Glycoprofiling Of Serum Glycoproteins From Patients With Diabetic Nephropathy

Background:Diabetic nephropathy is one of the major chronic complications of diabetes. It is a common disease, and it is also the main cause of end stage renal disease. With the increasing prevalence of diabetes in the world, the prevalence of diabetic nephropathy increased. The key to the treatment of diabetic nephropathy is early diagnosis and prevention and treatment, once entered the clinical proteinuria, can cause renal function can not be contained in the progressive deterioration, it is difficult to cure. The current study shows that there are some changes in the level of protein in the blood of patients with diabetic nephropathy, and some of the glycosylation of some proteins will also change to a certain extent. The aim of this study was to find the specific expression of glycoprotein in serum of diabetic nephropathy patients, and to provide experimental evidence for early detection and prevention of end stage renal failure.Methods:According to the clinical diagnosis results, the serum of the patients with diabetic nephropathy (40 cases) were collected. According to the gender and age of the patients, the healthy human serum (40 cases) were collected as the control group. In patients with diabetic nephropathy according to gender and 24-hour urinary protein(150～ g trace protein in urine, more than 500 g as proteinuria), serum creatinine values were divided into 4 groups, namely mild male, male severe and mild female, female severe; healthy controls by gender divided into 2 groups, the preparation of high coverage rate of lectin microarray analysis of clinical patients and the control sample protein glycan spectrum screened different sugar chain of the protein and its identification of lectin expression in each sample. Select sample validation results.Results:In the serum of male patients with DN, the signal value of the glycoprotein Bisecting GlcNAc、biantennary complex-type N-glycan with outer Gal、 Galα1-3(Fucα1-2)Gal、(GlcNAc)n, high mannose-type N-glycans、Ga1β1-3GalNAc,、 GalNAc、αGalNAc,Tn antigen、GalNAcα1-3((Fucα1-2))、Sia2-6Gal were highly expressed, and the signal value of Fucal-6 GlcNAc(core fucose), Bisecting GlcNAc, bi-antennary N-glycans, tri- and tetra-antennary complex-type N-glycan were lower expressed, the value of High-Mannose,、Mana 1-3Man,、Mana 1-6Man,、Man5-GlcNAc2-Asn、GalNAcα-1,3Gal, GalNAcα-1,3Galβ-1,3/4Glc、blood group H、T-antigen signal were higher expressed in the early stage and the later stage were low expressed.In the serum of female with DN, the glycoprotein of lectin recognition signal GalNAc、 GalNAcα-1,3 Gal、Sia2-6Gal、tri- and tetra-antennary complex-type N-glycan、 Fucαl-2Ga1β1-4Glc(NAc)、α- or β-linked terminal GalNAc,、(GalNAc)n were higher expressed; the value of the Galβ-1,4GlcNAc、Ga1β1-3 GlcNAc、GalNAcα/β1-3/6Gal、 α-D-Man、Fucα-1,6GlcNAc, α-D-Glc、sialyl-T(ST) tissue staining patterns signal were low expressed; the value of the Fucα1-6 GlcNAc(core fucose) signal were higher expressed in the early stage, the later stage were low expressed;the value of the trimers and tetramers of GlcNAc, core (GlcNAc) of N-glycan, oligosaccharide containing GlcNAc and MurNAc signal low expressed in the early stage, were higher expressed in the late stage. The results of lectin imprinting were in agreement with the experimental results.Conclusion:Lectin microarray analysis showed that there were differences in the serum glycoprotein chain structure and the control in patients with type 2 diabetes mellitus. The recognition of most of the lectin in serum of male patients had a tendency to increase or decrease with the aggravation of the disease, but there was no obvious rule in female patients. Sugar chain Sia2-6Gal and GalNAc in the serum of all patients were highly expressed; sugar chain bisecting GlcNAc, bi-antennary N-glycans, tri-and tetra-antennary complex-type N-glycan low expression in serum of patients with male, women in serum of patients with high expression. These changes will help to further understand the disease, and provide an important basis for the timely diagnosis and prevention of the formation of end stage renal failure in diabetic nephropathy.