Regulation of neurite extension by expression of LECT2 and neurotrophins based on findings in LECT2-knockout mice

Leukocyte cell-derived chemotaxin 2 (LECT2) was first isolated as a chemotactic factor from phytohemagglutinin-activated human T-cell leukemia SKW-3 cells. LECT2 is expressed in various tissues, including in the brain, stomach and liver, but the functions of LECT2 in the brain remains unclear. To elucidate these functions, we investigated the influence of a deficiency of LECT2 on the morphology of cultured hippocampal neurons during neuronal development, and examined the expression of neurotrophins (NGF, BDNF, and NT-3) and their receptors (TrkA, TrkB, TrkC, and p75NTR) in these neurons. The extension of axons and dendrites in neurons from LECT2-knockout (LECT2-KO) mice was shorter than that in neurons from wild-type mice during culture and significantly less than that in wild-type mice after 4 days in culture. Moreover, neurons from LECT2-KO mice showed different expression of NGF, BDNF and NT-3 during culture compared to wild-type mice. Our results show that LECT2 regulates the extension of axons and dendrites and the expressions of NGF, BDNF and NT-3 during neuronal development.