Hiba Sabra's current research demonstrates cell adhesion to the extracellular matrix plays a key role in their proliferation, differentiation or apoptosis. Therefore, this process is critical for normal development and tissue homeostasis. The deregulation of this mechanism often contributes to pathological situations. Thus, the deregulation of many genes involved in cell-cell or cell-extracellular matrix adhesions are linked to pathologies leading to developmental defects, tumor progression, or inflammation. Integrins are heterodimeric transmembrane receptors that play a major role in cell-extracellular matrix interactions. This role is not limited to a simple mechanical interaction since integrins also allow the transduction of the signals from the extracellular matrix to the cell in order to permit the latter to adapt to its microenvironment. In order to study the role of β1 integrins in bone development, they have implemented a mouse model with conditional inactivation of the Itgb1 gene based on the expression of recombinase Cre at the pre-osteoblastic stage. The mutated mice show a defect in bone development due to a low proliferation rate of osteoblasts. Contrary to what was generally accepted, this reduced proliferation is independent of the classical pathway involving the classical pathway of MAP kinases. On the other hand, it is controlled by Hippo: this signaling pathway has recently been identified in Drosophila and Mammals as a major inhibitory mechanism of cell proliferation. The transcription cofactor YAP, the end effector of this pathway, is a nucleo-cytoplasmic shuttle. Its expression is amplified in various cancers including osteosarcoma where this overexpression associated with that of Itgb1 is a factor of poor prognosis. Sibra's previous work has involved understanding how β1 integrins control the Hippo pathway, and thus proliferation.
- PhD, Grenoble Alpes University, France: Developmental Biology and Oncogenesis, 2017
- Master's in Health and Medicine Engineering, Grenoble Alpes University, specialty Medicinal Chemistry and Pharmacological Innovation, 2013
- Bachelor's in Biochemistry: Lebanese University, Lebanon, 2008-2011
- Cell biology and Biochemistry
- Cell signalling/Hippo pathway
- β1 integrins in bone development
β1 integrin-dependent Rac/group I PAK signaling mediates YAP activation of Yes-associated protein 1 (YAP1) via NF2/ merlin Sabra H, Brunner M, Mandati V, Wehrle-Haller B, Lallemand D, Ribba AS, Chevalier G, Guardiola P, Block MR, Bouvard D. J Biol Chem. 2017 Nov. 24; 292(47): 19179-19197. doi: 10.1074/jbc.M117.808063. Epub 2017 Sep 29