Cao Qinghua, Foley Michael, Gill Anthony J, Chou Angela, Chen Xin-Ming, Pollock Carol A
Renal Medicine, Kolling Institute of Medical Research, Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Royal North Shore Hospital, St Leonards, NSW 2065, Australia.
The Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia.
Int J Mol Sci. 2024 Dec 6;25(23):13127. doi: 10.3390/ijms252313127.
Kidney fibrosis is the common pathological pathway in progressive chronic kidney disease (CKD), and current treatments are largely ineffective. The C-X-C chemokine receptor 4 (CXCR4) is crucial to fibrosis development. By using neural cell adhesion molecules as scaffolds with binding loops that mimic the shape of shark antibodies, fully humanized single-domain i-bodies have been developed. The first-generation i-body, AD-114, demonstrated antifibrotic effects in a mouse model of folic acid (FA)-induced renal fibrosis. The second-generation i-body, AD-214, is an Fc-fusion protein with an extended half-life, enhanced activity, and a mutated Fc domain to prevent immune activation. To investigate the renoprotective mechanisms of AD-214, RPTEC/TERT1 cells (a human proximal tubular cell line) were incubated with TGF-b1 with/without AD-214 and the supernatant was collected to measure collagen levels by Western blot. Mice with unilateral ureteral obstruction (UUO) received AD-214 intraperitoneally (i.p.) every two days for 14 days. Kidney fibrosis markers and kidney function were then analyzed. AD-214 suppressed TGF-b1-induced collagen overexpression in RPTEC/TERT1 cells. In UUO mice, AD-214 reduced extracellular matrix (ECM) deposition, restored kidney function, and limited leukocyte infiltration. In a scratch assay, AD-214 also inhibited macrophage migration. To conclude, i-body AD-214 attenuates UUO-induced kidney fibrosis by inhibiting leukocyte infiltration and macrophage migration.
肾纤维化是进行性慢性肾脏病（CKD）的常见病理途径，目前的治疗方法大多无效。C-X-C趋化因子受体4（CXCR4）对纤维化发展至关重要。通过使用神经细胞粘附分子作为支架，其结合环模仿鲨鱼抗体的形状，已开发出完全人源化的单域i型抗体。第一代i型抗体AD-114在叶酸（FA）诱导的肾纤维化小鼠模型中显示出抗纤维化作用。第二代i型抗体AD-214是一种Fc融合蛋白，具有延长的半衰期、增强的活性和突变的Fc结构域以防止免疫激活。为了研究AD-214的肾脏保护机制，将RPTEC/TERT1细胞（一种人近端肾小管细胞系）与TGF-β1一起培养，有或没有AD-214，并收集上清液通过蛋白质印迹法测量胶原蛋白水平。单侧输尿管梗阻（UUO）小鼠每两天腹腔内（i.p.）注射AD-214，共14天。然后分析肾脏纤维化标志物和肾功能。AD-214抑制TGF-β1诱导的RPTEC/TERT1细胞中胶原蛋白的过度表达。在UUO小鼠中，AD-214减少了细胞外基质（ECM）沉积，恢复了肾功能，并限制了白细胞浸润。在划痕试验中，AD-214还抑制了巨噬细胞迁移。总之，i型抗体AD-214通过抑制白细胞浸润和巨噬细胞迁移减轻UUO诱导的肾纤维化。
