Activated Drp1 regulates p62-mediated autophagic flux and aggravates inflammation in cerebral ischemia-reperfusion via the ROS-RIP1/RIP3-exosome axis.

BACKGROUND: Cerebral ischemia-reperfusion injury (CIRI) refers to a secondary brain injury that can occur when the blood supply to the ischemic brain tissue is restored. However, the mechanism underlying such injury remains elusive. METHODS: The 150 male C57 mice underwent middle cerebral artery occlusion (MCAO) for 1 h and reperfusion for 24 h, Among them, 50 MCAO mice were further treated with Mitochondrial division inhibitor 1 (Mdivi-1) and 50 MCAO mice were further treated with N-acetylcysteine (NAC). SH-SY5Y cells were cultured in a low-glucose culture medium for 4 h under hypoxic conditions and then transferred to normal conditions for 12 h. Then, cerebral blood flow, mitochondrial structure, mitochondrial DNA (mtDNA) copy number, intracellular and mitochondrial reactive oxygen species (ROS), autophagic flux, aggresome and exosome expression profiles, cardiac tissue structure, mitochondrial length and cristae density, mtDNA and ROS content, as well as the expression of Drp1-Ser616/Drp1, RIP1/RIP3, LC3 II/LC3 I, TNF-α, IL-1ß, etc., were detected under normal or Drp1 interference conditions. RESULTS: The mtDNA content, ROS levels, and Drp1-Ser616/Drp1 were elevated by 2.2, 1.7 and 2.7 times after CIRI (P < 0.05). However, the high cytoplasmic LC3 II/I ratio and increased aggregation of p62 could be reversed by 44% and 88% by Drp1 short hairpin RNA (shRNA) (P < 0.05). The low fluorescence intensity of autophagic flux and the increased phosphorylation of RIP3 induced by CIRI could be attenuated by ROS scavenger, NAC (P < 0.05). RIP1/RIP3 inhibitor Necrostatin-1 (Nec-1) restored 75% to a low LC3 II/LC3 I ratio and enhanced 2 times to a high RFP-LC3 after Drp1 activation (P < 0.05). In addition, although CIRI-induced ROS production caused no considerable accumulation of autophagosomes (P > 0.05), it increased the packaging and extracellular secretion of exosomes containing p62 by 4 - 5 times, which could be decreased by Mdivi-1, Drp1 shRNA, and Nec-1 (P < 0.05). Furthermore, TNF-α and IL-1ß increased in CIRI-derived exosomes could increase RIP3 phosphorylation in normal or oxygen-glucose deprivation/reoxygenation (OGD/R) conditions (P < 0.05). CONCLUSIONS: CIRI activated Drp1 and accelerated the p62-mediated formation of autophagosomes while inhibiting the transition of autophagosomes to autolysosomes via the RIP1/RIP3 pathway activation. Undegraded autophagosomes were secreted extracellularly in the form of exosomes, leading to inflammatory cascades that further damaged mitochondria, resulting in excessive ROS generation and the blockage of autophagosome degradation, triggering a vicious cycle.

Epidemiology and issues of NIV-treated AECOPD patients with hypercapnic respiratory failure in Shanghai: A multicentre retrospective survey.

OBJECTIVE: To investigate the epidemiology, clinical features, treatment and outcome of Noninvasive ventilation (NIV)-treated acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients in secondary hospitals of Shanghai. METHOD: Relying on Shanghai alliances for respiratory diseases, a retrospective observational study was performed in 34 secondary hospitals of Shanghai. The AECOPD patients treated with NIV and admitted to the respiratory department or respiratory intensive care unit were recruited between December 1, 2016, and November 30, 2017. RESULTS: There were 555 patients finally recruited in this study. The age was 75.8 ± 9.6 years old and 380 patients (68.5%) were male. 70.5% of all patients had respiratory acidosis (pH <7.35). 55.3% of all patients received nebulised bronchodilator and 77.7% were treated with systemic or inhaled corticosteroids during hospitalisation. 525 patients (94.6%) recovered successfully and the mortality was 3.2%. The hospitalisation was 15.3 ± 6.7 days and hospital expenses were 22 911 ± 13 595 RMB. Inadequate and nonstandard drug treatments were the most important problems during management. CONCLUSION: The NIV can be successfully used for AECOP patients in local hospitals of Shanghai, but accompanied by high costs and long hospital stays. However, the treatments for exacerbation and stable COPD patients are still insufficient.

Anesthetic management in untreated Bland-White-Garland syndrome: a case report and literature review.

Bland-White-Garland syndrome (BWGS) is a rare congenital coronary artery malformation. In adult patients with BWGS, left coronary artery is supplied by collateral vessels from dilated right coronary artery. When high-pressure coronary flow drains into the low-pressure pulmonary artery with little ventricle perfusion, it causes a "coronary steal". In this study, a 53-year-old man with untreated BWGS receiving choledochotomy under general anesthesia was presented. The patient suffered from chronic biliary calculi, atrial fibrillation, complete left bundle branch block, and chronic heart failure. The anesthetic management for choledochotomy in this patient presented a special challenge. Moreover, relevant literature search was performed for all the case reports of BWGS published in PubMed and MEDLINE from 1990 to 2018. In addition, a summary of underlying pathophysiology and anesthetic implications of patients with BWGS was provided.

Glutathione-S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and acute leukemia risk in Asians: a meta-analysis.

The association between glutathione-S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and risk of acute leukemia in Asians remains controversial. This study was therefore designed to evaluate the precise association in 23 studies identified by a search of PubMed and several other databases, up to December 2013. Using random or fixed effects models odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Heterogeneity across studies was assessed, and funnel plots were constructed to test for publication bias. The meta-analysis showed positive associations between GST polymorphisms (GSTM1 and GSTT1 but not GSTP1) and acute leukemia risk [(OR=1.47, 95% CI 1.18-1.83); (OR=1.32, 95% CI 1.07-1.62); (OR=1.01, 95% CI 0.84-1.23), respectively] and heterogeneity between the studies. The results suggested that the GSTM1 null genotype and GSTT1null genotype, but not the GSTP1 polymorphism, might be a potential risk factors for acute leukemia. Further well-designed studies are needed to confirm our findings.

Case scenario about TEE: Patient with dilated cardiomyopathy undergoing laparoscopic cholecystectomy.

A 42-year-old woman, who presented with DCM (American Society of Anesthesia, ASA class IV), suffered from gallstone for years, and was scheduled for laparoscopic cholecystectomy. Echocardiography demonstrated a severely dilated left ventricle with global hypokinesia and reduction of left ventricular systolic function, ejection fraction (EF) 34% with mild mitral regurgitation and severe tricuspid regurgitation. After intubation, a transesophageal echocardiography (TEE) probe was inserted. When the IAP was gradually ascended to 14 mmHg during the laparoscopy, EF fell to 19% and the systolic pressure fell to 78 mmHg and TEE showed severely poor wall motion. But the central venous pressure (CVP) still showed about 4 mmHg throughout the whole procedure. After decreasing the IAP to 10 mmHg, we adjusted the rate of pacemaker to 70 times per minute then the systolic pressure was kept at around 100 mmHg, and the diastolic pressure was kept at 60 mmHg. EF was 30% after the reduction of IAP and the adjusting of the heart rate set. TEE is a helpful monitor in anesthesia management of patients with DCM during noncardiac surgery and CVP is useless especially for the procedure with severe hemodynamic effects.