👤 Sergei S Makarov

Most genomic studies compare the genomes of long-living adults to those of the general population to identify potential genetic markers of longevity. We propose a refined approach: focusing on the genetic makeup of healthy, long-living adults to detect mechanisms promoting both longer lifespan and improved quality of life. To this end, we analyzed medical and genomic data from 3,703 long-living adults aged ≥90 years and 22,354 individuals aged 18-75 years (total N = 26,057). Using whole-genome sequencing (WGS) and a genome-wide association study (GWAS), we found that variants with significant and negative associations with longevity in the GWAS were located in genes such as APOE, APOC1, and CFAP46, which are implicated in an increased risk of age-related diseases. However, the presence or absence of these variants should not be considered a definitive determinant of longevity or sustained health after the age of 90. We found that healthy longevity was positively associated with variants within the MYO18B, TBC1D28, and LOC105376454 genes. To demonstrate the multifactorial nature of the examined phenotypes, we constructed polygenic score models that accounted for nonlinear interactions among the predictors. Trial registration: Clinical Trials NCT06268132 (for long-living adults). Registered 22 February 2024 (retrospectively registered). Show less

Early recognition of a risk of Alzheimer's disease (AD) remains a global challenge, and blood proteomic markers are of particular interest for wide-scale diagnostic use. Quantitative multiple reaction monitoring (MRM) approach demonstrates good reproducibility in the characteristic changes in the levels of reported candidate biomarkers (CBs) in different cohorts in AD. Following up on our previous study, we performed a joint analysis of 331 blood plasma samples from two different clinical cohorts of participants, comprising a total of 95 samples from patients with AD, 136 samples from patients with mild cognitive impairment (MCI), and 100 samples from controls. The obtained results confirm the significance of 37 CBs. A logistic regression-based algorithm was used to build protein classifiers, and a total of 21 important proteins were selected, 13 of which (ORM1, APOA4, LBP, HP, FN1, BCHE, APOE, PZP, A1BG, TF, SERPINA7, TTR, and F12) formed a universal panel that demonstrated strong classification performance in distinguishing AD patients from controls (ROC-AUC = 0.90) and in separating stable and progressing patients with MCI (ROC-AUC = 0.81). Overall, the analysis confirms the high potential of the MRM method for validating CBs in independent cohorts. Show less

Familial hypercholesterolemia (FH) is a prevalent hereditary disorder, with its monogenic form linked to an elevated risk of early-onset ischemic heart disease. Evaluating the prevalence and penetrance of pathogenic and likely pathogenic variants associated with this disorder would provide valuable information supporting routine FH screening of the general population. Such informed screening would facilitate early identification of at-risk individuals, enabling timely intervention and management. We analyzed genetic data from 4,856 individuals with various cardiovascular conditions for pathogenic and likely pathogenic variants in the PCSK9, APOB, and LDLR genes. The evaluation included comprehensive clinical assessments, instrumental examinations, and laboratory tests. All genetic data were obtained through the whole-genome sequencing of blood leukocytes. A total of 1.77% of participants carried pathogenic or likely pathogenic variants in the LDLR or APOB genes, and none in the PCSK9 gene. After adjusting for sex and age, the risk of ischemic heart disease was 1.3 times higher in carriers of pathogenic or likely pathogenic variants [95% CI 1.18-1.46; FH remains significantly underdiagnosed. Only 10.5% of carriers of pathogenic or likely pathogenic variants in the LDLR and APOB genes had a prior diagnosis of FH. Our findings suggest low diagnostic rates for this disorder in Eastern European populations and highlight the need for routine genetic screening of younger individuals. However, further research is needed to assess the clinical applicability and cost-effectiveness of such screening programs. Show less

Long-living adults often maintain cognitive function despite neuropathological changes, which is often attributed to cognitive resilience (CR)-a combined effect of cognitive and cerebral reserves. CR is influenced by genetic, clinical, sociodemographic, and environmental factors. We investigated genetic, clinical, and environmental predictors of CR in 198 dementia-free long-living adults via two neuropsychological examinations over a 2-year period, a geriatric assessment, and a genome-wide association study (GWAS). Limited mobility, reduced walking, hearing impairment, depression, anemia, lower quality of life, and decreased BMI were key accelerators of CI. Depression, hypercholesterolemia, and lack of hobbies increased the risk of mild cognitive impairment (MCI)-to-dementia progression. GWAS identified CR-associated genetic variants, including a missense mutation in Our findings corroborated established risk factors for cardiovascular diseases and identified population-specific patterns, with APOE ε4 showing no significant association. Both protein-coding regions and non-coding elements were implicated in CI, suggesting that it is underlain by complex regulatory mechanisms. Show less

