101
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Cellular and molecular mechanisms of kidney fibrosis. Mol Aspects Med 2018; 65:16-36. [PMID: 29909119 DOI: 10.1016/j.mam.2018.06.002] [Citation(s) in RCA: 280] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/12/2018] [Indexed: 12/14/2022]
Abstract
Renal fibrosis is the final pathological process common to any ongoing, chronic kidney injury or maladaptive repair. It is considered as the underlying pathological process of chronic kidney disease (CKD), which affects more than 10% of world population and for which treatment options are limited. Renal fibrosis is defined by excessive deposition of extracellular matrix, which disrupts and replaces the functional parenchyma that leads to organ failure. Kidney's histological structure can be divided into three main compartments, all of which can be affected by fibrosis, specifically termed glomerulosclerosis in glomeruli, interstitial fibrosis in tubulointerstitium and arteriosclerosis and perivascular fibrosis in vasculature. In this review, we summarized the different appearance, cellular origin and major emerging processes and mediators of fibrosis in each compartment. We also depicted and discussed the challenges in translation of anti-fibrotic treatment to clinical practice and discuss possible solutions and future directions.
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102
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Gremlin activates the Notch pathway linked to renal inflammation. Clin Sci (Lond) 2018; 132:1097-1115. [PMID: 29720422 DOI: 10.1042/cs20171553] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/27/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023]
Abstract
Preclinical studies suggest that Gremlin participates in renal damage and could be a potential therapeutic target for human chronic kidney diseases. Inflammation is a common characteristic of progressive renal disease, and therefore novel anti-inflammatory therapeutic targets should be investigated. The Notch signaling pathway is involved in kidney development and is activated in human chronic kidney disease, but whether Gremlin regulates the Notch pathway has not been investigated. In cultured tubular cells, Gremlin up-regulated gene expression of several Notch pathway components, increased the production of the canonical ligand Jagged-1, and caused the nuclear translocation of active Notch-1 (N1ICD). In vivo administration of Gremlin into murine kidneys elicited Jagged-1 production, increased N1ICD nuclear levels, and up-regulated the gene expression of the Notch effectors hes-1 and hey-1 All these data clearly demonstrate that Gremlin activates the Notch pathway in the kidney. Notch inhibition using the γ-secretase inhibitor DAPT impaired renal inflammatory cell infiltration and proinflammatory cytokines overexpression in Gremlin-injected mice and in experimental models of renal injury. Moreover, Notch inhibition blocked Gremlin-induced activation of the canonical and noncanonical nuclear factor-κB (NF-κB) pathway, identifying an important mechanism involved in the anti-inflammatory actions of Notch inhibition. In conclusion, Gremlin activates the Notch pathway in the kidney and this is linked to NF-κB-mediated inflammation, supporting the hypothesis that Notch inhibition could be a potential anti-inflammatory strategy for renal diseases.
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103
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Tiaolipiwei Acupuncture Reduces Albuminuria by Alleviating Podocyte Lesions in a Rat Model of Diabetic Nephropathy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:1913691. [PMID: 29849693 PMCID: PMC5937557 DOI: 10.1155/2018/1913691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/07/2018] [Accepted: 03/18/2018] [Indexed: 01/13/2023]
Abstract
Background Diabetic nephropathy is a common and serious complication of diabetes and a major cause of end-stage renal disease. Tiaolipiwei acupuncture is a safe treatment approach that may be effective for lowering albuminuria in diabetic nephropathy. Yet, the exact mechanisms of this therapeutic effect are unclear. Methods A rodent model of type 2 diabetic nephropathy (T2DN) was induced by a high-fat diet combined with low-dose streptozotocin. T2DN rats were treated with Tiaolipiwei acupuncture (ACU) for 4, 8, or 12 weeks. At the end of treatment, urinary and blood samples were collected for analysis. Transmission electron microscopy was used to observe morphological changes, and protein expression levels of nephrin, CD2AP, podocalyxin, and desmin were quantified in renal tissue. Results Compared to the T2DN groups, the T2DN + ACU groups showed significant improvements in 24-hour urinary protein, serum urea, cholesterol, and triglycerides at all time points. ACU treatment also improved the density of slit diaphragms. Simultaneously, ACU promoted the renal expression of nephrin, CD2AP, and podocalyxin and decreased the expression of desmin. Conclusion Our study suggests that Tiaolipiwei acupuncture ameliorates podocyte lesions to reduce albuminuria and prevent the progression of T2DN in a rat model.
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104
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Hong Q, Zhang L, Das B, Li Z, Liu B, Cai G, Chen X, Chuang PY, He JC, Lee K. Increased podocyte Sirtuin-1 function attenuates diabetic kidney injury. Kidney Int 2018; 93:1330-1343. [PMID: 29477240 PMCID: PMC5967974 DOI: 10.1016/j.kint.2017.12.008] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 11/09/2017] [Accepted: 12/13/2017] [Indexed: 02/08/2023]
Abstract
Podocyte injury and loss contribute to the progression of glomerular diseases, including diabetic kidney disease. We previously found that the glomerular expression of Sirtuin-1 (SIRT1) is reduced in human diabetic glomeruli and that the podocyte-specific loss of SIRT1 aggravated albuminuria and worsened kidney disease progression in diabetic mice. SIRT1 encodes an NAD-dependent deacetylase that modifies the activity of key transcriptional regulators affected in diabetic kidneys, including NF-κB, STAT3, p53, FOXO4, and PGC1-α. However, whether the increased glomerular SIRT1 activity is sufficient to ameliorate the pathogenesis of diabetic kidney disease has not been explored. We addressed this by inducible podocyte-specific SIRT1 overexpression in diabetic OVE26 mice. The induction of SIRT1 overexpression in podocytes for six weeks in OVE26 mice with established albuminuria attenuated the progression of diabetic glomerulopathy. To further validate the therapeutic potential of increased SIRT1 activity against diabetic kidney disease, we developed a new, potent and selective SIRT1 agonist, BF175. In cultured podocytes BF175 increased SIRT1-mediated activation of PGC1-α and protected against high glucose-mediated mitochondrial injury. In vivo, administration of BF175 for six weeks in OVE26 mice resulted in a marked reduction in albuminuria and in glomerular injury in a manner similar to podocyte-specific SIRT1 overexpression. Both podocyte-specific SIRT1 overexpression and BT175 treatment attenuated diabetes-induced podocyte loss and reduced oxidative stress in glomeruli of OVE26 mice. Thus, increased SIRT1 activity protects against diabetes-induced podocyte injury and effectively mitigates the progression of diabetic kidney disease.
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Affiliation(s)
- Quan Hong
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Lu Zhang
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Department of Nephrology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Bhaskar Das
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Zhengzhe Li
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Bohan Liu
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Guangyan Cai
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Xiangmei Chen
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Peter Y Chuang
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John Cijiang He
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Renal Section, James J Peters VAMC, Bronx, New York, USA.
| | - Kyung Lee
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
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105
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MDM2 controls NRF2 antioxidant activity in prevention of diabetic kidney disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1034-1045. [PMID: 29704532 DOI: 10.1016/j.bbamcr.2018.04.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/15/2018] [Accepted: 04/23/2018] [Indexed: 01/03/2023]
Abstract
Oxidative stress and P53 contribute to the pathogenesis of diabetic kidney disease (DKD). Nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of cellular antioxidant defense system, is negatively regulated by P53 and prevents DKD. Recent findings revealed an important role of mouse double minute 2 (MDM2) in protection against DKD. However, the mechanism remained unclear. We hypothesized that MDM2 enhances NRF2 antioxidant signaling in DKD given that MDM2 is a key negative regulator of P53. The MDM2 inhibitor nutlin3a elevated renal P53, inhibited NRF2 signaling and induced oxidative stress, inflammation, fibrosis, DKD-like renal pathology and albuminuria in the wild-type (WT) non-diabetic mice. These effects exhibited more prominently in nutlin3a-treated WT diabetic mice. Interestingly, nutlin3a failed to induce greater renal injuries in the Nrf2 knockout (KO) mice under both the diabetic and non-diabetic conditions, indicating that NRF2 predominantly mediates MDM2's action. On the contrary, P53 inhibition by pifithrin-α activated renal NRF2 signaling and the expression of Mdm2, and attenuated DKD in the WT diabetic mice, but not in the Nrf2 KO diabetic mice. In high glucose-treated mouse mesangial cells, P53 gene silencing completely abolished nutlin3a's inhibitory effect on NRF2 signaling. The present study demonstrates for the first time that MDM2 controls renal NRF2 antioxidant activity in DKD via inhibition of P53, providing MDM2 activation and P53 inhibition as novel strategies in the management of DKD.
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106
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Asfahani RI, Tahoun MM, Miller-Hodges EV, Bellerby J, Virasami AK, Sampson RD, Moulding D, Sebire NJ, Hohenstein P, Scambler PJ, Waters AM. Activation of podocyte Notch mediates early Wt1 glomerulopathy. Kidney Int 2018; 93:903-920. [PMID: 29398135 PMCID: PMC6169130 DOI: 10.1016/j.kint.2017.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 11/07/2017] [Accepted: 11/09/2017] [Indexed: 01/26/2023]
Abstract
The Wilms' tumor suppressor gene, WT1, encodes a zinc finger protein that regulates podocyte development and is highly expressed in mature podocytes. Mutations in the WT1 gene are associated with the development of renal failure due to the formation of scar tissue within glomeruli, the mechanisms of which are poorly understood. Here, we used a tamoxifen-based CRE-LoxP system to induce deletion of Wt1 in adult mice to investigate the mechanisms underlying evolution of glomerulosclerosis. Podocyte apoptosis was evident as early as the fourth day post-induction and increased during disease progression, supporting a role for Wt1 in mature podocyte survival. Podocyte Notch activation was evident at disease onset with upregulation of Notch1 and its transcriptional targets, including Nrarp. There was repression of podocyte FoxC2 and upregulation of Hey2 supporting a role for a Wt1/FoxC2/Notch transcriptional network in mature podocyte injury. The expression of cleaved Notch1 and HES1 proteins in podocytes of mutant mice was confirmed in early disease. Furthermore, induction of podocyte HES1 expression was associated with upregulation of genes implicated in epithelial mesenchymal transition, thereby suggesting that HES1 mediates podocyte EMT. Lastly, early pharmacological inhibition of Notch signaling ameliorated glomerular scarring and albuminuria. Thus, loss of Wt1 in mature podocytes modulates podocyte Notch activation, which could mediate early events in WT1-related glomerulosclerosis.
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Affiliation(s)
- Rowan I Asfahani
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK
| | - Mona M Tahoun
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK; Clinical and Chemical Pathology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Eve V Miller-Hodges
- MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, Scotland
| | - Jack Bellerby
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK
| | - Alex K Virasami
- Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Robert D Sampson
- Institute of Ophthalmology, University College of London, London, UK
| | - Dale Moulding
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK
| | - Neil J Sebire
- Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | | | - Peter J Scambler
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK
| | - Aoife M Waters
- Programme of Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College of London, London, UK; Great Ormond Street Hospital NHS Foundation Trust, London, UK.
