TP6 - SASKit

Senescence-related biomarkers and signaling pathways in blood and brain of stroke models

Stroke is the most common cause of dependency worldwide, usually due to cognitive impairment. Stroke is linked to senescence, and metabolic factors such as hyperlipidemia and defective glucose metabolism account for its second largest risk factor. Both for gauging prognostic outcome and theranostic interventions, senescence/apoptosis markers emerge as promising candidates. Little is known on how these markers, usually obtained from blood, correspond to markers in brain, and how in turn both relate to cognitive dysfunction.
We will identify biomarker candidates on a pathomechanistic basis using brain hypoxia/ischemia in vitro models of both normal mice, and of a metabolically perturbed mouse strain with defective metabolism (UCP2-/- mouse) that we identified as senescence-prone. For this purpose, we will subject living 450 µm thick frontal somatosensory cortex slices of mice to hypoxia/hypoglycemia mimicking stroke conditions until the tissue is electrically silent, and monitor evoked field potentials (and degree of recovery), as well as latency to anoxic negativity in electrophysiological recordings to quantify ischemia tolerance. After slice extraction, using histological techniques we will quantify apoptosis/senescence and match these data to protein array kit data, and custom protein expression analytics with particular attention to expression of senescence/apoptosis and related pathways. Additionally, the effects on gene expression of associated targets will be tested. These data will be entering analyses by the computational groups.
Next we will translate these findings to the in vivo setting by quantifying markers in a mouse stroke model (middle cerebral artery occlusion, MCAO), in healthy and UCP2-/- mice. To discern age-related effects, we will study groups of young and old (6 vs. 12-18 months) mice. To compare effects for tissue vs. blood, we will run measurements for both. Specifically, we provide samples for transcriptomics analyses, and perform protein profiling. Further, to allow for correlation to functional outcome (and corresponding to the clinical data in subproject 5), we will assess stroke-dependent dysfunctions via sensorimotor tests in these mice, and also test for synaptic plasticity. All data are fed to subproject 1 and 2, and we take insights from there to design additional experiments.