Uloga TLR2 u modulaciji sinaptičke plastičnosti i oporavka poslije ishemijskoga oštećenja mišjega mozga [The role of TLR2 in synaptic plasticity and functional recovery after ischemic lesion of mice brain]

Postischemic neuroinflammation depends on innate immunity that is predominantly relying on the TLR signaling. To determine the role of TLR2 on the functional recovery and reactive synaptogenesis, research was conducted inducing ischemic brain lesions (MCAO) in mice lacking the Tlr2 gene investigating postischemic events at the level of mRNA and protein expression, angiogenesis, neuronal network and neurological symptoms. Functional deficits had later and more mild onset in Tlr2-/- mice and also displayed a prolonged chronic phase of recovery compared to wild type (WT). qRT-PCR revealed an increase in the mRNA expression of several components of the TLR2 signalling: MyD88, FADD and CASP8. Western blot of synaptic markers (DLG4, synaptophysin) and a marker of axonogenesis (GAP43) revealed their changed profile in the acute phase and a significant increase in their expression 1 month after ischemia in Tlr2-/- mice compared to their WT controls. Neuronal network density was lower in Tlr2-/- mice and they showed slower maturation of the microvascular network with lesser bifurcations, compared to the WT mice. TLR2 was shown to influence the dynamics of postischemic recovery indicating a therapeutic potential of timed modulation of the TLR2 response. The therapeutic window can be determined using colocalisation of CASP3 and GAP43

Molecular mechanisms of microglia- and astrocyte-driven neurorestoration triggered by application of electromagnetic fields

Aim To propose potential mechanisms of action of electromagnetic fields (EMF) on astrocytes and microglia and to elucidate the role of heat shock proteins (HSP), adenosine triphosphate (ATP), calcium ions (Ca2+), and hypoxia-inducible factor 1α (HIF1α) in neurorestoration following the application of EMF. Methods We reviewed the existing studies within the public domain and cross-evaluated their results in order to conclude on the molecular mechanisms of microgliaastrocyte crosstalk at work during EMF treatment. Results The existing studies suggest that EMF induces the increase of HSP70 expression and inhibition of HIF1α, thus decreasing inflammation and allowing the microgliaastrocyte crosstalk to initiate the formation of a glial scar within the central nervous system. Furthermore, by potentially up-regulating A2A and A3 adenosine receptors, EMF increases cAMP accumulation from astrocytes and reduces the expression of inflammatory cytokines TNF α and IL-8, thus initiating neurorestoration. Conclusion The microglia-astrocyte crosstalk during EMF treatment is crucial for the initiation of neurorestoration. Elucidating the exact mechanisms of EMF actions upon microglia and astrocytes, and its role in neurorestoration could be a key step in further research of the therapeutic potential of EMFs in various neurological disorders

Neural stem cells from mouse strain Thy1 YFP-16 are a valuable tool to monitor and evaluate neuronal differentiation and morphology

To analyse events following transplantation of stem cells in the brain robust tools for tracing stem cells are required. Here we took advantage of the mouse strain B6.Cg-Tg(Thy1-YFP)16Jrs/J (Thy1 YFP-16), where yellow fluorescent protein (YFP) is under control of the promoter of Thy1 gene. This allows visualising whole neurons, i.e. their cell body, axons and dendrites. In this work fluorescent cells were followed during embryonic development, in vitro differentiation, and after transplantation in the healthy and stroke-affected mouse brain. During embryonic development Thy1-YFP positive cells were first observed on E12.5 and subsequently located in the prosencephalon, rhombencephalon, spinal cord and peripheral nerves. Quantitative analysis by RT-PCR and immunocytochemistry revealed that Thy1-YFP positive cells during embryo development and in vitro differentiation were expressing nestin and SOX2 then MAP2, β3-tubulin and NeuN. Thy1-YFP positive cells isolated from E14.5 represented 21.88±053% (SD) of the cultivated neurons and this remained constant along in vitro differentiation. On the other hand, proportion of Thy1-YFP positive cells reached 50% of neurons in perinatal and one month old mouse brain. Neural stem cells isolated from Thy1 YFP-16 mouse strain transplanted near hippocampus of the healthy and stroke-affected brain were distinguishable by YFP fluorescence. They differentiated into mature neurons and were detectable even 14 weeks after transplantation, the end point of our experiment. In conclusion, stem cells originating from Thy1 YFP-16 mice represent an outstanding tool to monitor neurogenesis enabling morphological analyses of new neurons and their projections, in particular after transplantation in the brain

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents

Aim To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Methods Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Results Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. Conclusion MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema

Data-driven spatio-temporal modelling of glioblastoma

Mathematical oncology provides unique and invaluable insights into tumour growth on both the microscopic and macroscopic levels. This review presents state-of-the-art modelling techniques and focuses on their role in understanding glioblastoma, a malignant form of brain cancer. For each approach, we summarise the scope, drawbacks, and assets. We highlight the potential clinical applications of each modelling technique and discuss the connections between the mathematical models and the molecular and imaging data used to inform them. By doing so, we aim to prime cancer researchers with current and emerging computational tools for understanding tumour progression. Finally, by providing an in-depth picture of the different modelling techniques, we also aim to assist researchers who seek to build and develop their own models and the associated inference frameworks.Comment: 30 pages, 3 figures, 3 table

