Influence of Hypoxia Inducible Factor-1α of Endothelial Progenitor Cells on Left Ventricular Function in Experimental Myocardial Infarction

Based on the promotion of myocardial activity via endothelial progenitor cells (EPCs) subsequent to acute myocardial infarction (AMI), our research was designed to explore the influence of excessive HIF-1α expression in expanded EPCs (eEPCs) on promotion of the activity of left ventricle subsequent to MI. Isolation of EPCs from cord blood was performed before transduction with the help of retroviral vector with or without HIF-1α expression. Transplantation was performed subsequent to ligation of the left anterior descending coronary artery in mice. Ejection fraction (EF) of left ventricle was promoted via transplantation after 2 weeks. Excessive HIF-1α expression enhanced EF of left ventricle and decreased the extent of MI. It was revealed via functional studies that excessive HIF-1α expression enhanced proliferation of EPCs triggered by low oxygen concentration and suppressed cell death in the region of infarction. Moreover, markers of endothelium CD31, VEGF, and eNOS were upregulated. Transplantation of eEPCs with excessive HIF-1α expression in AMI can promote myocardial activities by increasing differentiation, generation of vessels, proliferation of eEPCs, and suppressing cell death. The above findings propose that regulation of EPCs via HIF-1α enhances the activity as well as mobilization of EPCs, indicating that reinforcement of expression of HIF-1α is beneficial for coronary heart disease.

Effects of neutrophil extracellular traps during human respiratory syncytial virus infection in vitro

The human respiratory syncytial virus (hRSV) is the most common cause of severe lower respiratory tract diseases in young children worldwide, leading to a high number of hospitalizations and significant expenditures for health systems. Neutrophils are massively recruited to the lung tissue of patients with acute respiratory diseases. At the infection site, they release neutrophil extracellular traps (NETs) that can capture and/or inactivate different types of microorganisms, including viruses. Evidence has shown that the accumulation of NETs results in direct cytotoxic effects on endothelial and epithelial cells. Neutrophils stimulated by the hRSV-F protein generate NETs that are able to capture hRSV particles, thus reducing their transmission. However, the massive production of NETs obstructs the airways and increases disease severity. Therefore, further knowledge about the effects of NETs during hRSV infections is essential for the development of new specific and effective treatments. This study evaluated the effects of NETs on the previous or posterior contact with hRSV-infected Hep-2 cells. Hep-2 cells were infected with different hRSV multiplicity of infection (MOI 0.5 or 1.0), either before or after incubation with NETs (0.5–16 μg/mL). Infected and untreated cells showed decreased cellular viability and intense staining with trypan blue, which was accompanied by the formation of many large syncytia. Previous contact between NETs and cells did not result in a protective effect. Cells in monolayers showed a reduced number and area of syncytia, but cell death was similar in infected and non-treated cells. The addition of NETs to infected tissues maintained a similar virus-induced cell death rate and an increased syncytial area, indicating cytotoxic and deleterious damages. Our results corroborate previously reported findings that NETs contribute to the immunopathology developed by patients infected with hRSV.

The Mechanism of Human Umbilical Mesenchymal Stem Cells (HUMSC) on Biological Behavior of Human Papillomavirus (HPV) Cells Through Restraining the Programmed Cell Death Protein 1/Programmed Cell Death Ligand 1 (PD-1/PD-L1) Signal Pathway

Biological behavior of HPV cell was observed by HUMSC through restraining PD-1/PD-L1 signal pathway. And HUMSC was adopted as target cell for the treatment on HPV. The rat HPV model was established and divided into three groups including blank group, control group and test group according to different reagents being injected into rats. Use HE staining method to observe the cancerous transformation of tumor tissue sections. The gene presentation of PD-1/PD-L1 and lymphocyte was detected with Western blot. The invasion and migration condition of cancer cells was observed from experiment in vitro. The quantity of cancer cells in test group was the least. And invasion and migration ability in test group was the weakest. The control group was the second. The number of tumor cells in the blank group was the largest. Strongest ability to invade and migrate. The presentation of PD-L1 was restrained partly by HUMSC. The increasing of immune-associated cells could be prompted by HUMSC. The quantity of CD3+, CD4+ and CD8+ in PB was the most in test group. The expression of blank groups is the lowest than others restrained by HUMSC. And quantity of abundant immune cells including CD3+, CD4+ and CD8+ could be activated partly through activating immune action of body. And monitoring function of immune system on HPV cells could be increased effectively. The invasion and migration ability in vitro of HPV could be reduced partly.