51
|
Matsuda J, Namba T, Takabatake Y, Kimura T, Takahashi A, Yamamoto T, Minami S, Sakai S, Fujimura R, Kaimori JY, Matsui I, Hamano T, Fukushima Y, Matsui K, Soga T, Isaka Y. Antioxidant role of autophagy in maintaining the integrity of glomerular capillaries. Autophagy 2019; 14:53-65. [PMID: 29130363 DOI: 10.1080/15548627.2017.1391428] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Autophagy is a lysosomal degradation system by which cytosolic materials and damaged organelles are broken down into basic components. To explore the physiological role of autophagy in glomerular endothelial cells (GEnCs), we compared the autophagic flux among cells in the kidney under starvation. Inhibition of autophagy by chloroquine administration significantly increased the number of autophagosomes or autolysosomes in GEnCs and proximal tubular cells, but not in podocytes, suggesting that the GEnCs exhibit substantial autophagic activity. Next, we analyzed endothelial and hematopoietic cell-specific atg5-deficient mice (atg5-conditional KO [cKO] mice). Glomeruli of 4-wk-old atg5-cKO mice exhibited slightly distended capillary loops accompanied by an accumulation of reactive oxygen species (ROS). Glomeruli of 8-wk-old atg5-cKO mice showed a lobular pattern with thickening of the capillary loops and mesangial matrix expansion; however, the vasculature of other organs was preserved. The atg5-cKO mice died by 12 wk of age, presumably due to pancytopenia resulting from the defect in their hematopoietic lineages. Therefore, we subjected 4-wk atg5-cKO mice to irradiation followed by bone marrow transplantation from normal littermates. Transplanted mice recapitulated the glomerular phenotypes of the atg5-cKO mice with no obvious histological changes in other organs. Twelve-mo-old transplanted mice developed mesangiolysis and glomerulosclerosis with significant deterioration of kidney function. Administration of N-acetyl-l-cysteine, a ROS scavenger, to atg5-cKO mice rescued the glomerular phenotypes. These data suggest that endothelial autophagy protects glomeruli from oxidative stress and maintains the integrity of glomerular capillaries. Enhancing endothelial autophagy may provide a novel therapeutic approach to minimizing glomerular diseases.
Collapse
Affiliation(s)
- Jun Matsuda
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Tomoko Namba
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Yoshitsugu Takabatake
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Tomonori Kimura
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Atsushi Takahashi
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Takeshi Yamamoto
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Satoshi Minami
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Shinsuke Sakai
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Ryuta Fujimura
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Jun-Ya Kaimori
- b Department of Advanced Technology for Transplantation , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Isao Matsui
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Takayuki Hamano
- c Department of Comprehensive Kidney Disease Research (CKDR) , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Yoko Fukushima
- d Department of Ophthalmology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| | - Keiko Matsui
- e Department of Hematology and Oncology , Tokai University School of Medicine , 143 Shimokasuya, Isehara , Kanagaw , Japan
| | - Tomoyoshi Soga
- f Institute for Advanced Biosciences , Keio University , Tsuruoka , Yamagata , Japan
| | - Yoshitaka Isaka
- a Department of Nephrology , Osaka University Graduate School of Medicine , 2-2 Yamada-oka, Suita , Osaka , Japan
| |
Collapse
|
52
|
Zhong F, Lee K, He JC. Role of Krüppel-like factor-2 in kidney disease. Nephrology (Carlton) 2019; 23 Suppl 4:53-56. [PMID: 30298668 DOI: 10.1111/nep.13456] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2018] [Indexed: 12/13/2022]
Abstract
Krüppel-like factor-2 (KLF2) is a transcription factor that plays a major role in the regulation of endothelial cell function. KLF2 protects against endothelial cell injury through its anti-inflammatory, anti-thrombotic and anti-angiogenic effects to maintain the normal vascular integrity. Our recent data indicate that KLF2 is down-regulated in glomerular endothelial cells of patients with diabetic kidney disease and that endothelial cell-specific reduction in KLF2 expression in experimental model of diabetic kidney disease exacerbates glomerular endothelial cell injury and accelerates the disease progression. KLF2 is a key transcriptional regulator of endothelial nitric oxide synthase, and its renoprotective function may be mediated through the increased endothelial nitric oxide synthase expression. As KLF2 expression is stimulated by shear stress, we also investigated the role of KLF2 in the nephrectomy mouse model, in which the endothelial KLF2 expression would be increased through glomerular hyperfiltration in the remnant kidney. Reduction of endothelial KLF2 led to increased glomerular endothelial cell injury and progressive kidney disease in uninephrectomized mice. Interestingly, KLF2 expression is also reduced in nephrectomy patients with progressive kidney disease as compared to those with the non-progressive disease. Together, these studies indicate a critical role of KLF2 in maintaining normal glomerular endothelial cell function and that deficiency of KLF2 leads to more progressive kidney disease.
Collapse
Affiliation(s)
- Fang Zhong
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kyung Lee
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John C He
- Department of Medicine, Nephrology Division, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| |
Collapse
|
53
|
Kikuchi R, Stevens M, Harada K, Oltean S, Murohara T. Anti-angiogenic isoform of vascular endothelial growth factor-A in cardiovascular and renal disease. Adv Clin Chem 2019; 88:1-33. [PMID: 30612603 DOI: 10.1016/bs.acc.2018.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Accumulating evidence suggests that pathologic interactions between the heart and the kidney can contribute to the progressive dysfunction of both organs. Recently, there has been an increase in the prevalence of cardiovascular disease (CVD) and chronic kidney disease (CKD) due to increasing obesity rates. It has been reported that obesity causes various heart and renal disorders and appears to accelerate their progression. Vascular endothelial growth factor-A (VEGF-A) is a major regulator of angiogenesis and vessel permeability, and is associated with CVD and CKD. It is now recognized that alternative VEGF-A gene splicing generates VEGF-A isoforms that differ in their biological actions. Proximal splicing that includes an exon 8a sequence results in pro-angiogenic VEGF-A165a, whereas distal splicing inclusive of exon 8b yields the anti-angiogenic isoform of VEGF-A (VEGF-A165b). This review highlights several recent preclinical and clinical studies on the role of VEGF-A165b in CVD and CKD as a novel function of VEGF-A. This review also discusses potential therapeutic approaches of the use of VEGF-A in clinical settings as a potential circulating biomarker for CVD and CKD.
Collapse
Affiliation(s)
- Ryosuke Kikuchi
- Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
| | - Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Kazuhiro Harada
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
54
|
Targeted delivery of nitric oxide via a 'bump-and-hole'-based enzyme-prodrug pair. Nat Chem Biol 2018; 15:151-160. [PMID: 30598545 DOI: 10.1038/s41589-018-0190-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 11/02/2018] [Indexed: 12/28/2022]
Abstract
The spatiotemporal generation of nitric oxide (NO), a versatile endogenous messenger, is precisely controlled. Despite its therapeutic potential for a wide range of diseases, NO-based therapies are limited clinically due to a lack of effective strategies for precisely delivering NO to a specific site. In the present study, we developed a novel NO delivery system via modification of an enzyme-prodrug pair of galactosidase-galactosyl-NONOate using a 'bump-and-hole' strategy. Precise delivery to targeted tissues was clearly demonstrated by an in vivo near-infrared imaging assay. The therapeutic potential was evaluated in both rat hindlimb ischemia and mouse acute kidney injury models. Targeted delivery of NO clearly enhanced its therapeutic efficacy in tissue repair and function recovery and abolished side effects due to the systemic release of NO. The developed protocol holds broad applicability in the targeted delivery of important gaseous signaling molecules and offers a potent tool for the investigation of relevant molecular mechanisms.
Collapse
|
55
|
Alghamdi TA, Batchu SN, Hadden MJ, Yerra VG, Liu Y, Bowskill BB, Advani SL, Geldenhuys L, Siddiqi FS, Majumder S, Advani A. Histone H3 Serine 10 Phosphorylation Facilitates Endothelial Activation in Diabetic Kidney Disease. Diabetes 2018; 67:2668-2681. [PMID: 30213824 DOI: 10.2337/db18-0124] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 08/30/2018] [Indexed: 11/13/2022]
Abstract
The posttranslational histone modifications that epigenetically affect gene transcription extend beyond conventionally studied methylation and acetylation patterns. By examining the means by which podocytes influence the glomerular endothelial phenotype, we identified a role for phosphorylation of histone H3 on serine residue 10 (phospho-histone H3Ser10) in mediating endothelial activation in diabetes. Culture media conditioned by podocytes exposed to high glucose caused glomerular endothelial vascular cell adhesion protein 1 (VCAM-1) upregulation and was enriched for the chemokine CCL2. A neutralizing anti-CCL2 antibody prevented VCAM-1 upregulation in cultured glomerular endothelial cells, and knockout of the CCL2 receptor CCR2 diminished glomerular VCAM-1 upregulation in diabetic mice. CCL2/CCR2 signaling induced glomerular endothelial VCAM-1 upregulation through a pathway regulated by p38 mitogen-activated protein kinase, mitogen- and stress-activated protein kinases 1/2 (MSK1/2), and phosphorylation of H3Ser10, whereas MSK1/2 inhibition decreased H3Ser10 phosphorylation at the VCAM1 promoter. Finally, increased phospho-histone H3Ser10 levels were observed in the kidneys of diabetic endothelial nitric oxide synthase knockout mice and in the glomeruli of humans with diabetic kidney disease. These findings demonstrate the influence that histone protein phosphorylation may have on gene activation in diabetic kidney disease. Histone protein phosphorylation should be borne in mind when considering epigenetic targets amenable to therapeutic manipulation in diabetes.
Collapse
Affiliation(s)
- Tamadher A Alghamdi
- 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
| | - Mitchell J Hadden
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Veera Ganesh Yerra
- 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
| | - Bridgit B Bowskill
- 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
| | | | - Ferhan S Siddiqi
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Syamantak Majumder
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| |
Collapse
|
56
|
Maestroni S, Zerbini G. Glomerular endothelial cells versus podocytes as the cellular target in diabetic nephropathy. Acta Diabetol 2018; 55:1105-1111. [PMID: 30155580 DOI: 10.1007/s00592-018-1211-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 08/09/2018] [Indexed: 12/11/2022]
Abstract
It usually takes several years (in some cases, decades) for predisposed individuals to move from the onset of type 1 or type 2 diabetes to the development of microalbuminuria, the first sign of diabetic nephropathy. This long, complication-free, period represents the best possible moment to start a successful preventive strategy (primary prevention) aimed to avoid or at least to postpone the increase of albumin excretion rate. Prevention is based on understanding and counteracting the initial mechanisms leading to the development of the disease and unfortunately, in case of diabetic nephropathy, most of them remain unclear. Little is also known about which, among endothelial cells and podocytes, represent the first glomerular target of the complication. Selective damage of the endothelium or of the podocyte results, as a common consequence, in an increase of albumin excretion rate. Albuminuria by itself cannot therefore be of help to solve the case. Endothelium and podocytes are involved in a continuous cross-talk and by studying the impact of diabetes on this "communication" process it should be possible to obtain some information regarding the weak component of the glomerular filter. Finally, the careful investigation of the mechanisms leading to the development podocyturia, a recently identified glomerular dysfunction associated to the pathogenesis of diabetic nephropathy, could contribute to shed some more light on the very early stages of this complication.
