Cardiovascular Defects Research Articles

Zebrafish as a Model to Study Vascular Elastic Fibers and Associated Pathologies.

Many extensible tissues such as skin, lungs, and blood vessels require elasticity to function properly. The recoil of elastic energy stored during a stretching phase is provided by elastic fibers, which are mostly composed of elastin and fibrillin-rich microfibrils. In arteries, the lack of elastic fibers leads to a weakening of the vessel wall with an increased risk to develop cardiovascular defects such as stenosis, aneurysms, and dissections. The development of new therapeutic molecules involves preliminary tests in animal models that recapitulate the disease and whose response to drugs should be as close as possible to that of humans. Due to its superior in vivo imaging possibilities and the broad tool kit for forward and reverse genetics, the zebrafish has become an important model organism to study human pathologies. Moreover, it is particularly adapted to large scale studies, making it an attractive model in particular for the first steps of investigations. In this review, we discuss the relevance of the zebrafish model for the study of elastic fiber-related vascular pathologies. We evidence zebrafish as a compelling alternative to conventional mouse models.

Severe phenotypes of B3GAT3-related disorder caused by two heterozygous variants: a case report and literature review

BackgroundLinkeropathies refers to a series of extremely rare hereditary connective tissue diseases affected by various glycosyltransferases in the biosynthesis of proteoglycans. We report for the first time two heterozygous variants of B3GAT3 in a Chinese infant, in whom Marfan syndrome was suspected at birth.Case presentationA 2-month-old boy from a non-consanguineous Chinese family without a family history presented severe phenotypes of joint dislocation, obvious flexion contractures of the elbow, arachnodactyly with slightly adducted thumbs, cranial dysplasia, foot abnormalities and aortic root dilation; Marfan syndrome was suspected at birth. Our patient was the youngest, at the age of 2 months, to experience aortic root dilation. Two B3GAT3 variants, NM_012200.2, c.752T>C, p.V251A and c.47C>A, p.S16*, with heterozygosity were identified in the patient by whole-exome sequencing; the variants were inherited from his parents. During close follow-up, significant changes in the cranial profile and obvious external hydrocephalus were present at the age of 7 months, which differs from previously reported cases.ConclusionWe diagnosed a patient with congenital heart defects at an early age with a B3GAT3-related disorder instead of Marfan syndrome and expanded the spectrum of B3GAT3-related disorders. We also provide a literature review of reported B3GAT3 cases; for at least one of the variants, this is the first report of genotype–phenotype correlations in individuals with cardiovascular defects being related to the acceptor substrate-binding subdomain of B3GAT3.

Activating RAC1 variants in the switch II region cause a developmental syndrome and alter neuronal morphology.

RAC1 is a highly conserved Rho GTPase critical for many cellular and developmental processes. De novo missense RAC1 variants cause a highly variable neurodevelopmental disorder. Some of these variants have previously been shown to have a dominant negative effect. Most previously reported patients with this disorder have either severe microcephaly or severe macrocephaly. Here, we describe eight patients with pathogenic missense RAC1 variants affecting residues between Q61 and R68 within the switch II region of RAC1. These patients display variable combinations of developmental delay, intellectual disability, brain anomalies such as polymicrogyria and cardiovascular defects with normocephaly or relatively milder micro- or macrocephaly. Pulldown assays, NIH3T3 fibroblast spreading assays and staining for activated PAK1/2/3 and WAVE2 suggest that these variants increase RAC1 activity and over-activate downstream signalling targets. Axons of neurons isolated from Drosophila embryos expressing the most common of the activating variants are significantly shorter, with an increased density of filopodial protrusions. In vivo, these embryos exhibit frequent defects in axonal organization. Class IV dendritic arborization neurons expressing this variant exhibit a significant reduction in the total area of the dendritic arbour, increased branching and failure of self-avoidance. RNAi knock down of the WAVE regulatory complex component Cyfip significantly rescues these morphological defects. These results establish that activating substitutions affecting residues Q61-R68 within the switch II region of RAC1 cause a developmental syndrome. Our findings reveal that these variants cause altered downstream signalling, resulting in abnormal neuronal morphology and reveal the WAVE regulatory complex/Arp2/3 pathway as a possible therapeutic target for activating RAC1 variants. These insights also have the potential to inform the mechanism and therapy for other disorders caused by variants in genes encoding other Rho GTPases, their regulators and downstream effectors.

