Influence of transplantation of neural stem cells on the expression of genes involved in the programmed cell death following ischemic brain stroke

Ishemijski moždani udar, te posljedične tkivna hipoksija i ishemija, uzrokuju značajno oštećenje moždanog tkiva. Jedan od pristupa u potrazi za pronalaskom uspješne obnove oštećenog tkiva uključuje primjenu matičnih stanica. U ovom istraživanju osnovni cilj bio je istražiti kako transplantacija živčanih matičnih stanica u mozak miša zahvaćen ishemijskim moždanim udarom utječe na ekspresiju gena uključenih u programiranu staničnu smrt. Istražili smo staničnu smrt posredovanu proteinom AIF (Aifm1), nekroptozu (Ripk1, Ripk3, Mlkl) te apoptozu (Casp3). Nakon što je moždani udar induciran privremenom okluzijom lijeve srednje moždane arterije, živčane matične stanice su transplantirane u striatum zahvaćene polutke (lijeve, ipsilateralne) mozga 24 h nakon moždanog udara. Miševi su žrtvovani 15 dana nakon induciranja moždanog udara te su za analizu ekspresije navedenih gena korištene obje polutke mozga. Transplantacija živčanih matičnih stanica u mozak miševa zahvaćenih moždanim udarom značajno je smanjila ekspresiju gena Aifm1 i Casp3 koji potiču staničnu smrt. Istovremeno, ekspresija gena uključenih u nekroptozu (Ripk1, Ripk3, Mlkl) značajno je povišena nakon moždanog udara, dok injiciranje medija nakon moždanog udara smanjuje njihovu ekspresiju. Nalaz da transplantacija živčanih matičnih stanica održava visoku ekspresiju gena Ripk3 te Mlkl može se objasniti njihovom novootkrivenom ulogom u prometu staničnih vezikula. Ischemic brain stroke is followed by significant tissue damage caused by hypoxia and ischemia. One of the most utilized experimental approaches for treatment of tissue hypoxia includes application of stem cells. In this study, we have analysed the effects of neural stem cell (NSC) transplantation in the mouse brain affected by stroke, on the expression of genes involved in programmed cell death: AIF-mediated cell death (Aifm1), necroptosis (Ripk1, Ripk3, Mlkl) and apoptosis (Casp3). Stroke had been induced by transient left middle cerebral artery occlusion (tMCAO) and NSC in proliferation supporting medium or the medium alone were transplanted in the striatum of affected (ipsilatheral) hemisphere 24 h following stroke. Mice had been sacrificed 14 days following stroke and both hemispheres were used for gene expression analysis. Transplantation of NSC in the mouse brain affected by stroke significantly downregulated damage-supportive genes Aifm1 and Casp3. Moreover, expression of genes involved in necroptosis (Ripk1, Ripk3, Mlkl) was increased following stroke, injection of proliferation supporting medium managed to reduce their level but transplantation of NSC supported high expression levels of Ripk3 and Mlkl for which was recently shown that play important roles in endosomal trafficking and extracellular vesicle generation.