A total of 60 adult male Sprague Dawley (SD) rats were randomly divided into 3 groups: the
Sham group (n=20), DR group (n=20) and DR +
lncRNA ANRIL knockdown group [DR +
lncRNA ANRIL
small interfering RNA (
siRNA) group, n=20]. DR model in rats was established by
intraperitoneal injection of
streptozocin (STZ; 60 mg/kg). Meanwhile, a certain dose of
lncRNA ANRIL
siRNA was added dropwise into rat eyes of DR +
lncRNA ANRIL
siRNA group during model induction to downregulate
lncRNA ANRIL expression in the retina. 16 weeks later, rat
retinal tissues were taken to extract total
RNA and
protein. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was applied to detect the expression levels of
lncRNA ANRIL,
interleukin-1 (IL-1),
IL-6 and
monocyte chemotactic protein-1 (MCP-1) in each group of the rat retina. Pathological structure of rat
retinal tissues in each group was observed via
hematoxylin and
eosin (H&E) staining. Immunohistochemistry was adopted to measure the expression levels of B-cell lymphoma-2 (Bcl-2),
Bcl-2-associated X protein (Bax) and P65 in each group of
retinal tissues. In addition, the
retinal vascular permeability in each group of rats was detected by fluorescent staining. Finally, Western blotting was utilized to determine the expressions of genes in the P65 signaling pathway.
RESULTS: Compared with rats in the
Sham group,
lncRNA ANRIL was upregulated in rat
retinal tissues harvested from the DR +
lncRNA ANRIL
siRNA group (p<0.05). After knockdown of
lncRNA ANRIL in the
retinal tissues of DR rats, pathologic damage was alleviated notably, and the levels of inflammatory markers (IL-1, IL-10 and MCP-1) were lowered markedly (p<0.05). The
protein expressions of Bax and P65 decreased evidently, while the
protein level of Bcl-2 increased markedly (p<0.05) in DR rats with ANRIL knockdown. Furthermore, Western blotting results revealed that inhibition of
lncRNA ANRIL could prominently repress the phosphorylation level of P65 in the
retinal tissues of DR rats (p<0.05).
CONCLUSIONS: