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Abstract P1150: Self-Efficacy is Associated with Health Behaviors Related to Cardiovascular Risk among Hispanic/Latinx and Somali Immigrants to the United States

Introduction: Despite being healthier than the general population on arrival, immigrants to the US often face systemic barriers to healthy lifestyle behaviors and increased risk of cardiovascular disease (CVD). Self-efficacy has been associated with healthy diet and physical activity behaviors, but associations and construct validity have not been well studied in large samples of immigrant populations. Hypothesis: Self-efficacy for a healthy diet and physical activity will be associated with better dietary quality and intake and more physical activity, respectively. We also assessed the construct validity of measurement scales in this population. Methods: Set in southeast Minnesota and embedded with the Rochester Healthy Community Partnership, a 20-year community-based participatory research partnership, the Healthy Immigrant Community study enrolled Hispanic/Latinx and Somali immigrants into a randomized intervention to reduce obesity and CVD risks. Baseline assessments included biometric measures and self-reports of dietary intake, physical activity, and quality of life in English, Spanish, or Somali. Two self-efficacy items (“How confident are you that you can eat a healthy diet?”; “How confident are you that you can participate in regular exercise or physical activity?”) were rated as a percentage interval (0%=not at all confident; 25%; 50%=somewhat confident; 75%; 100%=very confident). Results: In total, 451 participants, 268 (59%) Hispanic/Latinx and 183 (41%) Somali, completed baseline assessments for this analysis. The mean age was 45 years (range=18-87), 59% were female, and 37% lacked health insurance over ≤12 months. Participants reporting more confidence to eat a healthy diet were more likely to eat fruits and vegetables as snacks ( p =<0.001), and less likely to drink fruit drinks or sports drinks ( p =0.02) or regular soda ( p =<0.001). Those reporting more confidence to be physically active were also reported higher levels of physical activity ( p =0.001). Validated self-efficacy scales had a wide distribution of scores, suggesting that the measures can be appropriately used among these immigrant communities. Conclusion: Higher self-efficacy for a healthy diet and physical activity were significantly associated with healthier eating and physical activity behaviors. Lifestyle interventions to reduce CVD risk may benefit from incorporating culturally tailored strategies to enhance self-confidence and support health equity in immigrant communities.

Abstract P3090: 3-Minute Heart Health App: A Feasibility Study

Background: Cardiovascular (CV) health can be estimated using CV risk factors or can be evaluated more precisely by investigating individual fitness and subclinical disease. Current options involve expensive procedures requiring specialist monitoring and interpretation or radiation exposure and have inequitable access. In contrast, the change in heart rate in one minute after maximum exercise, or heart rate recovery (HRR) is a significant predictor of mortality that does not require specialized equipment and can be done in many settings. In this feasibility study, we aim to assess max heart rate achieved by adults after two minutes of exercise and determine HRR using a Bluetooth heart rate monitor. Methods: We developed the 3-Minute Heart Health App to facilitate this accessible approach to evaluating heart health. We partnered with a primary care clinic to enroll healthy, asymptomatic patients after their visit and listed the study on the University StudyFinder website. For this ongoing pilot study, the app is being paired with a chest band heart rate monitor. When exercise begins, the app provides a countdown timer and displays the patient’s percent of age-adjusted max heart rate (MHR) achieved. After 2 minutes of exercise, the app signals participants to stop and heart rate is monitored for 1 minute. The app then displays the age-adjusted Heart Fitness Grade and HRR (Figure 1). Results: Pilot testing has allowed us to strategically design and optimize the user experience while exploring feasibility of this approach. Of eight patients approached in clinic, seven consented and enrolled. An additional four participants were recruited via StudyFinder. Age ranged from 23 to 73 years; 10/11 were able to achieve >70% of MHR and 7/11 reached >85% of MHR in 2 minutes. Average HRR was 39 bpm; all but 1 had HRR >25bpm. Participant feedback included desiring different exercises to increase heart rate and alternative heart rate monitor devices. There was overall enthusiasm about a routine evaluation of cardiovascular health that participants can monitor over time. Conclusion: Our preliminary findings suggest that the 3-Minute Heart Health test is acceptable and can be implemented in an outpatient setting This study is ongoing and more data are being collected to further determine acceptability and to evaluate characteristics of participants who reach a target MHR with normal/abnormal HRR.

