Analiziran je prostorno-vremenski izražaj koneksina (Cx37, Cx40, Cx43 i Cx45), renina, sinaptopodina, nefrina, CD31 i α-SMA u nefronima i JGA ljudskih prenatalnih zdravih bubrega, postnatalnih zdravih bubrega te u bubrezima s nefrotskim sindromom Finskog tipa (CNF). U istraživanju su korištene tehnike dvostruke imunofluorescencije, elektronske mikroskopije i statističkog mjerenja površina ispod krivulje (AUC) histograma intenziteta fluorescencije. Tijekom razvoja bubrega, Cx45 pokazuje jaku ekspresiju u proksimalnim bubrežnim kanalićima, dok su Cx37 i Cx40 umjereno do jako izraženi u distalnom dijelu nefrona. U glomerulima, Cx43 i Cx45 ko-lokaliziraju u podocitima, mezangijskim stanicama i parijetalnim epitelnim stanicama, kao i s biljezima za podocite (sinaptopodin, nefrin). Različiti koneksini također pokazuju i ko-ekspresiju s endotelnim (CD31) i glatkim-mišićnim (α-SMA) biljezima u zidu krvnih žila. Cx37, Cx40 i Cx43 imaju najjači intenzitet tijekom razdoblja koje prati nefrogenezu, dok je najveći intenzitet signala za Cx45 povezan sa sazrijevanjem nefrona. S obzirom na navedeno prostorno-vremensko uzorkovanje, Cx45 vjerojatno ima ulogu u diferencijaciji proksimalnih kanalića, a Cx37, Cx40 i Cx43 u diferencijaciji distalnih kanalića. Tijekom razvoja bubrega, jaka ekspresija Cx40 u JGA postupno opada, dok ekspresija Cx37, Cx43 i Cx45 raste te se nastavlja i u postnatalnom razdoblju. Bubrezi zahvaćeni CNF-om pokazuju pojačan izražaj Cx43 u distalnim kanalićima, promijenjeni citoplazmatski raspored Cx45 u proksimalnim kanalićima te ukupan porast ekspresije Cx40 i Cx37. U CNF-bubrezima Cx40 ko-lokalizira sa brojnim intersticijskim miofibroblastima. Povećane razine Cx37, Cx43 i Cx45 u CNF-bubrezima ko-lokaliziraju s reninskim stanicama. Reninske stanice u KBB uzrokovanom CNF-om javljaju se i u ekstraglomerularnim mezangijskim stanicama, što ukazuje na njihov povratak u prethodne embrionalne stadije kao posljedica pokušaja kompenzacije oštećenja bubrežnog tkiva. Cx40 vjerojatno ima važnu ulogu u diferencijaciji JGA tijekom razvoja bubrega, dok Cx37, Cx43 i Cx45 održavaju pravilnu bubrežnu funkciju u postnatalnom razdoblju. Naše istraživanje pokazuje važnu ulogu koneksina u nefrogenezi, diferencijaciji glomerularnih stanica, razvoju krvnih žila i kontroli arterijskog tlaka, kako u zdravom bubrežnom tkivu tako i u CNF-u., Our study analyzed the spatio-temporal patterning of connexins (Cx37, Cx40, Cx43 and C45), renin, synaptopodin, nephrin, CD31 and α-SMA in the nephron and JGA of developing, postnatal healthy human kidneys and in the nephrotic syndrome of the Finnish type (CNF). For data analysis we used double immunofluorescence, electron microscopy and statistical measuring of area under curve (AUC) of flouorescence intensity histograms. During kidney development, strong expression of Cx45 characterized proximal tubules, while Cx37 and Cx40 showed moderate-to-strong expression in developing cells of distal nephron. In the glomeruli, Cx43 and Cx45 co-localized with markers for podocytes (synaptopodin, nephrin), with mesangial and parietal epithelial cells. Different connexins also showed coexpression with endothelial (CD31) and VSMC (α-SMA) markers in vascular walls. Cx37, Cx40 and Cx43 peak in signalling intensity accompanied kidney nephrogenesis, while Cx45 peak signalling associated the nehron maturation. Based on the Cx spatio-temporal patterning, Cx45 is considered to be important in differentiation of proximal tubules, while Cx37, Cx40 and Cx43 in distal tubules cell differentiation. During kidney development, strong expression of Cx40 in the JGA gradually decreased, while the expression of Cx37, Cx43 and Cx45 increased and continued in the postnatal period as well. CNF kidneys showed increased Cx43 expression in distal tubules, disorganized cytoplasmic Cx45 expression in proximal tubules, and overall elevation of Cx40 and Cx37 in kidney tissue. In CNF-kidneys, Cx40 co-localized with abundant interstitial myofibroblasts. Increased levels of Cx37, Cx43 and Cx45 which colocalized with renin cells also characterized CNF kidneys. Renin cells in chronic kidney disease (CKD) caused by CNF reappeared in extraglomerular mesangial cells which could imply their return to embryonic patterning, which is compensatory to the damage of the kidney tissue. Cx40 probably has a significant role in the formation of the JGA in developing kidneys, while Cx37, Cx43 and Cx45 take over that role in postnatal maintenance of kidney function. Our study showed important role of Cxs in nephrogenesis, differentiation of glomerular cells, blood vessel development and blood pressure control in the healthy kidney tissue and in the CNF.