Mesangial angiogenesis and interstitial eosinophilic infiltration in diabetic nephropathy are associated with elevated CD248 expression

To investigate the factors associated with angiogenesis within the glomerular mesangial area and interstitial eosinophilic infiltration in diabetic nephropathy (DN). The NCBI database identified differentially expressed genes (DEGs) in DN patients linked to angiogenesis and inflammation. Bioinformatics analyzed these genes and mechanisms. <i>In vivo</i> (DN patients and db/db mice) and <i>in vitro</i> experiments explored glomerular mesangial angiogenesis and interstitial eosinophilic infiltration mechanisms. Twenty-five independent DEGs associated with DN were identified, and CD248 was associated with vessel formation and inflammatory cells. Biological analysis suggested CD248 mainly promoted vessel formation and eosinophilic infiltration <i>via</i> VEGFC and CCL-5, respectively. In DN patients, neovascularization with CD31-positive endothelial cells was observed in the mesangial regions, which was accompanied by increased expression of CD248 and VEGFC. Eosinophilic infiltration was observed in the renal interstitium, and the degree of eosinophilic infiltration was positively correlated with the intensity of CD248 expression. Serial section analysis revealed that areas with increased eosinophilic infiltration exhibited stronger infiltration of CD3-positive cells and elevated CCL-5 expression. Similar findings were discovered in the db/db mice, with WB results demonstrating higher expression levels of CD248, CCL-5, and VEGFC in the renal tissues of db/db mice compared with m/m mice. <i>In vitro</i>, CD248 expression is low in mesangial cells, but increased under high-glucose/LPS. CD248 siRNA reduced high-glucose/LPS-induced VEGFC/CCL-5. In DN, CD248 may contribute to mesangial angiogenesis and renal interstitial eosinophilic infiltration; these pathological processes may be associated with the elevated expressions of VEGFC and CCL-5, respectively.

本研究旨在探讨糖尿病肾病（diabetic nephropathy, DN）中肾小球系膜区血管生成及肾间质嗜酸性粒细胞浸润的相关影响因素。研究通过NCBI数据库筛选出DN患者中与血管生成及炎症相关的差异表达基因（differentially expressed genes, DEGs），并采用生物信息学方法对这些基因及其作用机制进行分析。通过<i>in vivo</i>（DN患者及db/db小鼠）和<i>in vitro</i>实验，探究肾小球系膜区血管生成及肾间质嗜酸性粒细胞浸润的机制。研究共鉴定出25个与DN相关的独立差异表达基因，其中CD248与血管形成及炎症细胞相关。生物学分析表明，CD248主要通过<i>via</i> VEGFC和CCL-5分别促进血管形成和嗜酸性粒细胞浸润。在DN患者中，肾小球系膜区可见CD31阳性内皮细胞形成的新生血管，同时伴随CD248和VEGFC表达水平的升高；肾间质中可见嗜酸性粒细胞浸润，且浸润程度与CD248表达强度呈正相关。连续切片分析显示，嗜酸性粒细胞浸润增加的区域中，CD3阳性细胞浸润更强，且CCL-5表达水平升高。在db/db小鼠中也发现了类似结果，蛋白质印迹（Western Blot, WB）结果显示，与m/m小鼠相比，db/db小鼠肾组织中CD248、CCL-5和VEGFC的表达水平更高。<i>in vitro</i>实验中，系膜细胞中CD248表达较低，但在高糖/脂多糖（lipopolysaccharide, LPS）刺激下表达升高；CD248小干扰RNA（small interfering RNA, siRNA）可降低高糖/脂多糖诱导的VEGFC/CCL-5表达。在DN中，CD248可能参与系膜区血管生成及肾间质嗜酸性粒细胞浸润；这些病理过程可能分别与VEGFC和CCL-5表达升高相关。