The Male-Biased Expression of miR-2954 Is Involved in the Male Pathway of Chicken Sex Differentiation

Many expression data showed miRNAs have a potential function on regulating gonadal differentiation in animals, but their function is rarely studied in vivo, especially in chickens. Using the comprehensive expression profiles analysis, the specific male-biased miR-2954, which is significantly higher expressed in male embryos and gonads at all detected stages, was firstly screened during the early stages of chicken embryogenesis and gonadogenesis. In sex-reversed female gonads treated with aromatase inhibitors, the expression of miR-2954 was increased, which was consistent with the up-regulation of DMRT1 and SOX9. The injection of vivo-morpholino of miR-2954 significantly inhibited the expression of miR-2954 in chicken embryos, and the down-regulation of miR-2954 decreased the expression of testis-associated genes DMRT1 and SOX9, while the expression of ovary-associated genes and the gonadal morphology did not change obviously. These results confirm that miR-2954 coincides with testicular differentiation in chicken embryos, but whether it might be an upstream cell autonomous factor to sex development in birds still need to be further determined.

miR-2954 Inhibits PI3K Signaling and Induces Autophagy and Apoptosis in Myocardium Selenium Deficiency

BACKGROUND/AIMS

Selenium (Se) deficiency can lead to several cardiac diseases, including Keshan disease in humans, mulberry heart disease in pigs and cardiac injury in chickens. MicroRNAs have been a research focus in recent years and have been shown to participate in a new avenue of cell death-autophagy, which can play a significant role in several types of heart disease.

METHODS

MicroRNAome analysis showed that the expression of miR-2954 was increased in the myocardium of selenium-deficient chickens, and PI3K was predicted to be the target gene. The target relationship between miR-2954 and PI3K was verified with a double fluorescence enzyme assay and RNA Protein Interaction Prediction and molecular docking software. qRT-PCR and western blotting were used to detect the expression of PI3K and related pathway components in selenium-deficient chickens and miR-2954 knockout/overexpression cardiomyocytes.

RESULTS

In this study, we observed that miR-2954 overexpression led to inhibition of PI3K pathway in vivo and in vitroled to inhibition of the PI3K pathway in vivo and in vitro.

CONCLUSION

The expression of miR-2954 was increased in selenium-deficient myocardium, whereas overexpression of miR-2954 led to autophagy and apoptosis of myocardial cells during cardiac injury through regulation of the PI3K pathway; whether this phenomenon is a self-protection mechanism of the organism or damage caused by miR-2954 requires further study. Our findings provides new insight apoptosis in cardiomyocytes; additionally, we aim to provide a new direction for the diagnosis and targeted treatment of myocardial diseases.