ROS/TNF-α Crosstalk Triggers the Expression of IL-8 and MCP-1 in Human Monocytic THP-1 Cells via the NF-κB and ERK1/2 Mediated Signaling

• Published in: International journal of molecular sciences Vol. 22; no. 19; p. 10519
• Main Authors: Akhter, Nadeem, Wilson, Ajit, Thomas, Reeby, Al-Rashed, Fatema, Kochumon, Shihab, Al-Roub, Areej, Arefanian, Hossein, Al-Madhoun, Ashraf, Al-Mulla, Fahd, Ahmad, Rasheed, Sindhu, Sardar
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2021; MDPI
• Subjects: Body mass index; Chemokines; Cytokines; Fibroblasts; Flow cytometry; Gene expression; Hypoxia; Inflammation; Insulin resistance; Kinases; Metabolic disorders; Metabolic syndrome; Microscopy; Neutrophils; Obesity; Overweight; Oxidative stress; Protein expression; Proteins; Reactive oxygen species; Tumor necrosis factor-TNF
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms221910519

IL-8/MCP-1 act as neutrophil/monocyte chemoattractants, respectively. Oxidative stress emerges as a key player in the pathophysiology of obesity. However, it remains unclear whether the TNF-α/oxidative stress interplay can trigger IL-8/MCP-1 expression and, if so, by which mechanism(s). IL-8/MCP-1 adipose expression was detected in lean, overweight, and obese individuals, 15 each, using immunohistochemistry. To detect the role of reactive oxygen species (ROS)/TNF-α synergy as a chemokine driver, THP-1 cells were stimulated with TNF-α, with/without H2O2 or hypoxia. Target gene expression was measured by qRT-PCR, proteins by flow cytometry/confocal microscopy, ROS by DCFH-DA assay, and signaling pathways by immunoblotting. IL-8/MCP-1 adipose expression was significantly higher in obese/overweight. Furthermore, IL-8/MCP-1 mRNA/protein was amplified in monocytic cells following stimulation with TNF-α in the presence of H2O2 or hypoxia (p ˂ 0.0001). Synergistic chemokine upregulation was related to the ROS levels, while pre-treatments with NAC suppressed this chemokine elevation (p ≤ 0.01). The ROS/TNF-α crosstalk involved upregulation of CHOP, ERN1, HIF1A, and NF-κB/ERK-1,2 mediated signaling. In conclusion, IL-8/MCP-1 adipose expression is elevated in obesity. Mechanistically, ROS/TNF-α crosstalk may drive expression of these chemokines in monocytic cells by inducing ER stress, HIF1A stabilization, and signaling via NF-κB/ERK-1,2. NAC had inhibitory effect on oxidative stress-driven IL-8/MCP-1 expression, which may have therapeutic significance regarding meta-inflammation.