Mitochondrial DNA variants associated with diseases are widely studied in contemporary populations, but their prevalence has not yet been investigated in ancient populations. The publicly available ...AmtDB database contains 1443 ancient mtDNA Eurasian genomes from different periods. The objective of this study was to use this data to establish the presence of pathogenic mtDNA variants putatively associated with mitochondrial diseases in ancient populations. The clinical significance, pathogenicity prediction and contemporary frequency of mtDNA variants were determined using online platforms. The analyzed ancient mtDNAs contain six variants designated as being "confirmed pathogenic" in modern patients. The oldest of these, m.7510T>C in the MT-TS1 gene, was found in a sample from the Neolithic period, dated 5800-5400 BCE. All six have well established clinical association, and their pathogenic effect is corroborated by very low population frequencies in contemporary populations. Analysis of the geographic location of the ancient samples, contemporary epidemiological trends and probable haplogroup association indicate diverse spatiotemporal dynamics of these variants. The dynamics in the prevalence and distribution is conceivably result of de novo mutations or human migrations and subsequent evolutionary processes. In addition, ten variants designated as possibly or likely pathogenic were found, but the clinical effect of these is not yet well established and further research is warranted. All detected mutations putatively associated with mitochondrial disease in ancient mtDNA samples are in tRNA coding genes. Most of these mutations are in a mt-tRNA type (Model 2) that is characterized by loss of D-loop/T-loop interaction. Exposing pathogenic variants in ancient human populations expands our understanding of their origin and prevalence dynamics.
Atypical chemokine receptor 3 (ACKR3), formerly referred to as CXCR7, is considered to be an interesting drug target. In this study, we report on the synthesis, pharmacological characterization and ...radiolabeling of VUF15485, a new ACKR3 small-molecule agonist, that will serve as an important new tool to study this
-arrestin-biased chemokine receptor. VUF15485 binds with nanomolar affinity (pIC
= 8.3) to human ACKR3, as measured in
ICXCL12 competition binding experiments. Moreover, in a bioluminescence resonance energy transfer-based
-arrestin2 recruitment assay VUF15485 acts as a potent ACKR3 agonist (pEC
= 7.6) and shows a similar extent of receptor activation compared with CXCL12 when using a newly developed, fluorescence resonance energy transfer-based ACKR3 conformational sensor. Moreover, the ACKR3 agonist VUF15485, tested against a (atypical) chemokine receptor panel (agonist and antagonist mode), proves to be selective for ACKR3. VUF15485 labeled with tritium at one of its methoxy groups (
HVUF15485), binds ACKR3 saturably and with high affinity (
= 8.2 nM). Additionally,
HVUF15485 shows rapid binding kinetics and consequently a short residence time (<2 minutes) for binding to ACKR3. The selectivity of
HVUF15485 for ACKR3, was confirmed by binding studies, whereupon CXCR3, CXCR4, and ACKR3 small-molecule ligands were competed for binding against the radiolabeled agonist. Interestingly, the chemokine ligands CXCL11 and CXCL12 are not able to displace the binding of
HVUF15485 to ACKR3. The radiolabeled VUF15485 was subsequently used to evaluate its binding pocket. Site-directed mutagenesis and docking studies using a recently solved cryo-EM structure propose that VUF15485 binds in the major and the minor binding pocket of ACKR3. SIGNIFICANCE STATEMENT: The atypical chemokine receptor atypical chemokine receptor 3 (ACKR3) is considered an interesting drug target in relation to cancer and multiple sclerosis. The study reports on new chemical biology tools for ACKR3, i.e., a new agonist that can also be radiolabeled and a new ACKR3 conformational sensor, that both can be used to directly study the interaction of ACKR3 ligands with the G protein-coupled receptor.
One of the best documented Indo-European civilizations that inhabited Bulgaria is the Thracians, who lasted for more than five millennia and whose origin and relationships with other past and ...present-day populations are debated among researchers. Here we report 25 new complete mitochondrial genomes of ancient individuals coming from three necropolises located in different regions of Bulgaria - Shekerdja mogila, Gabrova mogila and Bereketska mogila - dated to II-III millennium BC. The identified mtDNA haplogroup composition reflects the mitochondrial variability of Western Eurasia. In particular, within the ancient Eurasian genetic landscape, Thracians locate in an intermediate position between Early Neolithic farmers and Late Neolithic-Bronze Age steppe pastoralists, supporting the scenario that the Balkan region has been a link between Eastern Europe and the Mediterranean since the prehistoric time. Spatial Principal Component Analysis (sPCA) performed on Thracian and modern mtDNA sequences, confirms the pattern highlighted on ancient populations, overall indicating that the maternal gene pool of Thracians reflects their central geographical position at the gateway of Europe.
In an effort to better understand the complex genetic background of Alzheimer's disease (AD) we performed high-coverage whole-exome sequencing of a DNA pool assembled of 66 Bulgarian AD patients. We ...focused our analysis on genes demonstrated to have association with AD in previous studies, i.e. PSEN1, PSEN2, APP, APOE, TREM2, HFE, CLU and CR1. In these genes, we established six pathogenic/likely pathogenic variants in the sequenced pool, three common and three rare. Two of these variants showed statically non-significant difference between Bulgarian AD patients and Bulgarian control exomes, the hemochromatosis variant rs104894002 (HFE) and rs7412 (APOE), which, notwithstanding its pathogenicity score, has putative protective role against AD. Three of the remaining four pathogenic/likely pathogenic variants were estimated to significantly differ in frequency between the analyzed AD patient pool and controls. These are the rs429358 (APOE) polymorphism, a well-established risk factor for Alzheimer's disease, the rs28936380 (PSEN2) and rs104894002 (TREM2), also ascertained to be associated with AD. The performed study validates the role of three pathogenic/likely pathogenic variants in AD related genes in the multifaceted genetic etiology of Alzheimer's disease.
