The Prolonged Activation of the p65 Subunit of the NF-Kappa-B Nuclear Factor Sustains the Persistent Effect of Advanced Glycation End Products on Inflammatory Sensitization in Macrophages

Abstract

Advanced glycation end products (AGEs) prime macrophages for lipopolysaccharide (LPS)-induced inflammation. We investigated the persistence of cellular AGE-sensitization to LPS, considering the nuclear content of p50 and p65 nuclear factor kappa B (NFKB) subunits and the expression of inflammatory genes. Macrophages treated with control (C) or AGE-albumin were rested for varying intervals in medium alone before being incubated with LPS. Comparisons were made using one-way ANOVA or Student t-test (n = 6). AGE-albumin primed macrophages for increased responsiveness to LPS, resulting in elevated levels of TNF, IL-6, and IL-1beta (1.5%, 9.4%, and 5.6%, respectively), compared to C-albumin. TNF, IL-6, and IL-1 beta secretion persisted for up to 24 h even after the removal of AGE-albumin (area under the curve greater by 1.6, 16, and 5.2 times, respectively). The expressions of Il6 and RelA were higher 8 h after albumin removal, and Il6 and Abca1 were higher 24 h after albumin removal. The nuclear content of p50 remained similar, but p65 showed a sustained increase (2.9 times) for up to 24 h in AGE-albumin-treated cells. The prolonged activation of the p65 subunit of NFKB contributes to the persistent effect of AGEs on macrophage inflammatory priming, which could be targeted for therapies to prevent complications based on the AGE–RAGE–NFKB axis.

Inactivation of Myostatin Delays Senescence via TREX1-SASP in Bovine Skeletal Muscle Cells

“…p65 is an important member of the NF-κB transcription factor family, playing crucial roles in both the cytoplasm and the nucleus, undergoing dynamic translocation under different environmental and conditional cues [47]. In its inactive state, p65 exists in the cytoplasm, and when it becomes active, it moves to the nucleus and takes part in biological processes such as the immune response, inflammation, and cell proliferation [48]. To further confirm this, TREX1 was overexpressed in the WT group, and TREX1 was interfered with in the MT-KO group.…”