Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Association of edentulism and all-cause mortality in Chinese older adults: do sex differences exist?

OBJECTIVES

Previous studies revealed that tooth loss or edentulism was related to mortality. However, research in developing countries with large numbers of elderly populations is rare, and whether sex differences exist in this relationship is unknown. This study aimed to investigate the association between edentulism and 7-year all-cause mortality among older adults in China and whether sex differences existed.

STUDY DESIGN

This was a prospective cohort study.

METHODS

Data were from 2011 to 2018 waves of the China Health and Retirement Longitudinal Study. A total of 6538 participants aged ≥60 years were included. Logistic models were adopted to estimate the risks of mortality according to edentulism.

RESULTS

The participants with edentulism at baseline were 20% more likely to die over 7 years after controlling for a set of covariates (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.02-1.42). Moreover, edentulism was associated with a 35% higher odds of death among male participants (OR = 1.35, 95% CI: 1.08-1.70), whereas a significant association was not found in female participants.

CONCLUSIONS

The findings demonstrated that baseline edentulism predicted all-cause mortality in Chinese older adults, and sex differences existed in this association. This study implied the importance of developing oral health education programs, incorporating dietary recommendations into dental care for edentulous patients, and expanding the coverage of dental services in the health insurance system to prevent edentulism and alleviate its negative outcomes for older adults.

Ca2+ efflux facilitated by co-transport of inorganic phosphate anion in the H+/Ca2+ antiporter YfkE

Ca²⁺ is an important signaling messenger. In microorganisms, fungi, and plants, H⁺/Ca²⁺ antiporters (CAX) are known to play key roles in the homeostasis of intracellular Ca²⁺ by catalyzing its efflux across the cell membrane. Here, we reveal that the bacterial CAX homolog YfkE transports Ca²⁺ in two distinct modes: a low-flux H⁺/Ca²⁺ exchange mode and a high-flux mode in which Ca²⁺ and phosphate ions are co-transported (1:1) in exchange for H⁺. Coupling with phosphate greatly accelerates the Ca²⁺ efflux activity of YfkE. Our studies reveal that Ca²⁺ and phosphate bind to adjacent sites in a central translocation pathway and lead to mechanistic insights that explain how this CAX alters its conserved alpha-repeat motifs to adopt phosphate as a specific "transport chaperon" for Ca²⁺ translocation. This finding uncovers a co-transport mechanism within the CAX family that indicates this class of proteins contributes to the cellular homeostasis of both Ca²⁺ and phosphate.

[The design method of the digital sequential tooth-sectioning guide for the extraction of mandibular impacted third molars]

Objective: To explore a method for digitally designing and fabricating a sequential tooth-sectioning guide that can assist in the extraction of mandibular horizontal impacted third molars, preliminarily evaluate its feasibility and provide a reference for clinical application. Methods: Twenty patients with mandibular low level impacted third molars who visited the Department of General Dentistry, Peking University School and Hospital of Stomatology from March 2021 to January 2022 were selected. Cone-beam CT showed direct contact between the roots and mandibular canal, and full range impressions of the patients' intraoral teeth were taken and optical scans of the dental model were performed. The patients' cone-beam CT data and optical scan data were reconstructed in three dimensions, anatomical structure extraction, registration fusion, and the design of the structure of the guide (including crown-sectioning guide and root-sectioning guide) by Mimics 24.0, Geomagic Wrap 2021, and Magics 21.0 software, and then the titanium guide was three dimension printed, and the guide was tried on the dental model. After confirmation, the guide was used to assist the dentist in the operation. We observed whether the guide was in place, the number of tooth splitting, the matching of tooth splitting with the preoperative design, the operation time, and whether there were any complications. Results: In this study, 20 sectioning guides were successfully printed, all of them were well fitted in the patients' mouth, the average number of section was 3.4 times, the tooth parts was better matched with the preoperative design, and the average operative time of the guides was (29.2±9.8) minutes without complications such as perforation of the bone cortex. Conclusions: The use of sequential sectioning guides to assist in the extraction of mandibular impacted third molars was initially validated to accurately replicate the preoperative sectioning design, and is expected to provide a digital solution to improve surgical precision and ensure safety. Further studies with larger sample sizes are needed to evaluate its accuracy and safety.