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107
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Aberrant Regulation of Notch3 Signaling Pathway in Polycystic Kidney Disease. Sci Rep 2018; 8:3340. [PMID: 29463793 PMCID: PMC5820265 DOI: 10.1038/s41598-018-21132-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 01/30/2018] [Indexed: 12/12/2022] Open
Abstract
Polycystic kidney disease (PKD) is a genetic disorder characterized by fluid-filled cysts in the kidney and liver that ultimately leads to end-stage renal disease. Currently there is no globally approved therapy for PKD. The Notch signaling pathway regulates cellular processes such as proliferation and de-differentiation, which are cellular hallmarks of PKD. Thus we hypothesized that the Notch pathway plays a critical role in PKD. Evaluation of protein expression of Notch signaling components in kidneys of Autosomal Recessive PKD (ARPKD) and Autosomal Dominant PKD (ADPKD) mouse models and of ADPKD patients revealed that Notch pathway members, particularly Notch3, were consistently upregulated or activated in cyst-lining epithelial cells. Notch3 expression correlated with rapidly growing cysts and co-localized with the proliferation marker, PCNA. Importantly, Notch inhibition significantly decreased forskolin-induced Notch3 activation and proliferation of primary human ADPKD cells, and significantly reduced cyst formation and growth of human ADPKD cells cultured in collagen gels. Thus our data indicate that Notch3 is aberrantly activated and facilitates epithelial cell proliferation in PKD, and that inhibition of Notch signaling may prevent cyst formation and growth.
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108
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Yang R, Hong H, Wang M, Ma Z. Correlation Between Single-Nucleotide Polymorphisms Within miR-30a and Related Target Genes and Risk or Prognosis of Nephrotic Syndrome. DNA Cell Biol 2018; 37:233-243. [PMID: 29356585 DOI: 10.1089/dna.2017.4024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
This study was aimed to figure out the association of single-nucleotide polymorphisms (SNPs) within miR-30a and its downstream molecules (i.e., Notch1, Snail1, p53, CD73, and TET1) with susceptibility to and prognosis of nephrotic syndrome (NS). In the aggregate, 265 patients and 281 healthy controls were gathered, and related laboratory indicators were examined. The miR-30a, Notch1, Snail1, TET1, p53, and CD73 expressions were also evaluated by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, or enzyme-linked immunosorbent assay. Besides, the SNPs were genotyped by RT-PCR with aid of ABI-PRISM™ 377 DNA sequencing instrument. As a result, the NS patients were correlated with remarkably higher 24-h protein excretion, random urine protein/creatinine (UPCR), and serum creatinine, along with lower estimated glomerular filtration rate and serum albumin, when compared with normal subjects (p < 0.05). Furthermore, significant correlations were present between miR-30a expression and the expressions of Notch1 (rs = -0.350), p53 (rs = -0.339), CD73 (rs = -0.300), TET1 (rs = -0.249), and Snail1 (rs = -0.829) (all p < 0.05). The SNPs of miR-30a [i.e., rs2222722 (C>T)], Notch1 [i.e., rs3124599 (G>A), rs3124591 (C>T), and rs139994842 (G>A)], Snail1 [i.e., rs6020178 (T>C)], p53 [i.e., rs1042522 (C>G)], and CD73 [i.e., rs9444348 (G>A) and rs4431401 (T>C)] were significantly correlated with both differed NS risk and altered hormone sensitivity to NS (all p < 0.05). Moreover, haplotype AC of CD73 and haplotype ATG of Notch1 were the helpful factors against NS (p < 0.05), yet haplotype GT of CD73 functioned oppositely (p < 0.05). The haplotype AT of CD73 was beneficial to the NS patients for that the carriers could be treated with hormones without severe complications (p < 0.05). Conclusively, the SNPs situated within miR-30a and its downstream molecules (i.e., Notch1, Snail1, p53, CD73, and TET1) could become the promising biomarkers for both NS diagnosis and prediction of NS prognosis.
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Affiliation(s)
- Ruiheng Yang
- Department of Nephrology, Liaocheng People's Hospital , Liaocheng, China
| | - Hong Hong
- Department of Nephrology, Liaocheng People's Hospital , Liaocheng, China
| | - Mengjun Wang
- Department of Nephrology, Liaocheng People's Hospital , Liaocheng, China
| | - Zhongchao Ma
- Department of Nephrology, Liaocheng People's Hospital , Liaocheng, China
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109
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Zhong Y, Lee K, He JC. SIRT1 Is a Potential Drug Target for Treatment of Diabetic Kidney Disease. Front Endocrinol (Lausanne) 2018; 9:624. [PMID: 30386303 PMCID: PMC6199382 DOI: 10.3389/fendo.2018.00624] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/01/2018] [Indexed: 11/13/2022] Open
Abstract
Multiple studies have demonstrated a critical role of Sirtuin-1 (SIRT1) deacetylase in protecting kidney cells from cellular stresses. A protective role of SIRT1 has been reported in both podocytes and renal tubular cells in multiple kidney disease settings, including diabetic kidney disease (DKD). We and others have shown that SIRT1 exerts renoprotective effects in DKD in part through the deacetylation of transcription factors involved in the disease pathogenesis, such as p53, FOXO, RelA/p65NF-κB, STAT3, and PGC1α/PPARγ. Recently we showed that the podocyte-specific overexpression of SIRT1 attenuated proteinuria and kidney injury in an experimental model of DKD, further confirming SIRT1 as a potential target to treat kidney disease. Known agonists of SIRT1 such as resveratrol diminished diabetic kidney injury in several animal models. Similarly, we also showed that puerarin, a Chinese herbal medicine compound, activates SIRT1 to provide renoprotection in mouse models of DKD. However, as these are non-specific SIRT1 agonists, we recently developed a more specific and potent SIRT1 agonist (BF175) that significantly attenuated diabetic kidney injury in type 1 diabetic OVE26 mice. We also previously reported that MS417, a bromodomain inhibitor that disrupts the interaction between the acetyl-residues of NF-κB and bromodomain-containing protein 4 (BRD4) also attenuates DKD. These results suggest that SIRT1 agonists and bromodomain inhibitors could be potential new therapuetic treatments against DKD progression.
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Affiliation(s)
- Yifei Zhong
- Division of Nephrology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Yifei Zhong
| | - Kyung Lee
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
| | - John Cijiang He
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY, United States
- Renal Section, James J. Peters VA Medical Center, Bronx, NY, United States
- John Cijiang He
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110
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Majumder S, Thieme K, Batchu SN, Alghamdi TA, Bowskill BB, Kabir MG, Liu Y, Advani SL, White KE, Geldenhuys L, Tennankore KK, Poyah P, Siddiqi FS, Advani A. Shifts in podocyte histone H3K27me3 regulate mouse and human glomerular disease. J Clin Invest 2017; 128:483-499. [PMID: 29227285 DOI: 10.1172/jci95946] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/31/2017] [Indexed: 01/09/2023] Open
Abstract
Histone protein modifications control fate determination during normal development and dedifferentiation during disease. Here, we set out to determine the extent to which dynamic changes to histones affect the differentiated phenotype of ordinarily quiescent adult glomerular podocytes. To do this, we examined the consequences of shifting the balance of the repressive histone H3 lysine 27 trimethylation (H3K27me3) mark in podocytes. Adriamycin nephrotoxicity and subtotal nephrectomy (SNx) studies indicated that deletion of the histone methylating enzyme EZH2 from podocytes decreased H3K27me3 levels and sensitized mice to glomerular disease. H3K27me3 was enriched at the promoter region of the Notch ligand Jag1 in podocytes, and derepression of Jag1 by EZH2 inhibition or knockdown facilitated podocyte dedifferentiation. Conversely, inhibition of the Jumonji C domain-containing demethylases Jmjd3 and UTX increased the H3K27me3 content of podocytes and attenuated glomerular disease in adriamycin nephrotoxicity, SNx, and diabetes. Podocytes in glomeruli from humans with focal segmental glomerulosclerosis or diabetic nephropathy exhibited diminished H3K27me3 and heightened UTX content. Analogous to human disease, inhibition of Jmjd3 and UTX abated nephropathy progression in mice with established glomerular injury and reduced H3K27me3 levels. Together, these findings indicate that ostensibly stable chromatin modifications can be dynamically regulated in quiescent cells and that epigenetic reprogramming can improve outcomes in glomerular disease by repressing the reactivation of developmental pathways.
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Affiliation(s)
- Syamantak Majumder
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Karina Thieme
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Sri N Batchu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Tamadher A Alghamdi
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Bridgit B Bowskill
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - M Golam Kabir
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Youan Liu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Suzanne L Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Kathryn E White
- Electron Microscopy Research Services, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | | | - Penelope Poyah
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ferhan S Siddiqi
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
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111
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Abou Daher A, El Jalkh T, Eid AA, Fornoni A, Marples B, Zeidan YH. Translational Aspects of Sphingolipid Metabolism in Renal Disorders. Int J Mol Sci 2017; 18:ijms18122528. [PMID: 29186855 PMCID: PMC5751131 DOI: 10.3390/ijms18122528] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 11/16/2017] [Accepted: 11/17/2017] [Indexed: 12/13/2022] Open
Abstract
Sphingolipids, long thought to be passive components of biological membranes with merely a structural role, have proved throughout the past decade to be major players in the pathogenesis of many human diseases. The study and characterization of several genetic disorders like Fabry’s and Tay Sachs, where sphingolipid metabolism is disrupted, leading to a systemic array of clinical symptoms, have indeed helped elucidate and appreciate the importance of sphingolipids and their metabolites as active signaling molecules. In addition to being involved in dynamic cellular processes like apoptosis, senescence and differentiation, sphingolipids are implicated in critical physiological functions such as immune responses and pathophysiological conditions like inflammation and insulin resistance. Interestingly, the kidneys are among the most sensitive organ systems to sphingolipid alterations, rendering these molecules and the enzymes involved in their metabolism, promising therapeutic targets for numerous nephropathic complications that stand behind podocyte injury and renal failure.
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Affiliation(s)
- Alaa Abou Daher
- Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.
| | - Tatiana El Jalkh
- Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.
| | - Assaad A Eid
- Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.
| | - Alessia Fornoni
- Department of Medicine, Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miami, FL 33136, USA.
| | - Brian Marples
- Department of Radiation Oncology, Miller School of Medicine/Sylvester Cancer Center, University of Miami, Miami, FL 33136, USA.
| | - Youssef H Zeidan
- Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon.
- Department of Radiation Oncology, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon.
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112
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Ito Y, Hoare M, Narita M. Spatial and Temporal Control of Senescence. Trends Cell Biol 2017; 27:820-832. [PMID: 28822679 DOI: 10.1016/j.tcb.2017.07.004] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 07/13/2017] [Accepted: 07/21/2017] [Indexed: 12/16/2022]
Abstract
Cellular senescence is an autonomous tumor suppressor mechanism leading to stable cell cycle arrest. Senescent cells are highly secretory, driving a range of different functions through the senescence-associated secretory phenotype (SASP). Recent findings have suggested that the composition of the SASP is dynamically and spatially regulated and that the changing composition of the SASP can determine the beneficial and detrimental aspects of the senescence program, tipping the balance to either an immunosuppressive/profibrotic environment or proinflammatory/fibrolytic state. Here, we discuss the current understanding of the temporal and spatial regulation of the SASP and the novel finding of NOTCH signaling as a regulator of SASP composition.
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Affiliation(s)
- Yoko Ito
- Cancer Research UK Cambridge Centre, Li Ka Shing Centre, University of Cambridge, Cambridge, CB2 0RE, UK
| | - Matthew Hoare
- Cancer Research UK Cambridge Centre, Li Ka Shing Centre, University of Cambridge, Cambridge, CB2 0RE, UK; Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Masashi Narita
- Cancer Research UK Cambridge Centre, Li Ka Shing Centre, University of Cambridge, Cambridge, CB2 0RE, UK.
