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Updated: Jun 4, 2025
Unilateral Ureteral Obstruction Model for Investigating Kidney Interstitial Fibrosis
Published on: April 25, 2025
Second Generation I-Body AD-214 Attenuates Unilateral Ureteral Obstruction (UUO)-Induced Kidney Fibrosis Through
Qinghua Cao1, Michael Foley2,3, Anthony J Gill4,5,6
1Renal 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.
Abstract:
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.
Insights
The novel i-body AD-214 effectively treats kidney fibrosis by inhibiting leukocyte infiltration and macrophage migration. This promising therapeutic candidate offers a new approach for chronic kidney disease (CKD) management.
Area of Science:
- Nephrology
- Immunology
- Biotechnology
Background:
- Kidney fibrosis, a hallmark of progressive chronic kidney disease (CKD), lacks effective treatments.
- The C-X-C chemokine receptor 4 (CXCR4) pathway is a key driver of kidney fibrosis.
- Fully humanized single-domain i-bodies, engineered using neural cell adhesion molecules, offer a novel therapeutic strategy.
Purpose of the Study:
- To investigate the renoprotective mechanisms of the second-generation i-body, AD-214, in preclinical models of kidney fibrosis.
- To evaluate the efficacy of AD-214 in suppressing fibrotic processes and improving kidney function.
Main Methods:
- AD-214's effect on collagen production was assessed in human proximal tubular cells (RPTEC/TERT1) stimulated with TGF-b1.
- A mouse model of unilateral ureteral obstruction (UUO) was used to evaluate AD-214's impact on kidney fibrosis markers and function.
- Macrophage migration was analyzed using a scratch assay.
Main Results:
- AD-214 suppressed TGF-b1-induced collagen overexpression in kidney cells.
- In UUO mice, AD-214 significantly reduced extracellular matrix deposition and improved kidney function.
- AD-214 treatment limited leukocyte infiltration and inhibited macrophage migration in the fibrotic kidneys.
Conclusions:
- The i-body AD-214 demonstrates significant antifibrotic effects in preclinical models of kidney fibrosis.
- AD-214 attenuates kidney fibrosis by inhibiting leukocyte infiltration and macrophage migration, suggesting its potential as a novel therapeutic agent for CKD.