The role of TLR2 in synaptic plasticity and functional recovery after ischemic lesion of mice brain

Osnovne odrednice postishemijske upale su signalni putovi urođene imunosti, od kojih su se najzastupljenijim pokazali putovi ovisni o TLR2 izraženim na stanicama mikroglije. S ciljem određivanja djelovanja TLR2 na funkcionalni oporavak i reaktivnu sinaptogenezu, provedeno je istraživanje na modelu ishemijskog oštećenja mišjeg mozga s onemogućenim Tlr2 genom (Tlr2-/-) pomoću okluzije središnje moždane arterije (engl. Medial Cerebral Artery Occlusion, MCAO) što je omogućilo promatranje postishemijskih zbivanja na razini izražaja mRNA, bjelančevina i struktura tkiva te njihovog odraza na neurološke simptome. Funkcionalno oštećenje mjereno testovima ponašanja kod Tlr2-/- miševa nastupa kasnije i u blažem obliku, te se njihov oporavak produljuje u odnosu na miševe divljeg tipa (engl. Wild Type, WT). Metodom qPCR-a uvrđene su promjene količine izražaja gena signalnog puta TLR2: MyD88, FADD i Casp8. Western Blot za biljege sinapsi (DLG4, sinaptofizin) i biljeg aksonogeneze (GAP43) pokazao je promijenjen profil izražaja u akutnoj fazi te značajni porast mjesec dana nakon ishemije kod Tlr2-/- u odnosu na WT miševe. Gustoća neuralne mreže bila je smanjena kod Tlr2-/- miševa u odnosu na WT kontrole, kao i broj grananja krvnih žila sa sporijim sazrijevanjem mikrovaskularne mreže. Utvrđeno je kako TLR2 utječe na dinamiku postishemijskog oporavka zajedno s neurološkim simptomima. Stoga terapijski potencijal leži u pravodobnoj modulaciji TLR2 odgovora. Pri tom je terapijski prozor moguće odrediti pomoću biljega neuralnog stresa CASP3 i GAP43.Postischemic neuroinflammation depends on innate immunity that is predominantly relying on the TLR signaling. To determine the role of TLR2 on the functional recovery and reactive synaptogenesis, research was conducted inducing ischemic brain lesions (MCAO) in mice lacking the Tlr2 gene investigating postischemic events at the level of mRNA and protein expression, angiogenesis, neuronal network and neurological symptoms. Functional deficits had later and more mild onset in Tlr2-/- mice and also displayed a prolonged chronic phase of recovery compared to wild type (WT). qRT-PCR revealed an increase in the mRNA expression of several components of the TLR2 signalling: MyD88, FADD and CASP8. Western blot of synaptic markers (DLG4, synaptophysin) and a marker of axonogenesis (GAP43) revealed their changed profile in the acute phase and a significant increase in their expression 1 month after ischemia in Tlr2-/- mice compared to their WT controls. Neuronal network density was lower in Tlr2-/- mice and they showed slower maturation of the microvascular network with lesser bifurcations, compared to the WT mice. TLR2 was shown to influence the dynamics of postischemic recovery indicating a therapeutic potential of timed modulation of the TLR2 response. The therapeutic window can be determined using colocalisation of CASP3 and GAP43

The role of TLR2 in synaptic plasticity and functional recovery after ischemic lesion of mice brain