Collapse
Affiliation(s)
- Silvia Maestroni
- Complications of Diabetes Unit, Division of Immunology, Transplantation and Infectious Diseases, Diabetes Research Institute (DRI), IRCCS San Raffaele Scientific Institute, 20132, Milano, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Division of Immunology, Transplantation and Infectious Diseases, Diabetes Research Institute (DRI), IRCCS San Raffaele Scientific Institute, 20132, Milano, Italy.
| |
Collapse
|
57
|
Zhou L, Xu DY, Sha WG, Shen L, Lu GY. Long non-coding RNA MALAT1 interacts with transcription factor Foxo1 to regulate SIRT1 transcription in high glucose-induced HK-2 cells injury. Biochem Biophys Res Commun 2018; 503:849-855. [DOI: 10.1016/j.bbrc.2018.06.086] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 06/17/2018] [Indexed: 10/28/2022]
|
58
|
Cassis P, Locatelli M, Cerullo D, Corna D, Buelli S, Zanchi C, Villa S, Morigi M, Remuzzi G, Benigni A, Zoja C. SGLT2 inhibitor dapagliflozin limits podocyte damage in proteinuric nondiabetic nephropathy. JCI Insight 2018; 3:98720. [PMID: 30089717 DOI: 10.1172/jci.insight.98720] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/21/2018] [Indexed: 12/21/2022] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors have pleiotropic properties beyond blood glucose-lowering effects and modify important nonglycemic pathways, leading to end-organ protection. SGLT2 inhibitors display renoprotective effects in diabetic kidney disease, which creates a rationale for testing the therapeutic potential of this drug class in nondiabetic chronic kidney disease. Here, we have shown that dapagliflozin provided glomerular protection in mice with protein-overload proteinuria induced by bovine serum albumin (BSA), to a similar extent as an ACE inhibitor used as standard therapy for comparison. Dapagliflozin limited proteinuria, glomerular lesions, and podocyte dysfunction and loss. We provide the observation that SGLT2 was expressed in podocytes and upregulated after BSA injections. Through in vitro studies with cultured podocytes loaded with albumin we have identified what we believe to be a novel mechanism of action for SGLT2 inhibitor that directly targets podocytes and relies on the maintenance of actin cytoskeleton architecture. Whether SGLT2 inhibitors represent a possible future therapeutic option for some patients with proteinuric glomerular disease who do not have as yet an effective treatment will require ad hoc clinical studies.
Collapse
Affiliation(s)
- Paola Cassis
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Monica Locatelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Domenico Cerullo
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Simona Buelli
- 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
| | - Sebastian Villa
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Marina Morigi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.,Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| |
Collapse
|
59
|
Fu J, Wei C, Zhang W, Schlondorff D, Wu J, Cai M, He W, Baron MH, Chuang PY, Liu Z, He JC, Lee K. Gene expression profiles of glomerular endothelial cells support their role in the glomerulopathy of diabetic mice. Kidney Int 2018; 94:326-345. [PMID: 29861058 PMCID: PMC6054896 DOI: 10.1016/j.kint.2018.02.028] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 01/15/2023]
Abstract
Endothelial dysfunction promotes the pathogenesis of diabetic nephropathy (DN), which is considered to be an early event in disease progression. However, the molecular changes associated with glomerular endothelial cell (GEC) injury in early DN are not well defined. Most gene expression studies have relied on the indirect assessment of GEC injury from isolated glomeruli or renal cortices. Here, we present transcriptomic analysis of isolated GECs, using streptozotocin-induced diabetic wildtype (STZ-WT) and diabetic eNOS-null (STZ-eNOS-/-) mice as models of mild and advanced DN, respectively. GECs of both models in comparison to their respective nondiabetic controls showed significant alterations in the regulation of apoptosis, oxidative stress, and proliferation. The extent of these changes was greater in STZ-eNOS-/- than in STZ-WT GECs. Additionally, genes in STZ-eNOS-/- GECs indicated further dysregulation in angiogenesis and epigenetic regulation. Moreover, a biphasic change in the number of GECs, characterized by an initial increase and subsequent decrease over time, was observed only in STZ-eNOS-/- mice. This is consistent with an early compensatory angiogenic process followed by increased apoptosis, leading to an overall decrease in GEC survival in DN progression. From the genes altered in angiogenesis in STZ-eNOS-/- GECs, we identified potential candidate genes, Lrg1 and Gpr56, whose function may augment diabetes-induced angiogenesis. Thus, our results support a role for GEC in DN by providing direct evidence for alterations of GEC gene expression and molecular pathways. Candidate genes of specific pathways, such as Lrg1 and Gpr56, can be further explored for potential therapeutic targeting to mitigate the initiation and progression of DN.
Collapse
Affiliation(s)
- Jia Fu
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA; National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Chengguo Wei
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Weijia Zhang
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Detlef Schlondorff
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jinshan Wu
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Minchao Cai
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Wu He
- Flow Cytometry Shared Resource Facility, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Margaret H Baron
- Division of Hematology and Medical Oncology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Peter Y Chuang
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
| | - John Cijiang He
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Renal Program, James J. Peters VA Medical Center at Bronx, New York, New York, USA.
| | - Kyung Lee
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
| |
Collapse
|
60
|
Martens RJ, Houben AJ, Kooman JP, Berendschot TT, Dagnelie PC, van der Kallen CJ, Kroon AA, Leunissen KM, van der Sande FM, Schaper NC, Schouten JS, Schram MT, Sep SJ, Sörensen BM, Henry RM, Stehouwer CD. Microvascular endothelial dysfunction is associated with albuminuria. J Hypertens 2018; 36:1178-1187. [DOI: 10.1097/hjh.0000000000001674] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
61
|
Daehn IS. Glomerular Endothelial Cell Stress and Cross-Talk With Podocytes in Early [corrected] Diabetic Kidney Disease. Front Med (Lausanne) 2018; 5:76. [PMID: 29629372 PMCID: PMC5876248 DOI: 10.3389/fmed.2018.00076] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/07/2018] [Indexed: 12/11/2022] Open
Abstract
Diabetic kidney disease (DKD) is one of the major causes of morbidity and mortality in diabetic patients and also the leading single cause of end-stage renal disease in the United States. A large proportion of diabetic patients develop DKD and others don't, even with comparable blood glucose levels, indicating a significant genetic component of disease susceptibility. The glomerulus is the primary site of diabetic injury in the kidney, glomerular hypertrophy and podocyte depletion are glomerular hallmarks of progressive DKD, and the degree of podocyte loss correlates with severity of the disease. We know that chronic hyperglycemia contributes to both microvascular and macrovascular complications, as well as podocyte injury. We are beginning to understand the role of glomerular endothelial injury, as well as the involvement of reactive oxygen species and mitochondrial stress, which play a direct role in DKD and in other diabetic complications. There is, however, a gap in our knowledge that links genetic susceptibility to early molecular mechanisms and proteinuria in DKD. Emerging research that explores glomerular cell's specific responses to diabetes and cell cross-talk will provide mechanistic clues that underlie DKD and provide novel avenues for therapeutic intervention.
Collapse
Affiliation(s)
- Ilse Sofia Daehn
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, The Charles Bronfman Institute for Personalized Medicine, New York City, NY, United States
| |
Collapse
|
62
|
Yu SMW, Bonventre JV. Acute Kidney Injury and Progression of Diabetic Kidney Disease. Adv Chronic Kidney Dis 2018; 25:166-180. [PMID: 29580581 DOI: 10.1053/j.ackd.2017.12.005] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/15/2017] [Accepted: 12/22/2017] [Indexed: 12/23/2022]
Abstract
Diabetic kidney disease, commonly termed diabetic nephropathy (DN), is the most common cause of end-stage kidney disease (ESKD) worldwide. The characteristic histopathology of DN includes glomerular basement membrane thickening, mesangial expansion, nodular glomerular sclerosis, and tubulointerstitial fibrosis. Diabetes is associated with a number of metabolic derangements, such as reactive oxygen species overproduction, hypoxic state, mitochondrial dysfunction, and inflammation. In the past few decades, our knowledge of DN has advanced considerably although much needs to be learned. The traditional paradigm of glomerulus-centered pathophysiology has expanded to the tubule-interstitium, the immune response and inflammation. Biomarkers of proximal tubule injury have been shown to correlate with DN progression, independent of traditional glomerular injury biomarkers such as albuminuria. In this review, we summarize mechanisms of increased susceptibility to acute kidney injury in diabetes mellitus and the roles played by many kidney cell types to facilitate maladaptive responses leading to chronic and end-stage kidney disease.
Collapse
|
63
|
Lim JH, Kim HW, Kim MY, Kim TW, Kim EN, Kim Y, Chung S, Kim YS, Choi BS, Kim YS, Chang YS, Kim HW, Park CW. Cinacalcet-mediated activation of the CaMKKβ-LKB1-AMPK pathway attenuates diabetic nephropathy in db/db mice by modulation of apoptosis and autophagy. Cell Death Dis 2018; 9:270. [PMID: 29449563 PMCID: PMC5833853 DOI: 10.1038/s41419-018-0324-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/05/2018] [Accepted: 01/15/2018] [Indexed: 02/06/2023]
Abstract
Apoptosis and autophagy are harmoniously regulated biological processes for maintaining tissue homeostasis. AMP-activated protein kinase (AMPK) functions as a metabolic sensor to coordinate cellular survival and function in various organs, including the kidney. We investigated the renoprotective effects of cinacalcet in high-glucose treated human glomerular endothelial cells (HGECs), murine podocytes and C57BLKS/J-db/db mice. In cultured HGECs and podocytes, cinacalcet decreased oxidative stress and apoptosis and increased autophagy that were attributed to the increment of intracellular Ca2+ concentration and the phosphorylation of Ca2+/calmodulin-dependent protein kinase kinaseβ (CaMKKβ)-Liver kinase B1 (LKB1)-AMPK and their downstream signals including the phosphorylation of endothelial nitric oxide synthase (eNOS) and increases in superoxide dismutases and B cell leukemia/lymphoma 2/BCL-2-associated X protein expression. Interestingly, intracellular chelator BAPTA-AM reversed cinacalcet-induced CaMKKβ elevation and LKB1 phosphorylation. Cinacalcet reduced albuminuria without influencing either blood glucose or Ca2+ concentration and ameliorated diabetes-induced renal damage, which were related to the increased expression of calcium-sensing receptor and the phosphorylation of CaMKKβ-LKB1. Subsequent activation of AMPK was followed by the activation of peroxisome proliferator-activated receptor γ coactivator-1α and phospho-Ser1177eNOS-nitric oxide, resulting in a decrease in apoptosis and oxidative stress as well as an increase in autophagy. Our results suggest that cinacalcet increases intracellular Ca2+ followed by an activation of CaMKKβ-LKB1-AMPK signaling in GECs and podocytes in the kidney, which provides a novel therapeutic means for type 2 diabetic nephropathy by modulation of apoptosis and autophagy.
Collapse
Affiliation(s)
- Ji Hee Lim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea.,Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hyung Wook Kim
- Division of Nephrology, Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea
| | - Min Young Kim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea.,Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Tae Woo Kim
- Department of Hematology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Eun Nim Kim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yaeni Kim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sungjin Chung
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Young Soo Kim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Bum Soon Choi
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yong-Soo Kim
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yoon Sik Chang
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hye Won Kim
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Bucheon, Korea
| | - Cheol Whee Park
- Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea. .,Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, Korea.
| |
Collapse
|
64
|
Palygin O, Ilatovskaya DV, Levchenko V, Endres BT, Geurts AM, Staruschenko A. Nitric oxide production by glomerular podocytes. Nitric Oxide 2017; 72:24-31. [PMID: 29128399 DOI: 10.1016/j.niox.2017.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 09/27/2017] [Accepted: 11/07/2017] [Indexed: 01/18/2023]
Abstract
Nitric Oxide (NO), a potent vasodilator and vital signaling molecule, has been shown to contribute to the regulation of glomerular ultrafiltration. However, whether changes in NO occur in podocytes during the pathogenesis of salt-sensitive hypertension has not yet been thoroughly examined. We showed here that podocytes produce NO, and further hypothesized that hypertensive animals would exhibit reduced NO production in these cells in response to various paracrine factors, which might contribute to the damage of glomeruli filtration barrier and development of proteinuria. To test this, we isolated glomeruli from the kidneys of Dahl salt-sensitive (SS) rats fed a low salt (LS; 0.4% NaCl) or high salt (HS; 4% NaCl, 3 weeks) diets and loaded podocytes with either a combination of NO and Ca2+ fluorophores (DAF-FM and Fura Red, respectively) or DAF-FM alone. Changes in fluorescence were observed with confocal microscopy in response to adenosine triphosphate (ATP), angiotensin II (Ang II), and hydrogen peroxide (H2O2). Application of Ang II resulted in activation of both NO and intracellular calcium ([Ca2+]i) transients. In contrast, ATP promoted [Ca2+]i transients, but did not have any effects on NO production. SS rats fed a HS diet for 3 weeks demonstrated impaired NO production: the response to Ang II or H2O2 in podocytes of glomeruli isolated from SS rats fed a HS diet was significantly reduced compared to rats fed a LS diet. Therefore, glomerular podocytes from hypertensive rats showed a diminished NO release in response to Ang II or oxidative stress, suggesting that podocytic NO signaling is dysfunctional in this condition and likely contributes to the development of kidney injury.
