Laboratory of Stem Cell Biology:2

About	Group under the leadership of Dr. Ludmyla Kolchinskaya.	Group under the leadership of Prof. Evgeniya V Pushchina	Group under the leadership of Dr. Igor Prudnikov and Dr Vladimir Tsyvkin	Some results of Dr. Igor Prudnikov and Dr Vladimir Tsyvkin

This group deals with normal and pathological conditions of mitochondrial work in the adult and embryo nervous tissue. Mainly the interest is in the field of ATP-dependent potassium channel (K ATP+-channel) of mitochondrial membranes. It was found that the effect of K+ uptake on reactive oxygen species (rOS) production in the brain mitochondria under steady-state conditions (state 4) was determined by potassium-dependent changes in the membrane potential of the mitochondria (ΔΨ m). The influence of mitochondrial permeability transition pore (mpTp) opening on rOS production in the rat brain mitochondria was studied also. It was shown that rOS production is regulated differently by the rate of oxygen consumption and membrane potential, dependent on steady-state or non-equilibrium conditions. Under steady-state conditions, at constant rate of Ca2+-cycling and oxygen consumption, rOS production is potential-dependent and decreases with the inhibition of respiration and mitochondrial depolarization. The ATP-dependent transport of K+ was shown to be ∼40% of the potential-dependent K+ uptake in the brain mitochondria. Based on the findings of the experiments, the potential-dependent transport of K+ was concluded to be a physiologically important regulator of ROS generation in the brain mitochondria and that the functional activity of the native K ATP + -channel in these organelles under physiological conditions can be an effective tool for preventing ROS overproduction in brain neurons.

Another interest of Dr Ludmyla Kolchinskaya is the investigation of natural toxins. Among them is venom of spider Black Widow. Dr Kolchinskaya with colleagues obtained protein from this venom that forms the sodium channels in cell membrane. The mystifying feature of this protein is in fact that the exact amino acid sequence of toxin is very similar to transmembrane receptor of the mesengial cells (macrophages) in kidney. And function of latrotoxin-like receptor proteins is not known yet.

The principal articles.

• OV Akopova, LI Kolchinskaya, VI Nosar, AN Smirnov. The effect of permeability transitionpore opening on reactive oxygen species production in rat brain mitochondria. 2011, Ukr Biochem.J, 83, # 6

• OV Akopova, LI Kolchinskaya, VI Nosar, VA Bouryi, IN Mankovska, VF Sagach. Effect of potential-dependent potassium uptake on production of reactive oxygen species in rat brain mitochondria. 2014, Biochemistry (M), v 79, #1, P. 44-53

• LI Kolchinskaya, MK Malysheva, YT Terletskaya, IO Trikash. The ability of latrotoxin-like brain protein to induce fusion of negatively charged liposomes. 1994, Journal of Neurochem., v 63, P.58