The changes in miR-130b levels in human serum and the correlation with the severity of diabetic nephropathy.

BACKGROUND

Circulating microRNA 130b has been closely associated with multiple diseases in humans such as cancer, obesity and diabetes mellitus. This study evaluates the correlation between serum miR-130b and the severity of diabetic nephropathy evaluated by measurement of albuminuria.

METHODS

Three hundred twenty-seven patients with type 2 diabetes mellitus (T2DM) were divided into three groups: normoalbuminuria group [diabetes mellitus, urinary albumin to creatinine ratio (UACR) < 30 mg/g, n = 137], microalbuminuria group (DN1, UACR 30-300 mg/g, n = 122) and macroalbuminuria group (DN2, UACR > 300 mg/g, n = 68). The levels of serum miR-130b were validated by real-time polymerase chain reaction. Serum transforming growth factor β1 (TGF-β1), hypoxia inducible factor 1α (HIF-1α) and fibronectin were determined by enzyme-linked immunosorbent assay.

RESULTS

Compared with control, serum miR-130b levels were significantly decreased in T2DM patients and further decreased in the patients of diabetes mellitus, DN1 and DN2 groups (p < 0.001). Furthermore, age-adjusted and sex-adjusted regression analyses showed that decreased level of serum miR-130b, increased levels of glycated haemoglobin (HbA1c ), homeostatic model assessment of insulin resistance (HOMA-IR), triglyceride (TG), low-density lipoprotein (LDL), serum creatinine, blood urea nitrogen (BUN), TGF-β1, HIF-1α and fibronectin were significantly correlated with UACR (p < 0.05). In addition, serum miR-130b levels were inversely correlated with HbA1c , HOMA-IR, TG, LDL, BUN, TGF-β1, HIF-1α and FN (p < 0.05).

CONCLUSION

Our findings suggest that serum miR-130b may be a new biomarker for the early diagnosis of DN in T2DM. Circulating miR-130b may possibly be involved in the pathological mechanism of DN, such as lipid metabolic disorders, oxidative stress, extracellular matrix deposition and renal fibrosis.