Glyceryl triacetate promotes blood-brain barrier recovery after ischemic stroke through lipogenesis-mediated IL-33 in mice.

BACKGROUND: Lipid metabolism has a crucial role in neural repair in neurodegenerative diseases. We recently revealed that lipogenesis-mediated interleukin-33 (IL-33) upregulation lead to blood-brain barrier (BBB) repair after ischemic stroke. However, manipulating the key enzyme fatty acid synthase (FASN) to enhance lipogenesis was very challenging. Glyceryl triacetate (GTA) was used as a donor of acetate and precursor of acetyl coenzyme A, the key substrate for de novo lipogenesis catalyzed by FASN. Therefore, we hypothesized that GTA would promote lipogenesis the peri-infarct after ischemic stroke and contribute to the BBB repair through IL-33. METHODS: Middle cerebral artery occlusion (MCAO) was performed on C57BL mice and GTA was gavage administrated (4 g/kg) on day 2 and 4 after MCAO. Lipogenesis was evaluated by assessment of the protein level of FASN, lipid droplets, and fatty acid products through liquid chromatography-mass spectrometry in the peri-infarct area on day 3 after MCAO, respectively. BBB permeability was determined by extravasation of Evans blue, IgG and dextran, and levels of tight junction proteins in the peri-infarct area on day 7 after MCAO, respectively. Infarct size and neurological defects were assessed on day 7 after MCAO. Brain atrophy on day 30 and long-term sensorimotor abilities after MCAO were analyzed as well. The inhibitor of FASN, C75 and the virus-delivered FASN shRNA were used to evaluate the role of FASN-driven lipogenesis in GTA-improved BBB repair. Finally, the therapeutic potential of recombinant IL-33 on BBB repair and neurological recovery was evaluated. RESULTS: We found that treatment with GTA increased the lipogenesis as evidenced by lipid droplets level and lauric acid content, but not the FASN protein level. Treatment with GTA increased the IL-33 level in the peri-infarct area and decreased the BBB permeability after MCAO. However, infarct size and neurological defect score were unchanged on day 7 after MCAO, while the long-term recovery of sensorimotor function and brain atrophy were improved by GTA. Inhibition of lipogenesis using C75 or FASN shRNA reversed the beneficial effect of GTA. Finally, exogenous IL-33 improved BBB repair and long-term functional recovery after stroke. CONCLUSION: Collectively, we concluded that treatment with GTA improved the BBB repair and functional recovery after ischemic stroke, probably by the enhancement of lipogenesis and IL-33 expression.

MicroRNA-137-mediated lysine demethylase 4A regulates the recovery of spinal cord injury via the SFRP4-Wnt/ß-Catenin axis.

OBJECTIVE: Spinal cord injury (SCI) causes great harm to the normal life of patients. Histone demethylase is involved in many biological processes, including SCI. Hence, this study explored the role and mechanism of histone lysine demethylase 4A (KDM4A) in SCI. METHODS: The acute SCI (ASCI) rat model was established after spinal compression and the SCI neuronal model was induced via treating PC12 cells with lipopolysaccharide (LPS). KDM4A expression during SCI was detected. The microRNA (miRNA) targeting KDM4A was predicted and verified. The miRNA and KDM4A expression patterns were intervened in LPS-stimulated PC12 cells to evaluate their combined effects on neuronal cells in SCI. The downstream pathways of KDM4A were predicted, and SFRP4 and H3K9me3 expressions were determined. After the intervention of SFRP4 in LPS-treated cells, ß-Catenin expression and the effect of SFRP4 on neuronal cells in SCI were detected. Finally, the effectiveness of the miR-137/KDM4A/SFRP4/Wnt/ß-Catenin axis was verified in vivo. RESULTS: KDM4A was abnormally elevated in SCI. miR-137 targeted KDM4A. miR-137 effectively inhibited the apoptosis of LPS-challenged PC12 cells, which could be reversed after overexpressing KDM4A. KDM4A promoted SFRP4 expression through demethylation of H3K9me3. Overexpression of SFRP4 blocked the Wnt/ß-Catenin pathway and promoted apoptosis of LPS-stimulated cells. In vivo, miR-137 overexpression remarkably improved SCI symptoms, accompanied by obviously increased ß-Catenin expression and notably decreased KDM4A and SFRP4 expressions, while overexpressed KDM4A treatment showed the opposite trend in the presence of miR-137. CONCLUSION: We demonstrated that miR-137 targeted KDM4A and then downregulated SFRP4 to ameliorate SCI in a Wnt/ß-Catenin-dependent manner.

Electric Insulating Irrigations Mitigates Esophageal Injury Caused by Button Battery Ingestion.