Collapse
Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | |
Collapse
|
65
|
Exosomes from high glucose-treated glomerular endothelial cells trigger the epithelial-mesenchymal transition and dysfunction of podocytes. Sci Rep 2017; 7:9371. [PMID: 28839221 PMCID: PMC5571220 DOI: 10.1038/s41598-017-09907-6] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/31/2017] [Indexed: 01/08/2023] Open
Abstract
New data indicate that abnormal glomerular endothelial cell (GEC)-podocyte crosstalk plays a critical role in diabetic nephropathy (DN). The aim of our study is to investigate the role of exosomes from high glucose (HG)-treated GECs in the epithelial-mesenchymal transition (EMT) and dysfunction of podocytes. In this study, exosomes were extracted from GEC culture supernatants and podocytes were incubated with the GEC-derived exosomes. Here, we demonstrate that HG induces the endothelial-mesenchymal transition (EndoMT) of GECs and HG-treated cells undergoing the EndoMT secrete more exosomes than normal glucose (NG)-treated GECs. We show that GEC-derived exosomes can be internalized by podocytes and exosomes from HG-treated cells undergoing an EndoMT-like process can trigger the podocyte EMT and barrier dysfunction. Our study reveals that TGF-β1 mRNA is enriched in exosomes from HG-treated GECs and probably mediates the EMT and dysfunction of podocytes. In addition, our experimental results illustrate that canonical Wnt/β-catenin signaling is involved in the exosome-induced podocyte EMT. Our findings suggest the importance of paracrine communication via exosomes between cells undergoing the EndoMT and podocytes for renal fibrosis in DN. Thus, protecting GECs from the EndoMT and inhibiting TGF-β1-containing exosomes release from GECs is necessary to manage renal fibrosis in DN.
Collapse
|
66
|
Antiangiogenic Therapy for Diabetic Nephropathy. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5724069. [PMID: 28835895 PMCID: PMC5556994 DOI: 10.1155/2017/5724069] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/16/2017] [Accepted: 06/13/2017] [Indexed: 12/28/2022]
Abstract
Angiogenesis has been shown to be a potential therapeutic target for early stages of diabetic nephropathy in a number of animal experiments. Vascular endothelial growth factor (VEGF) is the main mediator for abnormal angiogenesis in diabetic glomeruli. Although beneficial effects of anti-VEGF antibodies have previously been demonstrated in diabetic animal experiments, recent basic and clinical evidence has revealed that the blockade of VEGF signaling resulted in proteinuria and renal thrombotic microangiopathy, suggesting the importance of maintaining normal levels of VEGF in the kidneys. Therefore, antiangiogenic therapy for diabetic nephropathy should eliminate excessive glomerular angiogenic response without accelerating endothelial injury. Some endogenous antiangiogenic factors such as endostatin and tumstatin inhibit overactivation of endothelial cells but do not specifically block VEGF signaling. In addition, the novel endothelium-derived antiangiogenic factor vasohibin-1 enhances stress tolerance and survival of the endothelial cells, while inhibiting excess angiogenesis. These factors have been demonstrated to suppress albuminuria and glomerular alterations in a diabetic mouse model. Thus, antiangiogenic therapy with promising candidates will possibly improve renal prognosis in patients with early stages of diabetic nephropathy.
Collapse
|
67
|
Zhang MZ, Wang X, Yang H, Fogo AB, Murphy BJ, Kaltenbach R, Cheng P, Zinker B, Harris RC. Lysophosphatidic Acid Receptor Antagonism Protects against Diabetic Nephropathy in a Type 2 Diabetic Model. J Am Soc Nephrol 2017; 28:3300-3311. [PMID: 28739650 DOI: 10.1681/asn.2017010107] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/19/2017] [Indexed: 01/06/2023] Open
Abstract
Lysophosphatidic acid (LPA) functions through activation of LPA receptors (LPARs). LPA-LPAR signaling has been implicated in development of fibrosis. However, the role of LPA-LPAR signaling in development of diabetic nephropathy (DN) has not been studied. We examined whether BMS002, a novel dual LPAR1 and LPAR3 antagonist, affects development of DN in endothelial nitric oxide synthase-knockout db/db mice. Treatment of these mice with BMS002 from 8 to 20 weeks of age led to a significant reduction in albuminuria, similar to that observed with renin-angiotensin system inhibition (losartan plus enalapril). LPAR inhibition also prevented the decline in GFR observed in vehicle-treated mice, such that GFR at week 20 differed significantly between vehicle and LPAR inhibitor groups (P<0.05). LPAR inhibition also reduced histologic glomerular injury; decreased the expression of profibrotic and fibrotic components, including fibronectin, α-smooth muscle actin, connective tissue growth factor, collagen I, and TGF-β; and reduced renal macrophage infiltration and oxidative stress. Notably, LPAR inhibition slowed podocyte loss (podocytes per glomerulus ±SEM at 8 weeks: 667±40, n=4; at 20 weeks: 364±18 with vehicle, n=7, and 536±12 with LPAR inhibition, n=7; P<0.001 versus vehicle). Finally, LPAR inhibition minimized the production of 4-hydroxynonenal (4-HNE), a marker of oxidative stress, in podocytes and increased the phosphorylation of AKT2, an indicator of AKT2 activity, in kidneys. Thus, the LPAR antagonist BMS002 protects against GFR decline and attenuates development of DN through multiple mechanisms. LPAR antagonism might provide complementary beneficial effects to renin-angiotensin system inhibition to slow progression of DN.
Collapse
Affiliation(s)
- Ming-Zhi Zhang
- Division of Nephrology and Hypertension, Department of Medicine, .,Vanderbilt Center for Kidney Disease, and
| | - Xin Wang
- Division of Nephrology and Hypertension, Department of Medicine
| | - Haichun Yang
- Department of Pathology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Agnes B Fogo
- Vanderbilt Center for Kidney Disease, and.,Department of Pathology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Brian J Murphy
- Fibrosis Discovery Biology or Chemistry, Bristol-Myers Squibb, Pennington, New Jersey; and
| | - Robert Kaltenbach
- Fibrosis Discovery Biology or Chemistry, Bristol-Myers Squibb, Pennington, New Jersey; and
| | - Peter Cheng
- Fibrosis Discovery Biology or Chemistry, Bristol-Myers Squibb, Pennington, New Jersey; and
| | - Bradley Zinker
- Fibrosis Discovery Biology or Chemistry, Bristol-Myers Squibb, Pennington, New Jersey; and
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Department of Medicine, .,Vanderbilt Center for Kidney Disease, and.,United States Department of Veterans Affairs, Nashville, Tennessee
| |
Collapse
|
68
|
Plotnikov EY, Silachev DN, Popkov VA, Zorova LD, Pevzner IB, Zorov SD, Jankauskas SS, Babenko VA, Sukhikh GT, Zorov DB. Intercellular Signalling Cross-Talk: To Kill, To Heal and To Rejuvenate. Heart Lung Circ 2017; 26:648-659. [DOI: 10.1016/j.hlc.2016.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 11/22/2016] [Accepted: 12/06/2016] [Indexed: 12/16/2022]
|
69
|
EP4 inhibition attenuates the development of diabetic and non-diabetic experimental kidney disease. Sci Rep 2017; 7:3442. [PMID: 28611444 PMCID: PMC5469816 DOI: 10.1038/s41598-017-03237-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/25/2017] [Indexed: 01/13/2023] Open
Abstract
The therapeutic targeting of prostanoid subtype receptors may slow the development of chronic kidney disease (CKD) through mechanisms that are distinct from those of upstream COX inhibition. Here, employing multiple experimental models of CKD, we studied the effects of inhibition of the EP4 receptor, one of four receptor subtypes for the prostanoid prostaglandin E2. In streptozotocin-diabetic endothelial nitric oxide synthase knockout mice, EP4 inhibition attenuated the development of albuminuria, whereas the COX inhibitor indomethacin did not. In Type 2 diabetic db/db mice, EP4 inhibition lowered albuminuria to a level comparable with that of the ACE inhibitor captopril. However, unlike captopril, EP4 inhibition had no effect on blood pressure or hyperfiltration although it did attenuate mesangial matrix accumulation. Indicating a glucose-independent mechanism of action, EP4 inhibition also attenuated proteinuria development and glomerular scarring in non-diabetic rats subjected to surgical renal mass ablation. Finally, in vitro, EP4 inhibition prevented transforming growth factor-ß1 induced dedifferentiation of glomerular podocytes. In rodent models of diabetic and non-diabetic CKD, EP4 inhibition attenuated renal injury through mechanisms that were distinct from either broadspectrum COX inhibition or “standard of care” renin angiotensin system blockade. EP4 inhibition may represent a viable repurposing opportunity for the treatment of CKD.
Collapse
|
70
|
Alghamdi TA, Majumder S, Thieme K, Batchu SN, White KE, Liu Y, Brijmohan AS, Bowskill BB, Advani SL, Woo M, Advani A. Janus Kinase 2 Regulates Transcription Factor EB Expression and Autophagy Completion in Glomerular Podocytes. J Am Soc Nephrol 2017; 28:2641-2653. [PMID: 28424277 DOI: 10.1681/asn.2016111208] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/20/2017] [Indexed: 12/20/2022] Open
Abstract
The nonreceptor kinase Janus kinase 2 (JAK2) has garnered attention as a promising therapeutic target for the treatment of CKD. However, being ubiquitously expressed in the adult, JAK2 is also likely to be necessary for normal organ function. Here, we investigated the phenotypic effects of JAK2 deficiency. Mice in which JAK2 had been deleted from podocytes exhibited an elevation in urine albumin excretion that was accompanied by increased podocyte autophagosome fractional volume and p62 aggregation, which are indicative of impaired autophagy completion. In cultured podocytes, knockdown of JAK2 similarly impaired autophagy and led to downregulation in the expression of lysosomal genes and decreased activity of the lysosomal enzyme, cathepsin D. Because transcription factor EB (TFEB) has recently emerged as a master regulator of autophagosome-lysosome function, controlling the expression of several of the genes downregulated by JAK2 knockdown, we questioned whether TFEB is regulated by JAK2. In immortalized mouse podocytes, JAK2 knockdown decreased TFEB promoter activity, expression, and nuclear localization. In silico analysis and chromatin immunoprecipitation assays revealed that the downstream mediator of JAK2 signaling STAT1 binds to the TFEB promoter. Finally, overexpression of TFEB in JAK2-deficient podocytes reversed lysosomal dysfunction and restored albumin permselectivity. Collectively, these observations highlight the homeostatic actions of JAK2 in podocytes and the importance of TFEB to autophagosome-lysosome function in these cells. These results also raise the possibility that therapeutically modulating TFEB activity may improve podocyte health in glomerular disease.
Collapse
Affiliation(s)
- Tamadher A Alghamdi
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - 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
| | - Kathryn E White
- Electron Microscopy Research Services, Newcastle University, Newcastle upon Tyne, United Kingdom; and
| | - Youan Liu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Angela S Brijmohan
- 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
| | - Suzanne L Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Minna Woo
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada;
| |
Collapse
|
71
|
Hum JM, O'Bryan LM, Tatiparthi AK, Cass TA, Clinkenbeard EL, Cramer MS, Bhaskaran M, Johnson RL, Wilson JM, Smith RC, White KE. Chronic Hyperphosphatemia and Vascular Calcification Are Reduced by Stable Delivery of Soluble Klotho. J Am Soc Nephrol 2017; 28:1162-1174. [PMID: 27837149 PMCID: PMC5373441 DOI: 10.1681/asn.2015111266] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 10/01/2016] [Indexed: 12/22/2022] Open
Abstract
αKlotho (αKL) regulates mineral metabolism, and diseases associated with αKL deficiency are characterized by hyperphosphatemia and vascular calcification (VC). αKL is expressed as a membrane-bound protein (mKL) and recognized as the coreceptor for fibroblast growth factor-23 (FGF23) and a circulating soluble form (cKL) created by endoproteolytic cleavage of mKL. The functions of cKL with regard to phosphate metabolism are unclear. We tested the ability of cKL to regulate pathways and phenotypes associated with hyperphosphatemia in a mouse model of CKD-mineral bone disorder and αKL-null mice. Stable delivery of adeno-associated virus (AAV) expressing cKL to diabetic endothelial nitric oxide synthase-deficient mice or αKL-null mice reduced serum phosphate levels. Acute injection of recombinant cKL downregulated the renal sodium-phosphate cotransporter Npt2a in αKL-null mice supporting direct actions of cKL in the absence of mKL. αKL-null mice with sustained AAV-cKL expression had a 74%-78% reduction in aorta mineral content and a 72%-77% reduction in mineral volume compared with control-treated counterparts (P<0.01). Treatment of UMR-106 osteoblastic cells with cKL + FGF23 increased the phosphorylation of extracellular signal-regulated kinase 1/2 and induced Fgf23 expression. CRISPR/Cas9-mediated deletion of fibroblast growth factor receptor 1 (FGFR1) or pretreatment with inhibitors of mitogen-activated kinase kinase 1 or FGFR ablated these responses. In summary, sustained cKL treatment reduced hyperphosphatemia in a mouse model of CKD-mineral bone disorder, and it reduced hyperphosphatemia and prevented VC in mice without endogenous αKL. Furthermore, cKL stimulated Fgf23 in an FGFR1-dependent manner in bone cells. Collectively, these findings indicate that cKL has mKL-independent activity and suggest the potential for enhancing cKL activity in diseases of hyperphosphatemia with associated VC.
