Abstract:
Autoreactivity of the complement system may escalate the development of diabetic nephropathy. We used the BTBR OB mouse model of type 2 diabetes to investigate the role of the complement factor mannan-binding lectin (MBL) in diabetic nephropathy. Female BTBR OB mice (n = 30) and BTBR non-diabetic WT mice (n = 30) were included. Plasma samples (weeks 12 and 21) and urine samples (week 19) were analyzed for MBL, C3, C3-fragments, SAA3, and markers for renal function. Renal tissue sections were analyzed for fibrosis, inflammation, and complement deposition. The renal cortex was analyzed for gene expression (complement, inflammation, and fibrosis), and isolated glomerular cells were investigated for MBL protein. Human vascular endothelial cells cultured under normo- and hyperglycemic conditions were analyzed by flow cytometry. We found that the OB mice had elevated plasma and urine concentrations of MBL-C (p < 0.0001 and p < 0.001, respectively) and higher plasma C3 levels (p < 0.001) compared to WT mice. Renal cryosections from OB mice showed increased MBL-C and C4 deposition in the glomeruli and increased macrophage infiltration (p = 0.002). Isolated glomeruli revealed significantly higher MBL protein levels (p < 0.001) compared to the OB and WT mice, and no renal MBL expression was detected. We report that chronic inflammation plays an important role in the development of DN through the binding of MBL to hyperglycemia-exposed renal cells.
摘要:
补体系统的自身反应性可能会加剧糖尿病肾病的发展。我们使用2型糖尿病的BTBROB小鼠模型来研究补体因子甘露聚糖结合凝集素(MBL)在糖尿病肾病中的作用。包括雌性BTBROB小鼠(n=30)和BTBR非糖尿病WT小鼠(n=30)。分析血浆样本(第12周和第21周)和尿液样本(第19周)的MBL,C3,C3-片段,SAA3和肾功能标志物。分析肾组织切片的纤维化,炎症,和补体沉积。分析了肾皮质的基因表达(补体,炎症,和纤维化),并对分离的肾小球细胞进行MBL蛋白检测。通过流式细胞术分析在正常和高血糖条件下培养的人血管内皮细胞。我们发现与WT小鼠相比,OB小鼠具有升高的MBL-C的血浆和尿液浓度(分别为p<0.0001和p<0.001)和更高的血浆C3水平(p<0.001)。OB小鼠的肾脏冷冻切片显示肾小球中MBL-C和C4沉积增加,巨噬细胞浸润增加(p=0.002)。与OB和WT小鼠相比,分离的肾小球显示出明显更高的MBL蛋白水平(p<0.001),未检测到肾脏MBL表达。我们报道,慢性炎症通过MBL与高血糖暴露的肾细胞结合在DN的发展中起重要作用。