Smad7 inhibits AngII-mediated hypertensive nephropathy in a mouse model of hypertension.

The TGFß (transforming growth factor ß)/SMAD and NF-κB (nuclear factor κB) signalling pathways play a key role in hypertensive nephropathy. The present study examined whether targeting these pathways by SMAD7, a downstream inhibitor of both pathways, blocks AngII (angiotensin II)-induced hypertensive kidney disease in mice. A doxycycline-inducible SMAD7-expressing plasmid was delivered into the kidney by a non-invasive ultrasound-microbubble technique before and after AngII infusion. Results showed that pre-treatment with SMAD7 prevented AngII-induced progressive renal injury by inhibiting an increase in proteinuria and serum creatinine while improving the glomerular filtration rate. Similarly, treatment with SMAD7 in the established hypertensive nephropathy at day 14 after AngII infusion halted the progressive renal injury. These preventive and therapeutic effects of SMAD7 on hypertensive kidney injury were associated with inhibition of AngII-induced up-regulation of SMURF2 (SMAD-specific E3 ubiquitin protein ligase 2) and Sp1 (specificity protein 1), blockade of TGFß/Smad3-mediated renal fibrosis and suppression of NF-κB-driven renal inflammation. Moreover, overexpression of SMAD7 also prevented AngII-induced loss of renal miR-29b, an miRNA with an inhibitory role in both TGFß/Smad3 and NF-κB pathways. In conclusion, SMAD7 may be a therapeutic agent for AngII-mediated hypertensive nephropathy. Inhibition of the Sp1/SMAD3/NF-κB/miR-29b regulatory network may be a mechanism by which SMAD7 inhibits hypertensive nephropathy.

A novel risk factor of contrast associated acute kidney injury in patients after enhanced computed tomography: a retrospective study.

Background: Contrast associated acute kidney injury (CA-AKI) is a major cause of acute renal failure and the incidence of CA-AKI is still high in recent years. Risk stratification is traditionally based on glomerular filtration rate(GFR). Hence, the aim of this study was to explore the novel risk factors for CA-AKI after enhanced computed tomography (CT). Methods: A retrospective cohort study was conducted in 632 in-hospital patients undergoing enhanced CT. The patients were divided into CA-AKI and no-CA-AKI groups. For comparative analyses, we applied one-to-four cohorts of those two groups using propensity score-matching methods addressing the imbalances of age, gender, weight, and smoking. The baseline clinical and biochemical data were compared. Logistic regression analysis was employed to investigate the CA-AKI risk factors. The receiver operating characteristic (ROC) curve was adopted to test the value of RDW in predicting CA-AKI after enhanced CT. Results: 25 (3.96%) patients suffered from CA-AKI. Those subjects who developed CA-AKI had advanced age, severer renal functional injury, lower albumin, higher baseline RDW, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) than those without CA-AKI. It also exhibited more severe anemia including decreased hemoglobin and red blood cell count (all p < 0.05). The baseline RDW, albumin and PLR between the two groups were statistically significant different after PSM. Binary logistic regression analysis showed that baseline RDW, albumin and eGFR were correlated with CA-AKI after contrast-enhanced CT examination. The RDW exhibited moderated discrimination ability for predicting CA-AKI beyond eGFR, with an AUC of 0.803 (95% CI [0.702-0.90]) vs 0.765 (95% CI [0.70-0.83]). Conclusion: Increased baseline RDW and decreased eGFR are risk factors for CA-AKI after enhanced CT. RDW exhibited good predictive value and can be used as an early warning marker for patients suffering from CA-AKI after enhanced CT.

Emergency irradiation with 3.4 Gy/2f in sellar/suprasellar germinoma patients with rapid visual acuity decline.

BACKGROUND: Rapid visual acuity (VA) decline was a common complaint in patients with sellar/suprasellar germinoma. In our hospital, 3.4 Gy/2f of emergency irradiation was applied to save patient VA and enable subsequent chemoradiotherapy. This study aimed to investigate the efficacy of emergency irradiation with 3.4 Gy/2f in patients with sellar/suprasellar germinoma who had rapid VA decline. METHODS: From January 2014 to December 2017, 33 patients with sellar/suprasellar germinoma who complained of VA decline within 3 months received 3.4 Gy/2f of emergency irradiation in Beijing Tiantan Hospital. The best-corrected VA (BCVA) and mean deviation (MD) were measured. Correlations between visual function change and clinical factors, including age at diagnosis, duration of VA decline, extent of tumor regression, serum level of tumor markers, were analyzed. RESULTS: Among 33 patients with sellar/suprasellar germinoma, the median diameter and volume of sellar/suprasellar lesions were 32 mm (range: 5-55 mm) and 12.9 cm (range 0.6-58.5 cm), respectively. Data on pre- and post-emergency-irradiation BCVA were obtained in 32 patients. For the right eyes, BCVA was improved in 23 patients (71.9%), unchanged in 7 (21.9%), and worsened in 2 (6.2%); and for the left eyes, these numbers were 27 (84.4%), 4 (12.5%), and 1 (3.1%), respectively. In terms of the logarithm of the minimum angle of resolution (logarithm of the minimum angle of resolution = Log (1/BCVA) score, the improvement was significant in both eyes (P < 0.001). In terms of MD, six patients had paired data and the improvement was marginal in the right eyes (P = 0.068) and significant in the left eyes (P = 0.043). However, no clinical factor was found to have correlation with visual function improvement. CONCLUSION: In sellar/suprasellar germinoma patients with VA decline, 3.4 Gy/2f of emergency irradiation was effective in improving visual function.

