Natasa Karas-Kuzelicki

Dr. Natasa Karas-Kuzelicki


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 September 2020 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MGMaša Vidmar Golja
Maša Vidmar Golja
ASAlenka Smid
Alenka Smid
NKNatasa Karas-Kuzelicki
Natasa Karas-Kuzelicki
JTJurij Trontelj
Jurij Trontelj
KGKsenija Geršak
Ksenija Geršak
IMIrena Mlinaric-Rascan
Irena Mlinaric-Rascan
Adequate levels of folates are essential for homeostasis of the organism, prevention of congenital malformations, and the salvage of predisposed disease states. They depend on genetic predisposition, and therefore, a pharmacogenetic approach to individualized supplementation or therapeutic intervention is necessary for an optimal outcome. The role of folates in vital cell processes was investigated by translational pharmacogenetics employing lymphoblastoid cell lines (LCLs). Depriving cells of folates led to reversible S-phase arrest. Since 5,10-methylenetetrahydrofolate reductase (MTHFR) is the key enzyme in the biosynthesis of an active folate form, we evaluated the relevance of polymorphisms in the MTHFR gene on intracellular levels of bioactive metabolite, the 5-methyltetrahydrofolate (5-Me-THF). LCLs (n = 35) were divided into low- and normal-MTHFR activity groups based on their genotype. They were cultured in the presence of folic acid (FA) or 5-Me-THF. Based on the cells’ metabolic activity and intracellular 5-Me-THF levels, we conclude supplementation of FA is sufficient to maintain adequate folate level in the normal MTHFR activity group, while low MTHFR activity cells require 5-Me-THF to overcome the metabolic defects caused by polymorphisms in their MTHFR genes. This finding was supported by the determination of intracellular levels of 5-Me-THF in cell lysates by LC-MS/MS. FA supplementation resulted in a 2.5-fold increase in 5-Me-THF in cells with normal MTHFR activity, but there was no increase after FA supplementation in low MTHFR activity cells. However, when LCLs were exposed to 5-Me-THF, a 10-fold increase in intracellular levels of this metabolite was determined. These findings indicate that patients undergoing folate supplementation to counteract anti-folate therapies, or patients with increased folate demand, would benefit from pharmacogenetics-based therapy choices.

5 November 2020 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
JOJasna Omersel
Jasna Omersel
NKNatasa Karas-Kuzelicki
Natasa Karas-Kuzelicki
Precision medicine approaches based on pharmacogenomics are now being successfully implemented to enable physicians to predict more efficient treatments and prevention strategies for a given disease based on the genetic background of the patient. This approach has already been proposed for vaccines, but research is lagging behind the needs of society, and precision medicine is far from being implemented here. While vaccinomics concerns the effectiveness of vaccines, adversomics concerns their side effects. This area has great potential to address public concerns about vaccine safety and to promote increased public confidence, higher vaccination rates, and fewer serious adverse events in genetically predisposed individuals. The aim here is to explore the contemporary scientific literature related to the vaccinomic and adversomic aspects of the three most-controversial vaccines: those against hepatitis B, against measles, mumps, and rubella, and against human Papilloma virus. We provide detailed information on the genes that encode human leukocyte antigen, cytokines and their receptors, and transcription factors and regulators associated with the efficacy and safety of the Hepatitis B and Measles, Mumps and Rubella virus vaccines. We also investigate the future prospects of vaccinomics and adversomics of a COVID-19 vaccine, which might represent the fastest development of a vaccine ever.

31 October 2009 in Leukemia Research
Verified
Journal Article
Closed access
NKNatasa Karas-Kuzelicki
Natasa Karas-Kuzelicki
MMMiha Milek
Miha Milek
JJJanez Jazbec
Janez Jazbec
IMIrena Mlinaric-Rascan
Irena Mlinaric-Rascan

4 November 2022 in Nutrients
Verified
Journal Article
Open access
PDF file
JOJosko Osredkar
Josko Osredkar
ŽGŽiva Miriam Geršak
Živa Miriam Geršak
NKNatasa Karas-Kuzelicki
Natasa Karas-Kuzelicki
JTJanja Snoj Tratnik
Janja Snoj Tratnik
DMDarja Mazej
Darja Mazej
KGKsenija Geršak
Ksenija Geršak
Trace elements, including zinc (Zn) and copper (Cu), are known to play important roles in human health. The present study aimed to assess the levels of Zn and Cu in cord blood and maternal milk and to analyze their association with maternal and infant characteristics and pregnancy outcomes in a Slovenian study population of mothers and their neonates recruited within the PHIME prospective cohort study. The study included 324 mothers, but the data on Zn and Cu levels in both cord blood and maternal milk was available for 243 mothers. Questionnaires were used to assess the socio-demographic and health status of the mothers, their lifestyle habits (including detailed nutritional habits), and their residential and occupational histories. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure Zn and Cu levels in cord blood and maternal milk. Low Zn levels in cord blood were associated with lower gestational age and birth weight and were correlated with an increased probability of the birth of small for gestational age (SGA) infants. Maternal smoking influenced the Cu levels in both cord blood and maternal milk. Cord blood Cu levels were higher and Cu levels in maternal milk were lower in smoking compared to non-smoking mothers. Most importantly, a decreased Zn/Cu ratio in cord blood was associated with lower gestational age and lower birth weight. This indicates the overall positive effects of Zn and negative effects of Cu on pregnancy outcomes.

22 October 2018 in Pharmacogenomics
Verified
Journal Article
Open access
DUDunja Urbančič
Dunja Urbančič
AŠAlenka Šmid
Alenka Šmid
GSGabriele Stocco
Gabriele Stocco
GDGiuliana Decorti
Giuliana Decorti
IMIrena Mlinarič-Raščan
Irena Mlinarič-Raščan
NKNatasa Karas-Kuzelicki
Natasa Karas-Kuzelicki
Aim: SNPs in the gene for TPMT exemplify one of the most successful translations of pharmacogenomics into clinical practice. This study explains the correlation between common SNPs and variable number of tandem repeats (VNTR) in promoter of the gene. Materials & methods: We determined VNTR polymorphisms, as well as TPMT*2 and TPMT*3 SNPs and TPMT activity in Slovenian and Italian individuals and lymphoblastoid cell lines. Results: We observed a previously unreported VNTR allele, AB7C, in a TPMT*3A heterozygous individual. VNTRs with two (AB2C) and three or more (ABnC, n ≥ 3) B motifs were statistically significant in complete linkage disequilibrium (D′ = 1, r2 = 1, p < 0.0001) with the TPMT*3C and TPMT*3A alleles, respectively. Conclusion: The study provides insights into the stepwise evolution of TPMT*3 alleles from *3C to *3A, with increasing number of B motifs in the VNTR region. Graphical abstract

1 January 2022 in Toxicology and Applied Pharmacology
Verified
Journal Article
Closed access
MKMaša Kenda
Maša Kenda
DADamjan Avsec
Damjan Avsec
TZTaja Zore
Taja Zore
EKEva Kogovšek
Eva Kogovšek
UFUrsa Pecar Fonovic
Ursa Pecar Fonovic
MDMarija Sollner Dolenc
Marija Sollner Dolenc