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Buelli S, Imberti B, Morigi M. The complement C3a and C5a signaling in renal diseases: a bridge between acute and chronic inflammation. Nephron Clin Pract 2024:000538241. [PMID: 38452744 DOI: 10.1159/000538241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/04/2024] [Indexed: 03/09/2024] Open
Abstract
The complement system, a cornerstone of the innate immune defense, typically confers protection against pathogens. However, in various clinical scenarios the complement's defensive actions can harm host cells, exacerbating immune and inflammatory responses. The central components C3 and C5 undergo proteolytic cleavage during complement activation, yielding small active fragments C3a and C5a anaphylatoxins. Traditionally these fragments were associated with inflammation via the specific receptors C3a receptor (R), C5aR1 and C5aR2. Recent insights, however, spotlight the excessive C3a/C3aR and C5a/C5aR1 signaling as culprits in diverse disorders of inflammatory and autoimmune etiology. This is particularly true for several kidney diseases, where the potential involvement of anaphylatoxins in renal damage is supported by the enhanced renal expression of their receptors and the high levels of C3a and C5a in both plasma and urine. Furthermore, the production of complement proteins in the kidney, with different renal cells synthesizing C3 and C5, significantly contributes to local tissue injury. In the present review, we discuss the different aspects of C3a/C3aR and C5a/C5aR signaling in acute and chronic kidney diseases, and explore the therapeutic potential of emerging targeted drugs for future clinical applications.
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Buelli S, Locatelli M, Carminati CE, Corna D, Cerullo D, Imberti B, Perico L, Brigotti M, Abbate M, Zoja C, Benigni A, Remuzzi G, Morigi M. Shiga Toxin 2 Triggers C3a-Dependent Glomerular and Tubular Injury through Mitochondrial Dysfunction in Hemolytic Uremic Syndrome. Cells 2022; 11:cells11111755. [PMID: 35681450 PMCID: PMC9179250 DOI: 10.3390/cells11111755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/13/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli is the predominant offending agent of post-diarrheal hemolytic uremic syndrome (HUS), a rare disorder of microvascular thrombosis and acute kidney injury possibly leading to long-term renal sequelae. We previously showed that C3a has a critical role in the development of glomerular damage in experimental HUS. Based on the evidence that activation of C3a/C3a receptor (C3aR) signaling induces mitochondrial dysregulation and cell injury, here we investigated whether C3a caused podocyte and tubular injury through induction of mitochondrial dysfunction in a mouse model of HUS. Mice coinjected with Stx2/LPS exhibited glomerular podocyte and tubular C3 deposits and C3aR overexpression associated with cell damage, which were limited by C3aR antagonist treatment. C3a promoted renal injury by affecting mitochondrial wellness as demonstrated by data showing that C3aR blockade reduced mitochondrial ultrastructural abnormalities and preserved mitochondrial mass and energy production. In cultured podocytes and tubular cells, C3a caused altered mitochondrial fragmentation and distribution, and reduced anti-oxidant SOD2 activity. Stx2 potentiated the responsiveness of renal cells to the detrimental effects of C3a through increased C3aR protein expression. These results indicate that C3aR may represent a novel target in Stx-associated HUS for the preservation of renal cell integrity through the maintenance of mitochondrial function.
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Affiliation(s)
- Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
- Correspondence: ; Tel.: +39-035-42131; Fax: +39-035-319-331
| | - Monica Locatelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Claudia Elisa Carminati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Daniela Corna
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Domenico Cerullo
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Barbara Imberti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Luca Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Maurizio Brigotti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40126 Bologna, Italy;
| | - Mauro Abbate
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
| | - Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Via Stezzano 87, 24126 Bergamo, Italy; (M.L.); (C.E.C.); (D.C.); (D.C.); (B.I.); (L.P.); (M.A.); (C.Z.); (A.B.); (G.R.); (M.M.)
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Morigi M, Perico L, Corna D, Locatelli M, Cassis P, Carminati CE, Bolognini S, Zoja C, Remuzzi G, Benigni A, Buelli S. C3a receptor blockade protects podocytes from injury in diabetic nephropathy. JCI Insight 2020; 5:131849. [PMID: 32161193 DOI: 10.1172/jci.insight.131849] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 01/29/2020] [Indexed: 12/14/2022] Open
Abstract
Renal activation of the complement system has been described in patients with diabetic nephropathy (DN), although its pathological relevance is still ill-defined. Here, we studied whether glomerular C3a, generated by uncontrolled complement activation, promotes podocyte damage, leading to proteinuria and renal injury in mice with type 2 diabetes. BTBR ob/ob mice exhibited podocyte loss, albuminuria, and glomerular injury accompanied by C3 deposits and increased C3a and C3a receptor (C3aR) levels. Decreased glomerular nephrin and α-actinin4 expression, coupled with integrin-linked kinase induction, were also observed. Treatment of DN mice with a C3aR antagonist enhanced podocyte density and preserved their phenotype, limiting proteinuria and glomerular injury. Mechanistically, ultrastructural and functional mitochondrial alterations, accompanied by downregulation of antioxidant superoxide dismutase 2 (SOD2) and increased protein oxidation, occurred in podocytes and were normalized by C3aR blockade. In cultured podocytes, C3a induced cAMP-dependent mitochondrial fragmentation. Alterations of mitochondrial membrane potential, SOD2 expression, and energetic metabolism were also found in response to C3a. Notably, C3a-induced podocyte motility was inhibited by SS-31, a peptide with mitochondrial protective effects. These data indicate that C3a blockade represents a potentially novel therapeutic strategy in DN for preserving podocyte integrity through the maintenance of mitochondrial functions.