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113
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Zhang H, Nair V, Saha J, Atkins KB, Hodgin JB, Saunders TL, Myers MG, Werner T, Kretzler M, Brosius FC. Podocyte-specific JAK2 overexpression worsens diabetic kidney disease in mice. Kidney Int 2017; 92:909-921. [PMID: 28554737 PMCID: PMC5610635 DOI: 10.1016/j.kint.2017.03.027] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 03/03/2017] [Accepted: 03/09/2017] [Indexed: 01/11/2023]
Abstract
Activation of JAK-STAT signaling has been implicated in the pathogenesis of diabetic kidney disease. An increased expression of JAK-STAT genes was found in kidney glomerular cells, including podocytes, in patients with early diabetic kidney disease. However, it is not known whether increased expression of JAK or STAT isoforms in glomerular cells can lead to worsening nephropathy in the setting of diabetes. Therefore, we overexpressed JAK2 mRNA specifically in glomerular podocytes of 129S6 mice to determine whether this change alone could worsen diabetic kidney disease. A 2-3 fold increase in glomerular JAK2 expression, an increase similar to that found in humans with early diabetic kidney disease, led to substantial and statistically significant increases in albuminuria, mesangial expansion, glomerulosclerosis, glomerular fibronectin accumulation, and glomerular basement membrane thickening, and a significant reduction in podocyte density in diabetic mice. Treatment with a specific JAK1/2 inhibitor for 2 weeks partly reversed the major phenotypic changes of diabetic kidney disease and specifically normalized expression of a number of downstream STAT3-dependent genes implicated in diabetic kidney disease progression. Thus, moderate increases in podocyte JAK2 expression at levels similar to those in patients with early diabetic kidney disease can lead directly to phenotypic and other alterations of progressive diabetic glomerulopathy. Hence, inhibition of these changes by treatment with a JAK1/2 inhibitor suggests that such treatment may help retard progression of early diabetic kidney disease in patients.
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Affiliation(s)
- Hongyu Zhang
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Viji Nair
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jharna Saha
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kevin B Atkins
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jeffrey B Hodgin
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Thomas L Saunders
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Transgenic Animal Model Core, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Thomas Werner
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Matthias Kretzler
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Frank C Brosius
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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114
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Ying Q, Wu G. Molecular mechanisms involved in podocyte EMT and concomitant diabetic kidney diseases: an update. Ren Fail 2017; 39:474-483. [PMID: 28413908 PMCID: PMC6014344 DOI: 10.1080/0886022x.2017.1313164] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Epithelial–mesenchymal transition (EMT) is a tightly regulated process by which epithelial cells lose their hallmark epithelial characteristics and gain the features of mesenchymal cells. For podocytes, expression of nephrin, podocin, P-cadherin, and ZO-1 is downregulated, the slit diaphragm (SD) will be altered, and the actin cytoskeleton will be rearranged. Diabetes, especially hyperglycemia, has been demonstrated to incite podocyte EMT through several molecular mechanisms such as TGF-β/Smad classic pathway, Wnt/β-catenin signaling pathway, Integrins/integrin-linked kinase (ILK) signaling pathway, MAPKs signaling pathway, Jagged/Notch signaling pathway, and NF-κB signaling pathway. As one of the most fundamental prerequisites to develop ground-breaking therapeutic options to prevent the development and progression of diabetic kidney disease (DKD), a comprehensive understanding of the molecular mechanisms involved in the pathogenesis of podocyte EMT is compulsory. Therefore, the purpose of this paper is to update the research progress of these underlying signaling pathways and expound the podocyte EMT-related DKDs.
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Affiliation(s)
- Qidi Ying
- a Department of Pharmacology, Pharmacy , China Pharmaceutical University , Nanjing , Jiangsu , China
| | - Guanzhong Wu
- a Department of Pharmacology, Pharmacy , China Pharmaceutical University , Nanjing , Jiangsu , China
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115
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Sirt6 deficiency exacerbates podocyte injury and proteinuria through targeting Notch signaling. Nat Commun 2017; 8:413. [PMID: 28871079 PMCID: PMC5583183 DOI: 10.1038/s41467-017-00498-4] [Citation(s) in RCA: 211] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 07/04/2017] [Indexed: 02/06/2023] Open
Abstract
Podocyte injury is a major determinant of proteinuric kidney disease and the identification of potential therapeutic targets for preventing podocyte injury has clinical importance. Here, we show that histone deacetylase Sirt6 protects against podocyte injury through epigenetic regulation of Notch signaling. Sirt6 is downregulated in renal biopsies from patients with podocytopathies and its expression correlates with glomerular filtration rate. Podocyte-specific deletion of Sirt6 exacerbates podocyte injury and proteinuria in two independent mouse models, diabetic nephropathy, and adriamycin-induced nephropathy. Sirt6 has pleiotropic protective actions in podocytes, including anti-inflammatory and anti-apoptotic effects, is involved in actin cytoskeleton maintenance and promotes autophagy. Sirt6 also reduces urokinase plasminogen activator receptor expression, which is a key factor for podocyte foot process effacement and proteinuria. Mechanistically, Sirt6 inhibits Notch1 and Notch4 transcription by deacetylating histone H3K9. We propose Sirt6 as a potential therapeutic target for the treatment of proteinuric kidney disease. Podocytes are essential components of the renal glomerular filtration barrier and podocyte dysfunction leads to proteinuric kidney disease. Here Liu et al. show that Sirt6 protects podocytes from apoptosis and inflammation by increasing autophagic flux through inhibition of the Notch pathway.
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116
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Hlushchuk R, Styp-Rekowska B, Dzambazi J, Wnuk M, Huynh-Do U, Makanya A, Djonov V. Endoglin inhibition leads to intussusceptive angiogenesis via activation of factors related to COUP-TFII signaling pathway. PLoS One 2017; 12:e0182813. [PMID: 28859090 PMCID: PMC5578572 DOI: 10.1371/journal.pone.0182813] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/25/2017] [Indexed: 12/11/2022] Open
Abstract
Angiogenesis is a highly coordinated, extremely complex process orchestrated by multiple signaling molecules and blood flow conditions. While sprouting mode of angiogenesis is very well investigated, the molecular mechanisms underlying intussusception, the second mode of angiogenesis, remain largely unclear. In the current study two molecules involved in vascular growth and differentiation, namely endoglin (ENG/CD105) and chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) were examined to unravel their specific roles in angiogenesis. Down- respectively up-regulation of both molecules tightly correlates with intussusceptive microvascular growth. Upon ENG inhibition in chicken embryo model, formation of irregular capillary meshwork accompanied by increased expression of COUP-TFII could be observed. This dynamic expression pattern of ENG and COUP-TFII during vascular development and remodeling correlated with formation of pillars and progression of intussusceptive angiogenesis. Similar findings could be observed in mammalian model of acute rat Thy1.1 glomerulonephritis, which was induced by intravenous injection of anti-Thy1 antibody and has shown upregulation of COUP-TFII in initial phase of intussusception, while ENG expression was not disturbed compared to the controls but decreased over the time of pillar formation. In this study, we have shown that ENG inhibition and at the same time up-regulation of COUP-TFII expression promotes intussusceptive angiogenesis.
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Affiliation(s)
| | | | | | - Monika Wnuk
- Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Uyen Huynh-Do
- Department of Nephrology and Hypertension, Inselspital Bern, Bern, Switzerland
| | - Andrew Makanya
- Institute of Anatomy, University of Bern, Bern, Switzerland
- Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya
| | - Valentin Djonov
- Institute of Anatomy, University of Bern, Bern, Switzerland
- * E-mail:
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117
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Matoba K, Kawanami D, Nagai Y, Takeda Y, Akamine T, Ishizawa S, Kanazawa Y, Yokota T, Utsunomiya K. Rho-Kinase Blockade Attenuates Podocyte Apoptosis by Inhibiting the Notch Signaling Pathway in Diabetic Nephropathy. Int J Mol Sci 2017; 18:ijms18081795. [PMID: 28820432 PMCID: PMC5578183 DOI: 10.3390/ijms18081795] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/14/2017] [Accepted: 08/15/2017] [Indexed: 12/12/2022] Open
Abstract
Podocyte apoptosis is a key process in the onset of diabetic nephropathy. A significant body of evidence shows that the Notch signaling pathway plays a central role in this process. We found that Rho-kinase mediates transforming growth factor β (TGF-β)-induced Notch ligand Jag1 expression. Importantly, TGF-β-mediated podocyte apoptosis was attenuated by Rho-kinase inhibition. Mechanistically, Rho-kinase regulated Jag1 induction via the extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) but not Smad pathways. Consistently, the Rho-kinase inhibitor fasudil prevented albuminuria and the urinary excretion of nephrin in db/db mice and reduced the prevalence of podocyte apoptosis and Jag1 expression. Finally, the expression of Jag1 and apoptosis markers such as Bax and cyclin-dependent kinase inhibitor 1A (CDKN1A) was decreased in podocytes derived from db/db mice treated with fasudil. The present study provides evidence that Rho-kinase plays a key role in podocyte apoptosis. Rho-kinase is an attractive therapeutic target for diabetic nephropathy.
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Affiliation(s)
- Keiichiro Matoba
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Daiji Kawanami
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Yosuke Nagai
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Yusuke Takeda
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Tomoyo Akamine
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Sho Ishizawa
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Yasushi Kanazawa
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Tamotsu Yokota
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
| | - Kazunori Utsunomiya
- Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo 105-8461, Japan.
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118
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Transcriptome-based network analysis reveals renal cell type-specific dysregulation of hypoxia-associated transcripts. Sci Rep 2017; 7:8576. [PMID: 28819298 PMCID: PMC5561250 DOI: 10.1038/s41598-017-08492-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/10/2017] [Indexed: 12/19/2022] Open
Abstract
Accumulating evidence suggests that dysregulation of hypoxia-regulated transcriptional mechanisms is involved in development of chronic kidney diseases (CKD). However, it remains unclear how hypoxia-induced transcription factors (HIFs) and subsequent biological processes contribute to CKD development and progression. In our study, genome-wide expression profiles of more than 200 renal biopsies from patients with different CKD stages revealed significant correlation of HIF-target genes with eGFR in glomeruli and tubulointerstitium. These correlations were positive and negative and in part compartment-specific. Microarrays of proximal tubular cells and podocytes with stable HIF1α and/or HIF2α suppression displayed cell type-specific HIF1/HIF2-dependencies as well as dysregulation of several pathways. WGCNA analysis identified gene sets that were highly coregulated within modules. Characterization of the modules revealed common as well as cell group- and condition-specific pathways, GO-Terms and transcription factors. Gene expression analysis of the hypoxia-interconnected pathways in patients with different CKD stages revealed an increased dysregulation with loss of renal function. In conclusion, our data clearly point to a compartment- and cell type-specific dysregulation of hypoxia-associated gene transcripts and might help to improve the understanding of hypoxia, HIF dysregulation, and transcriptional program response in CKD.
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119
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Han SH, Wu MY, Nam BY, Park JT, Yoo TH, Kang SW, Park J, Chinga F, Li SY, Susztak K. PGC-1 α Protects from Notch-Induced Kidney Fibrosis Development. J Am Soc Nephrol 2017; 28:3312-3322. [PMID: 28751525 DOI: 10.1681/asn.2017020130] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 06/06/2017] [Indexed: 12/14/2022] Open
Abstract
Kidney fibrosis is the histologic manifestation of CKD. Sustained activation of developmental pathways, such as Notch, in tubule epithelial cells has been shown to have a key role in fibrosis development. The molecular mechanism of Notch-induced fibrosis, however, remains poorly understood. Here, we show that, that expression of peroxisomal proliferation g-coactivator (PGC-1α) and fatty acid oxidation-related genes are lower in mice expressing active Notch1 in tubular epithelial cells (Pax8-rtTA/ICN1) compared to littermate controls. Chromatin immunoprecipitation assays revealed that the Notch target gene Hes1 directly binds to the regulatory region of PGC-1α Compared with Pax8-rtTA/ICN1 transgenic animals, Pax8-rtTA/ICN1/Ppargc1a transgenic mice showed improvement of renal structural alterations (on histology) and molecular defect (expression of profibrotic genes). Overexpression of PGC-1α restored mitochondrial content and reversed the fatty acid oxidation defect induced by Notch overexpression in vitro in tubule cells. Furthermore, compared with Pax8-rtTA/ICN1 mice, Pax8-rtTA/ICN1/Ppargc1a mice exhibited improvement in renal fatty acid oxidation gene expression and apoptosis. Our results show that metabolic dysregulation has a key role in kidney fibrosis induced by sustained activation of the Notch developmental pathway and can be ameliorated by PGC-1α.
