Int J Biol Sci 2012; 8(7):1075-1084. doi:10.7150/ijbs.4742
Reduced Activity of Protein Kinase C in the Frontal Cortex of Subjects with Regressive Autism: Relationship with Developmental Abnormalities
1. NYS Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314, USA.
Autism is a neurodevelopmental disorder with unknown etiology. In some cases, typically developing children regress into clinical symptoms of autism, a condition known as regressive autism. Protein kinases are essential for G-protein-coupled receptor-mediated signal transduction, and are involved in neuronal functions, gene expression, memory, and cell differentiation. Recently, we reported decreased activity of protein kinase A (PKA) in the frontal cortex of subjects with regressive autism. In the present study, we analyzed the activity of protein kinase C (PKC) in the cerebellum and different regions of cerebral cortex from subjects with regressive autism, autistic subjects without clinical history of regression, and age-matched control subjects. In the frontal cortex of subjects with regressive autism, PKC activity was significantly decreased by 57.1% as compared to age-matched control subjects (p = 0.0085), and by 65.8% as compared to non-regressed autistic subjects (p = 0.0048). PKC activity was unaffected in the temporal, parietal and occipital cortices, and in the cerebellum in both autism groups, i.e., regressive and non-regressed autism as compared to control subjects. These results suggest brain region-specific alteration of PKC activity in the frontal cortex of subjects with regressive autism. Further studies showed a negative correlation between PKC activity and restrictive, repetitive and stereotyped pattern of behavior (r= -0.084, p = 0.0363) in autistic individuals, suggesting involvement of PKC in behavioral abnormalities in autism. These findings suggest that regression in autism may be attributed, in part, to alterations in G-protein-coupled receptor-mediated signal transduction involving PKA and PKC in the frontal cortex.
Keywords: Autism, behavior, protein kinase C, protein kinases, regression, signal transduction.
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How to cite this article:
Ji L, Chauhan A, Chauhan V. Reduced Activity of Protein Kinase C in the Frontal Cortex of Subjects with Regressive Autism: Relationship with Developmental Abnormalities. Int J Biol Sci 2012; 8(7):1075-1084. doi:10.7150/ijbs.4742. Available from http://www.ijbs.com/v08p1075.htm