The development of blood tests for the early detection of individual predisposition to socially significant diseases remains a pressing issue. In this pilot study, multiple reaction monitoring mass spectrometry (MRM-MS) with a BAK-270 assay was applied for protein concentrations analysis in blood plasma from 21 healthy volunteers of the European cohort. The levels of 138 plasma proteins were reliably and precisely quantified in no less than 50% of samples. The quantified proteins included 66 FDA-approved markers of cardiovascular diseases (CVD), and other potential biomarkers of pathologies such as cancer, diabetes mellitus, and Alzheimer's disease. The analysis of individual variations of the plasma proteins revealed significant differences between the male (11) and female (10) groups. In total, fifteen proteins had a significantly different concentration in plasma; this included four proteins that exhibited changes greater than ±1.5-fold, three proteins (RBP4, APCS, and TTR) with higher levels in males, and one (SHBG) elevated in females. The obtained results demonstrated considerable agreement with the data collected from 20 samples of a North American cohort, which were analyzed with the similar MRM assay. The most significant differences between the cohorts of the two continents were observed in the level of 42 plasma proteins (including 24 FDA markers), of which 17 proteins showed a ≥1.5-fold change, and included proteins increased in North Americans (APOB, CRTAC1, C1QB, C1QC, C9, CRP, HP, IGHG1, IGKV4-1, SERPING1, RBP4, and AZGP1), as well as those elevated in Europeans (APOF, CD5L, HBG2, SELPLG, and TNA). The results suggest a different contribution of specific (patho)physiological pathways (e.g., immune system and blood coagulation) to the development of socially significant diseases in Europeans and North Americans, and they should be taken into account when refining diagnostic panels. Show less

Protein complexes often represent an ensemble of different assemblies with distinct functions and regulation. This increased complexity is enabled by the variety of protein diversification mechanisms that exist at every step of the protein biosynthesis pathway, such as alternative splicing and post transcriptional and translational modifications. The resulting variation in subunits can generate compositionally distinct protein assemblies. These different forms of a single protein complex may comprise functional variances that enable response and adaptation to varying cellular conditions. Despite the biological importance of this layer of complexity, relatively little is known about the compositional heterogeneity of protein complexes, mostly due to technical barriers of studying such closely related species. Here, we show that native mass spectrometry (MS) offers a way to unravel this inherent heterogeneity of protein assemblies. Our approach relies on the advanced Orbitrap mass spectrometer capable of multistage MS analysis across all levels of protein organization. Specifically, we have implemented a two-step fragmentation process in the inject flatapole device, which was converted to a linear ion trap, and can now probe the intact protein complex assembly, through its constituent subunits, to the primary sequence of each protein. We demonstrate our approach on the yeast homotetrameric FBP1 complex, the rate-limiting enzyme in gluconeogenesis. We show that the complex responds differently to changes in growth conditions by tuning phosphorylation dynamics. Our methodology deciphers, on a single instrument and in a single measurement, the stoichiometry, kinetics, and exact position of modifications, contributing to the exposure of the multilevel diversity of protein complexes. Show less

Fully phosphorothioate antisense oligonucleotides (ASOs) with locked nucleic acids (LNAs) improve target affinity, RNase H activation and stability. LNA modified ASOs can cause hepatotoxicity, and this risk is currently not fully understood. In vitro cytotoxicity screens have not been reliable predictors of hepatic toxicity in non-clinical testing; however, mice are considered to be a sensitive test species. To better understand the relationship between nucleotide sequence and hepatotoxicity, a structure-toxicity analysis was performed using results from 2 week repeated-dose-tolerability studies in mice administered LNA-modified ASOs. ASOs targeting human Apolipoprotien C3 (Apoc3), CREB (cAMP Response Element Binding Protein) Regulated Transcription Coactivator 2 (Crtc2) or Glucocorticoid Receptor (GR, NR3C1) were classified based upon the presence or absence of hepatotoxicity in mice. From these data, a random-decision forest-classification model generated from nucleotide sequence descriptors identified two trinucleotide motifs (TCC and TGC) that were present only in hepatotoxic sequences. We found that motif containing sequences were more likely to bind to hepatocellular proteins in vitro and increased P53 and NRF2 stress pathway activity in vivo. These results suggest in silico approaches can be utilized to establish structure-toxicity relationships of LNA-modified ASOs and decrease the likelihood of hepatotoxicity in preclinical testing. Show less