miR-4443 targets TRIM14 to suppress metastasis and energy metabolism of papillary thyroid carcinoma (PTC) in vitro.

Tripartite motif-containing protein 14 (TRIM14) is a tumor-promoter in papillary thyroid carcinoma (PTC). We found that miR-4443 expression was significantly downregulated in PTC tumor tissue, and was negatively associated with TRIM14. This study was designed to investigate the relationship between miR-4443 and TRIM14 on metastasis and energy metabolism in PTC and the underlying mechanisms. To this end, human PTC cells (SW1736 and MZ-CRC-1) were transfected with a miR-4443 mimic or miR-4443 inhibitor + siRNA-TRIM14, and then dual-luciferase assay, Transwell, Seahorse, and western blot analyses were performed to assess the function of miR-4443 and the underlying mechanism. We found that ectopic expression of miR-4443 inhibited PTC cell migration, invasion, ATP production, and aerobic glycolysis, while inhibition of miR-4443 had the opposite effect. miR-4443 directly targeted TRIM14 and reduced both TRIM14 mRNA and protein levels. Silencing TRIM14 significantly reversed miR-4443 inhibition-induced PTC cell migration, invasion, ATP production, aerobic glycolysis, and phosphorylation of the transcription factor STAT3. These findings suggest that miR-4443 is a tumor suppressor in PTC and inhibits metastasis and energy metabolism via the suppression of TRIM14 signaling.

[Effect of repeated horizontal acceleration exposure on cardiac structure in New Zealand rabbits].

Objective: To observe the effects of repeated horizontal -Gx acceleration exposure on cardiac structure in New Zealand rabbits. Methods: Twenty New Zealand rabbits were divided into 2 groups (n=10): control group and -Gx acceleration exposure group. The rabbits in -Gx acceleration exposure group were exposed to -3. 6 Gx with 2 s, at intervals of 5 min, repeated 20 times daily, with a total of 30 d; the control group didn't undergo the acceleration stress. After the last -Gx acceleration exposure, the animals were killed by intravenous injection of air, and two small pieces of myocardium were immediately dissected from the left ventricles for structure examination using optical microscope and transmission electron microscope. Results: There was no significant difference in the myocardial cell morphology and arrangement observed under the optical microscope between the -Gx acceleration exposure group and the control group; the myocardial fibers arranged in disorder, myocardial cell edema, nuclear membrane expansion, vascular endothelial basement membrane separation were observed in the -Gx acceleration exposure group under transmission electron microscope, compared with the control group. Conclusion: -Gx acceleration exposure can lead to ultrastructural damage in rabbit cardiac myocytes. It suggested that the more attention should be paid to the effect and protection of long-term horizontal -Gx acceleration exposure on the cardiac function of carrier fighter pilots.

Rapid inhibitory effect of glucocorticoids on airway smooth muscle contractions in guinea pigs.

The common disease asthma is characterized by the obstruction, inflammation and increased sensitivity of the airways. Glucocorticoids (GCs) are one of the most potent anti-inflammatory agents available for treating allergic disease. In this study, we report that the GC budesonide (BUD) can rapidly inhibit the histamine-induced contractions of airway smooth muscle in a process mediated by non-genomic mechanisms. The tracheas of albino Hartley guinea pigs were used. We measured the effects of BUD on the increased isometric tension of trachea segment rings and the shrinking of single airway smooth muscle cells (ASMCs) induced by histamine. With the application of each reagent, the changes in the isometric tension of the segment rings upon maximum contraction and at four time points were recorded. We found that BUD significantly suppressed the increase in isometric tension induced by histamine in guinea pigs within 15 min. We also observed that BUD can reduce the histamine-induced shrinking of single ASMCs in an even shorter time. Mifepristone (RU486) and actidione did not depress the inhibitory effect of BUD. The results preclude action via genomic-mediated responses that usually take several hours to occur. We conclude therefore that GCs have a rapid non-genomic inhibitory effect on guinea pig airway smooth muscle contractions, and provide a new way to investigate this non-genomic mechanism. Further study can provide theoretical evidence for the clinical application of GCs in asthma and other allergic diseases.

[Rapid inhibitory effect of glucocorticoids on peak of [Ca2+]i and PLC in airway smooth muscle].

OBJECTIVE: In this study, we pretreated the mice ASMCs by dexamethasone (Dex) within 10 min, to test the peak of [Ca2+]i and phospho-PLCbeta (ser1105) in the cells by treated with Ach. METHODS: The peak of [Ca2+]i was measured by Fura-2/AM methods and the phospho-PLCbeta-ser1105 was by Western blot, and compared with dexamethasone pretreated groups. Glucocorticoid receptor antagonist RU486 and the protein synthesis inhibitor cycloheximide groups were settled in our study. RESULTS: Glucocorticoids (GCs) significantly decreased the resting values and peak of [Ca2+]i elevation and elevated the intracellular levels of phospho-PLCbeta (ser1105) in 10 min. Neither the RU486 nor cycloheximide could alter the inhibitory effects of glucocorticoids stated above. CONCLUSION: Our results demonstrate that glucocorticoids exert rapid inhibitory effects. The series of signal changes in this process that restrain the peak of [Ca2+]i may be responsible for the rapid nongenomic inhibitory effects of GCs by reducing the activity of PLC.