Study on regulation of macrophage-associated lectin-1 expression by hypoxia-inducible factor-1α in hypoxia and oxidized low-density lipoprotein environment

Kadeyanmu·ABULIMITI; SHI Lin; YAN Fei

doi:10.3969/j.issn.1672-5301.2024.05.015

Abstract：Objective To investigate the regulatory effect of hypoxia-inducible factor-1α(HIF-1α)on the expression of myeloid DAP-12-associated lectin-1(MDL-1)on macrophage surfaces in the environment associated with atherosclerosis(AS),characterized by hypoxia and oxidized low-density lipoprotein(ox-LDL)and the impact of this regulation on the biological characteristics of macrophages.Methods This study was conducted in March 2022 at the Institute of Cardiovascular Diseases,Clinical Medical Research Academy,Xinjiang Medical University.The RAW 264.7 murine monocyte-macrophages were divided into four groups:the control group,hypoxia+ox-LDL group,hypoxia+ox-LDL+DMOG group and hypoxia+ox-LDL+2ME2 group.The expression levels of MDL-1,hypoxia-inducible factor-1α(HIF-1α),cyclin D1(CCND1),cysteine protease3(Caspase3),cysteine protease-1(Caspase1)and NOD-like receptor protein 3(NLRP3)were analyzed using Western Blot technique.The cell proliferation and viability were assessed using the CCK-8 assay and trypan blue staining method.The levels of inflammatory markers such as LDH,IL-1β,IL-6 and TNF-α were determined using ELISA kits.Results The changes in protein expression and cellular functions of RAW 264.7 murine monocyte-macrophages under various treatment conditions were evaluated.In the hypoxia+ox-LDL group,compared to the control group,there was a significant increase in the expression of MDL-1,HIF-1α,Caspase3,Caspase1 and NLRP3,while the expression of CCND1 was significantly reduced(P<0.05);additionally,the levels of LDH,IL-1β,IL-6 and TNF-α significantly increased[(340.267±41.338)U/L vs.(154.667±20.044)U/L,(89.251±8.488)pg/ml vs.(49.623±5.070)pg/ml,(36.642±4.730)ng/ml vs.(20.619±0.884)ng/ml,1104.515±46.411 pg/m vs.(785.291±40.339)pg/ml,P<0.01],but there was a significant decrease in cell proliferation capacity and viability[OD value(0.296±0.065)vs.(0.570±0.032),viability(69.108±7.816)%vs.(98.147±0.781)%,P<0.01].The hypoxia+ox-LDL+DMOG group,compared to the hypoxia+ox-LDL group,showed significant decrease in protein expression and inflammatory markers,and improvement in cell proliferation and viability(P<0.01).In contrast,there were exacerbated inflammatory responses and cellular damage in the hypoxia+ox-LDL+2ME2 group,with increased expression of proteins and inflammatory markers and further reduced cellular activity(P<0.01).Conclusion HIF-1α regulates the expression of MDL-1 in the environment of hypoxia and ox-LDL,subsequently affecting the proliferation,survival and secretion of inflammatory factors in macrophages.These biological characteristics may play a significant role in the pathophysiological process of AS.