Takahashi Yutaka, Carpino Nick, Cross James C, Torres Miguel, Parganas Evan, Ihle James N
Howard Hughes Medical Institute, Department of Biochemistry, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
EMBO J. 2003 Feb 3;22(3):372-84. doi: 10.1093/emboj/cdg057.
Suppressor of cytokine signaling 3 (SOCS3) binds cytokine receptors and thereby suppresses cytokine signaling. Deletion of SOCS3 causes an embryonic lethality that is rescued by a tetraploid rescue approach, demonstrating an essential role in placental development and a non-essential role in embryo development. Rescued SOCS3-deficient mice show a perinatal lethality with cardiac hypertrophy. SOCS3-deficient placentas have reduced spongiotrophoblasts and increased trophoblast secondary giant cells. Enforced expression of SOCS3 in a trophoblast stem cell line (Rcho-1) suppresses giant cell differentiation. Conversely, SOCS3-deficient trophoblast stem cells differentiate more readily to giant cells in culture, demonstrating that SOCS3 negatively regulates trophoblast giant cell differentiation. Leukemia inhibitory factor (LIF) promotes giant cell differentiation in vitro, and LIF receptor (LIFR) deficiency results in loss of giant cell differentiation in vivo. Finally, LIFR deficiency rescues the SOCS3-deficient placental defect and embryonic lethality. The results establish SOCS3 as an essential regulator of LIFR signaling in trophoblast differentiation.
细胞因子信号转导抑制因子3(SOCS3)与细胞因子受体结合,从而抑制细胞因子信号传导。SOCS3的缺失会导致胚胎致死,而四倍体拯救方法可挽救这种致死现象,这表明SOCS3在胎盘发育中起重要作用,而在胚胎发育中并非必需。经拯救的SOCS3缺陷小鼠表现出围产期致死并伴有心脏肥大。SOCS3缺陷的胎盘海绵滋养层细胞减少,滋养层二级巨细胞增多。在滋养层干细胞系(Rcho-1)中强制表达SOCS3可抑制巨细胞分化。相反,SOCS3缺陷的滋养层干细胞在培养中更容易分化为巨细胞,这表明SOCS3负向调节滋养层巨细胞分化。白血病抑制因子(LIF)在体外促进巨细胞分化,而LIF受体(LIFR)缺陷会导致体内巨细胞分化丧失。最后,LIFR缺陷挽救了SOCS3缺陷的胎盘缺陷和胚胎致死。这些结果确立了SOCS3作为滋养层分化中LIFR信号传导的重要调节因子。