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The Cdk5/p35 kinases modulate leptin-induced STAT3 signaling
Yi He1, Abba J Kastin, Hung Hsuchou
1Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
Journal of Molecular Neuroscience : MN
|January 22, 2009
Summary
Cyclin-dependent kinase 5 (Cdk5) activation influences leptin signaling. The p35 activator of Cdk5 is a novel modulator of leptin-induced signal transducer and activator of transcription 3 (STAT3) pathway.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Signaling
Background:
- Cyclin-dependent kinase 5 (Cdk5) is crucial for brain development and synaptic plasticity.
- p35 is the neuronal-specific activator of Cdk5.
- Leptin signaling regulates various physiological processes, including energy balance and neuronal function.
Purpose of the Study:
- To investigate the role of Cdk5 and its activator p35 in leptin signaling.
- To determine if Cdk5 activation modulates leptin-induced STAT3 activation.
- To identify p35 as a potential regulator of leptin-mediated neuronal responses.
Main Methods:
- Co-localization studies of p35/p25 with leptin receptor (ObR) in hypothalamic neurons.
- Overexpression of p35 to assess its effect on STAT3 transcriptional activation.
- Induction of leptin in differentiated SH-SY5Y cells to measure Cdk5, p35, p25, and pSTAT3 levels.
- Inhibition of Cdk5 activity using roscovitine or dominant-negative Cdk5 to evaluate pSTAT3 activation.
Main Results:
- p35 and its metabolite p25 were found in the same neurons as the leptin receptor (ObR) in the hypothalamus.
- p35 overexpression induced STAT3 transcriptional activation in a cellular model.
- Leptin treatment increased Cdk5, p35, and p25 expression, coinciding with pSTAT3 levels.
- Inhibition of Cdk5 reduced leptin-induced pSTAT3 activation.
- Cdk5 activation by p35 sustained leptin-induced pSTAT3 activation for 3-6 hours.
Conclusions:
- Cdk5 activation by p35 plays a significant role in modulating leptin signaling.
- p35 is identified as a novel regulator of leptin-induced STAT3 signaling in neurons.
- These findings suggest a new mechanism by which Cdk5 influences neuronal function in response to leptin.
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