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Yifei Zhong,
Edward Y Chen,
Ruijie Liu,
Peter Y Chuang,
Sandeep K Mallipattu,
Christopher M Tan,
Neil R Clark,
Yueyi Deng,
Paul E Klotman,
Avi Ma'ayan,
John Cijiang He
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ABSTRACT: The Connectivity Map database contains microarray signatures of gene expression derived from approximately 6000 experiments that examined the effects of approximately 1300 single drugs on several human cancer cell lines. We used these data to prioritize pairs of drugs expected to reverse the changes in gene expression observed in the kidneys of a mouse model of HIV-associated nephropathy (Tg26 mice). We predicted that the combination of an angiotensin-converting enzyme (ACE) inhibitor and a histone deacetylase inhibitor would maximally reverse the disease-associated expression of genes in the kidneys of these mice. Testing the combination of these inhibitors in Tg26 mice revealed an additive renoprotective effect, as suggested by reduction of proteinuria, improvement of renal function, and attenuation of kidney injury. Furthermore, we observed the predicted treatment-associated changes in the expression of selected genes and pathway components. In summary, these data suggest that the combination of an ACE inhibitor and a histone deacetylase inhibitor could have therapeutic potential for various kidney diseases. In addition, this study provides proof-of-concept that drug-induced expression signatures have potential use in predicting the effects of combination drug therapy.
Journal of the American Society of Nephrology 04/2013; · 9.66 Impact Factor
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ABSTRACT: With the widespread use of combination antiretroviral agents, the incidence of HIV-associated nephropathy has decreased. Currently, HIV-infected patients live much longer and often suffer from comorbidities such as diabetes mellitus. Recent epidemiological studies suggest that concurrent HIV infection and diabetes mellitus may have a synergistic effect on the incidence of chronic kidney disease. To address this, we determined whether HIV-1 transgene expression accelerates diabetic kidney injury using a diabetic HIV-1 transgenic (Tg26) murine model. Diabetes was initially induced with low-dose streptozotocin in both Tg26 and wild-type mice on a C57BL/6 background, which is resistant to classic HIV-associated nephropathy. Although diabetic nephropathy is minimally observed on the C57BL/6 background, diabetic Tg26 mice exhibited a significant increase in glomerular injury compared with nondiabetic Tg26 mice and diabetic wild-type mice. Validation of microarray gene expression analysis from isolated glomeruli showed a significant upregulation of proinflammatory pathways in diabetic Tg26 mice. Thus, our study found that expression of HIV-1 genes aggravates diabetic kidney disease.Kidney International advance online publication, 16 January 2013; doi:10.1038/ki.2012.445.
Kidney International 01/2013; · 6.61 Impact Factor
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ABSTRACT: Retinoic acid decreases proteinuria and glomerulosclerosis in several animal models of kidney disease by protecting podocytes from injury. Our recent in vitro studies suggest that all-trans retinoic acid induces podocyte differentiation by activating the retinoic acid receptor-α (RARα)/cAMP/PKA/CREB pathway. When used in combination with all-trans retinoic acid, an inhibitor of phosphodiesterase 4 further enhanced podocyte differentiation by increasing intracellular cAMP. Additionally, we found that Am580, a specific RARα agonist, has similar renal protective effects as all-trans retinoic acid in a rederived colony of HIV-1 transgenic mice with rapidly progressive renal failure (HIV-Tg) that mimics human HIV-associated nephropathy. Treatment with either the inhibitor of phosphodiesterase 4, roflumilast, or Am580 significantly reduced proteinuria, attenuated kidney injury, and improved podocyte differentiation in these HIV-Tg mice. Additional renal protective effects were found when roflumilast was combined with Am580. Consistent with the in vitro data, glomeruli from HIV-Tg mice treated with both Am580 and roflumilast had more active phosphorylated CREB than with either agent alone. Thus, phosphodiesterase 4 inhibitors could be used in combination with RARα agonists to provide additional renal protection.
Kidney International 01/2012; 81(9):856-64. · 6.61 Impact Factor
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ABSTRACT: Membranous nephropathy (MN) is the most common cause of idiopathic nephrotic syndrome in adults and the cause is known to be due to the injury of podocytes located in the glomeruli. Astragalus membranaceus has been used for the treatment of patients with MN in China for a long time. The beneficial effect of Astragalus membranaceus on proteinuria of patients with MN has been well documented. However, the mechanism of astragalus membranaceu in alleviation of MN is still not completely understood. Therefore, in the current study, we employed a podocyte injury model induced by complement membranous attack complex to examine the mechanism of astragalus membraneceus in the treatment of MN. We found that complement membranous attack complex could increase lactate dehydrogenase (LDH) release from podocytes and astragaloside IV (AS-IV) could prevent LDH release from podocytes in a time- and dose-dependent pattern. Moreover, AS-IV restored podocyte morphology and cytoskeleton loss induced by complement membranous attack complex. Furthermore, AS-IV was able to reduce phosphorylation of JNK and ERK1/2 induced by complement membranous attack complex. In conclusion, the mechanism of Astragalus membranaceus in the treatment of MN may be related to its attenuation of podocyte injury through regulation of cytoskeleton and mitogen activated protein kinase.
Phytotherapy Research 11/2011; 26(6):892-8. · 2.09 Impact Factor
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ABSTRACT: Development of pharmacologic agents that protect podocytes from injury is a critical strategy for the treatment of kidney glomerular diseases. Retinoic acid reduces proteinuria and glomerulosclerosis in multiple animal models of kidney diseases. However, clinical studies are limited because of significant side effects of retinoic acid. Animal studies suggest that all trans retinoic acid (ATRA) attenuates proteinuria by protecting podocytes from injury. The physiological actions of ATRA are mediated by binding to all three isoforms of the nuclear retinoic acid receptors (RARs): RARα, RARβ, and RARγ. We have previously shown that ATRA exerts its renal protective effects mainly through the agonism of RARα. Here, we designed and synthesized a novel boron-containing derivative of the RARα-specific agonist Am580. This new derivative, BD4, binds to RARα receptor specifically and is predicted to have less toxicity based on its structure. We confirmed experimentally that BD4 binds to RARα with a higher affinity and exhibits less cellular toxicity than Am580 and ATRA. BD4 induces the expression of podocyte differentiation markers (synaptopodin, nephrin, and WT-1) in cultured podocytes. Finally, we confirmed that BD4 reduces proteinuria and improves kidney injury in HIV-1 transgenic mice, a model for HIV-associated nephropathy (HIVAN). Mice treated with BD4 did not develop any obvious toxicity or side effect. Our data suggest that BD4 is a novel RARα agonist, which could be used as a potential therapy for patients with kidney disease such as HIVAN.
PLoS ONE 01/2011; 6(11):e27945. · 4.09 Impact Factor