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Affiliation(s)
- Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Luca Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Monica Locatelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Paola Cassis
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Claudia Elisa Carminati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Silvia Bolognini
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.,"L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
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Zoja C, Buelli S, Morigi M. Shiga toxin triggers endothelial and podocyte injury: the role of complement activation. Pediatr Nephrol 2019; 34:379-388. [PMID: 29214442 DOI: 10.1007/s00467-017-3850-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/12/2017] [Accepted: 11/10/2017] [Indexed: 02/07/2023]
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) is the offending agent in post-diarrhea-associated hemolytic uremic syndrome (HUS), a disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney failure, with thrombi occluding the renal microvasculature. Endothelial dysfunction has been recognized as the trigger event in the development of microangiopathic processes. Glomerular endothelial cells are susceptible to the toxic effects of Stxs that, via nuclear factor kappa B (NF-κB) activation, induce the expression of genes encoding for adhesion molecules and chemokines, culminating in leukocyte adhesion and platelet thrombus formation on the activated endothelium. Complement activation via the alternative pathway has been seen in patients during the acute phase of STEC-associated HUS. Experimental evidence has highlighted the role of complement proteins in driving glomerular endothelium toward a thrombogenic phenotype. At the glomerular level, podocytes are also an important target of Stx-induced complement activation. Glomerular injury as a consequence of podocyte dysfunction and loss is thus a mechanism that might affect long-term renal outcomes in the disease. New approaches to targeting the complement system may be useful therapeutic options for patients with STEC-HUS.
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Affiliation(s)
- Carlamaria Zoja
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy.
| | - Simona Buelli
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy
| | - Marina Morigi
- Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via Stezzano, 87, 24126, Bergamo, Italy
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Buelli S, Zoja C, Remuzzi G, Morigi M. Complement Activation Contributes to the Pathophysiology of Shiga Toxin-Associated Hemolytic Uremic Syndrome. Microorganisms 2019; 7:microorganisms7010015. [PMID: 30634669 PMCID: PMC6352217 DOI: 10.3390/microorganisms7010015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/21/2018] [Accepted: 01/07/2019] [Indexed: 02/06/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) infections have become a threat to public health globally because of the severe illnesses that they can trigger, such as hemorrhagic colitis and the post-diarrheal hemolytic uremic syndrome (HUS), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. Glomerular endothelial cells are primary targets of Stx which, after binding to its specific receptor globotriaosylceramide, upregulates proinflammatory proteins involved both in the recruitment and adhesion of leukocytes and thrombus formation at the site of endothelial injury. In this review, we discuss the role of complement activation in promoting glomerular microvascular dysfunction, providing evidence from experimental models and patients with STEC-HUS. Within the glomerulus, an important target for Stx-induced complement activation is the podocyte, a cell type that is in close contact with endothelial cells and participates in maintaining the filtration barrier. Recently, podocyte injury and loss have been indicated as potential risk factors for long-term renal sequelae in patients with STEC-HUS. Therapeutic approaches targeting the complement system, that may be useful options for patients with STEC-HUS, will also be discussed.
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Affiliation(s)
- Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, 20157 Milan, Italy.
| | - Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
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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: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Buelli S, Perico L, Benigni A. Untangling the Knot in Diabetic Nephropathy: The Unanticipated Role of Glycocalyx in the Antiproteinuric Effect of Endothelin Receptor Antagonists. Diabetes 2016; 65:2115-7. [PMID: 27456616 DOI: 10.2337/dbi16-0020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Simona Buelli
- IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Bergamo, Italy
| | - Luca Perico
- IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Bergamo, Italy
| | - Ariela Benigni
- IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Bergamo, Italy
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Morigi M, Locatelli M, Rota C, Buelli S, Corna D, Rizzo P, Abbate M, Conti D, Perico L, Longaretti L, Benigni A, Zoja C, Remuzzi G. A previously unrecognized role of C3a in proteinuric progressive nephropathy. Sci Rep 2016; 6:28445. [PMID: 27345360 PMCID: PMC4921969 DOI: 10.1038/srep28445] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/02/2016] [Indexed: 12/16/2022] Open
Abstract
Podocyte loss is the initial event in the development of glomerulosclerosis, the structural hallmark of progressive proteinuric nephropathies. Understanding mechanisms underlying glomerular injury is the key challenge for identifying novel therapeutic targets. In mice with protein-overload induced by bovine serum albumin (BSA), we evaluated whether the alternative pathway (AP) of complement mediated podocyte depletion and podocyte-dependent parietal epithelial cell (PEC) activation causing glomerulosclerosis. Factor H (Cfh−/−) or factor B-deficient mice were studied in comparison with wild-type (WT) littermates. WT+BSA mice showed podocyte depletion accompanied by glomerular complement C3 and C3a deposits, PEC migration to capillary tuft, proliferation, and glomerulosclerosis. These changes were more prominent in Cfh−/− +BSA mice. The pathogenic role of AP was documented by data that factor B deficiency preserved glomerular integrity. In protein-overload mice, PEC dysregulation was associated with upregulation of CXCR4 and GDNF/c-Ret axis. In vitro studies provided additional evidence of a direct action of C3a on proliferation and CXCR4-related migration of PECs. These effects were enhanced by podocyte-derived GDNF. In patients with proteinuric nephropathy, glomerular C3/C3a paralleled PEC activation, CXCR4 and GDNF upregulation. These results indicate that mechanistically uncontrolled AP complement activation is not dispensable for podocyte-dependent PEC activation resulting in glomerulosclerosis.
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Affiliation(s)
- Marina Morigi
- 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
| | - Cinzia Rota
- 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
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Paola Rizzo
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Mauro Abbate
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Debora Conti
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Luca Perico
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Lorena Longaretti
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- 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
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Buelli S, Perico L, Galbusera M, Abbate M, Morigi M, Novelli R, Gagliardini E, Tentori C, Rottoli D, Sabadini E, Saito T, Kawano M, Saeki T, Zoja C, Remuzzi G, Benigni A. Mitochondrial-dependent Autoimmunity in Membranous Nephropathy of IgG4-related Disease. EBioMedicine 2015; 2:456-66. [PMID: 26137589 PMCID: PMC4485911 DOI: 10.1016/j.ebiom.2015.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 01/13/2023] Open
Abstract
The pathophysiology of glomerular lesions of membranous nephropathy (MN), including seldom-reported IgG4-related disease, is still elusive. Unlike in idiopathic MN where IgG4 prevails, in this patient IgG3 was predominant in glomerular deposits in the absence of circulating anti-phospholipase A2 receptor antibodies, suggesting a distinct pathologic process. Here we documented that IgG4 retrieved from the serum of our propositus reacted against carbonic anhydrase II (CAII) at the podocyte surface. In patient's biopsy, glomerular CAII staining increased and co-localized with subepithelial IgG4 deposits along the capillary walls. Patient's IgG4 caused a drop in cell pH followed by mitochondrial dysfunction, excessive ROS production and cytoskeletal reorganization in cultured podocytes. These events promoted mitochondrial superoxide-dismutase-2 (SOD2) externalization on the plasma membrane, becoming recognizable by complement-binding IgG3 anti-SOD2. Among patients with IgG4-related disease only sera of those with IgG4 anti-CAII antibodies caused low intracellular pH and mitochondrial alterations underlying SOD2 externalization. Circulating IgG4 anti-CAII can cause podocyte injury through processes of intracellular acidification, mitochondrial oxidative stress and neoantigen induction in patients with IgG4 related disease. The onset of MN in a subset of patients could be due to IgG4 antibodies recognizing CAII with consequent exposure of mitochondrial neoantigen in the context of multifactorial pathogenesis of disease. In a patient with IgG4-related disease, glomerular CAII increases and colocalizes with IgG4 deposits. IgG4 from patient's serum reacts against CAII expressed by podocytes. IgG4 causes acidification, mitochondrial dysfunction and ROS-dependent cytoskeletal alterations in cultured podocytes. IgG4 induces the externalization on the plasma membrane of clustered SOD2, becoming recognizable by complement-binding IgG3.
