PDGF-BB enhances alpha1beta1 integrin-mediated activation of the ERK/AP-1 pathway involved in collagen matrix remodeling by rat mesangial cells.

Platelet-derived growth factor-BB (PDGF-BB) has been implicated in the pathogenesis of progressive glomerulonephritis (GN). Previous studies have reported that PDGF-BB stimulates mesangial cells (MCs)-induced collagen matrix remodeling through enhancement of alpha1beta1 integrin-dependent migratory activity. To determine the cell signaling pathway responsible for abnormal MC-related mesangial matrix remodeling in progressive GN, we studied the involvement of the extracellular signal-regulated kinase (ERK)/activator protein-1 (AP-1) pathway in PDGF-BB-enhanced collagen gel contraction.

[Expression mechanisms of inducible type nitric oxide synthasegene via interleukin-1 receptor signaling].

The functional study on NF-kB bindings sites in transcription-regulatory region of rat inducible type nitric oxide synthase (iNOS) has been carried out by reporter assay to learn the signaling mechanisms of actions of interleukin-1 (IL-1). By progressive excision of 5'-ends of the insert and introduction of mutagenesis of each NF-kB binding site, it has been shown that 3 kB sites are essential for IL-1-induced signaling pathway in a mutually dependent manner.

[Role of protein kinase C isozymes in cellular functions and pathological conditions].

Protein kinase C (PKC) is a superfamily of lipid-dependent protein Ser/Thr kinases consisting of at least 10 isozymes. The present article summarizes the papers presented at the congress symposium of the 74th Annual Meeting of the Japanese Pharmacological Society, in which six special topics regarding PKC isozyme-dependent cellular functions and pathological disorders were discussed. Using a GFP-tagged PKC expression technique, each PKC subtype was suggested to vary its targeting-site in each cell in response to each stimulus and that the targeting to the specific compartment is necessary for the specific cellular responses (NS).