Human DIXDC1 is a member of Dishevelled-Axin (DIX) domain containing gene family which plays important roles in Wnt signaling and neural development. In this report, we first confirmed that expression of Ccd1, a mouse homologous gene of DIXDC1, was up-regulated in embryonic developing nervous system. Further studies showed that Ccd1 was expressed specifically in neurons and colocalized with early neuronal marker Tuj1. During the aggregation induced by RA and neuronal differentiation of embryonic carcinoma P19 cells, expressions of Ccd1 as well as Wnt-1 and N-cadherin were dramatically increased. Stable overexpression of DIXDC1 in P19 cells promoted the neuronal differentiation. P19 cells overexpressing DIXDC1 but not the control P19 cells could differentiate into Tuj1 positive cells with RA induction for only 2 days. Meanwhile, we also found that overexpression of DIXDC1 facilitated the expression of Wnt1 and bHLHs during aggregation and differentiation, respectively, while inhibited gliogenesis by down-regulating the expression of GFAP in P19 cells. Thus, our finding suggested that DIXDC1 might play an important role during neurogenesis, overexpression of DIXDC1 in embryonic carcinoma P19 cells promoted neuronal differentiation, and inhibited gliogenesis induced by retinoic acid.
MOESM1 [Identification of the expression of Ccd1 in mouse multiple tissues by Western blot. Nine adult mice tissues were isolated and disassociated with lysis buffer. Expression of Ccd1 was detected by Western blot analysis. A major band about 53 kDa and a weak band about 40 kDa were both detected which appeared to correspond to Ccd1B and Ccd1C protein, respectively.] (EPS 162 kb)
MOESM2 [Overexpression of DIXDC1 facilitates the expression of Wnt1a during RA-induced aggregation in P19 cells. Two selected DIXDC1 overexpression clones and pcDNA4-P19 control cells were induced with RA for 4 days to aggregate. RNA at different aggregation stages is isolated and analyzed. RNA expression of exogenous DIXDC1, endogenous Ccd1, and Wnt1a were detected by reverse transcription PCR. Besides, Zeocin resistance gene contained in pcDNA4 vector was also amplified to confirm the positive clones.] (EPS 310 kb)