RESUMO
In recent years, the research hot in the field of solid tumor and blood tumor focuses on the myeloid-derived suppressor cells (MDSCs).In tumors, MDSCs not only exert immunosuppression by inhibiting T cell proliferation, destroying the functions of natural killer cells and recruiting regulatory T cells, but also play non-immunosuppression roles in the promotion of angiogenesis and tumor metastasis.All of these hinder the anti-tumor therapy, and particularly affect the curative effect, which are related with a poor clinical prognosis.MDSCs can be used as prognostic markers, which provide new targets for immunotherapy.
RESUMO
Objective To investigate the spatiotemporal expression patterns and the relationship of α-sarcomeric actin(α-SCA) ,α-smooth muscle actin(α-SMA) and intermediate filament protein desmin with the maturation of the prenatal and the neonatal mouse hearts. Methods Serial sections of the embryo mouse and the neonatal mouse hearts were immunostained with antibodies against α-SCA, α-SMA and desmin. Results Ventricle and outflow tract of embryonic day(ED) 9 heart showed stronger expression of α-SCA and α-SMA, but desmin expression was lower. In the atrium, the expressions of α-SCA and α-SMA were restricted to the dorsal and ventral walls. In the sinus venosus, only a few weakly stained α-SCA positive cells were detected. No desmin expression was found in the atrium and sinus venosus. The expressions of α-SCA, α-SMA and desmin were increased to their highest level at ED 12. The higher expression of α-SCA remained to the postnatal stages. After ED 12, the expressions of α-SMA and desmin gradually decreased in different parts of the heart, but their expressions in the right ventricle persisted longer. After birth,desmin expression was mainly concentrated in the Z lines of I bands and intercalated disks. Conclusion The presence of spatiotemporal differences in the expression of α-SMA and desmin reveals regional differences in cardiomyocyte maturation in various parts of the embryonic mouse heart. The right ventricle shows a relatively slow pace of maturation. The α-SMA may contribute to a peristaltoid contraction pattern of the embryonic myocardium with a slow shortening speed, and a relatively higher level of desmin is required for the maturation of the sarcomere.