Quadricuspid Aortic Valve: An Introduction for Clinicians.

Quadricuspid aortic valve (QAV) is a congenital heart anomaly in which the aortic valve has four cusps of various size possibilities, as opposed to the three symmetrical cusps generally observed. This cardiac valvular abnormality is rarely identified, with an estimated incidence rate of 0.013% to 0.043%, although recent technological advancements in diagnostics have contributed to an increase in detection. Historically, it had been typically encountered during open heart surgery or postmortem; however, it is presently diagnosed primarily via ultrasound echocardiography, and could go undetected unless specifically considered. It was first reported by Babington in 1847, and since then approximately 300 cases have been published. This condition is sporadically associated with additional congenital cardiovascular defects, with coronary artery irregularities being the most common. In more than half of published QAV incidences it has led to the progressive development of aortic regurgitation (AR) usually sans aortic stenosis, particularly amongst elderly patients, often requiring surgical intervention after 50 years of age. A fifth of total instances, but two-thirds of instances with AR, warrant surgery seldom amidst complications, with reconstructive tricuspidization preferred over valve replacement.

Complex chronic conditions among children born to women with schizophrenia

PurposeMaternal schizophrenia is linked to complications in offspring near the time of birth. Whether there is also a higher future risk of the child having a complex chronic condition (CCC) – a pediatric condition affecting any bodily system expected to last at least 12 months that is severe enough to require specialty care and/or a period of hospitalization – is not known. MethodsIn this population-based health administrative data cohort study (Ontario, Canada, 1995–2018), the risk for CCC was compared in 5066 children of women with schizophrenia (the exposed) vs. 2,939,320 unexposed children. Adjusted hazard ratios (aHR) were generated for occurrence of any CCC, by CCC category, and stratified by child sex, and child prematurity. ResultsCCC was more frequent in the exposed (7.7 per 1000 person-years [268 children]) than unexposed (4.2 per 100 person-years [124,452 children]) – an aHR of 1.25 (95% CI 1.10–1.41). aHRs were notably higher in 5 of 9 CCC categories: neuromuscular (1.73, 1.28–2.33), cardiovascular (1.94, 1.64–2.29), respiratory (1.83, 1.32–2.54), hematology/immunodeficiency (2.24, 1.24–4.05) and other congenital or genetic defect (1.59, 1.16–2.17). The aHR for CCC was more pronounced among boys (1.32, 1.13–1.55) than girls (1.16, 0.96–1.40), and of similar magnitude in term (1.22, 1.05–1.42) and preterm infants (1.18, 0.95–1.46). ConclusionsThe risk for a CCC appears to be higher in children born to women with schizophrenia. This finding introduces opportunities for targeted preconception counselling, optimization of maternal risk factors, and intervention to support a vulnerable parent population who will experience unique challenges caring for a child with CCCs.

Prevalence of critical congenital heart defects and selected co-occurring congenital anomalies, 2014-2018: A U.S. population-based study.

Critical congenital heart defects (CCHDs) are one of the most common types of birth defects and can lead to significant morbidity and mortality along with surgical or catheter interventions within the first year of life. This report updates previously published estimates of CCHD prevalence with the latest population-based surveillance data from 19 birth defect surveillance programs. The U.S. population-based surveillance programs submitted data on identified cases of 12 CCHDs and co-occurring cardiovascular and chromosomal birth defects from 2014 to 2018. We estimated prevalence by program type and maternal and infant characteristics. Among nine programs with active case ascertainment that collect more than live births, we estimated the percentage of co-occurring cardiovascular and chromosomal birth defects for the 12 CCHDs. We identified 18,587 cases of CCHD among all participating programs. Overall CCHD prevalence was 19.6 per 10,000 live births among all 19 programs and 20.2 per 10,000 live births among active programs. Among maternal racial/ethnic groups, infants/fetuses born to American Indian/Alaska Native mothers showed the highest overall prevalence for all CCHDs (28.3 per 10,000) along with eight of the 12 individual CCHDs. Among 7,726 infants/fetuses with CCHD from active case ascertainment programs, 15.8% had at least one co-occurring chromosomal birth defect. Our study provides prevalence estimates for CCHDs by maternal and infant characteristics along with co-occurrence with cardiovascular and chromosomal birth defects among infants/fetuses with CCHD using one of the largest and most recent cohorts since the implementation of widespread CCHD screening. These data can provide a basis for future research to better understand risk factors for these defects.

