Dataset Information

Protective effects of dexmedetomidine on cerebral ischemia/reperfusion injury via the microRNA-214/ROCK1/NF-κB axis.

ABSTRACT:

Background

Cerebral ischemia/reperfusion injury (CIRI) is a complication of surgical procedure associated with high mortality. The protective effect of dexmedetomidine (DEX) on CIRI has been explored in previous works, yet the underlying molecular mechanism remains unclear. Our study explored the protective effect of DEX and its regulatory mechanism on CIRI.

Methods

A CIRI rat model was established using middle cerebral artery occlusion (MCAO). Neurological deficit scores for rats received MCAO modeling or DEX treatment were measured. Cerebral infarction area of rats was detected by TTC staining, while damage of neurons in hippocampal regions of rats was determined by hematoxylin-eosin (HE) staining. Apoptosis rate of neurons in hippocampal regions was examined by TUNEL staining. The dual-luciferase assay was performed to detect the binding of microRNA-214 (miR-214) to Rho-associated kinase 1 (ROCK1).

Results

DEX treatment significantly reduced infarction area of MCAO rats and elevated miR-214 expression. Injection of miR-214 inhibitor attenuated the effect of DEX in MCAO rats by increasing the area of cerebral infarction in rats and apoptosis rate of hippocampal neurons. ROCK1 was targeted and negatively regulated by miR-214. The overexpression of ROCK1 led to activation of NF-κB to aggravate CIRI.

Conclusion

Therapeutic effects of DEX on CIRI was elicited by overexpressing miR-214 and impairing ROCK1 expression and NF-κB activation. Our finding might provide novel insights into the molecular mechanism of DEX in rats with CIRI.

SUBMITTER: Liu W

PROVIDER: S-EPMC8365892 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundReperfusion of ischemic tissue has adverse impact on the myocardium. Dexmedetomidine (Dex) is a α2-adrenergic receptor (α2-AR) agonist with sedative and analgesic effects. Macrophage migration inhibition factor (MIF) is a pressure-regulating cytokine and is responsible for inflammatory and immune diseases. This study aims to reveal the consequences of Dex on myocardial ischemia-reperfusion injury (IRI) in young mice.MethodsFifty mice were raised and examined. At the end of the experiment, all mice were euthanized. The anterior descending department of the left coronary artery in mice was under ischemia for 60 min, then the ligation line was released and reperfused for 120 min to establish the IRI model. Mice were randomly divided into Sham, control, treatment using 4,5-dihydro-3-(4-hydroxyphenyl)-5-isoxazoleacetic acid (ISO-1), Dex treatment, and Dex combined ISO-1 treatment groups. Interleukin (IL)-6, IL-10 and tumor necrosis factor (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) and ATP levels were recorded. The expressions of MIF, P-adenosine monophosphate-activated kinase α (AMPKα), glucose transporter (GLUT)4, Bax and Bcl-2 were detected by Western Blot (WB). Hematoxylin and Eosin (H&E) staining was used to study cell morphology. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Echocardiography was carried out at the end of reperfusion, and the infarct size was calculated by Electron microscopy.ResultsI/R + Dex group showed significantly increased IL-6 and TNF-α levels and reduced myocardial cell necrosis and apoptosis. H&E staining showed alleviated myocardial disorder, myocardial cell swelling, myocardial fiber fracture, and inflammatory cell infiltration in I/R + Dex group. Myocardial cell necrosis and apoptosis were significantly reduced in I/R + Dex group. ATP level in myocardial tissue of mice in I/R group was substantially decreased, while that in Dex group was increased. WB results showed that MIF, P-AMPK α, GLUT4 and Bcl-2 levels were increased and Bax levels were decreased in I/R + Dex group.ConclusionDex may exert myocardial protection in young mice through MIF/AMPK/GLUT4 axis.