Collapse
Affiliation(s)
- Julia M Hum
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Linda M O'Bryan
- Biotechnology Discovery Research, Lilly Research Laboratories
| | - Arun K Tatiparthi
- Lead Optimization Toxicology and Pharmacology, Covance Inc., Greenfield, Indiana
| | - Taryn A Cass
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Erica L Clinkenbeard
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana
| | - Martin S Cramer
- Biotechnology Discovery Research, Lilly Research Laboratories
| | | | | | - Jonathan M Wilson
- Tailored Therapeutics, Eli Lilly and Company, Indianapolis, Indiana; and
| | | | - Kenneth E White
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, Indiana;
| |
Collapse
|
72
|
McCarty MF. Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications. Healthcare (Basel) 2017; 5:E15. [PMID: 28335416 PMCID: PMC5371921 DOI: 10.3390/healthcare5010015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/23/2017] [Accepted: 03/06/2017] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.
Collapse
Affiliation(s)
- Mark F McCarty
- Catalytic Longevity, 7831 Rush Rose Dr., Apt. 316, Carlsbad, CA 92009, USA.
| |
Collapse
|
73
|
Qi H, Casalena G, Shi S, Yu L, Ebefors K, Sun Y, Zhang W, D'Agati V, Schlondorff D, Haraldsson B, Böttinger E, Daehn I. Glomerular Endothelial Mitochondrial Dysfunction Is Essential and Characteristic of Diabetic Kidney Disease Susceptibility. Diabetes 2017; 66:763-778. [PMID: 27899487 PMCID: PMC5319717 DOI: 10.2337/db16-0695] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/13/2016] [Indexed: 12/11/2022]
Abstract
The molecular signaling mechanisms between glomerular cell types during initiation/progression of diabetic kidney disease (DKD) remain poorly understood. We compared the early transcriptome profile between DKD-resistant C57BL/6J and DKD-susceptible DBA/2J (D2) glomeruli and demonstrated a significant downregulation of essential mitochondrial genes in glomeruli from diabetic D2 mice, but not in C57BL/6J, with comparable hyperglycemia. Diabetic D2 mice manifested increased mitochondrial DNA lesions (8-oxoguanine) exclusively localized to glomerular endothelial cells after 3 weeks of diabetes, and these accumulated over time in addition to increased urine secretion of 8-oxo-deoxyguanosine. Detailed assessment of glomerular capillaries from diabetic D2 mice demonstrated early signs of endothelial injury and loss of fenestrae. Glomerular endothelial mitochondrial dysfunction was associated with increased glomerular endothelin-1 receptor type A (Ednra) expression and increased circulating endothelin-1 (Edn1). Selective Ednra blockade or mitochondrial-targeted reactive oxygen species scavenging prevented mitochondrial oxidative stress of endothelial cells and ameliorated diabetes-induced endothelial injury, podocyte loss, albuminuria, and glomerulosclerosis. In human DKD, increased urine 8-oxo-deoxyguanosine was associated with rapid DKD progression, and biopsies from patients with DKD showed increased mitochondrial DNA damage associated with glomerular endothelial EDNRA expression. Our studies show that DKD susceptibility was linked to mitochondrial dysfunction, mediated largely by Edn1-Ednra in glomerular endothelial cells representing an early event in DKD progression, and suggest that cross talk between glomerular endothelial injury and podocytes leads to defects and depletion, albuminuria, and glomerulosclerosis.
Collapse
Affiliation(s)
- Haiying Qi
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Gabriella Casalena
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Shaolin Shi
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Liping Yu
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Kerstin Ebefors
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Yezhou Sun
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Weijia Zhang
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Vivette D'Agati
- Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Detlef Schlondorff
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Börje Haraldsson
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Erwin Böttinger
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Ilse Daehn
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
| |
Collapse
|
74
|
Majumder S, Advani A. VEGF and the diabetic kidney: More than too much of a good thing. J Diabetes Complications 2017; 31:273-279. [PMID: 27836681 DOI: 10.1016/j.jdiacomp.2016.10.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 10/18/2016] [Indexed: 02/06/2023]
Abstract
Over a decade and a half has passed since the publication of early reports hinting at a pathogenetic role for vascular endothelial growth factor ("VEGF") in the development of diabetic kidney disease. In diabetic rats, renal mRNA levels of the VEGF-A isoform were upregulated and administration of a VEGF-A neutralizing antibody attenuated albuminuria: VEGF was "bad" in diabetic nephropathy. Since that time, our understanding of the complexity of the renal VEGF system has advanced. Unlike its experimental counterpart, human diabetic nephropathy is associated with diminished VEGF-A levels and experience in the oncological setting has taught us that VEGF blocking therapy can cause adverse renal effects in patients. Correspondingly, investigational studies in cultured cells and rodent models have demonstrated that the biological effects of the VEGF system are dependent not only on the amount of VEGF, but also the type of VEGF, its sites of action and the prevailing milieu. Here we reflect back on the discoveries that have been made since those initial reports that shone the spotlight on the importance of the VEGF system in the diabetic kidney and we consider that the role of VEGF in diabetic nephropathy extends well beyond being "too much of a good thing".
Collapse
Affiliation(s)
- Syamantak Majumder
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.
| |
Collapse
|
75
|
Shankar A, Jain M, Lim MJ, Angara K, Zeng P, Arbab SA, Iskander A, Ara R, Arbab AS, Achyut BR. Anti-VEGFR2 driven nuclear translocation of VEGFR2 and acquired malignant hallmarks are mutation dependent in glioblastoma. ACTA ACUST UNITED AC 2016; 8:172-178. [PMID: 28149448 DOI: 10.4172/1948-5956.1000410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Anti-angiogenic therapies (AATs), targeting VEGF-VEGFR pathways, are being used as an adjuvant to normalize glioblastoma (GBM) vasculature. Unexpectedly, clinical trials have witnessed transient therapeutic effect followed by aggressive tumor recurrence. In pre-clinical studies, targeting VEGFR2 with vatalanib, increased GBM growth under hypoxic microenvironment. There is limited understanding of these unanticipated results. Here, we investigated tumor cell associated phenotypes in response to VEGFR2 blockade. METHODS Human U251 cells were orthotopically implanted in mice (day 0) and were treated with vehicle or vatalanib on day 8. Tumor specimens were collected for immunohistochemistry and protein array. Nuclear translocation of VEGFR2 was analyzed through IHC and western blot. In vitro studies were performed in U251 (p53 and EGFR mutated) and U87 (p53 and EGFR wildtype) cells following vehicle or vatalanib treatments under normoxia (21% O2) and hypoxia (1% O2). Proliferation, cell cycle and apoptosis assays were done to analyze tumor cell phenotypes after treatments. RESULTS Vatalanib treated animals displayed distinct patterns of VEGFR2 translocation into nuclear compartment of U251 tumor cells. In vitro studies suggest that vatalanib significantly induced nuclear translocation of VEGFR2, characterized in chromatin bound fraction, especially in U251 tumor cells grown under normoxia and hypoxia. Anti-VEGFR2 driven nuclear translocation of VEGFR2 was associated with increased cell cycle and proliferation, decreased apoptosis, and displayed increased invasiveness in U251 compared to U87 cells. CONCLUSIONS Study suggests that AAT- induced molecular and phenotypic alterations in tumor cells are associated with mutation status and are responsible for aggressive tumor growth. Therefore, mutation status of the tumor in GBM patients should be taken in to consideration before applying targeted therapy to overcome unwanted effects.
Collapse
Affiliation(s)
- Adarsh Shankar
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Meenu Jain
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Mei Jing Lim
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Kartik Angara
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Peng Zeng
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Syed A Arbab
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Asm Iskander
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Roxan Ara
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Ali S Arbab
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| | - Bhagelu R Achyut
- Tumor Angiogenesis Lab, Cancer Center, Augusta University, 1410 Laney Walker Blvd, CN3124A, Augusta, GA 30912, USA
| |
Collapse
|
76
|
Sun H, Tian J, Xian W, Xie T, Yang X. Pentraxin-3 Attenuates Renal Damage in Diabetic Nephropathy by Promoting M2 Macrophage Differentiation. Inflammation 2016; 38:1739-47. [PMID: 25761429 DOI: 10.1007/s10753-015-0151-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As one of the most important long-term complications of diabetes, diabetic nephropathy (DN) is the major cause of end-stage renal disease and high mortality in diabetic patients. The long pentraxin 3 (Ptx3) is a member of a superfamily of conserved proteins characterized by a cyclic multimeric structure and a conserved C-terminal domain. Several clinical investigations have demonstrated that elevated plasma Ptx3 levels are associated with cardiovascular and chronic kidney diseases (CKD). However, the therapeutic effect of Ptx3 on DN has never been investigated. In our current study, we showed a crucial role for Ptx3 in attenuating renal damage in DN. In our mouse hyperglycemia-induced nephropathy model, Ptx3 treatment showed significantly increased expression of nephrin, acetylated nephrin, and Wilm's tumor-1 protein (WT-1) when compared with control. The number of CD4(+) T cells, CD8(+) T cells, Ly6G(+) neutrophils, and CD11b(+) macrophages were all significantly lower in the Ptx3-treated group than that in the control group in DN. The IL-4 and IL-13 levels in the Ptx3-treated group were markedly higher than that in the control group in DN. Correspondingly, the Ptx3-treated group showed increased numbers of Arg1- or CD206-expressing macrophages compared with the control group. Furthermore, inhibition of Ptx3-treated macrophages abrogated the alleviated renal damage induced by Ptx3 treatment. In conclusion, Ptx3 attenuates renal damage in DN by promoting M2 macrophage differentiation.
Collapse
Affiliation(s)
- Huaibin Sun
- Department of Hemodialysis, Qilu Hospital, Shandong University, Jinan, China
| | | | | | | | | |
Collapse
|
77
|
Zhong F, Mallipattu SK, Estrada C, Menon M, Salem F, Jain MK, Chen H, Wang Y, Lee K, He JC. Reduced Krüppel-Like Factor 2 Aggravates Glomerular Endothelial Cell Injury and Kidney Disease in Mice with Unilateral Nephrectomy. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2021-2031. [PMID: 27317905 DOI: 10.1016/j.ajpath.2016.03.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 02/18/2016] [Accepted: 03/29/2016] [Indexed: 12/13/2022]
Abstract
Loss of functional nephrons induces compensatory glomerular hyperfiltration and hypertrophy, leading to the progression of chronic kidney disease. Krüppel-like factor 2 (KLF2), a shear-stress-inducible transcription factor, confers protection against endothelial injury. Because glomerular hyperfiltration is associated with shear stress, we hypothesized that KLF2 may be an important factor in the compensatory response to unilateral nephrectomy (UNX). To test this hypothesis, endothelial cell-specific Klf2 heterozygous knockout mice (KO) and their wild-type littermate control (WT) underwent either UNX or sham-operation. WT-UNX mice developed compensatory renal hypertrophy as expected, whereas KO-UNX mice did not. KO-UNX mice exhibited higher blood pressure, reduced glomerular filtration rate, and significant increase in proteinuria and glomerulosclerosis compared to WT-UNX. Expression of endothelial nitric oxide synthase (official name Nos3), a known transcriptional target gene of KLF2, was significantly reduced and dysregulation of other endothelial genes was also observed in the glomeruli of KO-UNX when compared to WT-UNX and sham-operated mice. Furthermore, both podocyte number and expression of podocyte markers were also significantly reduced in KO-UNX glomeruli, indicating a potential cross talk between glomerular endothelial cells and podocytes. Finally, decreased renal expression of KLF2 in nephrectomy patients was associated with the progression of kidney disease. Taken together, our data demonstrate a protective role of KLF2 against glomerular endothelial cell injury and progression of chronic kidney disease in the model of compensatory renal hypertrophy.
