Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA280

Poster Communications

Insulin-like growth factor 1, Sirtuin 1, Sirtuin 3 and brain injure in mice chronic cerebral hypoperfusion

O. Harmatina1, T. Lapikova-Bryhinska1, T. Voznesenskaya1, N. Grushka1, O. Kondratska1, R. Krasilnikov2, A. Portnychenko1

1. Bogomoletz institute of Physiology National academy of sciences of Ukraine, Kyiv, Ukraine. 2. NMMCC "Main Military Clinical Hospital", Kyiv, Ukraine.

Chronic brain hypoperfusion (ChCH) is a factor of risk for central nervous system (CNS) diseases, such as chronic brain ischemia, degenerative diseases, and others. Pathophysiological mechanisms of ChCH are still being investigated. By using complex approach, including genetic and functional methods of investigation, we anticipate to exhibit part of mechanisms underlying ChCH. The present study investigated changes of IGF1, SIRT1 and SIRT3 expression levels in brain under ChCH induced by unilateral occlusion common carotid artery (CCA). The experiments were carried out on male C57Bl/6j mice 6 weeks old (weight 18-20 g), divided into four experimental groups: (1) control sham group, n=10; (2) ChCH group, n=10; (3) ChCH+nicotinamide (NAM, 200 mg/kg, 10 d, i.p.) group, n=10; (4) ChCH+resverstrol (RV, 10 mg/kg, 10 d, i.p.) group, n=10. All manipulations were carried out in anesthetized with ketamine (60 mg/kg, i.p.) mice. ChCH was performed using left CCA ligation. In 8 weeks, mice brain were excised; brain tissues from left and right hemispheres immediately studied the features of DNA damage using the single cell gel electrophoresis assay (known as DNA comet assay), frozen hemispheres were stored at -80 °C until used for real-time PCR to determine IGF1, SIRT1 and SIRT3. The duplex ultrasonography was done in 8 weeks after left CCA ligation for the resistive index (RI) evaluation of right CCA and basilar artery (BA). All data are presented as a mean±standard error of the mean (SEM). One-way analysis of variance was executed to compare means between homogeneous groups accompanied by Bonferroni's post hoc test. The results of the Comet assay showed that ChCH was accompanied by an increase of DNA damage (comets within classes 3 and 4) index of neurons from the unilateral side (the side of CCA ligation) 6.9 times (p<0.001), by a decrease level of IGF1, SIRT1, SIRT3 gene expression 11.8, 9.3 and 20.2 times respectively compared with the control, p<0.05. In modeling of ChCH, from the unilateral side DNA damage index in neurons was reduced by treatment with NAM and RV by 89.6% and by 92.4% respectively compared to control p<0.001. From the unilateral side NAM and RV was increased the levels of SIRT1 1.7 and 3.5 times, of SIRT3 2.9 and 5.2 times, of IGF1 3.5 and 5.7 times respectively compared with the ChCH, p<0.05. Under ChCH, RI of the right CCA and BA was increased by 52.26% and by 84.16% respectively compared with control, P<0.05. NAM and RV was decreased RI of the right CCA by 12.54% and by 23.76% respectively and of BA by 26.36% and by 21.52% respectively compared with ChCH, p<0.05. Taken together, these data indicate that nicotinamide and resveratrol can detect positive effect on ChCH-induced brain injure by attenuating DNA breaks, which is partly attributable to the upregulation of SIRT1, SITR3, IGF1-mediated signaling pathway.

Where applicable, experiments conform with Society ethical requirements