Environmental awareness factors in the genesis of psychosomatic dysfunctions of students of higher education institutions

The substantiation of the conceptual foundations of ecological awareness by the subject of practical research is the cognitive goal of this article. The purpose of the article is to substantiate the influence of factors of the formation of environmental awareness in the genesis of psychosomatic dysfunctions of students of higher education institutions. In the research process, such methods as analysis, systematization, synthesis, generalization, concretization, comparison and psychodiagnostic methods were applied, using such methods as "Aesop", "Alternative", "Dominant" and the method "Assessment of the level of development of personality’s adaptive abilities of A. Maklakov, S. Chermianina". Due to the author's psychodiagnostic questionnaire, by using quantitative and qualitative assessment criteria, individuals with psychosomatic dysfunctions were selected and divided into three groups: individuals with cardiovascular defects, with gastrointestinal tract dysfunction, and skin defects. The scientific novelty is the conceptual basis of the study of students' environmental awareness in the structure of psychosomatic interactions under the conditions of the eco-environment of higher education institutions. Interrelation between psychological stability and the level of life stress in the educational institution's eco-environment was experimentally revealed. It turned out that a high level of life tension is not a constitutional prerequisite for the emergence of psychosomatic complaints. In the subjects of the experimental group with a high level of subjective stress, a low indicator of psychological stability is a predicate for the development of psychosomatic dysfunctions (the probability of the disease was 92%), while high indicators of stability contribute to the preservation of health (somatization took only 10%). In addition, a high level of psychological stability of an individual is associated with a developed imagination and creativity in non-standard situations, with a high level of stress. Adequate awareness and assessment of the situation, a person's persistent experience of his actions and circumstances, which are the result of personal choice and responsibility, in somatically ill individuals with high vitality acquire the value of a resource, experience that allows to adapt to health problems, harmoniously transforming meaningful life orientations. Somatic complaints of such respondents are caused by unpleasant life events, pessimistic and depressed mood in their surroundings, that is, all those components of modern life that have already become a habit in interaction with the environment.The conclusion indicates the interdependence of mental and emotional factors in the formation of environmental awareness of students in institutions of higher education, explains the concept of complex psychosomatic processes that support the integrity of the organism. The imbalance between psyche and somatics produced by this interaction determines the level of professional training of the student in the educational environment. Their conceptual basis is psychogenies of the somatoform type, with predominant vegetative disorders, which is connected with the psychoanalytic interpretation of an unconscious intrapsychic neurotic complex. The origin of the symptomatology imitating physical pathology is explained by conversion mechanisms as a result of the lack of adaptive psychological protection and stability.

Riscos dos efeitos teratogênicos da isotretinoína e suas propriedades farmacológicas em mulheres sexualmente ativas

Introduction: Isotretinoin, also known as 13-cis-retinoic acid, belongs to the group of compounds derived from vitamin A. Objective: This work aims at women with active sexual life and during pregnancy, the teratogenic effects of the drug, as well as how to describe your clinical indication. Methodology: This is a systematic review of the literature, of scientific articles, in the databases indexed in the SciELO, Google Scholar, Birene, VHL and PubMED data portal, between 2000 and 2020. Results: Isotretinoin can be used in various dermatoses. The main adverse reactions include: dryness of the mucous membranes and skin. Teratogenicity being the main adverse effect, causing craniofacial anomalies, cardiovascular defects, cleft palate, ocular, auricular, skeletal and CNS anomalies. The acne treatment protocol with the use of isotretinoin determines some restrictions; in women of childbearing age, requires that they undergo two pregnancy tests, both of which must be negative. This drug is subject to special control provided for in Ordinance 344/1998. Conclusion: Thus, isotretinoin requires greater care in women who are sexually active, due to its high teratogenicity, in which case it is necessary to advise them on the use of contraceptives during treatment with isotretinoin.