Collapse
Affiliation(s)
- Fang Zhong
- Department of Medicine/Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Nephrology, Hang Zhou Hospital of Traditional Chinese Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Sandeep K Mallipattu
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York
| | - Chelsea Estrada
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York
| | - Madhav Menon
- Department of Medicine/Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Fadi Salem
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mukesh K Jain
- Department of Medicine, Case Cardiovascular Institute Research Institute, Case Western Reserve University, Cleveland, Ohio
| | - Hongyu Chen
- Department of Nephrology, Hang Zhou Hospital of Traditional Chinese Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yongjun Wang
- Department of Nephrology, Hang Zhou Hospital of Traditional Chinese Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Kyung Lee
- Department of Medicine/Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - John C He
- Department of Medicine/Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York; Renal Section, James J. Peters Veterans Affairs Medical Center, Bronx, New York.
| |
Collapse
|
78
|
Von Willebrand factor regulates complement on endothelial cells. Kidney Int 2016; 90:123-34. [PMID: 27236750 DOI: 10.1016/j.kint.2016.03.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 02/10/2016] [Accepted: 03/03/2016] [Indexed: 11/20/2022]
Abstract
Atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura have traditionally been considered separate entities. Defects in the regulation of the complement alternative pathway occur in atypical hemolytic uremic syndrome, and defects in the cleavage of von Willebrand factor (VWF)-multimers arise in thrombotic thrombocytopenic purpura. However, recent studies suggest that both entities are related as defects in the disease-causing pathways overlap or show functional interactions. Here we investigate the possible functional link of VWF-multimers and the complement system on endothelial cells. Blood outgrowth endothelial cells (BOECs) were obtained from 3 healthy individuals and 2 patients with Type 3 von Willebrand disease lacking VWF. Cells were exposed to a standardized complement challenge via the combination of classical and alternative pathway activation and 50% normal human serum resulting in complement fixation to the endothelial surface. Under these conditions we found the expected release of VWF-multimers causing platelet adhesion onto BOECs from healthy individuals. Importantly, in BOECs derived from patients with von Willebrand disease complement C3c deposition and cytotoxicity were more pronounced than on BOECs derived from normal individuals. This is of particular importance as primary glomerular endothelial cells display a heterogeneous expression pattern of VWF with overall reduced VWF abundance. Thus, our results support a mechanistic link between VWF-multimers and the complement system. However, our findings also identify VWF as a new complement regulator on vascular endothelial cells and suggest that VWF has a protective effect on endothelial cells and complement-mediated injury.
Collapse
|
79
|
Batchu SN, Majumder S, Bowskill BB, White KE, Advani SL, Brijmohan AS, Liu Y, Thai K, Azizi PM, Lee WL, Advani A. Prostaglandin I2 Receptor Agonism Preserves β-Cell Function and Attenuates Albuminuria Through Nephrin-Dependent Mechanisms. Diabetes 2016; 65:1398-409. [PMID: 26868296 DOI: 10.2337/db15-0783] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 02/01/2016] [Indexed: 11/13/2022]
Abstract
Discovery of common pathways that mediate both pancreatic β-cell function and end-organ function offers the opportunity to develop therapies that modulate glucose homeostasis and separately slow the development of diabetes complications. Here, we investigated the in vitro and in vivo effects of pharmacological agonism of the prostaglandin I2 (IP) receptor in pancreatic β-cells and in glomerular podocytes. The IP receptor agonist MRE-269 increased intracellular 3',5'-cyclic adenosine monophosphate (cAMP), augmented glucose-stimulated insulin secretion (GSIS), and increased viability in MIN6 β-cells. Its prodrug form, selexipag, augmented GSIS and preserved islet β-cell mass in diabetic mice. Determining that this preservation of β-cell function is mediated through cAMP/protein kinase A (PKA)/nephrin-dependent pathways, we found that PKA inhibition, nephrin knockdown, or targeted mutation of phosphorylated nephrin tyrosine residues 1176 and 1193 abrogated the actions of MRE-269 in MIN6 cells. Because nephrin is important to glomerular permselectivity, we next set out to determine whether IP receptor agonism similarly affects nephrin phosphorylation in podocytes. Expression of the IP receptor in podocytes was confirmed in cultured cells by immunoblotting and quantitative real-time PCR and in mouse kidneys by immunogold electron microscopy, and its agonism 1) increased cAMP, 2) activated PKA, 3) phosphorylated nephrin, and 4) attenuated albumin transcytosis. Finally, treatment of diabetic endothelial nitric oxide synthase knockout mice with selexipag augmented renal nephrin phosphorylation and attenuated albuminuria development independently of glucose change. Collectively, these observations describe a pharmacological strategy that posttranslationally modifies nephrin and the effects of this strategy in the pancreas and in the kidney.
Collapse
MESH Headings
- Acetamides/therapeutic use
- Acetates/pharmacology
- Animals
- Cell Line
- Cell Survival/drug effects
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/pathology
- Diabetic Nephropathies/physiopathology
- Diabetic Nephropathies/prevention & control
- Humans
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Insulin/agonists
- Insulin/metabolism
- Insulin Secretion
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/metabolism
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation
- Phosphorylation/drug effects
- Podocytes/drug effects
- Podocytes/metabolism
- Podocytes/pathology
- Podocytes/ultrastructure
- Prodrugs/therapeutic use
- Protein Processing, Post-Translational/drug effects
- Pyrazines/pharmacology
- Pyrazines/therapeutic use
- RNA Interference
- Receptors, Epoprostenol/agonists
- Receptors, Epoprostenol/genetics
- Receptors, Epoprostenol/metabolism
- Renal Insufficiency/complications
- Renal Insufficiency/metabolism
- Renal Insufficiency/pathology
- Renal Insufficiency/prevention & control
Collapse
Affiliation(s)
- Sri N Batchu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Syamantak Majumder
- 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
| | - Kathryn E White
- Electron Microscopy Research Services, Newcastle University, Newcastle upon Tyne, U.K
| | - Suzanne L Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Angela S Brijmohan
- 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
| | - Kerri Thai
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Paymon M Azizi
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Warren L Lee
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| |
Collapse
|
80
|
Optimizing inhibition of the renin-angiotensin system in hypertension. J Hypertens 2016; 34:838-41. [PMID: 27027379 DOI: 10.1097/hjh.0000000000000895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
81
|
Abstract
PURPOSE OF REVIEW The glomerulus is a unique structure required for filtration of blood, while retaining plasma proteins based on size and charge selectivity. Distinct cell types form the structural unit that creates the filtration barrier. Structurally, fenestrated endothelial cells line the capillary loops and lie in close contact with mesangial cells. Podocytes are connected by specialized intercellular junctions known as slit diaphragms and separated from the endothelial compartment by the glomerular basement membrane. In order for this highly specialized structure to function, cross-communication between these cells must occur. RECENT FINDINGS Although classical studies have established key roles for vascular endothelial and platelet-derived growth factors in glomerular cross-communication, novel paracrine signaling pathways within the glomerulus have recently been identified. In addition, unique cellular pathways of established signaling cascades have been identified that are important for maintaining glomerular barrier function in health and disease. SUMMARY Here, we will review our current understanding of the processes of cross-communication between the unique cellular constituents forming the glomerular filtration unit. We will highlight recent findings of cellular crosstalk via signaling pathways that regulate glomerular barrier function in pathophysiological conditions.
Collapse
|
82
|
Wu D, Yang X, Zheng T, Xing S, Wang J, Chi J, Bian F, Li W, Xu G, Bai X, Wu G, Jin S. A novel mechanism of action for salidroside to alleviate diabetic albuminuria: effects on albumin transcytosis across glomerular endothelial cells. Am J Physiol Endocrinol Metab 2016; 310:E225-37. [PMID: 26646098 DOI: 10.1152/ajpendo.00391.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/01/2015] [Indexed: 11/22/2022]
Abstract
Salidroside (SAL) is a phenylethanoid glycoside isolated from the medicinal plant Rhodiola rosea. R. rosea has been reported to have beneficial effects on diabetic nephropathy (DN) and high-glucose (HG)-induced mesangial cell proliferation. Given the importance of caveolin-1 (Cav-1) in transcytosis of albumin across the endothelial barrier, the present study was designed to elucidate whether SAL could inhibit Cav-1 phosphorylation and reduce the albumin transcytosis across glomerular endothelial cells (GECs) to alleviate diabetic albuminuria as well as to explore its upstream signaling pathway. To assess the therapeutic potential of SAL and the mechanisms involved in DN albuminuria, we orally administered SAL to db/db mice, and the effect of SAL on the albuminuria was measured. The albumin transcytosis across GECs was explored in a newly established in vitro cellular model. The ratio of albumin to creatinine was significantly reduced upon SAL treatment in db/db mice. SAL decreased the albumin transcytosis across GECs in both normoglycemic and hyperglycemic conditions. SAL reversed the HG-induced downregulation of AMP-activated protein kinase and upregulation of Src kinase and blocked the upregulation Cav-1 phosphorylation. Meanwhile, SAL decreased mitochondrial superoxide anion production and moderately depolarized mitochondrial membrane potential. We conclude that SAL exerts its proteinuria-alleviating effects by downregulation of Cav-1 phosphorylation and inhibition of albumin transcytosis across GECs. These studies provide the first evidence of interference with albumin transcytosis across GECs as a novel approach to the treatment of diabetic albuminuria.
Collapse
Affiliation(s)
- Dan Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and Department of Endocrinology, Institute of Geriatric Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiaoyan Yang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Tao Zheng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Shasha Xing
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Jianghong Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Jiangyang Chi
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Fang Bian
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Wenjing Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Gao Xu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Xiangli Bai
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Guangjie Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and
| | - Si Jin
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology and Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; and Department of Endocrinology, Institute of Geriatric Medicine, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| |
Collapse
|
83
|
Achyut BR, Shankar A, Iskander ASM, Ara R, Knight RA, Scicli AG, Arbab AS. Chimeric Mouse model to track the migration of bone marrow derived cells in glioblastoma following anti-angiogenic treatments. Cancer Biol Ther 2016; 17:280-90. [PMID: 26797476 DOI: 10.1080/15384047.2016.1139243] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Bone marrow derived cells (BMDCs) have been shown to contribute in the tumor development. In vivo animal models to investigate the role of BMDCs in tumor development are poorly explored. We established a novel chimeric mouse model using as low as 5 × 10(6) GFP+ BM cells in athymic nude mice, which resulted in >70% engraftment within 14 d. In addition, chimera was established in NOD-SCID mice, which displayed >70% with in 28 d. Since anti-angiogenic therapies (AAT) were used as an adjuvant against VEGF-VEGFR pathway to normalize blood vessels in glioblastoma (GBM), which resulted into marked hypoxia and recruited BMDCs to the tumor microenvironment (TME). We exploited chimeric mice in athymic nude background to develop orthotopic U251 tumor and tested receptor tyrosine kinase inhibitors and CXCR4 antagonist against GBM. We were able to track GFP+ BMDCs in the tumor brain using highly sensitive multispectral optical imaging instrument. Increased tumor growth associated with the infiltration of GFP+ BMDCs acquiring suppressive myeloid and endothelial phenotypes was seen in TME following treatments. Immunofluorescence study showed GFP+ cells accumulated at the site of VEGF, SDF1 and PDGF expression, and at the periphery of the tumors following treatments. In conclusion, we developed a preclinical chimeric model of GBM and phenotypes of tumor infiltrated BMDCs were investigated in context of AATs. Chimeric mouse model could be used to study detailed cellular and molecular mechanisms of interaction of BMDCs and TME in cancer.
