Regulation of stimulus-induced interleukin-8 gene transcription in human adrenocortical carcinoma cells - Role of AP-1 and NF-κB

Nanoparticles for Directed Immunomodulation: Mannose-Functionalized Glycodendrimers Induce Interleukin-8 in Myeloid Cell Lines

New therapeutic strategies for personalized medicine need to involve innovative pharmaceutical tools, for example, modular nanoparticles designed for direct immunomodulatory properties. We synthesized mannose-functionalized poly(propyleneimine) glycodendrimers with a novel architecture, where freely accessible mannose moieties are presented on poly(ethylene glycol)-based linkers embedded within an open-shell maltose coating. This design enhanced glycodendrimer bioactivity and led to complex functional effects in myeloid cells, with specific induction of interleukin-8 expression by mannose glycodendrimers detected in HL-60 and THP-1 cells. We concentrated on explaining the molecular mechanism of this phenomenon, which turned out to be different in both investigated cell lines: in HL-60 cells, transcriptional activation via AP-1 binding to the promoter predominated, while in THP-1 cells (which initially expressed less IL-8), induction was mediated mainly by mRNA stabilization. The success of directed immunomodulation, with synthetic design guided by assumptions about mannose-modified dendrimers as exogenous regulators of pro-inflammatory chemokine levels, opens new possibilities for designing bioactive nanoparticles.

Chromatin-embedded reporter genes: Quantification of stimulus-induced gene transcription

Receptors and ion channels expressed on the cell surface ensure proper communication between the cells and the environment. In multicellular organism, stimulus-regulated gene transcription is the basis for communication with the environment allowing individual cells to respond to stimuli such as nutrients, chemical stressors and signaling molecules released by other cells of the organism. Hormones, cytokines, and mitogens bind to receptors and ion channels and induce intracellular signaling cascades involving second messengers, kinases, phosphatases, and changes in the concentration of particular ions. Ultimately, the signaling cascades reach the nucleus. Transcription factors are activated that respond to cellular stimulation and induce changes in gene transcription. Investigating stimulus-transcription coupling combines cell biology with genetics. In this review, we discuss the molecular biology of stimulus-induced transcriptional activators and their responsiveness to extracellular and intracellular signaling molecules and to epigenetic regulators. Stimulus-induced gene expression is measured by several methods, including detection of nuclear translocation of transcription factors, phosphorylation or DNA binding. In this article, we emphasize that the most reliable method to directly measure transcriptional activation involves the use of chromatin-embedded reporter genes.