were associated with an increased risk of appetite loss at discharge, whereas ambulatory status (OR: 0.57, 95%CI: 0.39-0.83, P = 0.004) and the use of ACE-I/ARB (OR: 0.70, 95% CI: 0.50-0.98, P = 0.04) were related to a decreased risk in the presence of appetite loss. The cumulative 1-year incidence of all-cause death (primary outcome measure) was significantly higher in patients with appetite loss than in those without appetite loss (31.0% vs. 15.0%, P<0.001). The excess adjusted risk of appetite loss relative to no appetite loss remained significant for all-cause death (hazard ratio (HR): 1.63, 95%CI: 1.29-2.07, P<0.001). CONCLUSIONS: Loss of appetite at discharge was associated with worse 1-year mortality in patients with ADHF. Appetite is a simple, reliable, and useful subjective marker for risk stratification of patients with ADHF.

Public assistance in patients with acute heart failure: a report from the KCHF registry.

AIMS: There is a scarcity of data on the post-discharge prognosis in acute heart failure (AHF) patients with a low-income but receiving public assistance. The study sought to evaluate the differences in the clinical characteristics and outcomes between AHF patients receiving public assistance and those not receiving public assistance. METHODS AND RESULTS: The Kyoto Congestive Heart Failure registry was a physician-initiated, prospective, observational, multicentre cohort study enrolling 4056 consecutive patients who were hospitalized due to AHF for the first time between October 2014 and March 2016. The present study population consisted of 3728 patients who were discharged alive from the index AHF hospitalization. We divided the patients into two groups, those receiving public assistance and those not receiving public assistance. After assessing the proportional hazard assumption of public assistance as a variable, we constructed multivariable Cox proportional hazard models to estimate the risk of the public assistance group relative to the no public assistance group. There were 218 patients (5.8%) receiving public assistance and 3510 (94%) not receiving public assistance. Patients in the public assistance group were younger, more frequently had chronic coronary artery disease, previous heart failure hospitalizations, current smoking, poor medical adherence, living alone, no occupation, and a lower left ventricular ejection fraction than those in the no public assistance group. During a median follow-up of 470 days, the cumulative 1 year incidences of all-cause death and heart failure hospitalizations after discharge did not differ between the public assistance group and no public assistance group (13.3% vs. 17.4%, P = 0.10, and 28.3% vs. 23.8%, P = 0.25, respectively). After adjusting for the confounders, the risk of the public assistance group relative to the no public assistance group remained insignificant for all-cause death [hazard ratio (HR), 0.97; 95% confidence interval (CI), 0.69-1.32; P = 0.84]. Even after taking into account the competing risk of all-cause death, the adjusted risk within 180 days in the public assistance group relative to the no public assistance group remained insignificant for heart failure hospitalizations (HR, 0.93; 95% CI, 0.64-1.34; P = 0.69), while the adjusted risk beyond 180 days was significant (HR, 1.56; 95% CI, 1.07-2.29; P = 0.02). CONCLUSIONS: The AHF patients receiving public assistance as compared with those not receiving public assistance had no significant excess risk for all-cause death at 1 year after discharge or a heart failure hospitalization within 180 days after discharge, while they did have a significant excess risk for heart failure hospitalizations beyond 180 days after discharge. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02334891 (NCT02334891) and https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000017241 (UMIN000015238).

Spotlight on the Binding Affinity of Ion Channels for Phosphoinositides: From the Study of Sperm Flagellum.

The previous studies revealed that many types of ion channels have sensitivity to PtdIns(4,5)P2, which has been mainly shown using heterologous expression system. On the other hand, there remains few evidence showing that PtdIns(4,5)P2 natively regulate the ion channel activities in physiological context. Our group recently discovered that a sperm specific K+ channel, Slo3, is natively regulated by PtdIns(4,5)P2 in sperm flagellum. Very interestingly, a principal piece, to which Slo3 specifically localized, had extremely low density of PtdIns(4,5)P2 compared to the regular cell plasma membrane. Furthermore, our studies and the previous ones also revealed that Slo3 had much stronger PtdIns(4,5)P2 affinity than KCNQ2/3 channels, which are widely regulated by endogenous PtdIns(4,5)P2 in neurons. Thus, the high-PtdIns(4,5)P2 affinity of Slo3 is well-adapted to the specialized PtdIns(4,5)P2 environment in the principal piece. This study sheds light on the relationship between PtdIns(4,5)P2-affinity of ion channels and their PtdIns(4,5)P2 environment in native cells. We discuss the current understanding about PtdIns(4,5)P2 affinity of diverse ion channels and their possible regulatory mechanism in native cellular environment.

Starting Neurohormonal Antagonists in Patients With Acute Heart Failure With Mid-Range and Preserved Ejection Fraction.