Interactive Effects of Dietary Inflammatory Index with BMI for the Risk of Stroke among Adults in the United States: Insight from NHANES 2011-2018

BACKGROUND AND AIM

Research on the correlation between Dietary Inflammation Index (DII) and stroke is limited. Patients with high body mass index (BMI), as a high-risk group for stroke, require attention. Therefore, we aimed to examine the interactive effects of dietary inflammation and BMI on the risk of stroke among adults in the United States.

METHODS AND RESULTS

Overall, 9,384 participants were included in this study. The exposure variable was the DII, which was calculated based on the overall inflammatory effect score, and the outcome was stroke. Overall, there was a positive relationship between DII (as a continuous variable) and stroke. Increased level of DII was significantly associated with increased risk of stroke (odds ratio [OR]: 1.21, 95% CI: 1.06-1.38), which was enhanced by higher BMI (OR: 1.35, 95% CI: 1.15-1.58) with significant additive interactions. There was a significant secondary interaction of copresence of BMI ≥25 kg/m2, systolic blood pressure (SBP) ≥140 mmHg, and high DII for increased stroke, with a further increase in OR to 1.41 (1.19-1.67).

CONCLUSIONS

This cross-sectional study shows that the relationship between higher DII levels and the significant increase in stroke prevalence was further amplified in patients with SBP ≥140 mmHg and higher BMI.

Global Prevalence and Factors Associated with Frailty among Community-Dwelling Older Adults with Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Frailty may increase the risk of adverse outcomes and the presence of comorbidities in hypertension. Understanding the prevalence of frailty in older adults with hypertension is of great importance, whereas estimates of the prevalence of frailty in this population vary greatly.

OBJECTIVES

A systematic review and meta-analysis was conducted to estimate the pooled prevalence of frailty and prefrailty among community-dwelling older adults with hypertension, and to examine the risk factors associated with (pre)frailty in this population.

METHODS

PubMed, Web of Science, The Cochrane Library, EMBASE, and CINAHL were searched from the inception to May 10, 2023. Investigators assessed eligibility, extracted data, and evaluated methodological quality. The pooled prevalence of frailty and prefrailty was calculated using the random-effects model. Meta-regression analysis and subgroup analysis were conducted to explore sources of heterogeneity. Sensitivity analysis was undertaken by the leave-one-out method and by removing studies with moderate/high risk of bias. The Mantel-Haenszel or inverse variance method was used to estimate risk factors of frailty.

RESULTS

A total of 14 studies met the inclusion criteria, involving 185,249 participants. The pooled prevalence in older adults with hypertension was 23% (95% CI 0.09-0.36) for frailty and 46% (95% CI 0.38-0.54) for prefrailty. The pooled prevalence of frailty was greater in studies with a higher proportion of females (24%, 95% CI 0.05-0.50), using multidimensional tools to define frailty (30%, 95% CI 0.10-0.51) and conducted in Western Pacific (27%, 95% CI 0.17-0.39). Age, female sex, depression, and previous hospitalizations were risk factors of frailty among older adults with hypertension.

CONCLUSION

Frailty and prefrailty are prevalent in community-dwelling older adults with hypertension, and limited risk factors are identified. This implicates the importance of frailty assessment integrated into the routine primary care for older adults with hypertension in community settings as well as the understanding of potential factors.

Mono- and biallelic variant effects on disease at biobank scale

Identifying causal factors for Mendelian and common diseases is an ongoing challenge in medical genetics1. Population bottleneck events, such as those that occurred in the history of the Finnish population, enrich some homozygous variants to higher frequencies, which facilitates the identification of variants that cause diseases with recessive inheritance2,3. Here we examine the homozygous and heterozygous effects of 44,370 coding variants on 2,444 disease phenotypes using data from the nationwide electronic health records of 176,899 Finnish individuals. We find associations for homozygous genotypes across a broad spectrum of phenotypes, including known associations with retinal dystrophy and novel associations with adult-onset cataract and female infertility. Of the recessive disease associations that we identify, 13 out of 20 would have been missed by the additive model that is typically used in genome-wide association studies. We use these results to find many known Mendelian variants whose inheritance cannot be adequately described by a conventional definition of dominant or recessive. In particular, we find variants that are known to cause diseases with recessive inheritance with significant heterozygous phenotypic effects. Similarly, we find presumed benign variants with disease effects. Our results show how biobanks, particularly in founder populations, can broaden our understanding of complex dosage effects of Mendelian variants on disease.