Vascular Endothelial (VE)-cadherin-mediated adherens junctions involvement in cardiovascular progenitor cell specification.

Vascular Endothelial cadherin, a type II classical cadherin, is the major cadherin molecule participating in homotypic cell-cell adhesion structures between endothelial cells. It associates with cytoplasmic and membrane cytoskeletal elements to form endothelial adherens junctions (AJs), pivotal in regulating endothelial barrier function in the adult. VE-cadherin-mediated AJs are also involved in signaling via direct or indirect associations with receptors. The generation of mutant animals, especially mice and zebrafish, revealed many details concerning the role of VE-cadherin-mediated AJs in cardiovascular development. In general, VE-cadherin knockout (KO) in mice is embryonic lethal due to severe cardiovascular defects, and major signaling pathways as well as vascular formation cues were discovered in developing endothelium. However, there is little information regarding AJs formation and their components in cardiovascular progenitors. We have characterized in detail the activation pattern of mouse VE-cadherin promoter (Pvec) in a mouse embryonic stem cells (ESCs) differentiation system in vitro. Surprisingly, we found that it is activated transiently in cardiac progenitors that belong to the second heart field. Based on Pvec activation, we isolated this population in vitro and found that it can self-renew by induction of the Wnt/β-catenin pathway. Next, we successfully established cell culture conditions that allowed self-renewal of this population that consists of endothelial and cardiac progenitors. Transplantation in rat hearts showed that they can survive and differentiate to cardiomyocytes and endothelial cells. Although further characterization is needed, these cells can be used in cell-based therapies as well as in drug screening.

Neural crest cells and their potential therapeutic applications

Neural crest (NC) is a population of cells, formed at the intersection between non-neural ectoderm and neural tube. Neural crest progenitors are multipotent, have capacity to extensive migration and self-renewal. They can be differentiated into various cells types from craniofacial skeletal tissues to components of peripheral nervous system. Influence of signaling molecules and transcription factors, which are expressed at the different stages regulate development of NC. The regulatory network of genes determines the processes of induction, specification, migration and differentiation of neural crest cells (NCC). The purpose of this article is to compare the characteristics of NCC, obtained from tissues of the embryo, fetus and adult; experimental strategies for obtaining NCC from embryonic stem cells, induced pluripotent stem cells, skin fibroblasts; comparison of the potential of different cell types for therapeutic use in a clinical setting. Embryonic stem NCC are differentiated to the trunk, cranial, cardiac, circumpharyngeal and vagal according to the area of their initial migration. Mature stem NCC can be obtained from the dorsal root ganglia, red bone marrow, hair follicle, skin, intestines, carotid body, heart, cornea, iris, dental pulp, hard palate and oral mucosa. Genetic mutations may lead to failure of regulation of NC development, which leads to many congenital human diseases such as cardiovascular defects, craniofacial abnormalities and intestinal aganglionosis, collectively known as neurocristopathies. The identification and isolation of multipotent stem NCC derived from adult tissues, embryonic stem cells, and induced pluripotent stem cells are promising source for regenerative medicine.

Co-occurrence of congenital anomalies by maternal race/ethnicity among infants and fetuses with Down syndrome, 2013-2017: A U.S. population-based analysis.

Individuals with Down syndrome (DS) have a higher prevalence of additional congenital anomalies, especially cardiovascular defects, compared to the general population. Several reports have indicated that the prevalence of DS among live births varies by race and ethnicity within the United States. We aim to examine variations in co-occurring congenital anomalies by maternal race/ethnicity among infants and fetuses diagnosed with DS born during 2013-2017. State birth defect surveillance systems (N= 12) submitted data on infants and fetuses diagnosed with DS born during 2013-2017. We calculated the prevalence of co-occurring major and minor congenital anomalies, by organ system, and four selected cardiovascular birth defects, all stratified by maternal race/ethnicity. Among 5,836 cases of DS, 79.7% had one or more co-occurring congenital anomalies. There was a higher percentage of co-occurring congenital anomalies among infants and fetuses born to Hispanic mothers. The lowest percentage of co-occurring congenital anomalies, including three out of the four individual cardiovascular conditions examined, was among infants/fetuses born to non-Hispanic American Indian/Alaska Native mothers. We describe differences in DS co-occurrence with additional congenital anomalies among maternal racial/ethnic groups. These data may help focus future research on differences among racial/ethnic groups in the diagnosis and reporting of co-occurring congenital anomalies in infants/fetuses diagnosed with DS.

