PhD Scientific Days 2018

Budapest, April 19–20, 2018

Investigation of D-serine transport in SH-SY5Y cell line and cortical astrocytes

Vincze, István

Péter Lakatos, Dániel Tóka, Fruzsina Bagaméry, Tamás Tábi, Éva Szökő
Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary

Language of the presentation

English

Text of the abstract

Introduction: D-serine is a co-agonist of glutamatergic NMDA receptor. Hypofunction of NMDA receptors has been studied in several central nervous system diseases, e.g. schizophrenia and bipolar disorder. Decreased level of D-serine may play an important role in the pathophysiological mechanisms. Different transport systems modulate extracellular D-serine concentration, inclusive of sodium dependent ASCT1 and 2, as well as sodium-independent asc1.
Aims: Characterization of D-serine uptake in SH-SY5Y neuroblastoma cell line and comparison to primary astrocytes.
Method: Cells were incubated with different concentrations of D-serine. The intracellular concentration was measured by a capillary electrophoresis – laser induced fluorescence detection method developed in our laboratory. The effect of various amino acids and sodium-free environment on the D-serine uptake was investigated. Data was evaluated by OriginPro 8 SRO v8.0724 software.
Results: Time- and dose dependent D-serine uptake to both cell types was observed. Main transport form was found sodium-dependent since in sodium-free environment about 80% less D-serine uptake was measured. D-serine uptake was concentration dependently inhibited by neutral amino acids, substrates of these transporters. In case of L-alanine and L-threonine a two-step inhibition characteristic was noticed in both cell types. Previously L-glutamine was reported as a preferential inhibitor of ASCT2. However it caused complete inhibition in two steps in SH-SY5Y cells and astrocytes alike similarly to the other examined neutral amino acids. Recent data show that ASCT1 can be selectively inhibited by trans-4-hydroxy-L-proline (t-proline). In both cell types D-serine uptake was moderately inhibited in two steps by t-proline. In its selective concentration range t-proline reduced D-serine transport by about 30%, which supposedly related to ASCT1 transporter.
Conclusion: The characteristic of D-serine uptake was similar in both cell types. Mainly sodium-dependent D-serine transport was observed and at least two transporter systems are considered to be responsible for it.

Data of the presenter

Doctoral School of Pharmaceutical Sciences
Experimental and Clinical Pharmacology
Supervisor: Éva Szökő
szoko.eva@pharma.semmelweis-univ.hu