OBJECTIVETo explore the expression of Toll-like receptor 4 (TLR4) and tumor necrosis factor-α (TNF-α) on peripheral-blood mononuclear cells (PBMCs) and their correlation with myocardial perfusion in patients with diabetic cardiomyopathy (DCM).

METHODSThe expression of TLR4 and TNF-α mRNA on PBMCs were examined by SYBR Green I real-time quantitative reverse transcription polymerase chain reaction (RT-PCR), the levels of TLR4 and TNF-α were examined by flow cytometric analysis and enzyme-linked immuno sorbent assay (ELISA) on DCM group (n = 20), Type 2 diabetic group (n = 22) and control group (n = 20). Myocardial perfusion was visualized by single-photon emission computed tomography (SPECT).

RESULTSThe expressions of TLR4 and TNF-α mRNA/protein on PBMCs in DCM group were significantly higher than in Type 2 diabetic group, and higher in Type 2 diabetic group than in control groups (P < 0.05); summed stress score (SSS) and summed rest score (SRS) of myocardial perfusion in DCM group were significantly higher than in Type 2 diabetic group, and higher in Type 2 diabetic group than in control groups (P < 0.01). The expression of TLR4, TNF-α was positively correlated with SSS (r = 0.75, P < 0.05; r = 0.931, P < 0.005) and SRS (r = 0.78, P < 0.005; r = 0.789, P < 0.005). SSS and SRS in DCM group were also positively correlated with soluble vascular cell adhesion molecule-1 (sVCAM-1) (r = 0.728, P < 0.005; r = 0.738, P < 0.005) but there was no correlation between SSS and SRS and brain natriuretic peptide, LVEF, E/A, HbA1c, FBG, FIN and LDL-C (P > 0.05).

CONCLUSIONThe increased expression of TLR4 and TNF-α mRNA/protein on PBMCs and increased serum sVCAM-1 is linked with reduced myocardial perfusion in DCM group. TLR4 and TNF-α may thus play a critical role in the myocardial perfusion inflammation injury in these patients.