Intravenous antagomiR-494 lessens brain-infiltrating neutrophils by increasing HDAC2-mediated repression of multiple MMPs in experimental stroke

Abstract

Background: Neutrophil infiltration and phenotypic transformation are believed to contribute to neuronal damage and clinical outcome in ischemic stroke. Emerging evidence suggests that HDAC2 is an epigenetic regulator of inflammatory cells. Here, we investigated whether miR-494 affects HDAC2-mediated neutrophil infiltration and phenotypic shift. Methods: The miR-494 levels in neutrophils from AIS patients were detected by real-time PCR. C57BL/6J mice were subjected to transient middle cerebral artery occlusion, and the N1/N2 neutrophil shift was examined. Cortical neurons were subjected to oxygen-glucose deprivation and stimulated with supernatant from differently treated neutrophils or were cocultured with neutrophils; neuronal injury was detected, and ChIP-Seq was performed to clarify which genes are the binding targets of HDAC2. Finally, a transwell assay was conducted to examine neutrophil migration. Results: Compared to the control subjects, AIS patients had increased neutrophil expression of miR-494, and in AIS patients, elevated miR-494 expression in neutrophils was a predictor of worse neurological outcomes. MiR-494 correlates with the upregulation of adhesion molecules in neutrophils of AIS patients. Systemically administered antagomiR-494 partly shifts neutrophils into the N2 phenotype in MCAO mice. AntagomiR-494-treated neutrophils exert a neuroprotective role in vitro. ChIP-seq revealed that HDAC2 targets multiple MMP genes in neutrophils of AIS patients. Further in vitro and in vivo experiments showed that antagomiR-494 repressed expression of MMP genes, including MMP7, MMP10, MMP13, and MMP16, to reduce the number of brain-infiltrating neutrophils by regulating HDAC2. Conclusion: MiR-494 may serve as an alternative predictive biomarker of the outcome of AIS patients, and antagomiR-494 treatment decreased the expression of multiple MMPs and the infiltration of neutrophils partly by targeting HDAC2.

A Network Pharmacology to Explore the Mechanism of Calculus Bovis in the Treatment of Ischemic Stroke

“…Their mRNAs were dramatically increased in the cortex of the mouse ischemia model in which thrombus was induced [57]. Decreasing levels of MMPs significantly ameliorated transgression of neutrophils, which resulted in neuroprotection against ischemic stroke [58]. Targeted inhibition of the PI3K/AKT/MMP-9 signaling pathway suppressed tumor invasion and metastasis [59], but this has not been tested in neuronal cells.…”

Preclinical and clinical progress for HDAC as a putative target for epigenetic remodeling and functionality of immune cells

“…A class I HDACi, CI-994, suppressed the accumulation of neutrophils and expression of inflammatory cytokines in a mouse model of spinal cord injury (SCI), thus contributing to promoting functional recovery, especially during the early stages of SCI [39]. Our group demonstrated HDAC2-mediated neutrophil infiltration and N1/N2 phenotypic shift following ischemic stroke [40]. In summary, HDAC and HDACi play necessary roles in the differentiation, NETosis, immune responses, and migration of neutrophils under normal and pathological conditions.…”