Predicting the structural basis of targeted protein degradation by integrating molecular dynamics simulations with structural mass spectrometry

Targeted protein degradation (TPD) is a promising approach in drug discovery for degrading proteins implicated in diseases. A key step in this process is the formation of a ternary complex where a heterobifunctional molecule induces proximity of an E3 ligase to a protein of interest (POI), thus facilitating ubiquitin transfer to the POI. In this work, we characterize 3 steps in the TPD process. (1) We simulate the ternary complex formation of SMARCA2 bromodomain and VHL E3 ligase by combining hydrogen-deuterium exchange mass spectrometry with weighted ensemble molecular dynamics (MD). (2) We characterize the conformational heterogeneity of the ternary complex using Hamiltonian replica exchange simulations and small-angle X-ray scattering. (3) We assess the ubiquitination of the POI in the context of the full Cullin-RING Ligase, confirming experimental ubiquitinomics results. Differences in degradation efficiency can be explained by the proximity of lysine residues on the POI relative to ubiquitin.

Application of machine learning to identify top determinants of fibrofatty plaque burden by CCTA in humans with psoriasis

Introduction

Fibrofatty plaque burden (FFB) is a high-risk, vulnerable plaque feature comprised of an atheromatous core and fibrous cap with increased risk of coronary artery disease (CAD) [1]. Psoriasis (PSO) is a chronic inflammatory disease linked with atherosclerotic risk and premature cardiovascular disease, driven in part by vulnerable plaque rupture [2,3]. Machine learning (ML) previously showed the prognostic value of FFB in predicting 5-year risk of cardiac-related mortality in patients with CAD [4]. Whether ML can predict FFB in psoriasis is understudied.

Purpose

To use ML to identify top determinants of FFB by CCTA in PSO.

Methods

320 consecutive participants with psoriasis were recruited as part of an ongoing cohort study, of whom 307 had FFB analyzed with coronary computed tomography angiography (CCTA) and quantified by QAngio CT (Medis, The Netherlands). 140 out of 182 potential determinants were subjected to ML algorithms analyzed by random forest and validated by 5-fold cross validation to select the top determinants based on R-square criteria. Lipid concentration and size were measured by nuclear magnetic resonance (NMR) and sdLDL-C was calculated by Sampson's formula.

Results

The top 21 determinants of FFB at baseline were grouped into 3 categories: cardiometabolic risk factors (BMI, sex, DBP, mean arterial pressure, exercise, heart rate, glucose, anxiety, psoriasis disease duration), clinical measurements (basophils, platelets, hemoglobin, RBC, alkaline phosphatase, ALT, creatinine, neutrophil-to-lymphocyte ratio), and lipoproteins (LDL particle size, apolipoprotein A1, apolipoprotein B-to-A1 ratio, calculated sdLDL-C).

Conclusion

ML confirmed that FFB strongly correlates with cardiometabolic risk factors, clinical measurements, and lipoproteins. Further investigations into these top determinants of FFB over time may provide insight into potential therapeutic interventions that decrease cardiovascular risk in patients with chronic inflammatory diseases and should be validated in larger studies.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was supported by the National Heart, Lung and Blood Institute (NHLBI) IntramuralResearch Program (ZIA-HL-06193). This research was made possible through the NIH MedicalResearch Scholars Program, a public-private partnership supported jointly by the NIH andcontributions to the Foundation for the NIH from the Doris Duke Charitable Foundation,Genentech, the American Association for Dental Research, the Colgate-Palmolive Company, andother private donors.

Effect of a home-based resistance exercise program in elderly participants with osteoporosis: a randomized controlled trial

The effectiveness of home-based resistance exercise in elder participants with osteoporosis remains unclear. This study demonstrates the beneficial effects of this mode of exercise on improving physical function, increasing confidence in exercise, and reducing fear of falling.