Prodrug activation in malaria parasites mediated by an imported erythrocyte esterase, acylpeptide hydrolase (APEH)

The continued emergence of antimalarial drug resistance highlights the need to develop new antimalarial therapies. Unfortunately, new drug development is often hampered by undesirable drug-like properties of lead compounds. Prodrug approaches temporarily mask undesirable compound features, improving bioavailability and target penetration. We have found that lipophilic diester prodrugs of phosphonic acid antibiotics, such as fosmidomycin (Fsm), exhibit significantly higher antimalarial potency than their parent compounds [R.L. Edwards et al. , Sci. Rep. 7 , 8400 (2017)]. However, the activating enzymes for these prodrugs were unknown. Here, we show that an erythrocyte enzyme, acylpeptide hydrolase (APEH), is the major activating enzyme of multiple lipophilic ester prodrugs. Surprisingly, this enzyme is taken up by the malaria parasite, Plasmodium falciparum , where it localizes to the parasite cytoplasm and retains enzymatic activity. Using a fluorogenic ester library, we characterize the structure–activity relationship of APEH and compare it to that of P. falciparum esterases. We show that parasite-internalized APEH plays an important role in the activation of substrates with branching at the alpha carbon, in keeping with its exopeptidase activity. Our findings highlight a mechanism for antimicrobial prodrug activation, relying on a host-derived enzyme to yield activation at a microbial target. Mutations in prodrug-activating enzymes are a common mechanism for antimicrobial drug resistance [E. S. Istvan et al. , Nat. Commun. 8 , 14240 (2017); K. M. V. Sindhe et al. , mBio 11 , e02640-19 (2020); J. H. Butler et al. , Acs Infect Dis. 6 , 2994–3003 (2020)]. Leveraging an internalized host enzyme would circumvent this, enabling the design of prodrugs with higher barriers to drug resistance.

Abstract P1157: Changes in Artificial Intelligence-Enabled Electrocardiogram-Derived Age During Mental Stress Testing and Risk of Major Adverse Cardiovascular Events in Patients With Coronary Heart Disease

Background: The gap between artificial intelligence-derived age (ECG-Age) and chronological age has been validated as a strong predictor of increased cardiovascular morbidity and mortality, independent of age, and is a potential biomarker of biological aging. Acute stress may cause real-time, transient changes in autonomic function via electrophysiological signals that, when repeated over time, may contribute to biological aging and represent mechanisms linking stress and Major Adverse Cardiovascular Events (MACE). We hypothesized that acute mental stress induced in a laboratory is associated with increased ECG and that this increase is associated with a higher risk of MACE among individuals with stable coronary heart disease (CHD). Methods: We pooled two prospective cohorts of participants with stable CHD from a university-based hospital network in Atlanta. Stress was induced using a standardized mental stress test (public speaking task) and measured 12-lead ECGs during rest, mental stress, and recovery periods. To measure ECG-age, we utilized a published algorithm using a neural network on >500,000 independent patients. The study endpoint was MACE including nonfatal myocardial infarction, hospitalization for heart failure, or cardiovascular death. The difference in ECG-Age between resting and acute mental stress was used to define the stress Age-Gap. Cox proportional hazard regression modeled the association of stress Age-Gap operationalized as tertiles adjusting for chronological age, sex, race, cardiovascular risk factors, and baseline Cohen perceived stress scale. Results: 442 participants in the total sample pool (38% women). Over a 5-year median follow-up, 95 participants (21%) experienced MACE. At rest, the mean chronologic age was 55.7±9.9 years, and ECG-Age was 57.1 ±10.7 years, with rest Age-Gap of 0. 9±9.6 (p=0.16). During stress, the stress Age-Gap of 1.95±9.8 (p<0.0001), while recovery Age-Gap was 1.1±10.3 (p=0.13). Those that demonstrated the largest ECG-Age positive change between rest and stress by ECG (top tertile) had a higher risk for MACE when compared to those with the lowest or negative ECG age change (bottom tertile), see Figure. Conclusion: Among patients with stable CHD, acute mental stress caused changes in biological age as measured by AI-ECG consistent with accelerated biological aging. Such changes were associated with MACE. These results uncover accelerated biological aging as a mechanism linking acute stress to CVD outcomes.