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Affiliation(s)
- Seung Hyeok Han
- Department of Internal Medicine, Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul, Korea.,Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mei-Yan Wu
- Severance Biomedical Science Institute, Brain Korea 21 PLUS, Yonsei University College of Medicine, Seoul, Korea; and.,Department of Nephrology, The First Hospital of Jilin University, Changchun, China
| | - Bo Young Nam
- Severance Biomedical Science Institute, Brain Korea 21 PLUS, Yonsei University College of Medicine, Seoul, Korea; and
| | - Jung Tak Park
- Department of Internal Medicine, Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul, Korea
| | - Tae-Hyun Yoo
- Department of Internal Medicine, Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul, Korea
| | - Shin-Wook Kang
- Department of Internal Medicine, Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul, Korea.,Severance Biomedical Science Institute, Brain Korea 21 PLUS, Yonsei University College of Medicine, Seoul, Korea; and
| | - Jihwan Park
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Frank Chinga
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Szu-Yuan Li
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
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120
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Li SY, Park J, Qiu C, Han SH, Palmer MB, Arany Z, Susztak K. Increasing the level of peroxisome proliferator-activated receptor γ coactivator-1α in podocytes results in collapsing glomerulopathy. JCI Insight 2017; 2:92930. [PMID: 28724797 DOI: 10.1172/jci.insight.92930] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/06/2017] [Indexed: 01/07/2023] Open
Abstract
Inherited and acquired mitochondrial defects have been associated with podocyte dysfunction and chronic kidney disease (CKD). Peroxisome proliferator-activated receptor γ coactivator-1α (PGC1α) is one of the main transcriptional regulators of mitochondrial biogenesis and function. We hypothesized that increasing PGC1α expression in podocytes could protect from CKD. We found that PGC1α and mitochondrial transcript levels are lower in podocytes of patients and mouse models with diabetic kidney disease (DKD). To increase PGC1α expression, podocyte-specific inducible PGC1α-transgenic mice were generated by crossing nephrin-rtTA mice with tetO-Ppargc1a animals. Transgene induction resulted in albuminuria and glomerulosclerosis in a dose-dependent manner. Expression of PGC1α in podocytes increased mitochondrial biogenesis and maximal respiratory capacity. PGC1α also shifted podocytes towards fatty acid usage from their baseline glucose preference. RNA sequencing analysis indicated that PGC1α induced podocyte proliferation. Histological lesions of mice with podocyte-specific PGC1α expression resembled collapsing focal segmental glomerular sclerosis. In conclusion, decreased podocyte PGC1α expression and mitochondrial content is a consistent feature of DKD, but excessive PGC1α alters mitochondrial properties and induces podocyte proliferation and dedifferentiation, indicating that there is likely a narrow therapeutic window for PGC1α levels in podocytes.
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Affiliation(s)
- Szu-Yuan Li
- Renal-Electrolyte and Hypertension Division of Department of Medicine, and Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.,Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jihwan Park
- Renal-Electrolyte and Hypertension Division of Department of Medicine, and Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Chengxiang Qiu
- Renal-Electrolyte and Hypertension Division of Department of Medicine, and Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Seung Hyeok Han
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | | | - Zoltan Arany
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Katalin Susztak
- Renal-Electrolyte and Hypertension Division of Department of Medicine, and Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
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121
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Shukla R, Pandey N, Banerjee S, Tripathi YB. Effect of extract of Pueraria tuberosa on expression of hypoxia inducible factor-1α and vascular endothelial growth factor in kidney of diabetic rats. Biomed Pharmacother 2017. [PMID: 28648975 DOI: 10.1016/j.biopha.2017.06.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUNDS Kidney hypoxia represents a unifying mechanism in the pathogenesis of diabetic nephropathy. Hypoxia-induced factor (HIF)-1α mediates the metabolic responses of renal hypoxia by modulating the expression of VEGF. In the present study, we investigated the effect of Pueraria tuberosa extract (PTY-2r) on the expression of HIF-1α, VEGF and nephrin in streptozotocin (STZ) induced diabetic nephropathy (DN). METHODS The model of diabetic nephropathy (DN) was produced by intraperitoneal injection of 55mg/kg of STZ and maintained for 60days. These DN-rats were randomly divided into three groups, i.e., DN, DN+PTY-2r (100mg/100g), and DN+PTY-2r (50mg/100g). A normal control (NC) group was administrated with drug vehicle. Expression of HIF-1α, VEGF and nephrin were evaluated in the renal tissue. RESULTS Blood glucose, urine protein, serum creatinine, and urea, level were significantly raised along with decreased creatinine clearance in DN rats. Immunofluorescence and Western blot analysis showed significantly increased expression of HIF-1α & VEGF and decreased expression of nephrin in DN control rats. The PTY-2r treatment significantly reversed these changes in a dose-dependent manner. Correlation analysis showed that the expression of VEGF was positively correlated with that of HIF-1α and negatively correlated with nephrin. CONCLUSIONS The PTY-2r can improve the chronic hyperglycemic condition induced kidney damage, and may delay the development of diabetic nephropathy by inhibiting the expression of HIF-1α and VEGF, thereby restoring the expression of nephrin.
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Affiliation(s)
- Rashmi Shukla
- Department of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Nidhi Pandey
- Department of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Somanshu Banerjee
- Department of Zoology, Institute of Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Yamini B Tripathi
- Department of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India.
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122
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Beaudreuil S, Lorenzo HK, Elias M, Nnang Obada E, Charpentier B, Durrbach A. Optimal management of primary focal segmental glomerulosclerosis in adults. Int J Nephrol Renovasc Dis 2017; 10:97-107. [PMID: 28546764 PMCID: PMC5436760 DOI: 10.2147/ijnrd.s126844] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a frequent glomerular kidney disease that is revealed by proteinuria or even nephrotic syndrome. A diagnosis can be established from a kidney biopsy that shows focal and segmental glomerulosclerosis. This histopathological lesion may be caused by a primary podocyte injury (idiopathic FSGS) but is also associated with other pathologies (secondary FSGS). The first-line treatment for idiopathic FSGS with nephrotic syndrome is a prolonged course of corticosteroids. However, steroid resistance or steroid dependence is frequent, and despite intensified immunosuppressive treatment, FSGS can lead to end-stage renal failure. In addition, in some cases, FSGS can recur on a graft after kidney transplantation: an unidentified circulating factor may be implicated. Understanding of its physiopathology is unclear, and it remains an important challenge for the scientific community to identify a specific diagnostic biomarker and to develop specific therapeutics. This study reviews the treatment of primary FSGS and the recurrence of FSGS after kidney transplantation in adults.
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Affiliation(s)
- Séverine Beaudreuil
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre.,INSERM Unit 1197, Paris-Sud University Hospital, Villejuif, France
| | - Hans Kristian Lorenzo
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre.,INSERM Unit 1197, Paris-Sud University Hospital, Villejuif, France
| | - Michele Elias
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre
| | - Erika Nnang Obada
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre
| | - Bernard Charpentier
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre.,INSERM Unit 1197, Paris-Sud University Hospital, Villejuif, France
| | - Antoine Durrbach
- Department of Nephrology Dialysis Transplantation, Paris-Sud University Hospital, Le Kremlin Bicêtre.,INSERM Unit 1197, Paris-Sud University Hospital, Villejuif, France
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123
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Yang Q, Guo B, Sun H, Zhang J, Liu S, Hexige S, Yu X, Wang X. Identification of the key genes implicated in the transformation of OLP to OSCC using RNA-sequencing. Oncol Rep 2017; 37:2355-2365. [PMID: 28259920 DOI: 10.3892/or.2017.5487] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 01/02/2017] [Indexed: 11/06/2022] Open
Abstract
Oral lichen planus (OLP) is a chronic inflammatory disease that may transform to oral squamous cell carcinoma (OSCC), while its carcinogenesis mechanisms are not entirely clear. This study was designed to identify the important genes involved in the malignant transformation of OLP to OSCC. After RNA-sequencing, the differently expressed genes (DEGs) in OLP vs. normal and OSCC vs. normal groups, respectively, were identified by limma package in R language, and then clustering analysis were conducted by Pheatmap package in R language. Weighed gene co-expression network analysis (WGCNA) was performed for the DEGs to screen disease-associated modules. Using Cytoscape software, co-expression networks were constructed for the genes involved in the modules. Enrichment analysis was conducted for the genes involved in the co-expression networks using GOstat package in R language. Finally, quantitative real-time PCR (qRT-PCR) experiments were conducted to validate the key genes. There were, respectively, 223 and 548 DEGs in OLP vs. normal and OSCC vs. normal groups. WGCNA identified the blue modules for the DEGs in the two groups as disease-associated modules. Moreover, 19 common DEGs (including upregulated BCL9L, PER2 and TSPAN33, and downregulated GMPS and HES1) associated with both OLP and OSCC were identified. In the co-expression networks, BCL9L, HES1, PER2 and TSPAN33 might function in OLP via interactions (such as BCL9L-TSPAN33 and HES1-PER2). qRT-PCR analysis showed that BCL9L, PER2 and TSPAN33 were significantly upregulated, and GMP and HES1 were downregulated. These findings indicated that BCL9L, GMPS, HES1, PER2 and TSPAN33 affected the transformation of OLP to OSCC.
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Affiliation(s)
- Qiaozhen Yang
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Bin Guo
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Hongying Sun
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Jie Zhang
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Shangfeng Liu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Saiyin Hexige
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Xuedi Yu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Xiaxia Wang
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
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124
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Bhagat TD, Zou Y, Huang S, Park J, Palmer MB, Hu C, Li W, Shenoy N, Giricz O, Choudhary G, Yu Y, Ko YA, Izquierdo MC, Park ASD, Vallumsetla N, Laurence R, Lopez R, Suzuki M, Pullman J, Kaner J, Gartrell B, Hakimi AA, Greally JM, Patel B, Benhadji K, Pradhan K, Verma A, Susztak K. Notch Pathway Is Activated via Genetic and Epigenetic Alterations and Is a Therapeutic Target in Clear Cell Renal Cancer. J Biol Chem 2017; 292:837-846. [PMID: 27909050 PMCID: PMC5247657 DOI: 10.1074/jbc.m116.745208] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/22/2016] [Indexed: 01/15/2023] Open
Abstract
Clear cell renal cell carcinoma (CCRCC) is an incurable malignancy in advanced stages and needs newer therapeutic targets. Transcriptomic analysis of CCRCCs and matched microdissected renal tubular controls revealed overexpression of NOTCH ligands and receptors in tumor tissues. Examination of the TCGA RNA-seq data set also revealed widespread activation of NOTCH pathway in a large cohort of CCRCC samples. Samples with NOTCH pathway activation were also clinically distinct and were associated with better overall survival. Parallel DNA methylation and copy number analysis demonstrated that both genetic and epigenetic alterations led to NOTCH pathway activation in CCRCC. NOTCH ligand JAGGED1 was overexpressed and associated with loss of CpG methylation of H3K4me1-associated enhancer regions. JAGGED2 was also overexpressed and associated with gene amplification in distinct CCRCC samples. Transgenic expression of intracellular NOTCH1 in mice with tubule-specific deletion of VHL led to dysplastic hyperproliferation of tubular epithelial cells, confirming the procarcinogenic role of NOTCH in vivo Alteration of cell cycle pathways was seen in murine renal tubular cells with NOTCH overexpression, and molecular similarity to human tumors was observed, demonstrating that human CCRCC recapitulates features and gene expression changes observed in mice with transgenic overexpression of the Notch intracellular domain. Treatment with the γ-secretase inhibitor LY3039478 led to inhibition of CCRCC cells in vitro and in vivo In summary, these data reveal the mechanistic basis of NOTCH pathway activation in CCRCC and demonstrate this pathway to a potential therapeutic target.