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Affiliation(s)
- Simona Buelli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Luca Perico
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Miriam Galbusera
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Mauro Abbate
- 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
| | - Rubina Novelli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Elena Gagliardini
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Chiara Tentori
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Rottoli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ettore Sabadini
- Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Takao Saito
- General Medical Research Center, Faculty of Medicine, Fukuoka University, Japan
| | - Mitsuhiro Kawano
- Department of Rheumatology, University School of Medicine, Kanazawa, Japan
| | - Takako Saeki
- Department of Internal Medicine, Red Cross Hospital, Nagaoka, Japan
| | - Carlamaria Zoja
- 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 Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
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Zoja C, Corna D, Locatelli M, Rottoli D, Pezzotta A, Morigi M, Zanchi C, Buelli S, Guglielmotti A, Perico N, Remuzzi A, Remuzzi G. Effects of MCP-1 inhibition by bindarit therapy in a rat model of polycystic kidney disease. Nephron Clin Pract 2014; 129:52-61. [PMID: 25531096 DOI: 10.1159/000369149] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Experimental and clinical evidence suggested that monocyte chemoattractant protein-1 (MCP-1/CCL2) has a role in the development of interstitial inflammation and renal failure in polycystic kidney disease (PKD). We investigated whether bindarit, an inhibitor of MCP-1/CCL2 synthesis, could influence the evolution of PKD in PCK rats. METHODS PCK rats were treated from 5 to 15 weeks of age with vehicle or bindarit. Sprague-Dawley rats served as control. For in vitro studies, murine podocytes were exposed to albumin with or without bindarit. RESULTS MCP-1 mRNA was upregulated in the kidney of PCK rats and reduced by bindarit. Treatment limited overexpression of MCP-1 protein by epithelial cells of dilated tubules and cysts, and interstitial inflammatory cells. Excessive renal accumulation of monocytes/macrophages was lowered by bindarit by 41%. Serum creatinine slightly increased in PCK rats on vehicle and was similar to controls after bindarit. Kidney and liver cysts were not affected by treatment. Bindarit significantly reduced progressive proteinuria of PCK rats. The antiproteinuric effect was associated with the restoration of the defective nephrin expression in podocytes of PCK rats. Bindarit limited podocyte foot process effacement and ameliorated slit diaphragm frequency. In cultured podocytes, bindarit reduced MCP-1 production in response to albumin and inhibited albumin-induced cytoskeletal remodeling and cell migration. CONCLUSION This study showed that although bindarit did not prevent renal cyst growth, it limited interstitial inflammation and renal dysfunction and reduced proteinuria in PKD. Thus, bindarit could be considered a therapeutic intervention complementary to therapies specifically acting to block renal cyst growth.
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Locatelli M, Buelli S, Pezzotta A, Corna D, Perico L, Tomasoni S, Rottoli D, Rizzo P, Conti D, Thurman JM, Remuzzi G, Zoja C, Morigi M. Shiga toxin promotes podocyte injury in experimental hemolytic uremic syndrome via activation of the alternative pathway of complement. J Am Soc Nephrol 2014; 25:1786-98. [PMID: 24578132 DOI: 10.1681/asn.2013050450] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli is the offending agent of postdiarrhea-associated hemolytic uremic syndrome (HUS), a disorder of glomerular ischemic damage and widespread microvascular thrombosis. We previously documented that Stx induces glomerular complement activation, generating C3a responsible for microvascular thrombosis in experimental HUS. Here, we show that the presence of C3 deposits on podocytes is associated with podocyte damage and loss in HUS mice generated by the coinjection of Stx2 and LPS. Because podocyte adhesion to the glomerular basement membrane is mediated by integrins, the relevance of integrin-linked kinase (ILK) signals in podocyte dysfunction was evaluated. Podocyte expression of ILK increased after the injection of Stx2/LPS and preceded the upregulation of Snail and downregulation of nephrin and α-actinin-4. Factor B deficiency or pretreatment with an inhibitory antibody to factor B protected mice against Stx2/LPS-induced podocyte dysregulation. Similarly, pretreatment with a C3a receptor antagonist limited podocyte loss and changes in ILK, Snail, and α-actinin-4 expression. In cultured podocytes, treatment with C3a reduced α-actinin-4 expression and promoted ILK-dependent nuclear expression of Snail and cell motility. These results suggest that Stx-induced activation of the alternative pathway of complement and generation of C3a promotes ILK signaling, leading to podocyte dysfunction and loss in Stx-HUS.
