Abstract

Chronic kidney disease (CKD) is a common and serious condition in felines. Accordingly, several cell therapies have been studied over the past decades for effective treatments. This study aimed to develop a new lineage of renal progenitor cells for use in cats with CKD. Metanephric and mesonephric progenitor cells were obtained from mesonephros and metanephros tissues of feline conceptuses at four distinct gestational stages. The cultured cells were characterized by their morphology, tumorigenic potential, immunophenotype determined by flow cytometry, and differentiation potential. We then conducted a pilot study in CKD-affected cats, comparing intraperitoneal injections of cultured metanephric progenitor cells (n = 4) to a placebo solution (n = 3). All four cell types exhibited adhesion and colony formation, but showed no tumorigenic potential. Cells tested positive for renal progenitor markers (CD117, Nephron, and WT1), confirming their identity. Treated cats showed no statistically significant differences (p <= 0.05) in any of the data analyzed. However, caregivers reported a voluntary increase in appetite after cell administration. Veterinarians confirmed this information during double-blind evaluations conducted after treatment. Although this data are qualitative, no clinical deterioration was observed in cats. Our results suggest that this new lineage of renal progenitor cells did not induce immediate adverse effects, thus supporting its potential for use in cell-based therapies. However, further studies are needed to evaluate its efficacy in treating renal diseases.