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Affiliation(s)
- Tushar D Bhagat
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Yiyu Zou
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Shizheng Huang
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Jihwan Park
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Matthew B Palmer
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Caroline Hu
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Weijuan Li
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Niraj Shenoy
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Orsolya Giricz
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Gaurav Choudhary
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Yiting Yu
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Yi-An Ko
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - María C Izquierdo
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Ae Seo Deok Park
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | | | - Remi Laurence
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Robert Lopez
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Masako Suzuki
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - James Pullman
- the Department of Pathology, Montefiore Medical Center, Bronx, New York 10467
| | - Justin Kaner
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | | | - A Ari Hakimi
- the Sloan Kettering Cancer Center, New York, New York 10065, and
| | - John M Greally
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | | | | | - Kith Pradhan
- From the Albert Einstein College of Medicine, Bronx, New York 10461
| | - Amit Verma
- From the Albert Einstein College of Medicine, Bronx, New York 10461,
| | - Katalin Susztak
- the Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104,
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125
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Dai H, Liu Q, Liu B. Research Progress on Mechanism of Podocyte Depletion in Diabetic Nephropathy. J Diabetes Res 2017; 2017:2615286. [PMID: 28791309 PMCID: PMC5534294 DOI: 10.1155/2017/2615286] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/05/2017] [Accepted: 03/05/2017] [Indexed: 12/13/2022] Open
Abstract
Diabetic nephropathy (DN) together with glomerular hyperfiltration has been implicated in the development of diabetic microangiopathy in the initial stage of diabetic diseases. Increased amounts of urinary protein in DN may be associated with functional and morphological alterations of podocyte, mainly including podocyte hypertrophy, epithelial-mesenchymal transdifferentiation (EMT), podocyte detachment, and podocyte apoptosis. Accumulating studies have revealed that disruption in multiple renal signaling pathways had been critical in the progression of these pathological damages, such as adenosine monophosphate-activated kinase signaling pathways (AMPK), wnt/β-catenin signaling pathways, endoplasmic reticulum stress-related signaling pathways, mammalian target of rapamycin (mTOR)/autophagy pathway, and Rho GTPases. In this review, we highlight new molecular insights underlying podocyte injury in the progression of DN, which offer new therapeutic targets to develop important renoprotective treatments for DN over the next decade.
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Affiliation(s)
- Haoran Dai
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
| | - Qingquan Liu
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
- *Qingquan Liu: and
| | - Baoli Liu
- Department of Nephrology, Shunyi Branch, Beijing Hospital of Traditional Chinese Medicine, Station East 5, Shunyi District, Beijing 101300, China
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
- *Baoli Liu:
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126
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Lee HW, Khan SQ, Khaliqdina S, Altintas MM, Grahammer F, Zhao JL, Koh KH, Tardi NJ, Faridi MH, Geraghty T, Cimbaluk DJ, Susztak K, Moita LF, Baltimore D, Tharaux PL, Huber TB, Kretzler M, Bitzer M, Reiser J, Gupta V. Absence of miR-146a in Podocytes Increases Risk of Diabetic Glomerulopathy via Up-regulation of ErbB4 and Notch-1. J Biol Chem 2016; 292:732-747. [PMID: 27913625 DOI: 10.1074/jbc.m116.753822] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 12/01/2016] [Indexed: 12/31/2022] Open
Abstract
Podocyte injury is an early event in diabetic kidney disease and is a hallmark of glomerulopathy. MicroRNA-146a (miR-146a) is highly expressed in many cell types under homeostatic conditions, and plays an important anti-inflammatory role in myeloid cells. However, its role in podocytes is unclear. Here, we show that miR-146a expression levels decrease in the glomeruli of patients with type 2 diabetes (T2D), which correlates with increased albuminuria and glomerular damage. miR-146a levels are also significantly reduced in the glomeruli of albuminuric BTBR ob/ob mice, indicating its significant role in maintaining podocyte health. miR-146a-deficient mice (miR-146a-/-) showed accelerated development of glomerulopathy and albuminuria upon streptozotocin (STZ)-induced hyperglycemia. The miR-146a targets, Notch-1 and ErbB4, were also significantly up-regulated in the glomeruli of diabetic patients and mice, suggesting induction of the downstream TGFβ signaling. Treatment with a pan-ErbB kinase inhibitor erlotinib with nanomolar activity against ErbB4 significantly suppressed diabetic glomerular injury and albuminuria in both WT and miR-146a-/- animals. Treatment of podocytes in vitro with TGF-β1 resulted in increased expression of Notch-1, ErbB4, pErbB4, and pEGFR, the heterodimerization partner of ErbB4, suggesting increased ErbB4/EGFR signaling. TGF-β1 also increased levels of inflammatory cytokine monocyte chemoattractant protein-1 (MCP-1) and MCP-1 induced protein-1 (MCPIP1), a suppressor of miR-146a, suggesting an autocrine loop. Inhibition of ErbB4/EGFR with erlotinib co-treatment of podocytes suppressed this signaling. Our findings suggest a novel role for miR-146a in protecting against diabetic glomerulopathy and podocyte injury. They also point to ErbB4/EGFR as a novel, druggable target for therapeutic intervention, especially because several pan-ErbB inhibitors are clinically available.
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Affiliation(s)
- Ha Won Lee
- From the Departments of Internal Medicine and
| | | | | | | | - Florian Grahammer
- the Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Jimmy L Zhao
- the Department of Medicine, New York Presbyterian/Weill Cornell Medical Center, New York, New York 10065.,the Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Kwi Hye Koh
- From the Departments of Internal Medicine and
| | | | | | | | - David J Cimbaluk
- Pathology, Rush University Medical Center, Chicago, Illinois 60612
| | - Katalin Susztak
- the Department of Medicine, Renal Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Luis F Moita
- the Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
| | - David Baltimore
- the Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Pierre-Louis Tharaux
- the Paris Cardiovascular Centre (PARCC), Institut National de la Santé et de la Recherche Médicale (INSERM), 75015 Paris, France and the Université Paris Descartes, Sorbonne Paris Cité, 75270 Paris, France
| | - Tobias B Huber
- the Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany.,the BIOSS Center for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany.,the FRIAS, Freiburg Institute for Advanced Studies and ZBSA-Center for Systems Biology, Albert-Ludwigs-University, 79104 Freiburg, Germany, and
| | - Matthias Kretzler
- the Division of Nephrology, University of Michigan, Ann Arbor, Michigan 48109
| | - Markus Bitzer
- the Division of Nephrology, University of Michigan, Ann Arbor, Michigan 48109
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Morimoto M, Myung C, Beirnes K, Choi K, Asakura Y, Bokenkamp A, Bonneau D, Brugnara M, Charrow J, Colin E, Davis A, Deschenes G, Gentile M, Giordano M, Gormley AK, Govender R, Joseph M, Keller K, Lerut E, Levtchenko E, Massella L, Mayfield C, Najafian B, Parham D, Spranger J, Stenzel P, Yis U, Yu Z, Zonana J, Hendson G, Boerkoel CF. Increased Wnt and Notch signaling: a clue to the renal disease in Schimke immuno-osseous dysplasia? Orphanet J Rare Dis 2016; 11:149. [PMID: 27816064 PMCID: PMC5097426 DOI: 10.1186/s13023-016-0519-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/23/2016] [Indexed: 12/20/2022] Open
Abstract
Background Schimke immuno-osseous dysplasia (SIOD) is a multisystemic disorder caused by biallelic mutations in the SWI/SNF-related matrix-associated actin-dependent regulator of chromatin, subfamily A-like 1 (SMARCAL1) gene. Changes in gene expression underlie the arteriosclerosis and T-cell immunodeficiency of SIOD; therefore, we hypothesized that SMARCAL1 deficiency causes the focal segmental glomerulosclerosis (FSGS) of SIOD by altering renal gene expression. We tested this hypothesis by gene expression analysis of an SIOD patient kidney and verified these findings through immunofluorescent analysis in additional SIOD patients and a genetic interaction analysis in Drosophila. Results We found increased expression of components and targets of the Wnt and Notch signaling pathways in the SIOD patient kidney, increased levels of unphosphorylated β-catenin and Notch1 intracellular domain in the glomeruli of most SIOD patient kidneys, and genetic interaction between the Drosophila SMARCAL1 homologue Marcal1 and genes of the Wnt and Notch signaling pathways. Conclusions We conclude that increased Wnt and Notch activity result from SMARCAL1 deficiency and, as established causes of FSGS, contribute to the renal disease of most SIOD patients. This further clarifies the pathogenesis of SIOD and will hopefully direct potential therapeutic approaches for SIOD patients. Electronic supplementary material The online version of this article (doi:10.1186/s13023-016-0519-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marie Morimoto
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Child & Family Research Institute, Vancouver, BC, Canada
| | - Clara Myung
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Child & Family Research Institute, Vancouver, BC, Canada
| | - Kimberly Beirnes
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Child & Family Research Institute, Vancouver, BC, Canada
| | - Kunho Choi
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Child & Family Research Institute, Vancouver, BC, Canada
| | - Yumi Asakura
- Department of Endocrinology & Metabolism, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Arend Bokenkamp
- Department of Pediatric Nephrology, VU University Medical Center, Amsterdam, The Netherlands
| | - Dominique Bonneau
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Milena Brugnara
- Department of Pediatrics, University of Verona, Verona, Italy
| | - Joel Charrow
- Division of Genetics, Birth Defects and Metabolism, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Estelle Colin
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Amira Davis
- Seattle Children's Hospital, Seattle, WA, USA
| | | | - Mattia Gentile
- Department of Medical Genetics, Hospital Di Venere - ASL Bari, Bari, Italy
| | - Mario Giordano
- Pediatric Nephrology and Dialysis Unit, Ospedale Pediatrico Giovanni XXIII, Bari, Italy
| | - Andrew K Gormley
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rajeshree Govender
- Department of Pediatrics and Child Health, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Mark Joseph
- Department of Pediatric Nephrology, Phoenix Children's Hospital, Phoenix, AZ, USA
| | - Kory Keller
- Child Development and Rehabiliation Center, Oregon Institute on Disability & Development, Oregon Health & Science University, Portland, OR, USA
| | - Evelyne Lerut
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Elena Levtchenko
- Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Laura Massella
- Division of Nephrology, Bambino Gesù Children's Hospital and Research Institute, Rome, Italy
| | | | - Behzad Najafian
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - David Parham
- Department of Pathology, Children's Hospital Los Angeles and Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Peter Stenzel
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - Uluc Yis
- Department of Pediatrics, Division of Child Neurology, Dokuz Eylül University, School of Medicine, İzmir, Turkey
| | - Zhongxin Yu
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jonathan Zonana
- Child Development and Rehabiliation Center, Oregon Institute on Disability & Development, Oregon Health & Science University, Portland, OR, USA
| | - Glenda Hendson
- Department of Anatomic Pathology, Children's and Women's Health Centre of British Columbia, Vancouver, BC, Canada
| | - Cornelius F Boerkoel
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada. .,Child & Family Research Institute, Vancouver, BC, Canada. .,Provincial Medical Genetics Program, Department of Medical Genetics, Children's and Women's Health Centre of British Columbia, 4500 Oak Street, Room C234, Vancouver, BC, V6H 3N1, Canada.