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Affiliation(s)
- Monica Locatelli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Simona Buelli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Anna Pezzotta
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Luca Perico
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Susanna Tomasoni
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Daniela Rottoli
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Paola Rizzo
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Debora Conti
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Joshua M Thurman
- Division of Nephrology and Hypertension, University of Colorado Denver School of Medicine, Aurora, Colorado; and
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Carlamaria Zoja
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
| | - Marina Morigi
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy;
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Buelli S, Rosanò L, Gagliardini E, Corna D, Longaretti L, Pezzotta A, Perico L, Conti S, Rizzo P, Novelli R, Morigi M, Zoja C, Remuzzi G, Bagnato A, Benigni A. β-arrestin-1 drives endothelin-1-mediated podocyte activation and sustains renal injury. J Am Soc Nephrol 2013; 25:523-33. [PMID: 24371298 DOI: 10.1681/asn.2013040362] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Activation of endothelin-A receptor (ET(A)R) by endothelin-1 (ET-1) drives epithelial-to-mesenchymal transition in ovarian tumor cells through β-arrestin signaling. Here, we investigated whether this pathogenetic pathway could affect podocyte phenotype in proliferative glomerular disorders. In cultured mouse podocytes, ET-1 caused loss of the podocyte differentiation marker synaptopodin and acquisition of the mesenchymal marker α-smooth muscle actin. ET-1 promoted podocyte migration via ET(A)R activation and increased β-arrestin-1 expression. Activated ET(A)R recruited β-arrestin-1 to form a trimeric complex with Src leading to epithelial growth factor receptor (EGFR) transactivation and β-catenin phosphorylation, which promoted gene transcription of Snail. Increased Snail expression fostered ET-1-induced migration as confirmed by Snail knockdown experiments. Silencing of β-arrestin-1 prevented podocyte phenotypic changes and motility and inhibited ET(A)R-driven signaling. In vitro findings were confirmed in doxorubicin (Adriamycin)-induced nephropathy. Mice receiving Adriamycin developed renal injury with loss of podocytes and hyperplastic lesion formation; β-arrestin-1 expression increased in visceral podocytes and in podocytes entrapped in pseudo-crescents. Administration of the selective ET(A)R antagonist sitaxsentan prevented podocyte loss, formation of the hyperplastic lesions, and normalized expression of glomerular β-arrestin-1 and Snail. Increased β-arrestin-1 levels in podocytes retrieved from crescents of patients with proliferative glomerulopathies confirmed the translational relevance of these findings and suggest the therapeutic potential of ET(A)R antagonism for a group of diseases still needing a specific treatment.
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Affiliation(s)
- Simona Buelli
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy
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13
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Gagliardini E, Perico N, Rizzo P, Buelli S, Longaretti L, Perico L, Tomasoni S, Zoja C, Macconi D, Morigi M, Remuzzi G, Benigni A. Angiotensin II contributes to diabetic renal dysfunction in rodents and humans via Notch1/Snail pathway. Am J Pathol 2013; 183:119-30. [PMID: 23707238 DOI: 10.1016/j.ajpath.2013.03.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 02/26/2013] [Accepted: 03/19/2013] [Indexed: 01/13/2023]
Abstract
In nondiabetic rat models of renal disease, angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. Herein, we wanted to explore the role of Ang II in diabetic nephropathy by a translational approach spanning from in vitro to in vivo rat and human studies, and to dissect the intracellular pathways involved. In isolated perfused rat kidneys and in cultured human podocytes, Ang II down-regulated nephrin expression via Notch1 activation and nuclear translocation of Snail. Hairy enhancer of split-1 was a Notch1-downstream gene effector that activated Snail in cultured podocytes. In vitro changes of the Snail/nephrin axis were similar to those in renal biopsy specimens of Zucker diabetic fatty rats and patients with advanced diabetic nephropathy, and were normalized by pharmacological inhibition of the renin-angiotensin system. Collectively, the present studies provide evidence that Ang II plays a relevant role in perpetuating glomerular injury in experimental and human diabetic nephropathy via persistent activation of Notch1 and Snail signaling in podocytes, eventually resulting in down-regulation of nephrin expression, the integrity of which is crucial for the glomerular filtration barrier.
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Affiliation(s)
- Elena Gagliardini
- Mario Negri Institute of Pharmacology Research, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
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14
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Mele C, Iatropoulos P, Donadelli R, Calabria A, Maranta R, Cassis P, Buelli S, Tomasoni S, Piras R, Krendel M, Bettoni S, Morigi M, Delledonne M, Pecoraro C, Abbate I, Capobianchi MR, Hildebrandt F, Otto E, Schaefer F, Macciardi F, Ozaltin F, Emre S, Ibsirlioglu T, Benigni A, Remuzzi G, Noris M. MYO1E mutations and childhood familial focal segmental glomerulosclerosis. N Engl J Med 2011; 365:295-306. [PMID: 21756023 PMCID: PMC3701523 DOI: 10.1056/nejmoa1101273] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Focal segmental glomerulosclerosis is a kidney disease that is manifested as the nephrotic syndrome. It is often resistant to glucocorticoid therapy and progresses to end-stage renal disease in 50 to 70% of patients. Genetic studies have shown that familial focal segmental glomerulosclerosis is a disease of the podocytes, which are major components of the glomerular filtration barrier. However, the molecular cause in over half the cases of primary focal segmental glomerulosclerosis is unknown, and effective treatments have been elusive. METHODS We performed whole-genome linkage analysis followed by high-throughput sequencing of the positive-linkage area in a family with autosomal recessive focal segmental glomerulosclerosis (index family) and sequenced a newly discovered gene in 52 unrelated patients with focal segmental glomerulosclerosis. Immunohistochemical studies were performed on human kidney-biopsy specimens and cultured podocytes. Expression studies in vitro were performed to characterize the functional consequences of the mutations identified. RESULTS We identified two mutations (A159P and Y695X) in MYO1E, which encodes a nonmuscle class I myosin, myosin 1E (Myo1E). The mutations in MYO1E segregated with focal segmental glomerulosclerosis in two independent pedigrees (the index family and Family 2). Patients were homozygous for the mutations and did not have a response to glucocorticoid therapy. Electron microscopy showed thickening and disorganization of the glomerular basement membrane. Normal expression of Myo1E was documented in control human kidney-biopsy specimens in vivo and in glomerular podocytes in vitro. Transfection studies revealed abnormal subcellular localization and function of the A159P-Myo1E mutant. The Y695X mutation causes loss of calmodulin binding and of the tail domains of Myo1E. CONCLUSIONS MYO1E mutations are associated with childhood-onset, glucocorticoid-resistant focal segmental glomerulosclerosis. Our data provide evidence of a role of Myo1E in podocyte function and the consequent integrity of the glomerular filtration barrier.
