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
THERIOGENOLOGY
Authors: Wen, Zexing; Pan, Yangyang; Cui, Yan; Peng, Xiumei; Chen, Ping; Fan, Jiangfeng; Li, Guyue; Zhao, Tian; Zhang, Jian; Qin, Shujian; Yu, Sijiu
Abstract
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. (C) 2017 Published by Elsevier Inc.
Age Dependence of Hematopoietic Progenitor Survival and Chemokine Family Gene Induction after Gamma Irradiation in Bone Marrow Tissue in C3H/He Mice
RADIATION RESEARCH
Authors: Ariyoshi, Kentaro; Takabatake, Takashi; Shinagawa, Mayumi; Kadono, Kyoko; Daino, Kazuhiro; Imaoka, Tatsuhiko; Kakinuma, Shizuko; Nishimura, Mayumi; Shimada, Yoshiya
Abstract
Age at exposure is a critical factor that influences the risk of radiation-induced leukemia, which arises from hematopoietic stem and progenitor cells. However, little is known about the effect of age on the radiation response of these cells. In this study, we examined the radiation response of hematopoietic stem and progenitor cells in infant (1-week-old), juvenile (3-week-old), and adult (8- and 14-week-old) C3H/He mice, which are susceptible to radiation-induced myeloid leukemia. We first observed an age-dependent increase in the radioresistance of hematopoietic stem and progenitor cells after in vivo irradiation. However, in vitro irradiation of progenitor cells did not show any age differences, suggesting that radiation sensitivity in vivo is dependent on the bone marrow microenvironment rather than to intrinsic properties of progenitors themselves. Expression profiles of bone marrow tissues identified chemokine and cytokine family genes, whose expression differed between infant and adult tissues at time points before and after irradiation. Among the selected thirteen cytokines reported to be radioprotective, we observed increased expression of Csf1, Csf2, Cxcl12, Fgf1, Fgf7, Il1a, Il1b and Kitl after irradiation, mostly in adult tissues. Specifically, Csf2, Fgf1 and Il1b expression, as revealed by qPCR, were significantly enhanced in adult bone marrow tissue after irradiation, but were unresponsive to irradiation in infant tissue. These results suggest that the higher susceptibility of infant hematopoietic stem and progenitor cells to the cell killing effect of ionizing radiation may be attributed to a failure to induce a subset of radioprotective cytokines in the immature bone marrow microenvironment. (C) 2014 by Radiation Research Society