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128
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Abstract
BACKGROUND The activation of the Notch signaling pathway has been shown to play an important role in diabetic nephropathy (DN) development. Besides, Notch-1 is a target gene in miR-34a. However, the regulation of the podocyte lesions involved in DN by miR-34a has not been identified. METHODS This study utilized miR-34a mimics and small interfering RNA transfection to construct miR-34a overexpression and lower-expression model to investigate the effect of miR-34a on the regulation of the Notch signaling pathway and podocyte lesions in DN. Western blotting and real-time quantitative polymerase chain reaction were applied for the quantitative testing of mRNA and protein expression. Apoptosis of podocyte was detected by TUNEL staining. RESULTS In high-glucose (HG) conditions, miR-34a overexpression inhibited the expression of Notch 1, Jagged 1, NICD, Hes 1, and Hey 1 proteins. Further, cleaved caspase-3, Bax, and phosphorylation of p53 (p-p53) were reduced significantly. Therefore, miR-34a overexpression inhibited the Notch signaling pathway and podocyte lesions induced by HG. β-arrestin was slightly reduced in HG conditions. Meanwhile, miR-34a overexpression could remit the inhibition. CONCLUSION Results from this study provide evidence that miR-34a may offer a new approach for the treatment of diabetes.
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Affiliation(s)
- Xiangying Zhang
- Department of Endocrinology, Tianjin Hospital, Tianjin, P.R. China
- Correspondence: Xiangying Zhang, Department of Endocrinology, Tianjin Hospital. Liberation South Road No. 406, Hexi District, Tianjin 300211, China (e-mail: )
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129
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Leierer J, Mayer G, Kronbichler A. Primary focal segmental glomerulosclerosis: miRNAs and targeted therapies. Eur J Clin Invest 2016; 46:954-964. [PMID: 27651302 DOI: 10.1111/eci.12676] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 09/07/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND Primary focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome. AIMS The pathogenic steps leading to primary FSGS are still obscure, although evidence suggests that circulatory factor(s) are involved in the onset of disease. RESULTS Recent technical advances allow the analysis of miRNA expression in tissues and body fluids, leading to reports of miRNAs involved in the molecular mechanisms of FSGS-aetiopathogenesis. Moreover, investigations have also highlighted miRNAs that might serve as biomarkers for primary FSGS. DISCUSSION/CONCLUSIONS The aim of this review was to summarize reports showing a direct relation between miRNAs and primary FSGS. In addition, the impact of identified miRNAs on treatment response, prediction of the disease onset as well as the regulation in different disease activities is summarized.
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Affiliation(s)
- Johannes Leierer
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria.
| | - Gert Mayer
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria
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130
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LaFoya B, Munroe JA, Mia MM, Detweiler MA, Crow JJ, Wood T, Roth S, Sharma B, Albig AR. Notch: A multi-functional integrating system of microenvironmental signals. Dev Biol 2016; 418:227-41. [PMID: 27565024 PMCID: PMC5144577 DOI: 10.1016/j.ydbio.2016.08.023] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 12/20/2022]
Abstract
The Notch signaling cascade is an evolutionarily ancient system that allows cells to interact with their microenvironmental neighbors through direct cell-cell interactions, thereby directing a variety of developmental processes. Recent research is discovering that Notch signaling is also responsive to a broad variety of stimuli beyond cell-cell interactions, including: ECM composition, crosstalk with other signaling systems, shear stress, hypoxia, and hyperglycemia. Given this emerging understanding of Notch responsiveness to microenvironmental conditions, it appears that the classical view of Notch as a mechanism enabling cell-cell interactions, is only a part of a broader function to integrate microenvironmental cues. In this review, we summarize and discuss published data supporting the idea that the full function of Notch signaling is to serve as an integrator of microenvironmental signals thus allowing cells to sense and respond to a multitude of conditions around them.
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Affiliation(s)
- Bryce LaFoya
- Biomolecular Sciences PhD Program, Boise State University, Boise, ID 83725, USA
| | - Jordan A Munroe
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Masum M Mia
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Michael A Detweiler
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Jacob J Crow
- Biomolecular Sciences PhD Program, Boise State University, Boise, ID 83725, USA
| | - Travis Wood
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Steven Roth
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Bikram Sharma
- Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Allan R Albig
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA; Biomolecular Sciences PhD Program, Boise State University, Boise, ID 83725, USA.
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131
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Nuclear translocation of IQGAP1 protein upon exposure to puromycin aminonucleoside in cultured human podocytes: ERK pathway involvement. Cell Signal 2016; 28:1470-8. [DOI: 10.1016/j.cellsig.2016.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 06/16/2016] [Accepted: 06/19/2016] [Indexed: 11/18/2022]
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132
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The role of mechanistic target of rapamycin in maintenance of glomerular epithelial cells. Curr Opin Nephrol Hypertens 2016; 25:28-34. [PMID: 26625863 DOI: 10.1097/mnh.0000000000000181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Recent studies have emerged to reveal the pivotal roles of mechanistic target of rapamycin (mTOR) signaling not only in the maintenance of the physiological functions of renal cells but also in the pathogenesis of renal cell dysfunctions and kidney diseases. We introduce the current understanding of mTOR signaling, and its crucial roles in glomerular epithelial cell biology and the pathophysiology related to kidney diseases. RECENT FINDINGS mTOR, a Ser/Thr kinase, forms two distinct functional complexes, mTORC1 and mTORC2. Recent studies revealed that physiologic levels of mTORC1 and mTORC2 activity play key roles in maintaining podocyte and glomerular functions. However, aberrant activation of mTORC1 or loss of mTORC2 activity in podocytes may underlie the pathogenesis of glomerular disorders, including diabetic kidney disease. SUMMARY An effective treatment for mTORC1-associated podocyte and glomerular dysfunction may require the attenuation of mTORC1 activity in the setting of both an intact mTORC2 pathway and normal basal mTORC1 activity in order to preserve physiologic podocyte functions.
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133
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McNicholas BA, Eng DG, Lichtnekert J, Rabinowitz PS, Pippin JW, Shankland SJ. Reducing mTOR augments parietal epithelial cell density in a model of acute podocyte depletion and in aged kidneys. Am J Physiol Renal Physiol 2016; 311:F626-39. [PMID: 27440779 PMCID: PMC5142165 DOI: 10.1152/ajprenal.00196.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/12/2016] [Indexed: 02/06/2023] Open
Abstract
Parietal epithelial cell (PEC) response to glomerular injury may underlie a common pathway driving fibrogenesis following podocyte loss that typifies several glomerular disorders. Although the mammalian target of rapamycin (mTOR) pathway is important in cell homeostasis, little is known of the biological role or impact of reducing mTOR activity on PEC response following podocyte depletion, nor in the aging kidney. The purpose of these studies was to determine the impact on PECs of reducing mTOR activity following abrupt experimental depletion in podocyte number, as well as in a model of chronic podocyte loss and sclerosis associated with aging. Podocyte depletion was induced by an anti-podocyte antibody and rapamycin started at day 5 until death at day 14 Reducing mTOR did not lead to a greater reduction in podocyte density, despite greater glomerulosclerosis. However, mTOR inhibition lead to an increase in PEC density and PEC-derived crescent formation. Additionally, markers of epithelial-to-mesenchymal transition (platelet-derived growth factor receptor-β, α-smooth muscle actin, Notch-3) and PEC activation (CD44, collagen IV) were further increased by mTOR reduction. Aged mice treated with rapamycin for 1, 2, and 10 wk before death at 26.5 mo (≈75-yr-old human age) had increased the number of glomeruli with a crescentic appearance. mTOR inhibition at either a high or low level lead to changes in PEC phenotype, indicating PEC morphology is sensitive to changes mediated by global mTOR inhibition.
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Affiliation(s)
| | - Diana G Eng
- Division of Nephrology, University of Washington, Seattle, Washington; and
| | - Julia Lichtnekert
- Division of Nephrology, University of Washington, Seattle, Washington; and
| | | | - Jeffrey W Pippin
- Division of Nephrology, University of Washington, Seattle, Washington; and
| | - Stuart J Shankland
- Division of Nephrology, University of Washington, Seattle, Washington; and
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134
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Pullen N, Fornoni A. Drug discovery in focal and segmental glomerulosclerosis. Kidney Int 2016; 89:1211-20. [PMID: 27165834 PMCID: PMC4875964 DOI: 10.1016/j.kint.2015.12.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/23/2015] [Accepted: 12/29/2015] [Indexed: 11/26/2022]
Abstract
Despite the high medical burden experienced by patients with focal segmental glomerulosclerosis, the etiology of the condition remains largely unknown. Focal segmental glomerulosclerosis is highly heterogeneous in clinical and morphologic manifestations. While this presents challenges for the development of new treatments, research investments over the last 2 decades have yielded a surfeit of potential avenues for therapeutic intervention. The development of many of those ideas and concepts into new therapies, however, has been very disappointing. Here, we describe some of the factors that have potentially contributed to the poor translational performance from this research investment, including the confidence we ascribe to a target, the conduct of experimental studies, and the availability of selective reagents to test hypotheses. We will discuss the significance of genetic and systems traits as well as other methods for reducing bias. We will analyze the limitations of a successful drug development. We will use specific examples hoping that these will guide a consensus for investment and drive greater translational quality. We hope that this substrate will serve to exemplify the tremendous opportunity for intervention as well as facilitate greater collaborative effort between industry, academia, and private foundations in promoting appropriate validation of these targets. Only then will we have achieved our goal for curative therapies for this devastating disease.
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Affiliation(s)
- Nick Pullen
- Pfizer Global Research & Development, Cambridge, Massachusetts, USA.
| | - Alessia Fornoni
- Katz Family Drug Discovery Center and Division of Nephrology and Hypertension, University of Miami Miller School of Medicine, Miami, Florida, USA.
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135
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Abstract
Chronic kidney disease (CKD) represents a leading cause of death in the United States. There is no cure for this disease, with current treatment strategies relying on blood pressure control through blockade of the renin-angiotensin system. Such approaches only delay the development of end-stage kidney disease and can be associated with serious side effects. Recent identification of several novel mechanisms contributing to CKD development - including vascular changes, loss of podocytes and renal epithelial cells, matrix deposition, inflammation and metabolic dysregulation - has revealed new potential therapeutic approaches for CKD. This Review assesses emerging strategies and agents for CKD treatment, highlighting the associated challenges in their clinical development.