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Affiliation(s)
- Caterina Mele
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Paraskevas Iatropoulos
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Roberta Donadelli
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Andrea Calabria
- Department of Medicine, Surgery and Dentistry, Università degli Studi di Milano, Milan, Italy
| | - Ramona Maranta
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Paola Cassis
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Simona Buelli
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Susanna Tomasoni
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Rossella Piras
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Mira Krendel
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Serena Bettoni
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
| | - Marina Morigi
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Massimo Delledonne
- Center of Functional Genomics, Department of Biotechnologies, University of Verona, Verona Italy
| | - Carmine Pecoraro
- Department of Nephrology and Dialysis ‘Santobono’ Hospital, Napoli, Italy
| | | | | | - Friedhelm Hildebrandt
- Department of Pediatrics, University of Michigan, Ann Arbor MI, USA
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor MI, USA
| | - Edgar Otto
- Department of Pediatrics, University of Michigan, Ann Arbor MI, USA
| | - Franz Schaefer
- Pediatric Nephrology Division, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Fabio Macciardi
- Department of Medicine, Surgery and Dentistry, Università degli Studi di Milano, Milan, Italy
| | - Fatih Ozaltin
- Department of Pediatric Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Sevinc Emre
- Department of Pediatric Nephrology, Instanbul Medical Faculty, Instanbul University, Instanbul, Turkey
| | - Tulin Ibsirlioglu
- Department of Pediatric Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ariela Benigni
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori Science and Technology Park Kilometro Rosso, Bergamo, Italy
- Unit of Nephrology and Dialysis, Ospedali Riuniti di Bergamo, Bergamo Italy
| | - Marina Noris
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases ‘Aldo e Cele Daccò’, Ranica, Bergamo, Italy
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15
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Cravedi P, Abbate M, Gagliardini E, Galbusera M, Buelli S, Sabadini E, Marasà M, Beck LH, Salant DJ, Benigni A, D'Agati V, Remuzzi G. Membranous nephropathy associated with IgG4-related disease. Am J Kidney Dis 2011; 58:272-5. [PMID: 21658826 DOI: 10.1053/j.ajkd.2011.05.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Accepted: 03/31/2011] [Indexed: 12/24/2022]
Abstract
Immunoglobulin G4 (IgG4)-related systemic disease is a rare condition characterized by high levels of circulating IgG4 and IgG4-positive plasma cell infiltrates in various organs, including the pancreas, salivary glands, biliary tract, liver, lung, and kidney. We describe a case of a 54-year-old man with IgG4-related systemic disease presenting with autoimmune pancreatitis and Mikulicz disease. Steroid therapy decreased circulating IgG4 levels and promoted regression of clinical signs. Thereafter, an increase in serum IgG4 values was followed by the occurrence of nephrotic-range proteinuria. Kidney biopsy showed membranous nephropathy with no IgG4-positive cell infiltrates. A search for circulating immune complexes was negative, and antibodies against M-type phospholipase A(2) receptor could not be detected. Western blot analyses identified circulating IgG3 reacting with superoxide dismutase 2. This case suggests that membranous nephropathy represents an additional renal manifestation of IgG4-related systemic disease, with a pathogenesis possibly associated with neoproduction of autoantibodies targeting podocyte antigen(s).
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Affiliation(s)
- Paolo Cravedi
- Mario Negri Institute for Pharmacological Research, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica, Italy
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Morigi M, Galbusera M, Gastoldi S, Locatelli M, Buelli S, Pezzotta A, Pagani C, Noris M, Gobbi M, Stravalaci M, Rottoli D, Tedesco F, Remuzzi G, Zoja C. Alternative pathway activation of complement by Shiga toxin promotes exuberant C3a formation that triggers microvascular thrombosis. J Immunol 2011; 187:172-80. [PMID: 21642543 DOI: 10.4049/jimmunol.1100491] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Shiga toxin (Stx)-producing E.coli O157:H7 has become a global threat to public health; it is a primary cause of diarrhea-associated hemolytic uremic syndrome (HUS), a disorder of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure with thrombi occluding renal microcirculation. In this study, we explored whether Stx triggers complement-dependent microvascular thrombosis in in vitro and in vivo experimental settings of HUS. Stx induced on human microvascular endothelial cell surface the expression of P-selectin, which bound and activated C3 via the alternative pathway, leading to thrombus formation under flow. In the search for mechanisms linking complement activation and thrombosis, we found that exuberant complement activation in response to Stx generated an increased amount of C3a that caused further endothelial P-selectin expression, thrombomodulin (TM) loss, and thrombus formation. In a murine model of HUS obtained by coinjection of Stx2 and LPS and characterized by thrombocytopenia and renal dysfunction, upregulation of glomerular endothelial P-selectin was associated with C3 and fibrin(ogen) deposits, platelet clumps, and reduced TM expression. Treatment with anti-P-selectin Ab limited glomerular C3 accumulation. Factor B-deficient mice after Stx2/LPS exhibited less thrombocytopenia and were protected against glomerular abnormalities and renal function impairment, indicating the involvement of complement activation via the alternative pathway in the glomerular thrombotic process in HUS mice. The functional role of C3a was documented by data showing that glomerular fibrin(ogen), platelet clumps, and TM loss were markedly decreased in HUS mice receiving C3aR antagonist. These results identify Stx-induced complement activation, via P-selectin, as a key mechanism of C3a-dependent microvascular thrombosis in diarrhea-associated HUS.
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Affiliation(s)
- Marina Morigi
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
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Gagliardini E, Buelli S, Benigni A. Endothelin in Chronic Proteinuric Kidney Disease. Contributions to Nephrology 2011; 172:171-184. [DOI: 10.1159/000328697] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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18
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Buelli S, Gastoldi S, Morigi M, Galbusera M, Locatelli M, Rottoli D, Pezzotta A, Pagani C, Noris M, Remuzzi G, Zoja C. Complement (C) activation contributes to microvascular thrombosis in Shiga toxin-associated HUS. Mol Immunol 2009. [DOI: 10.1016/j.molimm.2009.05.206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Macconi D, Chiabrando C, Schiarea S, Aiello S, Cassis L, Gagliardini E, Noris M, Buelli S, Zoja C, Corna D, Mele C, Fanelli R, Remuzzi G, Benigni A. Proteasomal processing of albumin by renal dendritic cells generates antigenic peptides. J Am Soc Nephrol 2008; 20:123-30. [PMID: 19092126 DOI: 10.1681/asn.2007111233] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The role of dendritic cells (DC) that accumulate in the renal parenchyma of non-immune-mediated proteinuric nephropathies is not well understood. Under certain circumstances, DC capture immunologically ignored antigens, including self-antigens, and present them within MHC class I, initiating an autoimmune response. We studied whether DC could generate antigenic peptides from the self-protein albumin. Exposure of rat proximal tubular cells to autologous albumin resulted in its proteolytic cleavage to form an N-terminal 24-amino acid peptide (ALB1-24). This peptide was further processed by the DC proteasome into antigenic peptides that had binding motifs for MHC class I and were capable of activating syngeneic CD8+ T cells. In vivo, the rat five-sixths nephrectomy model allowed the localization and activation of renal DC. Accumulation of DC in the renal parenchyma peaked 1 wk after surgery and decreased at 4 wk, concomitant with their appearance in the renal draining lymph nodes. DC from renal lymph nodes, loaded with ALB1-24, activated syngeneic CD8+ T cells in primary culture. The response of CD8+ T cells of five-sixths nephrectomized rats was amplified with secondary stimulation. In contrast, DC from renal lymph nodes of five-sixths nephrectomized rats treated with the proteasomal inhibitor bortezomib lost their capacity to stimulate CD8+ T cells in primary and secondary cultures. These data suggest that albumin can be a source of potentially antigenic peptides upon renal injury and that renal DC play a role in processing self-proteins through a proteasome-dependent pathway.
