Tex46 knockout male mice are sterile secondary to sperm head malformations and failure to penetrate through the zona pellucida

Each year, infertility affects 15% of couples worldwide, with 50% of cases attributed to men. It is assumed that sperm head shape is important for sperm-zona pellucida (ZP) penetration but research has yet to elucidate why. We generated testis expressed 46 (Tex46) knockout mice to investigate the essential roles of TEX46 in mammalian reproduction. We used RT-PCR to demonstrate that Tex46 was expressed exclusively in the male reproductive tract in mice and humans. We created Tex46-/- mice using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system and analyzed their fertility. Tex46 null spermatozoa underwent further evaluation using computer-assisted sperm analysis, light microscopy, and ultrastructural microscopy. We used immunoblot analysis to elucidate relationships between TEX46 and other acrosome biogenesis-related proteins. Mouse and human TEX46 are testis-enriched and encode a transmembrane protein which is conserved from amphibians to mammals. Loss of the mouse TEX46 protein causes male sterility primarily due to abnormal sperm head formation and secondary effects on sperm motility. Tex46 null spermatozoa morphologically lack the typical hooked sperm head appearance and fail to penetrate through the ZP. Electron microscopy of the testicular germ cells reveals malformation of the acrosomal cap, with misshapen sperm head tips and the appearance of a gap between the acrosome head and the nucleus. TEX46 is essential for sperm head formation, sperm penetration through the ZP, and male fertility in mice, and is a putative contraceptive target in men.

Bisphenol A (BPA) and Cardiovascular or Cardiometabolic Diseases

Bisphenol A (BPA; 4,4'-isopropylidenediphenol) is a well-known endocrine disruptor. Most human exposure to BPA occurs through the consumption of BPA-contaminated foods. Cardiovascular or cardiometabolic diseases such as diabetes, obesity, hypertension, acute kidney disease, chronic kidney disease, and heart failure are the leading causes of death worldwide. Positive associations have been reported between blood or urinary BPA levels and cardiovascular or cardiometabolic diseases. BPA also induces disorders or dysfunctions in the tissues associated with these diseases through various cell signaling pathways. This review highlights the literature elucidating the relationship between BPA and various cardiovascular or cardiometabolic diseases and the potential mechanisms underlying BPA-mediated disorders or dysfunctions in tissues such as blood vessels, skeletal muscle, adipose tissue, liver, pancreas, kidney, and heart that are associated with these diseases.

Acute effects of empagliflozin on open-loop baroreflex function and urinary glucose excretion in rats with chronic myocardial infarction

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have exerted cardioprotective effects in clinical trials, but underlying mechanisms are not fully understood. As mitigating sympathetic overactivity is of major clinical concern in the mechanisms of heart failure treatments, we examined the effects of modulation of glucose handling on baroreflex-mediated sympathetic nerve activity and arterial pressure regulations in rats with chronic myocardial infarction (n = 9). Repeated 11-min step input sequences were used for an open-loop analysis of the carotid sinus baroreflex. An SGLT2 inhibitor, empagliflozin, was intravenously administered (10 mg/kg) after the second sequence. Neither the baroreflex neural nor peripheral arc significantly changed during the last observation period (seventh and eighth sequences) compared with the baseline period although urinary glucose excretion increased from near 0 (0.0089 ± 0.0011 mg min-1 kg-1) to 1.91 ± 0.25 mg min-1 kg-1. Hence, empagliflozin does not acutely modulate the baroreflex regulations of sympathetic nerve activity and arterial pressure in this rat model of chronic myocardial infarction.

Serum proteomic identification and validation of two novel atherosclerotic aortic aneurysm biomarkers, profilin 1 and complement factor D

BACKGROUND

Effective diagnostic biomarkers for aortic aneurysm (AA) that are detectable in blood tests are required because early detection and rupture risk assessment of AA can provide insights into medical therapy and preventive treatments. However, known biomarkers for AA lack specificity and reliability for clinical diagnosis.

METHODS

We performed proteome analysis of serum samples from patients with atherosclerotic thoracic AA (TAA) and healthy control (HC) subjects to identify diagnostic biomarkers for AA. Serum samples were separated into low-density lipoprotein, high-density lipoprotein, and protein fractions, and the major proteins were depleted. From the proteins identified in the three fractions, we narrowed down biomarker candidates to proteins uniformly altered in all fractions between patients with TAA and HC subjects and evaluated their capability to discriminate patients with TAA and those with abdominal AA (AAA) from HC subjects using receiver operating characteristic (ROC) analysis. For the clinical validation, serum concentrations of biomarker candidates were measured in patients with TAA and AAA registered in the biobank of the same institute, and their capability for the diagnosis was evaluated.

