Colony-stimulating factor 2 enhances the developmental competence of yak (Poephagus grunniens) preimplantation embryos by modulating the expression of heat shock protein 70 kDa 1A.

Colony-stimulating factor 2 (CSF2) is known to promote the development and survival of rodents and ruminants preimplantation embryos; however, the effect of CSF2 on yak embryos has not been reported. The objective of this study was to investigate the effects of CSF2 on the developmental competence of yak embryos cultured in vitro in modified synthetic oviduct fluid (mSOF) medium and on the expression pattern of heat shock protein 70 kDa 1A (HSPA1A). In each experiment, cumulus-oocyte complexes (COCs) were matured in vitro and fertilized with frozen-thawed semen. Zygotes were treated with varying concentrations of CSF2 (0, 10, 50, 100 ng/mL) until day 8 after fertilization. Embryo development was calculated as the percentage of oocytes that formed embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula and blastocyst stages. The total cell numbers (TCN) per blastocyst and their allocation to the inner cell mass (ICM) and trophectoderm (TE) lineages were determined using differential CDX2 staining. The expression of HSPA1A was examined by quantitative real-time PCR (qRT-PCR) and immunochemistry to determine the mRNA and protein levels. The results showed that treatment with 50 ng/mL CSF2 significantly (P < 0.05) increased the rate of blastocyst formation (19.01% versus 9.93%) and the TCN per blastocyst (96.94 versus 81.41) compared to the control group. However, no significant differences were observed in the other stages of development. qRT-PCR analysis confirmed that treatment with 50 ng/mL CSF2 significantly (P < 0.05) inhibited the expression of HSPA1A mRNA in blastocysts cultured in vitro relative to the control group, but there were no significant differences between the other treatment groups. Immunocytochemical analysis confirmed that HSPA1A protein accumulation was gradually reduced in yak blastocysts cultured in 0, 10, 100 or 50 ng/mL CSF2, however, no significant differences were observed between the 10 and 100 ng/mL treatments (P > 0.05). In conclusion, these findings demonstrate that CSF2 inhibits the expression of HSPA1A to facilitate yak blastocyst formation and increase cell numbers.

[Effect of echinacoside-containing serum in promoting mesenchymal stem cell osteogenic differentiation and ZHX3 expression in rats].

To investigate the effect and possible mechanism of echinacoside-containing serum on the osteogenic differentiation in rat bone marrow mesenchymal stem cells. Rat bone marrow mesenchymal stem cells were cultivated by the whole bone marrow adherence method. The 3rd generation of cells were divided into 3 groups: the blank control group, the classic osteogenic-induced group and the 10% echinacoside-containing serum group. The expression of alkaline phosphatase and osteocalcin were detected by ELISA. The ex- pression of ZHX, protein was detected by Western blot technique. RT-PCR technique was used to detect the expression of ZHX3mRNA. According to the result, the expressions of the alkaline phosphatase and osteocalcin in the classic osteogenic-induced group and the 10% echinacoside-containing serum group were significantly higher than that of the blank control group (P <0. 01). And expressions of the alkaline phosphatase activity and osteocalcin in the 10% echinacoside-containing serum group were significantly higher than that in the classic osteogenic-induced group (P < 0.01). Meanwhile, the classic osteogenic-induced group and the 10% echinacoside-containing serum group showed obviously higher ZHX3 protain and mRNA expression than that of the black control group, with significant differences (P < 0.01); the 10% echinacoside-containing serum group showed obviously higher ZHX3 protain and mRNA expression than that of the classic osteogenic-induced group, with a significant difference (P < 0.01). In conclusion, 10% echinacoside-containing serum can promote the differentiation of the bone marrow mesenchymal stem cells cultured in vitro. Its mechanism may be correlated with the increase in the ZHX3expression.

[Influences of zinc on concentrations of cyclin D2 and cyclin-dependent kinase 4 of human umbilical cord blood-derived mesenchymal stem cells].

OBJECTIVE: To explore effects of zinc on the contents of cyclin D2, cyclin-dependent kinase 4 (CDK4), and their DNA and total cellular protein in human umbilical cord blood-derived mesenchymal stem cells (hUCBMSCs). METHODS: hUCBMSCs were isolated and cultured by density gradient centrifugation adherence method in vitro. At the serial subcultivation, the hUCBMSCs were randomly divided into 7 groups. In control group, hUCBMSCs were cultured with DMEM medium (containing 15%FBS). In treatment groups, hUCBMSCs were cultured with DMEM medium (containing 15%FBS plus ZnSO4.7H2O). The final concentrations of zinc were 0.5, 1.5, 2.5, 3.5, 4.5, and 5.5 mg/L, respectively. The cellular surface antigens of CD29, CD34, CD44, and CD45 at the 3rd generation of hUCBMSCs were detected by flow cytometry. MTT assay was used to detect cell activity of the 3rd generation of hUCBMSCs. The optimum concentration of zinc was selected by the results of MTT as experimental group. The cell growth curves of experimental group and control group were drown by counting cell. The cell surface antigen, reproductive cycle, and DNA content were detected by flow cytometry mothers. The contents of cyclin D2 and CDK4 were detected by Western blot method. RESULTS: The positive expression rates of CD29 and CD44 were more than 70% in hUCBMSCs. The cell activity of 2.5 mg/L treatment group was superior to other treatment groups, as experimental group. At 7, 14, and 28 days, the contents of DNA, total cellular protein, cyclin D2, and CDK4 of hUCBMSCs were significantly higher in experimental group than those in control group (P < 0.01). The percentage of hUCBMSCs at S stage and proliferation index in experimental group were also significantly higher than those in control group (P < 0.01). CONCLUSION: Zinc (0.5-4.5 mg/L) has the promoting effect on the hUCBMSCs activity, and 2.5 mg/L is the optimal concentration. Zinc (2.5 mg/L) can accelerate the proliferation and DNA reproduction of hUCBMSCs and increase the contents of cyclin D2, CDK4, and cellular total protein.