Multiple Phenotypes in Adult Mice following Inactivation of the Coxsackievirus and Adenovirus Receptor (Car) Gene

To determine the normal function of the Coxsackievirus and Adenovirus Receptor (CAR), a protein found in tight junctions and other intercellular complexes, we constructed a mouse line in which the CAR gene could be disrupted at any chosen time point in a broad spectrum of cell types and tissues. All knockouts examined displayed a dilated intestinal tract and atrophy of the exocrine pancreas with appearance of tubular complexes characteristic of acinar-to-ductal metaplasia. The mice also exhibited a complete atrio-ventricular block and abnormal thymopoiesis. These results demonstrate that CAR exerts important functions in the physiology of several organs in vivo

Deletion of Smad7 enhances ANG II-induced renal inflammation.

<p><b>A:</b> TNFα. <b>B:</b> IL-1β. <b>C:</b> F4/80⁺ macrophages. Immunohistochemistry (IHC, i, ii) and real-time PCR (iii) analyses show that deletion of Smad7 enhances ANG II-induced renal inflammation with up-regulation of TNFα and IL-1β, and an increased macrophage infiltrate when compared with Smad7 WT mice. Each bar represents means ± SE for groups of 6 mice. Scale bar, 50 µM. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 compared with saline (SL) control mice. ^#<i>P</i><0.05, ^##<i>P</i><0.01 when compared with ANG II-infused Smad7 WT mice.</p

Deletion of Smad7 enhances ANG II-induced activation of TGF-β1/Smad3 signaling in the kidney.

<p><b>A:</b> TGF-β1 expression detected by immunohistochemistry (i ii) and real-time PCR (iii). <b>B:</b> Activation of Smad3 determined by immunohistochemistry for phospho-Smad2/3 nuclear translocation (i, ii) and Western blots for phosphorylation levels of Smad3 in the kidney (iii, iv). <b>C:</b> Smad7 protein levels. Note that ANG II induces degradation of renal Smad7 protein in the Smad7 WT. Each bar represents means ± SE for groups of 6 mice. Scale bar, 50 µM. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 compared with saline (SL) control mice. ^#<i>P</i><0.05, ^##<i>P</i><0.01,^###<i>P</i><0.001 when compared with ANG II-infused Smad7 WT mice.</p

Deletion of Smad7 enhances ANG II-induced renal injury.

<p><b>A:</b> Systolic blood pressure. <b>B:</b> Proteinuria. <b>C: S</b>erum creatinine. <b>D:</b> Creatinine clearance (CCR). <b>E:</b> Histological damage [periodic acid-Schiff (PAS)-stained sections]. Note that disruption of Smad7 enhances ANG II-mediated renal injury, including higher levels of proteinuria and serum creatinine, a greater fall in CCR, and histological damage such as glomerular hypercellularity, vascular sclerosis (arrows), and ECM deposition when compared with Smad7 WT mice, despite equal levels of high blood pressure. Values are means ± SE for groups of 6 mice. Scale bar, 50 µM. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 compared with saline (SL) control mice.^#<i>P</i><0.05,^##<i>P</i><0.01, ^###<i>P</i><0.001 compared with ANG II-infused Smad7 WT mice.</p

Deletion of Smad7 enhances ANG II-induced activation of NF-κB/p65 in the kidney.

<p><b>A:</b> Immunohistochemistry detects that deletion of Smad7 enhances phospho-NF-κB/p65 nuclear translocation in the hypertensive kidney. <b>B:</b> Western blot analysis shows that disruption of Smad7 promotes IκBα degradation through phosphorylation, thereby enhancing NF-κB activation as determined by significantly increasing phosphorylation of p65 in the hypertensive kidney. <b>C.</b> Real-time PCR shows that deletion of Smad7 significantly inhibits IκBα mRNA expression in mice after ANG II infusion. Each bar represents means ± SE for groups of 6 mice. Scale bar, 50 µM. *<i>P</i><0.05, ***<i>P</i><0.001 compared with saline (SL) control mice. ^#<i>P</i><0.05,^##<i>P</i><0.01 when compared with ANG II-infused Smad7 WT mice.</p

Deletion of Smad7 enhances ANG II-induced renal fibrosis.

<p><b>A:</b> Collagen I. <b>B:</b> α-SMA. Immunohistochemistry (IHC, i, ii), real-time PCR (iii), and Western blot (WB, iv, vi) analyses show that deletion of Smad7 enhances ANG II-induced renal fibrosis when compared with Smad7 WT mice. Each bar represents means ± SE for groups of 6 mice. Scale bar, 50 µM. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 compared with saline (SL) control mice. ^#<i>P</i><0.05, ^##<i>P</i><0.01, ^###<i>P</i><0.001 compared with ANG II-infused Smad7 WT mice.</p