ZFIN ID: ZDB-PUB-150227-6
Depletion of the IKBKAP ortholog in zebrafish leads to hirschsprung disease-like phenotype
Cheng, W.W., Tang, C.S., Gui, H.S., So, M.T., Lui, V.C., Tam, P.K., Garcia-Barcelo, M.M.
Date: 2015
Source: World journal of gastroenterology   21(7): 2040-6 (Journal)
Registered Authors:
Keywords: Enteric nervous system, Hirschsprung disease, IKBKAP, Morpholinos, Zebrafish
MeSH Terms:
  • Animals
  • Carrier Proteins/genetics*
  • Disease Models, Animal
  • Enteric Nervous System/embryology*
  • Enteric Nervous System/metabolism
  • Gene Expression Regulation, Developmental
  • Gene Knockdown Techniques
  • Genetic Predisposition to Disease
  • Hirschsprung Disease/embryology
  • Hirschsprung Disease/genetics*
  • Hirschsprung Disease/metabolism
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism
  • Humans
  • Immunohistochemistry
  • Morpholinos/administration & dosage
  • Phenotype
  • Proto-Oncogene Proteins c-ret/genetics
  • Proto-Oncogene Proteins c-ret/metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors/genetics
  • Transcription Factors/metabolism
  • Zebrafish/embryology
  • Zebrafish/genetics*
  • Zebrafish/metabolism
  • Zebrafish Proteins/deficiency
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed: 25717236 Full text @ World J. Gastroenterol.
To investigate the role of IKBKAP (inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein) in the development of enteric nervous system (ENS) and Hirschsprung disease (HSCR).
In this study, we injected a morpholino that blocked the translation of ikbkap protein to 1-cell stage zebrafish embryos. The phenotype in the ENS was analysed by antibody staining of the pan-neuronal marker HuC/D followed by enteric neuron counting. The mean numbers of enteric neurons were compared between the morphant and the control. We also studied the expressions of ret and phox2bb, which are involved in ENS development, in the ikbkap morpholino injected embryos by quantitative reverse transcriptase polymerase chain reaction and compared them with the control.
We observed aganglionosis (χ (2), P < 0.01) and a reduced number of enteric neurons (38.8 ± 9.9 vs 50.2 ± 17.3, P < 0.05) in the zebrafish embryos injected with ikbkap translation-blocking morpholino (morphant) when compared with the control embryos. Specificity of the morpholino was confirmed by similar results obtained using a second non-overlapping morpholino that blocked the translation of ikbkap. We further studied the morphant by analysing the expression levels of genes involved in ENS development such as ret, phox2bb and sox10, and found that phox2bb, the ortholog of human PHOX2B, was significantly down-regulated (0.51 ± 0.15 vs 1.00 ± 0, P < 0.05). Although we also observed a reduction in the expression of ret, the difference was not significant.
Loss of IKBKAP contributed to HSCR as demonstrated by functional analysis in zebrafish embryos.