Data Management And Sharing System of China National Clinical Research Center for Neurological Diseases

Journal：SCIENCE TRANSLATIONAL MEDICINE

Publication type: Research Article

IF(IF): 17.956

PMID: 34349037 Link To Pubmed Full text Download

Acute brain insults elicit pronounced inflammation that amplifies brain damage in intracerebral hemorrhage (ICH). We profiled perihematomal tissue from patients with ICH, generating a molecular landscape of the injured brain, and identified formyl peptide receptor 1 (FPR1) as the most abundantly increased damage-associated molecular pattern (DAMP) receptor, predominantly expressed by microglia. Circulating mitochondrial N-formyl peptides, endogenous ligands of FPR1, were augmented and correlated with the magnitude of brain edema in patients with ICH. Interactions of formyl peptides with FPR1 activated microglia, boosted neutrophil recruitment, and aggravated neurological deficits in two mouse models of ICH. We created an FPR1 antagonist T-0080 that can penetrate the brain and bind both human and murine FPR1. T-0080 attenuated brain edema and improved neurological outcomes in ICH models.

The goal of this study was to investigate the molecular mechanisms governing inflammatory brain injury after ICH. To this end, this study used two experimental ICH models in wild-type and Fpr1−/− mice. Power analysis was performed to determine sample size in these experiments involving patients with ICH, ICH mice, and in vitro cell cultures. We collected brain tissues (n = 11) and blood samples (n = 80) from patients with ICH within 72-hour onset, as well as blood samples from healthy individuals (n = 47). We included all patients with ICH in which the mRS score was available in 3 months follow up (n = 30). Bulk RNA-seq was performed to analyze the gene expression profile of perihematomal area in patients with ICH. Blood mitochondrial N-formyl peptides were assessed by ELISA. To determine the role of FPR1 in ICH injury, no less than six mice were included per experimental group for the assessment of neurological deficits, brain edema and hematoma size, immune cell infiltration, cytokine/chemokine expression in the brain, and the effectiveness, pharmacokinetics, and toxicology of T-0080 in vivo. In experiments that use culturing cells to measure neutrophil migration and cytokine expression in microglia, at least six samples were included in each treatment group. Experimental subjects were assigned randomly to all experimental groups. The exact values of sample size (n) are provided in figure legends. Experimental groups, data collection, and data analysis were blinded by using different investigators or masking sample labels. Sample exclusion was done as a result of mouse death after surgery. All experiments presented were successfully reproduced for at least three times.