Consequences of ionizing radiation exposure to the cardiovascular system.

Ionizing radiation is widely used in various industrial and medical applications, resulting in increased exposure for certain populations. Lessons from radiation accidents and occupational exposure have highlighted the cardiovascular and cerebrovascular risks associated with radiation exposure. In addition, radiation therapy for cancer has been linked to numerous cardiovascular complications, depending on the distribution of the dose by volume in the heart and other relevant target tissues in the circulatory system. The manifestation of symptoms is influenced by numerous factors, and distinct cardiac complications have previously been observed in different groups of patients with cancer undergoing radiation therapy. However, in contemporary radiation therapy, advances in treatment planning with conformal radiation delivery have markedly reduced the mean heart dose and volume of exposure, and these variables are therefore no longer sole surrogates for predicting the risk of specific types of heart disease. Nevertheless, certain cardiac substructures remain vulnerable to radiation exposure, necessitating close monitoring. In this Review, we provide a comprehensive overview of the consequences of radiation exposure on the cardiovascular system, drawing insights from various cohorts exposed to uniform, whole-body radiation or to partial-body irradiation, and identify potential risk modifiers in the development of radiation-associated cardiovascular disease.

Uterus Transplantation: The Translational Evolution of a Clinical Breakthrough.

Women suffering from absolute uterine factor infertility (AUFI), due to either lack of a uterus or one unable to sustain neonatal viability, presented as one of the last frontiers in conquering infertility. Following systematic animal research for over a decade, uterus transplantation was tested as a treatment for AUFI in 2012, which culminated in the first human live birth in 2014. The development of uterus transplantation from mouse to human has followed both the Moore Criteria for introduction of a surgical innovation and the IDEAL concept for evaluation of a novel major surgical procedure. In this article we review the important pre-clinical animal and human studies that paved the way for the successful introduction of human uterus transplantation a decade ago. We discuss this in the context of the Moore Criteria and describe the different procedures of preparation, surgeries, post-operative monitoring, and use of assisted reproduction in human uterus transplantation. We review the world-wide activities and associated results in the context of the IDEAL concept for evaluation of surgical innovation and appraise the ethical considerations relevant to uterus transplantation. We conclude that rigorous application of the Moore Criteria and strict alignment with the IDEAL concept has resulted in the establishment of uterus transplantation as a novel, safe and effective infertility therapy that is now being used worldwide for the treatment of women suffering from AUFI.

The role of the International Society for Stem Cell Research (ISSCR) guidelines in disease modeling.

Human stem cell-based modeling systems are valuable tools that can greatly improve the clinical translation of basic research. Importantly, the successful application of human stem cell-based models to biomedical research depends on the widespread adoption of ethical principles and practical standards. To achieve this outcome, the International Society for Stem Cell Research (ISSCR) provides a comprehensive set of recommendations that aim to promote the ethical usage of human stem cells and to ensure rigor and reproducibility within the field. Understanding and implementing these recommendations should be a top priority for investigators around the world.

Membrane Curvature Promotes ER-PM Contact Formation via Junctophilin-EHD Interactions.

Contact sites between the endoplasmic reticulum (ER) and the plasma membrane (PM) play a crucial role in governing calcium regulation and lipid homeostasis. Despite their significance, the factors regulating their spatial distribution on the PM remain elusive. Inspired by observations in cardiomyocytes, where ER-PM contact sites concentrate on tubular PM invaginations known as transverse tubules (T-tubules), we hypothesize that the PM curvature plays a role in ER-PM contact formation. Through precise control of PM invaginations, we show that PM curvatures locally induce the formation of ER-PM contacts in cardiomyocytes. Intriguingly, the junctophilin family of ER-PM tethering proteins, specifically expressed in excitable cells, is the key player in this process, while the ubiquitously expressed extended synaptotagmin 2 does not show a preference for PM curvature. At the mechanistic level, we find that the low complexity region (LCR) and the MORN motifs of junctophilins can independently bind to the PM, but both the LCR and MORN motifs are required for targeting PM curvatures. By examining the junctophilin interactome, we identify a family of curvature-sensing proteins, Eps15-homology domain containing proteins (EHDs), that interact with the MORN_LCR motifs and facilitate junctophilins' preferential tethering to curved PM. These findings highlight the pivotal role of PM curvature in the formation of ER-PM contacts in cardiomyocytes and unveil a novel mechanism for the spatial regulation of ER-PM contacts through PM curvature modulation.

ADMET-AI: a machine learning ADMET platform for evaluation of large-scale chemical libraries.