RESULTS

Profilin 1 (PFN1) and complement factor D (CFD) showed the most contrasting profiles in all three fractions between patients with TAA and HC subjects and were selected as biomarker candidates. The PFN1 concentration decreased, whereas the CFD concentration increased in the sera of patients with TAA and AAA when compared with those of HC subjects. The ROC analysis showed that these proteins could discriminate patients with TAA and AAA from HC subjects. In the validation study, these candidates showed significant concentration differences between patients with TAA or AAA and controls. PFN1 and CFD showed sufficient area under the curve (AUC) in the ROC analysis, and their combination further increased the AUC. The serum concentrations of PFN1 and CFD also showed significant differences between patients with aortic dissection and controls in the validation study.

CONCLUSION

PFN1 and CFD are potential diagnostic biomarkers for TAA and AAA and measurable in blood samples; their diagnostic performance can be augmented by their combination. These biomarkers may facilitate the development of diagnostic systems to identify patients with AA.

Computational and Experimental Analyses for Pathogenicity Prediction of ACVRL1 Missense Variants in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a vascular disease caused by the defects of ALK1/ACVRL1 receptor signaling. In this study, we evaluated 25 recently identified ACVRL1 missense variants using multiple computational pathogenicity classifiers and experimentally characterized their signal transduction capacity. Three extracellular residue variants showed no detectable cell surface expression and impairment of bone morphogenetic protein 9 (BMP9) responsiveness of SMAD-dependent transcription in luciferase assays. Four variants with amino acid replacement in the motifs essential for the intracellular kinase function lost SMAD-dependent signaling. Most of other variations in the kinase domain also caused marked downregulation of signaling; however, two variants behaved as the wild-type ACVRL1 did, while computational classifiers predicted their functional abnormalities. Three-dimensional structure prediction using the ColabFold program supported the significance of the L45 loop and NANDOR domain of ACVRL1 for its association with SMAD1 and BMPR2, respectively, and the variations in these motifs resulted in the reduction of SMAD signaling. On the other hand, two of the GS domain variants maintained high signal transduction capacity, which did not accord with their computational pathogenicity prediction. These results affirm the requirement of a combinatory approach using computational and experimental analyses to accurately predict the pathogenicity of ACVRL1 missense variants in the HHT patients.

Differences in patient characteristics, clinical practice and outcomes of cardiac implantable electric device therapy between Japan and the USA: a cross-sectional study using data from nationally representative administrative databases

OBJECTIVES

To identify differences in patient characteristics, clinical practice and outcomes of cardiac implantable electronic device (CIED) therapy between Japan and the USA.

DESIGN

A cross-sectional study.

SETTING

Nationally representative administrative databases from Japan and the USA containing hospitalisations with first-time implantations of pacemakers, implantable cardioverter-defibrillators (ICD) and cardiac-resynchronisation therapy with or without defibrillators (CRTP/CRTD).

PARTICIPANTS

Patients hospitalised with first-time implantations of CIEDs.

OUTCOME MEASURES

In-hospital mortality, in-hospital complication and 30-day readmission rates.

RESULTS

Overall, 107 339 (median age 78 (71-84), 48 415 women) and 295 584 (age 76 (67-83), 127 349 women) records with CIED implantations were included from Japan and the USA, respectively. Proportion of women in defibrillator recipients was lower in Japan than in the USA (ICD, 21% vs 28%, p<0.001; CRTD, 24% vs 29%, p<0.001). Length of stay after CIED implantation was longer in Japan than in the USA for all device types (conventional pacemaker, 8(7-11) vs 1 (1-3) days, p<0.001; leadless pacemaker, 5 (3-9) vs 2 (1-5) days, p<0.001; ICD, 8 (7-11) vs 1 (1-3) days, p<0.001, CRTP, 9 (7-13) vs 2 (1-4) days, p<0.001; CRTD, 9 (8-14) vs 2 (1-4) days, p<0.001). In-hospital mortality after CIED implantation was similar between Japan and the USA ((OR) (95% CI), conventional pacemaker 0.58 (0.83 to 1.004); ICD 0.77 (0.57 to 1.03); CRTP 0.85 (0.51 to 1.44); CRTD 1.11 (0.81 to 1.51)), except that after leadless pacemaker implantation in Japan was lower than that in the USA (0.32 (0.23 to 0.43)). 30-day readmission rates were lower in Japan than in the USA for all device types (conventional pacemaker 0.55 (0.53 to 0.57); leadless pacemaker 0.50 (0.43 to 0.58); ICD 0.54 (0.49 to 0.58); CRTP 0.51 (0.42 to 0.62); CRTD 0.57 (0.51 to 0.64)).

CONCLUSIONS

International variations in patient characteristics, practice and outcomes were observed. In-hospital mortality after CIED implantation was similar between Japan and the USA, except in cases of leadless pacemaker recipients.

Purpose in life (Ikigai) and employment status in relation to cardiovascular mortality: the Japan Collaborative Cohort Study

OBJECTIVES

To investigate whether having a purpose in life (Ikigai) is associated with risk of cardiovascular disease (CVD) mortality and whether the association varies by employment status.