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136
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Hu C, Sun L, Xiao L, Han Y, Fu X, Xiong X, Xu X, Liu Y, Yang S, Liu F, Kanwar YS. Insights into the Mechanisms Involved in the Expression and Regulation of Extracellular Matrix Proteins in Diabetic Nephropathy. Curr Med Chem 2016; 22:2858-70. [PMID: 26119175 DOI: 10.2174/0929867322666150625095407] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 06/15/2015] [Accepted: 06/24/2015] [Indexed: 02/06/2023]
Abstract
Diabetic Nephropathy (DN) is believed to be a major microvascular complication of diabetes. The hallmark of DN includes deposition of Extracellular Matrix (ECM) proteins, such as, collagen, laminin and fibronectin in the mesangium and renal tubulo-interstitium of the glomerulus and basement membranes. Such an increased expression of ECM leads to glomerular and tubular basement membranes thickening and increase of mesangial matrix, ultimately resulting in glomerulosclerosis and tubulointerstitial fibrosis. The characteristic morphologic glomerular mesangial lesion has been described as Kimmelstiel-Wilson nodule, and the process at times is referred to as diabetic nodular glomerulosclerosis. Thus, the accumulation of ECM proteins plays a critical role in the development of DN. The relevant mechanism(s) involved in the increased ECM expression and their regulation in the kidney in diabetic state has been extensively investigated and documented in the literature. Nevertheless, there are certain other mechanisms that may yet be conclusively defined. Recent studies demonstrated that some of the new signaling pathways or molecules including, Notch, Wnt, mTOR, TLRs and small GTPase may play a pivotal role in the modulation of ECM regulation and expression in DN. Such modulation could be operational for instance Notch through Notch1/Jagged1 signaling, Wnt by Wnt/β- catenin pathway and mTOR via PI3-K/Akt/mTOR signaling pathways. All these pathways may be critical in the modulation of ECM expression and tubulo-interstitial fibrosis. In addition, TLRs, mainly the TLR2 and TLR4, by TLR2- dependent and TGF-β-dependent conduits, may modulate ECM expression and generate a fibrogenic response. Small GTPase like Rho, Ras and Rab family by targeting relevant genes may also influence the accumulation of ECM proteins and renal fibrosis in hyperglycemic states. This review summarizes the recent information about the role and mechanisms by which these molecules and signaling pathways regulate ECM synthesis and its expression in high glucose ambience in vitro and in vivo states. The understanding of such signaling pathways and the molecules that influence expression, secretion and amassing of ECM may aid in developing strategies for the amelioration of diabetic nephropathy.
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Affiliation(s)
| | - L Sun
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China.
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137
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Edeling M, Ragi G, Huang S, Pavenstädt H, Susztak K. Developmental signalling pathways in renal fibrosis: the roles of Notch, Wnt and Hedgehog. Nat Rev Nephrol 2016; 12:426-39. [PMID: 27140856 DOI: 10.1038/nrneph.2016.54] [Citation(s) in RCA: 279] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Kidney fibrosis is a common histological manifestation of functional decline in the kidney. Fibrosis is a reactive process that develops in response to excessive epithelial injury and inflammation, leading to myofibroblast activation and an accumulation of extracellular matrix. Here, we describe how three key developmental signalling pathways - Notch, Wnt and Hedgehog (Hh) - are reactivated in response to kidney injury and contribute to the fibrotic response. Although transient activation of these pathways is needed for repair of injured tissue, their sustained activation is thought to promote fibrosis. Excessive Wnt and Notch expression prohibit epithelial differentiation, whereas increased Wnt and Hh expression induce fibroblast proliferation and myofibroblastic transdifferentiation. Notch, Wnt and Hh are fundamentally different signalling pathways, but their choreographed activation seems to be just as important for fibrosis as it is for embryonic kidney development. Decreasing the activity of Notch, Wnt or Hh signalling could potentially provide a new therapeutic strategy to ameliorate the development of fibrosis in chronic kidney disease.
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Affiliation(s)
- Maria Edeling
- Renal Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, 415 Clinical Research Building, Philadelphia, Pennsylvania 19104, USA.,Department of Molecular Nephrology, Internal Medicine D, University Hospital Albert-Schweitzer-Straße 33, Münster 48149, Germany
| | - Grace Ragi
- Renal Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, 415 Clinical Research Building, Philadelphia, Pennsylvania 19104, USA
| | - Shizheng Huang
- Renal Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, 415 Clinical Research Building, Philadelphia, Pennsylvania 19104, USA
| | - Hermann Pavenstädt
- Department of Molecular Nephrology, Internal Medicine D, University Hospital Albert-Schweitzer-Straße 33, Münster 48149, Germany
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, 415 Clinical Research Building, Philadelphia, Pennsylvania 19104, USA
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138
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Abstract
Diabetes is increasing in prevalence and is the leading cause of end-stage renal disease in the United States. Diabetic kidney disease is considered a proteinuric glomerular disease. Although the glomerulus is composed of various cell types, research suggests that podocytes are critical to overall glomerular health. Podocyte injury has been identified as a pivotal event resulting in proteinuric kidney disease, glomerulosclerosis, and loss of renal function. Thus, understanding the signaling mechanisms that trigger podocyte injury in diabetic kidney disease might allow for the development of targeted therapeutics to prevent or ameliorate progression to end-stage renal failure. This review focuses on the role of podocytes in diabetic kidney disease.
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Affiliation(s)
- Jamie S Lin
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Katalin Susztak
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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139
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Zhao Y, Qiao X, Wang L, Tan TK, Zhao H, Zhang Y, Zhang J, Rao P, Cao Q, Wang Y, Wang Y, Wang YM, Lee VWS, Alexander SI, Harris DCH, Zheng G. Matrix metalloproteinase 9 induces endothelial-mesenchymal transition via Notch activation in human kidney glomerular endothelial cells. BMC Cell Biol 2016; 17:21. [PMID: 27130612 PMCID: PMC4850690 DOI: 10.1186/s12860-016-0101-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 04/22/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Endothelial-mesenchymal transition (EndoMT) is a major source of myofibroblast formation in kidney fibrosis. Our previous study showed a profibrotic role for matrix metalloproteinase 9 (MMP-9) in kidney fibrosis via induction of epithelial-mesenchymal transition (EMT). Inhibition of MMP-9 activity reduced kidney fibrosis in murine unilateral ureteral obstruction. This study investigated whether MMP-9 also plays a role in EndoMT in human glomerular endothelial cells. RESULTS TGF-β1 (10 or 20 ng/ml) induced EndoMT in HKGECs as shown by morphological changes. In addition, VE-cadherin and CD31 were significantly downregulated, whereas α-SMA, vimentin, and N-cadherin were upregulated. RT-PCR revealed that Snail, a known inducer of EMT, was upregulated. The MMP inhibitor GM6001 abrogated TGF-β1-induced EndoMT. Zymography indicated that MMP-9 was also upregulated in TGF-β1-treated HKGECs. Recombinant MMP-9 (2 μg/ml) induced EndoMT in HKGECs via Notch signaling, as evidenced by increased formation of the Notch intracellular domain (NICD) and decreased Notch 1. Inhibition of MMP-9 activity by its inhibitor showed a dose-dependent response in preventing TGF-β1-induced α-SMA and NICD in HKGECs, whereas inhibition of Notch signaling by γ-secretase inhibitor (GSI) blocked rMMP-9-induced EndoMT. CONCLUSIONS Taken together, our results demonstrate that MMP-9 plays an important role in TGF-β1-induced EndoMT via upregulation of Notch signaling in HKGECs.
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Affiliation(s)
- Ye Zhao
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia.,The School of Biomedical Sciences, Chengdu Medical College, Chengdu, 610500, PR China
| | - Xi Qiao
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia.,Department of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, WuYi Road 382, Taiyuan, 030001, Shanxi, PR China
| | - Lihua Wang
- Department of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease Institute, WuYi Road 382, Taiyuan, 030001, Shanxi, PR China
| | - Tian Kui Tan
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Hong Zhao
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Xinjian Road 56, Taiyuan, 030001, Shanxi, PR China
| | - Yun Zhang
- Experimental Centre of Science and Research, the First Clinical Hospital of Shanxi Medical University, Xinjian Road 382, Taiyuan, 030001, Shanxi, PR China
| | - Jianlin Zhang
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Xinjian Road 56, Taiyuan, 030001, Shanxi, PR China
| | - Padmashree Rao
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Qi Cao
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Yiping Wang
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Ya Wang
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Yuan Min Wang
- Centre for Kidney Research, Children's Hospital at Westmead, 212 Hawkesbury Road, Sydney, NSW, Australia
| | - Vincent W S Lee
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Stephen I Alexander
- Centre for Kidney Research, Children's Hospital at Westmead, 212 Hawkesbury Road, Sydney, NSW, Australia
| | - David C H Harris
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia
| | - Guoping Zheng
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, the University of Sydney, 176 Hawkesbury Road, Sydney, NSW, 2145, Australia.
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140
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Abstract
Transforming growth factor-β (TGF-β) is the primary factor that drives fibrosis in most, if not all, forms of chronic kidney disease (CKD). Inhibition of the TGF-β isoform, TGF-β1, or its downstream signalling pathways substantially limits renal fibrosis in a wide range of disease models whereas overexpression of TGF-β1 induces renal fibrosis. TGF-β1 can induce renal fibrosis via activation of both canonical (Smad-based) and non-canonical (non-Smad-based) signalling pathways, which result in activation of myofibroblasts, excessive production of extracellular matrix (ECM) and inhibition of ECM degradation. The role of Smad proteins in the regulation of fibrosis is complex, with competing profibrotic and antifibrotic actions (including in the regulation of mesenchymal transitioning), and with complex interplay between TGF-β/Smads and other signalling pathways. Studies over the past 5 years have identified additional mechanisms that regulate the action of TGF-β1/Smad signalling in fibrosis, including short and long noncoding RNA molecules and epigenetic modifications of DNA and histone proteins. Although direct targeting of TGF-β1 is unlikely to yield a viable antifibrotic therapy due to the involvement of TGF-β1 in other processes, greater understanding of the various pathways by which TGF-β1 controls fibrosis has identified alternative targets for the development of novel therapeutics to halt this most damaging process in CKD.
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141
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Hu B, Phan SH. Notch in fibrosis and as a target of anti-fibrotic therapy. Pharmacol Res 2016; 108:57-64. [PMID: 27107790 DOI: 10.1016/j.phrs.2016.04.010] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 04/13/2016] [Indexed: 02/07/2023]
Abstract
The Notch pathway represents a highly conserved signaling network with essential roles in regulation of key cellular processes and functions, many of which are critical for development. Accumulating evidence indicates that it is also essential for fibrosis and thus the pathogenesis of chronic fibroproliferative diseases in diverse organs and tissues. Different effects of Notch activation are observed depending on cellular and tissue context as well as in both physiologic and pathologic states. Close interactions of Notch signaling pathway with other signaling pathways have been identified. In this review, current knowledge on the role of the Notch signaling with special focus on fibrosis and its potential as a therapeutic target is summarized.
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Affiliation(s)
- Biao Hu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Sem H Phan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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142
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Zoja C, Zanchi C, Benigni A. Key pathways in renal disease progression of experimental diabetes. Nephrol Dial Transplant 2016. [PMID: 26209738 DOI: 10.1093/ndt/gfv036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes mellitus and the leading cause of end-stage kidney disease. Both diabetes and chronic kidney disease are risk factors for cardiovascular disease, and diabetic patients with renal involvement are three times more likely to eventually die of cardiovascular disease than diabetic patients without signs of renal failure. In type 2 diabetes, microalbuminuria is a marker of renal dysfunction and a crucial predictor of cardiovascular disease. Inhibitors of angiotensin II synthesis/activity, while preventing micro- or macroalbuminuria, also reduced cardiovascular events in diabetic patients. However, the effectiveness of renin angiotensin system blocking agents depends on the time when treatment is started, and imperfect renoprotection may occur if therapy begins at an advanced disease phase. This raises the need to identify novel multidrug approaches that simultaneously inhibit additional pathways other than angiotensin II for those diabetic patients who remain at high risk of both poor renal and cardiovascular outcomes. Studies in animal models of diabetes have contributed to defining relevant cellular mechanisms underlying the pathogenesis of DN that could represent possible targets for therapies. The pathogenesis of DN is multifactorial, involving a complex series of molecular processes. In this review, we report evidence obtained in experimental models of DN on some specific processes and pathways implicated in DN that may be crucial for managing this disease.
