Functional Study Of Kctd10Gene

KCTD10(potassium channel tetramerisation domain-containing10) gene belongs to PDIP1gene family, which contains a BTB/POZ domain, a potassium channel tetramerisation (K-tetra) domain (a relative of BTB/POZ domain) at the N-terminus, and a PCNA-binding motif at the C-terminus. Further functional study showed KCTD10is inducible by TNF-α, and interacts with the small subunit of DNA polymerase8and PCNA. To study the physiological functions of KCTD10in mammals, we established KCTD10floxed mutant mice (KCTD10LoxP) by homologous recombination, and conventional knockout mice were generated by Cre/loxP system.The heterozygous KCTD10knockout mice (KCTD10+/-) were viable and fertile, displayed no abnormities. But the homozygous (KCTD10-/-) were embryonic death, died around E10.5because of angiogenesis defects. The yolk sacs of the abnormal embryos were normal-sized, but no obvious vitelline circulation observed. For the embryos, they were severely underdeveloped and enlarged pericardial space showing the heart defects. PECAM-1immunostaining showed both the yolk sac and the whole embryos were abnormal in the homozygous (KCTD10-/-) embryos, the vascular is much thinner, more disorganized than that of the wild type. The main arteries such as umbilical artery (UA), the internal carotid artery (ICA), dorsal aorta (DA), arterial branches, and cardinal veins were all abnormal. Hemotoxylin/eosin-staining paraffin sections revealed that due to enlarged endothelial-lined lacunae between the endodermal and mesodermal layers in KCTD10deficient mice, it is failed to remodel the primary vascular plexus to form the large blood vessels. KCTD10disruption also resulted in heart development failure. The mutant embryos had the enlarged pericardial edema, histological analysis by H&E staining showed that the myocardial wall were relatively thinner than that of the wild type embryos, and KCTD10-1embryos exhibited cardiac valve formation defects.Further study showed that the KCTD10is inducible by VEGF in a time and dose dependent manner in HUVE cells, indicating that KCTDIO is the downstream target gene of VEGF signaling. Quantitative real-time PCR and western blot showed that some key members in Notch signaling such as DLL4, Notch1, and Notch4were upregulated in KCTD10deficient embryos and in KCTD10knockdown HUVE cells, while the Jagged1, another ligand for Notch signaling, was not affected by the disruption of KCTD10.Our results suggested that KCTD10plays important roles in mammal’s development especially in the embryonic angiogenesis and heart development by negatively regulating the Notch signaling pathway, but how KCTD10affected the Notch signaling still need to be further elucidated.