Study Of Extracellular Matrix Components And Cellular Adhesion Molecules In Diabetic Retinopathy

Objective To investigate the change of the serum extracellular matrix (ECM), vascular basement membrane components and vascular endothelial cell adhesion molecule in various stages of diabetic retinopathy (DR), and evaluate the relationship between these components and the vascular basement membrane or endothelial cell damages.Methods 85 type 2 diabetes patients (40 men and 45 women) were divided into three groups based on severity of diabetic retinopathy graded as: no signs diabetic retinopathy group (NDR), background diabetic retinopathy group (BDR) and proliferative diabetic retinopathy group (PDR). The serum levels of type IV collagen (IV C) and laminin (LN) were determined by radioimmunoassay. The serum level of soluble vascular cell adhesion molecule-1 (sVCAM-1) was measured in duplicate by enzyme-linked immunosorbent assay. Fundus examination all patients was performed by one ophthalmologist using an ophthalmoscope or fundus fluorescein angiography (FFA). All patients were not complicated with the increase of serum creatinine or blood urine nitrogen(BUN), high urinary albumin excretion rate (UAER) or 0 2-niicro globulin ( (3 2-MG) or hypertension. 20 healthy persons were selected as control group(8 men and 12 women).Results The serum LN, IV C and sVCAM-1 levels in patients with NDR, BDR and PDR were higher than those of control group. In PDR group, The serum LN, IV C and sVCAM-1 levels were significant difference incomparison with control group(P<0.01), and NDR group(P<0.01). In BDP group, The serum LN, IV C and sVCAM-1 levels were significant difference in comparison with control group (P<0.01). In NDR group, IV C and sVCAM-1 levels were significant difference except serum LN in comparison with control group(P>0.05).There were significant difference in serum IV C and LN levels(P<0.01), except sVCAM-l(P>0.05), between the PDR and the BDR groups, there was no significant difference in serum IV C and LN, sVCAM-1 (P>0.05) between the BDR and NDR groups.Fast blood glucose in all diabetic patients were not significant correlated( F = l .99,P>0.05). Among three groups, the positive correlation was found in the fast serum insulin, the post 2 hours blood glucose and the post 2 hours serum insulin, respectively( F=3.25 and F=4.8,F=6.00, P < 0.05). Knowing diabetic duration and the BMI were significant differences in diabetic patients with NDR, BDR and PDR groups( F=10.95 and F=9.86, P < 0.05), respectively. No significant correlation were found among serum IVC,LN sVCAM-1 in all diabetic patients.( r =0.119, r =0.167 and r = -0.210; P > 0.05, respectively). In addition, the BMI were negative by correlated with the knowing diabetic duration, (r = -0.488, P < 0.05)Conclusions The development of diabetic microangiopathy is a latent process from the functional damage to disorder of histo-morphology. In early stsge of DR, the functional alteration had happened on vascular endothelium cell and basement membrane, yet was not obvious on morphologic change. Serum IV C,LN and sVCAM-1 levels shown increasing by degree in this stage, which was not only relation to the interaction of ECM components, and AMs, but also to the abnormal function of them. The results suggest that the investigation on theinterrelation and change of ECM components and AMs might show better4values for exploring the pathogenesis and development process of the diabetic microangiopathy. The study might be implicated in the process of the DR for early diagnosis and therapy of diabetic microangiopathy. Measurement of serum IV C, LN and sVCAM-1 levels in DR patients may be reliable clinical markers for assessing the functionary and morphologic alteration on the vascular endothelial cell and basic membrane.