β3-integrin is required for differentiation in OC-2 cells derived from mammalian embryonic inner ear
Brunetta, Ivan, Casalotti, S., Hart, Ian R, Forge, Andrew and Reynolds, Louise E 2012. β3-integrin is required for differentiation in OC-2 cells derived from mammalian embryonic inner ear. BMC Cell Biology. 13 (1), p. 5.
|Authors||Brunetta, Ivan, Casalotti, S., Hart, Ian R, Forge, Andrew and Reynolds, Louise E|
The mammalian inner ear contains the organ of Corti which is responsible for the conversion of sound into neuronal signals. This specialised epithelial tissue is the product of a complex developmental process where a common precursor cell type differentiates into the sound transducing hair cells and the non-innervated supporting cells. We hypothesised that integrin proteins, which are involved in cell attachment to extracellular matrix proteins and cellular signalling, play a role in the differentiation process of the precursor inner ear epithelial cells. To test our hypothesis we have utilised a cell line (OC-2) derived from E13 embryonic immortomouse inner ears. In vitro, by switching the incubation temperature from 33°C to 39°C, the OC-2 cells can be induced to differentiate and express hair cells markers, such as Myosin VIIa. The OC-2 cells are thus a useful model system for testing mechanism of hair cells differentiation.
We have identified 4 integrin subunits which are expressed in OC-2 cells: α6, αv, β1 and β3. Among these, the relative level of expression of the αv, β1 and β3 subunits increased in a time dependent manner when the cells were exposed to the differentiating temperature of 39°C, most notably so for β3 which was not detectable at 33°C. Treatment of fully differentiated OC-2 cells with siRNA against the four integrin subunits reduced the expression of not only the respective integrin proteins but also of the hair cell marker Myosin VIIa. Conversely over-expression of β3 was sufficient to induce the expression of Myosin VIIa at 33°C.
Our data demonstrate that modulation of integrin expression is associated with the differentiation process of the OC-2 cells. This suggests that the maturation of the organ of Corti, from where OC-2 cells are derived, may also depend on changes of gene expression associated with integrin expression.
|Keywords||organ of Corti; mammalian inner ear; integrin expression|
|Journal||BMC Cell Biology|
|Journal citation||13 (1), p. 5|
|Web address (URL)||http://dx.doi.org/10.1186/1471-2121-13-5|
|17 Mar 2012|
|Publication process dates|
|Deposited||19 Nov 2012|
|Funder||Hearing Research UK|
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