Near infrared light fluorescence imaging-guided biomimetic nanoparticles of extracellular vesicles deliver indocyanine green and paclitaxel for hyperthermia combined with chemotherapy against glioma.

BACKGROUND: We investigated the therapeutic effect of targeting extracellular vesicles (EVs) loaded with indocyanine green (ICG) and paclitaxel (PTX) on glioma. METHODS: Raw264.7 cells were harvested to extract EVs for the preparation of ICG/PTX@RGE-EV by electroporation and click chemistry. We evaluated the success of modifying Neuropilin-1 targeting peptide (RGE) on the EV membrane of ICG/PTX@RGE-EV using super-resolution fluorescence microscopy and flow cytometry. Spectrophotometry and high performance liquid chromatography (HPLC) were implemented for qualitative and quantitative analysis of the ICG and PTX loaded in EVs. Photothermal properties of the vesicles were evaluated by exposing to 808-nm laser light. Western blot analysis, cell counting kit 8 (CCK-8), Calcein Acetoxymethyl Ester/propidium iodide (Calcein-AM/PI) staining, and flow cytometry were utilized for assessing effects of vesicle treatment on cellular behaviors. A nude mouse model bearing glioma was established to test the targeting ability and anti-tumor action of ICG/PTX@RGE-EV in vivo. RESULTS: Under exposure to 808-nm laser light, ICG/PTX@RGE-EV showed good photothermal properties and promotion of PTX release from EVs. ICG/PTX@RGE-EV effectively targeted U251 cells, with activation of the Caspase-3 pathway and elevated apoptosis in U251 cells through chemotherapy combined with hyperthermia. The anti-tumor function of ICG/PTX@RGE-EV was confirmed in the glioma mice via increased accumulation of PTX in the ICG/PTX@RGE-EV group and an increased median survival of 48 days in the ICG/PTX@RGE-EV group as compared to 25 days in the PBS group. CONCLUSION: ICG/PTX@RGE-EV might actively target glioma to repress tumor growth by accelerating glioma cell apoptosis through combined chemotherapy-hyperthermia.

Postconditioning with sevoflurane protects against focal cerebral ischemia and reperfusion injury involving mitochondrial ATP-dependent potassium channel and mitochondrial permeability transition pore.

OBJECTIVES: Postconditioning with sevoflurane has been shown to protect against focal cerebral ischemia and reperfusion injury. However, the mechanism remains elusive. In this study, we tested the hypothesis that mitochondrial ATP-sensitive potassium (mitoKATP) and mitochondrial permeability transition pore (mPTP) play roles in the neuroprotection of postconditioning with sevoflurane. METHODS: Adult male Sprague-Dawley rats were subjected to MCAO for 90 minutes and then treated with sevoflurane at the beginning of reperfusion. The infarct volume, neurological deficit score, and brain edema were evaluated at 24 hours. Apoptosis were studied by TUNEL. The neuroprotective effect with or without 5-hydroxydecanoate (5-HD), a selective mitoKATP channel blocker or atractyloside (ATR), and an mPTP opener were analyzed. RESULTS: Postconditioning with sevoflurane significantly decreased neurological deficit scores, infarct volume, and brain edema and also reduced apoptotic cells. 5-HD and ATR abolished the neuroprotective effect, respectively. 5-HD or ATR alone had no effect on ischemia and reperfusion injury. DISCUSSION: Our data suggest that mitoKATP and mPTP play crucial roles in the neuroprotection of postconditioning with sevoflurane.

Postconditioning with sevoflurane protects against focal cerebral ischemia and reperfusion injury via PI3K/Akt pathway.

