Integrin expression and IgA nephropathy: in vitro modulation by IgA with altered glycosylation and macromolecular IgA.

Integrin expression and IgA nephropathy: In vitro modulation by IgA with altered glycosylation and macromolecular IgA. Background Signal transduction by mesangial cell (MC) integrins regulates cell growth and survival, extracellular matrix production, and organization. The aim of the study was to investigate human MC integrin modulation by differently glycosylated IgA and macromolecular IgA, which are thought to play a pathogenetic role in IgA nephropathy (IgAN). Methods MCs were incubated with purified human polymeric IgA, heat-aggregated IgA, IgA glycoforms generated by enzymatic hydrolysis of saccharide residues and serum fractions from IgAN patients, and controls isolated by lectin affinity and containing IgA with peculiar glycan patterns. Integrins were quantitated by flow cytometry. Results Cultured MCs highly expressed α v β 3 and some α 3 β 1 ; α v β 3 was up-regulated by matrix components ( P v β 3 expression on cultured MCs ( P v expression on cultured MCs more than healthy controls. Conclusions These data support the hypothesis that IgA glycation plays a role in modulating the cell–matrix interaction, and that this mechanism can be operating in IgAN.