DESIGN

Prospective cohort study.

SETTING

Residents in 45 municipalities, Japan.

PARTICIPANTS

29 517 men and 41 984 women aged 40-79 years, free of CVD and cancer at baseline from 1988 to 1990.

PRIMARY OUTCOME MEASURES

CVD mortality.

RESULTS

During the median follow-up of 19.1 years, 4680 deaths (2393 men and 2287 women) from total CVD were observed. Greater Ikigai was associated with a lower risk of CVD mortality, and the result was stronger for men than for women. Stratified by employment status, the inverse association was confined to unemployed persons. Among unemployed persons, the multivariable HRs of total CVD were higher for moderate and high versus low levels of Ikigai. Multivariable HRs (95% CIs) were 0.74 (0.57 to 0.97) and 0.69 (0.52 to 0.93), P for trend <0.044, respectively in men, and 0.78 (0.64 to 0.95) and 0.77 (0.61 to 0.97), P for trend=0.039 in women. No association was observed among the employed, including part-time workers, self-employed and homemakers for both men and women. Such an inverse association remained even after excluding early deaths within 5 years from the baseline survey.

CONCLUSION

Higher levels of Ikigai were associated with a lower risk of CVD mortality, especially for unemployed men and women.

Machine learning model for predicting out-of-hospital cardiac arrests using meteorological and chronological data

OBJECTIVES

To evaluate a predictive model for robust estimation of daily out-of-hospital cardiac arrest (OHCA) incidence using a suite of machine learning (ML) approaches and high-resolution meteorological and chronological data.

METHODS

In this population-based study, we combined an OHCA nationwide registry and high-resolution meteorological and chronological datasets from Japan. We developed a model to predict daily OHCA incidence with a training dataset for 2005-2013 using the eXtreme Gradient Boosting algorithm. A dataset for 2014-2015 was used to test the predictive model. The main outcome was the accuracy of the predictive model for the number of daily OHCA events, based on mean absolute error (MAE) and mean absolute percentage error (MAPE). In general, a model with MAPE less than 10% is considered highly accurate.

RESULTS

Among the 1 299 784 OHCA cases, 661 052 OHCA cases of cardiac origin (525 374 cases in the training dataset on which fourfold cross-validation was performed and 135 678 cases in the testing dataset) were included in the analysis. Compared with the ML models using meteorological or chronological variables alone, the ML model with combined meteorological and chronological variables had the highest predictive accuracy in the training (MAE 1.314 and MAPE 7.007%) and testing datasets (MAE 1.547 and MAPE 7.788%). Sunday, Monday, holiday, winter, low ambient temperature and large interday or intraday temperature difference were more strongly associated with OHCA incidence than other the meteorological and chronological variables.

CONCLUSIONS

A ML predictive model using comprehensive daily meteorological and chronological data allows for highly precise estimates of OHCA incidence.

A lower maximum bite force is a risk factor for developing cardiovascular disease: the Suita study

Decreases in masticatory function are believed to be related to the development of cardiovascular disease (CVD) through inappropriate nutritional intake. This study focused on maximum bite force (MBF), which is an objective, quantitative index of masticatory function, and its association with the development of CVD (stroke and coronary heart disease) was investigated. The subjects were 1547 participants of the Suita study with no history of CVD who underwent medical and dental health examinations between June 2008 and June 2013. In addition to undergoing a basic physical examination at baseline, their MBF was measured. They subsequently underwent follow-up surveys for the development of CVD (mean follow-up, 3.5 years). The association between baseline MBF and the development of CVD was investigated by multivariate adjustment using a Cox proportional hazards model. CVD developed in 32 subjects during follow-up. The trend test showed a significant association between baseline MBF and CVD in a model that combined men and women. When analysed by sex, the trend test found a significant association between baseline MBF and CVD in women. Low MBF, which is an objective and quantitative index of masticatory function, may be a risk factor for the development of CVD.

The role of Epac in the heart

As one of the most important second messengers, 3',5'-cyclic adenosine monophosphate (cAMP) mediates various extracellular signals including hormones and neurotransmitters, and induces appropriate responses in diverse types of cells. Since cAMP was formerly believed to transmit signals through only two direct target molecules, protein kinase A and the cyclic nucleotide-gated channel, the sensational discovery in 1998 of another novel direct effecter of cAMP [exchange proteins directly activated by cAMP (Epac)] attracted a great deal of scientific interest in cAMP signaling. Numerous studies on Epac have since disclosed its important functions in various tissues in the body. Recently, observations of genetically manipulated mice in various pathogenic models have begun to reveal the in vivo significance of previous in vitro or cellular-level findings. Here, we focused on the function of Epac in the heart. Accumulating evidence has revealed that both Epac1 and Epac2 play important roles in the structure and function of the heart under physiological and pathological conditions. Accordingly, developing the ability to regulate cAMP-mediated signaling through Epac may lead to remarkable new therapies for the treatment of cardiac diseases.