Abstract P1145: Feasibility of a Culturally-tailored Diet and Physical Activity Intervention for Zimbabwean Immigrants in the US

Background: CVD risk factors are a significant health concern among African immigrants in the US. Zimbabwean immigrants in the US have high rates of hypertension, obesity, hyperlipidemia, and diabetes. Culturally tailored interventions are effective in reducing CVD risk in African Americans but given the unique cultural differences between African immigrants and other African Americans, r interventions tailored specifically for African immigrants are needed. Objective: We assessed the feasibility of a culturally targeted lifestyle intervention (LIFESTYLE) for Zimbabwean immigrants in the US. LIFESTYLE is based on CDC dietary and physical activity guidelines for Americans, customized with input from a community advisory board comprised of members from the same community, a nutritionist, and an exercise scientist to include foods and physical activities preferred by the Zimbabwe immigrants. Methods: A 12-week community-based intervention study was conducted in the New England region. LIFESTYLE utilized a pre&post-intervention design, followed by focus group interviews. Feasibility was assessed by the ability to recruit and retain participants, their engagement in prescribed intervention activities, and their feedback in post-intervention focus group interviews. Day 1 activities included consent, demonstration of recommended food portions, physical activity, educational modules on nutrition and physical activity and completion of research questionnaires. A research coordinator conducted weekly check-ins. Weight, waist-circumference, BP, HbA1C, and physical activity were recorded. Focus group interviews were conducted on the last day of the study. Results: Of the 35 participants who initially agreed to participate, 25(71%) came. Of these, 23(92%) enrolled, 1 dropped out at week 2 and another at week 11. Overall, 21(91%) completed the study. Findings from post-intervention focus group interviews include: portion control was manageable; check-in reminders were helpful; activities enhanced family time; the food questionnaire was cumbersome; and achieving 150 minutes weekly of physical activity was challenging. Conclusion: LIFESTYLE intervention for Zimbabwean immigrants was feasible as indicated by high participation and adherence to the intervention. Areas of improvement identified include recruitment as nearly 30% (10/35) who initially agreed to participate were no-shows; decreasing questionnaire burden, and enhancing support for engagement and adherence.

A simple, statistically robust test of discrimination

In observational studies of discrimination, the most common statistical approaches consider either the rate at which decisions are made (benchmark tests) or the success rate of those decisions (outcome tests). Both tests, however, have well-known statistical limitations, sometimes suggesting discrimination even when there is none. Despite the fallibility of the benchmark and outcome tests individually, here we prove a surprisingly strong statistical guarantee: Under a common nonparametric assumption, at least one of the two tests must be correct; consequently, when both tests agree, they are guaranteed to yield correct conclusions. We present empirical evidence that the underlying assumption holds approximately in several important domains, including lending, education, and criminal justice—and that our hybrid test is robust to the moderate violations of the assumption that we observe in practice. Applying this approach to 2.8 million police stops across California, we find evidence of widespread racial discrimination.

Abstract 035: Time-restricted eating for weight loss maintenance: a pilot feasibility and acceptability, randomized controlled trial.

