Kaiso differentially regulates components of the Notch signaling pathway in intestinal cells

Abstract

BackgroundIn mammalian intestines, Notch signaling plays a critical role in mediating cell fate decisions; it promotes the absorptive (or enterocyte) cell fate, while concomitantly inhibiting the secretory cell fate (i.e. goblet, Paneth and enteroendocrine cells). We recently reported that intestinal-specific Kaiso overexpressing mice (Kaiso Tg) exhibited chronic intestinal inflammation and had increased numbers of all three secretory cell types, hinting that Kaiso might regulate Notch signaling in the gut. However, Kaiso’s precise role in Notch signaling and whether the Kaiso Tg secretory cell fate phenotype was linked to Kaiso-induced inflammation had yet to be elucidated.MethodsIntestines from 3-month old Non-transgenic and Kaiso Tg mice were “Swiss” rolled and analysed for the expression of Notch1, Dll-1, Jagged-1, and secretory cell markers by immunohistochemistry and immunofluorescence. To evaluate inflammation, morphological analyses and myeloperoxidase assays were performed on intestines from 3-month old Kaiso Tg and control mice. Notch1, Dll-1 and Jagged-1 expression were also assessed in stable Kaiso-depleted colon cancer cells and isolated intestinal epithelial cells using real time PCR and western blotting. To assess Kaiso binding to the DLL1, JAG1 and NOTCH1 promoter regions, chromatin immunoprecipitation was performed on three colon cancer cell lines.ResultsHere we demonstrate that Kaiso promotes secretory cell hyperplasia independently of Kaiso-induced inflammation. Moreover, Kaiso regulates several components of the Notch signaling pathway in intestinal cells, namely, Dll-1, Jagged-1 and Notch1. Notably, we found that in Kaiso Tg mice intestines, Notch1 and Dll-1 expression are significantly reduced while Jagged-1 expression is increased. Chromatin immunoprecipitation experiments revealed that Kaiso associates with the DLL1 and JAG1 promoter regions in a methylation-dependent manner in colon carcinoma cell lines, suggesting that these Notch ligands are putative Kaiso target genes.ConclusionHere, we provide evidence that Kaiso’s effects on intestinal secretory cell fates precede the development of intestinal inflammation in Kaiso Tg mice. We also demonstrate that Kaiso inhibits the expression of Dll-1, which likely contributes to the secretory cell phenotype observed in our transgenic mice. In contrast, Kaiso promotes Jagged-1 expression, which may have implications in Notch-mediated colon cancer progression.Electronic supplementary materialThe online version of this article (doi:10.1186/s12964-017-0178-x) contains supplementary material, which is available to authorized users.

Kaiso-induced intestinal inflammation is preceded by diminished E-cadherin expression and intestinal integrity

“…This array was comprised of 76 patient cases of which, 4 were Crohn’s disease tissues, 5 were normal intestinal tissues and the remaining 67 represented intestinal adenocarcinomas and metastatic carcinomas. I mmuno h isto c hemistry (IHC) was performed on this TMA and murine intestinal tissues as previously described [14, 24, 28]. The primary antibodies used were as follows: rabbit anti-Ki67 1:150 (Spring Biosciences, Pleasanton, CA); rabbit anti-ZO-1 1:250 (Santa Cruz, Dallas, TX), mouse anti-Claudin2 1:250 (Abcam, Cambridge, MA), mouse anti-p120 catenin (clone 15D2, [29]), mouse anti-β-catenin 1:10,000 (BD Biosciences, Franklin Lakes, NJ), mouse anti-E-cadherin 1:5,000 (BD Biosciences, Franklin Lakes, NJ).…”

Dancing from bottoms up – Roles of the POZ-ZF transcription factor Kaiso in Cancer

“…Indeed, expression of the Notch pathway target gene Hes1 was decreased in Kaiso Tg/+ mice [46], hinting at a novel role for Kaiso in regulating cell fate decisions through Notch signalling in the murine intestine. Notably, Kaiso represses the expression of both the Notch1 receptor and the Notch ligand Dll-1 in CRC cell lines [53] but promoted Jagged-1 expression, which is implicated in colon cancer progression. This finding provides an additional mechanism whereby Kaiso may promote CRC and adds another layer of complexity to Kaiso’s role in intestinal homeostasis and colon cancer.…”

Stem Cell Signaling Pathways in the Small Intestine

“…In the mice, Kaiso inhibits the expression of Notch1 and Dll1. Consequently, Kaiso-mediated repression of the genes promotes the increase in secretory cells [82]. This finding reveals a novel signaling pathway via Kaiso in regulating Notch-mediated small intestinal homeostasis.…”

“…For instance, combined loss of both Dll1 and Hes1 results in increased secretory cell types [21,80,81]. Robinson et al [82] recently reported that the poxvirus and zinc finger transcription factor, Kaiso, regulates the secretory cell lineage in coordination with Notch signaling in intestinal-specific Kaiso-overexpressing mice. In the mice, Kaiso inhibits the expression of Notch1 and Dll1.…”