Hypoxia Induces Autophagy in Human Dendritic Cells: Involvement of Class III PI3K/Vps34

Abstract

Hypoxia is a component of both physiological and pathological conditions, including inflammation, solid tumors, and lymphoid tissues, where O2 demand is not balanced by O2 supply. During their lifespan, dendritic cells (DCs) are exposed to different pO2 and activate different adaptive responses, including autophagy, to preserve their viability and functions. Autophagy plays multiple roles in DC physiology. Very recently, we demonstrated that hypoxia shapes autophagy in DCs upon their differentiation state. Here, we proposed a role for PI3Ks, and especially class III PI3K/Vps34, that could be relevant in hypoxia-induced autophagy, in either immature or mature DCs. Hypoxia inhibited mTOR phosphorylation and activated a pro-autophagic program. By using different pharmacological inhibitors, we demonstrated that hypoxia-induced autophagy was mediated by PI3Ks, especially by Vps34. Furthermore, Vps34 expression was enhanced by LPS, a TLR4 ligand, along with the promotion of autophagy under hypoxia. The Vps34 inhibitor, SAR405, abolished hypoxia-induced autophagy, inhibited pro-survival signaling and viability, and increased the expression of proinflammatory cytokines. Our results underlined the impact of autophagy in the maintenance of DC homeostasis at both cell survival and inflammatory response levels, therefore, contributing to a better understanding of the significance of autophagy in DC physiology and pathology.

Chloroquine attenuates hypoxia-mediated autophagy to curb thrombosis- anex vivoandin vivostudy

“…in 2022, hypoxia increases acidity in dendritic cells causing increase in lysotracker fluorescence along with reduced LAMP1 intensity. 28 Importantly, we also observed a reduced fluorescence intensity of LAMP1 in platelets exposed to 10% oxygen concentration along with decrease in LAMP2A protein expression (Fig. 2d and 2e) .…”

Autophagy Modulates the Migration of Retinal Pericytes Induced by Advanced Glycation End Products

“…It can promote the degradation and circulation of cellular components and play an important role in maintaining cell homeostasis. Under stressful conditions such as starvation, oxidative stress, hypoxia, and cytotoxicity, autophagy is basically an adaptive response [20][21][22]. Previous studies showed that autophagy is associated with the survival of DR-related pigment epithelial cells, endothelial cells, and Muller cells in a high-glucose condition [23][24][25].…”