BACKGROUND: The clinical benefits of neurohormonal antagonists for patients with heart failure (HF) with mid-range and preserved ejection fraction (HFmrEF and HFpEF) are uncertain.Methods and Results: This study analyzed 858 consecutive patients with HFmrEF (EF: 40-49%) or HFpEF (EF ≥50%), who were hospitalized for acute HF, and who were discharged alive, and were not taking angiotensin-converting enzyme inhibitors (ACE)-I/ angiotensin II receptor blockers (ARB) or ß-blockers at admission. The study population was classified into 4 groups according to the status of prescription of ACE-I/ARB and ß-blocker at discharge: no neurohormonal antagonist (n=342, 39.9%), ACE-I/ARB only (n=128, 14.9%), ß-blocker only (n=189, 22.0%), and both ACE-I/ARB and ß-blocker (n=199, 23.2%) groups. The primary outcome measure was a composite of all-cause death or HF hospitalization. The cumulative 1-year incidence of the primary outcome measure was 41.2% in the no neurohormonal antagonist group, 34.0% in the ACE-I/ARB only group, 28.6% in the ß-blocker only group, and 16.4% in the both ACE-I/ARB and ß-blocker group (P<0.001). Compared with the no neurohormonal antagonist group, both the ACE-I/ARB and ß-blocker groups were associated with a significantly lower risk for a composite of all-cause death or HF hospitalization (HR: 0.46, 95% CI: 0.28-0.76, P=0.002). CONCLUSIONS: In hospitalized patients with HFmrEF and HFpEF, starting both ACE-I/ARB and a ß-blocker was associated with a reduced risk of the composite of all-cause death or HF hospitalization compared with patients not starting on an ACE-I/ARB or ß-blocker.

Current use of inotropes according to initial blood pressure and peripheral perfusion in the treatment of congestive heart failure: findings from a multicentre observational study.

OBJECTIVES: Current guidelines restrict the use of inotropes for the treatment for heart failure (HF) unless the patients are hypotensive or hypoperfused because of safety concerns. This study sought to characterise the contemporary real-world use of inotropes and associated long-term outcomes according to systolic blood pressure (sBP) and perfusion status. DESIGN: A multicentre prospective cohort study. SETTING: This study was nested from the Kyoto Congestive Heart Failure registry, which included consecutive Japanese patients admitted for HF. PARTICIPANTS: We categorised 3995 patients into two groups: sBP ≥90 mm Hg and warm profile group, and sBP <90 mm Hg or cold profile group. In each group, patients were stratified across the use of inotropes within 24 hours of hospital presentation. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was all-cause death throughout follow-up. Secondary outcomes included cardiovascular death throughout follow-up, all-cause death during index hospitalisation and after discharge, and HF hospitalisation. RESULTS: A total of 793 patients (20%) presented with sBP <90 mm Hg or cold profile, whereas 3202 patients had sBP ≥90 mm Hg and warm profile; 276 patients (35%) in the sBP <90 mm Hg/cold group and 312 patients (10%) in the sBP ≥90 mm Hg/warm group received initial inotropic treatment. Adjusted excess risk of inotrope use relative to no inotrope for the primary outcome measure was significant in the sBP ≥90 mm Hg/warm group (adjusted HR), 1.36; 95% CI 1.09 to 1.72, p=0.006) but not in the sBP <90 mm Hg/cold group (adjusted HR, 1.28, 95% CI 0.96 to 1.69, p=0.09). Risk for postdischarge all-cause death and HF hospitalisation was not significantly different between the patients with inotropes and no inotropes in both groups. CONCLUSION: Inotrope use in the absence of hypotension and hypoperfusion is still common, but associated with a worse long-term prognosis. TRIAL REGISTRATION NUMBER: UMIN000015238.

Coronary angiography in patients with acute heart failure: from the KCHF registry.

