ABSTRACT
Coronaviruses (CoVs) are a group of common viruses that can infect humans and pose a great threat to global public health. Mounting evidence has shown that seven zoonotic CoVs can infect human through cross-species transmission. These continuously occurring yet unpredictable events of CoVs repeatedly crossing species barriers have attracted special attention to CoVs and caused panic worldwide. It is generally believed that the spike (S) protein is the key factor determining the cross-species transmission and the invasion potential of CoVs. This review focused on the new-found coronaviruses with potential cross-species transmission capabilities, and summarized and analyzed the research progress in S protein-mediated viral invasion as well as the potential mechanisms, aiming to provide reference for developing effective prevention and control strategies against potential cross-species transmission of CoVs in the future.
ABSTRACT
Coronaviruses (CoVs) are a group of ancient and common viruses, posing a severe threat to the health of humans and other animals. Currently, seven human CoVs (HCoVs) have been identified. They are all animal-derived zoonotic pathogens that jump the species barrier from their natural host animals to humans in a direct or indirect manner and lead to interpersonal transmission. The receptor binding domain (RBD) on the S1 subunit of CoV spike (S) protein is one of the key factors determining the cross-species transmission and the invasion potential. This review summarized and analyzed the transmission modes of seven HCoVs and the available structures of HCoV-RBD that mediated the cross-species transmission in order to better understanding the mechanism of CoV cross-species transmission and providing valuable knowledge in response to the potential cross-species transmission of novel CoVs in the future.
ABSTRACT
BACKGROUND:Induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles have been confirmed in various tissue repairs, which are expected to become more effective and safe therapy for articular cartilage repair. OBJECTIVE:To overal understand the research progress in the use of induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles in articular cartilage repair. METHODS: A computer-based search of PubMed and CNKI was performed by the first author for articles related to stem cel treatment of osteoarthritis published from 2003 to 2015. The keywords were “articular cartilage injury, bone marrow mesenchymal stem cels” in English and Chinese, respectively. In the same field, articles published recently or in authorized journals were preferred. RESULTS AND CONCLUSION:Articular cartilage injury is stil a difficulty in the orthopedics. Many repair methods have been reported, but they al have limitations. Induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles bring a new hope for patients with articular cartilage injury. However, there are stil many problems to be solved, such as extracting and purifying a large amount of cels, proliferation and differentiation potentials, and mechanism underlying cartilage repair.
ABSTRACT
Objective: To investigate whether lipopolysaccharide induced parkin expression and mitophagy in macrophages.Methods:The murine peritoneal primary macrophages were aseptically isolated from Kunming mice and cultured in complete medium.The mitochondrial membrane potential of macrophages was detected by flow cytometry,after the cells were stimulated with 200 ng/ml LPS and labeled mitochondria with JC-1.The parkin mRNA level of macrophages was detected by RT-PCR, protein levels of parkin and autophagic related protein LC3 Ⅱ and LC3 Ⅰ were determined by Western blot.The distribution and co-localization of parkin with LC3 and mitochondria in macrophages were respectively observed by laser scanning confocal microscope, before and after the cells were treated with LPS.Results: Flow cytometry results after JC-1 staining showed that mitochondrial membrane potential in macrophages was declined after stimulation with 200 ng/ml LPS, and continuously decreased with prolonged treatment time.The mRNA levels of parkin were increased slightly within 6 h after LPS stimulation,but parkin proteins were increased significantly within 6 h after LPS stimulation.The results of parkin distribution showed that parkin was evenly distributed in the cytoplasm at normal status, but became the obvious punctate distribution after LPS stimulation in macrophages.Western blot results showed LC3 Ⅱ/LC3 Ⅰ levels were increased after LPS stimulation, indicating the appearance of macrophage autophagy.Confocal microscopy showed that there were co-localization of parkin,LC3 and mitochondrial in macrophages after LPS stimulation.Conclusion:Parkin expression is increased significantly and mediated mitochondrial autophagy in macrophages after LPS stimulation, which is involved in the clearance of damaged mitochondria,thereby playing a role in regulating macrophage inflammatory response.
ABSTRACT
Aim To study the effect of simvastatin on the production of reactive oxygen species ( ROS ) and the secretion of interleukin-1 beta ( IL-1β) in oxidized low density lipoprotein ( oxLDL )-induced macropha-ges. Methods After the murine macrophage J774A. 1 was treated with 0,50,100,200 mg·L-1 oxLDL, the contents of aggregated lipid in macrophages were ob-served and determined by oil red O staining. Then, the oxLDL-primed macrophages were treated with 0 . 5 ,1 . 0μmol·L-1 simvastatin, the production of ROS was de-termined by flow cytometry and the expressions of pro-caspase-1 , cleaved caspase-1 and mature IL-1βon pro-tein level were determined by Western blot. Results The oil red O staining results showed that oxLDL could induce obvious lipid aggregation in macrophages, and reached the saturation point with 100 mg·L-1 concen-tration. Flow cytometry results indicated that oxLDL could induce the production of ROS in macrophages, up to 167% ± 0. 47%, and ROS level decreased to 139% ± 0. 97% in a dose-dependent manner after treatment with simvastatin. Western blot indicated that simvastatin could inhibit the expression of cleaved caspase-1 and mature IL-1β in macrophages triggered by oxLDL;compared with oxLDL group, the expression of cleaved caspase-1 and mature IL-1β decreased in simvastatin treated group, and all results had statistical significance ( P<0. 05 ) . Conclusion In the lipid ag-gregation model of macrophages induced by oxLDL, simvastatin can inhibit the production of ROS, caspase-1 activation, and secretion of IL-1β in macrophages.