Deficiency of lysyl hydroxylase 2 in mice causes systemic endoplasmic reticulum stress leading to early embryonic lethality
Deficiency of lysyl hydroxylase 2 in mice causes systemic endoplasmic reticulum stress leading to early embryonic lethality
复制标题
DOI：
10.1016/j.bbrc.2019.03.091
复制
发表时间：
2019-05-07
影响因子：
3.1
通讯作者：
Tanzawa, Hideki
中科院分区：
文献类型：
--
作者：
Kasamatsu, Atsushi;Uzawa, Katsuhiro;Tanzawa, Hideki
赖氨酰羟化酶 2 (LH2) 是一种内质网 (ER) 驻留酶，可催化纤维状胶原蛋白端肽中赖氨酸残基的羟基化。这是决定胶原蛋白交联途径命运的关键修饰，有助于胶原纤维的稳定性。研究表明，LH2功能异常会导致多种疾病，包括成骨不全、纤维化和癌症转移。然而，令人惊讶的是，LH2 缺陷的动物模型尚未见报道。在本研究中，为了更好地了解LH2的功能，我们通过CRISPR/Cas9技术制备了LH2基因敲除小鼠。 LH2 缺陷通过基因分型聚合酶链反应 (PCR)、逆转录酶 PCR 和免疫组织化学分析得到证实。纯合LH2敲除（LH2(-/-)）胚胎无法正常发育，并在早期胚胎阶段E10.5死亡，其心脏共同心室异常，即心室壁不足、心室壁薄、细胞排列松散。在LH2(-/-)小鼠中，内质网应激反应基因ATF4和CHOP显着上调，导致Bax和cleaved caspase-3水平增加。这些数据表明 LH2 通过 ER 应激介导的细胞凋亡途径在心脏发育中发挥重要作用。 (C) 2019 Elsevier Inc. 保留所有权利。
Lysyl hydroxylase 2 (LH2) is an endoplasmic reticulum (ER)-resident enzyme that catalyzes the hydroxylation of lysine residues in the telopeptides of fibrillar collagens. This is a critical modification to determine the fate of collagen cross-linking pathway that contributes to the stability of collagen fibrils. Studies have demonstrated that the aberrant LH2 function causes various diseases including osteogenesis imperfecta, fibrosis, and cancer metastasis. However, surprisingly, a LH2-deficient animal model has not been reported. In the current study, to better understand the function of LH2, we generated LH2 gene knockout mice by CRISPR/Cas9 technology. LH2 deficiency was confirmed by genotyping polymerase chain reaction (PCR), reverse transcriptase-PCR, and immunohistochemical analyses. Homozygous LH2 knockout (LH2(-/-)) embryos failed to develop normally and died at early embryonic stage E10.5 with abnormal common ventricle in a heart, i.e., an insufficient wall, a thin ventricular wall, and loosely packed cells. In the LH2(-/-) mice, the ER stress-responsive genes, ATF4 and CHOP were significantly up-regulated leading to increased levels of Bax and cleaved caspase-3. These data indicate that LH2 plays an essential role in cardiac development through an ER stress-mediated apoptosis pathway. (C) 2019 Elsevier Inc. All rights reserved.