Abstract: Objective To investigate the effects of liraglutide (LIR) on pyroptosis, inflammatory cell infiltration and nuclear factor-κB (NF-κB) pathway in rats with type 2 diabetic nephropathy (DN). 
Methods A total of 45 rats were selected, from which 10 were randomly selected as control group, and the other 35 rats were used to establish DN model. A total of 30 rats were used to estabolish models sucecessfully and randomly divided into three groups (DN group, high-dose LIR group and low-dose LIR group), with 10 rats in each group. High- and low-dose LIR groups were given LIR100 and 200 g·kg-1·d-1, respectively, while control group and DN group were given the same amount of normal saline. After 2 weeks of continuous intragastolic administration, renal function indexes and the serum inflammatory factors were measured, and the inflammatory cell infiltration was evaluated by inflammatory cells. DNA damage was detected by TUNEL staining, and the expression levels of Caspase-1, interleukin-1β (IL-1β), interleukin-18 (IL-18), NF-κB pathway related proteins were detected.
Results Compared with the control group, the levels of fasting blood glucose(FBG), 24 h urine total protein (UTP), blood urea nitrogen (BUN), tumor necrosis factor-α (TNF-α), IL-1β, interleukin-6 (IL-6), the number of inflammatory cells, and the rate of TUNEL positive cells in DN group were increased, and the protein expressions of Caspase-1, IL-1β, IL-18, Toll like receptor 4 (TLR4), P-NF-κB/NF-κB and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) were up-regulated (P＜0.05). Compared with DN group, the levels of FBG, UTP and BUN, TNF-α, IL-1β and IL-6, inflammatory cell count and TUNEL positive cell rate were decreased in low-dose and high-dose LIR groups, and the expression of Caspase-1, IL-1β, IL-18, TLR4, P-NF-κB/NF-κB and NLRP3 protein were decreased (P＜0.05). Compared with low-dose LIR group, the levels of FBG, UTP and BUN, TNF-α, IL-1β and IL-6, inflammatory cell count and TUNEL positive cell rate were decreased in high-dose LIR group, and the expression of Caspase-1, IL-1β, IL-18, TLR4, P-NF-κB/NF-κB and NLRP3 protein were decreased (P＜0.05). 
Conclusion LIR can improve inflammatory cell infiltration and inhibit pyroptosis in type 2 DN rats, and its mechanism may be related to inhibition of NF-κB pathway. 

Key words: diabetic nephropathies, liraglutide, NF-kappa B