Background: Time-restricted eating (TRE) interventions demonstrate heterogeneity in the eating window duration. The purpose of this study was to examine the feasibility, acceptability, and adherence of two TRE strategies (10-hr vs 6-hr). Methods: Eligible participants had ≥5% non-surgical weight loss (self-reported) within the last 3 months and BMI: 20.5-45 kg/m 2 ; were 25-65 y; had an eating window >12 h/day and completed a 4-week (wk) run-in to determine weight stability and eating window length. Participants were randomized to a self-selected 10 h (TRE10) or 6 h (TRE6) eating window for 12 weeks. Both arms received 8 educational and behavioral counseling sessions via videoconferencing (WebEx). Participants in both arms were asked to enter all eating occasions (foods and caloric beverages) into a smartphone application (MyCircadianClock) to assess eating window adherence. Feasibility and acceptability were determined based on retention and participant experience using an investigator-developed questionnaire (TRE Experience Questionnaire [TRE-EQ]). Mann-Whitney U test was used to compare data between the two arms. Baseline data are reported as means and standard deviations. Results: Participants were 46±10 y, 55% White, 36% African American, 27% Hispanic, and mostly female (73%) with a BMI of 30.1±6.2 kg/m 2 . The average self-reported weight loss before randomization was 9.2%±4.3%. A total of 29 participants were enrolled and 22 (n=11/arm) were randomized. Retention was 90%, with only two participants dropping out during the study, one from each arm. Additionally, TRE-EQ data indicates the participants in the TRE10 agreed to more statements around less hunger (p=0.09), their assigned program was easy to follow (p=0.02), their assigned program fits their daily routine (p=0.08) and they were adherent to their eating window (p=0.03) compared to participants in the TRE6 arm. Data from the mCC app suggests no difference between TRE10 and TRE6 regarding eating window adherence (p=0.41). There was a trend for the TRE10 arm to log fewer days with at least one eating occasion outside the designated eating window than the TRE6 arm (p=0.06). Conclusions: A 12-week 10-hr TRE intervention is more feasible and acceptable for adults with recent weight loss compared to a 6-hr TRE intervention.

Abstract P1168: The Association Between Self-Perceived Risk of Heart Disease and Barriers and Motivators to Research Participation

Purpose: Prior studies have investigated how barriers and motivators (B&M) impact women’s participation in heart health-related research, but there is limited understanding of how women’s perceptions of their own heart health risk impact such B&M. This study aimed to investigate the association between self-perceived risk of heart disease and B&M to heart health-related research participation. We hypothesize that self-perceived risk of heart disease will be associated with encountering increased barriers or motivators to research participation on average. Methods: Data from the Barriers and Motivators to Research survey from the American Heart Association’s Millennial Women’s Health Study (MWHS) were used to conduct this analysis. B&M were measured using the established B&M research scale employed in prior health research. B&M were tallied among each participant and the number of total B&M were counted. We performed descriptive statistics and the association between B&M and perceived risk of heart disease was assessed by performing one-way ANOVA Kruskal-Wallis tests for nonparametric data. Results: A total of 200 women participated in the study. Of these, 39% were Black and 21% were Hispanic, with an average age of 44 (10.9). Sixty-five percent of women within the study population perceived themselves to be at risk of heart disease and 60% of the population reported that they did not experience barriers, instead reporting that they felt motivated to participate in research. We found that there was no significant difference in average total amount of barriers or motivators between any groups that perceived themselves to be at risk of heart disease ( = 8.5, = 4, p = 0.07, = 7.6, = 4, p = 0.11). Additionally, women who reported a single barrier to participation in research were more likely to report encountering at least 3 motivators to research participation. Conclusion: Women who perceived themselves to be at risk for heart disease reported strong motivation to participate in heart-related research. Although most women in our sample did not report encountering barriers to participation, those who did identified barriers such as difficulty finding time to participate and lack of interest in learning about the information research may provide about their health. Further research is necessary to gain a deeper understanding of the specific motivators and barriers experienced by women from minoritized backgrounds when invited to participate in heart research.

Coronavirus endoribonuclease antagonizes ZBP1-mediated necroptosis and delays multiple cell death pathways

Identifying conserved mechanisms used by viruses to delay host innate responses can reveal potential targets for antiviral therapeutics. Here, we investigated coronavirus nonstructural protein 15 (nsp15), which encodes a highly conserved endoribonuclease (EndoU). EndoU functions as an immune antagonist by limiting the accumulation of viral replication intermediates that would otherwise be sensed by the host. Despite being a promising antiviral target, it has been difficult to develop small-molecule inhibitors that target the EndoU active site. We generated nsp15 mutants of the coronaviruses severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and mouse hepatitis virus (MHV)-A59 and identified conserved residues within the amino-terminal domain that are required for EndoU activity. Loss of EndoU activity caused the activation of host sensors, which limited viral replication in interferon-responsive cells and attenuated disease in MHV-infected mice. Using transcriptional profiling, we found that MHV EndoU mutant viruses upregulate multiple host sensors, including Z-form nucleic acid-binding protein 1 (ZBP1). We found that nsp15 mutants induced early, robust ZBP1-mediated necroptosis. EndoU mutant viruses also induced ZBP1-independent apoptosis and pyroptosis pathways, causing early, robust cell death that limits virus replication and pathogenesis. Overall, we document the importance of the amino-terminal domain for EndoU function. We also highlight the importance of nsp15/EndoU activity for evading host sensors, delaying cell death, and promoting pathogenesis.

