Autophagy protects peripheral blood mononuclear cells from high glucose-induced inflammation and apoptosis

Roya Jahangard; Shadi Sadat Seyyed Ebrahimi; Akram Vatannejad; Reza  Meshkani

doi:10.18502/abi.v1i1.14064

Roya Jahangard Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Shadi Sadat Seyyed Ebrahimi Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Akram Vatannejad Department of Comparative Biosciences, Faculty of Veterinary Medicine, University of Tehran, Iran
Reza Meshkani Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/abi.v1i1.14064

Keywords: High glucose, PBMC, autophagy, inflammation, apoptosis, LC3-II

Abstract

Previous works have linked high concentrations of glucose to cellular toxicity through autophagy modulation. However, the ways in which high glucose (HG) regulates inflammation and apoptosis in peripheral blood mononuclear cells (PBMCs) have not been well characterized. In the present study, the role of autophagy in inflammatory responses and apoptotic death of PBMCs exposed to HG was investigated. 33mM glucose (HG) increased the level of LC3-II at 12h, 24h, and 48h. NH4Cl, a lysosome inhibitor that can block autophagic flux, further promoted LC3-II accumulation in HGtreated cells at 12h, 24h, and 48h. The protein level of p62 significantly decreased from 12h to 48h in HG-treated cells, suggesting an induction of autophagic flux in HG-treated PBMCs. Inhibiting autophagy with chloroquine (CQ) significantly augmented HGinduced PBMCs apoptotic death, as demonstrated by increased cleaved PARP and Cyt C levels and an increased percentage of apoptotic (YO-PRO-1 positive and PI negative) cells. Furthermore, CQ pretreatment exacerbated HG-induced TNF-α, IL-6, and IL-1β mRNA expression in PBMCs. In conclusion, this data revealed that the autophagy system could be activated in HG-treated PBMCs. The results also indicated that the induction of autophagy might play an adaptive and protective role in HG-induced inflammation and apoptotic death of PBMCs.