L-selenomethionine induces zebrafish embryo cardiovascular defects via down-regulating expression of lrp2b

Selenium plays crucial roles in maintaining the growth and development of vertebrates including humans. However, excessive selenium in cells will lead to developmental defects and disease. Selenium has been reported to cause severe malformation in zebrafish embryos, but there are few studies on the mechanism of selenium excess-induced cardiovascular defects. In this study, the fertilized zebrafish embryos were treated with selenium for 96 h post fertilization (hpf). Under selenium stress, wild-type embryos showed pericardial edema, heart rate decrease, ectopic accumulation of hemoglobin; fli1-eGFP transgenic zebrafish displayed intersegmental vessel injury; and myl7-eGFP transgenic zebrafish exhibited atrial area increase. RNA-seq data and qRT-PCR results indicated that the expressions of cardiovascular development genes were up-regulated in selenium-stressed embryos. The expressions of lipid metabolism-related and selenium metabolism-related genes were evaluated in embryos. Among the tested genes, the expression of lrp2b was down-regulated in both 24 hpf and 96 hpf embryos. Furthermore, lrp2b-knockdown embryos exhibited the cardiac defects similar to selenium-stress embryos, and the over-expression of lrp2b rescued the selenium-induced defects, indicating that lrp2b might play a key role in regulating selenium cardiotoxicity. In summary, our research evaluates the cardiotoxicity of excessive selenium, and reveals the molecular mechanism of cardiovascular defects in selenium-exposed zebrafish embryos.

Cardiovascular and connective tissue disorder features in FLNA-related PVNH patients: progress towards a refined delineation of this syndrome

BackgroundFLNA Loss-of-Function (LoF) causes periventricular nodular heterotopia type 1 (PVNH1), an acknowledged cause of seizures of various types. Neurological symptoms are inconstant, and cardiovascular (CV) defects or connective tissue disorders (CTD) have regularly been associated. We aimed at refining the description of CV and CTD features in patients with FLNA LoF and depicting the multisystemic nature of this condition.MethodsWe retrospectively evaluated FLNA variants and clinical presentations in FLNA LoF patient with at least one CV or CTD feature, from three cohorts: ten patients from the French Reference Center for Rare Vascular Diseases, 23 patients from the national reference diagnostic lab for filaminopathies-A, and 59 patients from literature review.ResultsHalf of patients did not present neurological symptoms. Most patients presented a syndromic association combining CV and CTD features. CV anomalies, mostly aortic aneurysm and/or dilation were present in 75% of patients. CTD features were present in 75%. Variants analysis demonstrated an enrichment of coding variants in the CH1 domain of FLNA protein.ConclusionIn FLNA LoF patients, the absence of seizures should not be overlooked. When considering a diagnosis of PVNH1, the assessment for CV and CTD anomalies is of major interest as they represent interlinked features. We recommend systematic study of FLNA within CTD genes panels, regardless of the presence of neurological symptoms.

22q11.2 recurrent copy number variation-related syndrome: a retrospective analysis of our own microarray cohort and a systematic clinical overview of ClinGen curation

