Insulin-Attenuated Inflammatory Response of Dendritic Cells in Diabetes by Regulating RAGE-PKCβ1-IRS1-NF-κB Signal Pathway: A Study on the Anti-Inflammatory Mechanism of Insulin in Diabetes

Figure 5

PKCβ1 played a critical role in AGEs-BSA-stimulated BMDCs immune maturation. (a) Flow cytometric analysis was performed for cell surface CD83, CD86, and MHC-II expression examinations. CGP53353 attenuated AGEs-BSA-induced CD83 and CD86 upregulation; (b) the concentrations of TNF-α, IFN-γ, IL-6, IL-1b, and CCL2 in the supernatants of the culture were measured by ELISA; (c, d) the expressions of cytokines and chemokines mRNA in BMDCs were analyzed by real-time quantitative RT-PCR. CGP53353 attenuated proinflammatory cytokine and chemokine secretion in BMDCs and upregulated the expression of IL-10; (e, f) the expressions of NF-κB, IκB, phosphorylated PKCβ1, and serine phosphorylated IRS1 were determined by western blot in the presence of PMA or CGP53353. The phosphorylation of NF-κB and IκB were downregulated following direct PKCβ1 inhibition. In addition, the serine phosphorylation of IRS1 was found to decrease upon direct PKCβ1 inhibition. Data are expressed as ; ; vs. control group; ^# vs. AGEs-BSA group; ^Δ vs. group. AGEs-BSA: advanced glycosylation end-bovine serum albumin; BMDCs: bone marrow-derived dendritic cells; RAGE: receptor for advanced glycation end products; pPKC: phosphorylated protein kinase C; IRS1: insulin receptor subunit-1; TNF-α: tumor necrosis factor-α; IFN-γ: interferon-γ; MHC-II: major histocompatibility complex-II; NF-κB: nuclear factor-κB.

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