MOTIVATION: The emergence of large chemical repositories and combinatorial chemical spaces, coupled with high-throughput docking and generative AI, have greatly expanded the chemical diversity of small molecules for drug discovery. Selecting compounds for experimental validation requires filtering these molecules based on favourable druglike properties, such as Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET). RESULTS: We developed ADMET-AI, a machine learning platform that provides fast and accurate ADMET predictions both as a website and as a Python package. ADMET-AI has the highest average rank on the TDC ADMET Leaderboard, and it is currently the fastest web-based ADMET predictor, with a 45% reduction in time compared to the next fastest public ADMET web server. ADMET-AI can also be run locally with predictions for one million molecules taking just 3.1 h. AVAILABILITY AND IMPLEMENTATION: The ADMET-AI platform is freely available both as a web server at admet.ai.greenstonebio.com and as an open-source Python package for local batch prediction at github.com/swansonk14/admet_ai (also archived on Zenodo at doi.org/10.5281/zenodo.10372930). All data and models are archived on Zenodo at doi.org/10.5281/zenodo.10372418.

Generation of two familial hypercholesterolemia patient-specific induced pluripotent stem cell lines harboring heterozygous mutations in the LDLR gene.

Familial hypercholesterolemia (FH) is a genetic disorder affecting the metabolism of lipoprotein, characterized by elevated levels of plasma concentrations of low-density lipoprotein cholesterol (LDLC). The most common FH cause is mutations within the gene that encodes for the LDL receptor (LDLR) protein. Two induced pluripotent stem cell (iPSC) lines were generated from patients with FH, each carrying a single heterozygous mutation in the LDLR gene, one is a missense mutation, c.631C > T, and the other is a splice-site mutation, c.313 + 1G > A. Both iPSC lines exhibited strong expression of pluripotency markers, demonstrated the ability to differentiate into derivatives of the three germ layers, and maintained normal karyotypes. These derived iPSC lines represent powerful tools for in vitro modeling FH and offer a promising platform for therapeutic development.

Deciphering Congenital Heart Disease Using Human Induced Pluripotent Stem Cells.

Congenital heart disease (CHD) is a leading cause of birth defect-related death. Despite significant advances, the mechanisms underlying the development of CHD are complex and remain elusive due to a lack of efficient, reproducible, and translational model systems. Investigations relied on animal models have inherent limitations due to interspecies differences. Human induced pluripotent stem cells (iPSCs) have emerged as an effective platform for disease modeling. iPSCs allow for the production of a limitless supply of patient-specific somatic cells that enable advancement in cardiovascular precision medicine. Over the past decade, researchers have developed protocols to differentiate iPSCs to multiple cardiovascular lineages, as well as to enhance the maturity and functionality of these cells. With the development of physiologic three-dimensional cardiac organoids, iPSCs represent a powerful platform to mechanistically dissect CHD and serve as a foundation for future translational research.

Generation of two induced pluripotent stem cell lines from patients with Williams syndrome.

Williams syndrome (WS) is a relatively rare genetic disorder. It arises from a microdeletion in chromosome 7q11.23, resulting in the loss of one copy of more than 20 genes. Disorders in multiple systems, including cardiovascular and nervous systems, occur in patients with WS. Here, we generated two human induced pluripotent stem cell (iPSC) lines from WS patients. Both lines expressed pluripotency markers at gene and protein levels. They possessed normal karyotypes and the potential to differentiate into three germ layers. They serve as a useful tool to study disease mechanism, test drugs, and identify promising therapeutics for patients with WS.

Impact of Prior Biologic or Janus Kinase Inhibitor Therapy on Efficacy and Safety of Etrasimod in the ELEVATE UC 52 and ELEVATE UC 12 Trials.