Letter by Dai et al Regarding Article, “Tadalafil for Treatment of Combined Postcapillary and Precapillary Pulmonary Hypertension in Patients With Heart Failure and Preserved Ejection Fraction”

Abstract P1010: Prediction Algorithms of Sarcopenia in US Older Adults

Sarcopenia is a significant risk factor for falls, disability, and mortality in US older adults. Currently, simple screening tools identifying sarcopenia in US older adults remain less clear. PURPOSE: The study developed simple prediction algorithms for sarcopenia using several anthropometric variables from the National and Nutrition Health Examination Survey (NHANES). Methods: The study participants included 3,377 men and women aged 60 to 80. All participants completed baseline anthropometric measurements, clinical evaluations, gait speed, 5 times sit-to-stand test (SST), and body composition assessment. Sarcopenia was defined as the combination of low muscle mass and SST or slow gait speed following the guidelines of the European Working Group on Sarcopenia in Older People (EWGSOP) and the Foundation for the National Institutes of Health (FNIH). Low muscle mass was classified using the appendicular skeletal muscle mass (ASM) divided by height in meters squared as <7.0 kg/m 2 in men and <5.5 kg/m 2 in women or ASM divided by body mass index (BMI) as <0.789 in men and <0.512 in women. Slow gait speed was classified as <0.8 m/s in both men and women. Low muscle strength was classified as greater than 15 seconds of SST. Multivariate stepwise logistic regression models were used to develop prediction algorithms for sarcopenia. Harrel’s c-statistics were used to measure the discrimination, and the Hosmer-Lemeshow Chi-square statistics were used for calibration measures. The bootstrap procedures were used to cross-validate the developed prediction model’s accuracy. Results: The prediction algorithms for sarcopenia included age, sex, BMI, and waist girth using EWGSOP criteria (cases = 74), indicating the c-statistics of 0.94 with bootstrap cross-validation c-statistics of 0.9416. The P-value of the Hosmer-Lemeshow statistics was 0.92. Using FNIH criteria to define sarcopenia (cases = 224), age, sex, height, BMI, and waist girth maximized the discrimination index (c-statistics = 0.95) with the bootstrap cross-validation of 0.949. There was a valid calibration measure (P-value for the Hosmer-Lemeshow statistics = 0.18). Conclusion: There was good discrimination and calibration measures to predict sarcopenia using EWGSOP criteria (age, sex, BMI, and waist girth) and FNIH criteria (age, sex, height, BMI, and waist girth). Public health agencies should consider recommending these simple prediction algorithms for screening sarcopenia across community-based US older adults.

RNA-targeted proteomics identifies YBX1 as critical for efficient HCMV mRNA translation

Viruses have evolved unique strategies to circumvent host control of protein synthesis and enable viral protein synthesis in the face of the host response. Defining the factors that regulate viral messenger RNA (mRNA) translation is thus critical to understand how viruses replicate and cause disease. To identify factors that might regulate viral mRNA translation, we developed a technique for identifying proteins associated with a native RNA expressed from its endogenous promoter and genomic locus. This approach uses a guide RNA to target dCas13b fused to a biotin ligase domain to a specific RNA, where it covalently labels proteins in close proximity. Using this approach, we identified multiple proteins associated with transcripts encoding the human cytomegalovirus (HCMV) IE1 and IE2 proteins and found that several associated proteins positively or negatively regulate HCMV replication. We confirmed that one such protein, the cellular Y-box binding protein 1 (YBX1), binds to HCMV immediate early mRNAs and is required for efficient viral protein expression and virus replication. Ablating YBX1 expression reduced the association of HCMV immediate early mRNAs with polysomes, demonstrating a role for YBX1 as a positive regulator of viral RNA translation. These results provide a powerful tool for unraveling RNA–protein interactions that can be used in a wide range of biological processes and reveal a role for YBX1 as a critical regulator of HCMV immediate early gene expression.