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Affiliation(s)
- Daniela Macconi
- Mario Negri Institute for Pharmacological Research, Via Gavazzeni 11, 24125 Bergamo, Italy
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Zanchi C, Zoja C, Morigi M, Valsecchi F, Liu XY, Rottoli D, Locatelli M, Buelli S, Pezzotta A, Mapelli P, Geelen J, Remuzzi G, Hawiger J. Fractalkine and CX3CR1 mediate leukocyte capture by endothelium in response to Shiga toxin. J Immunol 2008; 181:1460-9. [PMID: 18606701 DOI: 10.4049/jimmunol.181.2.1460] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Shiga toxins (Stx) are the virulence factors of enterohemorrhagic Escherichia coli O157:H7, a worldwide emerging diarrheal pathogen, which precipitates postdiarrheal hemolytic uremic syndrome, the leading cause of acute renal failure in children. In this study, we show that Stx2 triggered expression of fractalkine (FKN), a CX3C transmembrane chemokine, acting as both adhesion counterreceptor on endothelial cells and soluble chemoattractant. Stx2 caused in HUVEC expression of FKN mRNA and protein, which promoted leukocyte capture, ablated by Abs to either endothelial FKN or leukocyte CX3CR1 receptor. Exposure of human glomerular endothelial cells to Stx2 recapitulated its FKN-inducing activity and FKN-mediated leukocyte adhesion. Both processes required phosphorylation of Src-family protein tyrosine kinase and p38 MAPK in endothelial cells. Furthermore, they depended on nuclear import of NF-kappaB and other stress-responsive transcription factors. Inhibition of their nuclear import with the cell-penetrating SN50 peptide reduced FKN mRNA levels and FKN-mediated leukocyte capture by endothelial cells. Adenoviral overexpression of IkappaBalpha inhibited FKN mRNA up-regulation. The FKN-mediated responses to Stx2 were also dependent on AP-1. In mice, both virulence factors of Stx-producing E. coli, Stx and LPS, are required to elicit hemolytic uremic syndrome. In this study, FKN was detected within glomeruli of C57BL/6 mice injected with Stx2, and further increased after Stx2 plus LPS coadministration. This was associated with recruitment of CX3CR1-positive cells. Thus, in response to Stx2, FKN is induced playing an essential role in the promotion of leukocyte-endothelial cell interaction thereby potentially contributing to the renal microvascular dysfunction and thrombotic microangiopathy that underlie hemolytic uremic syndrome due to enterohemorrhagic E. coli O157:H7 infection.
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Affiliation(s)
- Cristina Zanchi
- Mario Negri Institute for Pharmacological Research, Bergamo, Italy
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21
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Morigi M, Buelli S, Zanchi C, Longaretti L, Macconi D, Benigni A, Moioli D, Remuzzi G, Zoja C. Shigatoxin-induced endothelin-1 expression in cultured podocytes autocrinally mediates actin remodeling. Am J Pathol 2007; 169:1965-75. [PMID: 17148661 PMCID: PMC1762486 DOI: 10.2353/ajpath.2006.051331] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Shigatoxin (Stx) is the offending agent of post-diarrheal hemolytic uremic syndrome, characterized by glomerular ischemic changes preceding microvascular thrombosis. Because podocytes are highly sensitive to Stx cytotoxicity and represent a source of vasoactive molecules, we studied whether Stx-2 modulated the production of endothelin-1 (ET-1), taken as candidate mediator of podocyte dysfunction. Stx-2 enhanced ET-1 mRNA and protein expression via activation of nuclear factor kappaB (NF-kappaB) and activator protein-1 (Ap-1) to the extent that transfection with the dominant-negative mutant of IkappaB-kinase 2 or with Ap-1 decoy oligodeoxynucleotides reduced ET-1 mRNA levels. We propose a role for p38 and p42/44 mitogen-activated protein kinases (MAPKs) in mediating NF-kappaB-dependent gene transcription induced by Stx-2, based on data that Stx-2 phosphorylated p38 and p42/44 MAPKs and that MAPK inhibitors reduced transcription of NF-kappaB promoter/luciferase reporter gene construct induced by Stx-2. Stx-2 caused F-actin redistribution and intercellular gaps via production of ET-1 acting on ETA receptor, because cytoskeleton changes were prevented by ETA receptor blockade. Exogenous ET-1 induced cytoskeleton rearrangement and intercellular gaps via phosphatidylinositol-3 kinase and Rho-kinase pathway and increased protein permeability across the podocyte monolayer. These data suggest that the podocyte is a target of Stx, a novel stimulus for the synthesis of ET-1, which may control cytoskeleton remodeling and glomerular permeability in an autocrine fashion.
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Affiliation(s)
- Marina Morigi
- Mario Negri Institute for Pharmacological Research, Unit of Nephrology and Dialysis, Azienda Ospedaliera, Ospedali Riuniti di Bergamo, Via Gavazzeni 11, 24125 Bergamo, Italy.
