Regulatory mechanism of the SNHG3/miR-302a-3p/E2F1 feedback loop in nerve repair post cerebral ischemic stroke

Objective: Cerebral ischemic stroke (CIS) remains a primary cause of death worldwide. The current knowledge has identified the implication of microRNAs (miRNAs) in the pathophysiology of CIS. This study investigated the mechanism of miR-302a-3p in nerve repair post-CIS. Methods: A middle cerebral artery occlusion (MCAO) model was established in mice to simulate CIS. miR-302a-3p expression in brain tissues of MCAO mice was up-regulated by injecting agomiR-302a-3p. The neurological deficit of MCAO mice was evaluated through neurological function score, forelimb placing test, and balance beam walking test. Neuronal damage was measured using Nissl staining. The concentrations of nerve injury-related factors (S100B and GFAP) and the contents of neuroinflammatory factors (TNF-α and IL-1β) in serum were examined using ELISA kits. miR-302a-3p, E2F1, and long non-coding RNA (lncRNA) SNHG3 expressions in brain tissues of MCAO mice were determined using RT-qPCR and Western blot. The binding relationships between miR-302a-3p and E2F1 and E2F1 and SNHG3 were validated using dual-luciferase and ChIP assays, respectively. Results: miR-302a-3p expression was reduced in brain tissues of MCAO mice. miR-302a-3p overexpression increased the number of neurons, decreased the concentrations of S100B and GFAP, reduced the contents of TNF-α and IL-1β, promoted nerve repair, and alleviated CIS-induced brain injury. miR-302a-3p targeted E2F1 expression, and E2F1 activated SNHG3 transcription. E2F1 overexpression or SNHG3 overexpression reversed the effect of miR-302a-3p overexpression on nerve repair in MCAO mice. Conclusion: miR-302a-3p overexpression repressed SNHG3 transcription by targeting E2F1 expression, thereby promoting nerve repair and alleviating CIS.

MiR-16 exacerbates neuronal cell growth and inhibits cell apoptosis by targeting AKT3 in cerebral ischemia injury

Purpose: To evaluate the role of miR-16 in ischemic neuronal injury.Methods: An oxygen-glucose deprivation (OGD) model of ischemic neuronal injury was established in human brain cortical neuron HCN-2 cell line via hypoxic treatment. The mRNA or protein expressions of miR-16, AKT3, Bax and Bcl-2 were assessed by quantitative real time-polymerase chain reaction (qRTPCR) or western blot assay. Targetscan online software was applied to predict potential targets of miR-16. Cell proliferation was measured by CCK-8 assay while the relationship between miR-16 and AKT3 was determined by Luciferase reporter assay.Results: MiR-16 was overexpressed after OGD treatment. MiR-16 overexpression significantly promoted the proliferation of cortical neurons and inhibited their apoptosis, while miR-16 inhibition produced an opposite effect. The expression of AKT3 was increased after miR-16 inhibition, but it was decreased when miR-16 was overexpressed. In addition, luciferase reporter gene results showed that miR-16 targeted AKT3. Functional experiments showed that AKT3 overexpression reversed the effect of miR-16 overexpression on ischemic injury.Conclusion: MiR-16 regulates neuronal cell growth and cell apoptosis through AKT3 expression.These results present new potential therapeutic targets for the treatment of cerebral ischemic stroke.

Bioactive Flavonoids Icaritin and Icariin Protect against Cerebral Ischemia–Reperfusion-Associated Apoptosis and Extracellular Matrix Accumulation in an Ischemic Stroke Mouse Model

Stroke, which is the second leading cause of mortality in the world, is urgently needed to explore the medical strategies for ischemic stroke treatment. Both icariin (ICA) and icaritin (ICT) are the major active flavonoids extracted from Herba epimedii that have been regarded as the neuroprotective agents in disease models. In this study, we aimed to investigate and compare the neuroprotective effects of ICA and ICT in a middle cerebral artery occlusion (MCAO) mouse model. Male ICR mice were pretreated with both ICA and ICT, which ameliorated body weight loss, neurological injury, infarct volume, and pathological change in acute ischemic stroke mice. Furthermore, administration of both ICA and ICT could also protect against neuronal cell apoptotic death, oxidative and nitrosative stress, lipid peroxidation, and extracellular matrix (ECM) accumulation in the brains. The neuroprotective effects of ICT are slightly better than that of ICA in acute cerebral ischemic stroke mice. These results suggest that pretreatment with both ICA and ICT improves the neuronal cell apoptosis and responses of oxidative/nitrosative stress and counteracts the ECM accumulation in the brains of acute cerebral ischemic stroke mice. Both ICA and ICT treatment may serve as a useful therapeutic strategy for acute ischemic stroke.