Disruption of Smad7 promotes ANG II-mediated renal inflammation and fibrosis via Sp1-TGF-ß/Smad3-NF.κB-dependent mechanisms in mice.

Smad7 is an inhibitory Smad and plays a protective role in obstructive and diabetic kidney disease. However, the role and mechanisms of Smad7 in hypertensive nephropathy remains unexplored. Thus, the aim of this study was to investigate the role and regulatory mechanisms of Smad7 in ANG II-induced hypertensive nephropathy. Smad7 gene knockout (KO) and wild-type (WT) mice received a subcutaneous infusion of ANG II or control saline for 4 weeks via osmotic mini-pumps. ANG II infusion produced equivalent hypertension in Smad7 KO and WT mice; however, Smad7 KO mice exhibited more severe renal functional injury as shown by increased proteinuria and reduced renal function (both p<0.05) when compared with Smad7 WT mice. Enhanced renal injury in Smad7 KO mice was associated with more progressive renal fibrosis with elevated TGF-ß/Smad3 signalling. Smad7 KO mice also showed more profound renal inflammation including increased macrophage infiltration, enhanced IL-1ß and TNF-α expression, and a marked activation of NF-κB signaling (all p<0.01). Further studies revealed that enhanced ANG II-mediated renal inflammation and fibrosis in Smad7 KO mice were also associated with up-regulation of Sp1 but downregulation of miR-29b expression. Taken together, the present study revealed that enhanced Sp1-TGF-ß1/Smad3-NF-κB signaling and loss of miR-29 may be mechanisms by which deletion of Smad7 promotes ANG II-mediated renal fibrosis and inflammation. Thus, Smad7 may play a protective role in ANG II-induced hypertensive kidney disease.

Smad7 inhibits angiotensin II-induced hypertensive cardiac remodelling.

AIMS: Smad7 plays a negative regulatory role in many inflammatory diseases, but its effect on hypertensive disease remains unknown. The present study tested the hypothesis that overexpression of Smad7 may have therapeutic potential for angiotensin II (Ang II)-mediated hypertensive cardiac remodelling. METHODS AND RESULTS: Hypertensive heart disease was induced in mice by subcutaneous infusion of Ang II for 28 days and treated with Smad7 by a non-invasive ultrasound-microbubble-mediated inducible Smad7 gene transfer. We found that cardiac Smad7 was largely reduced in the hypertensive heart and overexpression of cardiac Smad7 protected against the fall in the left ventricular (LV) ejection fraction (EF), an increase in LV mass, and cardiac inflammation and fibrosis such as up-regulation of pro-inflammatory cytokines (IL-1ß, TNF-α) and fibrotic markers (collagen I, α-SMA), and infiltration of CD3(+) T cells and F4/80(+) macrophages. Further studies revealed that inactivation of the Sp1-TGF-ß/Smad3-NF-κB (NF-κB, nuclear factor κB) pathways and prevention of cardiac miR-29 loss were mechanisms by which overexpression of Smad7 inhibited Ang II-mediated cardiac remodelling. Importantly, we also found that treatment with Smad7 when hypertensive cardiopathy established at day 14 halted the progression of cardiac injury by blunting the fall of EF and an increase in LV mass, and blocking TGF-ß/Smad3-mediated cardiac fibrosis and NF-κB-driven inflammation. CONCLUSION: Smad7 plays a protective role in Ang II-induced cardiac remodelling via mechanisms involving the Sp1-TGF-ß/Smad-NF-κB-miR-29 regulatory network. Thus, Smad7 may be a novel therapeutic agent for hypertensive cardiovascular diseases.

Deficiency of Smad7 enhances cardiac remodeling induced by angiotensin II infusion in a mouse model of hypertension.

Smad7 has been shown to negatively regulate fibrosis and inflammation, but its role in angiotensin II (Ang II)-induced hypertensive cardiac remodeling remains unknown. Therefore, the present study investigated the role of Smad7 in hypertensive cardiopathy induced by angiotensin II infusion. Hypertensive cardiac disease was induced in Smad7 gene knockout (KO) and wild-type (WT) mice by subcutaneous infusion of Ang II (1.46 mg/kg/day) for 28 days. Although equal levels of high blood pressure were developed in both Smad7 KO and WT mice, Smad7 KO mice developed more severe cardiac injury as demonstrated by impairing cardiac function including a significant increase in left ventricular (LV) mass (P<0.01),reduction of LV ejection fraction(P<0.001) and fractional shortening(P<0.001). Real-time PCR, Western blot and immunohistochemistry detected that deletion of Smad7 significantly enhanced Ang II-induced cardiac fibrosis and inflammation, including upregulation of collagen I, α-SMA, interleukin-1ß, TNF-α, and infiltration of CD3(+) T cells and F4/80(+) macrophages. Further studies revealed that enhanced activation of the Sp1-TGFß/Smad3-NF-κB pathways and downregulation of miR-29 were mechanisms though which deletion of Smad7 promoted Ang II-mediated cardiac remodeling. In conclusions, Smad7 plays a protective role in AngII-mediated cardiac remodeling via mechanisms involving the Sp1-TGF-ß/Smad3-NF.κB-miR-29 regulatory network.