3,4-Dihydroxyacetophenone attenuates oxidative stress-induced damage to HUVECs via regulation of the Nrf2/HO-1 pathway

Abstract

It has been reported that oxidative stress plays a prominent role in diabetic macrovascular diseases. 3,4-Dihydroxyacetophenone (3,4-DHAP) has been found to have a variety of biological activities. However, few studies have assessed the antioxidant capacity of 3,4-DHAP and the underlying mechanisms. Thus, the aim of the present study was to explore the effects of 3,4-DHAP on oxidative stress in human umbilical vein endothelial cells (HUVEC s). HUVEC s were pre-treated with 3,4-DHAP and then exposed to high glucose conditions. Cell viability and cytotoxicity were measured using an MTT assay. Reactive oxygen species (ROS) levels were measured using an inverted fluorescence microscope and a fluorescent enzyme labeling instrument. Protein expression levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), microtubule-associated protein 1A/1B-light chain 3 (LC 3) and poly AD P-ribose polymerase-1 (PAR P-1) were measured using western blotting, and mRNA expression of Nrf2 and HO-1 were measured through reverse transcription-quantitative PCR (RT-qPCR ). Nrf2 nuclear translocation was evaluated using immunofluorescence analysis and autophagosomes were observed using transmission electron microscope (TEM). The results of the present study demonstrated that compared with the control group, cell viability of the high glucose group was reduced and cell cytotoxicity of the high glucose group was increased. RO S production in the high glucose group was clearly enhanced. In addition, high glucose upregulated Nrf2 and HO-1 protein and mRNA expression levels. Nuclear translocation of Nrf2 in the high glucose group was also increased. The formation of autophagosomes in the high glucose group was also higher than that in the control group. Furthermore, LC 3-II /LC 3-I and PAR P-1 protein expression levels were increased after treatment with high glucose. However, compared to the high glucose group, 3,4-DHAP (10 μmol/l) significantly enhanced cell viability. 3,4-DHAP markedly decreased the production of RO S, increased Nrf2 and HO-1 protein and mRNA expression levels, and promoted nuclear translocation of Nrf2 in HUVEC s. In addition, 3,4-DHAP promoted the formation of autophagosomes, and notably increased the protein expression levels of LC 3-II /LC 3-I and PAR P-1. Moreover, it was determined that compared to the 3,4-DHAP group, treatment with 3,4-DHAP and ML385 enhanced cell viability, and decreased RO S production, Nrf2 and HO-1 protein and mRNA expression levels, nuclear translocation of Nrf2, and LC 3-II /LC 3-I and PAR P-1 protein expression levels. Collectively, the results of the present study showed that 3,4-DHAP protected HUVEC s against oxidative stress via regulation of the Nrf2/HO-1 pathway, by increasing autophagy and promoting DNA damage repair.