INTRODUCTION

This study aims to evaluate the effect of a home-based resistance exercise (HBRE) program versus control on physical function, exercise self-efficacy, falling efficacy, and health-related quality of life (HRQOL).

METHODS

This randomized controlled trial included 72 elderly participants with osteoporosis. Participants in the intervention group received a 12-week HBRE program, and the control group received usual care. The primary outcome was physical function, including muscle strength and balance ability; secondary outcomes were exercise self-efficacy, falling efficacy, and HRQOL. Within-group and between-group changes in outcome were evaluated by t-test and rank-sum test.

RESULTS

A total of 68 subjects were included in the final analysis. Improvement in physical function was significantly greater in the HBRE group compared with controls. On a psychological level, exercise self-efficacy and falling efficacy improved significantly in the HBRE group; no significant change was observed in the control group. Most of the dimensions of HRQOL demonstrated improvements as well. The adherence was 85.29%, with no adverse events related to the exercise.

CONCLUSION

A 12-week HBRE program was safe non-pharmacological therapy for elderly participants with osteoporosis, improving physical function, exercise self-efficacy, reduced fear of falling, and improved HRQOL.

TRIAL REGISTRATION

Chinese Clinical Trial Register: ChiCTR2100051455. Registered 23.09.21. Retrospectively registered.

[Preconception reproductive health and birth outcome cohort in Chongqing: the cohort profile]

Birth cohort is an important platform to study the effect of early-life exposure on health outcome, but large cohorts to investigate the effect of preconception exposure, especially paternal exposure, on reproductive health and birth outcome are limited. The Preconception Reproductive Health and Birth Outcome Cohort (PREBIC) is a prospective birth cohort study which pays equal attention to the contribution of environmental, psychological, behavioral as well as other factors to reproductive health and adverse birth outcomes in both men and women in Chongqing, China. PREBIC started in 2019 and plans to recruit 20 800 reproductive-age couples with child-bearing willingness. Followed up was conducted to understand the conception status of the women within two years. Women in pregnancy would be visited at first, second, third trimesters and after delivery. The offspring would be monitored until 2 years old to understand the incidences of preterm birth, low birth weight, birth defects, neurodevelopmental disorders and other outcomes. Related information and biospecimen collections (including semen, peripheral blood, urine, placenta, umbilical cord, cord blood and oral swab) were scheduled in each period. By January 2022, PREBIC had recruited 8 698 participants from all 38 districts in Chongqing. The goal of PREBIC is to establish one of the largest prospective preconception birth cohorts covering both men and women, which might provide a unique insight to understand the effects of the full reproductive cycle on reproductive health and adverse outcomes, with especial emphasis on preconception exposures.

[Cone-beam CT analysis of external root resorption of maxillary incisors before and after traction of impacted canines]

Objective: To analyze the external root resorption of incisors caused by maxillary canine impaction, and to explore the changes of incisor external root resorption after orthodontic treatment. Methods: Twenty-four patients with impacted maxillary canines leading to external root resorption of incisors treated in Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University from July 2011 to January 2019 were selected. The age ranged from 10 to 14 years [(12.3±1.6) years], including 11 males and 14 females. The maxillary incisors with external root resorption before treatment were included in the resorption group (21 central incisors and 22 lateral incisors), and the maxillary incisors without external root resorption were used as the control group (26 central incisors and 21 lateral incisors). Cone-beam CT was taken before treatment, immediately after treatment and one year after treatment. At the one year follow-up 15 patients were collected (10 central incisors and 12 lateral incisors in the resorption group, while 16 central incisors and 12 lateral incisors in the control group). The root length and tooth volume of maxillary incisors were measured and analyzed before canine traction, after canine traction finished and at the one year follow-up. Results: After the treatment of maxillary impacted canines, the root length and volume of the central and lateral incisors in both resorption group and control group were significantly less than that before treatment (P<0.05). At the one year follow-up, the root length and volume of the incisors (central incisors in the resorption group and the central and lateral incisors in control group) were significantly less than those immediately after impacted canine traction (P<0.05). During the canine traction, the difference of the volume change in lateral incisors between the resorption group [(17±6) mm³] and the control group [(12±5) mm³] was statistically significant (t=2.51, P<0.05). During the one year follow-up period, the difference between the changes of the root length in maxillary central incisors in the resorption group [(0.5±0.4) mm] and in the control group [(0.2±0.1) mm] was statistically significant (t=2.35, P<0.05). Conclusions: For maxillary incisors with external root resorption caused by impacted maxillary canines, the external root resorption could not stop immediately after the treatment of impacted canines. The root resorption in maxillary lateral incisors mainly occured during the traction process, while the root resorption in maxillary central incisors existed during the orthodontic treatment and in the follow-up period.

