MT4-MMP is expressed in regions of the hypothalamus that regulate thirst.

<p>(<b>A</b>) β-gal staining of MT4-MMP null mouse brain reveals intense blue staining. No staining is present in the wildtype controls. (<b>B</b>) β-gal staining is mainly within the cortex of the MT4-MMP null mice (12.5X). (<b>C</b>) β-gal staining is present in scattered neurons within the hypothalamus (100X), including the anterior hypothalamic area and lateral hypothalamic area, which are known to regulate thirst. (D) Inset shows high power view (400X) of the hypothalamus revealing blue staining within neurons.</p

MT4-MMP null mice have increased urine osmolarity compared to control mice.

<p>(<b>A</b>) Urine osmolarity obtained at baseline (0) and following 24 hr water deprivation (24) reveals that MT4-MMP null mice have higher baseline urine osmolarity (*p = 0.0164) vs C57/BL6 time point 0. Both groups of animals appropriately concentrate their urines following water deprivation. (<b>B</b>) Plasma osmolarity, (<b>C</b>) Plasma sodium and (<b>D</b>) Blood urea nitrogen were the same in both groups.</p

Adult MT4-MMP null have subtle abnormalities in the renal papilla.

<p>(<b>A–B</b>) No gross abnormalities are seen in low power (50X) images of H and E stained kidneys from MT4-MMP null mice (A) when compared to C57/BL6 controls (B). (<b>C–F</b>) Tubules in the deep papilla of MT4-MMP null kidneys are less tightly packed and show subtle evidence of disorganization (C, E). C–D, H&E, 200X; E–F, PAS, 400X. (<b>G–H</b>) The cortex of MT4-MMP null kidneys appear morphologically normal with no apparent decrease number of glomeruli, PAS, 200X.</p

MT4-MMP localization in the mouse kidney.

<p>(<b>A–B</b>) β-galactosidase staining kidneys from 5week old MT4-MMP null mice shows staining in the cortex and medulla (A, 50X DIC) with the most intense staining seen in the papilla (B, 200X DIC). (<b>C–F</b>) Staining with a specific antibody directed against MT4-MMP in wildtype mice shows expression throughout the metanephric mesenchyme and ureteric bud at E12.5 (C, 100X). MT4-MMP expression is abundant in the cortical regions during embryonic development (E18.5, D, 50X), but by 2weeks of age, most of the expression is localized to the papilla regions (E–F, 50X and 200X, respectively). (<b>G–H</b>) Staining with a specific antibody directed against MT4-MMP in MT4-MMP null and wildtype mice, demonstrating specificity of the antibody for MT4-MMP (200X). (<b>I–J</b>) Immunoblot of inner medullary collecting duct cells derived from wild type mice (IMCD), MT4-MMP null mice (Null) or IMCD cells from MT4-MMP null mice reconstituted with MT4-MMP (Recon), illustrating specificity of the antibody for MT4-MMP (I). Ponceau staining was performed on the nitrocellulose of the immunoblot to demonstrate equal loading of the lysates (J).</p

MT4-MMP null mice do not have abnormalities in aquaporin 1, 2 or ENaC expression.

<p>Immunostaining was performed for (<b>A–B</b>) Aquaporin I, (<b>C–D</b>) Aquaporin 2, and (<b>E–F</b>) ENaCβ (50X).</p