N-arachidonoylphenolamine alleviates ischaemia/reperfusion-induced cardiomyocyte necroptosis by restoring proteasomal activity

Necroptosis and apoptosis contribute to the pathogenesis of myocardial ischaemia/reperfusion (I/R) injury and subsequent heart failure. N-arachidonoylphenolamine (AM404) is a paracetamol lipid metabolite that has pleiotropic activity to modulate the endocannabinoid system. However, the protective role of AM404 in modulating I/R-mediated myocardial damage and the underlying mechanism remain largely unknown. A murine I/R model was generated by occlusion of the left anterior descending artery. AM404 (20 mg/kg) was injected intraperitoneally into mice at 2 and 24 h before the I/R operation. Our data revealed that AM404 administration to mice greatly ameliorated I/R-triggered impairment of myocardial performance and reduced infarct area, myocyte apoptosis, oxidative stress and inflammatory response accompanied by the reduction of receptor interacting protein kinase (RIPK)1/3- mixed lineage kinase domain-like (MLKL)-mediated necroptosis and upregulation of the immunosubunits (β2i and β5i). In contrast, administration of epoxomicin (a proteasome inhibitor) dramatically abolished AM404-dependent protection against myocardial I/R damage. Mechanistically, AM404 treatment increases β5i expression, which interacts with Pellino-1 (Peli1), an E3 ligase, to form a complex with RIPK1/3, thereby promoting their degradation, which leads to inhibition of cardiomyocyte necroptosis in the I/R heart. In conclusion, these findings demonstrate that AM404 could prevent cardiac I/R damage and may be a promising drug for the treatment of ischaemic heart disease.

Experimental and numerical study of SO2 removal from a CO2/SO2 gas mixture in a Cu-BTC metal organic framework

The mechanism of SO₂ removal from a CO₂/SO₂ gas mixture in a copper benzene-1, 3, 5-tricarboxylate (Cu-BTC) material is investigated at the molecular level by the grand canonical Monte Carlo method. The effects of seven kinds of force-field relationships among CO₂, SO₂ and Cu-BTC on the selectivity for a SO₂/CO₂ gas mixture at different temperatures are studied in detail. The accuracy of the simulation model is validated by the experimental data. The results show that more SO₂ molecules are adsorbed than CO₂, and the electrostatic interactions involving SO₂ are more sensitive to temperature than CO₂ is. The multilayer desorption for SO₂ and CO₂ occurs in large-square channels. The effect of the electrostatic interactions involving SO₂ is stronger than the interactions of CO₂. The forms of CO₂ and SO₂ adsorption in Cu-BTC with electrostatic interactions are Cu²⁺∙∙∙OCO and Cu²⁺∙∙∙OSO, respectively.

[In vivo characteristics of spinal kinematics in senile degenerative lumbar spondylolysis]

Objective: To investigate the in vivo kinematics of the lumbar degenerative spondylolysis (LDS) in senile patients. Methods: From March to October in 2014, nine L(4-5) LDS patients [mean age (74±9) years] and nine healthy volunteers [mean age, (54±4) years] were recruited. Combined fluoroscopy and CT scanning technique were used to obtain the three dimension kinematic data of the vertebral anatomical structures (vertebral body anterior margin, vertebral body posterior margin, facet joints and spinous process) in various postures (supine, standing, flexion and extension) under physical loads, and to compare the stability of different anatomical structures. The L(4-5) segmental disc angle was also measured in different postures. Paired-samples t test was applied to compare the displacement differences between the two groups. Results: During flexion-extension motion, all anatomical structures of the LDS group were slightly larger than those in normal group, but the statistical difference was not obvious (all P>0.05). For normal group, in anterior-posterior and cranial-caudal direction, sub-movement analysis showed that the anterior vertebral body margin at the flexion range of motion [(-1.07±0.84) mm, (-1.27±1.01) mm] were larger than the extension range of motion [(0.66±1.38) mm, (0.63±0.99) mm] (t=3.21, 4.03, both P<0.05). Whereas for LDS group, in anterior-posterior and cranial-caudal direction, sub-movement analysis showed that the anterior vertebral body margin at the extension range of motion [(1.46±1.26) mm, (1.17±0.54) mm] were significantly greater than the flexion range of motion [(-0.43±0.47) mm, (-0.45±1.24) mm] (t=4.22, 3.59, both P<0.05). The disc angles of the LDS group were all smaller than those in normal group, but the statistical difference was not obvious (all P>0.05). However, the disc angles were significantly different under different postures, the flexion were both the smallest in the normal group and LDS group. Conclusions: The senile LDS patients may not necessarily have instability, stability may also occur in these patients. Increasing extension range of motion is one of the kinematic characteristics in senile patients with LDS. The intervertebral stability should be taken into account, but if instability develops, surgical procedure should be suggested for elderly patients with LDS.