Collapse
Affiliation(s)
- B R Achyut
- a Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University , Augusta , GA , USA
| | - Adarsh Shankar
- a Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University , Augusta , GA , USA
| | - A S M Iskander
- a Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University , Augusta , GA , USA
| | - Roxan Ara
- a Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University , Augusta , GA , USA
| | | | - Alfonso G Scicli
- c Cellular and Molecular Imaging Laboratory, Henry Ford Health System , Detroit , MI , USA
| | - Ali S Arbab
- a Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University , Augusta , GA , USA
| |
Collapse
|
84
|
Nagasu H, Satoh M, Kiyokage E, Kidokoro K, Toida K, Channon KM, Kanwar YS, Sasaki T, Kashihara N. Activation of endothelial NAD(P)H oxidase accelerates early glomerular injury in diabetic mice. J Transl Med 2016; 96:25-36. [PMID: 26552047 PMCID: PMC4874489 DOI: 10.1038/labinvest.2015.128] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 09/12/2015] [Accepted: 09/18/2015] [Indexed: 11/09/2022] Open
Abstract
Increased generation of reactive oxygen species (ROS) is a common denominative pathogenic mechanism underlying vascular and renal complications in diabetes mellitus. Endothelial NAD(P)H oxidase is a major source of vascular ROS, and it has an important role in endothelial dysfunction. We hypothesized that activation of endothelial NAD(P)H oxidase initiates and worsens the progression of diabetic nephropathy, particularly in the development of albuminuria. We used transgenic mice with endothelial-targeted overexpression of the catalytic subunit of NAD(P)H oxidase, Nox2 (NOX2TG). NOX2TG mice were crossed with Akita insulin-dependent diabetic (Akita) mice that develop progressive hyperglycemia. We compared the progression of diabetic nephropathy in Akita versus NOX2TG-Akita mice. NOX2TG-Akita mice and Akita mice developed significant albuminuria above the baseline at 6 and 10 weeks of age, respectively. Compared with Akita mice, NOX2TG-Akita mice exhibited higher levels of NAD(P)H oxidase activity in glomeruli, developed glomerular endothelial perturbations, and attenuated expression of glomerular glycocalyx. Moreover, in contrast to Akita mice, the NOX2TG-Akita mice had numerous endothelial microparticles (blebs), as detected by scanning electron microscopy, and increased glomerular permeability. Furthermore, NOX2TG-Akita mice exhibited distinct phenotypic changes in glomerular mesangial cells expressing α-smooth muscle actin, and in podocytes expressing increased levels of desmin, whereas the glomeruli generated increased levels of ROS. In conclusion, activation of endothelial NAD(P)H oxidase in the presence of hyperglycemia initiated and exacerbated diabetic nephropathy characterized by the development of albuminuria. Moreover, ROS generated in the endothelium compounded glomerular dysfunctions by altering the phenotypes of mesangial cells and compromising the integrity of the podocytes.
Collapse
Affiliation(s)
- Hajime Nagasu
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Minoru Satoh
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Emi Kiyokage
- Department of Anatomy, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Kengo Kidokoro
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Kazunori Toida
- Department of Anatomy, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Keith M Channon
- Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Yashpal S Kanwar
- Department of Pathology and Medicine, Northwestern University, Chicago, IL, USA
| | - Tamaki Sasaki
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Naoki Kashihara
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| |
Collapse
|
85
|
Abstract
Kidney glomeruli ultrafilter blood to generate urine and they are dysfunctional in a variety of kidney diseases. There are two key vascular growth factor families implicated in glomerular biology and function, namely the vascular endothelial growth factors (VEGFs) and the angiopoietins (Angpt). We present examples showing not only how these molecules help generate and maintain healthy glomeruli but also how they drive disease when their expression is dysregulated. Finally, we review how manipulating VEGF and Angpt signalling may be used to treat glomerular disease.
Collapse
|
86
|
Lin X, You Y, Wang J, Qin Y, Huang P, Yang F. MicroRNA-155 deficiency promotes nephrin acetylation and attenuates renal damage in hyperglycemia-induced nephropathy. Inflammation 2015; 38:546-54. [PMID: 24969676 DOI: 10.1007/s10753-014-9961-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
MiR-155 has been reported to be involved in both innate and adaptive immune responses. But the role of miR-155 in hyperglycemia-induced nephropathy is still unknown. In our current study, 3-month-old male wild-type C57 mice and Mir-155(-/-) mice were used to establish hyperglycemia-induced nephropathy. In our hyperglycemia-induced nephropathy model, the expression of podocyte injury marker desmin was markedly increased in the diabetes group when compared with control. Diabetes also significantly decreased the levels of nephrin and acetylated nephrin, whereas the expression of miR-155 was markedly increased in diabetes group when compared with control. MiR-155(-/-) mice showed significantly increased expression of nephrin, acetylated nephrin, and Wilm's tumor-1 protein (WT-1) when compared with wild-type control. MiR-155 deficiency results in significantly decrease in IL-17A expression both in vivo and in vitro. And the increased expression of WT-1, nephrin, and ac-nephrin was reversed with additional treatment of rmIL-17. Furthermore, we found that the inhibited Th17 differentiation induced by miR-155 deficiency was dependent on increased expression of SOCS1. In conclusion, miR-155 deficiency promotes nephrin acetylation and attenuates renal damage in hyperglycemia-induced nephropathy. This was associated with inhibited IL-17 production through enhancement of SOCS1 expression.
Collapse
Affiliation(s)
- Xu Lin
- Department of Nephrology, the Affiliated Hospital of Youjiang Medical University for Nationalities, 18 Zhongshan Road, Baise, China
| | | | | | | | | | | |
Collapse
|
87
|
Tesch GH, Ma FY, Han Y, Liles JT, Breckenridge DG, Nikolic-Paterson DJ. ASK1 Inhibitor Halts Progression of Diabetic Nephropathy in Nos3-Deficient Mice. Diabetes 2015; 64:3903-13. [PMID: 26180085 DOI: 10.2337/db15-0384] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/06/2015] [Indexed: 01/04/2023]
Abstract
p38 mitogen-activated protein kinase (MAPK) signaling promotes diabetic kidney injury. Apoptosis signal-regulating kinase (ASK)1 is one of the upstream kinases in the p38 MAPK-signaling pathway, which is activated by inflammation and oxidative stress, suggesting a possible role for ASK1 in diabetic nephropathy. In this study, we examined whether a selective ASK1 inhibitor can prevent the induction and progression of diabetic nephropathy in mice. Diabetes was induced in hypertensive endothelial nitric oxide synthase (Nos3)-deficient mice by five low-dose streptozotocin (STZ) injections. Groups of diabetic Nos3(-/-) mice received ASK1 inhibitor (GS-444217 delivered in chow) as an early intervention (2-8 weeks after STZ) or late intervention (weeks 8-15 after STZ). Control diabetic and nondiabetic Nos3(-/-) mice received normal chow. Treatment with GS-444217 abrogated p38 MAPK activation in diabetic kidneys but had no effect upon hypertension in Nos3(-/-) mice. Early intervention with GS-444217 significantly inhibited diabetic glomerulosclerosis and reduced renal dysfunction but had no effect on the development of albuminuria. Late intervention with GS-444217 improved renal function and halted the progression of glomerulosclerosis, renal inflammation, and tubular injury despite having no effect on established albuminuria. In conclusion, this study identifies ASK1 as a new therapeutic target in diabetic nephropathy to reduce renal inflammation and fibrosis independent of blood pressure control.
Collapse
Affiliation(s)
- Greg H Tesch
- Department of Nephrology, Monash Medical Centre, Clayton, Victoria, Australia Monash University Department of Medicine, Clayton, Victoria, Australia
| | - Frank Y Ma
- Department of Nephrology, Monash Medical Centre, Clayton, Victoria, Australia Monash University Department of Medicine, Clayton, Victoria, Australia
| | - Yingjie Han
- Department of Nephrology, Monash Medical Centre, Clayton, Victoria, Australia Monash University Department of Medicine, Clayton, Victoria, Australia
| | | | | | - David J Nikolic-Paterson
- Department of Nephrology, Monash Medical Centre, Clayton, Victoria, Australia Monash University Department of Medicine, Clayton, Victoria, Australia
| |
Collapse
|
88
|
Ueda S, Ozawa S, Mori K, Asanuma K, Yanagita M, Uchida S, Nakagawa T. ENOS deficiency causes podocyte injury with mitochondrial abnormality. Free Radic Biol Med 2015; 87:181-92. [PMID: 26119782 DOI: 10.1016/j.freeradbiomed.2015.06.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/20/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
The contribution of endothelial nitric oxide synthase (eNOS) to podocyte integrity remains unclear. This study therefore examined podocytes and mitochondrial abnormalities in eNOS deficient mice. Absence of eNOS caused glomerular hypertrophy, along with occasional glomerular sclerosis and mesangiolysis. While many glomeruli did not have such advanced lesions, ultrastructural analysis showed cellular hypertrophy, vacuolization, lysosomal enlargement, and microvillus formation in podocytes of eNOS knockout (KO) mice. Increased oxidative stress was associated with mitochondrial abnormalities, including an increase in number, coupled with a reduction in size, of mitochondria in podocytes of eNOS-KO mice. While the levels of expression of several mitochondrial proteins were not altered, the d-17 mutation in mitochondrial DNA was significantly associated with the eNOS deficiency. Renal ATP level in the renal cortex and mitochondrial respiration in the primary podocytes were significantly lower in eNOS-KO mice, suggesting that renal mitochondria may be functionally impaired. Podocytes cultured with endothelial conditioned medium lacking NO consistently showed a greater degree of mitochondrial fragmentation and an increase in mitochondrial oxidative stress, with these mitochondrial alterations rescued by an NO donor. In conclusion, eNOS may be necessary to maintain podocyte integrity, especially mitochondrial function.
Collapse
Affiliation(s)
- Shuko Ueda
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Shota Ozawa
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Saitama, Japan
| | - Kiyoshi Mori
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan
| | - Katsuhiko Asanuma
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan; Department of Nephrology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shunya Uchida
- Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Takahiko Nakagawa
- TMK Project, Medical Innovation Center, Kyoto University, Kyoto, Japan.
| |
Collapse
|
89
|
Achyut BR, Shankar A, Iskander ASM, Ara R, Angara K, Zeng P, Knight RA, Scicli AG, Arbab AS. Bone marrow derived myeloid cells orchestrate antiangiogenic resistance in glioblastoma through coordinated molecular networks. Cancer Lett 2015; 369:416-26. [PMID: 26404753 DOI: 10.1016/j.canlet.2015.09.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/29/2015] [Accepted: 09/09/2015] [Indexed: 12/29/2022]
Abstract
Glioblastoma (GBM) is a hypervascular and malignant form of brain tumors. Anti-angiogenic therapies (AAT) were used as an adjuvant against VEGF-VEGFR pathway to normalize blood vessels in clinical and preclinical studies, which resulted into marked hypoxia and recruited bone marrow derived cells (BMDCs) to the tumor microenvironment (TME). In vivo animal models to track BMDCs and investigate molecular mechanisms in AAT resistance are rare. We exploited recently established chimeric mouse to develop orthotopic U251 tumor, which uses as low as 5 × 10(6) GFP+ BM cells in athymic nude mice and engrafted >70% GFP+ cells within 14 days. Our unpublished data and published studies have indicated the involvement of immunosuppressive myeloid cells in therapeutic resistance in glioma. Similarly, in the present study, vatalanib significantly increased CD68+ myeloid cells, and CD133+, CD34+ and Tie2+ endothelial cell signatures. Therefore, we tested inhibition of CSF1R+ myeloid cells using GW2580 that reduced tumor growth by decreasing myeloid (Gr1+ CD11b+ and F4/80+) and angiogenic (CD202b+ and VEGFR2+) cell signatures in TME. CSF1R blockade significantly decreased inflammatory, proangiogenic and immunosuppressive molecular signatures compared to vehicle, vatalanib or combination. TCK1 or CXCL7, a potent chemoattractant and activator of neutrophils, was observed as most significantly decreased cytokine in CSF1R blockade. ERK MAPK pathway was involved in cytokine network regulation. In conclusion, present study confirmed the contribution of myeloid cells in GBM development and therapeutic resistance using chimeric mouse model. We identified novel molecular networks including CXCL7 chemokine as a promising target for future studies. Nonetheless, survival studies are required to assess the beneficial effect of CSF1R blockade.
