Lectin Histochemistry of the Normal Feline Kidney

SIMPLE SUMMARY: Cats are highly susceptible to chronic kidney disease (CKD); however, the pathophysiological mechanisms of feline CKD have not been fully elucidated. To understand the mechanisms of CKD, it is important to clarify the changes in glycosylation of diseased renal cells. Lectins are specific probes used to explore changes in the carbohydrate moiety of cellular components. No study has yet demonstrated lectin binding patterns in normal feline kidneys. In the present study, we performed a lectin histochemical analysis of normal feline kidneys and evaluated the lectin-binding pattern in each nephron segment. Eight lectins, WGA, s-WGA, RCA-I, ConA, PNA, SBA, DBA, and UEA-I, were used as probes in the present study. The lectin binding pattern in each nephron segment was determined for each lectin, and a feline-specific lectin-binding pattern was established in the normal kidney. The present study provides a basis for future glycopathological studies of feline CKD. ABSTRACT: Lectins have a strict binding specificity to carbohydrate moieties of cellular components, and can thus indicate changes in the glycosylation of cells in diseases. However, lectin-binding patterns in nephron segments of feline kidneys have not been fully surveyed. The present study reported lectin-binding patterns in normal feline kidneys by histochemical investigations of eight commercially available lectin detection kits. Kidneys from four normal cats (intact males, 23–27 months old) were fixed in 4% paraformaldehyde, and embedded in paraffin; lectin histochemistry was performed for WGA, s-WGA, RCA-I, ConA, PNA, SBA, DBA, and UEA-I lectins. WGA, RCA, and ConA binding was observed from Bowman’s capsule to the collecting ducts, while only WGA was detected in the glomerular capillary. s-WGA was observed from the proximal tubules to the collecting ducts, showing discriminative heterogeneous binding. PNA and SBA were detected in the distal nephrons, such as the thin limbs of the loops of Henle, distal tubules, and collecting ducts. UEA-I binding was observed in the thick ascending limbs of the loops of Henle, especially in the macula densa regions. DBA lectin showed no positive labeling in nephrons. The observed binding patterns may prove beneficial for the analysis of changes in glycosylation in feline kidney diseases.