Introduction:
The aim of the study was to investigate the effects and mechanisms of long non-coding RNA (lncRNA) in diabetes-induced renal injury, both in vivo and in vitro.

Material and methods:
Sixty healthy subjects and 30 patients with diabetic nephropathy (DN) were enrolled in this study. The lncRNA ANRIL expression was measured by RT-qPCR assay in serum. Further, the ANRIL expression in kidney tissue of normal, 10-day DN, and 20-day DN rat models was measured. ELISA was used to measure levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-6 (IL-6), and tumor necrosis factor (TNF)-α. Renal pathology was evaluated by hematoxylin-eosin (HE) staining, cell apoptosis by TUNEL assay, relative protein expression by immunohistochemical (IHC) assay, and relative mRNA expression by RT-qPCR assay. In the cell experiments, LDH, MDA, SOD, IL-6, and TNF-α levels were measured by enzyme-linked immunosorbent assay (ELISA); cell proliferation by Cell Counting Kit-8 (CCK-8); cell apoptosis by flow cytometry; and relative mRNA and protein expression by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB) assay. The nuclear factor κB (NF-κB) (p65) nuclear volume of difference groups was evaluated by cell immunofluorescence.

Results:
lncRNA ANRIL was significantly higher in DN patients than healthy subjects. Compared with the sham group, the ANRIL expression and LDH, MDA, IL-6 and TNF-α concentrations were significantly increased, and SOD concentrations and cell apoptosis rate were significantly decreased with increasing time. Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κB(p65) mRNA and protein expression levels were significantly up-regulated.

Conclusions:
lncRNA ANRIL knockdown could improve diabetes-induced renal injury via regulation of TLR4/NF-κB(p65).