Exposure to radiation provokes cellular responses, which are likely regulated by gene expression networks. MicroRNAs are small non-coding RNAs, which regulate gene expression by promoting mRNA degradation or inhibiting protein translation. The expression patterns of both mRNA and miRNA during the radiation-induced lung injury (RILI) remain less characterized and the role of miRNAs in the regulation of this process has not been studied. The present study sought to evaluate miRNA and mRNA expression profiles in the rat lung after irradiation.

Objective To investigate the effect of heme oxygenase-1 ( HO-1 ) on the acute radiation-induced skin injury by gene transfer.Methods Thirty-three male SD rats were randomly divided into three groups as PBS-injected group,Ad-EGFP-injeeted group and Ad-HO-1-injected group ( n =11 ).In each group,three rats were used for determining the expression of target gene and the other rats were irradiated on the buttock skin with 40 Gy electron beam generated by a linear accelerator.Immediately after irradiation,rats were administered with a subcutaneous injection of PBS,Ad-EGFP or Ad-HO-1,respectively.Subsequently,the skin reactions were measured twice a week using the semi-quantitative skin injury scale.Results The strong positive expression of HO-1 was observed in subcutaneous dermal tissue after injection of Ad-HO-1.Compared to the PBS-injected group or the Ad-EGFP-injected group,a significant mitigation of skin injury was observed in Ad-HO-1-injected mice 14 d after irradiation (q =0.000-0.030,P ＜ 0.05 ).Conclusions HO-1 could significantly mitigate radiation-induced acute skin injury and Ad-HO-1 could be used to treat radiation-induced skin injury.

OBJECTIVE:Radiation-induced skin injury remains a serious concern for radiation therapy. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant and anti-apoptotic properties. However, the role of HO-1 in radiation-induced skin damage remains unclear. This study aims to elucidate the effects of HO-1 on radiation-induced skin injury in rats.METHODS:A control adenovirus (Ad-EGFP) and a recombinant adenovirus (Ad-HO1-EGFP) were constructed. Rats were irradiated to the buttock skin with a single dose of 45 Gy followed by a subcutaneous injection of PBS, 5 × 109 genomic copies of Ad-EGFP or Ad-HO1-EGFP (n = 8). After treatment, the skin MDA concentration, SOD activity and apoptosis were measured. The expression of antioxidant and pro-apoptotic genes was determined by RT-PCR and real-time PCR. Skin reactions were measured at regular intervals using the semi-quantitative skin injury score.RESULTS:Subcutaneous injection of Ad-HO1-EGFP infected both epidermal and dermal cells and could spread to the surrounding regions. Radiation exposure upregulated the transcription of the antioxidant enzyme genes, including SOD-1, GPx2 and endogenous HO-1. HO-1 overexpression decreased lipid peroxidation and inhibited the induction of ROS scavenging proteins. Moreover, HO-1 exerted an anti-apoptotic effect by suppressing FAS and FASL expression. Subcutaneous injection of Ad-HO1-EGFP demonstrated significant improvement in radiation-induced skin injury.CONCLUSIONS:The present study provides evidences for the protective role of HO-1 in alleviating radiation-induced skin damage in rats, which is helpful for the development of therapy for radiation-induced skin injury.