Glucagon-Like Peptide 1 Receptor Agonist Improves Renal Tubular Damage in Mice with Diabetic Kidney Disease

Abstract

Purpose

This study aims to investigate the renal protective effect of glucagon-like peptide 1 receptor agonist (GLP-1RA) on improving renal tubular damage in diabetic kidney disease (DKD) and to explore the potential mechanism of GLP-1RA on renal tubular protection.

Methods

Long-acting GLP-1RA was used to treat DKD mice for 12 weeks. The label-free quantitative proteomic analysis of renal proteins was conducted to explore the differentially expressed proteins (DEPs) in the renal tissues of the control, DKD and GLP-1RA groups. The DEPs and markers of renal tubular injury were verified by qPCR in vivo and in vitro. The expression of glucagon-likepeptide-1 receptor (GLP-1R) in renal tubules was determined by immunofluorescence staining.

Results

GLP-1RA treatment significantly improved the tubular damages in kidney tissues of DKD mice and mTEC cells stimulated by high glucose (HG). Proteomics analysis revealed that 30 proteins in kidney tissue were differentially expressed among three groups. Seminal vesicle secretory protein 6 (SVS6) was the most differentially expressed protein in kidney tissues among three groups of mice. The expression changes of Svs6 mRNA in vitro and in vivo detected by qPCR were consistent with the results of proteomic analysis. Furthermore, reduction of Svs6 expression by SVS6 siRNA could attenuate HG-stimulated tubular injury in mTEC cells. Immunofluorescence staining also found that GLP-1R was widely expressed in renal tubules in vitro and in vivo.

Conclusion

GLP-1RA significantly improved renal tubular damage in DKD mice. SVS6 may be a potential therapeutic target for GLP-1RA in the treatment of DKD.

Keywords:

• diabetic kidney disease
• glucagon-like peptide-1 receptor agonist
• renal tubular injury
• seminal vesicle secretory protein 6

Abbreviations

GLP-1RA, glucagon-like peptide 1 receptor agonist; DKD, diabetic kidney disease; DEPs, the differentially expressed proteins; mTEC, murine kidney proximal tubular epithelial cells; GLP-R, glucagon-like peptide-1 receptor; eGFR, glomerular filtration rate; T2DM, type 2 diabetes mellitus; STZ, streptozotocin; SPF, the specific pathogen-free; HFD, high-fat diet; Scr, Serum creatinine; BUN, blood uric nitrogen; H&E, Hematoxylin and Eosin; PASM, Periodic Acid-Silver Methenamine; PAS, periodic acid-Schiff; LFQ, label-free quantification; GO, gene ontology; BP, biological process; MF, molecular function; CC, cell population points; KEGG, the Kyoto Encyclopedia of Genes and Genomes; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; FABP-1, fatty acid binding protein 1; KIM-1, kidney injury molecule-1; NGAL, neutrophil gelatinase-associated lipocalin; SGLT2, sodium-glucose co-transporter 2; COL1A1, collagen type I alpha 1 chain; COL3A1, collagen type III alpha 1 chain; FN1, fibronectin 1; SVS6, seminal vesicle secretory protein 6; CPT2, carnitine palmitoyl transferase 2; APOA1, apolipoprotein A1; GSTT1, glutathione S-transferase theta 1; MUP20, major urinary protein 20; NAMPT, nicotinamide phosphoribosyl transferase.

Ethics Approval

All animal experiments were approved by the Animal Ethics Committee of Tongji Hospital, Tongji University School of Medicine (2021-DW-(003)). This study was conducted in accordance with the Guide for the Care and Use of Laboratory Animals (NIH Publication, 8th Edition, 2011), and Animal Research: Reporting of In Vivo Experiments guidelines. All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.

Disclosure

The authors declare that they have no conflicts of interest for this work.

Additional information

Funding

This study was sponsored by the National Natural Science Foundation of China (Grant No. 81974105, 81670805, 81800705), Shanghai Pujiang Program (Grant No. 2019PJD050), Novo Nordisk China Diabetes Young Scientific Talent Research Funding, Psychosomatic Medicine Project of Key Developing Disciplines of Shanghai Municipal Health Commission (2019ZB0202), the Science and Technology Innovation Program of Shanghai (Grant No. 16411954700), Scientific research project of Shanghai Municipal Health Commission (Grant No. 20194Y0460), Cultivation project for National Natural Science Foundation of Shanghai Tongji Hospital, and Doctoral Fund of Northern Jiangsu Hospital (Grant No. BSQDJ0142).