Guohai Xu

Protective Effect of Sevoflurane Postconditioning against Cardiac Ischemia/Reperfusion Injury via Ameliorating Mitochondrial Impairment, Oxidative Stress and Rescuing Autophagic Clearance.

Background and Purpose Myocardial infarction leads to heart failure. Autophagy is excessively activated in myocardial ischemia/reperfusion (I/R) in rats. The aim of this study is to investigate whether the protection of sevoflurane postconditioning (SPC) in myocardial I/R is through restored impaired autophagic flux. Methods Except for the sham control (SHAM) group, each rat underwent 30 min occlusion of the left anterior descending coronary (LAD) followed by 2 h reperfusion. Cardiac infarction was determined by 2,3,5-triphenyltetrazolium chloride triazole (TTC) staining. Cardiac function was examined by hemodynamics and echocardiography. The activation of autophagy was evaluated by autophagosome accumulation, LC3 conversion and p62 degradation. Potential molecular mechanisms were investigated by immunoblotting, real-time PCR and immunofluorescence staining. Results SPC improved the hemodynamic parameters, cardiac dysfunction, histopathological and ultrastructural damages, and decreased myocardial infarction size after myocardial I/R injury (P < 0.05 vs. I/R group). Compared with the cases in I/R group, myocardial ATP and NAD+ content, mitochondrial function related genes and proteins, and the expressions of SOD2 and HO-1 were increased, while the expressions of ROS and Vimentin were decreased in the SPC group (P < 0.05 vs. I/R group). SPC significantly activated Akt/mTOR signaling, and inhibited the formation of Vps34/Beclin1 complex via increasing expression of Bcl2 protein (P < 0.05 vs. I/R group). SPC suppressed elevated expressions of LC3 II/I ratio, Beclin1, Atg5 and Atg7 in I/R rat, which indicated that SPC inhibited over-activation of autophagy, and promoted autophagosome clearance. Meanwhile, SPC significantly suppressed the decline of Opa1 and increases of Drp1 and Parkin induced by I/R injury (P < 0.05 vs. I/R group). Moreover, SPC maintained the contents of ATP by reducing impaired mitochondria. Conclusion SPC protects rat hearts against I/R injury via ameliorating mitochondrial impairment, oxidative stress and rescuing autophagic clearance.

Sevoflurane Postconditioning Protects Rat Hearts against Ischemia-Reperfusion Injury via the Activation of PI3K/AKT/mTOR Signaling

Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway plays a key role in myocardial ischemia-reperfusion (I/R) injury. Mammalian target of rapamycin (mTOR), a downstream target of PI3K/AKT signaling, is necessary and sufficient to protect the heart from I/R injury. Inhaled anesthetic sevoflurane is widely used in cardiac surgeries because its induction and recovery are faster and smoother than other inhaled anesthetics. Sevoflurane proved capable of inducing postconditioning effects in the myocardium. However, the underlying molecular mechanisms for sevoflurane-induced postconditioning (SPC) were largely unclear. In the present study, we demonstrated that SPC protects myocardium from I/R injury with narrowed cardiac infarct focus, increased ATP content, and decreased cardiomyocyte apoptosis, which are mainly due to the activation of PI3K/AKT/mTOR signaling and the protection of mitochondrial energy metabolism. Application of dactolisib (BEZ235), a PI3K/mTOR dual inhibitor, abolishes the up-regulation of pho-AKT, pho-GSK, pho-mTOR, and pho-p70s6k induced by SPC, hence abrogating the anti-apoptotic effect of sevoflurane and reducing SPC-mediated protection of heart from I/R injury. As such, this study proved that PI3K/AKT/mTOR pathway plays an important role in SPC induced cardiac protection against I/R injury.

NAF-1 antagonizes starvation-induced autophagy through AMPK signaling pathway in cardiomyocytes.

