Project description:Clinical experiment: gut microbiota pattern in stroke patients (stroke dysbiosis index, SDI) was an independent predictor for early outcome of ischemic stroke patients
Project description:Clinical experiment: gut microbiota pattern in stroke patients (stroke dysbiosis index, SDI) was an independent predictor for early outcome of ischemic stroke patients
Project description:In the acute phase of ischemic stroke, endothelial cell (EC) dysfunction leads to breakdown of the blood-brain barrier with increased vascular permeability, vascular inflammation, and transendothelial migration of leukocytes. ECs are also critical for long-term regenerative processes, such as post-stroke angiogenesis, enabling the transition from brain injury to repair. Yes-associated protein 1 (YAP) and WW domain-containing transcriptional regulator 1 (TAZ) are co-transcriptional regulators of EC proliferation and apoptosis. Several studies showed that YAP/TAZ is essential for developmental angiogenesis. However, the role of YAP/TAZ in adult angiogenesis and particularly in experimental stroke is unknown. Here, we subjected mice with an inducible EC-specific deletion of YAP and TAZ (YT-iKO) to 30-min middle cerebral artery occlusion (MCAo) followed by reperfusion to investigate the effects of endothelial YAP/TAZ on acute and long-term outcome after ischemic stroke. First, we examined mRNA expression of genes related to YAP/TAZ signaling in ischemic brain tissue, such as Id1, Smad6, Ankrd and Ccn2. We found a transient induction with highest expression levels acutely after stroke. Surprisingly, endothelial YAP/TAZ deficiency resulted in reduced lesion volumes 28 days after MCAo, whereas acute lesion size 3 days after stroke did not differ. Moreover, Yap/Taz iEC-KO animals showed no gross differences in vessels morphology 28 days after stroke, and no effect was detected on blood vessel density and EC density. We therefore speculated whether angiogenesis-independent effects of YAP/TAZ might also be associated with improved long-term outcome after stroke. To better understand the underlying mechanisms, we performed RNA sequencing of ECs isolated from ischemic brain tissue of YT-iKO compared with CTRL animals 72h post stroke. Here, we identified differently expressed gene sets involved in inflammatory responses. Therefore, we studied the non-endothelial tissue environment of the brain. We found, that EC YAP/TAZ deletion led to increased expression of anti-inflammatory genes accompanied by increased infiltration of myeloid cells, suggesting a protective phenotype. Besides, acute microglia proliferation was reduced in Y/T-iKO animals. Overall, our results provide new insights into the role of endothelial YAP/TAZ in neuroinflammation after cerebral ischemia. YAP/TAZ may therefore be a potential therapeutic target for the treatment of ischemic stroke.
Project description:To detect mRNAs in ischemic stroke animals we dissected contralateral (CL) and peri-ischemic (PI) cortex of transient middle cerebral artery occlusion (tMCAo) mice wild-type and ciRS-7 KO We performed differentially expression analysis of RNA-seq of wild-type and ciRS-7 KO tMCAo ischemic mice
Project description:The purpose of this project was to elucidate gene expression in the peripheral whole blood of acute ischemic stroke patients to identify a panel of genes for the diagnosis of acute ischemic stroke. Peripheral blood samples were collected in Paxgene Blood RNA tubes from stroke patients who were >18 years of age with MRI diagnosed ischemic stroke and controls who were non-stroke neurologically healthy. The results suggest a panel of genes can be used to diagnose ischemic stroke, and provide information about the biological pathways involved in the response to acute ischemic stroke in humans. Total RNA extracted from whole blood in n=39 ischemic stroke patients compared to n=24 healthy control subjects.
Project description:Ischemic stroke is one of the leading causes of disability and mortality worldwide, recognizing aging as a prominent risk factor and determinant of dismal outcome. Aging is known to lead to overall frailty due to multifactorial changes, but pathogenic mechanisms underlying poor outcome remain unclear. Here we show that deterioration in elderly stroke is preceded by neutrophil accumulation and clogging in the ischemic brain microcirculation leading to a worse no-reflow phenomenon. With high-dimensional single-cell profiling over time of the brain's, blood's, and bone marrow's immune response, we could delineate after stroke four main neutrophil clusters in the blood whose quantitative and temporal dynamic of release is deranged in the bone marrow of the old. In the elderly, stroke triggers an early surge in the blood of the CD62Llo neutrophil subset characterized by a signature of bone marrow proximity, senescence, and oxidative stress. Functionally, transfer of this neutrophil subset displaying prominent thrombogenic features in young stroke mice leads to increased clogging of the ischemic brain microcirculation, worse no-reflow and outcome. Interrogating the blood leukocyte landscape of a large human stroke cohort with extensive single-cell proteome analyses, we confirmed that older stroke patients display a similar precocious accumulation of blood CD62Llo neutrophil subset, worse reperfusion and outcome. Our results demonstrate how age-related alterations in the process of neutrophil differentiation and release from the bone marrow have a relevant pathogenic role in the major cerebrovascular disorder affecting the world population, that unleash emergency granulopoiesis.