Cardiopulmonary transit time: A novel PET imaging biomarker of in vivo physiology for risk stratification of heart transplant recipients

BACKGROUND

Myocardial blood flow (MBF) can be quantified using dynamic PET studies. These studies also inherently contain tomographic images of early bolus displacement, which can provide cardiopulmonary transit times (CPTT) as measure of cardiopulmonary physiology. The aim of this study was to assess the incremental prognostic value of CPTT in heart transplant (OHT) recipients.

METHODS

94 patients (age 56 ± 16 years, 78% male) undergoing dynamic 13N-ammonia stress/rest studies were included, of which 68 underwent right-heart catherization. A recently validated cardiac allograft vasculopathy (CAV) score based on PET measures of regional perfusion, peak MBF and left-ventricular (LV) ejection fraction (LVEF) was used to identify patients with no, mild or moderate-severe CAV. Time-activity curves of the LV and right ventricular (RV) cavities were obtained and used to calculate the difference between the LV and RV bolus midpoint times, which represents the CPTT and is expressed in heartbeats. Patients were followed for a median of 2.5 years for the occurrence of major adverse cardiac events (MACE), including cardiovascular death, hospitalization for heart failure or acute coronary syndrome, or re-transplantation.

RESULTS

CPTT was significantly correlated with cardiac filling pressures (r = .434, P = .0002 and r = .439, P = .0002 for right atrial and pulmonary wedge pressure), cardiac output (r = - .315, P = .01) and LVEF (r = - .513, P < .0001). CPTT was prolonged in patients with MACE (19.4 ± 6.0 vs 14.5 ± 3.0 heartbeats, P < .001, N = 15) with CPTT ≥ 17.75 beats showing optimal discriminatory value in ROC analysis. CPTT ≥ 17.75 heartbeats was associated with a 10.1-fold increased risk (P < .001) of MACE and a 7.3-fold increased risk (P < .001) after adjusting for PET-CAV, age, sex and time since transplant.

CONCLUSION

Measurements of cardiopulmonary transit time provide incremental risk stratification in OHT recipients and enhance the value of multiparametric dynamic PET imaging, particularly in identifying high-risk patients.

Differential ion dehydration energetics explains selectivity in the non-canonical lysosomal K+ channel TMEM175

Structures of the human lysosomal K⁺ channel transmembrane protein 175 (TMEM175) in open and closed states revealed a novel architecture lacking the canonical K⁺ selectivity filter motif present in previously known K⁺ channel structures. A hydrophobic constriction composed of four isoleucine residues was resolved in the pore and proposed to serve as the gate in the closed state, and to confer ion selectivity in the open state. Here, we achieve higher-resolution structures of the open and closed states and employ molecular dynamics simulations to analyze the conducting properties of the putative open state, demonstrating that it is permeable to K⁺ and, to a lesser degree, also Na⁺. Both cations must dehydrate significantly to penetrate the narrow hydrophobic constriction, but ion flow is assisted by a favorable electrostatic field generated by the protein that spans the length of the pore. The balance of these opposing energetic factors explains why permeation is feasible, and why TMEM175 is selective for K⁺ over Na⁺, despite the absence of the canonical selectivity filter. Accordingly, mutagenesis experiments reveal an exquisite sensitivity of the channel to perturbations that mitigate the constriction. Together, these data reveal a novel mechanism for selective permeation of ions by TMEM175 that is unlike that of other K⁺ channels.