BACKGROUND AND AIMS: Etrasimod is an oral, once daily, selective sphingosine 1-phosphate [S1P]1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis [UC]. This subgroup analysis evaluated the efficacy and safety of etrasimod 2 mg once daily vs placebo by prior biologic/Janus kinase inhibitor [bio/JAKi] exposure in ELEVATE UC 52 and ELEVATE UC 12. METHODS: Pre-defined efficacy endpoints were assessed at Weeks 12 and 52 in ELEVATE UC 52 and Week 12 in ELEVATE UC 12 in bio/JAKi-naïve and -experienced patients, and at Week 12 [pooled] based on prior advanced therapy exposure mechanism. RESULTS: In the ELEVATE UC 52 and ELEVATE UC 12 analysis populations, 80/274 [29.2%] and 74/222 [33.3%] patients receiving etrasimod and 42/135 [31.1%] and 38/112 [33.9%] patients receiving placebo, respectively, were bio/JAKi-experienced. In both bio/JAKi-naïve and -experienced patients, a significantly greater proportion receiving etrasimod vs placebo achieved clinical remission (p<0.05) in ELEVATE UC 52 at Weeks 12 [naïve: 30.9% vs 9.7%; experienced: 17.5% vs 2.4%] and 52 [naïve: 36.6% vs 7.5%; experienced: 21.3% vs 4.8%]; in ELEVATE UC 12, this was observed only for bio/JAKi-naïve patients [naïve: 27.7% vs 16.2%, p=0.033; experienced: 18.9% vs 13.2%, p=0.349]. Similar patterns were observed for most efficacy endpoints. Among patients with prior anti-integrin exposure [N=90], a significantly greater proportion achieved clinical response [54.1% vs 27.6%, p=0.030], but not clinical remission [9.8% vs 3.4%, p=0.248], with etrasimod vs placebo. CONCLUSIONS: Bio/JAKi-naïve and -experienced patients had clinically meaningful induction and maintenance treatment benefits with etrasimod vs placebo.

The Effect of Etrasimod on Fecal Calprotectin and High-sensitivity C-reactive Protein: Results From the ELEVATE UC Clinical Program.

BACKGROUND: Biomarkers offer potential alternatives to endoscopies in monitoring ulcerative colitis (UC) progression and therapeutic response. This post hoc analysis of the ELEVATE UC clinical program assessed potential predictive values of fecal calprotectin (fCAL) and high-sensitivity C-reactive protein (hsCRP) as biomarkers and associated responses to etrasimod, an oral, once-daily, selective sphingosine 1-phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active UC, in 2 phase 3 clinical trials. METHODS: In ELEVATE UC 52 and ELEVATE UC 12, patients were randomized 2:1 to 2 mg of etrasimod once daily or placebo for 52 or 12 weeks, respectively. Fecal calprotectin/hsCRP differences between responders and nonresponders for efficacy end points (clinical remission, clinical response, endoscopic improvement-histologic remission [EIHR]) were assessed by Wilcoxon P-values. Sensitivity and specificity were presented as receiver operating characteristics (ROC) curves with area under the curve (AUC). RESULTS: In ELEVATE UC 52 and ELEVATE UC 12, 289 and 238 patients received etrasimod and 144 and 116 received placebo, respectively. Baseline fCAL/hsCRP concentrations were generally balanced. Both trials had lower week-12 median fCAL levels in week-12 responders vs nonresponders receiving etrasimod for clinical remission, clinical response, and EIHR (all P < .001), with similar trends for hsCRP levels (all P < .01). For etrasimod, AUCs for fCAL/hsCRP and EIHR were 0.85/0.74 (week 12; ELEVATE UC 52), 0.83/0.69 (week 52; ELEVATE UC 52), and 0.80/0.65 (week 12; ELEVATE UC 12). CONCLUSIONS: Fecal calprotectin/hsCRP levels decreased with etrasimod treatment; ROC analyses indicated a prognostic correlation between fCAL changes during induction and short-/long-term treatment response.

We show associations between fecal calprotectin (fCAL) and high-sensitivity C-reactive protein (hsCRP) levels with efficacy outcomes among patients receiving 2 mg of etrasimod once daily, and that fCAL levels may be an early indicator of the achievement of long-term efficacy end point achievement.

Analysis of tofacitinib safety in ulcerative colitis from the completed global clinical developmental program up to 9.2 years of drug exposure.