In July 2021, we organized a virtual symposium aimed at early-career investigators (ECIs) in G protein-coupled receptor (GPCR) research: the first Transatlantic ECI GPCR Symposium. Here, we discuss ...the proceedings of this symposium and the unique networking events with GPCR leaders including the Nobel Laureates Dr. Robert Lefkowitz and Dr. Brian Kobilka.
Objectives:
The aim of the present study was to evaluate the clinical relevance of mutations in tumor suppressor genes using whole-exome sequencing data from centenarians and young healthy ...individuals.
Methods:
Two pools, one of centenarians and one of young individuals, were constructed and whole-exome sequencing was performed. We examined the whole-exome sequencing data of Bulgarian individuals for carriership of tumor suppressor gene variants.
Results:
Of all variants annotated in both pools, 5080 (0.06%) are variants in tumor suppressor genes but only 46 show significant difference in allele frequencies between the two studied groups. Four variants (0.004%) are pathogenic/risk factors according to single nucleotide polymorphism database: rs1566734 in PTPRJ, rs861539 in XRCC3, rs203462 in AKAP10, and rs486907 in RNASEL.
Discussion:
Based on their high minor allele frequencies and presence in the centenarian group, we could reclassify them from pathogenic/risk factors to benign. Our study shows that centenarian exomes can be used for re-evaluating the clinically uncertain variants.
To better define the structure and origin of the Bulgarian paternal gene pool, we have examined the Y-chromosome variation in 808 Bulgarian males. The analysis was performed by high-resolution ...genotyping of biallelic markers and by analyzing the STR variation within the most informative haplogroups. We found that the Y-chromosome gene pool in modern Bulgarians is primarily represented by Western Eurasian haplogroups with ∼ 40% belonging to haplogroups E-V13 and I-M423, and 20% to R-M17. Haplogroups common in the Middle East (J and G) and in South Western Asia (R-L23*) occur at frequencies of 19% and 5%, respectively. Haplogroups C, N and Q, distinctive for Altaic and Central Asian Turkic-speaking populations, occur at the negligible frequency of only 1.5%. Principal Component analyses group Bulgarians with European populations, apart from Central Asian Turkic-speaking groups and South Western Asia populations. Within the country, the genetic variation is structured in Western, Central and Eastern Bulgaria indicating that the Balkan Mountains have been permeable to human movements. The lineage analysis provided the following interesting results: (i) R-L23* is present in Eastern Bulgaria since the post glacial period; (ii) haplogroup E-V13 has a Mesolithic age in Bulgaria from where it expanded after the arrival of farming; (iii) haplogroup J-M241 probably reflects the Neolithic westward expansion of farmers from the earliest sites along the Black Sea. On the whole, in light of the most recent historical studies, which indicate a substantial proto-Bulgarian input to the contemporary Bulgarian people, our data suggest that a common paternal ancestry between the proto-Bulgarians and the Altaic and Central Asian Turkic-speaking populations either did not exist or was negligible.
Contemporary genetic methods have not yet solved the 'missing heritability' problem of complex diseases such as Alzheimer's disease (AD). The impact of rare or less common variation on human complex ...diseases and traits remains to date barely investigated. In this study rare population variants detected using whole-exome sequencing were employed to examine how molecular pathways are prioritized in four groups: Alzheimer's disease (AD) patients, Frontotemporal dementia (FTD) patients, young and healthy individuals and centenarians. The set of prioritized genes in AD patients associated with Semaphorin interactions pathways, contrasting with the results of the other groups. We identified rare pathogenic, likely pathogenic and variants of unknown significance in these prioritized genes in AD patients. The results of this study offer evidence that semaphorin pathways play a role in AD genetic etiology.
Many bladder cancer (BC) patients with early disease are asymptomatic and diagnosed at advanced stage when the therapeutic options are limited. This necessitates the development of reliable ...predictive molecular biomarkers that will ensure a positive therapeutic response in every patient. The aim of this study was to screen for alterations in gene expression levels related to drug sensitivity and resistance that may be further explored as potential predictive therapeutic biomarkers. Gene expression analysis of the 168 genes from two panels for Cancer drug resistance and metabolism (PAHS004) and Cancer Drug Targets (PAHS507z) was performed. A total of 47 transitorial cell bladder cancer samples of stage pTa, pT1, pT2 were investigated using the pooling method, which allows reducing the effect of biological variation and detecting only significant expression changes. Differential gene expression was calculated using the ΔΔCt method with GPDH as a housekeeping gene. The 4.0-fold change in gene expression was used as the cut-off threshold to determine upregulation or downregulation compared to normal bladder tissue (negative control). Significance of the differences in the expression profiles was assessed by nonparametric one-way analysis of variance (ANOVA) with Dunn's multiple comparison tests and Mann-Witney test. We demonstrated a correlation of tumor invasion and several up-regulated genes related to chemotherapy resistance. For the first time, this study demonstrated overexpression of CDK8, CDK9, FIGF, HDAC11, IGF1 and PDGFRA genes in muscle-invasive bladder carcinomas. These genes and their proteins could be used as potential biomarkers for bladder cancer progression or prospective therapeutic targets.
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