Erythropoietin promotes myocardial infarction repair in mice by improving the function of Sca-1+ stem cells.

Myocardial infarction (MI) is one of the leading causes of death in the world. With the improvement of clinical therapy, the mortality of acute MI has been significantly reduced. However, as for the long-term impact of MI on cardiac remodeling and cardiac function, there is no effective prevention and treatment measures. Erythropoietin (EPO), a glycoprotein cytokine essential to hematopoiesis, has anti-apoptotic and pro-angiogenetic effects. Studies have shown that EPO plays a protective role in cardiomyocytes in cardiovascular diseases, such as cardiac ischemia injury and heart failure. EPO has been demonstrated to protect ischemic myocardium and improve MI repair by promoting the activation of cardiac progenitor cells (CPCs). This study aimed to investigate whether EPO can promote MI repair by enhancing the activity of stem cell antigen 1 positive stem cells (Sca-1+ SCs). Darbepoetin alpha (a long-acting EPO analog, EPOanlg) was injected into the border zone of MI in adult mice. Infarct size, cardiac remodeling and performance, cardiomyocyte apoptosis and microvessel density were measured. Lin- Sca-1+ SCs were isolated from neonatal and adult mouse hearts by magnetic sorting technology, and were used to identify the colony forming ability and the effect of EPO, respectively. The results showed that, compared to MI alone, EPOanlg reduced the infarct percentage, cardiomyocyte apoptosis ratio and left ventricular (LV) chamber dilatation, improved cardiac performance, and increased the numbers of coronary microvessels in vivo. In vitro, EPO increased the proliferation, migration and clone formation of Lin- Sca-1+ SCs likely via the EPO receptor and downstream STAT-5/p38 MAPK signaling pathways. These results suggest that EPO participates in the repair process of MI by activating Sca-1+ SCs.

Knockdown of CHPF suppresses cell progression of non-small-cell lung cancer.

Purpose: The aim of the present study was to explore the role of CHPF in non-small-cell lung cancer (NSCLC) and to develop an shRNA vector-based therapy to repress the expression of CHPF gene in NSCLC cell lines. Methods: In this study, we used immunohistochemical staining to verify the expression of CHPF in NSCLC tissue. Then, we determined the expression of CHPF gene in different NSCLC cell lines with RT-PCR and Western blotting. Specific CHPF shRNA was used to knockdown the expression of CHPF. Celigo image cytometry, cell cycle analysis, and flow cytometry assay were performed. Results: The results showed that expression level of CHPF was higher in NSCLC tissues than normal lung tissues. Further, we established that CHPF expression knockdown in NSCLC cells could substantially restrain the cell proliferation, apoptosis, and cell cycle in vitro. Conclusion: On the basis of these results, we concluded that CHPF expression has an important role in the progression of human NSCLC cells. Therefore, its interference could possibly be used as a potential therapeutic target against NSCLC.

[Optimization of isolation and culture of Lin- Sca-1+ cardiac stem cells from newborn mice].

Cardiac stem cells (CSCs) transplantation has been recognized to be effective on the treatment of myocardial infarction (MI), but some techniques still need to be developed in the isolation and culture of CSCs, which is the key problem restricting the clinical application of CSCs. This study was focused on the isolation of Lin- (lineage-negative) Sca-1+ (stem cell antigen-1-positive) CSCs from newborn C57BL/6J mice (0-3 d) by mixed enzymatic-explant isolation in combination with immunomagnetic separation. The digesting time, digesting frequency, incubation temperature, stirring speed, centrifugation time and rotational speed were strictly controlled in the experiment. In order to increase the survival rate of CSCs, the medium changing time and manner were optimized in primary CSCs culture. The percentages of Sca-1+ cells in primary and passage cells were detected by flow cytometry and immunofluorescence staining. The results showed that: (1) the proportion of Lin- Sca-1+ cells within the collected cells could be as high as (85.03 ± 5.60)% after isolation and purification; (2) In vitro culture of Lin- Sca-1+ CSCs grew into spheres on the 5th day, and over the whole bottom of the dish on the 7th day. The growth curve showed that the cells were in logarithmic growth phase on the 3rd day; (3) Immunofluorescence staining data showed that the expression of Sca-1, the CSCs membrane-specific marker, was decreased after subculture, and flow cytometry data showed that the percentages of Sca-1+ cells were (71.82 ± 2.63)%, (58.38 ± 3.70)% and (46.19 ± 4.72)% in passage 1 (P1), P3, and P5 CSCs, respectively. The above results suggest that high purity of Lin- Sca-1+ CSCs can be obtained by enzymolysis combined with immunomagnetic separation method. Moreover, the CSCs culture system is stable. In our experiment, the Sca-1+ CSCs isolation and culture method has been successfully established, and it is simple, stable, effective and reliable. The method can provide a stable methodological basis for the treatment of MI by Lin- Sca-1+ CSCs transplantation.