BACKGROUND AND AIMS: Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We report an integrated summary of tofacitinib safety from the completed global UC clinical program (9.2 years maximum tofacitinib exposure). METHODS: This analysis included patients receiving tofacitinib 5 or 10 mg twice daily (b.i.d.) from completed phase 2/3 placebo-controlled studies, an open-label, long-term extension study and a randomized phase 3b/4 study. Proportions and incidence rates (IRs; unique patients with events/100 patient-years [PY] of exposure) were evaluated for deaths and adverse events (AEs) of special interest (AESI). RESULTS: Overall, 1157 patients received ≥1 dose of tofacitinib 5 or 10 mg b.i.d.; 938 (81.1%) were in the predominant dose tofacitinib 10 mg b.i.d. group; 552 (47.7%) received tofacitinib for ≥2 years; total exposure: 3202.0 PY; 994 (85.9%) experienced AEs; 254 (22.0%) experienced serious AEs. Median treatment duration: 1.7 (range 0.0-9.2) years. IRs (95% CI) for combined tofacitinib doses: deaths 0.24 (0.10-0.48); serious infections (SIs) 1.80 (1.37-2.32); herpes zoster (HZ; non-serious and serious) 3.24 (2.63-3.94); serious HZ 0.24 (0.10-0.48); opportunistic infections 0.96 (0.65-1.36); malignancies (excluding non-melanoma skin cancer [NMSC]) 0.88 (0.59-1.26); NMSC 0.71 (0.45-1.07); major adverse cardiovascular events 0.27 (0.12-0.52); deep vein thrombosis 0.06 (0.01-0.22); pulmonary embolism 0.18 (0.07-0.40); and gastrointestinal perforations 0.09 (0.02-0.27). CONCLUSIONS: Except for HZ and SIs, IRs for AESI were <1 case/100 PY. Safety was consistent with previous analyses of shorter exposure and tofacitinib's known safety profile, including real-world data. CLINICALTRIALS: GOV: NCT00787202; NCT01465763; NCT01458951; NCT01458574; NCT01470612; NCT03281304.

Personalized transcriptome signatures in a cardiomyopathy stem cell biobank.

BACKGROUND: There is growing evidence that pathogenic mutations do not fully explain hypertrophic (HCM) or dilated (DCM) cardiomyopathy phenotypes. We hypothesized that if a patient's genetic background was influencing cardiomyopathy this should be detectable as signatures in gene expression. We built a cardiomyopathy biobank resource for interrogating personalized genotype phenotype relationships in human cell lines. METHODS: We recruited 308 diseased and control patients for our cardiomyopathy stem cell biobank. We successfully reprogrammed PBMCs (peripheral blood mononuclear cells) into induced pluripotent stem cells (iPSCs) for 300 donors. These iPSCs underwent whole genome sequencing and were differentiated into cardiomyocytes for RNA-seq. In addition to annotating pathogenic variants, mutation burden in a panel of cardiomyopathy genes was assessed for correlation with echocardiogram measurements. Line-specific co-expression networks were inferred to evaluate transcriptomic subtypes. Drug treatment targeted the sarcomere, either by activation with omecamtiv mecarbil or inhibition with mavacamten, to alter contractility. RESULTS: We generated an iPSC biobank from 300 donors, which included 101 individuals with HCM and 88 with DCM. Whole genome sequencing of 299 iPSC lines identified 78 unique pathogenic or likely pathogenic mutations in the diseased lines. Notably, only DCM lines lacking a known pathogenic or likely pathogenic mutation replicated a finding in the literature for greater nonsynonymous SNV mutation burden in 102 cardiomyopathy genes to correlate with lower left ventricular ejection fraction in DCM. We analyzed RNA-sequencing data from iPSC-derived cardiomyocytes for 102 donors. Inferred personalized co-expression networks revealed two transcriptional subtypes of HCM. The first subtype exhibited concerted activation of the co-expression network, with the degree of activation reflective of the disease severity of the donor. In contrast, the second HCM subtype and the entire DCM cohort exhibited partial activation of the respective disease network, with the strength of specific gene by gene relationships dependent on the iPSC-derived cardiomyocyte line. ADCY5 was the largest hubnode in both the HCM and DCM networks and partially corrected in response to drug treatment. CONCLUSIONS: We have a established a stem cell biobank for studying cardiomyopathy. Our analysis supports the hypothesis the genetic background influences pathologic gene expression programs and support a role for ADCY5 in cardiomyopathy.

Generation of induced pluripotent stem cell lines from patients with LQT1 caused by heterozygous mutations in the KCNQ1 gene.

Long QT Syndrome (LQTS) is a genetic heart disorder that can induce cardiac arrhythmias. The most prevalent subtype, LQT1, stems from rare variants in the KCNQ1 gene. Utilizing induced pluripotent stem cells (iPSCs) enables detailed cellular studies and personalized medicine approaches for this life-threatening condition. We generated two LQT1 iPSC lines with single nucleotide nonsense mutations, c.1031 C > T and c.1121 T > A in KCNQ1. Both lines exhibited typical iPSC morphology, expressed high levels of pluripotent markers, maintained normal karyotype, and possessed the capability to differentiate into three germ layers. These cell lines serve as important tools for investigating the biological mechanisms underlying LQT1 due to mutations in the KCNQ1 gene.