Abstract MP35: Community Prevalence of the Cardiovascular-Kidney-Metabolic (CKM) Syndrome: The Dallas Heart Study

Introduction: The recent AHA presidential advisory on Cardiovascular-Kidney-Metabolic Syndrome (CKM) proposed a novel staging scheme, but limited data exist regarding CKM stage prevalence in the community. Prior population-based studies have lacked subclinical imaging measures, and have not reported variability by age, gender, and race/ethnicity. Methods: We estimated the population prevalence of CKM stages in Dallas County, from among 2,817 participants in the population-sampled Dallas Heart Study who attended study Visit 1 (2000-2002). Participants underwent protocol measurement of body composition, lipids, fasting blood sugar, serum creatinine, NT-proBNP, hs-cTnT, urinary albumin and creatinine, coronary artery calcium by cardiac CT (CAC), and cardiac function and mass by cardiac MRI. These were used to operationalize the following CKM stages: 0 – no CKM risk factors; 1 – excess or dysfunctional adiposity (body mass index, waist circumference, and fasting blood glucose); 2 – metabolic risk factors (hypertriglyceridemia, hypertension, diabetes, metabolic syndrome) and chronic kidney disease; 3 – subclinical cardiovascular diseases (CAC, LV hypertrophy or dysfunction by cardiac MRI, elevated cardiac biomarkers (NT-proBNP or hs-cTnT), high AHA-PREVENT or KDIGO scores); 4 – prevalent cardiovascular diseases (coronary heart disease, heart failure, atrial fibrillation, stroke). We used sampling weights to estimate the prevalence of CKM stages in Dallas County in 2000-2002 overall and by age category (30-44, 45-59, 60-65 years), gender, and race/ethnicity. Results: Among the 2,817 participants with a mean age of 44±10 years, the sample weighted demographics were 50% women, 52% non-Hispanic White, 20% non-Hispanic Black, and 26% Hispanic race/ethnicity. Among Dallas County adults, only 10% were CKM Stage 0 (no risk factors). The weighted prevalence of CKM Stages 1 through 4 was 16%, 46%, 23%, and 5%, respectively ( Figure A) . CKM stage prevalence was similar between men and women, while CKM Stage 4 was more frequent among older individuals and among non-Hispanic Black compared with non-Hispanic White and Hispanic individuals ( Figure B ). Conclusion: The public health burden of CKM is substantial. Ninety percent of Dallas County residents in 2000-2002 had some form of CKM syndrome, nearly half demonstrated metabolic dysfunction (Stage 2), and nearly one-fourth had subclinical cardiovascular disease (Stage 3).

Abstract MP48: Null Causal Associations between Circulating Caffeine Levels and its Metabolites with Cardiac Function and Heart Failure

Introduction: Observational studies have shown that coffee consumption relates to a decreased risk of heart failure (HF). Our recent findings indicate that caffeine metabolism, not caffeine itself, relates to the onset of HF. The causal effect of circulating caffeine levels on HF and cardiac function is largely inconclusive. Hypothesis: We hypothesize that circulating caffeine level is not causally associated with cardiac function and HF. Methods: We extracted the summary results from genome-wide association (GWAS) studies of plasma caffeine, HF, and 15 cardiac structure and function measures for left atrium, left ventricle, and right ventricle from public databases. Genetic instruments of caffeine were selected if the variants were associated with caffeine at p<5×10 -8 . After clumping at r<0.001, two independent lead variants on gene CYP1A2 , rs2472297, and AHR , rs4410790, were included in the analysis. Using the two-sample Mendelian Randomization (MR) approach, we examined the associations between caffeine level, cardiac function measurements, and HF on each selected variant, and pooled estimates were generated using the inverse-variance weighted method. Results: The summary of caffeine, cardiac function, and HF was from GWAS of European descent, consisting of 9,876 participants from six cohorts, up to 29,506 participants from UK Biobank, and 47,309 cases and 93,014 controls from the Heart Failure Molecular Epidemiology for Therapeutic Targets study, respectively. CYP1A2 and AHR were not causally associated with HF individually or jointly (Odds Ratio meta =1.001, 95% CI = 0.999, 1.004). Both genes also yield insignificant results between caffeine levels and measures of the left ventricle, left atrium, and right ventricle, key parameters underlying HF ( Figure ). Conclusion: We observed no causal association between circulating caffeine and the risk of HF, suggesting health-beneficial effects of coffee consumption may relate to the improved molecular pathways instead of circulating caffeine levels.