Objective: Accidental ingestion of button batteries (BB), usually occurred in children and infants, will rapidly erode the esophagus and result in severe complications, even death. It has been recommended that treatment of this emergent accident as soon as possible with drinking of pH-neutralizing viscous solutions such as honey and sucralfate before surgical removal can mitigate the esophageal injury. Recently, we reported that the electric insulating solutions such as edible oils could mitigate tissue damage in BB-exposed esophageal segments. In this study, we compared the protective effect of kitchen oil with honey or sucralfate, the recommended pH-neutralizing beverages, and with their mixture on esophageal injury caused by BB ingestion in pig esophageal segments and in living piglets. Methods: Effect of olive oil irrigations was compared to that of honey or sucralfate irrigations in the BB-damaged esophageal segments freshly collected from the local abattoir and in live Bama miniature piglets with the proximal esophagus exposed to BB for 60 min. Also, the effect of olive oil and honey mixture (MOH) irrigations was assessed in live animals. The BB voltage was recorded before insertion and after its removal. Gross and histological analysis of the esophageal injury was performed after BB exposure in segmented fresh esophagus and 7 days after BB exposure in live animals, respectively. Results: Olive oil irrigations demonstrated better protective effect against BB-induced esophageal damage, compared to honey or sucralfate for BB-induced esophageal damage in vitro. But in vivo study showed that olive oil alone exacerbated esophageal injury because all esophagi irrigated with olive oil perforated. Surprisingly, irrigations with the MOH showed considerable protective effect for BB-induced esophageal damage in live animals, significantly better than irrigations with honey alone. The MOH decreased BB discharge, reduced area of surface injury, attenuated injured depth of esophageal wall thickness, and downed the mucosal injury index in comparison to using honey alone. Conclusion: Irrigations with olive oil alone couldn't prevent the BB discharge and is harmful for BB ingestion before surgical removal. However, mixed with honey, olive oil very effectively prevents the BB discharging and produces better esophageal protection than honey.

De novo Lipogenesis in Astrocytes Promotes the Repair of Blood-Brain Barrier after Transient Cerebral Ischemia Through Interleukin-33.

Astrocytes experience significant metabolic shifts in the "sensitive period" of neurological function recovery following cerebral ischemia. However, the changes in astrocyte lipid metabolism and their implications for neurological recovery remain unknown. In the present study, we employed a mouse middle cerebral artery occlusion model to investigate the changes in de novo lipogenesis and interleukin-33 (IL-33) production in astrocytes and elucidate their role in blood-brain barrier (BBB) repair in the subacute phase of cerebral ischemia. Neurological behavior evaluation was used to assess functional changes in mice. Pharmacological inhibition and astrocyte-specific downregulation of fatty acid synthase (FASN) were used to evaluate the role of de novo lipogenesis in brain injury. Intracerebroventricular administration of recombinant IL-33 was performed to study the contribution of IL-33 to BBB disruption. Extravasation of Evans blue dye, dextran and IgG were used to assess BBB integrity. Western blotting of tight junction proteins ZO-1, Occludin, and Claudin-5 were performed at defined time points to evaluate changes in BBB. It was found that de novo lipogenesis was activated, and IL-33 production increased in astrocytes at the subacute stage of cerebral ischemia injury. Inhibition of lipogenesis in astrocytes decreased IL-33 production in the peri-infarct area, deteriorated BBB damage and interfered with neurological recovery. In addition, supplementation of IL-33 alleviated BBB destruction and improved neurological recovery worsened by lipogenesis inhibition. These findings indicate that astrocyte lipogenesis increases the production of IL-33 in the peri-infarct area, which promotes BBB repair in the subacute phase of cerebral ischemia injury and improves long-term functional recovery.

Adiponectin Treatment Attenuates Cerebral Ischemia-Reperfusion Injury through HIF-1α-Mediated Antioxidation in Mice.

Adiponectin (ADPN) plays an important role in cerebral ischemia-reperfusion injury. Although previous studies have confirmed that ADPN pretreatment has a protective effect on ischemic stroke, the therapeutic effect of ADPN on ischemic stroke and the underlying mechanism are still unclear. In order to clarify these questions, focal transient cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in mice and ADPN was administered for three times at 6 h, 24 h, and 48 h after reperfusion. Meanwhile, a virus-delivered HIF-1α siRNA was used before ADPN administration. The infarct volume, neurological score, cellular apoptosis, and oxidative stress were assessed at 72 h after reperfusion. The long-term outcome of mice after stroke was recorded as well. The results indicated that ADPN treatment reduced the infarct volume (P = 0.032), neurological deficits (P = 0.047), cellular apoptosis (P = 0.041), and oxidative responses (P = 0.031) at 72 h after MCAO. Moreover, ADPN increased both the protein level and transcriptional activity of HIF-1α as evidenced by the transcription levels of VEGF (P = 0.046) and EPO (P = 0.043) at 72 h after MCAO. However, knockdown of HIF-1α partially reversed the antioxidant and treatment effect of ADPN after cerebral ischemia. In the observation of long-term outcome after ADPN treatment, it demonstrated that ADPN not only prevented the cerebral atrophy (P = 0.031) and the neurological function decline (P = 0.048), but also promoted angiogenesis (P = 0.028) after stroke. In conclusion, our findings suggest that ADPN is effective in treatment of ischemic stroke which could be attributed to the increased antioxidant capacity regulated by HIF-1α.

[Regulatory T cells are involved in sevoflurane preconditioning-induced mouse brain protection against cerebral ischemia injury].

