Objective To establish an intestinal organoid-based assay to investigate the radiation mitigation effect of epiregulin in vitro. Methods Intestinal crypts were released from tissue incubated with EDTA. Intestinal crypts seeded in 3D matrigel were irradiated at 24 h after plating. The radiation mitigation effect of epiregulin was evaluated by measuring the survival rate, size and budding numbers of the organoid after irradiation, and the basic FGF was used as a positive control of epiregulin. Results Radiation-induced lethality and dose-dependent survival curve of the intestinal organoid were consistent with in vivo data. Treatment with epiregulin (400 ng/ml) at 24 h post-radiation significantly increased survival rate of 8 Gy X-ray irradiated intestinal organoid in comparison with non-treated group [(12.56 ± 1.02)％vs. (4.73 ± 0.38)％, t=12.43,P<0.05]. Conclusions Epiregulin has radiation mitigation effect on intestinal organoid and could serve as a potential medical countermeasure to mitigate gastrointestinal toxicity.

ObjectiveTo explore the impact of autonomic nerve function on motor function in patients with post-stroke depression (PSD) from the perspective of regional homogeneity (ReHo). MethodsFrom January to December, 2020, a total of 60 inpatients and outpatients with cerebral infarction in the Affiliated Brain Hospital of Nanjing Medical University were divided into control group (n = 30) and PSD group (n = 30). Two groups were assessed using Fugl-Meyer Assessment (FMA), modified Barthel Index (MBI) and Hamilton Depression Scale (HAMD). Heart rate variability (HRV) was measured. Ten patients in each group were selected randomly to undergo resting state functional magnetic resonance imaging (rs-fMRI) to calculate ReHo. ResultsAll HRV indices were lower in PSD group than in the control group (|t| > 2.092, P < 0.05). In PSD group, FMA and MBI scores showed positive correlations with 24-hour standard deviation of normal-to-normal R-R intervals (SDNN), the root mean square of successive differences between normal heartbeats over 24 hours (RMSSD), the percentage of differences between adjacent normal R-R intervals over 24 hours that were greater than 50 ms (PNN50), total power (TP), very low frequency power (VLF) and low frequency power (LF) (r > 0.394, P < 0.05), and showed negative correlations with HAMD scores (|r| > 0.919, P < 0.001). HAMD scores in PSD group were negatively correlated with SDNN, RMSSD, PNN50, TP and VLF (|r| > 0.769, P < 0.001). Compared with the control group, the ReHo increased in PSD group in the right rectus gyrus (142 voxels, t = 6.575), the left medial and paracingulate gyri (204 voxels, t = 4.925) (GRF correction, P_-Voxel < 0.005，P_-Cluster < 0.05); and reduced in the right cerebellum (191 voxels, t = -6.487), the left middle temporal gyrus (140 voxels, t = -5.516), and the left precentral gyrus (119 voxels, t = -4.764) (GRF correction, P_-Voxel < 0.005，P_-Cluster < 0.05) in PSD group. ConclusionAutonomic nerve function is related to motor dysfunction in patients with PSD. The modulation of emotional, cognitive and motor brain regions by the autonomic nervous system may play a role in influencing the motor function in patients with PSD.