Emerging evidence has demonstrated that postconditioning with sevoflurane provided neuroprotection. In this study, we investigated the neuroprotective effect of different concentrations of sevoflurane in rats with middle cerebral artery occlusion (MCAO). Furthermore, we tested the hypothesis that the neuroprotective effect of postconditioning with sevoflurane is associated with inhibition of apoptosis and mediated by activation of the phosphoinositide-3-kinase/Akt (PI3K/Akt) pathway. Adult male Sprague-Dawley rats were subjected to MCAO for 90 min and then treated with sevoflurane at the beginning of reperfusion. The infarct volume, neurological deficit scores and brain edema were evaluated at 24 hours. Spatial learning and memory was examined by Morris water maze. Apoptosis and apoptosis-related proteins were studied by TUNEL, immunohistochemistry and western blot. The neuroprotective effect and the amount of p-Akt after sevoflurane administration with or without wortmannin were analyzed. Postconditioning with sevoflurane 1.0 minimum alveolar concentration (MAC) and 1.5 MAC significantly decreased neurological deficit scores, infarct volume and brain edema and markedly improved spatial learning and memory. Postconditioning also reduced apoptotic cells, upregulated Bcl-2 and downregulated P53 and Bax. Wortmannin abolished the neuroprotective effect and prevented the increasing of p-Akt. Our data suggest postconditioning with sevoflurane (1.0 MAC and 1.5 MAC) not only reduced infarct volume but also improved learning and memory. Our study further showed that this neuroprotective effect may be partly due to the activation of PI3K/Akt pathway and inhibiting neuronal apoptosis.

Sevoflurane postconditioning reduces myocardial reperfusion injury in rat isolated hearts via activation of PI3K/Akt signaling and modulation of Bcl-2 family proteins.

Sevoflurane postconditioning reduces myocardial infarct size. The objective of this study was to examine the role of the phosphatidylinositol-3-kinase (PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro- and antiapoptotic proteins in sevoflurane postconditioning. Isolated and perfused rat hearts were prepared first, and then randomly assigned to the following groups: Sham-operation (Sham), ischemia/reperfusion (Con), sevoflurane postconditioning (SPC), Sham plus 100 nmol/L wortmannin (Sham+Wort), Con+Wort, SPC+Wort, and Con+dimethylsulphoxide (DMSO). Sevoflurane postconditioning was induced by administration of sevoflurane (2.5%, v/v) for 10 min from the onset of reperfusion. Left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximum increase in rate of LVDP (+dP/dt), maximum decrease in rate of LVDP (-dP/dt), heart rate (HR), and coronary flow (CF) were measured at baseline, R30 min (30 min of reperfusion), R60 min, R90 min, and R120 min. Creatine kinase (CK) and lactate dehydrogenase (LDH) were measured after 5 min and 10 min reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion. Total Akt and phosphorylated Akt (phospho-Akt), Bax, Bcl-2, Bad, and phospho-Bad were determined by Western blot analysis. Analysis of variance (ANOVA) and Student-Newman-Keuls' test were used to investigate the significance of differences between groups. The LVDP, + or - dP/dt, and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion (P<0.05). The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9 + or - 8)% vs. (42.4 + or - 9.4)%, respectively; P<0.05]. The SPC group also had increased the expression of phospho-Akt, Bcl-2, and phospho-Bad, and decreased the expression of Bax. Wortmannin abolished the cardioprotection of sevoflurane postconditioning. Sevoflurane postconditioning may protect the isolated rat heart. Activation of PI3K and modulation of the expression of pro- and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.

Effects of sevoflurane preconditioning and postconditioning on rat myocardial stunning in ischemic reperfusion injury.

Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevoflurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period (20 min), the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout for 5 min before ischemia. Hearts in the sevoflurane postconditioning group underwent equilibration and ischemia, followed immediately by sevoflurane exposure for the first 5 min of reperfusion. The control group received no treatment before and after ischemia. Left ventricular pressure, heart rate, coronary flow, electrocardiogram, and tissue histology were measured as variables of ventricular function and cellular injury, respectively. There was no significant difference in the duration of reperfusion ventricular arrhythmias between control and sevoflurane preconditioning group (P=0.195). The duration of reperfusion ventricular arrhythmias in the sevoflurane postconditioning group was significantly shorter than that in the other two groups (P<0.05). +/-(dP/dt)(max) in the sevoflurane preconditioning group at 5, 10, 15, 20, and 30 min after reperfusion was significantly higher than that in the control group (P<0.05), and there were no significant differences at 40 min after reperfusion among the three groups (P>0.05). As expected, for a 20-min general ischemia, infarct size in heart slices determined by 2,3,5-triphenyltetrazolium chloride staining among the groups was not obvious. Sevoflurane postconditioning reduces reperfusion arrhythmias without affecting the severity of myocardial stunning. In contrast, sevoflurane preconditioning has no beneficial effects on reperfusion arrhythmias, but it is in favor of improving ventricular function and recovering myocardial stunning. Sevoflurane preconditioning and postconditioning may be useful for correcting the stunned myocardium.