BackgroundChromosomal 22q11.2 dosage changes in the recurrent region can lead to a series of clinically variable pediatric syndromes. This study conducted a retrospective analysis of microarray tested cases with 22q11.2 recurrent copy number variations (CNVs) at our laboratory from September 2018 to August 2021, and provides a systematical clinical overview of ClinGen curation.MethodsThe data of 34 microarray tested cases with 22q11.2 recurrent CNVs at our laboratory from September 2018 to August 2021 were retrospectively analyzed, and the variant types, abnormal chromosome regions, clinical phenotypes, and follow-up information were evaluated and summarized. A ClinGen Dosage Sensitivity Map was retrieved for “22q11.2”. The information of each 22q11.2 recurrent region was collected and systematically classified.ResultsWe reported 34 cases (including 18 22q11.2 microdeletion cases and 16 microduplication cases) from 8,465 microarrays. Of the 22q11.2 recurrent CNV-carried samples, 74% (25/34) comprised prenatal amniotic fluid or villus, and up to 50% (17/34) of the cases contained the proximal A–D interval. Across these 22q11.2 microdeletion samples, the congenital cardiovascular defect, which mainly included the tetralogy of fallot, ventricular septal defect, and patent foramen ovale, was identified as the most common feature (13/18, 72%). However, 22q11.2 microduplication cases exhibited a broad range of highly variable phenotypes, spanning from severe abnormality to mild characteristics and even the completely normal phenotype. This study also systematically reviewed the ClinGen dosage sensitivity curation on 22q11.2 recurrent regions, and found that A–D/A–B haploinsufficiency score reached “3”, responsible for DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS). Also, A–D/A–B triplosensitivity score “3” could further account for multiple variable phenotypes.ConclusionsTaken together, this study provides clinical overview of the ClinGen curation and data support for the American College of Medical Genetics and Genomics (ACMG) evaluation in the pathogenicity of each interval involved in 22q11.2 recurrent deletion and duplication. Certainly, more evidences on the genotype-phenotype contributions of different 22q11.2 recurrent CNVs need to be gathered.

Congenital Tracheal Stenosis as a Complication of a Congenital Cardiovascular Defect

Congenital Tracheal Stenosis as a Complication of a Congenital Cardiovascular Defect

DYNAMICS OF FREQUENCY AND PECULIARITIES OF THE STRUCTURE OF CONGENITAL MALFORMATIONS IN SOUTH UKRAINE (MONITORING STUDY)

Background. In Ukraine, the unfavorable demographic situation makes monitoring of the birth rate of children with congenital malformations urgent issue to identify regional features of epidemiology and develop methods for prenatal diagnosis and prognosis. 
 Objective. Objective of this study is to characterize the frequency dynamics, to identify structural features of congenital malformations of newborns in Kherson region over a 20-year period (2000-2019) and to compare the prevalence of various nosological forms of malformations in the region, in Ukraine and in European countries.
 Methods. Research methods: epidemiological, medical-statistical. 
 Results. In Kherson region, the average frequency of congenital malformations over the past 20 years is: for newborns – 31.57±1.25‰; for live births – 31.38±1.11‰; for stillborns – 197.7±0.65 per 10,000. In the structure of defects, cardiovascular malformations are leading (31.77%), musculoskeletal malformations (25.14%), genital malformations (17.5%). Increased prevalence of developmental anomalies in the region is mainly associated with an increase in the frequency of model malformations recorded by EUROCAT (r=0.69, p<0.05). The increase in the total frequency of congenital malformations is caused by increased number of births of children with cardiovascular defects (by 4.67‰), genital defects (by 1.21‰), other congenital malformations (by 1.55‰), multiple malformations (by 0.37‰).
 Conclusion. Monitoring results showed an increase in congenital malformations incidence in Kherson region over a 20-year period by 7.94‰ possibly caused by population decline due to negative natural and mechanical growth. The prevalence of hereditary defects is at the same level. The frequency of some nosological forms significantly exceeds in the region compare to that in Ukraine and Europe: cardiovascular defects – in 1.5 times, genital malformations – in nearly 3 times, musculoskeletal defects – almost twice.