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Affiliation(s)
- Carlamaria Zoja
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Cristina Zanchi
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ariela Benigni
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
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143
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Nagata M. Podocyte injury and its consequences. Kidney Int 2016; 89:1221-30. [PMID: 27165817 DOI: 10.1016/j.kint.2016.01.012] [Citation(s) in RCA: 327] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/12/2015] [Accepted: 01/27/2016] [Indexed: 01/02/2023]
Abstract
Podocytes maintain the glomerular filtration barrier, and the stability of this barrier depends on their highly differentiated postmitotic phenotype, which also defines the particular vulnerability of the glomerulus. Recent podocyte biology and gene disruption studies in vivo indicate a causal relationship between abnormalities of single podocyte molecules and proteinuria and glomerulosclerosis. Podocytes live under various stresses and pathological stimuli. They adapt to maintain homeostasis, but excessive stress leads to maladaptation with complex biological changes including loss of integrity and dysregulation of cellular metabolism. Podocyte injury causes proteinuria and detachment from the glomerular basement membrane. In addition to "sick" podocytes and their detachment, our understanding of glomerular responses following podocyte loss needs to address the pathways from podocyte injury to sclerosis. Studies have found a variety of glomerular responses to podocyte dysfunction in vivo, such as disruption of podocyte-endothelial cross talk and activation of podocyte-parietal cell interactions, all of which help us to understand the complex scenario of podocyte injury and its consequences. This review focuses on the cellular aspects of podocyte dysfunction and the adaptive or maladaptive glomerular responses to podocyte injury that lead to its major consequence, glomerulosclerosis.
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Affiliation(s)
- Michio Nagata
- Kidney and Vascular Pathology, University of Tsukuba, Ibaraki, Japan.
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144
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Gao F, Yao M, Cao Y, Liu S, Liu Q, Duan H. Valsartan ameliorates podocyte loss in diabetic mice through the Notch pathway. Int J Mol Med 2016; 37:1328-36. [PMID: 26985716 DOI: 10.3892/ijmm.2016.2525] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 03/01/2016] [Indexed: 11/06/2022] Open
Abstract
The Notch pathway is known to be linked to diabetic nephropathy (DN); however, its underlying mechanism was poorly understood. In the present study, we examined the effect of Valsartan, an angiotensin II type 1 receptor antagonist, on the Notch pathway and podocyte loss in DN. Diabetes was induced in mice by an intraperitoneal injection of streptozotocin and and this was followed by treatment with Valsartan. Levels of blood glucose, kidney weight and body weight, as well as proteinuria were measured. Samples of the kidneys were also histologically examined. The relative levels of Jagged1, Notch1, Notch intracellular domain 1 (NICD1), Hes family BHLH transcription factor 1 (Hes1) and Hes-related family BHLH transcription factor with YRPW motif 1 expression (Hey1) in the glomeruli were determined by immunohistochemical analysis, western blot analysis and RT-qPCR. The B-Cell CLL/Lymphoma 2 (Bcl-2) and p53 pathways were examined by western blot analysis. Apoptosis and detachment of podocytes from the glomerular basement membrane were examined using a TUNEL assay, flow cytometric analysis and ELISA. The number of podocytes was quantified by measuring Wilms tumor-1 (WT-1) staining. We noted that the expression of Jagged1, Notch1, NICD1, Hes1 and Hey1 was increased in a time-dependent manner in the glomeruli of mice with streptozotocin (STZ)-induced diabetes. Moreover, in diabetic mice, Valsartan significantly reduced kidney weight and proteinuria, and mitigated the pathogenic processes in the kidneys. Valsartan also inhibited the activation of Notch, Bcl-2 and p53 pathways and ameliorated podocyte loss in the glomeruli of mice with STZ-induced diabetes. Taken together, these findings indicated that Valsartan exerted a beneficial effect on reducing podocyte loss, which is associated with inhibition of Notch pathway activation in the glomeruli of diabetic mice.
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Affiliation(s)
- Feng Gao
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Min Yao
- Department of Biochemistry, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Yanping Cao
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Shuxia Liu
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Qingjuan Liu
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
| | - Huijun Duan
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
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145
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Kramer J, Schwanbeck R, Pagel H, Cakiroglu F, Rohwedel J, Just U. Inhibition of Notch Signaling Ameliorates Acute Kidney Failure and Downregulates Platelet-Derived Growth Factor Receptor β in the Mouse Model. Cells Tissues Organs 2016; 201:109-17. [PMID: 26939110 DOI: 10.1159/000442463] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2015] [Indexed: 11/19/2022] Open
Abstract
Ischemic acute kidney injury (AKI) is associated with high morbidity and frequent complications. Repeated episodes of AKI may lead to end-stage renal failure. The pathobiology of regeneration in AKI is not well understood and there is no effective clinical therapy that improves regeneration. The Notch signaling pathway plays an essential role in kidney development and has been implicated in tissue repair in the adult kidney. Here, we found that kidneys after experimental AKI in mice showed increased expression of Notch receptors, specifically Notch1-3, of the Notch ligands Jagged-1 (Jag1), Jag2 and Delta-like-4 (Dll4) and of the Notch target genes Hes1, Hey2, HeyL, Sox9 and platelet-derived growth factor receptor β (Pdgfrb). Treatment of ischemic mice with the x03B3;-secretase inhibitor DBZ blocked Notch signaling and specifically downregulated the expression of Notch3 and the Notch target genes Hes1, Hey2, HeyL and Pdgfrb. After DBZ treatment, the mice developed less interstitial edema and displayed altered interstitial inflammation patterns. Furthermore, serum urea and creatinine levels were significantly decreased from 6 h onwards when compared to control mice treated with DMSO only. Our data are consistent with an amelioration of the severity of kidney injury by blocking Notch activation following AKI, and suggest an involvement of Notch-regulated Pdgfrb in AKI pathogenesis.
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Affiliation(s)
- Jan Kramer
- Department of Virology and Cell Biology, University of Lx00FC;beck, Lx00FC;beck, Germany
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146
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Podocyte directed therapy of nephrotic syndrome-can we bring the inside out? Pediatr Nephrol 2016; 31:393-405. [PMID: 25939817 DOI: 10.1007/s00467-015-3116-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 12/15/2022]
Abstract
Several of the drugs currently used for the treatment of glomerular diseases are prescribed for their immunotherapeutic or anti-inflammatory properties, based on the current understanding that glomerular diseases are mediated by immune responses. In recent years our understanding of podocytic signalling pathways and the crucial role of genetic predispositions in the pathology of glomerular diseases has broadened. Delineation of those signalling pathways supports the hypothesis that several of the medications and immunosuppressive agents used to treat glomerular diseases directly target glomerular podocytes. Several central downstream signalling pathways merge into regulatory pathways of the podocytic actin cytoskeleton and its connection to the slit diaphragm. The slit diaphragm and the cytoskeleton of the foot process represent a functional unit. A breakdown of the cytoskeletal backbone of the foot processes leads to internalization of slit diaphragm molecules, and internalization of slit diaphragm components in turn negatively affects cytoskeletal signalling pathways. Podocytes display a remarkable ability to recover from complete effacement and to re-form interdigitating foot processes and intact slit diaphragms after pharmacological intervention. This ability indicates an active inside-out signalling machinery which stabilizes integrin complex formations and triggers the recycling of slit diaphragm molecules from intracellular compartments to the cell surface. In this review we summarize current evidence from patient studies and model organisms on the direct impact of immunosuppressive and supportive drugs on podocyte signalling pathways. We highlight new therapeutic targets that may open novel opportunities to enhance and stabilize inside-out pathways in podocytes.
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147
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The role of Notch signaling in kidney podocytes. Clin Exp Nephrol 2016; 21:1-6. [DOI: 10.1007/s10157-016-1247-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/07/2016] [Indexed: 10/22/2022]
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148
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Abstract
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions. Foot processes interdigitate with foot processes from adjacent podocytes and form a network of narrow and rather uniform gaps. The fenestrated endothelial cells retain blood cells but permit passage of small solutes and an overlying basement membrane less permeable to macromolecules, in particular to albumin. The cytoskeletal dynamics and structural plasticity of podocytes as well as the signaling between each of these distinct layers are essential for an efficient glomerular filtration and thus for proper renal function. The genetic or acquired impairment of podocytes may lead to foot process effacement (podocyte fusion or retraction), a morphological hallmark of proteinuric renal diseases. Here, we briefly discuss aspects of a contemporary view of podocytes in glomerular filtration, the patterns of structural changes in podocytes associated with common glomerular diseases, and the current state of basic and clinical research.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
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149
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Rinschen MM, Bharill P, Wu X, Kohli P, Reinert MJ, Kretz O, Saez I, Schermer B, Höhne M, Bartram MP, Aravamudhan S, Brooks BR, Vilchez D, Huber TB, Müller RU, Krüger M, Benzing T. The ubiquitin ligase Ubr4 controls stability of podocin/MEC-2 supercomplexes. Hum Mol Genet 2016; 25:1328-44. [PMID: 26792178 DOI: 10.1093/hmg/ddw016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/16/2016] [Indexed: 11/13/2022] Open
Abstract
The PHB-domain protein podocin maintains the renal filtration barrier and its mutation is an important cause of hereditary nephrotic syndrome. Podocin and its Caenorhabditis elegans orthologue MEC-2 have emerged as key components of mechanosensitive membrane protein signalling complexes. Whereas podocin resides at a specialized cell junction at the podocyte slit diaphragm, MEC-2 is found in neurons required for touch sensitivity. Here, we show that the ubiquitin ligase Ubr4 is a key component of the podocin interactome purified both from cultured podocytes and native glomeruli. It colocalizes with podocin and regulates its stability. In C. elegans, this process is conserved. Here, Ubr4 is responsible for the degradation of mislocalized MEC-2 multimers. Ubiquitylomic analysis of mouse glomeruli revealed that podocin is ubiquitylated at two lysine residues. These sites were Ubr4-dependent and were conserved across species. Molecular dynamics simulations revealed that ubiquitylation of one site, K301, do not only target podocin/MEC-2 for proteasomal degradation, but may also affect stability and disassembly of the multimeric complex. We suggest that Ubr4 is a key regulator of podocyte foot process proteostasis.
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Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany,
| | - Puneet Bharill
- Department II of Internal Medicine, Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart, Blood, and Lung Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Priyanka Kohli
- Department II of Internal Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | | | - Oliver Kretz
- Renal Division, University Hospital Freiburg, Freiburg, Germany, Neuroanatomy, University of Freiburg, Freiburg, Germany
| | - Isabel Saez
- Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Bernhard Schermer
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | | | - Sriram Aravamudhan
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany and
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Blood, and Lung Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Vilchez
- Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Tobias B Huber
- Renal Division, University Hospital Freiburg, Freiburg, Germany, BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Roman-Ulrich Müller
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Marcus Krüger
- Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Thomas Benzing
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany,
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150
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Murata A, Hayashi SI. Notch-Mediated Cell Adhesion. BIOLOGY 2016; 5:biology5010005. [PMID: 26784245 PMCID: PMC4810162 DOI: 10.3390/biology5010005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/12/2016] [Accepted: 01/13/2016] [Indexed: 02/06/2023]
Abstract
Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of Notch family members dating back to metazoan evolution. We hypothesize that Notch family members may have initially emerged as cell adhesion molecules in order to mediate multicellularity in the last common ancestor of metazoan organisms.
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Affiliation(s)
- Akihiko Murata
- Department of Molecular and Cellular Biology, Division of Immunology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
| | - Shin-Ichi Hayashi
- Department of Molecular and Cellular Biology, Division of Immunology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
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