The ERK1/2-ATG13-FIP200 signaling cascade is required for autophagy induction to protect renal cells from hypoglycemia-induced cell death

New insight in treating autoimmune diseases by targeting autophagy

Autophagy is a highly conserved biological process in eukaryotes, which degrades cellular misfolded proteins, damaged organelles and invasive pathogens in the lysosome-dependent manner. Autoimmune diseases caused by genetic elements, environments and aberrant immune responses severely impact patients' living quality and even threaten life. Recently, numerous studies have reported autophagy can regulate immune responses, and play an important role in autoimmune diseases. In this review, we summarised the features of autophagy and autophagy-related genes, enumerated some autophagy-related genes involved in autoimmune diseases, and further overviewed how to treat autoimmune diseases through targeting autophagy. Finally, we outlooked the prospect of relieving and curing autoimmune diseases by targeting autophagy pathway.

CK1δ/ε inhibition induces ULK1-mediated autophagy in tumorigenesis

INTRODUCTION

Autophagy is an important mechanism of cell homeostasis maintenance. As essential serine/threonine-protein kinases, casein kinase I family members affect tumorigenesis by regulating a variety of cellular progression. However, the mechanism by which they regulate autophagy remains unclear.

MATERIALS AND METHODS

We silenced CK1δ/ε in cancer cells and observed cell morphology, the expression of autophagy-related genes, and its impact on cancer cell growth and viability. By inhibiting CK1δ/ε-induced upregulation of autophagy genes, we profiled the regulatory mechanism of CK1δ/ε on autophagy and cancer cell growth. The impact of CK1δ/ε inhibition on tumor cell growth was also assessed in vivo.

RESULTS

Here, we found that CK1δ/ε played an important role in ULK1-mediated autophagy regulation in both lung cancer and melanoma cells. Mechanically, silencing CK1δ/ε increased ULK1 expression with enhanced autophagic flux and suppressed cancer cell proliferation, while ULK1 knockdown blocked the activation of autophagy caused by CK1δ/ε inhibition. By silencing CK1δ/ε in syngeneic mouse model bearing LLC1 murine lung cancer cells in vivo, we observed tumor growth suppression mediated by CK1δ/ε inhibition.

CONCLUSION

Our results provide evidence for the role of CK1δ/ε in the regulation of tumorigenesis via the ULK1-mediated autophagy, and also suggest the impact of CK1δ/ε inhibition on tumor growth and its significance as a potential therapeutic target.

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

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.