Down-Regulation of Long Non-Coding RNA AK139328 Reduces Cell Inflammation and Apoptosis in Cerebral Ischemia Reperfusion Injury

Cerebral ischemia-reperfusion injury (CIRI) refers to the phenomenon that the ischemic injury of brain leads to the injury of brain cells, and ischemic injury is further aggravated after the recovery of blood reperfusion. In this study, we first constructed Oxygen and glucose deprivation/reoxygenation (OGD/R) injury model of PC12 cells, we found that the expression of LncRNA AK139328 in model cells was significantly increased through RT-qPCR. Subsequently, we interfered LncRNA AK139328 in model cells by plasmid transfection and found that interfering LncRNA AK139328 could significantly reduce the expression of inflammatory factors, including TNF a, IL-1β, IL-6, McP-1, and oxidative stress-related factors, including ROS, MDA, LDH, while the expressions of SOD and GSHPx were significantly increased. Flow cytometry was used to detect cell apoptosis, and apoptosisrelated proteins bcl-2, Bax, cleaved-caspase3 and cleaved PARP-1 were detected by western blot. Results show that interfering LncRNA AK139328 could reduce the apoptosis rate of OGD/R cells and the expression of Bax, cleaved caspase3 and cleaved PARP-1, while increasing the expression of bcl-2. Meanwhile, we found that after interfering LncRNA AK139328, the expressions of Nrf2, HO-1, NQO-1 and phosphorylated-P65 increased, while P65 showed no significant changes. This may be related to Nrf2/HO-1 and NF-κB signaling pathways. In a word, our study showed that interfering with LncRNA AK139328 can reduce cell inflammation and apoptosis in CIRI.

Ghrelin reduces cerebral ischemic injury in rats by reducing M1 microglia/macrophages

The purpose of this study was to investigate the effect of Ghrelin on the polarization of microglia/ macrophages after cerebral ischemia (CI) in rats. 60 wild-type SD rats were randomly divided into sham group, CI group, CI+Ghrelin group, 20 rats in each group. The modified Longa suture method was used to establish the middle cerebral artery occlusion (MCAO) model in rats. Before surgery, Ghrelin was injected subcutaneously (100μg/kg, twice a day) for 4 consecutive weeks. After modeling, neurological function scores were performed with three behavioral experiments: mNSS score, Corner test, and Rotarod test, to evaluate the recovery of neurological function after Ghrelin treatment. At the same time, the brain tissues were collected and stained with 2,3,5-triphenyltetrazolium chloride (TTC) to detect the cerebral infarct volume. RT-qPCR was used to detect the expression of TNF-α and IL-1β in the ischemic brain tissue, and the TUNEL staining was used to detect the apoptosis of brain tissue. Flow cytometry was used to detect the percentage of M1 type microglia/macrophages which were isolated by trypsin digestion of fresh cerebral cortex. Then, the Western blotting and immunofluorescence method were used to detect the phosphorylation level of AKT (P-AKT) and AKT. Compared with the CI group, the neurological function of the rats in the CI+Ghrelin group was dramatically improved, and the cerebral infarction area was dramatically reduced. At the same time, the expression of TNF-α and IL-1β in the ischemic brain tissue of rats in the CI+Ghrelin group decreased, and the apoptotic cells in the brain tissue also decreased. Compared with the CI treatment group, the activation of M1 microglia/macrophages in the cortex of the ischemic side of the infarct and the peri-infarct area in the CI+Ghrelin group was dramatically inhibited. At the same time, the ratio of P-AKT/AKT of the brain tissue in the CI+Ghrelin group was dramatically higher than that of the CI group. In the rat cerebral ischemia model, Ghrelin can promote the repair of brain damage and the recovery of neurological function after ischemia. Its mechanism may be related to activating AKT to selectively reduce M1 microglia/macrophages, reducing inflammation and cell apoptosis in brain tissue.

Minocycline improves learning and memory functions in ischemic stroke rats via reduction of cerebral ischemia-induced neuroinflammation and apoptosis

Purpose: To study the effect minocycline on learning and memory functions in ischemic stroke rats, and the underlying mechanism. Methods: 60 adult male SD rats were randomly divided into control group, ischemic brain damage (6 and 24 h MACO) groups; and 6 and 24 h minocycline groups, with 12 rats in each group. The volume of cerebral infarction, neuronal cell apoptosis, NF-κB protein expression, learning and memory ability, and the number of Iba-1+CD206-positive cells, and CD206/CD68 mRNA expressions in sham group, 6 h MACO group and 6 h minocycline group were determined and compared. Results: The number of iba-1 +CD206-positive cells, expression level of CD206 mRNA, frequency of platform crossing, and percentage of third quadrant route in 6 h minocycline group were significantly higher than the corresponding values in 6 h MACO group. However, the cerebral infarction volume, number of Nini-positive cells, and the NF- B protein expression levels were markedly reduced, relative to corresponding values in 6 h MACO rats. The number of iba-1+CD206-positive cells was significantly lower in 6 h MACO rats than in sham rats, while the expression level of CD68 mRNA was significantly higher (p < 0.05). The number of TUNEL-positive cells in 6 and 24 h minocycline groups were markedly lower than that in 6 h MACO group (p < 0.05). Conclusion: Minocycline improves learning and memory of ischemic stroke rats by relieving the neuroinflammation induced by cerebral ischemia and cell apoptosis. Thus, the compound can be further developed for management learning and memory deficits in stroke patients.

