Diagnostic performance of circulating MicroRNAs in acute ischemic stroke: A protocol for systematic review and meta-analysis

LncRNA Small Nucleolar RNA Host Gene 11 (SNHG11) Participates in Hypoxia/Reoxygenation-Induced Adrenal Phaeochromocytoma (PC12) Cell Damage in a ceRNA-Dependent Manner

How to prevent cerebral ischemia-reperfusion injury (CI/R) is critical for treating ischemic stroke. LncRNA SNHG11 can participate in several diseases by competing endogenous RNA (ceRNA), but its’ role in CI/R is unclear. Hypoxia/reoxygenation model (H/R group) cells were set and separated into control team; H/R team; H/R+SNHG11 team and H/R+si-SNHG11 team followed by analysis of LncRNA SNHG11 by real-time PCR, LncRNA SNHG11 subcellular distribution by FISH assay, MTT assay for cell proliferation, flow cytometry for apoptosis, ROS and LDH content and PTEN expression by Western blot. In H/R group, SNHG11 level significantly increased and cell proliferation significantly decreased, along with increased cell apoptosis, ROS activity, LDH content and PTEN expression in comparison of control group (P-value less than 0.05); The foregoing variation was promoted further by the H/R group after overexpression of SNHG11 (P-value below 0.05) and reversed after transfection of SNHG1 siRNA (P <0.05). LncRNA SNHG11 is mainly localized on the cell membrane. miR-16 is a SNHG11 targeted miRNA. Transfection of miR-16 mimics into PC12 cells in H/R group can significantly promote cell proliferation, inhibit apoptosis, reduce ROS activity, LDH content and PTEN expression versus the H/R group (P-value less than 0.05). SNHG11 level in H/R condition is increased and might target miR-16 to regulate PTEN expression and oxidative stress, leading to apoptosis and damage.

Exosomes containing miR-122-5p secreted by LPS-induced neutrophils regulate the apoptosis and permeability of brain microvascular endothelial cells by targeting OCLN

OBJECTIVE

To explore the effect of exosomes containing miR-122-5p secreted by lipopolysaccharide (LPS)-induced neutrophils on the apoptosis and permeability of brain microvascular endothelial cells (BMECs).

METHODS

Neutrophils in blood were isolated, purified and identified. LPS-induced neutrophils were co-cultured with BMECs. Untreated or LPS-induced neutrophil exosomes were isolated and identified with a transmission electron microscope. miR-122-5p expressions in the exosomes were detected by real-time quantitative polymerase chain reaction, and then the exosomes were co-cultured with BMECs. Bioinformatics analysis was performed to predict the downstream target gene of miR-122-5p, and OCLN was selected as the subject. Dual luciferase reporter assay was carried out to verify the interactive relationship between OCLN and miR-122-5p. LPS and miR-122-5p were used to treat neutrophils, and then exosomes were collected. Exosome or OCLN was embedded in BMECs. The proliferation, colony forming ability and apoptosis of BMECs were detected by cholecystokinin octopeptide, clone formation assay and flow cytometry, respectively. Corresponding kits were used to detect the activities of reactive oxygen species, superoxide dismutase, malondialdehyde and catalase. Vascular endothelial growth factor and tight junction proteins (ZO-1 and Claudin-5) expressions were measured by Western blot for cell permeability evaluation.

RESULTS

miR-122-5p had an increased expression in LPS-induced neutrophil exosomes and could promote oxidative stress, apoptosis and permeability increase of BMECs and the inhibition of BMECs proliferation and colony formation (P<0.05). miR-122-5p targeted the binding with OCLN and down-regulated OCLN expression. OCLN overexpression partly decreased the malignant effect of miR-122-5p on BMECs (P<0.05).

CONCLUSION

LPS can induce neutrophils to secrete exosomes containing miR-122-5p. The down-regulation of OLCN expression can aggravate BMECs injury.