The ameliorative effects of interleukin-33 on repetitive stereotyped behaviors and social deficits in autism and its mechanisms

Hu Limin; Yang Jiahan; Duan Lian; Gao Yuan; Li Lili

doi:10.3969/j.issn.1671-6450.2026.01.015

Abstract：Objective To investigate the effects of IL-33 on social deficits and repetitive stereotyped behaviors in the BTBR T+Itpr3tf/J(BTBR)mouse model of autism.Methods The experiment will be conducted at the Children's Hospital Affiliated to Soochow University from January 2025 to June 2025.Ten 6-week-old male BTBR mice were selected and ran-domly divided into the BTBR+Vehicle group(n=5)and the BTBR+IL-33 group(n=5)according to the random number table method.Five C57BL/6(B6)mice were selected as the B6+Vehicle group.The BTBR+IL-33 group received daily intraperito-neal injections of IL-33(300 ng/mouse)for 7 consecutive days,while the B6+Vehicle and BTBR+Vehicle groups were admin-istered an equivalent volume of saline.Following treatment,behavioral tests were conducted,including self-grooming,social interaction,three-chamber social test,and novel object recognition.After the behavioral experiments,brain tissue samples were collected.Dendrites were detected by Golgi staining,the pathological morphology of brain tissue was observed by transmission electron microscopy,and protein expression was detected by Western blot.Results The interaction time of mice in the B6+Vehicle group and the BTBR+IL-33 group was longer than that in the BTBR+Vehicle group(t=10.523,7.201,all P＜0.001),and the self-grooming time was shorter than that in the BTBR+Vehicle group(t=4.750,14.114,all P＜0.001).The TS1 of mice in the B6+Vehicle group and the BTBR+IL-33 group was greater than that of TOb(t=14.992,14.521,all P＜0.001).The social preference index of mice in the B6+Vehicle group and the BTBR+IL-33 group was greater than that of mice in the BTBR+Ve-hicle group(t=10.570,10.48,all P＜0.001).The social novelty preference index of mice in the B6+Vehicle group and the BT-BR+IL-33 group was greater than that of mice in the BTBR+Vehicle group(t=16.768,14.162,all P＜0.001).There was no sta-tistically significant difference in the novel object recognition index between the B6+Vehicle group mice and the BTBR+Vehi-cle group mice,or between the BTBR+Vehicle group mice and the BTBR+IL-33 group mice(t=0.485,0.527,P=0.640,0.612).The dendritic spine density and dendrite complexity of mice in the BTBR+Vehicle group were both higher than those in the B6+Vehicle group and the BTBR+IL-33 group(t=2.944,2.734,P=0.021,0.032).The expression level of ULK1 in the brains of mice in the B6+Vehicle group and the BTBR+IL-33 group was higher than that in the BTBR+Vehicle group(t=3.324,3.687,P=0.011,0.007).The expression level of ATG12 in the B6+Vehicle group and the BTBR+IL-33 group was higher than that in the BTBR+Vehicle group(t=3.792,3.174,P=0.005,0.013).There was no difference in the expression levels of Beclin1,ATG5,and ATG16L1 between the BTBR+Vehicle group and the BTBR+IL-33 group(t=1.083,0.300,1.857,P=0.312,0.771,0.101).Conclusion IL-33 ameliorates repetitive stereotyped behaviors and social deficits in BTBR mice by upregulating ULK1 and ATG12 expression,thereby improving neuronal structure and function.