Osnovne odrednice postishemijske upale su signalni putovi urođene imunosti, od kojih su se najzastupljenijim pokazali putovi ovisni o TLR2 izraženim na stanicama mikroglije. S ciljem određivanja djelovanja TLR2 na funkcionalni oporavak i reaktivnu sinaptogenezu, provedeno je istraživanje na modelu ishemijskog oštećenja mišjeg mozga s onemogućenim Tlr2 genom (Tlr2-/-) pomoću okluzije središnje moždane arterije (engl. Medial Cerebral Artery Occlusion, MCAO) što je omogućilo promatranje postishemijskih zbivanja na razini izražaja mRNA, bjelančevina i struktura tkiva te njihovog odraza na neurološke simptome. Funkcionalno oštećenje mjereno testovima ponašanja kod Tlr2-/- miševa nastupa kasnije i u blažem obliku, te se njihov oporavak produljuje u odnosu na miševe divljeg tipa (engl. Wild Type, WT). Metodom qPCR-a uvrđene su promjene količine izražaja gena signalnog puta TLR2: MyD88, FADD i Casp8. Western Blot za biljege sinapsi (DLG4, sinaptofizin) i biljeg aksonogeneze (GAP43) pokazao je promijenjen profil izražaja u akutnoj fazi te značajni porast mjesec dana nakon ishemije kod Tlr2-/- u odnosu na WT miševe. Gustoća neuralne mreže bila je smanjena kod Tlr2-/- miševa u odnosu na WT kontrole, kao i broj grananja krvnih žila sa sporijim sazrijevanjem mikrovaskularne mreže. Utvrđeno je kako TLR2 utječe na dinamiku postishemijskog oporavka zajedno s neurološkim simptomima. Stoga terapijski potencijal leži u pravodobnoj modulaciji TLR2 odgovora. Pri tom je terapijski prozor moguće odrediti pomoću biljega neuralnog stresa CASP3 i GAP43.Postischemic neuroinflammation depends on innate immunity that is predominantly relying on the TLR signaling. To determine the role of TLR2 on the functional recovery and reactive synaptogenesis, research was conducted inducing ischemic brain lesions (MCAO) in mice lacking the Tlr2 gene investigating postischemic events at the level of mRNA and protein expression, angiogenesis, neuronal network and neurological symptoms. Functional deficits had later and more mild onset in Tlr2-/- mice and also displayed a prolonged chronic phase of recovery compared to wild type (WT). qRT-PCR revealed an increase in the mRNA expression of several components of the TLR2 signalling: MyD88, FADD and CASP8. Western blot of synaptic markers (DLG4, synaptophysin) and a marker of axonogenesis (GAP43) revealed their changed profile in the acute phase and a significant increase in their expression 1 month after ischemia in Tlr2-/- mice compared to their WT controls. Neuronal network density was lower in Tlr2-/- mice and they showed slower maturation of the microvascular network with lesser bifurcations, compared to the WT mice. TLR2 was shown to influence the dynamics of postischemic recovery indicating a therapeutic potential of timed modulation of the TLR2 response. The therapeutic window can be determined using colocalisation of CASP3 and GAP43

The role of TLR2 in synaptic plasticity and functional recovery after ischemic lesion of mice brain

Osnovne odrednice postishemijske upale su signalni putovi urođene imunosti, od kojih su se najzastupljenijim pokazali putovi ovisni o TLR2 izraženim na stanicama mikroglije. S ciljem određivanja djelovanja TLR2 na funkcionalni oporavak i reaktivnu sinaptogenezu, provedeno je istraživanje na modelu ishemijskog oštećenja mišjeg mozga s onemogućenim Tlr2 genom (Tlr2-/-) pomoću okluzije središnje moždane arterije (engl. Medial Cerebral Artery Occlusion, MCAO) što je omogućilo promatranje postishemijskih zbivanja na razini izražaja mRNA, bjelančevina i struktura tkiva te njihovog odraza na neurološke simptome. Funkcionalno oštećenje mjereno testovima ponašanja kod Tlr2-/- miševa nastupa kasnije i u blažem obliku, te se njihov oporavak produljuje u odnosu na miševe divljeg tipa (engl. Wild Type, WT). Metodom qPCR-a uvrđene su promjene količine izražaja gena signalnog puta TLR2: MyD88, FADD i Casp8. Western Blot za biljege sinapsi (DLG4, sinaptofizin) i biljeg aksonogeneze (GAP43) pokazao je promijenjen profil izražaja u akutnoj fazi te značajni porast mjesec dana nakon ishemije kod Tlr2-/- u odnosu na WT miševe. Gustoća neuralne mreže bila je smanjena kod Tlr2-/- miševa u odnosu na WT kontrole, kao i broj grananja krvnih žila sa sporijim sazrijevanjem mikrovaskularne mreže. Utvrđeno je kako TLR2 utječe na dinamiku postishemijskog oporavka zajedno s neurološkim simptomima. Stoga terapijski potencijal leži u pravodobnoj modulaciji TLR2 odgovora. Pri tom je terapijski prozor moguće odrediti pomoću biljega neuralnog stresa CASP3 i GAP43.Postischemic neuroinflammation depends on innate immunity that is predominantly relying on the TLR signaling. To determine the role of TLR2 on the functional recovery and reactive synaptogenesis, research was conducted inducing ischemic brain lesions (MCAO) in mice lacking the Tlr2 gene investigating postischemic events at the level of mRNA and protein expression, angiogenesis, neuronal network and neurological symptoms. Functional deficits had later and more mild onset in Tlr2-/- mice and also displayed a prolonged chronic phase of recovery compared to wild type (WT). qRT-PCR revealed an increase in the mRNA expression of several components of the TLR2 signalling: MyD88, FADD and CASP8. Western blot of synaptic markers (DLG4, synaptophysin) and a marker of axonogenesis (GAP43) revealed their changed profile in the acute phase and a significant increase in their expression 1 month after ischemia in Tlr2-/- mice compared to their WT controls. Neuronal network density was lower in Tlr2-/- mice and they showed slower maturation of the microvascular network with lesser bifurcations, compared to the WT mice. TLR2 was shown to influence the dynamics of postischemic recovery indicating a therapeutic potential of timed modulation of the TLR2 response. The therapeutic window can be determined using colocalisation of CASP3 and GAP43