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Updated: Apr 17, 2026
Organotypic Hippocampal Slice Cultures
Published on: February 3, 2011
OGD induced modification of FAK- and PYK2-coupled pathways in organotypic hippocampal slice cultures
Malgorzata Ziemka-Nalecz1, Joanna Jaworska1, Joanna Sypecka1
1NeuroRepair Department, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
Abstract:
Focal adhesion kinase (FAK) and proline-rich tyrosine kinase (PYK2) are two related non-receptor tyrosine kinases which are thought to play a role in transducing extracellular matrix (ECM)-derived survival signals into cells. The functions of FAK and PYK2 are linked to autophosphorylation of their specific tyrosine residues, Tyr-397 in FAK and Tyr-402 in PYK2, and then association with different signalling proteins which mediate activation of downstream targets such as ERK and JNK mitogen-activated kinase cascades. Thus, modulation of FAK as well as PYK2 autophosphorylation may affect several intracellular pathways and may participate in a variety of pathological settings. The present study provides a systematic investigation of the influence of experimental ischemia, induced by oxygen-glucose-deprivation, on the FAK- and PYK2-mediated signalling in organotypic hippocampal slice cultures. OGD induced primary down-regulation of FAK and PYK2 autophosphorylation (at Tyr 397 and Tyr 402, respectively) at 24-48 h of reoxygenation was accompanied by the diminution of phosphorylation/activation of Src and JNK. In contrast, the activity of Akt and ERK1/2 remained on the control level. It indicates that Akt kinase as well as ERK1/2 does not interfere with OGD-induced neuronal damage. The inhibition of the early step of FAK and PYK2 activation demonstrated by the decrease of tyrosine autophosphorylation may comprise an important portion of the response expressed by modulation of some coupled signal transduction pathways.
Insights
Focal adhesion kinase (FAK) and proline-rich tyrosine kinase (PYK2) signaling are downregulated by oxygen-glucose deprivation (OGD) in hippocampal slices. This OGD-induced inhibition of FAK/PYK2 autophosphorylation impacts neuronal survival pathways.
Area of Science:
- Neuroscience
- Cell Signaling
- Molecular Biology
Background:
- Focal adhesion kinase (FAK) and proline-rich tyrosine kinase (PYK2) are non-receptor tyrosine kinases involved in signal transduction from the extracellular matrix.
- Their functions are regulated by autophosphorylation at specific tyrosine residues (Tyr-397 for FAK, Tyr-402 for PYK2), influencing downstream pathways like ERK and JNK.
- Dysregulation of FAK and PYK2 signaling is implicated in various pathological conditions.
Purpose of the Study:
- To investigate the impact of experimental ischemia, induced by oxygen-glucose deprivation (OGD), on FAK- and PYK2-mediated signaling pathways.
- To analyze the role of these kinases in neuronal damage within organotypic hippocampal slice cultures.
Main Methods:
- Organotypic hippocampal slice cultures were subjected to oxygen-glucose deprivation (OGD) to induce experimental ischemia.
- Levels of autophosphorylation of FAK (Tyr-397) and PYK2 (Tyr-402) were assessed post-reoxygenation.
- The phosphorylation status and activation of downstream signaling molecules, including Src, JNK, Akt, and ERK1/2, were analyzed.
Main Results:
- OGD led to a primary downregulation of FAK and PYK2 autophosphorylation at Tyr-397 and Tyr-402, respectively, 24-48 hours after reoxygenation.
- This inhibition of FAK/PYK2 autophosphorylation was associated with reduced phosphorylation and activation of Src and JNK.
- Conversely, the activity of Akt and ERK1/2 remained unchanged, suggesting they are not directly involved in OGD-induced neuronal damage.
Conclusions:
- The early inhibition of FAK and PYK2 activation, evidenced by decreased tyrosine autophosphorylation, is a significant component of the cellular response to OGD.
- Modulation of these signaling pathways may play a crucial role in the pathological processes associated with ischemic conditions in the hippocampus.
- These findings highlight FAK and PYK2 as potential targets for therapeutic interventions in ischemic brain injury.