Cytological screening and 15 years' follow-up (1986-2001) for early esophageal squamous cell carcinoma and precancerous lesions in a high-risk population in Anyang County, Henan Province, Northern China.

BACKGROUND: Anyang County and nearby Linzhou (formerly Linxian) in Henan, Northern China have been well recognized as the highest incidence area for esophageal squamous cell carcinoma (SCC) in the world. SCC remains the leading cause of cancer-related death in these areas and the natural history for esophageal precancerous lesions is not clear. METHODS: In the present study, to determine the significance of cytological examination and natural history for SCC, esophageal balloon cytological screening and follow-up studies have been performed 2273 symptom-free subjects in Anyang County since 1986. Based on cellular morphological changes, esophageal epithelial cells were classified as normal (NOR), inflammation (IN), hyperplasia (HYP), dysplasia (grades I and II) (DYS I and DYS II), near squamous cell carcinoma (NSCC) and SCC. RESULTS: The prevalence of NOR, IN, HYP, DYS I, DYS II, and NSCC was 22.7, 3.6, 33.6, 21.5, 10.7, and 3.8%, respectively, in males and 25.8, 5.7, 33, 18.9, 10.4, and 3.8%, respectively in females. No difference was observed between the male and female subjects (p > 0.05). Of the 2273 subjects examined, 2199 subjects entered the final follow-up analysis (97%). During the 15 years' follow-up on these subjects, 94 new cases (4.2%, 94/2199), including 91 with SCC (97%, 91/94, 58 males and 33 females) and 3 with GCA (3%, 3/94, one male and two females) were identified with a mean time of 8 +/- 4.6 years after entry of the follow-up. The incidence for SCC in males was higher than that in females (p < 0.05). The rate for SCC development increased apparently from the groups of NOR (2.4%) to DYS I (5%), DYS II (8.3%), and NSCC (10.3%) (p < 0.001). The prevalence of DYS and NSCC increased significantly with age. CONCLUSIONS: The present results indicate that esophageal balloon cytology is a reliable approach for early SCC and precancerous lesions screening and that DYS and NSCC are important markers for high-risk subjects with predisposition to SCC. Close follow-up to the subjects with HYP, DYS and NSCC may shed light on the natural history for human esophageal carcinogenesis.

Histochemical studies on intestinal metaplasia adjacent to gastric cardia adenocarcinoma in subjects at high-incidence area in Henan, north China.

AIM: To characterize the histochemical type and pattern of intestinal metaplasia (IM) adjacent to gastric cardia adenocarcinoma (GCA) and distal gastric cancer (GC) in Linzhou, Henan Province, China. METHODS: Alcian-blue-periodic acid Schiff and high iron diamine-Alcian blue histochemical methods were performed on 142 cases of IM, including 49 cases of GCA and 93 cases of GC. All the patients were from Linzhou, Henan Province, China, the highest incidence area for both GCA and squamous cell carcinoma. Radio- or chemotherapy was not applied to these patients before surgery. RESULTS: The detection rate of IM in tissues adjacent to GCA tissues was 44.9%, which was significantly lower than that in GC tissues (80.64%, P<0.01). The rates of both incomplete small intestinal and colonic IM types identified by histochemistry in GCA tissues (31.82% and 63.64%, respectively) were significantly higher than those in GC (5.33% and 21.33%, respectively, P<0.01). CONCLUSION: IM in GCA and GC should be considered as a separate entity. Further research is needed to evaluate whether neoplastic progression of IM is related to its mucin profile in GCA.