Data resources in PLM (Product Lifecycle Management) systems are becoming more and more huge and complex. The heterogeneity of data type and the dependencies among technical information make difficult for users in database exploitation: to query and to share the data. In this paper, we present an ontology-based approach as a promising solution to overcome this issue. An ontology graph-based query interface has been developed with the aim to enhance the knowledge sharing among different types of users (non-technical or coming from diverse expert domains) and then to facilitate the database exploitation. An example in Bio-Imaging domain will be presented as an application field.