PMID- 35414608 OWN - NLM STAT- MEDLINE DCOM- 20220414 LR - 20220530 IS - 2053-8790 (Print) IS - 2053-8790 (Electronic) IS - 2053-8790 (Linking) VI - 9 IP - 1 DP - 2022 Apr TI - Metformin improves renal injury of MRL/lpr lupus-prone mice via the AMPK/STAT3 pathway. LID - 10.1136/lupus-2021-000611 [doi] LID - e000611 AB - OBJECTIVE: Lupus nephritis (LN) is a major complication and cause of death among patients with SLE. This research used in vivo and in vitro experiments to explore the therapeutic potential of metformin in kidney injury from LN-induced inflammation. METHODS: In vivo study, 8-week-old MRL/MpJ-Faslpr/J (MRL/lpr) mice were randomly divided into two groups (n=12 each): daily administration of 0.3 mg/mL metformin in drinking water and control (water only). Body weight and urinary samples were measured biweekly. Mice were sacrificed after 8-week treatment to harvest serum, lymph nodes, spleen and kidneys. In vitro study, human kidney-2 (HK-2) cells were pretreated with 1 mM metformin for 1 hour and then stimulated with 20 microg/mL lipopolysaccharides (LPS) or 10 ng/mL tumour necrosis factor-alpha (TNF-alpha) for another 48 hours. Protein was collected for subsequent analysis. RESULTS: We found that metformin administration improved renal function in MRL/lpr lupus-prone mice, measured by decreased urea nitrogen and urinary proteins. Metformin reduced immunoglobulin G and complement C3 deposition in glomeruli. The treatment also downregulated systemic and renal inflammation, as seen in decreased renal infiltration of F4/80-positive macrophages and reduced splenic and renal MCP-1 (monocyte chemoattractant protein-1) and TNF-alpha, and renal IL-1beta (interleukin 1beta) expression. Metformin administration decreased renal expression of necroptosis markers p-RIPK1 (phosphorylated receptor-interacting protein kinase 1) and p-MLKL, along with tubular injury marker KIM-1 (kidney injury molecule-1) in lupus mice. In addition, metformin alleviated the necroptosis of HK-2 cells stimulated by LPS and TNF-alpha, evidencing by a decrease in the expression of necroptosis markers p-RIPK1, p-RIPK3 and p-MLKL, and the inflammasome-related markers NLRP3 (NLR family pyrin domain containing 3), ASC (apoptosis-associated speck-like protein containing a CARD), caspase-1. Mechanistically, metformin treatment upregulated p-AMPK (phosphorylated AMP-activated protein kinase) and downregulated p-STAT3 (phosphorylated signal transducer and activator of transcription 3) expression in the kidneys. Moreover, AMPKalpha2 knockdown abolished the protective effects of metformin in vitro. CONCLUSIONS: Metformin alleviated kidney injury in LN though suppressing renal necroptosis and inflammation via the AMPK/STAT3 pathway. CI - (c) Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. FAU - Chen, Xiao-Cui AU - Chen XC AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Wu, Dan AU - Wu D AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Wu, Hong-Luan AU - Wu HL AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Li, Hui-Yuan AU - Li HY AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Yang, Chen AU - Yang C AUID- ORCID: 0000-0001-8937-4508 AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Su, Hong-Yong AU - Su HY AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Liu, Ze-Jian AU - Liu ZJ AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Huang, Xiao-Rong AU - Huang XR AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Lu, Xing AU - Lu X AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Huang, Li-Feng AU - Huang LF AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Zhu, Shao-Ping AU - Zhu SP AD - Laboratory Animal Center, Guangdong Medical University, Zhanjiang, Guangdong, China. FAU - Pan, Qing-Jun AU - Pan QJ AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - An, Ning AU - An N AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China an347@163.com hf-liu@263.net. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. FAU - Liu, Hua-Feng AU - Liu HF AD - Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang, Institute of Nephrology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China an347@163.com hf-liu@263.net. AD - Guangdong Provincial Key Laboratory of Autophagy and Major Chronic Non-communicable Diseases co-sponsored by province and city, Zhanjiang, Guangdong, China. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - England TA - Lupus Sci Med JT - Lupus science & medicine JID - 101633705 RN - 0 (Lipopolysaccharides) RN - 0 (NLR Family, Pyrin Domain-Containing 3 Protein) RN - 0 (STAT3 Transcription Factor) RN - 0 (STAT3 protein, human) RN - 0 (Tumor Necrosis Factor-alpha) RN - 9100L32L2N (Metformin) RN - EC 2.7.11.31 (AMP-Activated Protein Kinases) SB - IM MH - AMP-Activated Protein Kinases/metabolism/pharmacology MH - Animals MH - Humans MH - Inflammation MH - Kidney/metabolism MH - Lipopolysaccharides/metabolism/pharmacology/therapeutic use MH - *Lupus Erythematosus, Systemic/complications/drug therapy MH - *Lupus Nephritis/complications/drug therapy MH - *Metformin/pharmacology/therapeutic use MH - Mice MH - Mice, Inbred MRL lpr MH - NLR Family, Pyrin Domain-Containing 3 Protein/metabolism MH - STAT3 Transcription Factor/metabolism/pharmacology/therapeutic use MH - Signal Transduction/physiology MH - Tumor Necrosis Factor-alpha/metabolism/pharmacology/therapeutic use PMC - PMC9006817 OTO - NOTNLM OT - Lupus Erythematosus, Systemic OT - Lupus Nephritis OT - Therapeutics COIS- Competing interests: None declared. EDAT- 2022/04/14 06:00 MHDA- 2022/04/15 06:00 PMCR- 2022/04/11 CRDT- 2022/04/13 05:34 PHST- 2021/11/09 00:00 [received] PHST- 2022/03/30 00:00 [accepted] PHST- 2022/04/13 05:34 [entrez] PHST- 2022/04/14 06:00 [pubmed] PHST- 2022/04/15 06:00 [medline] PHST- 2022/04/11 00:00 [pmc-release] AID - 9/1/e000611 [pii] AID - lupus-2021-000611 [pii] AID - 10.1136/lupus-2021-000611 [doi] PST - ppublish SO - Lupus Sci Med. 2022 Apr;9(1):e000611. doi: 10.1136/lupus-2021-000611.