Katinka Tarnóczi

Ms. Katinka Tarnóczi

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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Journal Article
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CBCsenge Böröczky
Csenge Böröczky
APAlexandra Paszternák
Alexandra Paszternák
RLRudolf Laufer
Rudolf Laufer
KTKatinka Tarnóczi
Katinka Tarnóczi
NSNoémi Sikur
Noémi Sikur
TTTamás Tábi
Tamás Tábi
Neuroinflammation is a key process in Alzheimer’s disease (AD). We aimed to examine the development and evaluation of a comprehensive in vitro model that captures the complex interplay between neurons and immune cell types. Retinoic acid-differentiated SH-SY5Y neuroblastoma cells exposed to LPS-conditioned media (CM) from RAW264.7 macrophages, BV2 microglia, and HL60 promyelocytic cells differentiated into neutrophil- or monocyte-like phenotypes were analyzed. The effects of CM containing inflammatory factors on neuronal viability and function were systematically evaluated. Neuronal oxidative stress, mitochondrial function, autophagy and protein aggregates were analyzed. The involvement of insulin resistance was studied by assaying glucose uptake and determining its IC50 values for cell viability improvement and GSK3β phosphorylation. After short-term exposure (3 h), most inflammatory CMs induced peroxide production in neurons, with the strongest effect observed in media from DMSO- or RA-differentiated HL60 cells. Mitochondrial membrane potential was markedly reduced by LPS-stimulated BV2 and HL60-derived CMs. Prolonged exposure (72 h) revealed partial normalization of oxidative stress and mitochondrial membrane potential. Glucose uptake was significantly impaired in cells treated with LPS-activated RAW264.7, BV2, and DMSO-differentiated HL60 cell media, while insulin partially rescued this effect, except for the CM of BV2 cells. Notably, insulin IC50 increased dramatically under LPS-treated BV2 cells induced inflammation (35 vs. 198 pM), confirming the development of insulin resistance. Immune cell-specific inflammation causes distinct effects on neuronal oxidative stress, mitochondrial function, protein aggregation, insulin signaling and viability. LPS-activated BV2-derived CM best recapitulates AD-related pathology, offering a relevant in vitro model for further studies.

Verified
Journal Article
Open access
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APAlexandra Paszternák
Alexandra Paszternák
KVKamilla Varga
Kamilla Varga
RGRamá Gyöngyössy
Ramá Gyöngyössy
KTKatinka Tarnóczi
Katinka Tarnóczi
NSNoémi Sikur
Noémi Sikur
TTTamás Tábi
Tamás Tábi
Alzheimer’s disease (AD) is characterized by mitochondrial dysfunction, oxidative stress, insulin resistance, and aberrant protein aggregation. Neurodegeneration model with neuronal insulin resistance was induced in SH-SY5Y human neuroblastoma cells by streptozotocin (STZ). We evaluated the neuroprotective effects of resveratrol (RZV) and three structural analogs: oxyresveratrol (OXI), monomethyl resveratrol (MONO), and trimethyl resveratrol (TRI). Mitochondrial function, plasma membrane integrity, oxidative stress) and autophagy were studied by fluorescent assays. Phosphorylated GSK3 levels were measured by ELISA as an indicator of insulin sensitivity. TRI exhibited significant mitochondrial protective effects and strongly induced autophagy. OXI demonstrated excellent antioxidant activity but showed no detectable mitochondrial protective or autophagy-inducing effects. RZV and MONO exhibited moderate antioxidant effects along with strong insulin-sensitizing and autophagy-inducing properties. Insulin sensitivity was most potently restored by RZV (IC50 = 54 pM) and MONO (IC50 = 50 pM), whereas TRI (IC50 = 160 pM) was less potent, and OXI (IC50 = 97 pM) showed moderate potency. Our findings suggest that the neuroprotective effects of resveratrol analogs significantly depend on their molecular structure and that they exert their beneficial effects through distinct mechanisms. This research may contribute to the development of novel, multi-target compounds for the treatment of neurodegenerative diseases.

9 August 2024 in Molecules
Verified
Journal Article
Open access
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KTKatinka Tarnóczi
Katinka Tarnóczi
OGOrsolya Geda
Orsolya Geda
TTTamás Tábi
Tamás Tábi
ÉSÉva Szökő
Éva Szökő
Gangliosides are sialic acid-containing glycosphingolipids that play an essential role in many biological and pathophysiological processes. They are present in high amounts in the central nervous system and their abnormal metabolism or expression has been observed in many diseases. We have developed and validated a sensitive capillary electrophoresis laser-induced fluorescence (CE-LIF) method for the separation and quantification of oligosaccharides digested from nine gangliosides of high biological relevance. APTS was used for the labeling of the glycans. Reverse polarity CE was performed for the separation of the labeled glycans bearing negative charges. The optimized background electrolyte is a 15 mM lithium acetate buffer with pH of 5 containing 5% w/v linear polyacrylamide, which allows for the separation of all nine gangliosides. Validation parameters including linearity, precision, and accuracy were evaluated. LOQ and LOD were in the nM range, comparable to those of LC-MS techniques. The method was used to identify and quantify the ganglioside pattern of glioblastoma and neuroblastoma cell lines. The presented method is a valuable tool for further investigations aiming at understanding the role of gangliosides in various neurological diseases or CNS tumors.