Collapse
Affiliation(s)
- B R Achyut
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Adarsh Shankar
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - A S M Iskander
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Roxan Ara
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Kartik Angara
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Peng Zeng
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA
| | | | - Alfonso G Scicli
- Cellular and Molecular Imaging Laboratory, Henry Ford Health System, Detroit, MI, USA
| | - Ali S Arbab
- Tumor Angiogenesis Laboratory, Biochemistry and Molecular Biology, Cancer Center, Georgia Regents University, Augusta, GA, USA.
| |
Collapse
|
90
|
Fu J, Wei C, Lee K, Zhang W, He W, Chuang P, Liu Z, He JC. Comparison of Glomerular and Podocyte mRNA Profiles in Streptozotocin-Induced Diabetes. J Am Soc Nephrol 2015; 27:1006-14. [PMID: 26264855 DOI: 10.1681/asn.2015040421] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/12/2015] [Indexed: 12/16/2022] Open
Abstract
Evaluating the mRNA profile of podocytes in the diabetic kidney may indicate genes involved in the pathogenesis of diabetic nephropathy. To determine if the podocyte-specific gene information contained in mRNA profiles of the whole glomerulus of the diabetic kidney accurately reflects gene expression in the isolated podocytes, we crossed Nos3(-/-) IRG mice with podocin-rtTA and TetON-Cre mice for enhanced green fluorescent protein labeling of podocytes before diabetic injury. Diabetes was induced by streptozotocin, and mRNA profiles of isolated glomeruli and sorted podocytes from diabetic and control mice were examined 10 weeks later. Expression of podocyte-specific markers in glomeruli was downregulated in diabetic mice compared with controls. However, expression of these markers was not altered in sorted podocytes from diabetic mice. When mRNA levels of glomeruli were corrected for podocyte number per glomerulus, the differences in podocyte marker expression disappeared. Analysis of the differentially expressed genes in diabetic mice also revealed distinct upregulated pathways in the glomeruli (mitochondrial function, oxidative stress) and in podocytes (actin organization). In conclusion, our data suggest reduced expression of podocyte markers in glomeruli is a secondary effect of reduced podocyte number, thus podocyte-specific gene expression detected in the whole glomerulus may not represent that in podocytes in the diabetic kidney.
Collapse
Affiliation(s)
- Jia Fu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | | | - Kyung Lee
- Division of Nephrology, Department of Medicine
| | | | - Wu He
- Flow Cytometry Shared Resource Facility, Icahn School of Medicine at Mount Sinai, New York; and
| | | | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China;
| | - John Cijiang He
- Division of Nephrology, Department of Medicine, Renal Program, James J. Peters VA Medical Center at Bronx, New York.
| |
Collapse
|
91
|
Tsai IJ, Chou CH, Yang YH, Lin WC, Lin YH, Chow LP, Lee HH, Kao PG, Liau WT, Jou TS, Tsau YK. Inhibition of Rho-associated kinase relieves C5a-induced proteinuria in murine nephrotic syndrome. Cell Mol Life Sci 2015; 72:3157-71. [PMID: 25790939 PMCID: PMC11113791 DOI: 10.1007/s00018-015-1888-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 02/14/2015] [Accepted: 03/13/2015] [Indexed: 02/05/2023]
Abstract
Childhood nephrotic syndrome is mainly caused by minimal change disease which is named because only subtle ultrastructural alteration could be observed at electron microscopic level in the pathological kidney. Glomerular podocytes are presumed to be the target cells whose protein sieving capability is compromised by a yet unidentified permeability perturbing factor. In a cohort of children with non-hereditary idiopathic nephrotic syndrome, we found the complement fragment C5a was elevated in their sera during active disease. Administration of recombinant C5a induced profound proteinuria and minimal change nephrotic syndrome in mice. Purified glomerular endothelial cells, instead of podocytes, were demonstrated to be responsible for the proteinuric effect elicited by C5a. Further studies depicted a signaling pathway involving Rho/Rho-associated kinase/myosin activation leading to endothelial cell contraction and cell adhesion complex breakdown. Significantly, application of Rho-associated kinase inhibitor, Y27632, prevented the protein leaking effects observed in both C5a-treated purified endothelial cells and mice. Taken together, our study identifies a previously unknown mechanism underlying nephrotic syndrome and provides a new insight toward identifying Rho-associated kinase inhibition as an alternative therapeutic option for nephrotic syndrome.
Collapse
Affiliation(s)
- I-Jung Tsai
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Hung Chou
- Department of Obstetrics and Gynecology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yao-Hsu Yang
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Wei-Chou Lin
- Department of Pathology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yen-Hung Lin
- Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lu-Ping Chow
- Graduate Institute of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hsiao-Hui Lee
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Pei-Gang Kao
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Wan-Ting Liau
- Department of Obstetrics and Gynecology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Tzuu-Shuh Jou
- Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yong-Kwei Tsau
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| |
Collapse
|
92
|
You H, Gao T, Cooper TK, Morris SM, Awad AS. Arginase inhibition: a new treatment for preventing progression of established diabetic nephropathy. Am J Physiol Renal Physiol 2015; 309:F447-55. [PMID: 26041444 DOI: 10.1152/ajprenal.00137.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/29/2015] [Indexed: 12/21/2022] Open
Abstract
Our previous publication showed that inhibition of arginase prevents the development of diabetic nephropathy (DN). However, identification of targets that retard the progression of established DN-which is more clinically relevant-is lacking. Therefore, we tested the hypothesis that arginase inhibition would prevent the progression of established DN. Effects of arginase inhibition were compared with treatment with the angiotensin-converting enzyme inhibitor captopril, a current standard of care in DN. Experiments were conducted in Ins2(Akita) mice treated with the arginase inhibitor S-(2-boronoethyl)-l-cysteine (BEC) or captopril starting at 6 wk of age for 12 wk (early treatment) or starting at 12 wk of age for 6 wk (late treatment). Early and late treatment with BEC resulted in protection from DN as indicated by reduced albuminuria, histological changes, kidney macrophage infiltration, urinary thiobarbituric acid-reactive substances, and restored nephrin expression, kidney nitrate/nitrite, kidney endothelial nitric oxide synthase phosphorylation, and renal medullary blood flow compared with vehicle-treated Ins2(Akita) mice at 18 wk of age. Interestingly, early treatment with captopril reduced albuminuria, histological changes, and kidney macrophage infiltration without affecting the other parameters, but late treatment with captopril was ineffective. These findings highlight the importance of arginase inhibition as a new potential therapeutic intervention in both early and late stages of diabetic renal injury.
Collapse
Affiliation(s)
- Hanning You
- Department of Medicine, Division of Nephrology, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Ting Gao
- Department of Medicine, Division of Nephrology, Penn State University College of Medicine, Hershey, Pennsylvania
| | - Timothy K Cooper
- Department of Comparative Medicine, Penn State University College of Medicine, Hershey, Pennsylvania; and
| | - Sidney M Morris
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alaa S Awad
- Department of Medicine, Division of Nephrology, Penn State University College of Medicine, Hershey, Pennsylvania;
| |
Collapse
|
93
|
Lubbad L, Öberg CM, Dhanasekaran S, Nemmar A, Hammad F, Pathan JY, Rippe B, Bakoush O. Reduced glomerular size selectivity in late streptozotocin-induced diabetes in rats: application of a distributed two-pore model. Physiol Rep 2015; 3:3/5/e12397. [PMID: 26009635 PMCID: PMC4463827 DOI: 10.14814/phy2.12397] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Microalbuminuria is an early manifestation of diabetic nephropathy. Potential contributors to this condition are reduced glomerular filtration barrier (GFB) size- and charge selectivity, and impaired tubular reabsorption of filtered proteins. However, it was recently reported that no significant alterations in charge selectivity of the GFB occur in early experimental diabetic nephropathy. We here aimed at investigating the functional changes in the GFB in long-term type-1 diabetes in rats, applying a novel distributed two-pore model. We examined glomerular permeability in 15 male Wistar rats with at least 3 months of streptozotocin (STZ)-induced diabetes (blood glucose ∼20 mmol/L) and in age-matched control rats. The changes in glomerular permeability were assessed by determining the glomerular sieving coefficients (θ) for FITC-Ficoll (molecular radius 20–90 Å) using size exclusion HPLC. The values of θ for FITC-Ficoll of radius >50 Å were significantly increased in STZ-diabetic rats compared to age-matched controls (θ for 50–69 Å = 0.001 vs. 0.0002, and θ for 70–90 Å = 0.0007 vs. 0.00006, P < 0.001), while θ for FITC-Ficoll <50 Å tended to be lower in diabetic rats than in controls (θ for 36–49 Å = 0.013 vs. 0.016, ns). According to the distributed two-pore model, there was primarily an increase in macromolecular transport through large pores in the glomerular filter of diabetic rats associated with a loss of small-pore area. Deterioration in the glomerular size selectivity due to an increase in the number and size-spread of large pores, with no changes in the permeability of the small-pore system, represent the major functional changes observed after 3 months of induced experimental diabetes.
Collapse
Affiliation(s)
- Loay Lubbad
- Department of Surgery, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Carl M Öberg
- Department of Nephrology, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Subramanian Dhanasekaran
- Department of Pharmacology and Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Abderrahim Nemmar
- Department of Physiology, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Fayez Hammad
- Department of Surgery, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Javed Y Pathan
- Department of Internal Medicine, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bengt Rippe
- Department of Nephrology, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Omran Bakoush
- Department of Internal Medicine, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| |
Collapse
|
94
|
Siddiqi FS, Chen LH, Advani SL, Thai K, Batchu SN, Alghamdi TA, White KE, Sood MM, Gibson IW, Connelly KA, Marsden PA, Advani A. CXCR4 promotes renal tubular cell survival in male diabetic rats: implications for ligand inactivation in the human kidney. Endocrinology 2015; 156:1121-32. [PMID: 25549045 DOI: 10.1210/en.2014-1650] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Binding of the receptor CXCR4 to its ligand stromal cell-derived factor 1 (SDF-1) promotes cell survival and is under the influence of a number of regulatory processes including enzymatic ligand inactivation by endopeptidases such as matrix metalloproteinase 9 (MMP-9). In light of the pivotal role that the SDF-1/CXCR4 axis plays in renal development and in the pathological growth of renal cells, we explored the function of this pathway in diabetic rats and in biopsies from patients with diabetic nephropathy, hypothesizing that the pro-survival effects of CXCR4 in resident cells would attenuate renal injury. Renal CXCR4 expression was observed to be increased in diabetic rats, whereas antagonism of the receptor unmasked albuminuria and accelerated tubular epithelial cell death. In cultured cells, CXCR4 blockade promoted tubular cell apoptosis, up-regulated Bcl-2-associated death promoter, and prevented high glucose/SDF-1-augmented phosphorylation of the pro-survival kinase, Akt. Although CXCR4 expression was also increased in biopsy tissue from patients with diabetic nephropathy, serine 339 phosphorylation of the receptor, indicative of ligand engagement, was unaffected. Coincident with these changes in receptor expression but not activity, MMP-9 was also up-regulated in diabetic nephropathy biopsies. Supporting a ligand-inactivating effect of the endopeptidase, exposure of cultured cells to recombinant MMP-9 abrogated SDF-1 induced Akt phosphorylation. These observations demonstrate a potentially reno-protective role for CXCR4 in diabetes that is impeded in its actions in the human kidney by the coincident up-regulation of ligand-inactivating endopeptidases. Therapeutically intervening in this interplay may limit tubulointerstitial injury, the principal determinant of renal decline in diabetes.
Collapse
Affiliation(s)
- Ferhan S Siddiqi
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital (F.S.S., L.H.C., S.L.A., K.T., S.N.B., T.A.A., K.A.C., P.A.M., A.A.), Toronto, Canada M5B 1T8; EM Research Services (K.E.W.), Newcastle University, Newcastle upon Tyne, United Kingdom NE2 4HH; Ottawa Hospital Research Institute (M.M.S.), University of Ottawa, Ottawa, Canada K1Y 4E9; and Department of Pathology (I.W.G.), University of Manitoba, Winnipeg, Canada R3A 1R9
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
95
|
Roganović J, Djukić LJ, Kršljak E, Tanić N, Stojić D. Reduced muscarinic parotid secretion is underlain by impaired NO signaling in diabetic rabbits. Oral Dis 2015; 21:634-40. [PMID: 25703905 DOI: 10.1111/odi.12327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/23/2015] [Accepted: 02/10/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The influence of experimental diabetes (alloxan, 100 mg kg(-1) ) was studied on rabbit parotid gland function. MATERIAL AND METHODS Carbachol-induced parotid secretion in vivo, and in vitro quantification of inducible nitric oxide synthase (iNOS) mRNA expression, by real-time RT-PCR, and activity of superoxide dismutase (SOD) and total antioxidant capacity (TAC) in commercial colorimetric assays were measured in parotid glands of non-diabetic and diabetic rabbits. RESULTS Carbachol-induced dose-dependent increase in parotid secretion significantly reduced in diabetic rabbits. Functional studies in the presence of muscarinic receptor and nitric oxide synthase (NOS) antagonists revealed that in M3 receptor-mediated carbachol secretion, nitric oxide, deriving mainly from neuronal NOS (nNOS) in control, and iNOS in diabetic rabbits, was involved. Also, upregulation of iNOS mRNA expression and enhanced SOD activity and TAC were detected in diabetic glands. CONCLUSIONS Our data suggest that decreased M3 receptor-mediated parotid secretion in diabetic rabbits appears to be due to alterations in NO signaling, mainly due to iNOS induction, accompanied by elevated antioxidant response.