Sufentanil alleviates cerebral ischemia-reperfusion injury by inhibiting inflammation and protecting the blood-brain barrier in rats

Stroke is a brain system disease with a high fatality rate and disability rate. About 80% of strokes are ischemic strokes. Cerebral ischemia-reperfusion injury (CIRI) caused by ischemic stroke seriously affects the prognosis of stroke patients. The purpose of this study is to investigate the effect of sufentanil (SUF) on CIRI model rats. We used middle cerebral artery occlusion (MCAO) to make the CIRI model in rats and monitored region cerebral blood flow (rCBF) to ensure that blood flow was blocked and recanalized. We used ELISA and RT-PCR to detect the expression of inflammatory factors in rat serum and brain tissue. In addition, we detected the expression of metalloproteinase (MMP) 2, MMP9 and collagen IV in brain tissues and performed Evans blue (EB) assay to determine the permeability of the blood-brain barrier (BBB). Finally, we clarified the apoptosis of brain tissue through the TUNEL staining and the detection of caspase3, Bcl2 and Bax. Various concentrations of SUF, especially 5, 10 and 25 μg/kg of SUF, all alleviated the infarct size, neurological function and brain edema of MCAO rats. SUF pretreatment also effectively reduced the expression of inflammatory cytokines in MCAO rats, including interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF)-α. In addition, SUF also inhibited MMP2 and MMP9 and promoted the expression of collagen IV, indicating that SUF attenuated the destruction of the BBB. SUF also inhibited caspase3 and Bax rats and promoted Bcl2 in MCAO rats, thus inhibiting cell apoptosis. SUF pretreatment effectively improved the neurological function and cerebral infarction of MCAO rats, inhibited excessive inflammation in rats, protected the BBB, and inhibited cell apoptosis in brain tissue.

Post-Ischemic Brain Neurodegeneration in the Form of Alzheimer’s Disease Proteinopathy: Possible Therapeutic Role of Curcumin

For thousands of years, mankind has been using plant extracts or plants themselves as medicinal herbs. Currently, there is a great deal of public interest in naturally occurring medicinal substances that are virtually non-toxic, readily available, and have an impact on well-being and health. It has been noted that dietary curcumin is one of the regulators that may positively influence changes in the brain after ischemia. Curcumin is a natural polyphenolic compound with pleiotropic biological properties. The observed death of pyramidal neurons in the CA1 region of the hippocampus and its atrophy are considered to be typical changes for post-ischemic brain neurodegeneration and for Alzheimer’s disease. Additionally, it has been shown that one of the potential mechanisms of severe neuronal death is the accumulation of neurotoxic amyloid and dysfunctional tau protein after cerebral ischemia. Post-ischemic studies of human and animal brains have shown the presence of amyloid plaques and neurofibrillary tangles. The significant therapeutic feature of curcumin is that it can affect the aging-related cellular proteins, i.e., amyloid and tau protein, preventing their aggregation and insolubility after ischemia. Curcumin also decreases the neurotoxicity of amyloid and tau protein by affecting their structure. Studies in animal models of cerebral ischemia have shown that curcumin reduces infarct volume, brain edema, blood-brain barrier permeability, apoptosis, neuroinflammation, glutamate neurotoxicity, inhibits autophagy and oxidative stress, and improves neurological and behavioral deficits. The available data suggest that curcumin may be a new therapeutic substance in both regenerative medicine and the treatment of neurodegenerative disorders such as post-ischemic neurodegeneration.

Heterogeneity of the Relative Benefits of TICI 2c/3 over TICI 2b50/2b67

Purpose Incomplete reperfusion after mechanical thrombectomy (MT) is associated with a poor outcome. Rescue therapy would potentially benefit some patients with an expanded treatment in cerebral ischemia score (eTICI) 2b50/2b67 reperfusion but also harbors increased risks. The relative benefits of eTICI 2c/3 over eTICI 2b50/67 in clinically important subpopulations were analyzed. Methods Retrospective analysis of our institutional database for all patients with occlusion of the intracranial internal carotid artery (ICA) or the M1/M2 segment undergoing MT and final reperfusion of ≥eTICI 2b50 (903 patients). The heterogeneity in subgroups of different time metrics, age, National Institutes of Health Stroke Scale (NIHSS), number of retrieval attempts, Alberta Stroke Programme Early CT Score (ASPECTS) and site of occlusion using interaction terms (pi) was analyzed. Results The presence of eTICI 2c/3 was associated with better outcomes in most subgroups. Time metrics showed no interaction of eTICI 2c/3 over eTICI 2b50/2b67 and clinical outcomes (onset to reperfusion pi = 0.77, puncture to reperfusion pi = 0.65, onset to puncture pi = 0.63). An eTICI 2c/3 had less consistent association with mRS ≤2 in older patients (>82 years, pi = 0.038) and patients with either lower NIHSS (≤9) or very high NIHSS (>19, pi = 0.01). Regarding occlusion sites, the beneficial effect of eTICI 2c/3 was absent for occlusions in the M2 segments (aOR 0.73, 95% confidence interval [CI] 0.33–1.59, pi = 0.018). Conclusion Beneficial effect of eTICI 2c/3 over eTICI 2b50/2b67 only decreased in older patients, M2-occlusions and patients with either low or very high NIHSS. Improving eTICI 2b50/2b67 to eTICI 2c/3 in those subgroups may be more often futile.