Notch-dependent EMT is attenuated in patients with aortic aneurysm and bicuspid aortic valve.

Bicuspid aortic valve is the most common congenital heart malformation and the reasons for the aortopathies associated with bicuspid aortic valve remain unclear. NOTCH1 mutations are associated with bicuspid aortic valve and have been found in individuals with various left ventricular outflow tract abnormalities. Notch is a key signaling during cardiac valve formation that promotes the endothelial-to-mesenchymal transition. We address the role of Notch signaling in human aortic endothelial cells from patients with bicuspid aortic valve and aortic aneurysm. Aortic endothelial cells were isolated from tissue fragments of bicuspid aortic valve-associated thoracic aortic aneurysm patients and from healthy donors. Endothelial-to-mesenchymal transition was induced by activation of Notch signaling. Effectiveness of the transition was estimated by loss of endothelial and gain of mesenchymal markers by immunocytochemistry and qPCR. We show that aortic endothelial cells from the patients with aortic aneurysm and bicuspid aortic valve have down regulated Notch signaling and fail to activate Notch-dependent endothelial-to-mesenchymal transition in response to its stimulation by different Notch ligands. Our findings support the idea that bicuspid aortic valve and associated aortic aneurysm is associated with dysregulation of the entire Notch signaling pathway independently on the specific gene mutation.

Genotype imputation and polygenic score estimation in northwestern Russian population.

Numerous studies demonstrated the lack of transferability of polygenic score (PGS) models across populations and the problem arising from unequal presentation of ancestries across genetic studies. However, even within European ancestry there are ethnic groups that are rarely presented in genetic studies. For instance, Russians, being one of the largest, diverse, and yet understudied group in Europe. In this study, we evaluated the reliability of genotype imputation for the Russian cohort by testing several commonly used imputation reference panels (e.g. HRC, 1000G, HGDP). HRC, in comparison with two other panels, showed the most accurate results based on both imputation accuracy and allele frequency concordance between masked and imputed genotypes. We built polygenic score models based on GWAS results from the UK biobank, measured the explained phenotypic variance in the Russian cohort attributed to polygenic scores for 11 phenotypes, collected in the clinic for each participant, and finally explored the role of allele frequency discordance between the UK biobank and the study cohort in the resulting PGS performance.

Case Report: Supernormal Vascular Aging in Leningrad Siege Survivors.

Age-related changes in the vascular system play an important role in the biological age and lifespan of a person and maybe affected from an early age onward. One of the indicators of changes in the vascular system is arterial wall stiffness and its main measure, i.e., carotid-femoral pulse wave velocity (cfPWV). We examined arterial wall stiffness in a sample of 305 Leningrad Siege survivors to assess how hunger and stressful conditions during fetal development and early childhood affected the state of the cardiovascular system at a later age and what factors may neutralize the negative impact sustained in early childhood. Here, we presented an evaluation of two unique patients with supernormal vascular aging (SUPERNOVA) phenotype from this cohort and described the details of congruence between hereditary resistance and practiced lifestyle yielding slower biological aging rate.

Draft Genome Sequence of Coxiella burnetii Historical Strain Leningrad-2, Isolated from Blood of a Patient with Acute Q Fever in Saint Petersburg, Russia.

This is the announcement of a draft genome sequence of Coxiella burnetii strain Leningrad-2, phase I. The strain, which is mildly virulent in infected guinea pigs, was isolated in 1957 from the blood of a patient with acute Q fever in Leningrad (now Saint Petersburg), Russia.

NOTCH1 Mutations in Aortic Stenosis: Association with Osteoprotegerin/RANK/RANKL.

