ESPN 54th Annual Meeting

ESPN 2022


 
Interaction between renin and kallikrein is important during human kidney development and in the control of blood pressure in healthy and CNF kidneys
IVONA KOSOVIC 1 NATALIJA FILIPOVIC 1 MARIJAN SARAGA 2 MERICA GLAVINA DURDOV 3 KATARINA VUKOJEVIC 1 MIRNA SARAGA-BABIC 1

1- DEPARTMENT OF ANATOMY, HISTOLOGY AND EMBRYOLOGY, UNIVERSITY OF SPLIT, SCHOOL OF MEDICINE, SPLIT, CROATIA
2- DEPARTMENT OF PAEDIATRICS, UNIVERSITY HOSPITAL IN SPLIT, SPLIT, CROATIA
3- DEPARTMENT OF PATHOLOGY, UNIVERSITY HOSPITAL IN SPLIT, SPLIT, CROATIA
 
Introduction:

Blood pressure is controlled by kallilkrein-kinin system (KKS) and renin-angiotenzin-aldosteron system (RAAS). In developing kidneys, renin progenitor cells appear in the kidney arterial tree and juxtaglomerular apparatus (JGA), while kallikrein expression characterizes distal nephron. Both renin and kallikrein seem to influence kidney development and maturation. Data on kallikrein expression are conflicting, especially during human kidney development. In this study, we analyze the spatiotemporal and functional relationship between kidney renin and kallikrein during human development, in the postnatal period, and in the nephrotic syndrome of the Finnish type (CNF).

Material and methods:

The spatiotemporal expression of renin and kallikrein was analyzed in human kidneys by double immunofluorescence techniques in paraffin sections of 10 human conceptuses 8 to 38 weeks old, in 1,5-year-old healthy kidney tissues and in the CNF.

Results:

In the embryonic period, renin - kallikrein expression characterized metanephric cup cells, S-form nephrons, immature glomeruli, and collecting ducts (CD). In fetal and postnatal kidneys, kallikrein was partly expressed in distal tubules (DT) and CD, and strongly along connecting tubules (CT), while renin expression characterized DT and CD, and partly CT. Their co-expression was observed in small areas of DT and CT. In CNF kidneys, renin and kallikrein co-expression was stronger and with longer overlapping areas than in the healthy kidneys. 

Conclusions:

Our data suggested the interaction of renin and kallikrein during kidney maturation and in the blood pressure control. The two proteins were predominantly expressed in neighboring structures, while their co-expression characterized CT region. In CNF, their changed expression indicated increased efforts of affected kidneys in the blood pressure control.