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.

Monocyte chemotactic protein-1 and CC chemokine receptor 2 polymorphisms and prognosis of renal cell carcinoma.

Monocyte chemoattractant protein-1 (MCP-1) and its receptor CC chemokine receptor 2 (CCR2) play a major role in inflammation and proliferation of cancers. We investigated a possible association between polymorphisms in MCP-1 and CCR2 genes (MCP-1 -2518A/G and CCR2 190G/A or V64I) and the risk as well as prognosis of renal cell carcinoma (RCC). Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 416 RCC cases and 458 age-matched healthy controls. Frequency of MCP-1 2518GG genotype for cases and controls was 0.384 and 0.286, respectively; individuals carrying the GG genotype had a 1.89-fold increased risk of RCC than those with AA genotype (95 % confidence interval [CI] 1.24-2.81, p = 0.002; data were adjusted for age and sex). Frequency of CCR2 190AA (64I/64I) genotype for cases and controls was 0.175 and 0.076, respectively; subjects having AA genotype had a 2.68-fold increased risk of RCC compared to those with the wild-type GG genotype (95 %CI 1.71-4.17, p = 4.3 × 10(-6); data were adjusted for age and sex). When analyzing the survival rate of RCC, patients with MCP-1 -2518GG genotype revealed significantly shorter survival time compared to cases with MCP-1 -2518AA and AG genotypes (p = 0.003). Similarly, RCC cases carrying CCR2 190AA genotype showed significantly shorter survival rate than patients with GG or GA genotypes (p < 0.001). These data suggested that MCP-1 -2518A/G and CCR2 190G/A polymorphisms are new risk factors for RCC and could be used as prognostic markers for this malignancy.

[Urine protein from patients with lupus nephritis stimulates transdifferentiation and high expression of collagen in renal tubular cells].

OBJECTIVE: To investigate the effects of urine protein on the renal tubular-interstitial fibrosis in the patients with lupus nephritis (LN). METHODS: Protein was isolated and purified from the urine of six patients with primary LN, 1 male and 5 females, aged 27.4, and incubated with renal tubular cells of the line HK-2 for 0, 1, 2, 12, 24, or 48 h respectively. The mRNA expressions of transforming growth factor beta1(TGF-beta1), collagen I (COL I), and alpha-smooth muscle actin (alpha-SMA) in the HK-2 cells were detected by RT-PCR, and the. protein expressions of TGF-beta1, COL I, and alpha-SMA were detected with Western blotting and indirect immunofluorescence. RESULTS: The urine protein from the LN patients dose-and time-dependently increased the mRNA and protein expressions of TGF-beta1, COL I, and alpha-SMA in the HK-2 cells. The TGF-beta1 mRNA level 48 h after incubation was 0.39 +/- 0.03, significantly higher than that at the beginning of incubation (0.27 +/- 0.02, P < 0.01), and the TGF-beta1 protein level 48 h after incubation was 0.37 +/- 0.03, 1.7 times that at the beginning of incubation (0.27 +/- 0.04, P < 0.01). The COL I mRNA level 48 h after incubation was 0.38 +/- 0.02, significantly higher than the baseline level (0.22 +/- 0.03, P < 0.01); and the COL I protein level 48 h after incubation was 0.44 +/- 0.03, significantly higher than the baseline level (0.19 +/- 0.02, P < 0.01). The alpha-SMA mRNA level 48 h after incubation was 0.66 +/- 0.04, significantly higher than the baseline level (0.44 +/- 0.03, P < 0.01), and the alpha-SMA protein level 48 h after incubation was 0.43 +/- 0.02, significantly higher than the baseline level (0.24 +/- 0.03, P < 0.01). CONCLUSION: Urine protein may play an important role in the renal tubular-interstitial fibrosis by inducing the production of extracellular matrix and phenotype change in HK-2 cells.

[Integrated Chinese and western medicinal treatment on systemic lupus erythematosus characterized by hypoplastic bone marrow].

OBJECTIVE: To study the clinical effect of combined treatment with gamma-globulin, corticosteroids, immunosuppressor and Chinese medicines on systemic lupus erythematosus (SLE) patients characterized by hypoplastic bone marrow (HBM). METHODS: Nineteen patients were randomly assigned to two groups, the treated group (10 cases) received combined therapy of prednisone and cyclophosphamide (CTX) plus Chinese medicine Langchuang Recipe after being treated impactively with gamma-globulin. The control group (9 cases) was treated with prednisone and CTX. Changes of hypoplastic bone marrow, peripheral white blood cell (WBC), complement C3, 24 h urinary protein excretion, and lupus activity index (LAI) were observed, and a follow-up was carried out for one year. RESULTS: After one-month treatment, the bone marrow hypoplasia was relieved significantly in the treated group (P < 0.05, P < 0.01), showing an improvement superior to that in the control group (P < 0.05, P < 0.01); after three months treatment, the level of complement C3 increased (P < 0.01), while the 24 h urinary protein excretion and LAI decreased in the treated group (P < 0.05), showing significant difference as compared with those in the control group (P < 0.05, P < 0.01). In the follow-up period, 3 cases withdrew from the trial because of infection and 4 cases manifested full moon-face and acne in the control group, while no adverse reaction was found in the treated group. CONCLUSION: Treatment with integrated Chinese and Western medicine could effectively improve bone marrow hypoplasia, alleviate the clinical symptoms, suppress the activity of lupus in patients, and reduce the adverse reaction of treatment, showing a superiority to the treatment with prednisone combining with CTX.

[Clinical effect of treatment with lipo-prostaglandin E1 on the patients with chronic glomerulonephritis].

OBJECTIVE: To investigate potential mechanism underlying lipo-prostaglandin E1 (PGE1) in treatment of patients with chronic glomerulonephritis. METHODS: The recommended dose of 20 microg lipo-PGE1 for treatment of chronic glomerulonephritis was as a daily dose by continuous intravenous infusion or intravenous injection for 4 weeks. The levels of interleukin-1 (IL- 1), tumor necrosis factor-alpha (TNF-alpha), blood urea nitrogen (BUN), serum creatinine (SCr) and clearance of creatinine (CCr) were measured before and after treatment. RESULTS: After treatment with lipo-PGE1, levels of IL-1, TNF-alpha, BUN and SCr were lower than those before treatment (all P<0.01), but CCr values were higher than those before treatment (P<0.05). CONCLUSION: Lipo-PGE1 can reduce the renal inflammatory response and improve the renal function in the patients with chronic glomerulonephritis.

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.