Propofol protects PC12 cells from cobalt chloride-induced injury by mediating miR-134.

OBJECTIVE: Propofol (PRO) was reported to exert a neuroprotective effect by decreasing microRNA-134 (miR-134), a brain-specific miRNA, thus, the role of PRO against cobalt chloride (CoCl2)-induced injury in rat pheochromocytoma cells (PC12) via mediating miR-134 was explored. METHODS: CoCl2-induced PC12 cells treated with PRO were transfected with or without miR-134 negative control (NC)/ inhibitor/mimic, and the following detections were then performed using cell counting kit-8 (CCK-8), Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) and Hoechst 33258 staining. Autophagy was observed by transmission electron microscope (TEM). Mitochondrial membrane potential (MMP) was detected by Rhodamine-123 (Rh123) staining, and reactive oxygen species (ROS) by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining. Protein and gene expressions were measured by Western blotting and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), respectively. RESULTS: PRO reversed the CoCl2-induced decrease in the PC12 cell viability and increased miR-134 in a dose-dependent manner. CoCl2 increased LC3II/I ratio and Beclin-1 expression, but decreased p62 expression, which was abolished by PRO. In addition, an increased cell apoptosis rates triggered by CoCl2 were reduced by PRO with the down-regulations of Bax and Caspase-3 and the up-regulation of Bcl-2. Furthermore, PRO decreased methylenedioxyamphetamine (MDA), nitric oxide (NO) and ROS in CoCl2-induced PC12 cells accompanying the increase in glutathione peroxidase (GSH-Px) and MMP. The effects of PRO on autophagy, apoptosis and oxidative stress in CoCl2-induced PC12 cell were reversed by miR-134 mimic. CONCLUSION: PRO may mitigate CoCl2-induced autophagy in PC12 cells with decreased apoptosis and improved oxidative stress via mediating miR-134.

Diverse morphological lesions and serious arrhythmias with hemodynamic insults occur in the early myocardial contusion due to blunt impact in dogs.

To investigate the morphology and hemodynamics of the early myocardial contusion, an animal model of cardiac contusion was established by impact to the precordial region at sternum at velocity of 10.0m/s with a mechanical elastic-cord propelled impactor in 19 dogs. The electrocardiogram and both the left and right intra-ventricular pressures were recorded continuously throughout the experiment. Histological and immunohistochemical examinations of myoglobin, creatine kinase-MB and fibrinogen were conducted. At the moment of impact, abrupt over-pressures within the left and right ventricles occurred with concomitant serious arrhythmias followed by variety of cardiac conduction disorders and depressed left and right ventricular systolic pressures during the observation times. Histologically, lesions of myocardial contusions were identified at subepicardial, myocardial or subendocardial layer as interstitial hemorrhage, disruption or coagulative necrosis as well as contraction band necrosis of the muscle fibers, which might be categorized into the hemorrhagic, necrotized and mixed forms. The three forms of lesions were found to exist independently, or co-existed in a heart. However, severity of the lesions varied greatly with different parts even within a heart. Intravascular thromboses were occasionally discovered post-impact. Immunohistochemically, loss of myoglobin and creatine kinase-MB from cardiac cells, and accumulation of fibrinogen at the cell membranes were detected 5min post-impact. The intracellular accumulation of fibrinogen increased with extension of post-impact intervals. Our results indicate that diverse morphological lesions concomitant with hemodynamic compromise and serious, even fatal arrhythmias occur in the early myocardial contusion, and intravascular thromboses are occasionally produced, suggesting that traumatic myocardial ischemic lesion may be induced due to blunt impact to the precordial region.

[Immunohistochemical study on contents of beta-amyloid, alpha-actin and collagen IV in cerebral small vessels with unknown type of pathological lesion].

OBJECTIVE: To investigate the structural characteristics of the cerebral small vessels with an unknown type of pathological lesion (UTPL). METHODS: Contents of beta-amyloid, alpha-actin and collagen IV in cerebral small vessels with UTPL were studied by Congo red staining, immunohistochemical staining and computer image analysis. RESULTS: The low expression levels of alpha-actin and collagen IV (P<0.05) were observed in tunica media of the vessels with UTPL, and no positive expression of beta-amyloid (P>0.05) was observed in these vessel walls. The expressions of proteins mentioned above in UTPL were different from those of cerebral amyloid angiopathy(CAA) and hyaline arteriolosclerosis. CONCLUSION: UTPL was different from CAA or hyaline arteriolosclerosis in pathologic feature.