Objective To determine whether regulatory T cells (Tregs) are involved in sevoflurane preconditioning-induced brain protection against cerebral ischemia/reperfusion injury. Methods C57BL/6 mice were preconditioned with sevoflurane and then subjected to the middle cerebral artery occlusion modeling. The brain infarct volume and neurological score were assessed at 48 hours after cerebral reperfusion. Meanwhile, the proportion of Tregs in the spleen was analyzed by flow cytometry. Then, CD25 neutralizing antibody was administrated by intraperitoneal injection, following with the analysis of cerebral ischemia/reperfusion injury and the proportion of Tregs in the spleen after sevoflurane preconditioning. Results Compared with a control group, sevoflurane preconditioning markedly mitigated the cerebral ischemia/reperfusion injury in the mice including the infarct volume and neurological score. In the meantime, sevoflurane preconditioning significantly increased the proportion of Tregs in the spleen at 48 hours after cerebral reperfusion. Compared with the isotype antibody group, the CD25 neutralizing antibody reversed the increase of Tregs induced by sevoflurane preconditioning at 48 hours after reperfusion, which was also associated with the reversal of sevoflurane preconditioning-induced protectetion against cerebral ischemia/reperfusion injury. Conclusion Tregs are involved in sevoflurane preconditioning-induced cerebral protection against ischemia/reperfusion injury.

Dose determination of sufentanil for intravenous patient-controlled analgesia with background infusion in abdominal surgeries: A random study.

OBJECTIVES: Sufentanil has been widely used in epidural PCA, while its use in intravenous PCA has rarely been reported. Based on its use in target controlled infusion, we reckoned that the effect-site concentration of sufentanil would be steady if background infusion is given in intravenous PCA. This prospective, single center, randomized study with a three arm parallel group design aims to find out the appropriate dose of sufentanil when used in intravenous PCA with background infusion in abdominal surgeries. METHODS: Patients diagnosed with gastrointestinal cancer and consented to the study were recruited. The analgesia pump with one of three different doses of sufentanil (1.5, 2.0 or 2.5 µg/kg) was attached to the patient through peripheral venous line right after surgery. The primary endpoint was pain scale VAS up to 48 hours postoperatively. RESULTS: In our study 90 patients were analyzed. In group B (SF 2.0) and C (SF2.5), patients had better pain relief than in group A (SF 1.5). There was no difference between group B and C in pain intensity at rest. While in group C more patients got pain relived at activity than in group B. All three groups had low and similar incidence of adverse effects of sufentanil. CONCLUSION: The dose 2.5 µg/kg of sufentanil with background infusion is preferred because of better pain alleviation at activity without increase of adverse effects up to 48 hours after surgery.

Neuroprotective effect of Shenqi Fuzheng injection pretreatment in aged rats with cerebral ischemia/reperfusion injury.

Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral ischemia and reperfusion. Aged rats (20-22 months) were divided into three groups: sham, model, and treatment. Shenqi Fuzheng injection or saline (40 mL/kg) was injected into the tail vein daily for 1 week, after which a cerebral ischemia/reperfusion injury model was established. Compared with model rats that received saline, rats in the treatment group had smaller infarct volumes, lower brain water and malondialdehyde content, lower brain Ca(2+) levels, lower activities of serum lactate dehydrogenase and creatine kinase, and higher superoxide dismutase activity. In addition, the treatment group showed less damage to the brain tissue ultrastructure and better neurological function. Our findings indicate that Shenqi Fuzheng injection exerts neuroprotective effects in aged rats with cerebral ischemia/reperfusion injury, and that the underlying mechanism relies on oxygen free radical scavenging and inhibition of brain Ca(2+) accumulation.

Resveratrol attenuates the blood-brain barrier dysfunction by regulation of the MMP-9/TIMP-1 balance after cerebral ischemia reperfusion in rats.

The collapse of the blood-brain barrier (BBB) is one of the fundamental pathophysiology changes during cerebral ischemia reperfusion injury. Resveratrol has been recently reported to reduce cerebral ischemic damage by regulating the matrix metalloproteinase-9 (MMP-9). But, more direct evidence for the explanation of the BBB protected by resveratrol against cerebral ischemia reperfusion is still lacking. Therefore, the present study was aimed to investigate the regulation of BBB integrity by resveratrol after cerebral ischemia reperfusion and to determine the role of the MMP-9 and its endogenous inhibitor TIMP-1 balance in this process. Cerebral ischemia was induced by middle cerebral artery occlusion in rats. The BBB function was evaluated by brain water content and the Evans blue dye extravasation; the activities of MMP-9 and TIMP-1 were detected by using gelatin zymography analysis, and cellular apoptosis was examined by TUNEL staining. We confirmed that resveratrol reduced the cerebral ischemia reperfusion damage, brain edema, and Evans blue dye extravasation. Moreover, we found that resveratrol improved the balance of MMP-9/TIMP-1 in terms of their expressions and activities. A TIMP-1 neutralizing antibody reversed those neuroprotective effects of resveratrol. In conclusion, resveratrol attenuated the cerebral ischemia by maintaining the integrity of BBB via regulation of MMP-9 and TIMP-1.