Wang Zhen, Schwartz Robert J, Liu Jing, Sun Fei, Li Qi, Ma Yanlin
Hainan Provincial Key Laboratory for Human Reproductive Medicine and Genetic Research, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou, China.
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, China.
Front Cell Dev Biol. 2021 Apr 1;9:654682. doi: 10.3389/fcell.2021.654682. eCollection 2021.
SET and MYND domain-containing protein 1 (Smyd1) is a striated muscle-specific histone methyltransferase. Our previous work demonstrated that deletion of Smyd1 in either cardiomyocytes or the outflow tract (OFT) resulted in embryonic lethality at E9.5, with cardiac structural defects such as truncation of the OFT and right ventricle and impaired expansion and proliferation of the second heart field (SHF). The cardiac phenotype was accompanied by the downregulation of ISL LIM Homeobox 1 (Isl1) and upregulation of atrial natriuretic factor (ANF). However, the mechanisms of Smyd1 regulating Isl1 and ANF during embryonic heart development remain to be elucidated. Here, we employed various biochemical and molecular biological approaches including chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR), pGL3 fluorescence reporter system, and co-immunoprecipitation (CoIP) and found that Smyd1 interacted with absent small homeotic-2-like protein (ASH2L) and activated the promoter of Isl1 by trimethylating H3K4. We also found that Smyd1 associated with HDAC to repress ANF expression using trichostatin A (TSA), a deacetylase inhibitor. In conclusion, Smyd1 participates in early heart development by upregulating the expression of Isl1 and downregulating the expression of ANF.
含SET和MYND结构域蛋白1（Smyd1）是一种横纹肌特异性组蛋白甲基转移酶。我们之前的研究表明，在心肌细胞或流出道（OFT）中缺失Smyd1会导致胚胎在E9.5时死亡，并伴有心脏结构缺陷，如OFT和右心室截断，以及第二心脏场（SHF）的扩张和增殖受损。心脏表型伴随着ISL LIM同源盒1（Isl1）的下调和心钠素（ANF）的上调。然而，Smyd1在胚胎心脏发育过程中调节Isl1和ANF的机制仍有待阐明。在此，我们采用了多种生化和分子生物学方法，包括染色质免疫沉淀聚合酶链反应（ChIP-PCR）、pGL3荧光报告系统和免疫共沉淀（CoIP），发现Smyd1与缺失的小同源异型2样蛋白（ASH2L）相互作用，并通过三甲基化H3K4激活Isl1的启动子。我们还发现，使用去乙酰化酶抑制剂曲古抑菌素A（TSA），Smyd1与HDAC相关联以抑制ANF表达。总之，Smyd1通过上调Isl1的表达和下调ANF的表达参与早期心脏发育。
