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The clinical use of doxorubicin (DOX) is limited by its cardiotoxicity, which is closely associated with oxidative stress. Xinmailong (XML) is a bioactive peptide extracted from American cockroaches, which has been mainly applied to treat chronic heart failure in China. Our previous study showed that XML attenuates DOX-induced oxidative stress. However, the mechanism of XML in DOX-induced cardiotoxicity remains unclear. Heme oxygenase-1 (HO-1), an enzyme that is ubiquitously expressed in all cell types, has been found to take antioxidant effects in many cardiovascular diseases, and its expression is protectively upregulated under DOX treatment. Lysosome and autophagy are closely involved in oxidative stress as well. It is still unknown whether XML could attenuate doxorubicin-induced lysosomal dysfunction and oxidative stress in H9c2 cells via HO-1. Thus, this study was aimed at investigating the involvement of HO-1-mediated lysosomal function and autophagy flux in DOX-induced oxidative stress and cardiotoxicity in H9c2 cells. Our results showed that XML treatment markedly increased cell proliferation and SOD activity, improved lysosomal function, and ameliorated autophagy flux block in DOX-treated H9c2 cells. Furthermore, XML significantly increased HO-1 expression following DOX treatment. Importantly, HO-1-specific inhibitor (Znpp) or HO-1 siRNA could significantly attenuate the protective effects of XML against DOX-induced cell injury, oxidative stress, lysosomal dysfunction, and autophagy flux block. These results suggest that XML protects against DOX-induced cardiotoxicity through HO-1-mediated recovery of lysosomal function and autophagy flux and decreases oxidative stress, providing a novel mechanism responsible for the protection of XML against DOX-induced cardiomyopathy.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important causative agents to swine industry, which has been epidemic more than 30 years. The emergence and recombination of new virus strains bring great challenges to the prevention and control of PRRSV. In the present study, we reported and characterized a novel PRRSV strain, designated as JS2021NADC34, which was for the first time isolated from clinical samples in Jiangsu province, China. Phylogenetic analysis demonstrated that JS2021NADC34 belonging to sublineage 1.5 of PRRSV-2 and was highly related to NADC34-like strains. Genetically, JS2021NADC34 strain had a continuous 100 aa depletion in NSP2, as compared to VR-2332 strain, which was consistent with most reported NADC34-like strains. Moreover, there were several amino acid substitutions occurred in the antigenic regions of GP2-GP5. Similar to other reported NADC34-like PRRSV in China, JS2021NADC34 had no recombination with other domestic strains, which indicates this sublineage of PRRSV may be directly transported from the United States and have not undergone extensive mutation and recombination with local strains yet.

Objectives. Unknown onset stroke (UOS) is usually excluded from intravenous thrombolysis concerning the unclear symptom onset time. Attempts have been done to use thrombolytic therapy in these patients. The current meta-analysis was done to examine the efficacy and safety of intravenous thrombolysis in UOS. Methods. PubMed, Web of Science, and Cochrane Library were searched for studies comparing thrombolysis with conservative therapy among UOSs. Data of good outcome (mRS, 0-2), mortality, and intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) were extracted and analyzed using the Revman 5.2 software. Results. In total, 8 studies with 1271 subjects (542 with thrombolysis and 729 with conservative therapy) were included in this meta-analysis. The data showed that patients receiving thrombolysis had a higher incidence of 90-day good outcome (P=0.0005) than conservative therapy. The comparison of discharge (P=0.89) and 90-day mortality (P=0.10) in both groups did not find any significances. The incidences of ICH (P=0.42) and sICH (P=0.06) were relatively comparable between the two therapies. Conclusions. Intravenous thrombolysis is a better choice for UOS patients for its efficacy and safety. In addition, pretreatment imaging assessment is beneficial for improving the efficacy of thrombolytic therapy. However, it needs more supporting evidences for clinical use in the future.