RBPMS, an RNA-Binding Protein That Mediates Cardiomyocyte Binucleation and Cardiovascular Development

SummaryNoncompaction cardiomyopathy is a common congenital cardiac disorder associated with abnormal ventricular cardiomyocyte trabeculation and impaired pump function. The genetic basis and underlying mechanisms of this disorder remain elusive. We show that genetic deletion of R NA b inding p rotein with m ultiple s plicing ( Rbpms ), an uncharacterized RNA binding and splicing factor, causes perinatal lethality in mice due to congenital cardiovascular defects. Loss of Rbpms causes premature onset of cardiomyocyte binucleation and cell cycle arrest during development. Human iPSC-derived cardiomyocytes with RBPMS gene deletion have a similar blockade to cytokinesis. Sequencing analysis revealed that RBPMS plays a role in RNA splicing and influences RNAs involved in cytoskeletal signaling pathways. We found that RBPMS mediates isoform switching of the heart-specific LIM domain protein Pdlim5 . Loss of Rbpms leads to abnormal accumulation of Pdlim5 -short isoforms, disrupting cardiomyocyte cytokinesis. Our findings connect premature cardiomyocyte binucleation to noncompaction cardiomyopathy and highlight the role of Rbpms in this process.

Obesity-Induced Inflammation Co-Operates with Clonal Hematopoiesis of Indeterminate Potential (CHIP) Mutants to Promote Leukemia Development and Cardiovascular Disease

▪Obesity is an increasing epidemic world-wide responsible for enhancing the risk for developing Type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD) and cancer. However, it is unclear if and how obesity contributes to the transformation of pre-leukemic stem and progenitors (pre-LHSC/Ps) into full-blown leukemia such as acute myeloid leukemia (AML) or severe form of myeloproliferative neoplasm (MPN) or CVD. We hypothesized that obesity induced chronic inflammation might be responsible for clonal selection of pre-LHSC/Ps bearing pre-leukemic clonal hematopoiesis of indeterminate potential (CHIP) mutations such as DNMT3A, TET2, ASXL1, and JAK2 and for promoting the progression of early-onset MPN, AML/leukemia and CVD. To study the linkage between obesity and CHIP in humans, we first examined the UK biobank. After exclusions, the final study cohort included 47,466 unrelated participants free of T2DM at baseline and having valid CHIP measurements. The mean (SD) age at enrollment was 56.5 (8.0), 45.0% were male, 43.9% never smoked, and 82.6% self-reported as European decedents. At baseline, the mean (SD) body mass index (BMI) was 27.3 (4.7) kg/m 2, with 43.0% overweight and 23.6% obese, and the overall mean (SD) waist-to-hip ratio (WHR) was 0.87 (0.09). CHIP was present among 5.8% of the study population the most common mutations on the DNMT3A (3.7%) and TET2 (1.0%) genes; large CHIP clone defined as CHIP mutation with variant allele fraction >10% was present among 2.4% of the study population. Individuals with CHIP mutations on average had higher WHR. The presence of CHIP mutation was associated with a 0.0028 increase of WHR (p=0.03). Furthermore, CHIP prevalence increased with higher WHR: the percentage of participants with CHIP was 4.93%, 5.75%, 6.56% in the lowest, middle, and highest WHR quintiles respectively, signifying that dysfunctional metabolism may accelerate expansion of clonal hematopoiesis (CH). To better define the mechanism of obesity driven CH, we utilized several novel mouse models bearing Tet2 -/-, Dnmt3a +/-, Asxl1 +/- and Jak2 +/- mutations to mimic the human pre-LHSC/Ps condition and obesity, in the form of leptin deficient Lep Ob/Ob (Ob/Ob) mutation, which induces obesity and T2DM. We show that both the compound mutant (Tet2 -/-;Ob/Ob, Dnmt3a +/-;Ob/Ob, Asxl1 +/-;Ob/Ob and Jak2 +/-;Ob/Ob) and CHIP mutant bone marrow (BM; Tet2 -/-, Dnmt3a +/-, Asxl1 +/- and Jak2 +/-) transplanted into Ob/Ob mice develop rapid growth of mature myeloid cells and HSC/Ps leading to severe form of MPN/AML as well as CVD. This was associated with upregulation of pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α. Flow cytometry analysis of LSK and progenitor cells isolated from Tet2 -/-;Ob/Ob mice revealed an up-regulation of intracellular Ca2+ levels. We hypothesized that up-regulated Ca2+ signaling in Tet2 -/-; Ob/Ob HSC/Ps promotes aberrant signaling leading to an early-onset of severe MPN/AML. We performed a competitive transplantation experiment using, Tet2 -/-: Boy/J BM cells (1:1 ratio) into Ob/Ob and WT recipients. After 8 weeks post transplantation, we investigated the role of Ca2+ blockers in driving CH in Ob/Ob recipients using pharmacological inhibitors, either individually, or in combination, of metformin (100 mg/kg, orally), nifedipine (100 mg/kg, orally), MCC950 (30 mg/kg, orally) and anakinra (10 mg/kg, i.p). The combination treatment markedly reduced monocytes, neutrophils, WBC counts, and improved RBCs, hematocrits and platelets. The spleen and liver, heart, body weights and blood glucose levels were significantly reduced, along with a greater re-emergence of normal CD45.1 wild-type cells in the PB, BM, and spleen and a significant reduction in Tet2 mutant CD45.2 pre-LHSC/Ps and myeloid cells in the PB, BM, and spleen. Importantly, the frequency of leukemic blasts, LSK cells, ST-HSCs, LT-HSCs and granulocyte macrophage progenitors (GMP) were significantly reduced. Furthermore, the combination of drug treatment showed greater heart protective activity by reducing the atherosclerotic lesions in Ob/Ob recipients bearing CHIP by suppressing Ca2+ signaling. Taken together, these data suggest that obesity is highly associated with the presence of CHIP in humans and that targeting CHIP mutant cells with a combination of metformin/nifedipine/MCC950/anakinra is a safe and inexpensive way to rescue CH and its associated leukemic and cardiovascular defects. DisclosuresNatarajan: Amgen: Research Funding; Apple: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Boston Scientific: Research Funding; Blackstone Life Sciences: Consultancy; Genentech: Consultancy; Foresite Labs: Consultancy.

