Objective       To investigate the expression of Slit2/Robo1 and its relationship with the proliferation of glomerular endothelial cells in the patients with early diabetic nephropathy (DN)

and evaluate the clinical significance of the signal pathway. Methods      Renal tissues of 19 patients with early DN [at classes Ⅰ～Ⅱa of Tervaert’s classification

24- h urinary albumin excretion between 30 and 500 mg

estimated glomerular filtration rate (eGFR) 90 mL/( min·1.73 m2)] were collected

and another 15 normal renal tissues were also harvested as control. HE staining

PAS staining and electron microscopy were used to observe the glomerular morphology of the obtained tissues. Immunohistochemical staining was employed to detect the expression of Slit2

Robo1 and CD31 in the glomerular specimens

and then the correlation of the expression of Slit2 and Robo1 with CD31 was analyzed

and the correlation of their expression with 24-h urinary albumin excretion and eGFR was also analyzed. Results      Pathological observation displayed that typical morphological features of early DN

including glomerular hypertrophy

slightly expanded mesangial matrix

thickened glomerular basement membrane

telangiectasia

and enlarged and increased vascular endothelial cells were seen in the DN group. Slit2 was expressed in the vascular endothelial cells

tubule epithelial cells and mesangial cells. Robo1 was expressed in the vascular endothelial cells

tubule epithelial cells and podocyte cells. CD31 was highly expressed in the renal tissues from the DN patients than the non-diabetic control. The expression levels of Slit2 and Robo1 were also strongly expressed in the DN group than the non-diabetic control (P0.01). The Slit2 or Robo1 expression was positively correlated with that of CD31 in the DN (r=0.73

P0.01; r=0.72

P0.01)

and the expression levels of Slit2

Robo1 and CD31 were positively correlated with DN patients’ eGFR (r=0.78

P0.01; r=0.81

P0.01; r=0.57

P0.05) and with DN patients’ 24-h urinary albumin excretion (r=0.46

P0.05; r=0.49

P0.05; r=0.47

P0.05). Conclusion      Slit2/Robo1 signaling pathway may promote pathological angiogenesis in early DN by participating in the proliferation of glomerular endothelial cells

and then accelerate the progression of urinary protein.