NAF‐1 (nutrient‐deprivation autophagy factor‐1), an autophagy‐related gene‐related (ATG) protein, has been implicated in the autophagic pro‐survival response. However, its role in autophagy has not been examined in the cardiomyocytes. In this study, we found that nutritional stress (NS) induced by glucose deprivation strongly induced autophagy in cultured neonatal rat cardiomyocytes, which was associated with NAF‐1 down‐regulation in cardiomyocytes under NS conditions. Furthermore, we demonstrate that ectopic expression of NAF‐1 was sufficient to inhibit autophagy in cardiomyocytes under glucose deprivation conditions. Moreover, results of the co‐immunoprecipitation assay indicate that NAF‐1 antagonized autophagy by promoting the interaction between Beclin1 and Bcl‐2 in NS‐induced cardiomyocytes. Importantly, our results indicate that overexpression of NAF‐1 significantly inhibited AMPK activity and protected cardiomyocytes from NS‐induced cell death. Taken together, these data show that ectopic expression of NAF‐1 antagonizes the degree of autophagy in cardiomyocytes and enhances cell survival during starvation conditions.

Posterior pericardiotomy for the prevention of atrial fibrillation after coronary artery bypass grafting: A meta-analysis of randomized controlled trials

BACKGROUND Posterior pericardiotomy (PP) has been shown to be effective in patients after cardiac surgery complicated by a reduced the incidence of atrial fibrillation (AF). However, the role of PP in patients following coronary artery bypass graft (CABG) remains ambiguous. We aimed to systematically evaluate the efficacy of PP in preventing postoperative AF in adult patients after CABG. METHODS Studies were identified by searching multiple electronic databases (PubMed, Embase, and the Cochrane Library) through February, 2016, and by reviewing reference lists of obtained articles. The outcome measure was the incidence of postoperative AF. The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity. RESULTS Ten randomized trials incorporating 1648 patients were included in this meta-analysis (822 in the PP group and 826 in the control group). The cumulative incidence of AF was 10.6% in the PP group and 24.9% in the control group. Meta-analysis with all studies using a random-effects model suggested that PP had significant effect on the prevention of postoperative AF (I(2) 55%; P<0.00001; OR, 0.36; 95% CI, 0.23-0.56; RR, 0.45; 95% CI, 0.31-0.64). Sensitivity analyses by methodological quality and surgical technique yields similar results. CONCLUSIONS This meta-analysis indicates that PP shows beneficial efficacy in preventing postoperative AF in adult patients after CABG. This finding encourages the use of PP to prevent postoperative AF after CABG, but, more high quality randomized controlled trials are still warranted to confirm the safety.

Dasatinib Treatment for Imatinib Resistant or Intolerant Patients with Chronic Myeloid Leukaemia

Chronic myeloid leukaemia (CML) is a genetically associated malignancy of haematopoietic stem cells, characterized by a t(9;22) translocation that forms the Philadelphia chromosome and creates a novel fusion gene, BCR—ABL. Treatment with molecular-targeted therapy is usually initiated with imatinib, an inhibitor of BCR—ABL tyrosine kinase. Imatinib resistance is, however, observed in some CML patients, especially in those with advanced disease. Through computerized literature searches, a systematic analysis was conducted to examine the efficacy and benefits of dasatinib therapy for imatinib resistant or intolerant CML patients in the chronic phase (CP), accelerated phase (AP) and fatal blast crisis phase (BC). In terms of major haematological and cytogenetic responses, this meta-analysis showed no significant differences in dasatinib treatment between myeloid BC-CML and lymphoid BC-CML patients with imatinib resistance or intolerance. Dasatinib therapy was, however, significantly more effective in improving major haematological and cytogenetic responses for CP-CML patients than for AP-CML patients with imatinib resistance or intolerance.

