Objective To observe the effect of neuregulin-1(NRG-1)on retinal ganglion cells(RGCs)in Zucker Di-abetic Fatty(ZDF)rats and explore the mechanism of NRG-1 in exerting neuroprotective effects on the retina.Methods Twenty-four 8-week-old male ZDF rats(24 eyes)were selected.Diabetic obese rat models were established by feeding a high-fat and high-sugar diet(Purina 5008).After 16 weeks,they were randomly divided into the ZDF group and the NRG-1 group(12 rats in each group).Rats in the NRG-1 group received intravitreal injection of human recombinant NRG-1(once a week for a total of two times),rats in the ZDF group were used as negative controls,and Zucker lean control(ZLC)rats were selected as blank controls(ZCL group).The changes in the number of RGCs in rats of each group were observed by immunofluorescence staining.The protein expressions of NOD-like receptor family pyrin domain containing protein 3(NLRP3),Caspase-1,and Gasdermin D(GSDMD)in the retina of rats in each group were observed by immuno-histochemistry and Western blot.Results After 16 weeks of eating a high-fat diet,compared with the ZLC group,the fasting blood glucose of rats in the ZDF group significantly increased(P＜0.001).The results of immunofluorescence stai-ning showed that the RGCs of rats in the ZLC group were continuously and neatly arranged;compared with the ZLC group,the number of RGCs of rats in the ZDF group significantly decreased(P＜0.001);compared with the ZDF group,the num-ber of RGCs of rats in the NRG-1 group significantly increased(P＜0.01).The immunohistochemical results showed that there were statistically significant differences in the average optical density values of NLRP3,Caspase-1 and GSDMD in the retina of rats in each group(all P＜0.01);compared with the ZLC group,the average optical density values of NLRP3,Caspase-1 and GSDMD in the retina of rats in the ZDF group were higher(all P＜0.01);compared with the ZDF group,the average optical density values of NLRP3,Caspase-1 and GSDMD in the retina of rats in the NRG-1 group significantly de-creased(all P＜0.05).Western blot results showed that there were statistically significant differences in the protein ex-pression levels of Brn3a,NLRP3,Caspase-1 and GSDMD in the retina of rats among all groups(all P＜0.01);compared with the ZLC group,the protein expression of Brn3a significantly decreased,while the protein expressions of NLRP3,Caspase-1 and GSDMD significantly increased in the ZDF group(all P＜0.01);compared with the ZDF group,the protein expression of Brn3a significantly increased,while the protein expressions of NLRP3,Caspase-1 and GSDMD significantly decreased in the NRG-1 group(all P＜0.01).Conclusion After retinal lesions occur in diabetic rats,NLRP3,Caspase-1 and GSDMD are all significantly activated.NRG-1 can reduce the expressions of NLRP3,Caspase-1 and GSDMD,reducing damage to RGCs.