Project description:Ischemic stroke is one of the most common causes of mortality worldwide and is a primary cause of disability and mortality in adults. There is an unmet need for drugs that can effectively treat ischemic stroke. Hence, the present study explored the neuroprotective effects of andrographolide (Andro) in a mouse model of bilateral common carotid artery occlusion, and systematically evaluated the potential mechanisms underlying its effects. The effects of Andro on mouse brain tissue following cerebral ischemia‑reperfusion injury (CIRI) were evaluated by histopathological (H&E and Nissl) and immunofluorescence [glial fibrillary acidic protein (GFAP) and neuronal nuclei (NeuN)] staining. A traditional Chinese medicine‑based network pharmacology method was performed to establish and analyze compound‑target‑disease and function‑pathway networks in order to elucidate the possible mechanisms responsible for the protective role of Andrographis paniculata in CIRI. In addition, western blot analysis and RT‑qPCR was performed to evaluate the expression and activation of signaling proteins predicted to be involved in this mechanism. The amelioration of histopathological alterations was observed in mice pre‑treated with Andro. Immunofluorescence staining revealed that Andro decreased the expression of GFAP and increased the expression of NeuN, and significantly decreased the levels of pro‑inflammatory cytokines (IL‑1β, IL‑6 and TNF‑α). Network pharmacology analysis revealed that neuroinflammatory response and apoptosis were associated with the effects of Andrographis paniculata on CIRI. Western blot analysis revealed that the mice pre‑treated with Andro exhibited an upregulated protein expression of tropomyosin receptor kinase B (TrkB), p‑PI3K and p‑Akt, as well as a decrease in the expression of GFAP and an increase in the expression of NeuN. In addition, the data of RT‑qPCR indicated that the mice pre‑treated with Andro exhibited a significantly decreased expression of encoding IL‑1β mRNA, IL‑6 mRNA and TNF‑α mRNA in the brain compared to the untreated mice following CIRI. On the whole, the findings of the present study suggest that pre‑treatment with Andro exerts a protective effect against CIRI, which may be partly related to its potential to reduce neuroinflammatory response and apoptosis in patients with stroke.

Project description:Ischemic stroke is a clinically common cerebrovascular disease whose main risks include necrosis, apoptosis and cerebral infarction, all caused by cerebral ischemia and reperfusion (I/R) injury. This process has particular significance for the treatment of stroke patients. Notoginseng leaf triterpenes (PNGL), as a valuable medicine, have been discovered to have neuroprotective effects. However, it was not confirmed that whether PNGL may possess neuroprotective effects against cerebral I/R injury. To explore the neuroprotective effects of PNGL and their underlying mechanisms, a middle cerebral artery occlusion/reperfusion (MCAO/R) model was established. In vivo results suggested that in MCAO/R model rats, PNGL pretreatment (73.0, 146, 292 mg/kg) remarkably decreased infarct volume, reduced brain water content, and improved neurological functions; moreover, PNGL (73.0, 146, 292 mg/kg) significantly alleviated blood-brain barrier (BBB) disruption and inhibited neuronal apoptosis and neuronal loss caused by cerebral I/R injury, while PNGL with a different concertation (146, 292 mg/kg) significantly reduced the concentrations of IL-6, TNF-α, IL-1 β, and HMGB1 in serums in a dose-dependent way, which indicated that inflammation inhibition could be involved in the neuroprotective effects of PNGL. The immunofluorescence and western blot analysis showed PNGL decreased HMGB1 expression, suppressed the HMGB1-triggered inflammation, and inhibited microglia activation (IBA1) in hippocampus and cortex, thus dose-dependently downregulating inflammatory cytokines including VCAM-1, MMP-9, MMP-2, and ICAM-1 concentrations in ischemic brains. Interestingly, PNGL administration (146 mg/kg) significantly downregulated the levels of p-P44/42, p-JNK1/2 and p-P38 MAPK, and also inhibited expressions of the total NF-κB and phosphorylated NF-κB in ischemic brains, which was the downstream pathway triggered by HMGB1. All of these results indicated that the protective effects of PNGL against cerebral I/R injury could be associated with inhibiting HMGB1-triggered inflammation, suppressing the activation of MAPKs and NF-κB, and thus improved cerebral I/R-induced neuropathological changes. This study may offer insight into discovering new active compounds for the treatment of ischemic stroke.