Igarashi Tadashi, Tajiri Yumiko, Sakurai Masahiro, Sato Eimei, Li Dan, Mukai Kuniaki, Suematsu Makoto, Fukui Emiko, Yoshizawa Midori, Matsumoto Hiromichi
Laboratory of Animal Breeding and Reproduction, Division of Animal Science, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Japan.
Biol Reprod. 2009 Nov;81(5):948-55. doi: 10.1095/biolreprod.109.078162. Epub 2009 Jul 8.
Tubulointerstitial nephritis antigen-like 1 (Tinagl1, also known as adrenocortical zonation factor 1 [AZ-1] or lipocalin 7) has been cloned from mouse adrenocortical cells and is known to be closely associated with zonal differentiation of adrenocortical cells. In cell culture systems, TINAGL1 is a matricellular protein that interacts with both structural matrix proteins and cell surface receptors. However, the physiological roles of TINAGL1 and regulation of its expression are still not clearly understood. In the present study, the expression and localization of TINAGL1 in peri-implantation mouse embryos was examined. During preimplantation, the expression of both Tinagl1 mRNA and TINAGL1 protein was increased just prior to implantation. In blastocysts, TINAGL1 expression was localized to the trophectoderm. Using a progesterone-treated, delayed-implantation model, TINAGL1 was found to be upregulated in implantation-competent blastocysts after estrogen treatment. During postimplantation, TINAGL1 expression was restricted to extraembryonic regions. Marked expression was detected in the Reichert membrane on Embryonic Days 6.5 (E6.5) and E7.5. Colocalization of laminin 1 and TINAGL1 was also examined. Using an anti-LAMA1 antibody, colocalization of LAMA1 and TINAGL1 was observed in postimplantation embryos. Colocalization was also detected in the Reichert membrane. Immunoprecipitation analysis determined that LAMA1 and TINAGL1 interact in embryos on E7.5. These results demonstrate that after implantation, TINAGL1 is an extraembryonic tissue-specific protein. In particular, TINAGL1 is a novel component of the Reichert membrane that interacts with laminin 1. These results suggest that TINAGL1 most likely plays a physical and physiological role in embryo development at postimplantation.
肾小管间质性肾炎抗原样1（Tinagl1，也称为肾上腺皮质带分化因子1 [AZ - 1]或脂质运载蛋白7）已从小鼠肾上腺皮质细胞中克隆出来，并且已知与肾上腺皮质细胞的带分化密切相关。在细胞培养系统中，TINAGL1是一种基质细胞蛋白，它与结构基质蛋白和细胞表面受体都相互作用。然而，TINAGL1的生理作用及其表达调控仍不清楚。在本研究中，检测了TINAGL1在植入前小鼠胚胎中的表达和定位。在植入前，Tinagl1 mRNA和TINAGL1蛋白的表达在植入前刚有所增加。在囊胚中，TINAGL1表达定位于滋养外胚层。使用孕酮处理的延迟植入模型，发现雌激素处理后，TINAGL1在具有植入能力的囊胚中上调。在植入后，TINAGL1表达局限于胚外区域。在胚胎第6.5天（E6.5）和E7.5天，在瑞氏膜中检测到明显表达。还检测了层粘连蛋白1和TINAGL1的共定位。使用抗LAMA1抗体，在植入后胚胎中观察到LAMA1和TINAGL1的共定位。在瑞氏膜中也检测到共定位。免疫沉淀分析确定LAMA1和TINAGL1在E7.5天的胚胎中相互作用。这些结果表明，植入后，TINAGL1是一种胚外组织特异性蛋白。特别是，TINAGL1是瑞氏膜的一种新成分，它与层粘连蛋白1相互作用。这些结果表明，TINAGL1很可能在植入后胚胎发育中发挥物理和生理作用。
