Table 3.

Summary of immunostaining of CLDN10, CLDN16, and CLDN19 in the mouse renal tubule and collecting system

	Megalin/LRP2		UMOD			NKCC2			NCC	NCX1	AQP2	AE1	Pendrin
	Cortex	OSOM	Cortex	OSOM	ISOM	Cortex	OSOM	ISOM	Cortex	Cortex	Cortex, OSOM, ISOM	Cortex, OSOM, ISOM	Cortex
CLDN10	£	£	***, TJ: **	***, TJ: **	***, TJ: **				0	0	0	$	$
CLDN16	#	#				***, TJ: ***	***, TJ: ***	Very rare, TJ:?	0 or unusual		0	$	$
CLDN19	0	0	***, TJ: **	***, TJ: **	***TJ: very rare				**TJ: *, ∼50% of DCTs	**TJ: *, rare	***no TJ staining	***no TJ staining	***no TJ staining

Localization was determined by costaining for the following specific markers in immunofluorescence: megalin/LDL receptor-related protein 2 (LRP2), uromodulin (UMOD), Na⁺-K⁺-2Cl⁻ cotransporter (NKCC2), Na⁺-Cl⁻ cotransporter (NCC), Na⁺/Ca²⁺ exchanger isoform 1 (NCX1), aquaporin-2 (AQP2), Cl⁻/${\text{HCO}}_3^{-}$

anion exchanger isoform 1 (AE1), and pendrin. DCT, distal convoluted tubule; ISOM, inner stripe of the outer medulla; OSOM, outer stripe of the outer medulla. *, **, and ***, Expression with increasing intensity. 0, Expression absent or below the limit of detection. TJ, Expression at the tight junction. £, Costaining of megalin-claudin (CLDN)10 was not performed in mouse kidney sections because the proximal tubule could be identified according its morphology. CLDN10 was expressed at tight junctions in the proximal tubule. The staining in the proximal tubule was weaker than that in the thick ascending limb of Henle’s loop. #, Costaining of megalin-CLDN16 was not performed in mouse kidney sections. However, no CLDN16 staining could be found in the proximal tubule that was identified according its morphology. $, Costainings of AE1-CLDN10, pendrin-CLDN10, AE1-CLDN16, and pendrin-CLDN16 were not performed in mouse kidney sections because we did not find any CLDN10 and CLDN16 staining in tubules expressing AQP2. ?, Expression at the tight junction could not be confirmed nor excluded.