Significant amplification of electromagnetic waves in disordered dispersive temporal multilayered structures with randomness in plasma frequency or dielectric permittivity

Cas9-mediated gene-editing frequency in microalgae is doubled by harnessing the interaction between importin α and phytopathogenic NLSs

Pathogen-derived nuclear localization signals (NLSs) enable vigorous nuclear invasion in the host by the virulence proteins harboring them. Herein, inspired by the robust nuclear import mechanism, we show that NLSs originating from the plant infection–associated Agrobacterium proteins VirD2 and VirE2 can be incorporated into the Cas9 system as efficient nuclear delivery enhancers, thereby improving the low gene-editing frequency in a model microalga, Chlamydomonas reinhardtii , caused by poor nuclear localization of the bulky nuclease. Prior to evaluation of the NLSs, IPA1 (Cre04.g215850) was first defined in the alga as the nuclear import-related importin alpha (Impα) that serves as a counterpart adaptor protein of the NLSs, based on extensive in silico analyses considering the protein’s sequence, tertiary folding behavior, and structural basis when interacting with a well-studied SV40TAg NLS. Through precursive affinity explorations, we reproducibly found that the NLSs mediated the binding between the Cas9 and Impα with nM affinities and visually confirmed that the fusion of the NLSs strictly localized the peptide-bearing cargoes in the microalgal nucleus without compensating for their cleavage ability. When employed in a real-world application, the VirD2 NLS increases the mutation frequency (~1.12 × 10 −5 ) over 2.4-fold compared to an archetypal SV40TAg NLS (~0.46 × 10 −5 ) when fused with Cas9. We demonstrate the cross-species versatility of the Impα-dependent strategy by successfully applying it to an industrial alga, Chlorella Sp. HS2. This work, focused on affinity augmentation, provides insights into increasing the frequency of gene editing, which can be advantageously used in programmable mutagenesis with broad applicability.

Abstract P2052: Expanding Opportunities for Black and Hispanic Undergraduate Students Pursuing Science, Medical and Health-Related Careers with the American Heart Association’s Scholars Program

Introduction: Black and Hispanic students entering science, medical and health-related careers remain disproportionately low due to systemic inequities in educational support and opportunities. Recognizing the significant role undergraduate (UG) pathway programs play in preparing students for advanced careers, the American Heart Association (AHA) established the AHA Scholars Program. This program expands opportunities for individuals enrolled in Historically Black Colleges and Universities and Hispanic-Serving Institutions to receive mentorship and engage in research and career-enriching experiences, fostering their academic and career growth to empower them to become healthcare professionals and researchers. Objectives: To gather information on the current employment and education status of individuals who participated in the program over the past eight years, and to understand how participation in the program impacted their career and education paths. Methods: A cross-sectional survey was administered to 250 unique alumni in May 2024. Eighty-four individuals completed the survey, representing a response rate of 40%. Descriptive statistics and content analysis were used to analyze quantitative and qualitative questions, respectively. Results: Among respondents who completed their UG degrees, 68% reported pursuing/completing postgraduate (PG) education, with about 59% pursuing/completing a PG degree program in a science or health-related field. Among employed respondents, 65% reported working in a science or health-related industry. Many respondents felt their program experience prepared them very well or more than adequately for PG education (81%) and a career in a health-related field (78%). Almost 76% of respondents indicated their program experience had a substantial positive impact on their overall career progression. Receiving professional skill development, learning how to engage in networking opportunities, gaining research experience, and increasing self-confidence were other ways the program helped respondents prepare for their PG education or career. Conclusion: By creating opportunities for students to engage in skill-building and career-enriching experiences, the AHA Scholars Program has demonstrated its potential to support and promote the advancement of Black and Hispanic students in science, medical and health-related fields, contributing to the development of a more diverse workforce and the advancement of health equity.