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22
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Macconi D, Abbate M, Morigi M, Angioletti S, Mister M, Buelli S, Bonomelli M, Mundel P, Endlich K, Remuzzi A, Remuzzi G. Permselective dysfunction of podocyte-podocyte contact upon angiotensin II unravels the molecular target for renoprotective intervention. Am J Pathol 2006; 168:1073-85. [PMID: 16565484 PMCID: PMC1606571 DOI: 10.2353/ajpath.2006.050701] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 11/20/2022]
Abstract
Ameliorating the function of the glomerular barrier to circulating proteins by blocking angiotensin II (Ang II) translates into less risk of progression toward end-stage renal failure in diabetic and nondiabetic nephropathies. However, the mechanisms underlying this barrier protection are not clear. Specialized contacts between adjacent podocytes are major candidate targets, and the actin cytoskeleton is emerging as a regulatory element. Here, we present data demonstrating that Ang II induced reorganization of F-actin fibers and redistribution of zonula occludens-1 (ZO-1) that is physically associated with actin in murine podocytes. These effects were paralleled by increased albumin permeability across podocyte monolayers. The F-actin stabilizer jasplakinolide prevented both ZO-1 redistribution and albumin leakage, suggesting that actin cytoskeleton rearrangement is instrumental to podocyte permselective dysfunction induced by Ang II. Changes in both F-actin and ZO-1 patterns were confirmed in glomeruli of rat isolated perfused kidneys on short infusion of Ang II, leading to increased protein excretion. Podocyte dysfunction was mediated by Ang II type 1 receptor and was partly dependent on Src kinase-phospholipase C activation. These data demonstrate that strategies aimed at stabilizing podocyte-podocyte contacts and targeting the relevant intracellular signal transduction are crucial to renoprotection.
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Affiliation(s)
- Daniela Macconi
- "Mario Negri" Institute for Pharmacological Research, Via Gavazzeni 11, 24125 Bergamo, Italy.
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Galbusera M, Buelli S, Gastoldi S, Macconi D, Angioletti S, Testa C, Remuzzi G, Morigi M. Activation of porcine endothelium in response to xenogeneic serum causes thrombosis independently of platelet activation. Xenotransplantation 2005; 12:110-20. [PMID: 15693841 DOI: 10.1111/j.1399-3089.2005.00203.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Endothelial cell activation and microvascular thrombosis are hallmarks of hyperacute xenograft rejection. However, the molecular determinants of platelet-endothelial interaction and thrombus formation are poorly understood. This study investigated whether: (i) xenogeneic human serum (HS), as a source of xenoreactive antibodies and complement, activates porcine aortic endothelial cells (PAEC) to promote thrombus formation under high shear stress; (ii) the endothelial adhesive proteins vitronectin receptor and P-selectin are involved in the von Willebrand factor (VWF)-platelet interaction during the thrombotic process under flow; (iii) reactive oxygen species (ROS) are activated by complement and served as intracellular signals for adhesive protein up-regulation. METHODS The PAEC were pre-exposed for 90 min in static conditions to medium plus 10, 20, and 50% HS or 20% porcine serum (PS), as control, then cells were perfused at 50 dynes/cm2 in a parallel plate flow chamber with human blood and area occupied by thrombi was measured. The role of complement in HS-induced thrombus formation was assessed by incubating PAEC with 20% HS in the presence of soluble complement receptor type 1 (sCR1) before blood perfusion. The effect of platelet activation was assessed using human blood treated or not with ADP and then flowed over PAEC pre-exposed to 20% HS or 20% PS as control. To identify the endothelial adhesive proteins involved in thrombus formation PAEC treated with 20% HS were then incubated with anti-vitronectin receptor antibody, anti-P-selectin antibody or P-selectin glycoprotein ligand-1 (PSGL-1), the soluble ligand of P-selectin, before the adhesion assay. Confocal microscopy was used to detect changes in endothelial adhesive protein expression. VWF interaction with platelet receptors GPIb and alphaIIbbeta3 was assessed adding aurin tricarboxylic acid (ATA) and anti-alphaIIbbeta3 antibody to blood before perfusion. The ROS involvement in xenogeneic serum-induced thrombus formation was determined studying the intracellular production of hydrogen peroxide (H2O2). The effect of antioxidants and metal chelators on HS-induced thrombus formation was evaluated treating PAEC with pyrrolidine dithiocarbamate (PDTC) or 1,3-dimethyl-2-thiourea (DMTU) before and during incubation with 20% HS followed by blood perfusion. The effect of antioxidants and sCR1 on ROS generation was investigated treating PAEC with PDTC or DMTU before and during incubation with 20% HS. Intracellular ROS generation was measured by fluorescence spectroscopy using the probe dihydrorhodamine 123 (DHR-123). RESULTS Human serum but not PS caused thrombus formation on PAEC under high shear stress. Blockade of complement activation by sCR1 prevented xenogeneic serum-induced thrombus formation. Activated platelets did not promote thrombus formation on resting endothelium, and did not further increase platelet deposition on xenogeneic serum-treated PAEC. Vitronectin receptor and P-selectin were up-regulated on the endothelial surface by HS. Their functional blockade by specific antibodies prevented platelet deposition and thrombus formation. H2O2 production significantly increased when PAEC were exposed to the xenogeneic condition. Antioxidants and sCR1 completely prevented thrombus formation by reducing excessive ROS production and the expression of vitronectin receptor and P-selectin. CONCLUSIONS Xenogeneic complement induces endothelial cell activation and thrombosis which is independent of platelet activation. Complement deposition elicits a rapid generation of ROS that lead to overexpression of endothelial adhesive molecules instrumental for platelet deposition.