Effects of hyperbaric factors on lidocaine-induced apoptosis in spinal neurons and the role of p38 mitogen-activated protein kinase in rats with diabetic neuropathic pain

The application of lidocaine can lead to nerve damage. Evidence suggests that patients with diabetic neuropathy are at a higher risk for neurotoxicity. In the present study, the successful induction of diabetic neuropathic pain (DNP) in rats via a high-sugar, high-fat diet and intraperitoneal injection of 1% streptozotocin was verified and pronounced tactile allodynia was observed. It was found that intrathecal injections of hyperbaric lidocaine produced motor blocks of longer durations in the DNP model rats than in nondiabetic rats, or in DNP model rats injected with isobaric lidocaine. Histology of the lumbar 4–5 spinal cord revealed a significant difference in neuropathology between the DNP and nondiabetic rats. Moreover, edematous neurons and TUNEL-positive cells were observed in the hyperbaric lidocaine group. It was also found that the inhibition of p38 mitogen-activated protein kinase (p38MAPK) played a neuroprotective role in response to hyperbaric lidocaine-induced apoptosis in DNP rats, which indicates that p38MAPK plays a key role in the regulation of hyperbaric lidocaine-induced apoptosis in DNP rats. These findings suggest that hyperbaric lidocaine can promote spinal cord neuronal apoptosis in rats with DNP. Furthermore, p38MAPK might play a key role in the regulation of hyperbaric lidocaine-induced apoptosis in rats with DNP.

Effect of a Stellate Ganglion Block on Acute Lung Injury in Septic Rats

A stellate ganglion block (SGB) is a clinical sympathetic block which can inhibit the body systemic inflammatory response. However, whether and how SGB can attenuate the sepsis-induced acute lung injury remains unclear. Here, we evaluated the effect of SGB on sepsis-induced acute lung injury in rats. Ninety healthy Sprague Dawley (SD) male rats were divided into three groups: the sham operation group (S group), sepsis group (Sep group), and SGB group. The sepsis model rats were produced by cecum ligation and puncture (CLP), and blood samples were taken from the abdominal aorta of the rats at different time points for evaluating the concentration of TNF-α, IL-6, and IL-10 by enzyme-linked immunosorbent assay (ELISA). The rats were sacrificed, and lungs were collected to measure the wet/dry (W/D) lung tissue weight ratio, score the lung tissue pathological damage by microscopic examination, determine the myeloperoxidase (MPO) activity by spectrophotometry, and measure nuclear factor-kappa B (NF-κB) p65 expression by Western blot. The concentration of serum TNF-α, IL-6, and IL-10, lung tissue W/D ratio, pathological injury score, MPO activity, and expression of NF-κB p65 were higher in the Sep group compared with the S group at T1–4. Furthermore, the concentration of serum TNF-α and IL-6, lung tissue W/D ratio, pathological damage score, MPO activity, and expression of NF-κB p65 were reduced and the concentration of IL-10 was increased in the SGB group compared with the Sep group at T1–4. The successful sepsis model rats were induced by CLP, and SGB attenuated the sepsis-induced acute lung injury in rats.

Protective and therapeutic effects of Danhong injection on acute pancreatitis‑associated lung injury

Lung functional impairment caused by acute pancreatitis (AP) is the primary contributor to AP‑associated mortality. Previous studies have reported that AP‑associated lung injury is associated with systemic inflammatory response syndrome and oxidative stress. In the present study, the protective effects of Danhong injection (DHI), a widely used Chinese Traditional Medicine preparation, on AP‑associated lung injury in rats was examined. The myeloperoxidase activity, malondiadelhyde level and superoxide dismutase activity determination demonstrated the anti‑inflammatory and anti‑oxidative properties of DHI. The results of western blotting and reverse‑transcription‑semi‑quantitative polymerase chain reaction indicated that DHI could protect rats against AP‑associated lung injury, and the protective effect was associated with the suppression of nuclear factor‑κB activation and cell adhesion molecule expression, and the reduction of neutrophil infiltration and oxidative stress levels. As demonstrated by HE staining, DHI inhibited the pancreas and lung tissue injury. Therefore, DHI could be a potential candidate for the treatment of patients with AP‑associated lung injury.