Abstract P1015: Human Blood Proteome Profiles Across Middle and Late Adulthood Exhibit Three Life-Stage Waves Differentially Linked to Age-Related Diseases

Introduction: The circulating proteome has emerged as a crucial resource for predicting biological aging. Recent studies identified life-stage specific waves of proteomic expression; however, little is known about the relations between life-stage proteomic waves and age-related disorders. Hypothesis: Life-stage proteomic waves during middle and late adulthood are differentially associated with diseases and mortality. Methods: The study included a total of 53,105 participants (aged 39-70 years) from the UK Biobank study, with the measurements of 2,922 Olink plasma proteins. We used differential expression-sliding window analysis (DE-SWAN) to analyze differential expression of protein levels within a window of 10 years, while sliding the window in increments of 2 year from middle to old. We constructed a coefficient-weighted protein scores for aging waves, and then used the Cox models to assess the associations between protein scores and the risk of 22 leading diseases and mortality. Results: We identified three distinct life-stage proteomic waves peaking at ages 50, 56, and 67, comprising 943, 708, and 1,103 differentially expressed proteins, respectively. Protein scores from all waves showed significant and varying associations with 10 diseases across neurodegenerative, cardiovascular, autoimmune, respiratory, metabolic, and liver categories. The protein scores of age 56 wave demonstrated the strongest associations with most diseases including ischaemic stroke, ischaemic heart disease, rheumatoid arthritis, systemic lupus erythematosus, chronic obstructive pulmonary disease, lung cancer, and mortality (Hazard ratio [HR] ranges: 1.30-2.10). There were distinct association patterns for specific diseases. For instance, Alzheimer's dementia showed a peak risk at age 56 (HR 1.34), rising from age 50 (HR 1.25) and remaining essentially unchanged at age 67 (HR 1.31). In contrast, vascular dementia displayed consistently higher risk at ages 50 and 56 (HR 1.59), followed by a decline at age 67 (HR 1.48). Liver diseases showed a unique pattern, with the highest risk at age 50 (HR 2.74), followed by a gradual but monotonically decrease through ages 56 (HR 2.38) and 67 (HR 2.00). Conclusions: Our findings indicate life-stage specific association patterns between circulating proteomic profiles and risks of a wide spectrum of diseases, highlighting the essentiality of age-based strategies in prevention and treatment of diseases.

Some new evidence using fractional integration about trends, breaks and persistence in polar amplification

Photoreduction of mercuric bromides in polar ice

In the polar regions, which are vulnerable receptors of mercury pollution, atmospheric mercury depletion events (AMDEs) efficiently convert elemental mercury (Hg(0)) into oxidized mercury (Hg(II)) via bromine oxidation. Hg(II) subsequently deposits onto snow and sea ice. While field observations have shown that a large percentage of deposited mercury is re-emitted from the ice to the atmosphere by a photoinduced process, the fundamental photochemistry that drives the re-emission process remains unknown. Here, using multiconfigurational quantum chemistry, we find that the photoreduction of HgBr 2 , HgBr 3 − , and HgBr 4 2− in ice is more efficient than in the gas phase. This results from the influence of water molecules on the molecular geometry and electronic structure of mercuric bromides in ice, which enhances the absorption intensities at wavelengths relevant in the troposphere (λ > 290 nm), as compared to gas phase. Kinetic modeling shows that ~30 to 60% of deposited mercury in AMDEs can be reemitted due to the photoreduction of mercuric bromides in ice, in agreement with field observations. Our results reveal a photoreduction mechanism of sunlight-induced excited state chemistry of mercuric bromides on ice. These findings strongly suggest that this chemistry should be incorporated into atmospheric models to account for ice-atmosphere mercury cycling in the polar environments, currently not considered.