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Truong LD, Trostel J, Garcia GE. Absence of nicotinic acetylcholine receptor α7 subunit amplifies inflammation and accelerates onset of fibrosis: an inflammatory kidney model. FASEB J 2015; 29:3558-70. [PMID: 25985801 DOI: 10.1096/fj.14-262493] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 05/04/2015] [Indexed: 01/06/2023]
Abstract
Inflammation is regulated by endogenous mechanisms, including anti-inflammatory cytokines, adenosine, and the nicotinic acetylcholine receptor α7 subunit (α7nAChR). We investigated the role of α7nAChR in protection against the progression of tissue injury in a model of severe, macrophage-mediated, cytokine-dependent anti-glomerular basement membrane (GBM) glomerulonephritis (GN), in α7nAChR-deficient (α7(-/-)) mice . At d 7 after the injection of anti-GBM antibody, kidneys from α7(-/-) mice displayed severe glomeruli (P < 0.0001) and tubulointerstitial lesions (P < 0.001) compared to kidneys from WT mice. An important finding was the presence of severe glomerulosclerosis in α7(-/-) mice in this early phase of the disease. Kidneys of α7(-/-) mice showed greater accumulation of inflammatory cells and higher expression of chemokines and cytokines than did those of WT mice. In addition, in α7(-/-) fibrotic kidneys, the expression of fibrin, collagen, TGF-β, and tissue inhibitor of metalloproteinase (TIMP)-2 increased, and the expression of TIMP3 declined. The increase in counterregulatory responses to inflammation in α7(-/-) nephritic kidneys did not compensate for the lack of α7nAChR. These findings indicate that α7nAChR plays a key role in regulating the inflammatory response in anti-GBM GN and that disruption of the endogenous protective α7nAChR amplifies inflammation to accelerate kidney damage and fibrosis.
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Affiliation(s)
- Luan D Truong
- *Department of Pathology and Division of Nephrology, Department of Medicine, and The Methodist Hospital, Baylor College of Medicine, Houston, Texas, USA; and Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado, USA
| | - Jessica Trostel
- *Department of Pathology and Division of Nephrology, Department of Medicine, and The Methodist Hospital, Baylor College of Medicine, Houston, Texas, USA; and Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado, USA
| | - Gabriela E Garcia
- *Department of Pathology and Division of Nephrology, Department of Medicine, and The Methodist Hospital, Baylor College of Medicine, Houston, Texas, USA; and Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado, USA
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Kim JC, Whitaker-Menezes D, Deguchi M, Adair BS, Korngold R, Murphy GF. Novel expression of vascular cell adhesion molecule-1 (CD106) by squamous epithelium in experimental acute graft-versus-host disease. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 161:763-70. [PMID: 12213703 PMCID: PMC1867240 DOI: 10.1016/s0002-9440(10)64235-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vascular cell adhesion molecule-1 (VCAM-1; CD106), the receptor for VLA-4, is an important mediator of adhesive and co-stimulatory interactions that govern cutaneous immune responses. Initial studies designed to elucidate temporal aspects of endothelial adhesion molecule induction in murine acute graft-versus-host disease (aGVHD) revealed unexpected and novel VCAM-1 expression by cutaneous and mucosal epithelial cells. Immunohistochemical techniques confirmed VCAM-1 staining as early as 7 days after transplantation in a distinctive subpopulation of squamous epithelial cells that normally occupy focal domains within the epidermal basal cell layer, the follicular infundibulum, and the dorsal lingual epithelium. Specifically, VCAM-1 expression was intimately associated with rete ridge-like prominences in footpad epidermis and in dorsal lingual epithelium. VCAM-1, as evaluated by serial section-labeling techniques, was preferentially expressed at sites of early epithelial infiltration by CD4(+) T cells. Western blot analysis confirmed expression of the 110-kd isoform of VCAM-1 in epithelium isolated from aGVHD animals, and immunoelectron microscopy demonstrated VCAM-1 reactivity restricted exclusively to epithelial cell plasma membranes. It is concluded that VCAM-1 is selectively expressed by discrete squamous epithelial subpopulations in murine aGVHD. As such, VCAM-1 may play a previously unrecognized role in mediating interactions between donor effector T lymphocytes and host epithelial cell targets.
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Affiliation(s)
- Judith C Kim
- Department of Pathology, The Jefferson Center for Dermatopathology Laboratories for Cutaneous Research, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107-6799, USA
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Allen AR, McHale J, Smith J, Cook HT, Karkar A, Haskard DO, Lobb RR, Pusey CD. Endothelial Expression of VCAM-1 in Experimental Crescentic Nephritis and Effect of Antibodies to Very Late Antigen-4 or VCAM-1 on Glomerular Injury. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.9.5519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The migration of leukocytes into glomeruli in crescentic glomerulonephritis is fundamental to pathogenesis, and offers important therapeutic opportunities. We addressed the importance of VCAM-1, and its leukocyte ligand very late antigen-4 (VLA-4), in such leukocyte migration. In a rat model of nephrotoxic nephritis, glomerular expression of VCAM-1, studied by immunohistochemistry, was up-regulated by day 6 of nephritis. To quantify kidney endothelial VCAM-1 expression, a differential radiolabeled mAb technique was used, which demonstrated that protein expression was not up-regulated by day 2 of nephritis, but rose threefold between days 2 and 5, and remained elevated until at least day 28. An in vivo study was then performed, using blocking mAbs to either VCAM-1 or VLA-4, starting mAb treatment on the day prior to disease induction, and continuing until animals were sacrificed at day 7. mAbs to VLA-4 significantly attenuated renal injury (albuminuria, glomerular fibrinoid necrosis, and crescent formation), but mAbs to VCAM-1 had no significant effect. Surprisingly, the number of leukocytes within glomeruli was unaffected by anti-VLA-4 mAb therapy, despite the reduction in renal injury. Paradoxically, classical markers of macrophage activation were increased in the anti-VLA-4- and anti-VCAM-1-treated animals. This study demonstrates that kidney endothelial VCAM-1, in contrast to ICAM-1, is not up-regulated by day 2 of nephrotoxic nephritis, and plays little part in early leukocyte influx into glomeruli. However, VLA-4 is an important mediator of glomerular injury, operating after transendothelial leukocyte migration, and presumably binding to alternate ligands within the kidney.
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Affiliation(s)
| | - Julie McHale
- †British Heart Foundation Cardiovascular Medicine Unit, National Heart and Lung Institute, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom; and
| | | | | | | | - Dorian O. Haskard
- †British Heart Foundation Cardiovascular Medicine Unit, National Heart and Lung Institute, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom; and
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