Background. The NOTCH pathway is known to be important in the pathogenesis of calcific aortic valve disease, possibly through regulators of osteoprotegerin (OPG), receptor activator of nuclear factor κB (RANK), and its ligand (RANKL) system. The purpose of the present study was to search for possible associations between NOTCH1 gene mutations and circulating levels of OPG and soluble RANKL (sRANKL) in patients with aortic stenosis (AS). Methods. The study was performed on 61 patients with AS including 31 with bicuspid and 30 with tricuspid aortic valves. We applied a strategy of targeted mutation screening for 10 out of 34 exons of the NOTCH1 gene by direct sequencing. Serum OPG and sRANKL levels were assessed. Results. In total, 6 genetic variants of the NOTCH1 gene including two new mutations were identified in the study group. In an age- and arterial hypertension-adjusted multivariable regression analysis, the serum OPG levels and the OPG/sRANKL ratio were correlated with NOTCH1 missense variants. All studied missense variants in NOTCH1 gene were found in Ca(2+)-binding EGF motif of the NOTCH extracellular domain bound to Delta-like 4. Conclusion. Our results suggest that the OPG/RANKL/RANK system might be directly influenced by genetic variants of NOTCH1 in aortic valve calcification.

Seventy years after the siege of Leningrad: does early life famine still affect cardiovascular risk and aging?

OBJECTIVE: To assess the cardiovascular health, markers of cardiovascular aging and telomere length in survivors of the siege of Leningrad, who were either born during the siege or lived in the besieged city in their early childhood. METHODS: Survivors of the Leningrad siege (n = 305, 64-81 years) and a control group of age and sex-matched individuals (n = 51, 67-82 years) were examined in terms of a observational retrospective cohort study. All participants were interviewed regarding risk factors, cardiovascular diseases, and therapy. Blood pressure measurement, anthropometry, echocardiography, and electrocardiography were performed according to standard guidelines. Fasting lipids and glucose were measured. Relative telomere length was measured by quantitative PCR, and the ratio of telomere repeat copy number to single gene copy number (T/S) was calculated for each DNA sample. RESULTS: Survivors had lower anthropometric parameters (height, weight, and BMI) and higher high-density lipoprotein level. There were no significant differences in the prevalence of cardiovascular diseases and target organ damage between groups. However, survivors had shorter telomere length: T/S ratio 0.44 (0.25; 0.64) vs. controls 0.91 (0.47; 1.13) (P < 0.0001), both in men and women, with clear association with the period of famine in early life. Exposure to famine in childhood and intrauterine period of life was associated with a higher prevalence of hypertension and shorter telomere length. CONCLUSION: Early-life famine, especially started in the intrauterine period and late childhood, may contribute to accelerated aging with telomere shortening in both sexes, but has no direct effect on the prevalence of cardiovascular diseases and risk factors after seven decades since exposure.

Variants in the NOTCH1 gene in patients with aortic coarctation.

BACKGROUND AND OBJECTIVE: Malformations of the left ventricular outflow tract are one of the most common forms of congenital heart disorders. Recently, it has been shown that mutations in the NOTCH1 gene can lead to bicuspid aortic valve, aortic aneurysm, and hypoplastic left heart syndrome. The aim of our study was to estimate the frequency of NOTCH1 gene mutations/substitutions in patients with aortic coarctation, isolated or combined with bicuspid aortic valve. DESIGN AND PATIENTS: The study included 51 children with coarctation. Detailed family history was obtained for every study subject, and echocardiographic data were obtained for the relatives when available. We applied a strategy of targeted mutation screening for 10 out of 34 exons of the NOTCH1 gene by direct sequencing. Control DNA was obtained from 200 healthy donors. RESULTS: In more than half of the cases, coarctation was combined with bicuspid aortic valve, and in approximately half of the cases, it was combined with hypoplasia of the aortic arch or descending aorta. Familial history of congenital heart disease was observed in 34.3% of the cases. In total, 29 variants of the NOTCH1 gene were identified in the patient group and in the control subjects. Four of those variants led to amino acid exchange, of which only one, R1279H, was identified in both the patient group and in the controls. This variant was significantly overrepresented in the patients with aortic coarctation compared with those in the control group (P < .05). We conclude that the R1279H substitution in the NOTCH1 gene is significantly overrepresented in patients with aortic coarctation and, therefore, may represent a disease-susceptibility allele.