Evaluation of CML TKI Induced Cardiovascular Toxicity and Development of Potential Rescue Strategies in a Zebrafish Model.

Tyrosine kinase inhibitors (TKIs) to BCR-ABL1 have been successfully used to treat chronic myeloid leukemia (CML), however, multiple TKI-associated adverse events have been reported and become an emerging problem in patients. The mechanisms of TKI-induced toxicity are not fully understood and it remains challenging to predict potential cardiovascular toxicity of a compound. In this study, we established a zebrafish model to evaluate potential in vivo cardiovascular toxicity of TKIs. We treated the endothelium labeled Tg(kdrl:EGFP) transgenic zebrafish embryos with TKIs then performed confocal imaging to evaluate their vascular structure and function. We found that among FDA approved CML TKIs, ponatinib (the only approved TKI that is efficacious to T315I mutation) is the most toxic one. We then evaluated safety profiles of several clinical stage kinase inhibitors that can target T315I and found that HQP1351 treatment leads to vasculopathies similar to those induced by ponatinib while the allosteric ABL inhibitor asciminib does not induce noticeable cardiovascular defects, indicating it could be a promising therapeutic reagent for patients with T315I mutation. We then performed proof-of-principle study to rescue those TKI-induced cardiovascular toxicities and found that, among commonly used anti-hypertensive drugs, angiotensin receptor blockers such as azilsartan and valsartan are able to reduce ponatinib or HQP1351 induced cardiovascular toxicities. Together, this study establishes a zebrafish model that can be useful to evaluate cardiovascular toxicity of TKIs as well as to develop strategies to minimize TKI-induced adverse events.

Machine learning-based identification of patients with a cardiovascular defect

Cardiovascular diseases had been for a long time one of the essential medical problems. As indicated by the World Health Association, heart ailments are at the highest point of ten leading reasons for death. Correct and early identification is a vital step in rehabilitation and treatment. To diagnose heart defects, it would be necessary to implement a system able to predict the existence of heart diseases. In the current article, our main motivation is to develop an effective intelligent medical system based on machine learning techniques, to aid in identifying a patient’s heart condition and guide a doctor in making an accurate diagnosis of whether or not a patient has cardiovascular diseases. Using multiple data processing techniques, we address the problem of missing data as well as the problem of imbalanced data in the publicly available UCI Heart Disease dataset and the Framingham dataset. Furthermore, we use machine learning to select the most effective algorithm for predicting cardiovascular diseases. Different metrics, such as accuracy, sensitivity, F-measure, and precision, were used to test our system, demonstrating that the proposed approach significantly outperforms other models.