A stepwise-targeting strategy for the treatment of cerebral ischemic stroke

Background Effective amelioration of neuronal damages in the case of cerebral ischemic stroke (CIS) is essential for the protection of brain tissues and their functional recovery. However, most drugs can not penetrate the blood–brain barrier (BBB), resulting in the poor therapeutic outcomes. Results In this study, the derivatization and dual targeted delivery technologies were used to actively transport antioxidant melatonin (MLT) into the mitochondria of oxidative stress-damaged cells in brain tissues. A mitochondrial targeting molecule triphenylphosphine (TPP) was conjugated to melatonin (TPP-MLT) to increase the distribution of melatonin in intracellular mitochondria with the push of mitochondrial transmembrane potential. Then, TPP-MLT was encapsulated in dual targeted micelles mediated by TGN peptide (TGNYKALHPHNG) with high affinity for BBB and SHp peptide (CLEVSRKNG) for the glutamate receptor of oxidative stress-damaged neural cells.TGN/SHp/TPP-MLT micelles could effectively scavenge the overproduced ROS to protect neuronal cells from oxidative stress injury during CIS occurrence, as reflected by the improved infarct volume and neurological deficit in CIS model animals. Conclusions These promising results showed this stepwise-targeting drug-loaded micelles potentially represent a significant advancement in the precise treatment of CIS. Graphical Abstract

The Neuroprotective Effect of l-Borneolum on Cerebral Ischemic Stroke by Regulating Dll4/Notch1 Pathway

Aiml-Borneolum is a monoterpene compound witch deserved from Blumea balsamifera (L.) DC, this study aimed to investigate the potential mechanism of l-borneolum on cerebral ischemic stroke (CIS) rats and provide evidence for the development of l-borneolum in CIS.MethodsPermanent middle cerebral artery occlusion (pMCAO) model rats were applied to this study. Neurological function was assessed by modified neurological severity scores (mNSS) and Longa neurological function scoring methods. The pathological changes of cerebral tissue were evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (HE) staining. Ultrastructure of blood brain barrier (BBB) was observed by transmission electron microscopy. Additionally, the expression of Notch1, Dll4, Hey1, Hes1, Hes5, VEGFA and p65 in the cortex were determined by Western blotting (WB) while expression of caspase 3 were determined by immunohistochemical method (IHC). Resultsl-Borneolum improved neurological function in a dose-dependently. l-Borneolum significantly alleviated brainstem edema and inflammation, as well as improved the ultrastructure of capillary and BBB in cortex. Moreover, 0.2 g/kg l-borneolum substantially decreased the protein expressions of Dll4, Notch1, Hes1, Hes5, and VEGFA in the cortex while decreased the level of Caspase-3 in the cortex of rats. Conclusionsl-Borneolum could repair neurological function by regulating Dll4/Notch1 signaling pathway.

Influence of complex physical rehabilitation on the dynamics of recovery of cognitive functions in patients who have been cerebral ischemic stroke

The article presents the results of a study of the effect of a complex physical rehabilitation on the dynamics of restoration of cognitive impairments in patients in the early recovery period of the cerebral ischemic stroke. The study included 83 patients. All patients under study were distributed to the main group and the comparison group. The average age of the patients was 66,0 ± 2,3 years. Patients of two groups received standard drug therapy aimed at secondary prophylaxis. The patients under study from the main group additionally undertook a course of physical rehabilitation treatment within 21 days. Assessment of the condition of cognitive functions was carried out with the help of psychodiagnostic scales before the onset and after completion of treatment. The study showed that the use of a complex rehabilitation treatment, which includes drug therapy within the framework of secondary prophylaxis and course of physical rehabilitation can significantly affect the improvement of the state of moderately impaired cognitive functions in patients with a hemispheric ischemic stroke.