AIMS: Little is known about the characteristics and outcomes of patients who undergo coronary angiography during heart failure (HF) hospitalization, as well as those with coronary stenosis, and those who underwent coronary revascularization. METHODS AND RESULTS: We analysed 2163 patients who were hospitalized for HF without acute coronary syndrome or prior HF hospitalization. We compared patient characteristics and 1 year clinical outcomes according to (i) patients with versus without coronary angiography, (ii) patients with versus without coronary stenosis, and (iii) patients with versus without coronary revascularization. The primary outcome measure was the composite of all-cause death or HF hospitalization. Coronary angiography was performed in 37.0% of patients. In the multivariable logistic regression analysis, factors independently associated with coronary angiography were age < 80 years [adjusted odds ratio (OR) = 1.76, 95% confidence interval (CI) = 1.41-2.20, P < 0.001], men (adjusted OR = 1.28, 95% CI = 1.03-1.59, P = 0.02), diabetes (adjusted OR = 1.27, 95% CI = 1.02-1.60, P = 0.04), no atrial fibrillation or flutter (adjusted OR = 1.45, 95% CI = 1.17-1.82, P < 0.001), no prior device implantation (adjusted OR = 1.81, 95% CI = 1.13-2.91, P = 0.01), current smoking (adjusted OR = 1.40, 95% CI = 1.05-1.87, P = 0.02), no cognitive dysfunction (adjusted OR = 1.90, 95% CI = 1.34-2.69, P < 0.001), ambulatory status (adjusted OR = 2.89, 95% CI = 2.03-4.10, P < 0.001), HF with reduced ejection fraction (adjusted OR = 1.55, 95% CI = 1.24-1.93, P < 0.001), estimated glomerular filtration rate ≥ 30 mL/min/1.73 m2 (adjusted OR = 1.93, 95% CI = 1.45-2.58, P < 0.001), no anaemia (adjusted OR = 1.27, 95% CI = 1.02-1.59, P = 0.04), and no prescription of ß-blockers prior to admission (adjusted OR = 1.32, 95% CI = 1.03-1.68, P = 0.03). Patients who underwent coronary angiography had a lower risk of the primary outcome [adjusted hazard ratio (HR) = 0.70, 95% CI = 0.58-0.85, P < 0.001]. Among the patients who underwent coronary angiography, those with coronary stenosis (38.9%) did not have lower risk of the primary outcome measure than those without coronary stenosis (adjusted HR = 0.93, 95% CI = 0.65-1.32, P = 0.68). Among the patients with coronary stenosis, those with coronary revascularization (54.3%) did not have higher risk of the primary outcome measure than those without coronary revascularization (adjusted HR = 1.36, 95% CI = 0.84-2.21, P = 0.22). CONCLUSIONS: In patients with acute HF, patients who underwent coronary angiography had a lower risk of clinical outcomes and were significantly different from those who did not undergo coronary angiography.

Ischemic Stroke in Acute Decompensated Heart Failure: From the KCHF Registry.

Background Heart failure (HF) is a known risk factor for ischemic stroke, but data regarding ischemic stroke during hospitalization for acute decompensated HF (ADHF) are limited. Methods and Results We analyzed the data from a multicenter registry (Kyoto Congestive Heart Failure [KCHF] Registry) that enrolled 4056 consecutive patients with ADHF in Japan (mean age, 78 years; men, 2238 patients [55%]; acute coronary syndrome [ACS], 239 patients [5.9%]). We investigated the incidence and predictors of ischemic stroke during hospitalization for ADHF. During the hospitalization, 63 patients (1.6%) developed ischemic stroke. The median interval from admission to the onset of ischemic stroke was 7 [interquartile range: 2-14] days, and the most common underlying cause was cardioembolism (64%). Men (OR, 1.87; 95%CI, 1.11-3.24), ACS (OR, 2.31; 95%CI, 1.01-4.93), absence of prior HF hospitalization (OR, 2.21; 95%CI, 1.24-4.21), and high B-type natriuretic peptide (BNP)/N-terminal proBNP (NT-proBNP) levels (above the median) at admission (OR, 3.15; 95%CI, 1.84-5.60) were independently associated with ischemic stroke. In patients without ACS, the independent risk factors for ischemic stroke were fully consistent with those in the main analysis. Higher quartiles of BNP/NT-proBNP levels were significantly associated with higher incidence of ischemic stroke (P for trend, <0.001). Patients with ischemic stroke showed higher in-hospital mortality, longer length of hospital stay, and poorer functional status at discharge. Conclusions During hospitalization for ADHF, 1.6% of the patients developed ischemic stroke. Men, ACS, absence of prior HF hospitalization, and high BNP/NT-proBNP levels at admission were independently associated with ischemic stroke.

Heterologous functional expression of ascidian Nav1 channels and close relationship with the evolutionary ancestor of vertebrate Nav channels.

Voltage-gated sodium channels (Nav1s) are responsible for the initiation and propagation of action potentials in neurons, muscle, and endocrine cells. Many clinically used drugs such as local anesthetics and antiarrhythmics inhibit Nav1s, and a variety of inherited human disorders are caused by mutations in Nav1 genes. Nav1s consist of the main α subunit and several auxiliary ß subunits. Detailed information on the structure-function relationships of Nav1 subunits has been obtained through heterologous expression experiments and analyses of protein structures. The basic properties of Nav1s, including their gating and ion permeation, were classically described in the squid giant axon and other invertebrates. However, heterologous functional expression of Nav1s from marine invertebrates has been unsuccessful. Ascidians belong to the Urochordata, a sister group of vertebrates, and the larval central nervous system of ascidians shows a similar plan to that of vertebrates. Here, we report the biophysical properties of ascidian Ciona Nav1 (CiNav1a) heterologously expressed in Xenopus oocytes. CiNav1a exhibited tetrodotoxin-insensitive sodium currents with rapid gating kinetics of activation and inactivation. Furthermore, consistent with the fact that the Ciona genome lacks orthologous genes to vertebrate ß subunits, the human ß1 subunit did not influence the gating properties when coexpressed with CiNav1a. Interestingly, CiNav1a contains an ankyrin-binding motif in the II-III linker, which can be targeted to the axon initial segment of mammalian cortical neurons. Our findings provide a platform to gain insight into the evolutionary and biophysical properties of Nav1s, which are important for the development of targeted therapeutics.