Objective: To investigate whether microRNA-34a (miR-34a) participates in lipopolysaccharide (LPS) mediated sepsis related renal function impairment via Kruppel-like factor 4 (KLF4).
Methods: Thirty healthy male Sprague-Dawley (SD) rats, weighing 180-200 g, were randomly divided into two groups: control group and model group, with 15 rats in each group. The SD rats from model group were injected with LPS 7.5 mg/kg to induce sepsis related renal function impairment model, the SD rats from control group were injected with normal saline. The serum creatinine concentration (SCr) and blood urine nitrogen (BUN) content was detected by multifunction biochemical analyzer; the morphological changes of renal tissue were observed by hematoxylin and eosin stain (HE) staining; the expression of miR-34a and KLF4 gene in plasma and renal tissue were detected by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR); the protein expression of KLF4 in renal tissue was detected by Western Blot; the target gene of miR-34a was verified by double luciferase reporter gene analysis.
Results: Compared with control group, inflammatory cell infiltration in renal tissue was increased in model group, the SCr and BUN were significantly increased [SCr (μmol/L): 142.5±10.6 vs. 46.4±5.6, BUN (mmol/L): 31.6±6.2 vs. 8.5±1.2, both P < 0.01], the gene expression of miR-34 in plasma and renal tissue were significantly increased (2-ΔΔCt: 2.26±0.11 vs. 1.14±0.05 in plasma, 4.23±0.12 vs. 1.12±0.04 in renal tissue, both P < 0.01), the gene and protein expressions of KLF4 were significantly decreased [KLF4 gene (2-ΔΔCt): 0.52±0.03 vs. 1.21±0.06, KLF4 protein (A value): 0.72±0.03 vs. 1.05±0.04, both P < 0.01], which indicated that kidney injury occurred in rats. Pearson correlation analysis showed that plasma miR-34a was positively correlated with SCr and BUN (r value were 0.678, 0.721, respectively, both P < 0.05). Double luciferase reporter assay confirmed that KLF4 was the target gene of miR-34a.
Conclusions: The miR-34a participates in LPS mediated sepsis related renal function impairment via KLF4.