Collapse
Affiliation(s)
- J Roganović
- Department of Pharmacology in Dentistry, School of Dental medicine, University of Belgrade, Belgrade, Serbia
| | - L J Djukić
- Department of Pharmacology in Dentistry, School of Dental medicine, University of Belgrade, Belgrade, Serbia
| | - E Kršljak
- Department of Physiology, School of Dental medicine, University of Belgrade, Belgrade, Serbia
| | - N Tanić
- Department of Neurobiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - D Stojić
- Department of Pharmacology in Dentistry, School of Dental medicine, University of Belgrade, Belgrade, Serbia
| |
Collapse
|
96
|
Luo Z, Aslam S, Welch WJ, Wilcox CS. Activation of nuclear factor erythroid 2-related factor 2 coordinates dimethylarginine dimethylaminohydrolase/PPAR-γ/endothelial nitric oxide synthase pathways that enhance nitric oxide generation in human glomerular endothelial cells. Hypertension 2015; 65:896-902. [PMID: 25691623 DOI: 10.1161/hypertensionaha.114.04760] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dimethylarginine dimethylaminohydrolase (DDAH) degrades asymmetric dimethylarginine, which inhibits nitric oxide (NO) synthase (NOS). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that binds to antioxidant response elements and transcribes many antioxidant genes. Because the promoters of the human DDAH-1 and DDAH-2, endothelial NOS (eNOS) and PPAR-γ genes contain 2 to 3 putative antioxidant response elements, we hypothesized that they were regulated by Nrf2/antioxidant response element. Incubation of human renal glomerular endothelial cells with the Nrf2 activator tert-butylhydroquinone (20 μmol·L(-1)) significantly (P<0.05) increased NO and activities of NOS and DDAH and decreased asymmetric dimethylarginine. It upregulated genes for hemoxygenase-1, eNOS, DDAH-1, DDAH-2, and PPAR-γ and partitioned Nrf2 into the nucleus. Knockdown of Nrf2 abolished these effects. Nrf2 bound to one antioxidant response element on DDAH-1 and DDAH-2 and PPAR-γ promoters but not to the eNOS promoter. An increased eNOS and phosphorylated eNOS (P-eNOSser-1177) expression with tert-butylhydroquinone was prevented by knockdown of PPAR-γ. Expression of Nrf2 was reduced by knockdown of PPAR-γ, whereas PPAR-γ was reduced by knockdown of Nrf2, thereby demonstrating 2-way positive interactions. Thus, Nrf2 transcribes HO-1 and other genes to reduce reactive oxygen species, and DDAH-1 and DDAH-2 to reduce asymmetric dimethylarginine and PPAR-γ to increase eNOS and its phosphorylation and activity thereby coordinating 3 pathways that enhance endothelial NO generation.
Collapse
Affiliation(s)
- Zaiming Luo
- From the Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, DC
| | - Shakil Aslam
- From the Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, DC
| | - William J Welch
- From the Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, DC
| | - Christopher S Wilcox
- From the Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, DC.
| |
Collapse
|
97
|
Tanaka M, Furuhashi M, Okazaki Y, Mita T, Fuseya T, Ohno K, Ishimura S, Yoshida H, Miura T. Ectopic expression of fatty acid-binding protein 4 in the glomerulus is associated with proteinuria and renal dysfunction. Nephron Clin Pract 2015; 128:345-51. [PMID: 25592475 DOI: 10.1159/000368412] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 09/17/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Fatty acid-binding proteins (FABPs) are a family of intracellular lipid chaperones. Among FABPs, FABP1 (liver FABP) is expressed in proximal tubular epithelial cells in the kidney, and urinary FABP1 has been reported to reflect damage of proximal tubular epithelial cells. However, roles of other FABP isoforms in renal pathologies have not been reported. Recently, FABP4 (adipocyte FABP/aP2) was reported to be expressed in peritubular capillaries (PTCs), but not in glomerular capillaries in the normal kidney. We examined the hypothesis that pathological conditions alter the level and localization of FABP4 expression in the kidney, which mediates renal dysfunction. METHODS A total of 112 consecutive patients who underwent renal biopsy were retrospectively enrolled. Expression of FABP4 protein and mRNA in the kidney was examined by immunohistochemistry and in situ hybridization, respectively. The ratio of FABP4-positive area to total area within glomeruli (G-FABP4-Area), urinary protein level (U-Protein), and change in estimated glomerular filtration rate (eGFR) 1 year after biopsy were examined. RESULTS FABP4 protein and mRNA were expressed not only in PTCs, but also in endothelial cells and macrophages in the glomerulus. G-FABP4-Area was correlated with U-Protein (r = 0.497, p < 0.001). As a subanalysis, in patients with IgA nephropathy (n = 34), G-FABP4-Area was significantly larger in cases with an endocapillary proliferative lesion, and change in eGFR was negatively correlated with G-FABP4-Area at baseline (r = -0.537, p = 0.008). CONCLUSION Ectopic FABP4 expression in the glomerulus is induced by renal diseases and is closely associated with proteinuria and renal dysfunction.
Collapse
Affiliation(s)
- Marenao Tanaka
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
98
|
Okazaki Y, Furuhashi M, Tanaka M, Mita T, Fuseya T, Ishimura S, Watanabe Y, Hoshina K, Akasaka H, Ohnishi H, Yoshida H, Saitoh S, Shimamoto K, Miura T. Urinary excretion of fatty acid-binding protein 4 is associated with albuminuria and renal dysfunction. PLoS One 2014; 9:e115429. [PMID: 25506691 PMCID: PMC4266652 DOI: 10.1371/journal.pone.0115429] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/23/2014] [Indexed: 12/22/2022] Open
Abstract
Background Fatty acid-binding protein 4 (FABP4/A-FABP/aP2) is expressed in not only adipocytes and macrophages but also peritubular capillaries in the normal kidney. We recently demonstrated that ectopic expression of FABP4, but not FABP1 known as liver FABP (L-FABP), in the glomerulus is associated with progression of proteinuria and renal dysfunction. However, urinary excretion of FABP4 has not been investigated. Methods Subjects who participated in the Tanno-Sobetsu Study, a study with a population-based cohort design, in 2011 (n = 392, male/female: 166/226) were enrolled. Urinary FABP4 (U-FABP4) and urinary albumin-to-creatinine ratio (UACR) were measured. Change in estimated glomerular filtration rate (eGFR) was followed up one year later. Results In 93 (23.7%) of the 392 subjects, U-FABP4 level was below the sensitivity of the assay. Subjects with undetectable U-FABP4 were younger and had lower UACR and higher eGFR levels than subjects with measurable U-FABP4. U-FABP4 level was positively correlated with age, systolic blood pressure and levels of serum FABP4 (S-FABP4), triglycerides, hemoglobin A1c (HbA1c), urinary FABP1 (U-FABP1) and UACR (r = 0.360, p<0.001). Age, S-FABP4, U-FABP1 and UACR were independent predictors of U-FABP4. On the other hand, systolic blood pressure, HbA1c and U-FABP4 were independently correlated with UACR. Reduction in eGFR after one year was significantly larger in a group with the highest tertile of baseline U-FABP4 than a group with the lowest tertile. Conclusions Urinary FABP4 level is independently correlated with level of albuminuria and possibly predicts yearly decline of eGFR. U-FABP4 would be a novel biomarker of glomerular damage.
Collapse
Affiliation(s)
- Yusuke Okazaki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
- * E-mail:
| | - Marenao Tanaka
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tomohiro Mita
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takahiro Fuseya
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shutaro Ishimura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yuki Watanabe
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Kyoko Hoshina
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Akasaka
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hirofumi Ohnishi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
- Department of Public Health, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hideaki Yoshida
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shigeyuki Saitoh
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
- Department of Nursing, Division of Medical and Behavioral Subjects, Sapporo Medical University School of Health Sciences, Sapporo, Japan
| | | | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| |
Collapse
|
99
|
Fu J, Lee K, Chuang PY, Liu Z, He JC. Glomerular endothelial cell injury and cross talk in diabetic kidney disease. Am J Physiol Renal Physiol 2014; 308:F287-97. [PMID: 25411387 DOI: 10.1152/ajprenal.00533.2014] [Citation(s) in RCA: 193] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Diabetic kidney disease (DKD) remains a leading cause of new-onset end-stage renal disease (ESRD), and yet, at present, the treatment is still very limited. A better understanding of the pathogenesis of DKD is therefore necessary to develop more effective therapies. Increasing evidence suggests that glomerular endothelial cell (GEC) injury plays a major role in the development and progression of DKD. Alteration of the glomerular endothelial cell surface layer, including its major component, glycocalyx, is a leading cause of microalbuminuria observed in early DKD. Many studies suggest a presence of cross talk between glomerular cells, such as between GEC and mesangial cells or GEC and podocytes. PDGFB/PDGFRβ is a major mediator for GEC and mesangial cell cross talk, while vascular endothelial growth factor (VEGF), angiopoietins, and endothelin-1 are the major mediators for GEC and podocyte communication. In DKD, GEC injury may lead to podocyte damage, while podocyte loss further exacerbates GEC injury, forming a vicious cycle. Therefore, GEC injury may predispose to albuminuria in diabetes either directly or indirectly by communication with neighboring podocytes and mesangial cells via secreted mediators. Identification of novel mediators of glomerular cell cross talk, such as microRNAs, will lead to a better understanding of the pathogenesis of DKD. Targeting these mediators may be a novel approach to develop more effective therapy for DKD.
Collapse
Affiliation(s)
- Jia Fu
- Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu, China; and
| | - Kyung Lee
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Peter Y Chuang
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Zhihong Liu
- Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu, China; and
| | - John Cijiang He
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
100
|
Effects of folic acid on renal endothelial function in patients with diabetic nephropathy: results from a randomized trial. Clin Sci (Lond) 2014; 127:499-505. [PMID: 24724807 DOI: 10.1042/cs20140111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
UNLABELLED Endothelial dysfunction has been shown to promote podocyte injury and albuminuria in diabetes, highlighting the importance of the interaction between renal endothelial cells and podocytes. Folic acid (FA) improves nitric oxide synthase (NOS) function and reduces progression of diabetic nephropathy in animal models. We tested whether high-dose FA treatment improves renal endothelial function and albuminuria in human subjects with incipient diabetic nephropathy. Following a double-blind, randomized, cross-over design, 28 patients with Type 2 diabetes and albuminuria were allocated to 4 weeks' treatment with placebo and high-dose FA (5 mg/day). Renal nitric oxide (NO) production determined as the response of renal plasma flow (RPF) to NOS inhibition with NG-monomethyl-L-arginine (L-NMMA) (4.25 mg/kg intravenously), renal oxidant stress as response of RPF to vitamin C infusion (3 mg/kg) and albuminuria were determined after each treatment phase. Neither the reduction in RPF to L-NMMA nor the increase in RPF to vitamin C infusion differed between treatment phases (ΔRPF to L-NMMA -74±71 ml/min per m2 during placebo compared with -63±56 ml/min per m2 during FA, P=0.57; ΔRPF to vitamin C: +93±118 ml/min per m2 compared with +94±108 ml/min per m2; P=0.70). In line with the lack of effect on the renal endothelium, albuminuria was not affected by FA treatment (110±179 mg/day during placebo compared with 87±146 mg/day during FA; P=0.12). High-dose FA treatment does not improve renal endothelial function and fails to reduce albuminuria in human subjects with diabetic nephropathy. Novel treatment options for oxidant stress and endothelial dysfunction in patients with diabetes are urgently needed.
Collapse
|