Background: Oxidative stress is crucial for the development of ionizing radiation-induced intestinal injuries and inflammation. Taurine is a sulfur-containing amino acid distributed in tissues and organs throughout the body. It possesses several important physiological functions, including anti-oxidative activity and anti-inflammatory effects. Aims: To investigate the therapeutic effect and underlying mechanism of taurine against radiation-induced intestinal injuries. Methods: CCK-8 assay and DCFH-DA, a fluorescence probe of intracellular reactive oxygen species (ROS) were applied to determine the effects of taurine on radiation-induced inhibition of cell viability and ROS accumulation in human intestinal epithelial cell line HIEC-6. The modulatory effects of taurine on expressions of oxidative stress-related genes in intestinal cells after exposure to radiation were measured by real-time PCR in in vitro and in vivo studies. The roles of taurine in maintenance of intestinal morphology and suppression of cell apoptosis in mice receiving whole body radiation were assessed by HE staining and TUNEL staining. Results: In in vitro study, taurine improved the radiation-induced inhibition of cell viability and reduced intracellular ROS accumulation in HIEC-6 cells. The expression levels of catalase (CAT) and glutathione peroxidase 1 (GPx1) in HIEC-6 cells were up-regulated by taurine treatment. In vivo study showed that taurine activated the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway, alleviated intestinal villi disorganization and loss of crypt cells, and suppressed cell apoptosis in mice after radiation. Conclusions: Taurine can reduce the intracellular ROS accumulation via activating Nrf2/HO-1 antioxidant signaling pathway, and thereby, exerts protective effect against radiation-induced intestinal injuries. It might be a candidate for treatment of intestinal injuries in patients undergoing radiotherapy.

Objective:To evaluate the effect of botulinum neurotoxin A (BoNT/A) on prevention of chronic migraine (CM) in mice and explore the potential mechanism.Methods:Twenty-four male C57BL/6 mice were randomly divided into control group, nitroglycerin (NTG) group, and BoNT/A+NTG group ( n=8). Mice in the latter two groups were intraperitoneally injected with 10 mg/kg NTG on the 1 st, 3 rd, 5 th, 7 th and 9 th d of experiments to establish CM models. Mice in the BoNT/A+NTG group were injected with 0.18 U/100 μL BoNT/A one h before the first injection of NTG. Mice in the control group were injected with the same dose of normal saline. Basal mechanical withdrawal threshold (MWT) and evoked MWT 2 h after NTG in the facial and hindpaw regions on the 1 st, 3 rd, 5 th, 7 th and 9 th d of experiments were evaluated by von Frey filament test. The motor function of mice 2 h after NTG injection was tested by rotarod test on the 1 st, 3 rd, 5 th, 7 th and 9 th d of experiments. On 9 th d of experiments, the mice were sacrified; the calcitonin gene-related peptide (CGRP), synaptosomal-associated protein 25 (SNAP25), glial fibrillary acidic protein (GFAP) and TRP channel protein expressions in the trigeminal ganglia (TG) and trigeminal nucleus caudalis (TNC), and NOD-like receptor protein 3 (NLRP3) inflammatory factor pathway-related protein expressions in TNC were detected by Western blotting; real-time quantitative PCR (RT-qPCR) was used to detect the NLRP3 inflammatory factor pathway-related mRNA expressions in TNC. The CGRP expression in TNC was detected by immunofluorescent staining. Results:(1) As compared with the control group, the NTG group had significantly decreased basal facial MWT on the 7 th and 9 th d of experiments ( P<0.05); as compared with the NTG group, the BoNT/A+NTG group had significantly increased basal facial MWT on the 7 th and 9 th d of experiments ( P<0.05). As compared with the control group, the NTG group had significantly decreased evoked facial MWT on the 5 th and 9 th d of experiments ( P<0.05); as compared with the NTG group, the BoNT/A+NTG group had significantly increased evoked facial MWT on the 5 th and 9 th d of experiments ( P<0.05). As compared with the control group, the NTG group had significantly decreased basal and evoked MWT in the hindpaw regions on the 3 rd, 5 th, 7 th and 9 th d of experiments ( P<0.05); as compared with the NTG group, the BoNT/A+NTG group had significantly increased basal and evoked MWT in the hindpaw regions on the 3 rd, 5 th, 7 th and 9 th d of experiments ( P<0.05). (2) There was no significant difference in running time on rotarod among the three groups ( P>0.05). (3)Western blotting results showed that as compared with those in the control group, the CGRP and SNAP25 protein expressions were significantly increased in TG of the NTG group ( P<0.05); and those in the BoNT/A+NTG group were significantly decreased as compared with those in the NTG group ( P<0.05). As compared with those in the control group, the CGRP and NLRP3 protein expressions were significantly increased in TNC of NTG group ( P<0.05); and those in the BoNT/A+NTG group were significantly decreased as compared with those in the NTG group ( P<0.05). (4)RT-qPCR results showed that as compared with that in the control group, the IL-1β mRNA expression in TNC of the NTG group was significantly increased ( P<0.05), and that in the BoNT/A prevention group was statistically decreased as compared with that in the NTG group ( P<0.05). (5) Immunofluorescent staining results showed that as compared with that in the control group, the CGRP expression in TNC of the NTG group was significantly increased, and that in the BoNT/A+NTG group was significantly decreased as compared with that in the NTG group ( P<0.05). Conclusion:BoNT/A can reduce the SNAP25 expression in TG, reduce the CGRP release in TG and TNC, and prevent CM onset; BoNT/A can regulate NLRP3 level in TNC.

OBJECTIVE To investigate the effects of GSTP1， XRCC1， ABCB1， MTHFR gene polymorphisms on efficacy and toxic effect of chemotherapy regimen containing oxaliplatin in patients with stage Ⅲ and Ⅳ colorectal cancer patients. METHODS Clinical data of 76 patients with stage Ⅲ and Ⅳ colorectal cancer who received chemotherapy regimen containing oxaliplatin （XELOX，FOLFOX） were collected from the Second Affiliated Hospital of Soochow University from September 2018 to March 2020. The correlation of genotypes with progression-free survival （PFS） and toxic effect was analyzed by using univariate and multivariate COX regression model. RESULTS Carriers of the ABCB1 3435T＞C locus C allele （TC/CC） had a significantly higher risk of progression compared to TT genotype patients [HR＝2.39， 95%CI （1.05，5.50）， P＝0.038]. The risk of progression in patients at stage Ⅳ was significantly higher than those at stage Ⅲ [HR＝8.11， 95%CI（3.39，19.40）， P＜0.001]. Chemotherapy regimen， Karnofsky performance status score and tumor site had no significant effect on disease progression （P＞0.05）. Mutations in gene loci were not correlated with adverse reactions （P＞0.05）. CONCLUSIONS Patients carrying ABCB1 TC/CC and receiving chemotherapy regimen containing oxaliplatin have a higher risk of disease progression， which may be associated with longer PFS in patients （TT genotype） with stage Ⅳ colorectal cancer receiving the chemotherapy， while GSTP1， XRCC1， and MTHFR gene polymorphisms have no significant impact.