Carbon black nanoparticles induce HDAC6-mediated inflammatory responses in 16HBE cells

Abstract

Long-term inhalation of carbon black nanoparticles (CBNPs) leads to pulmonary inflammatory diseases. Histone deacetylase 6 (HDAC6) has been identified as an important regulator in the development of inflammatory disorders. However, the direct involvement of HDAC6 in CBNPs-induced pulmonary inflammatory responses remains unclear. To explore whether HDAC6 participates in CBNPs-induced pulmonary inflammation, human bronchial epithelial cell line (16HBE cells) was transfected with HDAC6 small interference RNA (siRNA) and then exposed to CBNPs at concentrations of 0, 25, and 50 µg/ml for 24 h. Intracellular HDAC6 and intraflagellar transport protein 88 (IFT88) mRNA and protein were determined by real-time polymerase chain reaction and Western blot, respectively. The secretions of inflammatory cytokines including interleukin (IL)-8, tumor necrosis factor (TNF)-α, IL-6, and IL-1β were measured by enzyme-linked immunosorbent assay. CBNPs induced a significant increase in the expressions of IL-8 and IL-6, accompanied by a high level of intracellular HDAC6 mRNA when compared with a blank control group ( p < 0.05). However, there were no significant changes in the levels of TNF-α secretion, intracellular HDAC6 and IFT88 protein induced by CBNPs ( p > 0.05). The HDAC6 mRNA expression was significantly suppressed in HDAC6 siRNA-transfected cells ( p < 0.05). The secretions of IL-8, TNF-α, and IL-6 were significantly less in HDAC6 siRNA-transfected cells than that in normal 16HBE cells with exposure to 25 or 50 µg/ml of CBNPs, but intracellular IFT88 mRNA expression was markedly increased in HDAC6 siRNA-transfected cells when compared with normal 16HBE cells exposed to 50 µg/ml of CBNPs (all p < 0.05). Downregulation of the HDAC6 gene inhibits CBNPs-induced inflammatory responses in bronchial epithelial cells, partially through regulating IFT88 expression. It is suggested that CBNPs may trigger inflammatory responses in bronchial epithelial cells by an HDAC6/IFT88-dependent pathway.

The toxicity of nanoparticles and their interaction with cells: an in vitro metabolomic perspective

“…Many studies used conventional essays to measure this response. 119,120,121 However, these assays can also interfere with NPs during the measurement of inflammatory response in cell lines. Some inflammatory cytokines were reported to get adsorbed on the NP surface causing an interference (Figure 7a).…”

“…ELISA (enzyme-linked immunosorbent assay) or western blotting, and electrophoretic mobility shift assays (EMSAs) or real-time polymerase chain reaction (RT-PCR) systems are used for the measurement of cytokines and the related genetic expressions, respectively. 118–123…”

“…ELISA (enzyme-linked immunosorbent assay) or western blotting, and electrophoretic mobility shi assays (EMSAs) or real-time polymerase chain reaction (RT-PCR) systems are used for the measurement of cytokines and the related genetic expressions, respectively. [118][119][120][121][122][123] NPs were reported to induce an inammatory response in different cell lines. Many studies used conventional assays to measure this response.…”

Beyond Mendelian Inheritance: Genetic Buffering and Phenotype Variability

“…Apart from phenotypic variation associated with oxidative stress, histone deacetylase (HDAC) inhibitors were proposed to be beneficial for CF patients (Angles et al 2019 ). Interestingly, human bronchial epithelial cells exposed to environmental stress, including diesel exhaust particles, display increased HDAC6 mRNA expression levels (Lin et al 2020 ). HDAC’s mechanism of action in CF patients is not known, but HDAC molecules control transcriptional regulation and can interact with the ribosome, thus potentially controlling the expression of modifier genes.…”