Effects of serum from the obesity patients with diabetic mellitus on TLR4/NF-κB pathway in human THP-1 monocytes / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To investigate the effects of serum from the obesity patients and obesity patients with Diabetic mellitus on toll-like receptor 4/Nuclear factor -κB p65 (TLR/NF-κB) pathway in human THP-1 monocytes and to explore the inflammatory immune response in obesity.@*METHODS@#Peripheral serum was isolated from healthy volunteers (the control group), the obesity patients (Ob group) and the obesity patients with diabetic mellitus (the Ob with DM group), respectively, 20 in each group. THP-1 monocytes were incubated with the serum for 48 h. The monocytes and culture supernatant were collected. The phosphorylation level of NF-κB p65 protein in THP-1 monocytes was evaluated by Western blot as well as immunofluorescence assay. The TLR4 mRNA expression was evaluated by RT-PCR. ELISA was used to measure the monocyte chemotactic protein-1 (MCP-1) levels in the culture supernatant.@*RESULTS@#In the presence of serum, the obesity group and the obesity with diabetic mellitus group showed the up-regulated phosphorylation level of NF-κB p65 protein and TLR4 mRNA expression in THP-1 monocytes compared with the healthy control group (both P<0.05), and the MCP-1 levels in the obesity patients were up-regulated significantly compared with the healthy control group [healthy control group (26.4 ± 3.9) pg/mL, Ob group (45.8 ± 10.0) pg/mL, Ob with DM group (58.0 ± 15.3) pg/mL; P<0.05]. These parameters were further up-regulated in the obesity patients with diabetic mellitus patients.@*CONCLUSION@#The serum from the obesity patients or the obesity patients with diabetes can induce monocyte dysfunction, which might be related to the activation of TLR4/NF-κB signaling pathway.