[Frontiers in Bioscience E2, 133-142, January 1, 2010]
Ochratoxin A induces craniofacial malformation in mice acting on Dlx5 gene expression

Margherita Napoletano1, Davide Pennino1, Gaia Izzo2, Salvatore de Maria2, Raffaele Ottaviano1, Maddalena Ricciardi1, Roberto Mancini1, Antonella Schiattarella5, Ernesto Farina4, Salvatore Metafora1, Maria Cartenì2, Alberto Ritieni3, Sergio Minucci2, Franco Morelli1

1Institute of Genetics and Biophysics A. Buzzati Traverso C.N.R., Naples, Italy, 2Department of Experimental Medicine, Medical School, II University of Naples, Naples, Italy, 3Department of Food Science, University of Naples Federico II, Portici, Naples, Italy, 4Department of Odontostomatologic Science, II University of Naples, Naples, Italy, 5 Department of Molecular Biology and Biotherapy, National Cancer Institute G. Pascale, Naples, Italy

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Experimental animals
3.2. Ochratoxin Treatments
3.3. Embryo analysis
3.4. Dlx5 and Msx1 gene fragments purification
3.5. Dlx5 and Msx1 riboprobe preparation for ISH
3.6. Dlx5 and Msx1 In situ Hybridization
4. Results
4.1. Differentiation defects induced by ochratoxin A treatment
4.2. Dlx5 in situ hybridization
4.3. Msx1 in situ hybridization
5. Discussion
6. Acknowledgment
7. References

1. ABSTRACT

Ochratoxin A (OTA) is a mycotoxin produced by fungal of Aspergillus species absorbed in human through contaminate food in gastrointestinal tract. OTA has been demonstrated to be teratogenic in a number of species including mice and potentially human. Mice exposed in uterus to OTA develop craniofacial abnormalities such as exencephaly, microencephaly, microphthalmia and facial clefts. An important role in differentiation of maxillofacial are exerted by the Hox related genes Dlx and Msx. In the present investigation we have confirmed that 2.75 mg/kg body weight OTA, given at gestational day 7.5, induces significant developmental craniofacial anomalies in mice and we have demonstrated the down expression of Dlx5, a member of Dlx gene family, that seems to be responsible of the observed deformities. These results support the hypothesis that Dlx5 is a target for ochratoxin and the inhibition of its function, directly or indirectly, could be at origin of the observed differentiation defects.