RIPK2-Mediated Autophagy and Negatively Regulated ROS-NLRP3 Inflammasome Signaling in GMCs Stimulated with High Glucose.

Abstract

BACKGROUND:

Hyperglycemia plays a vital role in diabetic nephropathy (DN); autophagy and its potential upregulator receptor-interacting protein kinase 2 (RIPK2) are associated with ROS, which play a potential role in regulating NLRP3, and may be involved in inflammation in DN.

AIM:

In this study, we aimed to explore the mechanisms mediated by RIPK2 in autophagy and the relationship with ROS-NLRP3 of DN, by investigating the levels of RIPK2 and autophagy in glomerular mesangial cells (GMCs) stimulated with high glucose.

MATERIAL AND METHODS:

GMCs were divided into the following groups: normal group (NC), high glucose group (HG), and RIPK2 siRNA group. RIPK2, LC3, caspase1, and IL-1β levels were measured by western blotting and RT-PCR. Autophagosomes were measured by GFP-RFP-LC3; ROS were detected by DCFH-DA.

RESULTS:

High glucose upregulated RIPK2 and LC3 in GMCs during short periods (0-12 h) (p < 0.01), while RIPK2 and LC3 were significantly downregulated in the long term (12-72 h) (p < 0.01); these changes were positively correlated with glucose concentration (p < 0.01). In addition, levels of ROS, caspase1, and IL-1β increased in a time- and dose-dependent manner in the high glucose group, even with an increased expression of LC3 (p < 0.01). However, LC3 expression decreased in the siRIPK2 group, while levels of ROS, caspase1, and IL-1β increased (p < 0.01).

CONCLUSIONS:

Autophagy was activated by high glucose at short time periods but was inhibited in the long term, demonstrating a dual role for high glucose in autophagy of GMCs. RIPK2 regulates ROS-NLRP3 inflammasome signaling through autophagy and may be involved in the pathogenesis of DN.

• Authors: Chenlin Gao, Jiao Chen, Fang Fan, Yang Long, Shi Tang, Chunxia Jiang, Jiying Wang, Youhua Xu, Yong Xu
• Journal: Mediators of inflammation (Mediators Inflamm) Vol. 2019 Pg. 6207563 ( 2019) ISSN: 1466-1861 [Electronic] United States
• PMID: 31485193 (Publication Type: Journal Article)

Chemical References

• Inflammasomes
• NLR Family, Pyrin Domain-Containing 3 Protein
• Reactive Oxygen Species
• Glucose

Topics

• Animals
• Blotting, Western
• Cells, Cultured
• Enzyme-Linked Immunosorbent Assay
• Glucose (pharmacology)
• Inflammasomes (metabolism)
• Mesangial Cells (drug effects, metabolism)
• Mice
• NLR Family, Pyrin Domain-Containing 3 Protein (metabolism)
• Reactive Oxygen Species (metabolism)
• Real-Time Polymerase Chain Reaction
• Signal Transduction