Etrasimod for the Treatment of Ulcerative Colitis: Analysis of Infection Events From the ELEVATE UC Clinical Program.

BACKGROUND AND AIMS: Infections are a safety concern in patients with ulcerative colitis (UC). Etrasimod is an oral, once-daily (QD), selective sphingosine 1phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active UC. It leads to selective and reversible lymphocyte sequestration, and partial peripheral lymphocyte count decrease. We report infection events from the phase 3 ELEVATE program. METHODS: Proportions, incidence rates (IRs; per 100 patient-years) and descriptive analyses of all, serious, severe, herpes zoster, and opportunistic infections are reported in the Pivotal UC cohort (ELEVATE UC 52 and ELEVATE UC 12). Cox regression models evaluated potential baseline risk factors. RESULTS: In this analysis (n=787), proportions (IRs) of all infection events were similar for patients receiving etrasimod 2 mg QD (18.8% [41.1]) or placebo (17.7% [49.0]). Serious infections occurred in three (0.6%) and five (1.9%) patients receiving etrasimod and placebo, respectively. Two herpes zoster events were reported in each group (etrasimod: 0.4%; placebo: 0.8%); all localized and non-serious. One opportunistic infection event was reported in each group. No patient with an absolute lymphocyte count (ALC) <0.2 × 109/L reported serious/severe or opportunistic infections; no baseline risk factors were identified for such events. No deaths occurred. CONCLUSIONS: Patients receiving etrasimod demonstrated no increased risk of infection. The incidence of serious infections and herpes zoster was similar in each group. Among patients receiving etrasimod, no association between ALC <0.5 × 109/L and infection events was observed. Longer-term follow-up will further characterize the etrasimod safety profile.

Screening and diagnosis of cardiovascular disease using artificial intelligence-enabled cardiac magnetic resonance imaging.

Cardiac magnetic resonance imaging (CMR) is the gold standard for cardiac function assessment and plays a crucial role in diagnosing cardiovascular disease (CVD). However, its widespread application has been limited by the heavy resource burden of CMR interpretation. Here, to address this challenge, we developed and validated computerized CMR interpretation for screening and diagnosis of 11 types of CVD in 9,719 patients. We propose a two-stage paradigm consisting of noninvasive cine-based CVD screening followed by cine and late gadolinium enhancement-based diagnosis. The screening and diagnostic models achieved high performance (area under the curve of 0.988 ± 0.3% and 0.991 ± 0.0%, respectively) in both internal and external datasets. Furthermore, the diagnostic model outperformed cardiologists in diagnosing pulmonary arterial hypertension, demonstrating the ability of artificial intelligence-enabled CMR to detect previously unidentified CMR features. This proof-of-concept study holds the potential to substantially advance the efficiency and scalability of CMR interpretation, thereby improving CVD screening and diagnosis.

Incomplete-penetrant hypertrophic cardiomyopathy MYH7 G256E mutation causes hypercontractility and elevated mitochondrial respiration.

Determining the pathogenicity of hypertrophic cardiomyopathy-associated mutations in the ß-myosin heavy chain (MYH7) can be challenging due to its variable penetrance and clinical severity. This study investigates the early pathogenic effects of the incomplete-penetrant MYH7 G256E mutation on myosin function that may trigger pathogenic adaptations and hypertrophy. We hypothesized that the G256E mutation would alter myosin biomechanical function, leading to changes in cellular functions. We developed a collaborative pipeline to characterize myosin function across protein, myofibril, cell, and tissue levels to determine the multiscale effects on structure-function of the contractile apparatus and its implications for gene regulation and metabolic state. The G256E mutation disrupts the transducer region of the S1 head and reduces the fraction of myosin in the folded-back state by 33%, resulting in more myosin heads available for contraction. Myofibrils from gene-edited MYH7WT/G256E human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) exhibited greater and faster tension development. This hypercontractile phenotype persisted in single-cell hiPSC-CMs and engineered heart tissues. We demonstrated consistent hypercontractile myosin function as a primary consequence of the MYH7 G256E mutation across scales, highlighting the pathogenicity of this gene variant. Single-cell transcriptomic and metabolic profiling demonstrated upregulated mitochondrial genes and increased mitochondrial respiration, indicating early bioenergetic alterations. This work highlights the benefit of our multiscale platform to systematically evaluate the pathogenicity of gene variants at the protein and contractile organelle level and their early consequences on cellular and tissue function. We believe this platform can help elucidate the genotype-phenotype relationships underlying other genetic cardiovascular diseases.