Binding of Amadori glucose-modified albumin by the monocytic cell line MonoMac 6 activates protein kinase C epsilon protein tyrosine kinases and the transcription factors AP-1 and NF-kappaB

An affinity purification procedure is employed for the isolation of FL-specific binding proteins from MM6 cell membranes using magnetobeads coated with glycated polylysine and elution with FL and glycated 6-aminocaproic acid. Two main binding proteins were identified as membrane-bound nucleolin and cellular myosin heavy chain, which are glycosylated. This study shows that in these cells binding of short-term glycated albumin leads to activation of PKC, especially its isoform epsilon and this is linked to translocation of AP-1 and NF-kappaB into the nucleus. Consequently, an increased formation of IL-1ss mRNA is observed. The PKC inhibitor GO6976 prevents all these effects. Glycated albumin also stimulates activation of PTK. The PTK inhibitor genistein prevents activation of AP-1 indicating that PTK is also involved in this process, whereas NF-kappaB translocation is only dependent on PKC activation.