Purification of homogeneity and amino acid sequence analysis of a receptor protein for interleukin 1

A decrease in interleukin-1 receptor antagonist expression in the prefrontal cortex of schizophrenic patients

Interleukin-1 (IL-1) mediates psychological stress responses by regulating monoamine metabolism and secretion of corticotropin-releasing factor, and is therefore, implicated in various psychiatric diseases. To evaluate the contribution of IL-1 signaling to the brain pathology of schizophrenia, we measured protein and/or mRNA levels for IL-1beta and endogenous IL-1 receptor antagonist (IL-1RA) in the postmortem brain tissues of prefrontal and parietal cortex, putamen, and hypothalamus. Both protein and mRNA levels of IL-1RA were specifically decreased in the prefrontal cortex of schizophrenic patients, whereas IL-1beta levels were not significantly altered in all the regions examined. The IL-1RA decrease was not correlated with the dose of antipsychotics given to patients. There was no influence of this illness on protein levels for IL-1 receptor type 1 in the prefrontal cortex, either. In contrast, IL-1RA serum levels were increased in schizophrenic patients, especially in drug-free patients, as reported previously. These findings suggest that chronic schizophrenia down-regulates IL-1RA production the prefrontal cortex, irrespective of its impact on the periphery. IL-1RA reduction might reflect an immunopathologic trait of the prefrontal region in schizophrenic patients.

Activity and distribution of protein kinase C in liver during the acute-phase response

Activity and subcellular distribution of protein kinase C were estimated in liver cytosol and membrane fractions of rats carrying a turpentine-induced inflammation. Protein kinase C activity increases significantly 8 h after treatment in the membrane fraction, with concurrent reduction in the cytosol; 10 h after treatment the membrane-associated activity returns to normal, without concomitant recovery of that detected in the cytosol. The specific binding of phorbol dibutyrate to the liver membrane fraction increases but overall the effect is less evident and delayed in time. The changes are associated to alterations in the phosphorylation pattern of some liver proteins. Liver protein kinase C activity and intracellular distribution seem to be affected by a treatment which is known to induce an acute-phase response in the liver cells.