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Affiliation(s)
- Miriam Galbusera
- Mario Negri Institute for Pharmacological Research, Via Gavazzeni, Bergamo, Italy
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Morigi M, Buelli S, Angioletti S, Zanchi C, Longaretti L, Zoja C, Galbusera M, Gastoldi S, Mundel P, Remuzzi G, Benigni A. In response to protein load podocytes reorganize cytoskeleton and modulate endothelin-1 gene: implication for permselective dysfunction of chronic nephropathies. Am J Pathol 2005; 166:1309-20. [PMID: 15855633 PMCID: PMC1606387 DOI: 10.1016/s0002-9440(10)62350-4] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Effacement of podocyte foot processes occurs in many proteinuric nephropathies and is accompanied by rearrangement of the actin cytoskeleton. Here, we studied whether protein overload affects intracellular pathways, leading to cytoskeletal architecture changes and ultimately to podocyte dysfunction. Mouse podocytes bound and endocytosed both albumin and IgG via receptor-specific mechanisms. Protein overload caused redistribution of F-actin fibers instrumental to up-regulation of the prepro-endothelin (ET)-1 gene and production of the corresponding peptide. Increased DNA-binding activity for nuclear factor (NF)-kappaB and Ap-1 nuclear proteins was measured in nuclear extracts of podocytes exposed to excess proteins. Both Y27632, which inhibits Rho kinase-dependent stress fiber formation, and jasplakinolide, an F-actin stabilizer, decreased NF-kappaB and Ap-1 activity and reduced ET-1 expression. This suggested a role for the cytoskeleton, through activated Rho, in the regulation of the ET-1 peptide. Focal adhesion kinase (FAK), an integrin-associated nonreceptor tyrosine kinase, was phosphorylated by albumin treatment via Rho kinase-triggered actin reorganization. FAK activation led to NF-kappaB- and Ap-1-dependent ET-1 expression. These data suggest that reorganization of the actin cytoskeletal network in response to protein load is implicated in modulation of the ET-1 gene via Rho kinase-dependent FAK activation of NF-kappaB and Ap-1 in differentiated podocytes. Increased ET-1 generation might alter glomerular permselectivity and amplify the noxious effect of protein overload on dysfunctional podocytes.
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Affiliation(s)
- Marina Morigi
- Mario Negri Institute for Pharmacological Research, Via Gavazzeni 11, 24125 Bergamo, Italy.
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Donadelli R, Zanchi C, Morigi M, Buelli S, Batani C, Tomasoni S, Corna D, Rottoli D, Benigni A, Abbate M, Remuzzi G, Zoja C. Protein overload induces fractalkine upregulation in proximal tubular cells through nuclear factor kappaB- and p38 mitogen-activated protein kinase-dependent pathways. J Am Soc Nephrol 2004; 14:2436-46. [PMID: 14514721 DOI: 10.1097/01.asn.0000089564.55411.7f] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Investigated was the effect of high albumin concentrations on proximal tubular cell expression of fractalkine. Human proximal tubular cells (HK-2) were incubated with human serum albumin (HSA), which induced a dose-dependent increase in fractalkine mRNA associated with increased levels of both membrane-bound and soluble forms of the protein. To evaluate the role of nuclear factor kappaB (NF-kappaB) activation in HSA-induced fractalkine mRNA, HK-2 cells were infected with a recombinant adenovirus encoding the natural inhibitor of NF-kappaB, IkBalpha; a 43% reduction of fractalkine mRNA levels resulted. Similarly, when cells were infected with the recombinant adenovirus expressing dominant negative mutant of the IkB kinase 2, a 55% inhibition of fractalkine mRNA was achieved. p38 mitogen-activated protein kinase was activated by HSA and was involved in NF-kappaB-dependent transcription of fractalkine. In kidneys of mice with bovine serum albumin overload proteinuria, fractalkine mRNA levels were 2.3-fold greater than those of controls. Fractalkine expression was also induced in tubular epithelial cells in this model. Anti-CXCR1 antibody treatment limited interstitial accumulation of mononuclear cells. Protein overload is a promoter of fractalkine gene induction mediated by NF-kappaB and p38 activation in proximal tubular cells. Fractalkine might contribute to direct mononuclear cells into peritubular interstitium and enhance their adhesion property, which in turn would favor inflammation and disease progression.
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Affiliation(s)
- Roberta Donadelli
- Mario Negri Institute for Pharmacological Research and Unit of Nephrology and Dialysis, Azienda Ospedaliera, Ospedali Riuniti di Bergamo, Bergamo, Italy
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Morigi M, Macconi D, Zoja C, Donadelli R, Buelli S, Zanchi C, Ghilardi M, Remuzzi G. Protein overload-induced NF-kappaB activation in proximal tubular cells requires H(2)O(2) through a PKC-dependent pathway. J Am Soc Nephrol 2002; 13:1179-89. [PMID: 11961005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Abnormal traffic of proteins through the glomerular capillary has an intrinsic toxicity that results in tubular dysfunction and interstitial inflammation. It has been previously shown that in porcine proximal tubular cells high concentrations of albumin activated NF-kappaB, which is responsible for the enhanced synthesis of the inflammatory chemokine RANTES. This study investigates whether reactive oxygen species (ROS) served as second messengers in protein overload-induced NF-kappaB activation. Human proximal tubular cells (HK-2) were incubated (5 to 60 min) with human albumin and IgG (1 to 30 mg/ml). Both proteins induced a rapid or significant increase in hydrogen peroxide (H(2)O(2)) production at 5 min and persisting at 60 min. This effect was dose-dependent. The contribution of H(2)O(2) in regulating NF-kappaB activation was evaluated by using the antioxidants dimethyl-thiourea and pyrrolidine dithiocarbamate in protein-overloaded HK-2 cells. Both agents, by preventing H(2)O(2) generation, induced human albumin or IgG inhibited NF-kappaB activation. Stimulation of HK-2 with exogenous H(2)O(2) resulted in the activation of a NF-kappaB subunit pattern similar to that obtained after protein challenge. Specific inhibitors of protein kinase C (PKC) activity significantly prevented H(2)O(2) production and consequent NF-kappaB activation, suggesting that ROS generation in HK-2 cells occurs downstream of PKC activation. Either antioxidants or PKC inhibitor almost completely abolished the upregulation of the monocyte chemoattractant protein-1 gene induced by excess albumin, as evaluated by real-time PCR, thus supporting a role for PKC and ROS as critical signals for the expression of NF-kappaB-dependent inflammatory genes. To identify the enzymatic sources responsible for the increased H(2)O(2) production, the effect of dyphenyleneiodonium, an inhibitor of the membrane NADP(H) oxidase, was studied, as was the effect of rotenone, which blocks complex I of the mitochondrial respiratory chain. It was found that both agents significantly reduced the exaggerated H(2)O(2) induced by protein overload. These data indicate that exposure to excess proteins in proximal tubular cells induces the formation of ROS, which are responsible for NF-kappaB activation and consequent induction of NF-kappaB-dependent inflammatory signals.
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Affiliation(s)
- Marina Morigi
- Mario Negri Institute for Pharmacological Research, Bergamo, Italy.
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