Takahashi T, Suzuki H, Imai T, Shibata S, Tabuchi Y, Tsuchimoto K, Okano H, Hibi T. Musashi-1 post-transcriptionally enhances phosphotyrosine-binding domain-containing m-Numb protein expression in regenerating gastric mucosa.
PLoS One 2013;
8:e53540. [PMID:
23308249 PMCID:
PMC3537613 DOI:
10.1371/journal.pone.0053540]
[Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 11/30/2012] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE
Upregulation of the RNA-binding protein Musashi-1 (Msi1) has been shown to occur in rat gastric corpus mucosa after ethanol-induced mucosal injury. However, there is no direct evidence linking Msi1 with gastric regeneration. We examined the process of tissue repair after acute gastric mucosal injury with Msi1-knock-out (KO) mice to clarify the role of Msi1 and Msi1-dependent regulation of m-Numb expression in regenerating gastric mucosa.
METHODS
Acute gastric injury was induced in Msi1-KO and wild-type ICR mice by administering absolute ethanol. Expression of the splicing variants of m-Numb mRNA and protein in the gastric mucosa were analyzed by quantitative RT-PCR and western blotting, respectively.
RESULTS
We demonstrated that phosphotyrosine-binding domain-containing m-Numb expression was significantly upregulated at both the mRNA and protein levels in wild-type mice at 3 h after ethanol-induced acute gastric injury. In contrast, in Msi1-KO mice, the m-Numb protein was expressed weakly, and was associated with delayed regeneration of the injured gastric mucosal epithelium. In the Msi1-KO mouse, the ratio of m-Numb mRNA to total m-Numb mRNA in the heavy polysome fractions was lower than that in the wild-type mouse. Further, we showed that m-Numb-enhancement in gastric mucous cells induced the expression of prostate stem cell antigen and metallothionein-2. Under the m-Numb enhancing condition, the gastric cells exhibited enhanced cell proliferation and were significantly more resistant to H(2)O(2)-induced cell death than control cells.
CONCLUSIONS
Msi1-dependent post-transcriptional enhancement of m-Numb is crucial in gastric epithelial regeneration.
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