Objective To investigate the effect of non-coding RNA activated by DNA damage (NORAD) on acute lung injury (ALI) in septic rats by regulating the miR-155-5p/TLR6 molecular axis. Methods The rats were randomly divided into control group, model group, low NORAD expression no-load group (LV-sh-NC), low NORAD expression group (LV-sh-NORAD), low NORAD expression +miR-155-5p low expression no-load group (LV-sh-NORAD+NC antagomir), NORAD low expression +miR-155-5p low expression group (LV-sh-NORAD+miR-155-5p antagomir). ELISA kits were applied to detect interleukin (IL)-8, IL-1β, and tumor necrosis factor-α (TNF-α) levels; quantitative real-time polymerase chain reaction was applied to detect the expression of NORAD, miR-155-5p, and Toll-like receptor 6 (TLR6) genes in lung tissue of rats in each group. The ratio of wet weight to dry weight (W/D) of lung tissue was measured. The pathological changes of lung tissue were observed by hematoxylin-eosin staining, and apoptosis in lung tissue cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling. Western blot was applied to detect the expressions of TLR6, Bax, Bcl-2, and cleaved cysteinyl aspartate specific proteinase 3 caspase-3) proteins in cells. Dual luciferase reporter gene experiment was applied to verify the relationship between miR-155-5p and NORAD and TLR6. Results Compared with the control group, the lung tissue of rats in the model group and LV-sh-NC group was obviously damaged, the levels of serum IL-1β, TNF-α, IL-8, expression of NORAD and TLR6 mRNA in lung tissue, W/D ratio, apoptosis rate, expression of TLR6, Bax, and Cleaved-caspase-3 proteins were obviously increased, the expression of miR-155-5p and Bcl-2 proteins in lung tissue was obviously reduced (P<0.05). Down-regulation of NORAD expression could reduce lung tissue injury, serum IL-1β, TNF-α, IL-8 levels, mRNA expression of NORAD and TLR6 in lung tissue, W/D ratio, apoptosis rate, TLR6, Bax, Cleaved caspase-3 protein expression, and cleaved caspase-3 protein expression. The expression of miR-155-5p and Bcl-2 protein in lung tissue were significantly increased (P<0.05). Down-regulating the expression of miR-155-5p could reduce the improvement effect of negatively regulated NORAD on sepsis ALI rats (P<0.05). Conclusion Interference with NORAD can alleviate lung injury in ALI rats by regulating the miR-155-5p/TLR6 molecular axis.
ObjectiveTo investigate the expression of MicroRNA 155 (miR-155) in esophageal squamous cell carcinoma (ESCC) and analyze its correlation with clinicopathological features of ESCC. MethodsThis study included 54 patients with primary ESCC who underwent radical esophagectomy in Department of Thoracic Surgery, Henan Cancer Hospital of Zhengzhou University between January 2010 and November 2012. There were 47 males and 7 females with median age of 61 years (range, 45 to 82 years). Forty patients were in stage Ⅰ or Ⅱ and 14 patients in stage Ⅲ a+b. Expression of miR-155 was determined by SYBR Green qRT-PCR in ESCC tissue and corresponding adjacent normal mucosa in surgical samples from the 54 patients, and its correlation with clinicopathological features was analyzed. ResultsExpression of miR-155 was significantly lower in ESCC tissue than that in adjacent normal mucosa (Z=-4.258, P=0.000).Expression level of miR-155 was significantly correlated with lymph node metastasis (P=0.040), but not significantly correlated with smoking (P=0.430), drinking (P=0.429), age (P=0.769), gender (P=0.671), depth of invasion (P=0.230), differentiation degree (P=0.896) or pTNM (P=0.407) of ESCC. ConclusionUnder-regulation of miR- 155 expression in ESCC tissue may lead to disorders of inflammation response, immune response and relevant tumor suppressor, and may play a significant role in carcinogenesis and progression of ESCC.